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800Mbps Wireless Network Made With LED Light Bulbs
Mark.JUK writes "German scientists working at Berlin's Fraunhofer Institute for Telecommunications have set a new world record for Visible Light Communication technology after they succeeded in using regular red, blue, green and white LED light bulbs as the basis for building a new 800Mbps capable ultrafast Wireless Local Area Network. Dr. Anagnostis Paraskevopoulos explained: 'With the aid of a special component, the modulator, we turn the LEDs off and on in very rapid succession and transfer the information as ones and zeros. The modulation of the light is imperceptible to the human eye. A simple photo diode on the laptop acts as a receiver. The diode catches the light, electronics decode the information and translate it into electrical impulses, meaning the language of the computer.'
The solution, which could be installed on ceilings and would cover approximately 10 square meters, would be ideal for HD video streaming and inside Hospitals or Aircraft where traditional Wi-Fi is often banned. However visible light signals can easily be blocked, such as when a hand is passed in front of the transmitter."
Seriously, does anyone here on Slashdot need their summary dumbed down that far?
WARNING! This girl exceeds the MAXIMUM SAFE standards established by the FDA for BRATTINESS
It could just as easily be seen as a security feature. Drawing the shades is easier than encasing your room in Faraday cage. And while I'm at it, since when do hospitals ban Wi-Fi? The ones I've been around (Tufts Medical Center, Children's Hospital Boston & St. Elizabeth's) have all offered it for patient and visitor use.
The storm has LED some to believe that it is one bit of a self-propelled message that is transferred over thousands of miles. While working on solar energy, transfer of this information goes on during the night, preventing the thread to be derailed by Slashdot's nuclear proponents.
There is currently discussion whether the storm is a one (as seen from the side) or a zero (seen from top).
Hey, I tried to keep bring it back on topic.
Bert
I saw this on slashdot sometime last year... it's nice to see that the technology is catching on I guess, but it's still old news.
"However visible light signals can easily be blocked, such as when a hand is passed in front of the transmitter."
Some people would point out that this is not a flaw, it is a privacy feature. Try getting on the network with a wi-fi sniffer outside a room with the door closed and the curtains drawn. With this system, the privacy of your network is indeed much more private. -www.awkwardengineer.com
So... how does upstream work? Does every single one of the smart lights double as a receiver too?
What about us geeks that like the lights off?
Imagine my TV and my computer screen talk to each other at 800Mbps...
There is a spark in every single flame bait point.
Most of us feel pretty strongly that WiFi on planes is not dangerous and that it should be allowed as-is. But since there are some extremely stubborn and inflexible people involved in policy making. (I don't say decision making because I don't think they are capable of making any.) But what if this "LiFi" (Did I just coin a new term? I doubt it...) were deployed on airplanes and USB transceivers were sold/lend to passengers, I think that would pretty much end the controversy and debate over in-flight WiFi.
Old modems with external LEDs (as well as other network equipment with TX/RX LEDs) were susceptible to data leakage just by reading the LED modulations. This is just faster. http://www.alge.no/ebooks/Optical_tempest.pdf
Geek used to be a four letter word. Now it's a six-figure one.
'With the aid of a special component, the modulator, we turn the LEDs off and on in very rapid succession and transfer the information as ones and zeros.
I bet they had something to read the modulator signals on the other side.. an Anti-Modulator perhaps?
They could come up with some cool acronym for this system.. MOAMO ? noo.. i'm sure there's something better..
----- The internet has given everyone the ability to have their voice heard equally as loud.. even if they shouldn't be
Sure, this new technology is kinda cool, but it will require putting some equipment in the ceiling, and getting some network cable up there. Wouldn't it be simpler, cheaper, and more efficient to just put Ethernet plugs in the room?
Pics or it didn't happen.
