UMTS RNP Guideline Ed02

ED 02 RELEASED CONFIDENTIAL 6-Apr-2001

MCD UMTS_RNP_Guideline_ed02.doc 3DF 00902 UA10 VAZZA 1/198

UMTS RADIO NETWORK PLANNING GUIDELINE

CONFIDENTIALGuideline

TABLE OF CONTENTS

REFERENCED DOCUMENTS..................................................................................................................... 6

RELATED DOCUMENTS ............................................................................................................................. 6

PREFACE ........................................................................................................................................................ 6

SCOPE.............................................................................................................................................................. 6

INTRODUCTION ........................................................................................................................................... 61 RNP PROCESS DESCRIPTION........................................................................................................................ 82 WCDMA FUNDAMENTALS AND UMTS AIR INTERFACE........................................................................... 92.1 UMTS NETWORK ARCHITECTURE ............................................................................................................... 92.1.1 UE ( User Equipment) .............................................................................................................................. 92.1.2 UTRAN (UMTS Radio Access Network) .............................................................................................. 102.1.3 CN (Core network) ................................................................................................................................. 102.1.4 External networks ................................................................................................................................... 102.1.5 Interfaces ................................................................................................................................................ 112.1.6 Logical roles of the RNC........................................................................................................................ 112.1.6.1 CRNC .................................................................................................................................................. 112.1.6.2 SRNC & DRNC................................................................................................................................... 112.1.7 Mapping between GSM and UMTS ....................................................................................................... 122.2 STANDARDS AND USED FREQUENCY SPECTRUM........................................................................................ 122.3 MOBILE CLASSES ....................................................................................................................................... 142.4 BROADBAND PROPAGATION CHANNEL AND WCDMA BASIC CONCEPT ................................................... 142.4.1 Multiple Access Techniques................................................................................................................... 142.4.2 Broadband signal and Coherence bandwidth.......................................................................................... 152.4.3 Multipath propagation and RAKE receiver ............................................................................................ 162.5 SPREADING, SCRAMBLING AND MODULATION .......................................................................................... 162.5.1 Spreading ................................................................................................................................................ 162.5.2 Despreading ............................................................................................................................................ 172.5.3 Codes used.............................................................................................................................................. 182.5.3.1 Channelization codes ........................................................................................................................... 182.5.3.2 Scrambling codes................................................................................................................................. 192.5.4 Example for scrambling code allocation: Cell Search Process............................................................... 212.5.5 Spreading, scrambling and modulation .................................................................................................. 212.5.5.1 Uplink part ........................................................................................................................................... 212.5.5.2 Downlink part ...................................................................................................................................... 222.6 USER DETECTION MECHANISMS (QUICK OVERVIEW)................................................................................. 232.7 POWER CONTROL IN UMTS FDD.............................................................................................................. 232.7.1 General Power Control in UMTS ........................................................................................................... 232.7.1.1 Outer Loop Power Control .................................................................................................................. 24

02 010406 3DF 00902 UA10 VAZZA Y C. Brechtmann, PCS MH, AG

PCS/NPL/METHODS

01 010123 Draft 01 C. Brechtmann, PCS OA, UB, AG, MH, LSP, MG

PCS/NPL/METHODS

ED DATE(YYMMDD)

CHANGE NOTE APPRAISAL AUTHORITY ORIGINATORS



2.7.1.2 Inner Loop Power Control for dedicated channels .............................................................................. 242.7.1.3 Open Loop Power Control................................................................................................................... 262.7.1.4 Site selection diversity transmit power control.................................................................................... 262.8 HO TYPES & EVENTS ................................................................................................................................. 272.8.1 Hard handover ........................................................................................................................................ 272.8.2 Soft handover.......................................................................................................................................... 272.8.3 Softer handover....................................................................................................................................... 292.8.4 Power control in soft(er) handover ......................................................................................................... 292.8.4.1 Downlink PC in SHO .......................................................................................................................... 292.8.4.2 Uplink PC in SHO ............................................................................................................................... 302.8.5 Reporting events for Soft Handover and measurement reports .............................................................. 302.8.6 Filtering EC/N0 measures out of raw measures ....................................................................................... 312.9 RECEIVE & TRANSMIT DIVERSITY............................................................................................................. 312.9.1 Receiver diversity mechanisms .............................................................................................................. 322.9.1.1 Uplink receiver diversity ..................................................................................................................... 322.9.1.2 Downlink receiver diversity ................................................................................................................ 322.9.2 Downlink Transmit diversity mechanisms ............................................................................................. 332.9.2.1 Open loop downlink transmit diversity ............................................................................................... 342.9.2.2 Closed loop downlink transmit diversity for DPCH transmission....................................................... 352.10 CODECS SUPPORTED BY UTRAN .......................................................................................................... 352.10.1 Fixed Rate CODECs............................................................................................................................. 362.10.2 Adaptive Multi Rate CODECs ............................................................................................................. 363 CHANNEL TYPES AND RADIO RESOURCE MANAGEMENT........................................................................ 383.1 OVERVIEW ON CHANNEL TYPES AND NAMES ............................................................................................ 393.1.1 Physical channels.................................................................................................................................... 393.1.2 Transport channels.................................................................................................................................. 403.1.3 Logical channels ..................................................................................................................................... 423.1.4 Mapping between different channel types .............................................................................................. 433.2 THE PHYSICAL CHANNELS ......................................................................................................................... 433.2.1 The physical channels in Uplink............................................................................................................. 433.2.1.1 DPCH (DPDCH & DPCCH) in UL..................................................................................................... 433.2.1.2 PRACH................................................................................................................................................ 443.2.1.3 PCPCH................................................................................................................................................. 463.2.2 The physical channels in DL .................................................................................................................. 473.2.2.1 Downlink DPCH.................................................................................................................................. 483.2.2.2 CPICH – Common Pilot channel......................................................................................................... 493.2.2.3 PCCPCH – Primary Common Control Physical Channel ................................................................... 493.2.2.4 SCCPCH – Secondary Common Control Physical Channel ............................................................... 503.2.2.5 SCH – Synchronization Channel ......................................................................................................... 513.2.2.6 PDSCH – Physical Downlink Shared Channel.................................................................................... 513.3 RADIO RESOURCE MANAGEMENT FUNCTIONS ........................................................................................... 523.3.1 Radio Admission Control ....................................................................................................................... 543.3.1.1 Admission control for uplink............................................................................................................... 543.3.1.2 Admission Control for Downlink ........................................................................................................ 554 UMTS SERVICES AND TRAFFIC MODELING ............................................................................................. 574.1 UMTS SERVICES ....................................................................................................................................... 584.2 TRAFFIC MODELLING................................................................................................................................. 604.2.1 Microscopic Traffic Models ................................................................................................................... 604.2.2 Macroscopic Traffic Models................................................................................................................... 604.3 SERVICE DEFINITION ................................................................................................................................. 614.3.1 Circuit Switched Services....................................................................................................................... 614.3.1.1 Bit rate: ................................................................................................................................................ 614.3.1.2 Radio Quality and QoS........................................................................................................................ 624.3.1.3 Grade of Service (GoS) ....................................................................................................................... 62



4.3.1.4 Microscopic Traffic Model.................................................................................................................. 624.3.2 Packet Switched Services ....................................................................................................................... 634.3.2.1 Bit rates................................................................................................................................................ 644.3.2.2 QoS and Radio Quality........................................................................................................................ 654.3.2.3 Grade of Service .................................................................................................................................. 654.3.2.4 Microscopic Traffic Models ................................................................................................................ 654.4 MACROSCOPIC TRAFFIC MODEL FOR LINK BUDGET ANALYSIS............................................................... 674.4.1 Assumptions ........................................................................................................................................... 674.4.2 Concept................................................................................................................................................... 684.4.3 Inputs of the Macroscopic Traffic Model ............................................................................................... 694.4.3.1 Circuit Switched Services.................................................................................................................... 694.4.3.2 Packet Switched Services .................................................................................................................... 704.4.4 Outputs of the Macroscopic Traffic Model ............................................................................................ 704.4.4.1 Uplink .................................................................................................................................................. 704.4.4.2 Downlink ............................................................................................................................................. 714.5 ANNEX A: REQUIRED EB/N0 FOR SPEECH SERVICE ................................................................................. 724.5.1 Speech 8 kbit/s........................................................................................................................................ 724.5.2 Speech 12.2 kbit/s................................................................................................................................... 724.6 ANNEX B: REQUIRED EB/N0 FOR CIRCUIT SWITCHED SERVICES ............................................................. 744.6.1 CS 64 kbit/s ............................................................................................................................................ 744.6.2 CS 144 kbps............................................................................................................................................ 744.6.3 CS 384 kbit/s .......................................................................................................................................... 754.7 ANNEX C: REQUIRED EB/N0 FOR PACKET SWITCHED SERVICES ............................................................... 764.7.1 PS 64 kbit/s............................................................................................................................................. 764.7.2 PS 144 kbit/s ........................................................................................................................................... 764.7.3 PS 384 kbit/s ........................................................................................................................................... 775 LINK BUDGET AND INITIAL NETWORK DESIGN........................................................................................ 785.1 MULTISERVICE LINK BUDGET .................................................................................................................... 785.1.1 Uplink Analysis ...................................................................................................................................... 795.1.1.1 Uplink Iteration Process ...................................................................................................................... 805.1.2 Downlink Analysis ................................................................................................................................. 835.1.2.1 Downlink Iteration Process.................................................................................................................. 835.2 LINK BUDGET PARAMETERS...................................................................................................................... 875.2.1 Input Parameters for Link Budget Process ............................................................................................. 875.2.1.1 Service Inputs ...................................................................................................................................... 875.2.2 Transmission Parameters ........................................................................................................................ 895.2.3 UE specific parameters ........................................................................................................................... 905.2.4 Node B Specific Parameters ................................................................................................................... 905.2.5 Exemplary Link Budget.......................................................................................................................... 926 CELL PLANNING WITH PLANNING TOOL.................................................................................................... 966.1 INTRODUCTION .......................................................................................................................................... 966.2 WORKAROUND FOR UMTS CELL PLANNING............................................................................................. 966.3 DESCRIPTION OF THE WORKAROUND USING THE EXAMPLE OF OSTRAVA................................................. 966.3.1 Introduction and Process Description ..................................................................................................... 966.3.2 Input Data ............................................................................................................................................... 976.3.2.1 Databases ............................................................................................................................................. 976.3.2.2 Traffic .................................................................................................................................................. 986.3.3 A955 planning step ................................................................................................................................. 996.3.4 ILBT4RNP planning steps.................................................................................................................... 1006.3.4.1 Propagation model ............................................................................................................................. 1016.3.4.2 Input parameters ................................................................................................................................ 1016.3.4.3 ILBT4RNP output ............................................................................................................................. 1026.3.5 Comparison of the intermediate results ................................................................................................ 1036.3.6 Results & Conclusion of the workaround............................................................................................. 104



6.4 CODE PLANNING INSTEAD OF FREQUENCY PLANNING............................................................................. 1047 ANTENNA ENGINEERING........................................................................................................................... 1067.1 INTRODUCTION ........................................................................................................................................ 1067.2 ANTENNA TILT......................................................................................................................................... 1067.3 DIVERSITY ASPECTS ................................................................................................................................ 1067.3.1 RX Diversity......................................................................................................................................... 1067.3.2 TX STTD Diversity Gain ..................................................................................................................... 1087.4 ANXU (ANTENNA NETWORK FOR UMTS) ............................................................................................. 1097.4.1 Single Carrier Configuration with Transmit Diversity ......................................................................... 1107.4.2 Dual Single Carrier Configuration........................................................................................................ 1117.5 MHA (MAST HEAD AMPLIFIER).............................................................................................................. 1117.6 GSM AND UMTS/FDD CO-LOCATION.................................................................................................... 1137.6.1 RF Requirements .................................................................................................................................. 1137.6.1.1 Interference Mechanism .................................................................................................................... 1137.6.1.2 Decoupling requirements................................................................................................................... 1147.6.1.3 Receiver blocking .............................................................................................................................. 1177.6.1.4 Intermodulation ................................................................................................................................. 1207.6.1.5 Summary on the required decoupling................................................................................................ 1277.6.2 Antenna System Solutions.................................................................................................................... 1277.6.2.1 Dual Band Sites ................................................................................................................................. 1277.6.2.2 Feeder Sharing................................................................................................................................... 1367.6.2.3 Triple Band Sites ............................................................................................................................... 1377.6.3 Outlook to the future: Smart antennas (beam-forming)........................................................................ 1458 PRODUCTS AND MIGRATION STRATEGIES............................................................................................... 1468.1 INTRODUCTION ........................................................................................................................................ 1468.2 ROADMAP: RADIO ACCESS NETWORK EVOLUTION.................................................................. 1478.2.1 RELEASE 1: UMTS OVERLAY NETWORK.................................................................................... 1478.2.2 RELEASE 2: UMTS/GSM NETWORK INTEGRATION.................................................................. 1498.2.3 RELEASE 3GR3: UNIFIED RAN ARCHITECTURE ....................................................................... 1508.2.4 What is GERAN? ................................................................................................................................. 1518.2.5 Interoperability in a multi-vendor environment.................................................................................... 1528.3 PRODUCTS ............................................................................................................................................ 1528.3.1 Evolium Node B (MBS V1) ................................................................................................................. 1528.3.1.1 Possible configurations within one cabinet ....................................................................................... 1538.3.1.2 Baseband board capabilities .............................................................................................................. 1538.3.1.3 Radio performance values of MBS V1.............................................................................................. 1548.3.1.4 Iub interface to RNC.......................................................................................................................... 1558.3.2 Evolium MBS V2 ................................................................................................................................. 1558.3.3 RNC V1 ................................................................................................................................................ 1558.3.4 RNC Evolution ..................................................................................................................................... 1568.3.5 OMC ..................................................................................................................................................... 1568.3.5.1 OMC V1 ............................................................................................................................................ 1568.3.5.2 OMC V2 ............................................................................................................................................ 1588.4 MIGRATION STRATEGIES RECOMMENDED BY ALCATEL........................................................ 1588.4.1 Migration strategy recommended for incumbent operators.................................................................. 1588.4.2 Migration strategy recommended for greenfield operators .................................................................. 1618.5 ANNEX A.................................................................................................................................................. 1628.6 ANNEX B.................................................................................................................................................. 1648.7 ANNEX C.................................................................................................................................................. 1658.8 ANNEX D.................................................................................................................................................. 1669 DENSIFICATION STRATEGIES.................................................................................................................... 1679.1 INTRODUCTION ........................................................................................................................................ 1679.2 DENSIFICATION STRATEGIES.................................................................................................................... 1689.2.1 Adding carriers ..................................................................................................................................... 169



9.2.2 Sectorization ......................................................................................................................................... 1699.2.3 Adding cells .......................................................................................................................................... 1709.2.4 Microcells ............................................................................................................................................. 1719.2.4.1 Microcells and macrocells on the same channel................................................................................ 1729.2.4.2 Microcells and macrocells on different channels .............................................................................. 17210 MULTI OPERATOR ENVIRONMENT ......................................................................................................... 17410.1 INTRODUCTION ...................................................................................................................................... 17410.2 ADJACENT CHANNEL INTERFERENCE IN CASE OF UMTS FDD-FDD CO-EXISTENCE ........................... 17410.2.1 Capacity Loss due to adjacent operators’ co-existence ...................................................................... 17510.2.1.1 Uplink case ...................................................................................................................................... 17510.2.1.2 Downlink case ................................................................................................................................. 17610.2.1.3 How can it be avoided?.................................................................................................................... 17710.2.2 Dead zones.......................................................................................................................................... 17711 MEASUREMENTS...................................................................................................................................... 17911.1 MEASUREMENTS FOR PREDICTION MODEL CALIBRATION.................................................................... 17911.2 MEASUREMENTS OF CELL COVERAGE .................................................................................................. 18011.2.1 Coverage of Pilot Channel in DL Compared to GSM BCCH Channel .............................................. 18011.2.2 Impact of Service Type on Coverage ................................................................................................. 18011.2.3 Investigation on HO Gain................................................................................................................... 18111.2.3.1 Soft Handover Gain ......................................................................................................................... 18111.2.3.2 Softer Handover Gain ...................................................................................................................... 18211.2.3.3 Influence of the UE Speed............................................................................................................... 18311.2.3.4 Influence of the Interference Level.................................................................................................. 18311.2.4 Investigation on Power Control .......................................................................................................... 18311.2.4.1 Open Loop Power Control............................................................................................................... 18311.2.4.2 Closed Loop Power Control ............................................................................................................ 18311.2.4.3 Influence of the Propagation Environment ...................................................................................... 18411.2.4.4 Influence of the UE Speed............................................................................................................... 18511.3 INTERFERENCE MEASUREMENTS........................................................................................................... 18511.3.1 Dead zones.......................................................................................................................................... 18511.3.2 Influence of the Interference Level..................................................................................................... 18611.4 TRIAL MEASUREMENTS ......................................................................................................................... 18711.4.1 Co-Siting with GSM........................................................................................................................... 18711.4.2 Code Multiplex ................................................................................................................................... 18811.4.2.1 Test COD1: Orthogonality of Scrambling Codes on Downlink (Intercell) ..................................... 18811.4.2.2 Test COD2: Orthogonality on Spreading Codes on DL (Intracell) ................................................. 18811.5 NETWORK ACCEPTANCE PROCEDURE ................................................................................................... 19011.6 QOS MEASUREMENTS ........................................................................................................................... 19111.7 RECOMMENDED MEASUREMENT TOOLS FOR AIR INTERFACE MEASUREMENTS .................................. 19111.8 POSSIBLE MEASUREMENTS.................................................................................................................... 192

GLOSSARY/TERMINOLOGY................................................................................................................. 195

LIST OF ABBREVIATIONS ..................................................................................................................... 195



REFERENCED DOCUMENTS

Document references are given in the chapters!

[21.905] 3GPP specification TS21.905 V3.10 Release 1999

Useful document with explanations for UMTS abbreviations

RELATED DOCUMENTS

These documents give a good overview on the UMTS system.

[WCDMA] WCDMA for UMTS, Harri Holma & Antti Toskala, John Wiley & Sons, LTDPublished January 2000, ISBN 0471720518

[INTRO] Memorandum “Introduction to UMTS” Ref.: MCD/TD/BDC/JVPA/UMTS/2000/01

PREFACE

This document gives information required by radio network planning engineers to understand andplan a UMTS network.

SCOPE

This guideline is giving an introduction to the radio network planning related topics of the UMTSsystem. It is shown what input parameters are required to dimension and plan a UMTS radionetwork, how the dimensioning and planning is done and what kind of measurements are ofinterest.

INTRODUCTION

UMTS is the 3G mobile communication system specified by 3GPP. It is part of the IMT-2000standard provided by the ITU and consists of a WCDMA system based on FDD. A future TDD part isnot yet specified by 3GPP, thus not included in this document.

The guideline is intended to provide all necessary information required for planning a UMTSnetwork in FDD mode. It is assumed that the reader has already experience in planning othermobile communication systems, e.g. GSM.

Each chapter of this document contains its own introduction explaining the aim of the chapter. Findhereafter a short summary of contents of all chapters of the guideline:

1 RNP Process Description

This chapter deals with the overall RNP process. This process is valid for GSM and UMTS. The differentsteps of radio network planning are given together with input, output and interfaces.

2 WCDMA Fundamentals and UMTS Air Interface

This chapter gives an overview on the WCDMA technology used within UMTS. Power control andhandovers are explained in more detail.



3 Channel Types and Radio Resource Management

The different layers and their according channels used in FDD UMTS are explained in this chapter.Furthermore some aspects of Radio Resource Management like Radio Admission Control aredescribed.

4 UMTS Services and Traffic Modeling

Contrary to GSM a high variety of services with different requirements are possible in UMTS. Theseservices can be transmitted simultaneously. This requires a deeper understanding of services and trafficmodeling to be able to plan a UMTS network accurately.

5 Link Budget and Initial Network Design

Before doing the final cell planning, a rough dimensioning of the network is done. Therefore alinkbudget tool is used, which is presented in more detail in this chapter.

6 Cell Planning with planning tool

Starting with an initial design, methods to find a network layout which can be implemented, are givenin this chapter.

7 Antenna Engineering

Things to keep in mind when doing antenna engineering for UMTS with and without co-location ofGSM sites are presented in this chapter.

8 Products and Migration strategies

What products are currently available from Alcatel and what is the Alcatel strategy to migrate existingnetworks to 3G networks? Here you find the answer.

9 Densification strategies

There are different strategies possible to increase the capacity of an existing network. They areexplained in this chapter.

10 Multi operator environment

Having more than one UMTS operator in the same area may cause interference problems. How todeal with these problems is explained in this chapter.

11 Measurements

Measurements are necessary for a lot of different purposes, e.g. to test the QoS or the propagationconditions of a network. In the early phase of UMTS they are also important to understand thealgorithms used for HO. What is interesting to measure and how we can do it is described in thischapter.



1 RNP PROCESS DESCR IPTION

The RNP process description gives answers on the question – what is radio network planning (RNP).The main tasks included in RNP are bundled in packets. The inputs, contents, outputs and interfacesof each packet are given and explained. In addition the relation of each packet to the existing AIOmodules are shown.

As this process is the same for UMTS and GSM, a separated document has been created for theRNP process. This document can be found either in the PCS intranet or on DIAMS.

Document reference: RNP Process Description – 3DF 00902 UA00 DEZZA

Intranet: http://aww.rcd.alcatel.com/PCS



2 WCDMA FUNDAMEN TALS AND UMTS AIR INTERFACE

Referenced Documents

[UTRA] UMTS Terrestrial Radio Access 3DF 009955 0004 UAZZA

[25.213] Spreading and modulation (FDD) (Release 1999) 3GPP 25.213 V3.3.0

[25.214] Physical layer procedures (FDD) (Release 1999) 3GPP 25.214 V3.4.0

[25.101] UE Radio Transmission and Reception (FDD) (Release 1999)3GPP 25.101 V3.4.1

[25.331] RRC Protocol Specification (Release 1999) 3GPP 25.331 V3.4.1

[26.103] Speech CODEC List for GSM and UMTS 3GPP 26.103 V3.0.0

[WFI] 3 Day UMTS training held for ALCATEL in August 2000

[INTRO] Memorandum “Introduction to UMTS”Ref.: MCD/TD/BDC/JVPA/UMTS/2000/01

[WCDMA] WCDMA for UMTS, Holma & Toskala, John Wiley & Sons 2000,ISBN 0 471 72051 8

[OPNET] Study of soft handover with OPNET system simulations,Ref: MCD/TD/SYT/PBL/200816

[SysDesign] UTRAN System Design Document Ed.7, 3BK 10240 0005 DSZZA

2.1 UMTS network architec ture

The UMTS network includes not only the air interface of an UMTS network, but also the fixednetwork part with its connection to the core networks (packet and circuit switched). All main elementsof an UMTS network and the connection to the external networks are shown in Figure 1.

USIM

ME

Cu

UE

Node B

Node BIur

UTRAN

RNC

RNC

Node B

Node B

Iub

Uu

MSC/VLR

CN

GMSC

GGSN

HLR

SGSN

Iu

PLMN, PSTN,ISDN, ...

Internet

External Networks

RNS

RNS

Iu-CS

Iu-PS

Figure 1: Structure of the UMTS network [WCDMA]

The elements shown in Figure 1 are explained hereafter.

2.1.1 UE ( User Equipment)

The UE consists of two parts:



� The mobile equipment (ME) is the radio terminal used for radio communication over theUu interface

� The UMTS Subscriber Identity Module (USIM) is the equivalent smartcard to the SIM inGSM. It holds the subscriber identity, performs authentication algorithms, storesauthentication and encryption keys, etc.

2.1.2 UTRAN (UMTS Radio Access Network)

The UTRAN consists of one or several Radio Network Subsystems (RNS) each containing one RNCand one or several Node B:

� Node BThe Node B is the correspondent element to the BTS in GSM. Within Alcatel this part ofthe network is called the Multi-standard Base Station (MBS), as it is possible to integrateGSM modules as well (not in the early versions!)

� RNCThe Radio Network Controller (RNC) owns and controls the radio resources of theconnected Node Bs. The RNC can have three different logical roles: CRNC, SRNC,DRNC. See more details in chapter 2.1.6.

2.1.3 CN (Core network)

� HLRThe Home Location Register is a database located in the user’s home system that storesthe master copy of the user’s service profile.

� MSC/VLRThe Mobile Services Switching Center and Visitor Location Register are the switch (MSC)and database (VLR) serving the UE in its current location for circuit switched services.

� GMSCThe Gateway MSC (GMSC) is the MSC at the point where the UMTS PLMN is connectedto external circuit switched networks.

� SGSNThe Serving GPRS Support Node (SGSN) is the counterpart of the MSC/VLR for the packetswitched part of the network.

� GGSNThe Gateway GPRS Support Node (GGSN) is the counterpart of the GMSC in the packetswitched domain.

2.1.4 External networks

The UMTS network is connected to two kinds of external networks:

� Circuit switchedExamples for CS networks are: Existing telephone service, ISDN, PSTN

� Packet switchedBest example today for a packet switched network is the Internet



2.1.5 Interfaces

It is important to know, that all external UMTS interfaces are open interfaces. This means thattheoretically equipment of different vendors can be mixed if it fulfills the standards.

� Cu interfaceThe Cu interface is a standard interface for smartcards. In the UE it is the connectionbetween the USIM and the UE.

� Uu interfaceThe Uu interface is the WCDMA radio interface within UMTS. It is the interface throughwhich the UE accesses the fixed part of the network. This interface is the most importantone to understand for RNP issues.

� Iu interfaceThe Iu interface connects the UTRAN to the core network and is split in two parts. The Iu-CS is the interface between the RNC and the circuit switched part of the core network.The Iu-PS is the interface between the RNC and the packet switched part of the corenetwork.

� Iur interfaceThis RNC-RNC interface was initially designed in order to provide inter RNC soft HO, butmore features were added during the development. Four distinct functions areprovided now:

1. Basic inter-RNC mobility

2. Dedicated channel traffic

3. Common channel traffic

4. Global resource management

� Iub interfaceThe Iub interface connects the Node B and the RNC. Contrarily to GSM, this interface isfully open in UMTS and thus more competition is expected.

2.1.6 Logical roles of the RNC

2.1.6.1 CRNC

For each Node B the RNC to which the Node B is connected is the Controlling RNC (CRNC).

2.1.6.2 SRNC & DRNC

The Serving RNC (SRNC) for a certain connection is the RNC providing the Iu connection to the corenetwork. When the UE is in inter-RNC soft HO, more than one Iub and at least one Iur connection isestablished. Only one of the RNCs (the SRNC) is providing the Iu interface to the core network, allother ones are just routing information between Iub and Iur interface. These RNCs are called DriftRNC (DRNC). Figure 2 illustrates the logical role of SRNC and DRNC.



UE

Node B

Node B

Iur

SRNC

DRNC

Node B

Node B

Iub

MSC/VLR

SGSN

Iu

RNS

RNS

Iu-CS

Iu-PS

UE

Node B

Node B

Iur

SRNC

DRNC

Node B

Node B

Iub

MSC/VLR

SGSN

Iu

RNS

RNS

Iu-CS

Iu-PS

Figure 2: Logical role of SRNC and DRNC

2.1.7 Mapping between GSM and UMTS

For easy understanding of the new notations within a UMTS network, the correspondent parts of theGSM network are given in the table below.

Table 1: Mapping of notations between GSM and UMTS

GSM/GPRS UMTS

MS Mobile Station ME Mobile Equipment

SIM Subscriber Identity Module USIM UMTS SIM

- - UE User Equipment (USIM+ME)

Um Air interface Uu

BTS Base Station Node B Node B

Abis Iub

BSC Base Station Controller RNC Radio Network Controller

BSS Base Station Subsystem RNS Radio Network Subsystem

- Iur

A Iu-CS

Gb Iu-PS

MSC Mobile Switching Center MSC Mobile Switching Center

SGSN Serving GPRS Support Node SGSN Serving GPRS Support Node

OMC Operation & MaintenanceCenter

OMC dito

In this chapter, the air interface (Uu) part and its terminating devices UE and Node B areinvestigated in more detail.

2.2 Standards and used frequency spectrum

The ITU-R has produced high-level documents covering the performance, service type, and inter-working requirements for IMT-2000. Various international standards bodies such as the EuropeanTelecommunications Standards Institute (ETSI) are responsible for the detailed technicalspecifications of the equipment required to provide an IMT-2000 compatible service. A number of



different standards are likely to emerge; but they are expected to have sufficient inter-workingcapability to allow an integrated IMT-2000 service for subscribers. IMT-2000 networks will supportfive interface standards:

� IMT-DS UMTS Frequency Division Duplex (FDD)

� IMT-MC US CDMA 2000 standard

� IMT-TC UMTS Time Division Duplex (TDD)

� IMT-SC GSM EDGE (IS-136) standard

� IMT-FT DECT standard

The four Technical Specification Groups (TSGs) of the ETSI-supported 3rd Generation PartnershipProject (3GPP) have approved the detailed specification parts of their submission to the ITU-R for theIMT-2000 radio interface standard. This is a terrestrial radio interface specification known as theUniversal Terrestrial Radio Access Network (UTRAN). The UTRAN is based on a Wide-band CodeDivision Multiple Access (WCDMA) air interface.

Figure 3: IMT 2000 frequency spectrum compared to existing PLMN systems

In this document we are focusing on the FDD-WCDMA part of the IMT2000 system, the so calledFDD-UMTS. For this part, the following band is reserved:

UL: 1920 – 1980 MHz

DL: 2110 – 2170 MHz

As the UMTS carrier spacing is 5 MHz, the available bandwidth for the FDD part provides 12different channels. Depending on the country these 12 available licenses are given to differentoperators. An operator gets typically 2 or 3 licenses for paired (UL and DL) frequency bands. Thissmall amount of frequencies is due to the frequency reuse of 1 applied within a UMTS system.

The nominal channel spacing is 5 MHz, but this can be adjusted to optimize performance in aparticular deployment scenario. The channel raster is 200 kHz, which means that the centerfrequency must be an integer multiple of 200 kHz. The carrier frequency is designated by the UTRAAbsolute Radio Frequency Channel Number (UARFCN). The value of the UARFCN in the IMT2000band is defined as follows [25.101]:



Table 2: UTRA Absolute Radio Frequency Channel Number

Uplink Nu = 5 * (Fuplink MHz) 0.0 MHz � Fuplink ��3276.6 MHzwhere Fuplink is the uplink frequency in MHz

Downlink Nd = 5 * (Fdownlink MHz) 0.0 MHz � Fdownlink ��3276.6 MHzwhere Fdownlink is the downlink frequency in MHz

2.3 Mobile classes

For the terrestrial UTRAN system, the following mobile power classes are defined. They define themaximum output power of the UE [25.101].

Table 3: UE Power Classes

Power Class Maximum output power Tolerance1 +33 dBm +1/-3 dB2 +27 dBm +1/-3 dB3 +24 dBm +1/-3 dB4 +21 dBm ± 2 dB

Note: Up to now, only mobile class 4 has been entirely aproved by 3GPP

2.4 Broadband propagation channel and WCDMA basic concept

2.4.1 Multiple Access Techniques

In a mobile radio system, the radio channel has to be accessed by a great number of users. Amultiple access method has to be used in order to avoid interference in the receiver. The currentprinciples are

� TDMA (Time Division Multiple Access)

� FDMA (Frequency Division Multiple Access)

� CDMA (Code Division Multiple Access)

The data signals are modulated with user specific carrier signals. The orthogonality1 of the multipleaccess carrier signals represents the prerequisite for correctly detecting the data of all users.

� FDMA uses bandpass carrier signals which are non-overlapping in the frequency domain andtherefore orthogonal at any time.

� TDMA impulse carrier signals are non-overlapping in the time domain and orthogonal atsampling time.

� CDMA signature waveforms are generated from orthogonal code sequences (e.g. Walshsequences) or from quasi-orthogonal pseudo-noise (PN) sequences (e.g. Gold Sequences). Bymodulating the data with the user specific CDMA carrier signals, the original signal is spreadover the whole available frequency band.

1 Orthogonality of two functions g(t) and s(t) is given in the case, that their cross-correlation function

is equal to zero



timecode

channel bandwidth

Figure 4: In CDMA the different channels are only separated by code

2.4.2 Broadband signal and Coherence bandwidth

A signal is called broadband, if its coherence bandwidth is smaller than the signal bandwidth.Coherence bandwidth of a channel is defined as the range of frequency components whichexperience similar fading conditions. The coherence bandwidth of the channel depends on the localscattering environment. For most practical mobile channels 5MHz is much larger than the coherencebandwidth. Narrow band transmission (<200 kHz) the channel bandwidth is less than thecoherence bandwidth. Fading characteristics at different frequency components are identical. Forwide band transmission (>1 MHz) fading characteristics of spectral components tend to beuncorrelated

In narrow band transmission, when the receiver experiences a deep fade, signal quality is severelydegraded

� High BER

However in wide band systems because of uncorrelated fading of the spectral components deepfades affects only a portion of the spectrum

� Better signal quality

� Low BER

� Better robustness to fading

The differentiation between broadband and narrow band signals can also be made in the timedomain. If the delay spread of a signal is that big, that the received multipath signals of the nexttransmitted symbol interfere with the previous symbol, the channel is called a narrow band channel.



t

tt0

t1

t1

t0

Figure 5: Delay spreads of broad band (upper) and narrow band (lower) channels

2.4.3 Multipath propagation and RAKE receiver

One big advantage of the UMTS system is its capability to benefit from a multipath environment. Inthe upper part of Figure 4 we can see the delay spread of a broadband channel as used in UMTS.The received energy from the different multipaths of one signal overlaps much less than in thenarrow band case. Thus, the different multipaths can be combined by a special receiver technique,called RAKE receiver, to one improved signal. A RAKE receiver has several input paths (called RAKEfingers), where the signal can be delayed by an adjustable time. Selecting the delay time on eachfinger in that way, that the different multipaths entering the receiver at the same time, the signalscan be combined and thus an improved summary signal can be generated.

The delay time on each RAKE finger is determined automatically. The number of RAKE fingers is notfix and depends on the considered product.

Conclusion:

The UTRA system can take advantage from a multipath environment, e.g. dense urban areas.

2.5 Spreading, scrambling and modulation

2.5.1 Spreading

The UTRA system uses direct sequence (DS) spreading for both FDD and TDD mode. The principleconsists of multiplying the bipolar data signal bi(t) with a bipolar, broad band carrier signal si(t). Thissignal is user specific and therefor called signature waveform of the user i. The multiplication in thetime domain corresponds to a convolution in the frequency domain, so that the transmitted signal isalso broadband. The spreading factor SP describes the widening of its spectrum. The equivalent low-pass of the transmitted signals consists of chips, i.e. bipolar impulses of the duration Tc. One databit of the duration Tb=SP x Tc corresponds to SF chips during transmission.



� data signal consists of bipolar "bits"

� signature signal consists of bipolar "chips"

� chiprate = spreading factor × bitrate

data signal bi(t)

PN signature signal si(t)

spread signal gi(t)=bi(t) � si(t)

t

t

t

1

-1

1

1

-1

-1

Figure 6: Principle of spreading

Before the data signal bi can be spread, it has to be generated out of the user bits ui and thechannel coding bits. The channel coding bits are added to the data bit rate bi. Knowing the data bitrate bi, e.g. 960 kbit/s for the 384kbit/s data channel, the spreading factor is calculated. In thisexample the spreading factor would be (3840kbit/s bandwidth)/(960kbit/s data rate) = 4.

Due to this spreading the signal can be recovered out of the noise and interference at the receiverby de-spreading (auto-correlation). The received signal energy increase compared to the noise andinterference in dB is called the processing gain: PG [dB] = 10 x log SF.

Thus the processing gain can vary between 6 (SF = 4) and 24 (SF = 256).

2.5.2 Despreading

What is the sense of spreading the data signal onto the whole available channel bandwidth? Tworeasons we have seen in chapter 2.4.3 „Multipath propagation and RAKE receiver“:

1. Less fading sensible channel

2. Takes advantage from multipath environment

The main reason for spreading the data signal over the whole bandwidth is the ability to extract atthe receiver the wanted signal out of the total received power (interference, noise and useful signal)by doing correlation with the known user specific code. This is the main principle of Direct SequenceCDMA (DS-CDMA).

Principle:

timecode

channel bandwidth

timecode

channel bandwidth

Autocorrelation withknown code of channel 1

channel 1

Figure 7: Extracting the useful signal out of the overall noise



The overall received power consists of lots of overlaid transmitted channels using different codes.The wanted signal is extracted by correlating the whole received signal with the known code of thewanted signal. Due to correlation, the part of the total received signal using the same code as thecode used for correlation, will have increased power. At the same time signals using codes differentfrom the one used for correlation will be suppressed. This is leading in the ideal case to animproved SIR in the range of the processing gain PG.

2.5.3 Codes used

The spreading of the data signal onto physical channels is done in two steps:

1. ChannelizationChannelization codes transform every data bit into a number of chips. The number of chips perdata bit is the so called spreading factor SF.

2. ScramblingDuring the scrambling operation a complex scrambling code (real part for the I branch andimaginary part for the Q branch) is applied to the spread signal.The scrambling code is used to identify in UL the mobile and in DL the cell.

As this scrambling codes change very often between –1 and 1, they are responsible for increasingthe bandwidth. The channelization codes spread the signal to the chip rate of 3.84 Mbit/s, but donot really increase the required bandwidth of the signal to 3.84 MHz. A chiprate of 3.84 Mbit/s isonly leading to an required bandwidth of 3.84 MHz in case of altering the sign on a chip by chipbasis.

2.5.3.1 Channelization codes

Orthogonal Variable Spreading Factor (OVSF) codes are used as channelization codes, whichensure that a number of mobiles can share the same RF channel (frequency) without causingunacceptable interference. These codes allow Code Division Multiple Access (CDMA) to the sharedRF channel (frequency).

These spreading codes are of variable length and therefore offer spreading factors between 4 and256. In that way, different user bit rates can be realized. The codes are mutually orthogonal eventhough of different length, if they are synchronized. As synchronization is not possible betweendifferent mobiles, the orthogonal OVSF codes are not leading to orthogonal signals in UL. In DLthey are fully orthogonal assuming a ideal propagation channel, but due to multipaths in realenvironments, the signals using the codes are not fully orthogonal.

Figure 8 shows the OVSF code tree, which is generated by applying at each branch split the rule:Cnew,upper_branch = +Cold+Cold and Cnew, lower_branch = +Cold-Cold



SF = 1 SF = 2 SF = 4

c1,1 = (1)

c2,1 = (1,1)

c2,2 = (1,-1)

c4,1 = (1,1,1,1)

c4,2 = (1,1,-1,-1)

c4,3 = (1,-1,1,-1)

c4,4 = (1,-1,-1,1)

Figure 8: Code tree for generating OVSF codes

The code tree defines the code length used to provide the specified spreading factor. The higheruser data rate services use shorter codes and hence lower spreading factors (and associated de-spreading gain). A given mobile cannot use all channel codes simultaneously. A channel code canonly be used by a mobile if no other code on the path from the specific code to the root of the codetree, or in the sub-tree below the specific code, is used by any mobile. Thus the number of availablechannel codes is not fixed, but depends on the data rate and associated spreading factor of eachphysical channel used.

For each call, the mobile is allocated at least one uplink channel code, for an uplink DPCCH (seeexplanation on channel types in chapter 3). Usually, at least one further uplink channel code isallocated for an uplink DPDCH. Additional uplink channel codes may be allocated if the mobileneeds more DPDCHs. All channel codes used for the DPDCH must be orthogonal to the channelcode used for the DPCCH.

As each mobile using the same RF channel uses a unique uplink scrambling code, no co-ordinationof the allocation of uplink channel codes to mobiles is needed. They are allocated in a predefinedorder that exploits the design of the scrambling codes used by the mobile transmitter.

The mobile and the network may negotiate the number and length (spreading factor) of the channelcodes needed for the call, and the network allocates the necessary codes.

2.5.3.2 Scrambling codes

For the scrambling, there is the choice between short scrambling codes and long scrambling codes.The first option is used if there is multi user detection in the base station in order to simplify thecorrelation matrix computations. In case of single user detection, the second option is applied, forimproving the cross correlation properties and to assure a uniform distribution of the interference.

The short scrambling code is a complex code c’scramb = cI+jcQ, where cI and cQ are two differentcodes from the extended Very Large Kasami set of length 256. The long scrambling codes constituteof segments of 10ms (=38400 chips) of a set of Gold sequences with period 241-1. What longscrambling code to use is directly given by the short scrambling code.

Currently only single user detection is done within the Node Bs, thus long scrambling codes areused. Multi user detection is just an option for the future.



Downlink:

Each cell is allocated one and only one primary scrambling code. The primary CCPCH and primaryCPICH are always transmitted using the primary scrambling code. The other downlink physicalchannels can be transmitted with either the primary scrambling code or a secondary scramblingcode from the set associated with the primary scrambling code of the cell.

