Slashdot Mirror


10Gbps Wireless Transfers

Erasei writes "NTT Science and Core Technology Laboratory Group has developed a wireless communications that is capable of transmitting data at speeds of up to 10Gbps. In order to achieve such high data transmission speeds, the system uses the as-yet-unused 120GHz frequency band. The actual bandwidth the system uses is 17GHz, and the method of modulation employed is amplitude shift keying."

76 of 173 comments (clear)

  1. Getting faster by molywi · · Score: 5, Funny

    Yesterday there was an article about 19megabits.. now its 10gbps.. Wow, we are getting faster everyday!

    1. Re:Getting faster by Guspaz · · Score: 2, Informative

      That's 19 megabit over cell phone. This is not over cell phone.

      Regards, Adam.

    2. Re:Getting faster by cdrudge · · Score: 2

      Not to get too nit-pickey, but they are both wireless so I think the original comment still holds some merit.

    3. Re:Getting faster by ActiveSX · · Score: 5, Funny

      10 gbps/day increase. Kiss our asses, Moore.

  2. THIS JUST IN! by CoffeeJedi · · Score: 5, Funny

    A large number of birds seem to be falling out of the sky fully cooked near the NTT Science and Core Technology Laboratory Group headquarters near the experimental wireless data towers. More on this strange story as it develops.

    --
    May you be touched by His Noodly Appendage. RAmen.
    1. Re:THIS JUST IN! by Hadlock · · Score: 5, Funny

      actually, there's a space junk tracking facility somewhere in the pan handle of texas, at least, that's the radar sending station..... you'll see a flock of geese go flying past the mile long radar array and all of a sudden the whole flying V will start spiraling downwards till they nearly hit the ground, then suddenly fly upwards again, and spiral back down again until one of them finally spirals out of the radar's effective field, at which point the rest of the geese (or whatever) see one goose flying normally and follow after him. very strange.

      --
      moox. for a new generation.
  3. What range? by WittyName · · Score: 3, Informative

    Looks like about 2 feet. And it would seem to be highly directional.

    Not sure what this would be usefull for..

    --
    The law is a weapon of the government, not a protection for the likes of you. Surely you understand that.
    1. Re:What range? by Red+Herring · · Score: 4, Informative

      Did you read the article???

      "In the laboratory, a 10m range for the system has been confirmed, but NTT is expecting to try and extend the range to 100m." ..12 second...7 seconds....2 seconds... Submit!

      --
      #include "standard_disclaimer.h"
    2. Re:What range? by WittyName · · Score: 5, Interesting

      120Ghz? I can not think of an op-amp that works anywhere near the freq. Not to mention a waveguide to get your output to the antenna.

      As for omnidirectional, that would lower your effective point to point power further.

      At these freq's it could only be useful for point-to-point comms.

      I wonder why they did not just leave it all optical.

      --
      The law is a weapon of the government, not a protection for the likes of you. Surely you understand that.
    3. Re:What range? by LittleBigScript · · Score: 2, Insightful

      Well, this is perfect for high-speed data communications that need to be transfered from one desk to the one sitting across from it.

      I wonder how we could do that...oh! I know!

      High speed data communications in previously unused (and unregulated) spectrum. Anyway, how do you regulate light.

      I know, you may be wondering, won't this have serious side effects for people.

      Don't worry we'll test it on engineers and programmers.

    4. Re:What range? by swb · · Score: 3, Funny

      It'll be useful for trading movies with your 3cm optical disks on your cellphone.

    5. Re:What range? by DjMd · · Score: 5, Funny

      Actually I'm hoping to transmit from the desk to the object sitting at the desk...

      My current device uses the 560nm-800nm electromagentic spectrum. And while it can send a large volume of data quickly, my receiving unit processes the data, but most it is lost in storage. If only the process wasn't so lossy!

      Can anyone recommend any upgrades? I am still using the orginal neural network that came with this model...

