Performance Analysis Of IEEE802.11 DCF

In the recent years, with the rapid progress of wireless communication technology, the Wireless Local Networks (WLANs) have achieved a tremendous amount of growth. Wireless Local Area Network technology is widely used in all areas of society and becomes more and more popular because of its convenience, mobility and extendibility. At the same time, people have focused more attention on the performance of the Wireless Local Networks under any different environments.Because of the data transmission of IEEE 802.11 WLANs using a wireless channel, its unreliability decides that the performance of WLANs will be affect by a variety of collisions and interfere. So the research of performance has become more and more important.The most of research of WLANs base on Bianchi's Bidimensional Markov Model at present. In order to improve the accuracy of analysis, this paper, considering impacts of practical setting in the process of transmission, proposes a improved bidimensional Markov chains model for estimating the performance of IEEE802.11 DCF for a non-ideal channel in non-saturated conditions and then, using the improved model, analyzes the performances of IEEE802.11 DCF Wireless LANs, deriving the expressions of the saturation throughput. Then using the model above, the relationship of non-saturated throughput and arrival rate is analyzed. Secondly, considering the impacts of backoff and retry depends on the original model and get the saturated throughput about the different backoff and retry. In the end, the results from the model are verified by Simulation.