There is a one-to-one mapping between each primary scrambling code and 15 secondaryscrambling codes in a set such that i´th primary scrambling code corresponds to i´th set ofsecondary scrambling codes.

Hence, according to the above, scrambling codes k = 0, 1, …, 8191 are used.

The set of primary scrambling codes is further divided into 64 scrambling code groups, eachconsisting of 8 primary scrambling codes. The j´th scrambling code group consists of primaryscrambling codes 16*8*j+16*k, where j=0..63 and k=0..7.

Uplink:

The UL scrambling code is the scrambling code used by UE. Every UE has its specific UL scramblingcode. The network decides the uplink scrambling code (UL scrambling code number 0..224-1). Noexplicit allocation of the long scrambling code is thus needed.

Depending on the channel type, different scrambling codes are used, but for all of them there is onerelation valid:

The UL scrambling codes of PRACH and PCPCH preambles are subdivided into 512 code groups,having a one-to-one correspondence to the scrambling code used by the downlink. An overview onspreading and scrambling code usage is given in Figure 9.

Node B

SpreadingOVSF

(User identifier)

ScramblingPN

(Cell identifier)

UE

Descrambling Despreading

SpreadingOVSF

(User identifier)

ScramblingPN

(User identifier)DescramblingDespreading

1 2

34

1As the codes are sync. within the Node B, Orthogonal Codes are used to providesmall crosscorellation

2To provide a small crosscorellation to unsyncronized codes (from other Node Bs orfrom UEs), PN codes are used for scrambling in DL. One code for one cell !!!

As the UL isn’t syncronized, the OVSF codes aren’t used for spreading because oftheir orthogonality, but because of their easy generation for different req. lengths!

To provide a small crosscorellation to unsyncronized codes (from other UEs orNode Bs), PN codes are used for scrambling

3

4

DL

UL

Figure 9: Overview on spreading and scrambling code usage



2.5.4 Example for scrambling code allocation: Cell Search Process

During the cell search, the UE searches for a cell and determines the downlink scrambling code andframe synchronization of that cell. The cell search is typically carried out in three steps:

� Step 1: Slot synchronization

During the first step of the cell search procedure the UE uses the SCH’s primary synchronizationcode to acquire slot synchronization to a cell. This is typically done with a single matched filter (orany similar device) matched to the primary synchronization code which is common to all cells. Theslot timing of the cell can be obtained by detecting peaks in the matched filter output.

� Step 2: Frame synchronization and code-group identification

During the second step of the cell search procedure, the UE uses the SCH’s secondarysynchronization code to find frame synchronization and identify the code group of the cell found inthe first step. This is done by correlating the received signal with all possible secondarysynchronization code sequences, and identifying the maximum correlation value. Since the cyclicshifts of the sequences are unique the code group as well as the frame synchronization isdetermined.

� Step 3: Scrambling-code identification

During the third and last step of the cell search procedure, the UE determines the exact primaryscrambling code used by the found cell. The primary scrambling code is typically identified throughsymbol-by-symbol correlation over the CPICH with all codes within the code group identified in thesecond step. After the primary scrambling code has been identified, the Primary CCPCH can bedetected. And the system- and cell specific BCH information can be read.

If the UE has received information about which scrambling codes to search for, steps 2 and 3 abovecan be simplified.

2.5.5 Spreading, scrambling and modulation

As demodulation is the reciprocal of modulation, only the modulation is explained in more detailhere.

The UTRA system uses QPSK modulation. This means, that one transmitted symbol consists of twobits, one is transmitted with 0° phase shift (I branch, or real part) and the other one with 90° phaseshift (Q branch or imaginary part).

2.5.5.1 Uplink part

Concerning the uplink physical channels, one can distinguish between the two dedicated physicalchannels (Dedicated Physical Control Channel, DPCCH and Dedicated Physical Data Channel,DPDCH) and the Physical Random Access Channel (PRACH) which carries the random access burst.

For the QPSK modulation, the DPDCH bits are mapped to the in-phase (I) branch while the DPCCHbits belong to the quadrature (Q) branch. The spreading is done separately for each branch by twodifferent spreading codes cD and cC, which are called channelization codes. Both are then scrambledby the same mobile specific complex scrambling code cscramb which is therefore the signature of themobile in uplink direction. The in-phase part I and quadrature part Q are then separated again andmodulated with the signals cos(�t) and sin(�t) respectively (see Figure 10). The modulationfrequency is of course the center frequency of the used 5MHz band.



DPDCH

cD

I

DPCCH

cC

Q��j

I+jQ

cscramb

cos(��t)

sin(��t)

p(t)

p(t)

Real

Imag

Channelizationcodes (OVSF)

Figure 10: Uplink spreading, scrambling and modulation

2.5.5.2 Downlink part

Whereas in UL only one branch is used for traffic data and the other one for signaling, in DL bothbranches are used for signaling and data traffic. This is the reason, why in DL 1920 kbit/s data rateis possible and in UL only 960 kbit/s.

To be able to use both branches in DL, the data stream is subdivided and the two bit sequences aremapped to the I and Q branch, respectively ("Serial-to-parallel mapping"). The I and Q branchesare then spread to the chip rate with the same channelization code cch (real spreading) andsubsequently scrambled by the same cell specific scrambling code cscramb (real scrambling).

The channelization codes are also OVSF codes. In the downlink application, they preserve theorthogonality between downlink channels of different rates and spreading factors.

DPDCH/DPCCH

I

cch

Q

cos(��t)

sin(��t)

p(t)

p(t)

cscrambS�P

cch: channelization codecscramb: scrambling codep(t): pulse-shaping filter (root raised cosine, roll-off 0.22)

Figure 11: Downlink spreading, scrambling and modulation



2.6 User detection mechanisms (quick overview)

In Figure 12 the proposed multi user detection ,mechanisms for the UTRA system are shown. Todayonly the single user detection (SUD) is implemented in the Node Bs. This is due to the hugecalculation capacity required for performing multi user detection. More information about userdetection mechanisms can be found in [UTRA].

Single User Detection(SUD)

Interference Cancellation(IC)

Joint Detection(JD)

Multi User Detection(MUD)

CDMA Receiver

Figure 12: Possible multi user detection mechanisms in the UTRA system

2.7 Power Control in UMTS FDD

Find detailed information on power control in [25.214]. Summary in [WFI] or [INTRO]. This chapteris in accordance with [SysDesign]. This chapter is divided into 3 parts:

� General Power Control

� Uplink PC

� Downlink PC

2.7.1 General Power Control in UMTS

Evaluation of measurement reports and sending of power control commands is done by the servingradio network controller SRNC.

Unlike in GSM, the power control mechanism in UMTS is not based on selecting appropriate powerlevels to be used in the transmitter. Instead, the power control mechanism is based on a quality level(the Signal to Interference Ratio) that has to be achieved by transmitting with an appropriate powerlevel.

CDMA is very sensitive for what concerns power control: for the proper functioning of UMTS, it is ofvital importance to have a good power control mechanism: the signal to interference ratio (SIR) hasto be kept at a certain level. If the SIR is too low, the signal of a UE can not be de-spreaded andreconstructed any more. Since all users are transmitting simultaneously, the noise level depends(among others) on the number of users.

-> The more interference, the more a cell is congested

This means that interference (transmit power of other links) determines the usage and thusavailability of free radio resources. A good power control algorithm will optimize the usage of radioresources and thus increase the availability of radio resources.



Another very important goal (maybe the most important goal) of power control is to maintain thesignal quality on a radio link. Once a radio link has been established, we try to maintain it.

There are 2 types of power control:

� power control for common channels: Open Loop Power control

� power control for dedicated channels DPCCH/DPDCH and downlink shared channel DSCH:Closed Loop Power control

Closed loop power control is intended to reduce interference in the system by maintaining thequality of a UE-UTRAN communication (i.e. radio link) as close as possible to the minimum qualityrequired for the type of service requested by the user. Closed loop power control is relevant for thephysical layer channels that support dedicated transport channels (DCH) and for those that supportshared transport channels (DSCH).

Closed loop power control consists of two parts – an inner loop and outer loop. This chapter isdivided into subsections related to outer loop and inner loop power control for dedicated channelsfollowed by open loop power control for common channels.

2.7.1.1 Outer Loop Power Control

The parameter used by layer 1 for making inner loop power control decisions are determined by theouter loop power control algorithm. The outer loop control function manages the inner loop processby setting the SIR target parameter and the power up/down step sizes.

In general, the algorithm for generating the TPC bits can be described with the following rules:

SIRest >= SIRtarget � TPC command = “power down one step”

SIRest < SIRtarget � TPC command = “power up one step”

The frequency of the outer loop power control is typically in the range of 10 – 100 Hz.

2.7.1.2 Inner Loop Power Control for dedicated channels

The inner part of closed loop power control is also called fast power control (1500 Hz) since it isintended to respond to fast variations in propagation characteristics of the radio link (e.g. fast fadingat slow or medium speeds) as well as rapidly changing interference conditions. The power controlloop is closed because the receiver of the radio signal communicates commands back to the senderto adjust its transmitted power. Fast power control is considered to be part of the physical layer ofthe UTRA and is performed in the Node B and the UE.

The structure of the air interface enables power control commands called Transmit Power Control(TPC) command bits to be sent once per slot. TPC bits can tell the remote end of the loop to eitherpower up by a step or to power down by a step. The decision to power up or down is based on anestimate of the signal to interference ratio (SIR) of the channel. Since SIR is related to the quality ofthe radio link, the principle of managing the quality of the link is achieved.

As closed loop power control is slightly different for UL and DL, more details are given in chapters2.7.1.2.1 for uplink and 2.7.1.2.2 for downlink.

2.7.1.2.1 Uplink closed loop power control

Uplink power control in a CDMA system is very important because of the necessity of suppressingthe near-far effect. Assuming all mobiles transmitting with the same power, a mobile close the



receiver (Node B) would interfere the signal received from a mobile at the cell edge very strong,while the mobile at the cell edge doesn’t interfere the one close to the Node B. This effect is harmingall communications of mobiles having another mobile between themselves and the Node B. This isthe so called “Near-Far-Effect”.

The uplink inner-loop power control adjusts the UE transmit power in order to keep the receiveduplink signal-to-interference ratio (SIR) at a given SIR target.

The serving cells (cells in the active set) estimate signal-to-interference ratio SIRest of the receiveduplink DPCH. TPC commands are generated in the serving cells and transmitted once per slotaccording to the following rule:

� SIRest > SIRtarget then the TPC command to transmit is "0"

� SIRest < SIRtarget then the TPC command to transmit is "1"

Upon reception of one or more TPC commands in a slot, the UE derives a single TPC command(TPC_cmd) for each slot, combining multiple TPC commands if more than one is received in a slot.Two algorithms are supported by the UE for deriving a TPC_cmd. Which of these two algorithms isused is determined by a UE-specific higher-layer parameter, "PowerControlAlgorithm", and is underthe control of the UTRAN. If "PowerControlAlgorithm" indicates "algorithm1", then the layer 1parameter PCA shall take the value 1 and if "PowerControlAlgorithm" indicates "algorithm2" thenPCA shall take the value 2.

If PCA has the value 1, Algorithm 1 shall be used for processing TPC commands.

If PCA has the value 2, Algorithm 2 shall be used for processing TPC commands.

(Algorithm 1 and 2 are described in section 5.1.2.2.2 and 5.1.2.2.3 in 3GPP TS25.214 V3.3.0.)

The step size �TPC is a layer 1 parameter which is derived from the UE-specific higher-layerparameter "TPC-StepSize" which is under the control of the UTRAN. If "TPC-StepSize" has the value"dB1", then the layer 1 parameter �TPC shall take the value 1 dB and if "TPC-StepSize" has the value"dB2", then �TPC shall take the value 2 dB. The step size for the UL power control is thus 1 or 2 dB.

After deriving of the combined TPC command TPC_cmd using one of the two supported algorithms,the UE shall adjust the transmit power of the uplink DPCCH with a step of DPCCH (in dB) which isgiven by:

DPCCH = �TPC*�TPC_cmd.

Node B

Outer loop

Open loop

Inner loop

Closed Loop = Inner Loop + Outer Loop

Figure 13: Different UL power control mechanisms



2.7.1.2.2 Downlink closed loop power control

In Downlink both the inner and outer loop of the closed loop power control are performed in theUE. The UE generates TPC commands to control the network transmit power and send them in theTPC field of the uplink DPCCH. The UE checks the downlink power control mode (DPC_MODE)before generating the TPC command:

DPC_MODE = 0: The UE sends a unique TPC command in each slot and the TPC commandgenerated is transmitted in the first available TPC field in the uplink DPCCH

DPC_MODE = 1: The UE repeats the same TPC command over 3 slots and the new TPCcommand is transmitted such that there is a new command at the beginning ofthe frame. This mode is also called Slow Power control. Its advantage is ahigher precision of the TPC command.

Note: DPC_MODE=1 shall not be used in 3GR1.1 because 3GPP specs are not finalized.

The DPC_MODE parameter is a UE specific parameter controlled by the UTRAN.

The power control step size �TPC can take four values: 0.5, 1, 1.5 or 2 dB. It is mandatory forUTRAN to support �TPC of 1 dB, while support of other step sizes is optional.

In case of congestion (commanded power not available), UTRAN may disregard the TPC commandsfrom the UE.

2.7.1.3 Open Loop Power Control

The open loop power control is relevant for physical channels that support common transportchannels. In the definition of TS 25.214 V3.3.0 this is the UL PRACH. This physical channel is usedby the UE for establishing a connection to the network or sending small amounts of data. The OpenLoop Power control consists in setting the transmit power by measuring the path loss of the directlink and adding the interference level of the node B and a constant value.

Method:

On the BCCH, the node-B will indicate the transmit power of the PCCPCH (and also the requiredSIR). By measuring the received power-level, the UE can find the downlink pathloss including fading.From this path loss estimation and the knowledge of the uplink interference level and the requiredSIR, the transmit power needed on the PRACH channel can be determined.

2.7.1.4 Site selection diversity transmit power control

Site selection diversity transmit power control (SSDT) is another macro diversity method in softhandover mode. This method is optional in UTRAN.

Operation is summarized as follows. The UE selects one of the cells from its active set to be‘primary’, all other cells are classed as ‘non primary’. The main objective is to transmit on thedownlink from the primary cell, thus reducing the interference caused by multiple transmissions in asoft handover mode. A second objective is to achieve fast site selection without network intervention,thus maintaining the advantage of the soft handover. In order to select a primary cell, each cell isassigned a temporary identification (ID) and UE periodically informs a primary cell ID to theconnecting cells. The non-primary cells selected by UE switch off the transmission power. Theprimary cell ID is delivered by UE to the active cells via uplink FBI field. SSDT activation, SSDTtermination and ID assignment are all carried out by higher layer signaling



2.8 HO types & events

Definition: The list of cells involved in the soft/softer HO is called “Active Set”. The maximum size ofthe active set can be defined.

2.8.1 Hard handover

The hard handover (HO) is comparable to the HO procedure of GSM. The mobile is alwaysconnected to only one base station (Node B). When performing the HO to another Node B, theconnection to the former Node B is released.

All connections using a FACH channel (Fast Allocation CHannel, without power control and only forshort packages) or a DSCH (Downlink Shared CHannel, best channel for packet switched services)must use the hard HO. They can not benefit from soft HO gains.

Other hard HO:

� Inter-system HO between e.g. UTRA and GSM

� Inter-frequency HO between different UTRA carriers

Within 3GR1.1 no compressed mode is possible, which is necessary for hard handover. Hardhandover and support of DSCH are not included in 3GR1.1. This release is also not offering Inter-RNC cell reselection in idle mode.

2.8.2 Soft handover

Packet switched communications using a DCH channel and all circuit switched communications areable to perform a soft HO. Soft HO means, that the mobile receives the same signal from morethan one Node B and its transmitted signal is processed by more than one Node B. The number ofNode Bs to which the UE is connected is called the “Active Set”. This is increasing the number ofreceived multipaths in UL and DL and thus is leading to diversity gain (see chapter 2.8.4). If a NodeB is put into the active set of a mobile is depending on the pilot Ec/I0. The general scheme of SHOcan be seen in Figure 14.

For the description of the exemplary Soft Handover algorithm presented in this section the followingparameters are used (AS means Active Set):

� AS_ThThreshold for macro diversity (max difference for best signal in AS and candidate signal)

� AS_Th_HystHysteresis for the above threshold AS_Th

� AS_Rep_HystReplacement Hysteresis

� �TTime to Trigger

� AS_Max_SizeMaximum size of Active Set

The following figure describes this Soft Handover Algorithm.



AS_Th – AS_Th_HystAs_Rep_Hyst

As_Th + As_Th_Hyst

Cell 1 ConnectedEvent 1A

� Add Cell 2Event 1C �

Replace Cell 1 with Cell 3Event 1B �

Remove Cell 3

CPICH 1

CPICH 2

CPICH 3

Time

MeasurementQuantity

�T �T �T

Figure 14: Example of SHO algorithm

As described in the figure above:� If Meas_Sign is below (Best_Ss - As_Th - As_Th_Hyst) for a period of �T remove Worst cell in

the Active Set.� If Meas_Sign is greater than (Best_Ss - As_Th + As_Th_Hyst) for a period of �T and the Active

Set is not full add Best cell outside the Active Set in the Active Set.� If Active Set is full and Best_Cand_Ss is greater than (Worst_Old_Ss + As_Rep_Hyst) for a

period of �T add Best cell outside Active Set and Remove Worst cell in the Active Set.

Where:

� Best_Ss the best measured cell present in the Active Set� Worst_Old_Ss the worst measured cell present in the Active Set� Best_Cand_Set the best measured cell present in the monitored set� Meas_Sign the measured and filtered signal

In Figure 14 three different reporting events are used (1A, 1B, 1C). All standardized triggeringevents are given in chapter 2.8.5.

An example for a possible SHO algorithm is given hereafter:



Meas_Sign > Best_Ss– As_Th –

as_Th_Hyst for a period of ��T

Yes

No(Event 1B)

Remove Worst_Bs inthe Active Set

Meas_Sign > Best_Ss – As_Th+ as_Th_Hyst

for a period of ��T

No

Yes(Event 1A)

Add Best_Bs in the ActiveSet

Best_Cand_Ss > Worst_Old_Ss +As_Rep_Hyst

for a period of ��T

Yes(Event 1C)

No

Active Set Full

NoYes

Add Best BS in ActiveSet and Remove WorstBs from th Active Set

Begin

Figure 15: Flowchart of an simple SHO algorithm

2.8.3 Softer handover

A softer HO is a soft HO between cells of the same Node B, thus sectors of the same site. As this isnot improving the multipath conditions as much as soft HO does, the diversity gain is smaller.

2.8.4 Power control in soft(er) handover

In SHO, the UE has established more than one radio link. This requires special power controlfunctionality to identify the correct power control command.

2.8.4.1 Downlink PC in SHO

This is leading to the reception of more than one Power Control command in downlink (one fromeach Node B in the active set). If at least one of the Node Bs in the active set is sending a powerdown command, the UE will reduce its output power. It is enough, if one of the Node Bs is receivedcorrectly.



2.8.4.2 Uplink PC in SHO

In uplink, the UE is transmitting only one power control command for all connected Node Bs,leading to the same power up/down steps of all connected Node Bs. If at least one link has goodquality (the SIR target is met), the UE sends a power down command.

2.8.4.2.1 Power drifting

Due to UL transmission errors it is possible, that not all Node Bs in the active set receive the samepower control command. This is leading to “power drifting”: some Node Bs perform a power up,some a power down. This is degrading the performance of the SHO and should be avoided. Mainreason is that the Node Bs detect the PC commands independently and no MRC or selectioncombining can be done (would cause to much delay). Thus the error rate for PC commands can behigher than for transmitted user data.

2.8.5 Reporting events for Soft Handover and measurement reports

To find out the best cell or cells within UMTS, the UE measures the CPICH of all received neighborcells. The UE is told by UTRAN witch reporting events shall force the mobile to generate ameasurement report and sent it to the SRNC. This is different from GSM, where a measurementreport was generated at fixed time intervals (480 ms). So by using less reporting events within thehandover algorithms is leading to less measurement reports sent over the air interface.

In this chapter all HO events defined in 3GPP for intra-frequency measurements are listed. The HOalgorithms using this events are not standardized, but have to use reporting events out of the poolgiven by 3GPP [25.331].

Intra frequency reporting events

1A A primary CPICH enters the reporting range

- A measured CPICH stronger than the best CPICH minus the reporting range

- Periodically reporting possible if cell is not added to active set due to any reason (cell additionfailure)

1B A primary CPICH leaves the reporting range

1C A non–active primary CPICH becomes better than an active primary CPICH

- Non-active means, not in active set yet

- Periodic reporting possible if weakest cell is not removed from active set (cell replacement failure)

1D Change of best cell

1E A primary CPICH becomes better than an absolute threshold

1F A primary CPICH becomes worse than an absolute threshold



To additionally reduce the number of sent measurement reports, the system can apply two differentfeatures for each of the triggering events separately:

� A hysteresis value

� Time-to-trigger (the event condition must be fulfilled for a certain time before the event itselfis triggered)

For each cell an individual offset can be applied to force or delay a the event triggering byadding/subtracting the offset to the measured CPICH level at the UE.

2.8.6 Filtering EC/N0 measures out of raw measures

According to [OPNET] and [25.331] the EC/N0 measurements taken by the UE every timeslot (15times per 10ms) on the CPICH of a neighbor cell are filtered by the following formula:

Equation 1: Filtering the measurements

Ec/Io filtered (n) = F * Ec/Io averaged(n) + ( 1 – F ) * Ec/Io filtered (n -1)

Ec/Iofiltered (n) The filtered measurement for radio frame n

Ec/Ioaveraged (n) The measurement averaged over the last radio frame n

F F=(1/2)1/k with k being transmitted by the UTRAN: k=(0,1,2,3…9,11,13,15,17,19)

As shown in [OPNET] we can convert the F(k) into an averaging period for the measurements. Thisaveraging period of the measurements can be compared to the averaging window size used foraveraging the raw measurements in GSM.

In the following table, we have the relation for some values of k, F and averaging period

Table 4: Impact of parameter F on averaging period

K F Averaging period

0 1 0.01 s

1 0.7071 0.014 s

9 0.0442 0.226 s

11 0.0221 0.452 s

13 0.0110 0.905 s

15 0.0055 1.810 s

17 0.0028 3.620 s

Simulations done in [OPNET] are leading to the conclusion that a averaging period of approximately0.5s (k=11) is optimal for SHO performance.

2.9 Receive & Transmit diversity

In downlink the Node B is able to use space transmit diversity to compensate the missing spacediversity of the UE receive path. So transmit diversity exists only in downlink, contrary to receivediversity which is possible in both directions. Find hereafter more information about he differentdiversity schemes.



2.9.1 Receiver diversity mechanisms

2.9.1.1 Uplink receiver diversi ty

Three different uplink receiver diversity mechanisms are possible:

� MRC diversity at the Node B due to antenna diversity gain

� MRC diversity in Softer HO

� Selection Diversity in Soft HO

Each of the three mechanisms is explained in a separate chapter afterwards.

2.9.1.1.1 MRC diversity at the Node B due to antenna diversity gain

If for one sector at the Node B two antennas are installed, both received signals can be combined byusing Maximum Ratio Combining (MRC). This is the so called “antenna diversity” already knownfrom GSM.

2.9.1.1.2 MRC diversity in Softer HO

As Softer HO is the HO between two sectors of the same Node B, the Node B can use MRC tocombine the received signals of the same communication of the two sectors. As the antennas of thesectors in the regular case are located close to each other (similar to the distance the antennas ofone sector have to each other) the benefit of this additional diversity is quite small. The difference inthe received multipaths between the two sectors will not be big enough to benefit from the additionalMRC.

2.9.1.1.3 Selection Diversity in Soft HO

In case of Soft HO (HO between two cells not belonging to the same site/Node B) the difference inthe received multipath profiles is much bigger than in case of Softer HO. One can think, that this isleading to a high diversity gain, but unfortunately the combining of the two signals has to be doneat the RNC. To be able to do MRC at the RNC, high bit rates on the Iub interface are required (e.g.1.152 Mbit/s for a 144 Mbit/s LDD service because of 8 bit quantization instead of 1 bitquantization per symbol). Up to now the require info for doing MRC at the RNC is not transmitted,thus the RNC can only select the better signal out of the received ones (on a frame per frame basis),it can not use the different received signals to improve the received ones. This kind of diversity iscalled “selection diversity”.

2.9.1.2 Downlink receiver diversity

In downlink the UE is the receiver. As the UE has only one antenna for signal reception, no antennadiversity takes place. Due to the implemented RAKE receiver the UE is able to benefit strongly from amultipath environment by applying MRC. As the probability to have several multipaths is higher forbig distances between the transmit antennas, most benefit is expected from diversity during Soft HO.For Softer HO the diversity gain due to multipath propagation is expected to be less.



2.9.2 Downlink Transmit diversity mechanisms

The aim of transmit diversity is to increase the capacity of the downlink transmission. Indeed, two Rxantennas are usually used in the Node B receiver for RX diversity. It would be also possible to useseveral antennas in the UE, but this is not expected to be the case, since the extra complexity ofhaving several antennas in the UE would increase significantly the UE cost, weight and decrease theautonomy that is not desirable. Moreover, antennas spatially separated are not possible for smallhandsets, only polarization diversity would be possible. Transmit diversity aims to replace themissing antenna diversity in the UE receiver by a kind of antenna diversity in the Node B transmitter,thus enabling to improve the downlink performance and to avoid that the downlink limits the cellrange.

We can group transmit diversity techniques in two categories:

� The Open Loop transmit diversity consists in using two techniques:

� The STTD (Space Time Transmit Diversity) is a coding in time and space topermit the receiver to demodulate the data without additional complexity comparedto the non-diversity case.

� The TSTD (Time Switch Transmit Diversity) consists in transmitting thesignal alternatively on each antenna every slot.

� The Closed Loop transmit diversity (feedback mode) consists in weighting the signals transmittedby the two antennas. Contrary to the open loop TX diversity, the UE sends periodically weightinginformation to the Node B. These weights inform the Node B the how to adjust the amplitudesand the phases of the two transmission antennas. Two modes are possible: feedback modes 1and 2.

Table 5 summarizes which TX diversity type is allowed on which physical channel type.

Table 5: Application of TX diversity modes on downlink physical channel types

Physical channel type Open loop mode Closed loopTSTD STTD Mode

PCCPCH – X –SCH X – –SCCPCH – X –DPCH – X XPICH – X –PDSCH – X XAICH – X –CSICH – X –

Note 1: Simultaneous use of STTD and closed loop modes on the same physical channel is notallowed.

Note 2: If TX diversity is applied on any of the downlink physical channels it shall also be appliedon PCCPCH and SCH.

Note 3: The transmit diversity mode used for a PDSCH frame shall be the same as thetransmit diversity mode used for the DPCH associated with this PDSCH frame. Duringthe duration of the PDSCH frame, and within the slot prior to the PDSCH frame, thetransmit diversity mode (open loop or closed loop) on the associated DPCH may notchange. However, changing from closed loop mode 1 to mode 2 or vice versa, isallowed.



2.9.2.1 Open loop downlink transmit diversity

2.9.2.1.1 Space time block coding based transmit antenna diversity (STTD)

STTD is optional for the UTRAN, but its implementation is mandatory at the UE (and is of coursedeactivated if UTRAN does not support STTD transmit diversity). The main advantages of STTDinclude the use of the same orthogonal variable spreading factor (OVSF) code as non-diversityscheme for both antennas. Thus complexity at the UE to despread the signals coming from the twoantennas with two channelization codes is not increased. The STTD can be applied on DPDCH, P-CCPCH, S-CCPCH, AICH, and PICH channels.

The STTD encoding is applied on TPC, TFCI and Data symbols of the DPCH. Then, the DPCCH pilotpatterns defined by the standard are encoded and time multiplexed. The same spreading andscrambling codes are used for both antennas. These spread and scrambled signals are transmittedon antennas one and two after shaping by the FIR (emission Filter Impulse Response) and translatingin high frequency by the RF part (see Figure 16)

ENCData INT

MUX

TPCTFCI

MUXSTTD

Encoder Ant.2

Ant.1

PilotsAnt.2

Ant.1 FIR RFAnt.1

Spread /Scrambling

FIR RFAnt.2

Figure 16: Schematic Representation of STTD

The “diversity gain” provided by STTD is manifested by a reduction of the required receiveddownlink Eb/N0.

2.9.2.1.2 Time switched transmit diversity for SCH (TSTD)

Figure 17 illustrates the structure of the SCH transmitted by the TSTD scheme. In even numberedslots signals are transmitted on antenna 1, and in odd numbered slots signals are transmitted onantenna 2.

Antenna 1

Antenna 2

acsi,0

acp

acsi,1

acp

acsi,14

acp

Slot #0 Slot #1 Slot #14

acsi,2

acp

Slot #2

(Tx OFF)

(Tx OFF)

(Tx OFF)

(Tx OFF)

(Tx OFF)

(Tx OFF)

(Tx OFF)

(Tx OFF)

Figure 17: Structure of SCH transmitted by TSTD scheme



2.9.2.2 Closed loop downlink transmit diversity for DPCH transmission

The aim of transmit diversity is to maximize the received power at the UE. This is done bytransmitting the same signal with different amplitudes and phase shifts from two different antennas(of the same site). The optimal weighting factors are determined by the UE and sent back to theNode B by via the FBI field of the UL DPCCH.

The general transmitter structure to support closed loop mode transmit diversity for DPCHtransmission is shown in Figure 18. Channel coding, interleaving and spreading are done as innon-diversity mode. The spread complex valued signal is fed to both TX antenna branches, andweighted with antenna specific weight factors w1 and w2. The weight factors are complex valuedsignals (i.e., wi = ai + jbi ) in general, modifying amplitude and phase of the signal.

Spread/scramblew1

w2

DPCHDPCCH

DPDCH

Rx

Rx

��

CPICH1

Tx

�

CPICH2

Ant1

Ant2

Tx

Weight Generation

w1 w2

Determine FBI messagefrom Uplink DPCCH

Figure 18: DL transmitter structure for closed loop mode transmit diversity

2.10 CODECs supported by UTRAN

The GSM and UMTS standards define currently six different CODEC Types [26.103]:

Table 6: CODECS supported by the UTRAN

Name of the CODEC speech data bit rate

GSM Full Rate 13.0 kbit/s

GSM Half Rate 5.6 kbit/s

GSM Enhanced Full Rate 12.2 kbit/s

GSM Full Rate Adaptive Multi-Rate 4.75 – 12.2 kbit/s

GSM Half Rate Adaptive Multi-Rate 4.75 – 7.95 kbit/s

UMTS Adaptive Multi-Rate 4.75 – 12.2 kbit/s

Each of the six mentioned CODECS will be explained in more detail in this chapter.



2.10.1 Fixed Rate CODECs

For all three fixed rate CODECS, DTX may be enabled in uplink and in downlink independently ofeach other. DTX on or off is defined by the network on a cell basis and can not be negotiated at callsetup or during the call.

� GSM Full RateThe GSM Full Rate CODEC Type supports one fixed CODEC Mode with 13.0 kBit/s.

� GSM Half RateThe GSM Half Rate CODEC Type supports one fixed CODEC Mode with 5.60 kBit/s.

� GSM Enhanced Full RateThe GSM Enhanced Full Rate CODEC Type supports one fixed mode with 12.2 kBit/s.

2.10.2 Adaptive Multi Rate CODECs

Adaptive Multi-Rate (AMR) is a new CODEC defined by ETSI. This technology relies on a set of pre-defined "CODEC modes", each one providing optimum performance under specific radioconditions. AMR is therefore a technology allowing for the real-time optimisation of the speechcoding scheme with respect to current radio propagation conditions. With CODECs such as FR andEFR, the share of throughput given to speech coding and channel coding (speech protection) arefixed trade-offs.

AMR is able to adapt the sharing speech information / speech protection (CODEC modeadaptation) to current radio conditions, which can vary in a large scale, depending on location,speed, interference,… :

� When radio conditions are very good, speech protection is reduced and the speech informationshare is increased in order to improve speech quality,

� When radio conditions are bad, speech protection share is increased to always keep the bestpossible quality.

The CODEC mode adaptation is made up to each speech frame. This adaptation is illustrated inFigure 19:

Figure 19: Functionality of the GSM AMR CODECs

� GSM Full Rate Adaptive Multi-RateThe GSM Full Rate Adaptive Multi-Rate provides eight data rates in kbit/s:

12.2 10.2 7.95 7.40 6.70 5.90 5.15 4.75

� GSM Half Rate Adaptive Multi-RateThe GSM Half Rate Adaptive Multi-Rate provides six data rates in kbit/s:



7.95 7.40 6.70 5.90 5.15 4.75

� UMTS Adaptive Multi-RateThe UMTS Adaptive Multi-Rate provides eight data rates in kbit/s:

12.2 10.2 7.95 7.40 6.70 5.90 5.15 4.75



3 CHANNEL TYPES AND RADIO RESOURCE MANAGEMENT

Referenced documents

[Proc] UMTS Radio Procedures Pascal Pagani (PCS-F)

[Channels] UMTS Channels Celine Moignard (PCS-F)

[25.211] Physical Channels and mapping of transport channels onto physical channels3GPPTS 25.211 V3.4.0 (Release 1999)

[WCDMA] WCDMA for UMTS, Holma & Toskala, John Wiley & Sons 2000,ISBN 0 471 72051 8

[RAC&RLC] UTRAN Radio Admission control and Radio Load Control. P.Pagani

[OTC] Alcatel/Motorola document: UTRAN System Feature Requirements And ArchitectureSpecifications, FRAS Documents: Part 2: Overview of Telecom Functions, version 1.4http://slsy1b.stgl.sel.alcatel.de/umts/homepage/

[25.213] Spreading and modulation (FDD). 3GPP TS 25.213 V3.2.0 (Release 1999)

[SysDesign] UTRAN system Design Document Ed.7, 3BK 10240 0005 DSZZA

The UTRA radio interface is layered into three protocol layers [Proc]:

� Physical layer (L1)

� Data link layer (L2)

� Network layer (L3)

Layer 2 is split into following sub-layers: Medium Access Control (MAC), Radio Link Control (RLC),Packet Data Convergence Protocol (PDCP) and Broadcast/Multicast Control (BMC).

Layer 3 is partitioned into sub-layers where the lowest sub-layer, denoted as Radio Resource Control(RRC), interfaces with layer 2 and terminates in the UTRAN. The next sub-layer provides 'Duplicationavoidance' functionality.

The higher layer signaling such as Mobility Management (MM) and Call Control (CC) follows aprotocol architecture, which is similar to the current ITU-R protocol architecture, ITU-R M.1035.

Figure 20 shows a simple overview of the radio interface protocol architecture.



MAC

MM

Duplication Avoidance

RRC

BMCPDCPRLC

PHYLayer 1

Layer 2

Layer 3

CC

LogicalChannels

TransportChannels

Figure 20: Radio Interface Protocol Architecture

3.1 Overview on channel types and names

In UMTS three different channel types for data transmission and signaling are defined:

� Physical channels (Layer 1)

� Transport channels (Interface between layer 1 and 2)

� Logical channels (Interface between layer 2 and 3)

Each of these channel types and the mapping between them will be described in more detailhereafter.

3.1.1 Physical channels

Physical channels are channels really transmitted over the air. They are carrying transport channelswithin their frames and time slots. Find all physical channels in FDD mode in Table 7. Closerinvestigation of the physical channels is done in chapter 3.2 on page 43.

Table 7: Physical channels

Physical channel

AICH Acquisition Indication Channel

CPICH Common Pilot Channel

CSICH CPCH Status Indication Channel



Physical channel

DPCHDPCCH & DPDCH

Dedicated Physical ChannelDedicated Physical Control Channel & Dedicated PhysicalData Channel

DL-DPCCH for CPCH DL- Dedicated Physical Control Channel

PCCPCH Primary Common Control Physical Channel

PCPCH Physical Common Packet Channel

PDSCH Physical Downlink Shared Channel

PICH Paging Indication Channel

PRACH Physical Random Access Channel

SCCPCH Secondary Common Control Physical Channel

SCH Synchronization Channel

3.1.2 Transport channels

Transport channels are used as interface between Layer 1 and Layer 2 of the radio networkarchitecture. They are divided into

� Common transport channels (all except DCH)

� Dedicated transport channels (only DCH)

� Coded Composite Traffic Channels (CCTrCH)

What common or dedicated transport channels are defined is summarized in Table 8. There is alsoa short description of each channel given.

The CCTrCH is used to multiplex several transport channels into one new transport channel. ThisCCTrCH is than mapped to one or several physical channels depending on the required bit rate. ACCTrCH must fulfil the following criteria:

� A maximum of 5 transport channels can be multiplexed to one CCTrCH

� Only transport channels with the same active set can be mapped to one CCTrCH

� Different CCTrCHs can not be mapped onto the same physical channel

� Dedicated and common transport channels can not be multiplexed into the same CCTrCH

� For the common transport channels, only the FACH and PCH may belong to the same CCTrCH.

There are hence two types of CCTrCH:

� CCTrCH of dedicated type, corresponding to the result of coding and multiplexing of one or severalDCHs.

� CCTrCH of common type, corresponding to the result of the coding and multiplexing of a commonchannel, RACH in the uplink, DSCH ,BCH, or FACH/PCH for the downlink.

The reason for using CCTrCHs is to provide a more efficient usage of resources. Due to multiplexingof several channels into one channel and splitting of this new channel into pieces with the right sizefor fitting into a physical channel, the physical channel are used more efficient.



Table 8: Common and dedicated transport channels

Transport channels

RACH Random Access Channel

The Random Access Channel (RACH) is an uplink transport channel. The RACH is alwaysreceived from the entire cell. The RACH is characterized by a collision risk and by beingtransmitted using open loop power control.

The RACH is intended to be used to carry control information from the terminal, such asrequests to set up a connection. It can also be used to sent small amounts of packet data fromthe terminal to the network.

CPCH Common Packet Channel

The Common Packet Channel (CPCH) is an uplink transport channel and is a extension to theRACH. The CPCH is associated with a downlink DPCCH with special slot format (for fastpower control commands transmission and CPCH signaling). Before transmission on CPCHstarts, the FACH in downlink is used to provide power control and CPCH control commands.In the physical layer the main differences from the RACH are the use of fast power control(inner loop power control), a physical layer based collision detection mechanism and a CPCHstatus monitoring procedure.

FACH Forward Access Channel

The Forward Access Channel (FACH) is a downlink transport channel. The first FACH istransmitted over the entire cell with low data rate. Additional FACHs in the cell can betransmitted over only a part of the cell (e.g. beam forming antennas) using higher data rates.The FACH is not allowed to use fast PC (inner loop PC). It can be used to transmit packet datato the UE.

DSCH Downlink Shared Channel

The Downlink Shared Channel (DSCH) is a transport channel intended to carry dedicated userdata and/or control information; it can be shared by several users. In many aspects it issimilar to the FACH, but DSCH supports the fast power control as well as variable bit rateopen a frame-by-frame basis. The DSCH can be transmitted only over a part of the cell. It canemploy the different transmit diversity modes used by the associated downlink DCH. TheDSCH is always associated with a downlink DCH.

BCH Broadcast Channel

The Broadcast Channel (BCH) is a downlink transport channel that is used to broadcastsystem- and cell-specific information. The BCH is always transmitted over the entire cell andhas a single transport format.

The broadcast channel carries information like random access codes and access slots in thecell, or types of used transmit diversity. As it is mandatory to receive the BCH transportchannel to register to the corresponding cell, the BCH must be transmitted with relatively highpower.

PCH Paging Channel

The Paging Channel (PCH) is a downlink transport channel. The PCH is always transmittedover the entire cell to be able to initiated a communication with the UE. The PCH is sent by allcells within the location area of the mobile. The transmission of the PCH is associated with thetransmission of physical-layer generated Paging Indicators, to support efficient sleep-modeprocedures.



Transport channels

DCH Dedicated Channel

The Dedicated Channel is a downlink or uplink transport channel. The DCH is transmittedover the entire cell or over only a part of the cell using e.g. beam-forming antennas.

The contents of the DCH transport channel are not visible to the physical layer, thus the DCHcan carry user data and control information as well. The UTRAN will set the physical layerparameters depending on DCH carrying control or user data. The DCH supports

� Fast power control

� Fast data rate change on a frame-by-frame basis

� Soft HO

3.1.3 Logical channels

Logical channels are used as interface between Layer 2 and Layer 3 of the radio networkarchitecture.

Table 9: Logical control channels

Logical control channels

BCCH Broadcast Control Channel (DL)

System control information is broadcasted on the BCCH

PCCH Paging Control Channel (DL)

Paging information is broadcasted on the PCH channel.

CCCH Common Control Channel (DL & UL))

A bi-directional channel for transmitting control information between the network and UEs.The logical CCCH channel is always mapped onto RACH/FACH transport channels.

