Reducing Routing Loops under Dynamic Metrics in Wireless Mesh Networks

Many dynamic metrics for wireless mesh networks (WMNs) to improve communication quality are proposed so far. However, all of them have possibility to create temporary routing loops which may cause severe congestion and disruption of communications. In order that WMNs are regarded as a reliable infrastructure of the next generation, such routing loops are strongly desired to be liminated since they bring the possibility of ervice disruption. In this paper, we propose a mechanism called Loop-free Metric Range (LMR) to make existing dynamic metrics loop-free by restricting the range of metric values to change. LMR is applicable to a major part of existing etrics such as ETX, ETT, MIC, and so on without any message overhead. We show the mechanisms of LMR, theoretical results on the range of loop-free etric values, and simulation results on the effectiveness of LMR.