An Upward Priority Channel Preemption Scheme for Vertical Handoff in Cellular/WLAN Interworking

This paper proposes a novel upward priority channel Preemption Scheme (UPPS) for vertical handoff in a cellular/WLAN interworking networks. In order to improve the upward vertical handoff (UVH) dropping probabilities of voice and data calls while guaranteeing system performance and utilization of the cellular bandwidth, the proposed scheme defines priorities for newly cellular calls and UVH calls and designs newly bandwidth allocation scheme and priority preemption rule to modify the channel Preemption Model for Vertical handoff (PMV) scheme. Simulation results show that the proposed scheme enormously improves performance of the voice UVH call dropping probability and the data UVH call dropping probability at the cost of some increasing newly cellular call blocking probability that may tolerate uncritical while keeping high cellular bandwidth utilization compared with PMV. The proposed scheme has much significance in providing good QoS guarantees in cellular /WLAN interworking networks.