Mita Seminar Wcdma

7/29/2019 Mita Seminar Wcdma

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MITA seminarMITA seminarWCDMA technology on UTRANWCDMA technology on UTRAN

Mobile Internet Technical ArchitectureMobile Internet Technical Architecture --Vol. 1. Technologies and Standardization (pp. 155Vol. 1. Technologies and Standardization (pp. 155 -- 167)167)

October 29, 2003October 29, 2003

[email protected]@lut.fi


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ContentContent

Scenery

UTRAN architecture

WCDMA basics

Features

Services

Specifications

References


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SceneryScenery

UTRAN/WCDMA and MITA (1/2)UTRAN/WCDMA and MITA (1/2) UMTS (Universal Mobile Telecommunications System) is a 3rd

generation cellular system UTRAN (UMTS Terrestrial Radio Access Network) is radio access part

of UMTS

UTRAN is categorized as a Network Environment on MITAterminology, [2]

WCDMA based radio access technology

UTRAN/WCDMA provides services to which MITA interactionmodes can be mapped (or vice versa), [2]

Messaging (e.g. SMS and MMS) Browsing (e.g. asymmetric uplink/downlink bit rates)

Rich call (e.g. audio/video calls with different QoS requirements)


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SceneryScenery

UTRAN/WCDMA and MITA (2/2)UTRAN/WCDMA and MITA (2/2)

User Interface

Browsing Messaging Rich Call

ApplicationFramework Internet

Protocols

OS and PlatformSupport

MITA access technologies 2.5G GSM/EDGE uses

TDMA/FDMA technology

UTRAN uses WCDMA technology Etc.

UTRAN provides WCDMA basedAir interface access technology

Based on Wideband Code DivisionMultiple Access (WCDMA)

Each vendor provide ownplatform for UTRAN equipment

UTRAN

AccessTechnologies


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SceneryScenery

IMTIMT--2000 technologies and spectrum2000 technologies and spectrum IMT-2000 is the umbrella specification of all 3G systems, [1]

In addition to 2nd generation modulation schemes (e.g. EDGE)

several CDMA spread spectrum modulations co-exist Direct sequence (DS), Frequency Hopping (FH), Time Hopping (TH),Hybrid Modulation (HM), and MultiCarrier (MC)

Direct Sequence modulation is used by UTRAN CDMA2000 applies MultiCarrier modulation

AmericasIMT-2000:WCDMA, MC-CDMA (1.8 2 GHz)GSM/GERAN:EDGE (existing bands)

EuropeIMT-2000:WCDMA (1.9 & 2.1 GHz)GSM/GERAN:EDGE (1.8 GHz)

Japan

IMT-2000:WCDMA (1.9 & 2.1 GHz)

AsiaIMT-2000:WCDMA (1.9 & 2.1 GHz)GSM/GERAN:

EDGE (900 MHz & 1.8 GHz)

KoreaIMT-2000:WCDMA (1.9 & 2.1 GHz)


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UTRAN

UTRAN architectureUTRAN architecture

ElementsElements UTRAN consists of

Base stations (Node B) Controller (RNC)

Iur interface between twoRNCs Iub interface between RNC

and Node B

UTRAN is connected to Circuit switched CN (i.e. 3G

MSC) via Iu-CS interface Packet switched CN (3G

SGSN) via Iu-PS interface User equipment via Air

interface (Uu)

RNC

Node B

3G SGSN

MSCRNC

Iu-PS

Iub

IurIurIurIur

Iu-CS

Uu


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25.4x0

Transport

NetworkLayer

UTRAN architectureUTRAN architecture

Layered structureLayered structure UTRAN protocol architecture is based on layered structure, [1,

3] Protocols categorized to access and non-access strata Access stratum consists of transport network layer protocols Non-access stratum consists of radio network layer protocols

Transport NetworkControl plane

Transport NetworkUser plane

25.4x4 + 25.426

RadioNetworkLayer

25.4x5 + 25.42725.419

Transport NetworkUser plane

25.4x2

25.4x3

25.4x1Legend:x = 1, Iu interfacex = 2, Iur interfacex = 3, Iub interface

Control Plane User Plane


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Code 1

WCDMAWCDMA

Basics (1/2)Basics (1/2) WCDMA users share same radio resources whereas TDMA or

FDMA users have their own radio resources allocated, [1, 4]

