UMTS Network RadioUMTS Network RadioDimensioning & PlanningDimensioning & Planning

Dr. Dr. HatemHatem MOKHTARIMOKHTARI

UMTS Senior RF EngineerUMTS Senior RF Engineer

1

Presentation plan• Introduction

• Radio design consideration and assumptions

— Differences between GSM and UMTS design, UMTS concepts

— Services, traffic forecast , areas to be covered, quality of coverage

• Radio dimensioning

— Link budget, cell count

• Radio planning

— Radio planning tool

— Coverage analyses, Monte Carlo simulations

— Maps & Statistics

— RF design optimisation

• Conclusions

2

Introduction

• Designing a UMTS radio network needs to take into account the UMTS features:

— UMTS is a Wideband CDMA system

– Coverage and capacity are closely correlated

— UMTS is a multi-service system

– Voice and different data services share the same radio resource

• Before starting the UMTS network design, the design objectives should be clearly stated:

— Services to be offered

— Multi-service network capacity

— Multi-service coverage areas

— Quality of coverage of each service

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UMTS Design considerationsGSM Service Types

• GSM— Voice

— SMS

— Circuit switched data (9.6kbps/14.4kbps)

— Packet switched data (GPRS/E-GPRS)

• GSM is principally designed for voice traffic today.

• There is a need to revisit GSM network designs to quantify performance of data services i.e. GPRS and EDGE

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UMTS Design considerations (cont.)UMTS Service Types

• UMTS— Voice

— SMS

— Circuit switched data (nominally to 2 Mbps)

— Packet switched data (nominally to 2 Mbps)

• UMTS networks will be designed primarily for a mix of data services

• It is forecasted that there will be 12 million subscribers to 384kbps data services by 2005 (UMTS Forum Report #5)

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UMTS Design considerations (cont.)What’s the Difference?

• GSM

— Shared radio resource: channels can be dimensioned separately– e.g. partitioned voice, GPRS data resources

— Primarily voice service based design, with planned terminal capabilities to support only moderate rate data services.

— Quality of channels impacted by inter-cell interference.

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UMTS Design considerations (cont.) What’s the Difference? (cont.)

• UMTS

— Shared radio resource:- channels must be jointly dimensioned– i.e. mutual interference impacts capacity

— Quality and capacity impacted by intra-cell and inter-cell effects

— True wireless data system with terminals expected to offer multiple services up to typically 384kbps.– Packet switched services to dominate

Signal after de-spreadingNoise includes every other channel on carrier

SNRSignal

7

UMTS Design considerations (cont.)Radio design

• GSM— Linear process

– Coverage, Capacity and Parameter planning largely independent and sequential

— Static modeling adequate for both initial and detailed planning

• UMTS/WCDMA/CDMA— Nonlinear process

– Coverage, Capacity and Parameter Planning highly interrelated

— Static modeling for ‘first pass’ initial design for new entrants

— Dynamic modeling for detailed design

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UMTS Design considerations (cont.)UMTS/CDMA concepts

• Cell range & cell capacity are limited by— interference in uplink

— power in downlink

• Cell breathing

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UMTS Design considerations (cont.)UMTS/CDMA concepts (cont.)

• Interference limited system

• Ec/Io determines the coverage performance, NOT signal strength

f

P P

f

Before spreading After spreading

USEFUL SIGNAL

INTERFERENCE

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UMTS Design considerations (cont.)UMTS/CDMA concepts (cont.)

P

f

P

fAfter de-spreading After band pass filter

SIR_after_de-spreading (Eb/No) = SIR_before_de-spreading * Processing_Gain

- Eb/No is the main factor that determines call performance such as FER

- Handoff parameters are based on Ec/Io value

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UMTS design process

Design Targets

Coverage Planning

Capacity Planning

Parameter Planning

• Iterative— considering multiple service

usage across region

• Nonlinear— Coverage planning

– Geographical service availability

— Capacity planning– Ensuring sufficient capacity

in network

— Parameter planning– Network optimization

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PlaNet Tool and Database

• PlaNet tool:Planet version 2.8 with W-CDMA module from MSI

• PlaNet database20m resolution clutter and terrain database

Hardware platforms (used by Nortel):

UNIX environment:Sun UltraSparc1 with 256 MB RAM, 4 GB hard drive, and Solaris 2.5.1. Operating System

PC environment:Dell Precision 410 with 366+ MHz processor, 1 GB RAM, 9 GB hard drive, and Windows NT 4.0 with Service Pack 4

• Over 10 years of experience (GSM, TDMA, CDMA…)

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• Suggested UMTS Application with Planet 2.8:

• UMTS Coverage design is based on PCCPCH, it is handled by Planet as a regular Pilot Channel

• Overall power required by UMTS overhead channels is added together under a single Planet defined overhead channel

