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Energy-Efficient Aggregate Query Evaluation in Wireless Sensor Networks
Zhuoyuan Tu and Weifa Liang

Wireless sensor networks,consisting of sensors equipped with energy-limited batteries, have been receiving significant attention and are increasingly being deployed for environmental monitoring and surveillance. Data generated by the sensors usually needs to be extracted and aggregated for a wide variety of purposes. Due to the serious energy constraint imposed on such a network, it is a great challenge to perform aggregate queries efficiently.In this paper, we consider the aggregate query evaluation problem in wireless sensor networks with an objective to prolong the network lifetime. To do so, we first introduce a node capability concept, which balances the residual energy and the consumed energy at each node, and propose a heuristic algorithm based on this concept. We then present an improved algorithm by incorporating group aggregation and conditional clauses into consideration. We finally evaluate the performance of the proposed algorithms against the existing algorithms through experimental simulations. The experimental results show that the proposed algorithms significantly outperform the existing ones in terms of network lifetime.

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