Slashdot Mirror
Using Visible Light for Data Transfer
James Evans writes "Wired has an article about a New Zealand company which has developed a technology to transmit data at speeds up to 400Mbps up to 4km. They are working to have it more resistant to changes in weather, as well as increasing the distance. It has a number of advantages, including lack of federal regulation of the spectrum, as it is of course, visible light."
In related terrestrial networking news, waytoomuchcoffee writes "Science Blog reports that the backbone for the World's Fastest Network is up and running. It's a fiber optic 40 gigabit per second connection between Chicago and LA. Teragrid is a project by the National Science Foundation designed to link up supercomputer centers."
How long do you suppose the lack of federal regulation will last?
So, I guess we can finally have mirrors that are mirrors? Excellent!!!
"We are accountable for not only what we do, but also that which we don't do." -- Moliere
Some places do have ordinances against light pollution. I wonder how this would fit in. Also, will it come with a warning, such as "Do not look at transmitter with remaining good eye"?
Donate background CPU time to fight cancer.
they better be careful at 400mbps, they may break the switch on their flashlight.
http://hksoul.myftp.org/
high speed morse code
Packet loss due to snow storm?
LAck of regulation is nice, but is there really a lot of regulation for InfraRed and UltraViolet?
It sounds like a VERY nice system for short-range, non-critical communictaions, but personally, I can't think of any points I would want to communicate to where I have line-of-sight... If I could get an inexpensive device that could communicate for about 10 miles, I would certainly get several.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
Doesn't this just sound like fiber optics without the fiber?
I seem to remember this being done a long time ago. I've got an electronics book with a schematic for a serial 28k transmitter using visible light.
--Quentin
The LED-color should be chosen according to the content transferred... users sharing pr0n via P2P could build their own red-light-destrict! --- I wonder if powerful LEDs will attract insects and such - the connection speed could be reduced drastically by bugs.
We have been streaming voice data over fiber-optic lines for a while now, and even digital data signals for networking. This sounds like fiber-optic transmission without the actual fiber-optic line! Very cool, indeed.
Perhaps this is the future of truly wireless computing?
One thing the article states is that the current range is about 11 km. This seems a little short. However, considering this is a line-of-sight type of thing, that does make sense. Give 'em time, and they'll get it down to hundres of miles with good reliability, and then I think we'd see a bit move towards it for WAN technology and business usage.
Be excellent to each other. And... PARTY ON, DUDES!
Didn't this company invent a dodgy battery that was going to save the world - but didn't??
I was thinking the same thing, since its visible, won't that make it easier for anyone to pick up what is being sent?
Except with morse code, I believe, you have to find the right frequency. Not much of a problem, but likely harder to find than a little light strobing across the street. Then there's the rather obvious quote from the article
On the other hand, bad weather, or anything that might block the light's path, can cause slowdowns or power failures.
"File transfer failed: Code 75(flock of seagulls)"
*honk*
This is my sig. It's prescription, I swear. I need it for reading things... on the other side of things
Sounds like a cool technology clean, high performant, low infrastructure, does not slice limbs off or create two headed babies. This should make it a very attractive sell to commerce and to the public
I would have some security concerns though since it makes it a lot easier for those of malicious intent to intercept the signal as its basically being broadcast in the open. The technology would seem to lend itself naturally to strong encryption though.
I think they could be onto something big here.
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
This company has a history of off beat and - doubtful "inventions". Then agin maybe they have learn't a lesson or two about "science"...
Consider this, most cellphones around the world operate at 1500MHZ and so have a seemingly impressive maximum THEORECTICAL data transfer rate of 750Mbits/sec. Unfortunately due to physical contraints on modulation systems a good rule of thumb is that the actual data rate provided is about 1/2000 of this and so we end up with around 375 Kbits/sec that is just coming out with 3G systems.
Now the optical band is out of the question for obvious reasons but if we could transmit in the THZ band or higher we could see massive improvements.
Consider this, going up as high as 10^16Hz would mean the PRACTICAL data rate going up to 5 Terrabits/Sec! Even a worst case senario would make multi megabit mobile data access available to all.
Now admittedly there is some problem with attenuation at these frequencies but this could simply be overcome by boosting the power. Overall it seems obvious that higher frequencies are the way to go.
So much to do, so little bandwidth.
--
Try Mozilla
(w/o fiber optic cables) will need some amazing error-correction code. There will be so much interference.
...using nothing more than a prism.
They wouldn't even know you where there!
Yes, if anyone's eyes can read signals at 400Mbps.
Er, in other words, no.
..when and if it improves, it'd be freaking awesome to use in space.
Light is obviously a wave ;)
... so the only security that realy works is the one you put inside the ray emission technology.
... ;)
How a short wave or long wave can be more or less secure ?!?
