Just a couple of weeks after Chinese scientists claimed a breakthrough in wireless internet connectivity using light- or “li-fi” – UK researchers have announced that they have achieved data transmission speeds of 10Gbit/s via “li-fi”.
Li-fi is a fast emerging technology that could see specialised LED lights bulbs providing low-cost wireless internet connectivity and researchers at the University of Strathclyde have developed a micro-LED bulb that allows streams of light to be beamed in parallel, multiplying the data that can be transmitted.
In tests the micro-LED light bulb was able to transmit 3.5Gbit/s via each of the three primary colours – red, green, blue – that make up white light suggesting that speeds of up to 10Gbit/s will be possible.
The research undertaken at Strathclyde forms part of a much bigger project known as the ultra-parallel visible light communications project. This is a joint venture between the universities of Edinburgh, St Andrews, Strathclyde, Oxford, and Cambridge, and funded by the Engineering and Physical Sciences Research Council.
Using a digital modulation technique called Orthogonal Frequency Divisional Multiplexing (OFDM), micro-LED light bulbs were able to handle millions of changes in light intensity per second, in effect behaving like a fast on/off switch allowing binary data to be transmitted at high speed.
The research backs claims made earlier this year from Germany”s Fraunhofer Heinrich Hertz Institute that data rates of up to 1Gbit/s per LED light frequency were possible in laboratory conditions.
Professor Harald Haas, who has been leading “li-fi” research for the last 10 years and coined the actual phrase, has set up a private company, PureVLC, to exploit the technology.
According to Professor Haas li-fi is cheaper and more energy-efficient than existing wireless radio systems given the ubiquity of LED bulbs and the fact that lighting infrastructure is already in place and LED transmitters could provide much more localised and consistent internet connectivity throughout buildings.