對登山客而言，搜尋與救援是非常重要的，為了能有效掌握登山客的行蹤，提出有效省電機制之追蹤系統，我們假設每一個登山客身上帶一個附有GPS接收器之無線感測器。當登山客在山中行走若遇到別的登山客，他們身上的無線感測節點會互相記錄彼此的位置資訊。這樣一來登山客身上的無線感測節點就會記錄一路上遇到的登山客，藉此達到追蹤的效果。為了要使無線感測節點可以延長使用壽命，一些省電機制都是讓無線感測節點進入睡眠模式來省電的。但是，這樣會對追蹤的效果有不好的影響。在這篇論文中，我們提出了兩個省電協定來解決這個問題。在第一個省電協定中，我們讓群組中鄰居數最大的無線感測節點當群組的領導者，然後讓群組的成員進入睡眠模式來達到省電的效果。此外，當數個群組連結在一起的時候便會形成一個大的群組並且可以藉此節省更多電力消耗。在第二個省電協定中，我們利用無線感測節點之間的相對速度來進行省電。無線感測節點可以進入睡眠模式進行省電，然後在他的鄰居要離開它的通訊範圍的時候省來交換資訊。節點在模擬結果中顯示我們的省電機制的確可以省電並且不會對追蹤效果有很大的影響。

Search and rescue are important issues for mountain hikers. In this thesis, we assume that every hiker carries a wireless sensor node with GPS receiver. When hikers meet in mountains, their sensor nodes can exchange the locations of each other. To save nodes energy, energy efficiency protocols usually make idle nodes sleep to achieve power conservation. However, protocols that make idle nodes sleep may sacrifice tracking quality of the tracking systems. In this thesis, we propose two energy efficiency protocols to solve this problem. In the first protocol, we choose node that has the most numbers of neighbors in a group to become the group leaders and make group members go into sleep mode to save energy. In addition, several small groups can be concatenated as a large group to save more energy. In the second protocol, we consider the relative moving speed between nodes to reduce their power consumption. A node can go into sleep mode and wakeup to exchange location information with its neighbors only at the moment that the neighbors will leave the node’s communication range. The simulation results show that our protocols can reduce energy consumption of nodes with acceptable tracking quality.

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