A long time ago if I was out and about, and had a file I needed to download, I had to wait until I was at work or home AND on my PC to download a modest 5 mb file. Even then I still had to wait for what felt like a lifetime! At the same time I prevented anyone from using the telephone (yes I am talking Dial Up). I wished for the day when everyone would have Broadband and WiFi. I wanted the day when the Internet ‘disappeared’ and was just a utility, however you were accessing the Internet. Well that day has been and gone, some people no longer have to wait for downloads and can stream relatively large files without it buffering (well parts of the UK can). Thank You Fibre Optic & 4G, we all love you.
The next big challenge is making the speed and capacity when on WiFI closer to the speeds Fibre Optic can deliver. Our appetite for large files appears to be insatiable, as is our desire to have them wirelessly. More and more services rely almost entirely on the Internet to work, and more of them are mobile specific. But, we are working with a finite resource, there is only so fast current WiFi can go, and only so much of the radio spectrum we can utilize for it.
Well there is potentially an answer, thanks to Professor Harald Haas and his team at Edinburgh University, and although it sounds a bit outlandish, the science is very, very solid.
The answer is light…
The basic premise is very simple, radio waves, infrared and visible light are all on the electromagnetic spectrum, we already use radio waves and infrared for wireless technology, so why not light?
Image: The Indian Awaaz
This is not science fiction, this is science fact, they already have it working, and there is a small network in Tallinn, Estonia that is using it. The light does not even need to be that bright (it can look virtually ‘off’ to the human eye) as the receiver looks for the minute differences in brightness of the light. Pulse changes that last for a nanosecond are all that it takes to transmit the data in binary, even on reflected light. The pulses are so fast and the differences in radiance so tiny that the human eye does not register them (phew!).
And if we fit LED bulbs everywhere, we are pretty much already there to be able to transmit data. There is still a lot of work to do before we see it everywhere, and clearly it has limitations (or advantages, depending on how you look at it). The biggest issue being that although radio waves can pass through solid objects, light does not. So with existing WiFi you can be in one room and use the signal from another room or floor (which you can’t do with light). The upside to this is that a LiFi network is naturally very secure; if you have it in your house you will not need a password to protect it, just buy thick curtains!
Of course there are other advantages, light is inherently safe, so even in places where WiFi cannot be used, like an aircraft at takeoff or an oil refinery, LiFi is perfectly safe to use, after all, these places already have lighting.
Long term the good part is that the light spectrum is much, much wider than the radio spectrum (10,000 times larger in fact), and in laboratory conditions they were able to generate speeds 100 times faster than WiFi (in similar conditions). So there is plenty of bandwidth, and plenty of scope to close the speed gap between wired broadband and mobile wireless connections.
The future really is bright, the future is every colour of the visible spectrum.
If you want to know more, check out these;
Prof Harald Haas gives a TED talk – https://www.ted.com/talks/harald_haas_a_breakthrough_new_kind_of_wireless_internet
LiFi on ‘iflscience.com’ – http://www.iflscience.com/technology/li-fi-internet-could-be-100-times-faster-wi-fi-0
