Improving capacity and QoS of VoIP in IEEE 802.11e wireless LANs

Abstract

Wireless local area networks (WLANs) have been rapidly developed in recent years for various applications. VoWLAN, which transmits VoIP data over WLANs, shows its amazing attraction and constitutes one of the most flourishing applications nowadays in WLANs. How to improve the capacity while providing QoS of VoWLAN is a big concern for network planners. In this paper, we propose and validate an improved Markov analysis model to study the performance of VoWLAN. Based on the developed analytical model, we bring forward a solution that boosts the capacity high enough to support larger number of calls than existing schemes, with fair call quality. The solution comes in two parts: Frame Enqueue Rear-end Aggregation and Device Differentiation Configuration. We demonstrate the performance of the proposed approach through extensive simulation based on NS-2 and Linux-based VoWLAN environment. The experimental results are very promising; the VoIP capacity was improved by 163.7%.