      (too subtle?)

      --
      DJMD - The fourth man - Planetary
    6. Re:What range? by spaceyhackerlady · · Score: 4, Informative
      High speed data communications in previously unused (and unregulated) spectrum. Anyway, how do you regulate light.

      Actually, 120 GHz is a fully regulated part of the radio spectrum. The Powers That Be regulate it (and assign users) up to 300 GHz. There is increasing interest in this part of the spectrum, partly because the lower frequencies are getting crowded in some parts of the world, and because atmosphereic attenuation (which is high at these frequencies) makes frequency reuse a lot easier. The military are interested too, since that same attenuation makes it hard for unfriendlies to listen in on tacitcal communications. Unless they're right in the middle of the battle, in which case they have other things to worry about...

      Anything beyond 300 GHz is terra incognita - electronic techniques become impractical, and optical techniques don't work well until you go lots higher in frequency. You can buy infrared data links that will shoot data across town, and they are not regulated (as radios) in any way. They require laser certification only.

      ...laura

    7. Re:What range? by mesocyclone · · Score: 3, Informative

      Specifically... as the frequency goes up, the amount of energy captured by an antenna of a given size goes down by the square of the wavelength. The directivity goes up by a complex relationship with the size of the antenna.

      Thus at very high frequencies you have to have exponentially more power to transmit the same distance, or you have to have an equivalently more directional antenna.

      This fact is one of the reasons that spectrum is so valuable. The higher the frequency, the more costly and less practical it is to use it for non-stationary applications. In addition, as you get to higher frequencies you run into more problems with attenuation due to atmosphere, rain, walls, earth, etc. In addition to that, transmitters are significantly less power efficient at higher frequencies.

      Add all that up and you have several exponentials retarding advances into higher frequencies.

      --

      The only good weather is bad weather.

  4. Any encryption challenges at that speed? by gregwbrooks · · Score: 5, Interesting
    Pardon my ignorance, but are there additional challenges on real-time encryption when wireless gets that fast?

    I'm not thinking so much of a peer-to-peer or client/server setup where there's a networking handshake, but more along the lines of a broadcast data stream meant for everyone (or maybe just a few certain someones) to pick up.

    --


    "It was a summer's tale: Just a boy, his Linux, and a head full of dreams..."
    1. Re:Any encryption challenges at that speed? by Anonymous Coward · · Score: 3, Interesting

      IPsec. It's just part of the data layer, thus is pretty much independent of the transmission layer (at least in terms of "media" (what's the right word for wireless? medialess media? air?)). As a plus, it works better than WEP anyway.

    2. Re:Any encryption challenges at that speed? by Abcd1234 · · Score: 4, Interesting

      Well, if you're planning on doing real-time encryption of that much data, odds are very good you're planning to use a hardware encryption widget of some kind. For example, according to this article, Xilinx has developed an FPGA that implements DES at 10 Gb/s. 'course, I'd imaging there are ASICs out there with even better performance (I only performed a cursory search).

    3. Re:Any encryption challenges at that speed? by XNormal · · Score: 2

      Encryption at these speeds with custom hardware is not too expensive.

      I don't think anyone is going to be broadcasting data on the 120GHz band, though. At these frequencies radio is strictly line-of-sight. Encryption and key management is relatively simple in a point-to-point application.

      --
      Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
  5. it will probably be slashdotted, not a major site by Anonymous Coward · · Score: 5, Informative

    NTT Develops 10Gbps Wireless System

    October 18, 2002 (TOKYO) -- NTT Science and Core Technology Laboratory Group has developed a wireless communications system using the 120GHz band.

    The system, which is capable of transmitting data at speeds of up to 10Gbps, was displayed at the "NTT R&D Forum 2002" event held Oct. 11 in Atsugi.

