TraX: a device-centric middleware framework for location-based services

Location-based services turned out not to be the "next big thing" following the success stories of GSM and SMS. The reasons for this are manifold and range from inaccurate cellular positioning technologies to a lack of competition in this field, both being closely related to the fact that positioning is controlled by a network-centric approach where the mobile network operator has the unique selling point for making position data available to third parties. However, things change: small, low-cost GPS receivers, either attachable to mobile devices or even integrated, are enjoying great popularity since their recent inception and are expected to become a standard feature of cell phones in the near future. In conjunction with mobile packet data services, they provide a basis for device-centric LBS platforms, where position data can be obtained directly from the mobile device. In this article the device-centric LBS middleware TraX, which focuses particularly on position management, advanced functions for interrelating the position data of several targets, and privacy protection, is presented. Due to its generic and open design, TraX can be reused for a broad range of different LBSs and thus fosters service diversity and multiprovider environments, both of which are essential for making the next generation of LBSs a success