DCCH Dedicated Control Channel (DL&UL)

The DCCH is a bi-directional channel, that transmits dedicated control information betweenUE and UTRAN. The DCCH is established during RRC connection establishment procedure.

Table 10: Logical traffic channels

Logical traffic channels

DTCH Dedicated Traffic Channel (DL&UL)

The DTCH carries user data. It can exist in UL & DL.

CTCH Common Traffic Channel (UL)

A common downlink traffic channel to transfer dedicated user information to all or a groupof UEs.



3.1.4 Mapping between different channel types

CCCH

CPCH DCH

DCCHDTCH

PCH BCH FACH DSCH DCH

PCCH BCCH CCCH CTCHDCCHDTCH

UPLINK DOWNLINK

LOGICALCHANNELS

TRANSPORTCHANNELS

PRACH DPCCHDPDCH SCCPCH PCCPCH PDSCH

DPCCHDPDCH

PHYSICALCHANNELS

PCPCH

SCH CPICH AICH PICH CSICH CD/CA-ICHStandalone physical channelswithout connection to transport layer

RACH

Figure 21: Mapping between logical, transport and physical channels

3.2 The physical channels

In this chapter the physical channels will be explained. They are separated into UL and DL channels,chapter 3.2.1 and 3.2.2 respectively.

3.2.1 The physical channels in Uplink

Physical Channels in UL

PRACH Physical Random Access Channel

The PRACH is used to carry the RACH transport channel.

PCPCH Physical Common Packet Channel

The PCPCH is used to carry the CPCH transport channel.

DPCH(DPCCH/DPDCH)

Dedicated Physical Channel

The DPCH is a summary of the two physical channels DPDCH and DPCCH.The DPCCH carries user dedicated control information and the DPDCHcarries user dedicated data.

3.2.1.1 DPCH (DPDCH & DPCCH) in UL

There are two types of uplink DPCH, the uplink DPDCH and the uplink DPCCH. The DPDCH andthe DPCCH are I/Q code multiplexed within each radio frame. This is different from the downlink,where DPDCH and DPCCH are time multiplexed on the same branch.



The uplink DPDCH is used to carry the DCH transport channel. There may be zero, one, or severaluplink DPDCHs on each radio link.

The uplink DPCCH is used to carry control information generated at Layer 1. There is one and onlyone uplink DPCCH on each radio link.

Figure 22 shows the frame structure of the uplink dedicated physical channels. Each radio frame oflength 10 ms is split into 15 slots, each of length Tslot = 2560 chips, corresponding to one power-control period.

Pilot Npilot bits

TPC NTPC bits

DataNdata bits

Slot #0 Slot #1 Slot #i Slot #14

Tslot = 2560 chips, 10 bits

1 radio frame: Tf = 10 ms

DPDCH

DPCCHFBI

NFBI bitsTFCI

NTFCI bits

Tslot = 2560 chips, Ndata = 10*2k bits (k=0..6)

Figure 22: Frame structure for uplink DPDCH/DPCCH

The control bits of the DPCCH are explained hereafter.

Pilot: The (mandatory) pilot bits are used for channel estimation for coherent detection. Byestimating the channel conditions, the receiver in the Node B can optimize its receiverparameters. If the pilot bits on the DPCCH are not sufficient for channel estimation,the CPICH (Common Pilot Channel) bits can be used for support.

TFCI: The (optional) Transport Format Combination Indicator (TFCI) informs the receiverabout the instantaneous transport format combination of the transport channelsmapped to the simultaneously transmitted uplink DPDCH of the radio frame.

FBI: The (optional) Feedback Indicator (FBI) is used to adjust the closed loop transmitdiversity parameters.

TPC: The Transmit Power control (TPC) carries in uplink the power control commands forthe Node B transmitter.

3.2.1.2 PRACH

The Random Access Channel (RACH) is an uplink transport channel that is used to carry controlinformation and user packets from the User Equipment (UE) to the Serving RNC (SRNC). When theUE wishes to send information on the RACH, it listens to the logical Broadcast Control Channel(BCCH) of the serving cell to learn the access parameters (and specifically the informationcontrolling the random access channel utilization). Using this access information, the UE initiatessending the RACH preamble. After the UE has completed its preamble transmission on the RACH, itlistens to the Acquisition Indication Channel (AICH) to determine if the Node B received the RACHpreamble without error. Assuming that the Node B has indicated successful reception, the UE thentransmits the message part of the RACH. The UE sets the power level based on parameters receivedon the BCCH. If the UE does not get a successful indication, it will retransmit the preamble after



using an algorithm to provide a random delay. The Node B accepts the message part of the logicalRACH and sends DCCH and User Data to the SRNC and CCCH to the CRNC.

The random-access transmission is based on a Slotted ALOHA approach with fast acquisitionindication. The UE can start the transmission at a number of well-defined time-offsets, denotedaccess slots. There are 15 access slots per two frames and they are spaced 5120 chips (2 slots!)apart.

Figure 23 shows the access slot numbers and their spacing to each other. Information on whataccess slots are available in the current cell is given by higher layers.

#0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14

5120 chips

radio frame: 10 ms radio frame: 10 ms

Access slot #0 Random Access Transmission

Access slot #1

Access slot #7

Access slot #14

Random Access Transmission

Random Access Transmission

Random Access TransmissionAccess slot #8

Figure 23: RACH access slot numbers and their spacing

The structure of the random-access transmission is shown in Figure 24. The random-accesstransmission consists of one or several preambles of length 4096 chips and a message of length 10ms.

Message partPreamble

4096 chips 10 ms

Preamble Preamble

Figure 24: Structure of the random-access transmission

Figure 25 shows the structure of the random-access message part. The 10 ms message is split into15 slots, each of length Tslot = 2560 chips. Each slot consists of two parts, a data part that carriesLayer 2 information and a control part that carries Layer 1 control information. The data and controlparts are transmitted in parallel.

The data part consists of 10*2k bits, where k=0,1,2,3. This corresponds to a spreading factor of256, 128, 64, and 32 respectively for the message data part.

The control part consists of 8 known pilot bits to support channel estimation for coherent detectionand 2 TFCI bits. This corresponds to a spreading factor of 256 for the message control part. TheTFCI value corresponds to a certain transport format of the current random-access message.



Pilot Npilot bits

DataNdata bits


Tslot = 2560 chips, 10*2k bits (k=0..3)

Random-access messageTRACH = 10 ms

Data

ControlTFCI

NTFCI bits

Figure 25: Structure of the random-access message part

This structure implies a (small) risk for collisions on the RACH. However, because of the usedpreamble codes and random scrambling codes used on random access channels, it is possible tohave up to 80 random-access attempts within a 10 ms frame.

3.2.1.3 PCPCH

The PCPCH is used to carry the CPCH.

The CPCH transmission is based on DSMA-CD (Digital Sense Multiple Access Collision Detection)approach with fast acquisition indication. The UE can start transmission at the beginning of anumber of well-defined time-intervals, relative to the frame boundary of the received BCH of thecurrent cell. The access slot timing and structure is identical to the RACH. The structure of the CPCHaccess transmission is shown in Figure 26. The CPCH access transmission consists of one or severalAccess Preambles [A-P] of length 4096 chips, one Collision Detection Preamble (CD-P) of length4096 chips, a DPCCH Power Control Preamble (PC-P) which is either 0 slots or 8 slots in length,and a message of variable length Nx10 ms.

4096 chips

P0P1

Pj Pj

Collision DetectionPreamble

Access Preamble Control Part

Data part

0 or 8 slots N*10 msec

Message Part

Figure 26: Structure of the CPCH access transmission

The frame structure and possible slot formats of the PCPCH can be found in [25.211].



3.2.2 The physical channels in DL

Table 11: Summary of downlink physical channels

Physical downlink channelsDPCH(DPDCH & DPCCH)

Dedicated Physical Channel

Dedicated Physical Data Channel (DPDCH) and Dedicated Physical Control Channel(DPCCH) are time multiplexed on the same DPCH.

See more details in 3.2.2.1

DL-DPCCH for CPCH DL- Dedicated Physical Control Channel

This special DPCCH is always associated with a CPCH for PC and signaling of the CPCH.

CPICH

(P-CPICH & S-CPICH)

Common Pilot Channel

The CPICH consists of two sub-channels, the primary CPICH (P-CPICH) and the secondaryCPICH (S-CPICH). Find more information in 3.2.2.2

PCCPCH Primary Common Control Physical Channel

It is used to carry the BCH transport channel. See 3.2.2.3

SCCPCH Secondary Common Control Physical Channel

used to carry to FACH and PCH. See 3.2.2.4

SCH Synchronization channel

The SCH is needed for the cell search of the mobile and consists of a Primary SCH and aSecondary SCH, which are sent in parallel. They are time multiplexed with the PCCPCH.See 3.2.2.5.

PDSCH Physical Downlink Shared channel

The PDSCH is used to carry the DSCH. A certain code for channelization is given to thePDSCH for one frame. During this frame all slots are allocated to one UE. The UE canchange every frame. Different UEs can be code multiplexed, using codes from the sameOVSF root during one frame. A UE knows when it has to decode the PDSCH by the DPCHwhich is necessarily associated with a PDSCH connection of each UE. See 3.2.2.6.

AICH Acquisition Indication Channel:

The AICH is used to sent an acknowledgement to the UE after correct reception of theRACH. The AICH is not visible to higher layers, thus directly controlled by the physicallayer. It has a spreading factor of 256 and consists of 15 repeated consecutive access slotsof 5120 chips duration (20 ms frame). 4096 chips are used by the AICH and for the other1024 chips the transmission is either off, or they are used by the CSICH or other possiblefuture physical channels. See more information in [25.211]

PICH Page Indication Channel

The Paging Indicator Channel (PICH) is a fixed rate (SF=256) physical channel used tocarry the paging indicators. The PICH is always associated with an S-CCPCH to which aPCH transport channel is mapped.

Once a PI message has been detected on the PICH, the UE decodes the next PCH frametransmitted on the SCCPCH whether there is a paging message intended for it.



Physical downlink channels

AP-AICH

CD/CA-ICH

CSICH

CPCH Access Preamble Acquisition Indicator Channel

CPCH Collision Detection/Channel Assignment Indicator Channel

CPCH Status Indication Channel

These physical channels have been specified for the CPCH access procedure. They carryno transport channels, but only information needed in the CPCH access procedure. See[25.211], [WCDMA]

Note: Find more information on all physical channels in [25.211]

3.2.2.1 Downlink DPCH

The main difference of DL DPCCH compared to UL DPCH is, that the DPDCH and DPCCH are timemultiplexed and both are transmitted on I and Q branch of the transmitter (QPSK modulation).Having the same symbol rate in UL and DL, the QPSK is leading to nearly (minus multiplexedcontrol bit rate) doubled possible bit rate for user data in DL.

Closed loop power control is used and two kinds of transmit diversity are possible: Closed loop andSTTD open loop.

Figure 9 shows the frame structure of the downlink DPCH. Each frame of length 10 ms is split into15 slots, each of length Tslot = 2560 chips, corresponding to one power-control period.

One radio frame, Tf = 10 ms

TPC NTPC bits



Data2Ndata2 bits

DPDCHTFCI

NTFCI bitsPilot

Npilot bitsData1

Ndata1 bits

DPDCH DPCCH DPCCH

Figure 27: Frame structure for downlink DPCH

The parameter k in Figure 27 determines the total number of bits per downlink DPCH slot. It isrelated to the spreading factor SF of the physical channel as SF = 512/2k. The spreading factor maythus range from 512 down to 4.

The exact number of bits of the different downlink DPCH fields (Npilot, NTPC, NTFCI, Ndata1 and Ndata2) isgiven in [25.211]. What slot format to use is configured by higher layers and can also bereconfigured by higher layers.

There are basically two types of downlink Dedicated Physical Channels; those that include TFCI (e.g.for several simultaneous services) and those that do not include TFCI (e.g. for fixed-rate services). Itis the UTRAN that determines if a TFCI should be transmitted.



3.2.2.2 CPICH – Common Pilot channel

The common pilot channel is an unmodulated code channel, which is scrambled by the cell specificscrambling code. The CPICH is for aiding the channel estimation for dedicated channels and forproviding the channel estimation reference for common channels. Two types of CPICH are defined,the primary and the secondary common pilot channel (P-CPICH & S-CPICH).

3.2.2.2.1 Primary Common Pilot Channel (P-CPICH)

The P-CPICH is used for performing measurements for handover and cell selection/reselection.

The Primary Common Pilot Channel (P-CPICH) has the following characteristics:

� The same channelization code is always used for the P-CPICH� The P-CPICH is scrambled by the primary scrambling code of the cell� There is one and only one P-CPICH per cell� The P-CPICH is broadcast over the entire cell

The Primary CPICH is the phase reference for the following downlink channels: SCH, PrimaryCCPCH, AICH, PICH. The Primary CPICH is also the default phase reference for all other downlinkphysical channels.

3.2.2.2.2 SCPICH - Secondary Common Pilot Channel

A Secondary Common Pilot Channel (S-CPICH) has the following characteristics:

� An arbitrary channelization code of SF=256 is used for the S-CPICH

� A S-CPICH is scrambled by either the primary or a secondary scrambling code

� There may be zero, one, or several S-CPICH per cell

� A S-CPICH may be transmitted over the entire cell or only over a part of the cell (e.g. beam forming antennas)

� A Secondary CPICH may be the reference for the Secondary CCPCH and the downlink DPCH. If this is thecase, the UE is informed about this by higher-layer signalling.

3.2.2.3 PCCPCH – Primary Common Control Physical Channel

The Primary CCPCH is a fixed rate (30 kbit/s, SF=256) downlink physical channels used to carry theBCH transport channel.

Figure 15 shows the frame structure of the Primary CCPCH. The frame structure differs from thedownlink DPCH in that no TPC commands, no TFCI and no pilot bits are transmitted. The PrimaryCCPCH is not transmitted during the first 256 chips of each slot. Instead, Primary SCH andSecondary SCH are transmitted during this period



Data18 bits


Tslot = 2560 chips , 20 bits


(Tx OFF)

256 chips

Figure 28: PCCPCH frame structure

3.2.2.4 SCCPCH – Secondary Common Control Physical Channel

The Secondary CCPCH is used to carry the FACH and PCH. There are two types of SCCPCH: thosethat include TFCI and those that do not include TFCI. It is the UTRAN that determines if a TFCIshould be transmitted, hence making it mandatory for all UEs to support the use of TFCI. The set ofpossible rates for the Secondary CCPCH is the same as for the downlink DPCH. The frame structureof the Secondary CCPCH is shown in Figure 29.



Pilot Npilot bits

DataNdata bits


TFCI NTFCI bits

Figure 29: SCCPCH frame structure

The parameter k in Figure 29 determines the total number of bits per SCCPCH slot. It is related tothe spreading factor SF of the physical channel as SF = 256/2k. The spreading factor range is from256 down to 4. The values for the number of bits per field are given in [25.211].

The FACH and PCH can be mapped to the same or to separate Secondary CCPCHs. If FACH andPCH are mapped to the same Secondary CCPCH, they can be mapped to the same frame. Themain difference between a CCPCH and a downlink dedicated physical channel is that a CCPCH isnot inner-loop power controlled. The main difference between the Primary and Secondary CCPCH isthat the transport channel mapped to the Primary CCPCH (BCH) can only have a fixed predefinedtransport format combination, while the Secondary CCPCH support multiple transport formatcombinations using TFCI. Furthermore, a Primary CCPCH is transmitted over the entire cell while aSecondary CCPCH may be transmitted in a narrow lobe in the same way as a dedicated physicalchannel (only valid for a Secondary CCPCH carrying the FACH).



3.2.2.5 SCH – Synchronization Channel

The Synchronization Channel (SCH) is a downlink signal used for cell search. The SCH consists oftwo sub channels, the Primary and Secondary SCH. The 10 ms radio frames of the Primary andSecondary SCH are divided into 15 slots, each of length 2560 chips.

Figure 30 illustrates the structure of the SCH radio frame.

Prim arySC H

SecondarySC H

256 ch ips

2560 chips

O ne 10 m s SC H rad io fram e

acsi,0

acp

acsi,1

ac p

ac si,14

acp

S lo t #0 S lo t #1 S lo t #14

Figure 30: Structure of Synchronization Channel (SCH)

The Primary SCH consists of a modulated code of length 256 chips, the Primary SynchronizationCode (PSC) denoted cp in

Figure 30, transmitted once every slot. The PSC is the same for every cell in the system.

The Secondary SCH consists of repeatedly transmitting a length 15 sequence of modulated codes oflength 256 chips, the Secondary Synchronization Codes (SSC), transmitted in parallel with thePrimary SCH. The SSC is denoted cs

i,k in

Figure 30, where I = 0, 1, …, 63 is the number of the scrambling code group, and k = 0, 1, …, 14is the slot number. Each SSC is chosen from a set of 16 different codes of length 256. This sequenceon the Secondary SCH indicates which of the code groups the cell's downlink scrambling codebelongs to.

The primary and secondary synchronization codes are modulated by the symbol as shown in figure18, which indicates the presence/ absence of STTD encoding on the P-CCPCH and is given by thefollowing table:

P-CCPCH STTD encoded a = +1P-CCPCH not STTD encoded a = -1

The SCH itself can have TSTD transmit diversity.

3.2.2.6 PDSCH – Physical Downlink Shared Channel

A PDSCH is allocated on a radio frame basis to a single UE. Within one radio frame, UTRAN mayallocate different PDSCHs under the same PDSCH root channelization code to different UEs basedon code multiplexing. Within the same radio frame, multiple parallel PDSCHs, with the samespreading factor, may be allocated to a single UE. This is a special case of multicode transmission.All the PDSCHs under the same PDSCH root channelization code are operated with radio framesynchronization.

PDSCHs allocated to the same UE on different radio frames may have different spreading factors.The frame and slot structure of the PDSCH are shown on Figure 31.



Slo t #0 Slo t #1 S lo t # i S lo t #14

T slot = 2560 chips, 20*2 k b its (k= 0 ..6 )

D ataN data b its

1 rad io fram e: T f = 1 0 m s

Figure 31: Frame structure for the PDSCH

For each radio frame, each PDSCH is associated with one downlink DPCH. The PDSCH andassociated DPCH do not necessarily have the same spreading factors and are not necessarily framealigned.

All relevant Layer 1 control information is transmitted on the DPCCH part of the associated DPCH,i.e. the PDSCH does not carry Layer 1 information. To indicate for UE that there is data to decodeon the PDSCH, two signaling methods are possible, either using the TFCI field of the associatedDPCH, or higher layer signaling carried on the associated DPCH.

In case of TFCI based signaling, the TFCI informs the UE of the instantaneous transport formatparameters related to the PDSCH as well as the channelization code of the PDSCH. In the othercase, the information is given by higher layer signaling. The channel bit rates and symbol rates forPDSCH are given in Table 12.

Table 12: Slot formats of DPSCH with possible spreading factors

Slot format #i Channel BitRate (kbps)

ChannelSymbol Rate(ksps)

SF Bits/Frame

Bits/ Slot Ndata

0 30 15 256 300 20 201 60 30 128 600 40 402 120 60 64 1200 80 803 240 120 32 2400 160 1604 480 240 16 4800 320 3205 960 480 8 9600 640 6406 1920 960 4 19200 1280 1280

3.3 Radio resource management functions

Radio resource management (RRM) is responsible for the utilization of the air interface resources.RRM is needed to guarantee quality of service (QoS), to maintain the planned coverage area and tooffer high capacity. Radio Resource Management is split in the following functions:

� Power controlaims at maintaining the right level of power to and from each mobile. This is further split inclosed loop and open loop power control - explained in chapter 2.

� Radio admission control (RAC)is a CRNC function, checking whether new calls can be accepted with the service characteristicsrequired by the users, and maintaining the quality of already established calls in the cells of thatCRNC. It is explained in section 0 of this chapter. RAC itself is part of the Connection admission



control which is split into Call/Connection Admission Control of the ATM network part (CAC)and RAC.

� Traffic volume measurementfunction supervises the user data flow, in order to adapt the allocated radio resource to theamount of data sent.

� Radio access bearer establishment, configuration and releaseaddresses the procedures of establishment of radio resources. It includes handling of radioparameters.

� Radio resource allocation and managementfunction is in charge of allocating the channelization codes and temporary user identifiers usedin the UTRAN. This includes the problem of reshuffling the code tree, so as to enable high bitrate connections.

� Radio load controlfunction aims at avoiding radio congestion. The section also indicates actions taken in case aradio congestion situation occurs.

� Radio channel coding and decodingdescribes the functions performed in the Node B to cope with the CDMA air interface. Amongother, this includes interleaving, rate matching, discontinuous transmission handling,compressed mode handling, and of course, mapping to physical channels.

� Packet scheduling, multiplexing and retransmissionaddresses the complex issue of dynamic optimization of resources both in downlink and uplink,in particular the use of common and shared channels.

� RACH detection and handlingis devoted to the resource management aspects related to the Random Access Channel.

Table 13 shows which elements of the RAN are involved in the execution of each Radio resourcemanagement (RRM) function.

Table 13 Radio resource management functions

Function

Node

B

CRN

C

SRNC

UE

Radio Resource Management

a) RF Power control Closed LoopRF Power Control, UL/DL Inner Loop

X XRF Power Control, UL Open Loop

X Xb) RF Power Control, UL/DL Outer Loop (= QOS control)

X Xc) Radio Admission Control

Xd) Traffic Volume Measurements per UE

Xe) Traffic Volume Measurements on common channels

Xf) Radio Access Bearer Establishment, Reconfiguration, and Release

Xg) Radio Resource Allocation and Management

Xh) Radio Load Control

Radio Overload Prevention X

Radio Overload handling X



Function

Node

B

CRN

C

SRNC

UE

Radio Resource Management

i) Radio Channel Coding/DecodingX X

j) NRT Services Scheduling, Multiplexing and Retransmission

CH scheduling X

CH scheduling X

Scheduling control on RACH X

AC on DCH X

transmission X Xk) RACH management

CH detection and control X X

CH handling for CCCH X

CH handling for DCCH and user data X

CI detection X

In this version of the document besides Power Control in chapter 2, only the Radio AdmissionControl function RAC is explained in more detail.

3.3.1 Radio Admission Control

In the CDMA system, since the uplink and downlink are asymmetric, the RAC algorithm is differentfor uplink and downlink. When the both RAC algorithm admit, the connection can be established.

The RAC part is in accordance with [SysDesign].

3.3.1.1 Admission control for uplink

Three types of admission control are desirable to be considered.

� Received power admission control

� Active user based admission control

� Channel element based admission control

3.3.1.1.1 Received power admission control

This algorithm is based on the noise rise calculation. The Node B always measures the noise rise.When the establishment of the new connection is requested, the RAC function makes a judgementwhether to grant the request by comparing the average actual noise rise in a certain period,assumed increment of noise rise caused by adding the new connection and the threshold noise risevalue predetermined.

This algorithm is highly reliable because it is based on the actual measurement value. However, it isnot easy to precisely analyze the increment of noise rise when the new connection is added because



the increment of the interference from the adjacent Node B, which is caused by adding the newconnection in question, should be taken into account.

To develop this algorithm, the following parameters will be needed.� The actual noise rise measured by Node B� The time of period to be used for averaging*� The threshold value*� The increments of noise rise for every service according to the actual noise rise at a given

time*

The parameters marked with asterisk should be able to change by software.

3.3.1.1.2 Active user based admission control

This algorithm is based on the number of active users. The RAC function makes a judgementwhether to grant the request by comparing the number of active users assumed after the newconnection is established and the maximum number of active users calculated logically. Since thereare several services and its capacity is different respectively, the calculation of total number of activeuses is complicated. One method is to decide a certain service as the standard, convert the numberof active user of the other services to that corresponding to the standard service.

This algorithm is the one based on the theory and the result of simulation, and used to complementthe noise rise based algorithm which is based on the actual measurement value

To develop this algorithm, the following parameters will be needed.

� The number of active users of each service in presence

� The weight to convert the number of active users of a certain service to that of the standardservice*

� The maximum number of active user of the standard service*


3.3.1.1.3 Channel element based admission control

This algorithm is based on the number of BB channels. The RAC function makes a judgementwhether to grant the request by comparing the number of BB channels used and the number of BBchannels available. It is necessary to consider that some BB channels should be reserved for thehandover users in the adjacent Node B according to the handover ratio.


� The number of BB channels to be used

� The number of BB channels reserved for handover user*

� The total number of BB channels that the Node B has


3.3.1.2 Admission Control for Downlink

Admission Control for Downlink shall have the three following parts:

� Transmit power based admission control� Active user based admission control



� Channel element based admission control

3.3.1.2.1 Transmit power based admission control

This algorithm is based on the transmit power available. The RAC function makes a judgementwhether to grant the request by comparing the transmit power available, which equals to thedifference between the maximum transmit power and the average transmit power used, and therequired transmit power for the new connection.


� The transmit power used

� The time of period to be used for averaging*

� The maximum transmit power

� The transmit power required for the new connection*


3.3.1.2.2 Active user based admission control

Same as uplink.

3.3.1.2.3 Channel element based admission control

Same as uplink.



4 UMTS SERVICES AND TRAFFIC MODELING

This chapter is dedicated to the traffic modeling in the network dimensioning approach.


[Agin_LL] Summary of UTRA/FDD Link Lever Performance Results, P. Agin,

Ref: TD/SYT/pag/740.99

[SysDesign] UTRAN System Design Document Ed.7, 3BK 10240 0005 DSZZA

RELATED DOCUMENTS

[Asp] Theory of Traffic Modelling, Version 1.5, X. Asperge, MND internal document

[ETSI] ETSI document TR101 112 v3.2.0. (1998-04), formerly UMTS 30.03 version 3.2.0.

[MND1] UMTS Radio Interface Dimensioning, S. Joga, MND internal document

[MND4] UMTS Radio Dimensioning Overview, Y. Dupuch and A. Gärtner, MND internaldocument

[POM] A page-oriented WWW traffic model for wireless system simulations, A. Reyes-Lecuona,E. Gonzalez-Parada, E. Casilari, J.C. Casasola and A. Diaz-Estrella in 16th

International Telegraphic Congress, Vol 2, pp 1271-1280, Edinburgh, June 1999

[Prob] "Probabilités", Jacques Neveu, Script of Ecole Polytechnique, Edition 1997

The chapter describes the UMTS multiservice concepts including the different service definitions andtraffic models.

In contrary to second generation mobile radio systems, where one single type of quality criteriadesigned for speech determines the radio design process, for UMTS a multitude of different bearerservices with different quality requirements have to be taken into account. Each service needs adifferent “portion” of the available resource, the air interface, dependent on parameters like the bit-rate, the maximum delay and the tolerable maximum bit error rate. Additionally, the user activity fordifferent services shows different statistical behaviour which has to be described by accordingstochastical traffic models in order to judge the expected traffic created by the service mix.

Since in a CDMA system the cell range is traffic dependent, reliable traffic models play an importantrole in the UTRA/FDD radio design.

In a CDMA system, a user is only taking resources (capacity) from the network if he is causinginterference for the other users, meaning that he is emitting (contribution to uplink interference) orreceiving (contribution to the downlink interference). Therefore, even for circuit switched services,where the user is assigned a circuit switched channel for the whole time of the connection, he doesnot block resources2 when he is not emitting (resp. receiving). That’s why the notion of “serviceactivity” has been introduced, described by the activity factor.

An additional aspect of the UMTS system consists in the multiservice. Due to the fact that users ofdifferent services are dynamically using resources from the same “pool”, there is a certain trunkingefficiency compared to a scenario where a given capacity is divided a priori between different

2 except the channelization codes



services. In the latter case, one can dimension the required resources for the different servicesseparately, in the former case, a common approach has to be found taking into account the trafficmix.

4.1 UMTS Services

The notion of “service” is used within the UMTS world with a variety of different meanings. At a firstglance, one would associate the word “service” with the user application, like web-browsing or e-mail. The following list represents an exemplary choice of such service applications:

Personal Communications

Voice

Voice over IP protocol

Voice mail

E-mail (without attachment)

Text / SMS messaging

Multimedia messages:

Still images, video, text, sound

Conversion of media

Video telephony / conference

Mobile office

Internet access, browsing

Intranet access, browsing

Corporate database access

E-mail with possible attachments

Rapid File/Data transfer

Collaborative working (tele-presence) (tele-work)

Agenda synchronisation with PDA

Expert on line

Remote diagnostics / maintenance (e.g. network administrator)

Location based services

Navigation services (position)

Traffic information (depending on where the car is and goes)

Tourist information / virtual tourist guide

Maps, images download (e.g. of neighbouring sites)

Time table / schedule information (train schedules)

Locator services



Fleet management (positioning and follow-up) (fleet management: taxis, trucks…)

Telemetry

Remote health monitoring

Remote data acquisition and transfer (e.g. gathering weather forecast data)

Remote monitoring & control

Remote surveillance / alarm

E-commerce

On-line banking

E-cash integrated in the mobile

Electronic ticketing

Interactive shopping, delivery

Intelligent brokering

Information services

Yellow pages

Push & pull news / information (launching search for information)

E-newspaper

Health

Education, training

Entertainment

Sports news

Interactive games

Gambling

E-magazines

Audio on demand

Video-clips on demand

However, in order to predict the impact of such a service application on coverage and capacity,other attributes have to be examined. In this context, a service is defined by the followingcharacteristics, which will be explained in detail in the next chapters:

� the connection type (circuit switched or packet switched)

� the user bit rate(s)

� the required QoS and the related radio quality in terms of Eb/N0 for uplink and downlink

� the required GoS for this service

� the statistical behaviour described by the according traffic model and its parameters



4.2 Traffic Modelling

It has to be mentioned that the notion of traffic model is used for two different aspect of traffic:

� On a first level, “traffic model” refers to modelling the statistical behaviour of one user using onegiven service: It gives probability density functions to reflect the user traffic generation. For betterdistinction, this could be called “microscopic traffic model”.

� On a second level, “traffic model” refers to the statistical modelling of the behaviour of amultitude of users using a limited resource in order to define the necessary resource allocation.Since in the UMTS system, users of different services with different microscopic traffic models aresharing the same resource, an overall traffic model approach is necessary. This overall model iscalled “macroscopic traffic model”.

4.2.1 Microscopic Traffic Models

Looking at the exemplary list of service applications, one understands intuitively that the statisticalbehaviour of the resource utilisation is different for each service. For example an “active” web user clicksonce in a while to download a page, generating small uplink traffic and very bursty downlink traffic, leavingblank times in between, which would allow to give the resource to another user at the same time, whereas avideo conference user blocks his uplink and downlink for the whole time of the session. However, it seemsquite clear that it is impossible to reflect the statistical behaviour of each user of every thinkable serviceapplication in analytical or even simulative prediction. Therefore, only a few traffic models are used foranalyse purpose, each of them represented by a set of parameters. Depending on the traffic model, one needstherefore a different number and type of parameters to characterise a service entirely. In the course of thispaper, one distinguishes between circuit switched and packet switched traffic model.In UMTS network predictions using simulations (e.g. Monte Carlo simulations), the subscribers (which arepotential users) of the different services are distributed randomly (according to a distribution function) on agiven area. Then, the behaviour of each of them is simulated according to the microscopic traffic modelapplied for the relevant service, so that at a “snapshot” in time, the position and number of active users andtheir service is determined. The following calculations are therefore deterministic, no “macroscopic” trafficmodel is needed. Radio Resource control algorithms decide over blocking and delay, so that after asufficiently high number of simulation runs, blocking resp. delay statistics can be elaborated to decide if theGoS is fulfilled for each service.

4.2.2 Macroscopic Traffic Models

In case of analytical predictions, we have to assure that the common “pool” of resources is sufficientto satisfy the traffic with the required GoS for each service by a macroscopic traffic model, takinginto account the behaviour of all subscribers using the different services.

The according example for a “macroscopic” traffic model in GSM is the good old Erlang B law forvoice, which produces for a given traffic intensity and number of available voice channels theaccording blocking probability, resp. gives the number of needed channels to treat the given trafficintensity with a required blocking probability. However, the example is not really applicable since itis dealing with monoservice.



4.3 Service Definition

4.3.1 Circuit Switched Services

The following table gives an overview on the input parameters defining a circuit switched service.

Bit rate User bit rate for the circuit connection

QoS and Radioquality

BER and associated Eb/N0 [dB] per multipath environment for uplink

BER and associated Eb/N0 [dB] per multipath environment for downlink

GoS Maximum acceptable Blocking Percentage

Microscopic Activity Factor for uplink

Activity Factor for downlink

Session inter-arrival time in sec

Session length in sec

Traffic ModellingParameter

Macroscopic Traffic intensity in Erlang within the cell

respectively:

Number of subscribers N within the given cell and trafficintensity �‘ per subscriber (in mErlang)

4.3.1.1 Bit rate:

A circuit switched connection implies a constantly available traffic channel of a given channelbandwidth in both uplink and downlink direction. Therefore, for characterisation of a circuit switchedcontains only one user bit rate3, which is the effective bit rate (information bit rate) of this circuitchannel.

The bit rates 64, 144 and 384 kbit/s for circuit switched data and 8kbit/s for speech have beendefined by 3GPP as reference bit rates in order to be able to compare simulation results of different3GPP members. Within a real UMTS system, there is a high granularity of possible user bit rates, sothat any other user bit rate together with any other BER requirement could occur. However, it is quiteclear that a prediction gets very complicated if one allows this granularity in service, so that ingeneral, service applications are mapped on the above bit rates for prediction purpose.

For the product release 3G R1.1 (see [SYSDESIGN]), the following bit rates are intended to beimplemented:

Speech will be implemented with the conversational AMR (adaptive multirate)

Speech Bit rate (Uplink / Downlink) kbit/s

Type “Conversational AMR” 4.75 – 12.2 / 4.75 – 12.2

The 9 AMR modes specified in TS26.071 are supported, and the AMR mode to be used can beconfigured by O&M.

3 The notion of user bit rate referes to the effective bit rate at RLC level, meaning without error

correction or channel codin bits. It is not to be confused with the channel bit rate



Additionally, the following circuit switched service is intended to be implemented in 3G R1.1

Circuit switched data Bit rate (Uplink / Downlink) kbit/s

Type “Conversational” 64/64

This type of service is intended to support ISDN services from CS domain, and a residual BER of 10-6

is thus allowed.

4.3.1.2 Radio Quality and QoS

The required radio quality is given by a Eb/N0 target value for uplink and one for downlink. Eb

represents the energy per information bit and N0 represents the overall noise (thermal noise, intra-cell and extra-cell interference) after the Rake receiver. The Eb/N0 is measured in the receiver afterthe data demodulation. The Eb/N0 target value is required to achieve a certain BER (Bit error rate).The mapping of BER and Eb/N0 is dependent on the particular multipath and propagationconditions, which also depend on the mobile speed, and on the used equipment. This means asthose conditions vary the Eb/N0 quality parameter also varies.

Alcatel has performed link level simulations which give for speech4 (8 and 12.2 kbit/s) and circuitswitched data (64, 144 and 384 kbit/s) for the 3GPP defined propagation environments PedestrianA and Vehicular A in combination with the mobile velocities 3, 50 and 120km/h the required radioqualities for uplink and downlink [Agin_LL]. The performance is expressed as the average receivedEb/N0 required to reach the required quality which was assumed to be a BER of 10-3 for speechservice and a BER of 10-6 for circuit switched services. Please refer to Annex A and B for theaccording result tables.

In 3GPP notation, the above mentioned circuit switched data services along with the BERrequirement are often referred to as “LCD” (Long Constrained Delay) data services.

4.3.1.3 Grade of Service (GoS)

The GoS for a circuit switched service is generally given in terms of maximal allowed blockingprobability in [%].

4.3.1.4 Microscopic Traffic Model

The traffic model applied to circuit switched services is a traditional birth-death process, also knownas Erlang-B-model. It is described by the following parameters:

� Session inter-arrival time 1/�� (in seconds)

time between the beginning of two consecutive sessions, it is an exponentially distributed randomvariable.

� Session length 1/�� (in seconds):

duration of the session, it is also an exponentially distributed random variable.

4 Speech is a classical circuit-switched service



t

I n t e r - a r r i v a l t i m e :e x p o n e n t i a l , p a r a m e t e r 1 /� a v e r a g e t i m e

S e s s i o n l e n g t h :e x p o n e n t i a l , p a r a m e t e r 1 /� a v e r a g e l e n g t h

Please note that the traffic intensity per user r’ which is an input of the macroscopic model, can bederived out of these parameters:

�

��

Note that the parameters are identical on both uplink and downlink for circuit services, which is nottrue for packet services.

For the circuit switched connections, where a constant traffic channel is elaborated, an activity factor� can be given. For example for speech which is a circuit switched service, the voice activity factor isaround 0.5, which means, that the channel is used only half of the time, because a user talking viathe downlink means a listening user in the uplink and vice versa. A listening and therefore nottransmitting user doesn't cause interference, which has to be taken into account for capacitycalculations. The application of the activity factor is also treated by the traffic model.

� Activity factor:

ratio between emitting periods within the session ant the total session duration, therefore probabilityto emit

4.3.2 Packet Switched Services

It has to be noted that uplink and downlink must be studied separately because asymmetry mayinduces strong variations on the parameters between uplink and downlink.

Uplink: Mean User bit ratePeak User bit rateMinimum User bit rate

Bit rate

Downlink: Mean User bit ratePeak User bit rateMinimum User bit rate

Uplink: BLER and associated Eb/N0 [dB] per multipath environmentQoS and Radioquality

Downlink BLER and associated Eb/N0 [dB] per multipath environment fordownlink



Uplink: acceptable maximum delay time dULx% and quantile x%

(in x% of the cases, the delay has to be lower than or equalto dx%.)

GoS

Downlink acceptable maximum delay time dDLx% and quantile x%


Microscopic Dependent on Traffic Model.

For page oriented model:

mean inter-arrival time

mean number of pages per session

standard deviation of the number of pages persession,

mean reading time

standard deviation of reading time

minimum page size

mean page size

mean inter packet time

packet multimodal distribution

Please note that only the mean page size is used later on in ourmacroscopic model


Macroscopic Data Volume per busy hour V (in kbit/busy hour) persubscriber

Number of subscriber N

4.3.2.1 Bit rates

Packet switched services are normally variable bit rate services and can therefore be described bythe mean bit rate and the peak bit rate. Sometimes, the minimum bit rate is given as well. Peak bitrate and minimum bit rate are instantaneous bit rates. The mean bit rate is referring to the averageover the transmitting time, meaning that times where the user isn’t sending anything are not takenfor the average.

Additionally, it has to be noted that the uplink bit rate can be completely different from the downlinkbit rate of the according service.

Alcatel has performed simulations on packet switched services where the bit rate is modeled asbeing constant in the simulations, but with a lower rate than the peak bit rate (peak bit rates of 64,144 and 384 kbps are modeled as a constant bit rate of 30.4, 60.8 and 243.2 kbps). This constantbit rate is equivalent to the mean bit rate.

Please note that this effective bit rate does not yet include the retransmission rate for erroneouspackets. Since BLER of 0.1 (see 4.3.2.2) has been acceptable value in the simulations, aretransmission of 10% of the blocks has to be taken into account additionally when looking at theeffective rate for the user.



In 3GPP notation, the above mentioned packet switched data services are often referred to as“UDD” (Unconstrained Delay Data) services.

In the Evolium product release 3G R1.1, the following bit rates are intended to be implemented[SysDesign]:

Packet Switched Data Bit rate (Uplink / Downlink) kbit/s

Type “Background” 64/128

64/384

384/384

4.3.2.2 QoS and Radio Quality

Alcatel has performed link level simulations which give for packet switched services with the peak bitrates of 64, 144 and 384 kbps the 3GPP defined propagation environments Pedestrian A andVehicular A in combination with the mobile velocities 3, 50 and 120km/h the required radioqualities for uplink and downlink [Agin_LL].

The performance is expressed as the average received Eb/N0 required to reach the quality of service(QoS). The required QoS was assumed to be a BLER (Block Error Rate) of 0.1 for packet switchedservices. Thanks to the retransmission of corrupted blocks, this BLER is acceptable. The user receivesonly non-erroneous packets. Please note that the retransmission rate of the packets is not yetincluded in the above user bit rate.

4.3.2.3 Grade of Service

The GoS is given in terms of delay. However, we are not talking about a maximum acceptabledelay, since in a packet system, the delay could reach infinity in very rare cases (this would be equalto a blocking of the packet), but we are referring to a percentile delay dx% , which induces that in x%of the cases, the delay has to be lower than or equal to dx%.

The acceptable delay may be different for uplink and downlink.

4.3.2.4 Microscopic Traffic Models

There are a multitude of traffic models for the traffic generated by a packet user, mainly dependingon the service application. It is intuitive that the statistical behaviour of a web user who asks fromtime to time for a page is different than from an e-mail user, who is sending e-mails with or withoutattachment by one click. However, as said already before, the number of different applied trafficmodels raises the complexity of prediction. In the following, the so called page oriented model(POM) for web-like service is explained shortly. For other models as the ETSI model or the pageoriented model for e-mail traffic, please refer to [Asp].

