3G Network Optimisation

Mycom International Confidential 1

Design and Optimisation of 3G

Networks

Payam Taaghol

Managing Director of Mycom - EMEA


PreliminaryNetwork Design

Site Acquisition, Town and Country Planning

Detailed NetworkDesign

PermittingProcurementContracting

Site Design &

Construction

EquipmentI&C

Pre-launchOptimisation

Performance Acceptance

Programme Management

Find Ideal Site Location

Find willing landlordObtain planning permitSign a rental agreement

Refine Site LocationsOrder transmission

Select subcontractorsSelect suppliers Order material

And manage delivery

Design siteConstruction

Rigging

Drive testingNetwork statistics

Meeting Key Performance Indicators

Install all equipmentConnect to networkConfigure and test





Site Design &

Construction

EquipmentI&C



Programme ManagementBusiness Objectives and High Level Design

EndEnd--toto--End Network DeploymentEnd Network Deployment


StepStep--1, Business Requirements and HLD1, Business Requirements and HLD

Expected Services and Data Rates Demand Models Mobility Models Traffic Models Staged Rollout Plan

Theory We do not really know what services We do not know the demand We do know exactly know 3g user

distribution We need coverage in big cities Why not go 384kbps and assume 60%

loading? How many sites? How much? Too expensive, so lets go for 64kbps How many sites? How much? OK this is better, but our competition

may go for 384kbps, why not 384kbps for?

How many sites? How much? central business districts? OK lets go!

Practice


UMTS Network Planning for a Particular or a Mixed Bearer rate

Coverage Capacity

Uplink, LinkBudgets

B / A

C > D No Capacity LimitedCoverage Limited Yes

HW Capacity

Erlangs/Site orSector

A

C D

No of Required Sites/Sectorsfor Coverage

No of Required Sites/Sectorsfor Capacity

Cell Radius

B

Traffic Prediction

Total Req. Er.

Mixed ServiceTraffic Model

InterferenceMargin

CapacityEnhancement

Options

Prop

rieta

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Spreadsheet Analysis



Lower uplink rates

9 Dimensioning for 12.2kbps, 144 kbps or 384kbps? 9 The true demand for high data rate uplink access is not know9 Variable rate coverage is reality9 Multirate applications and services are envisaged in UMTS allowing rate

changes during an active session

Higher uplink rates

Variable Rate Coverage

9 This will avoid over engineering the network and helps reduce the infrastructure costs



StepStep--2, Preliminary Network Planning2, Preliminary Network Planning





Site Design &

Construction

EquipmentI&C





Carried out by radio planners commonly known as RF Engineers

Using planning tools Propagation predictions

based on, available, existing and ideal new site locations

WE NEED A SITE HERE



Preliminary RFDesign Acceptance

Final RF Design Review (by cluster)

Final RF Design Acceptance

(by cluster)

Consolidation of Requirements

RF Design Acceptance Procedure

RFDatabases

Friendly Sites

SharedSites

Other Viable

Structure

CW Testing and Model

Tuning

Market Data Collection

Preliminary RF Plan

Preliminary RF Design Review

(per city)

SARFs, Site Visits,Candidate Selection,

Design Tuning,Initial Data Fill

Operator/Contractor

Jointly

Operator

RF Design Specifications

Radio Planning Guidelines

X% of sitesselected

Yes

No

iPlannerStage-1: Preliminary Design

Stage-2: Final Design

Detailed planning tool based analysis

Propagation Model Tuning

Digital Terrain Map Clutter Maps Design guidelines

OUTPUT-Search Rings or Search Area Request Forms (SARFs)


9Detailed Analysis

Define system requirementsCapacity, coverage, services and schedule

Acquire Data setsDigital terrain, streets, highways, railways, boundaries. Subscriber distribution. Friendly sites.

Detailed coverage requirements. Quality, probability of coverage & specific coverage goals.

Detailed capacity requirements. User services and traffic, GoS requirements / blocking prob.

Design analysis.Reverse and Forward links, capacity, coverage, best server,polluter and HO analysis.

Define system requirementsCapacity, coverage, services and schedule

Acquire Data setsDigital terrain, streets, highways, railways, boundaries. Subscriber distribution. Friendly sites.

Detailed coverage requirements. Quality, probability of coverage & specific coverage goals.

Detailed capacity requirements. User services and traffic, GoS requirements / blocking prob.

Design analysis.Reverse and Forward links, capacity, coverage, best server,polluter and HO analysis.

