A Time-Threshold-based Channel Scheme for vertical handoff in cellular/WLAN interworking

This paper proposes a novel Time-Threshold-based Channel Scheme (TTCS) for vertical handoff in a cellular/WLAN interworking networks. In order to improve the QoS of cellular ongoing voice calls further, the proposed scheme defines priorities for ongoing cellular voice calls within the dual cellular/WLAN coverage area by using a time-threshold value and modifies channel preemption scheme of the channel Preemption Model for Vertical handoff (PMV) scheme. Simulation results show that the proposed scheme eliminates DVH of prioritized ongoing cellular voice calls while keeping system performance and utilization of the bandwidth when carried traffic load is relatively lighter compared with PMV scheme.