Low-complexity Visible Light Networking with LED-to-LED communication
Visible Light Communication (VLC) is an emerging technology in which Light Emitting Diodes (LEDs) transport information wirelessly, using the visible light spectrum. While most of the research on VLC has focused on wideband white LEDs used in ambient illumination, narrowband and colored LEDs have received little attention. Short-range free-space optical communication based on narrowband LEDs as visible light transmitters and receivers enable a variety of applications, a scenario we refer as LED-to-LED communication. In this paper, we introduce the communication and networking protocols of LED-to-LED communication. Our work addresses fundamental challenges such as efficient collision detection medium access protocol and elimination of light flicker.We build a prototype and demonstrate bi-directional data exchange in a network of up to four LEDs. We further study the trade-offs in the system design and measure the achievable bit-rate and transmission distances.