Demonstration abstract: how many lights do you see?

We demonstrate a Visual Light Communication (VLC) system that enables LED lighting luminaires to communicate with cameras on mobile devices. Each LED pulses at a frequency above the humanly perceivable flicker threshold where cameras and photodiodes can still detect changes in light intensity. Our modulation scheme supports multiple light sources in a single collision domain, and works for both, line-of-sight (LOS) operation as well as from reflected surfaces like those found in architectural lighting. The spatial confinement of light makes this system ideal for use as localization landmarks. Our demonstration includes four LED ambient lights acting as location landmarks transmitting modulated data. A mobile device receiving and processing the signal displays the ID and RSSI of the closest landmark. Interacting with the system will allow users to see the practical effects of multiple-access, frequency of operation, distance from the lights, camera parameters and camera motion.