Passive Communication with Ambient Light

TL;DR

This paper introduces a passive visible light communication system where environmental reflections encode data, demonstrated through outdoor testing with a moving car, emphasizing the potential for ambient light-based data transfer.

Contribution

It proposes a novel passive communication method using ambient light modulation via reflective surfaces, and evaluates its feasibility in outdoor scenarios with moving objects.

Findings

Successful decoding of information from a moving car at 18 km/h

Identified key parameters affecting passive light communication performance

Demonstrated outdoor application viability

Abstract

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 at the light source. We instead propose that the environment itself modulates the ambient light signals: if mobile elements 'wear' patterns consisting of distinctive reflecting surfaces, single photodiode could decode the disturbed light signals to read passive information. Achieving this vision requires a deep understanding of a new type of communication channel. Many parameters can affect the performance of passive communication based on visible light: the size of reflective surfaces, the surrounding light intensity, the speed of mobile objects, the field-of-view of the receiver, to name a few. In this paper, we present our vision for a passive communication channel with visible light, the design challenges and the evaluation of an outdoor application where our receiver decodes information from a car moving at 18 km/h.