LTE Guidelines in ICS Designer v3 - · PDF file- RSRP overlapping area Physical Cell Ids and RSI 2D or 3D coverage analysis Automatic frequency assignment Automatic or manual neighbour

GUIDELINES FOR A LTE

NETWORK DESIGN AND

OPTIMISATION WITH ICS

designer

ADVANCED TOPOGRAPHIC DEVELOPMENT

& IMAGES

SOFTWARE DESIGNERS: P & D MISSUD

LTE FEATURES – ICS DESIGNER V2

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VERSIONS HISTORY

Version Date Writer

GUIDELINES FOR A

LTE NETWORK

DESIGN AND

OPTIMISATION WITH

ICS designer version

Remarks

1.1 05/10/2013 NEDHIF Sami 12.2.7

The present version of the guideline covers the features available in the release v.12.2.7. This document will be upadted at regulars intervals to ensure that it considers the latest uptates of ICS Designer.

Limited Warranty

This manual is subject to the limited warranty conditions as specified by the general operating

license of the whole package. ATDI reserves the right to modify this manual without prior

warning.



TABLE OF CONTENTS Versions History....................................................................................................................................... 2

Table of Contents .................................................................................................................................... 3

1. SCOPE ........................................................................................................................................... 5

2. LTE GENERAL WORKFLOW .................................................................................................... 6

3. LTE FEATURES ........................................................................................................................... 7

3.1. RSRP ...................................................................................................................................... 7

3.2. RSRQ...................................................................................................................................... 9

3.3. SNIR calculations .................................................................................................................. 9

3.4. DL Peak throughput plots ................................................................................................... 10

3.5. UL peak throughput plots ................................................................................................... 15

3.6. Traffic analysis and LTE schedulers ................................................................................. 17

3.7. PCI planning......................................................................................................................... 18

3.8. RSI and PRACH planning .................................................................................................. 19

3.9. LTE Handover and neighbour list analysis (intra-inter system) ..................................... 20

3.10. LTE Monte Carlos simulators ......................................................................................... 25

3.11. Automatic search of site ................................................................................................. 32

3.12. Automatic frequency planning ....................................................................................... 32

3.13. Automatic site optimization............................................................................................. 33

3.14. Refarming frequency band and inter system coexistence ......................................... 34

3.15. LTE Field strength exposure (2D&3D) .......................................................................... 36

3.16. LTE Propagation models ................................................................................................ 38

4. PRACTICAL CASE (SCOPE and INPUT DATA) .................................................................. 40

4.1. Scope of the study ............................................................................................................... 40

4.2. Cartographic layer ............................................................................................................... 41

4.3. Site and simulation parameters ......................................................................................... 42

3.3.1 Physical configurations of the LTE sites ....................................................................... 42

3.3.2 SNIR requirements .......................................................................................................... 43

3.3.3 RSCP sensitivity .............................................................................................................. 44

3.3.4 PDSCH (traffic channel) sensitivity ............................................................................... 45

3.3.5 Path budget and power allocation ................................................................................. 45

3.3.6 Propagation models selection ........................................................................................ 46

5. PRACTICAL CASE (RESULTS) .............................................................................................. 48

5.1. PHASE 1: NETWORK DESIGN ........................................................................................ 48



4.1.1 Methodology..................................................................................................................... 48

4.1.2 Automatic search site result ........................................................................................... 48

4.1.3 RSRP and RSRQ results ............................................................................................... 50

4.1.4 DL and UL Peak Throughput results ............................................................................. 52

4.1.5 SNIR coverage results .................................................................................................... 53

5.2. PHASE 2: NEIGHBOUR AND PCI PLANNING .............................................................. 54

5.2.1 Methodology..................................................................................................................... 54

5.2.2 Results .............................................................................................................................. 54

6. REFERENCES ............................................................................................................................ 58



1. SCOPE

This document is intended to provide:

- A general understanding of LTE (Long Term Evolution) radio aspects; - An overview of the main LTE features supported by ICS Designer ; - A pratical case describing a LTE network design study considering the technical

recommendations that can be used to develop radio network planning processes. However, the detailed specifications used on the practical case are outside the scope of this document. These processes, LTE parameters and input data are typically customized to suit the specific requirements of an operator.

The document is organized into the following sections:

• Section 1 presents an general overview of the LTE functionalities implemented in ICS Designer and and the steps to follows during a LTE network design.The figure points out the process and options that can be used during a LTE planning with the tool.

• Section 2 describes the general LTE aspects and requirements needed during a phase of deployement and optimisation. This section also focuses on the planning tool options considering the fundamental aspects of a LTE deployment such as, coverage and traffic analysis, throughput performance, spectrum re-farming ,mobility (intra-system and inter-RAT) and neighbour planning.

• Sections 3 et 4 focuses on a practical case describing a LTE network design in a urban area located

in Paris. This part illustrates a concret FDD LTE network scenario based on typical LTE e-nodeB configurations, link budget and target throughput,...The goal of this practical case is to present the methodolgy and capabilities of ICS Designer to assure a complet LTE network design (from scratch). This study will describe in details how to find and determinate the minimum number of LTE (macro cells, indoor solutions and microcells) sites via the ACP functions, how to calculate the LTE throughputs based on SNIR vs.Throughput table, how to improve the expected throughput and perform an automatic PCI planning… This practcal case doesn’t illustrate all the features and approachs which can be used in ICS Designer but it provides a good illustration of the flexibility and capability of the tool.

NOTES:

• All the features and modules described in this document are available on the standard version of ICS Designer (No additional costs for extra modules).

• There is no limitation or restrictions of the bandwidth or frequency bands and multi technologies can be supported in the same project (High flexibility of the tool).

• Free cartographic maps over the world, including DTM, Clutter layers and map/aerial images (until 20m resolution) are provided with the tool.



2. LTE GENERAL WORKFLOW

Set technical parameters

of the e-nodeB

Define or load the LTE

simulation parameter file

(.PRM)

Basic predictions:

-RSRP level

-RSRQ (dB)

-RSSI

-SNIR (control channels)

- SNIR (PUSCH)

- ACP (Automatic Cell

Planning)

-Import of LTE cells

-LTE cell configuration

(import by batch )

-Selection site based on

existing UMTS or GSM

- Propagation models

selection

-Characteristics of the UE

-Distance of calculation

(Km)

-Min RSRP sensitivity

(dBm)

- ICIC Enhancement

- % PDSCH and %

Overhead parameters can

be adjusted according to

the traffic scenario

- RSRP plot

- Best server RSRP,

- second server RSRP,

- Third server RSRP,

- RSRP probability,

- Max number of RSRP

channel

- RSRP overlapping area

2D or 3D coverage

analysis

Automatic frequency

assignment

Automatic or manual

neighbour cell allocation

Automatic or manual

Physical Cell Ids and RSI

allocation Various histogramme

analysis :

- Over the whole projet

- Inside a cluster area

defined by a drawn

polygon

- Arround a predefined

vector path)

Field strenght exposure

analysis (in 2D or 3D

modes).

e-node B setu parameter in ICS designer:

- LTE mode (FDD or TDD)

