4G Strategy: CSFB Access Delay Optimization

Background:

LTE CSFB Access Delay = LTE Call Setup + L2W Transition + WCDMA Call Setup

LTE Call Setup: from L3 Extended Service Request (LTE) to RRCConnectionRelease (LTE)

L2W Transition: from RRCConnectionRelease (LTE) to RRC Connection Request (WCDMA)

WCDMA Call Setup: from RRC Connection Request (WCDMA) to Alerting (WCDMA)

Fact Finding:

LTE CSFB L2W transition duration at call setup is longer due to read too many 3G system information..

 Pro :

•CSFB L2W transition duration would be much improved.                            

Cons :

•No negative impacts.

•

Execution Selection Criteria :

•UMTS RAN 16.0 version later

Analysis:

SIB3 schedule optimization，reduce SIB3 schedule period to 160ms; Turn on DMCR, postpone read SIB11 and other system information, reduce CSFB delay; Combine SIB7 and MIB, improve schedule efficiency and reduce system information schedule period.

 

Parameter Setting :

 

3G  Parameter	PERFENH_SIB3_MAX_PEROID_LIMIT_SWITCH	PERFENH_SIB3_SCHEDULE_OPT_SWITCH	DeferMcReadInd	PERFENH_SIB7MIB_COMBINE_SWITCH
Before	0 (Off)	0 (Off)	FALSE	0 (Off)
After	1 (On)	1 (On)	TRUE	1 (On)