Scientists Double Optical Fiber Transmission Capacity

ms writes: "Yesterday golem.de reported that the Optical Communication and High-Frequency Engineering Group at the University of Paderborn (Germany) claims to have made a technology practical which doubles the transmission capacity of optical fibers to 80 GBit/s. In their so-called "polarization division multiplex data transmission system" they don't only send one but two mutually orthogonal light waves through the fiber. They say the only big problem was the dispersal of the light waves which limits the data rate. Additional they had to fight against the phenomena that the polarization direction of the light waves changes while it goes through the fiber. Now, after two years of research, they invented an "automatic optical compensator of polarization mode dispersion" which fights both the limitations. With this gadget they were able to send data at a rate of twice 40 GBit/s (that's 85,899,345,920 Bps) over a test-line of 212 km. And "only the available equipment limited distance and data rate". As we all know, optical fibers build the (cronically overloaded) backbone of our beloved Net. (BTW: That's Net., not .Net!)" Here's the babelfish translation, too.

Comments

Hookup?

[itsnotme]

Any chance I can get a hookup into this? :-) I wouldnt mind downloading directly off that fiber line..

Moderation: Humor=+1 Underrated=+1 Insightful=+1

Mind Blown

[Zen Mastuh]

Just trying to grok "mutually orthogonal". Is that redundant, or just over my head? Not trying to nitpick, but to understand something my networking prof never explained.

Re:Mind Blown

[nanojath]

I'm not certain but I think it's just muddy syntax - I assume they just mean perpendicular. Orthoganl in this context I would assume means at right angles, and implies the mutually part - so yeah, sort of redundant or just badly stated.

Re:Mind Blown

[MrResistor]

Orthogonal is a math term, not a networking term.

In 2 dimensional space it's the same as perpendicular, but in 3 dimensions "perpendicular" is technically insufficient to describe the relationship. As you add dimensions orthogonality gets progressively more complicated, hence the addition of "mutually". It could be redundant depending on the situation, but better safe than sorry...

Re:Mind Blown

[wurp]

Orthogonal can either mean that the two don't affect each other, or that they are at right angles to each other. In this case, it means both - the angle of polarization of one beam of light is orthogonal to the angle of polarization of the other, and thus a polarization filter parallel to one beam of light passes it through unhindered and completely blocks the other beam. In this way you can process the two beams separately even though they are running down the same fiber.

But, yeah, mutually orthogonal is redundant. You have to have something to be orthogonal to, and if you're orthogonal to it, it must be orthogonal to you.

Re:Mind Blown

[eggnet]

They're just being clear as to what the light beams are orthogonal to, i.e. eachother, not some third object.

Cool

[Quasar1999]

Sweet... Can we use this new technology to ease the congestion over the trans-atlantic/pacific backbones???

Re:Cool

[NevDull]

Sorry, but any excess capacity will immediately be filled by script-kiddie ping floods.

Anyone ever done a study on what percentage of traffic passing over backbones is ICMP-echo and reply?

-NevDull

Re:Cool

[RetroGeek]

We did a test on a private WAN and about 50% of the traffic was heartbeats.

Re:Cool

[rtaylor]

You folks are using NetBeui as your filesharing system aren't ya?

Switch it to NetBeui over TCP/IP (if you wish to avoid NFS) and you'll cut the heartbeats to 1/10th.

Microsoft products and NetBeui are very chatty with the 'are you still there?' crap.

Babelfish translation...

[Anonymous Coward]

BabelFish Error 3012
We're sorry we've encountered an error with your request.
If you think this is a bug we should know about? Send us e-mail and let us know the following:

* What browser you were using.
* The operating system you are on.
* The type of translation you were trying when this error occurred.

Questions? Check out our FAQs.

The error encountered is:

Not a valid referer.


I didn't think I was an invalid reefer.

Dark fiber

[Foxxz]

This is going to help the industry alot. Right now there is pleanty of unused fiber, but the problem is the devices that use the fiber take too much room. if we build them smaller and faster we can increase capacity easily.

-Foxxz

Re:Dark fiber

[sllort]

This is going to help the industry alot. Right now there is pleanty of unused fiber, but the problem is the devices that use the fiber take too much room. if we build them smaller and faster we can increase capacity easily.

The other thing that would help the industry would be to stop going bankrupt. Most to all of the CLECs (PS/Inet anyone?) are bankrupt and insolvent, and the major carriers - WorldCom, Verizon, Global Crossing - have horrible credit ratings and a total freeze on capital equipment purchasing. Right now no one is buying next generation optical equipment. Look at Nortel stock... if you bought $1000 of Nortel stock last year, you'd have $43 today. I won't even mention Lucent. Those are the big boys - the small ones (cough Iron Bridge cough) are all dead or dying.

Optical equipment vendors have no customers. Optical equipment manufacturers are slashing R&D and personnel, and relying on existing revenue streams for survival.
Optical network carriers are nearly bankrupt.

...and NO ONE is paying for premium bandwidth.

So pretty much, this isn't gonna help anybody. The next advance in optical networking isn't going to be the next next-generation fiberoptic breakthrough. It's going to be a solvent carrier, or a paying customer for broadband.

Re:Dark fiber

[Anonymous Coward]

If you bought 1000 beers and returned the cans for $.05 each you would have $50.00

Therfore save money, drink more.

Re:Dark fiber

[taliver]

Look at Nortel stock... if you bought $1000 of Nortel stock last year, you'd have $43 today.


And If you'd had bought $1000 worth of beer last year, you'd have $75 due to the nickle from the deposit, and you'd have had 250 six packs... A much better ROI.

Re:Dark fiber

[GigsVT]

What I don't understand is that the demand is out there... at least among the people I talk to either on IRC or in person, everyone who is on POTS dial up is not there by choice. Maybe if they would have spent less time on the backbone and more time on the last mile, they wouldn't be insolvent.

Re:Dark fiber

[Shotgun]

No, the problem is that the devices that use the fiber are expensive and there is currently a glut of bandwidth. Oh, stop your screaming. It used to be that you'd pay $20/month for 64k of rarely used bandwidth. 64k is the nominal bandwidth assigned to a phone call in modern digital networks. If you made a long distance call (one that traversed central offices), you paid more and by the minute.

An always-on, connect instantly to anywhere in the world, ADSL line has several hundred K of bandwidth, and people scream at anything above $49.95/month. There currently is a glut of supply driving down prices. These next generation inventions will only see production if they can supply more bandwith at the same equipment cost.

In any case, the dark fiber will remain so until someone can light it really cheaply, or someone is willing to pay for the laser.

Re:Dark fiber

[mangu]

The other thing that would help the industry would be to stop going bankrupt.

That's a normal thing in industries. It happened in the 1890's when railroad equipment manufacturers went bankrupt. It happened in the 1930's when car manufacturers went bankrupt.

When an industry is growing, a lot of new companies are spawned. Then, there comes a period of readjustment, when the market gets saturated and there is a mass extinction among companies.

Re:Dark fiber

[Happy Monkey]

In a larger sense, though, the provider bankrupcies are a good business plan for the country. Some companies go bankrupt laying the infrastructure, and then sell it cheap to other companies. These new companies are not saddled with the huge debt from the construction, and can offer the service much cheaper. It's almost like government sponsored infrastructure projects, except the "taxpayers" are voluntary stock and venture capital gamblers.

The equipment manufacturer bankrupcies aren't so good, though.

Re:Dark fiber

[Anonymous Coward]

Video cards 2000's....

Re:Dark fiber

[Exantrius]

Look at Nortel stock... if you bought $1000 of Nortel stock last year, you'd have $43 today. I won't even mention Lucent. Those are the big boys - the small ones (cough Iron Bridge cough) are all dead or dying.


One of my teachers brought this up the other day... If you bought 1000 dollars worth of Nortel Stock, you'd have 43 dollars today. *BUT* if you had bought 1000 dollars worth of cheap beer, and recycled the cans, you'd have approximately 102 dollars.

So, with the way the economy is going, his advice was to stay away from tech stocks, and drink heavily...

Exantrius

Re:Dark fiber

[PD]

For 67 cents a can a beer that must have been Budweiser. Ack.

Re:Dark fiber

[Spy Hunter]

...and NO ONE is paying for premium bandwidth.

They should have ran all that fiber to the home instead. No one's using all the bandwidth because there's not enough people to deliver it to. We need broadband to the home that works well and is universally available. Until then the high-bandwidth content will not be feasable.

Re:Dark fiber

[ScottKin]

An excellent observation!

The major problems with the nefarious "last mile" are:

who owns the right-of-way?
who will pay for the CO upgrades (if needed)?