4.3.2.4.1 The Page-Oriented Web-Browsing Model

A three-level structure was created, considering session, page and packet levels based on behaviourof WWW users. The scheme is the following:



� Session level:

� Session inter-arrival time: time between the beginning of two consecutive sessions, it is anexponentially distributed random variable.

� Number of pages per session: number of web pages browsed by the user, it is a log-normal-distributed integer random variable.

� Page level:

� Time between pages (or reading time): corresponds to the time during which the userreads one page, it is a gamma-distributed random variable.

� Page size: the total amount of information in bytes transferred per page, it is a Pareto-distributed random variable. Values can be different on the uplink and downlink.

� Packet level:

� Packet inter-arrival time: time between two consecutive packets inside the same page.Uplink and downlink packets are treated separately. It is an exponentially distributed randomvariable.

� Packet size: number of bytes contained in each packet. It is a random variable following amultimodal distribution. Again, uplink and downlink packets are considered separately with twodifferent multimodal distributions. The transmission time of a packet equals its size divided bythe transmission bit rate (expressed in bytes per second).

In the simulation, a page must be entirely downloaded before reading: the sum of the sizes of thepackets of one page equals the size of the page (all sizes expressed in the same unit, for instancebytes).



Session level

Packet level

Page level

Page size:Pareto

R ead ing tim e:G am m a law

Session in ter-arrival tim e:exponential

Packet size:m ultim odal

In ter-packet tim e:exponen tial

N um ber of pages:log-norm al

T he sum of the b lue packet sizes equals the yellow page size (in by tes)

t

t

t

On the whole, nine parameters (mean inter-arrival time, mean number of pages per session,standard deviation of the number of pages per session, mean reading time, standard deviation ofreading time, minimum page size, mean page size, mean inter packet time, packet multimodaldistribution) are required to define completely a service. It has to be noted that those parameter arenot easily being obtained to fit to a given service application.

The page oriented model is suitable as a basis to achieve simulation results, however it’s far tocomplex to be applied on a analytical macroscopic model.

4.4 Macroscopic Traffic Model for Link Budget ANalysis

4.4.1 Assumptions

Ideally the model would be based on the whole protocols stack, and on the admission control andresource management procedures. But it is impossible to fit the reality with a simple analyticalmodel.

A resource C (bandwidth for example) is shared between the different users of the different services.A user of a CS service requiring a given amount of resource is only accepted if there is enoughremaining resource. A user of a PS service is served if the amount of resource required is lower thanthe remaining resource, or joins the queue.



CUser CS

User PS

enough space ?

blocked

no

no

queued

yes

Figure 32: Users sharing a resource C. (no priority; blockingfor CS users, queuing for PS users)

The only difference between PS and CS services in the model is that the first are queued and thesecond are blocked when there is not enough resource. This is a simplification because packethandling in an IP network is very different. When there is not enough bandwidth, the packet is notnecessarily queued, but transmitted with a lower bit rate. With the described model, a packet canonly be sent at maximum bit rate. If the bandwidth is not sufficient, the packet waits.

4.4.2 Concept

For the traffic treatment , we are using the property of a CDMA network, that a user is only usingnetwork capacity if he is generating interference for the others:

In a first step, we determine how many connections of one service we accept at maximum within agiven cell, so that in any possible case, the blocking (for circuit switched) and delay requirements (forpacket switched) are maintained. This corresponds to the classical reservation of channels for trafficdimensioning. However, the term “reservation” is deliberately avoided, since a channel is onlyexisting if a user is really transmitting (resp. receiving).

One could interpret this calculation as a kind of admission control (for CS) resp. radio resourcecontrol (for PS), since already at this stage, we are determining a certain number of calls (accordingto GoS requirements) are blocked resp. delayed. We are referring to this step as the “acceptancestep” of the macroscopic model.

In a second step, we will take into account the fact that not necessarily all of these acceptedchannels will be on air by treating the number of emitting channels for each service as a randomvariable. This makes the uplink load as well as the downlink transmit power (which are bothdependent on the interference in the cell and therefore on the number of emitting channels perservice) also random variables. By setting an according probability threshold, the UMTS servicecoverage predictions can be executed to cover most of the GoS without taking an unrealistic worstcase. This step is further on called the “outage step”.



This approach takes into the trunking efficiency between the different services into account, since theprobabilistic contribution of users of different services is maintained until the overall parameters(uplink load and downlink power) are calculated.

The overall process is illustrated in Figure 33.

CS 1CS 2PS 1PS 2PS 3

AcceptanceStep:

GoS:blocking (CS)delay (PS)

Number ofcommunicationsper service,occupation rate

Outagestep:

statistics� of cell load

(UL)� of power

(DL)

x (99%)

Figure 33 Process of Macroscopic Traffic Model

The traffic model is applied within each iteration of the link budget process (see chapter 5), meaningfor a fixed cell radius.

4.4.3 Inputs of the Macroscopic Traffic Model

4.4.3.1 Circuit Switched Services

The inputs given to the traffic model for each circuit service k by the planner are:

� traffic intensity ��‘k per subscriber (in mErlang)

� blocking probability5 Pkblock_thr

� Number of subscribers per sqkm

Since within one iteration of the link budget, the cell radius is fixed, this input can be transformedinto

Number of subscribers of service k Nk within the given cell

The total traffic intensity � within the cell is given by

kN��

5 Please note that the outage step increases the non-served and therefore blocked calls, so that the

probability should be lower than the one given by the operator. An estimation for the“combined outage probability” is given in [MND1]



4.4.3.2 Packet Switched Services

It has to be noted that for one service, the traffic parameters have to be given separately for uplinkand downlink, since no closed “circuit” is given. (We may need more channels of the same service inthe downlink than in the uplink). So all calculations have to be executed twice, once for uplink andonce for downlink.

All parameters have to be given for each service k and one determined link. For convenience, it hasbeen renounced to use the indices k, UL and DL for each parameter.

The packet switched input we will get for the traffic model from the for each packet switched servicek operator are

� Number of subscriber per sqkm, from which we can derive within the iteration of the link budgetprocess6 (see chapter 5)

Number of subscriber N

� For the Uplink

� Uplink data volume per busy hour VULk (in kbit/busy hour) per subscriber

� acceptable maximum delay time dkUL

and quantile xkUL % (in xk

UL % of the cases, the delay hasto be lower than or equal to dk

UL.)

� For the Downlink

� Downlink data volume per busy hour VDLk (in kbit/busy hour) per subscriber

� acceptable maximum delay time dkDL

and quantile xkDL % (in xk

DL % of the cases, the delay hasto be lower than or equal to dk

DL.)

4.4.4 Outputs of the Macroscopic Traffic Model

4.4.4.1 Uplink

If we know the number of emitting users per service in the uplink, we can derive the cell load and,after a few calculation steps, the minimum required received level of one mobile station of a servicek at the Node B, which is the input for the cell range prediction (see [MND1] and chapter 5)

The number of emitting users being a random variable, the cell load gets also a random variable.The cell load comprises contributions of all services. A statistical treatment of the cell load thereforeallows to treat the trunking efficiency coming from a multiservice environment and the serviceactivity. However, in order to perform the dimensioning, an according threshold has to be definedwithin the cumulative distribution function of this random variable, in order to derive thedimensioning cell load value.

We have to compute the probability density function (pdf) and cumulative distribution function (cdf)of the random variable cell load ULx~ .

6 within one iteration of the link budget process, the cell range is fixed



Then, the value of xUL is the value for which )~( ULUL xxP � = H.

(H is defined in order to satisfy the GoS requirements, see [MND1].

Figure 34 illustrates this procedure. If we dimensioned at 100%, including all thinkable worst cases,we perform an overdimensioning. By accepting for example only 1% of global outage in the outagestep, the dimensioning cell load decreases considerably, which means an enormous gain in cellrange standing against an only very small additional outage.

0

100%

Cum

ulat

ive

dens

ity fu

nctio

nof

the

traff

ic m

ix

99%

Cell Load X

Dimensioning point

Figure 34 Finding the dimensioning point at p=H in the cdf of the cell load (outage step)

The result of the traffic model (applied within the one iteration of the dimensioning process,meaning for a given cell radius) is therefore for the uplink

� a determined value xUL for the uplink cell load respecting all GoS requirements

4.4.4.2 Downlink

As the uplink cell load, the downlink transmission power PTotDL is calculated in a statistical way. The

downlink power does not only depend on the number and type of communications, but also on thelocation of the according users and the fact if they are in soft handover or not. The probabilisticimpact of the user’s location and the shadowing (which determines the soft handover state) iseleminated by an averaging and weighting procedure (see [MND1]) so that the transmission powerthen can be given as a random variable which only depends on the traffic inputs.

The probability density function (pdf) and therefore the cumulative distribution function (cdf) of DLTotP

~

can be derived and then treated analogously to the uplink cell load.

The result of the traffic model (applied within the one iteration of the dimensioning process,meaning for a given cell radius) is therefore for the downlink

� a determined value Ptot respecting all GoS requirements



4.5 ANNEX A: Required Eb/N0 For Speech service

Note: Simulation results are constantly subject to change due to equipment and parametersmodifications. In order to use the most recent results, please refer to MCD/TD/SYT result documents(see [Agin_LL])

4.5.1 Speech 8 kbit/s

Environment Speed Uplink Downlink

(km/h) 1 antenna 2 antennas 1 antenna

3 7.7 5.1 6.8

6 7.9 5.2 7.1

10 8.0 5.3 7.2

Vehicular A 25 8.1 5.4 7.2

50 8.3 5.5 7.4

120 8.9 6.3 7.6

200 9.5 7.0 8.4

350 11.1 8.5 10.4

3 7.2 4.2 6.5

6 7.7 4.8 7.1

Pedestrian A 10 7.8 4.7 7.6

25 8.2 4.8 8

50 8.6 5.0 8.3

120 9.1 5.8 8.5

Table 14: Rx Eb/N0 required for a BER of 10-3 in speech 8 kbps

4.5.2 Speech 12.2 kbit/s



3 6.9 4.1 6.1

Vehicular A 50 7.4 4.5 6.8

120 8.1 5.2 7.2

3 6.3 3.4 6.1


120 8.5 5.0 8.5



Table 15: Rx Eb/N0 required for a BER of 10-3 in speech 12.2 kbps



4.6 ANNEX B: Required Eb/N0 for Circuit switched services


The mention ‘NA’ indicates that the result is not available yet. The symbol ‘--’ indicates that thetarget BER cannot be reached for reasonable values of Eb/N0.

4.6.1 CS 64 kbit/s



3 5.4 2.5 5.4

Vehicular A 50 6.0 2.9 6.1

120 6.9 3.9 7.1

3 5.5 2.0 5.5


120 7.6 3.6 8.0

Table 16: Eb/N0 required for a BER of 10-6 in CS 64 kbps

4.6.2 CS 144 kbps



3 4.8 1.8 4.6

Vehicular A 50 5.4 2.2 5.4

120 6.4 3.0 6.0

3 5.4 1.3 4.57


120 7.0 2.8 --


7 For these simulations, the channel estimation was performed with the DPCCH instead of CPICH

(otherwise, the target BER could not be reached).



4.6.3 CS 384 kbit/s



3 3.72 0.7 4.58

Vehicular A 50 5.2 1.5 5.8

120 6.6 2.2 6.5

3 NA 0.2 5.01

Pedestrian A 50 NA 1.8 --

120 7.3 2.3 --


8 These simulations were performed with 6 fingers for the rake receiver instead of 4 (otherwise the

target BER could not be reached). In other situations, the performance gain with 6 fingersinstead of 4 is expected to be low (~0.2 dB).



4.7 Annex C: Required Eb/N0 for Packet Switched Services


4.7.1 PS 64 kbit/s



3 4.2 1.4 4.2

Vehicular A 50 4.7 1.9 4.7

120 5.6 2.8 5.1

3 3.7 0.8 3.8


120 5.7 2.3 6.0

Table 19: Eb/N0 required for a BLER of 0.1 in PS 64 kbps

4.7.2 PS 144 kbit/s



3 3.5 0.8 3.5

Vehicular A 50 4.0 1.2 4.2

120 4.9 2.2 4.7

3 3.0 0.1 3.1


120 5.0 1.7 5.6




4.7.3 PS 384 kbit/s



3 2.8 -0.2 3.2

Vehicular A 50 3.3 0.2 4.1

120 4.0 1.0 4.8

3 2.1 -0.8 2.7

Pedestrian A 50 3.5 -0.2 5.1

120 4.2 0.6 6.1




5 LINK BUDGET AND I NITIAL NETWORK DESIGN

Referenced Documents

[MND1] UMTS Radio Interface Dimensioning, S. Joga, MND internal document

Related Documents

[MND2] Radio Network Dimensioning, Y. Dupuch, MND internal document

[MND3] UMTS Radio Network Dimensioning, A. Gärtner and E. Salomon, MND internal document

[MND4] UMTS Radio Dimensioning Overview, Y. Dupuch and A. Gärtner, MND internal document

[A955V6] A955 V6 Specification: Calculations for Link Budget Based Planning Module for UMTS, A.Gärtner, PCS internal draft

[TD1] UTRAN Link budget parameters, N. Billy, Evolium Document, Draft version,

ref. MCD/TD/SYT/NBI/200xxx

The chapter gives an overview on the iterative UMTS link budget process. It is not in the scope of thisdescription to deliver the entire set of equations, which are described in [MND1].

We know from GSM planning that a planner has to elaborate a link budget to estimate the expectedcell radius in a given environment before starting a detailed radio network planning procedure. InGSM, this link budget elaboration constitutes a relatively simple operation and can be performedmanually, since it is dealing purely with propagation parameters.In UMTS, the situation gets much more complex and an iterative tool is needed to perform the cellrange analysis. This is due to the fact that in CDMA, the cell radius depends on the traffic. Takingthe uplink as an example, as the number of users or offered traffic load increases, the total noise atthe Base Station increases. Interference from other users in CDMA can be thought of as noise to areference user. If the reference user is already using the maximum allowed power on the uplink, toomany users at the cell will cause the reference user’s signal to be received with an insufficient marginabove the noise level at the Base Station. This phenomenon leads to the reference user no longerbeing covered by the Base Station, or in essence, a reduction in the coverage area of a cell. Thisdependence of the cell coverage radius on the loading can lead to an iterative procedure to balancethe coverage radius with the offered traffic.

5.1 Multiservice link budget

The link budget is a key element in the dimensioning process. It is used to derive the maximumallowable path loss and therefore the cell radius. This section introduces the concept implemented inthe tool AIRMUST [MND1] that allows to analyze and to bring a solution for the Uplink andDownlink. Both uplink and downlink analysis will result in a cell range value. The final cell range ofthe overall process is the smaller of the two. If this is the uplink range, the system is uplink limited, ifit’s the downlink range, the system is downlink limited.For the dimensioning, a completely homogenous network with a hexagonal cell structure, ahomogenous morphostructure, flat topographical environment and homogenous user distributionare assumed. Therefore, one cell is representative for the whole network, meaning that allparameters are valid for all cells. However, impact from other cells (interference, soft handover) istaken into account.In the following, both the uplink iteration process and the downlink iteration process are described



as an overview. If the reader is interested in the equations behind each step, he should refer to[MND1].

5.1.1 Uplink Analysis

A link budget is conventionally performed for one mobile located at the edge of the cell andtherefore transmitting at maximal power. Since in a multiservice environment, there are differenttypes of mobiles with different service characteristics, the link budget has to be elaborated for onemobile of each service type.The main target of the uplink is to figure out the increase of the interference level due to the trafficavailable in the cell. The curve below shows the relation between the traffic load (in per cent) andthe interference level (noise rise in dB). The point where the interference goes to infinity is called the“pole capacity”. The cell load is giving a percentage of air interface loading relational to that polecapacity.

Interference curve

0.00

5.00

10.00

15.00

20.00

25.00

0.00 20.00 40.00 60.00 80.00 100.00

Load

Noiserise(dB)

Figure 35 Interference noise rise over cell load

The interference in a cell depends on the thermal noise, on narrow band and wide bandinterference from another system, other users in the same cell and users from all the others cells.The intra-cell interference perceived by a mobile in the uplink is independent of the location of theother mobiles thanks to an effective power control, so that for the uplink link budget elaboration themobile distribution is not relevant.Once the level of interference has been calculated, the next step is to calculate the maximumallowable path loss (MAPL) in order to derive the cell radius.For a given cell load, the uplink maximal allowable pathloss for a service i depends on its Eb/N0

requirements, its user bit rate and the maximal mobile transmitting power for this service. Thismeans that in general, one will obtain different uplink coverage ranges for the different servicetypes.By adjusting the mobile transmitting power, different coverage scenarios can be achieved. Servicespecific gains, losses and margins have to be integrated if not all mobiles are suffering from thesame losses and taking advantage of the same gains, and/or if different margins are applied todifferent services. This can be the case e.g. for soft handover gains as well as body losses and evenpenetration margins, see section 5.2.1.1 for exemplary values.The strategy adopted in the dimensioning of the uplink is to provide one common cell boundary.Hence depending on the type of service proposed and the volume of traffic associated, the idea is tofind the limiting service (i.e. the service which reach its maximum power capabilities) and then matchall the other UE power to this service limiting cell range



5.1.1.1 Uplink Iteration Process

The iteration is started by assuming an interference noise rise value within the cell of i0dB=3dB to begenerated by the total traffic within the cell. For this fixed value, a link budget for each service canbe calculated, assuming a reference user i of the according service transmitting with maximum UEpower (which places him virtually at the edge of the cell).This is done by calculating according to Equation 2 the minimum required level for this service at theNode B and by applying all relevant gains, margins and losses on the maximum mobile transmitpower in order to deduce the maximum allowable path loss (MAPL), shown in Equation 3.

The sensitivity has to be calculated for a reference user i of each service k:

Required_leveli = NF + 10log(N0) + 10log(i0i)+ 10log[(Eb/N0)k]+ 10log(Rk)

Equation 2: Uplink minimum required level for a user i using service k

Where: Required_level Required level in dBm

N0 Thermal noise density

10log(N0)=-174dBm/Hz (valid at 20°C equal to293K)

koNbE

��

��

� : service k required Eb/N0 (non-logarithmic figure)

Note: kdBoN

bE ��

�

�

��

�

�

=10log[(Eb/N0)k]

Rk: Service k bit rate

NF Node B Noise figure in dB

(NF is sometimes also referred to as “noise factor”. )

i0i noise rise due to interference (non logarithmic figure)

Note: i0dB=10log(i0i)

For the maximum allowable pathloss, we get:

MAPLi = PkUL –Required_Leveli–�Losses - � Margins + � Gains

Equation 3: Uplink MAPL for user i using service k

where PkUL is the mobile power valid for service k (in dBm) and Losses, Margins and Gains are given

in dB.

The smallest MAPL of all services is then chosen as the limiting one. (Taking this MAPL as thedimensioning one implies that the other services won’t emit at maximum power)Applying a propagation model (e. g. the well known Hata formula), one can derive the accordingcell range.Now, for each service, the traffic (number of subscribers for each service) per cell can be deduced,since the number of subscriber per sqkm is known. Applying the traffic model described in detail inchapter 4 for circuit switched and packet switched services, one can derive in the “acceptance step”the number of “reserved channels” per service as well as their occupancy probability.

In the “outage step” of the traffic model, the uplink cell load xUL is calculated in a statistical way. Thecell load is treated as a random variable:



� ��

� �c

ULk

ob

c

ULk

ob

RRUL

kNE

RRUL

kNE

kk

ULUL Bfx.1

.1~

1�

��

� �

��

Where: fUL other cell to same cell interference ratio for Uplink

BkRandom variable: number of emitting channels ofservice k

koNbE

��

��

� : service k required Eb/N0

Rk: Service k bit rate

Rc: Chip rate

�: Number of services

Following the traffic model, the probability density function (pdf) and the cumulative distributionfunction (cdf) of the cell load can be derived. The dimensioning point (e.g. 99%) is chosen, and thecell load xUL is derived at this point out of the cdf. Please refer to chapter 4 for more details on thisprocess.

Once the cell load is determined, the according interference noise rise can be derived.

� � ).).((c

ULk

ob

RR

kNE

UL

io

xi

��

�

11

1

Equation 4: Uplink noise rise due to interference perceived by user i of service k

Please note that the perceived interference is different for users of different services. Therefore, thelimiting service has to be detected in each iteration.

In case we have n carriers, the cell load is assumed to be divided equally between the carriers, sothat each of them treats a cell load of xUL/n. Since we are looking at one carrier by the equations, wehave to replace xUL by xUL/n in Equation 4.

We are now at the end of one iteration step and have to compare the interference value with theprevious value. If the difference between the values is not small enough to be in a definedconvergence interval , we have to redo the above calculations with a new interference value. In caseof convergence, the radius calculated in the last iteration step is our uplink determined cell radius,which remains to be compared with the downlink determined radius, in order to find the limitingone. Figure 35 visualizes the uplink iteration process.



Assumption forinterference:

Ico=3dB

Calculate UL cellrange with Max UE

power for all services

Choose limiting cellrange

Deduce mean trafficper cell (knowingnb of sub/sqkm)

Application ofmacroscopic traffic andcell load calculation XUL

(e.g.@99%)

InterferencecalculationIc=f(XUL)

Comparison withprevious

interference value.Convergence?

NO

Current cell radiusis UL cell radius

YES

Adapt Ic

Figure 36 Uplink Iteration Process



5.1.2 Downlink Analysis

One of the main target of the downlink analysis consists in finding the maximum number of mobilethat can be connected to the base station with a good quality of service. However, contrary to theuplink analysis, for the downlink the position of the users has to be known, since the distance fromthe base station impacts the power share allocated to the mobile and hence both intracell andextracell interference.

5.1.2.1 Downlink Iteration Process

Intuitively, one would assume a uniform distribution of users. In the dimensioning approach, thisuniform distribution is approximated by a distribution of the users on concentric rings around thebase station.

In the following, the outline of the procedure is given:

As a starting point in the iteration, a cell range R is assumed.

If the total emitted power of the node B is known, the received power that a mobile of a certainservice j would require at a given distance r from the node B can be calculated:

)()()( rbPrarP jtotjj ��

Equation 5 Required power for a mobile of service j at location r

with

� �

� ��

� �

� ��

��

�

��

�

�

��

�

��

�

)(1

)(

)(1

)(

& ,0 rnAttenuatioWFNrb

rfra

mlgjI

C

jIC

j

jIC

jIC

j

�

��

wheref(r) other cell to same cell interference ratio at location r for downlink

(C/I)jrequired C/I for service j

C/I depends on Eb/N0 in the following way, depending on SHO status (innon-logarithmic figures:

� � � �c

DLj

ob

RRDL

jNE

jIC .� for mobiles not in SHO

� � � �gainSHOI

Cc

DLj

ob

RRDL

jNE

j _1. �� for mobiles in SHO

(SHO_gain is the gain on the required Eb/N0 given in non-logarithmicfigures)

�� orthogonality factor

N0Thermal Noise

F Downlink Noise Factor (non-logarithmic)



W Bandwidth

and

Attenuationg,l&m(r) contains the pathloss attenuation according to Hata and all gains, losses andmargins

As a starting value for calculations, we can take for Ptot the maximum available power. It has toadapted in each iteration.

As you can see above, the required power depends on the handover status of the mobile.

Weighting the resulting power values with the corresponding distribution and taking into accountmobiles being in SHO and mobiles not being in SHO is resulting for a given location in a receivedpower per user per service. Now, we can perform an averaging over all mobiles of each service jconnected to “our” node B, and get a mean required power Pj for a user of service j. (For theweighting and averaging procedure, please refer to [MND1]).

The mean transmitted power has to be calculated also for the common channels SCH and CPICH.Since we have assumed a cell range, we can derive by our traffic model (see chapter 4) base stationpower distribution.

As shown in chapter 4, the total required power at the node B is a random variable:

This random variable can be described by its pdf and cdf.

Keep in mind that we are looking in this context only at the statistic power variations due to trafficwhereas the power variations due to propagation (shadowing, fading) are treated by margins in thepower calculations.In the cdf (which is only valid for the assumed cell range), there are now two possibilities:

Case 1:

The 100% are reached already below the maximum allowed power (which is in general 43dBm forone carrier). This means that the maximum available power is never required and we have stillunused power resources, so that we can increase the cell radius and start the next iteration step.Figure 37 shows an example for this case.

0

100 %

Power in dBm

40dB (<43dB!)

cdf of DLpower

Figure 37 Example for power cdf: 100% value is reached for a value lower than the max. DL power



Case 2:

A probability value lower than 100% corresponds to the maximum allowed power. This value iscompared to a target value for this probability (e.g. 99%) which we had fixed beforehand. If thetarget value is not yet reached, we redo the iteration with a smaller cell range. If the value alreadyconverged to our target value, the current radius is our downlink radius

0

100 %

Power in dBm

cdf of DLpower

43dBm

75%<<99%

Figure 38 Example for power cdf: max. DL power corresponds to a value lower than 100%

In other words: we are checking if the power value at 99% is equal to our 43dBm. If not, we have toadapt the radius accordingly and redo the iteration process until this is the case.

In the case that we have more than one carrier, we have to increase the available poweraccordingly. E.g. for two carriers, we are assuming within the calculations to have an equivalentpower of 46dBm. However, the calculations change since the power for the common channels isneeded in each of the carriers, so that it has to be counted n times for n carriers.

Figure 39 shows the downlink process schematically.

If we have found the uplink radius being the limiting one, we can derive for the downlink by thesame process the actual transmit power for this radius at the 99% point (this has been done in theexemplary link budget of chapter 5.2.5. in which you will find a total DL transmit power of 41.3dBm, which is lower than the maximum available power of 43 dBm)

Please keep in mind that, although this procedure does not seem to be too complicate, theequations and calculations behind are very complex. Additionally, we need as an input previoussimulative results for the soft handover probabilities and the extracell interference factor at eachexamined location.



Assumption ofcell range R

Power calculation forone user of each service

at each position

Deduce the meanpower per user per

service

Calculate the cdf of thetotal power P to t applyingthe macroscopic traffic

model

Calculation of P to t at99% according tothe traffic model

Adapt cellrange

Pto t @ 99% equalto maximum

allowed power?

Current cell rangeis DL cell range

NO

YES

Figure 39 Downlink Iteration Process



5.2 Link Budget Parameters

5.2.1 Input Parameters for L ink Budget Process

5.2.1.1 Service Inputs

5.2.1.1.1 Circuit Switched Services

The parameters characterizing a circuit switched service have been defined in detail in chapter 4.Table 22 recalls those parameters needed as an input for the link budget process for each circuitswitched service.

Bit rate User bit rate for the circuit connection

QoS and Radioquality

Eb/N0 [dB] for uplink

Eb/N0 [dB] for downlink

Note that we have to chose one multipath environment for the linkbudget

GoS Maximum acceptable Blocking Percentage

Microscopic Activity Factor for uplink

Activity Factor for downlink


Macroscopic � Number of subscribers per sqkm

� traffic intensity �‘ per subscriber (in mErlang)

respectively

� Volume in kbit per busy hour

Table 22 Description of circuit switched service parameters

In addition, we have to provide the information, if soft handover is used (this wouldn’t be the case ifDSCH9 channels are used, which is theoretically possible, even if it does not make a lot of sense forcircuit switched services). For the SHO case, we have to give the according soft handover gain.

For each service, a penetration margin and a body loss have to be defined. It is considered, thatthere is no body loss with a mobile being held away from the body, which is true for most dataapplications. Therefore a margin of 3 dB is taken only for speech application and 0 dB for all theother services.

Table 23 gives a list of the required input parameters along with exemplary values for two services(speech 12.2 kbit/s and circuit switched data 64 kbit/s)

9 DCH (Dedicated channel) means one code per connection, DSCH (Downlink Shared Channel)

means sharing of code between different connections



User traffic parametersBearer throughput (kb/s)Traffic (speech: mErlang ; data: kbits @ BH)Blocking probabilitySubscribersNumber of subs per km2transmission parametersEb/N0 (dB)Soft handover use (DCH or DSCH mode)DL SHO Eb/N0 gainPenetration margin (dB)Body loss (dB)Activity factor (%)Maximum mobile Tx power (dBm)

TRUE eech 12.2 TRUE CS 64UL DL UL DL

5.7 7.8 4.2 7.1- TRUE - TRUE- 2.5 - 2.5

21 - 24 -

20

12.240 mE

2%

0100%

202

20

646000 kbits

2%

360%

2000

Service 2 Service 3speech 12.2 kb/s CS 64 kb/s

Table 23 Input Parameter to be given for each circuit service with exemplary values for speech 12.2kbit/s and CS64kbit/s

5.2.1.1.2 Packet Switched Services

The parameters characterizing a packet switched service have been defined in detail in chapter 4.recalls those parameters needed as an input for the link budget process for each packet switchedservice.

Uplink: Peak User bit rateBit rate

Downlink: Peak User bit rate

Uplink: Eb/N0 [dB] for uplink

(note: only one multipath environment is treated in theprediction)

QoS andRadio quality

Downlink Eb/N0 [dB] for downlink

(note: only one multipath environment is treated in theprediction)

Uplink: acceptable maximum delay time dULx% and quantile x%


GoS

Downlink acceptable maximum delay time dDLx% and quantile x%


Microscopic mean packet sizemean number of packets per page

Note that in the link budget approach, these parameters areassumed to be equal for all packet switched services.

TrafficModellingParameter

Macroscopic Data Volume per busy hour V (in kbit/busy hour) persubscriber

Number of subscriber N per sqkm



In addition, the information is needed if DCH or DSCH channels10 are used for the accordingpacket service. There is soft handover in DCH mode and only hard handover in DSCH mode.

User traffic parametersBearer throughput (kb/s)Volume (kbits @ BH)Delay (sec)Quantile for delaySubscribersNumber of subs per km2Transmission parametersEb/N0 (dB)Soft handover use (DCH or DSCH mode)DL SHO Eb/N0 gainPenetration margin (dB)Body loss (dB)Activity factor (%)Maximum mobile Tx power (dBm)

TRUE PS 144 TRUE PS 384UL DL UL DL

5000 15000 1340 4000

2.2 4.8 1.7 4.7- TRUE - TRUE- 2.5 - 2.5

24 - 24 -

0100%

200

100%

384

0.590%

40

20

190%

200

Service 2

144

Service 3PS 144 kb/s PS 384 kb/s

Table 24 Input Parameter to be given for each packet switched service with exemplary values forPS144kbit/s and 384 kbit/s

Traffic assumption Unit ValuePacket size Bytes 1000Number of packets per page - 25

Table 25 Packet switched traffic model parameters (valid for all packet switched services) with typicalvalues

5.2.1.1.3 Additional traffic modelling inputs

As described in chapter 4, as an additional input, the global outage probability has to be given. Inthis implementation, it is the same for uplink and downlink.

Admission control and outage QoS Unit ValueGlobal Outage probability % 1.00%

Figure 40 Input for Traffic Model

5.2.2 Transmission Parameters

Table 26 shows the radio input parameters along with typical values. Please note that theshadowing resp. fading margin for the downlink is lower than the margin for the uplink. This is dueto the fact that the DL margin is referring to the total transmit power distributed among all mobiles.The variance of this power around the mean value is much lower than for one specific connection,which is quite intuitive to understand: when one mobile is in a deep fade and therefore needs morepower, there a good chances that another mobile happens to have at the same moment excellentpropagation condition and needs less power, so that the total power is not affected. Alcatel has

10 Please refer to chapter 3 for more information on the channel structure



performed simulations to determine the according shadowing margin for a required coverageprobability. Please refer to [TD1] for a more detailed explanations on the fading margins.

A specific CDMA parameters is the interference factor f which gives the ratio between intracellinterference and extracell interference in uplink. Note that in downlink, this factor is locationdependent. The link budget tool AIRMUST therefore also needs the simulation results for thisdownlink function as an input. Another downlink relevant parameter is the orthogonality factor fwhich is dependent on the selected multipath environment. This orthogonality factor is a measure forthe loss of orthogonality between the code signals in the downlink. An orthogonality factor of 0means perfect orthogonality, an orthogonality factor of 1 means complete non-orthogonality.

Transmission parameters Unit ValueThermal noise dBm/Hz -174Chip rate kCh/s 3840Shadowing standard deviation dB 8UL shadowing margin dB 4.8UL Rayleigh fading margin dB 1.9UL f (I_extra / I_intra) - 0.7DL fading margin on Total Tx Power dB 2Orthogonality factor - 0.4Minimum coupling loss (MCL) dB 80

Table 26 Transmission input parameter with typical values

5.2.3 UE specific parameters

Table 27 gives the mobile specific input values.

UE characteristics Unit ValueAntenna gain dB 0Cable and connector losses dB 0Noise factor dB 8

Table 27 UE specific input parameters with typical values

5.2.4 Node B Specific Parameters

Table 28 shows the node B specific and antenna system related parameters. Please note that the useof an MHA (Mast Head Amplifier) reduces the global noise figure of the reception chain. Please referto chapter 7 for detailed explanation on the MHA use.



Node B Unit ValueMaximum Power dBm 43Cable and Connector Losses dB 3NodeB noise factor dB 4MHA:

MHA use TRUMHA Noise figure dB 2.5MHA gain dB 15

Global receiver noise factor dB 2.80Antenna gain :

tri-sectorised dB 17omni dB 11bi-sectorised dB 17hexa-sectorised dB 20

Table 28 Node B specific input parameters with typical values



5.2.5 Exemplary Link Budget

Figure 41 presents an exemplary result of the multiservice link budget process including the servicesspeech (12.2 kbit/s), CS 64 kbit/s, PS 144kbit/s and PS 384 kbit/s, in urban area, using tri-sectorized sites. The link budget is uplink limited (i.e. DL power is reduced to fit the MAPL). The linescontaining parameters which are not described in the input parameter section are explainedhereafter.

Figure 41 Exemplary Link Budget



The processing gain represents the ratio between chiprate and user bit rate in dB, meaning:

Processing Gain= 10log(Rc/Rb). It is given for UL and DL.

This line gives the mean downlink transmit power required in average for one user of the accordingservice. It is the result of the weighting over the power values of all user locations and all handoverstates.

The downlink transmit power dedicated to the common channels SCH and CPICH. In the currentimplementation, it is calculated as a percentage (15%) of the total transmitted downlink power in W,then transferred into dBm

For the uplink, this entry gives for each service the total transmit power (in dBm) of a mobile of thisservice which is located at the edge of the cell. One can detect the limiting service out of this linkbudget entry, which is the one transmitting at maximum mobile power.

For the downlink, this entry gives the total base station power (in dBm) dedicated to traffic channels.

This is a pure downlink entry. It gives the total transmitted base station power in dBm includingtraffic and common channels.

This line gives the total TX EIRP (meaning TX power minus cable losses plus antenna gain) for uplink(per service for a user located at the edge of the cell) and downlink in dBm.

This line gives the result for the minimum required received level per connection per service(sensitivity), for uplink and downlink in dBm. Please note that this is the reference sensitivity valid foran non-interfered case.

These lines give the minimum required received level for the common channels in downlink in dBm.



This downlink entry gives for each service the percentage of users that are in soft handover with theexamined nodeB, where this node B provides the best of all SHO links.

This downlink entry gives for each service the percentage of users that are in soft handover with theexamined nodeB, but where this node B does not provide the best of all SHO links.

This uplink entry gives the convergence result for the noise rise caused by interference.

This entry gives the uplink cell load xUL and the downlink cell load xDL (for definition of DL cell load,please refer to [MND1]

The uplink individual load per service is given by � �

� �c

ULk

ob

c

ULk

ob

RRUL

kNE

RRUL

kNE

.1

.�

�

�

and is used to calculate the

uplink cell load distribution (see section 5.1.1.1)

This line gives the resulting traffic intensity � for each service within each sector of the cell. (If thesurface of the sector is known, the intensity can be derived out of the number of subscribers persqkm and the service inputs). The traffic intensity is either referring to the Erlang B law (for circuitswitched services) or to the Erlang C law on page level (for packet switched services). This parameteris directly related to the macroscopic traffic modelling approach, to understand it better, please referto chapter 4.

This line gives the resulting GoS. For packet switched services, is gives the resulting percentile delayin seconds, whereas for circuit switched services, it gives the resulting total blocking probability perservice.

This line gives the number of carriers required to achieve the shown result.



This line gives the resulting maximum allowable pathloss. Please note that it is the limiting pathloss(either DL or UL limited, if UL is the limiting link, it is the pathloss of the limiting service). All othertransmit powers have been adapted to fit to this pathloss.

This is the resulting cell range in km.

This is the resulting site area, including the area of all sectors of the site (calculated with thestandard hexagonal area relations).



6 CELL PLANNING WIT H PLANNING TOOL

References

[SFRAS2] Alcatel SFRAS Documentation, Part 2, Version 1.4, “Overview of telecom functions”3BK 11203 0067 DSZZA, chapter 2.10.6.3

[ILBT4RNP] Linkbudget tool of MND department modified by PCS for planning purposes. The tool(EXCEL macro) can be obtained by contacting PCS department.

6.1 Introduction

At the time this guideline is written, no 3G planning tool is selected by Alcatel. A workaround usinga combined linkbudget/A955 RNP approach is used until a 3G tool is selected. This workaround ispresented in this chapter.

Further more the UTRA(N) parameters (CMA parameters) which have to be delivered by RNEs to theOMC people for configuring the UMTS network are not specified for the moment. It is clear, thatcode planning will substitute frequency planning in a CDMA network, thus it is explained in moredetail in this chapter.

6.2 Workaround for UMTS cell planning

The workaround presented here was already used to verify the a given UMTS network design for twodifferent projects: The UMTS study for tele.ring (Austria) in Vienna and the UMTS study for thePaegas (Poland) network in Ostrava.

Both studies are based on a given GSM network design. The goal of the study is to verify if thecoverage provided by pre-defined sites and a given traffic mix is sufficient. In case of a greenfieldoperator the same method can be applied by defining new sites instead of reusing given GSM sites.

6.3 Description of the workaround using the example of Ostrava

In this report the process of validating a given UMTS network design for the Paegas network inOstrava is shown. It is proofed, that the cells are able to handle the expected traffic.

6.3.1 Introduction and Process Description

The scope of the UMTS Radio network planning task for Paegas in Ostrava was to verify a givennetwork structure. Usual radio network planning consists in defining sites, where base stations haveto be installed for getting a radio network fulfilling the given radio requirements.

In this case, existing GSM network sites have to be reused for building up the new UMTS network.Therefore the planning task consists no longer in searching new sites, but in verifying a givennetwork for its ability to meet given quality of service requirements.



The applied network planning methodology mainly consists of 4 steps:

1. Collecting or defining the required input data

2. Use the Alcatel RNP tool A955 to calculate power distribution and strongest server plots

3. Use the ILBT4RNP tool to calculate the allowed size of a cell depending on the given traffic mix.

4. Compare the achieved cells sizes of the two tools and take the more limiting one.

The verification process is very fast and can be applied for other networks too.

6.3.2 Input Data

6.3.2.1 Databases

For the radio network planning part using A955 the morpho structure and the DEM (topo) databaseare required. They are used to get a reliable received power prediction.

As existing GSM sites had to be reused, the site, sector and antenna files currently used in Ostravahave been used to be sure to have no inconsistencies between the UMTS and the GSM site locations.

Some of the GSM sites have been selected to be reused for the UMTS network according to marketrequirements and site restrictions. To verify if it is possible to handle the expected UMTS traffic withthe selected cells was exactly the aim of this planning task.

The selected GSM sites are displayed on the topography map in Picture 1.



Picture 1: Selected sites for the Paegas UMTS network proposal – Ostrava

6.3.2.2 Traffic

The following traffic mix in table 2 is given for business users and consumer users.

For Circuit switched services the duration of the call and activity factors are important, for Packetswitched services the transmitted kbit per main busy hour (mbh) are of interest.

The given traffic mix is only valid for the start up phase of the UMTS network!

The subscriber density in subs/km² is given per service with the assumption of equality in all regionswithin Ostrava.



Table 29: Traffic mix and Subscriber density table used for the Ostrava UMTS planning

6.3.3 A955 planning step

The A955 radio network planning tool is in this planning context used for calculating the strongestserver areas. For each cell the size of the area is calculated where the cell has the strongest receivedpower and thus is quite probable the serving cell. One possible output of the tool is shown in thepicture below:



Picture 2: Calculating the “service” areas of the UMTS cells with A955

The strongest server calculation is based on the fieldstrength prediction of each cell.

6.3.4 ILBT4RNP planning steps

After calculating the cell size with A955 independent from the given traffic, it has to be checked ifthese cells can handle the traffic generated in their cell area. Therefore the tool [ILBT4RNP] is used,which allows to calculate the maximum allowed cell range (and thus cell area) assuming a certaintraffic mix and subscriber densities.

The propagation model used inside ILBT4RNP is of course adapted to the one used in A955. As theILBT4RNP does not take into account different morpho classes within one calculation run, a defaultmorpho class (lower urban) is selected. If the cell size calculated by ILBT4RNP is to small, theaverage morpho class of this cell is investigated more deeply and corrected if necessary. Afterwards,the cell range is recalculated and the cell size comparison is done again.



