800Mbps Wireless Network Made With LED Light Bulbs 175
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."
Summary designed for idiots... (Score:4, Informative)
Seriously, does anyone here on Slashdot need their summary dumbed down that far?
Re:Summary designed for idiots... (Score:5, Funny)
Re:Summary designed for idiots... (Score:5, Funny)
What do you mean?
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????
Re:Summary designed for idiots... (Score:5, Funny)
You're reading it with IE6. Opera users get full schematics in the original German.
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Re:Summary designed for idiots... (Score:5, Insightful)
At least it's technically accurate and well-written in addition to being dumbed down. I'll take that over your average mystery summary, which is misleading (either in the name of sensationalism or promotion), contains several typos, and at least one meaningless buzzword.
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800Mbps, how many libraries of congress per second is that?
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800Mbps, how many libraries of congress per second is that?
1.6 × 10^-5
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To be fair, not everyone here is an electrical engineer, and some may need a refresher of what a modulator is. The "language of the computer" part is stupid, but it is a direct quote, so I think we can excuse it.
Who cares if it's a direct quote, it's retarded to put it on slashdot. Would you post a summary that has a quote: "and Linux is a unix-type operating system, while Windows isn't". Direct quote or not, it's stupid to include.
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I read TFA. It is terrible. It includes gems such as:
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I especially love the "LED light bulbs" part...
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It's less a redundancy and more just entirely inappropriate.. LEDs are simply not light bulbs. That would be akin to me calling a candle a light bulb as well, because it's a device used to provide illumination.
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No contradiction. The first sentence emphasize the fact they are using readily available LEDs without any modification to them. Making sure the reader doesn't think they are using a new type of LEDs. The second sentence state beside the LEDs themselves, you need something to modulate the signal and link to the wired network and/or computer. The second sentence would have been sufficient to explain that entirely, but I guess they were so often asked it they were using new, special, specific purpose LEDs they
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TFA is not to blame here. The official press release [fraunhofer.de] (German) is similar stupid.
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I don't know what is worse, calling LEDs 'LED diodes' or 'LED light bulbs'
Yah, it's like saying, "I gotta go get some money from the ATM machine". Except probably more people say this than the summary's example. It reads like it was written for the average Walmart consumer.
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The idea is that the same 'bulbs' you use for lighting a room are also used for networking, downside of course is that you have to leave the room lights on all day but I guess it's intended for situations where the lights are left on all the time any
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Luckily, in LED lights the deadly mercury is replaced by harmless arsenic.
Signal-blocking (Score:2)
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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.
It probably depends on the part of the hospital you're in. In the ER areas of my local hospital there are signs forbidding the use of cell phones and other wireless devices. There aren't any such signs in the waiting room.
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Which is to say not at all?
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Which is to say "possibly, and with disastrous results should it occur"
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Which is to say, every day thousands of planes land just fine with wi-fi and cellular signals beaming out from dozens of electronic devices.
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I'm not trying to excuse it. I'm just stating that there is some reason buried down there, however shaky it may be (eg it's not just "because we said so!")
Upstream? (Score:1)
So... how does upstream work? Does every single one of the smart lights double as a receiver too?
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I was wondering this as well as the summary doesn't mention a transmitter in the laptop, only a receiver
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Usually at a much lower speed using IR.
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You mean except the method shown in this instructable, http://www.instructables.com/id/LEDs-as-light-sensors/ [instructables.com] ?
Just because it isn't very good at it doesn't mean it can't be forced to do the job.
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If you're thinking of using a separate bunch of LEDs as light sensors why wouldn't you use something better than LEDs for the task?
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Because that's all you might have in the drawer at the time.
Also, who needs a photodiode when you've got glass germanium diodes that you can shine light on?
These fancy kids and their specialized devices...
--
BMO
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Nice note, but it answers nothing. Less than nothing, you just trolled back and added nothing to the question or answer.
Even the comment about streaming video misses the reality that to receive streaming video, you must ASK for it. As in, uplink a request. Unless we also develop prescient mindreading networks. In which case, I didn't even need to type this...
Broadly speaking, this idea is half a network. I'm hoping they can do the other half.
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I'd think the best bet for the return channel (assuming you didn't want to use RF) would be to use IR. By using narrow band optical filtering it should be possible to avoid too much interference from other sources and for many applications the return channel can use a relatively low data rate.
LED's as photo-detectors (Score:2)
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.
