Researchers Beam 230Mb/sec Wireless Internet WIth LEDs

MikeChino writes "A group of scientists from Germany's Fraunhofer Institute have devised a way to encode a visible-frequency wireless signal in light emitted by plain old desklamps and other light fixtures. The team was able to achieve a record-setting data download rate of 230 megabits per second, and they expect to be able to double that speed in the near future. While the regular radio-frequency Wi-Fi most of us use currently is perfectly fine, it does have its flaws — it has a limited bandwidth that confines it to a certain spectrum and if you've ever had someone leech off of your connection, you know that it also leaks through walls. LED wireless signals would theoretically have none of these downsides."

Comments

No upsides either

[IICV]

"Leaking through walls" isn't a bug, it's a feature; I don't want to wire my whole house for Ethernet just to have wireless in every room, as that defeats the purpose.

Re:No upsides either

[Anonymous Coward]

It doesn't have upsides for your home, yes. It's hard to say why the summary tries to play that up as an advantage for home users. There are, however, plenty of situations where wireless may be desirable within a confined area, LOS exists to all end points and you want to make sure that no one outside of that area can attach to the network.

Re:No upsides either

[maxume]

That's a huge upside for linking up video devices though. No interference from the neighbors, no interference from the other room.

Re:No upsides either

[Anonymous Coward]

If you're all in the same room, this is just a very expensive plug. If you're not, it won't work. I'm not sure how else it could work.

Re:No upsides either

[Mr0bvious]

Huh? lack of wiring is not the only benefit of wireless.. How about being untethered to your network? That sounds like a pretty large benefit to me..

Re:No upsides either

[martas]

what if you could use the lighting that already exists in your house to do this? kinda like internet over power lines?

Re:No upsides either

[Anonymous Coward]

I tried that in my epilepsy classroom and everyone had a fit.

Re:No upsides either

[icebike]

what if you could use the lighting that already exists in your house to do this? kinda like internet over power lines?

Probably not. The summary mentions "plain old desk lamps", but TFA is specific in stating the lamps must be LED, which is still not common.

Incandescent can't be modulated at the frequencies necessary for anything much beyond S O S signals.

Of course once all your house lighting is converted to LED, your network might work provided you modulated at least one lamp in every room. This of course would leak out windows, which the Summary writer would be perfectly fine with, even tho he disparages leaking radio waves.

Re:No upsides either

[DigitAl56K]

Leaking through walls is not always a feature. I can't get the maximum benefit of my Wifi setup because I live in an apartment building and all my neighbors have devices chattering on every channel. All their routers are probably defaulted to high power, and there's nothing I can realistically do to improve my situation except switch to 802.11n/5G, which I did, and now I'm seeing more routers on that frequency range too.

I don't want to lose my through-walls access, but if it could be heavily supplemented by light within my own home then I have an extra channel that my neighbors systems won't degrade. Even better if the lights can work as repeaters so if I leave some doors open I can get good signal around many corners, and better still if they also support several invisible frequencies so that my signal strength doesn't depend on bright lighting (or any lighting!) and devices like IR remotes don't interfere when you use them. I've also heard others complain their microwave kills their wifi, and I don't know if that's true or not, but if it is then there is another practical problem solved by this technology.

Tell people about the practical benefits. As far as any security related story, I don't care. I already use WPA2/AES. 99.99% of the population probably doesn't care beyond that, either.

Re:No upsides either

[WrongSizeGlass]

This won't help any outdoor wireless networks so indoors is all they've got.

Re:No upsides either

[Nefarious Wheel]

what if you could use the lighting that already exists in your house to do this? kinda like internet over power lines?

Retailers already use this technology to change the display tags on shelves. After hours, they send a series of codes to modulate the fluorescent lighting in such a way that it sends new data to smart shelf tags. The shelf tags display a product name and a price. Changing the prices on those shelf tags are a major operational cost of grocery retailers.

Fujitsu is one of the firms offering this. Here's Fujitsu's system.

Re:No upsides either

[Anonymous Coward]

Why wire your house, just put mirrors everywhere.

Re:No upsides either

[Nefarious Wheel]

Why wire your house, just put mirrors everywhere.

Sorry, no. I have two daughters. It's hard enough to get them moving as it is.

Re:No upsides either

[sexconker]

Why wire your house, just put mirrors everywhere.

Just make sure to use an even number of mirrors.
Using an odd number of mirrors will flip your bits and should only be used when pairing two computers together.

Eventually most ports will automatically handle both setups, but Dell will inexplicably ship systems that don't for decades to come.

Re:No upsides either

[Anonymous Coward]

Indeed, incandescent lamps were used as a crude RMS integrator in one of the first automatic gain circuits...

Re:No upsides either

[blackC0pter]

While LED based internet is a nice idea, the technology is still immature. You should look at Laser based systems (Free Space Optical). They are deployed and running now. I am just about to sign up for such a service in Los Angeles. They offer up to 100Mb/s at rates about 1/4 to 1/5 the cost of hard fiber. I did a lot of research and the latency is extremely low on these laser based systems (near zero since it works at layer 1) but the downside is the attenuation in space due to rain, snow and fog. Basically, rain and fog increase the bit error rate and decrease the effective distance between two end points. However, the charts showed that this technology was viable at 500+ meters. In Los Angeles, the downtime will be negligible due to the weather. Also, the provider I am looking at doesn't have very large gaps between lasers so the weather will affect the system even less. Also, it's nice having a very fast connection to my datacenter in one wilshire from the office. Note, some of the FSO systems go up to 10Gbps.

Here is the ISP for the FSO system: http://www.aerioconnect.net/

Here is the equipment manufacturer for FSO systems: http://www.lightpointe.com/products/default.cfm

Re:No upsides either

[Midnight Thunder]

That's a huge upside for linking up video devices though. No interference from the neighbors, no interference from the other room.

There is probably another use (ironically based off 'NCIS: LA') which I can think of: temporary connection to a visual display device without needing a physical connection. Imagine the following:

You have a large display screen in the conference room with a line of sight receptor built in. You want to quickly show something to everyone in the room, but don't want to spend time leaning over to physically connect to the device or set up any special network connections (think security issues). Instead you simply point your iPad type device towards the screen and hey presto you are sharing what you see on your device with everyone else in the room. Since it is line of sight you know no one outside the room can tap it.

Beyond that you could do the same with game consoles. You charge up the device, remove it from its charging cradle and simply point it to the TV. No cables and easy way of deciding which device is making use of the TV.

Re:No upsides either

[mysidia]

That's what repeaters/bridges are for. You just need to convert the LED wireless to another technology, or extend the signal using repeaters.

An example of a repeater apparatus would be: you punch a hole in two opposite sides of a wall. Mount and power two appliances on the wall on each side.

When the appliance receives a signal, it repeats it into the wall.

Its neighbor appliance which just needs to receive the LED light repeated into the wall, receives that, and repeats it into the room it is mounted in.

Come to think of it... if you punch a hole in the ceiling instead, and mount the appliance up there, so it projects LED light into the attic, it may be able to receive the LED light projections from all the other 'repeaters' that were mounted to the ceiling.

For instance, by capturing reflections off of common structure in the crawlspace, where all the LEDs throughout the building can project to (without wall separation)

Also, it can look as innocuous as a smoke detector, or simply be built into the light fixture somehow.

Re:No upsides either

[mysidia]

It's harder to install, but no more encryption to worry about. e.g. The need for "secure wireless" will basically go away, and all be about physical install complexity.

This will make it accessible to more people, at a base level, in theory. People won't be able to install themselves as easily though, since to get whole-house wireless, some special arrangements will possibly be needed, beyond skills of average do-it-yourselfer

So it's more expensive... but people might adopt it, since they no longer need confusing WEP or WPA technologies (that keep getting broken/obsoleted), and can simply use plain old open wireless again.

Re:No upsides either

[h4rr4r]

If your room has no windows.

Re:No upsides either

[guyminuslife]

But what about interference from the LEDs on your monitor?

I mean sure, I guess this would be great for the people who can use a Braille interface...

Re:No upsides either

[petermgreen]

More than that even if you use LED lights you have the issue of the power supplies to contend with. I bet most PSUs won't pass through high frequency modulations.

