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Study On Top-k Query Processing Techniques In Wireless Sensor Networks

Posted on:2009-05-21Degree:MasterType:Thesis
Country:ChinaCandidate:X K YangFull Text:PDF
GTID:2178360308479731Subject:Computer application technology
Abstract/Summary:PDF Full Text Request
Wireless sensor network techniques have been promoted by the development of sensor technique, wireless communication technique, micro electronic technology and increasing maturity of micro electronic mechanism system. WSNs have been successfully used in various application areas and it has a bright future for its extensive use. However, most applications of wireless sensor networks are largely limited by finite battery energy. Top-k query is a typical query, which requests that wireless sensor networks must return k sensor datas in the special sensor field. In wireless sensor networks, because of continual detecting the data and transmitting all of data to sink, it is necessary to cost too much energy. Based on this consideration, the processing technique for top-k queries in wireless sensor network is studied and energy efficient difference-based top-k query are proposed.The existing processing techniques of top-k queries are reviewed. The features of snapshot top-k queries as well as continuous monitor query in wireless sensor networks are analyzed. As snapshot top-k query, Difference-Based Algorithm are formally proposed, an effective approach to process top-k query (e.g. find the k objects with the highest aggregation value) in wireless sensor networks. The processing of Difference-Based Algorithm top-k query can be divided into three main phases:Firstly, through defining the type and format of messages, got the partial sum and max value of some objects and product the candidate set, then partitioned the objects'difference and setted the objects' threshold. lastly, finished the final top-k query according to the message received. Doing this can suppress the transmission of messages and data in the wireless sensor networks, and get the final result using less cost transmitted in the wireless sensor networks.Extensive experiments show that the proposed DBA can reduce energy consumption and lengthen lifetime of wireless sensor network while top-k queries are processed.
Keywords/Search Tags:Wireless sensor network, Top-k query, Difference partition, Threshold, Message
PDF Full Text Request
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