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Fiberless Optical Networks
Alien54 writes "According to this Forbes Magazine article, the time for Fiberless Optical Networks may have arrived. Wireless optics have been given up for dead until very recently. But now better technology and lower product costs have enabled some to solve most of the problems. AirFiber (a company mentioned in the article above) is emerging as one of the favorites in wireless optics, and seems to have a set of good answers for the inevitable "bird and fog" questions: Can a flock of birds take down a network by flying through the lasers? Can a heavy fog send your precious information into the ether?"
Damn straight it dosen't make sense. But then again alot of things don't make sense. Like why in the hell some many people are using windows. (Hey it's my first bash MS post on slashdot.)
Are you sure (because I'm not) that you're not confusing the origins of TCP with the origins of Ethernet?
This next song is very sad. Please clap along. -- Robin Zander
Give me microwave anyday...
No, shit-for-brains, the poster said wireless system. Of course he's wrong, but that's not the point.
Pay attention to the words.
Your failure to grasp the point is astounding. Of course you wanted to say something. Your use of the moronic "go for it" to justify your irresponsible behaviour, followed quickly by the ironic "Go write something meaningful," speaks volumes.
Wouldn't this make your network a easy target for packet sniffing? All that a potential culprit need to is to point his/her own sensor skyward and they have read full access.
Similarly it would be trival for such an attacker to send their own data, issuing their own commands to machines etc...
This scenario, to me, obviates the need for encryption in such systems, increasing cost and complexity.
Having made these points, I realise that the problems apply to any unguided media (e.g. microwave links) and not just to 'open' light systems.
Practice random senselessness and act kind of beautiful.
Actually, the light coming out of the top of the Luxor in Las Vegas (not a laser, but highly collimated) has been known to kill a few birds now and then.
I have a positive modifier on Troll. When I mod someone Troll their karma should go UP!
The wavelength of the laser is 780nm. AirFiber uses the same type of semiconductor laser as that used in writable CD-ROMs. So does this mean that I can hack my redundant writeble CD-Rom drives into a redundant 622 Mbps Fiberless Optical Network?? COOL!!
Sig (appended to the end of comments you post, 120 chars)
And when we do, is it going to have the same limitations that the present ones do? Could different light frequencies be used to allow 'fuzzy' rather than binary computation? Or more importantly, could the instantaneous 3D alteration of circuts allow people to 'evolve' intellegent computers like the circut boards that were 'evolved' to recognize a specific tone without a clock. ... don't have the link handy. It was in Discover about 2 years ago if anyone knows what I'm talking about. Kind of like evolving an algorithm, but on the hardware scale.
Also, where are the replicators? I want food and all the restaraunts are closed, dammit. If I had a matter transporter I could go somewhere where it was daytime. And a warp drive would be nice, too--cut down on commute time!
I have a positive modifier on Troll. When I mod someone Troll their karma should go UP!
I am very sure. Terminal Control Protocol was designed by the U.S. Army for use with wireless teletype terminals.
It ofcourse under wnet many changes during the years (integration with NCP, changes to accomidate the OSI model), but it had its humble origins way back when.
Read Stevens.
I am very small, utmostly microscopic.
Hi, just want to tell you that this laser thing really is old. Here at Aachen (in the very western part of Germany) the student hostels "Die Türme" (the towers, called so for being the four heightest buildings here in Aachen) of the technical university RWTH use such a laser to connect their local network via the laser with the main computer facililty of the RWTH and the web. The laser is about 4 years old and has a max. bandwith of 40Mbit. And yes, fog and heavy rain is a problem. Have a look at: http://www.oph.rwth-aachen.de/ag/netzwerk/technik/ laser.html
for the technical data and here, you'll get a picture: http://www.oph.rwth-aachen.de/ag/netzwerk/technik/ laser.bilder.html
(No, that's not me on the picture)
. Sorry, all pages are in german.
by physically dipping into the lightstream with a dental mirror attached to an optic? (Kewl!)
"..don't you eat that yellow snow."
Actually, the article and the summary above call it Wireless Optics, not Wireless Fiber. It uses Optical technology without using Fiber Optics. It uses lasers.
The rest is the attack of the marketroids, I suppose
"It is a greater offense to steal men's labor, than their clothes"
Not the birds or the fog. But if this is takn up by a lot of ppl/companies, will we not see bandwidth pollution similar to what is/happening with devices that operate in the 3G spectrum? The portable (not mobile) phones, the radio lan cards that are made, the airport (from apple)(yeah bastratdised radio lan cards), [perhaps the previous could be summed up as 802.11].??
.plan = NULL;
.sig =
Do the following really mean anything? SCSA MCP CCSA CCNA
--I'm not actually after an answer!
No, X-rays wouldn't work. 1) X-rays are difficult to deal with - focus, detect, etc. Normal mirrors don't work for X-rays, you need special mirrors and use blazing angle reflections otherwise the X-rays just pass right through your mirror. 2) X-ray detectors are still a work very much in progress, and generally you won't get both time resolution and frequency resolution, which are cruical in this game.
Say you put one up on your building. Then you have one connection to the main office. How are you gonna convince other companies to put these up on their buildings so that YOU have a reliable network connection? Especially at 20G a building.
Although, laser tracking, laser power adjustment, and redundant paths are a good way to combat the previous problems with laser networking.
Thing I'm wondering is what is the maximum available bandwith with an unladen african swallow, hmm?
Zero. If it's carrying any data, it would therefore be a laden swallow. It doesn't even enter into it if it's African or European.