• Forward link power range for traffic channel is set for highest desired data rate at the cell edge

• Cell count design has to be based on this data rate i.e. most constraining service

UMTS Design

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UMTS Link Budget(Generic)

LINK BUDGET Macro cell Macro cell

GeneralIndoor

SuburbanIndoor Urban

S3 111 S3 111Spreading bandwidth (kHz) 3840 3840Thermal noise (kTB) (dBm) -108.2 -108.2Data rate (kbps) 60.8 60.8Bearer rate (kbps) 256 256Processing gain UPLINK 63.2 63.2Processing gain (dB) 18.0 18.0UPLINK CharacteristicsUser Equipment TransmitterMaximum UE TX power (dBm) / MEAN 21.0 21.0UE TX antenna gain (dBi) 0.0 0.0 Total UE TX EIRP (dBm) 21.0 21.0 Base Station ReceiverBS RX noise figure (dB) 3.3 3.3Baseline RX Eb/No (dB) (from SMG Marseilles 2.2 1.7BS RX Eb/No (dB) 1.4 0.9BS RX sensitivity (dBm) -121.5 -122.0BS RX antenna gain (dBi) 18.0 18.0 BS RX cable & connector losses (dB) 3.0 3.0 Maximum Reverse Path LossMaximum allowable isotropic path loss (dB) 157.5 158.0DOWNLINK CharacteristicsBase Station TransmitterBS TX antenna gain (dBi) 18.0 18.0 BS TX cable & connector losses (dB) 4.1 4.1 User Equipement ReceiverUE RX noise figure (dB) 5.0 5.0Baseline UE RX Eb/No (dB) with Tx DivBaseline UE RX Eb/No (dB) (from SMG Marseilles 1.6 1.1UE RX Eb/No (dB) 0.8 0.3UE RX sensitivity (dBm) -120.4 -120.9UE RX antenna gain (dBi) 0.0 0.0

• One link budget- per morphology

- environment- coverage type

- per service

• Only the most constra--ining service in eachmorphology was used for link budget calculation

• Important parameters:Base station noise figureReverse Eb/NoBuilding penetration lossArea and cell edge reliabilityFade marginHandoff gain

15

UMTS site database

• Important parameters:- Location- Antenna azimuth- Antenna downtilt- Antenna EIRP - Antenna height- Antenna type- Prediction model

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Coverage objective and clutter database (Barcelona)

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Terrain database Example (Barcelona)

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Design assumptions

• Services

— Required services:

– Speech,

– LCD64, 144, 384, 2048

– UDD64, 144, 384, 2048

— Environments - geographical regions

– Dense urban

– Urban

– Sub-urban

– Rural

• Service areas of coverage

— Accurate geographical definition of each service

– Service area polygons

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Design assumptions

• Quality of coverage

— Coverage types

– Outdoor

– Indoor (indoor penetration factor)

– In-car or in-train (in-car or in-train penetration factor)

— Quality of coverage

– Cell area reliability (Percentage of cell area being covered)

Speech LCD64 UDD64 UDD 144 UDD 384

Urban Indoor Indoor Indoor Indoor Indoor

Suburban Indoor Indoor Indoor Indoor Indoor

Rural Indoor Indoor Indoor Outdoor -

Roads Incar - - - -

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Design assumptions• Capacities

— Per service

— Per area

— Both Uplink & Downlink

— Geographical distribution (traffic maps)

• Traffic models

— Busy hour speech traffic : Erlang

— Busy second data traffic: Mbit/s

P e a k h o u r tra ffic S p e e ch(m Erl)

UDD144Up l in kM b it/s

UDD144Do w n l in k

M b it/s

UDD384Up l in k

(M b i t. /s)

UDD384Do w n l in k(M b it. /s)

Urb a n 345763 1,67 10,43 9,6 19,2S u b u rb a n 172881 0,84 5,22 4,8 9,6

Ru ra l 115254 0 0 0 0O th e r 12678 0 0 0 0

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Design assumptions

• All of the design assumptions are correlated

— Services

— Coverage types

— Service areas of coverage

— Capacities

— Quality of coverage

Design targets

• Radio network design results are highly dependant of the design assumptions

— Any change of one of the assumptions requires to re-do the design work

— Design assumptions => Number of sites=>M$ to be invested

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Radio dimensioning - Link Budget

• Per service

• Per morphology

— Environment

— Coverage type

• Quality of coverage

— Cell area reliability

• Capacity & Traffic load

— Uplink N-Pole capacity

— Uplink interference margin vs. traffic load

— Downlink interference margin vs. traffic load

— Frequency reuse factor

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Radio dimensioning - Link Budget

• Performance -Quality of service

— BS & MS Eb/No targets per service including diversity gain

• Cell sites

— Antenna height, gain

— Cable loss

— BTS power and Configuration

— Uplink power: mobile TX power

• Link budget balance

— cell radius based on UL pathloss

— determine BS output power per user, assuming:

