Summary: | 碩士 === 義守大學 === 資訊工程學系 === 102 === This study aimed to discuss the problem of relay node deployment of Wireless Sensor Networks on Euclidean plane which was how to deploy the minimum of relay nodes dynamically and effectively. In order to build heterogeneity two-tier network model, many general sensor nodes were distributed randomly and the extra advanced relay nodes were placed dynamically. The work of network model was composed of general nodes which collect the information of the environment and sent to the advanced relay nodes in foundation. Also, it collected the information which was sensed around the general nodes of transmission range and forward to the collection node or base station through other relay nodes to reduce entropy and the energy consumption of transmission will reduce relatively.
The purpose of this study is to identify how to deploy the minimum of relay nodes to reduce cost effectively. The deployment problem has been proven to a NP-hard problem. Therefore, it consumed a lot of computing time finding the best solution of the number of relay nodes. The study of uncomplicated algorithms was transformed refer to approximation algorithms which were presented by Tang, et al. (2005)
The algorithm used the characteristics of closely spaced of regular hexagon in tessellation geometry and the movement of vertically upward or horizontal rightward directions to optimize the number of relay nodes. According to the experimental data, this study was compared to static hexagon algorithm, and it showed that the number of relay nodes can reduce 8.29% averagely in the best case .
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