    The new system is four times as fast as the 2.5Gbps wireless system NTT put on show at the same event in 2001. This is the first time the laboratory experimented with a 10Gbps wireless system (photo). There are many potential uses for such a high-speed wireless technology, such as for 10Gbps wireless Ethernet links or for radio links between different buildings where a high volume of data has to be sent to and fro. NTT plans to announce the new system at the "Asia-Pacific Microwave Conference" (APMC) to be held in Kyoto in November.

    In order to achieve such high data transmission speeds, the system uses the as-yet-unused 120GHz frequency band. The actual bandwidth the system uses is 17GHz, and the method of modulation employed is amplitude shift keying (ASK), the simplest method of amplitude modulation for digital signals. According to an NTT source, by modifying the modulation method, the throughput rate will be improved.

    NTT also used optical communications technology to make the 120GHz system possible. A 120GHz optical pulse signal is generated, and then undergoes amplitude modulation. After modulation, the signal is picked up by a special photodiode capable of responding with the high-speed signal. The output from the photodiode is then transmitted as a wireless signal. The special photodiode used was developed with NTT's own technology, and can handle optical inputs of up to 300GHz.

    The main difference between last year's system and the new one is that the receiver frequency detection circuitry has been redesigned, meaning that the receiver can detect signals over a wider bandwidth, and thus the system can operate at faster speeds. The new detection circuit can receive signals from an 8.5GHz band at maximum. Because the system employs two detection circuits working in tandem, the finished system realizes more than a 17GHz band.

    At "NTT R&D Forum 2002," the system was shown transmitting non-compressed HDTV-quality (1.5Gbps) video data. In order to extend the range of the transmission, a 20cm-diameter lens was used to focus the beam. In the laboratory, a 10m range for the system has been confirmed, but NTT is expecting to try and extend the range to 100m.

  6. OK... keep us posted by Gruneun · · Score: 5, Insightful

    In order to extend the range of the transmission, a 20cm-diameter lens was used to focus the beam. In the laboratory, a 10m range for the system has been confirmed, but NTT is expecting to try and extend the range to 100m

    From a scientific standpoint, this is somewhat interesting. I don't see it being news, however, until they seriosuly decrease the size of the transmitters and/or increase the range. The transmitters look to be about the size of a shoebox, which is great for building-to-building, but let us know when they actually bump up the range to say... building-to-building distances.

    1. Re:OK... keep us posted by mekkab · · Score: 2

      For such a high speed, in the forseeable future you only need it for building to building MAN backbone.

      and from the article:
      "In the laboratory, a 10m range for the system has been confirmed, but NTT is expecting to try and extend the range to 100m."

      Bamn- there's your MAN infrastructure.

      --
      In the future, I would want to not be isolated from my friends in the Space Station.
  7. Fast Wireless by FeatherBoa · · Score: 4, Funny

    ...is called "fibre optic"; hundred terabits and look ma - no wires!

  8. wave propagation similar to infrared by Anonymous Coward · · Score: 5, Informative

    Radio waves at 120GHZ travel like light. The signal wont go through walls at all.

    1. Re:wave propagation similar to infrared by Anonymous Coward · · Score: 2, Interesting

      let alone work in the rain, does this have a large cost advantage over free space optics?

    2. Re:wave propagation similar to infrared by FuzzyDaddy · · Score: 5, Informative
      Actually, 120 GHz will penetrate walls, to some extent.

      Millimeter wave imaging can operate in this frequency, because there's an atmospheric window (read: longer range) around there, and because most non-conducting "solid" object appear translucent at that wavelength.

      So we would expect some penetration through walls. Especially the cheap drywall they use where I work

      Rain will reduce the range/bandwidth, but it should go through dust, smoke, L.A. fog, etc. pretty well.

      --
      It's not wasting time, I'm educating myself.
  9. Here, take this by Maradine · · Score: 5, Funny

    So, basically, what we're saying is, by the time we get to 1Tb/s, we're all going to have to be close enough that I might as well just hand you a floppy?