User signals are differentiated based on codes, [1, 4] CDMA modulation types, [1, 4]

Direct Sequence (DS,) Frequency Hopping (FH), Time Hopping (TH),Hybrid Modulation (HM), and MultiCarrier (MC)

Time

Frequency

Time

Frequency

Frequency 1

Frequency 2

Frequency n-1

Frequency n

Time

Frequency

Timeslot1

Timeslot2

Timeslotn-1

Timeslotn

Code 2

Code n-1Code n

FDMA TDMA CDMA


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WCDMAWCDMA

Basics (2/2)Basics (2/2)

Information is spread over frequencyband, [1, 4]

In UTRAN bandwidth is constant (effective

band is 3.84 MHz, 5 MHz with guardbands)

The better the spreading the lower thepower => interference decreases

The smaller the spreading the higher the

power => interference increases

UTRAN uses 10 ms frames, [1, 4] During single frame data rate is constant Data rates on consecutive frames may

vary 4.4 5.0 MHz

Frequency

Time

Power

10 ms

Energy

Frequency

Original signal

Spread signal


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WCDMAWCDMA

FeaturesFeatures

Macro diversity enables mechanisms tocope with system interference, [1, 3, 4]

Multiple simultaneous Node B connections (SoftHandover scenario)

Power control, [1, 3, 4] Objective is to minimise transmission power Aims to decrease interference => improves

overall performance Fast power control (1500 Hz cycles) Power control for downlink (decreases overall

interference) and uplink (near-far effect)

Partial security (spread code mechanism) User signals differentiated with different

spreading codes

Signal-to-interference ratio (SIR, a.k.a.Carrier-to-interference ratio, C/I), [4]

Signal can be recovered as long as despreadsignal is above interfering power

Power

Frequency

Widebandnoise level

Spread signal

De-spreadsignal


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WCDMAWCDMA

Services [1, 3, 4]Services [1, 3, 4]

Bit rates Circuit Switched connections up to 384 kbps Packet Switched connections up to on downlink 2Mbps (14.4 Mbps with

HSDPA), [1] Variable bit rates

Service multiplexing on single connectionDifferent QoS (e.g.speech, video and packet data)

Varying delays

QoS (from 10% FER to 106 bit error rate)

Co-existence of 2G and 3G systems (incl. Intersystem HOs)

Asymmetric uplink and downlink traffic

High spectrum efficiency (e.g. good frequency reuse)

Co-existence of FDD and TDD modes


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SpecificationsSpecifications

3GPP specifications (listed at the end of [1])

Encryption algorithms, etc.35-series

Test specifications.34-series

Security aspects.33-series

Operation and maintenance aspects.32-seriesUIM and interfaces between UIM and other entities.31-series

3GPP program management.30-series

Protocols within CN.29-series

Signaling protocols between radio subsystem and periphery of CN.28-series

Data application support functions.27-seriesCodecs.26-series

UTRA aspects.25-series

Non-access Stratum protocols (MS/UE CN).24-series

Technical realisation specifications describing interworking overseveral interfaces.

23-series

Services, service features, or platforms for services.22-series

Requirement specifications.21-series


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ReferencesReferences

1. Introduction to 3G Mobile Communications, 2nd Edition, J. Korhonen; ISBN1-58053-507-0

2. MITA, Mobile Internet Technical Architecture, Vol. 1 Technologies and

Standardization; Nokia; ISBN 951-826-668-93. UMTS Networks - Architecture, Mobility and Services; H. Kaaranen, A.

Ahtiainen, L. Laitinen, S. Naghian, V. Niemi; ISBN 0471-48654-X

4. WCDMA for UMTS Radio Access For Third Generation Mobile

Communications; Harri Holma, Antti Toskala; ISBN 0-471-72051-8


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Questions based on presentationQuestions based on presentation

1. What is the role of UTRAN/WCDMA in MITA concept?

2. Why macro diversity and power control are important features ofWCDMA?

3. How WCDMA services could be mapped to MITA interaction modes?

To be consideredTo be considered

1. GSM/EDGE and UMTS evolution?

2. How All-IP affects to radio access networks?

3. Trends on radio technology in future? What changes 4th generation willbring?

4. What kind of user equipments there will be in future (e.g. on a ten yeartime scale)?

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Mita Seminar Wcdma