3G Optimization Overview

UTRAN Optimisation Process29th May 2004

AgendaAgenda

Introduction and Objectives

Optimisation Phases Overview

Single Site Verification

RF Optimisation

Services Testing & Parameters Optimisation

Regular Reference Routes & Stats Analysis

Summary

To provide an overview of the overall optimisation

process

To introduce the different optimisation phases of a 3G

Radio Network

To prepare for more in-depth discussions of various

optimisation topics

Introduction & ObjectivesIntroduction & Objectives

AgendaAgenda




RF Optimisation



Summary

[1] Single Site Verification:

Every new site is tested and verified optimise coverage to be

functioning properly

Any installation or parameter errors must be rectified.

[2] RF Optimisation:

Once clusters of sites are ready, RF Optimisation can be

started in order to and minimise interference and pilot

pollution.

All RF-related failures or drop calls must be resolved.

Optimisation Approach Overview (1/3)Optimisation Approach Overview (1/3)

[3] Services Testing & Parameter Optimisation:

Comprehensive services testing should be carried out in areas

of good coverage to determine system performance

Causes of any failures must be identified and whenever

necessary relevant parameters should be optimised.

[4] Regular Reference Routes & Stats Analysis:

Regular testing & stats analysis will be needed to identify and

resolve any new issues as a result of (e.g. increased traffic).



Cluster of sites ready?


No

Re-optimisationNeeded?


NoYes

New Sites IntegratedNew Sites Integrated

Single Site VerificationSingle Site Verification

Services Testing &Parameter Optimisation


Regular Reference Route Testing & Stats Analysis


RF OptimisationRF Optimisation

Yes

AgendaAgenda




RF Optimisation



Summary

Single Site Verification (1/3)Single Site Verification (1/3)






No

NoYes



Services Testing &Parameter OptimisationServices Testing &

Parameter Optimisation



Yes

Single Site Verifications (2/3)Single Site Verifications (2/3)

Objectives:

1. Verify Coverage (RSCP & Ec/Io)

2. Verify scrambling codes

3. Verify no installation faults

4. Make test calls

Tools:

Scanner + UE

Process:

A detailed check list of various tests must be conducted.

Tests will include: call setups, reselection, handover, LA/RA upd

ate, PS attach & detach, PDP activation, etc.

If unusual low signal strength should check wrong feeder conne

ction (Tx/Rx main antenna, Rx diversity antenna), etc.

Single Site Verifications (3/3)Single Site Verifications (3/3)

An example Check list (to be discussed later)

□ □25 Overall performance and coverage area as expected by a brief drive test □ □

Notes: If the item is OK, mark the '√ ' on the '□ '; If the item is not OK, mark the '╳ ' on the '□ '; If the item is not checked, mark the '∕ ' on the '□ '.

□ □ □ □

□ □ □

□ □

□ □ □

□ □ □ □

□□

□□ □ □ □□ □

□□

□□ □ □ □□ □ □

□ □ □ □□ □ □ □

RemarksNew Expansion Migration Others

Site Expanded from:Site Migrated from RNC:

To:To RNC:

Site Connected to RNC:

Idle

Mod

e Site Migration: Others:

□ □ □ □

New Site: Site Expansion:

Mapinfo Update □Data Base Update □

ReminderSite Checklist

□ □□

24 Installed antenna is of the planned type □

□

□ □

□21 Soft handover for VP service to and from the 3G cells checked OK20

23 Inter-system handover for voice service to the 2G cells checked OK 22 Soft handover for PS service to and from the 3G cells checked OK

Soft handover for voice service to and from the 3G cells checked OK19 RA update proceduce is checked □

18 The PS service quality is good by the engineer feeling □ □ □□ □

15 PS attach is checked □ □ □ □

□ □□ □□

17 PS PDP activation and deactivation is checked □ □

14 The VP service quality is good by the engineer feeling□

Mobile terminating calls and mobile originating calls for voice service is checked

13 Mobile terminating calls and mobile originating calls for VP service is checked□ □ □□

□

□ □□ □ □

□□ □ □

7 Cell reselection from 2G to 3G is checked □ □ □□8 MO-SMS and MT-SMS □ □ □

□

The LAC/RAC is correctly defined ( SIB 1 )□ □

6 Cell reselection from 3G to 2G is checked 5 LA update proceduce is checked

□ □4 The neighbor list and parameters are as planned ( SIB 11 )

