Experimental Evaluation of a Novel Transmission Rate Assignment Scheme in Wireless Mesh Networks

IEEE 802.11 wireless interface supports multiple transmission rates. It is an important problem how to select the transmission rate so that the throughput is maximized. In a wireless mesh network (WMN), nodes are stationary placed in general. The characteristic of each link will not change significantly over relatively long time. It is effective to assign fixed transmission rate which achieves the best transmission performance at each link while link quality does not change significantly. There are two of for fixed transmission rate assignment schemes. One type assigns a transmission rate at each link (link-fixed), and the other assigns it at each node (node-fixed). In this paper, we propose a novel node-fixed transmission rate assignment scheme. Our proposed scheme tries to increase throughput on the condition that the network connectivity of all nodes in the WMN is kept. We evaluate the proposed scheme by experimental measurement using our testbed. Compared with the scheme that the same transmission rate is assigned to all nodes, our proposed scheme can improve the minimum throughput although the average throughput of both schemes is almost the same.