在無線感測器網路當中，會因為感測器使用不同的傳輸功率或是隱藏節點問題，造成網路中出現單向連結。在本篇論文中，我們針對存在單向連結的無線感測器網路，提出一個建構虛擬座標的方法，來幫助每個感測器指定相對應的虛擬座標。此方法不需要實際的地理位置資訊就可以進行虛擬座標的建構，此外我們也根據所建構的虛擬座標，提出一個相對應的路由協定。我們所提出的路由協定不需要花費大量的訊息，來獲知整個網路的拓樸資訊而且能夠保證傳輸。在實驗結果方面，我們將本論文所提出的方法 ABVCAp_Uni 與 GLDR + VLM 和 Euclidean 作比較，根據實驗顯示本論文所提出的方法，針對存在單向連結的無線感測器網路有較優良的結果。

A wireless sensor network has unidirectional links because sensors can have different transmission ranges, sensors have unstable transmission ranges, and a hidden terminal problem exists. In this thesis, we introduce a virtual coordinate assignment protocol (ABVCap_Uni) to assign virtual coordinates to nodes that have no geographic information in wireless sensor networks with unidirectional links, and we propose a routing protocol based on the ABVCap_Uni virtual coordinates. Our routing protocol guarantees packet delivery without computation and storage of global topology features in a discrete domain. Using
simulation, we evaluate the performance of the proposed routing protocol (ABVCap_Uni routing), the greedy landmark-descent routing protocol (GLDR+VLM routing), and the greedy routing protocol based on physical coordinates (Euclidean routing). The simulations demonstrate that our routing protocol ensures moderate routing path length cost overhead.

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