I happen to live in a small town (pop. 5000), and the switch served by this down is an antiquated Nortel DMS-10 - which is really nothing more than a souped-up PBX...no digital service, unless you want to buy a T1 or higher; hence, no ability to install DSLAMs. The Cable Monopoly here just recently upgraded to Digital service, but we've yet to hear about Cable Modem access for nearly a year.

If the area you are in is not economically condusive to having additional services provided to you, you can kiss any kind of broadband access good-bye - and don't even talk to me about Starband: 512kbits/sec is ok, but with 700mils latency, you can count me out there as well.

Peace,

ScottKin

Re:Dark fiber

[ScottKin]

Amen, and Amen!!!

I used to work for a major West Coast Tier 1 backbone provider that had a huge share of PSINet's service, as well as providing additional bandwidth for companies like WorldCom, Verizon, GC, Verio and dozens of other CLECs. Due to the "economic down-turn", the insolvency of my former employer's customers and/or their inability to understand what "net 90" meant in billing terms (some customers owed them millions of dollars and were in arears by months), I am now forced by a substantial lay-off to start looking for a new job in the Telecom Industry.

The only people to blame in all of this down-turn in the Technology sector of the economy are the companies that got started by some yuppie yutz thinking it would be a cool way to make $$$ by riding on the coat-tails of the "Internet Revolution" - sadly, the only thing "revolutionary" was the investors and company-owners/shareholders/Venture Capitalist's greed.

Wish me luck!

Re:Dark fiber

[Cato]

Have a look at fixed wireless technology - either LMDS/MMDS type technology (licensed, via a provider) or 802.11b wireless LANs (no provider needed, roll your own...). There are some people who have wired very remote communities using point-to-point wireless (to reach the place) then 802.11b to connect individual homes.

The latest LMDS technology gives great coverage and lower costs, but 802.11b (Wi-Fi) is a better bet for DIY. If you get subs from enough people it could easily become viable. Have a look at www.opentelco.net for examples of this.

Re:Dark fiber

[twelve80]

good luck in your job search

Interesting

[Methuseus]

Now we have the next question that comes to mind. I want to know if there's a software solution to all of this, or if the hardware itself has to be upgraded to take advantage of these speeds.

Also, I know it can be done over existing lines, which is great for the installed base, but it still doesn't help run them all over. I'm just lamenting the fact that they don't have, and probably won't have in my lifetime, fiber as widespread as telephone line. Sorry for the OT part.

Re:Interesting

[silicon_synapse]

Now we have the next question that comes to mind. I want to know if there's a software solution to all of this, or if the hardware itself has to be upgraded to take advantage of these speeds.

I would guess the hardware would need to be upgraded since two light streams are being transmitted through the fiber. Unless of course you could rig up a fork/splice (probably involving duct tape of course) with a transmitter on each fork, but I doubt it. I'm going to go out on a limb here and guess that this new technology won't be economically feasible for most people for a while. I'd love to be proven wrong though.

Re:Interesting

[wunne]

I guess in my country (DE) especially in Eastern Germany, fiber is more spread than copper. Due to this, this sounds to me like a fabulous solution to get more bandwidth. Anyway since Im a student at the University of Paderborn I must say that great stuff is happening here... ;)

*** Hm... this just tastes like inky nails...

Re:Interesting

[Capsaicin]

Im a student at the University of Paderborn I must say that great stuff is happening here... ;)

'Bout time it happened too. I had the misfortune of trying to use some machines at that uni about four years ago and found the system to be the slowest I have ever encountered. Certainly connectivity back to .au was so poor as to be unusable. Perhaps this is what provided the motivation for research into high speed data transmission?

Re:Interesting

[Anonymous Coward]

What if they put Y-splitters on each end, with a prism at the junction to split or combine the light, depending on which direction it's going in?

Re:Interesting

[silicon_synapse]

That could work if the transmitters are actually capable of generating the proper type of light AND can include what ever new error correction they they created. I don't know all the details, but I wouldn't hold my breath.

Great, now bring it to my casa...

[microbob]

Great, now bring it to my casa...or maybe light all the fiber that is already in the ground.

Re:Great, now bring it to my casa...

[ackthpt]

Su casa, is right. You're more likely to plop this between your router under the stairs to your workstation in the den sooner than you'll realize any benefit beyond your door. But, hey, there's always hope you'll see it before arthritis and failing eyesight set in.

Time for my own fibre supplement...

Remember

[Haxx]

that's 85,899,345,920 Bps

Up from 300 Bps 14 years ago. Not too shabby.

Re:Remember

[Anonymous Coward]

Wrong. 300bps was the speed of your f'ing modem, not the state of the art high bandwidth technology of the day.

A more appropriate comparison is to 56kbps modems we have today. 300 to 56000 in 14 years. That roughly a doubling of speed every 2 years. Slower than computer CPU development, but then we are limited by the telco equipment, aren't we.

Re:Remember

[jtdubs]

Interestingly, atleast to me, that's almost exactly 4x per year. As in 300 * 4^14 is almost exactly 85,899,345,920.

Justin Dubs

Re:Remember

[Tim Doran]

Well, that 300bps was what you could manage across an analogue telephone line with a commercially-available modem.

Telecom backbones, even 14 years ago, were waaay beyond 300bps. And this technology really is backbone stuff, not for us consumers *wistful sigh*

So how long until we can have fiber disks?

[taliver]

300km worth of cable = 10MBytes of storage with access times of 1 msec... So I guess we have to wait until we can pump bandwidth up 4 orders of magnitude to have a neat little system... (with 300km worth of cable in a drum...)

Re:So how long until we can have fiber disks?

[Anonymous Coward]

From your sig: "Time flies like an arrow"

What kind of fly is a "time" fly? Why do they like arrows?

Re:So how long until we can have fiber disks?

[keflex]

The sig itself is a play on the double meaning of the word "flies".

The comparison to the passage of time to the flight of an arrow is because both are swift.

Re:So how long until we can have fiber disks?

[rtaylor]

If you could make the cable dense enough to fit in a space the size of a normal harddrive -- and made it low power (already solid state) that would rock my world as a swap device.

I'm willing to accept an average of 1msec seeks (600km of fibre) to double capacity.

I love bablefish!

[nizo]

From the babelfish translation:

Additionally it possesses a controlling mean, which is to after-pursue even largest polarization modifications, as they occur on very long transmission circuits contrary to competitive systems also, noly-break.

Once I figure out what a noly-break is, I should be able to build my very own high speed home network!

Re:I love bablefish!

[chriss]

debalelized: In contrast to competitive systems it also contains a controlling unit, which will follow without causing interruptions even the largest changes in polarity, as they will occur in very long distance transmissions.

Go, girl! Into the bright/light future of home networking.

Chriss

Re:I love bablefish!

[Anonymous Coward]

I think a noly-break is a skateboard trick, but I could be wrong; I'm not a skater.

Re:I love bablefish!

[IVotedIn2000]

For some reason, Babel Fish translates "unterbrechungsfrei" as "noly-break". A much better translation would be "free of interruption".

The "backbone" of the whole internet

[mfdii]

The "backbone" of the whole internet and telephone net consists of optical fibers. For transmission capacity doubling each optical wavelength may carry two signals with mutually orthogonal vibration directions. The results of this technology could be outstanding.

Now when can I get this to the curb?

Fruit 'n Fiber

[Renraku]

Maybe some day cutting a fiber line would yield deadly results. Imagine accidently digging through a fiber line only to be cut in half by the power of the beam. That would rule! As if being electrocuted to death wasn't enough, soon we can be killed by data...I can see where the 'freak accident causes supergenius to be born' movies are going to come from..

Re:Fruit 'n Fiber

[ethereal]

Hmmm, if the countryside was littered with laser-blinded backhoe operators as a result of their slicing through the wrong cable, I don't know how that would be much worse than the current situation. You know what they will say: there are old backhoe operators, and bold backhoe operators, but there are no old, bold backhoe operators :)

Re:Fruit 'n Fiber

[Anonymous Coward]

Z-modem dropped carrier less often. :)

Just so you know.

Re:Fruit 'n Fiber

[Anonymous Coward]

and how much would it piss you off to be sliced in half by a warezed copy of windows xp going across the fiber?

Re:Fruit 'n Fiber

[Anonymous Coward]

And, to make matters worse, you were sliced in half by the telesurgery data of a gall bladder operation... Brings a new meaning to telesurgery.

Re:Fruit 'n Fiber

[Anonymous Coward]

i don't think all those 0-bits will do much harm

80 Gbit/s...

[albat0r]

to be able to throughput at that speed, I can't imagine the hardware that is needed...

I mean, I hope that nobody had the idea that he will be able to have it directly into his Athlon 1.4 Ghz... Poor fool...!

Re:80 Gbit/s...

[taliver]

mean, I hope that nobody had the idea that he will be able to have it directly into his Athlon 1.4 Ghz

Hmmm....

