Long before electricity and electric light were discovered, people used light for communication. There were many advantages over other methods: It travels at, well, the speed of light, for very long distances if not interrupted. And, as we learned in "The Return of the King," light is very dramatic.

Now the old medium is the message again as Li-Fi becomes a reality. Using light instead of radio waves has many advantages; it’s totally secure because it’s line of sight, it is extremely fast, perhaps as fast as 224 Gbps. People who worry about EMF from Wi-Fi (yes, there are people who do) could relax, and as the inventor of the term Li-Fi, Professor Harald Haas of Edinburgh University noted in World Architecture News, it could be just about everywhere and handle a lot more people.

The problem is there are too many people in a too confined space and everyone wants a share of the bandwidth, which is very limited. In London we have lights on the Tube and in shopping malls and all these lights could provide 10,000 times more capacity than we have with wi-fi. It’s a matter of using a big resource that is free for data communication.You could equip London’s street lights with Li-Fi, you can have it on the Underground and the airport. Piccadilly Circus is made of LEDs and these LEDs are the devices you use for Li-Fi.

lights in LondonChristmas lights in London; imagine the Li-Fi possibilities (Photo: Lloyd Alter)

Especially at Christmas; imagine if all those lights were broadcasting Li-Fi.

Li-Fi Bulb

The flurry of interest in Li-Fi right now is due to the recent announcement by an Estonian company, Velmenni, about its Jugnu smart LED bulb, right. But it’s really still vaporware, and Professor Haas isn’t far behind with PureLiFi. And yet another group led by Maite Brandt-Pearce of the University of Virginia has patented a system. According to an article in, it could be used everywhere.

“You can use it any place that has lighting,” Brandt-Pearce said. “In a stadium, in a parking lot, or from vehicle to vehicle if using LED headlights and taillights….Your alarm clock can communicate with your coffee maker that it is time to start making the coffee; Anything with an LED can talk to anything else with an LED. You don’t need a separate transmitter because you are not using radio waves.”

And since we are already paying for light anyway, it could save a lot of energy. Really, the only downside seems to be that it won’t work in bright sunlight, so those rare occasions when people want to connect beside the resort pool might be problematic. But for everywhere else, things are looking bright; as Professor Haas notes:

All we need to do is fit a small microchip to every potential illumination device and this would then combine two basic functionalities: illumination and wireless data transmission. In the future we will not only have 14 billion light bulbs, we may have 14 billion Li-Fis deployed worldwide for a cleaner, greener and even brighter future.

Bulb photo: Velmenni

Lloyd Alter ( @lloydalter ) writes about smart (and dumb) tech with a side of design and a dash of boomer angst.

Li-Fi could bring us faster Internet (and the light we need to read it)
In place of Wi-Fi, using light as Li-Fi is totally secure, offers extremely fast Internet and will save energy too.