Visible Spectrum Eyed for Communications
EDINBURGH, Scotland, Oct. 11, 2011 — At the University of Edinburgh, Harald Haas and his team specialize in finding innovative solutions to mobile communication challenges. Visible light communication may expand our window on the world, they said.
Using the visible light spectrum of LEDs offers a more energy-efficient source of light and is a viable alternative to an overburdened radio bandwidth system.
“There are many data-hungry applications, and the radio spectrum is limited,” Haas said.
“The use of wireless mobile applications is growing, and we are running out of radio spectrum to use. We had a few ideas and weren’t sure if they would work, but we worked on the release of radio-frequencies spectrum to provide more wireless capabilities for the future.”
The D-Light technical team. From left to right: Wasiu Popoola, Harald Haas and Mostafa Afgani. (Image: Peter Tuffy, University of Edinburgh)
“The visible light spectrum is 10,000 times larger than the radio- frequencies spectrum, so I wanted to uncover other possible technologies.”
Li-Fi is the term they coined to describe how their concept works. The light intensity of LEDs can be controlled very rapidly and is faster than the human eye can detect.
By a small device in the light fitting, digital information can easily be converted into minute variations in light, even at very low levels of light, and transfer to other devices many times faster than the data coming into the building.
The light emissions are harmless to humans and can be transmitted even if the light source is dimmed or reflected around the room.
Data security is another key advantage as the light data stream is available only to devices within the four walls in which it is transmitted.
Haas foresees Li-Fi as having a very practical benefit in the home, hospitals, schools, banks, public buildings, aircraft and even under water.
The researchers’ goal of producing an LED bulb that can be fitted to a standard light fitting, completely off the shelf and with very low energy requirement, has been achieved.
This simple lightbulb could change our understanding of mobile communication.
Haas and his team are now aiming to get their product to the market in January 2012.
D-Light project hits target
(Excerpts from the D-Light Project Blog posted on Sept. 20 by Gordon Povey)
The D-Light project at the University of Edinburgh has been active for close to two years and has made a number of advances in the field of visible light communication. Most notable is the work on special modulation methods and encoding schemes enabling large data rates to be achieved from commercial off-the-shelf components.
When the D-Light project began in January of 2010, it had two primary objectives. The first was technical and the second was commercial, to create a viable spin-out company. These objectives were to be achieved within two years.
The D-Light project team is pleased to announce that its main technical objective has been achieved. 102.5 Mb/s has recently been measured in normal lighting conditions (with sunlight and artificial lighting).
This was achieved using an off-the-shelf 18 W Osram Ostar white LED lamp. The desired test distance was achieved with measured error rates of better than 1:10,000 and all of the processing is being done in real time.
The great news is that the D-Light spin-out seed investment round is likely to be oversubscribed based on the interest expressed at this stage and so we might expand the goals of our seed phase.
For more information, visit: www.ed.ac.uk
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