Design and Performance Analysis of an Enhanced MAC Algorithm for the IEEE 802.11 DCF
In this paper, a performance improving MAC algorithm for the IEEE 802.11 DCF is proposed. The DCF controls the transmission based on carrier sense multiple access with collision avoidance (CSMA/CA), which decides a random backoff time with the range of contention window (CW) for each station. Normally, each station doubles the CW after collision, and reduces the CW to the minimum after successful transmission. This paper proposes an enhanced DCF algorithm that decreases the CW smoothly after successful transmission in order to reduce the collision probability by utilizing the current contention status information of WLAN. In addition, the throughput and delay performance for the unsaturated case is analyzed mathematically. Simulation results show that the suggested algorithm enhances the saturation throughput of WLAN. They also coincide well with the analytical results.
KeywordsMedium Access Control Medium Access Control Protocol Contention Window Distribute Coordination Function Access Delay
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