Requires Planning Tools




DTM

Typically 20m-100m horizontal resolution

0.5m-5m resolution



Clutter Maps

Typically between 10-100 clutter types

Resolution of 5m-100m






Site Design &

Construction

EquipmentI&C




StepStep--4, Detailed Network Plan4, Detailed Network Plan


Preliminary RFDesign Acceptance

Final RF Design Review (by cluster)

Final RF Design Acceptance

(by cluster)

Consolidation of Requirements

RF Design Acceptance Procedure

RFDatabases

Friendly Sites

SharedSites

Other Viable

Structure

CW Testing and Model

Tuning

Market Data Collection

Preliminary RF Plan

Preliminary RF Design Review

(per city)

SARFs, Site Visits,Candidate Selection,

Design Tuning,Initial Data Fill

Operator/Contractor

Jointly

Operator

RF Design Specifications

Radio Planning Guidelines

X% of sitesselected

Yes

No

iPlannerStage-1: Preliminary Design

Stage-2: Final Design

Site locations almost fixed

Every site has been visited and evaluated

More radio analysis

Normally done per cluster of site (10-30 sites)

OUTPUT- A design that meets the requirements, final site locations and type (site mix)



Traffic Forecasting

Coverage Planning

Capacity Planning

Pre-launch Optimization

2G TDMA Process Overview

Traffic Forecasting

Design Optimization

System Coverage & Capacity Planning

3G W-CDMA Process Overview

Pre Launch Optimization

Into Service

Deployment

Into Service

Deployment

Post-Launch Optimization Post-Launch

Optimization

Traffic Forecasting

Coverage Planning

Capacity Planning

Pre-launch Optimization

2G TDMA Process Overview

Traffic Forecasting

Design Optimization

System Coverage & Capacity Planning

3G W-CDMA Process Overview

Pre Launch Optimization

Into Service

Deployment

Into Service

Deployment

Post-Launch Optimization Post-Launch

Optimization

Planning Similarity and Differences



Ec/Io PlotsEc/Io Plots Signal Strength PlotsSignal Strength Plots

Ec/Io vs. Signal Strength

StepStep--8 and 9, Pre Launch Optimization8 and 9, Pre Launch Optimizationand Acceptanceand Acceptance


Before optimisation After optimisation

Areas with pilot quality Ec/Io > -12dB from 67% to 86% 19% increase in coverage area for the same loading (60%)



Second Tier

Cluster of Interest

First Tier

Second Tier

Cluster of Interest

First Tier

CDMA Analysis

1. Include at least 2 tiers around the cluster of interest in all predictions and simulations.

2. Ensure that the traffic maps and mobility models have correctly captured the clients needs.

3. Carry out pilot dominance analysis to identify problematic areas.

4. Focus on improving the pilot quality in problematic areas though design adjustments (tilt, azimuth, power).

5. Carry out forward and reverse link Eb/(No+Io) analysis to ensure traffic channel quality.



CDMA Analysis

6. Analyse handover regions.7. Analyse and minimise pilot

pollution.8. Increase system load in steps

to identify capacity limits.9. Push the interference out of

the dense and high traffic areas into rural areas.

Clutter Traffic Service Area Dense Urban High 100% Medium 100% Low 98% Urban High 100% Medium 98% Low 95% Suburban High 100% Medium 95% Low 85% Rural High 100% Medium 95% Low 75% Roads High 100% Medium 100% Low 95%

Area percentage Ec/Io > min Ec/Io



Dominance

9 Ec/Io dominance provides an overview of the design quality.

9 It also provides an indication as to where to focus design optimisation effort.



Pilot Quality9 A stronger signal does

not necessarily mean better quality.

9 Pilot Ec/Io is effectively determines the cell boundaries.

9 Facing sectors should be avoided.

9 Sites above 20m should be carefully investigated.

9 Typical target Ec/Io values range between 16 to 12.



Pilot of Polluters9 A polluter transmitter is a

transmitter that meets all criteria to enter in active-set but is not admitted due to the active-set limit size.

9 If there are more cells in the active set than the available RAKE fingers, slipover cells will act as interferes and are referred to as polluters.

9 1-2 pilot polluters are deemed acceptable.



Ec/Io

Pilot PollutionEb/No

Soft Handover Plots







Site Design &

Construction

EquipmentI&C






Site Integrated and Commissioned + Shakedown

Yes

No

Generate Datafill or Data Transcript

x% of the sites in cluster Ready?

