期刊名称：International Journal of Computer Science and Information Technologies
电子版ISSN：0975-9646
出版年度：2012
卷号：3
期号：3
页码：4189-4198
出版社：TechScience Publications
摘要：Wireless data broadcast is a promising technique for information dissemination that leverages the computational capabilities of the mobile devices, in order to enhance the scalability of the system. Under this environment, the data are continuously broadcast by the server, interleaved with some indexing information for query processing. Clients may then tune in the broadcast channel and process their queries locally without contacting the server. In location-based, mobile continual query (CQ) systems, two key measures of quality-of-service (QoS) are: freshness and accuracy. In continuous monitoring an air indexing framework that (i) outperforms the existing (i.e., snapshot) techniques in terms of energy consumption, while achieving low access latency, and (ii) constitutes the first method supporting efficient processing of continuous spatial queries over moving objects. So to achieve freshness, the CQ server must perform frequent query revaluations. To attain accuracy, the CQ server must receive and process frequent position updates from the mobile nodes. In this paper, we formulate this problem as a load flaking one, and develop MobiQual—a QoS-aware approach to performing both update load flaking and query load flaking. The design of MobiQual highlights three important features like Perquery QoS specification, 3) Low cost adaptation: MobiQual dynamically adapts, with a minimal overhead, to changing load conditions and available resources. Load flaking, the MobiQual approach leads to much higher freshness and accuracy in the query results in all cases, compared to existing approaches that lack the QoS-awareness properties of MobiQual, as well as the solutions that perform query-only or update-only load flaking.
关键词：Query processing; load flaking; Spatial databases; query;processing; location based services; wireless data broadcast; air;indexes.is
