Communications unit for seamless handover between networks and method of use therefor

A communications unit determines that a wireless link between itself and a first communications network has degraded beyond acceptable limits (FIG. 2, 200). The communications unit signals a second, unsynchronized, communications network during a pause in outgoing voice (230) in order to acquire a channel and continue the call using the second network. When the second communications network indicates that sufficient resources are available, the communications unit transmits a Handover Trigger to the second network (FIG. 4, 400). In response to the Handover Trigger, the first and second communications network establish a connection between each other (460, 470). When the connection has been established, the communications unit receives a channel assignment (500) and continues the call using the resources of the second communications network.