Patent ID: 8433282

Claim:
An emergency service handover method which is applied in a single radio voice system, with a user terminal UE having established an emergency session between a multimedia subsystem (IMS) domain and an emergency call center via LTE/SAE network, and the emergency session anchored to a service centralization and continuity application server (SCC AS) of a visited location, and the method comprising the following step: initiating, by an enhanced MSC, a session establishment request to the visited SCC AS for performing a handover from the IP multimedia subsystem domain to the circuit switched domain on a service layer when the enhanced mobile switching center (MSC) obtains information that a UE having established an emergency session needs to be switched to a CS domain, wherein an emergency session transfer number (STN) corresponding to the SCC AS in the visited location is preset in the enhanced MSC; and the enhanced MSC initiates the session establishment request to the visited SCC AS according to the emergency STN.