A high performance privacy-oriented location system

Many mobile applications can be greatly enhanced when provided with the locations of people and devices. Ultrasonic location systems have been shown to supply location information with centimeter accuracy at high update rates, Such high-performance systems, however, have relied upon a centralized or coordinated architecture, preventing the user from being in control of how their location information is handled and thus giving rise to privacy concerns. In this paper we present a privacy-oriented location system allowing users with mobile ultrasonic receivers to ascertain their position autonomously. We formulate a method of operation for the system, detail its implementation in a small office, and characterize the performance of the system. The utilization of broadband ultrasound makes it possible for the privacy-oriented location system to have competitive accuracy and high update rates, while allowing the user to be in direct control of their location information.