‘Li-Fi’ Could Unleash the Internet in Your Lights

Imagine simultaneously powering your laptop, displaying information and delivering Wi-Fi-like communications, all with the same LED technology used to illuminate your home. This radical, distinctive vision could soon be a reality with micron-size LEDs being developed by a consortium of UK universities.

Over the next four years, the group, led by the University of Strathclyde, will develop the technology to help unleash the full potential of “Li-Fi” — the transmission of Internet communications using visible light instead of the current radio and microwave signals — via the flickering of micron-size LEDs. The Li-Fi term was coined by project partner professor Harald Haas of the University of Edinburgh during a TED (Technology, Entertainment, Design) talk in July 2011.

LEDs flicker on and off imperceptibly thousands of times a second. By altering the length of the flickers, digital information can be sent 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.

In the long-term, larger LED lights such as this one could be replaced by arrays of micron-size LEDs, enabling tasks such as powering a laptop, providing illumination and displaying information to be carried out simultaneously. Courtesy of the EPSRC Press Office.

The LEDs are made from gallium nitride and can flicker on and off 1000 times quicker and transmit data faster than conventional white LEDs. Their tiny size also means that 1000 can fit into the same space as a single conventional bulb, enabling bandwidth to be increased by a total factor of 1 million over a similar area.

Besides providing an alternative to wireless Internet access, visible light communication also could be used to transmit data to electronic devices. For example, mobile phones equipped with a flash could be pointed at items affixed with electronic price tags in a store exhibit and display the price and all other information of each item on the phone.

“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,” said lead researcher Martin Dawson, a professor at the University of Strathclyde. “This is the kind of extraordinary, energy-saving parallelism that we believe our pioneering technology could deliver. This is the technology that could start to touch every aspect of human life within a decade.

Other members of the consortium include Cambridge and Oxford universities and the University of St. Andrews. The research is funded by the Engineering and Physical Sciences Research Council.

For more information, visit: www.strath.ac.uk