Location Assisted Fast Vertical Handover for UMTS/WLAN Overlay Networks

UMTS/WLAN integration offers considerable benefits for the users as well as for the mobile network. As soon as coverage is available, a mobile user should be able to switch seamlessly from the ubiquitous low bandwidth UMTS to a high bandwidth WLAN. This will improve his quality of service, but this also increases capacity in the cellular network. To be able to change between radio access technologies, an inter-RAT handover protocol is needed. If this handover protocol is not fast enough, the vehicular user will penetrate deep into the cell, underutilizing the available bandwidth with a lower overall performance as a result. In this paper we introduce a new vertical handover protocol which uses location information from the vehicle to predict where and when the handover should occur, thus optimizing user throughput and network performance. We consider its deployment on three UMTS/WLAN integration scenarios.