An Efficient Traffic Adaptive Backoff Protocol for Wireless MAC Layer

Abstract

To avoid collisions in wireless networks, medium access control (MAC) protocols, such as distributed coordination function (DCF), have been developed to assist each node to decide when and how to access the communication channel. Although DCF is widely used in 802.11 based wireless local area networks, its performance is limited because DCF does not take into account the traffic intensity and node density. In other word, DCF only knows collision occurs but does not know how severe of the collision. In this paper, we develop a novel traffic adaptive backoff (TAB) protocol. We use network allocation vector count to approximate the intensity of surrounding traffic and the density of the nodes. TAB protocol then chooses a random backoff time uniformly between a lower threshold and an upper threshold. Simulations results suggest that the TAB protocol improves network performance by achieving a better channel utilization and reducing the number of dropped packets.