Patent ID: 8184590

Claim:
A method for operating a dual-mode mobile communications device to hand off a call between first and second wireless networks operating under different communications protocols, comprising: establishing the call over the first wireless network between the dual-mode mobile communications device and a second device thereby setting up an initial communications channel, having at least one media stream, between the dual-mode communications device and the second device; operating the dual-mode mobile communications device: to detect a handoff condition for handing off the call between the first wireless network and the second wireless network; and to directly control, until establishment of at least one new media stream to connect the dual-mode mobile communications device to the second device over the second wireless network, handoff of the call to the second wireless network by executing a standalone client-side application on the dual-mode mobile communications device to solely originate and control an exchange of messages at the application layer, the exchange of messages modifying the communications channel.