Patent ID: 8488554

Claim:
A method for handover between different types of access systems, the method comprising: when a User Equipment (UE) handovers from a non-3GPP access system to a 3GPP access system, accessing, by the UE, a source Inter Access Systems Anchor (IASA) connected with the UE in the non-3GPP access system through the 3GPP access system, wherein the step of accessing the source IASA comprises: during a service activation process in the 3GPP access system, sending, by the UE, an Active Packet Data Protocol (PDP) Context Request containing an address of the source IASA to a 3GPP access gateway, wherein, the Active PDP Context Request comprises an IASA allocation identifier for indicating whether to allow the 3GPP access gateway to reallocate the address of the source IASA; and determining, by the 3GPP access gateway, whether it is necessary to reallocate the address of the source IASA; and if it is unnecessary to reallocate the address of the source IASA, creating a PDP context between the 3GPP access gateway and the source IASA.