It's great that they have achieved this speed with such simple technology. However, I wonder how useful this technology will really be. If you set your laptop down next to the TV, I wonder what kind of interference you'll get from the rapid fluctuations in light. I know the average techy type here is a troll living in the basement but what about the unwashed masses trying to use this in rooms above ground with the shades open? I wonder how much interference will all that light introduce, especially if you have lots of shiny bits in the window. I suppose they could really crank up the "LED (Light-Emitting Diode) light bulbs" to improve signal to noise ratio. But is that a practical solution? How about the really non-techy types wanting to use their wireless devices outside? How does it work when exposed to direct sunlight? If it doesn't, then what's the alternative? Traditional radio based wireless? We already have that.
I'm sure this is a great achievement but I'm just not sure if it's going to be practical for daily use for the average person. Though it may contribute to something that's useful. Perhaps as a semi-secure wireless network for higher security areas that are already closed off to the outside world. Maybe it would be good for dedicated areas that don't have the general purpose demands of the average consumer device. Maybe this will be integrated into some greater new technology further down the road. I know. We could use dedicated digital light transmissions to control the consumer devices in our homes. Oh. Wait...
Did you read it here?
If so, apparently, we are the only two.
And still, a year later, no significant discussion of the uplink. Not much if a WiFi replacement if it's one-way, is it?
Honestly, /. is drifting into the mediocraty. One more upgrade, and slashcode/CSS/javascript will make it entirely useless for all but the browser snobs.
deleting the extra space after periods so i can stay relevant, yeah.
I love LiFi. Great name. Sadly, it's in use, though not as a networking term. Sadly, the equipment generates light, so it still overlaps some of the lighting equipment using the name. It also could be used to stream movies, and if sold in such a narrow role, could overlap the televisions using the name.
IANAL, so it could just be dead in the water regardless. How does that work? If you're using an original name for a line of meat thermometers, can I use the same name for my gold-colored lunar lander foil? I recall that Goodyear sued Fuji over blimps, and The Beetles sued Steve Jobs' company over Apples, but each pair came to agreements as they were not in the same business, at least at the time.
This would be perfect to deploy in the National Radio Quiet Zone. As it is right now no one can have wireless in their home within thirty miles of the GBT.
LED's are frequently used as photo-detectors. They aren't wildly efficient, but they do work.
www.parallax.com/Portals/0/.../LEDLightEmitterandDetector7-31-07.pdf
It makes the optics so much simpler if you can use just one device for TX and RX.
we'll see this technology available to us in 7 years split into 20 tiers by our ISP's which will only offer that speed with a router that only kicks 5MB down and 750kbps up so its not really going to matter. Enjoy!
How do I watch a movie in the dark then?
...using a "real" light bulb in 80's. Breadboarded my own special "modulator" device in fact. Of course, since I didn't have a fancy laptop then, I had to wire up a demodulator as well. Stuffed everything into two cigar boxes. You could even hear the filament "ring" when you tapped the box. Very cool!
Damn, I should have filed a patent on it...
so, when i start blocking access to the internet, via my hand, will get charged as a terrorist?
A cool use of this might be broadcast. Everyone at a concert could receive a HD stream showing an alternate view.
(I see there is currently a 10 m limit)
Do the Blinkenlights act like Blinkenlights?
"However visible light signals can easily be blocked, such as when a hand is passed in front of the transmitter."*
*depending on the power of the light, and the translucence of the object. Visible light signals cannot be easily blocked, for example, if they are emitted by say an 80-million candlepower searchlight. For example, this would not be stopped by a hand, nor eyelids. Such might prove to complicate use on-board an airplane in other ways, however.
-Styopa
Shut. The. Fuck. Up.
I don't even care anymore if you're just that stupid or just trolling. STFU and GTFO.
Seems to me that this is a one-way digital broadcast. There's no mention about how the receiver talks back to the ... ceiling. As such, it's not really a network, is it?
If you set your laptop down next to the TV, I wonder what kind of interference you'll get from the rapid fluctuations in light.
Not that rapid.
A PAL signal has a bandwidth of about 8MHz (Including sound.) The TV is unlikely to output a signal with a higher frequency than that.