IFAIK, as loog as something emit you can track it
Cf. to WiFi drivings hack-party and the WEP lack of security
Looks like it should be pretty easy to DOS someone's receivers or at least confuse the crap out them with conflicting light sources. I suppose you could also point a laser at them and fry it totally.
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
Can you see what I'm saying?
You see? You see? Your stupid minds! Stupid! Stupid!
Fixed wireless communications based on lasers are already available commercially, and have been for a number of years. Do some searching on Google.
Perhaps someone with a better understanding of security could answer this question. How secure would this be if the data were encrypted before transmission? Also, wouldn't someone be able to tap into the line significantly easier than with radio waves? Seems to me that all one would need are a video camara and simple(?) video -> signal conversion software.
It is simply an application of this.
Security?
That was the first thing that occured to me when I read the post. It will probably be like everything else. First comes the technology, then years later everyone slaps themselves on the forhead for not thinking of making it secure from the beginning. Like Telnet, FTP, POP, 802.11, IM's, etc.....
People have been using visible light for data transfer for a while ;-)
...no-one can hear you leech.
By reading this comment, you immediately waive any and all rights regarding it.
Doing Free Space Optics isn't new. It's been done for many years now, although primarily with laser-based systems.
I work for a company that is currently developing a LED-based FSO system -- Omnilux.
The big push now in the FSO market is to find the right balance between performance and cost. Too many companies were trying too hard to push data longer distance, then faster, costs be damned.
400 mbs is slightly more than 2 bits a second YTC.
Or do you mean 400Mbs ?
I don't think a video camera would achive much, unless you have a video camera that can record over 400 million fps.
We've two sites, 2.5km apart with line of sight, right on the very very edge of the European legal limits for 802.11b wireless. Currently 2Mbps land line.
This might be quite good if it's low cost.
Government of the people, by corporate executives, for corporate profits.
So far most wireless services have proven insecure... I understand that you have to be in line-of-sight... But if someone is looking to find your data, what's to stop them?
reminds me of a slashdot story a while back about a group of people that was able to get your data transfer by looking at your (external) modem's LED.
I mean, same thing except, well, faster...
The cool part, though, is that now the router's status LEDs are actually good for something. You can theoretically face two routers toward eachother and that's IT! done! until some idiot walks between them. ha!
but really though, The thing with radio we seem to not be able to do with light yet is frequency modulation. If we can do that, I think we can push some very serious bandwidth through this spectrum.
The data-hiding possibilities are immense. you can technically send humongous amouts of data through a TV set, even, if it was made of as many LEDs as there are pixels, and by varying the each LED just ever-so-slighly. You can be watching the TV for pictures, and your Aibo would be sitting beside you, downloading zillions of bytes of data, and gaining consciousness (sorry just watched the animatrix, heh).
My life in the land of the rising sun.
But after reading the article, and seeing how they'd use LEDs (they don't say how big though), and the bandwidths involved, the lights would seem to be constanly on, do you think?
That'd mean no real lightwave pollution (it's all line-of-sight) and little visual pollution or distractions due to thousands of flashing lights?
Of course, I still have to wonder about the effects of different weather. I see it'll still work with a hand moving in front of it, but what about heavy smog days, or blizzards? Would torrential rain make problems with light refraction??
I guess it beats training swallows to carry coconuts engraved with data packets from rooftop to rooftop (they could grip 'em by the 'usks)
Hats off to the Kiwis for this one though, it sounds pretty exciting :)
Woohoo! I can't wait to see my IT Manager scaling our office building to deal with pigeons nesting on the transmitter!
"Nature will find a way..."
Sounds like this technology might be useful for communicating to scuba divers and underwater equipment.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
It could be as secure as wi-fi where the actual "media" is free for anyone to grap. What this means is that it requires strong crypto to be secure.
;)
I think the realiability is bigger issue. What if someone wants to cut your operations. Big piece of carton or huge van to front of emitter could quite efectively cut it. How's that for denial of service
Well, i admit that i havent read the article so i dont know how it actually operates but what about "light noise" from other sources.. Or other co-existing "light hubs" in the area. How do they effect the data and its reliability. Only way to prevent this (which i can think off) is using laser as transport medium light and thats not so new anymore is it. And DoS'n laser is even more simpler since the lightbean is really narrow usually and doesnt spread as "normal light".
yush
Great, I won't have to buy more crappy pringles in order to steal credit card numbers.. I already own a mirror..
I just want to say this is an awesome technology and I agree with Witehira's comment that this is a very important technology and it could very well change the world.
A very important point is that Infra Red light is absorbed by the cornia (outside) of the eye and dosnt penatrate to the retina where it can cause real damage. Visable light does penetrate (obviously) to the retina and WILL fuck your eyes up. I've worked with IR lasers for a few years, they are much safer than visable light devices.
