A Proposal of Communication Protocol to Improve the Throughput and Fairness of Multi-hop Wireless Networks and Its Evaluation

Abstract

WLANs have been used in a variety of places. The MAC protocol is an important item of WLANs, and directly affects the transmission efficiency. The distributed MAC protocol has the advantage of not requiring infrastructure such as access points, but it also has the problem that the total throughput decreases significantly when traffic is overloaded due to hidden node problems. In this paper, we focus on the MAC protocol and propose a new MAC protocol that provides a dynamically optimal back-off process in multi-hop wireless networks. To improve hidden node problems, we first conducted a theoretical analysis and found that the average idle slot spacing is a relevant indicator for traffic load. By using the average idle slot spacing and the number of neighbor nodes, the optimal CW (Contention Window) required to achieve high throughput can be configured. This paper compares the simulation results with those of conventional methods and evaluates them in terms of throughput, retransmission attempts, fairness, delay time, and number of collisions. The overall evaluation shows that the MAC protocol proposed in this paper has a better performance than the conventional method.