So you are talking about either rewiring your lights with a low voltage distribution system of some sort (possible but the cables get very big) or replacing the LED PSUs with something that can carry a signal across (say homeplug one side LED modulation the other)

There is also the question of what to do for the return link.

All in all nice idea but it needs some work to turn it into a practical product.

Re:No upsides either

[Interoperable]

That's really neat application! The trouble is that incandescent and fluorescent lamps would both be unable to transmit at a high bandwidth because they have a slow response time to a change in the electrical current. LEDs, on the other hand, respond much faster and would be appropriate for high-bandwidth applications.

Re:No upsides either

[Interoperable]

That's a really neat application!

There. Fixed that for myself. Uhg.

Re:No upsides either

[petermgreen]

Laser based systems have the advantage you can get an acceptable SNR over longer range. They have the downside that you have to aim them.

There is also the issue of needing absolute line of sight between the laser and receiver.

Re:No upsides either

[GrpA]

Even if it doesn't have windows open, you can still go through a closed or even shuttered window. Telescopes replace direction antennas and have phenomenal gain and accuracy. Lasers beamed back in can return signals and don't have to be visible ( You can control transmit spectrum a lot easier than receive spectrum ). AlGaAs based photonic detectors can pick up single photons and are sensitive enough to spot light coming through a thin gap in shutters or curtains. ( think more sensitive than military NV devices ).

Now, instead of being worried about people parking in cars just up the street, you need to worry about anything you can see from your house... Thos e hills 10km away? Not far enough. The highrise across the river? Huge risk.

The good news is that tinfoil is sufficient to stop all photons, so a few rolls of tinfoil and tinfoil plated tape will be all you need to secure the wireless visible spectrum devices in your house.

Until someone burns a ten micron hole in your defenses with an infra-red laser....

GrpA

Re:No upsides either

[Mitchell314]

So get rid of your monitor!

Re:No upsides either

[IICV]

Holy shit, apparently I live in the future and I didn't realize it.

Re:No upsides either

[Nefarious Wheel]

I don't see why the response time of a fluorescent lamp has to be slow. You're dealing with a plasma in a partially evacuated tube controlled by an electrical current. You could theoretically run a much higher frequency through the globe than the limited 50-60Hz power cycling. And given the sensitivity of the receptors, light variation wouldn't have to travel the length of the tube - a variation in light at the ends should be enough to do it.

What people haven't mentioned, however, is that this is essentially a one-way transmission.

In theory it could be a bidirectional transmission, but as the great philosopher Yogi Berra once said, "In theory there's no difference between theory and practice. In practice, there is."

Re:No upsides either

[TheLink]

Wonder how well it does against pranksters :).

Re:No upsides either

[Anonymous Coward]

Let's not forget that basements do not have windows. ...

Well, not where I'm from!

Re:No upsides either

[jellomizer]

Oddly enough the concept Is about 8 years old Granted back in them old days 10Mbs was still common, 100Mbs were still expensive to network and Gigabit networks were just starting to be put on some of the high end systems. But the idea has been around and as a possible security risk. I don't see this as a replacement for home networking but for site line of site it may be useful. but I would expect the technology real advantage would be in just hacking from analysising the lights on you 100mbs switch.

Re:No upsides either

[Anonymous Coward]

Funny thing is that 10+ years ago, there was a big bru-haha (sp?) about "Activity" LEDs on certain networking equipment. They blinked with every bit that came down the wire. With the right equipment, someone that has LoS of the LED could reconstruct the data stream fairly easily.

Once a bug, now a feature.

Re:No upsides either

[drkim]

A neon or florescent desk light might also work.
I believe that at one time secret spy messages were transmitted via a neon sign. (Can't remember context.)

Re:No upsides either

[linzeal]

Use a wireless dongle in a 20 oz tin can, not Pringles. Works better than a 500mw G adapter I bought off Ebay.

Re:No upsides either

[Anonymous Coward]

Incandescent can't be modulated *full-swing* at the frequencies necessary for anything much beyond S O S signals. The filament measurably (but not visibly, due to persistence of vision) brightens and dims with 50/60Hz cycles. I don't know what the upper limit of modulation would be before the signal was lost in noise or the filament's inductance became a factor. It's almost certainly not anywhere near high enough for this data rate, but to say that its limited to modulation in single digit Hz is absolutely false.

Re:No upsides either

[Noodlenoggin]

Why wire your house, just put mirrors everywhere.

I tried that already, however my wife made me remove the one from above he bed. Now I get use my interlazorwebs without actually getting up in the morning. :(

Re:No upsides either

[icebike]

Persistance of human vision is not the problem. Rather, the persistance of Incandesence. It takes time for a filiment to cool. This is why all naval signal lights were shuttered, rather than switched. Incandesent bulbs simply could not be switched as fast as a good signal man could send.

Re:No upsides either

[noisyinstrument]

People who live in glass houses shouldn't use plain text passwords.

Re:No upsides either

[SharpFang]

OTOH Incandesent can be modulated really fast by switching just as well. Think transmissive liquid crystal screen, the same kind as used in switching 3D glasses.

Re:No upsides either

[NoMaster]

I don't see why the response time of a fluorescent lamp has to be slow. You're dealing with a plasma in a partially evacuated tube controlled by an electrical current.

You're forgetting that what you see is not the plasma (it emits mainly short-wavelength UV), but the phosphor coating (which is excited by the UV & emits visible light). The phosphor coating is specifically chosen to be (relatively) slow, in order to filter out the 50/60Hz flicker.

In theory, you could use a faster phosphor and modulate the light output - but then you run into an issue with the half-life of the excited electron state. Basically, the electrons take a finite amount of time to drop from their excited state to their non-excited state (in the process releasing their energy as UV). This limits the maximum modulation frequency to somewhere ~5KHz. Again, this could probably be increased somewhat by the choice of plasma donor material, but there is a limit (e.g. I'd expect x-rays would be hard to contain ;-). And, since multi-bit encoding schemes like phase modulation are likely prove be tricky as best (aka 'improbable, if not impossible'), you're basically stuck with a maximum data transmission rate of half the modulation frequency - around 2.5Kbps.

May as well stick to Bluetooth...

Re:No upsides either

[t0p]

And the hazard to passing space traffic.

Re:No upsides either

[Anonymous Coward]

It takes time for a filiment to cool. This is why all naval signal lights were shuttered, rather than switched. Incandesent bulbs simply could not be switched as fast as a good signal man could send.

It depends on the power of the light bulb. Small ones, such as ones used indoors (up to 100W) have no problem with transmitting 100Hz (120Hz for North Americans) modulated light, as anyone who toyed with photocells and audio amplifiers can attest. However, naval signal reflectors are generally much higher power. Being such, their filaments are much thicker and thus have larger thermal capacity. When switched off, their light die out much slower. Besides, sudden current surges would badly affect signal lights' expected operating life time.

Re:No upsides either

[Anonymous Coward]

You just need an intricate system of mirrors.

Re:No upsides either

[Neoprofin]

It's neat, but unless the prices change constantly I can't imagine how rolling out this system and keeping it running is more cost effective than printing out and replacing paper labels that cost less than a penny each and only need to be updated every few weeks.

Re:No upsides either

[Mashdar]

I realize that your post was in jest, but I'd like to point out that laser communication is not as insecure as you make it sound. Presumably the laser will have a tight beam pattern and a near 100% absorbtion rate at the receiver, so there should be relatively little refraction (except that which occurs through the air). Assuming that a band is used which exists in normal sunlight, the reflection of said sunlight off the environment would overwhelm any refracted signal you are try to recover from next door, let alone from a hill 10km away. Even if you could detect it, the number of photos available would only give you an incomplete image of the signal, even from a few meters away, unless you were almost directly in the beam path, which (presumably) will not be pointed at a window.

Re:No upsides either

[CubicleView]

People who live in glass houses just want attention, it's best to ignore them.

Re:No upsides either

[mcgrew]

I think it's damned stingy to not share your wifi, unless it's affecting your own speeds. If it is you can disconnect or throttle a guest user.

There's a signal at my house from a computer named "hack me and I'll find you", which makes it damned hard NOT to.

Re:No upsides either

[valadaar]

Doesn't sound like keeping it running would be that expensive. You feed the new prices into a database, something reads the database and sends out the message. Classic automation.