I found an horizon calculator here, and at a height of just 50 feet (which is what, a 5-story building?) the horizon is ~9.5 miles.
This might be an issue in a suburban office park, but even here in little Baltimore we've got plenty of buildings higher than that. In particular, the World Trade Center in the harbor (which would never be confused with ones in New York) is 423 feet tall, giving an horizon of some 27 miles.
This next song is very sad. Please clap along. -- Robin Zander
The buildings are about 1/2 mile to a mile apart. 10mw Output power.
More info here: http://www.astroterra.com/
Fog is bad enough. What about people actively trying to do bad things to the network? Forget hacking. Just set off a smoke bomb. And what about packet sniffing? Send a model helicopter with an optical receiver to intercept the data...
So while you're sitting there telling us that it's all vapor and research, while companies around the world are currently using AirFiber technology to provide internet service.
Links you might want to look into...
h ttp://www.alphalink.com.au/~derekw/upntc vr.htmt s/laserlink.html/ members.mint.net/n1bug/tech/laser/lase rfr.htmle pairfaq.org/sam/lasersam.htm ://www.qsl.net/k3pgp/opening.htm
http://atrey.karlin.mff.cuni.cz/~clock/r0nj4/
http://www.hut.fi/Misc/Electronics/circui
http://www.geociti es.com/SiliconValley/Lakes/7156/laser.htm
http:/
http://opencollector.org/
http://www.r
http
The first link actually seems to be the best - instead of lasers, ultra-high brightness LED's are used - no great distances here, but aiming doesn't have to be as accurate, fog/rain/birds are less of a problem, the hardware interface is rather simple, and the LED's (and other parts) are cheap!
I support the EFF - do you?
Reason is the Path to God - Anon
"Most likely, yes. Anything that interrupts or degrades the signal will be a problem. What about thunderstorms, which tend to emit on a lot of frequencies?"
I don't know much about the other companies, but I know with AirFiber:
* Birds are not an issue; signals are rerouted (the network is redundant) as soon as the connection is broken, which then automatically relinks;
* Fog hasn't been a problem. Look at it this way -- if you can see a flashlight shining through the fog, you can see this laser.
* How would thunderstorms be a problem? We're not talking about RF frequenciese here!
You are right, of course, but there may still be other obstructions in the way. And, of course, with greater and greater distance (and higher buildings) sway is much more of a problem. I daresay with a 2-story building over 1/2 to 1 mile distance, sway is not an issue, but atop the World Trade Center the sway can be several feet.
Add to this the fact that even a laser will spread and scatter greatly after a distance as great as 27 miles. For various reasons, it's unlikely that optical wireless can be made to cover great distances any time in the immediate future.
These people looked deep into my soul and assigned me a number based on the order in which I joined.
"Who's going to try it first?"
Several companies are already currently using AirFiber's system.
I'm posting this over a (gasp!) 14.4Kbps modem because my cable modem service has been out for the last 18 hours. (ObIrony: the customer support line is just a recording, and the ISP's advice when your cable modem isn't working is to send e-mail to tech support.)
Meanhile the phone company keeps calling to sell us ADSL, but once the order is placed they forget all about it. (This has happened three times this year already.)
The problem is not the cost of materials; the problem, especially in cities, is in waiting for city bureaucracy to give a permit, paying a huge fee for the permit, digging up and later replacing concrete and steel to lay the cable, inch by inch, block by block. This gets ludicrously expensive even over inconsequential distances.
I haven't heard that TeraBeam has any solutions to these problems, but I know the folks at AirFiber have. As they mention in the article, they space the R2D2s based on weather patterns in the area.
Does anybody have figures on how much a well-focused laser will spread? I seem to recall that when you bounce it off the Moon, the area covered is measured in square miles, but I haven't looked it up.
I'm guesing that atmospheric conditions (and other buildings) represent the biggest obstacle.
This next song is very sad. Please clap along. -- Robin Zander
Thing I'm wondering is what is the maximum available bandwith with an unladen african swallow, hmm?
Most likely, yes. Anything that interrupts or degrades the signal will be a problem. What about thunderstorms, which tend to emit on a lot of frequencies?
Yup, thats pretty much how it works. the glasses generally work much the same way night vision glasses work, except that night vision glasses aplify visible light, whereas these would amplify light at frequencies that correspond to the laser you wanted to look at.
Running a 30 mile cable takes several months to a year. Running a laser for 30 miles would take a few weeks at most. To calibarate it, it would only take a few days.
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A classic example of this type of problem can be seen on our nation's (United States) highways (bear with me). Back in the dark ages, before the national highway system was built, people tended to settle near their places of employment. As the suburbs grew, the need for a larger traffic infrastructure became apparent. As a result, the highways were built; however, in many cases they were built with a) old technology b) poor planning for future growth and c) limited space. Now we're in the middle of huge construction projects all over the country to deal with these issues. Once again bear with me... So what does this have to do with IP networking, specifically wireless networking? Well - the issues are the same. As the demand for high speed connections grows (especially in residential areas), the infrastructure will have to mature. Due to space constraints, cost of land lines and other things mentioned by earlier posters, we can't really have new land lines sprouting up wherever. Not only that, but it's not in our best interests. Any solution will become obsolete someday, but wireless systems are more applicable to the situation at hand; if we are unable to adobt such strategies, we'll face similar problems on the Internet than what we do on today's highways. If anything I said wasn't apocryphal and totally based on opinion rather than fact, I apologize. I'm really looking for a forum to b*tch about the fricking construction project right near my house.
by ramping up the power but people might complain when we run out of birds.
