RTS threshold self-tuning algorithm based on delay analysis on 802.11 DCF

The medium access control (MAC) protocol is the main element that determines the efficiency in sharing the limited communication bandwidth of the wireless channel in wireless local area networks (WLANs). There are two access mechanisms: basic and request-to-send/clear-to-send (RTS/CTS). The RTS/CTS mechanism is an optional handshaking procedure used by the IEEE 802.11 wireless networks to reduce the possibility of collision. The RTS threshold value which determines when the RTS/CTS handshaking mechanism should be used is an important parameter to investigate, since different values will produce different performance characteristics in data transmission. This paper presents a Markov chain model to analyze the delay performance of the IEEE 802.11 wireless network, and then gives an algorithm dynamically adjusting the RTS threshold value in order to improve the performance of wireless networks. Both analytical and simulation results show that our algorithm can obtain a near best performance of 802.11 wireless networks.