PCS-Faulty EDGE+TRX Problem Description E6

7/29/2019 PCS-Faulty EDGE+TRX Problem Description E6

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TRAGE/TRADE/TADHE problemImpact on QOS, detection & workaround

PCS 2G ed 5


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TRAGE Problem description April 6th, 2006-Ed.5 Page 2 All rights reserved 2002, Alcatel

Scope

After the complain on performances of some Edge+ TRX, wewill highlight the impact on the QOS and the means to confirmthat the degradation is related to the faulty TRX, and notrelated to any other radio/FP issues


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Frequently asked questions

What is the origin of the problem?

TRAGE/TRADE/TADHE produced in Q1 and Q2 2005 to be confirmed

When hopping is activated the DL_Quality (BER) of the odd time slots is much higher than the even ones, dueto disturbances generated by the power amplifier on one synthesizer (LOB) on baseband board .

What are the concerned modules?

Only TRAGE , TRADE, and TADHE in indoor or outdoor cabinet

When does it occurs?

When the TRAGE is running in hopping mode; Either immediately after the introduction of the TRAGE/TRADEor after beeing in service for 2-4 weeks or more depending on the ambient temperature (it was notice toappear more quickly in outdoor BTS)

When it goes faulty does it trigger any alarm in the OMC?

Unfortunately no

What will be the difference between using the TRX as BCCH or TCH?

No difference, in both cases it will show the same set of symptoms if hopping is activated on the TRX(BBH incase of BCCH,BBH or SFH in case of TCH)

How to detect it ? What to do?

This is the scope of this presentation


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Impact on QOS MOBILY

CSSR

TRX_pref_mark = 7on the faulty TRX

RTCHAssignmentfailure


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Impact on QOS MOBILY

TRX

efficiency

TRE is locked and

the TRX is mappedto different TRE

The previous problem was reported in KSA Jan06

It appeared suddenly (suspected after the activation of frequency hopping) and cleared after locking the faulty TRE


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Impact on QOS CELCOM

Deactivat

e the

BBH

CSSR

CDR


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Impact on QOS CELCOM

OUT_HO_SUCC

INC_HO_SUCC

Deactivat

e the

BBH


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Confirm that only odd TS are faulty CELCOM

From Drive test

Good Quality on Even TS Bad Quality on Odd TS

It was noticed as well from drive test that the RX_Quality on the SDCCH of the odd TS is 7


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Procedures to detect the faulty EDGE + TRX

A) Through the RNO KPI's filter out the cells with bad CSSR.CDR,....

B) Request the Type 5 measurements for the cells with bad KPI only

C) Check if the mean call duration of the odd TS is relatively lower that the even ones

D) Double check with the drive test for suspicious cases

How to use the Type 5 Maco:

1- Copy the macro in the same folder of the type 5 counters for only1 BSC

2- Clear the dates/time from Imported_Data sheet

3- Run the Macro

4-Check if the odd TS have relatively low call duration than the even ones


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Confirm that only odd TS are faulty AREEBA

From Type 5

measurementscampaign (duringbusy hour +3hrsbefore + 3 hoursafter)

Low call duration on

odd TS

A small macro was created

to speed up the analysis of

Type5 measurements youcan run it in the same

folder of the Type 5 counter

for every BSC separately.

As it will be difficult to run

the type 5 on all the

cells,its better to filter out

the cells/TRX that have bad

KPIs than request the

type5 to confirm that the

problem is on the odd TS

only


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WORKAROUND

Temporary

Deactivate the hopping on the faulty TRAGE/TRADE/TADHE

If SHF (NH_RH) is activated ,use the TRAGE/TRADE/TADHE as BCCH

Swap TRAGE/TRADE/TADHE to the BTS where the hopping is not activated

Permanent

Repair/Replacement of all the faulty TRAGE/TRADE/TADHE

Documents

PCS-Faulty EDGE+TRX Problem Description E6