Patent ID: 8873540

Claim:
A method of providing a continuity control function comprising: providing a signaling anchor point in a multimedia subsystem for a first access signaling leg and a remote access signaling leg that initially form a signaling path for a call between a user element and a remote endpoint, the first access signaling leg being connected to the user element via a transferring-out subsystem; establishing a second access signaling leg toward a user element via a transferring-in subsystem; replacing the first access signaling leg with the second access signaling leg to update the signaling path, such that the second leg is anchored at the signaling anchor point; providing call signaling via the signaling path to transfer at least a portion of a bearer path used for the call between the user element and the remote endpoint, from a first network to a second network while maintaining continuity of the call, wherein the transferring-out subsystem is circuit-switched subsystem or the multimedia subsystem, and the transferring-in subsystem is the multimedia system or the circuit-switched subsystem, respectively, thereby the method transferring calls from the circuit-switched subsystem to the multimedia subsystem and transferring calls from the multimedia subsystem to the circuit-switched subsystem; receiving a request intended for the continuity control function to originate the call from the user element to the remote endpoint; terminating the first access signaling leg; identifying an address or number associated with the remote endpoint; and establishing the remote signaling leg for the call toward the remote endpoint using the address or number; wherein the user element will initiate a call to the continuity control function; wherein the address or number for the remote endpoint is identified from a message separate from the request and wherein the message is sent via a Unstructed Supplementary Service Data (USSD) channel.