- Bandwidth configuration (1.4; 3; 5;10; 15 or

20MHz) -

Site location, Antenna height , Cell ID , azimuts

, mecanical tilts

- Antenna mode (nb of Tx/Rx arrays):

-Max transmitted power, %RS power, %

PDSCH power, and % control channels power

-RBs traffic capacity

- RSRP min level

- PUSCH received power min (dBm)

- Min sensitivity (dBm) – Noise Floor value

Potential interference

analysis between the LTE

stations and existing

DVB-T network (Low

channel band)

- Standard antenna

-SIMO, Tx Div

-MIMO spatial multiplexing

-Multi user MIMO spatial multiplexing

-AAS (Antenna Adaptive Switch)

Open an existing project

or create a new one



3. LTE FEATURES

3.1. RSRP

RSRP is used to measure the coverage of the LTE cell on the DL. The UE will send RRC measurements reports that include RSRP values in a binned format. The reporting range of RSRP is defined from −140 to −40dBm with 1 dB resolution. The main purpose of RSRP is to determine the best cell on the DL radio interface and select this cell as the serving cell for either initial random access or intra-LTE handover. It is also important to check the non-

Figure 1: RSRP threshold and cell selection

ICS Designer allows to calculate easily RSRP coverage (pilot coverage) according to the technical parameters set on e-nodeB. This step is fundamental to determinate the service area of the cells. Advanced features are available to analyze and optimize (dominance, pollution, overshooting effects) the RSRP coverage:



RS

RP

cov

era

ge

Coverage/Network analysis/

RSRP coverage

analysis/Composite

coverage

This function computes the composite coverage of the RSRP (Reference

Signal Received Power) in dBm based on the "% Ref Signal" defined in the

parameters of the e-nodeB station.


RSRP coverage analysis

/Best Server coverage (16 b)

This function computes a best server map of the Reference Signal (RS).

RS

AN

ALY

SIS



/Overlapping

This function computes the overlapping areas of the RS transmitted by the

whole LTE network in the project.



/Simultaneous

This function computes the percentage of the RS simultaneously received

transmitted from the whole LTE network in the project. For example, if for

a given pixel the result is equal to 30% it means that the receiver will be

able to receive a RS signal from 30% of the stations available in the project



/Simultaneous except best

server

This is a map of simultaneous servers - Gives for each pixel the number of

servers with a RSRP less than the RSRP of the best server reduced by

delta (defined by the user) :

abs(FS_serving_sector-FS_other_sector)>=Delta



/Coverage probability

Calculates the probability of coverage based on RSRP threshold precision

corresponds to a pixel distance around the point being processed to

calculate the average of all these points, not the value exact on the current

point.

Coverage/Network

analysis/ RSRP coverage

analysis /Servers

Displays the first best RSRP server, the second…

RSRP (Reference Symbol Received Power): It is determined for a considered cell as the linear average over the power contributions (in [W]) of the resource elements that carry cell-specific reference signals within the considered measurement frequency bandwidth.

Figure 2: RSCP coverage prediction using

3GPP urban propagation model



3.2. RSRQ

The functions dedicated to the RSRQ allows to perform a complete analysis of the RS signal and to check the impact of the serving and surrounding cells.

Below the list of the functions dedicated to the RSRQ:

- First server RSRQ - Second server RSRQ - Third server RSRQ - Simultaneous servers

RSRQ (Reference Symbol Received Quality): Reference Signal Received Quality (RSRQ) is defined as the ratio N×RSRP/(EUTRA carrier RSSI), where N is the number of RB’s of the EUTRA carrier RSSI measurement bandwidth. The measurements in the numerator and denominator shall be made over the same set of resource blocks.

3.3. SNIR calculations

The Required SINR is the main performance indicator for LTE and the accurate knowledge required SINR is central to the authenticity of the throughput and thus the process of dimensioning. Required SINR depends up on the following factors:

- Modulation and Coding Schemes (MCS) - Propagation Channel Mode - Higher the MCS used, higher the required SINR and vice versa. This means that using QPSK

½ will have a lower required SINR than 16-QAM ½.

The SNIR (Signal to Interference plus Noise ratio) is express as follows:

� S: Useful signal (received power) � I own: Own cell interference (close to zero due to the orthogonally of subcarriers) � I oth: Other cell interference � N: Noise power

In LTE the SNIR PDSCH required replaces the Eb/N0 required of the UMTS Rel.99. The required SINR can be estimated by two different methods:



o By using the „Throughput vs. average SNIR tables. These tables are obtained as an Output of link level simulations. For each type of propagation channel models and different antenna configurations, different tables are needed (see table 1).

o By using the Alpha Shannon formula. Alpha-Shannon formula provides an approximation of the link level results. Thus, in this case, no actual simulations are needed, but factors used in Alpha-Shannon formula are needed for different scenarios

The “4G SNIR maps” function allows to perform SNIR plot coverage for the PDSCH (traffic) and control channels. The SNIR calculation can also take into account:

- The use of multi carriers on the same site (when more than one carrier is used per site) - RSRQ constraints to assure the reliability of the RS signal quality. - All the potential interferers (RSSI) from the LTE inter sites but also from the other network

systems (Digital broadcast network, UMTS, GSM…) - ICIC parameter activated to improve the SNIR performance (ICIC scheduler is used to reduce

risks of collision between PRB’s from inter sites).

Note that SNIR calculation are also used to analyses the radio link failure performance and the other physical channels PDCCH/ PCIFCH, PCH, PBCH, (as described in 3GPP TS 36.101)

For example, PDCCH’s performance is important not only because it delivers the scheduling information to the UEs but also because when a UE first tries to access the network, PDCCH failure can result in delayed access or access failure. During handover, PDCCH failure will cause handover failure since downlink messages (response from the eNodeB) cannot be successfully delivered to the UE.

3.4. DL Peak throughput plots

Per definition Peak throughput represents a theoretical upper bound on what can be achieved on the channel in terms of throughput or capacity. It is an ideal case since it assumes no frame erasures and should not be thought of as a sustainable throughput (refer to Section 5.5 for a definition of maximum sustainable throughput). The peak throughput depend on:

− Bandwith configuration (1.4; 3; 5..20MHz) − SNIR conditions (depends on the path loss attenuations, transmitted power...) − MCS (Modulation Coding Sheme) achieved − n°PRB allocated to PDSCH channels

The Peak throughput calculation requires a table of correspondence (between SNIR vs. Throughput) dedicated to the LTE configuration (Channel models, antenna system, traffic load…). Usually this table is provided by the vendor equipment. In ICS Designer, the table of “SNIR vs. Throughput” used for the



peak throughput calculation can be selected from an internal table implemented in the tool (using standards values as shown below) or from external tables (with the specific vendor’s recommendations): � SNIR vs. Throughput table by default in ICS Designe r:

In ICS Designer, the tables of SNIR vs. Throughput from the recommendations based on vendor recommendations are implemented by default. Those tables can be used for the following LTE configurations:

Bandwidth 5 MHz N° PRB 25 Channel models EPA 5 Hz DL Transmission mode SIMO 1x2, TX diversity 2x2, Open loop Spatial Multiplexing MIMO 2x2 UL Transmission mode SIMO

The Throughput (kbps) values in those table are defined as the date rate per resource block for a given SINR. The peak throughput result calculated on each pixel will be performed according to this table but also the cell load (number of RB used for the traffic allocation) specified in the e-nodeB setup tab of the station (as shown in the figure 2).

