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New Laser Data Transfer Rate Record Set At 26 Tbps

Roblimo posted more than 3 years ago | from the squeezing-gallons-of-data-through-a-straw dept.

Networking 127

MasterPatricko writes "Scientists at the Karlsruhe Institute of Technology (KIT), Germany have published a technique to push optical data transfer rates to new levels. The article says, 'The trick is to use what is known as a "fast Fourier transform" to unpick more than 300 separate colours of light in a laser beam, each encoded with its own string of information.'"

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127 comments

HDD Speeds (0)

Anonymous Coward | more than 3 years ago | (#36219282)

I wish HDDs supported even close to this speed :(

Re:HDD Speeds (1)

ls671 (1122017) | more than 3 years ago | (#36220878)

A Beowulf cluster of them does using raid 777.

Makes Sense... (3, Insightful)

WarpedCore (1255156) | more than 3 years ago | (#36219300)

So that one episode in Voyager where Seven of Nine makes a "Fourier Analysis" wasn't total bullshit?

Re:Makes Sense... (3, Informative)

Anonymous Coward | more than 3 years ago | (#36219406)

So that one episode in Voyager where Seven of Nine makes a "Fourier Analysis" wasn't total bullshit?

No, we've been doing Fourier analysis for decades. Fourier himself invented it in the 19th century.

Regarding the technique, it sounds like an optical-computing implementation of OFDM (orthogonal frequency division multiplexing) [wikipedia.org] , which is a core technology for ADSL and many other communications protocols. Electronic and radio OFDM is limited by peaking factor (the ratio of peak level to RMS level); doing this optically may get around this problem.

Re:Makes Sense... (0)

Anonymous Coward | more than 3 years ago | (#36219484)

No, we've been doing Fourier analysis for decades. Fourier himself invented it in the 19th century.

Hahahahaaaa, it is funny, because you ignore the joke and just stay serious...

Re:Makes Sense... (2)

blair1q (305137) | more than 3 years ago | (#36219674)

The word you are looking for is "WHOOSH!".

HTH

Re:Makes Sense... (1)

semi-extrinsic (1997002) | more than 3 years ago | (#36220896)

But surely, if they are using Fourier techniques, they could just transfer on infinitely many frequencies at once, yeah? I mean, such a device would have Tbps, puking in the face of this measly 12 Tbps in TFA...

Re:Makes Sense... (1)

semi-extrinsic (1997002) | more than 3 years ago | (#36220950)

would have Tbps

... and silly me for assuming /. supported a character encoding that became the de facto standard years ago.

:% s/Alt+221E/infinity/g

Re:Makes Sense... (0)

Anonymous Coward | more than 3 years ago | (#36221298)

... and silly me for assuming /. supported a character encoding that became the de facto standard more than 15 years ago.

FTFY. But don't mind the continued lack of Unicode because we got this brand new shiny Web 2.0 ajaxy interface that still has broken buttons all over the space and comes to a crawl even using Chrome on a quad core computer for an article with more than 200 posts.

Re:Makes Sense... (1)

elPetak (2016752) | more than 3 years ago | (#36219426)

And if the technology using photons keeps advancing maybe some day we'll have bridges like the ones in "The Dig".

Re:Makes Sense... (0)

Anonymous Coward | more than 3 years ago | (#36219500)

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

Re:Makes Sense... (1)

philmarcracken (1412453) | more than 3 years ago | (#36219654)

So the low slot tracking mod 'Fourier Transform' in EVE Online isnt total bullshit?

Re:Makes Sense... (2)

pclminion (145572) | more than 3 years ago | (#36219854)

Saying they used Fourier transforms is a "no shit" sort of statement. It's like saying you used a shovel when you dug a hole. You'd have to go out of your way NOT to use some aspect of Fourier theory in this problem space. By "used an FFT" they probably mean they're doing some form of OFDM modulation.

Re:Makes Sense... (2)

dogmatixpsych (786818) | more than 3 years ago | (#36221272)

We do the same thing with MRI scans to reduce scan times, varying the extent of the transform to alternate between speed and quality.

*Facepalm* (0)

Anonymous Coward | more than 3 years ago | (#36219302)

"At those speeds, the entire Library of Congress collections could be sent down an optical fibre in 10 seconds"

This got to be a joke.

Re:*Facepalm* (3, Funny)

swanzilla (1458281) | more than 3 years ago | (#36219428)

I'm not certain...British humor is puzzling.

