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Using IR Lasers Instead of Fiber
Artifice_Eternity writes: "Can't deal with the trouble, time or expense of digging up the street to get fiberoptic cable to your building in the big city? There's another way...infrared line-of-sight infrared lasers between your building and another one nearby. Repeaters and redundancy can keep the chain going reliably for miles, with gigabit data transmission rates."
And lets not forget how fragile the whole system would be. A mirror, heavy fog, lightening striking, etc. all come to mind. From what I've heard wireless repeaters attract lightening quite well, and a nice surge like a lightening bolt can bring makes a wireless network a little worthless.
Hopefully with all this new technology coming out, cheap wireless networks will be next on the list of things that are cool for geeks. I mean WHO DOESN'T have their own intranet in their house???
Ignore the "p2p is theft" trolls, they're just uninformed
I don't know much about laser communications, but wouldn't things like the above cause the laser to scatter making it unusable in the above conditions? I could especially see this with rain because of the refractive properties of water. I do know my school uses this to get bandwidth, and all I have known it for is unreliability.
What about cloudy days, storms, or even ice on the windows (provided the instrument is housed)? Would these things effect bandwidth? BOFH answer #556454: You can't get your files off the server right now because the cloud cover is too thick.
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
I don't think having many repeaters would be that good for latency. For gamers and more generally interactive communications a low ping is more important than huge bandwidth.
True warriors use the Klingon Google
"infrared line-of-sight infrared lasers" All products are approved by our Department of Redundancy Department. -Kevin
A number of years ago, a friend of mine was at University of Colorado. They had two computer centers which were connected by an infrared laser which was pointed out the window of one building to the other building. It had minor data loss during snowstorms, but was pretty reliable. One day the window broke, and a repair person came by and put a piece of plywood over the window until they could get a piece of glass big enough to repair it properly. He didn't understand why all the computer people started yelling at him.... after all, *he* couldn't see the invisible light beam going through the broken window :-)
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
I remember reading about this a long time ago. The site that had it is down, but there's a copy on archive.org.
Get with the times, Slashdot! "News for Nerds" doesn't mean "News the rest of the world heard months ago"!
I could be wrong but it just doesn't sound that reliable does it? You've got joe shmo goes walking through this beam...just happens to look into the laser...this is how law suits happen...
infrared line-of sight infrared lasers
:-)
Are these lasers really infrared?
sudo eat my shorts
Slashdot has to have had an article on this... I saw a segment on these things on CNN over a year ago.
Nothing new here... move along
Casual Games/Downloads
...if you're using "infrared line-of-sight infrared lasers", then it sounds to me like you've already got redundancy!
"I want sharks with frickin' infrared laserbeams attached to their frickin' heads!"
sudo eat my shorts
How is this better than a high gain antenna using radio waves? Radio waves can be focused with antennas and don't have such problems going through clouds and pidgeons that light does. If you focus the radio waves you shouldn't have problems running out of spectrum should you? For years you've been able to do wireless radio links line of sight, what advantage does using a "frickin' laser beam" give you?
internet is down again. I think a bird hit our IR transcever again.
or
internet is down again. I think there is bird crap on the lenses or the transcever...
ok now seriously what about fog or low clouds on tall buildings? wouldnt that also create noise/bouncback?
Should have the "free registration required" disclaimer in the /. story.
btw, does anyone mirror stories from NY Times without the free reg req?
last I looked they don't have any respect for statues. What makes people think that their rooftop mounted equipment will be safe?
It seems to me that some sort of wireless IR lasers would work well in newly built neighborhoods where many of the houses are built close to each other so that there may be less chance for problems with long range issues. But then there may be problems with some of the electronics inside interfering with this signle, I don't know. Then again, newly built neighborhoods still have it easy to lay cables. DSDN anyone?
