Performance of multihop wireless networks

TLDR

Existing wireless ad hoc routing protocols typically find routes with the minimum hop‑count. This paper presents experimental evidence from two wireless test‑beds that multiple minimum hop‑count paths exist, many with poor throughput, and suggests that link quality should be considered when choosing ad hoc routes, providing measured link characteristics to aid a better path quality metric. Many radio links have loss rates that are low enough for routing protocols to use them but high enough that retransmissions consume much capacity. Experimental evidence from two wireless test‑beds shows that multiple minimum hop‑count paths exist, many with poor throughput, leading minimum‑hop‑count routing to select routes with significantly less capacity than the best available paths.

Abstract

Existing wireless ad hoc routing protocols typically find routes with the minimum hop-count. This paper presents experimental evidence from two wireless test-beds which shows that there are usually multiple minimum hop-count paths, many of which have poor throughput. As a result, minimum-hop-count routing often chooses routes that have significantly 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 routing 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 choosing ad hoc routes; the paper presents measured link characteristics likely to be useful in devising a better path quality metric.