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The 1st Commercial-Grade All-Optical Switch? 73

joabj writes: "Today's Washington Post trumpeted the delivery of the first-ever commercial-grade optic-switch, by Corvis Corp. I'm not sure how commercially viable a switch the size of a refrigerator can be, though a commercial-grade all-photonic switch is indeed, as the WP points out, a "holy grail" of the optics industry--the missing piece for the 40-80 Gbps throughput for fiber optic cable that the industry is so hungering for these days. (Now, photonic signals must be converted into electrical signals to be switched, then back into light again -- slowing transmission speeds considerably.) Unfortunately neither the article (Free reg. req.) nor Corvis' own Web site explains what the winning technology was. There are a lot of competing ideas out there on how to switch optical signals. Is it MEMs? Liquid crystals? Curious minds want to know ..."

Initially, this sounds a lot like the optical switch announced by Agilent a little while ago, but with the bonus of being ready "within a few weeks" from workaday life. (Does that mean the equipment reported as delivered is still being installed or set up?) [Updated 11th Oct. 2000 4:05 GMT by timothy:] As a few people have pointed out in comments, that free registration is pretty painless ... since it's not necessary. Better than the other way around! ;)

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The 1st Commercial-Grade All-Optical Switch?

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  • neener neener
  • there is no free registration required for the washington post. you're thinking of the new york times.

    Internet killed the video star,
  • heh, takes up one rack unit space, lets see, for the speed benefits, can you say hell yeah???
  • Yes, now you too may be able one day to get your all you can from that pricy OC3 you got installed when you moved.
  • Unfortunately niether the article (Free reg. req.) nor Corvis' own Web site explains what the winning technology was. There are a lot of competing ideas out there on how to switch optical signals. Is it MEMs? Liquid crystals? Curious minds want to know ...

    It's something which when revealed will be "obvious" to everyone on ./ and which has plenty of prior art. Just kidding (I agree that most patents which appear on ./ are absurd, but if this company patents the technique that they used to make their switch it at least sounds like it would be a good use of the patent system for once).

  • by tylerh ( 137246 ) on Tuesday October 10, 2000 @12:32PM (#716468)
    The article says:
    Lucent...said it delivered a similar all-optical technology...last month to Global Crossing
    Lucent says here [lucent.com] they are using microscopic mirros, so corvis probably is too.
  • A very interesting article at http://biz.yahoo.com/prnews/000828/nm_lpth_ne.html reports how LightPath Technologies released its Optical Switch at the National Fiber Optics Engineers Conference in Denver, Colorado. Hmm, wonder what this will bring -- lower pricing or a law suit?
  • No, from now on all internet connections will be taxed becuase of the 'potential' to pirate. But it will be scale. Like if you buy one of these since you can cary more pirated works you must pay a higher tax. This tax will of course be used to make up for the decrease in sales because of the proliferation of pirated material.
  • Could it be here? [164.195.100.11]
  • This has almost nothing to do with the RIAA or the MPAA. It has nothing to do with Beowulf Clusters or the CueCat or Ayn Rand. It doesn't even have much to do with Linux or Rob Malda or RMS and his livestock habits. It isn't a story about the post-Columbine era or the alienation of the geek culture or the failure of the DMCA.

    This is, instead, a story about a big clunky horrible switch that, in ten years, will be the size of a frisbee and which we will all happily take for granted.
  • How about a little mirror that takes the incoming beam, and swings around to aim it at a proper outgoing sensor. The size is to hold the big-ass superconducting magnet needed to swing the mirror at Ghz speeds.

    So here's the question. How small would the mirror have to be so that it wouldn't have to swing faster than relativistic speeds, and then how much power would it take to make it move a 100 million times a second (Let's say 10Ghz optical switch, 1000 bit packet size)? Come on Physics students, step up to the plate. :)


    --

  • I hope the RIAA and the MPAA are paying attention.. think of what speeds like that would do for piracy!

    I've already had one of the Mexican spam sites order about 10 of these babies. We'll be downloading digital video from Hong Kong and Taipei and pumping it up to California for free.

    Who need DVDs when you can crank out theater-quality surround sound pictures at these speeds? There goes the backbone ....

