Does LiFi illuminate the way forward for future IFEC?

PureLiFi's LiFi-X product
PureLiFi’s LiFi-X product

Twenty years ago we had never heard of Wi-FI. But now a new technology called LiFi could pave the way for faster, more efficient, data transfers to personal devices in the aircraft cabin. “Get Connected’s” Steve Nichols takes a look.

LiFi, or Light Fidelity, is a technology you have probably never heard of. But if its inventor is right it could take the world by storm.

LiFi technology is the brainchild of Professor Harald Haas of the University of Edinburgh. The idea is simple – instead of using radio waves to transfer data from an access point or router to our personal device, why not use visible light instead?

“The benefits are enormous,” said Professor Haas, speaking at the London Aviation Festival. “We are running out of radio spectrum and Wi-FI is a technology that is inherently insecure and prone to hacking.

“But if we use light instead we eliminate a lot of the problems. You don’t need to regulate or licence the light spectrum, it can’t pass through walls, so you go a long way to getting rid of hacking issues, and the data throughputs are outstanding,” he said. “Plus visible light has 10,000 times more spectrum capacity than radio.”

Haas said that by using LED lamps that are modulated faster than the eye can detect it is possible to transfer data at speeds in the Gigabit range.

“It is rather like the technology being used in your TV remote control, but with a quantum leap forward in terms of speeds,” he said.

LiFi via modulated LEDs

PureLiFi's Professor Harald Haas.
PureLiFi’s Professor Harald Haas.

Haas said he demonstrated LiFi at a TED Global event in 2011. He was able to modulate an LED lamp and transfer high-definition TV data to a sensor. Jump forward five years and his system can now reach speeds of up to 10Gbps using a Gallium Nitride (GaN) micro LED. And it is getting better. A laser LED can now reach speeds of up to 100Gbps and he is working on a system that could transfer Terrabits per second.

“It’s clean technology and you can build LiFi transmitters into walls or ceilings,” he said. “Even the overhead passenger light on an aircraft could be used, which makes it ideal for streaming inflight entertainment to passengers’ own devices.”

In addition, the integration of illumination and data services in one unit could generate a reduction in both aircraft infrastructure complexity and energy consumption.

The other big benefit is that, unlike Wi-Fi, there is no limit as to how many people you can connect to a network.

Haas said that there were common misconceptions about LiFi’s performance.

“Many people think that LiFi can’t work when there is direct sunlight, but that isn’t so,” he said. “Our tests show it works perfectly well, with only a 10-11% degradation in data speeds. We are still able to achieve in excess of one Gigabit per second in direct sunlight.”

The other misconception is that the system needs to have a direct line of sight between the light and the receiver.

“No so,” said Haas. “If we bounce the light source off a wall it still works fine, after a short pause while it adjusts itself.”

But what if someone momentarily breaks the light beam? No problem, the system is able to cope without a glitch thanks to buffering.

Haas said that he first started research into using LiFi in aircraft cabins back in 2003.

“If the LiFi transmitter is built into overhead light it means that you don’t have to worry about cabling if you rearrange the cabin,” he said. “And an LED light has a design life of around 20 years.”

Haas now heads a commercial spin-off called PureLiFi. It is producing third-generation LiFi USB dongles that work with laptops and other devices and is about to equip an office in Paris with a complete LiFi network.

But for LiFi to really make its mark on the IFEC industry we’ll need to see it fitted to commercial devices like the iPhone, iPad or Galaxy Tab. Then the technology really could achieve adoption worldwide.

And Haas hinted at LiFi’s future. “If you look at the latest Apple iOS operating system you might find some code for LiFi,” he teased.

Apple could therefore include a LiFi capability in future versions of the iPhone, perhaps using the camera as the receiver.

The tech giant is also said to hold a patent for a lighting system – now why would it want that?



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