Re:*Facepalm* (1)

couchslug (175151) | more than 3 years ago | (#36219908)

Finally someone adopts a useful metric and they get ridiculed for it!

Re:*Facepalm* (1)

jd (1658) | more than 3 years ago | (#36220396)

If you only consider the paper materials, it would be. But after you factor in porn and torrented movies, you end up with quite a lot of information.

I was going to make a "Library of Congress" joke.. (2, Informative)

Anonymous Coward | more than 3 years ago | (#36219304)

But the FIRST line in the article was:

At those speeds, the entire Library of Congress collections could be sent down an optical fibre in 10 seconds.

Well played, BBC. Well played, indeed...

Re:I was going to make a "Library of Congress" jok (2)

_0xd0ad (1974778) | more than 3 years ago | (#36219448)

The best part is they were off by a factor of 8, since Tbps means terabits per second. Not so well played after all...

Re:I was going to make a "Library of Congress" jok (1)

toetagger (642315) | more than 3 years ago | (#36219646)

I know, it sucks having to wait 1:20 minutes for my LoCs instead of the average 0.17 minutes - I'm so disappointed in this new technology, so yesterday!

Re:I was going to make a "Library of Congress" jok (0)

Anonymous Coward | more than 3 years ago | (#36219516)

Sure, but what is that in Volkswagens?

Re:I was going to make a "Library of Congress" jok (0)

Anonymous Coward | more than 3 years ago | (#36220058)

Sure, but what is that in Volkswagens?

German or American?

Re:I was going to make a "Library of Congress" jok (0)

Anonymous Coward | more than 3 years ago | (#36220302)

And how many coconuts?

Re:I was going to make a "Library of Congress" jok (1)

smitty97 (995791) | more than 3 years ago | (#36219614)

I wanted to double check exactly what a "Library of Congress" was so I went right to the source [loc.gov] :

"Today the Law Library’s expansive reading room and its administrative offices occupy the second floor of the Madison Building, while the sub-basement provides more than a football field of compact collection storage space."

ugh.

Re:I was going to make a "Library of Congress" jok (0)

Anonymous Coward | more than 3 years ago | (#36220124)

AHHAHA That's the standard data density unit, LoC/Football field

Re:I was going to make a "Library of Congress" jok (1)

blair1q (305137) | more than 3 years ago | (#36219700)

But why, you should have asked, is the BBC giving figures in units of LoCs?

They don't have books in Blighty?

Re:I was going to make a "Library of Congress" jok (1)

tepples (727027) | more than 3 years ago | (#36219942)

But why, you should have asked, is the BBC giving figures in units of LoCs?

Is the Library of Parliament (or whatever they call it) as big as the Library of Congress? If not, that might be part of your answer.

Re:I was going to make a "Library of Congress" jok (1)

jd (1658) | more than 3 years ago | (#36220486)

The British version of the Library of Congress would be the combination of the National Archives and the British Library. Given the BBC partly functions in the manner of the FCC, you may need to include the BBC archives in there as well. The sum total of these three collections probably exceeds the Library of Congress but there's no collective name for all of this information.

Re:I was going to make a "Library of Congress" jok (1)

SuricouRaven (1897204) | more than 3 years ago | (#36221144)

The BBC doesn't function anything like the FCC. The body you're looking for there is OFCOM. They handle frequency allocation*, what little broadcast content regulation we have**, the sort of thing the FCC would handle in the US. The US doesn't really have a counterpart to the BBC. The closest would be PBS, but they differ in some very important ways.

*Much like the FCC, they'll occasionally say something about public benefit before auctioning it all off to the highest bidder.
**As we don't have that many radio broadcast channels, and cable/sat are outside OFCOM's direct oversight, they don't have much to do here. They occasionally send a strongly-worded letter.

Re:I was going to make a "Library of Congress" jok (0)

Anonymous Coward | more than 3 years ago | (#36219790)

wake me up when someone invents the Heisenberg compensator so we can beam the LoC in less then 10 seconds.

Re:I was going to make a "Library of Congress" jok (1)

Cynonamous Anoward (994767) | more than 3 years ago | (#36219938)

Boy, this will REALLY piss off the those entertainment fat cats...

They got upset because transferring a portion of their catalog no longer had a "cost" associated with it. What are they gonna do when transferring their entire catalog no longer even has a time-cost associated with it?

