DE2: Localization with the Rotating RSS Using a Single Beacon

Wireless localization technology has become an important part of pervasive computing applications. This paper presents DE², a wireless localization approach that is responsive to single beacon conditions. Unlike previous work that needs a priori knowledge of the scenario during the pre-deployment phase with significant human effort, or uses a certain number of beacons during the localization phase with high energy consumption, to accomplish localization, DE² leverages a single beacon without much prior human effort to locate multiple targets. The key challenge is how to utilize the limited information caught by a single beacon and little human effort to obtain the positions of multiple unknowns. The intuition underlying DE² is that, direction and distance constraints between an unknown position and the single beacon are adequate to determine the unknown position. When a user rotates around an RF receiver (the single beacon), the human body acts as a signal-blocking obstacle. It causes the signal from a transmitter (position-unknown) to the single receiver to attenuate in a certain scope. The blocking effect caused by a human body can be utilized to obtain the direction constraint between the unknown position and the single beacon. Moreover, a corresponding distance constraint is also concluded in the rotating RSS according to the RF propagation model. DE² pushes the limit of minimum beacons needed for localization without much pre-configuration effort. To demonstrate the utility of DE², we implement DE² in realworld single beacon wireless networks. The results show that these applications can significantly benefit from DE².