PLMN FREQUENCY SEARCH TRIGGERED BY CHANGE IN MOBILE COUNTRY CODE

摘要

PROBLEM TO BE SOLVED: To provide a method of efficiently identifying carrier frequencies in a wireless communication system by mobile User Equipment (UE).SOLUTION: A mobile UE 10 initiates a full search of all supported frequencies upon detecting a change in the Mobile Country Code (MCC) transmitted by a PLMN. The change in the MCC indicates a user crossed a border, and the frequency allocated for wireless communication may be different by that. The mobile UE 10 stores the current MCC. Upon obtaining an updated MCC, it is compared with the stored MCC. If the updated MCC is different from the stored MCC, the full frequency search is initiated. To prevent power consumption due to excessive searching, the UE waits for a predetermined duration after an MCC-initiated full search before conducting another full search, even if the MCC chances within that duration.