Lighting Up The Internet Of Things With Darkvlc

Visible Light Communication (VLC) holds a great potential to solve the spectrum crunch problem and to provide scalable connectivity to zillions of mobile and IoT devices. However, VLC commonly requires LED lights to be on, which fundamentally limits the applicable scenarios of VLC and makes VLC less attractive to mobile and IoT devices with tight energy budget. We present DarkVLC, a new VLC primitive that allows the VLC link to be sustained even when the LED lights appear dark or off. The key idea is to encode data into ultra-short light pulses imperceptible to human eyes yet detectable by devices equipped with photodiodes. Realizing DarkVLC faces several challenges to generate and deal with the ultra-short light pulses reliably. We describe our preliminary efforts to tackle these challenges and build a DarkVLC prototype using off-the-shelf LEDs and low-cost photodiodes. DarkVLC fundamentally broadens the application scenarios of VLC and provides a new ultra-low power, always-on connectivity affordable for mobile and IoT devices.