Re:No upsides either

[b4dc0d3r]

From a retailer's point of view, the object is not a cost-basis rationalization. More likely, this introduces the opportunity to introduce demand-based pricing, in other words more opportunities to update pricing.

Prices can be lowered on rainy days when sales are slower, enticing people to buy things because they are cheaper. Except for weather-related supplies, those automatically increase when the humidistat registers 80% humidity outside.

You can regulate the post-holiday sales signs and keep marked items clearly marked, while optimizing profit by lowering prices when sales fall. No need to red-sticker things with 50%, 75%, 80%, 90% off stickers and finally throw it away because it's covered in sticky.

When the weather man predicts snow and everyone runs out for milk, bread, and toilet paper, the registers can alert the manager of a spike in sales, and decide whether to announce low prices or price gouge.

It's a whole new world of free-market capitalism. Add on some random microphones and voice recognition, coupled with gmail-style keyword based advertising, and you can raise prices on things people mention from their shopping list - until they say "costs to much" or "too high" then it drops back to regular price.

That's the problem with people like you - always applying things to "now" instead of thinking about new ways to gouge your fellow humans for fun and profit.

Re:No upsides either

[david@ecsd.com]

It isn't the cost of the paper labels, it's the cost of the labor to replace the shelf tags. I work in retail and that costs craploads. And it isn't every few weeks sometimes it's weekly--you have sales, you have price changes, etc. And you're not just printing out one or two shelf tags to get that .01 each, you're printing out hundreds to make it cost effective, and then you have to ship them out to the stores--more labor--have someone sort them--even more labor. I can see an automated system paying for itself quickly.

Re:No upsides either

[Neoprofin]

I actually work in retail as well, and if the place you work is doing centralized printing and shipping of labels rather than just printing them off at $.04 a sheet with a Laserjet maybe this could help you. Major retailers, Target, Walmart, print all of their basic signage on site according to planograms or other similar systems, there is no sorting and putting up labels takes a tenth of the time that pulling stock to go with it does. The only thing our stores are shipped is the poster size advertising, which they would still need.

Sales in most places also include putting up signs, bright signs easily noticeable, as well as setting up special displays and moving product around. None of this can be automated and that's the every week work. Go to a grocery store that you're familiar with, ofter do they rearrange things? How often do the prices actually change on the majority of items?

Re:No upsides either

[Neoprofin]

So in order to gouge people $.20 cents on a gallon of milk you're going to roll out thousands of tiny, fragile screens that are larger and less readable than modern paper labels as well as the licensing of the software to watch these trends?

I'm not saying that might not be the case, I'm just saying that I'd like to see someone actually run the cost/benefit analysis before I believe that this is anything beyond a marketable but flawed idea.

Re:No upsides either

[icebike]

Those are not incandescent.

They are examples shuttered light sources.
http://en.wikipedia.org/wiki/Signal_lamp

I'm not aware of any standard desk lamps that include these things.

Re:No upsides either

[networkBoy]

I have 2 wi-fi APs, one encrypted, one open.
the open one has a separate link to the router and is untrusted. You have to accept that I may or may not be running a transparent proxy as MITM and that I may or may not trap your credentials, and that I may or may not server you the internet rendered as a single PNG of the page and an imagemap for URLs instead of html you were expecting and the imagemap and PNG are inverted vertically.
-nB

Re:No upsides either

[b4dc0d3r]

Yes.

You read this post in the thread? And read this link from that post?

This one? http://slashdot.org/comments.pl?sid=1579924&cid=31451930

I worked at Target, and spent some time being the label printer/sticker-onner guy. Even at slightly-above-minimum-wage it would have been a giant cost savings if we only used it for 2 months out of the year - November and December. Automatic pricing updates are one thing, but removing those stickers is a pain, and the cost of putting the sticker under the wrong product results in lost profit (see footnote). Getting the correct prices updated quickly and especially accurately throughout an entire store where daily sales are around $100k (Christmas sales, not all year long) - that would pay for itself right there.

I believe that is sufficient evidence that the cost/benefit analysis favors these things, with customer resistance being ignored. The shoes department at Kohl's already use these, have used it for at least 5 years in my area, I believe.

In addition to that, my point about altering prices stands. You're not gouging twenty cents on a gallon of milk - you're gouging on thousands of gallons of milk. It is the ultimate cost maximization tool. Uncle Bub's corner grocery isn't going to do this stuff - think Wal-Mart instead. The sheer volume of customers makes a single-penny adjustment to a single product for 1 day across all their stores a very lucrative proposition.

Knowing this, I'll fight back by keeping my UPC database synchronized and carrying around a barcode-reading camera-equipped cell phone to tell me what the prices have been on products, alerting me when this is in use so I can skip buying.

Footnote: Not theoretical lost profits like "lost sales due to piracy" lost. Customer sees the receipt or register show a price that didn't match the label, you hold up the line for a price check, some people in a hurry may drop their purchase altogether, you lose the difference between the marked and actual price. And the worst part is when a savvy customer knows the usual price and sees it marked lower, and buys more than they otherwise would have because a physical price tag gives them the right to claim false advertising or bait-and-switch pricing. I've been a backup cashier at the same Target, and as little as I got called to go run a register I saw this happen all the time. I was authorized to take the customer's word for small differences. I talked K-Mart into giving me a $35 item for $25 based on poorly labeled goods, that's a significant discount not including the manager's time.

So yeah, just get a part time job in a high-volume grocery or big box store and it will be pretty obvious very soon.

Re:No upsides either

[GrpA]

What you've said is correct.

The modulation transfer function decreases with angle of incidence so that the signal to noise ratio diminishes rapidly within a degree or two, possibly less. Yes, I know the term usually refers to optical/optoelectronic system losses in 2D space, but it's appropriate to this example too.

But I wasn't referring to "tapping" a laser ( there are ways to do that, even in daylight ) but rather using an IR laser to bounce a bright spot into the room from outside so that you establish a two-way communication with the targeted system.

Visible data systems systems aren't narrow two-way beams- they are usually spread out. ( Eg, Irda )

So even if you can't see the transmitter, you can fix a telescope with a sensitive receiver to something that reflects sufficiently to gain a signal from in the room - even a crack in a door - depending on brightness.

As for return signal? Beam an IR laser back into the room from anywhere and it will reflect light all around the room so that the receiver will pick it up.

It's a theoretical attack, but I've seen examples of the technology that does the receiving in the past and it's pretty sensitive. The same concept can be applied to picking up signals from a CRT reflected off walls and restoring them to an image based on time-domain over a 2D space.

You would be right to assume that distance makes a difference and that the practicalities of such an attack are limited by several factors.

However while most attacks of that nature would be "sniffing" attacks, with light it's possible to establish a connection, just like with WiFi.

Gaining access to an open "optical" network connector then becomes a possible security threat under some circumstances.

But yes, the original post was in jest, though the technology needed to compromise open-space optical communications systems is not that complicated to make...

GrpA

Re:No upsides either

[SharpFang]

Of course none does. But one could build one strictly for signal transmission purposes.

Re:No upsides either

[Nefarious Wheel]

I'm not saying that might not be the case, I'm just saying that I'd like to see someone actually run the cost/benefit analysis before I believe that this is anything beyond a marketable but flawed idea.

Turns out I was working for a major Australian grocery chain as an architect in their store systems division when I ran across the Fujitsu system. It's not just a 'marketable but flawed idea', it's a reliable working system that was already in place at some of our competitors. We were evaluating a number of automated shelf tag systems. They were all cost effective. Several independent grocery chains had already invested in them by then.

There is no organisation I've ever met quite as tight with a buck as retail groceries. They won't spend a dime if there isn't an ROI.

Re:No upsides either

[mcgrew]

That sounds like a good way to do it and is perfectly reasonable.

Just different ones

[MozeeToby]

LED wireless signals would theoretically have none of these downsides.

Nope, instead it'll have a whole range of different ones, such as requiring line of site.

Re:Just different ones

[wealthychef]

I don't think "site" means what you think it means.

Re:Just different ones

[Uranium-238]

You know what he meant really and he's quite right too. People could dick with these connections by putting a piece of paper infront of the transmitter or receiver. This just sounds like a uesless idea.

