From Data Modulation to Data Reflection: A Passive Communication System for Visible Light Signals

In this work, we propose a new communication system for illuminated areas, indoors and outdoors. Light sources in our environments – such as light bulbs or even the sun – are our signal emitters, but we do not modulate data using the light source. We instead propose that the environment itself modulates the light signals: if any mobile element ‘wears’ a pattern consisting of distinctive reflecting surfaces, a receiver could decode the disturbed light signals to read passive information. Mobility here is key to transfer the information to the destination, since objects or people passing by will disturb the surrounding light signals. Like barcode readers in our stores, light sources in our environments could be leveraged to monitor logistics and activities in cities and buildings. Achieving this vision requires a deep understanding of a new type of communication channel. Many parameters can affect the performance of passive communication signals based on visible light: the specific patterns of the reflective surfaces, the surrounding light intensity and the speed of the mobile objects, to name a few. In this position paper, we present an initial experimental and analytical approach to tackle some of the main challenges associated with realizing a passive communication channel with visible light.