Adaptive RTS/CTS mechanism for IEEE 802.11 WLANs to achieve optimal performance

In IEEE 802.11 WLANs, there are two types of access modes which perform very differently under different channel or traffic conditions: the basic access mode CSMA/CA and and an RTS/CTS based mechanisms. In seeking to balance between the use of the different modes, the contribution of this paper is threefold. Firstly, we present our development of a new method capable of calculating the access delay via an analytical model. Secondly, we report a comparison of the throughput and delay performance of basic and RTS/CTS mechanisms and the analysis of which mode should be chosen to obtain better throughput and delay performance under different conditions. Finally, we propose an adaptive RTS/CST mechanism that adjusts the RTS threshold adaptively in order to achieve optimal performance in a centralized or distributed way. Numerical results, and simulation results obtained using NS2 are provided.