A scalable location-based services infrastructure combining GPS and Bluetooth based positioning for providing services in ubiquitous environment

Several methodologies on the provisioning of the Location-Based Services (LBSs) solely using GPS-based positioning or combining several positioning techniques like GPS, GSM Cell-ID, Wi-Fi, Bluetooth and RFID etc. have been proposed over the past few years. Most of these systems do not focus on limited battery power, memory-constraint of the mobile devices, the heterogeneity of mobile platform and proper authentication checks before providing LBSs to the mobile user. Our proposed system utilizes low-cost, low-power Bluetooth wireless technology as indoor positioning technique and combines it with GPS-based positioning to accurately sense the location in outdoor environment. The inclusion of HTML-to-WML parser into the Middleware deployed on each Base Station (BS) enables the devices with micro browser to invoke the LBSs properly. The mobile client application developed in Java is portable and interoperable with a diverse set of mobile platforms. The client application can also run on devices not having support of location API. Scatternet support with our proposed LBS Infrastructure makes it scalable with increasing number of client devices. This paper also evaluates the performance of the Middleware in terms of connection setup time and service consumption time with respect to varying number of mobile clients.