Also it could get messy for a while what with all the headless pigeons and arms of careless windowcleaners falling about the place.
Bob.
That really doesn't make any sense--therefore, invest in it!
I now have incredibly high-tech phone misdirection and blocking devices! They're called "prisms".
Oh well. Even if it *does* work, my phone card still won't be activated, and I'll have to call the company somehow to tell them my phone service doesn't work...
I liked the paper-cups-and-string method much better. And I didn't have to rent the string! What am I doing now, leasing the air?
---
pb Reply or e-mail; don't vaguely moderate.
pb Reply or e-mail; don't vaguely moderate.
The abandoning of wires would save hours of diagnosing faults within wire connections for network administrators, and a laser data transmitter could be physically repointed at a different reciever with ease without even having to unplug cables and reconnecting them. With so much potential for this market, why is Air Fiber focusing on the outdoor market when they could perfect this technology for indoor usage with much less cost?
This idea also reminds me of the concept, which has been purported for years, that wireless optical could become the next medium for data transfer within a computer's processors once silicon had reached it's the height of potential. Whatever happened to those projects?
MashPotato - Mobile Array of Support Helpers for Potato
-- "I can't tell the future, I just work there." -- The Doctor
I work for a major Internet bandwidth carrier and know how long it takes to get fiber/DS1s/DS3s provisioned both in and out of the US -- for freeking ever. Totally unacceptable times for the fast moving business of technology that we all work in. DS3 in a month is a total miracle. DS1s get installed after about 6-9 weeks on average. Our customers get really impatient, and there is nothing that we can do because we rely on the Local Exchange Carriers to get the line to the customers. Getting the customers to the core is not an easy job.
2 00&cid=5 because I thought it was just plan funny, even for a troll post.
Having the ability to point a laser at some building across town, having been able to set it up in three days or less, would be flippin' awesome. Think about how great this would be for one time conferences and setting up temporary solutions. Who cares if it is not totally stable -- birds, fog, and your occasional script-kid gone cute with a big kite, trying to knock out your service.
The building at which I work does in fact have a wireless (not optical) Sonet connection, along with standard OC12s and OC48. It should be noted that the city which I work and live also is a current test bed for Sprint and their wireless broad band solutions (also not optical in nature). These are excellent and very viable solutions for a quick connection.
It should be noted that I had moderator points and *really* wanted to moderate up http://slashdot.org/comments.pl?sid=00/08/20/2234
No, the labor costs more then it costs for an expensive laser. Plus, if someone digs a line up, think about the problems that causes.
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This is a very good point. If a fiber line is obsolete, if needs to be dug up and what not. A wireless system just needs to be replaced.
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Guess I've offended the "community." Bet something whitty is coming my way. Woo hoo. Don't forget to tell your friends.
Oh yeah. I believe the sympatico internet is available only in Toronto right now, but it will be great for cottage country.
Even the samurai
have teddy bears,
and even the teddy bears
Even the samurai
have teddy bears,
and even the teddy bears
get drunk
I confess I thought perhaps you were recalling Ethernet's influence from AlohaNet and the collision detection / avoidance needed in a broadcast network.
This next song is very sad. Please clap along. -- Robin Zander
And would you have to put window cleaners on danger pay?
.... agggghh me arm!!!"
"When I'm cleaning windows
Bob.
People may use wireless optical stuff to simply avoid dealing with awful phone companies. Our t1 is upheld by the Verizon fiasco (may be in Fri) now. Att *could* do frame relay for us, as it is 2k for the drop and 1900 a month, in 30 to 45 business days. To expedite the delivery to 15 days, they want to bump us up to national service, so that would be 7k for the drop, and 5300 a month on a 36 month term = a 200k over 3 yr. commitment. We are actively looking at the lucent wireless gear, but building height on our new site is a problem.
Its misery like this that will help push people to find new high bandwidth solutions.
matt
I'm not being sarcastic, either ... I think that lasers could be dangerous. Even those laser pointing pens that kids love playing with can cause retina damage.
Can a network take down a flock of birds that are flying through the lasers?
Now that would be cool.
pronoblem
const double MAX_POWER=500.0*ONE_MEGAWATT
const double NORMAL_POWER=500.0*ONE_MILLIWATT
if (flockOfBirdsDetected()) {
setLaserOutputPower( MAX_POWER);
wait(1);
collectCookedDinner();
setLaserOutputPower( NORMAL_POWER);
}
Donte Alistair Anderson Roberts - hi son!
Karma: Chameleon
I can see how this would interfere with RFC 1149and RFC 2549 based networks. "War of the networks"? "Imminent death of the net predicted, film at 11"? It would take care of dinner nicely, though. Pass the cranberry sauce, please?
Stefan.
It takes a lot of brains to enjoy satire, humor and wit-
The truth shall make you fret. (Ankh-Morpork tImes motto)
that article in forbes seems to have more real info than the company site itself. but they still dont mention the frequency the lasers use. they dont say anything about beam width etc. the guy who did the interview with forbes says he used "special glasses" to view the beam, which almost certainly means theyre using infrared which therefore means water (eyes for example) is going to appear opaque to the beam. now if the beam power is going to be continually adjusted for atmospheric conditions (btw. what about heavy snow?) im guessing its going to have to be fairly intense at times. i dont know if i trust their cheery "it's even safe to look in the beam" propaganda. they could've at least given the laser CDRH/ANSI classification somewhere on the site.
- "Hear that?! The percolations are imminent! Cease your ingress!"
