本論文研究的重點在於 IEEE 802.11多跳的行動隨意網路中同步問題與省電機制， IEEE 802.11 分散協調式功能(Distributed Coordination Function; DCF)的省電機制是針對單跳網路所設計，所以應用於多跳(Multi-Hop)的行動隨意網路(Mobile Ad Hoc Network; MANET)時會發生同步問題，因此我們針對同步問題提出解決機制，並且針對原有的DCF省電機制在低網路交通量情況之下做一重新設計，使得在網路交通量較低的環境中能夠有更加顯著的省電效果。對於各行動節點尚未同步的網路，相關文獻中有提出改善機制使節點同步化，在部分機制中節點會增加保持於主動模式的信標週期而額外消耗一些能源，因此我們提出了一個可調式全醒週期同步機制(Adjustable Wake-Up Interval; AWI)來解決同步問題，同時將額外能源消耗盡可能地降低，在網路已逐漸同步後，使用AWI同步機制會減少保持於主動模式的信標週期節省能源消耗。此外，我們進一步提出一個適用於低網路交通量的動態調整ATIM視窗省電機制(Dynamic ATIM Window Adaptive; DAWA)，經模擬後DAWA省電機制在網路交通量不高時會有著比DCF省電機制還要良好的省電效果。最後將AWI與DAWA兩個機制做一整合，整合之後的AWI-DAWA機制適合於網路交通量不高的多跳行動隨意網路，在這樣的環境之下可讓節點達到同步，同時又可降低節點的能源消耗。

This thesis mainly focuses on synchronization and power saving for the IEEE 802.11 mobile ad hoc network (MANET). Since the IEEE 802.11 power saving (PS) scheme working in the distributed coordination function (DCF) mode was initially designed for single-hop networks, the asynchronous problem may occur when directly applying the PS scheme to the multi-hop MANET. Hence, we design a new synchronization mechanism and propose a new power saving mechanism working under the low traffic load condition. Due to the fact that synchronization schemes proposed in the literature still make nodes to be synchronized consume extra energy when staying in the periodical active mode, we propose an adjustable wake-up interval (AWI) synchronization mechanism to achieve synchronization with lower power consumption compared to those schemes previously proposed in the literature. Moreover, a dynamic ATIM window adaptive (DAWA) PS mechanism is also proposed for the low traffic load condition to further save power. Through simulation studies, we illustrate that DAWA PS mechanism outperforms the IEEE 802.11 PS scheme. Finally, integration of AWI and DAWA enables one to achieve both synchronization and low power consumption in the IEEE 802.11 MANET.

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