Abstract: A method for controlling operation modes of a medium access control layer by a mobile subscriber station in a broadband wireless access communication system including the mobile subscriber station and a serving base station providing service to the mobile subscriber station is provided. The method includes the steps of: mode-transiting into an idle mode when there is no data transmission between the serving base station and the mobile subscriber station during a predetermined first time interval in an awake mode; detecting movement of the mobile subscriber station in the idle mode into another paging zone covering a target base station, which is different from a paging zone covering the serving base station; and mode-transiting into the awake mode and performing location update together with the target base station when the movement of the mobile subscriber station is detected.