System and method for selecting a subsystem for message traffic in an

Abstract

A system and method are shown for selecting an outbound subsystem and an inbound subsystem to be used to communicate between a subscriber unit (10) and an integrated communication system having a number of subsystems (30, 50) that are capable of operating independently. The subscriber unit (10) stores in a memory (77) for each of the different types of messages that the subscriber unit (10) can handle, a list of the subsystems that can be used to communicate the message type wherein each list is ordered according to the subscriber unit's preference for using a subsystem for outbound messages of the particular type. When the subscriber unit receives control information from the integrated system identifying a particular type of message that the system expects to communicate to the subscriber unit, the subscriber unit identifies at least one outbound subsystem in the list stored for the received message type covering the area in which the subscriber unit is located. The subscriber unit then communicates this information to the integrated subsystem using an inbound channel of the most preferred identified subsystem having one. If none of the identified subsystems includes an inbound channel the subscriber unit identifies the most preferred inbound subsystem that the subscriber unit can access regardless of message type.