Yes, a modern TV is probably a HDTV with a 100Hz refresh rate that uses much higher pixel clock but it will probably still be way below 80MHz.
TA mentions a bitrate of 800Mbps. This will require a much higher frequency than the "rapid" fluctuations from any TV-set you can find.
Actually, my first thought was... (and this is a real stretch of imagination): What if alien life came to visit us and they could see the light that we could not. They'd walk into the room and be inundated with bright flashes of light and noise that we would not see. Could you imagine your reaction to that?
Every time I start to have faith in humanity, I ruin it by driving to work between 7 and 8 am.
My reaction would be to send a probe that doesn't react to that. But maybe that extremely advanced alien species ins't all that smart.
Rethinking email
For unknown reasons, cases of seizures have sky rocketed.
Who cares if it is a broadcast only system; think of the possibilities of this being applied in areas outside of sending video in an airplane (what a waste- just run the wires.) Its not new but it is faster than before.
IR light wouldn't be seen. add another LED and receiver and increase bandwidth (or lower it and just use IR.. in which case this isn't that new.)
Think how cheap it would be to embed additional information into displays! the closed captioning could be embedded along with other information; like URLs or products etc. an LED based display would be able to send such information and it would not impact image quality (although the data rate would be down since you'd not be able to control the colors without giving it away) Aim your smart phone or other device at a display and get additional information transmitted! without networking crap! Similar to the 2D barcodes but with more information and possibly hidden. an IR transmitter on a TV could do something similar cheaply on existing TVs which lack the LEDs in their displays.
Street lamps could contain location information... well just an idea; maybe it gives somebody else another better idea.
It could provide a cheap way to communicate to devices within a house; I've been hoping IR would do this for a long time... and we'd have some standards in place (like for TV remotes) but industry has continued to ignore IR technology except for laptops which have toyed with an alternative use.
Store lights and displays could send signals to devices; disneyland will probably figure out something for this...
Mostly its a cost and power issue; then it might find some niches-- wifi is embedded into so much stuff now...
Democracy Now! - uncensored, anti-establishment news
What we REALLY need are light bulbs that understand the binary language of moisture vaporators.
This is an old technology (although easily destroyed by clouds, smoke, hands in the air, and any other intercepting body), but for sos purposes, there have been talks about using this as a default means of comm for boats out at sea in distress , so as not to use too much energy trying to send out an sos, but at the same time, keep it going long enough someone could pick it up passing by....
I seem to recall yet2.com was trying to commercialize a similar technology based on IR, not visible light. Is this really all that novel?
Seriously, does anyone here on Slashdot need their summary dumbed down that far?
That would explain the right-leaning bias in the comment moderating of late.
1. Covers 10 square meters which is effectively a circle of radius of 1.6 meters. That is not very far at all.
2. One way communication. There would have to be a transmitter and receiver at both ends pointed at each other.
3. Line of sight only. What happens when someone stands between the receiver and transmitter? No signal.
4. Crosstalk; How well does this system work when there are several transmitters in the room? What about incandescent lights or florescent lights? If one wanted to have full coverage for a room a transmitter would be needed every 2.25 meters. That is a lot of transmitters.
5. Range; There is no mention of range. Considering that light power drops off at a rate relative to the square of the distance that might not be very far.
From the description it is a short range, easily interrupted broadcast device. There is a much simpler, more reliable, less expensive two way solution already in existence; CAT 5 cable.
This would be very handy if you were some kind of flying object, perhaps unidentified to ground-dwellers, and you wanted to communicate some kind of message. Just sayin'.
"In the absence of the ability to establish the attribute of truth they tried to establish the noble attributes."
And to avoid inconveniencing the passenger, we could even use some non-visible spectrum... Hum... what could we use ?
Ultra-violet light ? No... too problematic (reacts with object and produce visible light, etc.)
Maybe some lower frequency / longer wavelength ?
Once we solve this part, I'm sute we could use the technologies on PDAs, Phones... even to control home electronic devices from a distance.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]