Improved Performance Analysis Model Of IEEE 802.11 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.IEEE 802.11 wireless local area networks use the shared radio channel for information transmission, so there are some different problems with the wired networks, such as:near-far effect, hidden terminal problem, capture effect and so on. The media access control (MAC) technology which deals with those problems play an important role of the impact of the performance of the wireless LANs. Therefore, the research on MAC layer of wireless LAN is increasing rapidly. Anglicizing the throughput and delay accurately and effectively has been the wireless LAN research priorities.Currently, the IEEE802.11 wireless LAN MAC layer performance analysis can be divided into three categories:analysis using Markov chain model; analysis using queuing theory model; analysis using simulation. In this paper, In order to improve the accuracy of analysis, this paper, considering impacts of both finite retry limit and successive transmission, proposes a improved bidimensional Markov chains model for estimating the performance of IEEE802.11 DCF for a non-ideal channel and then, using the improved model, analyzes the performances of IEEE802.11 DCF Wireless LANs, deriving the expressions of the saturation throughput and the average packet delay. Then using the model above, the relationship of non-saturated throughput and arrival rate is analyzed. The results from the model are verified by Simulation.