Method for acquiring plmn of mobile communication terminal and method for providing plmn information of base station and base station for executing thereof in mobile communication system

PURPOSE: A method for obtaining a PLMN(Public Land Mobile Network) of a mobile communication terminal, a method for providing PLMN information of a base station and the base station for performing the method in a mobile communication system are provided to allow a mobile terminal positioned in a frequency overlap area to reliably obtain a home PLMN. CONSTITUTION: System information of a cell having the most powerful receiving strength is obtained(S1). PLMN information is extracted from the obtained system information and it is checked whether the corresponding cell is a home PLMN(S2). If the corresponding cell is not a home PLMN, a mobile terminal extracts overlap PLMN existence information as a cell overlap information from the system information(S3). A PLMN is searched with respect to slot synchronization of a signal strength smaller than the signal strength of slot synchronization that has obtained the current system information(S4). If a home PLMN is not obtained with respect to slot synchronization, a carrier frequency is changed and slot synchronization is obtained again(S6). Frame synchronization is obtained and system information is newly obtained(S7). If a home PLMN is obtained(S5), location registration is performed in the obtained PLMN(S8).