Performance study of wireless mesh networks routing metrics

Multihop wireless mesh networks are an attractive solution for providing last-mile connectivity. However, the shared nature of the transmission medium makes it challenging to fully exploit these networks. In an attempt to improve the radio resource utilization, several muting metrics have been specifically designed for wireless mesh networks. However, although some evaluations have been conducted to assess the performance of these metrics in some contrived scenarios, no overall comparison has been performed. We therefore studied the performance of the most popular routing metrics currently used in wireless mesh networks; Hop Count, Blocking Metric, Expected Tran- mission Count (ETX), Expected Transmission Tune (ETT), Modified ETX (mETX), Network Allocation Vector Count (NAVC) and Metric of Inteiference and Channel-Switching (MIC). We showed under various simulation scenarios that although all the metrics except NAVC offer the same end- to-end delay and packet loss ratio, differences can he distinguished in terms of traffic load repartition. In particular, the congestion-avoidance strategies of ETX, mETX, and MIC prevent the starvation of flows following longer paths and consequently provide a more uniform traffic repartition.