February 7, 2012


Meet Li-Fi, the LED-based alternative to household Wi-Fi (Michael Watts, February 2012, Wired )

Using off-the-shelf electronics, he can stream videos using an ordinary light bulb fitted with signal-processing technology of his own design. The lamp shines directly on to a hole cut into the oblong box on which it sits. Inside this box is a receiver that converts the light signal into a high-speed data stream, and a transmitter that projects the data on to a screen as a short video. If Haas puts his hand in front of the lamp, excluding the light, the video stops.

Haas, 43, holds the chair of mobile communications at Edinburgh University's Institute for Digital Communications. His demo is scientifically groundbreaking: it proves that large amounts of data, in multiple parallel streams, can be transferred using various forms of light (infrared, ultraviolet and visible). The technology, he says, has huge commercial potential. His device can be used with regular lighting and electronics -- albeit reconfigured -- and could transform the way we access everything from video to games, accelerating the speed of internet access by many hundreds of megabits. It could let us download movies from the lamps in our homes, read maps from streetlights and listen to music from illuminated billboards in the street.

Haas's discovery is based on a subset of optical technology called visible light communication (VLC), or Li-Fi, as it has been dubbed. VLC exploits a hack of human perception: light-emitting diodes can be switched on and off faster than the naked eye can detect, causing the light source to appear to be on continuously. Rapid on-off keying enables data transmission using binary code: switching on an LED is a logical "1", switching it off is a logical "0". Thereby flows the data.

The potential applications are enormous: divers working at depths could use light to communicate; air passengers could connect to the internet through the LEDs inside the aircraft. Haas sees the technology potentially disrupting industries from telecoms to advertising.

Enhanced by Zemanta

Posted by at February 7, 2012 7:01 AM

blog comments powered by Disqus