Patent ID: 8730916

Claim:
A method for implementing single radio voice call continuity, comprising: user equipment (UE) establishing an IP Multimedia Core Network Subsystem (IMS) session anchored to an enhanced mobile switch center (eMSC) with a remote user via a packet switch (PS) network; the PS network sending a handover request to the eMSC to request said IMS session to be handed over to gain access via a circuit switch (CS) network; and said eMSC receiving said handover request, establishing a media link, and relating a newly established media link with a remote media link of said IMS session, so that the UE can communicate with the remote user via the newly established media link and said remote media link; said eMSC sending a map request to an access gateway (AGW), and said map request carrying a line number L 1 of line resources used by a target mobile switch center (MSC) in the newly established media link to transmit CS media; and said AGW receiving said map request, and relating the line number L 1 with said remote media link, and allocating a line number L 2 of the line resources that are used in the newly established media link to transmit the CS media between the target MSC and the remote user, and sending said line number L 2 to said eMSC via a map response.