12-zxpos cna operation guide

7/28/2019 12-ZXPOS CNA Operation Guide

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ZXPOS CNA operation guide

ZTE University

XXX团队



Objectives

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

Master the functions of ZXPOS CNA

Master the usage of ZXPOS CNA



Contents

Coverage related test data analysis

Service related test data analysis

Setting event to locate fault point

CPICH RSCP analysis

CPICH EC/IO analysis

Best SC analysis

Pilot pollution analysis

UE TX power analysis

Coverage rate analysis

DL BLER analysis




CPICH RSCP analysis

CPICH RSCP is the pilot channel power received by UE. It is the main indicator tomeasure the downlink coverage. Generally, we setting different threshold to different

region in the initial phase. During optimization, we test the RSCP whether reach the

threshold or not. If RSCP is lower than the threshold, we must improve the coverage by

RF optimization. CPICH RSCP category

CPICH RSCP (dBm) Coverage Level Remark

RSCP -105 Level 6 Poor coverage, service can not be initiated

-105 RSCP -95 Level 5 Poor coverage. Outdoor Service can be initiated, but call

success rate will very low, call drop rate will be very high.

Indoor service can not be initiated.

-95 RSCP -85 Level 4 Normal coverage. Outdoor service can be initiated, low speed

data service can be initiated. But indoor service the call success

rate will be low, call drop rate will be high. -85 RSCP -75 Level 3 Good coverage. Both outdoor or indoor can initiated various

service. Outdoor will get medium speed and indoor will get

low speed data service.

-75< RSCP -65 Level 2 Better coverage. Both outdoor or indoor can initiated various

service. Outdoor will get high speed and indoor will get

medium speed data service.

RSCP >-65 Level 1 Excellent coverage




CPICH RSCP analysis

(a) UE test layer selection

(b) Scanner test layer selection





CPICH Ec/Io is also the main indicator to measure the downlink coverage. WCDMA is a

self – interference system, Coverage is up to CPICH RSCP and EC/IO.

CPICH Ec/Io category

CPICH Ec/Io（dB） Quality Level Remark

Ec/Io -15 Level 7 Very poor quality. Service can not be initiated

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

-13 Ec/Io -11 Level 5 Poor quality, Support low speed data service and bad quality voice

call.

-11 Ec/Io -9 Level 4 Normal quality. Support low speed data service and normal quality

voice call.

-9 Ec/Io -7 Level 3 Good quality, Support medium speed data service and good quality

voice call.

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

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





(a) UE test layer selection





CPICH 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 on

RSCP.

(a) UE teat layer selection


Via analyze the best serving cell , you will easily to locate the problem such as overshootcoverage, missing neighbor cell, unreasonable handover area and Feeder cable cross

connection





1.Overshoot coverageOvershoot coverage will cause the problem such as pilot pollution, frequently

handover, call failure and call drop problem.




2.Missing neighbor cell


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

Method 1：UE CPICH best SC compared with the Scanner CPICH best SC .Before call drop, if the EC/IO of UE active set Best SC is low, the EC/IO of

Scanner Best SC is excellent. At the same time the Scanner best SC scrambling

code 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, but

always stay in detect set, can not enter active set, that‟s missing neighbor cell.




3.Unreasonable handover area.


This situation also will cause call drop and handover failure.

Method：UE CPICH best SC compared with the Scanner CPICH best SC .Before call drop, if the EC/IO of UE active set Best SC is low, the EC/IO of

Scanner Best SC is excellent. At the same time the Scanner best SC scrambling

code is including in the Measurement signaling send by RNC, That‟s may beunreasonable handover area.





Pilot pollution means that all the signals strength in the test area are almost

the same. (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 the active will suffer from interference.

The reason is due to unreasonable coverage planning. Such as overshoot

coverage, Ring shape distribution of site location, wave guide effect, signal

reflection etc. Pilot pollution will cause low call success rate, handover

failure, loss of capacity, call drop etc.





CNA defines 2 arithmetic to analyze pilot pollution. Click Tools->Analysis Parameter

Setup , 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 the

problem.

Arithmetic 1 is related to number of signals in 1 area. Arithmetic 2 is related

to the timing delay of different signals.