  • http://inside.bell-labs.com/headlines/2000/august/ 1/bln1.html is the url
  • OOPS

    s/[Mm]irros/mirrors/

    What happened to my "r" key?
  • I'm not sure how commercially viable a switch the size of a refrigerator can be . . .

    The need to be first to market is likely the major reason for the size. Comments like

    "For the last six to eight months, this has been an industry of warning shots by all sorts of optical-equipment companies,"

    and

    At least one Corvis rival takes issue with the company's first-to-market claims. Lucent Technologies Inc. said it delivered a similar all-optical technology for commercial use last month to Global Crossing Ltd

    make it clear that first to market was first on their minds. The size wil probably drop by half every 8-12 months.

    1Alpha7

  • Of course, but since the RIAA and MPAA are all US-based, it will be far too late before they clue in. Mexican courts take years to resolve these things and you just need to have another shell company buy the hardware before the federales knock down the doors and foreclose.

    I'm listening to a mexican radio, oh wo oh wo ...

  • Really? I just posted a joke about this. I didn't think they would really do it using mirrors. Seems so ... crude ... somehow.


    --

  • Making an optical switch from a physical little piece of glass mounted over silver and moving it as quickly as possible is the dumbest thing I've ever heard. Seems analogous to making a hard drive that ran by hammering grooves into silly putty with a tiny, tiny jackhammer.
  • You think that optical switching is neat? You should see me do it. I just take some crack and hold onto a light switch...

  • You don't need to convert them into Electriccal signals.

    The reason I know this might be the same reason that I know that Marconi is a totally sucky company to work for.

    FatPhil
  • This is what Agilent is doing I believe... and I think Nortel is doing something similar as well.
  • The size wil [sic] probably drop by half every 8-12 months.

    Then you can use the leftover space in the NOC to install an actual refrigerator! And you can put all kinds of stuff in it, like six-packs of bee.. uh... soda.
  • I've got a bunch of optical switches in my house. By flipping them to the *on* position one is able to see things better at night.
  • by joabj ( 91819 ) on Tuesday October 10, 2000 @12:48PM (#716486) Homepage
    There are a lot of all-optical switches out there that are being worked on. In addition to Agilent, I can think of recent announcements by Chorum, SpectraSwitch, CoreTek, Nortel, and Tellium's optoelectronic hybrid model. . . .

    Personally, I take announcements of prototypes such as those above with a grain of salt. A prototype is still further away from production than most people realize. You can pretty much do anything you want within the limits of physics, given a big enough R&D budget (and snazzy enough PR department to tout your work). But for your prototype to A: work *all* the time in the field, B: and for a competitive price, and C: to be compatable with existing standards, are the hurdles that kills 99.5% of all new technologies. . . joab

  • It's non-linear optics.
    Basically if you pump the signal beyond the normal linear behaviour you an get different frequencies to behave completely differently from each other. You can get a "mirror" using total internal reflection for any single frequency in the FDM.

    Non-linear here means that when you add the signals together you don't get the sum of the inputs as the output!

    FatPhil
  • by dustintodd ( 50379 ) on Tuesday October 10, 2000 @12:49PM (#716488)
    This area of technology is so full of hype and marketing lingo it is hard to sort fact from fiction. Are they first? So what tomorrow someone else will be second with bigger this or that. I would not attach too much importance to the fact that a reporter got duped in to believing this was the "holy grail".

    But it is so interesting that optical switching has become the rock star of the day. Because essentially these are very low intelligence switches that perform very cool optical tricks. These devices are essentially circuit switched devices. But even that is probably too much credit they are static circuit switched devices. Because optical paths are setup by a network administrator. An IP router or carrier voice switch are far more intelligent then one of these devices. No one gets excited about add/drop muxes anymore but I am sure in their day it was big deal. Add/drop muxes became a commodity, just as optical switches probably will become some day. These devices, along with IP routers, ATM switches, ethernet switches, sonet muxes, dwdm, etc... are low glamor working class equipment of the carriers networks.