I guess LED screens can do the same (Score:2)
A good technology for air planes (Score:2)
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 Wi
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Its not a matter of feeling or not. Wi-fi has been proven to interfere with emergancy landing equipment. Don't believe me? Read for yourself. http://www.zdnet.com.au/wi-fi-proven-to-interfere-with-aircraft-339311113.htm [zdnet.com.au]
http://www.flightglobal.com/articles/2011/03/10/354179/wi-fi-interference-with-honeywell-avionics-prompts-boeing.html [flightglobal.com]
From your article:
A senior Boeing engineer stressed to ZDNet Australia that the levels of EMI required to affect a pilot's screen exceeds the levels produced by the normal operation of normal levels of Wi-Fi use.
"Boeing and Honeywell have concluded that actual EMI levels experienced during a flight where there is normal operation of a Wi-Fi system will not cause any blanking of a Phase 3 display. This is not a safety issue with currently operating 737s and 777s," a Boeing engineer said.
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I know... I saw those too -- they were posted to slashdot here before. Practially speaking, though, WiFi seems to work quite nicely on the Air-Tran flights I took over the holidays and I didn't notice anything when landing either.
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No it hasn't. They used a massively strongly signal, physical adjacent, than would ever be observed in the wild - unless the sole purpose was to create interference. Which oddly enough, was the entire purpose of the test.
Simple fact is, there exists no credible proof WIFI has EVER interfered with an aircraft.
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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.
It would also cost money in new equipment, so that's a bonus as well. Anything to get the consumer to pay more, or to make him need something to spend money on.
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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.
How many of you have done actual impact studies and considered things like out-of-spec transmitters, poorly repaired or perhaps modified wifi cards, etc?
Anecdotes are not data, but I had one particular laptop that, when the wifi was (inadvertently) turned on, prevented any PA announcements on one particular flight. And it was a bone-stock laptop with a bone-stock wifi card. After that discovery, the laptop was quickly retired, taken apart for the limited salvage value, and replaced with a new one.
It may w
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I tend to think that when you bring people with their personal crap (i.e. civilian passengers) onto a plane that does have anything that might be adversely affected by stray and random signals shielded, then someone needs to look at the company that designs and builds these flying deathtraps.
[Car analogy] To put it another way, if talking on cell phones caused a car's systems to fail or become unreliable, I think the first thing people would claim is that it's not a problem with the phone, but a problem wit
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My BMW came with a sticker in the upper-left corner of the windshield. Its text is verbatim:
"Important: Installation and operation of non-BMW approved accessories such as alarms, radios, amplifiers, radar detectors, wheels, suspension components, brake dust shields, telephones (including operation of any portable cellular phone from within the vehicle without using an externally mounted antenna) or transceiver equipment (eg. C.B., walkie-talkie, ham radio or similar) may cause extensive damage to the vehi
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Wires are a trip hazard. And while I generally agree plain old ethernet would be best for many things, it's just not gonna happen. Li-Fi would not be easy to install on planes. They would have to do all kinds of things to run the light transceivers above the seats... probably replacing the useless flight attendant calling button or the "no smoking" light.
As for working with mobile devices other than laptops? Well... I wonder if bluetooth could be used? A bluetooth dongle powered by battery might do the
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Obviously retrofitting old planes is not particularly preferred. But new planes are built all the time.
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Wires are a trip hazard.
Only if stupidly installed.
Don't many airlines already have power and headphone sockets for passengers? I don't see why ethernet ports would be any more of a problem.
Nothing new or groundbreaking here (Score:2)
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If only we had this Modulation tech 50+yrs ago! (Score:5, Funny)
'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..
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It's a DE-modulator.
Remember, the old MODEM acronym? Modulator/DEModulator?
My old ham radio days still haunt me. I know too much analog shit that still works.
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Wow, you are good at remembering words. By the way, what's that sound when something passes really close by your ear? Swosh? Wiih?
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> I'm looking forward to commercially available transmitters and receivers with at least 100mbps.
Oh, those are old news, in PCI or PCIe form, with fiber
optic connections, as an Ethernet variant.
>Point-to-point links for mesh networking
Not with THIS scheme; the description is clearly :== data source).
of one-way communication (light source
It's also an easily snooped scheme, so wouldn't be practical
in a security-conscious environment.
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"It's also an easily snooped scheme, so wouldn't be practical
in a security-conscious environment."
Well, if that's true, the Internet already isn't secure at the network layer, and..
Nevermind.