Can a flock of birds take down a network by flying through the lasers?
;)
Well, if you increase the power of the lasers, you could then only need to pose this question:
Can a network take down a flock of birds flying through the lasers?
Problem solved.
Beware to the people that are interested in optical networking, unless you are so interested purely from a research standpoint. Optical Networking is the term to be talking if you are a Venture Capitalist these days. VCs are just pumping more and more money into any company that has optical networking in its business description. And, just as dot-coms had their flops, so will optical networking. Optical Networking stocks are also flying through the roof, just as dot-coms did a year or two ago. I'll be wary of optical networking for a good while until several leaders truly come out ahead of the pack.
Optical Networking is ALREADY here. All the major network backbones run over fiber optics, hell even most cable companies have a hybrid fiber/coax network.
Also, the leader HAS emerged, it is Nortel, they sell $10+ billion/year of optical networking gear.
With the recent Lucent record of over 3 Tbs transfer speed across 300 km using "classic" fiber optics channels (reported on slashdot earlier) I see less utility value in pursing wireless fiber optics channels. The decreased material costs of fiber will be more then likely offset by increased costs in power consumption, due to attenuation of the signal in water molecules and solid particles. I think wireless fiber still has more than a few years to mature.
Firing lasers off through the sky is only a temporary solution. You will always get higher transfer rates using an actual fiber becuase it is such a better transmission medium. However, it is quite expensive to run fiber all over the place right now, as prices go down it will become more feasible and things like this will die off.
780 nme t.HTM
http://www.airfiber.com/products/faq/Html/helps
As for saftey if meets IEC Class 1 requirments.
The FAQ seems very comprehensive.
Wireless networks have several advantages over traditional land lines, especially in areas of rapid expansion. For one, the right of way issues are greatly reduced. It is a severe pain in the ass just filling out the forms to try to drag a cable across town, or across the state, or across several states. And it's not cheap either. The expense of actually laying the cable is also quite substantial. However, with wireless networks, you only need to setup a few base stations and boom, you've got a network.
Pretty soon, everyone and their mother (literally!) will be wanting / needing broadband access, and right now a lot of people (and businesses!) just don't live where it's possible to get broadband any time soon. DSL is great, but the limited range means a lot of people are left out, and the limited speeds makes it unsuitable for a lot of uses. The best hope for most locations is a cable modem or getting their own line laid, cable connections are not particularly suited for high bandwidth serving or businesses, and paying for your own line to be laid is just murderous. On the other hand, if someone could just install a wireless connection with T1 -> OC1 (or faster) speeds with little delay they would make a lot of people very happy.
Additionally, wireless networks are well suited to developing countries. There are lots of places on this Earth that lack even basic telephone service. By bringing wireless networks to these places, they can not only get phone service at much less the cost than they would be able to through more traditional setups, but they can actually get not too shabby connections to the wonderful world wide internet. In fact, many countries are deploying wireless telephone networks for precisely these reasons.
Well, look at it this way. Think about how long it takes to run a 30 mile fiber line.
True, that does suck, and it's still pretty expensive.
Now, think about how long it would take to run it wireless. Just point and shoot.
Easier said than done. You'd need to calibrate the transmitting device to probably the nearest thousandth of a degree in each direction to be able to hit your receiver about, say, 1 mile away. (very crude, out-of-my-arse calculations.)
The other issue is what might be in the way of the signal -- around Pittsburgh, for example, the terrain is rather hilly. It'd be hard to set up a link between downtown (even on top of the USX tower, ~850 feet high) and Greentree, only a mile or so away, as Mount Washington tends to get in the way. Not to mention what random building might pop up in between your two stations.
Bringing something like cable or DSL into new areas would be quicker and cheaper. The labor costs for laying the line is much higher then a more expensive wireless system.
True, in maybe the Midwest where there are no tall hills. Around here, we're stuck with the classic guided media, expensive as it might be.
DrQu+xum: Proof that the lameness filter doesn't work.
I'll be wary of optical networking for a good while until several leaders truly come out ahead of the pack.
Then Cisco will buy them and we'll all be back to the start.
It would make for a nifty way for a few houses to share a broadband connection, too, if the cost is a problem.
I wrote parts of this stuff
Well,
old radar used to be (still is?) microwave, so I've heard similar stories of foxes/cats coming to feed on the birds microwaved near commercial airports.
However, given that the mast probably was metal, it probably would have been a bad idea to microwave it. (visions of tesla coil lightning bolts arcing from the mast...)
I always thought big carriers should supplement their food by fishing. Does anyone know if they did this in the bad old days of sailing ships and salted meat?
OTOH, this may finally cure the pidgeon problem that most major cities seem to have.
--
... open up that data haven in Kinakuta I've been dreaming about all these years.
"If you look 'round the table and can't tell who the sucker is, it's you." -- Quiz Show
From the article:
"And, with asynchronous transfer mode technology (ATM), the lasers have become intelligent enough to track the laser beams between the two optical transceivers, so they never get off target."
How the heck is ATM going to keep the lasers on target? I think the author confused this with ATM signallig setting up SVC's on the fly to provide reliable data transfer through the network in the case of a link going down.
Fog that limits visibility to 10 meters? Where do you live?
Come spend a spring in New Orleans or London. We get fog that, literally, limits all visibility to less than 2 meters. That means it's very hard to make out your hand held at arm length. Very scary stuff.