A 400 MHz FSB at 64 bits... = 25Gb/sec.
At 1.4GHz, (if you could perhaps have some type of input that ran at the speed of the processor, instead of the FSB), you could handle 89.6 Gbits/sec... But you'd better not be doing anything else.

So it looks like a 800MHz, 128 bit FSB would do it. So, we're not quite there with of the shelf tech.

Re:80 Gbit/s...

[albat0r]

But you'd better not be doing anything

yeah, but if you want to do something with your connection, you must be able to do something else!

And also, you need a HD that can handle this too...

Langauge

[LagDemon]

Does anyone have a link to a good translation of the article? The translation at altavista is incomprehensible!

Thanks!

Re:Langauge

[Anonymous Coward]

With what do you deal with yourselves? I have always babelfishuebersetzungen found, in order to be completely readable and understandable!

Does orthagonality ...

[sporty]

Does orthagonality relate to the wavelength or the relative angles the light is sent? If the latter, any reason they couldnt' use colour as a second channel? (particular wavelengths)

Re:Does orthagonality ...

[Anonymous Coward]

It's the polarization of the light.

It's how 3D IMAX movies work.

Re:Does orthagonality ...

[astroboy]

The `orthogonality' here refers to polarization. For a little intro, see a page like this one at Case Western. Light's an electromagnetic wave, consisting of an electrical and a magnetic field at right angles to each other.

The beams in this article are orthogonal in the sense that channel #1 has it's E-field pointed prependicular to channel #2's E-field so they won't interfere with each other (so they're `orthogonal' in the usual compu-geek sense of the term, too.)

The german team seems to have solved two big engineering problems with sending two channels of information this way. One is to send a mean-polarized signal so that you can compare the two channels against it (kind of a carrier signal for polarization) to see which channel is which.

The other I confess to not understanding. Apparently there are sync problems -- signals carried one polarization may travel faster than the other polarization. I can only guess that this is a problem caused by inhomogenaities in fibre. Whatever its caused by, they've managed to measure it and compensate for it.

As for your other question, they definately can and do use frequency as a way of encoding information. Just like with radio signals, you can use the brightness of the light (amplitude modulation, or AM) or its color (frequency modulation, FM). In practice, FM is less problematic; the amplitude of a signal is easily confused by noise, whereas frequency is much less so.

Re:Does orthagonality ...

[norton_I]

Orthogonality in this case refers to modes of the electric field. A mode is labeled by a frequency and a polarization state. So, yes, two beams of different wavelength are orthogonal modes, and can be resolved by using a grating to diffract each component to a seperate detector. This is called WDM -- wavelength division multiplexing.

States with opposite polarization (horizontal and vertical, right and left circular, etc) are also orthogonal modes, and can be seperated, for instance, by a polarizing beam splitter. This is PDM.

The total bandwidth of a communication link is bps/mode * useful modes, so either increasing the number of frequencies or polarizations, or both, can improve bandwidth.

WDM is limited because each pulse actually covers a range of frequencies, and you need to choose them far enough apart that they don't overlap, or you won't be able to discriminate them well. PDM is limited because it is hard to get fibers to not fs*k with the polarization of light, plus there are only two orthogonal states, so you can only easily get a factor of 2 improvment in bandwidth.

Re:Does orthagonality ...

[Hal-9001]

Apparently there are sync problems -- signals carried one polarization may travel faster than the other polarization.

This phenomenon is called polarization-mode dispersion and we just covered it in my fiber-optic communications class. It occurs because of birefrigence, which is the phenomenon where different polarizations see different refractive indices. Since refractive index is the speed of light in vacuum divided by speed of light in a medium, this means signals with different polarizations will travel different speeds. Even worse, since fiber birefringence is probably stress-induced and varies over the length of the fiber, it is difficult to tell what the polarization axes of the fiber are so that you can minimize this effect.

Polarization-mode dispersion is a problem even when you're not multiplexing by polarization because it results in the ordinary and extraordinary polarization of a light pulse separating and possibly colliding with other pulses, thereby limiting the bandwidth of the fiber. On the other hand, if you use the ordinary polarization as one channel and the extraordinary polarization as a separate channel, both channels will propagate with zero polarization-mode dispersion and double the effective bandwidth of the fiber. They will propagate at different speeds, but that really isn't an issue as long as the light pulses that represent your 0's and 1's aren't spreading.

The trick is determining the ordinary and extraordinary axes of the fiber, which is the breakthrough that this group made. It sounds like they use a reference channel to determine the ordinary and extraordinary polarization axes of the fiber and also to measure the change in polarization introduced by the fiber so that they can demultiplex the two polarization channels. This is a very simple and elegant way to negate polarization mode dispersion and to enable polarization-division multiplexing.

Re:Does orthagonality ...

[univgeek]

I am currently doing my Master's thesis in Optical Network at UTD, so I guess I can comment on this.

The fiber on which the light travels cannot be made perfectly circular, this causes one mode of the light to travel faster than the other.

Normally this polarization mode dispersion (PMD) affects only the highest capacity channels say > 10Gbps. This is because at lower speeds other effects are predominant, and we can get to 40Gbps only by killing all the other effects.

The reason that we do not use only one mode of polarizad light to transmit the information is that the polarization direction changes randomly with time. Since the property of the fiber changes with stress, it has been reported that even a train running nearby (for fiber laid along railroad) is sufficient to change the polarization.

What I am curious is about the /controlling mean/. Since the polarization is going to be changing all the time, I guess they use a sort of pilot wave to sync the directions. From the translation, thats all Id hazard to guess.

As for AM Vs FM. most if not all fibers use AM. This is because the noise level is extremely low in the fiber, and also the noise mechanism itself i very different from plain radio transmission where the noise in AM is much more than noise in FM.
Also the lasers in use now, do not allow for a wide range of frequecy outputs to be controlled easily. Switching them on and off is much easier.
FM is used to modulate several radio frequecy channels over a light beam, this is called sub-carrier multiplexing.

Gee, that's swell

[ackthpt]

Now I can get spammed in half the time.

It's ironic that this article comes on the heels of some articles I just saw (in metamoderation) about how oversold services (DSL/Cablemodem) are. This would be a great thing, if any company still has the capital to lay new fiber, though I expect many are just trying to eke out a returns on what they already have. My ISP, Concentric/XO was last listed at $0.40 a share, and they're advertising cheep long distance, etc. right now.

Increasing capacity; increasing vulnerablility

[case_igl]

It seems every year we find a way to double the amount of data that we can send down fiber. As a result of this, companies are actually deploying less new fiber in the field and taking older lines out of commission.

One of the things that worries me about this is the increased vulnerability. In the past, huge fiber networks were used that can be one tenth the size today. All too often a clueless construction worker rips up a section of fiber and causes some havok.

Won't this kind of thing happen more frequently if less fiber is deployed that can handle more traffic? And does this bring us any closer to fiber to the curb - it doesn't seem like it.

Re:Increasing capacity; increasing vulnerablility

[sllort]

All too often a clueless construction worker rips up a section of fiber and causes some havok.

The industry euphimism for this phenomenon is a "backhoe failure". Metro fiberoptics are all deployed in a "ring" configuration - if a ring is cut, the traffic is sent the other direction on the ring withing 50 milliseconds. The operative protocol here is called SONET. SONET rings have been around for a long time, and they pretty much solve the issue of backhoe failures. Some vendors are pushing proprietary mesh-based architectures which offer even more redundancy.

The issue you bring up, however, does exist on one-way long-haul fiberoptic lines. Major carriers spend millions on 24 hour overflights by patrol helicopters to monitor these fibers for cuts - and some of the largest players in the telco field are oil suppliers because they already patrol their oil pipelines for just this kind of event; burying fiber next to the pipeline is cheap by comparison.

The massive transmission capabilities introduced by advances in fiberoptics DO give us more ability to heal networks, because they give us additional load-bearing capability during failure. The missing piece is actually building equipment which will heal the network effectively, in time. If you're truly interested in ongoing research in this area, open up google and ask it about "GMPLS".

Enjoy.

Re:Increasing capacity; increasing vulnerablility

[bluebomber]

All too often a clueless construction worker rips up a section of fiber and causes some havok.

Or a not-so-clueless "backhoe operator" takes a chunk out of a section of fiber, crippling the nation's communications infrastructure to enable other mayhem to take place. Be afraid. Be very afraid.

Re:Increasing capacity; increasing vulnerablility

[iabervon]

People have this tendancy to put all of the cables in the same place anyway, because you can dig a huge ditch or dig up all the streets once, and put in a whole bunch of cables, or because there's only a few paths that you can afford to dig up. Having greater capacity on each cable just means that you won't need as many cables in the same hole. Whatever makes a cable break is likely to kill the whole group. The redundency comes largely from wanting to connect each pair of points for normal operation, which means that you'll have other routes if one goes down.

