Fast handoff with differentiated services based on broadcasting scheduling for VoWLAN

摘要

Handoff will be occurred if the stations (STAs) move out of the area covered by access points (APs) in wireless local area network (WLAN) during voice over WLAN (VoWLAN) session. The handoff latency in conventional WLAN exceeds to one hundred milliseconds, which is unacceptable for voice over internet protocol (VoIP). This paper proposes a mechanism named fast handoff with differentiated services (FHDS), which can provide prioritised contention-free access through broadcasting scheduling. The impact of Non Real time Service upon VoIP is considered. VoIP packets and NRS packets are randomly generated by STAs. Various probabilities of generating VoIP packets are considered in order to analyse the performance of FHDS. Simulation results show that compared to existing solutions, FHDS can effectively improve the performance of VoWLAN in terms of handoff latency and resource utilisation. And the higher the probability is, the better improvement can be achieved by FHDS.