Packet distribution based tuning of RTS Threshold in IEEE 802.11

IEEE 802.11 Medium Access Control (MAC) protocol employs two techniques for packet transmission; the basic access scheme and the RTS/CTS-based reservation scheme. A parameter called RTS Threshold determines which scheme to use. If packet size is smaller than the RTS Threshold then the basic scheme is used otherwise the reservation scheme is used. With current standard, the RTS Threshold is fixed. In this paper, we, first point out the advantages and disadvantages of RTS/CTS based scheme. Then we state the problems of having a fixed RTS Threshold. Next, we present a numerical way to fix the RTS Threshold adaptively based on network traffic. The proposed adaptive scheme creates a balance between the basic scheme and the RTS/CTS based scheme and optimizes the network throughput. Considering multi-hop networks with hidden node problems we have validated our proposal through simulation.