本文通過對Ad Hoc 無線局域網(wǎng)的預(yù)約多址（PRMA）控制方式進行了分析，即通過一個中央站點依次輪詢各站點傳輸信息，采用嵌入Markov 鏈和概率母函數(shù)的分析方法，給出了輪詢系統(tǒng)的數(shù)學(xué)模型。然后給出一種輪詢調(diào)度策略的改進方法，將傳輸服務(wù)與轉(zhuǎn)移查詢做了并行處理，給出系統(tǒng)平均排隊隊長的精確解析，通過仿真實驗討論了改進方法對網(wǎng)絡(luò)性能的提高。
關(guān)鍵詞 Ad Hoc 網(wǎng)絡(luò)；預(yù)約多址協(xié)議；輪詢；平均排隊隊長

A Packet Reservation Multiple Access Protocol for Ad Hoc Wireless LANs YANG Zhi-jun1,3，XIE Ji-ping2， ZHAO Dong-feng3 (1. Information Center of Educational and Scientific Institute, Educational Department of Yunnan Province,Kunming 650223;2. Yunnan Radio & TV University，Kunming 650223,China; 3.Yunnan University, Kunming 650031,China) Abstract This paper analyzes the polling scheme in Ad Hoc wireless lans based on PRMA(Packet Reservation Multiple Access) and proposes a policy of parallel schedule for a polling system. The system enables simultaneous polling and transmissions of information packets. By the imbedded Markov chain theory and the generation function method, the mean values of queue length and information packed waiting time are explicitly obtained. Mathematical analysis and simulation results show that the parallel schedules are more efficient.
Key words Ad Hoc Network, PRMA, Polling system, Mean queue length