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To be fair, RONJA was delivering these 10MBps/1.4km links on Radio Shack grade LEDs at least a decade ago, and has "cheap and readily available bog-standard parts" as one of its design goals (last I looked, admittedly a while ago, they were using parts like the LM339 comparator literally scavenged from old floppy disk drives), not the latest and greatest single-source NDA'ed part.
(That said, I'd be very interested in actual technical details about the analog frontend that lets 'em pull off 800MB/s using com
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I wasn't trying to be clever, I was trying to be informative. I've met too many people who have no idea what modem' means.
More remarkable than that, however, is the long line of ACs creaming at the opportunity to call me out as dense.
Is it really that important? Really? Wow.
Non visible.... (Score:2)
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.
Why not just use ethernet? (Score:2)
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That damned plaster-and-lathe construction. Would that be wood lathes embedded in the plaster, or is it metal lathes?
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Here are some uses I can think of.
It may not be cheaper. Think of anyplace that you already use wifi.
How about in a home. Maybe as a replacement for DVI? Just put your laptop near your external monitor or TV and send video to it.
As a solution for wifi saturation. There are locations where you have a lot of wifi points and they can interfere with each other. This should be blocked by walls so it will provide a local wireless internet. Think of an office complex where each room could have it's own optical wif
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sure, but a lot of people just aren't tall enough to plug their laptops in with your solution. :-)
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A ceiling mount probably isn't needed. You could probably substitute a mirror, with the transmitter somewhere else in the room. Given the summary, I don't think this is point-to-point, but rather broadcast within a small volume. And the signaling system probably *would* be Ethernet, just not over cable.
Visible light spectrum maybe not the best choice? (Score:2)
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 y
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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?
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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.
Great for radio astronomy (Score:2)
This would be perfect to deploy in the National Radio Quiet Zone [nrao.edu]. As it is right now no one can have wireless in their home within thirty miles of the GBT [nrao.edu].
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I don't believe this stills holds true, or if so, it is not enforced. I know for a fact there are many wifi networks within 30 miles of Green Bank and quite a few (if not the vast majority) did not get clearance to have them.
Movies (Score:3)
How do I watch a movie in the dark then?
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I built something like this... (Score:2)
...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...
Broadcast (Score:2)
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)
So... (Score:2)
Correction (Score:3)
"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.
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Radio signals can also be blocked by a hand. Just ask any iPhone4 user.
I was going to say that in the case of the iPhone the radio signals are being blocked by a prick, but in interest of my karma I won't.
Oops.
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With multiple directional receivers you could also do multipath decoding of indirect reflections.
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A perfect cross thread argument against internet anonymity.
Someone posts a comment CLEARLY not intended to be serious.
And someone else responds (hiding behind AC), being a douchebag.
Thanks!
One Way? (Score:2)
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?
Think of the possibilities! (Score:2)
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; li
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Who cares if it is a broadcast only system;
I care. "Broadcast" is a very different with very different meanings "Network." Yes, an 800mbps light-based digital broadcast system is incredibly useful, but it's not being represented properly.
If we don't use the right terms and describe new technology properly, who will?
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Not reporters. Not marketing people. Not politicians. Not bloggers...
They are always messing the language up to the masses; while the experts end up with their own jargon even if they are attempting to not create a dialect of their own.
Point is understood; but this is a "discovery" (ok more like enhancement) of a data link layer technology and that level of tech is usually just 1 direction. It can be used within a network; duplicate it for going the other direction and then either figure out how to do full
already done (Score:2)
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....
Issues (Score:2)
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
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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
Re:It's not a bug, it's a feature! (Score:4, Funny)
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Eventually, someone will figure out an even more private method, like some kind of wire.
Surely you're not talking about fibre optics [techrepublic.com], since we already know those can be tapped. There is always at least one weak point in any data transmission medium. Anyone persistent enough will get whatever information they want from anyone they want.
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This is so 2010... (Score:2)
Did you read it here [inhabitat.com]?
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.
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Browser Snobs take specific pleasure in using Opera, Firefox, Safari, or Chrome. Sometimes more than one.
They consider us Luddites who continue using Internet Explorer to be less intelligent, slow, or jsut plain oblivious to the problems of IE, and the great opportunities of using another, more enlightened, browser.
This leaves me in a quandry. I have to use IE at work, both because it is specified as our only browser, and because some of my internal sites (and quite a few external ones) are most compatibl
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I remember a long time a ago. About a hack where someone was able to sniff a network with a security camera pointing on some 10Mbs hubs. Because the LED lights were blinking with the binary data on the traffic.
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If we did that, we wouldn't need this fancy super-fast LED network. Our bandwidth usage would drop 95%.