    And is that a run-on? Sheesh. Critics.

    --

    trustedworlds.net - gaming, security, and the gunk that lives in between

    1. Re:Here, take this by Jedi+Alec · · Score: 2, Funny

      At 1Tb/s, you'd better start shipping me trains full of DVD-R's ;)

      --

      People replying to my sig annoy me. That's why I change it all the time.
  10. 10 Gigs a second, eh? by LordYUK · · Score: 3, Funny

    Imagine the possibilities... we could slashdot hundreds more sights hundreds times faster!

    --
    This is my sig. Its pathetic.
  11. range, penetration and cost? by bigpat · · Score: 5, Interesting

    "In the laboratory, a 10m range for the system has been confirmed, but NTT is expecting to try and extend the range to 100m."

    10 meters would limit its usefulness, but 100 meters would make this very useful. Hopefully, this has a useful range.

    Could someone answer the question about how easily this frequency would pass through common substances, like walls?

    Also, there was no mention of weather they would seek to license their technology to make this widely available or just make this a very expensive specialized niche product.

    1. Re:range, penetration and cost? by Pow · · Score: 2, Interesting

      At 120GHz? There's no way radiowaves will pass thru walls at freq this high?
      Well maybe very very thin walls :)

    2. Re:range, penetration and cost? by winse · · Score: 2, Interesting

      If they can hit a certain price point this would be extremely usefull for temporary (or even permanent) backbone solutions....forget digging up the road to lay fiber. This would be an exciting technology if mass produced at the right price.

      --
      this sig is deprecated
  12. Not for the office by Pedrito · · Score: 5, Interesting

    This isn't office wireless. This is a very line-of-sight system that would be used, probably, between buildings, if they get it go that far, I would imagine.

    You'd never see anything like this in a home or office, as it couldn't penetrate a sheet of paper, let alone a wall of any type. I suppose it could penetrate if you put enough power into it, but then it would need enough power to melt through the wall before the communication could begin.

    1. Re:Not for the office by Zelet · · Score: 3, Funny

      That is okay... just hook up the microwave drill and you are on your way.

      --
      ...And when they came for me, there was no one left to speak out for me." - Martin Niemoeller (1892-1984)
  13. Mad, mad props to the RF guys on this one by InterruptDescriptorT · · Score: 5, Interesting

    I'm no EE, but I studied enough analog electronics design to know that creating RF circuits at that kind of frequency is no easy feat.

    Open up an 802.11 card for instance--these work at about 1/60th of that frequency--and look at the traces for an idea. It's not just what components are connected together--it's the layout of the traces that define most of the circuit. Inductors are little squiggles, a resistor is the thinning of a trace, etc., all of which is highly dependent on frequency.

    In other words, these guys are pretty slick and you just have to bow to them.

    --
    Karma: Excellent Birds (mostly as a result of listening to Laurie Anderson)
  14. Doesn't anyone read the article before posting?!? by rindeee · · Score: 2, Informative

    It is OPTICAL not RF. For Pete's sake, just use a friggin laser over open air. It's cheap, higher bandwidth and lets you do cool tricks using a couple of well used chalk board erasers. One use that leaps right to the front of MY mind is one of those nifty wireless video gadgets for your living room. "For only $750,000.00 you can beam S-Video quality signals from your DVD player to your big screen (up to 20 feet) WITHOUT WIRES!!!"

  15. Distance by I_am_Rambi · · Score: 3, Interesting

    In the laboratory, a 10m range for the system has been confirmed, but NTT is expecting to try and extend the range to 100m.

    Has anyone looked at the prototype they have in the picture? The transmitter and receiver are on the same table. Sure, I can understand 10gbps per sec over a few feet. They don't even know how this new technology will stand up in normal conditions. There is no way currently this will be used in mainstream. I don't know of anyone that is willing to sit within 10m of the transmitter to receive there wireless connection. I know this will be improved, but the distance will have to grow by leaps and bounds.

