NSEI Re-Planning Rule and Optimisation Experience

Shi Wei

Presentation Outline

• Why we need tuning NSEI?

• Need information for NSEI Re-Planning

• Results from NSEI Planning

Why need tuning NSEI ?

Time Series of Application Throughput during Cell Re-selection (Example)

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Cell Re-Selection

Duration ofService Gap

Observation Period For Cell Re-Selection

Each Cell Re-selection leadsTo a “Service Gap”

Comparison of Application Throughput and Service Delay for Intra and Inter-PCU Cell Re-Selections

Number of Samples

Throughput for Intra-PCU Re-selection [kbits/sec]

Throughput for Inter-PCU Re-selection [kbits/sec]

Duration of Intra-PCU Service delay [sec]

Duration of Inter-PCU Service delay [sec]

369 18.30 11.39 4.59 9.02

Intra-PCU cell re-selections provide much better performance than inter-PCU re-selections!

Comparison of Throughput during Cell Re-Selection for old and new PCU Plan

PCU Plan

Route Throughput for Intra-PCU Re-selection [kbits/sec]

Throughput for Inter-PCU Re-selection [kbits/sec]

Number Intra-PCU Re-selection

Number Inter-PCU Re-selection

Average Throughput for all Cell Re-selections [kbits/sec]

PRE A 18.71 9.94 31 59 12.96

PRE B 17.34 10.84 33 70 12.92

POST A 18.34 13.2 61 31 16.61

POST B 18.81 11.59 58 26 16.58

During the drive surveythe number of intra-PCU cell re-selections has increased significantly.

This will bring performance benefits.

TSL/PCU, GTRX/PCU, Cell/PCU Comparison un-balance

PCU Congestion QZMCC Ctiy PCU AverageTimeSlot Statistic

(GPRS+EDGE)

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Need information for NSEI Re-Planning

Need for NSEI Re-Planning•BSC Info•PCU type•NSEI per BSC active number •EDAP( EDGE) Information•Cell Re-selection number•Mapinfo (longitude. latitude. And road…, GPRS hot area….•Cell Information (site config ,adj , gtrx number, time slot…)•GPRS KPI•………

Interaction between Tasks

NSEI Planning

DeterminingNumber

of GPRS TSLs

DeterminenumberOf PCUs

OptimiseAdjacency Plan

Missing/Obsolete

Ensure cellsare on right BSC

Only if all tasks are addressed accurately will the NSEI-plan be optimal

Results from NSEI Planning

MapView of the old NSEI Plan -QuanZhou

The NSEI Plan is sub-optimal as:•“Connected” cells are not on the same PCU•The number of cells per PCU is not balanced

MapView of the new NSEI Plan -QuanZhou

The NSEI Plan is more optimal as:•“Connected” cells are on the same PCU•The number of cells per PCU is roughly balanced

MapView of the old&new NSEI-JinJiang

MapView of the old&new - SiShi

MapView of the old&new - NanAn

18 © 2005 Nokia V1-Filename.ppt / yyyy-mm-dd / Initials

市区 NSEI调整后的观察验证 -1

19 © 2005 Nokia V1-Filename.ppt / yyyy-mm-dd / Initials

市区 NSEI调整后的观察验证 -2

BSC_NAME NSEI PCU_RATE_0530 PCU_RATE_05608BSC582 1800 56.72% 0.69%BSC582 1820 23.35% 0.01%BSC586 4040 40.47% 0.15%BSC587 4400 30.80% 0.10%BSC587 4430 54.47% 0.62%BSC5A1 730 834.32% 0.00%BSC5A4 1000 73.82% 0.01%BSC5A4 1010 10.71% 0.15%BSC5C3 1400 14.41% 0.00%BSC5C6 3430 23.67% 0.06%BSC5E4 510 17.15% 0.00%BSC5E4 540 58.22% 0.02%

市区 NSEI调整后的观察验证 -3NSEI 调整后路测效果图：

市区 NSEI调整后的观察验证 -4

• 调整前后路测中出现的小区重选事件分析：

小区重选次数

所占百分比

NSEI修改前 PCU内部小区重选 123 51.68%

跨PCU小区重选 115 48.32%

NSEI修改后 PCU内部小区重选 160 58.82%

跨PCU小区重选 112 41.18%