No one needs this kind of speed. (0)

Anonymous Coward | more than 3 years ago | (#36219314)

No one will ever need more than 1 Tbps.

In the Matrix you will!! (0)

Anonymous Coward | more than 3 years ago | (#36219376)

n/t

Re:No one needs this kind of speed. (1)

Haedrian (1676506) | more than 3 years ago | (#36219398)

You wait until you try to download some HD 3D 'adult material'...

Re:No one needs this kind of speed. (1)

mcavic (2007672) | more than 3 years ago | (#36220452)

No one will ever need more than 1 Tbps.

Are you pulling a Bill Gates?

Re:No one needs this kind of speed. (1)

jd (1658) | more than 3 years ago | (#36220586)

Japanese domestic television is due to switch to a 7680x4320 at 60 frames per second format in 2020. Do not be surprised if the cable companies there seriously debate multi-terabit cables at least between studios and archives or distribution points. If you increase the quality to HDR (32bpp or greater), you start needing these kinds of speeds to the home.

Re:No one needs this kind of speed. (1)

jdgeorge (18767) | more than 3 years ago | (#36220994)

It may become possible to transmit a 7680x4320 60 frame per second feed on a Japanese television network, but:
1. Consumers will not have (or need) devices capable of displaying this quality of video
2. Most television content will not ever be produced in that format.

It seems to me that the most likely application would be that this standard would allow transmission of a high-quality digital movie to directly a theater, so the theater wouldn't ever have the movie "in house" (in order to mitigate piracy).

Re:No one needs this kind of speed. (1)

SuricouRaven (1897204) | more than 3 years ago | (#36221162)

Consumers will not have *eyes* capable of benefiting from that quality of video, unless you're planning to put them in some sort of device that occupies their entire field of view.

KIT (0)

Anonymous Coward | more than 3 years ago | (#36219338)

The name that has everyone snickering in Germany: A shameless attempt at raising associations with the MIT by giving a German university a similar name.

Re:KIT (1)

nedlohs (1335013) | more than 3 years ago | (#36219478)

Yeah, because "X Institute if Technology" is such an uncommon name.

It's not like there's IIT in Illinios of FIT in Florida or OIT in Oregan. Or a dozens of others of the form XIT and XYIT.

And if they used the other alternative "tech" they'd be copying caltech right?

Re:KIT (1)

Yvan256 (722131) | more than 3 years ago | (#36219510)

You mean like the IIITECH? (The International Internet Institute of Technology)

Re:KIT (1)

geogob (569250) | more than 3 years ago | (#36219754)

I work at the KIT and I can assure you that the goal of this new name (came from the fusion of the University of Karlsruhe and the Research Center of Karlsruhe) was to make it "sound" like MIT. I've even seen memos explaining that we should pronounce the letters KIT in English instead of German... which is both stupid and obvious in my opinion. The board of directors was pretty explicit on this topic. And yes, it has everyone snickering... maybe not in Germany, but in the old Forschungszentrum at least.

Re:KIT (1)

dave420 (699308) | more than 3 years ago | (#36219866)

Do you drink at Scruffy's? If you don't, maybe you should :)

Re:KIT (1)

geogob (569250) | more than 3 years ago | (#36220024)

Definitely not often enough.

Re:KIT (1)

maxwell demon (590494) | more than 3 years ago | (#36220158)

Yeah, because "X Institute if Technology" is such an uncommon name.

In Germany, it is.

BTW, I'm still waiting for the Schleswig-Holstein Institute of Technology. :-)

Re:KIT (1)

demonbug (309515) | more than 3 years ago | (#36219482)

The name that has everyone snickering in Germany: A shameless attempt at raising associations with the MIT by giving a German university a similar name.

And here I thought they were trying to associate themselves with David Hasselhoff. You know, KIT -> KITT -> The Hoff.

Re:KIT (0)

Anonymous Coward | more than 3 years ago | (#36219554)

For future reference, jokes aren't funny when you explain them.

Re:KIT (1)

The Grim Reefer2 (1195989) | more than 3 years ago | (#36220436)

The name that has everyone snickering in Germany: A shameless attempt at raising associations with the MIT by giving a German university a similar name.

With Germans obsession with David Hasselhoff, I figured it had more to do with KITT. [wikipedia.org]

More than meets the eye... (0)

Anonymous Coward | more than 3 years ago | (#36219360)

Maggie Madsen: Maybe it's a precaution, because isn't that what we're doing? The signal pattern is learning, it's EVOLVING on its own, and you need to move past Fourier transforms and start thinking quantum mechanics...

