Energy-efficient adaptive localization middleware based on GPS and embedded sensors for smart mobiles

In this paper, we propose an energy-efficient adaptive location middleware based on GPS as well as embedded sensors including an accelerometer and a geomagnetic sensor for smart mobiles. Smart mobiles provide Network-based or GPS-based locations for various applications. Network-based location does not have high accuracy but its level of energy consumption is low. In contrast, GPS-based location has high accuracy, but it is only available in outdoor environments and consumes much energy. Location-based services prefer GPS location for its higher accuracy, but continued use of GPS can drain the limited battery capacity of a smart mobile in a short time. The proposed method partially replaces the GPS-based positioning with the energy-efficient sensor-based one. Since there is a trade-off between accuracy and energy efficiency, this system reduces energy consumption to the extent where target levels of accuracy required by applications can be maintained. This scheme is implemented and evaluated on an Android-powered smart mobile. The experimental results show that the proposed method effectively reduces energy consumption while keeping the location error within acceptable limits in the case where a smart mobile is used as a car navigator.