A Novel MAC Protocol with Fast Collision Resolution for Wireless LANs

Design of efficient medium access control (MAC) protocols with both high throughput performance and highdegree of fairness performance is a major focus in distributed contention-based MAC protocol research. In this paper, we propose a novel and efficient contention-based MAC protocol for wireless local area networks, namely, the Fast Collision Resolution (FCR) algorithm. This algorithm is developed based on the following innovative ideas: to speed up the collision resolution, we actively redistribute the backoff timers for all active nodes; to reduce the average number of idle slots, we use smaller contention window sizes for nodes with successful packet transmissions and reduce the backoff timers exponentially fast when a fixed number of consecutive idle slots are detected. We show that the proposed FCR algorithm provides high throughput performance and low latency in wireless LANs. The extensive simulation studies show that the FCR algorithm could significantly improve the performance of the IEEE 802.11 MAC protocol if our efficient collision resolution algorithm is used and that the fairly scheduled FCR (FS-FCR) algorithm could simultaneously achieve high throughput performance and a high degree of fairness.