Performance analysis of DCF under two access mechanisms in IEEE 802.11a WLAN

IEEE 802.11a is a popular high-speed WLAN standard with a data rate up to 54 Mbps. The fundamental medium access control (MAC) mechanism of IEEE 802.11a is the contention-based distributed coordination function (DCF) which includes two packet transmission schemes, namely, the basic access and RTS/CTS mechanism. In this paper, by introducing a two-dimensional Markov model, we conduct an extensive analysis of saturation throughput and access delay of these two access mechanisms in IEEE 802.11a WLAN. The study reveals that, in contradiction to the situation in IEEE 802.11 WLAN, basic access mechanism is always more efficient than RTS/CTS mechanism in high-speed IEEE 802.11a WLAN. (7 pages)