Coverage在無線感測網路的研究中一直是很重要的研究主題，近年來探討Coverage的相關文獻大都假設已知感測節點精確位置。然而，在現存眾多的定位技術中，大都無法保證感測器所在位置資訊完全精準，這將使Coverage的計算錯誤，進而影響無線感測網路的監控品質。本論文所考慮的無線感測網路，是採用Bounding Box定位技術後，每個感測節點之位置資訊為一模糊區域，而非精確的位置，因此每個感測節點將無法確定其確實的覆蓋區域，在這樣的困境下，Coverage問題儼然已成為一新的挑戰。本論文提出新的Coverage評估方法，使其適用於感測節點只擁有模糊位置資訊的環境場景，並評估無線感測網路目前的覆蓋程度。最後，我們依據節省電量及平衡電量的考量，調整感測節點之感測半徑，使無線感測網路的覆蓋程度可滿足使用者所要求的覆蓋品質。

Coverage of wireless sensor networks has been studied intensively in recent year based on the assumption that each sensor knows its own accurate location. However, accurate location information of sensors is difficult to be obtained by applying most existing range-free localization technologies. Sensors with inaccurate location may result in incorrect estimation of coverage and hence reduce the monitoring quality. This paper considers a given wireless sensor networks which has been localized by applying Bounding Box mechanisms. Each sensor is aware of its inaccurate location information, denoted by a rectangle box, which represents that the sensor is located in the box. Consequently, coverage problem is a new challenge. This paper proposes a novel coverage estimation method to estimate the coverage of the given WSN. A decentralized algorithm is further proposed for adjusting sensor’s sensing range so that the probability of full coverage satisfies the user's demand.

第一章、簡介	1
第二章、網路環境與問題陳述	4
2.1 網路環境	4
2.2 問題陳述	4
第三章、提升監控區覆蓋機率機制	8
3.1 保守覆蓋區域及樂觀覆蓋區域的定義	8
3.2 p-Eval Scheme	10
3.2.1基本觀念和判斷規則	10
3.2.2計算網格之覆蓋機率	14
3.3 preq-coverage Scheme	21
第四章、實驗	28
4.1. 實驗環境參數	28
4.2. 實驗結果	28
第五章、結論	34
參考文獻	35
Conference Version	37

圖目錄
圖(一) 感測節點由兩次Mobile Anchor的Bounding Box Region定位，獲得一Bounding Box模糊位置資訊	2
圖(二) si有機會位於 區域內之例子，使得si的覆蓋範圍可覆蓋位置(x, y)	5
圖(三) 保守覆蓋區域 ，為si保證可覆蓋的區域	9
圖(四) 樂觀覆蓋區域 ，為si可能覆蓋的區域	10
圖(五) 感測節點si評估之網格集合Gi	11
圖(六) 感測節點si可完全覆蓋gm,n	12
圖(七) s1與s2滿足Property-1，可能獨立完全覆蓋gm,n	16
圖(八) s1與s2合作覆蓋gm,n	17
圖(九) s1與s2合作覆蓋gm,n	17
圖(十) 實際分佈角度	20
圖(十一) 最佳分佈角度	20
圖(十二) si調整感測半徑為ri,,new，則 	25
圖(十三) 在si評估的網格集合Gi中有三個空洞網格為 	25
圖(十四) 不同感測半徑對p-Eval Scheme之coverage rate影響	30
圖(十五) 不同感測半徑對Center評估演算法之coverage rate影響	30
圖(十六) 不同bounding box size對p-Eval Scheme之coverage rate影響	31
圖(十七) 不同bounding box size對Center評估演算法之coverage rate影響	31
圖(十八) Coverage estimate error rate	32
圖(十九) 在不同的感測節點數量下，對於執行不同preq要求的preq-coverage Scheme後，coverage rate之差異程度	33
圖(二十) 在不同的感測節點數量下，對於執行不同preq要求的preq-coverage Scheme後，average sensing range之差異程度	33

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