High Random Access Failure Rate!!!

[zeldalcl]

Dear all!
At the moment, we're facing the problem: cell has low random access success rate (RASR) in E******* system (less than 80%). I have been trying to research about that problem but i haven't known clearly the reason.
So i did:
1. I checked poorly BCCH/BSIC plan in that cell
2. I found the problem that relates to RAACCFA which has high value.
3. I checked TAMAX, TALIM in system, and Real Timing Advance has low value (less than 38).
Please, help me to solve and share more doccuments about this
Thank you very much...

[zeezzoo]

Dear all!
At the moment, we're facing the problem: cell has low random access success rate (RASR) in E******* system (less than 80%). I have been trying to research about that problem but i haven't known clearly the reason.
So i did:
1. I checked poorly BCCH/BSIC plan in that cell
2. I found the problem that relates to RAACCFA which has high value.
3. I checked TAMAX, TALIM in system, and Real Timing Advance has low value (less than 38).
Please, help me to solve and share more doccuments about this
Thank you very much...

dear kindly share the kpi formula so i can see how it's calculated first

[zeldalcl]

Thanhk for your reply!
That formular as follwing:
1. RASR = 100 * CNROCNT / (CNROCNT + RAACCFA + PDRAC) (%)
2. Random Access Attempts = CNROCNT + RAACCFA + PDRAC


Brs!

[zeezzoo]

dear check the attached file i think it will be very useful for you .it's kpi root cause analysis for e******* .

List of Contents
1. Structure of the document _________________________________________________________ 4
2. Random Access (RACH) Success _____________________________________________________ 5
2.1 Define _______________________________________________________________________________ 5
2.2 Measure _____________________________________________________________________________ 5
2.2.1 STS Counters and stats for monitoring Random Access Failure ____________________________________ 5
2.2.2 STS Counters for monitoring the RA request type _______________________________________________ 6
2.3 Analyze ______________________________________________________________________________ 6
2.3.1 Fish Bone diagram for the root cause analysis of poor Random Access Success ________________________ 6
2.3.2 Description of the root causes for poor RA Success Rate ___________________________________________ 6
3. Paging (PCH) Success ______________________________________________________________ 8
3.1 Define _______________________________________________________________________________ 8
3.1.1 Paging Process _____________________________________________________________________________ 8
3.1.2 Paging Capacity and Paging Group at the RBS __________________________________________________ 9
3.1.3 Paging Capacity at the BSC _________________________________________________________________ 10
3.1.4 Paging Strategies and MSC paging timers _____________________________________________________ 11
3.2 Measure ____________________________________________________________________________ 12
3.2.1 STS counters and stats for measuring Paging performance _______________________________________ 12
3.2 Measure ____________________________________________________________________________ 15
3.2.1 Fish bone diagram for the root cause analysis of poor Paging Success Rate __________________________ 15
4. Location Area updating (success rate) ________________________________________________ 18
4.1. Define ______________________________________________________________________________ 18
4.1.1. Location Area updating process _____________________________________________________________ 18
4.2. Measure ____________________________________________________________________________ 18
4.2.1. Location Area Dimensioning (from paging capacity point) _______________________________________ 18
4.3 Analyze _____________________________________________________________________________ 21
4.2.1 Fish bone diagram for the root cause analysis of poor Location Area Updating _______________________ 21
5. SDCCH Congestion Rate ___________________________________________________________ 23