Figure 3: E-nodeB traffic parameters with load traffic: 50%

Figure 4: SNIR vs. Throughput table by default in ICS Designer

� Import of external SNIR vs. Throughput table in ICS Designer:

A external table can be requested in an excel sheet via the “Import format 2” options with columns – SNIR (dB), Throughput in kbps per RB for SIMO antenna , Throughput in kbps per



RB for TxDiv antenna , Throughput in kbps per RB for MIMO antenna, Throughput in kbps per RB for UL STD”.

The procedure of import of external throughput tables can be described with the following typical case:

- Step 1: The user must to choose the % cell load used for the simulation (standard value: 50%) - Step 2: The % cell load must be set in the traffic parameter of the e-nodeBs (%RS signal,

%PDSCH channels, %control channels…) - Step 3: Select the column describing the SNIR vs. throughput value for the wanted % load traffic

(figure 4) - Step 4: Then, the user must to create a .CSV file with the values specified in the vendor table and

with the format 2 specified in ICS Designer (see figure 3). Note that, the throughputs values specified in the .CSV must be the throughput only per RB and not for all the RB allocated

Note that the peak throughput calculation in ICS Designer may takes into account multi criterions as the RSRQ reliability and the transmission modes used by the e-nodeBs (fixed transmission mode or AAS Adaptive mode switch antenna are supported):



Figure 5: Peak throughput calculation with AAS mode

Those options allows to analyze, improve the throughput performance of the network and also determinate the most appropriate transmission mode in the cell edge or cell center. Below, an illustration of the throughput performances with different transmission mode configurations:



Figure 6: Peak throughput plots with LTE network using single antenna

Figure 7: Peak throughput plots with LTE network using 2X2MIMO configuration (SU-SD)



Figure 8: Peak throughput plots with LTE network using AAS configuration

3.5. UL peak throughput plots

The UL Peak throughput calculation is performed via the function “4G Uplink SNIR” available in the menu “Statistics -> coverage -> 4G Uplink SNIR”

The UL SNIR calculation is done as follows:

First the best DL RSRP is calculated for all the activated stations.

Then UL SNIR PUSCH can be calculated with 2 modes:

� If « 1 sub / enodeB (random) » is checked, the function will select only one sub/station (stronger sub interferer from the random selection).

� If « 1 sub / enodeB (random) » is unchecked; power sum is applied (this power sum is based on the subscribers selected during the random selection).

Note 1 : Only the parented subscribers are taken into account by this function.

Note 2 : The parented sub doesn’t interfere his wanted station.

Note 3 : The Noise rise calculated with the mode “Subscriber distribution method (Monte-Carlo)” is the average noise rise per station for the whole passes.

Note 4 : If the subscribers are declared as “mobile”, their coordinates will be changed after each pass.

Better SNIR at the

cell edge

with TxDiv mode



Figure 9: UL SNIR map

Once SNIR plot coverage is displayed, the user needs just to import the “UL SNIR vs. Throughput” table.

Figure 10: UL peak throughput plots



3.6. Traffic analysis and LTE schedulers

The throughput an individual user may experience depends both on the MCS allocated (a function of the user’s characteristics and channel conditions especially RSCP, RSRQ and SNIR) and on the demands of other users sharing the channel resource. The sharing of the resources over the users is arbitrated by the scheduler. ICS Designer can simulate the behavior of the traffic for giving population of users according to various type of scheduler. ICS designer have introduce a traffic method of calculation based on the LTE schedulers which allows to determinate what is the best algorithm to apply according to a given traffic scenario. The LTE schedulers are the following:

− Max SNIR: The Priority is given to the current user has the greatest signal to noise ratio (SNR). MaxSNIR method allocates the radio resource constantly to the user who has the best spectral efficiency and therefore that will provide the best throughput on each EU. However, a negative effect of this allocation is that users close to the e-nodeB always have a disproportionate priority on users further away. When the network is congested, it is also common for mobile located on the cell edge that they don’t access at all to the radio resource. With Max SNR it is impossible to guarantee quality of service even minimal since it is exclusively or almost exclusively dependent on the relative position of the mobile. In addition, the Max SNR has another disadvantage: it does not take into account users' needs when assigning priorities.

− RR: This method (called “Rodin Robin”) involves allocating the same amount of RB users. However, the rate actually received will depend on the radio conditions (C / N + I, priority bearers).This method does not take into account the needs of users in terms of desired flow or maximum delay of packets. Users are then assigned a rate that is unrelated to their needs. Round Robin does not take into account the position, capabilities and needs of each user. It allocates the same amount of blindness resource units for all mobile without any possibility of differentiating services and thus ensure any quality of service.

− PF: This algorithm (called “Proportional Fair”) is considered as the most appropriate in terms of simplicity and performance. It consists in allocating RB iteratively so that the overall throughput provided to each user increases gradually in the same way. When a user has received that application flow, no more RB is assigned and the execution of the algorithm occurs with other users. The algorithm stops when all users are satisfied or all RB were distributed. UE get equal flow rates. In the end, the users with low demand are always advantaged because their desired flow is almost always provided; they are often fully satisfied In contrast with the other users who require more resources (note that in the case where all users have the same needs, scheduler "Robin Rodin" equivalent to the Max-Min Fair).

Figure 11: Parenting LTE module in ICS designer



The user needs to define the profile of the UE (max transmitted power, antenna height, transmission mode supported, traffic demand…) and generate the population of UE (per density per km² or over a polygon or per site…) then the LTE parenting function will calculate UE by UE the effective traffic received based on the selected algorithm. Note that during this parenting, DL and UL radio conditions are checked (RSCP, RSRQ and PUSCH). The “ICIC enhancement” option can be checked to reduce the risk of collision between RB transmitted by inter-cells as well the MIMO adaptive switch modes (AAS).

- Dynamic LTE traffic analysis based on parenting met hod: RB allocation and throughput calculation based on UE’s population (can be generated manually or imported via a .CSV file). The final result is a gglobal LTE Traffic QoS report by subscriber, station or for the entire network. Throughput and RB allocation distribution will depends on: � Profile and location of the UE � Channels setting of the cells and RB capacity dedicated to the traffic channel. � Transmission mode used: AAS (Antenna Adaptive Switch) mode or fixed mode

(Single antenna port SISO or SIMO, Tx Div/MISO, Spatial multiplexing MIMO, Multi user MIMO).

� Scheduler method (Max SNIR, RR, PF) � Pre-defined “SNIR vs. Throughput/RB” table

- LTE prospective planning: Automatic search of site to connect the orphan UE (when the UE

is not connected to the e-nodeB) due to a weak level of coverage or traffic congestion.

3.7. PCI planning

The menu “Coverage/Network planning/Physical layer cell identities...” allows to plan the PCI (Physical Layer Cell Identities) and the “PHY Group ID” (Physical Layer Cell Identity Group) in order to avoid any risk of collision between the neighbor cells.

