HANDOVER METHOD AND APPARATUS BETWEEN DIFFERENT SYSTEMS

摘要

A method and apparatus performs handover from a E-UMTS system to a UMTS system. An E-RAN of the E-UMTS system determines to perform the handove based on a measured signal strength of the UMTS system reported from a UE. Then, am E-CN of the E-UMTS system generates a PDP context and an MM context for the UE, and sets up a data tunnel for the UE to a GGSN of the UMTS system using the PDP/MM context. The E-CN sends to the UE a handover command message including information on an RB to be used by the UE to access the UMTS system. The UE accesses the UMTS system using the RB information, and forwards user data for the UE via a data transmission path composed of the E-CN, the data tunnel, a SGSN, and a RAN of the UMTS system.