...would be hacking the kernel to transmit remote control waves. Imagine the possibilities:
And if that doesn't work, you could always use it as a spare heat lamp (very desirable when running an overclocked system...)
redundancy my foot
the way to avoid the "flock of birds" problem is to use REALLY powerful lasers. Some dumb pigeon decides to fly through your data stream learns who is boss, and a hungry cat on the ground gets a hot meal...
sure, you can't see IR laser beams, but it might not take very much to look at the packets going over the beam: the tranceiver assemblies are supposed to already take care of interference from air turbulence, so they might not notice if someone refracts off a little bit of the beam to their own receiver.
two problems to overcome:
1) how are you going to get up a couple of floors to do this, and
2) what if (and I would hope they do) encrypt the data stream?
The "repeaters" in this case can be placed indoors, in front of a window. One of the reasons for developing this system was to bypass the trouble and expense of rooftop transmitters.
And note that even in my summary I mentioned redundancy -- multiple IR beams are designed to compensate for bad atmospheric conditions -- and each hop in the network is a short distance for the same reason.
When I was at USC they used to have lots of the farther away buildings connected on IR laser. It worked ok, until it rained. Packet loss went through the roof. Summer of '98 they dug up all the streets and put in loads of fiber.
I'm sick of seeing that snarky little comment on every link to nytimes.com. We know about the registration.
This is good for many reasons. The cost is
primarily in the one time purchase of the equipment. And it makes a lot of sense where line of sight is a shorter distance than a fibre cable must travel (tops of buildings in a congested city). These dont interfere with radio freqencies, so you don't have to concern yourself with noise, or creating noise. And its unlikely a backhoe will ever be a problem (as long as it doesn't block the line of sight).
The downside is the line of sight. You ALWAYS have to have line of sight. Rain, fog, clouds, trees, idiots with signs, they all can cause problems. Short distances are less of a concern, but you still have to maintain an almost perfect orientation. A little gust of wind can have you dropping packets.
But its probably a better solution than fibre where running fibre isn't an economically feasable solution. But no matter how good this is, fibre has far greater potential capacity, even though we don't yet have the technology to use all of it. It doesn't make sense to start building the internet backbone out of these things.
-Restil
Play with my webcams and lights here
What if you'd mount like 3 lasers in a row, all sending an recieving simultanuously? Even while raining there should be at least one clear line of sight per .001sec. Fog relatet problems could be overcome by using more power.
0 001 11 1
It's a window-to-window system, dummkopf.
Wow, it is really impressing.
...but you would only know that if you'd read it before posting.
Laser Guided Surface to Air Missiles! That's what the lasers are for.
We do not live in the 21st century. We live in the 20 second century.
Did you read the article?
Did you even read the summary carefully?
Infrared line-of-sight links have been done for well over a decade. Datapoint's Arcnet had an infrared link device called Arclight that they used for a line-of-sight link for several miles. It would flake out in rain or fog - because rain and fog both absorb and refract infrared. So it might as well have been as opaque as black smoke.
...
Arcnet was a self-healing token ring network with an underlying broadcast topology. So if two buildings were connected by Arclight and it went down, the network split into two rings, and when it came back up it healed into a single ring. Reconfig took miliseconds so it was no big deal.
You may not have heard of Datapoint. But have probably heard of the Intel. Seems Datapoint had a discrete-component standalone computer/smart terminal which was the basic node in their network - a diskless-workstation, fileserver, compute-server archetecture. They cut a deal with a semiconductor company called Intel to try to port their instruction set to a silicon chip for the next generation. But the resulting chip was too slow, so they went with another discrete component solution.
And Intel had cut the deal so they could sell the chip. So they took the chip to market, perhaps with a few tweaks, as the 8008 - first in the line that continued with the 8080, 8086, 80x86, Pentium,
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
I bet that gigabit lasers with a range of 1 km will become reasonably affordable, because there really wouldn't be much to them. Entire neighborhoods could wire themselves together without requiring permits from anyone (and maybe split the cost of a fiber connection to the internet backbone).
Yes, as many have commented this is old news. There haven't been any breakthroughs on this in several years. Let me rephrase that ... no significant breakthroughs.
...
