Study MAC Sub-layer Of WLAN And Design Based On ARM

Presently, development of WLAN technology changes with each new day, it is a hot spot of communication domain besides 3G The wireless local area network (Wireless LAN, WLAN), is a data communication system to provides the connection point to point and equal entity to equal entity through wireless medium. At present there are many kinds of WLAN standard, thereinto IEEE802.11x series standard which issued by IEEE is used most widely, this standard specify medium access control (MAC) layer and physics (PHY) layer of WLAN.The research and realization of MAC protocol is a key aspect to develope independent intellectual property rights WLAN product. The thesis takes research and design based on the IEEE802.11b standard. Thesis analysed respective characteristic and application situation of 3 kind of WLAN standard. Study network characteristic, components and the logical service interface of the IEEE802.11b WLAN, discussed two kind of basic networks models —BSS (Basiq Serve Set) and IBSS (Independment Basic Serve Set) of WLAN. Thesis anatomied 9 kind of basic services and relations between each kind of service which provided by the MAC layer. Has defined the MAC data, the management and the control frame structure.The thesis analyse two kinds of basical connect model of IEEE802.11b WLAN------DCF(distributional coordination control function) and PCF (centralism coordination control function) . Have a systematical and thorough analysis on DCF which based on CSMA/CA ( carry sense detected of multiple access of collision avoid) technology, studied carrier sense to intercept, stochastic avoidance mechanism, restoration and re-transmit of frame, channel control. Introduced the MAC level management function, has made a detailed introduction on synchronization maintenance, the capture and the scanning of beside the power management realization detail .The thesis have proposed a project of network interface card based on 32 ARM processor S3C4510B after analyzing in the MAC layer protocol. The thesis has designed MAC controller, designed hardware electric circuit of the MAC controller, has transplanted real-time core uC/OS-II to the S3C4510B processor, takes this as the the run environment of MAC protocol software . Finally according to the modularized program thought, has designed the MAC layer protocol software, has divided the entire protocol function into 7 functions modules, in detail introduced each agreement module function and the method of realizing module function, has designed program of 4 modules.