Design and evaluation of UMTS-WLAN interworking strategies

High tier wireless systems such as GPRS and UMTS provide users with high mobility but less bandwidth. On the other hand, low tier wireless systems such as wireless LAN offer high bandwidth with less mobility. The support of seamless roaming between heterogeneous wireless networks is regarded as one of the key issues in future mobile communication systems. The paper presents the design and evaluation of three possible UMTS-WLAN interworking strategies, i.e. Mobile IP approach, gateway approach, and emulator approach based on the current UMTS, WLAN and Mobile IP specifications. Recommendations to UMTS-WLAN interworking strategies according to different deployment scenarios are also discussed.