Re:Just different ones

[twidarkling]

Forget people being a dick, how about people just innocently wandering between transmitter and reciever? Or the user himself accidentally setting something down in the way? Too many ways to screw it up.

I think we had a story about LOS wireless before, and really, same as then, the only use I can see for it is in lab environments, where you usually don't have people wandering around in undefined patterns. Attach unit to roof on a per-row basis, aim all computers in that row at that reciever, and no one can accidentally interrupt the beam. Beyond that, I can't see a common residential use, or much industrial use.

Re:Just different ones

[mrclisdue]

If we continue to make a spelling mistake in each reply, at some point approaching infinity, we may have reconstructed the bible: to discover that you read it first on /..

chers,

Re:Just different ones

[Chris Burke]

Yeah I like how being able to go through walls is listed as a downside. Though I guess if leeches are your biggest concern, it is an improvement. They'd still exist, but you'd be a lot more likely to notice the guy sitting outside your window with a laptop than if he was in his own home.

I remember in college making a radio and a wireless speaker system on the same breadboard, using an LED to transmit the audio from the radio to the amplifier. It was a pretty cool thing to do in a lab, but it didn't occur to me to rush home and duplicate this amazing feat on my home stereo.

Re:Just different ones

[Maxo-Texas]

Nah, he's just playing fast and lose with spelling.

Re:Just different ones

[tlhIngan]

Forget people being a dick, how about people just innocently wandering between transmitter and reciever? Or the user himself accidentally setting something down in the way? Too many ways to screw it up.

I think we had a story about LOS wireless before, and really, same as then, the only use I can see for it is in lab environments, where you usually don't have people wandering around in undefined patterns. Attach unit to roof on a per-row basis, aim all computers in that row at that reciever, and no one can accidentally interrupt the beam. Beyond that, I can't see a common residential use, or much industrial use.

Who says using a light based PHY means it has to be direct line of sight? There's one common technology that uses light, yet for the most part, indirect line of sight works quite well. It's called Consumer IR, and it powers your remote controls. With many modern remotes, you don't have to aim the remote at the device, but you can bounce it off walls and furniture and have it work great.

Don't forget, 802.11b works on two different bands. One is 2.4GHz, another is IR.

Re:Just different ones

[Maxo-Texas]

Slashdot 57:30, If we covet making a spelling mistake for each wife, at some point we forsake other gods and we may do unto others before they can do unto us first on /..

Re:Just different ones

[WrongSizeGlass]

That's why we should just skip LED's and go straight to lasers. Or lightning. Need to download really big file? Try our 'lightning fast wireless service'.

Re:Just different ones

[twidarkling]

With many modern remotes, you don't have to aim the remote at the device, but you can bounce it off walls and furniture and have it work great.

Tell that to my fucking Blu-Ray player. The remote for my parents' 15 year old TV worked better at wider angles.

Besides, the article mentioned Visible Spectrum. Good luck reflecting that and maintaining usefulness.

Re:Just different ones

[Anonymous Coward]

Good luck reflecting that and maintaining usefulness.

I live in a hall of mirrors you insensitive clod.

Re:Just different ones

[Gilmoure]

Cats! That'll do in this stuff.

Re:Just different ones

[camperdave]

In businesses security is a big issue, and being able to stop a wireless signal at the office wall would be a huge plus.

Re:Just different ones

[Anonymous Coward]

Line-of-sight should not be a huge issue.

"The signal would be generated in a room by slightly flickering all the lights in unison."

Looks like something based off ambient lighting. A couple of light sources should be sufficient to get around LOS issues.

Re:Just different ones

[Chris Burke]

And losing your network connection because you were sitting at the wrong end of the conference table in your meeting would be a huge minus.

And having the signal stop at the wall but not at the window sounds like a major ding to the "huge plus", not to mention a recipe for a false sense of security.

In either case you'd have to secure your wireless network in a traditional fashion. So, why not just do that, and get the benefit of non-line-of-sight communication too?

Re:Just different ones

[noidentity]

That's why we should just skip LED's and go straight to lasers.

NOW I know why the sharks have their lasers... it's for communications!

Re:Just different ones

[Surt]

If you allow such people in your house, you really get what you deserve.

Re:Just different ones

[Cassius Corodes]

Yes... that would not be annoying at all.

Re:Just different ones

[The Mighty Buzzard]

Yeah but since this is /. you have to go the extra step and think of some of the creative uses you could put those to. For instance, say your neighbor's kid keeps waking you up by playing outside your window every morning.

"Gah, fucking kid!"
*reorients laser networking device that's been slightly modified*
$sudo ifup zap0
*chuckles maniacally*

Re:Just different ones

[Anonymous Coward]

Not really, unless you can see 10MHz flicker...

Re:Just different ones

[Anonymous Coward]

one word
one way glass.
if they can even find which one is your window, they still can not transmit.

Re:Just different ones

[h4rr4r]

IR is slow as hell and prone to interference from the sun! Sounds like a real winner

Re:Just different ones

[h4rr4r]

Except for the receiver. Unless you plan on making you whole laptop flicker.

Re:Just different ones

[mysidia]

Agree. Nobodie on slashdot knows how to run spell cheek anymore. Every conversation is full of speling erors and lots of Big Mistaks. :-)

Re:Just different ones

[mysidia]

They could pick a light frequency and intensity that is attentuated by the window glass, to make it hard/impossible for someone to use a window for that.

Or in the case of a business, they could use a security film targeted at the wireless frequency range.

Re:Just different ones

[h4rr4r]

One way glass is not one way. The moment it got dark outside the effect stops working.

Re:Just different ones

[mysidia]

Businesses that care have IT departments or consultants hired who know how to secure their own wireless infrastructure.

The primary risk is from rogue access points setup by some employee but not approved or known about by IT.

Or employees leaking/accidentally exposing what amount to their VPN credentials.

In either case, switching to a wireless technology stopped by the walls doesn't necessarily mitigate the later two.

An employee bringing a rogue AP, might use an older or different technology such as 802.11a, instead of the new-fangled LED wireless, then it's back to square one, same security issue.

Re:Just different ones

[HuguesT]

Excellent, thanks. Although things are funnier at 3:00am sometime, so anyway I'm told.

Re:Just different ones

[sootman]

My dad used to tell me not to stand in his light when he was reading or working on something. Someday my kid will be yelling at his kid to stop blocking his Internet.

Re:Just different ones

[Chris Burke]

So send everyone home before it gets dark. Sounds like a win to me. :)

Re:Just different ones

[Anonymous Coward]

May be interesting for you to know that many modern LCD televisions can interfere with infrared remote control...

Try putting the bluray player somewhere were it will not 'see' the light from the TV, and your remote for it may suddenly work a lot better.

Re:Just different ones

[cgenman]

Speaking of line-of-site, other than bandwidth what is the difference between networked LED signaling and a TV remote control?

Re:Just different ones

[t0p]

You know what he meant really

Ah yes, "you know what I mean". I've encountered this before. Captain, these are women

Re:Just different ones

[t0p]

Or brick up all the windows. You won't need 'em with all the flashing LEDs to read by.

Re:Just different ones

[VShael]

such as requiring line of site.

Holy crap. After spending years online, where people regularly talk about their "favourite websights" I thought the s-i-t-e spelling had become obsolete. Apparently, it has merely become interchangeable.

Re:Just different ones

[b4dc0d3r]

You misunderstand. Your site has to be in a straight line.

That way the receptionist in the front can get her e-mail. And no prairie-dogging, every time that happens our uptime drops like an Alaskan winter.

Re:Just different ones

[virg_mattes]

Point one, line of sight. Second, line of sight issues can be addressed by multiple "heads" that can cover a room. Like a cell tower, you'd communicate with the head that can see your LED best, and if you move out of sight your system would locate and lock on to another head. If you position them correctly, you can cover anywhere in a room this way.

Virg

Re:Just different ones

[virg_mattes]

Speaking of line-of-site, other than bandwidth what is the difference between networked LED signaling and a TV remote control?

The big difference is two-way communication. It's very seldom (if at all these days) that a TV ever sends data to the remote, so you only need the remote and TV to maintain line of sight while you're using the remote. Imagine the trouble if your TV only worked when it could see the remote.

