Provided is a method of obtaining public land mobile network (PLMN) information of a user equipment (UE), the method including receiving, by a UE access stratum (AS), a request for collecting the PLMN information from a UE non-AS (NAS), scanning at least one carrier in a frequency band supportable by the UE, determining, based on a result of the scanning, whether the at least one carrier is a carrier in an unlicensed frequency band, obtaining the PLMN information from at least one cell, based on a result of the determining, and providing, by the UE AS, the obtained PLMN information to the UE NAS.