MOBILE TERMINAL HANDOVER FROM A SECOND GENERATION NETWORK TO A THIRD GENERATION IP-BASED NETWORK

摘要

A method of handing over a mobile terminal from a second generation (2G) Anchor Mobile Switching Center (MSC(39)) in a 2G circuit-switched radio telecommunications network to a Serving General Packet Radio Service (GPRS) Service Node (SGSN(33)) in a third generation (3G) Internet Protocol (IP)-based radio telecommunications network. The handover is triggered not just by the availability of service by the 3G network, or by a stronger signal strength from the 3G network, but also by a request for a service that requires 3G coverage. In order to reduce potential handover delays, the mobile terminal is preregistered with the 3G network whenever 3G coverage is detected (44). A Handover Server (HOSV(35)) is implemented at the same hierarchical level as the MSC or the SGSN. The HOSV maintains backward compatibility with the 2G MSC during the handover procedure.