A Mechanism to Mitigate Collision Rate in Wireless Local Networks

Abstract

Presently, IEEE 802.11 DCF is MAC protocol applied in wireless local networks. DCF would be inefficient, since there are two types of overload: Collision time and channel`s idle time. Present paper, evaluated the performance and proposed an efficient MAC protocol for these networks called D-CW. D-CW will decrease both the channel`s idle time and the collision time. D-CW, by dividing the value of contention window (CW) by two, reduces the time required for a successful node forwarding, and by selecting variable contention window for packet forwarding from each node with a random uniform function, what if a successful forwarding or an unsuccessful one, decreases the collision time. Stations, after selecting a value from the window contention own, follow the Backoff mechanism, and after counting the number of their own idle slots, do the forwarding. Simulation results indicate D-CW can improve the throughput of the system, delay reduction and collision rate on 802.11 DCF significantly.