    Yea, trasmitting 10gbps is nice, but currently what use is it if you can't go within a few feet of the transmitter?

    1. Re:Distance by NegativeK · · Score: 2, Insightful

      Yea, trasmitting 10gbps is nice, but currently what use is it if you can't go within a few feet of the transmitter?

      You must learn to crawl before you can run.

      --
      This statement is false.
    2. Re:Distance by bravehamster · · Score: 4, Funny
      Sure, I can understand 10gbps per sec


      Wow, how'd they get the transmission rate to accelerate like that? ;)

      --
      ---- El diablo esta en mis pantalones! Mire, mire!
  16. Think of it as a laser by Anonymous Coward · · Score: 3, Informative

    It wont penetrate anything solid. It will do slightly better in fog than lasers, but not a hell of a lot ... in short, not terribly usefull.

  17. Obligatory Ronja link by BillX · · Score: 2, Informative

    "NTT also used optical communications technology to make the 120GHz system possible. ...After modulation, the signal is picked up by a special photodiode capable of responding with the high-speed signal. ...In order to extend the range of the transmission, a 20cm-diameter lens was used to focus the beam."

    Also known as Fast Ronja. Cool as hell though.

    --
    Caveat Emptor is not a business model.
  18. Speed is good, but by essiescreet · · Score: 2, Insightful

    I don't understand why people don't focus more on security and making the networks non-hackable (or at least reducing the chance) instead of speed. It's great that the thing will go so fast, but if no IT departments will use it because of security issues, it will sell about as good as freezers in the Antarctic.

    We develop wireless applications, and we'd sell probably twice as many if the hardware was secure, but sales would not go up at all if the speed of the networks was faster.

    1. Re:Speed is good, but by heby · · Score: 2, Informative

      these are two completely different issues - security is normally implemented on top of a high speed link (e.g. encryption) or on a level below (protecting cables physically from access etc.). the beauty of a layered system is that the different layers can be developed separately without interfering with other layers.

  19. Streaming "open source" video by dubiousmike · · Score: 2

    Now I can use my IPAQ as a wireless live video switcher.

  20. send me that file.... by 3ryon · · Score: 3, Interesting

    There are many potential uses for such a high-speed wireless technology, such as for 10Gbps wireless Ethernet links or for radio links between different buildings where a high volume of data has to be sent to and fro.

    Yeah, like 1.5 terabytes a day!

  21. What's Pikachu have to do with this? by stratjakt · · Score: 4, Funny

    There he is in the photo, between the two transmitter thingies.

    Does his thunderbolt attack provide the jiggawatts of power needed?

    Can we hit 100Gbps if he evolves into Raichu?

    Or, most importantly, will this technology help me catch 'em all?

    --
    I don't need no instructions to know how to rock!!!!
  22. It's Gbit/s, not Gbps -- And it's a big problem! by SysKoll · · Score: 3, Insightful

    Journalists are fond of using dumbed-down abreviations such as Gbps or other acronyms. But I encourage technical writers to use the correct term, which is Gbit/s. Just as Mbit/s, Kbit/s.

    There is something weird with computer science. People in this discipline badly need a common linguo because the field is evolving so fast. And yet, most CS practitionners couldn't be bothered to use the generally accepted vocabulary or abbreviations to describe their domain's problems. They invent their own, or incorrectly reuse existing jargon swiped from other disciplines.

    Even worse, each branch of CS reuses general vague terms and overloads them with a different meaning. What's a "server"? What's a "page"? Depends who's talking.

    As a result, CS is full of islands of disconnected knowledge and of specialists that cannot communicate with each other. Ever tried to have an OO programmer and a database admin talk to each other?

    Mathematicians don't speak each other's linguo. But they carefully avoid using overlapping terms to define different things. That's what we should aim to do.

