Modeling and throughput analysis of distributed WiFi networks

Throughput performance of WiFi networks, which employ the Carrier Sense Multiple Access (CSMA) technique, can be estimated fairly accurately using Bianchi's analytic solution provided all elements of the network are within the carrier sensing range of one another. However, this solution cannot be applied to networks that are spread over a wide area. A paper by Liew, et al proposed an interesting approximate solution for such networks. While this solution was shown to work well in a variety of conditions, it suffers from a limitation in that it requires all transmitter-receiver pairs to have independent and identically distributed (i.i.d.) transmission times. In this paper, we generalize some of the key results of Liew, et al by removing the restriction on transmission times, which leads to a solution technique that can be used to analyze CSMA networks where different transmitter-receiver pairs operate at different bit rates. We also provide a few examples to illustrate how well this technique works in different settings and compare it with solutions based on other methods.