Performance of multihop wireless networks: shortest path is not enough

Existing wireless ad hoc routing protocols typically nd routes with the minimum hop-count. This paper presents experimental evi-dence from two wireless test-beds which shows that there are usu-ally multiple minimum hop-count paths, many of which have poor throughput. As a result, minimum-hop-count routing often chooses routes that have signicantly less capacity than the best paths that exist in the network. Much of the reason for this is that many of the radio links between nodes have loss rates low enough that the rout-ing protocol is willing to use them, but high enough that much of the capacity is consumed by retransmissions. These observations suggest that more attention be paid to link quality when choos-ing ad hoc routes; the paper presents measured link characteristics likely to be useful in devising a better path quality metric. 1