    CS will keep being a cottage industry and a craftman discipline akin to voodoo, with cancelled project when wizardry fails, as long as all CS won't agree to speak a common language. Or at least a language where precision removes the overlapping meaning.

    Granted, a precise vocabulary will not cure all the ills of CS. It not a sufficient condition for clear communication. But it's one of the necessary conditions.

    So do your part. Write Gbit/s, not GBPS or other atrocities.

    -- SysKoll
    --

    --
    Mad science! Robots! Underwear! Cute girls! Full comic online! http://www.girlgeniusonline.com/

  23. Re:it will probably be slashdotted, not a major si by mirko · · Score: 4, Funny

    This would actually be quite funny if this site wer slashdotted as we are currentlydiscussing about its breakthrough in network technologies :-)

    --
    Trolling using another account since 2005.
  24. Frequency reliability by FrostedWheat · · Score: 3, Interesting

    I remember reading up on satellite signals some time ago, and how it said as the signals are such a high frequency (11-12Ghz) that they begin to show some of the properties of light. Most importantly that they cannot pass through as many objects. (Or something similar to that, I don't know much about the physics).

    My question is, how much would a heavy rain/hail/snow shower affect a long range link at these high frequencies?

  25. again, new tech but when will it be available? by chamenos · · Score: 4, Insightful

    i've already mentioned this before and i don't wish to sound like a trolling wet-blanket, but when is this going to be widely available and adopted? slashdot is chockful of articles of new and emerging technologies that promise ever-increasing leaps and bounds in all these high-tech gadgets that all of us love (which is why we're here on slashdot!). most of these gadgets or other new developments in science and technology only see the light of exhibition or convetion halls and after that, either lousy manging, marketing or just a bad business model kills the product in its infant stages.

    the article mentioned that this new wireless system uses a yet un-used 120GHz frequency. i personally feel that this can -both- be a disadvantage and advantage to its entry into the mainstream market. reason being, due to the 120GHz frequency being unused, widespread adoption might be made easier without any regulations but then again, that same lack of regulations would make it hard to regulate and control, and it might be open to abuses by users with malicious intent. worst still, all our beloved governments or telecommunication companies (for some countries, the above two are one and the same for all intents and purposes) will seize the opportunity to reap a handsome profit and end up killing the potential this product might have had in the market.

    another factor, and perhaps the -most- important factor to consider is cost. the system may be cheap to built and maybe it didn't cost that much to develop, but we all know capitalism isn't about selling products at a price that indicates its real worth, capabalities, and cost of manufacture or R&D. rather, market demand or greedy corporate figures play an important part, along with sleazy marketing methods that target the ill-informed but rich people, who buy into meaningless numbers generated by the afore-mentioned marketing folks. the success or failure depends on how well the balance, between reaping the most profits and at the same time allowing growth, expansion and demand of the product to propagate is upheld by those corporate capitalist (and usually greedy) folks.

    lastly, but not as importantly as the above factor, is whether the four times increase in speed is really needed, or is it on par with a 2.0GHz pentium 4, in that both only have impressive numbers to show off, which represent little of any real-world increase or -need- for performance for most mainstream users. but then again, i've just made a moot point haven't i? the sad reality is that the actual technology or the need for it isn't what sells. its how well its marketed (read: exaggerated and made pretty with big numbers) that really counts, ain't it?

    if anyone feels like modding me down, go right ahead. i just had to get that off my mind. i just can't help being a little more and more pessimistic each time a promise of some new-fangled gadget makes headlines on slashdot, only to make headlines a year or two later when it flops over on its belly.

  26. Re:why just now? by BeBoxer · · Score: 5, Informative

    not to mention (i'm guessing) a hella lot more range,

    You guessed wrong. The range goes down as the frequency goes up. The higher the frequency, the more the radiation behaves like light, which is really just terahertz radio. As you get higher and higher frequencies, walls and such become more and more opaque to the signals. Until eventually they won't travel thru the walls at all, just like light.

