Throughput and Delay Analysis of Half-Duplex IEEE 802.11 Mesh Networks

Emerging technologies for mesh networks can provide users with last-mile service to an access point by forwarding data through wireless relays instead of through expensive wireline infrastructure. While an extensive amount of literature on the subject has been amassed in the last decade, existing papers model network traffic flow solely as a function of routing topology, neglecting contention at the Media Access Control layer; as a result, the inbound flow to a relay station is independent of the transmission success rate from forwarding stations. This leads to overestimation of traffic flow, especially at network operation approaching full capacity, and in turn makes for inaccuracies in predicting throughput and delay. In our model, the inbound flow depends on the transmission success rate as well. Other novel contributions are the incorporation of a half-duplex contention model we developed in previous work, which captures both uplink and downlink traffic, and a generic framework to represent any mesh routing topology (minimum-hop, minimum-airtime, etc.).