Virg

Re:Just different ones

[b4dc0d3r]

The Mr. Wizard's World episode where they connected I think a record player's needle to a flashlight, and directed it at the portion of a home movie projector that reads the audio track and played the record back was pretty cool. That was probably in the earlier range between 1983 and 1990.

It did occur to me to rush home and duplicate this, but I was already home, and I was also maybe 10 years old, so nothing much came of it. Seems we keep rediscovering the same old thing, but being able to stand on others' shoulders makes it progressively easier to see practical application each time. So three cheers for limited patent lifetimes.

Re:Just different ones

[b4dc0d3r]

Are you saying you can't implement key pair encryption over this for some reason? Send scrambled data and it won't matter who's listening. By the time they decrypt it, your business plan has already publically failed and the intel they gathered is too old to be useful. As long as your vendor has a rigorous implementation of course, which is always a consideration.

Re:Just different ones

[mcgrew]

requiring line of site.

That was the worst pun I've seen all day.

Re:Just different ones

[wealthychef]

Yes, I know what he meant and he still misspelled a simple word in a public forum, for which he deserves mild ridicule. When people make errors like that they reduce the perception that they are careful thinkers, and inadvertently cast doubt on the substance of their argument. IMHO. I consider myself to be doing a service by laughing at them. You can thank me privately, I am a humble servant of the public good.
LOS wireless is a dubious concept, I agree!

Re:Just different ones

[Anonymous Coward]

They could pick a light frequency and intensity that is attentuated by the window glass, to make it hard/impossible for someone to use a window for that.

The point however is to use existing lighting.

Re:Just different ones

[Anonymous Coward]

That problem could be solved with high power Laser Emitting Diodes. If you route it properly, it would also solve any problems with unwanted pests. Just make sure that nothing of value (kids, spouse, visitors, etc.) get in the way.

Oh Great

[WrongSizeGlass]

A Desklamp? Other light fixtures? What's next, the overheard fluorescent lights??

Now everything I own, from my Star Wars light saber to my Krusty the Klown glow-in-the-dark alarm clock, could potentially with wireless signal. Oy carumba

Re:Oh Great

[weirdo557]

did you accidentally with your wireless signal

Re:Oh Great

[WrongSizeGlass]

Indeed I did. It appears I had an extra helping of dumbass for lunch, and I should never have that much at one sitting.

Re:Oh Great

[noidentity]

Now everything I own, from my Star Wars light saber to my Krusty the Klown glow-in-the-dark alarm clock, could potentially with wireless signal. Oy carumba

That's actually been a documented problem in some devices with status LEDs, which inadvertently leaked information due to being tied directly to the (serial) data line, rather than a low-pass filtered version of it.

Re:Oh Great

[zippthorne]

Apparently the National Security Agency, the federal agency responsible for military intelligence and the security of the U.S. government's communications, believes the threat to be low-risk.

Said a spokesman on his way into the building carrying a large box labeled "Etalons, 550nm, Tunable."

Re:Oh Great

[jgreco]

I keep having this vision of Cmdr. Data on that episode of TNG where he suddenly appears on the bridge with a rapidly flashing palm light. Maybe this will not only do our networking, maybe it'll be able to fix brainwashing too. (And if it can fix it, betcha someone can hack it to DO the brainwashing too...)

Blast from the past

[jpmorgan]

It's the return of IrDA!

Re:Blast from the past

[salesbot]

It's the return of IrDA!

only this version is Jonny Mnemonic compatible!

Re:Blast from the past

[idontgno]

And junkie dolphins can have forehead communications lasers as well as SQuIDs!

Perfect!

Re:Blast from the past

[mysidia]

Except now it's new and improved UvDA and VLDA . ultra-violet and visible light data association :)

Fraunhofer juggernaut

[Anonymous Coward]

http://en.wikipedia.org/wiki/Fraunhofer_Society

(anon, copied from wiki, I just thought people should be more aware that Fraunhofer is an amazingly huge beast.

It employs over 12,500, mainly scientists and engineers, with an annual research budget of about €1.2 billion

The Fraunhofer Society currently operates 59 institutes. These are Fraunhofer Institutes for:

* Algorithms and Scientific Computing - SCAI
* Applied Information Technology - FIT
* Applied Optics and Precision Engineering - IOF
* Applied Polymer Research - IAP
* Applied Solid State Physics - IAF
* Biomedical Engineering - IBMT
* Building Physics - IBP
* Center for Molecular Biotechnology- CMB
* Ceramic Technologies and Systems - IKTS
* Chemical Technology - ICT
* Communication Systems - ESK
* Computer Architecture and Software Technology - FIRST
* Computer Graphics Research - IGD
* Digital Media Technology - IDMT
* Electron and Plasma Technology - FEP
* e-Government - Fraunhofer eGovernment Center
* Environmental, Safety and Energy Technology - UMSICHT
* Experimental Software Engineering - IESE
* Factory Operation and Automation - IFF
* High-Speed Dynamics, Ernst-Mach-Institut - EMI
* Industrial Engineering - IAO
* Industrial Mathematics - ITWM
* Information and Dataprocessing - IITB
* Information Center for Regional Planning and Building Construction - IRB
* Integrated Circuits - IIS
* Integrated Systems and Device Technology - IISB
* Integrated Publication and Information Systems - IPSI
* Intelligent Analysis and Information Systems - IAIS
* Interfacial Engineering and Biotechnology - IGB
* Laser Technology - ILT
* Machine Tools and Forming Technology - IWU
* Manufacturing Engineering and Applied Materials Research - IFAM
* Manufacturing Engineering and Automation - IPA
* Material and Beam Technology - IWS
* Material Flow and Logistics - IML
* Mechanics of Materials - IWM
* Medical Image Computing - MEVIS
* Microelectronic Circuits and Systems - IMS
* Molecular Biology and Applied Ecology - IME
* Telecommunications, Heinrich-Hertz-Institut - HHI
* Non-Destructive Testing - IZFP
* Open Communication Systems - FOKUS
* Patent Center for German Research - PST
* Photonic Microsystems - IPMS
* Physical Measurement Techniques - IPM
* Process Engineering and Packaging - IVV
* Production Systems and Design Technology - IPK
* Production Technology - IPT
* Reliability and Microintegration - IZM

download is fine but how about uploads?

[Anonymous Coward]

appears quite unidirectional to me

Re:download is fine but how about uploads?

[Tuoqui]

Thats why you set up a send and receiving station on both ends. Just like how you have transmit and receive wires in your Ethernet cables.

Don't look into the light!?!

[tootalltom]

Anyone bother to ask the epileptics how they feel about this?

Re:Don't look into the light!?!

[Jeremi]

According to TFM, the flickering is slight enough to be imperceptible by humans. So unless epileptics have superhuman sensitivity to tiny light variations, I doubt they will notice anything either.

Re:Don't look into the light!?!

[magarity]

Don't worry, the flicker rate is so fast not even Bobby Fischer would complain about it.

Re:Don't look into the light!?!

[santax]

Hehehe, just as long as you made sure he didn't knew before hand it was flickering... *sorry, that man is both my hero (first part of life) as my anti-hero (his later days)*

Re:Don't look into the light!?!

[Anonymous Coward]

Not only that, but flickering a light at a speed that could transmit 230Mb, it's going to be so fast you're not going to be able to see it...even if it were from 0% to 100% intensity... Our eyes can't see flickering much past 75Hz or so...this is going to be in the MHz.

Re:Don't look into the light!?!

[MichaelSmith]

I have a seizure disorder, but according to my EEG I am not photosensitive. Generally you would worry about pulses below 100hz. This system sends data at megabits per second so there is no primary need to pulse at low frequencies. I a imagine that starting and stopping downloads (say) could generate visible pulses but I am sure the system could be designed not to behave that way.

I have read that usable data can be extracted from the TX/RX LEDS on some hubs and switches. I am more concerned about the 9-12Hz pulsing LED lights on bicycles. I don't use them on my bike.

Great!

[TrippTDF]

So now I'll have a strobe light effect every time I check my email!

Re:Great!

[smd75]

Do you have a strobe effect with your lights on normally? Im assuming this will be at a frequency higher than humans can perceive. Which doesnt require much above 60hz because thats what most lights operate at normally

Re:Great!

