Constructing Localized Maximum-Lifetime Data Aggregation Forests in Wireless Sensor Networks

• Main Authors: Liu, Song-Yu, 劉嵩裕
• Other Authors: Huang, Jiun-Long
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/28009512098759984046

碩士 === 國立交通大學 === 網路工程研究所 === 100 === In wireless sensor networks, energy effciency is a critical issue, especially for applica- tions such as environmental monitoring. Data gathering is the fundamental operation in these applications. It means that sensor nodes sense phenomena, and periodically report the sensed data to the base stations. In order to conserve energy max maximize sensor lifetime, a tree-based data aggregation is often used for collecting data from sensor nodes. Every node determines a parent node to transmit data while a parent node aggregates the data from child nodes to eliminate redundant transmission. In our work, we study the construction of a data aggregation forest where there are several base stations in a sensor network. We aim to prolong the network lifetime of a sensor network while the definition of network lifetime is the time until the first node depletes its energy. The problem is proven to be NP-complete. Hence, we propose a distributed algorithm which constructs a data aggregation forest effciently. To increase the network lifetime, the nodes with more energy should also keep more child nodes. Based on the concept, each node exchanges messages between its neighbor nodes to obtain local information. After the exchange, every node decides a parent node according to its neighbor table. Our solution includes procedure of route maintenance while there is node failure or addition. Moreover, forest adjustment is also adapted to consider the low energy nodes for prolonging the network lifetime. Finally, we evaluate our solution with numerical simulations. The results show that our algorithm can effciently construct a data aggregation forest which prolongs the network lifetime.