The Design And Impelmentation Of WLAN Access Point

The paper studies the wireless LAN Access Point (AP) based on the IEEE802.11b technology and brings forward an embedded scheme of WLAN AP system based on uClinux OS (Operating System) and ADM8628 microprocessor. The protocol of the IEEE802.11 MAC sublayer is analyzed and implemented. The WLAN AP hardware platform is designed, debugged and tested.Firstly, the basic framework of WLAN is built through the introduction of elements and related conceptions of IEEE802.11 WLAN. The functional architecture of MAC sublayer is discussed. After the whole functional architecture is introduced, we study the distributed coordination function (DCF) and the point coordination function (PCF). In DCF, we put special emphasis on the carrier-sense mechanism, MAC-Level acknowledgments, interframe space (IFS), random backoff time, and DCF access procedure. These analyses found the basis of the implementation of the soft modules in chapter 5.Secondly, we design the WLAN AP system. After a detailed introduction of uClinux and ADM8628, an embedded scheme of WLAN AP system based on uClinux OS (Operating System) and ADM8628 microprocessor is brought forward. The AP hardware platform is worked out . We debugg and test the related circuit modules and the test results are given.Finally, according to IEEE802.11 MAC protocol, we introduce the eight software modules of MAC of AP. Protocol_Control_AP module, Transmission module and Reception module are described systematically and implemented with C language.