Methods for operating a user equipment and a base station in a wireless communication system, and apparatus thereof are provided. The method comprises receiving, from a first base station, a measurement configuration, transmitting, to the first base station, a measurement report according to the measurement configuration, receiving, from a first base station, a RRC reconfiguration message triggering a handover to a second base station, wherein the RRC reconfiguration message includes access information required to access the second base station, performing a synchronization to the second base station, transmitting, to the second base station, a RRC reconfiguration complete message to confirm a completion of the handover, monitoring a physical downlink control channel, PDCCH, from the second base station based on a number of symbols used for the PDCCH of the second base station, wherein the RRC reconfiguration message includes the number of symbols used for the PDCCH of the second base station.