Extending GTP Protocol to Support Seamless Handover between UMTS and WLAN Access Network

Much of interest has been involved in integrating UMTS and WLAN networks in order to take full advantage of the two. In such an integrated network, UMTS subscribers can access to UMTS services through 3G or WLAN access networks. This is highly desirable because network operators will use WLAN hotspots to increase network coverage, while offering subscribers with high-speed connections to 3G networks. To achieve this goal, a mechanism for service continuity between UMTS and WLAN is required. 3GPP has defined architecture for WLAN access to 3GPP system, but intersystem handover has not been yet investigated. Based on this architecture, this paper proposes a solution for seamless handover between UMTS and WLAN. Results obtained from the implementation of the proposed mechanism on our experimental system are also described.