【正文】 重慶交通學(xué)院二 00 五屆畢業(yè)設(shè)計(jì)（論文） 論文 1 無線局域網(wǎng)媒體訪問控制機(jī)制研究 楊千里 摘 要 本文所研究的 DFS算法是在無線局域網(wǎng)現(xiàn)有的 MAC層訪問機(jī)制的基礎(chǔ)上，運(yùn)用循環(huán)隊(duì)列的思想提出的一種完全分布式的公平隊(duì)列調(diào)度算法，該算法通過修改 MAC層中的 DCF(Distributed Coordination Function)子協(xié)議，實(shí)現(xiàn)了在分布式環(huán)境下控制 。本文通過仿真對(duì)算法進(jìn)行了分析和研究，仿真結(jié)果表明該方法可以在一定范圍內(nèi)實(shí)現(xiàn)公平隊(duì)列調(diào)度。 關(guān)鍵詞 ，無線局域網(wǎng)，分布式協(xié)調(diào)功能，點(diǎn)協(xié)調(diào)功能，分布式公平調(diào)度 Abstract DFS algorithm is a type of distributed queue scheduling algorithm. Based on the access mechanism of MAC layer which is recent used in the wireless local works, DFS algorithm adopts the idea of round robin queue. Through modifying the DCF subprotocol of MAC layer, it achieve the purpose of controlling node to access wireless line resource fairly in the distributed environment. In this article, the author did some analyses and researches to this algorithm by simulation. The simulation results show that the DFS algorithm can carry fairly queue schedule in some areas. Keywords , Wireless LAN, DCF, PCF, DFS 重慶交通學(xué)院二 00 五屆畢業(yè)設(shè)計(jì)（論文） 論文 2 目 錄 ABSTRACT.................................................................................................................................................................... 1 摘要 ............................................................................................................................................................................. 1 引 言 ........................................................................................................................................................................ 4 第 1 章 緒論 ............................................................................................................................................................ 5 無線網(wǎng)絡(luò)的發(fā)展及研究現(xiàn)狀 ......................................................................................................................... 5 研究?jī)?nèi)容 .......................................................................................................................................................... 5 研究意義 .......................................................................................................................................................... 5 論文的研究方法及結(jié)構(gòu) ................................................................................................................................. 6 第 2章 無線局域網(wǎng)介紹 ....................................................................................................................................... 7 無線局域網(wǎng)的概念 .......................................................................................................................................... 7 無線局域網(wǎng)的主要標(biāo)準(zhǔn) ................................................................................................................................. 7 第 3章 ................................................................................................................................... 10 相關(guān)技術(shù) .......................................................................................................................... 10 ........................................................................................................................................ 10 幀間間隙 (IFS) .................................................................................................................................... 10 ................................................................................................................................................ 10 RTS/CTS 握手協(xié)議 .............................................................................................................................. 11 訪問媒體的機(jī)制 ............................................................................................................ 13 DCF ......................................................................................................................... 13 PCF.................................................................................................................................. 15 第 4章 IEEE 訪問機(jī)制改進(jìn) ......................................................................................................... 16 IEEE 訪問機(jī)制改進(jìn)方法 ....................................................................................................... 16 EDCF...................................................................................................................................................... 16 DFS...................................................................................................................................................... 16 BlackBurst ........................................................................................................................................... 16 研究方向 ...................................................................................................................................................... 16 CW 循環(huán)變化的規(guī)則 ......................................................................................... 17 ........................................................................................................................... 17 ................................................................................................................................... 18 ........................................................................................................................................................ 18 DFS算法 ............................................................................................................................................ 18 第 5章 DFS接入機(jī)制仿真 .......................................................................................................................