Research On Channel Access Technologies Optimization In A Dense WLAN Environment

In recent years, with the increasing demands for wireless applications, wireless communication technologies, especially WLAN technologies developed rapidly, and have achieved great results. However, in the dense WLAN scenario such as science and technology exhibition, the distribution density of the wireless nodes is high, the distribution is irregular and nodes are difficult to be controlled by a center controller, thus the delay of the wireless communication system becomes longer, the throughput of the system goes down and the fairness index of the system becomes poor, which affect the communication performance of wireless devices seriously.The poor communication qualities of the dense WLAN environment promote the researchers to seek novel channel access technologies to enhance the users’experience.In order to solve the poor communication problems come with present channel access technologies in a dense WLAN, this paper analyzes the DCF channel access technology and its optimization. Based on the results of this study, and considering the characteristics that the distribution density of the wireless nodes is high and APs are independent in a dense WLAN environment, we established a simulation model of the dense WLAN environment, and then developed a new self-adaptive channel access technology, it sets "the ratio of collision/free" as the judge standard that whether the channel access competition is fierce or not. And it modifies the initial contention window and the variation method of contention window. Simulation results indicate that, in a dense WLAN environment, compared with the traditional and present DCF channel access technologies, the saturation throughput and fairness index of new channel access technology is better in some degree.