6.3.4.1 Propagation model

For information, the path loss prediction algorithm used by ILBT4RNP (simplified Hata Okumura) isgiven hereafter:

L= A + B*log(d/km)

With:

A = 46.3 + 33.9*log(f/MHz) – 13.82*log(hBS) - KClutter

B = 44.9 – 6.55*log(hBS)

d distance in km

f frequency in MHz

hBS hight of BTS antenna

With the assumptions of hBS = 30m and f=2000MHz we get:

A [dB] = 137.79 – KClutter

B [dB] = 35.22

The morpho correction factor KClutter is selected according to the average morpho class within the cellif necessary (in the first run, the default morpho class “lower urban” is used).

6.3.4.2 Input parameters

A summary of all input parameters selected for the Paegas project is given in Picture 3.

The selected Eb/N0 targets are derived from simulations of the Technical Department.



Picture 3: Summary of all input parameters for the link budget calculation with ILBT4RNP

6.3.4.3 ILBT4RNP output

ILBT4RNP is generating numerous output values, but in this context only the following ones havebeen used (see also ):

� Maximum allowed cell range

� UL cell load

� DL Transmit Power of the Node B (total for all connections)



After the calculation ILBT4RNP provides in addition information about the cell range limitingparameter. In this project it has always been the UL transmit power!

6.3.5 Comparison of the intermediate results

After calculating the cell sizes with A955 and ILBT4RNP, the more limiting cell range has to betaken. Three scenarios have been distinguished:

1. A955 cell size < ILBT4RNP cell size

2. A955 cell size = ILBT4RNP cell size

3. A955 cell size > ILBT4RNP cell size

More explanations for each case are given below:

1. In the first case, nothing has to be done, as the traffic generated within the cell can be handledaccording to ILBT4RNP.

2. There is a tolerance factor of 10% applied for comparing the two calculated cell areas. If thedifference is below this tolerance, no action is performed to adapt them, because they are“equal” taking the accuracy of the results into account.

3. If the cell size calculated by A955 is bigger than the one calculated by ILBT4RNP, the users at thecell border will not be able to be connected to the network because of the weak UL transmitpower. Therefore the size of these cells is adapted according the max. allowed cell rangecalculated by ILBT4RNP.

After performing the necessary changes within the network, the new cell sizes are recalculated(because changing the size of one cell has of course influence on the surrounding cells also). Thenew cell sizes are again compared to the allowed ones and again modified if necessary.

In the Ostrava UMTS network project only two iterations have been necessary to achieve cells sizesbelow the allowed threshold given by ILBT4RNP. 8 cells still are bigger than allowed by the trafficmix (e.g. Nakladni 3 -> see Table 30). This does not mean, that there will be coverage holes afterinstalling the UMTS network, but during main busy hour not all services (according the given trafficmix) are available at the same time.

An extract of the used comparison table is shown in Table 30:



Table 30: Part of the table used for the comparison of the different results

….

In Table 30 it can be seen, that in most cases the allowed cell range is 0.91 km. This is due to thefact, that we use the default morpho class “lower urban” if there is no need for modification. Formodified morpho values other cell ranges appear. E.g. Nakladni 3 has an average morphocorrection factor of 13 (instead of 5), thus the cell range is 1.53 km (instead of 0.91 km).

Sites which are not part of the city area itself (rural sites) have been excluded from the investigationby setting a “rural site” flag. Of course sites located at the border of the network have a muchbigger strongest server area than sites in the middle of the network. Assuming a constant traffic mixover the whole area is then leading to an overload of this “rural sites”. The coverage area (strongestserver area) of these cells has been modified by restricting the maximum allowed cell range to theone given by ILBT4RNP. Thus, the cell areas shown in the strongest server plot (Picture 2), arereflecting the real service areas which can be expected after installing the network.

6.3.6 Results & Conclusion of the workaround

The proposed network design for the Paegas UMTS network is in most cases able to handle theexpected traffic. In total nine cells will not be able to handle all the traffic during main busy hour.This gap can be filled by optimization/densification works.

6.4 Code planning instead of frequency planning

In GSM the different communications are separated by time and frequency. This is no longer thecase for a CDMA based system like UMTS. Each communication is using the same frequency



bandwidth if only one 5MHz frequency band is used in the network. The communications areseparated by scrambling codes and channelization codes. The channelization codes are managedby the UTRAN itself and thus don’t have to be planned by the RNE. Scrambling codes are allocatedin the UL again by the UTRAN, but in DL they have to be assigned by the RNE.

In total there are 8192 DL scrambling codes available for normal operation. For compressed modeoperation (during inter frequency measurements and handovers) additionally 16384 scramblingcodes can be used by the system. The 8192 DL scrambling codes for normal operation aresubdivided into primary scrambling codes (512) and corresponding secondary scrambling codes(7680). To each primary scrambling 15 secondary ones are associated. Together they areconstituting a scrambling code group of 16 codes [SFRAS2]. The 512 primary scrambling codes areadditionally subdivided into 64 subgroups for speeding up the call setup process.

As the allocation of secondary scrambling codes is done by the URTRAN, the RNE only has to planthe primary scrambling code which is always used for CPICH and PCCPCH.

In UMTS the RNE must allocate for each cell one, and only one (primary) scrambling code. As thereare 512 primary scrambling codes available, it is no problem to assign to cells primary scramblingcodes which are not used by cells in the vicinity of the cell (which are receivable).

The rule to be applied when assigning primary scrambling codes is:Try to maximize the distance between cells using the same primary scrambling code.

When using a planning tool, this function will for sure be implemented.



7 ANTENNA ENGINEER ING


[AntRules] Antenna Engineering Rules, U.Birkel

3DF 00995 0000 PGZZA

[SiteShare] Site Sharing GSM/UMTS – RF Aspects, F. Falke, A. Gärtner and K. Daniel;3DC 21019 0005 TQZZA

[CoLoc] Co-Location of GSM1800 and UMTS/FDD Sites, A. Gärtner

Deliverable for Bouygues UMTS Project, Co-location workgroup

[Perf_TD] UTRA/FDD PERFORMANCE FOR SPEECH SERVICE WITH TRANSMIT DIVERSITY,

P. Agin, TD/SYT draft document

[Perf_SP] UTRA/FDD PERFORMANCE FOR SPEECH SERVICE

P. Agin, TD/SYT/pag/640.99

[ANXU] 3G UMTS ANTENNA NETWORK WITH INTEGRATED DIPLEXER – ANXU, R. Krukenberg

3BK11240 0002 DSZZA

7.1 Introduction

This document is a guideline on UMTS antenna engineering. It constitutes a complement fordocument [AntRules], treating all UMTS specific antenna engineering aspects by maintaining thevalidity of the general (non-GSM specific) antenna engineering rules described in [AntRules]. Theknowledge of [AntRules] is therefore a mandatory precondition to use this document.

7.2 Antenna Tilt

Since UMTS is an interference limited system, a reduction of the interference brings directly benefitsconcerning coverage and capacity. In order to reduce the downlink intercell interference, theapplication of antenna downtilts constitutes a good solution. In [AntRules], the concept is describedin detail.

7.3 Diversity Aspects

7.3.1 RX Diversity

As described in [AntRules], one can achieve a RX diversity gain through two uncorrelated receptionbranches.

In a UMTS system, this gain is manifested by a reduction of the required received uplink Eb/No. Thisis shown exemplarily in Table 31 by simulation results for an 8 kb/s voice channel. The simulationassumption was that the two RX signals were completely uncorrelated.



Environment Speed Uplink

(km/h) 1 antenna 2 antennas Div. Gain

3 7.7 5.1 2.6

6 7.9 5.2 2.7

10 8.0 5.3 2.7

Vehicular A 25 8.1 5.4 2.7

50 8.3 5.5 2.8

120 8.9 6.3 2.6

200 9.5 7.0 2.5

350 11.1 8.5 2.6

3 7.2 4.2 3.0

6 7.7 4.8 2.9


25 8.2 4.8 3.4

50 8.6 5.0 3.6

120 9.1 5.8 3.3

Table 31: Rx Eb/N0 required for a BER of 10-3 in speech 8 kbps and corresponding diversity gain

For an AWGN (additive white gaussian noise) channel, i.e. a channel with a constant power andadditive white gaussian noise, the antenna diversity gain is 3 dB. Indeed the noise of the tworeception antennas being uncorrelated, a maximum ratio combining of the signals of the twoantennas enables to decrease the overall noise variance of 3 dB.

For multipath channels like Pedestrian A and Vehicular A, the antenna diversity gain may be evenlarger. Indeed, since the Rayleigh fadings of the two antennas are uncorrelated, when the receivedpower is small for one of the antenna, there is a good probability that it is larger for the otherantenna. Thus, antenna diversity enables to decrease the received power variations, which has apositive impact on performance.

Thus, the larger the received signal power variations (or more generally the SIR variations when theinterference is not constant) without antenna diversity, the larger the antenna diversity gain.

For low speeds, the power control performs efficiently. Thus, the channel power variations are prettysmall and the channel is close to an AWGN channel. Therefore, the antenna diversity gain is closeto 3 dB. It can be a little lower than 3 dB, because of the extra noise due to interchip interferencethat is not AWGN. This effect is more visible in Vehicular A where the interchip interference issignificant. An additional aspect which decreases the gain in reality is the fact that the decorrelationbetween the antennas is not ideal in most of the cases.

For medium to large speeds, the power control does not work properly anymore. Therefore, thechannel variations are larger and the antenna diversity gain is (slightly) larger. This effect is morevisible in Pedestrian A where channel variations are large.

Finally, the antenna diversity gain is larger in Pedestrian A than in Vehicular A since the channelpower variations are larger and the interchip interference is lower in Pedestrian A.



The RX diversity gain therefore depends on the service, on the multipath profile and on the velocity.TD/SYT provides simulation results for different services. [Perf_TD], [Perf_SP] give the results forspeech.

In order to benefit, in a real system from gains which are in the same order of magnitude as givenin the simulations, one has to assure the decorrelation of the two reception branches by spacediversity or polarization diversity (see [AntRules]). For space diversity, this decorrelation can beachieved by applying the same separation rules as given in [AntRules]:

The distance where the two antennas can be assumed to be decorrelated is

� for horizontal separation: dH=20�, this means dH=3m for UMTS/FDD

� for vertical separation dV =15�, this means dV =2.25m for UMTS/FDD

According to [AntRules], a second condition has to be fulfilled: d>antenna height/10, where d is thedistance between the antennas

As in GSM, cross polarized antennas should be used in urban and suburban areas, whereas twoseparated vertical polarized antennas should be used in rural areas for space diversity.

Outlook:

More than two antennas could be used in the future, allowing an additional gain of approximately 3dB. The potential gain of receive antenna diversity with 2, 3 or 4 perfectly uncorrelated antennas isshown in Figure 42 for exemplarily for Pedestrian A environment and a speed of 3km/h. Theindicated BER is measured at the output of the channel decoder.

1e-006

1e-005

0.0001

0.001

0.01

0.1

1

-2 0 2 4 6 8 10

BE

R

Rx Eb/N0

Speech 8 kbps, Pedestrian A, 3 km/h, Uplink

1 rx antenna2 rx antennas3 rx antennas4 rx antennas

Figure 42: Receive antenna gain for Speech 8 kbps service in Pedestrian A, 3 km/h

7.3.2 TX STTD Diversity Gain

An introduction to the UMTS transmit diversity techniques can be found in chapter 2. As TSTD is onlyapplied for the SCH channel and closed loop diversity is not included in the MBS V1, in this chapteronly the expected gain due to STTD is given.

The diversity gain provided by STTD is manifested by a reduction of the required received downlinkEb/N0. The following table shows the effect exemplarily for a 8kb/s voice channel and the ETSI



defined multipath environments Vehicular A and Pedestrian A (see [Perf_TD]). TD/SYT link levelsimulations will provide values also for other services soon.

DownlinkEnvironment

Speed

(km/h) Without Txdiversity

STTD

3 6.8 6.6

6 7.1 6.9

10 7.2 7.0

Vehicular A 25 7.2 6.9

50 7.4 7.1

120 7.6 7.5

200 8.4 8.2

350 10.4 10.0

3 6.5 6.3

6 7.1 6.6

Pedestrian A 10 7.6 6.9

25 8 7.0

50 8.3 7.3

120 8.5 7.7

Table 32: Received Eb/N0 required for a BER of 10-3 in speech 8 kbps

Please note that using TX diversity has an additional advantage: Instead of using one TX branch withmaximal power of 25W (43dBm), we can now use two TX branches with 25W (43dBm) each, whichmeans that we have a gain of 3dB in the power budget. However, this is not a diversity gain sincewe are merely doubling the TX power.

Now, what does the TX diversity technique mean for antenna engineering? In order to benefit fromthe transmit diversity gain, we need two TX antennas per carrier which can be looked at as beinguncorrelated. This is given by two vertical polarised antennas which are separated by a certaindistance (“space diversity”). The according separation rules can be found in chapter 7.3.1 and in[AntRules]. Also the signals coming from the two branches of a cross polarised antenna can belooked at as being decorrelated (“polarisation diversity”). Therefore for operation with duplexer, wecan use each RX diversity antenna also for transmission with TX diversity.

7.4 ANXU (Antenna Network for UMTS)

The antenna network for UMTS (ANXU) will be integrated in the UMTS node B. It connects up to 2transmitters to 2 antennas and distributes received signals to the receivers. The ANXU is splitted intwo identical parts A and B.



The diplexer filters are designed to decouple the transmit and receive bands in order to use oneantenna for the received and transmitted signals.

The two receiving branches are containing low noise amplifiers (LNA) with software adjustable gain,remote DC feeds and power splitters for the connection of up to three receivers, providing signalsfor all diversity pathes. The possibility of supplying an external MHA (Mast Head Amplifier Unit) forthe receive path is integrated.

Figure 43 gives a schematic representation of the ANXU antenna network.

3 way RX SplitterA 3 way RX Splitter

B

LNA BLNA A

DiplexerDiplexer

Antenna BAntenna A

Filterblock BFilterblock A

TX_B_inTX_A_in RXA/B1 RXA/B2 RXA/B3

Figure 43 Schematic Representation of ANXU

7.4.1 Single Carrier Configuration with Transmit Diversity

If the downlink diversity is activated, two TX branches are needed for one carrier11. Therefore, weneed one ANXU per carrier. Figure 44 shows schematically the according configuration. All 6 RXoutput ports provide RX diversity information for carrier f1, which are combined in the RAKE receiver.

11 Keep in mind that we have at maximum 3 carriers for a UMTS/FDD sector (2 for some operators,

e.g. in Germany)



f1 STTDEncoder ANXU

ANTA ANTB

Figure 44:Configuration for Single Carrier Application with Downlink Diversity

7.4.2 Dual Single Carrier Configuration

In the case that no downlink diversity is desired, one can use the ANXU for 2 carriers (f1 and f2).Figure 45 shows the according configuration.

f1

ANXU

ANTA ANTB

f2

Figure 45 Configuration for Application for 2 carriers without Downlink Diversity

7.5 MHA (Mast Head Amplifier)

Low-noise antenna pre-amplifiers installed near the antennas are sometimes used in cellularsystems. They are referred to as "Tower Mounted Amplifiers" (TMA) or "Mast Head Amplifier" (MHA).

A masthead amplifier can be used at a UMTS base station (node B) to improve the effective receiversystem noise figure when a long length of feeder cable is used, which will be explained in detailbelow. The reduction in the receiver system noise figure is translated into an improvement in theuplink power budget. This can be interpreted as compensating the losses of the feeder andconnectors between the antenna and the input of the base station.

2x25W

2x25W



BTS / Node B

Feeder

Antenna

Tx / Rx

Duplexer

Duplexer

Tx Rx

MHA

Figure 46: Schematic representation of MHA application

For RX or RX/TX antenna diversity operation, the configuration has to be doubled (two MHAs, i.e.one for each antenna)

Within the MHA, the shown diplexers separate and recombine the signals on the Rx and Tx paths.They also provide sufficient out-of-band filtering and isolation between the two paths. Only the Rxsignals get amplified, thus, improving the quality of the uplink branch. In contrast, the MHA causesan additional attenuation of ca. 1 dB on the Tx path.

In case MHAs are present in the system, they have to be considered for the design of the antennasystem. For the downlink, the additional loss of 1dB has to be taken into account. For the uplink,unfortunately, the impact cannot be treated by adding a simple MHA gain within the power budget.Since the MHA reduces the total noise figure of the reception chain, one has to apply the total noisefigure of the reception chain in the calculations. The reception chain contains as elements the MHA,node B, cables and connectors, and perhaps diplexers or filters. The calculations can be done by theFriess Formula:

DXcableMHA

BS

cableMHA

DX

MHA

cableMHAtot ggg

ngg

ngn

nn��

�

�

�

�

�

�

��

111

Equation 6: Friess Formula with MHA

with 1010elementNF

elementn � and 1010elementG

elementg �

where NFelement is the noise figures in dB and Gelement is the gain in dB of the corresponding element(note that a loss is a negative gain!). The index “element” can be MHA, cable (denotes cables andconnectors), DX (denotes diplexer or filter) or BS (denotes node B). If there are no diplexers or filtersin the chain, nDX and gDX are set to 1.

In case we have no MHA, the Friess Formula becomes:



DXcable

BS

cable

DXcabletot gg

ngnnn

�

�

�

�

��

11

Equation 7 Friess Formula without MHA

Example:

Element Noise Figure (NF) GainMHA 2dB 12dBCable 25m 2dB -2dBNode B (incl. ANXU) 4dB

No diplexers or filters are used in the example.

Applying the Friess Formula, we get:

Noise Figure of MHA & cable & nodeB Noise Figure of cable & node B2.5dB 6dB

7.6 GSM and UMTS/FDD Co-location

Providers operating already a GSM system cannot afford to simply add new sites for the UMTSsystem. The existing GSM sites have to be re-used. Even new operators might be confronted withsites already equipped with base stations of another operator. However, using the same site for bothsystems is far from being trivial from the RF point of view. The most challenging aspect of UMTSAntenna Engineering is therefore to find antenna system solutions to make the co-location of UMTSNode B’s with existing GSM BTS’s possible, for both GSM 900 and GSM 1800.

7.6.1 RF Requirements

7.6.1.1 Interference Mechanism

Co-location of systems may cause interference resulting in performance degradation. In order tominimize this performance degradation to an acceptable defined level, decoupling requirementsbetween the systems have to be met.

The most important interference mechanisms are:

� Transmitter noise/ spurious emissions

The transmitter noise floor or transmitter spurious of system "A" within the receive band ofsystem "B" causes interference of system "B´s" receiver and vice versa. This could beavoided by increasing the stop band attenuation of system "A´s" antenna network in thetransmit path for the receive band of system "B", or by increasing decoupling between thetwo systems, either the air decoupling or the decoupling provided by the diplexer.

� Receiver blocking

Transmit signals of system "A" are blocking the receiver of system "B" and vice versa.Although the transmit signals of system “A” are received by “B” out-of-band (meaning notwithin “B”’s receive band), they can lead to a desensitization if they are too strong. This



could be avoided by increasing the stopband (out-of-band) attenuation of system "B´s"antenna network in the receive path for transmit frequencies of system "A", or byincreasing the decoupling between the two systems (air or diplexer decoupling).

� Intermodulation products

Intermodulation products are interfering the receivers of one or both systems. Significantintermodulation products are generated in nonlinear devices (especially mixers andamplifiers but also connectors), if two ore more strong signals are applied. In our case thestrong signals could be different transmit carriers either from system "A" or from system "B"or a combination of system "A´s" and "B´s" transmit carriers. For the consideration withinthis document, it is assumed that the TRE´s performance to avoid intermodulation isalready fixed. Not considered are interference mechanisms within one system, becausethey occur also without co-location.

7.6.1.2 Decoupling requirements

For the co-located systems, an antenna decoupling resp. diplexer decoupling of at least 30dB canbe assumed, no matter if the decoupling is provided by single band antennas, dual band antennasor diplexers. According to measurements [CoLoc], even side-by-side installations of single bandantennas provide this value. Therefore, only decoupling requirements exceeding 30dB are judged ascritical in the following and require adapted solutions. In the decoupling tables below, the value of30dB is therefore indicated even if a lower decoupling value would already be sufficient. Alldecoupling values are referring to an isolation between the antenna connectors. For calculation ofthe required decoupling, different cases are distinguished which look at the Alcatel equipmentperformance (EVOLIUM™ GSM and EVOLIUM™ UMTS) and the equipment performance accordingto GSM 05.05 and 3G TS 25.104 recommendation.

TX/ RX

TRE

Feeder

TX/ RX

UMTS Node B

ANC

TRE

Antennaconnectors

Antenna system

ANC

GSM BTS

Figure 47: Decoupling Reference Point



7.6.1.2.1 Decoupling Requirements due to Spurious Emissions

7.6.1.2.1.1 Co-located GSM1800 and UMTS sites

The spurious emissions resp. the transmitter noise floor are most critical in case of co-located GSM1800 – UMTS sites.

The limiting factor for decoupling requirements results from the GSM 1800 transmitter noise floor,the spurious emissions respectively, of the GSM 1800 BTS within the UMTS receive band.

There are historical reasons for that: At the time GSM 1800 was specified, no one expected anUMTS system working in the adjacent band. Therefore, the filter requirements for the GSM 1800 BTSare rather inadequate. According to the ETSI recommendation GSM 05.05, spurious emissionswithin a bandwidth of 3 MHz in the UMTS band have to be below –30 dBm at the antennaconnector. Note: Between GSM systems –98 dBm is specified. After mapping this requirement on3.84 MHz, which is the effective carrier bandwidth of UMTS, the maximum interference may reach-29 dBm. This is much higher than the interference level acceptable by the UMTS Node B.

For calculation of the required decoupling, two cases are distinguished. One includes the AlcatelEVOLIUM™ GSM 1800 equipment performance, the other is based on the GSM 05.05recommendation.

Spurious emissionsETSI: < -29 dBm

Alcatel : < -67 dBm

TX/ RX

EVOLIUMTM BTS 1800

ANC:UMTS band attenuation: 40 dB

TRE-level: TX spurious emissions:

< -27 dBm

Feeder

TX/ RX

UMTS Node B

Antenna ConnectionNetwork

Transceiver-level

Limiting interference level: < - 114 dBm

Antennaconnectors

Antenna system

ANC: Antenna Network CombinerTRE: Transceiver Equipment

Figure 48: Conditions for noise / spurious emission GSM 1800 � UMTS



To determine the decoupling requirements, an acceptable degradation of the Node B sensitivity of0.4dB (caused by the spurious emissions) has been assumed12.

Equipment type ETSI specifications (GSM 05.05) Alcatel EVOLIUM™ GSM 1800 BTS

Spuriousemissions(at BTS antennaconnector)

- 29 dBm TX, spurious emissions: - 27 dBm

ANC, attenuation in UMTS band: 40dB

- 27 dBm – 40 dB = - 67 dBm

Limitinginterferencelevel

Noise at UMTS receiver without GSM 1800 impact:

Thermal noise (-108 dBm) plus receiver noise figure (4 dB), i.e. –104 dBm(Pnoise [dBm] = -174 dBm + System Noise Figure [dB] + 10 log (BW [Hz])

Degradation of sensitivity by 0.4 dB acceptable (level 10 dB below noise floor)

-104 dBm – 10 dB = -114 dBm

Requireddecoupling

- 29 dBm – decoupling = -114 dBm

Decoupling = 85 dB

-67 dBm – decoupling = -114 dBm

Decoupling = 47 dB

Table 33: Decoupling calculation for GSM1800 transmitter noise/ spurious emissions within UMTSreceive band.

The calculation shows that a standard antenna decoupling of 30 dB is not sufficient for co-locatedGSM 1800 and UMTS systems. Additional measures have to be performed, presented later in thisdocument.

The spurious emissions of the UMTS node B within the GSM1800 are not critical. Therefore, adecoupling of 30dB from the UMTS antenna connector towards the GSM1800 antenna connector issufficient.

The resulting decoupling requirements are shown in Table 34.

Required decouplingfrom ... to �

GSM 1800(05.05)

GSM 1800(Alcatel)

UMTS (TS25.104)

UMTS (Alcatel)

GSM 1800 (05.05) � 85dB 85dB

GSM 1800(Alcatel)��

47dB 47dB

UMTS (TS 25.104) � 30dB 30dB

UMTS (Alcatel)�� 30dB 30dB

Table 34 Decoupling requirements due to spurious emissions for GSM1800 – UMTS co-location

Therefore, the 2 rightmost columns represent the limiting decoupling requirements.

7.6.1.2.1.2 Co-located GSM900 and UMTS sites

12 Rule of thumb:

0.1/0.2/0.4/1.0 dB degradation, if spurious level is 16/13/10/6 dB below noise floor



For the combination GSM 900 – UMTS, 30 dB antenna decoupling is enough for transmitter noise/spurious emission conditions.

The resulting decoupling requirements are shown in Table 35.

Required decouplingfrom �� to

GSM 900(05.05)

GSM 900(Alcatel)

UMTS (TS25.104)

UMTS (Alcatel)

GSM 900 (05.05) �� 30 dB(1) 30dB(1)

GSM 900 (Alcatel) �� 30dB 30dB

UMTS (TS 25.104) �� 30dB 30dB

UMTS (Alcatel)�� 30dB 30dB

Table 35 Decoupling requirements due to spurious emissions for GSM 900 – UMTS co-location

Note: The ANC of the EVOLIUM™ GSM 900 BTS provides with 65 dB attenuation in the 2 GHz band sufficientdecoupling for co-located UMTS sites. It can be assumed, that also other standard ETSI equipment with theirintegrated antenna network complies with the decoupling demand, but this has to be checked.

7.6.1.3 Receiver blocking

For this interference mechanism, the receiver out-of-band blocking characteristic measured at theantenna connector of the BTS/ Node B is very important. The minimum system decouplingrequirements are indicated in the next table:

BTSorNode B

TX power

AntennaAntenna

RX blocking TX power

BTSorNode B

Decoupling

Figure 49: Receiver blocking, principle



GSM 900 (RX) GSM 1800 (RX) UMTS (RX)

Specificationaccording to:

GSM05.05

Alcatel GSM05.05

Alcatel 3G TS25.104

Alcatel

GSM 05.05 46 dB 30 dB 61 dB 30 dBGSM 900 (TX)��

Alcatel 46 dB 30 dB 61 dB 30 dB

GSM 05.05 39 dB 30 dB 62 dB 30 dBGSM 1800 (TX)��


3G TS25.104

35 dB 30 dB 43 dB 30 dBUMTS (TX) ��


It is assumed, that the decoupling provided by the antenna/diplexer system is at least 30 dB. In fact,using Alcatel EVOLIUM™ equipment requires for certain combinations even less isolation than statedhere.

Table 36: Decoupling requirements

The significant improvement of the Alcatel EVOLIUM™ equipment results from the integratedantenna network filters.

Link budget examples in the following sub-chapters give an overview about the relation betweenantenna decoupling and the blocking level.

7.6.1.3.1 Receiver blocking between GSM 1800 and UMTS

Link budget Value

GSM 1800 TX output power (high power) 46.7 dBm

Assumed antenna decoupling - 30 dB

Assumed feeder and connector loss 0 dB

UMTS received power (@ 1800 MHz) 16.7 dBm

Specification ETSI Alcatel

UMTS blocking limit -15 dBm 20 dBm �

Blocking limit fulfilled No Yes

Table 37: Link budget for blocking evaluation, GSM 1800 blocks receiver of UMTS

� Value is based on ETSI blocking limits in addition with the integrated antenna network filters of the

EVOLIUM™ equipment.



Link budget Value

UMTS Node B TX output power 43.0 dBm



GSM 1800 received power (@ 2000 MHz) 13.0 dBm


GSM 1800 blocking limit 0 dBm 25 dBm �

Blocking limit fulfilled No Yes

Table 38: Link budget for blocking evaluation, UMTS blocks receiver of GSM1800

7.6.1.3.2 Receiver blocking between GSM 900 and UMTS

Link budget Value

GSM 900 TX output power 46.0 dBm



UMTS received power (@ 900 MHz) 16.0 dBm


UMTS blocking limit -15 dBm 25 dBm

Blocking limit fulfilled Yes Yes

Table 39: Link budget for blocking evaluation, GSM 900 blocks receiver of UMTS



Link budget Value

UMTS Node B TX output power 43.0 dBm



GSM 900 received power (@ 2000 MHz) 13.0 dBm


GSM 900 blocking 8 dBm 35dBm

Blocking limit fulfilled Yes Yes

Table 40: Link budget for blocking evaluation, UMTS blocks receiver of GSM900

7.6.1.3.3 Receiver blocking conclusion

Receiver blocking is no problem for co-located Alcatel equipment assuming an antenna decouplingof 30 dB (and even less). Co-location with equipment from other suppliers needs to be checkedcase-by-case.

7.6.1.4 Intermodulation

7.6.1.4.1 The basics

Intermodulation, also called non-linear distortion, is generated in non-linear devices. The transfercharacteristic of such devices, e.g. the V-I characteristic of a semiconductor diode or the outputversus input power characteristic of an amplifier, is non-linear. At high power levels, evenconnectors exhibit non-linear effects.

Figure 50 shows an amplifier’s transfer curve as an example. At low input levels, the output signal isalmost a linear function of the input signal. With increasing input level, the output level will be lessthan expected and eventually be limited to the saturated output power of the amplifier e.g. due topower supply constraints.



-20 -15 -10 -5 0 5 10 1525

30

35

40

45

50

Input power in dBm

Out

put p

ower

in d

Bm

Figure 50: Non-linear transfer characteristic of a power amplifier

Such a transfer curve could be approximated by a power series:Vout(t) = C1 �� Vin(t) + C2 �� Vin(t)

2 + C3 �� Vin(t)3 + C4 �� Vin(t)

4 + ...

The output signal of a non-linear device will not have the same shape as the input signal. Itsfrequency spectrum will have more components than the input signal. The new frequencycomponents are either harmonics of the input frequencies or a combination of the input components(mixing). These new frequencies are called intermodulation products. If the input signal is made upof two sinewave signals with frequencies f1 and f2, the output signal will contain frequencycomponents atfIM = m �� f1 + n �� f2 with m, n = 0, +1, +2, +3, ...

The sum of (the unsigned) n and m is called the order of the intermodulation product, e.g.fIM = 2 �� f1 - 1 �� f2 is called a third-order intermodulation product (IM3). Third-order intermodulationproducts arise from the third degree and higher odd degree power series term of the transfer curve.

Figure 51 shows a output spectrum with intermodulation products up to third order. The frequenciesf1 and f2 are the two tone excitations at the input of the device.



Figure 51: Two tone output spectrum with intermodulation products up to third order

The level of a specific intermodulation component depends on the coefficients of the power seriescontributing to this component, and the input power level applied to the non-linear device. Typically,high-order intermodulation products have lower levels than low-order intermodulation products.

Because of the higher order power series terms from which the intermodulation products will begenerated, the levels of the intermodulation products will rise more than linear with the input signallevel, e.g. third-order terms will rise by 3 dB if the input signal is raised by 1 dB. This is the reasonwhy intermodulation products are not a problem at low input power levels for a given device, but athigh input levels they might. The ratio of wanted signal to intermodulation product decreases withincreasing input signal level.

A typical scenario for co-located base stations is shown in Figure 52 below:



TX/ RX

Feeder

Diplexer

Antennas

GSM BTS

ANC

TRETRE

UMTS Node B

ANXU

TRETRE

TX/ RX TX/ RX

ANC

TRETRE

ANXU

TRETRE

TX/ RX

Feeder

Dual-band antenna

Diplexer

Diplexer

Air decoupling

GSM BTS UMTS Node B

Figure 52: Air decoupling (left side) and diplexer decoupling (right side) for co-located sites

Either air decoupling or diplexer decoupling is used to fulfil the decoupling requirements at the BTSresp. Node B connectors. In any case, the antennas are used for reception as well as fortransmission, the TX/RX duplexer function is integrated within the antenna network combiner (ANC)module.

It is assumed, that each system itself (not co-located) fulfils the requirements on intermodulationperformance in order not to degrade it´s own receivers. Only intermodulation mechanisms due tothe interaction of both systems are considered.

The reference point for intermodulation products inside a used receive channel is the BTS antennaconnector. As long as the interfering signal level is well below the system´s noise floor, almost noreceiver degradation will occur. As a rule of thumb the following degradation of the referencesensitivity will occur:

� 0.1 dB degradation, if intermodulation level is 16 dB below noise floor




The noise floor of the system is determined by

Pnoise [dBm] = -174 dBm + System Noise Figure [dB] + 10 log (Receive ChannelBandwidth [Hz])



For a typical receiver with a noise figure of 4 dB the noise floor is

–117.0 dBm for a GSM system

–104.2 dBm for a UMTS system.

Intermodulation problems due to co-location might rise, if transmit carriers from the co-locatedsystem "A" generate intermodulation products falling into a used receive channel of system "B" orvice versa. Also a combination of transmit frequencies of both systems might fall into a used receivechannel of either system "B" or system "A."

7.6.1.4.2 Lowest order intermodulation products which might fall inside a usedreceive channel

Only co-located systems of different types are taken into account in this chapter.

In the table below, the lowest order intermodulation products, which might fall inside a used RXchannel, are listed. Intermodulation between the own system´s transmit frequencies and the co-located system´s transmit frequencies as well as intermodulation between the co-located system´stransmit frequencies which could impact the own system have been taken into account.

Co-location Intermodulation products

GSM 1800 UMTS 3rd order: GSM 1800 TX within UMTS RX band

(e.g. 2 x 1879.8 MHz – 1 x 1820 MHz = 1939.6 MHz)

10th order: GSM 1800 and UMTS TX within GSM 1800 RX band

(e.g. 5 x 2153 MHz – 5 x 1810 MHz = 1715 MHz)

12th order: GSM 1800 and UMTS TX within UMTS RX band

(e.g. 6 x 2167.4 MHz – 6 x 1837.8 MHz = 1977.6 MHz)

GSM 900 UMTS 4th order: GSM 900 TX within UMTS RX

(e.g. 3 x 959.8 MHz – 1 x 935.2 = 1944.2 MHz)

9th order: GSM 900 and UMTS TX within GSM 900 band

(e.g. 3 x 2167.6 MHz – 6 x 935.4 MHz = 890.4 MHz)

12th order: GSM 900 and UMTS TX within UMTS RX band

(e.g. 9 x 930 MHz – 3 x 2140 MHz = 1950 MHz)

Table 41: Intermodulation products

The impact of Intermodulation products of order 6 and higher can be neglected.



7.6.1.4.3 Conclusion of Intermodulation interference

The intermodulation interference is particularly important for co-located GSM 1800 and UMTSsystems. Especially the third-order intermodulation products (IM3) of GSM 1800 transmitters maycause interference within the UMTS receive band. This means that IM3 products may occur withinthe UMTS receive band up to the frequency of 1955 MHz. This is the worst case valid for a GSM1800/ UMTS co-located site, where the lowest (f1 = 1805 MHz) and highest (f2 = 1880 MHz) GSM1800 frequency are used (fIM = -1 � f1 + 2 � f2) on the same site. Therefore, it is recommended forGSM 1800 operators to choose UMTS frequencies above fIM, where in any case no IM3 products ofthe own GSM 1800 frequencies occur.

The probability, that a third order intermodulation product falls into the UMTS receiver band (lowerthan 1955 MHz) is very low. This is illustrated by the following equations:

fIM = -1 � f1 + 2 � f2 < 1920 MHzf1 < f2

-1 � f1 + f2 = �; On site used GSM 1800 frequency band

fIM = �� + f2 < 1920 MHz

�� < 1920 MHz - f2

f2 max = 1880 MHz�� < 40 MHZ

If the GSM 1800 frequency band used within the same site is smaller than 40 MHz (whichcorresponds to 200 GSM carrier frequencies), no IM3 products fall in the UMTS receive band. This isalso valid for a larger used GSM 1800 frequency band, when the highest GSM 1800 frequency islower than 1880 MHz (f2 max <1880 MHz).

Thus, intermodulation interference is in most cases not relevant, because a distance between lowestand highest carrier frequency of 40 MHz will hardly be used within the same site.

In cases intermodulation products are falling in a used receive band, decoupling requirements haveto be derived accordingly. The following example should show how this can be done in a definedcase:

EXAMPLE:

GSM 1800 TX:

f1 = 1879.8 MHz and f2 = 1820 MHz, P = 46 dBm each at antenna connector

UMTS RX:

f = 1939.6 MHz

The third-order intermodulation product of the GSM 1800 transmitters falls into the UMTS receiveband (2 * 1879.8 MHz – 1820 MHz = 1936.6 MHz). The UMTS receiver´s noise floor is assumedto be –104 dBm. Allowing 0.4 dB UMTS receiver degradation the acceptable intermodulation levelat the UMTS antenna connector is approximately –114 dBm within the 3.84 MHz channelbandwidth.



Case 1: Intermodulation in the GSM 1800 transmitters

According to the GSM recommendation 05.05, the inband intermodulation attenuation hasto be 70 dBc13 in 300 kHz bandwidth. For a transmit power of 46 dBm, this means anintermodulation power of -24 dBm. The TX filter within the ANC module of the AlcatelEVOLIUM™ GSM 1800 BTS suppresses this level by at least additional 40dB within theUMTS receive band. At the GSM 1800 antenna connector the intermodulation level istherefore –64 dBm. To achieve the required intermodulation level of –114 dBm at theUMTS antenna connector, an additional attenuation of 50 dB by the GSM/ UMTS diplexeror air decoupling is required. An additional margin of 5 to 10 dB should be taken intoaccount, because the total intermodulation power is distributed over a 600 kHz bandwidth(additional 3 dB) and more than one GSM intermodulation product may fall inside a UMTSreceive channel. The required decoupling therefore would be 55 dB to 60 dB.

Case 2: Intermodulation in the UMTS receiver

According to the ETSI G3PP specification TS 25.104, the inband interfering signal level forthe UMTS receiver has to be –48 dBm. At this interfering level a wanted signal with a levelof -115 dBm can be received. An additional margin of 5 dB for the interfering level is takeninto account in order not to degrade a wanted signal at a level of –124 dBm (referencesensitivity level, Alcatel). The allowed interfere level without UMTS receive filter would be –48dBm – 5 dB = -53 dBm. For GSM 1800 transmit signals the Alcatel receive filter willprovide 90 dB suppression. With this filter the allowed interfere level at the UMTS antennaconnector is +37 dBm. Therefore 9 dB decoupling is already sufficient (TX power = 46dBm). This is less than in case 1.

Case 3: Intermodulation at the diplexer

In the case where a diplexer is used, the GSM transmitters have power levels of about46 dBm at the antenna connector of the diplexer The allowed intermodulation power levelis –114 dBm14. The attenuation has to be 160 dBc. This value is very critical for thediplexer and the antenna system. It is suggested to avoid this scenario by careful frequencyplanning.

13 dBc referes to a value “below carrier”, meaning that the useful power of the carrier is the

reference power, the dBc values indicate the difference in dB compared with this carrier power14 This acceptable interference power is derived analogously to the calculation in chapter 7.6.1.2.1



7.6.1.5 Summary on the required decoupling

In order to prevent performance degradation for co-located mobile systems, Alcatel proposes due tothe three interference mechanisms the following decoupling requirements:


Specification accordingto:

GSM05.05

Alcatel GSM05.05

Alcatel 3G TS25.104

Alcatel

GSM 05.05 85 dB

GSMspurious

85 dB

GSMspurious

GSM 900 (TX) ��

Alcatel 61 dB

Blocking

30 dB

GSM 05.05 85 dB

GSMspurious

85 dB

GSMspurious

GSM 1800 (TX)��

Alcatel 62 dB

Blocking

47 dB

GSMspurious

3G TS25.104

35 dBBlocking

30 dB 43 dB

Blocking

30 dBUMTS (TX) ��

Alcatel 35 dBBlocking

30 dB 43 dB

Blocking

30 dB

� It is assumed, that the decoupling provided by the antenna/diplexer system is at least 30 dB. In fact, usingAlcatel EVOLIUM™ equipment requires for certain combinations even less isolation than those 30dB

� Intermodulation (if applicable) has to be treated case by case

Table 42: Required decoupling

7.6.2 Antenna System Solutions

7.6.2.1 Dual Band Sites

7.6.2.1.1 GSM1800 with UMTS

7.6.2.1.1.1 Air decoupling with Single Band Antennas

Figure 53 shows a schematic representation of the air decoupling configuration for single bandantennas. A feeder cable to a GSM 1800 single-band antenna connects the GSM 1800 BTS.Similar, an extra feeder cable to an UMTS single-band antenna connects the UMTS node B.

It has to be noted that this configuration has to be doubled for the second antenna branch (keep inmind that we have mandatory RX diversity for UMTS).