Admiral Brigham: [with unintentional irony] There is nothing on Earth that complex!

Maggie Madsen: How about an organism, a living organism? Or some sort of DNA-based computer? I know that sounds crazy, but...

Re:More than meets the eye... (0)

SuricouRaven (1897204) | more than 3 years ago | (#36221290)

You got my hopes up there, thinking the quote might be from a much better book. I forgot the title, but it involves a sentient radio signal, an accidentally too-successful attempt to evolve artificial intelligence, wetware processors, and the eventual victory of a robotic caterpillar toy with a program more sophisticated than the owner expected.

The trick to make a first post (0, Offtopic)

cachimaster (127194) | more than 3 years ago | (#36219364)

Is to use what is know as a "web browser" to quickly surf the "internet"

Re:The trick to make a first post (0)

j33pn (1049772) | more than 3 years ago | (#36219452)

I would "mod you up" if I could.

FAIL (-1)

Anonymous Coward | more than 3 years ago | (#36219480)

FAIL

Unpick? (0)

Anonymous Coward | more than 3 years ago | (#36219368)

(v) To absolutely not pick. "The story submitter was unpicked from many dodgeball games growing up."

Thank goodness (1)

drb226 (1938360) | more than 3 years ago | (#36219408)

they used the American measuring system I'm familiar with: the Library-of-Congress.

At those speeds, the entire Library of Congress collections could be sent down an optical fibre in 10 seconds.

It surprised me that this came from bbc.co.uk

Re:Thank goodness (0)

Anonymous Coward | more than 3 years ago | (#36219528)

I have always wondered how big is a LoC? Meh too lazy to google or do any math today...

Re:Thank goodness (2)

_0xd0ad (1974778) | more than 3 years ago | (#36219572)

http://www.loc.gov/webarchiving/faq.html#5 [loc.gov]

As of April 2011, the Library has collected about 235 terabytes of data (one terabyte = 1,024 gigabytes). The archives grow at a rate of about 5 terabytes a month.

Re:Thank goodness (1)

TheLink (130905) | more than 3 years ago | (#36219632)

Are those TBs documents stored as scans or are just the text stored? Does it include compression?

Re:Thank goodness (1)

_0xd0ad (1974778) | more than 3 years ago | (#36219694)

Since they said "of information", I'm assuming they are talking about how much space it would take if the scanned text was run through OCR and stored without compression.

Re:Thank goodness (1)

smitty97 (995791) | more than 3 years ago | (#36219546)

what does that work out to in the metric system?

Re:Thank goodness (1)

idontgno (624372) | more than 3 years ago | (#36219630)

I believe the SI version is the "Library of Progress", since the metric system is relatively progressive and "pro" is clearly the opposite of "con" (the key prefix in the Congressional System).

Who whole damn library? (1)

Panaflex (13191) | more than 3 years ago | (#36219564)

Lets see what happens when we send Congress through this thing?

Re:Who whole damn library? (2)

blair1q (305137) | more than 3 years ago | (#36219726)

As this is a fairly large tube, they should all fit just fine, especially if the go in brain-first.

Re:Who whole damn library? (1)

mr1911 (1942298) | more than 3 years ago | (#36220810)

As this is a fairly large tube, they should all fit just fine, especially if the go in brain-first.

You realize he was talking about Congress, right?

Colors (1)

Iamthecheese (1264298) | more than 3 years ago | (#36219568)

Serious question: It seems like it could be possible to use an infinite number of colors with interpolated laster on pulse modulation to transmit an infinite amount of information. Why won't this work?

Re:Colors (1)

ledow (319597) | more than 3 years ago | (#36219586)

An infinitely complex sender/receiver apparatus?

Re:Colors (2)

vlm (69642) | more than 3 years ago | (#36219660)

Serious question: It seems like it could be possible to use an infinite number of colors with interpolated laster on pulse modulation to transmit an infinite amount of information. Why won't this work?

According to the Shannons theory it'll work just fine assuming you have infinite transmitter power with zero receiver noise so as to get that infinite SNR it would require.

On the other hand, dispersion thru any media, optical fiber, even air, will totally screw it up at an infinitely short distance. Basically you will not be surprised to know that light travels at different speeds in glass or whatever depending on its frequency... that is pretty much how a prism makes a rainbow... So your 1500 nm bitstream will rapidly cover an area of 1499.(lots a 9s) to 15.(lots of 0s)1.