Also saying use of visable light avoids licencing isues is a bit misleading.
As to my knowlage, no country regulates visable, IR or even UV unless in lasers (or other sources) where they may get to the powers likey to cause physical danger (not very relavent here, less so with IR rather than visable light).
Put your hand up if you need a licence for your IR TV remote controal!
Anyway, a practical solution would be to use lasers of differnet wavelengths and swich to the correct one depending on weatehr conditions. EG fog attenuates some wavlengths strongly, rain scatters a differnt set of wavelengths more readily, etc (As a crude example, consider the different wavelenghs reaching your eyes from the sun in these different weather conditions)
This technique of swithing to the most aproprate wavelength for the conditions is used in army laser range finders.
Anyone quoted by a reporter knows how little they understand
Don't believe what you read is the truth.
It I am not sure how this is article bestows very interesting or novel information. Granted, the article mentions the wavelengths used are "visible", and "red". My guess is that they are emitting somewhere between 600 and 800 nm (typical visibly range is from 400 nm (purpleish) to 700 nm (red) however this is not a strict cut off, and if bright enough, even above 830 nm is visiblish).
Most telecom takes place at about 1550 nm, well into the infrared, but this is primarily because the typical fiber has nice properties in this range (absorption and dispersion). Therefore I am not sure there is much fundamental difference between infrared light telecom and visible telecom. Indeed they use very similar laser material (GaAs-based or InP-based diodes), are modulated the same way, etc.
Possibly this is neat because it is free-space optical stuff. However this (as pointed out previously) is not new. There are companies that are in place as we speek. Maybe deregulation may be of interest, but if the light it kept at the same wavelength as in fiber, then there is no need for an electronic klugey transceiver (detect the light in the fiber at 1550nm and drive a laser to re-emit the same signal at 6xx nm). Instead, an add-drop filter could be slapped on to the end, pick off the right wavelength, and feed that to a fiber which could be collimated as the source. This collimated beam then could travel over kilometers with no trouble. An all optical solution has a much
just a thought
Free air optical networking isn't really a new idea. Infrared units are pretty common. I'm not sure what supposed advantage using visible light has over infrared... IR isn't regulated (at least in the US, I can't imagine that it would be anywhere).
I investigated this for networking a couple of buildings my company had near together. Pretty cool stuff. You could get a gigabit connection over a few km of thin air. Cheaper units did 155Mb and for dirt cheap you could get 10Mb. Short range units used LEDs. Longer range ones used lasers.
I've been wondering why consumer ISP's haven't taken to this yet. It's a great last mile solution.
--Keepiru
--slashsuckATvegaDOTfurDOTcom
Imagine that you might be able to upgrade a set of traffic lights to actually make something faster!
Extended Warranty? How can I lose!
I just read about this the other day in the book "Dealers of Lightning" (page 140). While they were developing the laser printer in the 70's, some of the researchers had to move to a different building 1KM away. They had line of sight between the two locations, so they rigged up a system of lasers and photodetectors to bridge their network between the two buildings.
The beam went over a public highway, and after one woman went into a ditch after it startled her one foggy morning, they coarsened the beam to make it invisible.
...have been using visible light as a data transfer medium for years...
As it's all black
Why is everyone acting like this is a new thing? Hams have been doing the same thing for years. There have been construction articles in popular electronics mags for years about going digital with a pair of LEDs.
-- Ed Carp, N7EKG erc@pobox.com PGP KeyID: 0x0BD32C9B What I'm up to: http://intuitives.mine.nu
Why it hasn't caught on?
2 words: Atmospheric conditions, fog, heavy rains, etc can and do impact on the bandwidth.
He tried to kill me with a forklift!
VITAL FACT!! US FCC controls light comm by law NOW.
Any ham buff knows "semaphores" and other visible light signallign technology is controlled by FCC, though illegitamately.
They can shut you down for waving FLAGS in a time of war.
Whats next, restrictions on what I can paint on my roof for sattelites to see?
Why am I the FIRST to point out the FCC laws here?
Is everyone ignornat today. (its 8am EST and the topic has been errant for many minutes already)
People will use headlights for another 50 years
:)
Tune your cars headlights so that the point directly to the oncoming driver's eyes, and you will get fined. AFAIK lighting around airports is regulated too, so that the airport landing lights are more visible to pilots. I think however that the airport case only affects people designing anythin bigger, like lighting highways/stadiums.
However, the leds used in the article propably don't endanger anyones life, and light is not a scarce resource, so hard to believe using leds for data transmission will be regulated
Unless ofcourse someone decides it endangers existing profit infrastructures... DMCA wasn't the first law done to protect profit..
signatures pending - ansa@kos.to - (dont mail there)
I'm not too clear on how this works. Wouldn't it be quite easy to disrupt a beam of light, through physical or other means? Seems you could put a piece of aluminum foil in it's path or disrupt the beam with other beams quite easily. And what about safety issues? Is it visible to drivers? I remember reading that when PARC first had a line of sight laser to connect two buildings across a highway, during inclement weather drivers would crash while distracted. If it's too high, would have to worry about aircraft. And since a laser can damage your eyes, wonder if this type of light can as well.
