What Is Li-Fi? The New Alternative To Wi-Fi

Philips Lighting just unveiled a small coup. It’s providing internet to an entire office in France with nothing but its lights. That’s right, a company known for LED bulbs and colorful mood lighting is expanding from interior decorator to serious IT player.

Philips is working with a technology called Li-Fi, an alternative to the Wi-Fi signals we’ve used in our laptops and smartphones for years now. You may not have heard of Li-Fi yet. But you will a lot, soon. Here’s everything you need to know about the technology, and how it could impact the design of your home, office, and gadgets to come.

WHAT IS LI-FI?

Li-Fi stands for Light-Fidelity. The term was first coined in 2011 in a TED Talk of all places by the University of Edinburgh professor Harald Haas, who had been developing it around that time. It’s been under further development by various researchers in the years since.

Li-Fi is basically just high-speed wireless data transmission . . . through light. That light can come from something as simple as a desktop lamp. The idea is that Li-Fi is built into the functional lighting that you’d want to turn on indoors anyway–except it’s also carrying your data.

HOW DOES IT WORK?

The light sends data through really fast flickering that the human eye can’t detect. The flickering, also known as “refresh rate” in the world of displays, occurs at 10 times the speed of the light coming from TVs and computer monitors. In other words, you won’t notice it.

A special dongle will do the trick to make today’s laptops and other devices capable of detecting Li-Fi. But down the road, your computer or smartphone could be equipped with two new Li-Fi-receiving components. One is a tiny light sensor. No big deal. Your devices already measure ambient light to manage auto brightness. The second is an infrared transmitter. That’s the exact same technology used in classic remote controls. Your computer would fire off requests to the internet much like we’ve been channel surfing for decades.

SOUNDS NEAT, BUT HOW IS LI-FI BETTER THAN WI-FI?

In a word, bandwidth. Our internet requires more and more bandwidth every day. High-resolution video. IoT devices. VR and AR. Right now, we transmit that data through radio waves. Whether it’s Wi-Fi to a laptop or 4G to a smartphone, it’s all just radio. (Granted, a fiber-optic backbone in the ground transmits a lot of the internet’s data, but it’s radio to get that data from the internet onto your device.)

Radio is incredibly crowded already, and it’s certain to fall short of our growing data demands–anywhere from 20 times to a whopping 667 times short within 20 years, depending on how things play out. So we need something else for wireless transmission. Enter Li-Fi. It has 2,600 times the capacity of the radio spectrum. That means we could meet our 20-year data demands using just 0.8% of the entire visible and invisible light spectrum.

THAT’S COOL FOR THE INTERNET, BUT WHAT DOES IT MEAN FOR ME?

Day to day, using Li-Fi would feel like using very fast Wi-Fi. Not much will change about the way you use the web. But Li-Fi also opens up how we design spaces around data. For example, Li-Fi works better in buildings with thick walls that tend to block radio signals. Radio transmission is a problem in healthcare, especially. With Li-Fi, these old or very large buildings might be “wired” as simply as upgrading the light fixtures.

Then there are day-to-day workflow possibilities to consider. It’s crazy to think about, but offices could build secure rooms simply by blocking out windows and light leakage. You wouldn’t even need to rely on passwords and encryption to keep hackers out (though Li-Fi can have all that technology, too). To turn off the lights would be to turn off a sensitive network connection.

Inside a home, Li-Fi lights could be installed with dimmers for mood lighting. But could they operate in complete darkness? Technically, the infrared portion of Li-Fi’s spectrum could be on at night without you seeing it at all. Or a single LED can transmit data, too. So instead of a bright overhead light, something more akin to a nightlight might suffice for some applications.

At the city scale, street lamps–and really, any LED–could take on the role of what’s been dubbed “light as service,” where it provides data to pedestrians, vehicles, and all sorts of infrastructure components that might be in need of massive amounts of data, fast. That’s because Li-Fi can actually still operate in sunlight by filtering out the sun’s part of the light spectrum.

HOW CLOSE ARE WE TO THIS LI-FI-LIT WORLD?

It’s tough to say right now. In labs, Li-Fi is operating at jaw-dropping speeds. But Philips Lighting’s grand office experiment is only running at 30Mbps. Another Li-Fi desk lamp that popped up at CES isn’t any faster, either. And 30 Mpbs is slower than the Wi-Fi we have today–only capable of streaming a couple Netflix shows simultaneously.

There are also problems to overcome at scale. How do these Li-Fi lights handle multiple users on the network all the time? Will we leave Wi-Fi everywhere anyway, just so there’s a connection if a light goes out or I put my phone in my pocket? It’s all considered solvable, but the tech is still immature.

Even still, Li-Fi is exciting stuff that should be on the radar of designers, architects, marketers, and urban planners. Because in the future, anyone with access to a light socket could become an information architect.