Spreading the Net with some blue-sky thinking

13-11-2015 | By Paul Whytock

A pioneering breakthrough on what would be a cheap and effective way of linking millions of people still without Internet was recently demonstrated by the University of Edinburgh’s Research Centre, led by Professor Harald Haas, the acknowledged founder of an optical wireless communication (OWC) related technology called Li-Fi (Light Fidelity).

Professor Haas reckons Li-Fi could bring the web to an extra four billion users. Now whether this would add fuel to the fire regularly stoked by the more negative industry observers that whine about the Internet crashing under the weight of its own success is a debatable point, albeit for another time.

Right now lets concentrate on this Li-Fi breakthrough. What is it?

OWC uses light from LEDs as an enabling way to deliver high-speed communication in much the same way as Wi-Fi with the LED lights being used as Li-Fi Internet access points.

The system uses visible light communications that works via pulsing LED bulbs that switch within nanoseconds. Although Li-Fi bulbs would have to be constantly on to transmit data, the bulbs would be dimmed to the point they were not visible. Direct line of sight is not needed for Li-Fi to transmit a signal and light reflected off walls might achieve 70 Mbit/s.

A big technical advantage of Li-Fi is it is safe in electromagnetic sensitive areas such as in aircraft cabins where it could function without causing interference. In addition to that safety characteristic Li-Fi has virtually limitless capacity because the visible light spectrum is at least 10,000 times larger than the whole radio frequency spectrum.

So this technology could potentially distribute the Web globally at little more than the cost of a solar-panel and an LED light and as such will have a major impact on people in rural communities and the developing world that do not have existing infrastructures for electricity, the Web and Wi-Fi.

Whilst LED light is used to transmit data the solar panel in such a system receives high-speed data. In effect, the solar panel achieves both functions of providing the energy for Li-Fi to work whilst also functioning as a broadband receiver.

Professor Haas has already demonstrated how Li-Fi can be used with solar cells to receive data so solar panels on houses or even smart watches can absorb power and receive data at the same time. With the help of this technology, smart watches could be powered and connected to the Internet through light.

These self-powered solar nodes will remove a major barrier to data communication growth. In conventional optical wireless communications, the received optical signal is usually discarded but could now be used to directly power the receiving terminal.

Not surprising then that some industry analysts have seen the light when it comes to Li-Fi and project it will achieve a compound annual growth rate of approximately 80% and be worth over €6 billion per annum by 2018.

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By Paul Whytock

Paul Whytock is Technology Correspondent for Electropages. He has reported extensively on the electronics industry in Europe, the United States and the Far East for over thirty years. Prior to entering journalism, he worked as a design engineer with Ford Motor Company at locations in England, Germany, Holland and Belgium.