無線充電感測網路，近幾年來被引起廣大的注意，而在過去的研究當中，因為行動充電車會受限於搭載的能量限制，沒有辦法確保整個場景中的Sensor都可以被充到電，所以若死亡的是場景較重要的Sensor時，可能導致在整個場景中產生覆蓋空洞，喪失原本無線感測網路最重要的功用。因此本篇論文利用行動充電車，提出一個考量優先順序的有效充電方法，可以確保在網路場景中可能會造成覆蓋空洞的Sensor被充到電，這樣就可以讓整個網路的生命週期可以有效的被延續。所以一開始Base Station會計算出Sensor的權重值，而根據這個權重值，優先考量權重值較高的Sensor，保證對於場景中較重要的Sensor都可以適時的被充電，透過每次將權重值較高的Sensor救起，達到延長整個網路生命週期的目的。最後，我們也透過實驗模擬的方式，驗證本論文提出的方法，確實可以有效的延長網路生命週期。

Wireless Rechargeable Sensor Networks attract much attention in recent years. In the past studies, not all sensors in the sensing field can be recharged due to the limited energy capacity a mobile recharging vehicle can carry. If a sensor playing a critical role in the sensing task fails to work due to the exhausted energy, the sensing task will be interrupted. As a consequence, the paper proposes a novel recharging mechanism taking the weights of sensors into consideration while a mobile recharging vehicle is going to recharge sensors such that an important sensor can have a higher priority to be recharged and the network lifetime can be efficiently sustained. The weight of each sensor will be determined by the Base Station. Based on the weight, the sensor with higher weight will be properly recharged to extend the network lifetime. Simulation results show that the proposed mechanism performs better in network lifetime.

目錄
第1章	緒論	1
1.1	前言	1
1.2	研究動機與目的	1
1.3	研究方法	4
1.4	論文架構	6
第2章	預備知識	7
2.1	論文概觀	7
2.2	網路場景與假設	7
2.3	Coverage-and- Energy-critical nodes	8
第3章 Priority-Based Energy Replenishment Scheme	11
3.1	Sensor的重要性	11
3.2	層級劃分與層級取捨選擇	14
3.3	電量補充方法與路徑規劃	20
3.4	Extend Priority-Based Energy Replenishment Scheme	26
第4章 實驗模擬	28
4.1	實驗場景及參數設定	28
4.2	實驗結果	29
第5章	結論	31
參考文獻	32
附錄-中文論文	35
附錄-英文論文	42

 
圖目錄
圖 1. 單純考量剩餘電量問題	4
圖 2. 考量覆蓋與剩餘電量問題	5
圖 3. 網路場景	7
圖 4. 工作時間	8
圖 5. Coverage Set	9
圖 6. Cover Set與剩餘電量比較圖	13
圖 7. 紅色層級取捨選擇示意圖	17
圖 8. 綠色層級取捨選擇示意圖	18
圖 9. 黃色層級取捨選擇示意圖	19
圖 10. 網路場景假設圖	21
圖 11. 權重值結果	21
圖 12. 劃分Sensor權重值層級結果	21
圖 13. 檢查 s4 是否納入行動充電車路徑中	22
圖 14. 紅色層級路徑規劃結果	23
圖 15. 檢查 s9 是否納入行動充電車路徑中	24
圖 16. s7 與 s3 路徑規劃結果	24
圖 17. 黃色層級充電路徑取捨案例	25
圖 18. 黃色層級路徑規劃結果	26
圖 19. 分群結果	27
圖 20. 效能比較Network Lifetime	29
圖 21. 充電後所有Sensor最低電量	30
 
