Research On MAC Protocol Technology And Back Off Algorithm In Wireless LAN

With the development of Internet and wireless technology, the wireless local area network technology (WLAN) is widely used in recent years. Having all the internet’s functions but no cable limit, WLAN is the combination of wireless communication technology and computer network, which is transmitted by wireless transmission. Furthermore, the infrastructure of WLAN does not need to be hidden in a wall or buried in the ground, whose mobility can coordinate the need in the possible using process at any time and place. Moreover, with a multiple access channel, the data interaction is completed by electromagnetic. Therefore, this individuality and mobility solves some unsolvable problems in the wired network, which gives some advantage to the multimedia applications as well.In the wireless LAN access technology, the IEEE802.11standard has been regarded as the relevant agreements, which mainly provides the PHY layer and the MAC layer properties. To improve system performance and resource usage, the IEEE802.11control (MAC) layer protocol shared access mechanism, is the main method to solve the problem. Hence, the research of wireless LAN MAC protocol technology research has a great significance for the communication field, which can improve the performance and function of WLAN and also have important prospects and value of science.Through to the wireless LAN MAC layer protocol analysis and the characteristics of wireless channel, this article studies the distributed coordination function on the IEEE802.11MAC layer DCF (Distributed Coordination Function). For the MAC protocol, this article discusses the network performance to affect the play channel reservation technology, priority access control, error control technique and the avoidance of technology respectively.Consequently, the wireless LAN MAC layer improves the packet average delay, packet loss rate and throughput performance. This article proposed the fairness distinction between sites back-off algorithm improvement based on the current research results, to obtain an average delay, low loss rate and maximum throughput for the target, through to the LI, BEB, MILD, EIED and MIMLD of several past wireless LAN DCF protocol back off algorithm comparison and analysis.Furthermore, this paper simulated the NS network tool for performance situation, based on fairness to distinguish site improvement back-off algorithm. The research results show, a transmitting station and a transmitting station can adapt to their own window regulating method according to the monitored whether the packet collisions and collision case.Not only improves the average packet delay, loss rate and throughput performance, but also ensures the terminal to transmit data between fairness principle.