Slashdot: Playing Favorites Since 1997
Eco-friendly, modern day smoke signals. Too cool! And speaking of cool, I wonder what users of this technology will do during a snow storm, heavy smog, etc.
They tried it in a conference. They wanted to telecast conference proceedings in a building some distance away using this method. They set up this equipment, tested everything the night before the opening day, works perfectly.
First day of conference. No signal. The receiver didn't see the transmitter at all. Total flop.
So they checked it thoroughly again that night. Everything was still working fine.
Next morning: same story. No signal.
This repeated on all 3 days of the conference.
Organizers were left scratching their heads. Funny part is, it worked at night and failed at day without their touching anything. Sabotage? The devil??
Later they found it was because the light beam was getting bent in daytime due the temperature gradient (same way that mirages occur). Poof.
Of course, these are just problems that will inevitably occur when a technology is in its nascent phase, I'm sure it'll get ironed out as it goes commercial.
The article talks about rain and fog, but is silent on the sunlight issue.
With their wide-open spaces and long, cold winters, it makes me wonder when Canadians will perform their first teledildonic extramarital love affair.
Sean
We set up a microwave link between two buildings several miles apart. We had to get a right of way from all the land owners inbetween.
I wasn't involved directly in that project, so I don't know if it was needed because it was microwaves, or just in general.
I wouldn't rush to think this is some sort of easy method to solve problems, though.
"Has [being a kidnapped teenage girl, raped repeatedly for months] changed you?" - Katie Couric to Elizabeth Smart
Visible light huh? Like... I can see it? Hmmmmm. Hope someone thinks to encrypt it :)
"If I could only live my life with my threshold at 4... " -- Wil Wheaton
"It take 9 months to bear a child, no matter how many women you assign to the job."
I don't imagine using this thing for sending a very important document/work. It looks more like a cheapest way to do fast networking. It's LIGHT. A flying duck cross over the lightbeam and BANG! :) This appart from other problems like insecurity (I mean, I think it's easier to do a light-receiver than a radio-receiver... more people would be able to 'investigate'), etc.
:D
Neighborhood network? perhaps. Just imagine a lanparty on my neighborhood, and every tv/vhs/dvd/thing-with-a-infrared-remote-control getting weird
drmad.
drmad
The same applies here as with any other netowrked communications...
Here's what I wrote in another thread:
If I actually care about something being secure, it's either done through SSH (or scp to copy files), or I use SSL encryption on my instant messaging, or PGP encrypted e-mails. I don't care if someone's able to tell who the recipient is and what the subject is. My ISP probably logs that anyway. Wireless networking as it is now supports all that and more. What's wrong with it then?
Follow me
This also in: scientists have discovered a way to use "smoke" to send "signals" over long distances! Depending on the "signature" of the "smoke", many bits of data can be sent over long distances without any wires or RF! Amazing!
It's 10 PM. Do you know if you're un-American?
I thought non-visible lasers were more dangerous (at least at the class 2 kind of level), since there's no blink response. The eye doesn't realise there's a problem until it's too late. I may be thinking of UV rather than IR, though...
A very important point is that Infra Red light is absorbed by the cornia (outside) of the eye and dosnt penatrate to the retina where it can cause real damage.
This is very interesting. I always thought that IR just could not be detected by the retina, out of range, if you will. Any idea how much it's attenuated. I've heard the cornea is one of the few elements of the human body not composed of cells.
Can IR radiation cause breakdown of the cornia, and bluring or clouding, like UV radiation can? Mother nature needs to innovate a UV stabilized cornea in the next incarnation of our species..... Wear your UV sunglasses outside folks, or you'll end up like my dog. Can't see a thing.
this technology has been available for decades, it's called free space optical datacom. As the link points out, there's even a google directory listing for providers of this technology.
there are significant limitations on this tech however. cheif among them is reliability in various weather conditions. rain, fog, snow, and passing birds tend to cause havok with a laser beam. setting a laser up to point to a target 1 or 2 kilometers away is no small feat, and even harder is making sure it stays on target months and years later.
there's a reason why most wireless shorthaul links use microwaves, as the laser technology really doesn't work very well.
I see this as a way to decentralize large fiber optic networks for public access. Its cheap and fast. And a broadcast system would be very usefull
for most people. ie news weather. Also security would be easy to implement with openssl. It will not replace fiber but create a webing network.
BBS are back. hehe
So that would make your eyeballs circumvention devices since its visable light?
