Zxpos cna operation guide

ZXPOS CNA operation guide

ZTE University

XXX团队

Objectives

At the end of this course, you will be able to：

Ø Master the functions of ZXPOS CNAØ Master the usage of ZXPOS CNA

Contents

n Coverage related test data analysis

n Service related test data analysis

n Setting event to locate fault point

ØCPICH RSCP analysis

ØCPICH EC/IO analysis

ØBest SC analysis

Ø Pilot pollution analysis

ØUE TX power analysis

ØCoverage rate analysis

ØDL BLER analysis

Coverage related test data analysisCPICH RSCP analysis

CPICH RSCP is the pilot channel power received by UE, is the main indicator tomeasure the downlink coverage. Generally, we setting different threshold to differentregion in the initial phase. During optimization, we test the RSCP whether reach thethreshold or not. If RSCP is lower than the threshold, we must improve the coverage myRF optimization. CPICH RSCP category

Excellent coverageLevel 1Rx >-65

Better coverage. Both outdoor or indoor can initiated variousservice. Outdoor will get high speed and indoor will getmedium speed data service.

Level 2-75<Rx £-65

Good coverage. Both outdoor or indoor can initiated variousservice. Outdoor will get medium speed and indoor will getlow speed data service.

Level 3-85 < Rx £ -75

Normal coverage. Outdoor service can be initiated, low speeddata service can be initiated. But indoor service the call successrate will be low, call drop rate will be high.

Level 4-95 < Rx £ -85

Poor coverage. Outdoor Service can be initiated, but callsuccess rate will very low, call drop rate will be very high.Indoor service can not be initiated.

Level 5-105 < Rx £ -95

Poor coverage, service can not be initiatedLevel 6Rx £ -105

RemarkCoverage LevelCPICH RSCP dBm）

Coverage related test data analysisCPICH RSCP analysis

(a) UE test layer selection

(b) Scanner test layer selection

Coverage related test data analysisCPICH EC/IO analysisCPICH Ec/Io is also the main indicator to measure the downlink coverage. WCDMA is aself – interference system, Coverage is up to CPICH RSCP and EC/IO.

CPICH Ec/Io category

Excellent quality. Support high speed data service.Level 1Ec/Io > -5

Better quality. Support high speed data service.Level 2-7 < Ec/Io £ -5

Good quality, Support medium speed data service and goodquality voice call.

Level 3-9< Ec/Io £ -7

Normal quality. Support low speed data service and normal qualityvoice call.

Level 4-11< Ec/Io £ -9

Poor quality, Support low speed data service and bad quality voicecall.

Level 5-13< Ec/Io £ -11

Poor quality. Low call success rate, high call drop rate.Level 6-15< Ec/Io £ -13

Very poor quality.。service can not be initiatedLevel 7Rx £ -15

RemarkQuality LevelCPICH Ec/Io（dB）

Coverage related test data analysisCPICH EC/IO analysis

(a) UE test layer selection


Coverage related test data analysisCPICH Best SC analysis

Best Sc means best serving cell. By analyze best SC, you can get the cell coverage area.CNA Defined 2 methods to analyze Best Sc，One is based on Ec/Io, other is based onRSCP.

(a) UE teat layer selection


Via analyze the best cell will help you to locate the problem such as overshoot coverage,missing neighbor cell, unreasonable handover area and Feeder cable cross connection

Coverage related test data analysisCPICH Best SC analysis

1.Overshoot coverageOvershoot coverage will cause the problem such as pilot pollution, frequent handover,cal failure and call drop problem.

Coverage related test data analysis

2.Missing neighbor cellCPICH Best SC analysis

Missing neighbor cell will cause the problem such as call drop, cell congestion etc.

Method 1：UE CPICH best SC Compare with the Scanner CPICH best SC .Before call drop, if the EC/IO of UE active set Best SC is low, the EC/IO ofScanner Best SC is excellent. At the same time the Scanner best SC scramblingcode is not including in the Measurement signaling send by RNC, That’s missingneighbor cell.

Method 2：Replay the driving test data, if one cell the EC/IO is excellent for a longtime, butalways stay in detect set, can not enter active, that’s missing neighbor cell.

Coverage related test data analysis

3.Unreasonable handover area.CPICH Best SC analysis

This situation also will cause call drop and handover failure.

