A Contention-Aware Routing Metric for Multi-Rate Multi-Radio Mesh Networks

We present a new routing metric for multi-rate multi-radio mesh networks, which takes into account both contention for the shared wireless channel and rate diversity in multi-radio multi-channel mesh networks. A key property of the proposed contention-aware transmission time (CATT) metric is that it is isotonic, hence can be applied to link-state routing protocols. We have implemented the CATT metric in the OLSR routing protocol, and evaluate it in a test-bed with mesh nodes each equipped with four radio interfaces. Our experiments show that the proposed routing metric significantly outperforms other metrics that have appeared in the literature, in a number of scenarios that correspond to different mesh network topologies.