"It's so convenient to have a system where everyone is a criminal" - A. Hitler
A lot of infrared (IR) lasers (common examples are Nd:YAG or Ti:sapphire) operate in the near infrared
Yep, you are right. Some near IR wavelengths will be let through the cornea, and you wont have the blink reflex to protect your eye. However, this is slightly misleeding as the vast majority of IR (at wavelenghts a little further from the visable) is safe. Especially at the power levels discussed here.
The only time it decomes dangerous is when the IR light is strong enough to heat the cornea!
For example, at 1.55 microns (wavelength most suited to optical fibre) the British Standard guidelines state the maximum permisable exposure to the eye at this wavelength is the same as skin. In simple laymans terms, it has to be strong enough to burn flesh (skin or eye) before it will damage the eye!
Of couse, the real bastard lasers are UV. A fairly dangerous wavelength (suntan anyone) that you cant see. Not good for your eyes either!
Anyone quoted by a reporter knows how little they understand
Don't believe what you read is the truth.
Not to be nitpicky--well, okay, to be nitpicky--the definition of "light" is the portion of the electromagnetic radiation spectrum that is visible to humans. Everything else is radiation. Although IR light and UV light is commonly seen, these are actually misnomers. (You wouldn't say x-ray light would you?).
Oh yeah, so my point is, in the title of the story "Visible Light" is redudant.
Sorry for the nitpicking--it's too early in the morning for my brain to come up with anything useful to say.
Check out http://www.plaintree.com - they use eye safe LEDs for transmission, with speeds up to 155 MBPS, or T1/E1 at ranges to 3KM. They are using this at the Ottawa airport. They have been in business since 1988.
My rights don't need management.
I've followed the FSO development for some years now and I wonder if this is finally the commercially breakthrough.. shtml ?tid=172 ... where some came up with the idea of an
BUT... I'm really afraid of all these big telco spiders, lobbying for total regulation of this kind of technology. There was a post on eventual WiFi regulation in the US:
http://yro.slashdot.org/yro/02/12/08/0156246
telecom company conspiracy... and for FSO, it's basically the same, the same "terrorists-use-it"-arguments apply.
Look at all the nice pictures of house to house
meshes at www.omnilux.net, the ISP people is suggested that they control the last mile, i.e. the inter-house connections. Ahh, labels that say: "The equipment on top of your roof is the isp's property. Any modification and/or circumvention strongly prohibited". A real nightmare. And this would prevent real changes in network topology, from the hierarchical-telephone-network type to the flat networks current protocols and computers
should be able to handle.
Not that I want to rant too much, but I'm very afraid looking at the development in other areas...
UV lasers can be bad, but they don't do retinal damage at short enough wavelengths. In fact, UV is used in "Laser Vision Correction", because it ablates the cornea nicely without penetrating at all into the retina.
For really severe retinal damage, visible and near IR are the worst.
It's not wasting time, I'm educating myself.
It's a fiber optic 40 gigabit per second connection between Chicago and LA.
Get your bits
On Route Sixty-Six
- Hail to our fearless misleader! Fool speed ahead!
It's easy to block 1 path. But if you have 10 or 20 light paths, it becomes less probable all of them are blocked. And making the lights in the invisible spectrum is a good idea.
Nothing new here, just application and enhancement..
---- Booth was a patriot ----
No, it is cheaper to lobby for law changes then to get it right the first time. Even though this route does nothing to protect privacy or security, it allows the companies to claim it is secure. Two perfect examples are the DMCA and what they did with the cellular and cordless phones frequency bands by constantly modifying the Communications Act or 1934.
Bad boys rape our young girls but Violet gives willingly.
Layer 1 security (physical access denial) is not good security. The best way to secure networks is to use secure protocols - wrap everything up in SSL.
As for the service interruption concern, it would seem prudent to use several redundant beams spaced at irregular vertical and horizontal intervals - wide enough so that a small flock of pigeons doesn't interrupt service.
Cotton shirts are nothing new compared to piled-on filthy animal skins, too, just application and enhancement.
(http://www-class.unl.edu/advt498/readings/commun
jrnl: http://tinyurl.com/c2l8yr / foes: http://tinyurl.com/ckjno5
A while ago I read a paper about setting up line-of-sight radio on each rooftop. A standing device with four horisontally rotating antennas would find four similar devices to hook up with.
With the LED technology to do the same, a whole city could be a web of pair-to-pair connections. You could literally route past around pigeons once there is a multitude of connections.
Match this technology with standard web techniques for routing.
--
Boerge
It's called the sign language...
hahaha, people suffering from epilepsy won't be able to surf the web anymore.
australian project gutenberg is better than the original.
I followed a few of the links and only in the first story did I see anything about this being used for data. Information on the manufacturer's page indicated it was for specifically for transmitting video and audio data. No mention of general networking capability.