5.1. Define ______________________________________________________________________________ 23
5.1.1 Load in mErlang on SDCCH due to different events _____________________________________________ 23
5.2. Measure ____________________________________________________________________________ 24
5.2.1 Traffic Theory ____________________________________________________________________________ 24
5.2.2 STS counters for measuring SDCCH congestion Rate ____________________________________________ 24
5.3 Analyze _____________________________________________________________________________ 25
5.3.1 Fish bone diagram for the root cause analysis high SDCCH congestion rate _________________________ 25
6. SDCCH Drop Rate ________________________________________________________________ 27
6.1 Define ______________________________________________________________________________ 27
6.2 Measure ____________________________________________________________________________ 27
6.2.1 SDCCH Drop Rate ________________________________________________________________________ 27
6.2.2 SDCCH Drop Reason ______________________________________________________________________ 27
6.3 Analyse _____________________________________________________________________________ 28
6.3.1 Fish bone diagram for the root cause analysis for high SDCCH drop rate ___________________________ 28
7. TCH Congestion Rate _____________________________________________________________ 30
7.1 Define ______________________________________________________________________________ 30
7.2 Measure ____________________________________________________________________________ 30
7.2.1 STS counters and stats for TCH Congestion Rate _______________________________________________ 30
7.3 Analyze _____________________________________________________________________________ 31
7.3.1 Fish bone diagram for the root cause analysis for high TCH Congestion Rate ________________________ 31
7.3.2 Half Rate Parameters ______________________________________________________________________ 32
7.3.3 Mean Opinion scores for Half Rate ___________________________________________________________ 33
7.3.4 Why Quality is so important? ________________________________________________________________ 34
7.3.5 Parameters controlling CLS _________________________________________________________________ 35
7.3.6 Parameters controlling HCS _________________________________________________________________ 37
7.3.7 Parameters controlling Assignment to another cell ______________________________________________ 38
8. TCH Drop Rate __________________________________________________________________ 40
8.1 Define ______________________________________________________________________________ 40
8.2 Measure ____________________________________________________________________________ 40
8.2.1 STS counters for TCH drop _________________________________________________________________ 41
8.3 Analyze ________________________________________________________________________ 42
8.3.1 Fish bone diagram for the root cause analysis for high TCH Drop Rate ______________________ 42
8.3.2 Power control parameters for MS ____________________________________________________________ 46
8.3.3 Power control parameters for BS _____________________________________________________________ 46
9. Handover _______________________________________________________________________ 47
9.1 Define ______________________________________________________________________________ 47
9.2 Measure ____________________________________________________________________________ 47
9.2.1 STS counters and stats for handover performance ______________________________________________ 47
9.3 Analyze _____________________________________________________________________________ 48
9.3.1 Fish bone diagram for the root cause analysis for high handover failure rate ________________________ 48
9.3.2 E1 Algorithm for Locating (EVALTYPE=1) ___________________________________________________ 49
9.3.3 E3 algorithm for Locating (EVALTYPE=3) ____________________________________________________ 50
9.3.4 Urgency condition handover trigger parameters ________________________________________________ 50

