在IEEE 802.16e無線廣域網路下設計一個整合的省電排程機制

An Integrated Power Saving Scheduling Algorithm in IEEE 802.16e Wireless Metropolitan Area Networks

李念聰(Nien-tsung Lee)

指導教授 ： 廖文華

大同大學/經營設計學院/資訊經營學系所/碩士(2008年)

摘要

在IEEE 802.16e (WiMAX，微波存取全球互通技術)無線廣域網路的環境中，由於多媒體的服務普及和類型多樣化，使得行動裝置(Mobile Subscribe Station，MSS)中同時存在單一(Unicast)與多重(Multicast)播送的資料。MSS通常都是利用電池供電，所以只能提供有限的電量。因此在MSS中，如何設計一個節能的機制，就成了一個重要的研究議題。在本論文中，對於同時有單一與多重播送的應用下，我們提出了一個基於多重播送服務的排程演算法(Multicast Services Based Scheduling, MSBS)來增進電力的使用效率，並使所有的資料傳輸能符合802.16e的架構下的傳輸品質。在MSBS演算法中，將單一播送的資料排程至多重播送資料的鄰近區間，而無法排程至上述區間的單一播送資料，若其資料能排程至下次的訊框(Frame)之中，則Base Station (BS)將暫存此資料至下次排程，以減少醒睡狀態的變化次數來達到節能的效果。另外，利用傳輸品質(Quality of Service，QoS)的參數來計算出每筆資料的最後期限(Deadline)，並以資料是否有超過此期限來判斷出資料是否有達到傳輸品質的保證。實驗的結果顯示MSBS演算法比先前的演算法能達到更好的節能效果並保證傳輸的品質。

關鍵字

IEEE 802.16 ； 微波存取全球互通技術 ； 節能 ； 排程 ； 服務品質

並列摘要

In mobile WiMAX (IEEE 802.16e), with the popularization of multimedia services, multicast and unicast services are coexisted in one mobile subscriber stations (MSS). In such network, power saving is a very important issue for battery powered mobile computing devices. In this paper we have proposed a Multicast Services Based Scheduling (MSBS) algorithm that improves energy efficiency for both unicast and multicast services, and conforms QoS requirements of MSSs in 802.16e wireless networks. MSBS schedules as many MSSs as possible into adjacent interval of their multicast data transmission periods and combines the unicast data of the remaining MSSs based on their deadline. Our scheme controls packets based on a deadline for each packet determined from QoS parameters and reduces energy consumption of MSSs by minimizing the energy for switching. Simulation results show that, MSBS can produce significant overall energy saving and prolonged lifetime of the MSSs.

並列關鍵字

Scheduling ； power saving ； WiMAX ； IEEE 802.16e ； Quality of service (QoS)

參考文獻

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