Research On WLAN Rate Adaptation Algorithm

The IEEE 802.11 devices provide multiple transmission rates in PHY layer, so the optimal rate can be chosen in an adaptive manner depending on the underlying channel condition in order to maximize the system performance. Many kinds of rate adaptation algorithms have been proposed so far. However, there is no algorithm that suits for any underlying channel condition. Once the channel conditions change, not only the rate adaptation algorithm can not improve the system throughput but also lead to the deterioration of the overall system performance.In this article, the state of the art of Rate Adaptation algorithms is surveyed. The algorithms have been divided into three major categories. By comparing different types of algorithms, we analyze their respective advantages and shortcomings of each method. Based on the analysis, a new rate adaptation algorithm called Adaptive Avoid Collision Rate Adaptation (Adaptive-ACRA) has been proposed.Finally, we have compared the new proposed algorithm with several existing algorithms by use of Network Simulator version 2 (NS-2), and the detail analysis of the simulator result have been done in the end of this article.