GSM 1800BTS

UMTSNode B

Feeder Feeder

air decoupling

GSM 1800 antenna UMTS antenna

Figure 53: Schematic representation of air decoupling

The antennas are separated either by a vertical distance dv or by a horizontal distance dh (see Figure54).

GSM 1800

dh

UMTS

dv

GSM 1800

UMTS

Figure 54: Horizontal and vertical distance of antennas

In case of Alcatel EVOLIUM™ GSM 1800 equipment is used, the decoupling between GSM 1800transmit port and UMTS receive port has to be 47 dB. Taking into account a feeder cable loss of2 dB for each feeder cable, the pure air decoupling has to provide 43 dB of isolation.



In case of a GSM 1800 BTS fulfilling only the ETSI requirements, the air decoupling has to be 81 dB,which is much more difficult to obtain.

In order to determine the required minimum distance between the antenna panels, decouplingmeasurements have been performed in co-operation with RFS Celwave. As typical examples, twocross-polarized single-band antennas have been used, both antennas with 17 dBi gain and ahorizontal beamwidth of 65 degree (APX206515-2T for UMTS, APX186515-2T for GSM 1800,supplier: RFS/ CELWAVE).

7.6.2.1.1.1.1 Horizontal antenna separation

Figure 55 shows the decoupling between the -45° branch of the GSM 1800 antenna and the +45°branch of the UMTS antenna, as a function of the frequency, for different horizontal distances, whichhas to be found the limiting one of all combination of -45° and +45° branches. It has to be noted,that the indicated coupling distances were measured between the two vertical middle axes of theantennas. This means that the coupling distance of 20cm according to Figure 55 refers to the “sideby side” position which is given as dh = 0 m according to Figure 54.Converted into a formula, this leads to:

dh = coupling distance minus 0.2 m.

Coupling Distance (cm)

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

1.7 1.7625 1.825 1.8875 1.95 2.0125 2.075 2.1375 2.2

Frequency (GHz)

Coup

ling

(dB

)

2050100150200

Figure 55: Decoupling between -45° plane of GSM 1800 antenna and +45° plane of UMTS antennaover frequency for different horizontal distances

One can see that the two antennas side by side already offer a decoupling of 40 dB, a result whichcan be expected for the GSM 1800/ UMTS dual band antenna as well. Currently, the antennasuppliers specify their dual-band antennas with 30 dB decoupling only.



To be better than 43 dB for all relevant frequencies, the coupling distance has to be more than 0.5m (dh = 0.3 m). With respect to a certain security/error margin, a minimum coupling distance of 1.0m (dh = 0.8 m) for horizontal separation is recommended15.

A decoupling of 81dB cannot be achieved by air decoupling with realistic antenna distances.Therefore, the pure air decoupling solution cannot be applied for a GSM1800 equipment whichonly fulfills the ETSI requirements. However, if one wishes to use a single band antenna solution inthis case, an external filter may be added to the GSM1800 BTS which reduces the decouplingrequirements (see chapter 7.6.2.1.1.3.1)

7.6.2.1.1.1.2 Vertical antenna separation

Figure 56 shows as an example the decoupling between the -45° branch of the GSM 1800 antennaand the +45° branch of the UMTS antenna, as a function of the frequency, for different verticaldistances. It has to be noted, that the distances are measured between the horizontal middle axes ofthe two antennas. This means if one wants to map the represented distances on the distance dv

indicated in Figure 54, which is the distance between the top of the UMTS antenna and the bottomof the GSM 1800 antenna, one has to subtract 1.3 m, which is the length of each antenna.

The according formula is:

dv = coupling distance minus 1.3 m.

Coupling Distance (cm)

-100

-90

-80

-70

-60

-50

-40

-30

-20

1.7 1.7625 1.825 1.8875 1.95 2.0125 2.075 2.1375 2.2

Frequency (GHz)

Cou

plin

g(d

B)

150200250300

Figure 56: Decoupling between -45° plane of GSM 1800 antenna and +45° plane of UMTS antennaover frequency for different vertical distances

To achieve a decoupling of more than 43 dB within the UMTS frequencies, the coupling distance hasto be wider than 1.5 m (dv = 0.2 m). With respect to a certain security/error margin, a minimumcoupling distance of 2.0 m (dv = 0.7 m) for vertical separation is recommended16.

15 Please note that these values only apply for sector antennas with the same main beam direction.

16 Please note that these values only apply for sector antennas with the same main beam direction.



The measurement examples indicate, that an air decoupling of > 81 dB for equipment only fulfillingthe ETSI requirements cannot be achieved for the majority of sites, as the antennas have to be toofar apart from each other.

7.6.2.1.1.2 Broadband Antenna with Diplexer

The required decoupling between the two systems can also be achieved by using a diplexer. It canbe used in combination with a broadband antenna which can be realised for GSM 1800 and UMTSsince the according bands are so close together in spectrum.

Figure 57 shows the schematic representation of a solution using a BTS-side diplexer, one feedercable and a GSM1800/UMTS broadband antenna. This combination has to be doubled for thesecond antenna branch.

The diplexer has to provide 47 dB (in case of Alcatel EVOLIUM™ GSM 1800 equipment, 85 dB forETSI equipment) from the GSM 1800 transmit port to the UMTS receive port. From the UMTStransmit port to the GSM 1800 receive port, 30 dB of isolation is required.

The main advantage of the configuration is the need for only one feeder cable and one antennapanel. A disadvantage could be the fact of having the same antenna characteristics for the GSM1800 and the UMTS band. No different electrical downtilt can be chosen for the two systems.

GSM 1800BTS

UMTSNode B

Feeder

Broadband antenna

Diplexer

Figure 57: Schematic representation of the configuration with diplexer and broadband antenna

7.6.2.1.1.3 Dual Band Antennas

7.6.2.1.1.3.1 GSM1800/UMTS Dual Band Antenna with Additional Filters

A dual band antenna is in fact nothing else than two single band antennas within one panel.According to most antenna suppliers’ specification, a decoupling of 30dB between the GSM 1800antenna and the UMTS antenna within this panel can be assumed. However, from Table 42 weknow that this is not sufficient, so that we have to reduce the decoupling requirements. This can bedone by an external filter.



The configuration shown schematically in Figure 58 includes an external filter directly after theGSM 1800 BTS, two feeder cables and a GSM 1800/ UMTS dual-band antenna. Again, thiscombination has to be doubled for the second antenna branch.

GSM 1800BTS

UMTSNode B

Feeder

Dualband antenna

Filter

Feeder

Figure 58: Schematic representation of configuration with an external filter, two feeder cables and aGSM1800/ UMTS dual-band antenna

The filter has to reduce the spurious emissions of the GSM 1800 BTS within the UMTS receive bandto achieve the required isolation, while relaxing the antenna decoupling value to 30 dB. Feedercable losses of 2 dB per feeder cable are taken into account.

The filter (with fc = 1900 MHz) lets pass the whole GSM 1800 receive and transmit frequencies, butprovides sufficient attenuation within the UMTS band.

The stopband (=out-of-band) attenuation � which has to be guaranteed is dependent on theperformance of the filter integrated within the GSM 1800 BTS, and therefore on the spurious outputpower Pspur. The power received from GSM 1800 spurious emissions within the UMTS band at theUMTS receive port shall not be higher than –114 dBm. Cable Loss Lcable is assumed to be 2 dB percable.

According to the ETSI requirements of GSM 05.05, the spurious emission Pspur within the bandwidthof one UMTS carrier is below –29 dBm. For Alcatel GSM 1800 EVOLIUM™ equipment –67 dBm canbe assumed, please refer to Table 33: Decoupling calculation for GSM1800 transmitter noise/spurious emissions.

For the received spurious power, the following equation is valid:

� � dBm1142 �� aircablespurrec aLPP �

� � aircablespurrequired aLP �� 2Pmaxrec�



ETSI specifications Alcatel EVOLIUM™ GSM1800equipment

Pspur = -29 dBm Pspur = -67 dBm

Prec,max = -114 dBm

Lcable = 4 dB

aair = 30 dB

�required = 51 dB �required = 13 dB

Table 43: Required filter characteristics

In order to be on the safe side for the filter specification, an additional margin of 5 dB should beconsidered resulting in an attenuation of 56 dB for the ETSI case, 18 dB for the Alcatel equipmentrespectively.

As a side effect, such a filter reduces the decoupling requirement for blocking of the GSM 1800 RXby the UMTS TX.

It has to be noted that such a filter may also be used to reduce the decoupling requirements andtherefore the required decoupling distance for the single band antenna solution described in chapter7.6.2.1.1.1



7.6.2.1.1.3.2 GSM1800/UMTS Dual Band Antenna with Two Diplexers

The configuration consists of one BTS-side diplexer, one feeder cable, one antenna side diplexer(preferably integrated in the antenna panel) and a GSM 1800/UMTS dual band antenna consistingof two antennas within one panel. This combination has to be doubled for the second antennabranch.

GSM 1800BTS

UMTSNode B

Feeder

Dualband antenna

Diplexer

Diplexer

Figure 59: Schematic representation of configuration with two diplexers and a GSM 1800/ UMTSdual-band antenna

The BTS-side diplexer has to provide 47 dB of decoupling from GSM 1800 transmit port to UMTSreceive port (in case of Alcatel EVOLIUM™ GSM 1800 equipment). For the antenna side diplexer, adecoupling value of 30 dB is largely sufficient.

The advantages of the configuration are that gain and electrical tilt can be chosen differently forGSM 1800 and UMTS. The disadvantage is the necessity of implementing two diplexers.

7.6.2.1.1.4 Summary on GSM1800/UMTS Solutions

Description Advantage Disadvantage CommentSingle band antennaswith air decoupling,two feeders

Existing GSM1800antenna system doesnot have to bemodified

Different mechanicaland electrical downtiltfor GSM1800 andUMTS antennapossible

High visual impact ofadditional UMTSantenna

High antennadistance required

Two feeder cablesrequired

For GSM 1800equipment which onlyfulfills ETSIrequirementsconcerning spurious,this solution is notpossible



Broadband antennawith one diplexer andone feeder

Only one feedercable required

Low visual impact(existing GSM1800antenna can bereplaced bybroadband antenna)

No differentmechanical orelectrical downtilt forGSM1800 and UMTS

diplexer required

Dual band antenna withtwo feeders andexternal filter

Different electricaldowntilt possible

No diplexer required

Low visual impact(existing GSM1800antenna can bereplaced by dualband antenna)

Two feeder cablesrequired

No differentmechanical downtilt

External filterrequired

Dual band antenna withone feeder and twodiplexers

Only one feedercable required

Different electricaldowntilt possible

Low visual impact

Two diplexersrequired (one of themwith high decouplingrequirements,therefore expensive)

No differentmechanical downtilt

7.6.2.1.2 GSM900 with UMTS

7.6.2.1.2.1 Air decoupling with Single Band Antennas

For the combination of GSM 900 with UMTS, concerning the installation of single-band antennas,no special conditions have to be considered, since 30dB of decoupling are easily obtained. Forsector antennas installed in the same main beam direction, in most cases, “side by side” installationof panel antennas is possible. To be on the secure side, the following values are recommended:

Vertical separation: dv=0.3m

Horizontal separation: dv=0.5m (only for sector antennas!)

If omni antennas are used, horizontal separation is not recommended since the antenna gainincreases the required separation drastically.

7.6.2.1.2.2 GSM900/UMTS Dual Band Antennas

A GSM 900/UMTS dual band antenna offers 30dB of decoupling at minimum (according toantenna supplier’s specification). Therefore, one can choose either a solution with two feeder cablesand without diplexers or with a common feeder cable and two diplexers. Please refer to chapter7.6.2.2 for a detailed explanation.

7.6.2.1.2.3 Summary on GSM900/UMTS Solutions

Description Advantage DisadvantageSingle band antennas with airdecoupling, two feeders Existing GSM900 antenna

system does not have to bemodified

High visual impact ofadditional UMTS antenna



Different mechanical andelectrical downtilt forGSM900 and UMTS antennapossible

Two feeder cables required

Dual band antenna with twofeeders Different electrical downtilt

possible

No diplexer required

Low visual impact

Two feeder cables required

No different mechanicaldowntilt

Dual band antenna with onefeeder and two diplexers Only one feeder cable

required

Different electrical downtiltpossible

Low visual impact

Two diplexers required

No different mechanicaldowntilt

7.6.2.2 Feeder Sharing

Dual-band systems are realized either with separated single-band antennas or dual-band antennas.For the combination of GSM1800 and UMTS, the third option consists in a broadband antenna.However, if the antenna system supports diversity (note that RX diversity is mandatory for UMTS) atleast two antenna branches per BTS sector and mobile system are necessary. This results in fourantenna branches for a dual-band BTS sector (except the solution with broadband antennas forGSM 1800 and UMTS, not further described in this document). Thus, without feeder sharing, fourfeeder cables are necessary. By using additional diplexers, two shared feeder cables are sufficient.The following example with a cross-polarized dual-band antenna describes the feeder sharing.

Dual-band antennas are characterized by being suitable for both frequency ranges with separateinput connectors. This leads to a double number of antenna connectors, compared to acorresponding single-band antenna; four connectors for dual-polarized dual-band antenna.

Feeder

Dual-bandantenna

-45°+45°

Diplexer Diplexer

Diplexer Diplexer

Feeder

Dual-bandantenna

Withintegrateddiplexers

Withoutdiplexers

Dual-band Dual-band

Diplexersat BTSlocation



Figure 60: Dual-band antenna, with and without diplexer application

By upgrading the dual-band antennas with additional diplexers (often integrated in the antennaradome), the number of antenna connectors will be reduced by a factor of two. The required feedersystem will be the same as for a single-band antenna system. This kind of application requiresfurther base station diplexers with a corresponding resplit function.

The additional costs for the diplexers will be justified, if the reduced expenditure of the feeder systemis predominant. Especially for the case of migrating a single-band to a dual-band system, theexisting feeder system can be used ensuring a fast installation during retrofit. It has to be checked,however, whether the feeder cable fulfils the demands for both systems in terms of losses (the feederattenuation increases with higher frequencies).

Note that for the broadband antenna solution, feeder sharing is the only thinkable solution sincethere is only one diplexer which is logically installed at the BTS side.

7.6.2.3 Triple Band Sites

With respect to the visual impact, triple-band antenna systems will be preferably realized either withsingle-band and dual-band antennas or with triple-band antennas. Nevertheless, configurationswith mono-band antennas are also feasible. The conditions concerning the decoupling requirementscan be taken from the dual-band co-located sites.

7.6.2.3.1 With dual-band antennas

In cases dual-band antennas are used the following variants are possible:

� GSM 900 single-band antenna, GSM 1800 / UMTS dual-band antenna

� GSM 900 / GSM 1800 dual-band antenna, UMTS single-band antenna

� GSM 900 / UMTS dual-band antenna, GSM 1800 single-band antenna

The preferred configuration is dependent on the existing antenna system and the evolution steps to atriple-band site. The network planning aspects pose a further requirement on the antennaarrangement.

7.6.2.3.2 With triple-band antennas

Triple-band antennas are necessary for those existing antenna sites using only one antenna persector and where additional panels are not allowed due to the visual impact.



GSM 1800BTS

UMTSNode B

Triple-band antenna

GSM 900BTS

Feeder Connection Matrix

Figure 61: Triple-band antenna

An isolation of 30 dB is not enough for the decoupling between GSM 1800 and UMTS. Thereforeadditional components must be implemented in order to fulfil the decoupling requirements (use ofdiplexer), or to decrease the decoupling requirements (use of GSM 1800 TX filter).

The connection possibilities are the same as already presented for the dual-band sites GSM 1800and UMTS. Figure 62 reminds the diplexer and filter solution:

Feeder

Filter

FeederFeeder

Diplexer

Diplexer

GSM 1800 GSM 1800UMTS UMTS

Diplexer application Filter application

Connection matrix

Figure 62: Connection possibilities for triple-band antenna

7.6.2.3.3 Feeder Sharing

A separated triple-band antenna system with diversity support needs at least six feeders per sector.With feeder sharing, this amount can be reduced. The minimum number per sector is two.

In order to fulfil the need to have only two feeder cables per sector for all three bands, the use oftriplexers are necessary. The following picture illustrates the triplexer application consisting of twodiplexers in combination with a triple-band antenna.



GSM 900 Triple-bandantenna

GSM 1800 UMTS

Diplexer

DiplexerTriplexer

Diplexer

DiplexerTriplexer

GSM 900 GSM 1800 UMTS

Feeder system

Antenna system

BTS systemsFigure 63:Triplexer application



If only diplexing between two mobile systems is applied, please refer to 7.6.2.1, four antenna feedercables per sector are then required.

One representative application is the diplexing of the GSM 1800 and UMTS mobile system. Thisleads to separated feeder cables between the GSM 900 and the GSM1800/ UMTS systems. Furtherbenefits are:

� Flexible choice of the feeder type (because the feeder attenuation increases with thefrequency)

� Diplexers improve at the same the decoupling between the systems which is, as weknow, critical between GSM1800 and UMTS

GSM 900 Triple-bandantenna

GSM 1800 UMTS

Diplexer

Diplexer


Feeder system

Antenna system

BTS systems

Figure 64: GSM 1800 / UMTS diplexing at triple-band site

7.6.2.3.3.1 Additional losses



The feeder sharing benefits have to be paid for with slightly increased losses in the feeder system.The next table collects the additional losses:

Component Loss

Diplexer GSM 900 - GSM 1800 0.3 dB

Diplexer GSM 900 - GSM1800 / UMTS 0.3 dB

Diplexer GSM 900 - UMTS 0.3 dB

Diplexer GSM 1800 - UMTS 0.5 dB

GSM 1800 filter 0.4 dB

Table 44: Feeder sharing losses

The feeder sharing influence on feeder´s system performance is clarified with the following example(Figure 65)

� Task: An existing GSM 900 antenna system shall be extended to a triple-band GSM 900/GSM 1800/ UMTS system.

� Condition: Because of space constraints, the existing feeder cables have to be shared forall frequency bands.

� Solution: Use of diplexers (triplexers) for feeder sharing.


Diplexer

DiplexerTriplexer

Diplexer

DiplexerTriplexer


Antenna systems

BTS systems

GSM 900

GSM 900

Feeder system

Figure 65: Feeder sharing task

Influence of feeder sharing (losses in dB)

Components GSM 900 GSM 1800 UMTS

2 Diplexers GSM 900-GSM1800

0.6 0.6 0.6



Influence of feeder sharing (losses in dB)

2 Diplexers GSM 1800-UMTS 1.0 1.0

Additional losses(jumpers, connectors)

0.5 0.5 0.5

Total loss 1.1 2.1 1) 2.1 1)

Table 45: Example for additional losses

Note: Remark: GSM1800/ UMTS signals have 50 % more signal attenuation compared with GSM 900signals over the same feeder cable.

7.6.2.3.4 Antenna Feeders

Apart from the higher loss experienced in the 2GHz band compared with the 900 and 1800MHzGSM bands, UTRAN networks impose no additional restrictions on the choice of antenna feedercable compared to those applicable to GSM networks.

When upgrading an existing 1800MHz antenna system (or dual 900/1800MHz band) forsimultaneous operation at 2GHz, the additional frequency dependent feeder loss is unlikely to besignificant. It is normally possible to use the existing 1800MHz feeder for both services, providedthat the additional loss associated with the dual (GSM/UMTS) band diplexers (cross-band couplers)is acceptable.

Using an existing 900 MHz band feeder for UMTS services may introduce unacceptable loss exceptwhere the feeder length is relatively short. The combination of longitudinal loss in the feedertogether with insertion losses in the two dual (GSM/UMTS) band diplexers (one at each end of thefeeder) may become unacceptable.

Factors to be taken into account when considering a common antenna feeder system for aUMTS/GSM network are the same as for a dual band GSM 900/1800MHz network. The followingtable compares attenuation of common types of antenna feeder at 900MHz, 1800MHz, and2000MHz:



Foam Dielectric Cable

Nom. Diameter Attenuation at 894 MHz Attenuation at 1.7 GHz Attenuation at 2 GHz

½” 0.72dB for 10m length

1.80dB for 25m length











7/8 ‘’ 0.40dB for 10m length












1 ¼’’ 0.30dB for 10m length












Table 46 Comparison of antenna feeder loss

7.6.2.3.5 MHA in Co-location Configurations

A MHA "transforms" the BTS input to the antenna connector of the MHA, compensating for thefeeder losses. The calculation of the respective required decoupling is similar to the processdescribed in the document so far. The differences:

� For the noise / spurious response calculation, the feeder loss can no longer be taken intoconsideration for reducing the interference signal.

� The signal delivered by the MHA to the BTS receiver can be higher, resulting in blocking.

� The low noise amplifier in the MHA has its own blocking limit to be considered.

In the following, two GSM/UMTS co-location configurations with MHA are shown.

7.6.2.3.6 One feeder cable with UMTS Mast Head Unit

Since in GSM, we are for most power budgets not uplink limited thanks to the high sensitivity of theEVOLIUMTM BTS, a configuration where only the UMTS part (which benefits from a RX loss reduction)is equipped with a mast head amplifier does make sense.



Diplexer

GSM

BTS

UMTS

BTS

ANXU

Ground Equipment

Feeder Cable

RF RF + DC DC Feed

GSM UMTS

Feeder Cable

Diplexer

RF

Dual Band Antenna

GSM UMTS

UMTS

MHA

Duplexer

Duplexer

LNA

Mast Head Unit

RF + DC

Figure 66 Configuration with one feeder cable and UMTS mast head unit

7.6.2.3.7 Two feeder cables with GSM and UMTS Mast Head Unit

GSM

BTS

UMTS

BTS

ANXU

Ground Equipment

FeederCables

RF + DC RF + DC

DC Feeds

GSM UMTS

ANCG/

Bias T

UMTS Feeder Cable

GSMMHA

Dual Band Antenna

GSM UMTS

UMTS MHA

Duplexer

Duplexer

LNA

Mast Head Units

RF + DC

GSM Feeder Cable

Duplexer

Duplexer

RF + DC

LNA

Figure 67: Configuration with two feeder cables and mast head unit for GSM and UMTS

Since the ANCG does not incorporate a DC Feed for a Mast Head Unit, a Bias T has to be introduced toassure the DC feed by the feeder cable.



7.6.3 Outlook to the future: Smart antennas (beam-forming)

The beam-forming concept consists in covering each sector by narrow beams with larger antennagain than conventional antenna diversity where each antenna covers the whole sector. Thistechnique relies on a linear antennas array (also known as smart antennas) in which the antennasspacing is of the order of half the wavelength (about 7.5 cm in UMTS).

4 beams4 beams

Figure 68: Adaptive beam-forming (on the left) vs. fixed beam-forming (on the right)

As illustrated in the figure, two main types of beam-forming exist:

� Fixed beam-forming that consists in having several fixed beams covering each sector andselecting the antenna that receives the signal with largest power,

� Adaptive beam-forming (also called adaptive arrays) where the received signals on the differentantennas are weighted and combined to maximize the signal-to-interference ratio. It enables tohave a large antenna gain in the direction of the useful signal and a low antenna gain in thedirection of interferers. A simplified algorithm is also possible where only the signal-to-noiseratio is maximized, which enables to decrease the complexity but reduces the performance gain.

The advantage of fixed beam-forming is to have a lower complexity: no weight estimation isrequired and the data estimation is performed only once (whatever the number of antennas)compared to as many times as the number of antennas for the adaptive beam-forming. However,the performance gain of adaptive beam forming is larger since it enables to get a diversity gain inaddition to the larger antenna gain achieved by both techniques.

Beam-forming may be used in uplink and in downlink. However, since in the FDD mode of UMTS,the downlink and uplink are on different frequency carriers, the fast fadings of both links are notcorrelated. Therefore, the best antenna (fixed beam-forming) or the optimum weights (adaptivebeam-forming) estimated from the uplink signal cannot be used in downlink. A solution consists inusing uplink weights averaged over a sufficient period of time (typically 100 ms) in downlink in orderto remove the impact of fast fading and retrieve the correlation between uplink and downlinksignals. However, in this case, the performance gain is lower than in uplink.



8 PRODUCTS AND MIG RATION STRATEGIES

References

[MIG02] Migration Strategies towards 3G & Products Draft 02

[UMTSRM] UMTS Roadmap: Status November 2000

[RNCV1] Evolium UMTS Radio Network Controllerpd_RNC_LCEd1.doc

[MBSV1 MBS V1 Features List (internal)

[FL0] Technical Feature List (R1,R2,R3) FL0.7U_EC Technical.xlsStatus: November 2000

[UMTSLB] Typical link budgets for UMTS FDD macrocellsUMTS-link-budget-Eb2.doc)

[GPRSRNP] GPRS/E-GPRS RNP aspectsRef. Nr.: 3DF 0095 0005 UAZZA

[OMCV1] Evolium UMTS OMC-R Product descriptionRef. Nr: 3DC 2176 0005 TQZZA

[MMSN] Migration to multiservice Networks ( K.Daniel)Migation_to_GERAN.ppt

[SysDesign] UTRAN system Design Document Ed.7, 3BK 10240 0005 DSZZA

[RadPerf] UTRAN Radio Performance Requirement, 3BK112400014DSZZA

Both the technical feature list and the roadmap are from November 2000, they might varyin a short/long term

8.1 Introduction

This document describes the radio access network migration from the second generation of mobilecommunications (GSM, GPRS) towards the third one (UMTS, E-GPRS) as proposed by Alcatel. WhileGSM is based on a circuit switched concept, GPRS has been introduced to provide end-to-endpacket-switched data transmission. With E-GPRS the next step of the GPRS evolution is introduced,by enhancing data rates with the Edge feature [GPRS-RNP].

The Radio Access Network (RAN) evolution, which is divided in several releases is described, as wellas the related Alcatel products for each RAN release. The key features provided in each RAN releaseare also pointed out in this document. In the last section migration strategies for incumbentoperators and Greenfield operators are given.



8.2 ROADMAP: RADIO ACCESS NETWORK EVOLUTION

The Alcatel/Fujitsu view on the evolution of the RAN towards 3G (UMTS/E-GPRS) consists of threereleases, called 3GR1 or R1, 3GR2 or R2 and 3GR3 or R3. With each release new products andfeatures are provided, the roadmap is shown in figure 1. Each of these releases will be described inthe following sections.

The table given in Annex A summarizes further RNP relevant features planned for the three UMTSreleases [FL0].

Node B

RNC

OMC

Releases

V1

V2

V2

V1

V1

V2

3GR1.1 R1.2 R1.3 R2.0 R2.1 R3

PR

OD

UCTS

Figure 69 Alcatel RAN Migration Roadmap (Status November 2000)

8.2.1 RELEASE 1: UMTS OVERLAY NETWORK

The first release called 3GR1 is based on the 3GPP Release of March and June 2000 specifications.

At this stage, an UMTS layer, able to operate UTRA-FDD only, will be deployed as overlay andindependent of the existing GSM/GPRS network.

This network release will be developed in three phases, which are called R1.1, R1.2 and R1.3,introducing new hardware elements and new features.

The Node Bs are called the MBS V1 (i.e. Version 1 of the “Multistandard Base Station”), although itis only UMTS capable, as well as the RNCs and OMC-Rs.

In the last phase of the 3GR1 release (R1.3) the V2 Multi-standard Base station will be available. Itwill be able to allow GSM and UMTS TRXs in the same cabinet.

In the 2G layer, GPRS functionality can be achieved with the HW releases G1 and G2 (basic GPRScapabilities) and G3 to G5 of Evolium HW equipment and the B6.2 SW release. The MFS, SGSNand GGSN are also part of the GPRS network. For more information on the 2G layer refer to[GPRSRNP].

Site sharing, and therefore transmission resources sharing, between Node B and BTS, is alsopossible and recommended in order to save costs. For more information about site sharing seechapter 7 of this guideline.



The most important supported features of Release R1 are listed in Table 47. Please see reference[FL0] to see the complete technical feature list:

Feature Release/Phase

FDD mode R1.1

Compatibility with UMTS 3GPP version March 00 R1.1

Compatibility with UMTS 3GPP version June 00 R1.2Power control R1.1Adaptive Multirate Codec R1.1STTD (Space Time Transmit Diversity) R1.1Soft & softer HO R1.1Intra cell hard HO R1.1Inter cell- Intra RNC cell reselection R1.1Inter cell- Inter RNC hard HO and cell reselection R1.1UMTS � GSM circuit HO R1.2UMTS � GPRS packet HO R1.2

Table 47: 3GR1 RAN most important features. Ref[FL0]

Note that handover between UMTS and GSM or UMTS and GPRS are only possible in one directionwith Release R1.2.

Figure 2 shows the RAN architecture of the 3GR1.1 release implemented as an overlay network incase of GSM/GPRS/UMTS coexistence.



UMTS RNC

UMTS RNC

Iur

Iub

Iub

IubMSC/VLR

SGSN

Gn?

Iu-CS

Iu-PS

Node B

Node B

Node B

UMTS OMC-R

BTS

BTS

GSM OMC-R

Abis

Abis

GGSNIP network(Internet)

GPRS

backbone

BSC/MFSX.25

X.25

IRouter

Gb

A

Circuit corenetwork(PSTN)

Figure 70: RAN architecture of the 3GR1.1 release (GSM/GPRS/UMTS) coexistence

8.2.2 RELEASE 2: UMTS/GSM NETWORK INTEGRATION

With release 2 a first integration between both networks takes place, with the introduction of the realmulti-standard equipment. The operation and maintenance functions can be carried out by oneOMC-R (V2) . Further with the introduction of the multi-standard RNC V2 and MBS V2 the sameplatform can be used for GSM and UMTS as shown in figure 3. The network layer protocol can beATM with IP. The main features introduced with this release are summarized in table 2.



RNC/BSCGSM/UMTS(RNC V2)

MSC/VLR

SGSN

Gn

Iu-CS

Iu-PS

Node B(MBS V1)

Node B/BTS(MBS V2)

GSM OMC-R

BTS

BTS

BSC/MFS

GGSN

IP network

(Internet)

GPRS

backbone

Circuit CoreNetwork(PSTN)

Gb

UMTS/GSMOMC-R V2

Figure 71: Release 3GR2.1(R2.1) integrated RAN architecture

Feature ReleaseQueuing (Radio resource management) R2.0Priority(Radio resource management) R2.0Inter-cell – Intra RNC hard HO R2.0GSM circuit- UMTS HO R2.0Support of micro-cellular and hierarchical cell structure R2.0GPRS packet – UMTS HO R2.0SSDT (Site Selection Diversity Transmission) R2.0Node B overload detection R2.0RNC overload detection R2.0

Table 48: Release 3GR2 mean features. Ref [FL0]

8.2.3 RELEASE 3GR3: UNIFIED RAN ARCHITECTURE

This radio access network release architecture is based on the release 5 of the September 2000status of the 3GPP specifications.

This RAN architecture is common for UMTS and GSM/GPRS systems. Both UTRA-TDD and UTRA-FDD modes can be supported.

GERAN (GSM/EDGE Radio Access Network) will be also supported by this network release beingconnected to the UMTS and to the GSM core network.



The transport layer protocol will be unified for GSM, E-GPRS and UMTS and can be ATM with IP (asrecommended by Alcatel).

The radio access network structure for the third release is shown in

Figure 72.

RNC/BSCGSM/UMTS

MSC/VLR

SGSN

GnNode B(MBS V1)

Node B/BTS(MBS V2)

BTS

Iu-CS

Iu-PS/Gb

GGSN

IP network(Internet)

GPRS

backbone

Circuit Corenetwork(PSTN)

UMTS/GSMOMC-R V2

Figure 72 uniform RAN structure for the 3GR3 release

Other features planned for this network release are : Microcells and associated Micro Node B,interference cancellation, Multi User Detection as well as the usage of Adaptive Array Antennas.

8.2.4 What is GERAN?

GERAN (GSM-EDGE Radio Access Network): GERAN is a terrestrial RAN, that will be connectedto an UMTS and a GSM core network, to offer multimedia services using GSM/EDGE radiotechnology.

GERAN is recommended for:GSM operators that will not get an UMTS licenseGSM-UMTS operators to provide UMTS-like features at a lower cost

GERAN standardization:

- GERAN standards formerly handled by ETSI as GSM standards

- GERAN now part of 3GPP and therefore follows 3GPP release scheduleR4 target: March 2001

R5 target: December 2001

- Technical Specification Group GERAN deals with both: GSM, GPRS, EDGE specifications(pre-R’99) and, pure GERAN specifications (R4 and beyond)



Iu-psGbA

Iu-cs (ffs)

MSUm

GSM/UMTSCore Network

BTS

BSC

BTS

BSC

Iur

GERAN

Figure 73 GERAN architecture

GERAN is planned to be supported with the 3GR3 Alcatel radio access network release.GERAN is a platform that provides the four UMTS bearer classes: conversational, streaming,interactive and background.

8.2.5 Interoperability in a multi-vendor environment

In the 3GPP specifications, the UMTS radio access network (UTRAN) interfaces (Iub, Iur, Iu) are fullyspecified, therefore no compatibility problems should appear when combining equipment fromdifferent suppliers in the same network.

However, there are not any compatibility tests results available, which demonstrate that UMTSequipment from different suppliers can be used within the same network without problems.

8.3 PRODUCTS

Along the migration process from GSM into UMTS new network elements are planned to beintroduced for a certain network release. However the RNC V2, OMC-R V2 and the Micro Node Bare neither fully specified nor developed and should be mentioned in this document only for anoutlook.

8.3.1 Evolium Node B (MBS V1)

The Evolium Node B is officially called MBS V1 (“Multi-standard Base Station Version 1”) formarketing reasons, although it can support only UMTS FDD mode. The main features are describedhereafter, for more information see Annex B.

� Developed by Fujitsu

� UMTS capable

� Evolium single Rack

� Indoor and outdoor configurations available

� Up to 6 TRX, 6 sectors

� Base band (BB) board capacity limited (4 boards needed, for a minimal 3*1, 16 AMR Channels)

� DSCH function not supported

� Multi-standard not possible



� Available for 3GR1 R1.1 release

� IP transport possible

� Can be extended by carriers, sectors or BB processing capacity

8.3.1.1 Possible configurations within one cabinet

An overview on all available configurations according to [SysDesign] is given in Table 49

Table 49: Available MBS1 configurations within one cabinet for 3GR1.1.

Configuration Tx power per.. Required no of modules

SectorsCarriers/sector

Txdiversity

sector[W]

carrier[W]

TRX TPA ANXU

no 20 20 1 1 11yes 20 20 1 2 1no 14 7 2 1 12yes 14 7 2 2 1

1

3 yes 12.6 4.2 3 2 1no 20 20 2 2 21yes 20 20 2 4 2no 14 7 4 2 22yes 14 7 4 4 2

2

3 yes 12.6 4.2 6 4 2no 20 20 3 3 31yes 20 20 3 6 3no 14 7 6 3 3

3

2yes 14 7 6 6 3

4 1 no 20 20 4 4 46 1 no 20 20 6 6 6

Note:TPA = Transmit Power Amplifier / ANXU = Integrated Antenna Network for UMTS

8.3.1.2 Baseband board capabilities

The Node B can have a maximum of 9 BB modules in 3GR1.1, desirable to have 18 modules in thefuture.

The BB module has two modes, “Dedicated channel mode” and “Common channel mode”, and itcan be changed by the software. The processing capacity of one BB module in each mode is asfollows (see Table 50)

Table 50: Baseband board capabilities

Mode Processing capacityDedicatedchannel mode

One of the following set of DCH can be processed by one module,- 16 DCHs for AMR voice or- 4 DCHs for 64kbps service or- 2 DCHs for 128kbps service or- 1 DCH for 384kbps serviceThe mixed traffic of the three services from the top in the above list also can be processed byone module. In this case, if the following formula is satisfied, the one BB module shall beable to process it.A*(1/16) + B*(1/4) + C*(1/2) <= 1where, A = No of AMR, B = No of 64k, C = No of 128k.



Mode Processing capacityAny DCH on any BB module can be assigned to any sector carrier freely.

Commonchannel mode

One module can process the following set of common channel as the maximum- 2 P-CCPCHs- 4 S-CCPCHs- 8 AICHs- 2 CPICHs- 2 PICHs- 2 SCHs- 16 PRACHsThis set of common channels on one BB module can be applied to only one sector-carrier.

In case the enhanced BB (capacity increased version) module is released, the Node B can operatedifferent type of BB modules simultaneously.

Baseband modules can be added/removed during normal operation of the Node B.

8.3.1.3 Radio performance values of MBS V1

Radio performance data of the MBSV1 in release 3GR1.1 are given hereafter.Radio feature PerformanceSupported UL frequency bandSupported DL frequency band

1920 – 1980 MHz2110 – 2170 MHzThe TX amplifier is able to amplify a 20 MHz bandwidthwithout software modification.

FDD TX/RX separation 190 MHzCharrier spacing 5MHz, possibility to fine tune in 200kHz stepsOutput power of Node B � 2 dB for normal conditions, �2.5 for extreme cond.PC step size for inner loop 0.5 dB / 1 dBMax. power of dedicated channelMin. power of dedicated channelMax. power of NodeBMin. power of NodeB

P_DedChannel_max = P_NodeB_max - 3 dBP_DedChannel_min = P_NodeB_max – 28 dBP_NodeB_maxP_NodeB_min = P_NodeB_max – 18 dB

CPICH power accuracy Within �2.1 dB compared to what is included in signalingmessage

Occupied bandwidth >99% of the transmitted spectrum are within 5MHzSpectrum emission mask Is given in [RadPerf]Adjacent channel emissions 5 MHz: ACLR > 45 dB

10 MHz: ACLR > 50 dBACLR = Adjacent channel leakage power ratio

Spurious emission Overall < -13 dBm1850-1910 MHz < -96 dBm at TX antenna connector1920-1980 MHz < -96 dBm at TX antenna connector921 – 960 MHz < -68 dBm to protect GSM 900 MS RX876 – 915 MHz < -98 dBm to protect GSM 900 BS RX1805 – 1880 MHz < -77 dBm to protect GSM 1800 MS RX1710 – 1785 MHz > -100 dBm to protect GSM 1800 BTS RXFor spurious emissions to adjacent channels of UMTS FDD see[RadPerf]

Sensitivities Guaranteed at antenna connector:–121.5 dBm with BER<0.001 / no RX diversity–124 dBm with BER<0.001 / with RX diversityTypical is 1 dB better.

C/I requirements for a 12.2 Kbit/schannel:

Co-channel: C=-91 dBm , I=-73dBm -> C/I=-18dBmAdj.-Channel: C=-115 dBm , I=-52dBm -> C/I=-63dBm



Radio feature PerformanceBlocking characteristics(interferer more than one channelapart)

1900-2000MHz:C=-115dBm, I=-40dBm -> C/I=-75dB (interferer is aWCDMA signal with one code)1-1900MHz and 2000-12750 MHz:C=-115dBm, I=-15dBm -> C/I=-100dB (interferer is a CWcarrier)

Receiver performance Total noise figure <4dB, typical <3dBANXU mandatory, MHA optional

Transmit diversity STTD is applied to PCCPCH, SCCPCH, DPCH, AICH, PICHTSTD is applied to SCH only.

Redundancy of TRX modules In case of failure of an TRX module, the calls are moved toanother TRX module of another sector, while maintaining thesame RX and TX antennas. Thus it looks like two sectorsbecame one.

Find more details in [RadPerf].

8.3.1.4 Iub interface to RNC

An E1 link is used to connect the MBS V1 to the RNC.Type Rate

[Mbps]Ports/module

Modules/Node B

Term.[ohm]

E1 2.048 4 1 75, 120

8.3.2 Evolium MBS V2

The Evolium Multi-standard Base Station Version 2 will be available for the release R1.3. UMTSmodules will be plugged into the EVOLIUM GSM BTS. That way , the former Evolium BTS becomesthe Evolium MBS V2, that is, GSM BTS and UMTS Node B capabilities within the same cabinet. Themain features of this product are listed below:

� Developed by Alcatel

� Multistandard (UMTS/GSM capable): 3 * 2 GSM + 3 * 1 UMTS in one rack, additional UMTSequipment in second rack

� Up to 12 TRXs per Node B

� Up to 6 sector per Node B

� Up to 3 TRXs per sector

� BB (Base Band processing) board capacity increased (64 AMR channels per board).

� IP addressing possible

� Not compatible with MBS V1(BB boards incompatible): Control /BB different and PA/ TRXdifferent.

In Annex C a complete feature list of the MBS V2 is provided.

8.3.3 RNC V1

The first version of the Evolium Radio Network controller will be only UMTS capable, and deliveredfor the first RAN release. The main features and listed below:

� Developed by Alcatel/ Fujitsu



� UMTS RNC in 2 cabinets

� Built around ATM switch.

� Hardware not optimized

� Traffic capacity: 500 Erlang + 6 MB/s data

In order to see the RNC V1 complete feature list see Annex D.

8.3.4 RNC Evolution

In the Roadmap shown in section 8.2, one can observe, that a RNC V2 is planned to be availablefor the RAN release 3GR2. The features of RNC V2 are still under development, and it is not yetmuch known about them. Anyway it will be a Multistandard RNC, that means, the same RNC will beused for GSM/GPRS and UMTS.

