Abstract: A method and apparatus are provided for allocating radio frequency carriers in a radio service area having a plurality of radio frequency TDMA carriers and FDMA carriers. The method includes the steps of receiving a call, when the received call is a FDMA call and a FDMA carrier is not available for the FDMA call, then preempting a pre-existing call on a TDMA carrier of the plurality of radio frequency TDMA carriers for the FDMA call and when the received call is a TDMA call and a TDMA slot is not available for the TDMA call, then preempting a pre-existing FDMA call on a TDMA capable carrier of the plurality of radio frequency TDMA carriers for the TDMA call.

Abstract: A zone controller is configured to send a first channel grant signal to a base site to assign a call to a first communication channel and then subsequently send a second channel grant signal to the base site upon determining that the call should be reassigned to a second communication channel. The base site, which is coupled to the zone controller, is configured to receive the second channel grant signal, and begin broadcasting the call on the second channel upon receiving the second channel grant signal. Once the call is being broadcast on the second channel, the base site transmits a transition grant signal to the communication units. Upon receiving the transition grant signal, the communication units switch from the first communication channel to the second communication channel. The call is deassigned from the first communication channel to make the first communication channel available for other calls or services.

Abstract: A system and method for dynamically re-associating remote sites among multiple zone controller. The system includes multiple zones, each having one or more zone controllers associated with multiple remote sites via a network. Upon a failure, loss of service, or other preset event, a remote site obtains a list of foreign zone controllers with which the remote site is capable of being associated with, selects one of the list of foreign zone controllers; and associates with the selected foreign zone controller.

Abstract: A method and apparatus are provided for allocating radio frequency carriers in a radio service area having a plurality of radio frequency TDMA carriers and FDMA carriers. The method includes the steps of receiving a call, when the received call is a FDMA call and a FDMA carrier is not available for the FDMA call, then preempting a pre-existing call on a TDMA carrier of the plurality of radio frequency TDMA carriers for the FDMA call and when the received call is a TDMA call and a TDMA slot is not available for the TDMA call, then preempting a pre-existing FDMA call on a TDMA capable carrier of the plurality of radio frequency TDMA carriers for the TDMA call.