And one last thing - I really hate links to companies that have very little real information on their products, only information about how their stock is doing and all the wonderful things they're working on and will soon revolutionize the world with but aren't *quite* ready yet. Don't forget to invest your dollars in us, okay?
all you need is a really big HDTV, and a Beowulf Cluster of digital camcorders with telescopic lenses.
Right?
What I wanna know is: am I gonna have an epileptic seizure looking at the tower?
"Times have not become more violent. They have just become more televised."
-Marilyn Manson
I'm just waiting for the first implementation of an epilepsy net virus that when encoded into light will cause people to fall down to the floor, shake vigorously and foam at the mouth.
That making shadow puppets is a DoS Attack?
The city lights up the night sky enough as it is; I can barely see the night sky. I can see this just adding to the mess...
OK so its a one word post but it raised the issue of security for the first time, and quite a discussion followed.
Why was it modded redundant?
Since the laser's light is coherent, you can use this interference to reconstruct subtle changes in the distance from the laser to the reflective surface. In other words, you can eavesdrop on someone by looking at how the windows in the room vibrate! Supposedly this was once used to find out what people were saying in an embassy.
At short distances you can use a grapefruit instead of a window, but talking into a grapefruit is just weird. :)
A quick look at the ARRL site shows that a 248 km 2-way communication took place as far back as 1991 on 768 THz/442 nm (probably a He-Cd laser). The other record at 474 THz/632.8 nm was probably a He-Ne laser. The funny letters in parens (DM34hb) are Maidenhead locators that are used to locate positions.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
I was driving to work North on Willows Rd in Redmond, WA today and I saw Terabeam's laser flashing away. It is pointed almost directly along the road to their satellite building to the South.
I haven't noticed it before, so I wondered if they had some beam dispersement issues. I got a little concerned that the laser was damaging my eyes. Hopefully the power on the lazer diode is turned down. You never know what is going on in development hardware ;)
The light looks like your run of the mill strobe light. The pattern looks like the LEDs on your hub. Not sure why because that flash speed is not consistent with the marketing info on www.terabeam.com.
Unfortunately the fog here in the valley tends to prohibit their use of the system.
Holland
What he said.
2 words: Atmospheric conditions, fog, heavy rains, etc can and do impact on the bandwidth
13 words
-- Insert wisdom here:
Aren't you a capable coder?
I think you guys are missing the article here. They aren't using lasers, they're using LEDs so they don't need to worry about the government regulations.
"File transfer failed: Code 76(Duran Duran)"
*honk*
The Kruger Dunning explains most post on
The FCC reserves blue for military use. Yellow and green will be reserved for commercial use, and licensed in 10nm blocks. Red is reserved for emergency purposes. The public is allowed to transmit orange and purple, purple only with an operator license.
Sales of orange housepaint are up, as are orange cars.
char *mySig;
If you needed to get right-of-way in order to send a microwave transmission between two spots, why is it that Hughes (Dish Network - or whoever they are called now) somehow has permission to "beam" their transmissions all over the f'in United States? I don't remember giving them "right-of-way" access to the ground my home sits on...
Reason is the Path to God - Anon
How long do you suppose the lack of federal regulation will last?
I don't know about the US. (The FCC has been moving to open, rather than close, bands for some time now.) But it's already banned in Britain.
You probably already know that radio broadcasting in Britain is (or was a few years back - just in case they've changed their mind) a government monopoly. People tried to work around that in various ways.
One of them was a company that did a cute hack: They shined an infrared laser straight up, and modulated it with an entire FM band full of radio stations (similar to the way you can put a private FM band on a cable TV wire). Anybody who wanted to could mount a photocell or infrared-sensing diode (in a little telescope) on their window sill, point it at the invisible pillar of light, and couple it to a radio to receive the new band. Business model was to rent the stations out as commercial broadcast stations with all of London as target market.
The agency in charge of the British radio monopoly (British Post Office?) complained. And parlement extended the top end of their jurisdiction from whatever the previous legal end of the microwave spectrum was to infinity.
So in Britain, if it's electromagnetic energy (even gamma rays) and you can use it to beamcast or broadcast information, you need a license.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Wouldnt having a flashing visible light that transmits data be a pretty big security hole? Wouldnt it be ridiculously easy to just tap into the signal. It seems to me this would create another wireless-type mess.
Still, the possibilities for data broadcasting seem pretty cool if they could ever get the distances to increase, but even now... distributing video across an office campus or something could use this tech for a low cost.
They shined an infrared laser straight up, and modulated it with an entire FM band full of radio stations [...]
