Practical applications
PureVLC isn't the only company working on this. In January, Casio demonstrated its take on the tech: flashing one smartphone screen - a flicker, again, imperceptible to humans - to send photo and message data to a second handset. Again, it was a relatively low-speed trial, but one made using everyday hardware.
Social communications: Casio's VLC app, Picapicamera
Casio has been working on this for some years now, as have other Japanese technology firms. A group of them formed the Visible Light Communications Consortium in 2004. But there, as here, there seems little to show for the years of experimentation.
Toshiba, for example, has a pair of maritime binoculars that can pick up a signal beamed from Japan's lighthouses at up to 2km, beyond the range of Wi-Fi. The signal tells the viewer about sailing conditions in the immediate vicinity of the lighthouse. Again, it's not a fast transfer: just 1.2Kbps. Enough for a short burst of compressed data, but not much more.
Then there's Reset. It has produced a diving mask that transmits the wearer's voice as a series of light pulses. A detector converts the light back to an audio output. This enables underwater conversations at distances of up to 30m. The catch: each mask costs ¥150,000 (£1200) and you need two to make it worth wearing one.
In the West, we have the Li-Fi Consortium. One of its first tasks: the slightly embarrassing point that "LiFi" is a trademark owned by someone else, in this case US company Luxim, which makes plasma light sources.
Wireless alternative
Casio's app is now available from the iTunes App Store. The software, Picapicamera, is designed to exchange snaps adorned with cartoons and text, but Casio says it's also ready to receive signals from digital billboards and domestic LED-backlit TVs - a key application for VLC, Casio reckons. It imagines phone owners grabbing discount vouchers, the location of the nearest stockist and such simply by pointing cameras at light sources, much as a few already do with QR codes.
But there's the rub: there are already many technologies that deliver small bursts of data for those willing to accept it. And while the lightbulb may be ubiquitous, so too are wireless networks - and these are generally turned on 24-7, not something you can always say for lights.
That doesn't mean the two are not complementary, and the ever-busy radio spectrum means some users may seek less crowded alternatives. Canny Wi-Fi users are already shifting into the relatively empty 5GHz band, but the arrival of faster version of Wi-Fi, such as 802.11ac, will steer more new users into that band, and that may persuade some folk to take a fresh look at light. ®
WTF is... Li-Fi?
COMMENTS
So...
it's Infrared- as used in millions of devices for decades? But with visible light? And slower? And your lights need to be on to use your LiFi device at home? If you'll excuse the pun in my sarcasm, that sounds Brilliant. There's nothing I like more than having some irritating light at the side of the room letting me use my new Wireless keyboard, or playing computer games in a well-lit room so my phone can sync.
Which retard thought this up, and how long will it take before they come up with the "revolutionary" idea that they could use an invisible wavelength of light for it?
One of the massive advantages that visible or IR light comms have over WiFi or Bluetooth- or even NFC- is security. You can have broadcast wireless data comms all over a building- and keep the contents secret by closing the blinds. Want to make an IR pay-wave system secure? You get coatings that would scatter any 'leaking' IR and stop it from being intercepted.
Plus it's almost certainly lower-power than Bluetooth for 'normal' speeds. And at Gigabit speeds is almost uncontested in the wireless space.
And using an IR one would mean you can control your TV/SkyBox/etc without needing the daft WiFi/ Bluetooth combination my Samsung supposedly-smart-TV requires.
tl;dr: IRDA FTW, LiFi Sux, Rant over for now.
There seems to be some misconception about 'the lamp needs to be shining bright' for this to work. This is not, in fact, the case - it's well possible to dim the light down very low indeed and still get data across. In fact, data transmission should be easier in a dark room - less interference. But even in full sunlight, a dim lamp will be able to transmit data without it being visibly 'on'.
The question isn't the data rate you can cram into the visible spectrum - it's hundreds of THz wide - but avoiding interference from all the other bulbs, and also feeding data to the sockets.
Re: So...
Quite a good rant: I'm not sure what your point is.
Data via light is no more inherently secure than any other electromagnetic transmission. What you suggest is the normal "security by obfuscation" approach which is known to be crap. Want security then add security.
The efficiency of electromagnetic transmissions is also largely independent of the frequency. Power is directly related to data rates and distance. Want efficiency then make it directional. Given the known heat losses still inherent to LED I doubt very much that it is more efficient than Bluetooth.
And so the wheel turns.
Been here before a few times haven't we?
I seem to remember Apricot/Sirius used to offer optical networking back in the 80s, then IRDA came along late 90s/early 00s and promised to take off.
Can't wait, this time we've got the electro-sensitive bunch who will discover a brand new bandwagon of lumino-sensitivity to jump on and sue from.
To answer your question, WTF is... Li-Fi?
Is it a high quality music reproduction system used in China?