There are 504 unique physical-layer cell identities. The physical-layer cell identities are grouped into 168 unique physical-layer cell-identity groups, each group containing three unique identities. The

Connectivity between e-node B and UEs (Min RSCP, Min RSRQ received by the UE and in PUSCH received by the e-nodeB) are checked then the e-nodeB is allocating the RBs according to the scheduler method used for the simulation. Once the e-nodeB RBs are allocated for the UE’s, the throughput offer is calculated according to a SNIR us Throughput (per RB) table map for the dedicated transmission mode used by the UE. If the AAS mode is selected, ICS designer will choose the best transmission mode for a given UE giving the best SNIR performances. Typically TxDiv transmission mode when the SNIR is poor (at the cell edge) or MIMO mode when the SNIR measured is high (typically when the mobile is close to the station). Of course, the choice of the transmission mode (when the AAS mode is selected) in ICS designer is also depending of the characteristics of the UE (EPA05, EPA70)



grouping is such that each physical-layer cell identity is part of one and only one physical-layer cell-identity group. A physical-layer cell identity NID cell = 3NID(1) +NID(2) is thus uniquely defined by a number NID (1) in the range of 0 to 167, representing the physical layer cell identity group, and a number NID(2) in the range of 0 to 2, representing the physical layer identity within the physical-layer cell identity group (see 3GPP TS 36.211 recommendations). Note that the LTE neighbour list must be previously generated before to launch the PCI planning (refer to the section “2.9 LTE Handover and neighbour list analysis”)

3.8. RSI and PRACH planning

The first step in the random-access procedure is the transmission of a random-access preamble. The main purpose of the preamble transmission is to indicate to the base station the presence of a random access attempt and to allow the base station to estimate the delay between the eNodeB and the terminal. The delay estimate will be used in the second step to adjust the uplink timing. The time–frequency resource on which the random-access preamble is transmitted is known as the Physical Random-Access Channel (PRACH). The e-nodeB broadcasts information to all terminals in which time–frequency resource random-access preamble transmission is allowed. As part of the first step of the random-access procedure, the terminal selects one preamble to transmit on the PRACH. In each cell, there are 64 preamble sequences available. Two subsets of the 64 sequences are defined as illustrated in Figure 14.9, where the set of sequences in each subset is signaled as part of the system information. As long as no other terminal is performing a random-access attempt using the same sequence at the same time instant, no collisions will occur and the attempt will, with a high likelihood, be detected by the eNodeB. ICS Designer the function “Coverage/Network/planning/Root Sequence Index Allocation” allows to perform and optimize the RSI (Root sequence index) allocation of the LTE sites depending of the neighbor relations between the cells. Note that new advanced allocation methods has been implemented (PRACH ZC sequence parameter for 3GPP, coverage range, extended radius…) in the last release.

Figure 12: RSI allocation window in ICS Designer



The number of root sequence index can be generated by several methods:

- By the user - From max coverage range - From extended radius

or

- From PRACH table (0-15) - From extended radius (site tab of the station) - From access radius (km

Object properties (F5): Add of Root Sequence Index (RSI)

3.9. LTE Handover and neighbour list analysis (intr a-inter system)

The handover procedures for E-UTRAN systems are described in the 3GPP TS 36.331. E-UTRAN supports two types of handover:

- Intra Radio Access Technology handovers divided into two categories: � HO intra system with intra-frequency neighbours � HO intra system with intra-frequency neighbours

When an LTE UE is powered on, it scans all E-UTRA Radio Frequency (RF) bands and starts to listen to the broadcast channels for synchronization. This is done to find a suitable cell for initial camping with the best radio conditions according to cell RSRP measurements. After cell selection, the UE registers to the network and starts to measure intra-frequency neighbours as candidates for cell reselection according to cell ranking criteria. Usually this means that reselection is performed if the radio conditions, according to RSRP measurements, are better than a configured threshold above that of the serving cell and if the RSRQ threshold is enough. The UE also measures the inter-frequency cells according to the neighbouring cell list. The prioritization between the intra and inter frequency layers depends of the strategy used by the operator but usually the intra frequency HO are often the first priority.

- Inter Radio Access Technology handovers: � HO between E-UTRAN (LTE) and UTRAN (3G) neighbours � HO between E-UTRAN (LTE) and GSM neighbours � HO between E-UTRAN (LTE) and Wi-Fi neighbours (3GPP release 12)

When the UE is not able to use intra or inter frequency neighbours with acceptable RSRP threshold, the core network will LTE UE is able to switch to UTRAN or GSM system. The advanced HO features on ICS Designer support all the types of HO supported by the E-UTRAN: Inter/Intra technology handovers.



The different options available in this function are the following:

- Handovers for intra-eNodeB and inter eNodeB (LTE-L TE) : � As shown in the figure 13, The HO algorithm used during the calculation is based on the

event A3 (better cell HO) and A5 (handover threshold based on RSRP). � The quality of the RS signal (RSRQ) can be checked during the HO calculation. In this

case, the degradation due to the RSRQ will be takes into account during the HO procedure.

� The Intra and inter frequency HO can be simulated separately. � The HO map can be calculated according to a predefined list of neighboor cells.

Figure 13: LTE<-> LTE handover process in ICS Designer

- Handovers for eNodeB and NodeB (LTE-3G) : : � As shown in the figure 14, The HO algorithm used during the calculation is based on the

RSRP serving cell for the e-nodeB and Ec/I0 plus RSCP thresholds for the nodeB � The quality of the RS signal (RSRQ) can be also checked during the HO calculation. In

this case, the degradation due to the RSRQ will be takes into account during the HO procedure.



Figure 14: LTE<-> 3G handover process in ICS Designer

- Handovers for eNodeB and BTS (LTE-2G) : : � As shown in the figure 15, The HO algorithm used during the calculation is based on the

RSRP serving cell for the e-nodeB and RSSI for the BTS � The quality of the RS signal (RSRQ) can be also checked during the HO calculation. In

this case, the degradation due to the RSRQ will be takes into account during the HO procedure.



Figure 15: LTE<->2G handover process in ICS Designer

The advanced “Neighbour calculation…” function in ICS Designer allows to perform the intra and Inter- frequency neighbour list required to plan the PCI allocations and avoid risk of collision between the PCI’s. The functions includes also the possibility to generate the inter system neighbour list (between LTE and 3G, LTE and Wi-Fi…) according to multi hysteresis criterions.



In the end of the calculation, a .CSV report giving the neighbour list by station is generated and the neighbour cells are automatically updated on the neighbour list box of the e-nodeB setup tab of the LTE station.



3.10. LTE Monte Carlos simulators

LTE Monte Carlo analysis functions in ICS Designer comprises downlink and uplink Best Server, Interference and Traffic analysis. ICS Designer performs several random trials, using a pseudo-random distribution to spread the UE over the map for each trial. The outputs of the analysis are quality and traffic reports. The Monte Carlo approach is very useful and efficient to validate or enhance the LTE network parameters in order to achieve the coverage and interference objectives for a given population of UE. Typically, the LTE Monte Carlo simulators can be used to validate the following criterions: For downlink:

− RSCP Levels − RSRQ levels − SNIR Levels

For uplink:

− PUSCH levels Once the e-nodeB network is configured (antenna height, bandwidth, transmitted power...) a population of UE can be generated (with one or several profiles) can be generated and randomly distributed on the project by different ways: Per density of km², over configured cells. Once the population is generated, the tool will calculate the average and the distribution of the coverage KPIs (RSCP, RSRQ, SNIR PDSCH and PUSCH).