Bit rate is proportional to bandwidth times the logarithm of the signal-to-noise ratio. To maximize bandwidth, you go up to higher and higher transmission frequencies. To maximize signal to noise ratio, you step up the transmission power. But in a wireless laser network, both of these steps have their disadvantages.
The first problem is essentially that the higher frequencies (e.g. infrared, which is on the order of microns, as opposed to microwave, which is on the order of centimeters) are more susceptible to various scattering phenomena. The most frequently mentioned is, of course, fog, dust, smog, etc. These scatterers are far to small to have any significant effect on, for example, cellular communications (transmitted signal has a wavelength of tens of centimeters, not microns), but they are excellent scatterers in smaller wavelengths. In addition, the atmosphere itself scatters visible light more and more effectively as you go to higher and higher frequencies, reaching a maximum somewhere in the ultraviolet. This is due to the electronic properties of diatomic nitrogen and oxygen and cannot be avoided. (As a side note, it is also why the sky is blue and sunsets are red). So, one cannot step around the fog problem by going to even higher frequencies. I believe, but am not certain, that fiberless lasers still operate in the IR.
The second problem, of course, is that stepping up the power output of the transmitter is expensive. A tenfold increase in bandwidth requires a thousandfold increase in signal to noise ratio. To see why this is so, imagine that with a given signal to noise ratio, you can resolve 16 signal strengths with a bit error rate of less than, say, 10^-8. This means that you can transmit 4 bits of information per symbol. To get twice as many bits per symbol, or double the bit rate, you need to be able to resolve 256 signal strengths - i.e. square your signal to noise ratio. To get 12 (three times as many) bits per symbol, you need to cube your S/N, and so on. Essentially, you have to double your S/N for each additional bit per symbol you wish to be able to resolve at a certain bit error rate. Hence the need for enormously increased power to achieve relatively modest increases in bandwidth.
So, with these constraints in mind, it will be interesting to see what optimum is achieved by TeraBeam et al, and how resilient their systems turn out to be.
Dave Bailey
Unless there a method that uses radio waves I can't see how that would be a problem. If you are using on/off states in binary to transfer informaion all the receiver needs to know is wheather there is light or not at any given time. I don't get it.
Respond to s
Ibag
"Me fail english? That's unpossible!" --Ralph
This reminds me of something more than 20 years back: Datapoint's "ArcLight", for their Arcnet.
Arcnet was a token-ring based network with a broadcast topology. Cut the connection between two parts and it immediately reconfigures into two nets. Plug it back in and it reconfigures into a single net.
Ran on 8080-based terminals.
To get between buildings they used a gadget with an infrared laser diode (which had just come out) and a photodiode - each behind a lens about 6 inches in diameter. The device looked somewat like a weatherproof half-height-full-width monitor case with a little bit of a lightshade and the screen replaced by a couple of big glass eyes.
In a city where most buildings weren't skyscrapers (so a little defocussing could deal with building sway and clear-air turbulence without too much energy loss and interference acceptance), clouds and fog were rare, and at a time when high-speed data lines were 300 baud, it was great. A LAN that spanned multiple buildings. If the fog rolled in the network partitioned until it went away (no data between the head office and the branch for a couple hours, but the nets WITHIN the buildings were still up. Birds were handled by retransmissions that were part of the normal protocol.
Something similar would be easy with IP these days: Run a low speed (56k, T1, whatever) between the buildings AND put up the high-speed link. On foggy days your bandwidth drops but your connection is still there. IP also understands flakey connections and rerouting around them, and TCP understands using retransmission to make a reliable connection over unreliable links.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
It's amazing. Take a perfectly normal concept, like meshed networks, and apply it to wireless, and suddenly, you have made some kind of great advancement of science.
I don't see how this is any different than normal problems. Ther are using a wireless PHI.. fine.
The only point the article has made is that the price of optical open-air laser networking gear has come way down, so now it is feasible to build meshed networks with it, and hence, overcome some of the inherent problems with it.
And if the equipment used to cost $150,000.. how much do you think the monthly rental for that DS3 cost anyway? Not cheap. It will quickly dwarf the cost of equipment.
Of course, when we talk about canned networks for corporations (which *IS* a big deal these days), this gets more interesting.
prices will go down for the fibre it self but you'll still have right-of-way issues to deal with using any kind of land-line.
Now, think about how long it would take to run it wireless. Just point and shoot.
Bringing something like cable or DSL into new areas would be quicker and cheaper. The labor costs for laying the line is much higher then a more expensive wireless system.
until (succeed) try { again(); }
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Can a flock of birds take down a network by flying through the lasers?
Maybe they could adapt RFC 1149 - A Standard for the Transmission of IP Datagrams on Avian Carriers and, instead of seeing the birds as a potential problem, use them as carriers. Sure, a device would have to print the scrolls of paper, and attach it to the birds. It would probably decrease bandwidth, as the mentioned RFC mentions: "Avian carriers can provide high delay, low throughput, and low altitude service.". It's worth a good read.
To deal with this, they could also use RFC 2549 - IP over Avian Carriers with Quality of Service .
-
Roses are #FF0000, Violets are #0000FF, find / -name '*base*' |xargs chown -R us && mv zig greatjustice
Then for example you could connect to your linux server from your basement 100 stories underground when nuclear warheads are going off above you.
Two small problems with that:
1. Your Linux server had better be in a reinforced building strong enough to withstand a nuclear blast.
2. Even if it was in such a building, the radiation from the nuclear blast would interfere with the wireless communication.
