Grid-based Barrier Coverage Management Protocol for Wireless Sensor Networks

[[abstract]]在崎嶇的海岸線上以人力監控入侵者是相當費時與耗費成本的。因此，使用無線感測網路進行監測是達到海岸防衛一個很有潛力的自動化應用。以往無線防禦網路的研究以分散式的方式建構防衛曲線，儘管可減少其建置成本，但形成防線的速度較慢，無法實際有效運用於入侵者監控的應用中。此外，使用集中式防線建構的方法，必須收集網路中所有節點的位置資訊與監控所得資料，集中式節點快速消耗的電量可能造成網路監控時間大幅縮短。本論文提出以網格為基礎之階層式網路架構，結合集中式與分散式兩種建置模式的優點與特性，藉由網格領導者 確保其管理範圍內防衛曲線的有效性。並綜合考慮電量消耗因素選擇最少數量的無線感測節點進行網路監控，以期達到有效的即時監控與快速分配防線運作之目標。本論文採用分散式的管理架構可動態更新各節點的的資訊，以快速回復無線感測節點因外在環境改變而導致防衛曲線失效的問題，並且藉由集中式的精確管理成員資訊與分散式交換鄰居資訊，即可得到精確的地形位置，無論在各種地形中皆可彈性的建置防線路徑與快速的修復、接替防線中斷等問題。在模擬比較中，可發現本論文所提出的演算法不單可快速建置防衛曲線，且可動態依節點剩餘電量挑選合適的無線感測防衛節點，以有效提高防衛曲線的建置的時間與快速的修復防線之目標。[[abstract]]It is time and cost consuming to monitor coastline events through human guards. Using emerging wireless sensor network to automatically monitor coastline events has great application potentials. Conventional barrier coverage protocols can be divided into distributed and centralized categories. Although distributed protocols have advantages of low deployment costs, large time is required to establish an effective barrier path. On the other hand, centralized protocols can effectively construct barrier coverage, but collecting node locations and events consume large amount of precious energy resources. In this paper, we propose a grid-based barrier management protocol which can not only balance energy consumption of all nodes, but also can establish barrier within short time. In each grid, grid head is responsible to construct barrier within a grid and ensure load balance within a grid. Simulation results reveal that the proposed protocol achieves fast barrier construction, dynamic active nodes selection, and network enhancement