期刊名称：International Journal of Computer Networks & Communications
印刷版ISSN：0975-2293
电子版ISSN：0974-9322
出版年度：2010
卷号：2
期号：1
出版社：Academy & Industry Research Collaboration Center (AIRCC)
摘要：The location-based alert services can be regarded as the one of the most practical location-based services. For the services, an alert service system for the services alerts mobile device users when they enter into or leave from predefined specific regions, and provides certain services previously asked by the users for special purposes such as security. For providing proper services the alert service system should acquire the location information of the users periodically. However, the system that handles the locations of the users may face serious problems as the number of users increases fast. Hence it is a critical issue to properly adjust the time interval of location data acquisitions while maintaining the accuracy of the services. In this paper we propose effective location acquisition algorithms; the speed-based acquisition algorithm, the angle–based acquisition algorithm, and the hybrid algorithm combining the speed with the angle-based algorithms. We also present three grid-based acquisition algorithms in which a longer time interval is used when a user is not near the alert areas. The proposed algorithms could reduce the amount of location information to be acquired based on the movement of the users. The average numbers of location acquisitions of the speed-based, the angle–based, and the hybrid algorithms were reduced by 19.2%, 35.8%, and 35.6% over the distance-based algorithm, respectively, while they maintained the almost same level of accuracy. Among the grid-based algorithms, the grid-angle acquisition algorithm further improved the average number of acquisitions by 5.2% over the angle-based algorithm, which is 41.0% improvement over the distance-based algorithm. The experimental results also show that all the grid-based algorithms showed almost equal accuracy
关键词：Location-based alert services; LBS; Location information acquisition; Distance-based acquisition;algorithm.>
