無線感測網路是一種為了某特定用途而使用大量感測裝置並透過無線傳輸方式所形成的網路。基於種種限制，感測節點所能搭載的電力通常都不會太高，且幾乎沒有機會充電，因此如何減少感測節點電力的消耗就成了無線感測網路中一重要的研究議題。不過相較於延長感測節點個別的壽命，如何能使感測網路中的感測節點其存活時間相近才是需要優先考量的。
為達到感測節點負載平衡和延長無線感測網路整體的壽命，基於「有向性散佈」而改良的方法先後被提出，大多是以電力相關資訊作為計算梯度的依據，透過梯度的計算選擇一條目前負載較輕或是電力較充足的路徑，以達到負載平衡的效果。但這些方法在決定路徑後，並沒有對路徑做適當的維護，因此仍然會造成些許的負載不平衡。本篇論文延續有向性散佈的架構，在計算梯度時以電力相關因素及路徑長度作為主要考量，並在路徑決定後能利用已知的梯度資訊在適當的時機自動切換路徑上的某路段，避開剩餘電量接近門檻值的感測節點，改善先前方法的不足，達到負載更平衡的效果。

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第一章 導論 1
1-1 無線感測網路的背景 1
1-2 研究動機與目的 5
1-3 論文架構 6
第二章 相關研究 7
2-1 Directed diffusion for wireless sensor networking[4] 8
2-2 An Efficient Gradient Mechanism of Directed Diffusion in Wireless Sensor Network[5] 9
2-3 Energy Aware Directed Diffusion for Wireless Sensor Networks[6] 12
2-4 A Global-Energy-Balancing Real-time Routing in Wireless Sensor Networks[7] 14
第三章 提出的方法 17
3-1 概略流程 18
3-2 詳細流程 19
3-2 特殊狀況之處理 28
第四章 模擬結果與討論 30
4-1 模擬工具 30
4-2 模擬參數設定 31
4-3 模擬圖及討論 32
第五章 結論 42
References 43

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