    The most interesting part is the ability split out or splice in individual wavelengths, neat trick.
  • The less that my signal is electronic, the harder it is to tap/spy on. Now if they could master that photon/quantum based security model, where the data is destroyed by being viewed, that would be sweet. :)
    -
  • by Anonymous Coward
    Dumbass.

    Shouldn't you be busy trying to find eligible cousins?
  • by Puk ( 80503 ) on Tuesday October 10, 2000 @12:50PM (#716491)
    The biggest problem with all-optical switches isn't the routing of the optical signals. They have several technologies, including MEMS-controlled mirrors, for doing this right now. Optical cross-connects are commercially available (though expensive) products.

    The difficulty with optical switches is in determining _where_ to switch the data without converting it to the electrical domain first. Plenty of schemes have been proposed where the data goes O->E to read the headers and decide where to switch it, and then optically switches the packet farther along the path (where the actualy signal of the packet never left the optical domain), but no one has come up with a switch that does it _all_ in the optical domain. Admittedly, few if any of these "mostly-optical" systems have been built.

    I'm not sure what Lucent and Corvis have done. It sounds to me like they have probably implemented one of these systems. They claim it's "all-optical", but I doubt that they have built this without at least the headers being converted to the electrical domain. Even so, it's an impressive achievement to have made a commercially viable product which does that much. It remains to be seen which way will end up being more cost-effective in the long run. After all, that's what matters in the industry. :)

    -Puk (Yes I'm Probably Wrong)
  • by Gumby ( 425 ) on Tuesday October 10, 2000 @12:50PM (#716492)
    One big issue with these optical switches is that they don't switch packets, they make persistent connections like a phone call. So optical data passes through cleanly, to ONE place. So this doesn't accomplish the function of a network switch at all. They're electronically controlled, so it's a lot better than manually re-routing a fiber patch panel, but that's all they do.
  • I don't think that's the kind of switch he's talking about.

    -The Reverend (I am not a Nazi nor a Troll)
  • Well, I thought it was apparent from the post that I was joking, but...

    On the other hand, some of the other posters are saying that they may actually be using microscopic mirrors, so the joke's on both of us.


    --

  • by account_deleted ( 4530225 ) on Tuesday October 10, 2000 @12:52PM (#716495)
    Comment removed based on user account deletion
  • I believe that with everything you just said, you were actually trying to say: "Why did this get posted to Slashdot?"
  • That's still opto-magnetic. or even opto-mechanical.
  • Make sure you partition the fridge off from the switch. All that light flinging around in there might skunk the brew.
  • Eh, you just can't spin a mirror and get switching, you need the mirror to spin according to the incoming information. This is a long way from what CD-ROMs do.
  • What do they mean "all-optical" switch? Does that mean that the light doesn't have to be converted to an electrical signal to be read, and can be read in the state it's in?
  • I mean seriously, just listen to it: "all-optical". I'll let it slide so far as to accept actual matter included in the switch, but for such a thing to be truly all-optical it can have no moving parts (or the parts need to move at light speed, which is of course impossible). Personally it seems like a all-optical switch is a long bit into the future.
  • by Lostman ( 172654 ) on Tuesday October 10, 2000 @01:05PM (#716502)
    An article at http://www.ciena.com/news/archive/2000/07/07.19.20 00pr.html explains how CIENA has already filed against Corvis charging that Corvis violated 3 patents relating to CIENA's optical networking communications systems and technology.

    How this will effect the switch is unknown as of yet.
  • by Doco ( 53938 ) <DanNO@SPAMoelke.com> on Tuesday October 10, 2000 @01:13PM (#716503)
    First off go to LightReading.com to get some general information on this technology arena.

    Corvis's switch is an all-optical switch. No eletrical regeneration involved. What it is switching is wavelengths of light. NOT packets. So, you can take a wavelength of light from one fiber and send it out another. This allows you to set up 2.5Gbps (OC-48) circuits quickly.

    What technology are they using - don't won't say. Almost all other people in this arena are basically splitting the dense-wave-division-multiplexed (DWDM) circuits into their individual wavelengths. Then routing them through micro-mirrors. The micro-mirrors allow you to connect any two fibers together optically. Then, the outputs from this are re-combined, optically amplified and transmitted.