On the other hand, the UMTS RNC V1 can be upgraded in order to increase its capacity.

8.3.5 OMC

The definitive features that will belong to the V2 OMC, are not yet consolidated, that is why notmuch information is provided about this element.

8.3.5.1 OMC V1

� Developed by Alcatel-Fujitsu

� Delivered with release 3GR1

� UMTS compatible

� Made of 2 subsystems:

- Element Manager (EM) , on Fujitsu platform: carries out fault management andequipment management.

- RNO: Carries out QoS follow up and radio configuration management. It is the UMTSadaptation of the GSM application today delivered by Alcatel in GSM networks.

- PM_DB: Performance Measurements handling. This database relies on METRICAsoftware.



Radio NetworkConfiguration andQoS Monitoring

PM Database

UMTSOMC-R

Fault and EquipmentManagement

RNC NodeB

PM_DB

EM

RNO-U

Figure 74 OMC V1 structure

� Configurations:

An UMTS OMC-R configuration is always made of one RNO-U server , one PM-DB server andone or several EM servers

R N O -U P M -D B

E M E M

IP N e tw o rk

U s e r T e r m in a ls

L A N

Figure 75 Example of OMC-R configuration with 2 EM servers

� Dimensioning

UMTS OMC-Rconfiguration

Number ofEM servers

Maximum number of RNC/NodeB/cells/carriers

Large 1 EM 1 4 RNC/ 500 NodeB / 1500 cells / 1500 carriers







Table 51 Capacities of the UMTS OMC-R (V1) different configurations. Ref [OMCV1]

8.3.5.2 OMC V2

� GSM and UMTS capable

� Not yet developed, different scenarios are being considered:

- OMC directly connected to the RNC & Node B

Possible reuse of EM installed H/W being analyzed

- OMC connected to the EM

RNO / NPA

Centralized fault and equipment management

8.4 MIGRATION STRATEGIES RECOMMENDED BY ALCATEL

In this chapter will be distinguished between two kinds of operators:

- Incumbent operators, which are considered here, are those who already have a GSM (2G)license and now have got an UMTS license as well

- Greenfield operators or new entrants are operators, who only have a UMTS license.

However, both of them are going to face the fact that nowadays mobile (GSM) subscribers are usedto get nearly nationwide coverage and large roaming possibilities, and they are not going toabandon this to get multimedia services. Therefore, an interoperability between GSM/GPRS/E-GPRSand UMTS becomes obligatory.

The following application strategy is recommended for the different technologies.

EDGE shall be used for small/medium cities (preferably in suburban areas)

UTRA FDD & E-GPRS for big towns with suburban and dense urban areas

UTRA TDD & E-GPRS for microcell layer, indoor coverage

GSM/GPRS for preferably rural areas and voice in all environments

Alcatel proposes different strategies for incumbent and for new entrants, they are describedhereafter.

8.4.1 Migration strategy recommended for incumbent operators

These operators already own a GSM network, either supplied by Alcatel or by another vendor. Inthis section we are only going to consider that the existing GSM equipment has been supplied byAlcatel.

The migration process proposed for these operators involves three steps:



Step 1: Existing GSM network enhancement by introducing GPRS network wide

In this step packet-switched data services can be introduced network wide by the introduction ofGPRS. Exemplary cell ranges for GSM and GPRS are given in Table 52 and Table 53 for TU 50.Note that the given cell ranges are considered as being coverage driven and they are unlike inUMTS independent of the traffic.

However, the achievable throughputs in these cells depend on the Carrier to Interferer Ratio (C/I)and are therefore dependent on the operators bandwidth and traffic. Thus the given bit rates areonly valid under specific radio conditions according to [GPRSRNP].

900, No FH, TU 50

G3 step 1 BTS G4 BTS

C.S. CS1 CS2 CS3 CS4 CS1 CS2 CS3 CS4

Max. bit Rate (Kbit/s) 8 12 14.4 20 8 12 14.4 20

urban, flat 3.52 2.72 2.38 1.37 3.78 2.92 2.56 1.37urban, hilly 1.79 1.37 1.21 0.69 1.90 1.49 1.29 0.69suburban, flat 5.70 4.39 3.86 2.23 6.12 4.72 4.15 2.23suburban, hilly 3.24 2.48 2.18 1.25 3.46 2.67 2.34 1.25forest, flat 7.40 5.71 5.01 2.89 7.95 6.14 5.39 2.89forest, hilly 5.12 3.92 3.46 1.99 5.46 4.22 3.70 1.99open area, flat 19.72 15.21 13.36 7.71 21.19 16.36 14.38 7.71open area, hilly 13.64 10.46 9.22 5.29 14.57 11.24 9.86 5.29

Table 52 GPRS 900 cell ranges in [km] coverage driven (no interference considered) [GPRSRNP]

1800, No FH, TU 50

G3 step 1 BTS G4 BTS

C.S. CS1 CS2 CS3 CS4 CS1 CS2 CS3 CS4

Max. bit Rate (Kbit/s) 8 12 14.4 20 8 12 14.4 20

Urban, flat 2.11 1.63 1.43 n.a 2.11 1.63 1.43 n.aurban, hilly 1.06 0.82 0.72 n.a 1.06 0.82 0.72 n.asuburban, flat 3.43 2.64 2.32 n.a 3.43 2.64 2.32 n.asuburban, hilly 1.92 1.49 1.31 n.a 1.92 1.49 1.31 n.aforest, flat 4.45 3.43 3.02 n.a 4.45 3.43 3.02 n.aforest, hilly 3.06 2.36 2.07 n.a 3.06 2.36 2.07 n.aopen area, flat 11.87 9.15 8.04 n.a 11.87 9.15 8.04 n.aopen area, hilly 8.15 6.29 5.51 n.a 8.15 6.29 5.51 n.a

Table 53 GPRS 1800 cell ranges in [km] coverage driven (no interference considered) [GPRSRNP]

Step 2: Introduce E-GPRS in suburban and urban areas

In this step the GSM/GPRS spectral efficiency is enhanced and data services at higher bit rates canbe introduced especially in suburban and urban areas.

Exemplary cell ranges are given in table 9 for TU 50. The given bit rates are possible only underspecific radio conditions according to [GPRSRNP].

G4 step 2 BTS

MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9



Max. Bit rate(Kbit/s)

8.8 11.2 14.8 17.6 22.4 29.6 44.8 54.4 59.2

urban, flat 4.20 3.69 2.85 1.98 1.66 1.45 0.92 0.86 0.64urban, hilly 2.12 1.87 1.44 1.00 0.84 0.73 0.47 0.44 0.32suburban, flat 6.81 5.99 4.60 3.21 2.69 2.36 1.49 1.40 1.04suburban, hilly 3.82 3.37 2.60 1.82 1.52 1.33 0.84 0.79 0.59forest, flat 8.84 7.78 5.98 4.18 3.49 3.06 1.94 1.82 1.35forest, hilly 6.03 5.33 4.11 2.88 2.39 2.10 1.33 1.25 0.93open area, flat 23.57 20.74 15.94 11.13 9.30 8.16 5.17 4.85 3.60open area, hilly 16.08 14.21 10.95 7.67 6.37 5.59 3.54 3.32 2.47

Table 54: Typical cell ranges for E-GPRS 900, coverage driven (no interference considered)[GPRSRNP]

G4 step 2 BTS

MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9

Max. Bit Rate(kbit/s)

8.8 11.2 14.8 17.6 22.4 29.6 44.8 54.4 59.2

urban, flat 1.98 1.76 1.37 0.84 0.94 0.79 0.43 0.39 n.aurban, hilly 1.00 0.90 0.69 0.43 0.47 0.40 0.22 0.20 n.asuburban, flat 3.22 2.86 2.23 1.37 1.52 1.29 0.69 0.63 n.asuburban, hilly 1.81 1.62 1.25 0.77 0.86 0.73 0.39 0.35 n.aforest, flat 4.18 3.72 2.89 1.78 1.97 1.67 0.90 0.81 n.aforest, hilly 2.86 2.57 1.98 1.22 1.36 1.15 0.62 0.56 n.aopen area, flat 11.15 9.92 7.70 4.75 5.25 4.45 2.39 2.17 n.aopen area,hilly

7.61 6.84 5.27 3.25 3.61 3.07 1.65 1.50 n.a

Table 55: Typical cell ranges for E-GPRS 1800, coverage driven (no interference considered)[GPRSRNP]

Step 3: Introduce UMTS in urban and dense urban areas

To achieve high quality multimedia services, UMTS is the most convenient technology, as it provideshigh bit rates and large capacity at the same time.

As explained in section 8.2 UMTS will be developed at first as an overlay network, and then, whenthe multistandard base stations are available, GSM-UMTS BTS/Node B will be available in the samecabinet .

In order to save costs site sharing can be also accomplished, for more details about this issue pleaserefer to chapter 7 of this guideline.

E-GPRS and GPRS/GSM are good complements for the UMTS technology, mainly in the first yearsof UMTS operation, where UMTS will be only deployed in urban areas, while E-GPRS, andGPRS/GSM will provide overall coverage.

Figure 10 shows the typical coverage scenario for an incumbent operator. GSM/GPRS coverage isintroduced networkwide according to step 1. Then E-GPRS is introduced in suburban and urbanareas where data services are required. In cities where high bitrate services become necessary UMTSwill be applied according to step 3.



GSM/GPRS

UMTS

E-GPRS

Figure 76 Coverage scenario for incumbent operators.

In case of UMTS the achievable cell ranges are dependant on the cell loading. Exemplary cellranges and achievable bitrates are given in Table 56.

With increasing data traffic densification strategies like cell sectorisation, microcells carriers or cellsaddition must be carried out, similar as it is done for voice in the case of GSM. For moreinformation about this topic please refer to chapter 9 of this guideline.

8.4.2 Migration strategy recommended for greenfield operators

Greenfield operators which only have a 3G license will be interested in a rapid deployment of theirUMTS network, in order to get as many subscribers as possible. In this case it does not make senseto deploy E-GPRS first. The network deployment will take place in two steps:

Step 1: UMTS deployment in urban areas:

They will start deploying UMTS only in urban areas, where the demand for multimedia services ismuch higher. In order to be able to offer full coverage to their subscribers, they will probably needto use incumbent operators networks for the not yet covered zones. Therefore they can makeroaming agreements for E-GPRS or GPRS services with other operators, which do not have an UMTSlicense and which can benefit from the opportunity to offer multimedia services to their customers.

Step 2: Overall UMTS coverage

The initially deployed UMTS network will be extended to suburban and rural areas. Further networkdensification strategies as described in chapter 9 might become necessary in the dense urban areasto handle increasing traffic.

Exemplary (macro) cell ranges, the site area and the number of subscribers (UE) per carrier of theNode Bs are summarized below in Table 56.

Dense urban Urban Sub-urban Rural

Range Area Range Area Range Area Range Area

km Km²

UE per

carrierkm Km²

UE per

carrierKm Km²

UE per

carrierkm Km²

UE per

carrier

Lightlyloaded

0.43 0.37 334 0.64 0.80 334 1.89 6.95 248 5.08 50.24 130

Typicallyloaded

0.41 0.32 493 0.60 0.70 493 1.76 6.00 360 4.77 44.38 174

Fullyloaded

0.38 0.29 630 0.57 0.63 630 1.71 5.71 426 4.67 42.47 234

Table 56: Approximate cell ranges and UE density per carrier for UMTS [UMTSLB]



Figure 77 shows an approximated coverage scenario for Greenfield operators. Such operators will tryto deploy an UMTS network as fast as possible. This process will take much time and will be verycostly, therefore they will just start developing an UMTS network in the main urban areas, where theneed for high bit rate multimedia services is large. For the rest of the territory they will need roamingarrangements with operators that have a 2G network , either with incumbent operators or with GSMoperators that did not get a 3G license. These networks will be also opened to the presence ofMVNOs (Mobile Virtual Network Operators) in order to share license fees and even investment costswith other operators and start adding, as soon as possible, subscribers and traffic for their network .

GSM/GPRS

UMTS

E-GPRS

Figure 77 coverage scenario for Greenfield operators

8.5 Annex A

In this annex , features regarding transmission interfaces (Iub, Iu, Iur), physical and transportchannels, channel coding, radio resource management, traffic management, Tele-services, bearerservices and security are listed. Ref [FL0].TRANSMISSION interfaces Release CommentIub TransmissionIub open for equipment from other providers 2.0Iub star 1.1Iub cascade (VP cross connection by Node B) 2.0 For V1 and V2 Node BIub cascade (AAL2 switching by Node B) NPIub redundancy (duplicated VP on duplicated physical interface) 2.0GSM in AAL1 circuit emulation 1.2Iu TransmissionIu open 1.2Iu CS SS7 1.1Iu PS SS7 1.1Iu PS SCTP/IP NPIu CS up to 64 kbps bearer 1.1Iu PS up to 384 kbps bearer 1.1Iu CS and Iu PS multiplexed on the same physical interface 1.1Iu CS and Iu PS multiplexed on different physical interfaces 1.2O&M flow multiplexed with Iu on the same physical interface NPIur TransmissionIur open 1.2Iur SS7 1.1Iur SCTP/IP NPUp to 16 Iur interfaces towards 16 RNC 1.1Iur and Iu multiplexed on the same physical interface 1.1Iur and Iu multiplexed on different physical interfaces NPPHYSICAL CHANNELS NP



First set 1.1 PCPICH / PCCPCH /SCCPCH / PRACH /DPDCH / DPCCH / SCH/PICH

Second set 2.0Transport ChannelsDCH 1.1DCH(DRAC) NPFAUSCH NPBCH 1.1RACH 1.1FACH 1.1PCH 1.1CPCH 2.0DSCH 2.0One radio access bearer per CCTrCH 1.1Multiple radio access bearers on one CCTrCH 1.1Multicode 1.1CHANNEL CODING32 Kbps Convolutional DCH/DCH 1.164 Kbps Turbo DCH/DCH 1.1128 Kbps Turbo DCH/DCH 1.1144 Kbps Turbo DCH/DCH 2.0384 Kbps Turbo DCH/DCH 1.1Error indication mechanisms from L1 1.1Change of transport channel due to QoS 2.0CRC attachment 1.1Radio interface acc. To 3GPP TS25.212) 1.1Compressed modePuncturing NPReduction of SF by 2 1.2Higher layer scheduling NPDownlink Primary and Secondary scrambling code 1.1Uplink Scrambling codesLong scrambling 1.1Short scrambling 2.0RADIO RESOURCE MANAGEMENTQueuing 2.0Classmark handling (FDD only, FDD+TDD, GSM+UMTS…) 1.2 Associated with

UMTS/GSM HOPower ControlOpen Loop Power Control 1.1Closed Loop Power Control 1.1Downlink Closed Loop Power Control 1.1Slow Downlink Closed Loop Power Control 1.1Downlink Closed Loop Power Control in compressed mode 1.1Downlink Power balancing 1.1Uplink Closed Loop Power Control 1.1Code-tree de-fragmentation 2.0Priority 2.0Adaptive Multirate Codec (AMR) 1.1Transmit Diversity scheme 1.1TRAFFIC MANAGEMENT



Support of microcellular and hierarchical cell structure 2.0Multiband solutions NPIntelligent traffic management NPLocation Service NPBEARER SERVICESAMR 1.1 Variable up to 12.2Conversational 1.1 64/64Streaming 1.2 14.4/14.4, 28.8/28.8,

57.6/57.6, 0/64, 64/0Interactive 1.2 64/128, 64/384, 384/384Background 1.1 64/128, 64/384, 384/384Multi RAB 1.1AMR + Interactive or Background 1.1Conversational + Interactive or Background 1.1TELESERVICESEmergency call 1.1Short Message ServiceSMS MT/PP 1.1SMS MO/PP 1.1SMS CB 2.0SECURITYAuthentication 1.1Encryption 1.1

8.6 Annex B

In this annex , the features of the Multistandard Base Station first version (MBS V1) are listed. Ref[FL0].

Features of MBS V1 Release Comments Multicarrier TPA with 20 W TX power 1.1 Support of improved HW 2.1 RX noise figure < 4 dB 1.1 RX sensitivity of -121 dBm (for 12.2 kbps channel, BER < 0.001) 1.1 Support of up to 6 TPA per Node B 1.1 Support of up to 6 TRX per Node B 1.1 Support of up to 9 TRX per Node B 2.1 Only reasonable together

with V2 BB board andchange of BB / COM

Support of up to 2 TRX per sector 1.1 Support of up to 3 TRX per sector 2.1 See 70 11 40 Support of up 6 sectors per Node B 1.1 Multi Standard UMTS/GSM configuration NP Evolium MEDI indoor cabinet for indoor configurations 1.1 Evolium MEDI outdoor cabinet for outdoor configurations 1.1 RX diversity 1.1 TX diversity 1.1 BB part redundancy 1.1 Load sharing PA part redundancy 1.1 Using TX diversity TRX part redundancy NP COM part redundancy 1.1 Plug & play - HW ready 1.1



Features of MBS V1 Release Comments Plug & play – SW NP Support of BB modules V1 1.1 16 AMR channels Support of upgraded BB modules V1 2.1 64 AMR channels +

DSCH E1 physical interface (3) 1.1 E3 physical interface (2) 1.2 STM1 physical interface (optical) 1.2 STM1 physical interface (electrical) NP VC4/STM1 1.2 VC3/STM1 NP Only if Orange AAL1 circuit emulation (2 possible circuit E1 as input) 1.2

8.7 Annex C

In this annex , the features of the Multistandard Base Station second version (MBS V2) are listed. Ref[FL0].

Features of MBS V2 Release Comments Multicarrier TPA with 30 W TX power 1.3 Maximum possible

output power percabinet?

RX noise figure < 4 dB 1.3 RX sensitivity of -121 dBm (for 12.2 kbps channel, BER <0.011)

1.3

Support of up to 6 TPA per Cabinet 1.3 Support of up to 12 TRX per Node B 1.3 Support of up to 3 TRX per sector 1.3 Support of up 6 sectors per Node B 1.3 Multi Standard UMTS/GSM configuration 1.3 Evolium MEDI indoor cabinet for indoor configurations 1.3 Evolium MEDI outdoor cabinet for outdoor configurations 1.3 Multi Rack configuration 1.3 RX diversity 1.3 TX diversity 1.3 BB part redundancy 1.3 RF part redundancy 1.3 Using TX diversity TRX part redundancy 1.3 Plug & play - HW ready 1.3 Plug & play – SW 2.0 Support of BB modules V2 1.3 64 AMR channels +

DSCH E1 physical interface 1.3 IMA nXE1 1.3 E3 physical interface 1.3 STM1 physical interface (optical) 1.3 STM1 physical interface (electrical) 1.3 Ethernet 101/10 BaseT physical interface for traffic 1.3 Only in IP option of

R'00 VC4/STM1 1.3 VC3/STM1 NP Only if Orange AAL1 circuit emulation 1.3



8.8 Annex D

In this annex , the features of the Radio Network Controller first version (RNC V1) are listed. Ref[FL0].

Features of RNC V1 Release Comments 500 Erlangs + 6 Mbps 1.1 1000 Erlangs + 12 Mbps 1.1 2000 Erlangs + 24 Mbps 2.0 3000 Erlangs + 36 Mbps 2.0 SPU module increased capacity NP DHT module increased capacity NP Support of 96 Node B 1.1 Support of 256 Node B 1.2 Support of 512 Node B NP Clock extraction from STM1 1.1 Stratum 3 clock accuracy level 1.1 Clock extraction from E1 NP Clock extraction from 2Mhz reference NP Defense mechanism for Control Unit 2.0 COM 2N, MMUX 6+1 APS mechanism - STM1 redundancy in transmissionnetwork

1.2 APS 1+1

Plug & play - HW ready 1.1 Plug & Play – SW NP E1 physical interface – Iub 1.2 E3 physical interface – Iub 1.2 Only if Orange VC4/STM1 Iub interface 1.2 VC3/STM1 Iub interface NP Only if Orange VC4/STM1 optical interface Iub, Iu and Iur 1.1 VC4/STM1 electrical interface Iub, Iu and Iur 2.0 ATM Mux/Demux of O&M VC from/to Node B 1.1



9 DENSIFICATION STRA TEGIES

References

[WFU] WCDMA for UMTS. Radio Access for third Generation Mobile Communications. H.Holma, A. Toskala. Ed. J.Wiley & Sons. Edition 2000.

[ASMC] Activation Strategy for Microcellular NetworksDoc. Ref:3DF 00 995 0000 UFZZA. Nov.98

[CapImp] Alcatel Offer to CG SAT. Capacity Improvement. Doc. Ref.: MAR 80595. Nov.98

9.1 Introduction

A satisfactory UMTS network performance can turn by time into a non-satisfactory one, if after theinitial network deployment, the traffic increases considerably.

In this chapter, a description of the different strategies that improve network’s architectureperformance is carried out. It mainly focuses on the downlink capacity due to the following reasons:

- In UMTS, the downlink capacity is assumed to be more important that the uplink capacitybecause of asymmetric downloading type of traffic.

Empty cells are rather uplink limited (i.e. MS are running out of power in case of large cell ranges),but when the traffic increases, the cell sizes are shrinking and the downlink becomes limitingbecause the Node B needs an extraordinary amount of power to serve all mobiles (i.e. the Node Bsare power limited).

- Figure 78 shows this effect quantitative for a macrocell. The maximum pathloss decreases as thecell load and the traffic increases.

145

147

149

151

153

155

157

159

161

163

165

100

200

300

400

500

600

700

800

900

1000

Cell Load [Kbps]

Max

imum

pat

h lo

ss [d

B]

downlinkuplink

Coverage isuplinklimited

Capacity isdownlinklimited

Figure 78: Example of coverage vs. capacity relation in downlink and uplink in macrocells



- The downlink air interface capacity is smaller than the uplink one: receiver techniques, likereceiver antenna diversity and multi-user detection, can be used in the base station but not in themobile station.

The WCDMA capacity is limited by interference. If the interference level increases, the capacitydecreases. The main causes of downlink capacity decrease are:

- Traffic increase: After some time of successfully system performance, the number of UMTSsubscribers increases so that the up to date capacity resources are not able to satisfy such a highdemand.

- Orthogonality of channelization codes : Due to the multipath channel behavior, theorthogonality between channelization codes is partially lost and the intra-cell user interfere witheach other causing intra-cell interference and reducing the downlink capacity.

- Number of channelization codes: The number of channelization codes available is limited withina scrambling code. If the Spreading Factor is SF, the maximum number of channelization codesis SF. This code limitation can affect the downlink capacity if the propagation environment isfavorable, and the network planning and hardware support such a high capacity, that allchannelization codes available must be utilized. That is, normally you will run out of DL powerbefore you run out of channelization codes.

If the downlink interference increases due to traffic increase or to any of the causes that have beenalready mentioned, it will result in downlink power shortage. The power will not be enough to serveall users. Therefore certain active users, depending on the admission control algorithm, will bedropped (for example the mobile demanding the largest power share). In other words, the cellsurface will shrink due to cell breathing phenomenon and some “holes” will appear in the network,where not only coverage but also high capacity is needed. The process mentioned before isillustrated in Figure 79.

AA

DD

BB

CC

Initial status

Trafficincrease

AA BB

DDCC

Consequences of trafficincrease: cell breathing�� Insufficient coverage

Figure 79 Coverage reduction due to traffic increase in a UMTS network

9.2 Densification strategies

When the demand for UMTS services increases, the capacity of the networks will have to be adaptedto the new market requirements.



There are some different methods to alleviate the capacity loss of a network, some of them are morecostly than others, and therefore a certain hierarchy is established in order to apply the “easy” onesfirst and the costly ones as a last resort, in order to save unnecessary costs. Such methods are listedhereafter:

If the maximum capacity is limited by the amount of interference in the air interface, ‘soft ‘ capacityimprovement strategies can be applied, these are listed hereafter:

� Traffic management: this includes network fine tuning (e.g. BSS parameters) and GSM/UMTStraffic management. For example, in case the GSM cells are unloaded, while UMTS is overloaded,it can be an option to transfer the UMTS voice traffic to the GSM layer by according BSSparameter settings.

� Transmit diversity (see chapter 2 of these guidelines for more information about this topic)

� Lower bit rate codec (see chapter 2 of these guidelines for more information about this topic)

If the previous mentioned solutions are insufficient more effective densification strategies must beapplied. Whereas the last one is the most costly one but also the most effective one.

- Adding carriers

- Sectorization

- Adding cells

- Micro-cells

A description of each one of these densification strategies is provided in the next sections.

9.2.1 Adding carriers

If the operator’s frequency allocation allows, the operator can take another carrier into use. W-CDMA supports efficient inter-frequency handovers (see Chapter 2 of these guidelines for more info)and several carriers can be utilized to balance the loading and to enhance the capacity per site.

Advantages

It is a very cost efficient method, if the new carrier is available.

It is possible to share one power amplifier between several carriers. This provides a more efficientuse of the power amplifier, since the loading can be divided between two carriers and the totalrequired transmission power per user is reduced, increasing the capacity.

Disadvantages

The license for a further carrier must be available.

9.2.2 Sectorization

Sectorization consists on dividing cells into two (formerly used for specific coverage scenarios), three(for densification), or even six (has been used in IS-95 CDMA) sub-cells or sectors.

The former omni-directional antenna is substituted by a double- or triple- or six- panel antennasystem; and the original base station equipment is extended to a two-, three- or six-sectorconfiguration. This is shown in the Figure 80. Due to the sectorization, the traffic per cell (one thirdof the old omni cell) decreases and therefore the cells sizes increase again.



Omni site

Node B

Tri-sector site

Sector 1

Sector 2

Sector 3

Node B 1

Node B 2

Node B 3

Figure 80 Principle of cell sectorization

Advantages

1. Sectorized sites simultaneously offer advantages in terms of coverage and in terms of capacity:Firstly, the radio coverage provided by panel antennas is much easier to tune and to adapt toterrain and building contours; secondly, sectored sites are less sensitive to interference fromother sites.

In an ideal case N sectors would give N times more capacity, but in practice the sectorizationefficiency is typically about 90%. This means that upgrading the site from an omni-site to athree-sector site gives a capacity increase of about 2.7, and to a six-sector site a capacityincrease of about 5.4 [WFU]. The increased number of sectors also brings improved coveragethrough a higher antenna gain.

2. Site sectorization process is also attractive in terms of operational costs, since more capacity canbe added without any need for finding and renting new sites.

Disadvantages

If the number of sectors is increased, the antennas must be replaced and therefore the radionetwork design changes. As the number of antennas increases, there might be problems due tovisual impact and civil works.

9.2.3 Adding cells

Adding cells or cell splitting pertains to the same class of network optimization processes than cellsectorization and is considered the next step in densification.

If the UMTS traffic density grows significantly, the cells surfaces will shrink due to the breathing cellphenomenon in order to be able to provide the active subscribers with the adequate quality ofservice. This will cause the appearance of “coverage holes” in high traffic density areas, due to thefact that the Node B downlink power is not enough to serve all the mobiles. Therefore new Node Bswill be introduced where more capacity is needed.

Advantages

The site density is increased, hence enhancing the offered capacity, supposing that each splitted oradded cell is provided with the same number of channels as each original cell.

Drawbacks

1. Cell splitting can be exploited up to the point in which Node Bs become so close to each otherthat the overall network performance starts worsening:



- The soft handover areas are so large that the higher handover activity would negatively affectthe network capacity (smallest site distances tbd).

- The amount of inter cell interference would also significantly increase, and this would also causea capacity diminution, due to the increasing signaling load.

Hence, beyond a certain limit, it is recommended to implement other spatial densification strategies,such as microcellular solutions.

2. New sites have to be acquired.

3. Even if only a few cells have been split it is necessary a new code allocation?

9.2.4 Microcells

In a UMTS Terrestrial Radio Access Network, a combination of macrocells and microcells in a lowerlayer can be used in order to solve situations where the macrocell capacity is insufficient. Thesesituations, in which microcells may be required, are the following:

- To provide coverage and a higher capacity in hot spots like a shopping mall, a stadium or abusiness area.

- To provide indoor coverage and capacity.

Advantages

With microcells, different traffic capacity gains can be achieved, depending on the availablechannels and the street layout of the considered traffic area.

The amount of intercell interference is lower and the orthogonality of the downlink codes higher inthe microcells where there is less multipath propagation than in macrocells. On the other hand, lessmultipath propagation gives less multipath diversity and therefore we assume there is a higher Eb/N0

requirement in microcells than in macrocells. In the Table 57 below exemplary simulation results ofdata throughputs in micro and macrocellular environments are shown.

Assumptions in the throughputs calculations

Macrocell Microcell

Downlink orthogonality 0.6 0.95

Other cell interference factor 0.65 0.2

UL Eb/No 1.5 dB 1.5 dB

UL loading 60% 60 %

DL Eb/No 5.5 dB 8.0 dB

DL loading 80% 80%

Data throughput in macro and microcell environments per sector per carrier

Macrocell Microcell

Uplink 1040 kbps 1430 kbps

Downlink 660 kbps 1440 kbps

Table 57 Comparison between microcell and macrocell environments [WFU]

The simulation results of Table 57 show that in macrocells the uplink throughput is much higherthan the downlink one, while in microcells the downlink and uplink capacities are quite balanced.



The downlink capacity depends more on the propagation and multipath environment that does theuplink one. The reason is the application of the orthogonal codes.

Drawbacks

In opposite to the conventional macrocells, microcells are characterized by an antenna installationbelow the rooftop level. Due to the fact that this reduces the minimum distance to the mobiles, therisk of interference is increased, as the Minimum Coupling Loss (MCL) becomes more critical.

The worst case would be a mobile, served by a macrocell and transmitting at its maximum power(24 dBm), getting near a full loaded micro Node B with receiving maximum sensitivity. In thisscenario, if the distance between the mobile and the micro Node B considerably decreases this mayresult in the blocking of the micro Node B. This scenario is shown in Figure 81.

Macro-CellMicro-Cell

Interference

Figure 81 Microcells scenario , interference between the macro and microcell layer

9.2.4.1 Microcells and macrocells on the same channel

If this option is chosen, one must take into account the side effects of this method. First, theoverlapping of the coverage zones of the macro and the microcell if both work within the samecarrier will bring pilot pollution17 and therefore interference rises, if a handover between both cellscan not be performed. Hence , the macrocell capacity is reduced, and the addition of the microcelldoes not represent a linear capacity raise .

It would be also possible to make a handover to the microcell every time that the macro cell is pilotpolluted, but such a measure would only bring a rise in the handover percentage, that causes acapacity reduction as well.

9.2.4.2 Microcells and macrocells on different channels

In this case, there are various possibilities to consider, they are summarized hereafter:

Option Nr. Macrocell Layer Microcell layer

1 FDD FDD

2 FDD TDD

Table 58: Possible hierarchical cells layers configuration

Note: TDD is not available in 3GR1.x.

Although in both cases adjacent channel interference problems would appear (see Chapter 10“Multioperator Environment” for more information) the option 2 is the recommended one by Alcatel

17 If in the macro cell the received Ec/Io coming from the micro cell is higher than a certain

threshold, the micro cell will be considered as a pilot polluter



(see Chapter 8 “Migration Strategies” for more information). Apart from these issues, there aresome other subjects that one must observe when deploying either option 1 or 2



10 MULTI OPERATOR ENVIRONMENT

References:

[SitSha] Site Sharing GSM-UMTS. RF aspectsRef: 3DC 21019 0005 TQZZA, Ed. 02

[25.492] RF system scenarios TR 25.942 V.2.1.3 (2000-03).3GPP 3G TSG RAN R99

[SysPerf] UTRAN Radio Performance Requirement, 3BK112400014DSZZA

10.1 Introduction

Adjacent channel interference will affect all wide band systems where guard bands are not possible.We can distinguish between four kinds of ACI sources:

- Multi-operator coexistence FDD-FDD (treated in the present document)

- Multi-mode coexistence TDD-FDD (not content of this guideline)

- UMTS-GSM (see chapter 7 of these guidelines) coexistence

- Multi-operator coexistence TDD-TDD (not content of this guideline)

In the present document, the Adjacent Channel Interference (ACI) phenomenon caused from Multi-operator coexistence FDD-FDD will be treated. Their causes and effects on the network performancewill be pointed out, as well as possible solutions and their impact on the network planning strategyto be carried out.

10.2 Adjacent channel inter ference in case of UMTS FDD-FDD co-existence

The adjacent channel interference is caused by transmitting non-ideal and imperfect receiverfiltering. In UL and DL the adjacent channel performance is limited by the performance of themobile. In the UL the main source of ACI is the non-linear power amplifier in the UE, whichintroduces adjacent channel leakage power. In the DL the limiting factor for ACI is the receiverselectivity of the WCDMA terminal.

The co-existence between two operators using adjacent bands has been taken into account in thescenarios of simulations used for specifying the equipment (node B and UE) radio requirements inthe 3GPP/WG4 [25.492]. These simulations are referring to co-existence scenarios where theadjacent band operators are not necessarily sharing the same sites but merely operating in the sameregion.

Adjacent Channel Leakage power Ratio (ACLR) is the ratio of the transmitted power to the powermeasured in an adjacent channel. According to [SysPerf], the ACLR shall be higher than the valuespecified in Table 59 for uplink and downlink.

Adjacent channel relative to UEchannel frequency separation

ACLR limit

5 MHz 45 dB10 MHz 50 dB

Table 59Requirements for adjacent channel performance [SysPerf]



NOTE: Requirement on the UE is planned to be reconsidered when the state of the art technologyprogresses.

10.2.1 Capacity Loss due to adjacent operators’ co-existence

10.2.1.1 Uplink case

The uplink case denotes the interference coming from UTRA FDD mobiles of an operator A to theUTRA FDD Node B of an operator B as shown in figure 1.

In the uplink, the adjacent channel interference causes noise rise, meaning an increase of thewideband interference level over the thermal noise in the Node B reception of operator B. The effectof the adjacent channel interference can be seen as a reduced uplink capacity.

Some Monte Carlo system simulations have been performed to quantify the capacity loss due to thepresence of an operator in the adjacent band in different co-existence scenarios. For detaileddescription of the simulated scenarios please refer to [25.942].

Mobile OperatorA: hightransmission Power

Macro celloperator A

Macro celloperator B

SignalInterference

Figure 82 Macrocell to Macrocell uplink adjacent channel interference scenario

Table 60 shows exemplary the uplink capacity losses for the FDD macro/ FDD macro case, whichcan reach up to 13% in some scenarios.

The Adjacent Channel Interference Power Ratio (ACIR) given in Table 60 is defined as the ratio ofthe total power transmitted from a source (Node B OR UE) to the total interference power affecting avictim receiver. The occurring interference corresponds to an approximate cell load as given in Table60. Two different scenarios have been investigated:

- Intermediate case, where the second system Node Bs are located at a half-cell radius shiftrespect to the first system ones

- Worst Case, where the second system Node Bs are located at the cell border of the first system



Intermediate case Worst caseACIR[dB]

Min Max Average Min Max Average

25 9.31% 8.18% 8.85% 13.00% 11.55% 12.25%

30 3.15% 2.60% 2.91% 4.58% 3.80% 4.19%

35 1.11% 0.93% 1.02% 1.43% 1.10% 1.34%

40 0.47% 0.30% 0.35% 0.50% 0.30% 0.43%

Table 60: Uplink capacity loss in % for the FDD macro/ FDD macro case.

10.2.1.2 Downlink case

The downlink case denotes the interference from UTRA FDD Node B of an operator B to a UTRAFDD UE belonging to an operator A.

Operator A’s mobile is receiving adjacent channel interference in the downlink from operator B’sNode B, this will bring the need to increase the downlink power of operator B allocated to thatconnection in order to compensate the increased interference in the UE reception. This powerincrease will allow that mobile to interfere with all other connections of this cell, that is why it ispreferable to drop that connection in downlink before the mobile gets extremely close to theoperator B’s Node B and causes additionally interference in the uplink connections of operator B(Figure 83).

Mobile OperatorA

Macro celloperator A

Macro celloperator B

Mobile OperatorB

Signal Interference

Figure 83 Macro to macro downlink adjacent channel interference scenario

Table 61 shows exemplary the downlink capacity losses for the FDD macro/ FDD macro case, whichcan be up to 15% in some scenarios. The same definitions as for Table 2 are valid. The occurringinterference corresponds to an approximate cell load as given in Table 61.

ACIR [dB] Intermediate case Worst case

Min Max Average Min Max Average

25 13.46% 6.50% 10.88% 15.30% 9.00% 13.28%

30 5.84% 2.60% 4.70% 7.16% 4.50% 6.16%

35 2.27% 1.00% 1.79% 2.80% 1.80% 2.32%

40 0.91% 0.10% 0.59% 1.29% 0.82% 0.99%

Table 61: Downlink capacity loss in % for the FDD macro/ FDD macro case.



10.2.1.3 How can it be avoided?

In order to avoid a decrease of the system performance, some strategies can be carried out whenplanning the network:

Large minimum coupling loss: It is recommended to maintain a coupling loss between Node B andUE antennas as high as possible by choosing appropriate Node B antenna locations, antennapatterns etc.

Node B co-location: Different operators should try to co-locate their Node Bs. Therefore, there willnot be large power differences at the both operators’ Node Bs and the adjacent channel attenuationwill be enough to fulfil the ACLR requirements (see Table 59) causing no adjacent channelinterference problems.

Adjustment of carrier spacing: Frequency coordination between the operators should be done whereever possible. The nominal WCDMA carrier spacing is 5 MHz, but can be adjusted within a 200 kHzraster according to the requirements of the adjacent channel interference.

Inter-frequency HO: Refer chapter 2 of this guideline.Desensitization: Reduces the sensitivity of the Node B receiver, i.e. increases the noise figure of the Node

B RF parts, making the Node B receiver less sensitive. This would also bring a considerable cellrange reduction; therefore this method is only recommended for small cells without UL coverageproblems.

10.2.2 Dead zones

The ‘dead zone’ area has been defined in RAN4 as the area close to a Node B, where UEsoperating in a neighboring frequency f1 receive and provoke a high level of downlink and uplinkinterference as described in the previous two sections. This may result in a loss of communication.

Note that dead zone areas exist in pure macrocell scenarios as well as in macro/micro scenarios,however the latter are usually more critical since the UE can get much closer to a microcell antenna,causing a small coupling loss between UE and Node B.

Serving cell (Operator A)

Interfering cell (Operator B)

Dead zone area

f1

f2

Figure 84 Dead Zone schematic representation

Therefore, if we can avoid large power differences of own mobiles and other mobiles at the NodeBs, we get enough adjacent channel attenuation and therefore reduce the ACI problems. This canbe done by avoiding scenarios where a mobile is far away from its serving cell (belonging to



operator A) but very close to a node B of operator B which then leads to minimizing thephenomenon of dead zones.

The solution consists therefore in a co-location of node B’s of two operators. This means that sitesharing has a positive impact of the performance of both operators’ systems if the RF requirementsof the previous chapters are fulfilled. Please refer to chapter 7 of this guideline.



11 MEASUREMENTS

[GenTest] Generic Test Plan for UMTS Field Trial

[SiteShare] Site Sharing GSM-UMTS: RF Aspects, chapter 2.3Ref. Nr.: 3DC210190005TQZZA

[BouyguesCoLoc] [Bouygues Co-Location Tests]

[Calibration Guide Line] [3DF009934000PGZZA]

This chapter is currently designed to give an idea what kind of test cases can be interesting to focuson.

Some of the interesting test cases are shown in this chapter more detailed and in section 11.8 a listof all test cases are available.

11.1 Measurements for Prediction Model Calibration

In the network planning of cellular networks usually macrocell prediction models are used for cellplanning. These models are based on empirical propagation formulas in combination with acorrection factor used to model the influence of the morpho structure.

These correction factors need to be adapted to the required region by a process of propagationmodel calibration . Basic input for this calibration are analogue field strength measurements. Thismeasurement type is described in the calibration guide line [3DF009934000PGZZA]. An analoguetest transmitter providing a simple CW signal will be installed in a region which represents thetypical morpho structure there. While driving around this station the received field strength will bemonitored and mapped to the position. Based on the calculated path loss the propagation modelwill be adapted to the measured values.

In terms of pathloss calculation the same procedure is required for UMTS networks to adapt theused prediction model to the morpho structure. Compared to a GSM network additional effects haveto be considered later on in a UMTS network planning process. The most important ones in case ofwave propagation are as follows:

- The signal used is a wide band signal.

- The wide band receiver is using multipath reception.

- The frequency band is higher than for GSM

In case of additional gain the following facts have to be considered:

- The number of used received paths are depending on UE HO status (number of cells in activeset) due to limited number of receiver fingers.

- The cell load is affecting the cell coverage by creation of interference (cell breathing).

- Fast PC may compensate the influence of fading.

- Additional gain may expected if the UE is in soft HO state.

All these facts are effecting an additional gain to the received signal strength and has to beconsidered in addition to the standard wave propagation.



Therefor this chapter will give you some ideas about the required measurements to investigate theseeffects.