– DL pathloss = UL pathloss

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Radio dimensioning - Cell count

LB @ X% loadDesign assumptions

ComparisonDecision

adjustload

Final number of sites

Cell size Cell capacity

# sites for coverage # sites for traffic

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Radio dimensioning - Multi-service

• Multi-services are supported by the same system

— LB per service

Radius 1 Radius 2 Cap 1 Cap 2 Cap nRadius n

Link Budget 1

Current Load

Link Budget 2 Link Budget n

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5 macro-zones

Radio dimensioning - Paris Example

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• Service areas and surfaces

Service Area PlaNet polygones Design criteria * SizeZone A Zone1 UDD 384 IndoorZone B Zone2 UDD 384 IndoorZone C Zone2 UDD 384 IndoorZone D Zone3 LCD 64 IndoorZone E Zone4 UDD144 Outdoor

Radio dimensioning - Paris Example

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• A service area is defined by:

— Environment (urban, suburban, rural…)

— Indoor penetration factor

— QOC & QOS

Pénétra tion Q oCZone A 21 dB 90%Zone B 18 dB 90%Zone C 15 dB 90%Zone D 12 dB 90%Zone E - 90%

Radio dimensioning - Paris Example

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Speech UDD 64 UDD 144 UDD 384 LCD 64 LCD 144Zone A Indoor Indoor Indoor Indoor IndoorZone B Indoor Indoor Indoor Indoor IndoorZone C Indoor Indoor Indoor Indoor IndoorZone D Indoor Indoor Indoor IndoorZone E Outdoor Outdoor Outdoor

• A service area is defined by:— Required services

— Coverage type (indoor, outdoor, in car …)

Radio dimensioning - Paris Example

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Radio dimensioning -Paris example

1st 1st CellCell CountCount

Zone 1Zone 1

N1 sitesN1 sites

First setof LB

2nd 2nd CellCell CountCount

Zone 2Zone 2

N2 sitesN2 sites

Second setof LB

4th 4th CellCell CountCount

Zone 4Zone 4

N4 sitesN4 sites

fourth setof LB

5th 5th CellCell CountCount

Zone 5Zone 5

N5 sitesN5 sites

fifth setof LB

3rd 3rd CellCell CountCount

Zone 3Zone 3

N3 sitesN3 sites

third setof LB

Number of sites is evaluated

on the basis of a coverage and a traffic study

Total # of sitesTotal # of sites

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Radio planning - Planning tool

• W-CDMA technology

• Multi-service

— Speech

— Data:

– LCD64, 144, 384, 2048

– UDD64, 144, 384, 2048

• Multi-carriers

• Different user types

UMTSCell

PlanningTool

Quality of

Service

Coverage Maps

UMTS CellPlanning Tool

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Radio planning - Prediction & Simulation

�PA�Tx/Rx link losses�Noise figure�Eb/No�Processing Gain�...

BTSBTS

�PA�Noise figure�Eb/No�Processing Gain�...

MSMS

Service

�Cable loss�Antenna pattern�sites configuration �sites constraints (reuse of existing sites)

SiteSite

Propagation ModelPropagation Model

Terrain Data BaseTerrain Data Base

Monte-Carlo Simulations Monte-Carlo Simulations

Statisticsdropped calls

hand-offsUL noise riseCell loading…

MapsPilot Ec/Io

UL Required MS EIRPSoft HO

sitesLocation & configuration

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Radio planning - Planning tool

• Coverage prediction

— Pathloss calculations

— Coverage based on design thresholds

• QOS simulations- Monte Carlo simulations

— UL/DL Eb/N0 targets

— Power allocation

— Power control

— Soft HO

Call dropsUplink noise riseHO regions and statistics

Cell PlanningTool

Coverage Maps Quality of Service

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Radio planning Coverage analysis

• Design Threshold— based on maximum allowable path loss for the most constraining

service.

— The required mobile received signal is calculated based on BS EIRP and on Maximum Path Loss.

Height database

Clutter database

User input

BS radiated power

antenna pattern

frequency

Received power at each bin

Design threshold=BS EIRP-Maximum Path Loss

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Radio planning - Monte Carlo simulations

•Users are randomly generated based on

•Poisson law•Traffic maps

•Successive shots

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Radio planning - Pilot Ec/Io

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Radio planning - UL Required Mobile EIRP

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Radio planning - RF Design Optimisation

• Standard optimisation:

— Antenna re-orientation

— antenna downtilt

— site re-location

• Site densification

— increase capacity

— increase the level of interference

• carrier overlay

Continuos process

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Conclusions

• Optimum network radio design requires accurate design

assumptions in terms of services, coverage, capacity, and

quality of service

• Capacity and coverage strongly correlated

• Multi service

— voice and data over the same radio resource