An Adaptive Time-Threshold Based Scheme for Voice Handoff Calls in Cellular Wireless Networks

This paper proposes a novel adaptive time- threshold based bandwidth allocation scheme (ATTS) for voice handoff calls in cellular wireless networks. The proposed scheme overcomes the flaws of the fixed time-threshold based bandwidth allocation scheme (FTTS) in the total admitted traffic and the blocking probability of new calls. In proposed scheme, bandwidth threshold for non-prioritized handoff calls and new calls can be varied adaptively based on instantaneous handoff call and new call arrival rates. This makes it possible that there is the increasing number of new calls which have successfully occupied bandwidth units in ATTS scheme when traffic load is heavier. Simulation results show that the proposed scheme improves new call blocking probability and bandwidth utilization with traffic load of given cell increasing while keeps low total handoff call dropping probability compared with FTTS scheme. The proposed scheme provides good QoS guarantees for both mobile users and service provider.