    This isn't for sure what Corvis is doing - but I would bet money that this is basically what they are doing.

    One problem with this is that you can't have two circuits on a fiber using the same wavelength of light. So, you would need something that shifts the wavelength of light being used. Nobody that I know of has a commercial product to do this.

    Press blurb about this particular thing is available in a Light Reading article. [lightreading.com]

    A couple of weeks ago, Corvis announced that they had revenue - from this shipment of course. [lightreading.com]

    One more link - Some hints to what technology they are using. [lightreading.com]

  • Just to correct myself, apparently they're not talking about a data switch (although it's impossible to tell from _any_ of the articles or product pages). What they have done is built an electronically controllable optical cross-connect. Some of them seem to have fairly decent switching rates, but nothing like what is needed for packet-level switching (note that 7.5 ms at _1_ gigabit is almost a megabyte of data != packet).

    While this is a very useful tool for designing and provisioning (and reconfiguring) networks, it is hardly a breakthrough, nor is it the "holy grail" of optical switching.

    -Puk "I Will Surely Have To Correct Myself Again"
  • It occurred to me that the O->E conversion may be skipped entirely if the O data is encoded in such a way that the 'header' can be read without doing some sort of fancy decoding, interpretation, then switching.

    Of course, this brings an optical switch into the realm of analog computing, instead of digital, but hey...

    Dunno if this is even possible inside of a fiber, but can one encode a holographic signal into the header? This depends on the signal being coherent in the fiber, but if you can take the signal and recombine it with a similarly coherent signal, you can get data out. This data is still optical, perhaps in the form of a grid pattern(barcode here!) which can be read and interpreted. At this point it would seem an electrical device is still needed to operate the switch...

    I dunno, how do they really encode this information? Just binary pulse data?

    The nick is a joke! Really!
  • by HaeMaker ( 221642 ) on Tuesday October 10, 2000 @01:24PM (#716506) Homepage
    I believe this works, not by using a header to assign an address, but by assigning a freqency to a destination and that frequency is then switched optically.

    The first switch reads the header and assigns the frequency, then the subsequent switches simply switch based on frequency (never reading the content of the packet). Then the last switch, (who owns that frequency) then converts it to electricity and sends it over the regular network (i.e. like ethernet...)

    One day, we will all be assigned frequencies like we are assigned IP addresses and all info will be transported by fiber.
  • I'm not sure how commercially viable a switch the size of a refrigerator can be

    That's because you don't know what you're talking about! Do you think that a company that can afford a switch this size cares that it's this "big"? You've obviously never seen how "big" a good unix box is.

    PS: Moderators: It's not flamebait, I have a clue....
  • The all-optical router promises to be another great peripheral; however, I doubt its stability. The signals are routed through mirrors; thousands of them able to fit on a quarter. The mirrors make adjustments within one hundredth/thousandth (I don't remember which) of a degree.

    My qualms come from the simple fact that this router will have to be on steady ground. This certainly wouldn't be useful in San Fran, Kobe, or anywhere near a fault line or artificial seismic activity.

  • Unfunny perhaps, but hardly a troll.

    I propose that moderation privileges be withheld until the candidate has passed a multiple choice exam on the meaning of the moderation descriptions.

    The grading script should probably be written by someone other than CmdrTaco.
    --

  • by Anonymous Coward on Tuesday October 10, 2000 @02:30PM (#716510)
    This is just pure stock ramping. I wish it was true as I have some friends at Corvis, unfortunatly, the switch is a long way off. Management wanted to release this PR after a concept trial that was sucessful, this switch is at least 5 months way from market + it's NOT all optical as headers are converted to good old fashioned electrial signals, the switching path is determined and then the packet is switched via MEMS tech.
    Lucent is the closest to an all optical switch followed (a fair way back) by an English company call goouch and housego (I think the spelling is slightly off there).
  • So since it doesn't do this (which would be cool):


    a) demux's (filters) one of say 160 wavelengths OC-48 you have on a single fiber.


    b) changes its wavelength, say from 1550nm to 1600nm (all optically)


    c) mux's it back onto another fiber with 159 other wavelengths and away it goes?