The other problem is you'd like to think single mode fiber Really Means single mode, but theres dispersion there too. I suppose if you had an infinitely small point source for the transmitter, and the fiber were perfectly straight...

http://en.wikipedia.org/wiki/Group_delay_and_phase_delay [wikipedia.org]

Re:Colors (1)

blair1q (305137) | more than 3 years ago | (#36219744)

There's also the fact that amplitude is not constant across the spectrum of a pulsed carrier. So there's still a finite bandwidth.

I'm pretty surprised they got 300 frequencies above the noise floor.

Re:Colors (1)

zach_the_lizard (1317619) | more than 3 years ago | (#36219668)

Not being a hardware geek, this is what I heard: Is it possible to recalibrate the phased tetryon emitters to modulate the warp field and provide infinite information?

On a moreassemble note, I would argue no, because of the limited amount of matter / energy in the universe, let alone any limits of the material.

Re:Colors (1)

maxwell demon (590494) | more than 3 years ago | (#36220338)

Not being a hardware geek, this is what I heard: Is it possible to recalibrate the phased tetryon emitters to modulate the warp field and provide infinite information?

No, because subspace interference would cause a tachyonic wave which would open a temporary worm hole which then would suck the information into a parallel universe.

Re:Colors (2)

peragrin (659227) | more than 3 years ago | (#36220702)

Not being a hardware geek, this is what I heard: Is it possible to recalibrate the phased tetryon emitters to modulate the warp field and provide infinite information?

No, because subspace interference would cause a tachyonic wave which would open a temporary worm hole which then would suck the information into a parallel universe.

ah so that is where Hawking radiation comes from. Parallel universes trying to send porn quickly.

Re:Colors (2)

pclminion (145572) | more than 3 years ago | (#36219702)

Serious question: It seems like it could be possible to use an infinite number of colors with interpolated laster on pulse modulation to transmit an infinite amount of information. Why won't this work?

The uncertainty principle, basically. In the real world, there's no such thing as light of a single frequency. This is due to some basic properties of Fourier transforms. All real light pulses are finite in duration, which means they contain a range of frequencies, not a single frequency. The only way to achieve light of a single precise frequency is for the pulse to be infinite in duration. That's not physically possible.

Re:Colors (1)

kaiser423 (828989) | more than 3 years ago | (#36220414)

Pretty much. It's a "god said" thing.

Think of it this way, to encode bits onto the light stream, they're modifying both the amplitude and the phase of the light wave. Think of a nice sine wave, and then think about inverting or reversing the phase at various points to represent the data (http://en.wikipedia.org/wiki/Phase_modulation). Then try and calculate what that final frequency of light is. It's not a single frequency anymore. Amplitude modulation is similar, when you change the amplitude of the signal, you can see that while the period stays the same, the slopes and rates of change for the signal change, which also smears it out across bandwidth.

The big driver in bandwidths right now is the encoding schemes. Items like QAM64 use 64 different phase/amplitude combinations to define bits. If you can keep the transmission medium phase and amplitude stable, and have exceedingly good transmitters and receivers, you can keep differentiating more combinations. Keep making the receivers/transmitters cleaner, and creating better fibers and you'll do better. I think that QAM256 is getting pretty standard, and we're looking at hitting QAM4096 and even more (of course, the rate at which you change it makes a difference, but for a given bandwidth that you fill, this is where we're going to be getting a lot of the rate increases).

Re:Colors (1)

b4upoo (166390) | more than 3 years ago | (#36219810)

Infinite being what it is one could never hope to complete even making discrete channels for colors as one would be creating each thread infinitely. Then there is the problem of little Johny digs into the cable. Who is going to be able to line up all of those color bands. Infinite speeds are for THE BIG GUY and not for mortals.

Re:Colors (1)

jab (9153) | more than 3 years ago | (#36220078)

Serious answer. An optical fiber is only transparent for a limited range of colors. As soon as you modulate a single color (monochromatic laser beam) the resulting light beam is by definition no longer monochromatic. Here's a fun, beginner oriented book [google.com] on the topic.

Re:Colors (0)

Anonymous Coward | more than 3 years ago | (#36220180)

Serious question: It seems like it could be possible to use an infinite number of colors with interpolated laster on pulse modulation to transmit an infinite amount of information. Why won't this work?