Re:Increasing capacity; increasing vulnerablility

[dragons_flight]

And does this bring us any closer to fiber to the curb - it doesn't seem like it.

WE have fiber to the curb. ;-)

As part of a experimental project the whole suburb where I live was wired with fiber to the curb. Unfortunately the telco since decided to put a hold on the project and hasn't really taken advantage of the investment. There was a debate about offer superior versions of DSL, but they decided that cost was too prohibitive for the small client base. They might be offering it to businesses, but they aren't to consumers.

It's not just a matter of having everything wired up, but there is also an issue of having a cost effective use for it. If you're surfing the internet and playing online games, DSL or Cable offers as much speed as most people need.

Right now the only visible consequence of the fiber to the curb, is that ALL of this suburb can get DSL regardless of their location relative to the CO. Now if only someone will hurry up with widespread videophones...

Re:Increasing capacity; increasing vulnerablility

[nexthec]

Ironicly, last week some num-nuts shot the Alaskan Oil pipleine with a rifle, causing the largest Alaska oil Pipe line spill in history. Brilliant ehh?

Re:Increasing capacity; increasing vulnerablility

[Paul Carver]

Is anyone really taking fiber out? In my experience DWDM systems are used to relieve "fiber exhaust" when all the fiber in an area is already being used and there's a demand for more capacity you take the OC48 muxes off the fiber and put DWDM muxes on it. Then you plug the OC48 muxes into the DWDM muxes leaving you with 30+ new channels (frequently called lambdas).

In case you weren't aware, people hate having the streets dug up. They hate the traffic delays and they hate the ruts that inevitably result from digging up pavement. Consequently, telecom companies have a tough time getting permits to lay new fiber. That's why being able to send more data without laying more fiber is a good thing.

If a ring is cut (I've heard it called "backhoe fade" as opposed to another poster's mention of "backhoe failure") it protection switches automatically if the tributaries are routed correctly, which they may not be. One side effect of using DWDMs is that they can protect the whole SONET rings riding them even if the low speed electrical tribs aren't routed with protection.

Re:Increasing capacity; increasing vulnerablility

[drinkypoo]

The industry euphimism for this phenomenon is a "backhoe failure". Metro fiberoptics are all deployed in a "ring" configuration - if a ring is cut, the traffic is sent the other direction on the ring withing 50 milliseconds.

That would be nice, but I can assure you that neither fiber nor power is laid out that way in the potrero hill area of San Francisco. To which metropolitan areas are you referring?

Re:Increasing capacity; increasing vulnerablility

[ConsumedByTV]

You mean this http://ens.lycos.com/ens/oct2001/2001L-10-08-06.ht ml right?

Re:Increasing capacity; increasing vulnerablility

[kiwaiti]

Imagine Joe R. Digger hitting

1. a single fiber (with a bit of protection around it)
2. a bundle of 100 fibres (same strength each) with a corresponding encapsulation

what will happen? case

1. JRD doesn't even notice, happily digs on, disrupting the connection
2. even if he didn't notice the (comparatively thick) cable, some of it might withstand the initial attempts of digging through, so he will take a look to find out what's causing the trouble

All numbers to be scaled to appropriate values. Correct me if I'm wrong.

Kiwaiti

Re:Increasing capacity; increasing vulnerablility

[iabervon]

Fiber optics aren't really stronger than the stuff that construction equipment is supposed to go through. Obviously, if there were a really vast number of cables, the person would probably notice that he's digging in cables and not dirt at all, but for a reasonable number of cables, he'll go right through.

The sensible design, anyway, is to put a pipe around the cables, which will ideally protect them from moisture, animals, tree roots, etc, and somewhat from the construction equipment. But it doesn't matter how many cables you put in the pipe, because the cables are of negligable strength, compared to the pipe, and putting each cable in a separate pipe would take up a prohibitive amount of space.

Re:Increasing capacity; increasing vulnerablility

[blair1q]

Sounds like the collar was a classic episode of COPS:

Daniel Carson Lewis, a 37 year old man from a town near the pipeline, was arrested for shooting the pipeline with a .338 caliber rifle. He has been charged with felony assault, criminal mischief, weapons misconduct, and driving while intoxicated, and is being held on $1.5 million bail.

--Blair

Re:Increasing capacity; increasing vulnerablility

[blair1q]

Interesting.

But I still think the primary reasons for using oil and rail lines is that the oil and rail companies already own the right of way. I can't imagine what it would take to get 3,000 miles of clear path across the U.S. in the 21st century. It probably saves several billion dollars in negotiations and leases.

Getting a little economy of scale on maintenance is a nice bonus.

--Blair

Nitpicks

[Anonymous Coward]

First, twice 40Gbps is not 85,899,345,920 bps, it is actually 80,000,000,000 +/- 1,000,000,000. We don't measure Gbps in powers of 2. Secondly, the internet backbone is not overloaded, but is running at about 20% capacity according to the people who operate it.

Re:Nitpicks

[ackthpt]

the internet backbone is not overloaded, but is running at about 20% capacity according to the people who operate it.

And on the declining revenues they're getting by on, my hat's off to those folks!

Patents, anyone?

[Anonymous Coward]

Thoughtfull /.'ers can ignore this.

Knee-jerk /.'ers, ask yourself: Once you've realized what a cool thing this is, and understand that hard work went into making it happen, are you then going to demand they make it "Open" and "Free" and not patent it, because Patents Are Bad and Sharing Intellectual Property is the Right of All Mankind? Or will you realize that they have a right to benefit from their hard work and wish them luck?

Great job, and I wish them great success, for the selfish reason that I wish to benefit from this technology and think it could actually reduce infrastructure costs, thus (somewhat slightly) reducing my costs (or at least delaying the next inevitable increase).

Re:Patents, anyone?

[eyeball]

Knee-jerk /.'ers, ask yourself: Once you've realized what a cool thing this is, and understand that hard work went into making it happen, are you then going to demand they make it "Open" and "Free" and not patent it, because Patents Are Bad and Sharing Intellectual Property is the Right of All Mankind? Or will you realize that they have a right to benefit from their hard work and wish them luck?

Good post. I agree with you, and naturally disagree with the "we must share all advances for the good of the people" attitude. Communism isn't counter-culture, anti-establishment, nor is it cool. It just plain sucks.

Re:Patents, anyone?

[GigsVT]

Good post. I agree with you, and naturally disagree with the "we must share all advances for the good of the people" attitude. Communism isn't counter-culture, anti-establishment, nor is it cool. It just plain sucks.

Good post for you too. It is one thing when people choose to share things for the advancement of all people, like GPL and public domain and such, but it is a different thing when you don't believe in property rights at all.

Bringing new meaning to the term Collision?

[MrResistor]

I don't know how much of a problem particle collisions are for photons, and it's probably a rare occurence, but it seems like the probablility would increase with the frequency...

IANAPE (I am not a photonics expert), but that was the first thing that popped into my head.

Slashdot posters have a short memory

[Rosco P. Coltrane]

"As we all know, optical fibers build the (cronically overloaded) backbone of our beloved Net.

Hmm, and same Timothy posted this article on June 25th about a lot of fiberoptic cables that have been put into the ground but haven't been put to work.
You gotta love the consistency of Slashdot posts :)

Re:Slashdot posters have a short memory

[Anonymous Coward]

It takes more than just fancy wires to be the 'backbone' of the Internet. He was referring to the ability to increase the bandwidth of that small amount of fiber that is in heavy use, even though there's plenty more to go around that may not be getting much use at all. I'm sure fiber cables in NY get worked out a lot more than some fiber optic cable in po-dunk North Dakota.

Re:Slashdot posters have a short memory

[sllort]

Hmm, and same Timothy posted this article [slashdot.org] on June 25th about a lot of fiberoptic cables that have been put into the ground but haven't been put to work.
You gotta love the consistency of Slashdot posts :)

Dark fiber is fiber with no optical equipment connected to it. Fiber is not the expensive part of optical networking. Air-conditioned environment-controlled closet space filled with millions of dollars of self-healing optical equipment is the expensive part. A lot of metro optical carriers use the benchmark of $100,000 per month per 7 foot rack in operating costs. The denser the equipment, the cheaper the equipment, the more of that dark fiber the carriers can light to form the backbone of the Internet.

So, in short, Slashdot was right and you were totally wrong. Or Insightful. Your choice.

Re:Slashdot posters have a short memory

[Hal-9001]

Digging up lots of ground to lay fiber is also pretty expensive. It also takes a lot of time. Telcos have to think long term, so they lay dark fiber so that it's there if they need it.

Re:Must defend

[Anonymous Coward]

which one of us took the lead, hmm?