Once a year we have a customer come to us to ask about this option. Once a year we trot out our proposal, rerun the numbers and submit it. It always comes down to two things:
1) Speed
2) Reliability
The speed of the lines is fantastic when you have a clear day and relative distance is kept. Any atmoshperic conditions out of the ordinary will kill the line. Now, if you're only interested in using it for a mail gateway or to transfer data for a nightly batch cycle it rocks. For regular WAN access you'll be answering the phone from the folks on the floor.
Reliability is a concern past the speed. Keeping the connections is sometimes more an art than science. The article does have an interesting take on parallel transmissions, but commerically available products are cost prohibitive to make it a viable alternative for most businesses.
The best line from the article is: "Transmitting lasers through the air and modulating them at gigabit rates is a new and potentially powerful development," said Dr. Daniel Leslie, a physicist at Trex Enterprises who is familiar with the new systems.
Now, if you want to see something cool check out Dr. Leslie's company web page: http://www.trexenterprises.com/laserrad.html
If only we could work a Pringles can into this
quote from the article:
The lasers can be mounted on buildings' walls or roofs or behind windows, but they all must have one essential: a clear line of sight between the transmitting laser and its receiver
so yes, you can go window to window, but you're not restricted to that.
We had this at the office where I used to work. It seemed to go down on a regular basis, for a different reason every time. However, my favorite has to be the time it went down because a homeless person put a sticky note on the lens!
`fortune -o`
believe it or not, radio waves are actually light waves found way the heck at the end of the spectrum (on the same side of ultra-violet in relation to the visible spectrum of light.). infrared on the other hand, is just outside the visible spectrum next to red. the radio waves have a shorter frequency by far, compared to the infrared which travels at a much faster rate. put it all together and what do ya get? more info is able to travel on the faster infrared beam. just one question, is it possible to use your internet connection to change channels on your neighbors tv? that would be a rockin' prank.
attempting a visual model...
infrared---visible spectrum---radio waves
-high frequency - mid - low freq-
have a look at here. they are selling this for years.
www.laserbit.hu
Why not try a different variation on the SLOP idea? Just look at my PUSSY post. I also posted the one about a bouguet of flowers. Look at them both. ENJOY!
But the technology has improved. I set this up for several companies in the mid-90's. While it worked fine 90% of the time, there are many factors that prevented widespread use.
I found that 2.4 or 5 ghz wireless repeated are far more reliable.
I can honestly say I would end my life if I was forbidden ANAL COCKS! How could I continue LIVING without ANAL COCKS? ANAL COCKS mean the world to me and to give them up would be to give up life!
Hmm, this is nothing new. You, yourself, can buy a several watt (yes watt) IR diode and modulate it using an AOM to at least 100's of Mbits a second and more very easily for under $1500. This would easily reach a target for miles if the reciver made use of a dichroic narrowband filter and some good ECC. However, as mentioned, line of sight must be maintained.
Divergence, not mentioned in the article, is also an issue. Especially with laser diodes, it doesn't matter what kind of miracle anamorphic lens system you have to decrease the divergence of the beam, becuase pretty soon that pencil thin dot is going to become several feet in diameter. THIS is what accounts to loss more than so called 'atmosphere' causes. Photodiodes/transistors operate at a power/cm^2 ratio, and the lower this is out of the rated area the more noise. So when the beam spreads out, the concentration of power thins out and you get noise because although all your signal is getting there, you can only sample a small fraction of its power. Having low divergence also works against you because it makes the system much more difficult to align. I would start with a very large beam, just enough to get a signal, and then progress to the smallest beam possible. Vibrations at the transmitter site will likely limit this, as tiny shifts in movement only a mm will cause the beam to jump several feet miles away.
Many here have mentioned the speed is on the slow side for this technology. Well, folks, this is optics and that means you can do things in parallel. If you need more speed, just shift the wavelength of the diode and multiplex it in. This is the same principle behind DWDM systems, only it's in freespace. You don't even need a fancy FB diode to do it -- most commercial diodes have a 30 nm linewidth, and by controlling the voltage and temperature you can easily shift up or down. In any case, adding another same-wavelength line is just as easy as adding another transmitter/receiver pair at either end. If only you could do that for fiber. Instead, you have to dig up the streets.