Figure 16: LTE Monte Carlo Simulator in ICS Designer

Figure 17: RSRQ (dB) simulation with Monte Carlo simulator



Figure 18: RSRQ (dB) distribution with Monte Carlo simulator

Figure 19: RSCP (dBm) simulation with Monte Carlo simulator



Figure 20: PUSCH (dBm) simulation with Monte Carlo simulator



Figure 21: SNIR (PDSCH) simulation with Monte Carlo simulator

The Monte carlo simulator can also be used to optimize the e-nodeb configuration in order to improve the coverage and interference KPI s parameters. The Monte carlo simulator is able to calculate the KPI distribution over the UE population with taking into account the variability of the e-nodeB parameters especially the folowing:

− Azimuth(°), − Electrical tilt(°) − Antenna height (m) − Percentage of transmit power dedicated to the RS signal − Percentage of transmit power dedicated to the PDSCH

signal − Percentage of transmit power dedicated to the control

channels − Antenna type (transmission mode: Standard, MIMO SM, Tx Div

, MISO, single antenna, SISO, SIMO, MU-MIMO)

For example, It is easy to check the impact in term of RSRQ(dB) and SNIR(PDSCH) when the electrical tilt applied for the e-nodeBs are between -4° and -8°



Figure 22: RSRQ distribution simulation with Monte Carlo simulator (Electrical Downtilt = -2°)

Figure 23: RSRQ distribution simulation with Monte Carlo simulator (Electrical Downtilt between -4° and -8°)

Figure 24: SNIR (PDSCH) distribution simulation with Monte Carlo simulator (Electrical Downtilt = -2°)



Figure 25: SNIR (PDSCH) distribution simulation with Monte Carlo simulator (Electrical Downtilt between-4° and -8°)

In this example SNIR (PDSCH), RSCP and RSRQ KPIs are degraded when the electrical downtilt applied to the Tx antennas is too high. The aerial configuration using -2° downtilt seems to be the most adapted for the dimensioning network. In the real LTE network, SNIR(PDSCH) level can be improved by the usage of AAS antennas as shown below with the new Monte Carlo simulation using AAS mode. Note that AAS mode and MIMO antennas doesn’t affect RSRP or RSRQ levels: RSRP doesn’t depend on the number of transmit antennas, as it is measured always from resource elements transmitted by one antenna at a time. The 3GPP has defined RSRP as the average power of a single resource element. The UE measures the power of multiple resource elements used to transfer the reference signal but then takes an average of them rather than summing them.

Figure 26: SNIR (PDSCH) distribution simulation with Monte Carlo simulator

(Electrical Down tilt = -2° and AAS mode activated)



3.11. Automatic search of site

Several automatic search site features to increase coverage & capacity are available in ICS Designer. Below a description of the main functions:

Feature name Menu Rules “Prospective planning” “Coverage/Network

planning/Prospective planning…”

This function allows to find the best locations for new sites in case of greenfield and densification scenarios. This function is based on coverage target assumption.

“Parenting LTE” “Subscriber/Parenting/ 4G parenting LTE”

This function is based on a population of LTE users (profiles and traffic demands must be defined). It allows to resolve the problems of the traffic network congestion (or low traffic QoS performance) by adding new sites in the hot spot area. This function takes into account DL/UL coverage criterions and traffic assumption.

3.12. Automatic frequency planning

The advanced Automatic frequency planning function in ICS Designer allows to perform a full and fractional automatic frequency planning for a LTE network.



3.13. Automatic site optimization

Several automatic optimization features of network parameters to increase coverage & capacity are available in ICS Designer.

Below a description of the main ACP features:

Feature name Menu Rules “ Station according to target coverage”

“Coverage/Station candidates/Station according to target coverage”

Allows to select (for all the activated stations) the sites required to achieve the coverage target (by clutter types). Allows to help the user in order to reduce the number of sites required at the minimum.

“Select station according to surface covered by station”

“Coverage/Station candidates/ Select station according to surface covered by station”

Allows to select (for all the activated stations) the sites for a coverage target (surface per km²) required by station.

“Route planning” “Coverage/Network planning/Route planning…”

Function dedicated to roads, highway, railway environments and it used to determinate automatically the best sites and configuration (azimuths, tilts) in order to cover of optimize the clutters defined as a “vector”.

“Prospective planning” “Coverage/Network planning/Prospective planning…”

This function allows to find the best locations for new sites in case of greenfield and densification scenarios. This function is based on coverage target assumption.

“Station optimizing” “Coverage/Network planning/ Station optimizing”

This function allows to optimize a set of parameters (tilt°, Antenna height, azimuth…) in order to improve the station coverage

Other LTE optimising features can be used to:

- Compare and to find for each cell the best equipment configuration (according to a pre-defined list of vendor configuration) in order to improve the target coverage.

- Simulate and compare the prediction results with the use of AAS (Adaptive Antenna Switch) - The user is also able to activate additional parameters such as ICIC parameter or power boosting

(applied to the RS, PDSCH or PDCCH channels) to improve weak coverage.



3.14. Refarming frequency band and inter system coe xistence

At WRC-07 (World Radiocommunication Conference), this resulted in different allocations to mobile services in the digital dividend bands in different regions: 800 MHz in Europe, Africa and Middle East and 700 MHz in Americas and Asia Pacific. WRC-12 corrected this imbalance by also allocating the 700 MHz band to the mobile service in Europe, Africa and Middle East, subject to confirmation by WRC-15. This delay permitted the necessary studies to achieve harmonization of the frequency plans using a combination of both the 700 MHz and 800 MHz bands throughout the world. Very good progress has been made in this regard.

The interference module used in ICS Designer is able to perform multi-technology technical coexistence studies in order to: • Quantify the impact of each technology over the other, • Analyze the affected population and services • Perform scenario analysis to quantify the impact of various tradeoffs: spectrum allocation,

interference impact, costs, etc… The interference between LTE and the other existing systems (like Digital broadcast network) but also the cases of refarming frequency band between the existing mobile network systems (for example between 3G and GSM in the 900 MHz band) can be easily performed . The NDF matrix (standards protection ratios) for all the interferences combination (4G vs. DVB-T, 2G vs. 2G, 2G vs. 3G, 3G vs. 2G, 3G Vs. 3G) are implemented in the tool. The flexibility of the tool allows to the user to support in the same project unlimited stations using different technologies.



Figure 27: Scenario describing the case 3G vs. 2G network when the 2G band [935MHz, 940MHz]

is migrated to the 3G system



Figure 28: LTE stations interference calculation on DVB-T network in ICS Design

(interfered areas are marked with pink color)

3.15. LTE Field strength exposure (2D&3D)

The potential health risk of radiofrequency electromagnetic fields (RF EMFs) emitted by cellular network are currently of considerable public interest. A very important issue is the requirement for coexistence between wireless equipment and people leaving around those type of transmitters. Existing national standards on electromagnetic radiation safety are based on the result of extensive research and consideration of any possible health risks. The recommendation about the maximum exposure level (µV/m) are depending on the countries and can be a subject of disputes between lobbies and operators.