Cluster Testing

Data Processing and Analysis

Modification Request(SW/HW)Change

Yes

No

Cluster Acceptance

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Review & Verify Datafill

Operator/Contractor

Operator/Contractor

OperatorSite on Air (Barred)Cluster in Commercial

ServicePerformance Monitoring

and PerformanceManagement

Acceptance Procedures

Datafill Upload

Stage-2

Stage-3

Stage-1Commercial Service

Code Plan (CP)Neighbour List (NL)

etc.

Procedures/Guidelines

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Acceptance Report

Acceptance Testing

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Bring a site live Test live site

against plans Drive test and

make test calls Analyze test calls Make changes Drive test again Carry out

acceptance testing

OUTPUT- Tuned network that meets the set performance targets for launch


What do we optimize?



Some Optimization parameters

9 Coverage probability (based on Ec/Io [correlated signal strength of pilot channel]) 9 Call blocking probability9 Call drop rate9 Call completion success rate9 Variable data rate performance9 Throughput at the edge of the cell (PS and CS bearers)9 End-to-end packet delay transfers9 Cell search time9 Inter-cell handover success rate9 Intersystem (UMTSGSM and UMTSGPRS [general packet

radio service]) handover/cell reselection success rate



Not all parameters have the same importance with different

operators.



Artificial Loading Conditions

9 In the absence of a large subscriber base, how would we optimizeUMTS?The truth is that most optimisation issues will not be evident in early

UMTS life until the subscriber base grows.This does not mean we have to wait until we hit a problem.Artificial loading in the form of noise can be generated at the receiver

(both Node-B and UE) to emulate increased interference.



9 Better designs require less optimisation.9With all the uncertainties in respect to the mix of services and

loading UMTS would require a long an on-going optimisation period.9 CDMA optimisation is more exhaustive as it happens as cell,

cluster and inter-cluster level.9With significantly smaller cell radii than GSM, controlling the

interference becomes an important issue.9 Advanced interference management algorithm using the outer

loop power control provisions of UMTS would be in great demand.9 Cell breathing has to be controlled in order to avoid an increased

handover failure rate or an increased other-cell interference.9Optimisation tools are in release- correct operation to be

confirmed.9QoS is an end-to-end measure. Tools that can analyse access,

Ongoing Optimization Issues



Dead Zone size depend on:- Geometry of the cells.- Minimum Coupling Loss (MCL dependant on antenna radiation pattern)- Adjacent Channel Selectivity (UE ACS >= 33dB)- Adjacent Channel Leakage power Ratio (UE ACLR >= 33@5 & 43@10 MHz)

(BS ACLR >= 45@5 & 50@10 MHz)

Dead Zone size depend on:- Geometry of the cells.- Minimum Coupling Loss (MCL dependant on antenna radiation pattern)- Adjacent Channel Selectivity (UE ACS >= 33dB)- Adjacent Channel Leakage power Ratio (UE ACLR >= 33@5 & 43@10 MHz)

(BS ACLR >= 45@5 & 50@10 MHz)

Operator A Operator BOperator ASubscriber

Operator ACoverage

Dead Zone~ 100m for 1Km cell


9 TEMS Investigation-WCDMA tool with Qualcomm UE real-time air-interface test tool Ability to tune and optimize WCDMA

networks UE-based measurements for

verification of true terminal behavior Verification of cell coverage, capacity,

accessibility, etc. Troubleshooting capabilities System verification of trial systems

9 TEMS Scanner-system verification and troubleshooting CPICH scanner-Scanning received

power of Scrambling code SCH scanner-scanning received power

of SCH



Drive Test Set up9 Equipment9 Anritsu Scanner9 2 x Samsung Z105 mobile

phones with Qualcom Chipset9 CF29 Tough book PC.



9Increased SectorisationAntenna patterns are not perfect and will result in increased interference

9Reduced cell radiusIncreased number of sites / equipment hence increased infrastructure cost

9Use of enhanced technologiesTransmit diversity: Fairly easy, planned for phase-1Intelligent antenna: Technology not mature enoughMultiuser Detectors: Technology not mature enough

Capacity Growth



Drive Testing & Benchmarking

Network Statistics & Call Trace

Transport

Core Network

Customer Feedback

OPEX Trade off

CAPEX Trade off

Performance Requirement

Corrective Decision

Features and Upgrades

Network Performance Monitoring & Analysis

End user Views

Trade off Analysis- Advanced Performance Management Tools

E2E Optimization (user experience) Expansion

Site Rationalization

Transmission Rationalization

Recommendation Report

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Breaking through the silos

Performance ManagementPerformance Management


Thank You

Documents

3G Network Optimisation