    So all it does is basically automates the process of Mux/Demux and changing patch panel cables. But the key is that there is no electrical conversion of the whole payload so if I just want one OC-48 channel way out in the country off of a 160 OC-768 backbone I don't slow down a shitload of terabits/s (half the net) for one 2.48 Gb/s channel.

    Have I got it right?

  • Some pictures! Available in "high resolution"....eight megabytes!! Good grief!
  • All this talk about micromirrors .. mechanical stuff, seems like an inelegant solution, don't it?

    All-solid-state nonelectric optical computing (OC) with photon-controlled fast-acting logic gates must be part of the equation of tomorrow's terabit speed network nodes. They got stuff in the OC labs like special polymer material that acts like transistors but switches state faster - and conducts streams of photons instead of current - the stuff changes light transmission properties when a control photon source is applied. Nothing electrical in sight. You can build logic circuitry faster than anything electronic and certainly anything mechanical with this stuff.

    It'll likely be 'commercially available' eventually, in some form - it's nowhere near practical for use or miniaturization yet, but in the long run it may replace the electronic processors in our computers and move the OEO barrier so that the all-electronic components are used only for less-critical photon-source, I/O and storage systems, and then only swift photons move about inside and connecting the crystalline hearts of all things fast and digital.

    Sorta off topic, and much much slower 'technology', does anyone have any pointers to projects dabbling in fluid logic gates, using only the dynamics of liquids in ducts and valves to set logic states and act on them? The experiments with water 'transistors' I've heard mentioned used a control source of liquid to nudge a stream from one fork in the flow path to another.

  • Actually, the most popular method of switching optical signals does use tiny mirrors. The other system (IIRC, by Hewlett-Packard and/or Agilent) uses tiny bubbles. No, I'm not making this up.

    [A tiny mirror] is the dumbest thing I've ever heard. Seems analogous to making a hard drive that ran by hammering grooves into silly putty with a tiny, tiny jackhammer.

    You mean like IBM's work on atomic-force microscope data storage [ibm.com]: tiny needles read and write pits on a plastic surface. ;-)

  • ...from some huge communications technology company or another that was advertising a method using microscopic bubbles. I don't know if this is actually in production anywhere, since PR ads tend to be full of vapor, but that's another possibility for the switching method.
  • I've designed a fully optical switch which utilizes micro-diffraction gratings combined with optical shift registers. It will use constructive interference combined with pulse coding to route the packets, a technology similar to CDMA used in wireless. I'll tell you more after I get my patent.
  • Is anyone trying to use solitons in nonlinear optical media to implement packet switching?
  • Everybody is doing all optical cross-connects [switching]. Real news would be optical routing/switching based on actual optical content without electrical conversion of signal. Oh...wait. That's optical logic -- provide enough optical logic for routing, and you will revolutionize computing -- IE, your company just invented and implemented large scale optical logic in a device smaller than a skyscraper....Goodbye Intel. Anyone have info on optical logic research that might actually be able to compete with electical logic densities and keep the device size reasonable?
  • No, it's definitely possible. Current switching techniques use Electro-optical modulators. For example, a Lithium Naiobate (LiNbO3) mach-zender interferometer, which basically alters it's index of refraction due to an electic potential across the path. It modulates in such a way that one can route the data through different paths by the intensity of the voltage. This is a common technique used to convert digital data into optical data. Similar methods can be used to route optical signals input to output, using the Electro-optical signal for routing.

    The cool part about all-optical switching is that you're now using an optical signal to tell the modulator which path to send the optical data. no more electric signal. There are a few methods in which to do this, but I'm not too familiar with them.

    Although, technically speaking, we've had all-optical switching for a long time now. When you send any AC electric signal down a transmission line, you're sending photons, believe it or not!

  • This method is already in use, it's called WDM, or wavelength-division multiplexing. Although typically a diffraction grating is used instead of a prism.
  • Yes, lots of folks. Nonlinear materials are VERY complex, but have so many cool uses.
  • I think he was referring to existing systems not the new "all optical" generation. It's the older systems which aren't all optical that convert to electrical, then route/switch, then convert back to optical.
  • Corvis' switch is probably using semiconductor optical amplifier (SOA) technology. To make an NxN switch, you passively split each of N incoming signals into N parts, and then send each part through an SOA (N^2 total SOA's).