In the interests of keeping this post on-topic, this is different from wireless/packet radio in that light and radio waves are two very different things. Light waves are on a *much* higher frequency, and as such aren't as prone to interference from man-made radiation (such as the nuclear blasts that sips brought up). But, the tradeoff is of course that there are line-of-sight issues.
=================================
I pledge allegiance to the flag...
of the Corporate States of America...
I just didn't have the time to read the whole /. article.
But you had plenty of time to post and waste everyone else's time.
...wireless environment, which you should know if you care to crack open any introductory text on the subject (I prefer Stevens , TCP/IP Architecture Vol.2).
Problems with signal degradation have already been solved. In fact, the U.S. military has been using wireless data communications for years. The speed isn't all there, but the basic problems have already been solved.
I am very small, utmostly microscopic.
Hrm. Lasers are inherently polarised. How easy is it to switch that polarisation and to transmit (say) error correction in the polarisation, information in the carrier?
like can your lasers take down a flock of birds...
Check out our infosecurity industry blog: http://securitymusings.com/
I wonder what birds flying through my data would look like? Fog I know, I see that all of the time.
Even the samurai
have teddy bears,
and even the teddy bears
Even the samurai
have teddy bears,
and even the teddy bears
get drunk
A Flock of Seagulls has migrated through the lasers' paths!
Ha! I kill me!
In addition to mesh networks, AirFiber's engineers are using weather histories.
:)
Come on, I won't even base whether or not to carry an umbrella on forecasting, I'm not going to trust my network to it.
You're right most optic fibre I've ever delt with has been wireless, no wire just glass or some other clear stuff.
But I spose they couldn't call it fibreless, because they would be alot of lans out there that can claim to have no optic fiber or fibreless.
You can't see a laser unless the light is directed at you. That's why they have to have smoke at laser light shows. Otherwise, nothign scatters the light from it's straigh path. Think of it like a stream of bullets. A number of those bullets has to be deflected from the stream and 'hit' your eye in order for you to 'see' the stream of bullets. I don't imagine that this scattered light would be too easily deciphered since it would probably just be a bunch of random ones and zeros.
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It's the end of my comment as I know it and I feel fine.
That's what you do currently with a standard voice line you lease it if I remember correctly.
Respond to s
Hmm this seems really, really vulnerable to just setting up a completely new set of mirrors to my house and suddently I could have a T-3 like line without paying :) I mean really what kind of safeguards prevent hijacking the data stream of some backup system and inserting an infinite look of Jigglypuff's song instead?
Respond to s
is a really big mirror. That'll teach 'em. But then isn't your datastream completely unguarded? You want to have some pretty good encrypt if anyone can just look at the laser and poof! There's all my data!
The Blaster Master Fighting for Truth, Justice, and Evil Pie since 1979
Optical transfers was one of the very first methods of communications, the smoke signals, and the (relativly) more modern morse code between light towers. The reasoning behind non-wireless optics is there is WAY to much interference natural light can even affect the noise, not to mention if you have expensive lasers or even moderately priced "laser" diodes strung everywhere to be taken down by a storm, a tree, birds, fog... a thousand factors. I feel that wireless optics will not come to light (no pun intended) for years, if ever though cause simply too expensive and there is good competetion in microwaves and other systems. You can read a basic intro to fiber optics at http://chrispy.darktech.org/fiber.html
Who's going to try it first? I think it's going to take a little while for this to spread. Most people don't have bandwidth to waste or to spend on trying things like this. It will be huge companies that have the time and money to spend doing it and eventually it will spread to people that actually use it or need it.
--And sektor spoke and said unto the people. Hey, buttwipe hand me the cheezeos.
We're using a 100Mbit laser right now to link our two buildings in San Francisco. Plenty of fog, never been a problem as far as connectivity.
Great technology, saves a lot of money in trenching to lay fiber. Now we're looking at a gigabit upgrade for the laser!
With the recent Lucent record of over 3 Tbs transfer speed across 300 km using "classic" fiber optics channels (reported on slashdot earlier) I see less utility value in pursing wireless fiber optics channels.
The decreased material costs of fiber will be more then likely offset by increased costs in power consumption, due to attenuation of the signal in water molecules and solid particles. I think wireless fiber still has more than a few years to mature.
People seem to be saying that this will be useless because of fog. Well, this is intended for high-bandwidth, short range applications. This is for getting between two adjacent dorms on campus, and does not replace the microwave radio technology for longer distances. You can try to use it for longer distances, just hacking around, or on non-critical links for gnutella or whatever.
You might be able to hack together your own network. People have done this using laser-pointer parts but these things burn out as they are not designed for full duty-cycle. Would surplus CD drives work better? And there's still a drift problem, but if you were to make a 3 x 3 grid (or larger) of detectors you could detect and correct drift before losing connectivity. This requires the affordability of multiple detectors.
There was a home-brew laser network project in australia that was eventually abandonded because they couldn't overcome drift problems. I can't find the URL right now, I'll post it later.
Beware to the people that are interested in optical networking, unless you are so interested purely from a research standpoint.
Optical Networking is the term to be talking if you are a Venture Capitalist these days. VCs are just pumping more and more money into any company that has optical networking in its business description. And, just as dot-coms had their flops, so will optical networking.
Optical Networking stocks are also flying through the roof, just as dot-coms did a year or two ago.
I'll be wary of optical networking for a good while until several leaders truly come out ahead of the pack.
You should never take life too seriously - You'll never get out of it alive.
Would some please explain how they're using a $20 CD-ROM Laser to communicate over a couple hundred meters?