    If you want long range, you need lower frequencies. If you want to send a signal across the ocean, you need KHz radio waves (short wave radio). If you want to send a signal around the state you need AM radio at ~1MHz. If you want to send your signal around a city you can use FM at ~100MHz. By the time you get up to 2.4GHz you can only send your signal across a few rooms. Yes, I know I'm simplifying the differences in transmission power. But a short wave ham can reach across the world with less power than an AM station uses to cover a state, and the AM station uses less power still than the FM station which only covers a city or so.

    Now, point to point is a whole different story. If you have direct line of sight you can send extremely high frequencies across significant distances. But the curvature of the Earth prevents you from sending stuff too far. Not to mention buildings and other obstructions.

  27. So why is IRDA so slow? by BeBoxer · · Score: 5, Insightful

    That's what I want to know. IR is way up in the THz range. You outta be able to modulate a least a Gbps onto it easily. Sure, it wouldn't go very far but so what. Is it just the difficulty in making emitters and detecters which are fast enough? That can't really be that hard. A gige optical SX GBIC module can be had for under $100. Hm. That makes me want to tear a couple apart and see if I can get a link running across a few feet of free space.

    1. Re:So why is IRDA so slow? by CyberKnet · · Score: 4, Informative

      There shouldn't be a problem making high speed transmitters or receivers fast enough for speeds higher than the current rate of transmission between IRDA devices.

      The problem is twofold.

      On one side, there is large demand for some things to remain backards compatible with legacy devices like VCRs and Stereos, which is much easier to do when your standard rate of transmission is lower.

      However, with that said, I believe the real "problem" with IRDA lies in on the error detection and correction side of things. The same is true of TCP/IP. It could be significantly faster (ala UDP) if we did not want guarenteed delivery.

      IRDA is significantly slower than things like microwave PTP because they leave room in the modulation timing for not quite perfectly aligned transmissions. Whilst motor skills in the human hand allow for the precision neccessary to enact a successful transmission, more often than not there will be either vertical or latteral movement in the outer extremities of the device (usually the end with the transmitting diode on it) which would cause transmissions with faster modulation to fail... as it is, the millisecond sync loss is (usually) able to be recovered from my simply resending the data sent since the last acknowledgement packet.

      In short, yes, you could do it, but you would have to hold those things *REALLY* steady, maybe to the point of having to set them on a solid surface whenever you wanted them to communicate... since the manufacturers are catering to the general unwashed masses, they create the device to be idiot proof ala very slow transmission speeds and large error windows.

      Hope this helps.

      --
      Video meliora proboque deteriora sequor - Ovidius
  28. Can the guys in Africa use it? by Digital+Soldier · · Score: 3, Informative

    Remember earlier in the week when /.ers were hammering the story about the guys in Africa who were using HF to send email using packet radio? Every frequency range has its up and down sides. Heck, I think the Navy uses (used?) ULF (Ultra Low Frequency) to communicate with submarines. Only problem is that at those frequencies, a one bandwidth length antenna is a few miles long....

    1. Re:Can the guys in Africa use it? by bagsc1 · · Score: 3, Interesting

      But on the plus side, a ULF transmitter in the Great Lakes can talk to a ship in New Zealand

    2. Re:Can the guys in Africa use it? by mesocyclone · · Score: 3, Interesting

      Actually a dipole (half wavelength) antenna at 10 kHz (one of the frequencies they use) is 3000 kilometers!

      But there is no rule that says antennas have to be any large fraction of a wavelength. A magnetic or electical antenna can be any size and have the same capture area as a dipole. This is because antennae do not have to be resonant to work - and a non-resonant antenna can be just as efficient as a resonant one, if you have a high efficiency circuit to tune out the reactance which results from the lack of resonance. This is one of the things an "antenna tuner" - familiar to ham radio operators does (the other is to transform the real portion of the impedance to a standard 50 ohms). However, it is hard to make efficient very tiny antennas. This is why these ELF systems have to use such high power.