Well, neither of us. We both got modded down to -1

Definition of mutually orthogonal

[Ghoser777]

In geometry, orthogonal just means perpendicular. But, according to searchStorage: "In computer terminology, something - such as a programming language or a data object - is orthogonal if it can be used without consideration as to how its use will affect something else. " So, the light waves are mutually orthogonal (they are data objects in this case), but I'm not exactly sure how to apply the definition to exactly what the scientists are doing with fiber optic cables.

F-bacher

Re:Definition of mutually orthogonal

[DMPilgrim]

The light signals are out of band from each other.

Huh?

[Anonymous Coward]

They whoed the what how many times?

mutually orthogonal

[MarkusQ]

Just trying to grok "mutually orthogonal". Is that redundant, or just over my head? Not trying to nitpick, but to understand something my networking prof never explained.

"mutually orthogonal" means (for a set of two or more elements) that each pair of elements is orthogonal--AFAIK, it's a synonym for "pairwise orthogonal". "orthogonal," of course, has lots of synonyms, including "linear independence," "at right angles," "having zero dot-product," "statistically uncorrelated," etc.

So, the three spacial dimensions, the set {phase of the moon, day of the week, time of day}, etc. are all "mutually orthogonal." When talking about a set of only two elements, the "mutually" is superfluous, but not redundant.

-- MarkusQ

Re:mutually orthogonal

[Anonymous Coward]

Got it!

--the Mastuh

Re:mutually orthogonal

[Anonymous Coward]

There's still something wonky about this sentence:

"they don't only send one but two mutually orthogonal light waves through the fiber"

The word 'mutual' implies more than one, but the above suggests that the innovation is in sending 'not only one [mutually orthogonal light wave]' but two. Huh? Am I just nitpicking to the extreme or does this make no sense?

Re:mutually orthogonal

[KingAzzy]

ah dont know what tha hell you just said but shooooeeee did it shore sound smart!

Re:mutually orthogonal

[Trepidity]

I'm guessing a clearer rephrasing of that sentence would be:

They don't send only one light wave through the fiber, but two orthogonal ones.

If only one light wave is being sent, the term "orthogonal" is completely meaningless; the innovation here is the ability to send two light waves simultaneously through the fiber, taking advantage of the fact that making them orthogonal will allow you to reconstruct both of the original waves at the other end, effectively doubling your capacity.

Re:mutually orthogonal

[mangu]

"orthogonal" implies in more than one element, so the "mutual" is redundant. If A is orthogonal to B, then B is, necessarily, orthogonal to A.

Re:mutually orthogonal

[MarkusQ]

Mutual 1...experienced or done by each of two or more parties with reference to the other or others...3 standing in a specified relation to each other...--1995 OED, concise

So there are two waves. One wiggles up-and-down; the other wiggles left-and-right. They are orthogonal, in that their wiggles are at right angles and thus don't effect each other at all. This mutual othogonality permits them to both pass through the same fiber at the same time, doubling the capacity.

-- MarkusQ

Re:mutually orthogonal

[Marticus]

Yes, but if A is orthogonal to B, and B is orthogonal to C; it does not automatically follow that A is orthogonal to C.

Re:mutually orthogonal

[Anonymous Coward]

nitpick: the mutual orthogonality permits them to be distinguished from each other. Of course you can send two beams of same polarization and frequency through the fiber, but you won't be able to distinguish/seperate the two at the other end.

I'll Take the Bait

[Zen Mastuh]

Imagine if HTML was patented way back in the 1.0 days. By now the owners of the patent would have:

• Charged so much (in the name of the Profit) as to run off all potential users
• Enlisted Congress to enact draconian penalties to prevent people from "stealing" the precious bodily^H^H^H^H^H^H intellectual property
• Bankrupted the company through poor business practices, letting the fruits of the engineers' labor rot away in some attorney's vault

Instead they gave freely and changed the world. ;)

Re:I'll Take the Bait

[Anonymous Coward]

Actually, whoever invented HTML, if they had patented it, probably could not have gotten anyone to use it. Once you disclose something to the public, you have exactly one year to patent it. In the case of a coding language, imagine if someone came to you and said, "I own this language, and I'd really like you to use it and pay me to use it." No one would buy. Things like HTML are developed, then used by those who want to. If enough people use it, it becomes a standard. By then, (i.e., once it is valuable), it can no longer be patented because of the one year deadline aforementioned. See 35 USC sec. 102.

Re:I'll Take the Bait

[Anonymous Coward]

It would be very difficult to patent a programming language, but they *can* be copyrighted. In fact, I believe Microsoft is trying to corner XML by hosting the database/repository for "vocabulary" in that programming language. When you submit to their database, you agree to yield copyrights on your submission to them. VIOLA, microsoft "owns" whatever XML is in their database, and they are (of course) trying to make their database (and hence the coding terms therein) the main one.

Now, while I totally agree with patenting inventions, I am against obtaining intellectual property rights by this kind of slick deal via copyright. (I don't even think computer programs are legal subject matter for copyright, but the Supreme Court disagrees with me unfortunately.) Microsoft does nothing but provide the forum for people to archive their contribution to a growing programming language, and in return they get ownership. Like I said, they are slick.

Mutually Orthogonal

[zentigger]

"Mutually orthogonal" refers to the fact that the optical carriers are travelling perpendicular to each other, but are travelling through the same space (transmitted concurrently), as opposed to being transmitted using a tdma-type technology where the signal would be pulsed on one axis and then other consecutively. This is very much like the technology used in satellite communications, where each transponder has A and B poles.

Anime

[Anonymous Coward]

Pendant show the Mystery Disk We'll take it to the Shrine Will it be that fabled Mystery Disk And release the Phoenix inside?

I was transported to a faraway land To a world where monsters rule I played the game like an ace Now we're in this place To save the monsters from the evil Moo

Monsters Rule!

Monster Rancher!

Monsters Rule!

it is an ill wind

[Anonymous Coward]

that blows no minds

Re:Must defend

[Anonymous Coward]

The reason I don't have a troll account like you is because I am too damn lazy to sign up for one.

Slupid Slashdot

[Anonymous Coward]

Why does IE do this now? When I hit back after a failed post due to some stupid crap my post is deleted. Why the fuck does it do that? I am using the same version of IE for months. V5.5 what the fuck.

Re:Must defend

[Anonymous Coward]

you mom has a lovely cunt

Modal or spectral?

[Magus311X]

dispersal of the light waves

Modal or spectral dispersion? I'm assuming they're using singlemode fiber, so it's likely spectral dispersion, for those who wonder (and lazy to read the article).

Re:Modal or spectral?

[Anonymous Coward]

those who wonder (and lazy to read the article).

Yeah yeah, you're so smart, look at fucking you. I hate people that pull out something they learned last semester that they won't remember in a couple weeks just to show off.

Call to troll

[Anonymous Coward]

Do you here that sound? It is the call of the troll saying that Slashdot must be shown the true meaning of troll power now! Come on trolls we can get the troll ratio up really high on this one. We are close to 3 to 1 on this one now. Lets get going. Show those karma whores that we have the numbers to stop there crap about linux and source and geek shit.

You need IBM!

[Anonymous Coward]

80gbps can be handled by "Fiber Saver", based on the zSeries mainframe system.

IBM, Solutions for a Small Planet.

SO YOU WANT TO BE A TROLL

[Anonymous Coward]

SO YOU WANT TO BE A TROLL

So you want to be a troll? Congratulations on choosing one of the most exciting and fulfilling pastimes known to man. Here are a few tips on what and how to post to help you get started.

1. Be concise. Ramble on too long and you'll lose 'em. An exception to this rule a long, detailed descriptoon of gay sex or some disgusting activity like cutting off your own penis.

2. Be repetitive. The more times people have to see your "suck onto my penis" ASCII, the more annoyed they'll become.

3. Gay porn is good, gay shiteating porn is better. Posting straight heterosexual porn should be avoided since most /. readers have tons of the stuff on their hard drives, and odds are, whatever you post, everyone's seen it already.

4. Cutting and pasting the CmdrTaco, Hemos, JonKatz, Michael's and Timothy's names into your gay porn story is a time-honored troll practise. As a rule, CmdrTaco's should be used as a "bottom", Hemos and JinKatz are usually used as a "top", Michael and Timothy switch off. Cutting and pasting CowboyNeal's name into gay porn is considered bad form and should be avoided.

5. Racist comments are very effective troll material. It is good practice to have your racist comment pretain to the parent story, for example: "AOL is for niggers!"

6. A less used but very effective troll is the smug, self-referential, cryptic comment. One of my favorite instances of this is the "Katy, I love you!" troll. People fucking hate that guy.

7. Another good troll is the anti-linux comment. If you are going to try this, it is best to make your comment as detailed and realistic as possible. No one's going to bite if you just post "linux bites ass".

