2g-3g idle reselection
DESCRIPTION
2G to 3G & 3G to 2G reselctionTRANSCRIPT
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1. 3G To 2G Reselection.
No Event
1 Inter-RAT Measurement triggering(GSM Cell Measuring Starting)
Squal>SsearchRAT
Squal = CPICH_EcNo measure – Qqualmin
CPICH_EcNo is the measured value of pilot in the serving cell.
SsearchRAT and Qqualmin are parameters in system information.
2 Evaluation GSM cell along with WCDMA cells
UE selects cells that accord with an "S rule"
"S Rule"
for FDD cells: Srxlev > 0 AND Squal > 0
Squal = Qqualmeas – Qqualmin
for TDD cells: Srxlev > 0
Srxlev = Qrxlevmeas - Qrxlevmin - Pcompensation
2. 2G To 3G Reseltion.
No. Event
1 Inter-RAT measurement trigering(Starting to measure WCDMA Cells)
Qsearch_I Threshold determine the triggering
Qsearch_I means the idle state of CS domain, Ericsson : QSI used for Idle & Packet Mode
Qsearch_C_Initial means building the connection phase of CS domain Ericsson : QSC for active mode
Qsearch_P means GPRS domain
2 Algoritham for reselecting 2G to WCDMA
after triggering UE update RLA_C & 6 strong WCDMA Cells level
RLA_C : Average Rx Level of serving cell & Neighbor Cells
[CPICH Ec/No > FDDqmin] & [CPICH RSCP > RLA_C + FDDqoff]
FDDqmin : Minimum Ec/No level for reselect
FDDqoff : Offset between GSM & WCDMA rx level for reselect
Important;
After selecting UTRAN cell FDDqoff value increase by 5db for 15s period
UE can not reselect UTRAN cell until 5 seconds if UE reselects a proper GSM cell