Summary: | 碩士 === 國立臺北教育大學 === 資訊科學系碩士班 === 103 === In a wireless sensor network, usually the control center (or called sink) is out of the communication range of the sensor node, and cannot directly receive the data sent from the sensor node. In such a case, relay nodes are used to forward the data so that the control center can receive the data from the sensor node. However, this problem becomes more complicated for WSNs with obstacles. This study investigates the deployment schemes of the relay nodes in WSNs with obstacles. First, the target area is divided into square grids, in which each grid cell has exactly one node (a sensor node, a relay node, or the control center). The minimum shortest path algorithm is applied to identify the shortest path from the sensor node to the control center. Then, relay nodes are deployed along the shortest path by computing the communication range. Meanwhile, a proposed obstacle avoidance algorithm is used to ensure that the communication between two consecutive relay nodes is not obstructed by the obstacles. Different minimum shortest path algorithms are considered in the proposed scheme. Besides, a web based automatic relay node deployment system was developed to verify the proposed scheme. Our experiments show that the developed system can effectively deploy the relay nodes while minimizing the number of relay nodes. Experiment results also show that the deployment based on Jump Point shortest path algorithm has the shortest average distance between two consecutive relay nodes; and he deployment based on A* shortest path algorithm has the minimum number of relay nodes.
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