A method of operating a terminal in a wireless communication system includes receiving, from a base station, system information including information on a first discontinuous reception (DRX) cycle; transmitting, to an access and mobility management function (AMF), a request message including information on a second DRX cycle based on the first DRX cycle; receiving, from the AMF, a response message about the request message, wherein the response message includes information determined based on whether the AMF assigns the second DRX cycle; and determining a DRX cycle of the terminal based on the response message.