Abstract: Apparatus and method for enabling a single communication system (100) to support at least two communication services. For example, one can support both cellular telephone services and trunked dispatch services by sharing some, but not all, of the system infrastructure. Access control gateways (201) and base stations (203) comprise common infrastructure elements, while two separate processors provide control for each service, these being a communication agent processor (104) to support telephone services, and a dispatch call processor (106) to support dispatch call services. These two independent processors each include a data base (303 and 307) that includes information concerning communication units (204-206) operating within the system. During a call set-up sequence, the access control gateway (201) receives a call request from a communication unit via a base station, and passes the request to the appropriate processor, which uses its corresponding database to support the requested service.

Abstract: A data communications system is described in which variable length messages are communicated between a general communications controller (GCC) and a plurality of portable and mobile radios. The variable length messages include a bit synchronization field, a message synchronization field and a plurality of channel data blocks for efficiently and reliably handling long strings of data or text. Each channel data block includes an information field, a parity field for error-connecting the information field and a channel state field indicating whether or not the radio channel is busy or free. The GCC is coupled to a cellular arrangement of channel communications modules (CCM's), which each include a radio transmitter and/or radio receiver. The mobile and portable radios communicate with the GCC by way of the CCM's.

Abstract: A data communications system is described in which variable length messages are communicated between a general communications controller (GCC) and a plurality of portable and mobile radios. The variable length messages include a bit synchronization field, a message synchronization field and a plurality of channel data blocks for efficiently and reliably handling long strings of data or text. Each channel data block includes an information field, a parity field for error-connecting the information field and a channel state field indicating whether or not the radio channel is busy or free. The GCC is coupled to a cellular arrangement of channel communications modules (CCM's), which each include a radio transmitter and/or radio receiver. The mobile and portable radios communicate with the GCC by way of the CCM's.