[Anonymous Coward]

It goes well with the porn! This is red light, right?

Re:No upsides either or side-by-sides

[Anonymous Coward]

No way ... is that too early for April Fools ???

I can Haz Beam-of-Light Interwebs ???

One small problem

[Anonymous Coward]

Any epileptic within a one mile radius is turned into a flesh-eating zombie.

FhG owns MP3

[tepples]

Fraunhofer Society (FhG) is the organization that owns the MP3 patents and licenses them through RCA.

Transparent walls

[lcampagn]

LEDs don't transmit through walls unless they happen to be transparent, like, say, a WINDOW. And while your GHz-based wireless signal drops off just down the block, the signals leaking through your window can be picked up from miles away with a telescope. Didn't we learn this from the modem-blinkenlights exploit like 10 years ago? I suppose most of us have also learned how to use encryption in the interim..

Re:Transparent walls

[zippthorne]

No, you can pick up any signal that leaks with an appropriate sized telescope. It's just that due to the wavelength, the telescope required to resolve an LED from four miles away will fit in a van, while the telescope required to resolve your wireless emissions would be pretty conspicuous.

No kitty, that's my pot pie!

[Anonymous Coward]

No, you can not haz beam of light interwebs. You are obviously a lolcat, and the only thing lolcats should do with beams of light is chase them. Who is a cute kitty? Who is? You! Yes you are!

Re:No kitty, that's my pot pie!

[Philip_the_physicist]

Lazercat is a lolcat, and he demands moar lazer.

Re:No kitty, that's my pot pie!

[wgoodman]

i'm currently finding the urge to stir my brain with a fork via my eye. thank you ever so much.

You won't notice it

[tepples]

So now I'll have a strobe light effect every time I check my email!

As long as the modulation they use on the LEDs is DC-free, your eyes won't pick up this strobing. A traditional light bulb flickers at 100 or 120 Hz, and you probably don't notice it. So you definitely won't notice flicker that's a million times faster.

Re:You won't notice it

[harrkev]

Since they got 230MB per second, you can safely assume that the modulation will be in the gigahertz. Good luck seeing that. If they use something like 8B/10B encoding, then they will get a guaranteed 50% duty cycle, so there will never be any brightness variation visible to the human eye.

Re:You won't notice it

[Anonymous Coward]

But I bet my cat will.

Re:You won't notice it

[Anonymous Coward]

You will need to upgrade that to be compatible with speeds over 100Mb/s, I would recommend cat 6 :)

Re:You won't notice it

[mysidia]

Ok... you won't notice it.. but what will your video Camera do? :)

They commonly detect refresh flicker from computer monitors.

Re:You won't notice it

[tepples]

My Aiptek handheld SD camcorder has both 50 Hz and 60 Hz anti-flicker modes. And if you have a camera pointed at a monitor, isn't that the analog hole that the media complain about?

Re:You won't notice it

[mysidia]

So they'll add 100/120Hz modes? Or maybe the 100hz frequency is high enough for the camera to not pick up the flicker

An idea that's been around

[dtmos]

US patent 6,542,270 ("Interference-robust coded-modulation scheme for optical communications and method for modulating illumination for optical communications"), issued April 1, 2003, assigns direct sequence spread spectrum-type codes to each overhead fluorescent light, so that communication and location-determination can be performed. The chip frequency of the coding scheme is fast enough that there is no human-audible or -visual effect, and supportable by electronic ballasts.

Utterly Stupid....

[loose electron]

If you really want to use optical communocation you might as well go infrared so you don't need to see it, similar to your TV remote.

Then you have all the problems (visible light or infrared) of orientation, line of sight and similar.

Hopefully the creator of this gadget has not quit their day job.

utterly stupid.

Re:Utterly Stupid....

[femto]

Not as dumb as you think. By using visible light, the system gets to use infrastructure that will be in place anyway. (Think this will be combined with data over powerlines? You betcha.) That saves energy and costs. In addition, the transmitter power is much higher than would be used for IR, so one gets greater SNR and higher speed data. The lighting system of a building also lights up every nook and cranny, overcoming most line of sight issues. Finally, the visible spectrum is pretty well unregulated, so bandwidth is free.

I think it's a killer application, and that it will soon be providing lots of people with day jobs.

Re:Utterly Stupid....

[dominious]

just because you don't see any potential applications it doesn't mean it's "utterly stupid". Line of sight is not so difficult if all I want is to stream from my laptop to the tv to watch a HD movie with some friends.

Ok this is /. No friends, forgot.

Re:Utterly Stupid....

[Anonymous Coward]

I can imagine a very useful situation for this: Spying
If you can turn something as innocuous as a light into your comms you have a secret network connection that no normal person would ever suspect existed. Extreme Big Brother environments have lights everywhere. Do you think even the most hardcore of spooks would think to check the frequency of the lights?

Re:Utterly Stupid....

[project-nova]

Visible-frequency wireless works by flickering all the lights in a room ever so slightly -- so slightly, in fact, that the human eye could never detect it.

The idea is to re-use your existing LED room lights to also transmit a data signal, *not* some completely new tech!

Re:Utterly Stupid....

[Anonymous Coward]

When you are pumping 10 Watts into a device, there is the 'green' argument for using that energy for more than just data transmission.

Re:Utterly Stupid....

[Nefarious Wheel]

I can imagine a very useful situation for this: Spying

Meh. Easier than that. Bounce a laser signal against any window (larger the better) where you want to hear the occupants. As the window responds to the change in internal pressure caused by the vibrations of speech, your return signal will reflect that change with a difference in the angle of the return beam. You do need to watch your beam alignment though, so that the return laser beam impacts your photoreceptor array. It's simple laser interferometry from that point. Stick the signal difference through an oscillator/amp and listen to all the boring crap being spoken on the other side of the window. FFT for noise cancellation.

Early push button office telephones had the clear plastic buttons illuminated by a light that was in circuit with the audio. You used to be able to read those directly with a telescope with a photodiode at the focus. Very easy thing to do.

Re:Utterly Stupid....

[h4rr4r]

What wireless antenna that normal folks have radiates 10 watts?

Re:Utterly Stupid....

[MattskEE]

I'm not sure if this was part of their reasoning, but it could be that there is more noise in the infrared region. There is quite a bit in visible as well to be sure, but just somebody walking around is emitting some infrared. Indoors if you control the lights you might control most of the visible spectrum.

There might also be issues scaling up the transmit power for high signal to noise ratios in the low bandgap materials needed for IR LEDs. Quite a bit of effort has already gone into scaling up power levels for high bandgap materials for lighting applications. Material issues also may limit the modulation speed of IR LEDs.

Of course it could just be that a research group is just trying to capitalize on existing LED developments to get more research funding in spite of it being a suboptimal solution.

Re:Utterly Stupid....

[mysidia]

Ok.. but who the heck has existing LED room lights? Most rooms are lit by incandescent light bulbs.

Sometimes work areas are lit by fluorescents or halogen floodlights, where the extra brightness is required, and the poor aesthetics are not an issue.

But noone's dumb enough to light rooms with LEDs. LEDs are OK for flashlights, indicator lights, and directed light applications (spotlights), and are not the least bit suitable for lighting an entire room, and they are way too expensive anyways (over 20x as expensive per bulb as an incandescent), so use of LED room lights is simply infeasible and doesn't make any sense.

Re:Utterly Stupid....

[izomiac]

Perhaps the increase in frequency allows for greater throughput. IR is under 400 THz while visible light goes up to about 800 THz. Any higher and you risk eye damage with long term exposure (UV-A*), or DNA damage (UV-B, UV-C, and up). Visible light also isn't absorbed quite so much by the atmosphere.

* Technically, Green, Blue, Violet, and UV-A all cause eye damage over time. UV-A can cause DNA damage indirectly, and skin damage, but I'm assuming low intensity here.

Re:Utterly Stupid....

[Zapo_Verde]

Cant even buy incandescent bulbs over here anymore. Kind of upset me when I went shopping for replacements. Could only get the curly fluorescent bulbs at 5x the cost. I miss the good ole days with incandescent lights that didn't give off light that looks like it came from an arc welder.

Re:Utterly Stupid....

[mysidia]

Maybe just find a source of real light bulbs. I'm in the US and get incandescents all the time, no problem, there must be some source available of them in your area.