Because there are not an infinite number of colors available. This technique uses pulses that combine to simulate a wider range of colors (not unlike the way you can combine the basic red/blue/yellow to create far more colors. It offers a serious increase in bandwidth in the sense that it lets you transmit different data-streams on each color, but it is still limited by our technological ability to actually generate the wavelengths of light, and then our ability to read and interpret them accurately at the other end.
 
Saying you could transmit infinite data over this system is like saying you can fit infinite data on a cd disk; it works up to a point with compression technologies and such, but still eventually maxes out from the bit size that can be physically written and read from the media.

Re:Colors (1)

LWATCDR (28044) | more than 3 years ago | (#36220552)

A. You can not generate an infinite number of colors. Each frequency of radiation is caused by a specific change in quantum state. "See black body".
B. Even with light you can have constructive and destructive harmonics. You would not want to use colors that can interfere with one another.
C. Your transmitting medium will be limited to what "colors" it can pass. Fiber optics are not good with passing X-Rays or Radio.
Yes Xrays, Gamma, and radio are really when you get down to it just other "colors" of light, the wave length is what is different. They are all part of the electromagnetic spectrum of which light and what we think of as color is just a small part. So you really don't have that infinite spectrum of colors you where talking about.
What this is called if frequency based multiplexing. As you can see you do not have the potential for an infinite amount of data but you do have what is known in the field as "an unholy mega crapload of potential bandwidth" or in Europe as a "Metric Mega crapload of potential bandwidth".

Re:Colors (1)

Fleetie (603229) | more than 3 years ago | (#36220674)

For exactly the same reason that you can't fit an infinite number of AM radio stations into a finite width of radio spectrum. The act of AM-ing a single frequency carrier f_c at data rate / frequency f generates sidebands each side of the carrier, so that the signal now spreads over (f_c - f) to (f_c + f), i.e. the bandwidth becomes (IIRC) 2f. Fleetie

HDD speeds (1)

DanCooper (2191988) | more than 3 years ago | (#36219612)

I really wish HDD speeds could come even close to this :(

Re:HDD speeds (1)

chemicaldave (1776600) | more than 3 years ago | (#36219704)

Why? Are there any practical home uses for that kind of speed?

Re:HDD speeds (1)

blair1q (305137) | more than 3 years ago | (#36219770)

Anything that removes latency is useful.

Just the time needed to load rendering library code as you browse around the web slows you down. A bigger cache only helps after the first time you load it; the first time is still bogged down in disk transfer. SSD would help, but then something else would become the tentpole.

Re:HDD speeds (1)

Anonymous Coward | more than 3 years ago | (#36220128)

Under Comcast's current pricing model I pay about $60 for 250GB per month. This service would cost just over $15 billion per month. Or if they were going to keep my current cap of 250GB per month, and I were able to use the full 26Tb connection, I would hit that limit in 0.0096 seconds of use. HP printer ink and Comcast's internet pricing model tend to look very similar.

Re:HDD speeds (1)

geogob (569250) | more than 3 years ago | (#36219786)

Just like channels in a fiber, if you get enough HDD in parallel, you might get somewhere close to it... (but don't ask me at what cost).

otherwise known as OFDM (1)

cats-paw (34890) | more than 3 years ago | (#36219680)

OFDM is the same modulation technique used for WLAN.

Seems like the hard part is generating that wide variety of wavelengths.

The thing which is kind of critical is that you need an FFT that you can process at several trillion operations a second.

The FA says they are doing this photonically, which to me, is the cool part.

Enlighten Me! (0)

Anonymous Coward | more than 3 years ago | (#36219686)

This comes from a lack of understanding of the field, but can someone explain to me what happens before and after, when transmitting data? The last I worked on hardware was with serial UARTs, so is someone willing to take a moment to explain better or to point me in the right direction to find more information on how it works?

The data is encoded into beams of light and transmitted from point to point. Upon "re-entry" into system at the end point, how is the information gathered and processed internally from this point? Does this rate of transmission get matched or have comparable mechanisms internal to the system? If data is moving at 26 Tbps, is it processed at anything even remotely similar, or does it fill a massive buffer?

Much appreciated!

