In telecommunications, visible light communication (VLC) is the use of visible light (light with a frequency of 400–800 THz/wavelength of 780–375 nm) as a transmission medium. VLC is a subset of optical wireless communications technologies.
The technology uses fluorescent lamps (ordinary lamps, not special communications devices) to transmit signals at 10 kbit/s, or LEDs for up to 500 Mbit/s over short distances. Systems such as RONJA can transmit at full Ethernet speed (10 Mbit/s) over distances of 1–2 kilometres (0.6–1.2 mi).
Specially designed electronic devices generally containing a photodiode receive signals from light sources,[1] although in some cases a cell phone camera or a digital camera will be sufficient.[2] The image sensor used in these devices is in fact an array of photodiodes (pixels) and in some applications its use may be preferred over a single photodiode. Such a sensor may provide either multi-channel (down to 1 pixel = 1 channel) or a spatial awareness of multiple light sources.[1]
VLC can be used as a communications medium for ubiquitous computing, because light-producing devices (such as indoor/outdoor lamps, TVs, traffic signs, commercial displays and car headlights/taillights[3]) are used everywhere.[2]
- ^ a b "Image Sensor Communication". VLC Consortium.[dead link]
- ^ a b "About Visible Light Communication". VLC Consortium. Archived from the original on December 3, 2009.
- ^ "Intelligent Transport System – Visible Light Communication". VLC Consortium. Archived from the original on January 28, 2010.