8. Sorry to say, but goatse is tired. Goatse is over. Goatse is so 2000. Time to move on. Deal with it.

9. Dont try to be too clever and for god's sake don't be arty. No one wants to read your intricately rhymed sonnet about Natalie Portman's asshole. No one.

10. Dont get all offended and hissy when you get flamed. It comes with the territory. Just ignore them or reply with a simple "YHBT. YHL. HAND. Hahahaha". Remember, you are not doing this to make friends. You are doing this to shock, offend, disgust, and annoy.

Well, that's it, happy trolling. If you have any questions or comments, feel free to EAT MY ASS YOU FUCKING LOSER. I can't believe you read this fucking message all the way to the end! What the fuck is wrong with you? Why don't you go back to downloading jpeg of the time Anna K.'s with her tit fell out of her topblSJeh398 HehsnPOwjJaaj dueu(203&*# 394juJDEj3w *HITLER*ueue29shHHd3j3jhnASDFASDFASFASDF

I have

[Anonymous Coward]

mere moments to post my final troll from this IP for the next 72 hours. Oh! I have at least 3 or 4 posts out there that are all about to collapse to -1 so this is it. Actually this isn't it. Hey taco ever heard of dynamic IP's What are you gonna do ban an entire class B network. Yeah send around 65K ips to there doom. Do it!

Hey its IP banning time

[Anonymous Coward]

Hey where are the mods. Hey yeah you mods. I said you fucking loser mods. Get your ass out here and start moding this shit down. Come on you know that is what you live for. Smacking around trolls really makes you lamerz day. Well I am here to oblige. Gte you asses together and start moding shit down like a motherfuck

100 percent Pure troll

[Anonymous Coward]

Certified Troll technology uses TrollVM to troll like you have never seen before. Now Troll goes anywhere with the power of troll once mod everywhere capability.

DWDM?

[skroz]

How does their technique differ from dense wave divisional multiplexing? Anyone know?

Re:DWDM?

[Anonymous Coward]

Is this similar to DVDA mentioned in the movie Orgasmo?

:) Sorry couldn't resist.

Re:DWDM?

[stain ain]

In WDM (I'm not sure the acronym is right) what you do is send more than one signal by using different light colours (frequencies) that don't interfer with each other.
What you do here is send two signals that have the same frequency but orthogonal polarizations so they don't interfere to each other either; imagine one of the waves going on the vertical direction while the other goes horitzontal, that would be orthogonal and you could recover both the vertical and the orthogonal one independently.

Re:DWDM?

[Snags]

DWDM (dense wavelength division multiplexing) referrs to multiplexing multiple optical signals on a fiber by having them exist at different wavelengths of light. This is very similar to how the cable TV line carries 100 or so channels of TV signal by having them at different frequencies.

The D (for dense) means that there are many such channels, often 40+. This article referrs to having two 40Gb/s channels at the same wavelength, but with opposite polarizations so they don't interfere with each other much. This same signal could be used as a base for a DWDM system to effectively double the current maximum speed of like 10Tb/s (40Gb/s * 250 channels).

SI prefixes != ^2

[yggdrazil]

80 Gbit/s != 85 899 345 920 bps

The prefixes kilo, mega, giga are SI prefixes and are always powers of 10, and should never, I repeat never, be used when talking about powers of 2. Use the terms "large gigabits/gigabytes" or "kibis, mebis and gibis" instead, to avoid confusion.

In telecommiunication measurements like bps, the SI prefixes have traditionally always been used properly.

Re:SI prefixes != ^2

[Anonymous Coward]

I tried to order another 512 mebibytes of ram for my computer but the sales rep called me racist names and hung up on me.

What did I do wrong?

Re:SI prefixes != ^2

[Anonymous Coward]

ROFL :)

Yeah, the purist stance doesn't hold out well in real life. We will just have to live with base 2 confusion.

80Gbps already implemented

[guerrouj]

I work for williamscommunications.com and we already use DWDM (Dense Wave Division Mulitiplexing), which allows multiple freqs of light down the same strand. OC-192 transport systems with DWDM, operate in duplex on a single fiber, delivering up to 80 Gbps in eight waves in each direction.

Work w/ this everyday, why is this news???

Re:80Gbps already implemented

[univgeek]

This is news because they put 80Gbps on a SINGLE wavelength. So your system would carry not 10*8 Gbps, but 80*8 Gbps. Now you gotta admit this is news :-)

Re:80Gbps already implemented

[rtaylor]

The fact that they've just doubled it to 160GBps in your case.

It's not DWDM that they're using -- but (from what I can tell) it also doesn't negate using DWDM along side.

Kinda like satelite transmissions using horizonal, vertical, left circular and right circular polorizations at the same frequency. Then for kicks they start using many channels in that manner.

How lame...

[Anonymous Coward]

They tried to block me because my IP had been moderated down too much in the last 72 hours. Don't they know about dial-up?

Re:How lame...

[mangu]

you're posting at -1 by default and you don't get bitchslapped

Cool! That's an unexpected side effect the moderazis had never thought about.

Another side effect is that I just NEED to troll, because I'm stuck at +50 and must get modded down to be able to see my karma climbing again...

Re:How lame...

[mangu]

Dude, that's going to be rough.

I know it ain't easy. You try to be a troll, and some asshole moderator gives you (+1, Funny)...

Still

[Anonymous Coward]

The mods still are as lame as shit. Come on you sit around on your ass and you can't even keep up with a few trolls on the top story on Slashdot. Yeah top story, must be a slow news day. Where is the we bombed the shit out of Kabul report or the government passes anti-slashdot poster laws. Yeah thats the main shit you find here as major stories. Oh and linux kicks everyones ass of course even though it actually gets kicked by everyone else. Haha your lame crap doesn't pass for news. Now mod this shit down!

It's the switches, stupid.

[NerveGas]

We already have much more fiber capacity than we can use. The real bottleneck of the Internet right now is... the switching. OC-768 units (38.8 gigabits/sec) won't even reach volume production until 2003 or later, and they wouldn't even handle half of one of these fibers, let alone multiple fibers coming from various locations. It's like running a 2" diameter fuel line to the engine of your Hyundai.

All-optical switches have been developed, but are not going to be widely deployed for some time. I have a feeling that even all-optical switches will be many years before they reach the speeds needed for 80 gb/s fibers.

The true improvement of the Internet will occur when switching capacity increases by at least an order of magnitude in a very short amount of time. Right now, good, guaranteed bandwidth is barely any less than it was back in 1997. Sure, as switching capacity slowly progresses to fill the needs of the backbone providers, the Internet keeps running - but you still end up paying out the nose for guaranteed bandwidth. Once the switches catch up with the fibers, however, that *might* change. Maybe.

steve

Re:It's the switches, stupid.

[Cato]

Somebody mod this up!

Even when you have all-optical switches, they will initially be circuit switches, with nailed-up optical paths betweeen edge devices, putting more stress on the edge routers because they have more circuits to switch between. People are researching packet switching and burst switching but that's even further off.

Re:It's the switches, stupid.

[Myself]

Yeah, mod BOTH of those up.

There's a huge difference between nailed-up connections and packet-level switching. I mean, hell, a punched-down copper jumper is about as sophisticated as the "optical switches" they have now.

When we get optical logic that can examine packet headers at high speeds, we'll see some development. But for right now, the bottleneck is the silicon chip at the end of the strand of glass.

THE PEOPLE SHOULD KNOW!

[Anonymous Coward]

Let everybody be warned that Miguel de Icaza is gay

Slashdot is slashdotted

[Anonymous Coward]

Must be Troll Tuesday

Microsoft imperialism: .NET, vs. NET, vs. *Net

[torpor]

I propose that in response to Microsoft's usurping of the dot, we counter-respond with an acquisition of the asterisk.

Thus, instead of using .NET, or The Net, or 'net, or Net, we all start using *Net.

That way we can pretty much cover all bases, since everyone knows that * is a wildcard - the All-unifying Infinite Eternal Symbol of All.

All those in favor, say "*me"...

Re:Microsoft imperialism: .NET, vs. NET, vs. *Net

[Anonymous Coward]

f*ck you

Beyond 80 Gbps already?

[JimDog]

I don't understand the importance of this discovery. I'm pretty sure existing DWDM systems can put at least 16 wavelengths on a single fiber at OC-192 (10 Gbps) speeds for a total capacity of 160 Gbps...

Re:Beyond 80 Gbps already?

[Anonymous Coward]

Thats what i was thinking! This seems like a step sideways for no good reason...

But hey, at least the marketing departments in all these companies are still alive and kicking.

You would think there was a chronic shortage of bandwidth out there (there is NOT, just look how many people are getting laid off and how many telcom companies are going under)

Re:Beyond 80 Gbps already?

