METHOD AND SYSTEM FOR SEAMLESSLY SWITCHING BETWEEN A TRUNKED MODE OPERATION AND A DIRECT MODE OPERATION

A method and a system for operating a subscriber unit to seamlessly switch between a trunked mode operation (TMO) and a direct mode operation (DMO) in a communication system. The communication system includes one or more subscriber units communicating in trunked mode operation on a first communication channel via a base station and the subscriber units communicating in direct mode operation on a second communication channel via a direct mode gateway station. When the subscriber units communicate in the TMO and when the signal quality on the first communication channel is below the predetermined threshold, the subscriber units automatically switch to the direct mode operation. When the subscriber units communicate in DMO and when the signal quality on the second communication channel is below the predetermined threshold, the subscriber units automatically switch to the trunked mode operation.