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The University of Edinburgh’s new bright idea

ByBrice Simon-Letcher

Dec 3, 2015

It is always good to see our University at the forefront of scientific and technological innovation. After major breakthroughs like the first successful cloning of a mammal (Dolly the sheep) or predicting the Higg’s Boson, Edinburgh could this time be set to revolutionise the world of wireless connectivity.

Li-fi technology, which stands for ‘Light fidelity’, was pioneered by Professor Harald Haas at the University’s College of Science and Engineering. It proposes to transmit data not through the traditional radio frequencies used by mobile and Wi-fi devices, but using light instead.

Both radio waves and visible light are part of a continuum known as the electromagnetic (EM) spectrum. The EM spectrum includes the familiar infrared and UV waves and X-rays, but only a specific portion of it, the visible light spectrum, is visible to the naked eye.

Haas first demonstrated in a 2011 TED talk in Edinburgh, which has been viewed almost 2 million times since, that a simple LED light bulb could be turned into an efficient and cost-effective data transmission device. By connecting an LED, light receiver (the equivalent of a Wi-Fi modem), and laptop, he showed an HD movie could be streamed onto the computer screen by the simple flick of a light switch.

This might sound like magic, but the underlying principles are actually the same as for Wi-Fi. So what makes Li-Fi such a brilliant idea?

There are are number of advantages to Li-Fi. The first is that it uses a portion of the EM spectrum 10,000 times the size of the radio frequency spectrum. With IT giant Cisco’s forecast of 1 billion extra Internet users by 2019, the risk of a “spectrum crunch”, meaning the saturation in the number of available radio frequencies, is an impending issue Li-Fi can avoid.

By relying on visible light, which as we know cannot cross physical boundaries like walls, Li-Fi also affords improved cyber-security by blocking access from outside networks. And if you visit the offices of Estonian start-up company Velmenni in Tallinn, you will find the Internet connection there is about 100 times faster than regular Wi-Fi, at 1GB per second. In fact, laboratory tests earlier this year found the maximum transmission rate of Li-Fi was a staggering 224 Gb per second.

Those with an eco-friendly perspective will also find that the energy requirements for Li-Fi are much lower than Wi-Fi. Interestingly, Haas has proposed in a recent TED talk in London that solar panels could be used as Li-Fi receivers while simultaneously generating electricity, and for a marginal added energetic cost. This could be of special import for rural and developing areas, where existing data connection networks and electrical power supplies are often under-provisioned.

More generally, Li-Fi could be looking to precipitate the advent of the ‘Internet of Things’, an age of global connectivity where household appliances (thermostats, water boilers, and even your kettle) will be able to communicate with each other and be remotely controlled from our digital devices. Most smartphones are already equipped with photosensitive cameras and light-emitting LEDs, and there are 14 billion lightbulbs already installed in homes around the world.

It is now up to Professor Haas’ start-up company pureLifi Ltd, and the industry as a whole, to usher the transition, which Haas hopes can occur within the next few decades. So why not go Li-Fi?

Image: Thomas Hosmer Shepherd

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