A Time-threshold-based Dynamic Priority Scheme for vertical handoff in cellular/WLAN interworking

This paper proposes a novel Time-threshold-based Dynamic Priority Scheme (TDPS) for vertical handoff in a cellular/WLAN interworking networks. In order to improve the non-prioritized Upward Vertical Handoff (UVH) call dropping probability while guaranteeing system performance, the proposed scheme defines dynamic priority for non-prioritized UVH calls and designs the newly bandwidth allocation scheme and priority preemption rule to modify Time-threshold-based Upward Priority Scheme (TUPS). Simulation results show that the proposed scheme enormously improves performance of the non-prioritized UVH call dropping probability while keeping high cellular bandwidth utilization and low prioritized UVH call dropping probability as well as low cellular call blocking probability compared with TUPS. The proposed scheme has much significance in providing good QoS guarantees in cellular/WLAN interworking networks.