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Could Li-Fi spark a communications revolution like Wi-Fi?

By Dick Meredith

Multi-tasking micro-lights now being developed could initiate an amazing transformation for the future of communications by using light to carry information over the internet.

Tiny light-emitting diode (LED) lights could deliver Wi-Fi-like internet communications, while simultaneously displaying information and providing illumination for homes, offices and many other locations.

Over the next four years, a consortium of universities in the United Kingdom will be developing this innovative technology to help unleash the full potential of “Li-Fi” - the transmission of internet communications using visible light rather than the radio waves and microwaves currently in use.

The project is being led by the University of Strathclyde, Scotland, with funding from the UK’s Engineering & Physical Sciences Research Council (EPSRC). Although the potential possibilities offered by Li-Fi are being explored all over the world, this EPSRC-funded consortium is pursuing a radical, distinctive vision that could deliver enormous benefits.

The term Li-Fi was coined by one of the partners in the project, Professor Harald Haas from the University of Edinburgh in a talk in July 2011. Underpinning Li-Fi is the use of LEDs, a rapidly spreading lighting technology that is expected to become dominant over the next 20 years.

Imperceptibly, LEDs flicker on and off thousands of times a second. By altering the length of the flickers, it is possible to send digital information to specially adapted PCs and other electronic devices - making Li-Fi the digital equivalent of Morse code.

This would make the visible part of the electromagnetic spectrum available for internet communications, easing pressure on the increasingly crowded parts now used.

But rather than developing Li-Fi LEDs about one square-millimetre (1-sq-mm) in size, which other researchers around the world are concentrating on, the EPSRC-funded team is developing tiny, micron-sized LEDs that potentially offer a number of major advantages:

Firstly, the tiny LEDs are able to flicker on and off 1,000 times quicker than the larger LEDs - this also means they can transmit data more quickly.

Secondly, 1,000 micron-size LEDs would fit into the space occupied by a single, larger, 1-sq-mm LED, with each of these tiny LEDs acting as a separate communication channel.

A 1-sq-mm-size array of micron-sized LEDs could therefore communicate a million times as much information as one 1-sq-mm LED.

Moreover, each micron-sized LED would act as a tiny pixel. Therefore one large LED array display - such as one used to light a living room, a meeting room or the interior of an aircraft -could also be used as a screen displaying information at exactly the same time as providing internet communications and the overall room lighting.

Professor Martin Dawson of Strathclyde University, who is leading the initiative, said: “Imagine an LED array beside a motorway helping to light the road, displaying the latest traffic updates and transmitting internet information wirelessly to passengers’ laptops, netbooks and smartphones. This is the kind of extraordinary, energy-saving parallelism that we believe our pioneering technology could deliver.”

Eventually, it could even be possible for the LEDs to incorporate sensing capabilities. For example, a mobile phone could be equipped with a flash that could be pointed at a shop display where everything has been given an electronic price tag, and the price of all the items and other information about them would show up on the phone’s display.

To enable the remarkable potential to be realised, the consortium has drawn together a unique breadth and depth of expertise unmatched by any other Li-Fi research team anywhere in the world.

Professor Dawson added: “The universities of Cambridge, Edinburgh, Oxford and St Andrews are all working with us, bringing specific expertise in complementary areas that will equip the consortium to tackle the many formidable challenges involved - in electronics, computing and materials, for instance - in making this vision a reality. This is technology that could start to touch every aspect of human life within a decade.”

London Press Service

London Press Service