METHOD FOR USER EQUIPMENT REALIZING HANDOFF ACROSS ACCESS NETWORKS IN ACTIVE STATE

摘要

A method for user equipment realizing handover across access networks in active state includes: during the process for a user equipment in active state handing over from an evolved packet system to a universal mobile telecommunications system or a global system for mobile communications, an evolved universal mobile telecommunication system radio access network notifies the user equipment whether this handover is a handover due to an incoming call of a circuit switched domain before informing the user equipment of performing the handover or when informing the user equipment of performing the handover; the user equipment will send a paging response message to a mobile switching center/visitor location register after handing over to the universal mobile telecommunications system or the global system for mobile communications if this handover is a handover due to an incoming call of the circuit switched domain. By using the present invention, it will help to the successful establishment of the circuit switched call after handover, and it can avoid the waste of circuit switched network resources.