□ □

Site Name:

□Frequency and Scrambling Code correctly defined

Site ID:

□No. Activity/Process

CPICH_RSCP > -85 dBm near site

Con

nect

ion

Mod

e

9

2 Cell selection and reselection parameters are as planned ( SIB 3 )1

3

12 The voice service quality is good by the engineer feeling1110 CPICH_EcIo > -8 dB near site

2-Name/Designation: Signature: Data:

Checked by:1-Name/Designation: Signature: Data:

PS

Remarks (Further comments):

Han

dove

r

26 Antenna Swapping TestGen

16 PS detach is checked □

AgendaAgenda




RF Optimisation



Summary







No

NoYes



Services Testing &Parameter OptimisationServices Testing &

Parameter Optimisation



Yes

RF Optimisation – Intro (1/2)RF Optimisation – Intro (1/2) Objectives:

1. Optimize CPICH and service coverage & cell dominance

2. Minimize interference & pilot pollution

3. Optimize neighbor list

4. Resolve any RF-related drop calls

Tools:

Scanner + UE with logging tool

Process:

Drive survey with a UE initially in a continuous AMR call.

Drop calls should be analyzed to determine if the causes are RF

related.

Solutions:

Neighbor list modification

Antenna tilt and/or azimuth changes.

Data Analysis

RF Optimisation – Intro (2/2)RF Optimisation – Intro (2/2)

Process Flow:Start

Identify any RF Issues

Identify candidate cells for changes

Determine amount of change

Identify nature of required changes

Implement changes

Repeat Drive Test

Yes

End

Problem Resolved

?

No

Drive Test

RF Optimisation – Analysis (1/8)RF Optimisation – Analysis (1/8)

Analysis Approach: Various plots from UE and

scanner need to be analysed:

Cell Dominance (best serving cell plots)

Down Link Coverage (CPICH RSCP & Ec/Io plots)

Uplink Coverage (UE Tx power plots)

Pilot Pollution (Pilot pollution table & Estimated Active set

size)

Neighbour list verification

SHO Performance

Drop Calls


Analysis of Cell Dominance:

To identify: Cells with no or poor

dominance

Cells with excessive

dominance

Best server differences

between scanner & UE

Scrambling Code plot of best serving cells


Analysis of DL CPICH Coverage:

To identify: Areas of poor coverage (i.e. poor RSCP & Ec/Io)

Areas of high interference (i.e. high RSCP but low Ec/Io)

CPICH RSCP Plot

CPICH Ec/Io Plot


Analysis of UL Coverage:

To identify: Uplink coverage limitation

(i.e. UE reaching max Tx

power)

UE Tx power.


To identify: Cells causing pilot

pollution

Locations where there

are too many soft

handoff candidates

Estimated active set size from scanner data.

SC Count % in Pollution Set8 206 12.9%9 165 10.3%

10 157 9.8%11 156 9.7%12 148 9.2%13 135 8.4%16 95 5.9%17 94 5.9%18 76 4.7%19 74 4.6%20 73 4.6%21 56 3.5%32 54 3.4%35 39 2.4%37 33 2.1%43 19 1.2%48 8 0.5%53 7 0.4%67 3 0.2%80 2 0.1%

130 2 0.1%

Analysis of Pilot Pollution:

Pilot pollution results


To identify: Any missing neighbours

though analysis scanner

data & RNC neighbour

list

Any missing neighbours

causing drop calls

Any unnecessary

neighbours.Neighbour list verification.

Analysis of Neighbour List:

009 576 Retain 018 82 14.2%Retain 010 46 8.0%Retain 016 31 5.4%Retain 032 20 3.5%Retain 011 18 3.1%

Add 130 17 3.0%Retain 021 17 3.0%Retain 008 12 2.1%Retain 020 6 1.0%Retain 012 5 0.9%Retain 017 2 0.3%

Remove 053 0 0.0%Remove 019 0 0.0%Remove 034 0 0.0%Remove 037 0 0.0%Remove 013 0 0.0%Remove 051 0 0.0%

70548 Ajman Central 25.41204 55.447

Nbr SCSample Count

%Latitude LongitudeSample Count

ActionSC Cell Site


Analysis of SHO Performance:

To determine soft hand off

success rate.