Method ：UE CPICH best SC Compare with the Scanner CPICH best SC .Before call drop, if the EC/IO of UE active set Best SC is low, the EC/IO ofScanner Best SC is excellent. At the same time the Scanner best SC scramblingcode is including in the Measurement signaling send by RNC, That’s may beunreasonable handover area.

Coverage related test data analysisPilot pollution analysis

Pilot pollution means that all the signals in the test area are not very different(All strong or weak). Generally, all the pilot channels RSCP is good enough,but EC/IO is weak. Now most WCDMA equipment support 3 cells in active set.So, if in 1 area, if over 3 signals the EC/IO is similar, means the signals in theactive will suffer from interference.

The reason is due to unreasonable coverage planning. Such as overshootcoverage, Ring shape distribution of site location, wave guide effect, signalreflection etc. Pilot pollution will cause low call success rate, handoverfailure, loss of capacity, call drop etc.


CNA defines 2 arithmetic to analyze pilot pollution. Click Tools->Analysis ParameterSetup , you can setup the parameter.。2 different arithmetic, the parameters also different, so the result also may be different.When analyze pilot pollution, you should combined this 2 arithmetic, to locate theproblem.

Arithmetic 1 is related to number of signals in 1 area. Arithmetic 2 is relatedto the timing delay of different signals.


Coverage related test data analysisPilot pollution solution

1. Adjust antenna parameter2. Adjust handover parameter (May be will cause handover slow or failure)3. Adjust the power parameter

Increase or decrease the cell transmit power.Disadvantage：

If increase the pilot channel output power, SCH, PCH channel the transmitpower also will be increase, may be the traffic channel transmit power will bedecrease.

If decrease the pilot channel transmit power, the signal will be weak, may be thecall quality will be decrease. So it’s not recommend to decrease the pilotchannel transmit power.

4. Add new site

Notice:Please verify the result, ensure the old problem be solved and not generate newproblem.

Coverage related test data analysisUE TX power analysis

UE TX Power is UE transmit power，it’s main indicator to measure the uplink coverage.When UE transmit the max power, but Node B still can not receive or decode the signalincorrect, will occur call drop.

UE TX Power category

Excellent coverageLevel 1-20≥RxBetter coverageLevel 2-10≥Rx >-20Good coverageLevel 30≥Rx >-10Normal coverageLevel 410≥Rx >0Poor coverageLevel 521≥Rx >10Very poor coverageLevel 6Rx >21

RemarkLevelCPICH RSCPdBm）



Reasons and solution of weak coverage on uplink：

1. Bad radio environment

Combine with CPICH RSCP analysis, If RSCP also low, the reason must be weak

coverage. The problem can be solved by adjust the engineering parameter, or cell

transmit power, or add new site.

2. Uplink interference

Downlink CPICH RSCP is excellent, but uplink UE TX power is too high.

Can be located by check the TCP and RTWP alarm. If TCP is not high, but RTWP

very high, means uplink suffer from interference. Check the interference or antenna

and feeder cable.

3. Heavy traffic load

Too many user, Both TCP and RTWP is very high. Balance the traffic to solve the

problem.

4.Large coverage area

Caused by path unbalance , Add TMA to increase uplink receive sensibility.

Coverage related test data analysisCoverage rate analysis

Samples RSCP≥X and Ec/Io ≥Y, These sample are the eligible samplesClick Tools->Analysis Parameter Setup, you can setup the parameters .

Coverage related test data analysisCoverage rate analysis

Coverage related test data analysisDL BLER analysis

Definition：Downlink block error rate. BLER=Error blocks/Total transmitted blocks. It’sthe main indicator to measure the transmit quality.

Effect：The higher the BLER is, The more retransmitted blocks are, the longer timingdelay is. For voice service, the call quality will be decrease. For data service, thethroughput will be decrease.

Service requirements：Voice service BLER<1%Real-time data service BLER<0.1%Non-real-time data service BLER<10%

Contents




ØCall setup and maintain KPI analysis

ØTiming delay KPI analysis

Service related test data analysis

Service related test data analysis means get the network KPI bystatistic the Un interface signaling. This KPI used to reflect thenetwork performance. Compare with OMC, you just can get less KPIfrom DT, and the KPI limited by time and test route.

