Patent ID: 8619618

Claim:
A method for access, comprising: judging, by a first Mobility Management Entity (MME), whether a Global Unique Temporary Identity (GUTI) of a user equipment (UE) is allocated by a System Architecture Evolution (SAE) network or mapped from a temporary identity of a Second Generation/Third Generation (2G/3G) network; when the GUTI is allocated by the SAE network, transmitting, by the first MME, the GUTI to an old MME and receiving a UE context of the UE from the old MME, wherein the UE context of the UE is sent by the old MME according to the GUTI; or when the GUTI is mapped from the temporary identity of the 2G/3G network, reconstructing, by the first MME, an old Routing Area Identification (old RAI) and a Packet Temporary Mobile Subscriber Identity (P-TMSI) from the GUTI, transmitting the old RAI and the P-TMSI to an old Serving General Packet Radio Service (GPRS) Support Node (old SGSN), and receiving the UE context of the UE from the old SGSN, wherein the UE context of the UE is sent by the old SGSN based on the old RAI and the P-TMSI.