3g to 2g handover v1

3G to 2G Handover Presentation

July 10, 2006

Current Setting

GSM

UMTS

IdleQsearch_I = AlwaysFDD Qmin = -13

DedicatedNot Allowed

IdleEcIoSsearchRAT = 4 (-14)

DedicatedRSCPthrown_3a = -100 dBmthrooth_3a = -100 dBmthruf_2dug = -97 dBmthruf_2f = -94 dBm

Makati-Mandaluyong-Pioneer

Poor Coverage &No Dominant Server.

Need to improve coverage

In Dedicated Mode, UE fall below -100 dBm in 2 sample. Trigger point from 3G to 2G <

-100 dBm.

In Idle Mode, EcIo still better than -14 even in low RSCP.

Hence no 3G to 2G cell reselection

Makati- Mandaluyong Bridge

No Handover from 3G to 2G. Served by Rockwell2Missing 3G to 2G neighbors

Makati- Mandaluyong Bridge (DT Logs)

UE already verified BSIC and Trigger Event 3a, however no reply from network.Need to perform IMSI trace for troubleshooting. Suspect similar problem with BPI

Buendia Avenue

Flyover Bridge from The Fort to Edsa

Burgos Street Makati

Poor Inter-RAT Handover SR

From statistics, 100% PS inter-RAT handover failure rateBPI, SAMAT, CUPANG – chosen for troubleshootingSAMAT – KPI : InterRAT HOSR CS = 75%, PS = 0%

Drive Test Result - SAMAT

From DT, PS Inter-RAT HO is successfulReply from TAC3 Munich -------- > Suspect Statistics Counter Problem

BPI Buendia

100% inter-RAT HO Failure CSDrive Test and IMSI Trace was conducted for troubleshootingResults of Trace : Core Network sending RANAP relocation failure with cause value o&minterventionEscalated to Core for troubleshootingVery Poor 3G Coverage.

No Outdoor Sites, current serve by BPI indoor.

Outdoor 3G node B required.NO 3G to 2G handover

BPI Buendia IMSI Trace

Action Plan

CS Inter-RAT HO- Define additional 3G to 2G neighbors list ( Done-

pending database execution)- Perform K12 & IMSI trace for Rockwell &

Mckinley- Re-verify with Drive Test and Statistics - Coordinate with Core on the signaling issue (BPI

Buendia)PS Inter-RAT HO

- Iu (RNC-SGSN) and Iub signaling trace will be conducted this week

- Issue escalated to Siemens TAC3- From DT, the result is ok- Suspect KPI counter problem (TAC3)

Propose New Setting

GSM

UMTS

IdleQsearch_I = AlwaysFDD Qmin = -13 -> -11

DedicatedNot Allowed

IdleEcIoSsearchRAT = 4 (-14) -> 6 (-12)

DedicatedRSCPthrown_3a = -100 dBm -> - 97throoth_3a = -100 dBm -> - 95thruf_2dug = -97 dBm -> -94thruf_2f = -94 dBm -> -90

Pro & Con

PRO : - Faster Handover/Cell reselection from 3G to 2G- Reduce missing neighbors problem due to

overshoot serving of 3G- Better 3G KPI

CON : - 3G coverage shrink- Non Continuous 3G coverage

3g to 2g handover v1

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