The 3D coverage feature in ICS Designer allows to calculate in 3D the field strength level in visibility only (LOS) or taking also into account the diffraction (LOS/NLOS). The dynamic 3D display engine has been implemented in order to be able to display the coverage in the façade and inside de the building. This feature allows to check easily and clearly the field strength level (dBµV/m or in V/m) generated by transmitters (2G/3G/LTE) and help the RF planner to find the best transmitter configuration in order to reduce the potential risk.

Figure 29: Dynamic 3D display engine in ICS Designer



Figure 30: 3D FS exposure result in the facades

Note that, in the work of the Copic (committee piloted by the French national regulator composed of the national French mobile network operators and various public actors), ATDI has been kindly asked (since 2009 until 2013) to study the population exposure to electromagnetic waves emitted by the antennas of mobile networks, ATDI was responsible to perform the following studies:

− Modeling of coverage (2G, 3G voice and HSDPA) different mobile networks in the current state ("State of Play");

− Impact on the coverage of the various networks of power reduction of certain issuers located in the experimental area;

− Reconfiguration of these networks following a power reduction by adding complementary sites to find or get as close as possible to cover the "state of play", ensuring that these new sites will not generate exposure levels exceeding the target threshold (0.6V / m or 1V / m).

− Modeling of coverage (2G, 3G voice and HSDPA) different mobile networks in the current state ("State of Play");

− Impact on the coverage of the various networks of power reduction of certain issuers located in the experimental area;

− Reconfiguration of these networks following a power reduction by adding complementary sites to find or get as close as possible to cover the "state of play", ensuring that these new sites will not generate exposure levels exceeding the target threshold (0.6V / m or 1V / m).



3.16. LTE Propagation models

Good propagation modeling is crucial for exact network planning and dimensioning

Various LTE propagation models are supported in ICS Designer :

� Usual empirical models such as Okumura-Hata, Hata extended, COST 231 models, …

� LTE 3GPP models (based on 3GPP TR 36.942 V8.3.0 recommendations)

� Geometrical models used for free space attenuation, diffraction loss and the subpath loss calculation. ATDI’s experience in using practically geometrical models (comparisons with measurements and customer remarks) allows providing acceptable prediction (compare to empirical models) even without any calibration of the propagation models. Those last models are very flexible because it allows to support any kind of LTE scenarios (from Network mobile operator or TETRA operator point of view) especially when the LTE receiver is a mobile UE, airplane or helicopter (for police, emergency or military operations). The geometrical models allows also to support inter technology analysis between LTE and UMTS, GSM and digital broadcast network for potential additional coexistence studies.

Empirical models

Okumura-Hata Hata extended COST 231

Frequency Range 150 MHz to 1.0 GHz

1.5 to 2.0 GHz

30 MHz to 2.0 GHz

1500 MHz to 2.0 GHz

eNodeB

Antenna Height

30 to 200 m

above roof-top

use effective height

30 to 200 m

above roof-top

30 to 200 m

above roof-top

UE Antenna Height 1 to 10 m 1 to 10 m 1 to 10 m

Range 1 to 20 km 1 to 100 km 1 to 20 km

Table 1: Applicability of the Okumura-Hata, Hata extd and Cost 231 propagation models

3GPP LTE Empirical models (TR 36.942 V8.3.0)

3GPP RURAL 3GPP URBAN

Frequency Range 150 MHz to 1.0 GHz

1.5 to 2.0 GHz 800 MHz to 2.0 GHz

eNodeB Antenna Height

30 to 200 m

above roof-top

4 to 50 m

above roof-top

UE Antenna Height 1 to 10 m 1 to 3m

Range 1 to 20 km 30 m to 6 km

Table 2: Applicability of the 3GPP propagation models



Geometrical models

ITU-R 525 (Free space model)

Deygout 1994 (Diffraction model)

Standard/Coarse Integration/Fine Integration

(Subpath models)

Frequency Range From 30 MHz to

450Ghz From 30 MHz

to 450Ghz From 30 MHz to

450Ghz

eNodeB Antenna Height

Any value

Any value

Any value

UE Antenna Height

Any value

Any value

Any value

Range

Any value

Any value

Any value

Table 3: Applicability of deterministic propagation models

The propagation model should be adjusted to the environment in which the sites will be built up. This means that propagation measurements and tuning of the model are recommended for real network deployment. The best results found without tuning are geometrical models.

Deterministic propagations models implemented means:

− Ddeterministic models can be used even without calibration or tuning (very useful during the nominal plan phase).

− Can be optimize via an automatic calibration when the site are deployed. − More flexibility in term of time of calculations. − E-UTRAN FDD/TDD, UMTS FDD/TDD, TETRA and all the frequency bands are fully

supported in the same project.



4. PRACTICAL CASE (SCOPE AND INPUT DATA)

4.1. Scope of the study

The scope of this study is to describe a practical case of an LTE network planning study using ICS Designer in a dense urban area located in Paris (France). The coverage requirements for the design are the following:

- Assure DL throughput ≥ 768 kb/s and transmits ≥ 256 kb/s UL (assuming DL MCS≥6 and UL MCS≥5)

- Cell edge coverage probability: 95% - Service area to cover : Urban area composed of streets/Roads/parks/ Buildings (8.6975 km² and

population: 80 000)



Technical assumptions:

- Frequency bands: [2515MHz ; 2535MHz] for Micro sites and [800MHz ; 850MHz] for macro sites; - LTE Macro, Micro and indoor stations can be used during the network design.

4.2. Cartographic layer

Different cartographic layers used in this study have been provided by ATDI:

- A digital terrain model (DTM) with a resolution of 4m providing the altitude of the ground over the whole area;

- Image servers;

- A building layer

- A ground occupancy layer containing 8 classes describing the nature of the ground for the following areas: open, buildings, vegetation, water and roads

Table 4: Clutters parameters used during the simulation

Figure 31: Cartographic layers used in ICS Designer



4.3. Site and simulation parameters

This section describes:

- Physical configuration of the LTE sites

- SNIR Requirement

- Link budget calculation/Power allocation of the site

- Sensitivities (RSRP/Trafic channel)

- Propagation model

3.3.1 Physical configurations of the LTE sites

Macro e-nodeB configuration:

− General parameters: � E-nodeB equipment: Flexi RF module (60w) � Channel Bandwidth: 5MHz � Total Number of PRBs: 25 � Mode: FDD � Tx Antenna Gain : 18dBi � Transmission mode: MIMO 2*2 (2Tx/2Rx) � Feeder losses : 0.4dB � Cyclic Prefix : Normal � Number of OFDM Symbols per Subframe: 14

− System overhead: � Number of PDCCH Symbols per Subframe: 3 � Reference Signal: 9.52% � Primary Synchronization Signal (PSS): 0.17% � Secondary Synchronization Signal (SSS): 0.17% � PBCH / PRACH: 0.31% � PDCCH (incl. PCFICH, PHICH) / PUCCH: 19.05% � Total System Overhead: 29.23%

