Characterizing Interference Model for Wireless Mesh Networks

Abstract

Wireless mesh networks (WMNs) have been proposed for realizing their goals, such as throughput and full connectivity, in wireless networks. The interference between nodes in WMNs is a critical limiting factor. Understanding of interference needs to develop novel approaches, such as channel re-assignment, route selection, and fair scheduling. Actually, throughput of WMNs has degraded when reassigning channels due to the intra and inters interference. In this paper, we study the extent problem of interference, which spreads the trials of channel re-assignment toward neighbor mesh routers. In particular, the extent of interference causes additional throughput degradation when compared to a pair-wise interference to a small fraction of the links. This implies that the pair-wise interference measurements may be optimistic when used to drive protocols in wireless mesh networks. We newly define an analytical model, which is referred to as a ripple effect problem. The defined model is a formal model of interference to estimate the maximum rate at which flows can safely send traffic without overloading network. The proposed model can exemplify how protocols should take the extent of interference into account. The simulation results show that the proposed model can exactly evaluate the attempts of channel reassignment occurred from mesh networks.