水底環境下的感測網路是一個幾乎未被探索過的領域。由於過去收集水中資料的方式，是將水中偵察裝置入水中，於結束任務再收回；因此無法提供即時性的服務，必須藉由船隻從海面送回陸地，再分析得到的數值，一般需要花幾個月的時間。此外，陸地環境的繞徑協定直接應用在水底環境，是十分沒有效率且耗能量的。針對以上問題，本論文提出了一個水底環境下省電的感測網路路徑協定。藉由在水面底下佈滿感測器，將數值迅速的從水底取得。為了因應水中環境與陸地環境的差異性，在演算法做了修正並且加入了水中壓力這個變數，大幅減少封包的傳送數量，降低感測器有限電量的消耗。本論文使用了ns-2 來驗證所提出的水底環境下省電的感測網路路徑協定，結果顯示了在與陸地環境相同效能下，水底環境的網路封包減少量是十分可觀的。

Underwater Sensor Network is an almost unexplored territory. In the past, researchers collect data under the sea by the way of sending oceanographic equipments into water and get it back at the end of mission. It often takes several months to detect and collect raw data, shuttle from oceans to coasts, and analyze the data. Therefore, real time service cannot be supported and the whole process takes lots of time. Besides, applying terrestrial routing protocols to underwater sensor networks is less efficient and waste of energy. This thesis proposes an energy-efficient routing protocol in underwater sensor networks. The protocol is designed to reduce the number of packets transferring in the network, namely decrease the energy consumption. The protocol has been evaluated using Network Simulator 2 (NS-2). The esults show that the number of reduced packets is considerable, and propagation delay in underwater nvironments should be taken into consideration when designing a new routing protocol. Extremely long delay in underwater acoustic channel and could lead to collapse of traditional terrestrial routing protocols.

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