Figure 32: Antenna diagram (H/V) used during the simulations



UE configuration:

− General parameters: � UE Power Class: 3 (0.2 W) � Transmission mode: 1TX/2RX � Tx Antenna gain: 0dBi � Channel mode: Enhanced Pedestrian A 5 Hz

3.3.2 SNIR requirements

We assume for this study a cell load (average resource utilization) equal to 50% that means the use of 50 RB over 100 for each LTE station. The table of correspondence SNIR (PDSCH) vs. Throughput used for the study is the following (vendor recommendations):

Downlink

(Kbps) Uplink (Kbps)

SINR EPA5 / 2x2MIMO EPA5 / SIMO

-5 525.72 474.48

-4 648.48 578.76

-3 788.16 700.32

-2 946.56 840.84

-1 1125.24 1001.52

0 1325.76 1183.68

1 1549.56 1388.04

2 1798.32 1614.96

3 2073.24 1864.2

4 2375.76 2135.04

5 2706.6 2426.16

6 3066.84 2735.28

7 3456.84 3059.76

8 3876.84 3395.76

9 4326.48 3739.32

10 4805.4 4085.4

11 5312.4 4428.48

12 5845.92 4762.8

13 6404.16 5082.24

14 6984.48 5380.56

15 7583.76 5651.88

16 8198.64 5890.44

17 8825.04 6090.96

18 9458.52 6249.00

19 10094.04 6360.96

20 10726.68 6424.2

21 11350.56 6438.72

22 11960.16 6438.72

23 12549.48 6438.72

24 13112.64 6438.72

25 13643.76 6438.72

26 14137.08 6438.72

Downlink (Kbps) Uplink (Kbps) SINR EPA5 / 2x2MIMO EPA5 / SIMO

-5 43.81 39.54

-4 54.04 48.23

-3 65.68 58.36

-2 78.88 70.07

-1 93.77 83.46

0 110.48 98.64

1 129.13 115.67

2 149.86 134.58

3 172.77 155.35

4 197.98 177.92

5 225.55 202.18

6 255.57 227.94

7 288.07 254.98

8 323.07 282.98

9 360.54 311.61

10 400.45 340.45

11 442.7 369.04

12 487.16 396.9

13 533.68 423.52

14 582.04 448.38

15 631.98 470.99

16 683.22 490.87

17 735.42 507.58

18 788.21 520.75

19 841.17 530.08

20 893.89 535.35

21 945.88 536.56

22 996.68 536.56

23 1045.79 536.56

24 1092.72 536.56

25 1136.98 536.56

26 1178.09 536.56



As shown in the table 7, the minimum SNIR required to achieve 768 Kbps in DL is -3dB:

As shown in the table 8, the minimum SNIR required to achieve 256 Kbps in UL is -5dB:

3.3.3 RSCP sensitivity

The RSCP sensitivity required can be deduced as follows:

Downlink SNIR required for the RS Signal (dB) -16 Noise figure (dB) 5 KTB (dBm) -101.4 KTBF (dBm) -96.4 Slow Fading Margin (dB) – Cell Edge Probability: 95% 13.2 Sensitivity on RS channels (dBm) -99.2

Table 7: RSCP sensitivity calculation

Notes:

Downlink

(Kbps) Uplink (Kbps)

SINR EPA5 / 2x2MIMO EPA5 / SIMO

27 14587.08 6438.72

28 14988.84 6438.72

29 15337.56 6438.72

30 15629.16 6438.72

31 15860.16 6438.72

32 16027.8 6438.72

33 16129.92 6438.72

34 16165.44 6438.72

35 16165.44 6438.72

36 16165.44 6438.72

Table 6:

DL SNIR vs. Throughput (with 50% load traffic)

(Channel models: EPA 5 Hz and Open loop Spatial

Multiplexing MIMO 2x2, BLER: 10%)

Downlink (Kbps) Uplink (Kbps) SINR EPA5 / 2x2MIMO EPA5 / SIMO

27 1215.59 536.56

28 1249.07 536.56

29 1278.13 536.56

30 1302.43 536.56

31 1321.68 536.56

32 1335.65 536.56

33 1344.16 536.56

34 1347.12 536.56

35 1347.12 536.56

36 1347.12 536.56

Table 5:

DL SNIR vs. Throughput (per RB)

(Channel models: EPA 5 Hz and Open loop Spatial

Multiplexing MIMO 2x2, BLER: 10%)



� KTB DL = -174dBm/Hz + 10 * log (15KHz*12* RB) = -174dBm/Hz + 10 * log (15KHz*12* 25) = -107.4dBm

In DL OFDM receiver looks at the whole bandwidth, thus all available Resources Blocks should be considered.

� KTB UL = -174dBm/Hz + 10 * log (15KHz*12* RB) = -174dBm/Hz + 10 * log (15KHz*12* 12) = -110.6dBm In SC-FDMA receiver looks only at the allocated bandwidth, thus not all but only assigned Resources Blocks are assumed in

sensitivity formula.

3.3.4 PDSCH (traffic channel) sensitivity

The traffic channel sensitivity required can be deduced as follows:

Downlink Minimum throughput required (kb/s) 768 SNIR required (dB) -3 Noise figure (dB) 5 KTB (dBm) -101.4 KTBF (dBm) -96.4 Slow Fading Margin (dB) – Cell Edge Probability: 95% 13.2 Sensitivity on PDSCH channels (dBm) -86.2

Table 8: PDSCH channel sensitivity calculation

Notes:

� The SNIR (dB) required for the DL/UL target throughput are defined in the vendor table of recommendation

� KTB DL = -174dBm/Hz + 10 * log (15KHz*12* RB) = -174dBm/Hz + 10 * log (15KHz*12* 25) = -107.4dBm

In DL OFDM receiver looks at the whole bandwidth, thus all available Resources Blocks should be considered.

� KTB UL = -174dBm/Hz + 10 * log (15KHz*12* RB) = -174dBm/Hz + 10 * log (15KHz*12* 12) = -110.6dBm In SC-FDMA receiver looks only at the allocated bandwidth, thus not all but only assigned Resources Blocks are assumed in

sensitivity formula.

3.3.5 Path budget and power allocation

One of the aim of the LTE link budget is to assure that the E-UTRAN air interface is able to support a balanced (DL/UL) connection in any location of the cell with acceptable radio conditions (in correlation with the wanted throughput targets in the cell edge). The BS and UE equipment configuration as well as the coverage threshold required (RS and traffic) validation is crucial for the reliability of the RF design network.

The below table describes the methodology to follow to establish and validate a standard link budget:



Table 9: Path budget and power allocation

When UE transmit power is less than eNodeB transmit power, UEs in idle mode may receive the eNodeB signals and successfully register in cells. However, the eNodeB cannot receive uplink signals because of limited power when UEs perform random access or upload data. In this situation, the uplink coverage distance is less than the downlink coverage distance. Imbalance between uplink and downlink involves limited uplink or downlink coverage. In order to use a balanced link budget, the radiated power used on the traffic channels for the base stations will be 34.2dBm. So for a traffic load of 50%, the nominal power is reduced to 37.3dBm.

