Tech Innovation

Li-Fi and why everybody is talking about Internet lightbulbs


There’s a new networking technology in town that promises speeds 100 times faster than Wi-Fi. Known as Li-Fi (Light Fidelity), the prototype technology uses visible light communication (VLC) to squirt data at speeds of up to 1Gbps; through your lightbulbs.

Communicating with light is an old idea. The Royal Navy’s morse code-flashing signal lamps date back to the late 19th century. Ditto the heliograph used by the British Army Signal Corps, which used mirrors to flicker light over long distances. While in 1880, inventor Alexander Graham Bell developed the photophone, a device capable of transmitting speech over modulated sunlight.

Where Wi-Fi uses radio signals to carry information, Li-Fi embeds a data stream into visible light by fluctuating the brightness of a typical LED bulb “at extremely high speeds” that are imperceptible to the human eye. AT least, this is how the technology is described by pureLiFi, the company set up by VLC pioneer Professor Harald Haas to develop it.

how lifi works

Haas demoed the technology at the 2015 TED Global Conference in London, showing how a video could be sent from a lamp to a laptop via a simple solar cell. As VLC is a line-of-sight technology, Li-Fi isn’t viewed as a direct replacement for Wi-Fi but as a companion to it. Haas believes that it’s perfectly suited for the coming Internet of Things (IoT) revolution; perfect for bringing internet access to more people in more places, closing the digital divide.

“Imagine distributing the internet to every corner of the world at little more than the cost of a solar-panel and an LED light,” he says.

Li-Fi might lack the range of Wi-Fi — the light signals obviously can’t go through walls. But the technology is a low-power solution that can achieve 1,000 times the data density and 100 times the speed (due to low interference). It’s also much more secure than Wi-Fi. For somebody to hack a Li-Fi connection, they would need to be in the same room.

Light-based technology won’t just give us superfast wireless networking. Silicon photonics research will ultimately deliver faster processors with optical interconnects, while a team of British scientists have recently made a breakthrough in integrated all-photonic non-volatile multi-level memory that uses light pulses to change the state of an germanium-antimony-tellurium alloy.

In the quest for more computing speed and ubiquitous connectivity, it seems that light will ultimately shine the way. — Dean Evans (@evansdp)

Main image credit: Shutterstock/DK.samco

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