| 摘要 |
In a network handover method, after UE located on an LTE network initiates a request message that requests circuit switched fallback CSFB, an MME instructs an eNB to move the UE from the LTE network to a 2G or 3G network, and requests an MSC to hand over the UE from the LTE network to a CS domain of the 2G or 3G network for the CSFB, so that the 2G or 3G network allocates a CS domain resource to the UE, where the CS domain resource is used to hand over the UE from the LTE network to the CS domain of the 2G or 3G network. Therefore, the UE can be handed over to a PS domain of the 2G or 3G network in a manner of being handed over from the LTE network to the CS domain of the 2G or 3G network. After handed over to the PS domain, the UE can perform a CS domain call. In embodiments of the present invention, an access delay of accessing the CS domain of the 2G or 3G network by the UE is reduced, entire voice call duration is shortened, and user experience is improved. Further, by determining that an IMS voice session does not exist, it is identified that the handover of the UE from the LTE network to the CS domain of the 2G or 3G network is triggered by the CSFB, so as to ensure that handover from the LTE network is properly performed. |
