It seems to be a new way of transferring files over light. Could it be a wireless version of fiber optics? Pure Lifi built a 'Li-1st' device. It is designed to send data signals with existing light from your lamp or ceiling light in a full duplex mode.
How this works sounds quite interesting and complex. It works like the power-line adapters you see on the market, but it is suited for lights essentially. It's an Ethernet-wired device that connects to a standard LED light. So basically, the LED flickers at a whopping million+ times per second. It works like Morse code on cat-nip. There is a receiver to listen in on the code the light is sending out. To put it in simpler form, basically like how wifi works.
This is exactly the same an using infra-red signals, like your TV remote. And will be pretty useless. Just like Infra-red. Reliability with this kind of thing is pretty bad.
Noise, if you can call it that in this situation, would be the most limiting factor, given that the average room has at least 3 to 5 seperate light sources all blinking at once (various appliances lights and whatnot) as well as the sun being one great annoyance as well. I can see great potential for it, but also great limitations.
I could see some very specific cases were this would be useful. IE, low bandwidth control signals to robots in factories or electrical equipment in the home, or possibly using it to cut down on all the radio emissions generated by WiFi since the FCC doesn't give a flying shit about light emissions in your home.
That being said, power line networks would do the same thing, and infrared would do the same job without giving anybody a headache. Even in the realm of secure network traffic, capturing these signals would be as simple as having a good telescope and a clear line of sight to a window, even miles away.
I cant see this being useful at outside some very specific situations were all other methods are somehow not working or useful.
One really good use for this would be in the realm of ultra long range, ultra high speed networking were building a land line would be impractical, or establishing radio dishes too costly. But that would only count if we were using lasers, not LEDs.
In its current incarnation, this is a technology without a real world use.
Did you know, it is possible to use the internet with high frequency sound waves (inaudible to humans) using a speaker and a microphone? The malware called badBIOS uses this technology.
Anyway, using LEDs to connet to the internet seems to have less health risks than Wi-Fi. In homes, Ethernet is still king and I doubt that will ever change.