Lightning: A Fast and Lightweight Acoustic Localization Protocol Using Low-End Wireless Micro-Sensors

Acoustic awareness is an important service in ubiquitous computing environments. This paper presents a lightweight acoustic event localization protocol, the Lightning protocol, to locate impulsive sound sources using arrays of wireless micro-sensors. This protocol utilizes domain-invariant knowledge of acoustic and electro-magnetic wave propagation to efficiently reduce the number of contending sensors in the localization process. It incurs $O(1)$ transmissions irrespective of the sensor density and guarantees $O(1)$ time delay in localization. Experiment resultS using UC Berkeley Motes demonstrate that the time delay for Lightning Protocol to locate hand clap sounds is in terms of milliseconds.