>> Bilal, Pan,
Can you summarize ? I’m a “bit” lost.
MS in idle mode, receives SI2 from serving, stating BCCH(n1)=24.
MS receives a frequency 24, decodes system information messages –> what are the important fields that are used in order to authorize cell reselection ?
NCC neighbor = NCC from serving cell ?
MNC+MCC neighbor = MNC+MCC from serving cell ?
>> ParaHO,
No risk of ping pongs ! Example with RXLEV ACCESS MIN = -110dBm in all cells :
MS camping on hPLMN :
a belongs to hPLMN
b belongs to vPLMN
MS receives RXLEV(a) = -109dBm and RXLEV(b) = -60dBm.
In this situation, MS will not leave “a” because “a” is still a valid cell (> than rxlev access min). As Pan said, there are other reasons to decide to leave a cell, including effects of interference in UL and DL, so ensure clean frequencies in BCCH.
CASE 2:
MS camping on vPLMN :
a belongs to hPLMN
b belongs to vPLMN
MS receives RXLEV(a) = -60dBm and RXLEV(b) = -109dBm
The MS will not leave cell B, because the rxlev(b) is not below rxlev access min.
I hope these examples are making sense to you ? As you can see, there is no reason for ping pong.
At MS switch off (cf Pan’s post), the MS will select a cell that belongs to previous LAC, so it will stay in vPLMN if it was in vPLMN before previous swith-off.