Research On The Performance Of WLAN Based On Priority MAC Access Mechanism

With the popularity of application for the wireless local area network, a various of new types of business have been put forward, different business have different requirements for the quality of service on network transmission. Data transmission services are mainly implemented in the data link layer and network layer, therefore the research on WLAN MAC and different business enhanced technology has important practical significance.In this paper, the research work is mainly based on IEEE802.11 standard and IEEE802.lle standard. Based on the analysis and research on standard, through OPNET network simulation tool, the performance of WLAN with different access mechanisms and different priority business has been enhanced and optimized.This paper is mainly study on DCF and PCF channel access method in the IEEE802.11 MAC standard. For the DCF channel access mechanism, the impaction on the performance of WLAN from the key performance parameters which includes the number of competition terminal and minimum competition window size is studied, through modeling wireless local area network and the analysis of simulation results, simulation results show that the right to reduce the size of minimum contention window can make up for the impact of delay which is brought from increased competition terminals. The research on PCF channel access mechanism focuses on the latency performance of network, through modeling and simulation of PCF access mechanism, and compared with the DCF access mechanism, simulation results show that the PCF mechanism have higher requirement of latency.The research on different priority access mechanism focused on enhanced distributed channel access mechanism which is new and support for QoS in IEEE802.lle, EDCA with the distinction priority business and DCF basic access mechanism are compared and analyzed. On the basis of theoretical analysis, the network model will be re-planning for different types of service with different priority business, the support for QoS from the distinction priority is comprehensive studied. Through the study on the performance indicators such as throughput and delay, it proves that the priority access mechanism can provide a good priority service for wireless terminals with different business types and the entire WLAN, it proofs the superior network performance of the priority access mechanism.