[JimDog]

Indeed, upon further research, we're already way beyond 80 Gbps on a single fiber. DWDM (dense wave division multiplexing) can increase the capacity of a single fiber to 1.6 Tbps, and soon to 3.2 Tbps with 80 wavelengths at OC-768 according to this press release from NEC. As the press release states, a 3.2 Tbps data rate is the equivalent of transmitting 1600 feature-length films every second.

Re:Beyond 80 Gbps already?

[JebOfTheForest]

maybe they meant they were using two, orthoganal (via the polarization) signals of the same wavelength, so that you can densely divide and multiplex that however you like, and you can double the resulting bandwidth via polarizing and recycling that wavelength.

16 wavelengths = 160 Gbps
16 wavelengths, twice each (one's all sideways from thuther) = 320 Gbps.

Though I'm just talking out of my ass.

Re:Beyond 80 Gbps already?

[cllajoie]

DWDM (Dense Wave Division Multiplexing) does indeed put more through a fiber then 80Gbs (current max is around 53Tbs). DWDM however only addresses the phase of a light wave as it goes through a fiber. Most of the dark fiber we have out there today can handle up to three different polarized waves (or set of phase multiplexed waves). Therefore this technology could in theory be couple with DWDM, allowing three DWDM signals to be multiplexed onto a single fiber, giving a total bandwidth of around 160Tbs per fiber. I say in theory because current DWDM trans/recievers are not yet up to this kind of job.

all you nerds

[Anonymous Coward]

get a life. patents are the american way. people who come up with good ideas should be compensated. just because some people abuse the system (rambus, etc.) with frivolous patent lawsuits doesn't mean that we should abolish it.

if you don't agree, go back to massachusettes, pinko!

Re:Handy guide to acronyms

[Anonymous Coward]

LINUX: Lots of Infantillistic Nerds Using X-rated gay pictures to masturbate.

Re:Handy guide to acronyms

[Anonymous Coward]

FREEBSD: Fucking Retards Eyeing Enviously Bosomy Sodomitic Dragqueens

THIS IS NOT NEWS

[SETY]

From the article I quote:

The system transmits data of two polarization channels with 40Gbit/s each, i.e., together 80Gb/s bit per second, over a 212km long optical fiber - much further than otherwise possible.

This is kind of an intresting experiemnt, but this is not news. The "otherwise possibe" part makes it sound like no one has done PMD compensation before, this is false. Here is why:

1. PMD compensators are being built by many research groups. You still can't call up an order one (AFAIK), but soon.
2. PMD (mean DGD, differential group delay). DGD changes with time and wavelength.
3. PMD on buried fiber varies slowly. It is easy to compensate.
4. Nortel, Alcatel and others with be releasing 40 GB/s (per WAVELENGTH) systems next year. They are suppose to run 100's of km, between regens and at many wavelengths (160?).

Here is a link with almost all peer reviewed papers on PMD:

Here one can see many references to PMD compensation and even some at bit rates of 160 GB/s. With PMD compensation the line speed isn't that important, it is the accuracy and speed of your compensation.

This is not a break through.

Re:THIS IS NOT NEWS

[DTCDAN]

Nortel, Alcatel and others with be releasing 40 GB/s (per WAVELENGTH) systems next year.

Do you really think Nortel will have anything left to release next year?

Re:THIS IS NOT NEWS

[SETY]

Well they only have a few important projects (7?), the 40 gig system being towards the top of that list.

Moderators are OUT! WE WON!!!!

[Anonymous Coward]

No post has been moderated down in the last half hour. This means we posted so many trolls that all moderators are out of points. TROLL ON DUDES!!!

Re:Moderators are OUT! WE WON!!!!

[mangu]

Mangu - A soon to be troll

No. you see, it's funnier to troll at +2, so I must keep mny karma above +25. If you look right above, funny: +1, offtopic: -1, trolling at (+2, offtopic): Priceless!

Mach 5

[Anonymous Coward]

Well????

I know all about cronic problems....

[CamelTrader]

cronically overloaded eh? Well, can't we just eliminate some crontab files? Usually when I have cronic problems, it's because users have improperly setup their cron tasks or set up too many of them. So we just get Al Gore (He invented the net, so he must have admin priveleges, right?) to go out and tidy up some of those crontab files, and we'll have this internet running at tip top speed in no time!

Optics explained...

[peter_gzowski]

I see some others posting explanations about physics behind this, but it seems a bit unsatisfactory for some. Here's my best shot at it:

There are two orthogonal polarization modes that propagate down fiber, meaning the there's a sort of up-down oscillation of the electric field (one mode), and a left-right oscillation (other mode). If fiber were perfect, you could send a signal along each polarization, and they wouldn't bother (interfere with) one another, but it's not. If you send polarized light down a fiber, it will not keep the same polarization (unless you use polarization-maintaining fiber, but that's a pain, and you can only send one polarization down).

So people generally send down (relavitively) unpolarized light. They modulate this one signal as fast as they can (getting about 40Gb/s), and then deal with dispersion as best they can.

Dispersion results from the spread in frequencies (colours) of your signal (each colour travels a different speed in the fiber) and also from the fact that a fiber has polarization mode dispersion (the part of the signal along one polarization axis travels at a different speed than the other part, called PMD from here on in). Both of these effects cause a pulse that you send down the fiber to be distorted (part of the pulse travels at a different speed than the other part). Chromatic dispersion (the first kind) has been dealt with (fibers have a wavelength at which the loss is lowest and a wavelength at which the chromatic dispersion is lowest, and it's been worked such that these two things are at basically the same wavelength), but PMD is a big limitation to pushing the capabilities of fiber. This was stated on the front page post:

They say the only big problem was the dispersal of the light waves which limits the data rate.

I think that should read "dispersion", not "dispersal".

So, what these guys have done is made a PMD compensator. Somehow it automatically makes sure that a given polarization of light stays in that polarization as it travels down the fiber. If one can preserve the polarization of both modes (which is different than polarization maintaining fiber, which takes ONE polarization of light and keeps it polarized), and then send a signal along each polarization axis, then one doesn't need to deal with PMD, because within a given signal, all the pulses are travelling at the same rate.

Then, if you don't have to deal with PMD, then there's very little to slow you down in pushing data through the fiber, basically just how fast you can modulate your laser (I think you could drive a LiNbO3 Mach-Zhender modulator up to about 80Gb/s or so, whereas I think in the article they were driving it at 40Gb/s). That's why they say the data rate was only limited by available equipment. I'm not sure how the PMD compensator works, I'll have to read the actual article more closely. I hope this helps!

Re:Optics explained...

[rtaylor]

If only we could coax fibre to work like waveguide. Then we could have a ton of 'sweetspots' for given multipcations of a base frequency.

Re:Optics explained...

[Anonymous Coward]

I'm curious as to how they made the compensator. There's a fellow design team in my class that is working on a Bragg fiber grating compensator for optic lines.

Capacity is great; Management is better

[tdogboy]

Making bigger and bigger pipes is the way of the net. The technology just has to get better by making the rates higher and the packages smaller.

The next question is, what do we do with all this new capacity? The telecommunications industry is finding all this out since so much infrastructure was built during the boom and everything went bust. There was so much infrastructure out there that was completely useless (think dark fiber) because of incomplete implementation.

They put plenty of fiber in the ground and run out of money before they can get any equipment to light it up. They put plenty of DWDM equipment to light the fiber but they can't sell a whole OC-48 to anyone at a competitive price. They get tons of metro networking equipment but they've just spent all their money and can't make a management system to turn up any metro circuits.

So, these kinds of technological improvements are the greatest thing in the world and they have to keep pushing the envelope. However, there must be concurrent development along all other lines to manage all these ass-kicking boxes and make them usable! If not, no one will buy it because it can't contribute to a sustainable business model.

Is it 2^10 or 10^3?

[supz]

Ok... I've heard different things about this all over the place. When you're talking about bandwidth, does a kilo mean 1000 or 1024? I read somewhere on the MRTG page that in bandwidth terms kilo is 1000, mega is 1000000, etc, and that in storage terms a kilo is 1024, mega is 1048576, etc.

In this post the submitter went against that and said giga is 10737418240 (which is not equal to 1024^3, but this is confusing enough as it is, so lets forget about it).

Which one is it? Is there an RFC that makes some kind of standard for all of this?

Re:Is it 2^10 or 10^3?

[Detritus]

Communications engineers deal with bits or symbols, not bytes. In that context, kilo and mega are almost always the normal SI meanings (10^n).

Re:Must defend

[Anonymous Coward]

Yo mommas like a brick: Dirty, flat on both sides, and always getting laid by mexicans.

Sounds like Star Trek

[grammar fascist]

..."automatic optical compensator of polarization mode dispersion"...

Next it'll be a nanite-enhanced inverse tachyon pulse Heisenberg compensator.