KPI categoryCall setup and maintain KPITiming delay KPI

Service related test data analysisCall setup and maintain KPI

RRC connection setup success rate.MeansReflect RCN or CELL capability for UE to access. RRC connection setup successmeans UE already establish the signaling link with network.

Here including 2 different situation：1 is service related ;Another is not related withservice（Such as location update、Inter-RAT cell reselection, register to network

etc.） The former used to measure the call access success rate，the result canbe used as the basis to configure channel. The latter used to measure the system

load.DefinitionRRC connection setup success rate=RRC connection setup success times/RRC

connection setup attempt timesRRC Connection setup success signaling：RRC Connection Setup Complete（Send by UE）

RRC connection setup attempt signaling：RRC Connection Request（Send byUE）


RAB assignment success rateMeansReflect the capability of ACCESS setup success.DefinitionRAB assignment success rate = RB setup success times/ RRC connection setup

attempt timesRB setup success signaling: Radio Bearer Setup Complete (Send by UE)RRC connection setup success signaling: RRC Connection Request (Send by UE)

Call setup success rateMeansReflect the capability of ACCESS setup success.

DefinitionCall setup success rate = call setup success times / RRC connection setup

attempt timesCall setup success signaling: Downlink Direct Transfer（Alerting）(UE receive)


CS call drop rateMeansReflect call maintain capabilityDefinitionCS call drop rate = CS call drop times/ CS call setup success timesCS call drop signaling: Call signaling is incompleteCall setup success signaling: Downlink Direct Transfer（Alerting） (UE receive)

PDP active success rateMeansReflect the procedure that UE get the dynamic IP address, and create therelated information in HLR, SGSN and GGSN.DefinitionPDP active success rate=PDP active success times/PDP active request timesPDP active request signaling: Downlink Direct Transfer（Active PDP Context

Request） (UE send)PDP active success signaling: Downlink Direct Transfer（Active PDP Context

Accept） (UE receive)


PS call drop rateMeansReflect PS call maintain capabilityDefinitionPS Call drop rate =PS call drop times / PS call setup success timesPS call drop signaling: call signaling incompletePS call setup success signaling: Downlink Direct Transfer（Active PDP Context

Accept） (UE receive)


KPI statisticClick Analysis->WCDMA L3 Message-KPI Analysis

Click <Statistics> button to get KPI


Custom KPIClick Analysis->WCDMA L3 Message->Custom Event Analysis to statistic the customKPI

Click <Go to Message> button then you can check the signaling in ‘View Message window’


Custom KPI

Service related test data analysisTiming delay KPI

Random access delayMeansReflect the service time features, it’s one of the most important indictors of thecustomer’s experience.DefinitionSignaling statistic, the time start from UE send “RRC Connection Request” andstop at UE receive “RRC Connection Setup”.

Initialized channel synchronization delayMeans

Reflect the service time features, it’s one of the most important indictors of thecustomer’s experience.

DefinitionSignaling statistic, time start from UE send “RRC Connection Request” and stop atUE send “RRC Connection Setup Complete” .


Call access delayMeans

Reflect the service time features, it’s one of the most important indictors ofthe

customer’s experience.DefinitionSignaling statistic, time start from UE send “RRC Connection Request” and stopat UE send “Radio Bearer Setup Complete”.

Call setup delayMeans

Reflect the service time features, it’s one of the most important indictors ofthe

customer’s experienceDefinitionSignaling statistic, time start from calling UE send “RRC Connection Request”and stop at receive “Alerting” from called UE.


PDP active delayMeansReflect the PS service PDP active quality, it’s one of the most important indictorsof the customer’s experience.DefinitionSignaling statistic, time start from UE send “Downlink Direct Transfer（Active PDPContext Request）” and stop at UE receive “Downlink Direct Transfer（Active PDPContext Accept）”.


Click Analysis->WCDMA L3 Message-Delay Analysis to statistic the KPI.

Contents




ØCall setup and maintain KPI analysis

ØTiming delay KPI analysis

Setting event to locate fault point

Use Marker Setting function to location fault point

Click button from the tool bar, Open ‘Marker Setting’ window to select the event you

want to check.

Setting event to locate fault point

Use Marker Setting function to location fault point

After select the corresponding event, the event will be displayed on the map.

Design

Zxpos cna operation guide