3.3.6 Propagation models selection

The recommended propagations models for the LTE study are the following deterministic models:

− Propagation model: ITU-R 525 − Diffraction model: Deygout 94 Method − Subpath model : Standard



Figure 33: Deterministic propagation model selection for LTE simulation ICS Designer



5. PRACTICAL CASE (RESULTS)

5.1. PHASE 1: NETWORK DESIGN

4.1.1 Methodology

In this section we will discuss the process for creating an LTE network design in ICS Designer based on the previous assumptions described before. A step by step process is provided.

1. STEP1: Once the empty project which contains the cartographic data (digital terrain model, clutter, building and Bing, Rim, Google, Geoportail images) is loaded, the first stage of the study will consist to create and configurate the macro and micro LTE sites with the technical parameters described in the section 3.3.1. All the parameters specific to this configuration will be saved into a .TRX file. This file may be used (by batch mode) to update a group of stations or used by the automatic search of site function. Typically a .TRX file can be created for each vendor (Ericsson, NSN, Huawei…) and equipment type (macro, micro, indoor or fetmocell…) and it can be used to update the configuration of one or several stations together.

2. STEP2: The second step is to determinate the number of sites and site locations required to achieve the target coverage and throughput. In practice, during a LTE deployment scenario most of the sites candidates are selected from a list of friendly sites (2G or 3G existing sites) and the rule of the RF planner will consist to find the best candidates and densify the network with the add of new Macro or Micro/Indoor sites. Use the Automatic search site function to generate automatically the LTE network design taking into consideration the required criteria based on the RSRP threshold. During this first step we assume the following assumptions and targets:

a. Only LTE Macro sites (using the 800MHz band) will be used during this phase b. The main target is to achieve at least 80% of the Indoor/Outdoor coverage c. All the geographical sites are located in building supports d. E-nodeB antenna heights: 4 meters above the roof top. e. An another pass will be applied in the second stage with Micro and Indoor sites (using

2.6GHz band) in order to reduce the cost and the number of Macro Site.

3. STEP3: Once the RSRP coverage target is achieved, launch the automatic frequency assignment in order to reduce the inter site interference and increase the global SNIR of the network.

4. STEP4: Check the RSRP overlapping area in order to detect the RSRP pollution area and then increase the downtilt of the interferer station.

5. STEP5: Once the RSRP target is achieved, launch the automatic frequency assignment in order to reduce the inter site interference and increase the global SNIR of the network.

6. STEP6: Check the RSRP overlapping area in order to detect the RSRP pollution area and then increase the downtilt of the interferer station.

7. STEP7: Launch the DL Peak throughput plot coverage based on the DL SNIR (PDSCH) taking into account the RSRQ requirement (Higher or equal to -16dB).

8. Check if the target throughput over the area is achieved. If not return to the step 1 9. Launch the DL Peak throughput plot coverage based on the UL SNIR (PDUCH) 10. Merge the two results DL/UL Peak throughput plot coverage

4.1.2 Automatic search site result

The result of the automatic network design calculation gives 20 MACRO sites and 3 MICRO sites:



Figure 34: Green colour= MACRO SITES; Blue colour: MICRO SITE

Figure 35: The shortcut “Shift +Z” allows to display the inter site distance between the new sites



4.1.3 RSRP and RSRQ results

Figure 36: RSRP coverage

As shown in the figure 37, the result is quite good: Continuous coverage is ensured (more than 96% with cell edge probability: 95%).

Figure 37: RSRP best server coverage



Figure 38: Number of simultaneous RS signals (except from the best signal)

The simultaneous RS signal plot allows to analyse the potential risks of RS pollution. In an area without a dominant cell, the receive level of the serving cell is similar to the receive levels of its neighboring cells and the receive levels of downlink signals between different cells are close to cell reselection thresholds. Receive levels in an area without a dominant cell are also unsatisfactory. The SINR of the serving cell becomes unstable and receive quality (RSRQ) becomes unsatisfactory. In this situation, a dominant cell is frequently reselected and changed in idle mode. As a result, frequent handovers or service drops occur on UEs in connected mode because of poor signal quality. An area without a dominant cell can also be regarded as a weak coverage area (see figure 40). The resolving problems with Lack of a Dominant Cell can be performed as follows: Determine cells covering an area without a dominant cell during network planning, and adjust antenna tilts and azimuths to increase coverage by a cell with strong signals and decrease coverage of other cells with weak signals. The optimisation features described in the sections 3.11 - 3.12 and 3.13 can be used to improve the RSRQ threshold and reduce the lack of dominant cell.

Risk of RSRP pollution



Figure 39: RSRQ coverage plot

4.1.4 DL and UL Peak Throughput results

Figure 40: DL Peak Throughput prediction plot



Figure 41: UL Peak Throughput with Noise rise=7dB

4.1.5 SNIR coverage results

Figure 42: DL/UL SNIR coverage



5.2. PHASE 2: NEIGHBOUR AND PCI PLANNING

5.2.1 Methodology

PHASE 2: NEIGHBOOR AND PCI PLANNING

− Step 1: Select the automatic neighboor list function and activate all the LTE sites. − Step 2: Launch an automatic PCI planning based on the previous neighboor list − Step 3: Display the LTE HO map taking into:

� The intra and inter frequency sites � The various hysteresis criterions (RSRQ/RSRP) � The previous list of intra and inter neighbors cells.

− Step 4: Launch the PRACH planning

5.2.2 Results

Figure 43: Automatic neighbour list calculation

Once the neighbour list is generated the user can perform the automatic PCI planning:



Figure 44: PCI planning report result



Figure 45: PCI allocation in the e-nodeB

Figure 46: Figure 42: Physical-layer cell-identity group allocation in the e-nodeB



The RSI allocation can be performed as follows:

Figure 47: RSI allocation report



Figure 48: RSI allocation planning result

6. REFERENCES

1. 3GPP TS 36.300 v8.0.0, “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access (EUTRAN);

2. 3GPP TR 36.942 V10.2.0, “Evolved Universal Terrestrial Radio Access (E-UTRA);

3. 3GPP TS 36.104, “Evolved Universal Terrestrial Radio Access (E-UTRA);

4. 3GPP TS 36.101, “Evolved Universal Terrestrial Radio Access (E-UTRA);

5. 11_RA4120BEN10GLA0 LTE_Deployment_Scenarios_v01 – Nokia Siemens Network;

6. 01_RA41201EN10GLA0 LTE EPC_Overview_v01 – Nokia Siemens Network ;

7. “Automatic Configuration of Random Access Channel Parameters in LTE Systems” KCA (Korea Communications Agency) (KCA-2011-08913-04003), and in part by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST)

8. “Neighbor Cell Relation List and Physical Cell Identity Self-Organization in LTE” Mehdi Amirijoo, Pål Frenger, Fredrik Gunnarsson, Harald Kallin, Johan Moe, Kristina Zetterberg (Wireless Access Networks, Ericsson Research, Ericsson AB, Sweden).



END OF THE DOCUMENT

Documents

LTE Guidelines in ICS Designer v3 - · PDF file- RSRP overlapping area Physical Cell Ids and RSI 2D or 3D coverage analysis Automatic frequency assignment Automatic or manual neighbour