Flow Starvation Mitigation for Wireless Mesh Networks

Wireless mesh networks can provide scalable highspeed Internet access at a low cost. Fair channel access among different nodes in the wireless mesh network, however, is an important consideration that needs technological solutions before mesh networks can be widely deployed. Lack of fairness significantly decreases the throughput of nodes that are more than one hop away from mesh gateways. We propose an analytical model and use simulation studies to establish the existence of starvation in mesh networks even when we can ameliorate problems due to exposed terminals. Motivated by the inability of standard medium access control (MAC) protocols to limit starvation, we propose a modification to the MAC protocol to alleviate flow starvation. Our proposed algorithm improves the channel usage of short-term flows with nodes that are multiple hops from the gateway by a factor of 7 in some cases with a penalty of 20% reduction in total throughput across all nodes. Our proposed algorithm also has a better performance than two other schemes in terms of a higher fairness index.

I. Introduction

Wireless mesh networks (WMN s) are being deployed to provide low-cost high-bandwidth Internet access on a large scale. In a WMN, stationary wireless mesh nodes (or routers) provide network connectivity for mobile wireless mesh clients. Multiple wireless mesh nodes are interconnected to form a wireless backbone. Several mesh nodes also serve as the gateways (GW), which connect to the Internet. The mesh architecture, in which all mesh nodes participate in creating an infrastructure for decentralized data transmission, makes a WMN a stable and economically viable solution for providing universal Internet access.