A Unified Metric for Routing and Rate Adaptation in Multi-Rate Wireless Mesh Networks

In this paper, we propose a new metric that is applicable both to routing and rate adaptation in multi-rate wireless mesh networks. Unlike many previous efforts, our metric is comprehensive; it considers several factors that affect end-to-end performance such as the effect of the relative positions of the links on a path when choosing the rates of operation and the importance of avoiding congested areas. We call our metric ETM (for Expected Transmission cost in Multi-rate wireless networks). We analytically derive the ETM metric. We show that the ETM metric can be used (a) to determine the best end-to-end path with a greedy routing approach and (b) it can be used to dynamically select the best transmission rate for each link on the path via a dynamic programming approach. Based on ETM, we design and implement the ETM-framework on an indoor wireless mesh network and compare its performance with that of the popular ETT and the recently proposed ETOP metrics. Our experiments show that the ETM-framework yields throughput improvements of up to 253\% and 368\% as compared with the ETT and ETOP frameworks.