Performance of IEEE 802.11 in wireless mesh networks

Abstract

This paper addresses the performance of the IEEE 802.11 MAC protocol in a wireless mesh network. The aim is to assess under which conditions the protocol's performance might be acceptable, in particular for delay sensitive traffic. A number of different scenarios is considered, with varying number of gateways, different sizes for the group of users, as well as different transmission and carrier sensing ranges. It is shown that the IEEE 802.11 performs poorly on heavy traffic, in particular for data flows subject to multiple hops. In addition, the protocol fails to dispense the available bandwidth fairly to the available bandwidth fairly to the requesting nodes. Improvements can be obtained by minimizing the number of hops required for the traffic to reach its destination. This can be achieved by increasing the number of gateways. Another alternative is to increase the transmission range, at the cost of spatial reuse. However, the latter option only translates into better performance if the carrier sense range is also decreased.