Achieving Throughput Fairness in Wireless Mesh Networks Based on IEEE 802.11

Abstract—In IEEE 802.11 based Wireless Mesh Networks (WMNs), unfair bandwidth sharing may arise since the CSMA/CA protocol is designed to provide per station fairness only in one hop. As the hop count from a mobile client to the gate-way node increases, throughput of the node decreases drastically. In this paper, we propose a fair bandwidth allocation scheme for multi-radio multi-channel WMNs. This scheme provides fair bandwidth sharing among the nodes in a WMN regardless of their hop distance from the gateway node. To achieve the fairness, we first estimate the number of active nodes attached to each router, and calculate effective weights of routers based on the estimation. Then, we differentiate the contention window of them using their weights. For that, we derive a multi-hop packet collision model. The proposed scheme is fully distributed, and does not require any global information. Through an extensive simulation study, we show that our scheme ensures per node fairness without loss of the total aggregate throughput. I