Abstract
Top-k monitoring is important to many wireless sensor applications. This paper exploits the semantics of top-k query and proposes an energy-efficient monitoring approach called FILA. The basic idea is to install a filter at each sensor node to suppress unnecessary sensor updates. Filter setting and query reevaiuation upon updates are two fundamental issues to the correctness and efficiency of the FILA approach. We develop a query reevaiuation algorithm that is capable of handling concurrent sensor updates. In particular, we present optimization techniques to reduce the probing cost. We design a skewed filter setting scheme, which aims to balance energy consumption and prolong network lifetime. Moreover, two filter update strategies, namely, eager and lazy, are proposed to favor different application scenarios. We also extend the algorithms to several variants of top-k query, that is, orderinsensitive, approximate, and value monitoring. The performance of the proposed FILA approach is extensively evaluated using real data traces. The results show that FILA substantially outperforms the existing TAG-based approach and range caching approach in terms of both network lifetime and energy consumption under various network configurations.
Original language | English |
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Pages (from-to) | 962-976 |
Number of pages | 15 |
Journal | IEEE Transactions on Knowledge and Data Engineering |
Volume | 19 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 2007 |
Scopus Subject Areas
- Information Systems
- Computer Science Applications
- Computational Theory and Mathematics
User-Defined Keywords
- Continuous query
- Data management
- Energy efficiency
- Sensor network
- Top-k