I have had the pleasure of working with a system from Coherent that really makes free space communications shine. The system automatically adjusts and aligns itself via electronic gyros and GPS. It tells you if the current location even has any type of line of sight and if it does it zeos in on the beam (e.g. "I'm pointing S-SW, can you see me?"). The hardest thing is you must have a current connection to the other end while performing the alignment, but this was easily accomidated for at my location with a cellular modem.
This stuff is really cool and there are definate applications for anywhere that has good line of sight. For example, cell towers frequently have good line of sight to one another, so this technology would make sense for that application. There are enough towers that the network could be constructed in a serial or star configuration, without the need for many land lines near the tower.
What would be even cooler would be somehow using the high voltage transmission towers and installing a small, low cost module on each one to jump from tower to tower, or even pole to pole. Since it's optical, you don't have to worry about interference or expensive shielding (yes, there are all-optical transceivers out there).
These are just some ideas but the technology itself finally seems to be maturing. There are lots of current applications and it seems that although most carriers have loads of dark fiber underground, so the cable isn't really the problem, but maybe these companies will help drive bandwidth prices down by enabling small yet very fast ISPs to pop up and use the technology without having to haggle over ground cable. The Internet Revolution per se, isn't going to continue until we all have true broadband (10 Mbps or more, preferably 100 Mbps) to the curb for $19.95 a month.
"I'll just chip in a bit for RedHat: I actually have that installed on my university machine." - Linus, '95
What registration?
In order to get the laser printer working from their ethernet computer network (both of which they invented) they had to connect from one building to another. The "easiest" way was to use two lasers from the roof of the building. They had to bring it down as in the fog it was kind of distracting to neighbours and aircraft.
An Eye for an Eye will make the whole world blind - Gandhi
Does anyone know what this stuff costs?
Less Talk, More Beer.
I suggested this very same idea to my Cisco CCNA instructor about 4 months ago, and he said that it would never work over even slightly long distances because of interference by such things as rain falling into the line of the laser.
And then 4 months on, I read this.. I should go into network device design.
"Hey! Unless this is a nude love-in, get the hell off my property!!"
Doesn't that just sound like the start of a commercial?
Order now, operators are standing buy.
"Everything you know is wrong. (And stupid.)"
Moderation Totals: Wrong=2, Stupid=3, Total=5.
It's a great idea, and I can imagine people setting up IR beams between their various campuses to get fast networks.
The only problem is, what control do you have over the airspace rights over your line-of-sight? How do you prevent someone building an office tower that blocks 10,000 IR beams? After all, you have purchased no rights to that space, you're simply relying on the fact there is currently no obstacle. if you eventaully complain, the owners and former owners might ask for twenty years back rent on the air space!
Hmmm, a homegrown version of this does sound affordable, read this article ...
http://www.cedmagazine.com/ced/0009/9001.htm
Excerpt...
TeraBeamÂ's Fiberless Optical Network system features a point-to-multipoint (hub-and-spoke) configuration using 1550 nm lasers. At the heart of the technology is a transmitter/receiver that is about the size of a small satellite dish (estimated to cost about $150 to construct) that
Granted a total network of this is gonna cost
a fair amount, but a non-redundant cross
campus link could be semi-affordable .
Ex-misltech
google "32 trillion offshore needs IRS attention"
One company is " Guaranteeing " 99.999 %, AKA (5) 9's reliability , and does it thru a "Mesh" type network setup . They may have beat the problem thru multiple links and sending traffic over multiple paths . Info here : http://www.cedmagazine.com/ced/0009/9001.htm Excerpt here : AirFiberÂ's OptiMesh topology supports a mesh network of point-to-point wireless optical links using 785 nm lasers, each operating at 622 Mbps. The links are established between rooftop nodes that serve as an access point for that building, as well as a relay point for traffic originating elsewhere in the mesh. Each pole-mounted node is equipped with up to four optical transceivers, a standard drop to the building (an OC-3c/STM-1 or OC-12c/STM-4 interface), a control processor, a compact ATM switch that picks out the traffic for the building it serves, and cross-platform element management system software. The company claims the OptiMesh system will deliver 99.999 percent reliability.