I could use one of those...

Just so you know...

[snubber1]

OT: Your .sig about kermit is not entirely true. See this

Re:Handy guide to acronyms

[Anonymous Coward]

VI: Vlad International (Homes for Boys)

Mmmm... fast....

[Swaffs]

"that's 85,899,345,920 Bps"

Remember when 14,400 bps was fast? Heck, remember when 56k was fast? :-)

Re:Mmmm... fast....

[Anonymous Coward]

no

USDA

[Winjer2k]

I worked as an Intern for the Department of Agriculture, and it's strictly a Microsoft shop. There was a madate set by someone up top that EVERY computer in the Department use Windows. It's kinda sad, considering how much M$ wanted to charge us for a WebDAV solution.

Triple? Quadruple?

[DahGhostfacedFiddlah]

How many differently-polarized light streams can be put through a single fibre before they can't be differentiated? Would it be technically possible to have hundreds, with a single "control" signal to let the receiver know where all of the other signals are relative to each other?

maximum possible bandwidth

[mlachmann]

The maximum possible bandwidth on an optical wire depends on how much energy you use to transmit it. For 1J/s it is 2*10^17 bit/s. Compared to their achievement of 1*10^11 bit/s, we have 21 doublings to go. That's not too many years.

Cronically overloaded?

[Chagrin]

• As we all know, optical fibers build the (cronically overloaded) backbone of our beloved Net.

If it's overloaded by cron, couldn't we just kill the cron daemon?

I have one of those....

[Anonymous Coward]

My father worked at AT&T repairing dataphones and early modems throughout the 80s. Because he did on-site work, he'd have a lot of spare parts floating in his work van. Well, over time, as companies upgraded to newer models, those spare parts ended up in our basement (they were considered junk to the company).

I now have a small black external modem, approx. 2" tall x 5" wide x 8" back. It has a serial port connector, and a phone jack, and an external power-supply (which is a 3" cube of about 5 pounds). Like all old modems, you could only chat with it in that now-familiar AT codes: ATZ / ATDP...

On the front of the box, there are 4 LEDs on the front and a tri-state switch to select your baud rate, 1200 bps, 600, and "Low". :)

It now sits next to the 8" floppy drive, the 20 MB hard drive, the 40 MB tape drive, and that good ol' EGA monitor

Beam me up

[Anonymous Coward]

Now, after two years of research, they invented an "automatic optical compensator of polarization mode dispersion" which fights both the limitations.

It's almost something out of the Star Trek universe!

Re:Triple? Quadruple?

[rtaylor]

Best you can get in openair is about 4 polorizations at any given frequency.

horizonal, vertical, left circular, and right circular. They're a bitch to collect all 4 at the receiving end though.

I doubt that fibre could handle the circular modes -- but I'm not a fibre person.

Hey Dummy (Patents, anyone?)

[Anonymous Coward]

Who are you arguing with? I didn't see any 'demands' to make it "Open" and "Free", did you?

It seems *you* are the only one who can't see the difference between cutting-edge work and One-Click Checkout at Amazon.

Doubling

[Anonymous Coward]

Doubling the performance? Hah, what's that?! Get them a new compiler!

backhoe failure

[Bios_Hakr]

I know this is a little off topic, but I think the correct term is "Backhoe Fade". A quick search turned up an "official" government project .

BTW, the word "fade" is a throwback to the time when most longhaul communications was done using troposcatter microwave systems. Small atmospheric changes such as rain, volcanic dust, solar flares and sunspots would cause the Recieve Signal Level to drop. Ok, Ok, who am I kidding; those bastards would fade at dawn, dusk, mid-day, mid-night, summer and winter solstace, equinox, and any time someone stood too close to the radio. A guy I knew actually shot a radio once for excessive fade. He claimed it was an accident, but the investigator was clued in by the fact that there were 3 holes in the radio...

Bps != bps

[AftanGustur]

Bytes per second != bits per second

Somebody please correct the story.

Four times the mouthful.

[nick_davison]

"polarization division multiplex data transmission system" [using an] "automatic optical compensator of polarization mode dispersion"

If it's twice as fast but takes four times as long to say it, does that actually mean its effect is half the speed? The article didn't say if the "test-line of 212 km" was just so they could write the name on the side.

And to think people believe we IT staff make up impenetrable terminology in an attempt to justify our salaries!

Useless for the backbone

[jeti]

I strongly suspect that this technique is pretty useless for large networks. Those use optical repeaters that work like a laser where the signal initiates the avalanche effect.

And I'm quite sure that the polarization will be lost that way. Since polarized signals cannot be made to work on the existing backbone, this idea will likely not make it to the market.

...overloaded...

[psych031337]

As we all know, optical fibers build the (cronically overloaded) backbone of our beloved Net

While I am always for extending bandwidth, I jump on the term "chronically overloaded" (note the letter "h", which seperates chronic from mere cronjobs)... Not long ago, regarding the 9/11 effects of everyone and their dog logging on to the net on the search for information, I read that the net backbone currently is anywhere between 40% and 50% at any given time. It took 9/11 to get peaks up to 80%-85%.

I tend to think being at half load most of the time is not anywhere near "chronical overload".

What capacity shortage?

[Kaneda]

This is really good news - more bandwidth over existing fibre is great.
But I question the assertion that our backbone is 'cronically overloaded'

Take a look at this, pulled off ft.com on 2001-09-06

> The enduring legacy of all this money is a glut of "bandwidth" - the
> capacity to transmit volumes of data and the basic raw material of all
> communications networks. This glut is so great that if the world's 6bn
> people were to talk solidly on the telephone for the next year, their words
> could be transmitted over the potential capacity within a few hours.
> Analysts estimate that only 1 or 2 per cent of the fibre optic cable buried
> under Europe and North America has even been turned on, or "lit". Some
> people point out that the remaining "dark" fibre needs additional investment
> to activate it and that it therefore does not represent a surplus. But that
> is of little comfort to the beleaguered telecoms industry. There are enough
> new ways of squeezing extra capacity out of existing, lit fibre to have
> caused a collapse in bandwidth prices.
> With new techniques to send multiple wavelengths of light down a single
> fibre, up to 160 separate "colours" of light can now be used to transmit
> data down a single strand of glass. Most modern networks use just a tenth of
> this potential today - or less than a thousandth if dark fibre is included.
> A similar overcapacity exists in undersea links, where each new Atlantic
> cable adds as much bandwidth as all the previous infrastructure put
> together. And mobile phone companies have committed more than $200bn in
> Europe alone to boost the bandwidth of their wireless internet services
> without any proof that consumers will use it or that the technology will
> work.

Re:Triple? Quadruple?

[rjforster]

No, 2 is the max. Circular polarisation is just horizontal AND vertical at the same time, with the same amplitude and 90 out of phase. So you will not be able to discriminate the channels if you add in extra horizonal and vertically polarised light as well.

And yes, fibre can handle circular modes, or any other polarisation state for that matter.

Last geeky point. Orthogonal can be rephrased as '2 polarisation states occupying antipodean points on the Poincaré Sphere'

Now that's the way to win a debate!

[Anonymous Coward]

If you can't rebut or disprove the facts supporting an argument, resort to ad hominem attacks. It works in rigged presidential debates and in slashdot.

I stand corrected

[MarkusQ]

*laugh* You are quite right. I was being sloppy in my statements, even though I had that point clear in my thoughts.

-- MarkusQ

Yeah, T-1 was introduced in 1957

[Myself]

in Newark, NJ. Nobody was using it for data back then of course, but squeezing 1.544 megabits/sec onto a copper pair, in order to move voice circuits around, is nothing new.

I wish the Slashdot team knew a bit more about telecom, they'd accept fewer of these stories and say fewer stupid things about them. "Chronically overloaded backbone" my ass, there are millions of miles of dark fiber out there. The glass isn't the problem, it's the silicon, the greenbacks, and the red tape that make things suck.

Aha! Way informative. mod that up!

[Myself]

I always wondered what the fuck circular polarization was. So you don't really need those curlicue antennae, you could just make two antennae, orient them 90 degrees from each other, and then set one a quarter wavelength behind the other, right?

Excellent point.. Mod that sucker up!

[Myself]

I don't personally have any experience with Erbium-doped fiber amplifiers, but someone here must...

Do EDFA's clobber polarization or not?

The heavy thing about this bandwidth

[ahfoo]

isn't even the net access part. It's the bandwidth itself as an interconnect between all those processors and RAM distributed all over the place.
It's not even being considered a commodity yet in real terms. The idea has been floated in the past, but it always lacked scale and interconnectedness at CPU speeds has been non-existant.
There are projects out there like SETI and whatever DIY stuff goes on, but a market hasn't evolved well. I guess it's because there are no apps.
Hmm.