METHOD, DEVICE AND COMMUNICATION SYSTEM FOR HANDING OVER FROM CIRCUIT SWITCHING DOMAIN TO PACKET SWITCHING DOMAIN

摘要

Embodiments of the present invention disclose a method for a handover from a circuit switched domain to a packet switched domain, a device, and a communications system, where one of CS to PS handover methods includes: receiving, by a target mobility management entity, a CS to PS handover request message which corresponds to a first UE and is from an MSC; triggering setup of a dedicated VoIP bearer which corresponds to the first UE and is between an SGW and an MGW, or, triggering setup of a dedicated VoIP bearer which corresponds to the first UE and is between the SGW and a PGW; sending a handover request message to a target access network to instruct the target access network to prepare a handover resource for the first UE; and sending a CS to PS handover response message corresponding to the first UE to the MSC, so that the first UE uses the dedicated VoIP bearer to bear a VoIP session between the first UE and the MGW after the first UE is handed over to the target access network. The solutions of the embodiments of the present invention help to maintain voice continuity when the UE is handed over from the CS domain to the PS domain.