Patent ID: 8411597

Claim:
A method for setting up a multimedia call, the method comprising: receiving, by a Mobile Switching Center, a multimedia request message, setting up, by the Mobile Switching Center, a multimedia call path to a Circuit Switched (CS) User Equipment (UE) according to the multimedia request message; negotiating, by the Mobile Switching Center, a media coding mode with the CS UE and negotiating a media coding mode with a peer UE according to the multimedia call path; and setting up, by the Mobile Switching Center, a multimedia call between the CS UE and the peer UE after determining a coding mode of the CS UE and the peer UE; wherein the multimedia request message is a call mode change request message sent by the CS UE, and indicates that the CS UE requires switching from a current voice call to the multimedia call; wherein, before setting up the multimedia call path to the CS UE according to the multimedia request message, the method further comprises disconnecting, by the Mobile Switching Center, the voice call from the CS UE after receiving the media stream change request message; and sending, by the Mobile Switching Center, a multimedia request setup message to the CS UE; and wherein the method further comprises instructing, by the Mobile Switching Center, the peer UE to hold a current call, and activating, by the Mobile Switching Center, the held call through a re-Invite/Update message after determining the coding mode of the CS UE and the peer UE.