No Password
BR,

[zeldalcl]

Thanks for your document!
I think that great document, I also usually use this document as reference to Troubleshooting problem in the Network.


BRs

[hendral]

dear check the attached file i think it will be very useful for you .it's kpi root cause analysis for e******* .

List of Contents
1. Structure of the document _________________________________________________________ 4
2. Random Access (RACH) Success _____________________________________________________ 5
2.1 Define _______________________________________________________________________________ 5
2.2 Measure _____________________________________________________________________________ 5
2.2.1 STS Counters and stats for monitoring Random Access Failure ____________________________________ 5
2.2.2 STS Counters for monitoring the RA request type _______________________________________________ 6
2.3 Analyze ______________________________________________________________________________ 6
2.3.1 Fish Bone diagram for the root cause analysis of poor Random Access Success ________________________ 6
2.3.2 Description of the root causes for poor RA Success Rate ___________________________________________ 6
3. Paging (PCH) Success ______________________________________________________________ 8
3.1 Define _______________________________________________________________________________ 8
3.1.1 Paging Process _____________________________________________________________________________ 8
3.1.2 Paging Capacity and Paging Group at the RBS __________________________________________________ 9
3.1.3 Paging Capacity at the BSC _________________________________________________________________ 10
3.1.4 Paging Strategies and MSC paging timers _____________________________________________________ 11
3.2 Measure ____________________________________________________________________________ 12
3.2.1 STS counters and stats for measuring Paging performance _______________________________________ 12
3.2 Measure ____________________________________________________________________________ 15
3.2.1 Fish bone diagram for the root cause analysis of poor Paging Success Rate __________________________ 15
4. Location Area updating (success rate) ________________________________________________ 18
4.1. Define ______________________________________________________________________________ 18
4.1.1. Location Area updating process _____________________________________________________________ 18
4.2. Measure ____________________________________________________________________________ 18
4.2.1. Location Area Dimensioning (from paging capacity point) _______________________________________ 18
4.3 Analyze _____________________________________________________________________________ 21
4.2.1 Fish bone diagram for the root cause analysis of poor Location Area Updating _______________________ 21
5. SDCCH Congestion Rate ___________________________________________________________ 23
5.1. Define ______________________________________________________________________________ 23
5.1.1 Load in mErlang on SDCCH due to different events _____________________________________________ 23
5.2. Measure ____________________________________________________________________________ 24
5.2.1 Traffic Theory ____________________________________________________________________________ 24
5.2.2 STS counters for measuring SDCCH congestion Rate ____________________________________________ 24
5.3 Analyze _____________________________________________________________________________ 25
5.3.1 Fish bone diagram for the root cause analysis high SDCCH congestion rate _________________________ 25
6. SDCCH Drop Rate ________________________________________________________________ 27
6.1 Define ______________________________________________________________________________ 27
6.2 Measure ____________________________________________________________________________ 27
6.2.1 SDCCH Drop Rate ________________________________________________________________________ 27
6.2.2 SDCCH Drop Reason ______________________________________________________________________ 27
6.3 Analyse _____________________________________________________________________________ 28
6.3.1 Fish bone diagram for the root cause analysis for high SDCCH drop rate ___________________________ 28
7. TCH Congestion Rate _____________________________________________________________ 30
7.1 Define ______________________________________________________________________________ 30
7.2 Measure ____________________________________________________________________________ 30
7.2.1 STS counters and stats for TCH Congestion Rate _______________________________________________ 30
7.3 Analyze _____________________________________________________________________________ 31
7.3.1 Fish bone diagram for the root cause analysis for high TCH Congestion Rate ________________________ 31
7.3.2 Half Rate Parameters ______________________________________________________________________ 32
7.3.3 Mean Opinion scores for Half Rate ___________________________________________________________ 33
7.3.4 Why Quality is so important? ________________________________________________________________ 34
7.3.5 Parameters controlling CLS _________________________________________________________________ 35
7.3.6 Parameters controlling HCS _________________________________________________________________ 37
7.3.7 Parameters controlling Assignment to another cell ______________________________________________ 38
8. TCH Drop Rate __________________________________________________________________ 40
8.1 Define ______________________________________________________________________________ 40
8.2 Measure ____________________________________________________________________________ 40
8.2.1 STS counters for TCH drop _________________________________________________________________ 41
8.3 Analyze ________________________________________________________________________ 42
8.3.1 Fish bone diagram for the root cause analysis for high TCH Drop Rate ______________________ 42
8.3.2 Power control parameters for MS ____________________________________________________________ 46
8.3.3 Power control parameters for BS _____________________________________________________________ 46
9. Handover _______________________________________________________________________ 47
9.1 Define ______________________________________________________________________________ 47
9.2 Measure ____________________________________________________________________________ 47
9.2.1 STS counters and stats for handover performance ______________________________________________ 47
9.3 Analyze _____________________________________________________________________________ 48
9.3.1 Fish bone diagram for the root cause analysis for high handover failure rate ________________________ 48
9.3.2 E1 Algorithm for Locating (EVALTYPE=1) ___________________________________________________ 49
9.3.3 E3 algorithm for Locating (EVALTYPE=3) ____________________________________________________ 50
9.3.4 Urgency condition handover trigger parameters ________________________________________________ 50

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BR,

This file already posted by someone else.

[Maik]

Hi,

thanks for this Document, Gr Maik

[Irna]

in Forums alot think described

[rezapa]

Thanks for the doc