Disclosed is a method for operating a moible station with a base station, as well as apparatus for performing this method. The method includes, when the mobile station is in an Autonomous mode of operation, autonomously transmitting from the mobile station to the base station of a reverse access channel or a reverse supplemental channel (Transition 3); in response to receiving an acknowledgement indication from the base station, that comprises a reverse channel assignment message for the mobile station, switching the mobile station to a Scheduled mode of operation (Transition 4) and transmitting data from the mobile station on an assigned reverse channel.