Enlighten Me! (1)

AnotherAnonymousUser (972204) | more than 3 years ago | (#36219698)

This comes from a lack of understanding of the field, but can someone explain to me what happens before and after, when transmitting data? The last I worked on hardware was with serial UARTs, so is someone willing to take a moment to explain better or to point me in the right direction to find more information on how it works? The data is encoded into beams of light and transmitted from point to point. Upon "re-entry" into system at the end point, how is the information gathered and processed internally from this point? Does this rate of transmission get matched or have comparable mechanisms internal to the system? If data is moving at 26 Tbps, is it processed at anything even remotely similar, or does it fill a massive buffer? Much appreciated!

Re:Enlighten Me! (0)

Anonymous Coward | more than 3 years ago | (#36219844)

I work in the fiber optic telecom field and basically in a DWDM system you take put a standard interface (like a 10G signal) on the box then you digitally wrap it using an ITU-T G.709 standard wrapper (in the case of 10G it would be an OCh107 or OCh111 wrapper). From there it is put on a NBO (narrow band optic) and is put into the mux/demux where it becomes a composite signal. When it gets to the other end it is demuxed, unwrapped and sent out a like interface.

Link to the original (2)

Simon80 (874052) | more than 3 years ago | (#36219730)

http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2011.74.html [nature.com] According to the abstract, the key contribution is an optical implementation of the Fast Fourier Transform (which is pretty cool). They only tested their work using fibre, not just laser beams or w/e is implied by the headline.

Analog FFT? (1)

hendrikboom (1001110) | more than 3 years ago | (#36219984)

Why not just use a prism?

Re:Analog FFT? (1)

Soft (266615) | more than 3 years ago | (#36220856)

You're right: in theory, it's the same as a prism plus a grid to separate the desired wavelengths. The point is, the optical setup described implements far finer and stabler a grid than remotely possible using conventional filters.

Ok... let me try and translate (2)

i_b_don (1049110) | more than 3 years ago | (#36220114)

I work in this field so let me see what I can do to translate what's happening and which parts are actually interesting. I dont' know the details of the experiment I'm only going off the article's summary and assuming they're correct. (BTW, while I"m an expert in a tiny slice of this field, my "expert" level knowledge doesn't extend to the whole pie. So some things I say may be assumptions I've made and can be wrong. If you see a mis-statement please correct me.)

First off, we do fiber optics all day long for internet backbone communications. We even do "multi-mode" optical (different color/wavelength lasers) all day long but only for short cable lengths. Neither of which is article worthy. This thing called a "fast Fourier transform" is just math that is taught in school and is nothing even close to revolutionary, it is simply a fundamental mathematical tool of everything in this field.

First off let me give you the basic framework. When you're talking about sending data at these speeds and over these lengths, you can forget the idea that you're sending lots of data down the line in nice waveforms. The data is so distorted that significant energy is put into compensating and un-distorting the waveforms. Fiber optics at these speeds just doesn't work at all without heavy duty data recovery techniques. So we send down the line data, get back garbled gibberish, apply techniques for removing errors and you can recover your data stream.

So typically when we do "long haul" fiber (> 1k or so) we do single mode fiber, this means a single frequency or color (remember your physics, each color is a different frequency of light). This is because different frequencies of light travel at very slightly different speeds down the fiber and if you have long enough fiber this difference in speeds becomes significant and starts to harm your ability to regenerate the information. Additionally one frequency can cause noise in another frequency band so keeping things to a single frequency makes things more stable at long haul lengths. This is why "traditional methods to separate the different colours will not work".

So Professor Freude and the article:
There are two steps forward here:

1. He's using a single laser to create different frequencies of light. I don't know if this is a common technique or not. I've typically hear of different colors of light being generated by different lasers but I am not an optics guy so I'm not sure.

2. He's using an optical method in place of a Fast Fourier Transform (FFT) instead of silicon that somehow helps him decode the data. An FFT mathematically converts from frequency domain to time domain so maybe he's just using a prism or something to separate the different frequencies as a pre-processor step and then pumping this into his processor, but I can't tell.

So Professor Freude and team and working on making "multi-mode" work at long haul. This is typically not done today so that's the step forward and since you can pack more information into your data stream if you include multiple frequencies, that's a nice win. but of course research success does not necessarily equal a marketable product.

(Again, I am not a guru here, so if you are, please politely correct any mis-statements I've made.)

d

Re:Ok... let me try and translate (1)

PacketShaper (917017) | more than 3 years ago | (#36220634)

I also work in the network field. Please allow me to correct a couple of your points.

