Patent ID: 8670411

Claim:
A method for realizing a single radio voice call continuity, comprising: S 1 : forwarding, by an IMS Control Point (ICP), an IMS session call request from a user equipment (UE- 1 ) to a remote leg, wherein the IMS session call request contains a transmission address F allocated by an Access Gateway (AGW) which is controlled by the ICP; S 2 : forwarding, by the ICP, an IMS session answer call from the remote leg to the UE- 1 via the PS network, wherein the IMS session answer call contains a transmission address D allocated by the AGW which is controlled by the ICP; S 3 : when a control net element of a Packet Switch (PS) network determines a handover of the UE- 1 to a Circuit Switch (CS) network is required, sending, by the control net element of the PS network, a handover request to an enhanced Mobile Switch Center (eMSC) to request a handover of the IMS session to a CS network access mode; S 4 : after receiving the handover request from the control net element of the PS network, carrying out, by the eMSC, a CS handover flow and sending, by the eMSC, a handover response to the control net element of the PS network to instruct the UE- 1 to change its access mode from a PS access mode to a CS access mode; S 5 : after receiving the handover request from the control net element of the PS network, sending, by the eMSC, a handover call request to the ICP; and S 6 : after receiving the handover call request from the eMSC, controlling, by the ICP, the AGW to correlate a media link established by the handover call request with a remote leg media link of the IMS session.