Abstract—IEEE 802.11 is the most popular Wireless LAN (WLAN) system in the world today. The primary medium access control (MAC) technique of 802.11 is distributed coordination function (DCF). DCF is a carrier sense multiple access with collision avoidance (CSMA/CA) scheme with binary slotted exponential back-off. In DCF of IEEE 802.11, The Request to send/Clear to send mechanism is very effective in terms of system performance, but this mechanism may lead to underutilization of resources as well, when either RTS or CTS fails to reach their respective destinations. In such a case, the nearby nodes of both the sender and receiver, after Updating their Network Allocation Vector (NAV) remain idle for the whole NAV period, even if there is no transmission on the channel, thus leading to a major wastage of the resources. So in this paper we propose a mechanism to overcome this problem, so that the time may be saved and the resources may be utilized efficiently.

Index Terms—Network allocation vector (NAV), RTS/CTS,distributed coordinated function (DCF).

Asad Ali is with the School of Electrical Engineering and Computer Science, National University of Science and Technology (NUST), Islamabad,Pakistan (e-mail: asad.ali@seecs.edu.pk).

Cite: Asad Ali, Member IACSIT, "Improving the Performance of the IEEE 802.11 Distributed Coordination Function," International Journal of Computer and Communication Engineering vol. 2, no. 1, pp. 16-19 , 2013.