【资料名称】：TEMS-Optimization and Log File Analysis in GSM

【资料作者】：Somer GOKSEL

【资料日期】：January 26, 2003

【资料语言】：英文

【资料格式】：PDF

【资料目录和简介】：

Somer GOKSEL
January 26, 2003
2
Contents
1 INTRODUCTION ........................................................................................................................................04
1.1 PURPOSE and SCOPE of OPTIMIZATION............................................................................. 04
1.2 OPTIMIZATION PROCESS...................................................................................................... 05
1.2.1 PROBLEM ANALYSIS ........................................................................................... 05
1.2.2 CHECKS PRIOR TO ACTION. ............................................................................... 05
1.2.3 DRIVE TEST............................................................................................................. 05
1.2.4 SUBJECTS to INVESTIGATE................................................................................. 06
1.2.5 AFTER the TEST...................................................................................................... 07
1.2.6 RECOMMENDATIONS........................................................................................... 07
1.2.7 TRACKING............................................................................................................... 08
1.2.8 OTHER OPTIMIZATION TOPICS.......................................................................... 08
1.3 BEFORE STARTING................................................................................................................. 09
2 DRIVE TEST ................................................................................................................................................10
2.1 TEMS INFORMATION............................................................................................................. 11
2.2 BASIC COUNTERS of NETWORK PERFORMANCE........................................................... 13
2.2.1 ACCESSIBILITY................................................................................................. 13
2.2.2 RETAINABILITY............................................................................................... 13
2.2.3 ACCESS FAILS................................................................................................... 13
2.3 IDLE MODE BEHAVIOR.......................................................................................................... 14
2.4 LOCATION UPDATE................................................................................................................ 16
2.5 CALL SET–UP............................................................................................................................ 17
2.6 CALL SET–UP PROCESS in LAYER 3 MESSAGES.............................................................. 19
3 ANALYSIS of LOG FILES..........................................................................................................................33
3.1 COVERAGE PROBLEMS......................................................................................................... 33
3.1.1 LOW SIGNAL LEVEL....................................................................................... 34
3.1.2 LACK Of DOMINANT SERVER...................................................................... 35
3.1.3 SUDDEN APPEARANCE/DISAPPEARANCE of NEIGHBORS.................... 36
3.1.4 FAST MOVING MOBILE.................................................................................. 37
3.1.5 SUDDEN DECREASE on SIGNAL LEVEL..................................................... 38
3.1.6 STABLE BEHAVIOR......................................................................................... 39
3.1.7 OSCILLATION on HOPPING CHANNELS..................................................... 40
3.1.8 SAME CELL IN THE NEIGHBOR LIST.......................................................... 41
3.1.9 RX LEVEL TOO CLOSED................................................................................ 42
3.1.10 RX LEVEL ALMOST THE SAME.................................................................... 43
3.1.11 LINE of SIGHT LOST........................................................................................ 44
3.1.12 LOG FILE RECORDING on RESUME............................................................. 45
3.1.13 DROP CALL DUE to BAD COVERAGE.......................................................... 46
3.1.14 ACCESS FAILS AFTER A DROP CALL.......................................................... 47
3.1.15 SOLUTIONS TO LOW LEVEL PROBLEMS................................................... 48
3.2 QUALITY PROBLEMS............................................................................................................. 49
3.2.1 BER and FER....................................................................................................... 49
3.2.2 BAD QUALITY and BAD FER.......................................................................... 50
3.2.3 BAD QUALITY – FER is OK............................................................................. 51
3.2.4 SQI....................................................................................................................... 52
3.2.5 COLLUSION Of MA LIST CAUSING LOW C/I.............................................. 53
3.2.6 C/I ASPECT......................................................................................................... 54
3.2.7 C/A ASPECT....................................................................................................... 54
3.2.8 C/I INTERFERENCE.......................................................................................... 55
3.2.9 TIME DISPERSION............................................................................................ 56
3
3.2.10 BAD QUALITY due to TIME DISPERSION..................................................... 57
3.2.11 INTER–SYSTEM INTERFERENCE.................................................................. 58
3.2.12 PROPAGATION BEHAVIOR............................................................................ 58
3.3 HANDOVER............................................................................................................................. 59
3.3.1 HANDOVER in LAYER 3 MESSAGES.............................................................61
3.3.2 TYPES of HANDOVER...................................................................................... 67
3.3.2.1 POWER BUDGET HANDOVER......................................................... 67
3.3.2.2 LEVEL HANDOVER............................................................................ 69
3.3.2.3 QUALITY HANDOVER....................................................................... 69
3.3.2.4 INTERFERENCE HANDOVER........................................................... 70
3.3.2.5 UMBRELLA HANDOVER................................................................... 70
3.3.2.6 MS DISTANCE HANDOVER.............................................................. 70
3.3.2.7 INTRACELL HANDOVER.................................................................. 71
3.3.2.8 INTRACELL HANDOVER BASED on QUALITY.............................72
3.3.2.9 RAPID FIELD HANDOVER................................................................ 73
3.3.2.10 DIRECTED RETRY HANDOVER....................................................... 73
3.3.2.11 SHORT NEIGHBOR LIST.................................................................... 74
3.3.3 HANDOVER PROBLEMS................................................................................. 75
3.3.3.1 LATE HANDOVER.............................................................................. 75
3.3.3.2 POWER CONTROL EFFECT.............................................................. 77
3.3.3.3 PING PONG HANDOVER................................................................... 78
3.3.3.4 UNNCESSARY HANDOVER.............................................................. 79
3.3.3.5 MISSING NEIGHBOR RELATION..................................................... 80
3.3.3.6 FAKE NEIGHBOR................................................................................ 81
3.3.3.7 BCCH MISSING FROM SERVING CELLS MBCCH LIST............... 82
3.3.3.8 NCC MISSING FROM SERVING CELLS NCCPERM LIST............. 82
3.3.3.9 SAME BSIC BCCH COMBINATION.................................................. 82
3.3.3.10 UNEXPECTED COVERAGE LAKE................................................... 83
3.3.3.11 ONE–WAY NEIGHBOR RELATION.................................................. 83
3.3.3.12 NEIGHBOR in ANOTHER BSC/MSC................................................. 83
3.3.3.13 HANDOVER FAILURE....................................................................... 85
3.4 DROP CALLS............................................................................................................................ 87
3.4.1 GENERAL REASONS FOR DROP CALLS...................................................... 88
3.4.2 DROP CALL DUE TO LOCKED CALL........................................................... 89
4 REPORTS of ANALYSIS .............................................................................................................................90
4.1 DOWNTOWN SEATTLE NETWORK PERFORMANCE RECOMMENDATION............... 90
4.2 LAKE SAMMAMISH AREA NETWORK PERFORMANCE RECOMMENDATION.......... 92
5 CONCLUSION...............................................................................................................................................94