Method and system for handoff between wireless networks
First Claim
1. 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.
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Accused Products
Abstract
A method and system for operating a standalone client in a dual-mode mobile communications device to hand off a call between first and second wireless networks operating under different communications protocols, using Session Initiation Protocol (SIP) and ISDN User Part (ISUP) signalling. The standalone client-side application, or handoff agent, directly controls handoff of the call to the second wireless network until at least one new media stream to connect the dual-mode mobile communications device to the second device is established over the second wireless network. The standalone client-side application solely originates and controls an exchange of messages at the application layer, the exchange of messages modifying the communications channel.
215 Citations
22 Claims
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1. 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:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A dual-mode mobile communications device for roaming between first and second wireless networks operating under different communications protocols, wherein a call is established 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 mobile communications device and the second device, comprising:
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a processor to execute instructions to enable; a roaming agent to detect a handoff condition for handing off the call between the first wireless network and the second wireless network; and a handoff agent 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 originating and controlling an exchange of messages at the application layer, the exchange of messages modifying the communications channel. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification