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.