Patent ID: 8483175
Filing Date: 2013-07-09
Classification: H04W

Abstract:
1. A method for inter-technology handoff of a communication session in a communication system comprising an Internet Protocol Multimedia Subsystem (IMS) capable of communicating with a user equipment via each of an intervening packet data network and an intervening circuit switched network, the method comprising: conveying forward link session traffic to, and receiving reverse link session traffic from, a user equipment via the packet data network; determining to hand off the communication session to the circuit switched network; in response to determining to hand off the communication session, conveying, by a Circuit Switched Proxy of the packet data network to a Voice Call Continuity Application Server of the IMS via a Circuit Switched Proxy/Voice Call Continuity Application Server interface, information received by the Circuit Switched Proxy from a target Mobile Switching Center of the circuit switched network, the target cell identity, and other information, and wherein the Circuit Switched Proxy supports an S6x interface for retrieving Voice Call Continuity Application Server and user equipment identification information from a Home Subscriber Server; instructing, by the Voice Call Continuity Application Server via the Circuit Switched Proxy of the packet data network, the target Mobile Switching Center to prepare for a handover; continuing to anchor the session in the Voice Call Continuity Application Server; acquiring, by a target Base Station Subsystem associated with the target Mobile Switching Center, the user equipment; and providing, by the target Base Station Subsystem, the user equipment with communication session services.