BeepBeep

We present the design and implementation of BeepBeep, a high-accuracy acoustic-based system for ranging and localization. It is a pure software-based solution and uses the most basic set of commodity hardware -- a speaker, a microphone, and some form of interdevice communication. The ranging scheme works without any infrastructure and is applicable to sensor platforms and commercial-off-the-shelf mobile devices. It achieves high accuracy through three techniques: two-way sensing , self-recording , and sample counting . We further devise a scalable and fast localization scheme. Our experiments show that up to one-centimeter ranging accuracy and three-centimeter localization accuracy can be achieved.