    When there is no current applied to an SOA, it is a strong absorber. So you only apply current to N of the N^2 SOA's, and those will be the only paths that allow light to pass. Then you take the N^2 paths and combine them in an interleaved pattern back into N paths forming the outputs of the switch.

    The article I read claims Corvis' switch is 6x6. The advantage over MEMS is that there are no moving parts. The disadvantage is that you cannot easily make big switches since this scales as N^2, and that the noise figure is fundamentally high because of the 1XN splitting loss.

    lightreading article [lightreading.com]

  • I read in a wired mag (can't remember which one) that the latest idea (which is probaby what's being used here) was basically a piezoelectric lattice (read: a variable diffraction grating)

    This lets you split a compound wave (light carrying information) into it's constituent waves and redirect them. Which was the main trouble area that was being encountered. Apparently figuring out what "packet" should go where was never really a problem.

  • So, this switch should be independant of any power supplies, because if it is all optical, what would be electrically powered.
  • You can architect a packet net around a slow circuit switch. The general idea is that you open up more or fewer circuits between the edge routers based on traffic level, so that effectively the backbone gets reconfigured as the traffic changes. This reconfiguration probably takes place on a scale in the range of seconds, far slower than the per-packet time.
  • You've got it pretty much exactly right. This is wavelength switching, not packet switching. You demux a DWDM transmission on a fiber, pass the resulting light through some kind of filter mechanism, then all of the destinations mux their incoming transmissions back into a DWDM stream.

    The tricky bit is filtering on the basis of wavelength. There's more information on LightChip's Website (http://www.lightchip.com).

    MJP
  • Just think back to the first US-made computer (ENIAC), and remember how big it was. It wasn't 'commercially viable' either, but did that stop them? Now look at the size of computers today. Then just think of how small optical switches will be about 50 years from now.....
  • Packet switching is incredibly slow compaired to circuit switching for data transfer. Sure a circuit takes a millisecond or so to switch while ackets can be switched thousands of times per millisecond. The power of circuit switches is you only need to make the switch once. If I send you something on a packet switched network every single packet needs to be switched and routed which not only increases the lag of the signal (so much time per hop) but you also face the chance of packets taking a slow path or never reaching their destination. Packet switching has incredible overhead. With circuit switching after the connection is made you've got a steady strait line to your destination. Instead of driving blindly on side streets you're cruising on your own personal freeway. Part of the speed from the Internet 2 (the exclusive realm of a couple corporations colleges and research labs) is that it is mostly circuit switched optical networks. Packet switching is more amorphous and came about due to the lack of reliable connections between early networked computers. Circuit switching can be designed to be as amorphous and is a bit more reliable for long information hauls.
  • The big problem people have to address with optical logic is heat dissapation. The trouble with most of the schemes people have come up with thus far is getting rid of the heat the devices produce.
  • Holy snickies....I always wanted to look at my tv and just turn it on. That's pretty cool that it can read my eye movements and turn on...now if i can just get an optical refrigerator.......

    "sex on tv is bad, you might fall off..."
  • What the hell kind of a unit is 'one-page emails per second' anyway? who cares, tell us in TV channels or something we can grasp thank-you-very-much-indeed.
  • More Lucent Info:

    On July 31, Lucent delivered it LamdaRouter to
    Global Crossing. It uses MEMS to route signals from fiber to fiber.

    How would this interact with the network layer stack (obviously it's layer 1) or U-plane vs C-plane?
  • > But for your prototype to A: work *all* the time
    > in the field, B: and for a competitive price,
    > and C: to be compatable with existing standards,
    > are the hurdles that kills 99.5% of all new
    > technologies. . .

    Out of the Obvious Bag, I draw a comment involving "Microsoft", "innovate", and "1 out of 3 ain't bad"...
  • figures, I just HAD to get some wrestler moderator who likes looking at guys in speedos...bleh

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