HartFi: An Energy-Efficient Localization System
Location-Based Applications (LBAs) are emerging to be the killer applications on mobile devices. To know the where-abouts of devices, various interfaces (i.e., GPS, Wi-Fi or cellular) can be used to sense their locations. Ideally, localization should be done all the time. However, keeping any of these interfaces running continuously would drain a device's battery rapidly. In this paper, the authors present a radical design of a collaborative localization system called HartFi, which enhances existing devices with a low-power 802.15.4-based WirelessHART interface. A salient feature of this added interface is that its energy consumption is up to two orders of magnitude less than that of a standard Wi-Fi interface; yet it provides a comparable range of coverage.