11.2 Measurements of Cell Coverage

The following tests are based on [GenTest]. As mentioned above the cell coverage is depending oncell load plus interference and takes advantage of additional effects of UMTS technology like HOgain or PC gain. Thereby we have to distinguish between UL and DL direction. The followingchapters will describe how to measure these gains.

11.2.1 Coverage of Pilot Channel in DL Compared to GSM BCCH Channel

This type of measurement is used to investigate the gain of the Rake receiver using multipathreception compared to standard GSM receivers. The measured channel is the CPICH for UMTS,which is transmitted by the Node B with full power and a BCCH for GSM. We investigate the effectof the pathloss and the multipath profile in different environments.

The measured entities are RSCP on CPICH with BLER / BER for WCDMA and RXLEV on BCCH withRXQUAL for GSM. The measurement should be done in the same environment for the Node B andthe BTS. Best case would be a co-located installation. In that case driving the same route would bepossible.

A call will be established and the measurement starts at the Node B and is going faraway to the cellborder. A call drop marks the end of the coverage area. Both measurements can be compared in amap to find the coverage range or putting the quality values in a graph along the distance MS - BS.

Due to the fact that the UL in WCDMA networks will be more critical than the DL (cell breathingdepending on traffic load) the measurement should be repeated in a high traffic situation withsimulated load. This can be done by feeding in noise into the Node B receiver using an AWGNgenerator. An earlier call drop due to bad quality in UL will be expected.

11.2.2 Impact of Service Type on Coverage

The received signal quality of the UE depends on their receiver sensitivity which is defined: Receiver

sensitivity = Thermal noise density + NF+ PG + Mi + 0NEb

With:

� Thermal noise density = -174 dBm

� NF: Noise figure, characteristic of the equipment

� PG = Processing gain jc RR /�

� Rc= chip rate (system), Rj = Bit rate depending on used service j

� Mi = Interference margin depending on interference coming from intra-cell and inter-cellinterference

� 0NEb = Required energy per user bit ( bE ) over noise ( 0N )



Due to the fact that the processing gain depends on the data rate, the required reception power andeven the required SIR will be different for each service bearer. Thus achievable coverage is different.A comparison with planning data will be performed for each service supported by the UMTSnetwork. From the measurements default margins can be extracted for the use in RNP.

The measured entities are Ec/Io, RSCP on DPDCH and BLER, BER of the DL transport channel.

A service will be established and the measurement starts at the BTS and is going faraway to the cellborder. The end of the coverage area is marked by a service drop. This procedure is repeated foreach service type.

Note: The formula given above for the receiver sensitivity is valid for a mono service case.

11.2.3 Investigation on HO Gain

11.2.3.1 Soft Handover Gain

Soft handover occurs when the UE is in communication with 2 Node Bs located at different sites. Thegain achieved by the soft handover is a gain in terms of achieved quality and in term of requiredpower. The quality is evaluated by the BLER or the BER according to the type of service, which isconsidered. Since the achievable BLER or BER depend also on the decoding function, the handovergain in terms of quality is related to the SIR gain. Since the handover is expected to improve thereception with a higher diversity, the combining gain reduces the required power. To test this gain,closed loop and open loop TPC (Transmit Power Control) should be enabled.

To test soft handover performance, two tests are performed. In the first test case, only one Node B isswitched on. In the second test case, both Node Bs are switched on. The UE is slowly moved over thearea. Set up one UE and all the Node Bs. Position the UE where it can receive the greatest numberof pilot channels, CPICH. This is equivalent to the location, where the number of radio links in theactive set is maximal and will determine the number of cells in soft handover in the overlap area.Then, the UE is slowly moved until radio links are deleted.

The following measurements are performed:

Node B

� We can compare the SIR versus BLER (or BER) with handover and the SIR versus BLER (or BER)without handover. Measurements on the radio links are available in the NBAP message,DEDICATED_MEASUREMENT_REPORTING. Following measurements can be performed in FDDmode: SIR value, SIR error value, transmitted code power value.

� Handover gain

= (UL SIR on RL1 before addition of RL2) – (UL SIR on RL1 after addition of RL)

or

= (DL transmitted code power value on RL1 before addition of RL2) – (DL transmitted code powervalue on RL1 after addition of RL2)

� Measurements: RSSI on the UTRA carrier, SIR/SIR_error on each RL, BLER (BLER is calculatedfrom number of CRC error counted at Node-B), BER, transmitted code power value on RL1,transmitted code power value on RL2 and transmit power at Node-B

RNC

� On the uplink and in the case of soft handover and not softer handover, we can compare theBLER and BER at each Node B and the BLER and BER after combining at the RNC.



� Measurements: BLER and BER at RNC

UE

� On the downlink, the gain consists in the reduction of emitted power on a former radio link afterthe addition of a new radio link.

� Handover gain = UE-received code strength on RL1 with handover – UE-received code strengthon RL1 without handover = Node B-transmitted code strength on RL1 with handover – Node B-transmitted code strength on RL1 without handover

� Measurements: BLER, BER, UE-transmitted power, UE-received power

11.2.3.2 Softer Handover Gain

Softer handover gain will be measured using a similar method to that used for soft handover. Twosectors of the same Node B with the biggest coverage overlap will be chosen. Softer handoveroccurs when the UE is in communication with 2 sectors of one Node B.

Like in the soft handover case, the gain achieved by the softer handover is a gain in term ofachieved quality and in term of required power.

To test softer handover performance, two tests are performed. In both test cases, only one Node B isturned on. In the first test case, only one sector is turned on. In the second test case, all the sectorsare turned on. The UE is slowly moved over the area. Position the UE where it can receive thebiggest number of pilot channels, CPICH. This is equivalent to the location, where the number ofradio links in the active set is maximal and will determine the number of sectors in softer handoverin the overlap area. Then, the UE is moved until one RL is dropped out of the active set.

Following measurements are performed:

Node-B side

� We can compare the SIR versus BLER (or BER) in softer handover and the SIR versus BLER (orBER) with only one RL. Measurements on the radio links are available in the NBAP message,DEDICATED_MEASUREMENT_REPORTING. Following measurements can be performed in FDDmode: SIR value, SIR error value, transmitted code power value.

� Handover gain= (UL SIR on RL1 before addition of RL2) – (UL SIR on RL1 after addition of RL)or= (DL transmitted code power value on RL1 before addition of RL2) – (DL transmitted codepower value on RL1 after addition of RL2)

� Measurements: RSSI on the UTRA carrier, SIR/SIR_error on each RL, BLER (BLER is calculatedfrom number of CRC error counted at Node-B), BER, transmitted code power value on RL1,transmitted code power value on RL2 and transmit power at Node-B

RNC side

No measurement is performed. There is no softer handover gain at RNC side.

UE side

� On the downlink, the gain consists of the reduction of emitted power on a former radio link afterthe addition of a new radio link

� Handover gain = (UE-received code strength on RL1 with handover) – (UE-received codestrength on RL1 without handover) = (Node B-transmitted code strength on RL1 with handover) –(Node B-transmitted code strength on RL1 without handover)



� Measurements: BLER, BER, UE-transmitted power, UE-received power.

11.2.3.3 Influence of the UE Speed

One could imagine that the UE speed could damage the quality of the reception and then, the softhandover zone will become larger for a fast UE. For this test, the overlap zone is already knownfrom previous tests. In the first test case, only one Node B is switched on. In the second test case,both Node Bs are switched on. The UE is driven fast over the area. For both test cases, samemeasurements as for soft/softer handover are performed.

Compare the results with those obtained with a slow UE.

11.2.3.4 Influence of the Interference Level

One could imagine varying the pilot strength by modifying the interference level. Noise could beadded for loading purpose at the Node B’s side. This could not be done at the MS-SIM side since itwould damage the pilot of both Node Bs. For this test, the overlap zone is already known fromprevious tests. In the first test case, only one Node B is switched on and the interference level isartificially raised. In the second test case, both Node Bs are switched on, and the increasedinterference level is kept at the first Node B. The UE is driven slowly over the area. For both testcases, same measurements as for soft/softer handover are performed.

Compare the results with those obtained with a Node B without interference.

11.2.4 Investigation on Power Control

11.2.4.1 Open Loop Power Control

Open Loop power control is performed both in the UTRAN and UE to set the initial power fortransmission.

In the uplink, open loop power control is used by the UE in order to set the transmission power ofthe PRACH. The initial power of the UE during random access is set using UE measurements on thePCCPCH and broadcast system information. The UE estimates the path loss by measuring thereceived power of P-CCPCH, and emits the required power in order for the Node B to receive thetarget power level.

In the downlink, open loop power control sets the initial power of the downlink DCH channels usingmeasurement reports from the UE.

The path loss indicated in the UE measurement reports should be compared with the path losscomputed from the measurements of the drive test system on the CPICH. This test is done within thepropagation tests.

11.2.4.2 Closed Loop Power Control

Downlink and uplink inner loop power control are located in both the UTRAN and UE.

The closed loop power control consists of an inner and outer loop.

Inner loop (UL)

� If SIR � SIR_target, then the Node B should set the TPC bits in the next transmitted downlink slotperiod such that the UE will lower its transmit power,



� If SIR < SIR_target, the Node B should set the TPC bits in the next transmitted downlink slotperiod such that the UE will increase its transmit power.

Outer Loop

Outer loop power control will be performed at the SRNC. Outer loop power control adjusts theSIR_target for the inner loop comparison. The adjustment is based on frame quality information. Thetarget SIR is sent periodically from the SRNC to each serving Node B.

In downlink, the Node B emits Transmit Power Control (TPC) commands permitting to power up ordown the UE power, after comparing the received SIR with the target SIR. The UE has the capabilityof changing the output power with a step size of 1, 2 and 3 dB according to the value of TPC, in theslot immediately after the TPC_cmd can be derived. The transmitter output power step due to innerloop power control shall be within the range shown under.

For the downlink inner power control, each UE can also emit TPC commands towards the Node B,which can change Node Bs emitting power.

First, we consider the case, where there is only one radio link in the active set. Either, all the othercells are shut down for this experiment, or there is the possibility to forbid a CPICH to trigger a RLaddition. Therefore, there is only one Node B, which is sending TPC commands to the UE and isreceiving TPC commands from it. Following measurements are performed both at the Node B andat the UE: received SIR [dB], target SIR [dB], received BLER [%], received BER [%].

We can perform a test with an activated handover. The handover tests have shown areas, on whichthere are several RL. We can compare the power measurements in this area. If this area is a softerhandover area, same measurements as above are performed since there is always only one Node Binteracting with the UE. If this area is a soft handover area, the RNC must perform selection amongframes coming from the Node Bs. Therefore, received BLER [%], received BER [%] must be measuredafter RNC selection. Furthermore, each Node B will send its own TPC bits. The UE must cope with allthe indications.

From the distribution of the power control error, the average power control error and standarddeviation of TPC error can be obtained.

The target SIR parameters are set by UTRAN on the Node B according to measurements (BLER/BER).Different sets of parameters could be tested. After a connection has been established, collectreceived SIR measurements at Node B and at UE, and target SIR measurements at RNC, along theroute. The speed is constant and low. The same procedure shall be performed twice: once with theouter loop power control enabled, once the outer loop power control disabled.

Calculate the Power Control error distribution according to:Power Control error = SIRTarget – SIRReceived

Calculate the average transmission power control error, and the standard deviation.

So the accuracy of the Power Control can be estimated and the effects of the outer loop powercontrol studied.

11.2.4.3 Influence of the Propagation Environment

When low diversity is provided, more variations of the transmitted power are observed and theaverage transmitted power is higher. Simulations have shown that the gain from the fast powercontrol is larger for those cases where only a little multipath diversity is available, like in thepedestrian environment.

The following procedure is performed twice: once with the Power Control disabled and once with thePower Control enabled. The UE initiates the service close to the Node B. Measurements of the



transmit and receive powers are performed at the Node B and at the UE, while the UE moves at aconstant slow speed away from the NodeB. Measurements are continued until the call is dropped atcell edge. If possible, take measurements of the received SIR. Various propagation environmentsshould be investigated: various multipath profile (indication at the RAKE receiver at the UE side andat the DCT at the Node B side), dense urban, urban and rural environment.

The Node B’s receive and transmit power profiles are plotted against the distance to the Node B,preferentially on a map. A comparison can be done between the results without Power Control andwhen the Power Control is active. The first group of graphs will show the decrease of received powerdue to the increasing pathloss. On the second group of graphs, one should see the increase in bothreceived and emitted power due to the Power Control.

11.2.4.4 Influence of the UE Speed

Simulations have shown that the gain from the fast power control is larger for low UE speed than forhigh UE speed. Fast power control is expected to compensate fast fading. This compensation causespeaks in the transmission power. For UE speed exceeding 50km/h, inaccuracies in the SIRestimation, power control signaling errors and the delay in power control loop degrade theperformances of the fast power control. The maximum cell range is obtained when the UE istransmitting full constant power, i.e. without the gain of fast power control.

The following procedure is performed twice: once with the Power Control disabled and once with thePower Control enabled. The UE initiates the service close to the Node B. Measurements of thetransmit and receive powers are performed at the Node B and at the UE, while the UE moves atconstant high speed away from the Node B. Measurements are continued until the call is dropped atcell edge. If possible, take measurements of the received SIR. This test must be done in anenvironment, which has been formerly investigated at a low speed. Several UE speeds may beinvestigated.

The Node B’s receive and transmit power profiles are plotted against the distance to the Node B,preferentially on a map.

11.3 Interference Measurements

The adjacent channel interference must be considered in any wideband system where large guardbands are not possible.

11.3.1 Dead zones

Danger of “Dead Zones” in case of operator co-existence



Serving cell (Operator A)

Interfering cell (Operator B)

Dead zone area

f1f2 of an other operator

Figure 85: Showing operators co-existence causing dead zones

The own frequency f1 of an UE could not be received if being nearby to a Node B of an otheroperator having the adjacent frequency f2 (see Figure 85).

The effect is that frequency f1 has not the sufficient quality in the cell center with the frequency f2, soan other operator generates a service area hole, a so-called dead zone. As summary, dead zonescan exist in a coexistence of at least two operators.

A solution would be a Co-location of UMTS operators, which avoids the occurrence of dead zones

Methods for measurements:

With the output powers of the wanted and interfering Node B set to the maximum Node B TX power,the UE is brought close to the adjacent channel interfering Node B.

The first test consists in measuring the CPICH reception for the two Node Bs with the drive testsystem and noting the cell selection done by the UE along a given road.

The second test consists in forcing the adjacent Node B to emit OCNS at full power on the adjacentband. Then, the UE is driven together with the drive test system along the test road. Acommunication is established with the “serving” Node-B. It must be studied if the cell range,meaning the limit for the reception, is influenced by the adjacent OCNS. The CPICH Ec/Io is alsomeasured.

11.3.2 Influence of the Interference Level

One could imagine varying the interference level in order to degrade the RF conditions. If OCNS isadded at the Node B’s side to emulate cell load on DL, the received SIR is decreased.

The UE initiates the service close to the Node B. Measurements of the transmit and receive powersare performed at the Node B and at the UE, while the UE moves at a constant high speed awayfrom the NodeB. Measurements are continued until the call is dropped at cell edge. If possible, takemeasurements of the received SIR. This test must be done in an environment, which has beenformerly investigated without adding interference. Several interference levels may be investigated.

The Node B’s receive and transmit power profiles are plotted against the distance to the Node B,preferentially on a map for various noise level.



11.4 Trial Measurements

11.4.1 Co-Siting with GSM

The document [SiteShare] presents a complete study of this topic. The required decoupling is given.In order to prevent performance degradation for co-located mobile systems, Alcatel proposes due to

the three interference mechanisms the following decoupling requirements, see chapter 7:

Table 62: Decoupling requirements


Specificationaccording to:

GSM05.05

Alcatel GSM05.05

Alcatel 3G TS25.104

Alcatel

GSM 05.05 46 dB

Blocking

30 dB 85 dB

GSMspurious

85 dB

GSMspurious

GSM 900 (TX)��

Alcatel 46 dB

Blocking

30 dB 61 dB

Blocking

30 dB

GSM 05.05 39 dB

Blocking

30 dB 85 dB

GSMspurious

85 dB

GSMspurious

GSM 1800 (TX)��

Alcatel 39 dB

Blocking

30 dB 62 dB

Blocking

47 dB

GSMspurious

3G TS25.104

35 dBBlocking

30 dB 43 dB

Blocking

30 dBUMTS (TX) ��

Alcatel 35 dBBlocking

30 dB 43 dB

Blocking

30 dB

Note: It is assumed, that the decoupling provided by the antenna/diplexer system is at least 30 dB. In fact, using AlcatelEVOLIUM™ equipment requires for certain combinations even less isolation than those 30dB. Intermodulation issuppressed by frequency planning.

� Isolation by using a diplexer for a dual-band antenna for GSM1800 and UMTS

� Isolation by using two diplexers for a dual-band antenna for GSM1800 and UMTS

� Filter for a dual-band antenna for GSM1800 and UMTS

The following measurements may applied:

- Measurement for GSM system

- Spurious emission received in UL

- Worse Rxlev, Rxqual distribution in DL / UL driving a specified route



- Measurement for UMTS system

- Spurious emission received in UL

- Increase of RSSI at BTS site

- Worse UL BLER values driving the referenced route

- Higher UE power required

A more detailed description of co-siting test is given in [BouyguesCoLoc].

11.4.2 Code Multiplex

11.4.2.1 Test COD1: Orthogonality of Scrambling Codes on Downlink (Intercell)

No theoretical result is available about the orthogonality of scrambling codes on downlink.

One could imagine testing the effect of code selection within one code family and from two differentcode families for two neighbouring cells in order to measure the interference between differentdownlink scrambling codes.

The first Node B is assigned first PSC from a particular group. The second Node B is turned off. TheUE is stationary inside the overlap area of 2 Nodes B. The CPICH RSCP, RSSI and Ec/No aremeasured. Then, the second Node B is assigned a different PSC from the same group and is turnedon. Same measurements are performed. After all 8 PSC of the group have been tested, the adjacentgroup of 8 PSC can then be selected and assigned to the second Node B. This test can be repeatedwith other combinations of code groups.

The averaged Ec/No values (y-axis) are plotted against the second Node B’s PSC 1, 2, 3…8 (of thesame group) on the x-axis, whereby the first Node B PSC is fixed. The baseline averaged Ec/Novalue for the case when only the first Node B was on-air is also shown on the plot.

In a second plot, the averaged Ec/No values are plotted against the second PSC 1, 2, 3 … 8 (of aadjacent group). More plots would be obtained if more PSC from different groups have beenassigned to the second Node B.

If desired, the measurement of averaged Ec/No can be performed at different UE speed using theabove combinations of PSC between two Nodes B.

Expected results: code-mapping strategy

11.4.2.2 Test COD2: Orthogonality on Spreading Codes on DL (Intracell)

The parameter will be derived from interference measurements by comparing the values obtainedwith or without the effect of the orthogonality. Two procedures have been developed, and it could beinteresting to compare the values given by each method.

Method 1:

The ETSI gives a theoretical method to derive the parameter from Eb/No computations.

Two simulations are made, one with white Gaussian noise and one with intra-cell interference. TheBER is then plotted as a function of Eb/No and Eb/Io respectively. These curves may differsignificantly, where the Eb/Io curve is to the left of the Eb/No curve. A difference of 10 dB meansthat a given Eb/Io gives the same BER as Eb/No = Eb/Io + 10. Consequently, a certain Io in thesystem simulations is equivalent to having 10 dB less No in the link-level simulations. Hence, it is



possible to say that the orthogonality removes 90% of the interference, or in other words anorthogonality factor of 10% is obtained (10% of the interference remains).

This test requires two series of measurements in the same conditions. The values of Eb/No will bemeasured by the UE (MS-SIM or drive test system) under different interference levels and the BER willbe measured accordingly. In order to be able to measure different levels of BER, the Power Controlfeature shall be switched off. The variations of Eb/No are performed while increasing the noise. Inthe first case, the noise is generated by an AWGN simulator, in the second case by a UMTS signalgenerator. The noise can be fed at the Node B level or at the UE, both solutions are describedbelow.

Measurement under real path conditions:

As we are testing the loss in the orthogonality due to the multipath propagation, a first solutionwould be to simulate the noise/UMTS signal from the Node B.

This solution would give the best results, as the real multipath would be used, which would allowspecific measurements, for example under different UE speeds.

Test scenario:

The UE is at a given distance from the Node B. The Power Control is switched off. A connection isestablished and the PN 9/15 signal (standardized signal) is sent from the Node B.

A first series of measurements of Eb/No and the received BER is performed, the signal beingdisturbed by increasing AWGN (until the communication is dropped).

The connection is re-established. A second series of measurements of the same parameters Eb/Ioand BER is performed, the noise being generated by the synchronized UMTS signal generator, withincreasing power until the communication drops.

This procedure can be also repeated for different environments and at different speeds if possible onthe same cell radius. Tests at different distances from the Node B can also be performed.

For testing in the lab, if the UMTS signal generator is connected directly to the UE, a fadingsimulator has to be added, with the suitable parameters in order to simulate the multipathconditions.

Results:

For each environment/speed, plot the BER in function of Eb/No for both noise generators, i.e.OCNS and AWGN, on a same graph.

The horizontal shift between the two curves represents the gain due to the orthogonality. As anexample, a difference of 5 dB means that a given interference Io with UMTS signals gives the samequality as the gaussian noise No = Io – 5 dB. � corresponds to the part of the remaininginterference, so �= –5 dB = 0,32.

Method 2:

The UE shall perform regularly mandatory measurements. The following gives the way theparameter � is derived from these measurements.

Sk,i is the power of the signal spread with the code k after transmission to the UE i with the pathlossLi, depending on the propagation environment and the UE position on the cell area. Forsimplification, we consider that no UE is in SHO.

ISCP: Interference Signal Code Power

RSSI: Received Signal strength Indicator

RSCP: Received Signal Code Power



ISCPj = � x � (k j) Sk,i + Iext + Nthermal , j being the code under study, here: j = CPICH

RSSIi = � (k) Sk,i + Iext + Nthermal

RSSIi = � (k) Sk,i + ISCPj - � x � (k j) Sk,i

RSSIi - ISCPj = � (k) Sk,i - � x � (k j) Sk,i

RSSIi - ISCPj = � x Sj,i + (1-�) x � (k) Sk,i

� (k) Sk,i = Ptot Li

Sj,i = RSCPj,i

RSCPj,i = Pj Li

RSSIi - ISCPj = � x RSCPj,i + (1-�) x Ptot RSCPj,i/ Pj

Per definition, SIR = RSCP/ ISCP and RSCPj,i / RSSI= (Ec/No) j,i

Pj is a system parameter.

Ptot is measured at the Node B’s antenna connector.

itot

0

citot

PP

SIR1

NE1

PP

�

��

�

�

��

�

�

��

�

SF is the spreading factor of the considered DPCH on downlink.

Pt is the transmitted power on the considered DPCH on downlink.

mii

DPCH

miCPICHi

i PtPtotSIR

SFPtIoEc

PPtot

,

, )(

�

�

��

��

Since we will compute the value from several measurements, the accuracy of the measurementsmust be known to check the validity of the method.

Test scenario:

The emit power of the CPICH is fixed. A communication is established between the UE and the NodeB. Measurements of the CPICH Ec/No and the CPICH SIR are performed, while the total emit powerat the Node B is measured thanks to a power meter. This procedure is repeated for differentenvironments, and at different speeds. The effect of the distance from the Node B and of theservice’s bitrate can also be studied.

The equation above is used to calculate the value of the parameter � for each environment/speed.

11.5 Network Acceptance Procedure

Acceptance tests must be specified clearly in the contract. The metholody of testing and theacceptance criteria must be clearly specified. This step can often be the bottleneck to obtaining thefinal payments, as well as the prospect of future expansion contract.



Acceptance tests can be conducted on a cluster, RNC or MSC basis. The cluster-based acceptance ispreferred as this allows for independent clusters test to be completed, even though other cells on theRNC or MSC are not ready. In general, it is also easier to pass the cluster-based acceptance teststhan RNC-based or MSC-based tests, since the cell counts are smaller. The RNS performanceduring busy hours would require further investigations.

The methodology of testing must be documented clearly. The equipment used to collect data mustbe calibrated and easy to set up. The equipment setup must be able to perform consistently, fromone run to another.

The acceptance criteria must be logical, specific and easy to quantify. For example, to determinethe data throughput from a cluster of cells, it may be important to clearly state the quality level(Ec/Io), time of the day and measurement duration when collecting the field data. Subsequent datapost-processing can then filter out the relevant data and compare them against the acceptancecriteria.

Responsibility: Network planning and network optimization department

Input to NP: Existing network design, field data, acceptance criteria

Output of NP: Verifications

Task of NP: Consultancy

11.6 QoS Measurements

When the UMTS Network is in operation, its performance can be observed by measurements, andthe result of those measurements can be used to visualize and optimize network performance.

11.7 Recommended Measurement Tools for Air Interface Measurements

� UMTS Drive test tool E7476A from Agilent which supports the following measurement entities:

� Primary Sync Channel Ec, Ec/Io, Eb, Eb/Io

� Secondary Sync Channel Ec, Ec/Io, Eb, Eb/Io

� Scrambling Code: Peak Ec, Peak Ec/Io, Peak Eb, Peak Eb/Io

� Scrambling Code: Aggregate Ec, Aggregate Ec/Io, Aggregate Eb, Aggregate Eb/Io

� Delay spread

� Carrier Frequency Error

� Time Stamp

� Position

� Mobil Station Simulator or test mobile supporting the measurements as specify in 3GPP.

� AWGN generator to feed in noise in to a Node B

� Protocol Analyzer for NBAP message trace



11.8 Possible Measurements

Test cases which could be planned during the set-up of a network or for existing network. These testcases are given in the following list.UMTS PROPAGATION

COVERAGE WITH THE PILOT AND THE SYNCHRONISATION CHANNELS

CELL SELECTION

COVERAGE IN TERMS OF SERVICE

INTERFERENCE ON ADJACENT CHANNEL

CO-SITTING WITH GSM

CODE MULTIPLEX

ORTHOGONALITY OF SCRAMBLING CODES ON DOWNLINK (INTERCELL)

ORTHOGONALITY ON SPREADING CODES ON DL (INTRACELL)

POWER CONTROL

OPEN LOOP POWER CONTROL

CLOSED LOOP POWER CONTROL

INFLUENCE OF THE PROPAGATION ENVIRONMENT

INFLUENCE OF THE UE SPEED

INFLUENCE OF THE INTERFERENCE LEVEL

SOFT HANDOVER

NEIGHBOURING CELL SEARCH

NEIGHBOURING CELL SEARCH IN CASE OF SOFT HANDOVER

NEIGHBOURING CELL SEARCH IN CASE OF SOFTER HANDOVER

SOFT HANDOVER AREA

SOFTER HANDOVER AREA

SOFT HANDOVER GAIN

SOFTER HANDOVER GAIN


INFLUENCE OF THE INTERFERENCE LEVEL

TUNING OF THE PARAMETERS

CAPACITY AND PERFORMANCES

PERFORMANCE IN AN UNLOADED NETWORK

CAPACITY IN A LOADED NETWORK

TEST SET OF THE DIFFERENT SERVICE BEARERS

AMR(12.2KBPS)-CODED VOICE SERVICE FOR ORIGINATING CALL

AMR(12.2KBPS)- CODED VOICE SERVICE FOR TERMINATING CALL

DATA(384KBPS) SERVICE

COMPARISON GSM/UMTS, MEASUREMENT OF THE

CPICH DETECTION AREA

CPICH DETECTION ON A LOADED CELL

UMTS COVERAGE FOR VOICE SERVICE

UMTS COVERAGE FOR VOICE ON ONE LOADED CELL

UMTS COVERAGE FOR DATA -384KBPS SERVICE

UMTS COVERAGE FOR DATA -384KBPS ON A LOADED CELL

MECHANICAL PERFORMANCE OF SOFT HANDOVER

MEASUREMENT OF THE SHO ZONES

TUNING OF THE PARAMETER “HYTERISIS”

TUNING OF THE PARAMETER “REPORTING RANGE“

TUNING OF THE PARAMETER “REPORTING DEACTIVATION THRESHOLD“

BEHAVIOUR OF MECHANICAL PERFORMANCE OF POWER CONTROL



INFLUENCE OF THE TPC STEPO SIZE

TEST OF THE DIFFERENT SERVICE BEARERS



AMR(12.2KBPS)-CODED VOICE SERVICE FOR ORIGINATING CALL

AMR(12.2KBPS)-CODED VOICE SERVICE FOR TERMINATING CALL

DATA(384KBPS) SERVICE

COMPARISON GSM/UMTS

MEASUREMENT OF THE CPICH DETECTION AREA

MEASUREMENT OF THE CPICH DETECTION ON A LOADED CELL

MEASUREMENT OF THE UMTS COVERAGE FOR VOICE SERVICE

MEASUREMENT OF THE UMTS COVERAGE FOR VOICE ON ONE LOADED CELL

MEASUREMENT OF THE UMTS COVERAGE FOR DATA-384KBPS SERVICE

MEASUREMENT OF THE UMTS COVERAGE FOR DATA-384KBPS ON A LOADED CELL

MECHANICAL PERFORMANCE OF SOFT HANDOVER

MEASUREMENT OF THE SHO ZONES

TUNING OF THE PARAMETER “HYSTERESIS »

TUNING OF THE PARAMETER “REPORTING RANGE“

TUNING OF THE PARAMETER “REPORTING DEACTIVATION THRESHOLD“

BEHAVIOUR AND MECHANICAL PERFORMANCE OF POWER CONTROL


INFLUENCE OF THE MOBILE SPEED

INFLUENCE OF THE TPC STEP SIZE

CHARACTERISATION OF SOFT HANDOVER DL GAIN

REFERENCE TEST WITH NO SHO

INFLUENCE OF THE PROPAGATION ENVIRONMENT WITH ACTIVATED SHO

INFLUENCE OF THE MOBILE SPEED WITH ACTIVATED SHO

CHARACTERISATION OF SOFTER HANDOVER DL GAIN

INFLUENCE OF THE PROPAGATION ENVIRONMENT WITH ACTIVATED SHO

INFLUENCE OF THE MOBILE SPEED WITH ACTIVATED SHO

VARIATION OF SOFT HANDOVER RATE IN FUNCTION OF TILT

INFLUENCE OF THE TILT ON SHO AREA

IMPACT OF PROPAGATION ON SENSITIVITY

UE SENSIBILITY FOR VOICE WITHOUT INTERFERENCE

UE SENSIBILITY FOR DATA 384KBPS WITHOUT INTERFERENCE

UE SENSIBILITY FOR VOICE WITH INTERFERENCE

UE SENSIBILITY FOR DATA 384KBPS WITH INTERFERENCE

CHARACTERISATION OF POWER IN DL

POWER ON DL FOR VOICE ON AN UNLOADED CELL

POWER ON DL FOR DATA-384KBPS ON AN UNLOADED CELL

POWER ON DL FOR VOICE ON A LOADED CELL

POWER ON DL FOR DATA-384KBPS ON A LOADED CELL

TEST SET: ACCESSIBILITY AND FILE TRANSFER

RESOURCE ALLOCATION FOR DATA(384KBPS) SERVICE

END-TO-END DELAY FOR DATA(384KBPS) SERVICE

DATA SERVICES

FILE TRANSFER

WEB AND WAP

MAILING SERVICES

STREAMING AUDIO/VIDEO

CHAT , ICQ , NEWS

PERFORMANCE OF TCP ON THE RADIO CHANNEL

TUNING OF MTU (MAXIMUM TRANSMISSION UNIT)

TUNING OF RECEIVER WINDOW SIZE, IN NUMBER OF MSS (MAXIMUM SEGMENT SIZE)

TUNING OF IRTO (INITIAL RETRANSMISSION TIME OUT)

PERFORMANCE OF TRAFFIC WEB

TEST SET: CONFORMANCE TESTING

UMTS TX SPURIOUS EMISSIONS



UMTS RX BLOCKING LEVEL

REFERENCE SENSITIVITY LEVEL

TEST SET: CO-LOCATION TESTS

ANTENNA DECOUPLING

GSM1800 REFERENCE MEASUREMENT

UMTS DISTURBANCES ON GSM1800 NETWORK

UMTS REFERENCE MEASUREMENT

DCS DISTURBANCES ON UMTS NETWORK

TEST SET: INTERFACE IU-PS BETWEEN RNS AND 3G-SGSN

UE INITIAL MESSAGE AND RAB ASSIGNMENT / RAB RELEASE

PAGING AND RAB ASSIGNMENT / RAB RELEASE

IU RELEASE REQUEST

DIRECT TRANSFER

DATA VOLUME REPORT

TEST SET: INTERFACE IU-CS BETWEEN RNS AND 3G- MSC/VLR

UE INITIAL MESSAGE AND RAB ASSIGNMENT / RAB RELEASE

PAGING AND RAB ASSIGNMENT / RAB RELEASE

IU RELEASE REQUEST

DIRECT TRANSFER

PROCEDURES FOR MOBILITY MANAGEMENT (MM) FOR CS SERVICES

MOBILITY MANAGEMENT FOR CS SERVICES: IMSI ATTACH

MOBILITY MANAGEMENT FOR CS SERVICES: IMSI DETACH

MOBILITY MANAGEMENT FOR CS SERVICES: AUTHENTICATION

MOBILITY MANAGEMENT FOR CS SERVICES: IDENTIFICATION

MOBILITY MANAGEMENT FOR CS SERVICES: TMSI REALLOCATION

MOBILITY MANAGEMENT FOR CS SERVICES: NORMAL LOCATION UPDATE

MOBILITY MANAGEMENT FOR CS SERVICES: PERIODIC LOCATION UPDATE

PROCEDURES FOR MM FOR PS SERVICES

MOBILITY MANAGEMENT FOR PS SERVICES: GPRS ATTACH

MOBILITY MANAGEMENT FOR PS SERVICES: GPRS DETACH

MOBILITY MANAGEMENT FOR PS SERVICES: AUTHENTICATION

MOBILITY MANAGEMENT FOR PS SERVICES: IDENTIFICATION

MOBILITY MANAGEMENT FOR PS SERVICES: TMSI REALLOCATION

MOBILITY MANAGEMENT FOR PS SERVICES: NORMAL ROUTING AREA UPDATE

MOBILITY MANAGEMENT FOR PS SERVICES: PERIODIC ROUTING AREA UPDATE

CALL CONTROL AND SESSION MANAGEMENT

CALL CONTROL PROCEDURES FOR CS

PDP CONTEXT ACTIVATION/DEACTIVATION



GLOSSARY/TERMINOLOGY

NYD Not yet defined in the current version of the document.

LIST OF ABBREVIATIONS

Explanations for all abbreviations used in 3GPP are given in [21.905]. Abbreviations used in thisdocument are given hereafter.

Abbreviation Full meaningACI Adjacent Channel InterferenceACLR Adjacent Channel Leakage RatioAI Acquisition IndicatorAICH Acquisition Indicator ChannelAIO All-In-OneAMR Adaptive MultirateANC Evolium Evolution Duplexer and Combiner StageANXU Antenna Network for UMTSAP Access PreambleAP-AICH Access Preamble Acquisition Indicator ChannelAPI Access Preamble IndicatorARQ Automatic Repeat RequestASC Access Service ClassAWGN Additive White Gaussian NoiseBB Base BandBCCH Broadcast Control ChannelBCH Broadcast ChannelBER Bit Error RateBLER Block Error RateBSC Base Station ControllerBSS Base Station SystemBTS Base Transceiver StationC- Control-CA Channel AssignmentCAI Channel Assignment IndicatorCC Call ControlCCC CPCH Control CommandCCCH Common Control ChannelCCH Control ChannelCCPCH Common Control Physical ChannelCCTrCH Coded Composite Transport ChannelCD Collision DetectionCD/CA-ICH Collision Detection/Channel Assignment Indicator ChannelCDF Cumulative Density FunctionCDI Collision Detection IndicatorCN Core NetworkCPCH Common Packet ChannelCPICH Common Pilot ChannelCRC Cyclic Redundancy CheckCRNC Controlling Radio Network ControllerCS Circuit Switched



Abbreviation Full meaningCSICH CPCH Status Indicator ChannelDC Dedicated Control (SAP)DCA Dynamic Channel AllocationDCCH Dedicated Control ChannelDCH Dedicated ChannelDEM Digital Elevation ModelDL DownlinkDPCCH Dedicated Physical Control ChannelDPCH Dedicated Physical ChannelDPDCH Dedicated Physical Data ChannelDRNC Drift Radio Network ControllerDS-CDMA Direct-Sequence Code Division Multiple AccessDSCH Downlink Shared ChannelDSMA-CD Digital Sense Multiple Access - Collison DetectionDTCH Dedicated Traffic ChannelDTX Discontinuous TransmissionEc/No Received energy per chip divided by the power density in the bandEMC Electromagnetic CompatibilityETSI European Telecommunications Standardization InstituteFACH Forward Access ChannelFAUSCH Fast Uplink Signalling ChannelFBI Feedback InformationFCS Frame Check SequenceFDD Frequency Division DuplexFEC Forward Error CorrectionFER Frame Error RateFSW Frame Synchronization WordGC General Control (SAP)GGSN Gateway GPRS Support NodeGMSC Gateway MSCGoS Grade of ServiceGSM Global System for Mobile CommunicationHLR Home Location RegisterHO HandoverICH Indicator ChannelIM IntermodulationISC International Switching CentreISCP Interference Signal Code PowerITU International Telecommunication Unionkbps kilo-bits per secondL1 Layer 1 (physical layer)L2 Layer 2 (data link layer)L3 Layer 3 (network layer)LAC Link Access ControlLAI Location Area IdentityLNA Low Noise AmplifierMAC Medium Access ControlMBS Multi-Standard Base StationMcps Mega Chip Per SecondMHA Mast Head AmplifierMM Mobility ManagementMND Mobile Network Design (Department within MCD)MS Mobile Station



Abbreviation Full meaningMSC A 2 generation Mobile Switching Center only supporting the A interfaceMUI Mobile User IdentifierOCCCH ODMA Common Control ChannelODCCH ODMA Dedicated Control ChannelODCH ODMA Dedicated ChannelODMA Opportunity Driven Multiple AccessODMA Opportunity Driven Multiple AccessODTCH ODMA Dedicated Traffic ChannelORACH ODMA Random Access ChannelOVSF Orthogonal Variable Spreading Factor (codes)PC Power controlPCCH Paging Control ChannelPCCPCH Primary Common Control Physical ChannelPCH Paging ChannelPCPCH Physical Common Packet ChannelPCS Professional Customer Services (Department within MCD)PDF Probability Density FunctionPDSCH Physical Downlink Shared ChannelPDU Protocol Data UnitPHY Physical layerPhyCH Physical ChannelsPI Paging IndicationPICH Page Indicator ChannelPMP Point to MultipointPOM Page Oriented ModelPRACH Physical Random Access ChannelPS Packet SwitchedPSC Primary Synchronisation CodePSTN Public Switched Telephone NetworkQoS Quality of ServiceQPSK Quaternary Phase Shift KeyingRACH Random Access ChannelRF Radio FrequencyRL Radio LinkRLC Radio Link ControlRNC Radio Network ControllerRNS Radio Network SubsystemRNTI Radio Network Temporary IdentityRRC Radio Resource ControlRSCP Received Signal Code PowerRSSI Received Signal Strength IndicatorRX ReceiveSAP Service Access PointSCCC Serial Concatenated Convolutional CodeSCCH Synchronisation Control ChannelSCCPCH Secondary Common Control Physical ChannelSCH Synchronisation ChannelSDU Service Data UnitSF Spreading FactorSFN System Frame NumberSGSN Serving GPRS Support NodeSI Status IndicatorSIR Signal-to-Interference Ratio



Abbreviation Full meaningSRNC Serving Radio Network ControllerSRNS Serving Radio Network SubsystemSSC Secondary Synchronisation CodeSSDT Site Selection Diversity TPCSTTD Space Time Transmit DiversityTBD To be definedTCH Traffic ChannelTDD Time Division DuplexTDMA Time Division Multiple AccessTFCI Transport Format Combination IndicatorTFI Transport Format IndicatorTMA Tower Mounted AmplifierTMSI Temporary Mobile Subscriber IdentityTPC Transmit Power ControlTSTD Time Switched Transmit DiversityTX TransmitU- User-UE User EquipmentUE/MS A terminal that supports USIM, SIM, the Uu interface and the Um interfaceUER User Equipment with ODMA relay operation enabledUL UplinkUMTS Universal Mobile Telecommunications SystemURA UTRAN Registration AreaUSIM UMTS Subscriber Identity ModuleUTRA UMTS Terrestrial Radio AccessUTRAN UMTS Terrestrial Radio Access NetworkUu UMTS Air InterfaceVLR Visitor Location RegisterVSWR Voltage Standing Wave RatioWCDMA Wide-band Code Division Multiple Access

List of Figures & List of Tables (TBD)

Index (TBD)

END OF DOCUMENT