1. A method performed by a terminal in a wireless communication system, the method comprising:receiving, from a first base station, a dedicated radio resource control (RRC) message for adding at least one secondary cell associated with a second base station;
receiving, on a primary cell associated with the second base station, a master information block (MIB) through a physical broadcast channel (PBCH);
identifying a system frame number (SFN) based on the MIB through the PBCH; and
applying the identified SFN to communicate with the at least one secondary cell associated with the second base station,
wherein the dedicated RRC message includes information for the at least one secondary cell except for information associated with the SFN.