Single mode vs. MultiMode fiber does not mean what you think it means (one wavelength vs. many) and as the name may suggest.
To simplify, MultiMode is for short distance runs, SingleMode is for long distance runs. A different wavelength (actually a "range" of wavelengths) are used for single mode to achieve longer distances.
What you were describing is actually called Multiplexing [wikipedia.org]

This is how super high data rates are achieved by cramming many different wavelength transmissions into the "tubes".

Re:Ok... let me try and translate (0)

Anonymous Coward | more than 3 years ago | (#36220668)

"Multi-mode" and "single-mode" are not what you describe. These names refer to the way light propagates inside the fiber, not the number of colors.

Re:Ok... let me try and translate (4, Informative)

Soft (266615) | more than 3 years ago | (#36220796)

We even do "multi-mode" optical (different color/wavelength lasers) all day long but only for short cable lengths.

I'm afraid you're mixing up frequency/wavelength modes with propagation modes. Most long-distance systems use several different wavelengths, that's what WDM is. But they use single-mode fibers, meaning that light at a given optical frequency (and polarization) can only propagate in a single way, thus at a given speed. Multi-mode fibers, with a wider core, let light propagate over different modes (different possible paths in the core for light rays, kind of), which plays havoc with the signal (pulses get echoes and whatnot), which is why they are used only for short distances.

The experiment described here uses OFDM, which in principle is akin to WDM but squeezing many wavelengths as close together as theoretically possible, too close to be separated by classical optical filters. Instead, you can separate them mathematically using an FFT, but that takes a lot of computing power. What the authors did is to implement FFT optically, which is very neat. It enables the use of OFDM at ultrahigh bit rates; and the details of OFDM are such that, used in the right way, it can be extremely resistant to signal degradation (look e.g. at Figure 4(c) in the Nature Photonics article, and think about how tightly a conventional system at that bit rate would have to manage dispersion).

What bugs me is that they describe their setup as performing better than plain coherent detection (Figure 5), which I have a hard time believing. Exactly how did they do the comparison, I wonder.

Doesn't matter. (1)

VortexCortex (1117377) | more than 3 years ago | (#36220120)

If spending profit to improve the worth of your company actually resulted in higher short term stock prices, maybe... Currently it does the opposite.

Want faster Internet? Too bad, that kills our stock prices -- the investors won't allow it, we have to charge the customers more without letting the investors latch on to that profit so that we can spend it on improving our services. Too bad it's illegal to do that once you go public.

If it costs anything beyond standard maintenance, it's not coming to the giant ISPs. That's what was so great about the smaller ISPs, they could risk more to provide better service and eventually end up with better stock prices in the end. The big ISPs of today are so immobile, the transition would take too long and cause the short-sighted investors jump ship.

Seen it happen many times, don't take my word for it, do your own damn research if you actually care -- but you don't; so let's just bitch about not having fiber to the home, and make excuses for why our speeds suck in the US compared to smaller places, while marveling at new advances that will never reach us.

Original paper link (1)

MasterPatricko (1414887) | more than 3 years ago | (#36220474)

Ughh. way to gut the summary I had written.

Anyway here's the original paper in nature photonics
http://dx.doi.org/10.1038/nphoton.2011.74 [doi.org]

Basically the advancement in this technique is to take several incoming tributaries of data and use an optical FT method (OFDM) to encode into a single laser for transmission. Apparently the encoding/decoding is simple and low-power enough to fit on a silicon chip so this technology seems very implementable, just by upgrading the hardware on either end of existing fiber optic cables.

The BBC article with their 0.1 Libraries of Congress per second was great too ;)

What is the point? (1)

Max_W (812974) | more than 3 years ago | (#36220546)

What's the point if ISP caps are 4 - 5 GB per month?

How about summarizing the ACTUAL NEWS instead??? (2)

Co0Ps (1539395) | more than 3 years ago | (#36220764)

Wow, the summary is completely misleading and tells you nothing about the actual news. It reads like they just figured out that they can use multiple frequencies to send additional bands of data. Everybody with a slightest clue about how optical data transmission works knows this already. The news in TFA however is that they have figured out how to encode this data with a single laser instead of one laser per band making it enormously more economic. A car analogy would be if someone had figured out how to make cars fly without wings, and the summary would be "a new vehicle pushes transportation to its limits. by sitting in a container with an engine one can travel much faster than walking." Facepalm.
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