Remember Li-Fi? Here’s what happened to Wi-Fi that works with light

Wi-Fi is everywhere. You’re probably using it right now to access this website, or have at some point used it to send or receive data. However, it’s not the only way to move data around without wires. Li-Fi is a somewhat forgotten alternative to Wi-Fi that’s still hanging on, waiting for the day its killer application arrives.

What is Li-Fi?

Wi-Fi works by sending radio signals back and forth between two devices. However, radio waves are just the name we give to a particular frequency range of the electromagnetic spectrum. The part that our eyes are sensitive to, and that we’re capable of seeing, is called visible light. Li-Fi uses visible and near-visible light, like infrared and ultraviolet, to send and receive information. This is also why it’s sometimes called VLC or “Visible Light Communication,” although the two terms are not actually interchangeable.

By pulsing the lights so fast that you can’t even tell with the naked eye, data is transmitted from the bulb to light-sensitive receivers. This means that you can use an LED light to carry your network signals. You could replace the main light in a room with a Li-Fi bulb, and connect everything with a light receiver.

What’s so great about Li-Fi anyway?

If we have Wi-Fi, which at this stage is fast and reliable, what’s the point of Li-Fi? There must be a reason why it was worth pursuing this technology, and indeed, the list of advantages is compelling.

The most obvious one is speed. Under testing conditions, Li-Fi has been shown to be capable of speeds up to 224Gbps. That’s quite a bit faster than the maximum theoretical speed of over 40Gbps for Wi-Fi 7.

Apart from the speed proposition, Li-Fi has the unique advantage of being unaffected by radio waves, since they’re in completely different parts of the EM spectrum. So issues like signal congestion in densely-populated places like apartment buildings or businesses won’t affect network performance. There’s also a security advantage. Visible light doesn’t pass through walls, so in theory (as long as you don’t have any windows) you could keep your transmissions confined to a specific area.

Why Li-Fi didn’t quite take off

While you can buy Li-Fi equipment without much trouble, and the technology has been standardized, it hasn’t exactly set the world on fire yet. After all, it’s highly unlikely you’ve even seen a Li-Fi setup in action.

Just as Li-Fi has some powerful strengths, it has serious limitations. Many of these are just the flipside of its advantages. For example, since it uses light that cannot pass through walls, your range is short. On top of this, you need line-of-sight. Anything that blocks the light between the transmitter and receiver is obviously going to be a problem. Also, while radio waves won’t interfere with Li-Fi, visible light sources, such as sunlight, can jam the signal.

On top of this, Wi-Fi has a massive advantage as the existing wireless technology of choice. To make the change, you’d have to somehow retrofit every device you want to use with Li-Fi, which is hard and potentially expensive in the best of cases, and literally impossible in others, such as with smartphones.

Does Li-Fi have a future?

Given Li-Fi’s unique strengths and weaknesses, I think it’s unlikely that it will ever supplant Wi-Fi or other radio-based technologies like it. Despite its niche appeal, Li-Fi has a bright future, when applied to the right problems. It’s likely that Li-Fi and Wi-Fi will end up complementing each other rather than one replacing the other. As LED lighting becomes the standard, it’s not unreasonable to think that future smart homes might have at least one Li-Fi bulb in each room, which could be the perfect solution for IoT devices without jamming up the airwaves.

Li-Fi could also be a good solution in places where radio interference is a serious issue, such as around sensitive medical equipment. The security benefits could be useful to military or government agencies, and there could even be Li-Fi technology built into streetlamps or traffic lights, perhaps to help with self-driving cars or other smart technologies like drones.

Li-Fi could be the technology that makes the most sense for data transmission in space, especially if we do end up moving data centers into space. 5G technology already has some limitations thanks to the density of millimeter-wave signals, and 6G network technology might combine radio and light-based systems to handle different parts of the network’s infrastructure.

Compared to Wi-Fi, Li-Fi is still in the very early stages of its maturity. It may seem quiet thanks to the lack of commercial products meant for everyday consumers, but in the background, things are moving forward. So don’t be surprised if one day even the light bulbs around you will be shooting around information packets.