PS RAB Drop Rate Analysis

Parameter Optimization to Improve PS Drop

> Internal Only

Content

★ Issue Description ★ Analysis and Suggestion ★ KPI Comparison ★ Plan of next step

© ZTE Corporation. All rights reserved.

> Internal Only

Parameter Description

© ZTE Corporation. All rights reserved.

> Internal Only

Parameter Description

© ZTE Corporation. All rights reserved.

> Internal Only

Issue Description RAB_PS_Drop_Rate 1.40%

1.20% 3RNCAYA1Z(234) 3RNCAYA2Z(235)

1.00%

PS Drop Rate Target = 0.5% 0.80%

3RNCAYA3Z(236)

3RNCAYA4Z(239) 3RNCAYA5Z(240)

0.60%

0.40%

3RNCNPT1Z(231) 3RNCNPT2Z(232) 3RNCNPT3Z(233)

0.20%

3RNCNPT4Z(237) 3RNCNPT5Z(238)

0.00%

In CW region, PS Drop Rate of most RNC worse than the KPI target 0.5%

© ZTE Corporation. All rights reserved.

> Internal Only

Analysis and Suggestion

From the statistic, above is the 4 main reasons of abnormal PS release. 34% of all RAB abnormal release is due to DRBC expiry .

© ZTE Corporation. All rights reserved.

> Internal Only

Analysis and Suggestion

From the DRBC statistic, most of RAB abnormal release come form DRBC(rate adjust) or DCHFACH © ZTE Corporation. All rights reserved.

> Internal Only

Analysis and Suggestion

MON

UDrbc

UDchEvUeTrv

Parameter

Before

After

dToPchThd

3

2

dToIdleThd

3

2

fToIdleThd

2

1

dToFachThd

1

2

rptThres1

4;0

6;0

We suggest to modify some DRBC parameter base on the analysis of statistic: 1. Event 4B Counter Threshold for CELL_DCH to PCH from 3 to 2 2. Event 4B Counter Threshold for CELL_DCH to Idle from 3 to 2 3. Event 4B Counter Threshold for CELL_FACH without DRX to Idle from 2 to 1 4. Event 4B Counter Threshold for Cell_Dch to Cell_FACH from 1 to 2 5.Traffic Volume Threshold of Event 4A/4B for DCH(16kbps) from 128 bytes to 512 bytes

© ZTE Corporation. All rights reserved.

> Internal Only

KPI Comparison

All NPT RNC modify DRBC parameter on 10th Sep. All AYA RNC modify DRBC parameter on 11th Sep. After DRBC parameter optimization, PS drop rate decreased lower than 0.5% © ZTE Corporation. All rights reserved.

> Internal Only

KPI Comparison

After optimization, RAB release due to DRBC expiry decreased too much. RAB release due to hard handover increased a little.

© ZTE Corporation. All rights reserved.

Thanks!

© ZTE Corporation. All rights reserved.