google "32 trillion offshore needs IRS attention"
http://www.cedmagazine.com/ced/0009/9001.htm Excerpt : AirFiberÂ's OptiMesh topology supports a mesh network of point-to-point wireless optical links using 785 nm lasers, each operating at 622 Mbps. The links are established between rooftop nodes that serve as an access point for that building, as well as a relay point for traffic originating elsewhere in the mesh. Each pole-mounted node is equipped with up to four optical transceivers, a standard drop to the building (an OC-3c/STM-1 or OC-12c/STM-4 interface), a control processor, a compact ATM switch that picks out the traffic for the building it serves, and cross-platform element management system software. The company claims the OptiMesh system will deliver 99.999 percent reliability.
google "32 trillion offshore needs IRS attention"
I'm surprised nobody's brought up the do-it-yourself option:
RONJA
It's been on slashdot a couple of times.
Sure it only uses LEDs but it could use lasers rather easily. It would only up the price, and possibly increase the bandwidth.
If Mr. Edison had thought smarter he wouldn't sweat as much. --Nikola Tesla
Ding Ding Ding... Correct !!! http://www.cedmagazine.com/ced/0009/9001.htm AirFiberÂ's OptiMesh topology supports a mesh network of point-to-point wireless optical links using 785 nm lasers, each operating at 622 Mbps. The links are established between rooftop nodes that serve as an access point for that building, as well as a relay point for traffic originating elsewhere in the mesh. Each pole-mounted node is equipped with up to four optical transceivers, a standard drop to the building (an OC-3c/STM-1 or OC-12c/STM-4 interface), a control processor, a compact ATM switch that picks out the traffic for the building it serves, and cross-platform element management system software. The company claims the OptiMesh system will deliver 99.999 percent reliability. Ex-MislTech
google "32 trillion offshore needs IRS attention"
And if a pigeon takes roost inter-beam? Highest technology foiled by lowest organisms, again?
You might want to look at London's Sohonet who have been running line-of-sight lasers around London for ages. Of course, they know what they're doing with regard to optics, weather, range, and sunlight.
They also use fibre and SDSL links, which are cheaper in most cases - they have only used lasers in the special cases where it's cheaper than fibre.
po-leez subschriben be to yot bewsletter
Because just like clouds, fog and condenstation another big problem is that most office buildings have these neat windows that keep out as much sun as possible.
These windows have the added bonus that they tend to reflect *any* kind of optical ray everywhere but inside.
In other words, this does not work, we tried and switched the whole lot for a radiowave solution after finding out that a UTP cable from one office building to the next also wasn't too practical. Birds kept s(h)itting on it, resulting in more packet loss than was acceptable. And it sorta made strange patterns in the wind too, I don't think it would pass any sort of city security council.
Ah well...
-- Si hoc legere scis nimium eruditionis habes.
I had the displeasure of using one of these units (I forget who made it, but the heads had FreeSpace written on their sides in blue letters) for nearly a year with the company I work for in downtown Austin. The first six months of using the system were just perfect and I loved the units, but as time wore on we started running into problems with them. Eventually it became a running joke in the IT department ("Why can't I ping the Exchange server? Must be the laser!"). I was constantly on the roof of our building having to manually aim the laser heads so they would realign. This system would work great as a backup unit for conventional fiber or a point to point circuit, but don't have enterprise critical servers sitting at one end of these things and think that the lasers will give everyone flawless connectivity for any drawn out time frame.
You, yourself, can buy a several watt (yes watt) IR diode
Jesus!
I hope anyone using that kind of power makes sure they know what they are doing.
Because the IR beam is invisible your eye will not have a blink reflex to bright IR light. The first you will know about getting an eyefull of a powerful IR laser is when you blind yourself (or someone else)
You have no pain receptors on your retina.
