6th ACM International Conference on Mobile Computing and Networking (ACM MOBICOM), Boston, MA, August 2000 (Slightly revised) The Cricket Location-Support System Nissanka B. Priyantha, Anit Chakraborty, and Hari Balakrishnan MIT Laboratory for Computer Science Cambridge, MA 02139 fbodhi, achakra, harig@lcs.mit.edu Abstract This paper presents the design, implementation, and evaluation of Cricket, a location-support system for in-building, mobile, locationdependent applications. It allows applications running on mobile and static nodes to learn their physical location by using listeners that hear and analyze information from beacons spread throughout the building. Cricket is the result of several design goals, including user privacy, decentralized administration, network heterogeneity, and low cost. Rather than explicitly tracking user location, Cricket helps devices learn where they are and lets them decide whom to advertise this information to; it does not rely on any centralized management or control and there is no explicit coordination between beacons; it provides information to devices regardless of their type of network connectivity; and each Cricket device is made from off-the-shelf components and costs less than U.S. $10. We describe the randomized algorithm used by beacons to transmit information, the use of concurrent radio and ultrasonic signals to infer distance, the listener inference algorithms to overcome multipath and interference, and practical beacon configuration and positioning techniques that improve accuracy. Our experience with Cricket shows that several location-dependent applications such as in-building active maps and device control can be developed with little effort or manual configuration. 1 Introduction The emergence of network-enabled devices and the promise of ubiquitous network connectivity has made the development of pervasive computing environments an attractive research goal. A compelling set of applications enabled by these…