Ing. En Comunicaciones Y Electrónica

Ericsson Confidential GSM NETWORKS KPI ROOT CAUSE ANALYSIS
Prepared (also subject responsible if other) No.

1 (50)

ESA/SK Subhash Panikar
Approved Checked

ESA/SK 06:0027
Date Rev Reference

Amos Phahla

2006-10-17

PA1

REP00271_A

Root Cause Analysis for Key Performance Indicators (KPI) for GSM Networks1

This document could be used as a guideline for GSM NetworkPerformance Measurements, Root Cause Analysis of Network Performance issues and as a reference document (along with ALEX) for activities spanning from a Basic Audit of Radio Network (BARN) to a Radio Network Optimisation (RNO) contract.

1

Ericsson Confidential GSM NETWORKS KPI ROOT CAUSE ANALYSIS
Prepared (also subject responsible if other) No.

2 (50)

ESA/SK Subhash Panikar
Approved CheckedESA/SK 06:0027
Date Rev Reference

Amos Phahla

2006-10-17

PA1

REP00271_A

List of Contents

1.

Structure of the document _________________________________________________________ 4
2.1 Define _______________________________________________________________________________ 5 2.2 Measure _____________________________________________________________________________ 5
2.2.1 STSCounters and stats for monitoring Random Access Failure ____________________________________ 5 2.2.2 STS Counters for monitoring the RA request type________________________________________________ 6

2. Random Access (RACH) Success _____________________________________________________ 5

2.3 Analyze ______________________________________________________________________________ 6
2.3.1 FishBone 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
3.1.1Paging 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 _____________________________________________________ 113.2 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 ____________________________________________________________________________ 184.2.1. 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___________________________________________________________ 235.1. 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...