By the way: Don't try that in the US. The FAA bans shining lasers up into the air where they might blind or distract pilots. Low power and near-horizontal or you're ban.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Commercial-wise, my "favorite" (I am not affiliated with them or anything - I just like the tech) company doing this is a company called AirFiber. What is most cool about the tech is that they have an "auto-alignment" system to compensate for any angular/distance changes in the laser. That would be cool unto itself, but what gives it geek cred (and is little known - though I remember reading an article about it either here or on some other site a few years ago) is that the mirror alignment system was originally designed and prototyped (perhaps even uses it today - dunno) using an automobile electric-mirror positioning system (basically a fancy pushbutton external mirror alignment).
Of course, any discussion about LaserComm or LEDComm wouldn't be complete without mentioning the homebrew Twibright Labs Ronja Project. There are also a few other such projects out there (none as advanced as Ronja, IMHO) - I have mentioned them in other comments on such articles here on /. - search for them if you care...
Reason is the Path to God - Anon
All I know is that I want an Evil tower with friggin laser beams transmitting evil data at 400MBPS.
WooooHAaaahahahaha!!!!!!!
One if by land, two if by sea...
and I KNOW there are regulations on their use (especially in public places) for data transfer.
...will arrive when we have the cheap and ubiquitous infrastructure that would allow every usable band of the electromagnetic spectrum (and perhaps some of that of sound) is conveying digital information.
Assuming you can decrypt some fraction of that information (it's targetted at anyone in range), everywhere you go you'd be immersed in spam, running commentary from live on-site bloggers, ads and catalog information for the store you just walked into, car and foot traffic density information, emergency advisories, etc, while simultaneously conventional long distance network traffic is routing through the same network. Every light will have transmission capability, and eventually every visible surface will be able to modulate its reflectivity for same.
Speed doesn't matter that much, the point would be to have as many different available routes available as possible- visible light here, and if weather gets in the way jump transmission over to a weather transparent frequency or go through a land line, or multiplex across all of them.
The technology for transmission and reception just has to get cheap enough so that adding a router and modulation capability into a room light or street lamp is a small percentage of the total cost.
Max Karma for the first person that launches a convex mirror satalite! Yeah, yeah, I know, clouds, etc...
Any sufficiently advanced influence is indistinguishable from control.
Mirrors on the moon, (creating a giant disco ball in the night sky), then you can really send a message out to the world. Of course the sun may become a problem.
Causing Chaos Everywhere,
Nik J.
The strange world of a loner, in a populous city, drowning in society
"Can you see me now?"
*align receiver again*
"Can you see me now??"
I prefer a void in conversation to a vacuous one.
Visable light, that means point my telescope with a photodiode on it to sniff. Right?
He may be a capable coder, but what patterns of light will cause epilepsy?
For the children, of course.
Anyway, in my experience the best kind of peace is a piece of ass.
easier?, no harder, the light beam is much tighter, leaving fewer positions to intercept the signal. reflections are going to be the big issue, but microwaves are even worse in this respect too,
the only thing easier is locating the signal in the first place. detection equipment for visible light is much more readily avalible (eyes vs. microwave recievers)
So would a DDoS attack be a couple of guys standing around the receiver taking flash photographs?
Seriously, I don't even think Xerox PARC can claim first post over this one.
Modest doubt is called the beacon of the wise. - William Shakespeare
There was a recent study done that shows that the light from LEds and lasers do the same damage to the eye at the same energy levels (Duh). (Poor rhesus monkeys...)
LEDs are extremely powerful these days (Green/blue "diode" lasers use a bright IR led to "pump" the laser cavity) So just saying they use LEds, which are obviously powerful enough and columnated enough to travel distances through weather, doesn't mean they are any less dangerous (Even if there really are no current gov. regulations to worry about).
LED == Laser for this application and the same common sense precautions would apply.
Contrary to popular belief, coding is not all free blow-jobs and beer. Those things cost MONEY!
It just so happens that Visible light is only Visible Light because we can see it. Obvious, right?
So, why can we see this range? Because our eyes are evolved to sense in this range.
So, why did our eyes evolve this way? Beacause these are the frequencies of maximum transmission by our atmosphere. So, there's the most energy to see in this range. Creatures that see in this range, for general purposes, can see better than other creatures. They get more food, they see their predators, etc., they reproduce.
So, by definition, a Visible Light system has the highest level of interference possible. Hmmm...
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
My but Mr. Babage is quick on the helioscope key.
Friends don't help friends install M$ junk.
The next time you see a refinery at night, notice how all of the thousands of lights at a distance seem to quaver. It's trying to tell you something but you don't know how to read it!
Friends don't help friends install M$ junk.
several companies already offer data links that use parts of the visible or near visible spectrum, see Nortel's product line for a high-speed SDH compatible laser link, gosh I can remember a appletalk laser link about 10 years ago...
Companies are developing technogy to transmit 40Gb/s over fiber per wavelength.
