摘要
在本論文中，我們藉由對感測涵蓋範圍 (sensing coverage) 的考量設計了在無線感測網路上的路由協定，稱之為基於涵蓋的路由協定 (Coverage-based routing protocols)。針對無線感測網路，多數已發展出來的路由協定都是基於能量如何有效的被運用為考量。然而，他們卻沒有針對如何維持感測涵蓋範圍的問題去設計其路由協定。在許多的應用上，感測裝置是被任意的散佈在欲觀察的區域。因此，這個欲觀察區域的某些地方可能被數個感測裝置點給涵蓋。同時，在觀察區域的另外一些地方可能僅僅被一個感測裝置點給涵蓋。這意味著當這些感測裝置消耗完他們的能量之後，不同的地方將造成涵蓋上不同程度的損失。所以，為了獲得較好的涵蓋表現，我們提出的路由協定是以每個感測裝置點涵蓋範圍與鄰近感測裝置點涵蓋範圍所造成的重疊量做為設計上的考量，亦即是從感測裝置點在觀察區的散佈情況 (即網路拓撲)考量每個感測裝置點有效的涵蓋。我們所提出的基於涵蓋的路由協定是根據原來LEACH (Low Energy Adaptive Clustering Hierarchy)和以格子為基礎的路由協定 (Grid-based routing protocols) 所修改而成的。在LEACH方面，我們修改了原來Cluster-Head 選取機制 (Cluster-head selection algorithm)讓感測裝置點當Cluster-head的機會與每個感測裝置點有效的涵蓋量有關。在以格子為基礎的路由協定方面，我們採用了相似的做法。模擬的結果顯示基於涵蓋的路由協定在整個網路的感測涵蓋表現上大約比相對應原來相關的路由協定有15% ~ 20% 的增益。

Abstract

In this thesis, we design the routing protocols with the consideration of sensing coverage for wireless sensor works, which is called coverage-based routing protocols. The majority of routing protocols have been developed for wireless sensor networks are based on energy-efficient consideration. However, they do not address the problem of preserving sensing coverage. In many applications, sensor nodes are deployed randomly over the desired area. Therefore, some area may be covered by several nodes. Concurrently, there may be also some other area that is covered by only one node. This implies that after nodes have used up their own energy resource, nodes in different area may result in different amount of coverage loss. Consequently, in order to obtain better coverage performance, the proposed routing protocols take the amount of overlapped coverage of each node into account, i.e. considering the effective coverage from the node distribution (i.e. network topology). The proposed coverage-based routing protocols are modified from the original LEACH and grid-based routing protocols. Simulation results show that coverage-based routing protocols perform approximately 15% ~ 20% better than the other related protocols in the term of network sensing coverage.

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