Li-Fi Is 100x faster than WiFi, but what’s the catch?

 This article has been republished here with permission of MakeUseOf

You’ve heard of Wi-Fi, now you need to hear about Li-Fi. Still in the nascent stage, this new technology could change how you use the Internet. It’s much faster than existing Wi-Fi tech, it’s more energy-efficient, and potentially more secure as well.

But of course, there are just as many downsides.

Li-Fi, or Light Fidelity, is suddenly in the news these days because an Estonian company called Velmenni conducted a real-world test where it was able to transfer data between devices at 1 Gbps, which is roughly 100 times faster than Wi-Fi in the real world. In lab tests, the fastest recorded speed was 224 Gbps!

And it all works with the simple power of light.

What Is Li-Fi?

Li-Fi’s biggest proponent is Harold Haas, a professor at The University of Edinburgh, and founder of the company pureLiFi, which is trying to bring the technology into real world markets.

Li-Fi is dependent entirely on light, specifically LED bulbs. In a way, it’s the next step in connected lighting. In the simplest terms, Li-Fi transfers data over light waves. By comparison, Wi-Fi uses radio waves.

This means that Li-Fi is completely wireless, much like existing Wi-Fi. Haas also stresses that it can operate with existing LED bulb technology. Note: “existing technology” doesn’t mean “existing LED bulbs” that you already have set up in your house. Li-Fi actually works on wireless protocols much like Wi-Fi’s 802.11.

In short, you’ll need new bulbs. Li-Fi will also require a new piece of technology in your smartphones and laptops: a photosensor. Photosensors (also called photodetectors) are sensors which can “read” incoming light.

How Does Li-Fi Work?

Li-Fi works much like the infrared technology in your television, and infrared works on a simple principle: an input command is given (e.g., “change channel” when you press a button) and that input is turned into binary code.

That code is then transmitted over infrared light waves by your remote’s sensor, and the light waves are received by your TV’s infrared sensor, which decodes the light and performs the intended input action.


PureLiFi’s infographic above shows how this works. The Internet and router/server is hooked to a cable, and the cable is attached to any number of LED bulbs in your house. The LED bulbs then transmit the data as modulating light waves while a photodetector on your phone or laptop picks up those light waves and decodes them.

So anywhere that your LED bulb is casting light that your photodetector can “see”, you’re ready to get Internet access — and at speeds faster than Wi-Fi.

Howevenr, this means that Li-Fi requires direct line-of-sight between the source (bulb) and recipient (phone or laptop), so while properly configured Wi-Fi can go through walls, you won’t be able to do that with Li-Fi.

What Makes Li-Fi So Promising?

Watch the demo above by Velmenni and you’ll see the huge potential of this technology. There are some obvious benefits over Wi-Fi:

  1. You won’t have to worry about congested radio waves and wireless dead zones.
  2. It’s much, much faster than existing Wi-Fi speeds.
  3. It’s more energy-friendly than Wi-Fi, which requires power-hungry masts. Also, if your photodetectors are solar cells, as Haas envisions, you might be able to use wireless battery charging and wireless Internet simultaneously.
  4. Li-Fi’s direct line-of-sight requirement means that it’s probably going to be more secure than Wi-Fi, since someone outside your home can’t hack into your system. But, as Techcrunch points out, a telephoto lens and optimally tuned photosensor could potentially change that.

The Problems With Li-Fi


While all of this sounds really good, there are some major problems that Li-Fi still has to overcome:

  1. Li-Fi cannot be used in direct sunlight (or other odd conditions with harsh lighting) since the photodetectors won’t be able to detect the modulating light waves. It’s unclear what counts as a poor condition, but as Velmenni’s and Haas’s demos have shown, it does work with some amount of ambient lighting.
  2. The line-of-sight requirement can be a major bottleneck. Let’s say you have one Li-Fi bulb in your living room and you want to move to your bedroom. Well, you better have another Li-Fi bulb set up there or you’ll be out of luck.
  3. Li-Fi is going to need reinvestment in lighting and wiring infrastructure.

Will Li-Fi Revolutionize the Internet?

Right now, it’s honestly too early to tell. Advocates of the technology suggest that instead of Li-Fi replacing your existing setup, it’ll be an additional connectivity source that boosts your usage. PureLiFi illustrates this by showing how you are likely to go from LTE to Wi-Fi to Li-Fi in your home:


We probably won’t see a mass rollout of Li-Fi anytime soon. PureLiFi is the leader in this regard and has so far joined up with one French company to hopefully go to market by the third quarter of 2016.

What Does All of This Mean?

The bottom line for you right now? Nothing changes.

Li-Fi seems like really cool technology and could help augment existing Wi-Fi and other wireless connectivity — it could potentially even replace it altogether — but actual usage for us consumers is a long, long time away.

Until that happens, check out Haas’s most recent demonstration of Li-Fi and be amazed by what the marriage of LED bulbs, Li-Fi, and solar cells could bring to our smart homes of the future:

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