在無線感測網路中，定位資訊的重要性不言可喻。雖然過去有許多演算法被提出。但定位精確度在移動式的感測網路仍然需要被改善。然而在改善的同時通常伴隨的是付出另外一個更大的代價─communication cost。用傳遞多hop的技術與跟鄰居交換資訊卻可能帶來sensor networks不可承擔的通訊負擔，甚至是廣播風暴的問題。在本論文中, 我們不增加任何communication cost就達到定位精確度提升。我們利用三種zero cost的資訊， 通訊半徑、收到的訊號強度以及過去的beacon，定位sensor。更值得注意的是我們的定位演算法比其他種演算法更適合用於低密度的anchor node環境下。低密度的anchor node環境對於一個sensor networks除了節省communication cost之外，更能縮減佈建成本。 In wireless sensor networks, the location information has major impact on many applications. The localization accuracy is not good enough, although substantial studies have been proposed to solve this problem on mobile sensor networks. Unfortunately, a large amount of resources, the communication cost, must be sacrificed in terms of promoting the localization accuracy. Using the technologies that broadcast multi-hop anchor information and exchange the neighbor information will cause hung communication cost that the sensor networks can’t work well and it will bring broadcast storm problem. In this thesis, we enhance the localization accuracy without increase any communication cost. In our proposed algorithm, we use three known information which are communication range, received RSS of beacon, and overdue beacons to locate normal node. It is noteworthy that our proposed algorithm performance is better than others algorithms in sparse anchor environments. Not only reduce device cost, but also reduce communication cost in low anchor density scenario.