Since fluorescents and LED cannot be dimmed, and do not work properly with motion-activated lights like I use throughout. The CFLs actually take too long to turn on -- and fluorescents suck a lot of electricity when first powered up, making them horribly inefficient for these applications.

The CFLs are supposed to last longer, justifying the price or something like that. In my experience, not the case, whenever I tried one somewhere, it wound up burning out within a few weeks, and so did the replacement, whereas incandescent in the same place lasts months. I suppose I could have just gotten two bad ones in a row, but i'm not chancing that again.

Or... time to make your own then?

Admittedly inefficient at 1500 Watts, however, lighting your house with homemade bulbs could get expensive and have certain dangers, and other aesthetic problems, but may be worth it.

Still, you could probably obtain a softer, less harsh/stressful color temperature than that fluorescent mercury-filled crap, with enough effort.

Re:Utterly Stupid....

[net28573]

I understand blue and violet being the damage causing colors however i do not understand how green is damaging considering that the method that people use to protect themselves when using black-lights that emit blue/violet light is by wearing yellow glasses which converts the blue into soothing non harmful green. explain it to me if i'm wrong... but then again all light is radiation and what does radiation eventually cause.

Re:Utterly Stupid....

[project-nova]

The sale of incandescents has been prohibited in Germany to promote newer and more energy-efficient lighting tech, such as LED even for rooms..

http://www.lampenwelt.de/produkt/Nebenartikel/LED-Kristallglasleuchte-mit-Fernbedienung-13-fl.html/

Re:Utterly Stupid....

[Anonymous Coward]

Sure... I mean, no way anybody at Fraunhofer would have thought of that, so we can completely rule out that they have a reason to develop this technology that goes beyond your objection...

What I want to know is:

[killmenow]

What happens if you cross the beams?

Re:What I want to know is:

[Anonymous Coward]

It's raining marshmallow.

I RTFA

[harrkev]

I RTFA. It says that they achieve the bandwidth by filtering out the blue light. This makes sense, as white LEDs are actually blue LEDs with phosphors added to get the other colors. Phosphors are similar to glow-in-the-dark stuff, so they retain light for a little while. Presumably, the blue filter is only needed over the receiver.

The one questions is: how does your laptop equipped with this technology talk back? Will your laptop have a multi-watt emitter on the top (read "bright white light") lighting up the room for the upstream traffic?

Re:I RTFA

[Chris Burke]

The one questions is: how does your laptop equipped with this technology talk back? Will your laptop have a multi-watt emitter on the top (read "bright white light") lighting up the room for the upstream traffic?

Naw, it's like some satellite internet connections. You use the LED for download, and upstream you use dialup. I'm sure it'll catch on. :)

Re:I RTFA

[c0lo]

I RTFA. It says that they achieve the bandwidth by filtering out the blue light

Proud, huh? Then, I suggest you doing it again:

Luckily, researchers were able to expand the bandwidth by leaps and bounds by filtering out all but the blue light (cool!).

Which makes sense, given that blue has a higher freq in the spectrum.
Otherwise it would be like: now, filter out the green and increase the bandwidth a.s.o.

Re:I RTFA

[c0lo]

On the same line, cannot stop wondering what's next?
I mean: to remove the limitations of walls being opaque to Vis light and increase the bandwidth, one can imagine using hard X-Rays and gamma radiation as a carrier for WiFi, ain't it?

Go figure: applying the Niquist-Shanon theorem, the bandwidth would be around 15 PHz: yes, right, peta-hertz, about 12 orders of magnitude higher than the puny 230 MHz - at this rate, one would download a BlueRay full-quality-rip movie in a matter of nanoseconds - that's for sure faster than any epileptic cat would be able to notice and throw a fit.

I just can't wait! No, seriously, I really can't hold my breath that long (i.e. until this quantum-leap technology becomes commercially available).

Re:I RTFA

[Anonymous Coward]

The one questions is: how does your laptop equipped with this technology talk back? Will your laptop have a multi-watt emitter on the top (read "bright white light") lighting up the room for the upstream traffic?

Maybe use the LED backlight in your laptop's screen?

Re:I RTFA

[IpalindromeI]

One problem with x-rays and gamma radiation:

X-rays are a form of ionizing radiation, and exposure to them can be a health hazard.

Because they are a form of ionizing radiation, gamma rays can cause serious damage when absorbed by living tissue and, are therefore a health hazard.

Oh, and ...

[dtmos]

Those interested in this LED-based technology can check out the IEEE 802.15.7 Visible Light Communication Task Group. Members of the Fraunhofer Institute are regular contributors to the standard.

Re:Oh, and ...

[xigxag]

Members of the Fraunhofer Institute are regular contributors to the standard.

In that case, it's bound to be cool. And by cool, I mean patent encumbered.

BTW, {nitpick} it's not "the" Fraunhofer Institute, it's "Fraunhofer Society," within which are various institutes. Probably the most famous is on the internet is the Fraunhofer Institute for Integrated Circuits (Fraunhofer IIS) in Erlangen, whence came the mp3 standard. But the one responsible for Visible Light Communication is Fraunhofer HHI in Berlin. {/nitpick}

Re:Oh, and ...

[dtmos]

In that case, it's bound to be cool. And by cool, I mean patent encumbered.

Not if they want the standard to be approved. 802.15 voters do not take kindly to approving standards for which they will then have to pay royalties to use. Politically, it's almost impossible to get a royalty-bearing patented technology into an 802.15 standard.

Re:Oh, and ...

[xtracto]

Thanks for the remark about the Fraunhofer Institute.

I always think it is really funny when I read news about Germany's "Fraunhofer Institute" doing this or "Max Planck Institute" doing that or "Leibinz Institute" doing the other (did I miss any other?); the fact is that in Germany there are dozens of institutes whose name starts with those words. Just in the city I am working I know there are at least 2 "Leibniz institutes" and more than 3 "Max Planck Institutes"

Re:Oh, and ...

[Anonymous Coward]

In that case, it's bound to be cool. And by cool, I mean patent encumbered.

Yes, unfortunately they still patent their developments, while everybody else has stopped this patent business... right? :)

Re:Oh, and ...

[LaminatorX]

I can see the data, man.

I accidentally

[ijakings]

I accidentally the entire visible spectrum.

This is great... but...

[troylanes]

I'm an epileptic you insensitive clod!

Re:This is great... but...

[MichaelSmith]

(pre woosh)

Photo sensitivity in seizure disorders is generally for pulses below 20Hz and definitely below 100Hz. It is legitimate to ask why bicycle head and tail lights are allowed to pulse at 9-12Hz.

It's the clacks!

[Anonymous Coward]

Vetinari abides.

I will screw with your download

[ParanoiaBOTS]

I will get an LED flashlights and screw your downloads all to hell

big whoop

[pablo_max]

We do the same thing at work with Interns and flashlights.

Re:big whoop

[cortesoft]

so THAT is how those MIT guys overcame the mythical man month problem!

If you want the signal to go through walls...

[NotQuiteReal]

The Fraunhofer Institute also has an audio-frequency wireless solution that will go through walls, with the proper amplification.

Very high bandwidth, it conveys a lot of information, especially in thin-walled multiple dwelling buildings.

Re:If you want the signal to go through walls...

[noidentity]

The Fraunhofer Institute also has an audio-frequency wireless solution that will go through walls, with the proper amplification.

Very high bandwidth, it conveys a lot of information, especially in thin-walled multiple dwelling buildings.

Unfortunately the teenagers who drive down the street at night also have this technology, though there's about zero information content to the "boom boom boom" sound it makes. It certainly penetrates walls, thick or thin, and is definitely audible.

Re:If you want the signal to go through walls...

[petermgreen]

Very high bandwidth
I dunno if you were being serious or trying to make a joke but the bandwidth and hence the data rate of audio are very limited (yes better modulation and techniques like MIMO can get more data rate out of the same bandwidth but there are limits)

I bet you would really struggle to get even a couple of hundred kilobits per second reliably out of free space audio transmission and that's assuming it was acceptable to drown out all other sound over most of the audio band.

Re:If you want the signal to go through walls...

