在無線區域網路中，為使行動主機在無資料傳輸時達到省電的效能，在IEEE 802.11 DCF通訊協定中定義了省電模式(Power Saving Mode, PSM)的運作規則，處於省電模式的行動主機可事先決定在哪些Beacon Interval的ATIM Window時段該醒來，以便得知鄰居是否有交換資料的需求。然而，PSM機制對於行動主機如何選擇醒來的ATIM Window並無詳細的規劃，為使各行動主機醒來的時段能有交集，許多先前的研究[1-4]以Quorum技術為基礎，使各主機能分散式地安排其醒睡時段。然而，這些醒睡的安排並未完全將行動主機通訊特性納入考量，這些特性包括相鄰行動主機才有共同醒來時段的需求，以及相鄰兩步(two-hop) 行動主機共同醒來將可能產生傳輸上的衝撞等重要特質，此外，醒睡的安排亦應符合電量平衡的原則。為提昇省電效能並增加傳輸成功率，本論文提出一架構在Quorum系統上的醒睡安排機制，考量上述通訊特性，搭配位置資訊以分散式的方法達到電量平衡和低電量消耗的目標。根據實驗結果，本論文所提出之演算法確實可改善現有研究之缺點，大符改善電量消耗及傳輸成功率，並可達到電量平衡的目地。 IEEE 802.11 specifies a Power Saving Mode (PSM) in order to save the energy consumptions of mobile stations. Following the standard of PSM, a number of studies [1-4] further discussed the wakeup/sleep scheduling of beacon intervals based on Quorum systems so that any pair of stations has common awake intervals for data exchange. However, the existing approaches did not take into account the following two communication properties. First, only the pair of one hop neighboring stations requires common beacon interval for data exchange. Second, the awake beacon intervals of any pair of two-hop neighboring stations should be totally different in order to avoid the potential collisions occurred due to hidden terminal problem. This thesis considers the above-mentioned two communication properties and aims to develop a location-aware scheduling algorithm for scheduling the sleep/awake beacon intervals. Performance study reveals that the proposed power saving mechanism outperforms existing approaches in terms of energy consumption and throughput.