Remember home made lasers can be an absolute bastard to align! A good staring point for information on home made lasers is Sams Laser FAQ
A good background to semicondutor lasers is Britney Spears Guide to Semiconductor Physics (Yep, its true! check out the link.)
Anyone quoted by a reporter knows how little they understand
Don't believe what you read is the truth.
I've been using one of these at home for about 20 years, to change the channel on my tv set.
While it's technically not a "laser", I feel its worth mentioning since I couldn't really have developed a healthy paunch without it.
I work for a company that was recently looking into importing these IR-laser wireless LAN connections from abroad and selling them in the UK/US. We decided it wasn't worth it for the following simple reasons:
1: who wants the connection to drop everytime a flock of birds flies infront, or the lense gets shit on. The models we looked at were unaffected by atmospheric conditions (so they claimed).
and 2: the damn things cost over $50,000. Theres no way its worth buying enough of them to get a proper redundant network, don't forget if you want this as your net connection you would need to pay for a 2mbit-155mbit line on top of these costs.
It sounds great at first, but isn't really useful except where you need to link between office LAN's and don't mind dropping shitloads of data.
It all sounds good, until a flock of birds fly by!
Skiers and Riders -- http://www.snowjournal.com
Lasers can also be made of microwaves. Microwaves travel through bad weather.
Since a laser is a dirctional transmission there should be little problem with interference.
Canon made a point to point near IR laser link, called 'CanoBeam' in 1999. I have tried their website to see whether it works in fog, but I can't get an answer. Anyone?
Someone might want to correct me on this, but I was under the impression that fiber was now usually ran through existing pipework such as sewers/storm sewers etc. in big cities. Feel free to tell me I'm wrong.
What?
Much like this proposal, carrier pigeons would provide a high latency connection. It's been fully considered; there's even an RFC on it:
Standard for the transmission of IP datagrams on avian carriers.
Opinions are not Informative, though they may be Insightful or Interesting.
Maybe there's a good reason why this is not a good idea, but here goes - Is there any good reason why you cannot string up fiberoptic clothesline-style? Or even use telephone pole-approach?
Both should be X times cheaper than tearing up a sizable portion of a pavement..
A decade? I examined this technology over 25 years ago, when I compared several commercial laser data links during a search for solutions to connect two buildings.
Clouds? If your building is that tall then you probably can solve the problem somehow -- such as by leasing nine square feet on a floor below cloud level.
Some of the commercial links run their laser through lenses which widen the beam to several inches across. One little raindrop can't block the beam. Blocking the beam requires heavy rain or many simultaneous raindrops along that long cylinder.
I used to work for a company in Soho, London that had three sites within a 400metre radius - their three individual LANs were linked together with two point to point laser systems, bandwidth was something like 100Mbps. Cost was NOT 50 000, but more like 10 000 per transceiver pair. The system was extremely reliable and quickly deployed this was about SIX YEARS ago - why is this news?
That was classic intercourse!
If the complex pays for a single t1 line, every apartment would have incredible internet speeds.
Talk about a good start up idea for every out of work techie out there. Start visiting these complexes, and offering your services to set up all the back end stuff. I'll bet they would jump at the chance. A single smart guy ought to be able to maintain the equipment for several complexes, and I'll bet you could charge monthly fees per unit.
Perhaps if they up the wattage... so that it burns through the rain/snow/birds...
The idea if creating local computer networks using the Chinese laser pointers is widely discussed here in Russia. The link can be made, and some enthusiasts really make it. The troubles come later.
Firstly, the link either should support Ethernet or be connected to the PC serving as a router. It's easy to make a, say, 38400 bps link using the laser pointer and infrared receiver from the TV remote control, but in the country where the average salary is $100 per month it will be impossible to find money for the router PC.
The 10-mbit/s link is much more sophisticated, and if you can produce it you can much easier obtain enough money to buy a 802.11. At least, living in a big enough city I cannot see-and-buy all the parts necessary to produce the link having the full schematics. Of course, I can order them and risk obtaining everything except the one critical part.