Vote for Pedro
If you want it more reliable use a few widely spaced beams and TCP/IP.
:-
It's probably quite hard to intercept a beam 10m above ground without people thinking
"hey why's that bloke standing on a ladder waving his laptop about between our two buildings"
or
"why is that bloke mucking about in a hot air ballon between our two skyscrapers?"
ok you might be able to pick up a tiny bit of the signal dispersed by rain/dust etc but it would be far harder to snoop than radio and probably harder than copper at ground level.
Anyone heard of VPN???
-ok so I'm probably feeding a troll but...
Wouldnt it be ridiculously easy to just tap into the signal
not if it is focused and highish up - you'd see anyone trying to snoop it.(ok fog might disperse it enough for someone with *VERY* good equipment to pick up).
Any way whats this about wireless being insecure??
I'd trust wireless as much as the cable link to my house, anything I want to be secure I use encryption (as does everyone else who shopps online etc).
When I was in 5th grade (the first time) we went on a field trip to visit some weird dude and his science museum-type-thing. He had a peg leg and was a little strange. He might have been famous, I don't really remember who he was. He may have affected me mor ethan I imagine, but anyway...
He made a mylar speaker on which he played music to silently to be heard. He reflected a beam of regular light off the mylar and it was picked up by a photovoltaic sensor on the other side of the room which amplified the signal and sent through a normal speaker.
Voila - sound transmitted by light, or light modulated by sound, however you want to see/hear it.
I always wanted to make a setup like that and "listen" to lightning.
I like my federal regulations in some instances. In some cases some things such as sending snail mail it's good. Depending on how they do it regulating sunlight could be advantages such as setting minumum quality standards for towers ready groupd of people to assist with the up keap.
Kill two birds with one stone,
get rid of those pesky pigeons and create a new information infrastructure.
New Zealand scientists have produced a breed of genetically modified sheep that produce a reflective woolen coat. This is expected to allow the delivery of high-speed internet into the homes of all kiwis
Glenn
The Smrt way to trade CFDs on the ASX
Correct me if I'm wrong, but as I know it, radio waves are regulated by the FCC, and light waves are regulated by the laws of physics.
Am I not correct?
So if I want to use a torch to send morse signals in UK, I need a license?
In principle, yes. And if you automate it, crank it up to 1200 baud or higher, and use it to broadcast entertainment or surf the net without a government-approved connection, they'll probably bother to enforce it, too.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
So now were have the technology to beem our MASSIVE (weta/lotr) around the country side :)
Dont underestimate NZ what ever you do, we may only have 3.99million people (and 49million sheep) but we are the L337st peoples
Oh... you mean here?
So, to get an infinite loop going you stick a mirror infront of it and point it back on itself? And this gives a new meaning to being hacked. Just put a beam splitter in its path and send on down the line to it's distination and other to your reciever?
Since its sensitive to voltage changes, what would a lightening storm do to it? And what about the new terrorist threat - bringing down a network with a flash gernade?
Oh, and new zoning laws.
-"Im sorry, I know this area is commercially zoned, but we can't let you build your office building over 2 stories high now."
>"But, when I bought the property they said I could build a 6 story office building here without having to get a special permit, that's the law in California, what changed?"
- "Well sir, you can't build any higher than 2 stories because the guy next to you site has subscirbed to a optical carrier and his reciever is on the 3rd story, If we let you build the building your describing you would cut off his recieption."
> "Well, can't he put an antenea up to get compensate for this?"
- "Yes, he probably could, but that area isn't zoned for anteneas higher than 6 stories."
Ya, neat technology, but I can't see anyone really relying on to call 911. I can hear it now - "my uncle in Barstow died because he had a heart attack during a dust storm and we couldn't get through to 911".
Maybe, they'll find a use for it , but I can't see this for any sort of wide spread overland transmittions.
Once agian, refer to sig!
The bandwidth stays the same. Said conditions lower the range of the systems.
When you're installing the system, you get one that has more power than you need during a clear day, so that it will have enough power to pierce the thickest fog you anticipate having in your area.
The unit I was specifically looking at was advertised as having a 2 km range in adverse conditions, and significantly more if only used in clear conditions. This was also for business-level connectivity, where we couldn't go down. In a home-consumer market, you could probably skimp on the margain for error a little more, and push the things out to (say) 4km, which gives you a pretty good radius to find an ISP. Also, the 2 km in rain+fog unit wasn't the most powerful one they had. Some of the 10Mb units (which I think would be perfect for home use) had range far in excess of that.
Application for Patent on a system of displaying information by using the refelective qualities of pigment and amibient light.
i'm glad Debian finally got into
polar-deep-freeze-we-arent-shitting-you state finally.
-- Seen on #Debian shortly before the release of Debian 2.0
- this post brought to you by the Automated Last Post Generator...