Abstract: This article addresses the problem of route selection in wireless mesh networks (WMNs). The traditional routing metrics adopt packet delivery ratio (PDR) as a representative metric of wireless link quality assessment. However, PDR measured by the broadcast-based probe method is affected by the size, number and transmission rate of probe packets, which influences the metric accuracy. In this paper, improved expected transmission count (iETX), a new routing metric of interference-aware link quality, is proposed for WMNs. Dispensing with traditional broadcast-based probing method, the iETX uses regional physical interference model to obtain PDR. Regional physical interference model is built upon the relationship between signal to interference plus noise ratio (SINR) and PDR, which contributes to the improvement of metric accuracy. The iETX comprehensively considers the effects of interference and link quality and minimizes the expected number of packet transmissions required for successful delivery, which helps find a path with minimum interference and high throughput. Simulation shows that the proposed metric can significantly improve the network performance.

Key words: WMNs, routing metric, link quality, interference