Scrambling Code plot of best serving cells

Number of Active Set Updates

Event CountEvent 1a - Cell Addition328Event 1b - Cell Removal306Event 1c - Cell Replacement64

Number of Active Set Update Completes

Event CountEvent 1a - Cell Addition326Event 1b - Cell Removal305Event 1c - Cell Replacement62

Soft-Handover Success Rate

Event RateEvent 1a - Cell Addition99.4Event 1b - Cell Removal99.7Event 1c - Cell Replacement96.9


Analysis of Drop Calls:

To identify: Exact cause of the drop calls

Drop calls

RF Optimisation – SolutionsRF Optimisation – Solutions

Antenna Optimisation: (in order of priority)

Antenna tilt

Antenna azimuth

Antenna location

Antenna height

Antenna type

Site location

New site

Neighbour List Optimisation: (in order of priority)

Add missing neighbors

Remove unnecessary neighbors

Neighbour List tuning

Antenna & SiteOptimisation

RF Optimisation – Process SummaryRF Optimisation – Process Summary

Drive test data(scanner + UE)

Neighbour list

Thresholds &KPIs

AnalysisDominance

Best server scrambling code

CPICH CoverageCPICH RSCP & Ec/Io

DL Interference CPICH Ec/Io

UL Coverage UE Tx power

Neighbour ListScanner vs. RNC neighbours

Pilot PollutionScanner active set size

Drop calls Causes analysis

AgendaAgenda




RF Optimisation



Summary

Services Testing & Parameter Optimisation (1/6)Services Testing & Parameter Optimisation (1/6)






No

NoYes







Yes


Once RF optimisation is completed detailed testing of

CS and PS services should be completed

During testing, end-to-end logs should be collected (i.e.

UE as well as RAN & when necessary CN)

Any failures (e.g. call set-up, drop calls, etc) MUST be

analysed to determine exact causes

Any system defects must be raised to Technical

Support for resolution

Appropriate parameters should be identified for

possible optimisation to resolve failures or to reduce

impact of any system defects


Determine (Non-RF) Failure Causes

Determine (Non-RF) Failure Causes

Services TestingServices Testing

No

Improve via Parameters?Improve via Parameters? Optimise ParametersOptimise Parameters

Yes

No

No

System Defect?System Defect? Raise DefectRaise Defect

Yes

100 % Success Rate?100 % Success Rate?

End

Yes


Basic Parameters Optimisation Steps:

Identify candidate parameters

Identify various trade-offs

Decide on suitable metrics for analysis of results

Decide on parameter ranges to be tested

Define test cases and drive routes including various environmen

ts & clutter

Execute tests

Perform detailed analysis (logs as well as network stats)

Conclude parameters values that provide optimum trade-offs


Define Test Cases & select drive routes

Define Test Cases & select drive routes

Perform TestsPerform Tests

Data Analysis &

Conclusions

Data Analysis &

Conclusions

CandidateParameters

Clutter & Environment

factors

ParametersRanges

Trade Offs AnalysisMetrics


Potential Parameter Optimisation Candidates:

Reselection parameters

Handover parameters

Power control parameters

Admission and congestion control

Common control channel powers

Etc.

AgendaAgenda




RF Optimisation



Summary

Regular Testing & Stats Analysis (1/4)Regular Testing & Stats Analysis (1/4)






No

NoYes







Yes


Optimisation is an on-going activity and as a result:

Regular drive tests of designated routes should be carried out

(e.g. on monthly basis)

Routine analysis of network stats to identify any reduction in net

work performance


Regular Drive Testing- Objectives:

To benchmark network performance and user experience (e.g.

call setup SR, call drop rate, PS throughputs, etc)

To identify any degradation in coverage and/or increase in

interference as a result of increased traffic or changes in

environment

To assess impact of newly introduced RAN features.

To monitor the progress of on-going optimisation activities.


Routine Network Stats analysis - Objectives:

To benchmark network performance, particularly during the bus

y hour.

To monitor traffic volumes and patterns as well as traffic profiles

(i.e. mix of services).

To assess impact of parameter changes as part of parameter

optimisation exercises.

To identify poorly performing cells that need investigation to

establish underlying cause of poor performance.

To provide triggers for network upgrade decisions.

AgendaAgenda




RF Optimisation



Summary

Optimisation Approach OverviewOptimisation Approach Overview






No

NoYes







Yes

3G Optimization Overview

Documents

Transcript of 3G Optimization Overview