Achieving Congestion Diversity in Multi-Hop Wireless Mesh Networks

This paper reports on a comprehensive study comparing congestion-aware routing algorithms for wireless mesh networks with a state-of-the-art shortest-path routing protocol: Link-Quality Source Routing (LQSR). In particular, a set of congestion-aware protocols in the literature, Backpressure (BP), Enhanced-Backpressure (E-BP) and Congestion Diversity Protocol (CDP) are suitably adapted for implementation on 802.11-compatible radios. A testbed consisting of 802.11g nodes is deployed to empirically compare the performance of these congestion-aware routing protocols against LQSR. The results show that, under moderate to heavy UDP traffic, CDP delivers significant improvement compared to LQSR in 80-90 percent of the instances studied, while backpressure-based routing algorithms (BP and E-BP) frequently show significant degradation with respect to LQSR for both UDP and TCP traffic.