I dont't discuss the special extra rugged tripod for the roof-mounting of all this illumination, bands of young vandals, necessity to obtain the roof access permit (I don't need it, but in Moscow it's a rule!), old crazy ladies calling KGB and informing about the martians landing on the roof, necessity to place somewhere a router PC that produces the infernal noise and the Communication Supervision authority that begins to want a lot of money every time when the network gives a first cent of profit.
So the typical Russian LAN still uses the UTP, Ethernet and the military phone cables hanging between the buildings. These cables give the excellent ranges!
Low-power infrared laser beams are prone to disruptions by snow, rain and fog...
Then why not use a high-power laser? If the light were visible, I think the effect might even look cool. Imagine all of the buildings on campus connected by glowing beams of light! Of course, the lasers would have to be far enough above the ground to prevent terrorists from disrupting the network with duct tape or umbrellas.
"Leave the strategizing to those of us with planet-sized brains." -Tycho
Basically, they run a line in the pavement with a pavement saw and stuff fibre down the cracks. You can do a few kilometers in a week or so -- it's fast and you don't have to trench.
-- DrZaius - Minister of Sciences and Protector of the Faith
I have seen cat5 to fiber converters that are fairly cheep. Being a hardware kinda guy, I have thought about removing the usual transiver pair, and seperate the detector and emitter, place the detector and emitter in seperate 15$ scopes from say walmart, and give it a go. Should work well in a several block radius, except for the normal disruptions of rain snow, birds ect..
thats great until it snows, or rains, or a bird does its business on the device.
Why stick up for big business?
I work with near-infrared lasers on a regular basis (I do biomedical optics research) and I can tell you that despite the text of the article, 1550nm is quite cabable of cooking an eyeball. The reason they use 1550nm for telecomm is that it sits in the center of an absorbtion minimum (one of the water window) which minimizes losses, but that also increases its penetration through your eyeball. I really wonder if these things comply with ANSI Z136 (laser safety standard, here in MA required by state law; I don't know about NY). From the text of the article, I have my doubts.
Near-IR lasers, even at quite low output powers, are extremely dangerous eye hazards simply because the beam is invisible. You don't know you're getting an eye-full until your vision starts to fade (permanently!).
-JS
Vanity of vanities, all is vanity...
You're all stating that this optical link would be severely hampered by weather/birds/plywood, but what about using several laser beams all transmitting the same signal (or a slightly dephased variation of the same signal) ? Heck, if IR light has certain shortcomings, why not place a different wavelength-laser right next to it and let them complement each other's strengths and weaknesses ? I don't know squat about lasers but it's just a thought.
-Billco, Fnarg.com
Fun things to do at work with a laser:
1) You could use a mirror and direct the laser to use as a microwave for lunch.
2) You could use it to blind unsuspecting coworkers.
3) you could wave your hands through the laser light to disrupt productivity of other co workers.
We stopped using this 5 years ago. It is useless when it rains or snows. Once a day for about 15 minutes it would flake out as the sun shined into the receiver.
"Why?!? the files where are the files?"
"The networks down."
"OH MY GOD!"
"WHY!"
"BIRDS, BIRDS EVERYWHERE BLOCKING IR?"
"WHATS IR?"
You are SO ready for IBM infastructure.
Was that the part where you said infrared twice? :)
Actually the weather, especially fog, has some impact on the IR-link, as also some other posts pointed out. So this isn't quite as funny as some moderators thought. A students quarter near my place was linked to the net via an IR-link, since there was a convenient light of sight to the university. But they where very happy when they got a copper link, since they could count on loosing net connection when there was fog.
Also there were often other problems, apparently with the antenna and the signal converter sitting behind it (i only know that sometimes people had to go to the roof to fiddle with the equipment to get the link working again). So you probably should only go for an IR-link if you can stand the occasional downtime, or in sunny countries, where the waether doesn affect the line of sight.
--
"By the way if anyone here is in advertising or marketing... kill yourself." -- Bill Hicks
Yup -
all the way back in the early 90s! It was far, far cheaper to rig this up to get data connectivity across Huntington Ave in Boston than to tunnel underneath the T tracks. The city of Boston has a special levy they charge you yearly if you've got cabling running under the tracks. They can't charge you anything for IR-laser.
