Performance evaluation of routing metrics for wireless mesh networks

Abstract

An optimal routing metric has a potential to improve performance of a wireless network. A number of routing metrics were designed with mobile ad hoc networks (MANETs) in mind. These routing metrics might be useful in wireless mesh networks (WMNs) but the fact that WMNs and MANETs are two different types of wireless networks with different features might not allow optimal performance of some or all existing routing metrics that were designed for MANETs. These differences in WMNs and MANETs make it important to firstly test if these existing routing metrics can work in WMNs. These existing routing metrics have been compared by different scholars in the literature, but the manner in which they were compared was not consistent, which makes it difficult to draw conclusions as to which routing metric works best for WMNs. The goal of this study was to evaluate the performance of existing routing metrics for Wireless Mesh Networks with a view to designing an optimal one. The goal of this work was achieved by evaluating the performance of existing routing metrics through NS2 simulation tool installed in Ubuntu Linux version 9.10. Recommendation of design criteria for designing an optimal routing metric for WMNs. Four routing metrics (HOP, ETX, RTT, and EETT) were chosen for evaluation after comparing twenty existing routing metrics. As the first part of the researcher’s contribution to knowledge, the four (hop count, expected transmission count, per-hop round trip time, ix and exclusive expected transmission) routing metrics were compared under a consinstant manner (using the same routing protocol, performance metric, and WMNs environment). The overall results of the experiments show that ETX outperformed all the other routing metrics that were simulated. However, the study has shown that ETX is not the best routing metric for WMNs. Thus as the second part of contribution to the body of knowledge, promting the researcher to further recommend four features for designing an optimal routing metric for WMNs. The four features proposed by the researcher were wight pathawareness, efficient wight path algorithm design, quality of service-awareness, and network scalability.