Method and system for seamlessly switching between a trunked mode operation and a direct mode operation

A subscriber unit for seamlessly switching between a trunked mode operation and a direct mode operation, the subscriber unit comprising:

• a transceiver operated to communicate on a first communication channel in trunked mode operation via at least one base station and on a second communication channel in direct mode operation via at least one direct mode gateway station that is configured to relay communications between the first communication channel and the second communication channel;
• a memory operated to maintain attributes associated with the first communication channel and the second communication channel;
• and
• a processor coupled to the transceiver and the memory, the processor configured to:
• determine, via the transceiver, when communicating using the first communication channel in trunked mode operation, whether the signal quality on the first communication channel is below a predetermined threshold, and in response to determining that the signal quality on the first communication channel is below the predetermined threshold, use the attributes associated with the second communication channel to automatically switch the transceiver to the direct mode operation for communicating on the second communication channel;
• and
• determine, via the transceiver, when communicating using the second communication channel in direct mode operation, whether the signal quality on the second communication channel is below a predetermined threshold, and in response to determining that the signal quality on the second communication channel is below the predetermined threshold, use the attributes associated with the first communication channel to automatically switch the transceiver to the trunked mode operation for communicating on the first communication channel.

A system for operating a subscriber unit to seamlessly switch between a trunked mode operation and a direct mode operation, the system comprising:

• one or more subscriber units;
• a base station for providing trunked mode communications between the one or more subscriber units operating in trunked mode operation using a first communication channel;
• and
• a direct mode gateway station for providing direct mode communications between the one or more subscriber units operating in direct mode operation using a second communication channel that is configured to relay communications between the first communication channel and the second communication channel,
• wherein when the one or more subscriber units communicate using the first communication channel in the trunked mode operation, the one or more subscriber units determine whether the signal quality on the first communication channel is below a predetermined threshold, and in response to determining that the signal quality on the first communication channel is below the predetermined threshold, the one or more subscriber units use the attributes associated with the second communication channel to automatically switch to the direct mode operation for communicating on the second communication channel;
• and
• wherein when the one or more subscriber units communicate using the second communication channel in the direct mode operation, the one or more subscriber units determine whether the signal quality on the second communication channel is below a predetermined threshold, and in response to determining that the signal quality on the second communication channel is below the predetermined threshold, the one or more subscriber units use the attributes associated with the first communication channel to automatically switch to the trunked mode operation for communicating on the first communication channel.