I mean, with such a weak laser, wouldn't the beam degrade in just a few feet in PERFECT conditions? Even without fog, air will still scatter a laser. Or maybe I just missing something obvious.
Has anybody thought about the security issues?
One of the advantadges to fiber is that it is incredibly difficult to tap, and the tap can be easily detected. Is the same true of wireless optical? And is tapping even relevant? I would assume that in the case of the Internet, you've got Carnivore tapping you, but otherwise fiber lines can pretty much be assumed secure. In the case of private networks, anyone with the budget for wireless optical could probably come up with a good encryption scheme. But is there anything I've missed here in the tapping issue?
Did anyone care to read the FAQ's on their web site??
The link is only has a reliable range of 200 to 500 meters.
That's less than 1/2 a mile folks!!!
Your better off, using an RF solution if you need more distance.
Fairly easy to change the polarization, in fact you can do it with no moving parts (there's a device called a Pockels cell which can rotate the polarization of a beam by an arbtrary amound depending on how much voltage you apply to a crystal).
The purchasers of bandwidth understand:
- "Fiber" to mean very fast data sent via light (in something called "fibers" or "fiber optics" or something like that...)
- "Wireless" to mean signals sent between two stations without any hardware spanning the distance. (Just install a box at each end and maybe an antennaish thing on the roof.)
So "wireless fiber" produces the idea of sending high-speed data via light between two sites with gadgets on the roof without anything but open space in between them.
Even if the words don't really make sense when you look at them closely.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
And when we do, is it going to have the same limitations that the present ones do? Could different light frequencies be used to allow 'fuzzy' rather than binary computation? Or more importantly, could the instantaneous 3D alteration of circuts allow people to 'evolve' intellegent computers like the circut boards that were 'evolved' to recognize a specific tone without a clock. ... don't have the link handy. It was in Discover about 2 years ago if anyone knows what I'm talking about. Kind of like evolving an algorithm, but on the hardware scale.
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It's the end of my comment as I know it and I feel fine.
Very true, except at what wavelengths? I have Foglights on my car. How are they supposed to do me any good? Simply, it is a wavelength that doesn't reflect back off the moisture and create more glare. Or atleast thats the theory. I'm sure you could pick a wavelength or two with a laser that would be even more effective.
wow, what a hottie i wanna fuck here right now. everyone go check that cutie out.
In it's goal? Really light beams are not terribly reliable as a technology for transmitting. I think a set of wireless transmitters would be better. Then for example you could connect to your linux server from your basement 100 stories underground when nuclear warheads are going off above you. Unless you get a bunch of little mirrors around and set them up all over the world it would fail. Of course it takes a few script kiddies (read vandals with black paper or baseball bats) to ruin your day. Maybe if you are sending the beams into space. But even then you would fail because it would take trillions and be almost like irridium was a spruce goose.
Respond to s
$20K per building? and you have to wire several buildings to form a mesh? I'm still not sure this is a good deal, that would depend on the number of buildings recomended for a network on a given city and that would depend on the weather and other common interferences in that area plus the average distance between buildings...
anyway, if they're using cheap CD-ROM lasers, why don't they just have 30 of them going from one building to the other in several different angles and heights and have all of them transmit the same signal. that way you would have to stop all lasers at the same time to drop a bit.... dunno, maybe that doesn't add up either. how much is a CD-ROM laser this days when a cheap unit costs under 50 bucks? what about the receivers?
There are two kinds of people in the world: Those with good memory.
25 years ago, the carrier I was on had a big honking radar. We used to hear scuttlebutt that the techs would get seagulls off the mast by mircowaving them. We figured it explained mystery meat and scab steak.
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Infuriate left and right
I took his remark to mean that if there are lots and lots of R2-D2s around, instead of direct long distance links, you would reroute thru closer neighbors.
Sort of like if long distance phone calls are out, you call Aunt Martha who calls cousin Bob and so on, each being a bit closer, until the final local call goes thru.
I did something similar once, when home to work was not a local flat rate call. A friend in between, who was a local call to each place, installed an extra phone and set it up to call forward.
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Infuriate left and right
"With new eFog, your point-to-point wireless optical data communications link can be enhanced into a local area network!"
Next quarter, analysts forecast the public release of eClouds which will allow for a wide area network with a range of approximately 7 miles.
Kevin Fox
Kevin Fox
OK, I must just be dumb or out of it, or something along that line. But, why do they call it wireless fiber? It doesn't make sense, a fiber is a solid object, a "wire" if you will. Wireless would imply that the "wire" does not exist. Why not just come up with a fun buzzword that actually makes sense?!?
Wow, you didn't even read the Slashdot blub, did you? You just asked the same question (only with different wording) that was asked the the initial post.
Mr or Mrs moderator, please think before you select an option from the pulldown menu and click on "Moderate", ok?
I just love reading about these new technologies regarding bandwidth...
If you just sit back and think about it, it's so amazing. 3 years ago, a cable modem or adsl in your bedroom was unheard of almost...now people are running isp's from their house.
It isn't long before 56k modems are going to be obselete.
--
CashWars
It has been infused with pork bacon juices.
*This will work only in areas that really close together such as the building across the street. This technology is a Good Thing(tm) but it not a cure all for communication needs. I hope it is marketing as such.
I am not claiming to be an expert in the study of laser dynamics, nor do I profess to be all-knowing in the field of architectural engineering; however, something that they stated in the article DID get my attention.
The author stated that one of the many hurdles in the past with this type of technology was the swaying that occurs, quite by design, in many of today's taller buildings. In the past, this motion caused an obvious problem with regard to focusing the laser beam on the respective target.
