Performance Improvement of Voice over Multihop 802.11 Networks

Extensive studies on supporting voice traffic over wireless 802.11 networks have been carried out in the literature. Most of them were focused only on one hop infrastructure mode. This paper addresses the issue of voice over multihop wireless networks. Through simulation considering a simple topology, we identify the voice traffic bottleneck in 802.11 MAC and thus propose a burst queue (BQ) scheme to cooperate with 802.11b and 802.11e MAC protocols. Extensive simulation results under variety of circumstances show that BQ scheme can support 50%~100% more voice calls and obtain 20%~50% lower delay at the cost of a little higher loss ratio which is tolerable to voice flows. Even for the grid and random topology, our BQ scheme can provide smaller packet loss ratio, and shorter end-to-end delay.