Pilot pollution solution

1. Adjust antenna parameter 2. 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 transmit

power also will be increase, may be the traffic channel transmit power will be

decrease.

If decrease the pilot channel transmit power, the signal will be weak, may be the

call quality will be decrease. So it‟s not recommend to decrease the pilot

channel transmit power.

4. Add new site

Notice:

Please verify the result, ensure the old problem be solved and not generate new

problem.





UE TX Power is UE transmit power ，it‟s main indicator to measure the uplink coverage.

When UE transmit the maximum power, but Node B still can not receive or decode the

signal correctly, will occur call drop.UE TX Power category

UE TX power dBm） Level Remark

TX >21 Level 6 Very poor coverage 21≥ TX >10 Level 5 Poor coverage

10≥ TX >0 Level 4 Normal coverage

0≥ TX >-10 Level 3 Good coverage

-10≥ TX >-20 Level 2 Better coverage

-20≥ TX Level 1 Excellent coverage





Samples RSCP≥X and Ec/Io ≥Y, These sample are the eligible samples

Click Tools->Analysis Parameter Setup, you can setup the parameters .




DL 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 timing

delay is. For voice service, the call quality will be decrease. For data service, the

throughput will be decrease.

Service requirements：

Voice service BLER<1%

Real-time data service BLER<0.1%

Non-real-time data service BLER<10%



Contents




Call setup and maintain KPI analysis

Timing delay KPI analysis




Service related test data analysis means get the network KPI by

statistic the Uu interface signaling. This KPI used to reflect the

network performance. Compare with OMC, you just can get less KPI

from DT, and the KPI limited by time and test route.

KPI category

Call setup and maintain KPI

Timing delay KPI





RRC connection setup success rate.

Means

Reflect RNC or CELL capability for UE to access. RRC connection setup success

means the signaling link between UE and network have already been established.

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.

Definition

RRC 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 by

UE）





RAB assignment success rate

Means

Reflect the capability of ACCESS setup success.

Definition

RAB 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 rate

Means

Reflect the capability of ACCESS setup success.

Definition

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

attempt times

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





CS call drop rate

Means

Reflect call maintain capability

Definition

CS call drop rate = CS call drop times/ CS call setup success times

CS call drop signaling: Call signaling is incomplete

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

PDP active success rate

Means

Reflect the procedure that UE get the dynamic IP address, and create the

related information in HLR, SGSN and GGSN.

DefinitionPDP active success rate=PDP active success times/PDP active request times

PDP 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 rate

Means

Reflect PS call maintain capability

Definition

PS Call drop rate =PS call drop times / PS call setup success times

PS call drop signaling: call signaling incompletePS call setup success signaling: Downlink Direct Transfer （ Active PDP Context

Accept） (UE receive)





KPI statistic

Click Analysis->WCDMA L3 Message-KPI Analysis

Click <Statistics> button to get KPI





Custom KPI




Timing delay KPI

Random access delay

Means

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

customer‟s experience.

Definition

Signaling statistic, the time start from UE send “RRC Connection Request” and

stop at UE receive “RRC Connection Setup”.

Initialized channel synchronization delay

Means

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

customer‟s experience. Definition

Signaling statistic, time start from UE send “RRC Connection Request” and stop at

UE send “RRC Connection Setup Complete” .




Timing delay KPI

Call access delay

Means

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

the customer‟s experience.Definition

Signaling statistic, time start from UE send “RRC Connection Request” and stopat UE send “Radio Bearer Setup Complete”.

Call setup delay

Means

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

the customer‟s experience Definition

Signaling statistic, time start from calling UE send “RRC Connection Request”

and stop at receive “Alerting” from called UE.




Timing delay KPI

PDP active delay

Means

Reflect the PS service PDP active quality, it‟s one of the most important indictors of

the customer‟s experience.

DefinitionSignaling statistic, time start from UE send “Downlink Direct Transfer （ Active PDP

Context Request）” and stop at UE receive “Downlink Direct Transfer （ Active

PDP Context Accept）”.




Timing delay KPI

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



Contents




Call setup and maintain KPI analysis

Timing delay KPI analysis




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.




Use Marker Setting function to location fault point

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

12-zxpos cna operation guide

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