表目錄
表一. 實驗的模擬參數設定。	28

[1]	B. Carbunar, A. Grama, J. Vitek, and O. Carbunar, “Coverage preserving redundancy elimination in sensor networks,” in Proceedings of the 1st IEEE Communications Society Conference on Sensor and Ad Hoc Communications and Networks (SECON), Oct. 2004, pp. 377-386.
[2]	K. W. Fan, Z. Zheng, P. Sinha, “Steady and fair rate allocation for rechargeable sensors in perpetual sensor networks,” in Proceedings of the 6th ACM conference on Embedded network sensor systems (SenSys), 2008, pp. 239-252.
[3]	S. Guo, C. Wang, Y. Yang, “Mobile data gathering with wireless energy replenishment in rechargeable sensor networks,” in Proceedings of the IEEE INFOCOM, Apr. 2013, pp. 1932-1940.
[4]	H. Gupta, S. R. Das and Q. Gu, “Connected sensor cover : self-organization of sensor networks for efficient query execution, ” in Proceedings of the ACM International Symposium on Mobile Ad Hoc Networking and Computing (MOBIHOC), 2003, pp. 189-200.
[5]	L. He, L. Kong, Y. Gu, J. Pan, T. Zhu, “Evaluating the on-demand mobile charging in wireless sensor networks ,” IEEE Transactions on Mobile Computing, vol. 14, no. 9, pp. 1861-1875, 2015.
[6]	L. He, P. Cheng, Y. Gu, J. Pan, T. Zhu, C. Liu, “Mobile-to-mobile energy replenishment in mission-critical robotic sensor networks,” in Proceedings of the IEEE INFOCOM, Apr. 2014, pp. 1195-1203.
[7]	A. Kurs, A. Karakis, R. Moffatt, J. D. Joannopoulos, P. Fisher, and M. Soljacic, “Wireless power transfer via strongly coupled magnetic resonances,” Science, vol. 317, pp. 83, 2007.
[8]	W. Liang, X. Ren, X. Jia, X. Xu, “Monitoring quality maximization through fair rate allocation in harvesting sensor networks,” IEEE Transactions on Parallel and Distributed Systems, vol. 24, no. 9, pp. 1827-1840, 2013.
[9]	K. Li, H. Luan, C. C. Shen, “Qi-ferry: energy-constrained wireless charging in wireless sensor networks,” in Proceedings of the IEEE Wireless Communications and Networking Conference (WCNC), Apr. 2012, pp. 2515-2520.
[10]	X. Ren, W. Liang, W. Xu, “Maximizing charging throughput in rechargeable sensor networks ,” in Proceedings of 23rd International Conference on Computer Communication and Networks (ICCCN), Aug. 2014, pp. 1-8.
[11]	Y. Shi, L. Xie, Y. T. Hou, H. D. Sherali, “On renewable sensor networks with wireless energy transfer,” in Proceedings IEEE INFOCOM, Apr. 2011, pp. 1350-1358.
[12]	K. Shih, Y. Chen, C. Chiang, B. Liu, “Geo-BASS: Distributed Geometric-Based Activity Scheduling Schemes for Wireless Sensor Networks,” in Proceedings of the Workshop on Wireless, Ad Hoc, and Sensor Networks (WASN 2005), Aug. 2005.
[13]	C. M. Vigorito, D. Ganesan, and A. G. Barto, “Adaptive control of duty cycling in energy-harvesting wireless sensor networks,” in Proceedings of 4th IEEE Communications Society Conference on Sensors, Mesh and Ad Hoc Communications and Networks (SECON), Jun. 2007, pp. 21-30.
[14]	C. Wang, J. Li, F. Ye, Y. Yang, “NETWRAP: An ndn based real-time wireless recharging framework for wireless sensor networks ,” IEEE Transactions on Mobile Computing, vol. 13, no. 6, pp. 1283-1297, 2014.
[15]	C. Wang, J. Lin, F. Ye, Y. Yang, “Recharging schedules for wireless sensor networks with vehicle movement costs and capacity constraints,” in Proceedings of IEEE International Conference on Sensing, Communication, and Networking (SECON), June 2014, pp.468-476.
[16]	C. Wang, Y. Yang, J. Li, “Stochastic mobile energy replenishment and adaptive sensor activation for perpetual wireless rechargeable sensor networks,” in Proceedings of the IEEE Wireless Communications and Networking Conference (WCNC), Apr. 2013, pp. 974-979.
[17]	L. Xie, Y. Shi, Y. T. Hou, W. Lou, H. D. Sherali, S. F. Midkiff, “On renewable sensor networks with wireless energy transfer: The multi-node case,” in Proceedings of 9th IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks (SECON), Jun. 2012, pp. 10-18.
[18]	F. Ye, G. Zhong, J. Cheng, S.Lu and L.Zhong,“PEAS:A robust energy conserving protocol for long-lived sensor network,” in Proceedings of the 23rd International Conference on Distributed Computing Systems (ICDCS), May 2003, pp. 28-37.
[19]	M. Zhao, J. Li, Y. Yang, “A framework of joint mobile energy replenishment and data gathering in wireless rechargeable sensor networks,” IEEE Transactions on Mobile Computing, vol. 13, no. 12, pp. 2689-2705, 2014.