3G/UMTS

PLMN Selection - in VPLMN (Cell Reselection)

If UE has camped on to the cell with VPLMN and is in IDLE mode, it has to perform following procedures

i) periodically attempts to obtain service on its HPLMN (if the EHPLMN list is not present or is empty) or one of its

EHPLMNs (if the EHPLMN list is present)

ii) (if failed in previous step) periodically attempts to a higher priority PLMN/access technology combinations listed in ‘User Controlled PLMN Selector’ or ‘Operator Controlled PLMN Selector’

I said the term "periodically". Then how this "peridicity" is determined ?

The periodicity  T minutes may be stored in the SIM (Higher Priority PLMN search period), T is either in the range 6 minutes to 8 hours in 6 minute steps or it indicates that no periodic attempts shall be made. If no value is stored in the SIM, a default value of 60 minutes is used