Patent ID: 8913101

Claim:
A method for transferring a video call between access networks, comprising: initiating, by an Internet Protocol (IP) multimedia subsystem (IMS) call establishment request message sent by a terminal in a packet switching (PS) domain, an IMS video call of the terminal, wherein the request message for initiating the IMS video call carries an indication that the terminal supports single radio video call continuity (vSRVCC) pre-negotiation; determining whether the terminal and a network side support a pre-negotiated circuit switching (CS) video call parameter; pre-negotiating the CS video call parameter in the PS domain through IMS signaling to obtain the pre-negotiated CS video call parameter when both the terminal and the network side are determined to support the pre-negotiated CS video call parameter; and establishing a CS video call according to the pre-negotiated CS video call parameter after a video call of a terminal is transferred from the PS domain to a CS domain.