A method for informing a subscriber unit of an incoming call as well as a cellular satellite communication system and ringing alarm message for use in this method

摘要

A satellite communication system provides users with global cellular coverage. To facilitate delivery of calls to users having subscriber units, a fixed channel is defined wherein subscriber units are notified of incoming calls. Subscriber units monitor this ring alert channel and examine subscriber unit IDs transmitted in a ring alert message contained therein. When a subscriber unit determines from the subscriber unit ID that a call is being directed to it, it calls into a network to receive a call. Subscriber units also monitor this fixed channel to receive a control channel directory identifying the location of a subscriber unit's broadcast (control) channels.