Optimization And Implementation Of MAC Protocol Based On IEEE 802.11

With the popularity of Mobile Terminal, WLAN, based on IEEE802.11, has got the great development and is widely used in work and life due to its advantages of flexibility, convenient, easy expansion, low cost and etc. However, compared with the traditional network, WLAN still has a wide gap in performance and service quality. Except from the inherent weakness of physical medium, MAC protocol, realizing medium shared, whether good or not played a significant role in network performance. In order to make WLAN can better satisfy the requirement of modern communication network, the performance analysis and protocol optimization to MAC protocol of WLAN based on IEEE802.11 has the important research significance and application value.For making an intensive study of main content in MAC protocol. Improved methods are put forward, which will start from backoff arithmetic and transmission delay of end to end. Mainly for the defects in traditional BEB algorithm and other algorithms, a new improved algorithm, using a parameter that reflected the network status, is raised for achieving the change of respective window as per loaded condition with different network. Through NS2 stimulating the experiment, the result testified that the improved algorithm has great effect on improving network throughput, fairly accessing and reducing network delay. In addition, processing network allocation vector(NAV) in sectional, reducing excessive waiting time, not only transmission delay of end to end can be solved, but also invalid block can be avoided as well. And experiment showed that using sectional NAV can distinctly improve the channel utilization and network throughput. After analyzing the demand of MAC layer protocol, it was separated as 7 functional parts. Meanwhile, the presentation for design framework of code implementation and the specialized description for implementing algorithm improvement, which caused software design for MAC layer protocol were achieved eventually.Channel utilizatio n and network throughput act better by improving MAC layer protocol from the backoff arithmetic and transmission delay. And the software design plan of improved algorithm has established a good foundation for building a wireless network terminal with super ior performance.