[b4dc0d3r]

"boom boom boom" is the sync header, that's how you know in what order to reassemble the data stream. Maybe now you realize why the "lyrics" don't make any sense. You are conditioned to take your network packets in any order, but still cling to the quaint notion of ordered audio streaming. Fascinating.

No problem

[Anonymous Coward]

The modulation frequency is much too high to be perceptible. If an encoding is used which has a constant light/dark ratio, the light will look perfectly steady. (LEDs are often driven with an unfiltered pulse width modulation signal in the kHz range and that doesn't cause problems with epileptics. This technique uses hundreds of MHz.)

Seizure LAN

[Anonymous Coward]

I just had a seizure thinking about it.

Wait for the first idiots to...

[Hurricane78]

...protect themselves from desk lamp radiation.

After all, it’s 3000 times more powerful! So it must be like... OMGDEADLYWTFBBQ!!!1!1one(lim (x->0) (sin(x)/x))

Re:Wait for the first idiots to...

[Hurricane78]

Hey moderators: Did you forget what humor is again?? ;)

Actually the “3000 times more powerful” is true. Look it up.

I remember a DIY LED netsystem....

[Ogi_UnixNut]

...called Ronja, only 10-mbits/sec, but ~1.4km range, and it could all be built by yourself. Quite cool IMO. You can find out more info (on the now bit dated) site here: http://ronja.twibright.com/

Re:I remember a DIY LED netsystem....

[EkriirkE]

I've been looking for this site again forever, thanks! It's applied to many-a-slashdot story claiming to have invented something similar

related idea

[sonamchauhan]

A light pen that 'reads' an 'imperceptible flickering' LCD screen to both figure out which point its touching, and the data the PC wants to send at that point

Re:related idea

[BillX]

Granted they have to update it a bit for LCD, but...

http://en.wikipedia.org/wiki/NES_Zapper

Re:related idea

[sonamchauhan]

I remember playing with one of those as a kid :)

Also remember a similar idea:
http://www.sonycsl.co.jp/person/rekimoto/pickdrop/

Sounds familiar.

[Anonymous Coward]

Wow, I've never seen a device which used light and line of sight to communicate before!

Where is this useful?

[MikShapi]

This would be
[a] a dedicated technology you need to explicitly buy gear for, rather than use what you implicitly get in nearly every device you buy - phone, lappie, printer, home SAN, what have you.
[b] they wont sell as many radios as the wifi people do, so dont expect anywhere near the same price for a device with a radio on it.
[c] Wifi would advance faster (in bandwidth and price primarily). As would Wireless USB, Bluetooth 4.0, etc.
[d] you'd need to go back to the days of pointint irda devices. Consumer inconvenience.

This would have an advantage where you want to set up line-of-sight comms, wireless doesnt cut it (cuz you're in an appartment building in the middle of Hong Kong or something), and cabled ethernet is not good enough. AND the consumer is sufficiently inconvenienced by wifi to go through this hassle.

Which accounts for about 0.00000000000001% of the consumer base. (The vast majority of which, as stated, couldn't be f#@!%ed and will opt to use Wifi anyway)

Who's funding this? PALM?

zenith space commander

[mirix]

zenith made the first remote controls, they used ultrasonic chimes for signaling. A side affect was the TV would change channels when people dropped pots and pans.

IR sucks. visible sucks even more, because there happens to be a lot of interference. I suppose they could compensate for static levels of ambient light, but you still need line of sight, which is a pain... and you need light, which is a pain if you're watching a movie in the dark on a laptop or so...

RF is really the only way for mobile stuff. Fixed links between fixed installations could be light/laser though. Have fun aligning the laser though, and enjoy the light pollution for less focused light sources. Not to mention that rain, snow, and fog tend to render optical systems useless.

Re:zenith space commander

[sincewhen]

A side affect was the TV would change channels when people dropped pots and pans.

I used to get my old Sony TV to change channels by jiggling my keychain in front of it. I never figured out exactly how/why keys could generate the required IR signal.

IrDA died for a good reason.

[teh dave]

In case they hadn't noticed, IrDA is dead for a good reason. The fact that the last two versions of it are much faster than Bluetooth (2.x) is irrelevant, it's too much of an inconvenience for most of its potential users in comparison to Bluetooth. It was great before Bluetooth came about and I used the latest versions of it with my old phone because it was much faster than Bluetooth, and I never had a problem with it for that purpose. Most potential users prefer the convenience of Bluetooth though, for obvious reasons. My new phone doesn't have IrDA, and hardly any new phones do, and as far as consumers go, that technology is all but dead. I can see LED networking going the same way.

Re:IrDA died for a good reason.

[Anonymous Coward]

Now that they're doing multipath over radio, i.e. recognizing reflected and delayed signals to achieve higher data rates, they should be able to do the same for light-based communication and avoid the line-of-sight problem. This would overcome the major downside of IRDA and make it competitive again.

but wait..

[Anonymous Coward]

I'm waiting for this to be implemented in the common household and watch the number of seizures go up from all the blinking lights around the house.

Maybe it's useful in homes?

[twoDigitIq]

If you could get the same throughput in your home power circuit, and plug cheap LED devices into wall outlets in every room then you might be able to implement this as a wireless option in homes. Or you might give yourself (and your dog) seizures.

Is it just me, or...

[russotto]

...does this seem like absolutely nothing groundbreaking at all. OK, we can transmit information by pulsing LEDs. People have been doing that for years. The fact you don't put an optical fiber in front of it doesn't seem all that interesting.

Digital video

[BillX]

I assume the 230Mb/s is for stuff like delivering digital video to your TV without plugging cables.

"Wow, this movie looks even better in digital!"

"Here, let me turn the lights out so we can wa...oh."

Audio is Very High Bandwidth

[NotQuiteReal]

Obviously you don't know the acronym "TMI".

Every instance of TMI I have ever experienced was delivered via audio frequencies. Q.E.D.

Re:Audio is Very High Bandwidth

[Mitchell314]

Every instance of the TMI I've experience made me glow in the dark. :P

Desk lamps, OK, that's one way

[HuguesT]

Now how do we communicate the other way ? Like from the laptop back to the router ? How do I twiddle the house lights from there. Inquiring minds want to know.

BTW what kind of light sensor did they use ? Cheap hopefully.

Shark Network!

[tjstork]

Now my laser sharks can be networked as well, for total precision!

Bandwidth Meter

[multimediavt]

Downloading from couch with laptop facing "array" across room, 100% signal strength

Dog walks into room between laptop and array, 30% signal strength while dog passes

Child walks in room and stands in front of you to talk to you, 0% signal strength until conversation ends, or kid dies for cutting off your slashdot post mid submit!

Wife walks in with credit card bill with pr0n charges, array gets smashed and you get served.

No good can come from this!

1975 here we come...

[flyingfsck]

Geez, I played with LED data links when I was in high school and LEDS came in all colours provided that it was red. Years later I used the power LED of a device (woohoo, we had green too by then) for a debug data link. Now you *really* got to get off my lawn...

Re:1975 here we come...

[pclminion]

Years later I used the power LED of a device (woohoo, we had green too by then) for a debug data link.

And your data link was 230 megabits per second?

Re:1975 here we come...

[Anonymous Coward]

I remember using a piece of glass that reflected infrared wavelengths to do communications around a corner using the same LED's for a high school science class circa 1980. I think everyone was doing it back then. I was only transmitting tones though. It died for a reason.

lights off

[amn108]

Let's be clear about one disadvantage of a LED network - you can't download AND sleep at the same time, because people like to sleep with the lights off.

Wireless?

[The Creator]

Shouldn't they call it fiberless?

What about upload?

[beschra]

TFA only mentions download rates. Where's the other half of the communication equation?

Notes

[fulldecent]

I read about this at FOE 2010 in Japan.

This technology is anticipated for lab-like environments and obviously the baud rate is high enough that humans are not affected.

Also, this technology will power Boeing's Dreamliner for connection of audio signals from the remote headset to the entertainment system. The obvious questions are: what if I dont want light (it will be dim... very dim); what if I cover the headphones (it wont work); what about powering them (no response there).

Is this new technology called...

[FiloEleven]

Blinkenlights?

disco virus

[Anonymous Coward]

This is all well and good until someone downloads a "disco virus" which creates beautiful light strobes but has everyone in the room fall to the floor in epileptic spasms.