It's not a bad solution for short distances, and relatively moderate bandwidth. Although I suspect duplication and redundancy could improve both.
Could be a problem if you don't want to get interrupted playing quake.
Although this can be solved by cranking up the effect to a few gigawatts.
Didn't the french have a problem with this in Paris with La Grande Arche de la Defense? They couldn't figure out why their laser, from one side of the building to the other, would lose connectivity at random times durnig the day. Turns out the pigeons were flying through the beam and interrupting service. I guess the only way around that would be to build a massive network of glass tubes all over the city.
The idea is a good one. Time and again this concept has surfaced, it gets a little hype and then is lost again. What it needs is adoption on a large scale and ways to bring this to the domestic user.
Find a job you like and you will never work a day in your life.
1. During a good snow, it will not cross a street (200ft, +-10). (Commercial units. Had a demonstrable five mile range on a pretty day.
2. I don't know where you are located, but when it snows or rains here, it snows and rains pretty much all over the city (Anchorage, AK). Redundancy only works if a few of your transports get interrupted. Otherwise you get sit back and answer the user support line and make up excuses while watching the routes flap in the routing table.
3. Glass windows in many larger buildings are infrared mirrors. Heat loss reduction. Don't even think about the cost of changing one in a space-frame building. Equipment goes outside.
4. By the time we got "redundantised" and "routerised" to make the system even remotely reliable, paying the local one of the LECs for SONET transport was looking pretty good.
I might be tempted to use this where the sun shines a lot, or in large enclosed structures, or to some place completely inacessable by other means, but I don't think it's ready for prime time.
*whup* "Get along, little electrons. Heeyah!"
1245 gigabits to cook a thawed weener or 7232 for a frozen one.... Anybody got a long pointy stick... I'm hungry...
The race isn't always to the swift... but that's the way to bet!
I've looked into this technology for a client. The fSONA company, at least, uses laser light (1550 nm) that is eye safe.
Need a Linux consultant in New Orleans?
Username: "crappywebsite"
Password: "slashdot"
I tried to log in as "slashdot", with password "slashdot", which someone on Slashdot usually sets up. It told me, first of all, that my address "FakeAddress@hotmail.com" was already taken. (!) But then it started saying that "Slashdot" was already taken, and started tacking random numbers onto the end. So I finally got frustrated and registered "crappywebsite", given how long it took to register an account... *grin*
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suwain_2
hmmm, Is it foggy out right now?
maybe that could be your answer.
Paying taxes to buy civilization is like paying a hooker to buy love.
There's another way...infrared line-of-sight infrared lasers between your building and another one nearby.
:)
-1 Redundant
"How to build infrared video transmiter"...
Gives you scematics and part list.
Blahahablaha......
It's a neat technology, for sure. Very useful for avoiding installing fibre. And it's perfect for connecting things which are line-of-site.
Also relevant, how this was applied to Sept 11th Telco problems in NYC
-- Joe Crawford, web journeyman: San Diego California USA
SO many speak of things they know not of. Lasers are attenuated by many things in the atmosphere including humidity. You can select laser frequencies that are attenuated less by atmospheric effects but you cannot eliminate it. You can also kick up the power SOME. Lasers with very little power can cause severe damage to eyes and even skin. Read the warning label of the scanners at the store. They say don't look at the beam because they can cause eye damage. These are low power Class 1 lasers. Bump up the power to Class 2 or higher and you have severe eye risks. But you aren't looking directly at the beam? No problem, specular reflection (the bright reflections) have nearly zero power loss and present the possibility of eye hazard where you least expect them. By the way most of these lasers are in the infrared portion of the spectrum that you can't see. Your first indication of a problem is when you start having eye troubles.
I'm all for the technology but widespread use of it without careful consideration should not to be done. Cool trick if it gets past a problem at an acceptable level of performance but NOT a be all end all answer.
Build big giant DOMES over everything. ;)
I can't believe nobody's ever thought of this before.
[insert witty comment here]