My question that I pose to any of the good Slash-Dotters out there that ARE experts in the above mentioned fields, is how this stumbling block may have been overcome with the new technology that has just become available in the past few years???
My first thought was that that the trajectory of the beam could be manipulated in small increments using small positioning motors that moved merely the lenses. That technology, however, has been around (in varying degrees of accuracy of course) for quite some time.
There is then the issue of the degree to which taller buildings sway. Some building, particularly ones build in earthquake prone areas, have a great degree of elasticity engineered into them to prevent them from succumbing to the stresses of outside movement. This can range from fractions of an inch to, in extreme cases, several feet. Does this add yet another restraint to the application of this technology - the height of the building???
Finally, I reverted back to the analogy that was made several times comparing the equipment used for this technology to resembling R2-D2. I then visualized the comical scene of a droid-like device at the top floor of a skyscraper fidgeting back-and-forth, attempting to maintain contact with a counterpart in an adjacent building as the wind of a storm blew violently. Not exactly the type of infrastructure I would want any of my LAN's built upon!!!
Beer is proof that God loves us and wants us to be happy. -- Benjamin Franklin
There's no need to go to higher optical frequencies to increase capacity. The carrier frequency of a 1.3 micron infrared laser is 230 terahertz. It's easy to see that a few hundreds of megabits per seconds barely scratch the theoretical capacity.
I could be wrong, but my understanding of optical transmission is that it generally does not modulate the signal onto the native frequency of the light but uses pulses to encode the signal. On...off...on......
I believe that it is kind of difficult to get electronic circuits to oscillate at Terahertz.
Therefore, the bandwidth is a function of the electronic circuit, not the optical circuit. Of course, when 100% optical switches are ready........
As a thought, I wonder if you could borrow some of the spread spectrum techniques for optical transmission. E.g. Would it be possible to recover a signal from a light source that has been dispersed?
"I have been around the world and found that only stupid people are breeding" -- Harvey Danger
I did some research into IR wireless a couple of years ago and came up with the following (mostly from corporate literature):
1) An interesting application of this technology is for a business with offices on opposite sides of national borders. International law makes it very difficult to drop a land line across the border, as well as to get an RF license for traditional wireless. A couple of IR units can solve the problem nicely.
2) Corporate literature at the time stated that birds can SEE the lasers much as the reporter could with the special glasses. They therefore tend to avoid the beams.
3) The average limit was 1/2 mile, at which point, speeds up to 155Mbps could be obtained. Much greater distances could be achieved at the cost of bandwidth.
4) Something people seem to be leaving out is that because this is laser, the beam is a straight-line path. The maximum possible length of a link would be about 7 miles due to the curvature of the earth. Of course, this article discusses building wireless networks spread across multiple buildings, but the point is, you would have trouble making a single connection 'across town'.
5) There were numerous companies involved in this when I looked into it back in '98. Most of my info came from a company called Air Optics. I don't know if they're still around, but their literature was definitely impressive.
These people looked deep into my soul and assigned me a number based on the order in which I joined.
I would really like this thing to be tested here in Oslo, where we can get a shitloadd of snow from time to time.
;) ), it's going to have a real problem. I don't think the net. admin is oging to be happy if he has to climb up on the roof each day to scrape snow off the $ 100 000 gadget...
Unless the canister is heated, mounted on a pole or the lasers are 10 Watts (Strong enough to melt the snow
Which is why there are a number of countries which lack land phones or even reliable power but have cell phones in abundance.
This next song is very sad. Please clap along. -- Robin Zander
Most of Dave's comments are relevant to RF communication, not to optical.
Capacity is proportional to the logarithm of (1+signal to noise ratio). A small but significant difference. The result is that for a given power budget it is always better to use as much bandwidth as possible unless you are limited by arbitrary constraints such as the FCC's dumb frequency management practices.
There's no need to go to higher optical frequencies to increase capacity. The carrier frequency of a 1.3 micron infrared laser is 230 terahertz. It's easy to see that a few hundreds of megabits per seconds barely scratch the theoretical capacity.
You've got so much bandwidth in optical that more than one bit per symbol makes absolutely no sense. In fact, you want LESS than one information bit per symbol by using forward error correction codes.
The right frequency to choose is in the atmospheric window wavelengths - those least absorbed by water vapor.
In fog conditions the cumulative attenuation per meter is so high that even a hundredfold increase in laser power will not make a significant increase in the effective range. You are stuck with a few hundreds of meters. Deal with it. AirFiber's architecture looks like the right way to do it. Even if you ignore the bird problem, with a relay every few hundreds of meters the end-to-end reliability drops exponentially with the number of hops the signal has to go through. A mesh architecture can cover long distances while still maintaining adequate availability.
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Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
This wavelength is around the peak of the first Atmospheric window. It's also cheap because it's the wavelength used by CD readers.
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Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
I think this may be a more econimical solution than fiber. but i doubt it will ever be as reliable.
firstly, this is useless long distanc unless you still have a lot of these R2-D2s because of geographic problems, plus the general curvature of the earth (alright the cuvature of the earth is pretty big)
secondly, I tend to doubt this will work in very thick fog. I've seen fog that limits vision to 10 meters.
thirdly, these devices have to be atleast somewhat outdoors, and that makes them a lot more easily damaged than underground cables.
I think they will be a useful, much cheaper resource for a lot of people, but I don't think they will be as reliable as underground. It depends on what you need.
"It's because they're stupid. That's why everybody does everything."- Homer Jay Simpson