Energy-Efficient Cooperative Opportunistic Positioning for Heterogeneous Mobile Devices

The fast growing popularity of smartphones and tablets enables us the use of various intelligent mobile applications. As many of those applications require position information, a smart mobile device provides positioning methods such as GPS, WiFi, or Cell-ID based positioning services. However, those positioning methods have different characteristics of energy efficiency, accuracy, and service availability. In this paper, we present an Energy- Efficient Cooperative and Opportunistic Positioning System (ECOPS) for heterogeneous mobile devices. ECOPS facilitates mobile devices with estimated locations using WiFi in cooperation with a few available GPS broadcasting devices, in order to achieve high energy efficiency and accuracy within available budget constraints. ECOPS estimates the location using heterogeneous positioning services and the combination methods including a received signal strength indicator, 2D trilateration, and available power measurement of mobile devices. The evaluation shows that ECOPS significantly reduces energy consumption and achieves the good accuracy of a location.