      HOWEVER, on a submarine, the resonant wavelength of a trailing wire antenna is *much* lower, because the speed of propagation in the waveguide formed by the antenna, insulation and salt water is much lower than the speed of light. Thus these antennas need only be a few hundred or thousand meters long to be reasonably efficient.

      As an aside, my father invented this antenna in his PhD thesis about 50 years ago.

      --

      The only good weather is bad weather.

    3. Re:Can the guys in Africa use it? by mesocyclone · · Score: 2

      oops!

      --

      The only good weather is bad weather.

  29. Re:It's Gbit/s, not Gbps -- And it's a big problem by 4of12 · · Score: 2

    I always like the people who were kind enough to be precise, where

    B (byte, octet) = 8 * b (bit)
    so that Gbps and GBps are different.

    And while we're on the subject, of course, where

    GB = about 7 % more than 10**9
    where it's even more helpful to put a "2" subscript on the G to indicate 2**30 instead of 10**9.

    It's usually too much to hope for from most news sources. Usually only academic papers care enough to be precise with their nomenclature.

    --
    "Provided by the management for your protection."
  30. Refracting radio waves through a lens? by patbob · · Score: 2, Interesting

    It sounds like they are optically processing the signal and then converting it to electrical using a special photodiode. Later through, they talk about needing a lens to focus the signal. I'm aware that some radio frequencies can be refracted by matter, but if, as others has said, this frequency range would be stopped by most matter, then what could they be making the lens out of? Or are they pulling a switcheroo and using somethig other than the 120GHz band to demo the technology?

    --
    Welcome to the net of 1000 lies. Upgrades are scheduled soon that should bring us to the 10,000 lies mark.
  31. latency and speed issues. by papasui · · Score: 3

    I love wireless technology, it's great. But what I want to see is wireless that I can use while riding with my wife on the freeway at 80mph, and with latency thats good enough to game on. Obviously the bandwidth is there for live video streaming, but the latency with my 802.11b network + encryption is still a bit too high.

  32. No, I saw the freq. by WittyName · · Score: 2, Insightful

    And applied some common physics. This is just a lab stunt.

    Back to my original point, I see no way for this to be useful.. This will never leave the lab until you get it down to a few chips!

    The 17GHz bandwidth of the signal is quite impressive, though.

    --
    The law is a weapon of the government, not a protection for the likes of you. Surely you understand that.
  33. For goodness sakes! by Anonymous Coward · · Score: 2, Insightful

    Read the article. Yeah, it's not commercially viable. Yeah, it can't be used for much in the way of practical applications. And yeah, the picture of two boxes siting on a table doesn't really impress anybody.

    But! Use your imagination here! Think of the posibilities - we're talking about a fast data transfer rate over short distances. Yeah 10m for now and with perhaps 100m in the future (building to building?) and what then? 1000m. Progress takes time.

    And yes lasers can be used with high bandwidth (although you'll be lucky to make a photodiode with that good a bandwidth (~8.6GHz) - the only way I know of doing this is to use a broad resonant photodiode and this needs RF modulation and demodulation to make a useful signal - might be interesting to find out more about the "special" photodetector they developed) but higher frequency should be less susceptable to atmospheric noise and detection noise. Pro's and con's - might not be useful now but give it a couple of years and then we'll see.

  34. something old in here by Raiford · · Score: 3
    ... the method of modulation employed is amplitude shift keying.

    The article being low on content no explanation for ASK other than its simplicity. Isn't this method very susceptible to interference and noise ? Could this performance be achieved with MSK or QPSK ?

    --
    "player 4 hit player 1 with 0 stroms"
  35. heh by AugstWest · · Score: 2

    the system uses the as-yet-unused 120GHz frequency band. The actual bandwidth the system uses is 17GHz, and the method of modulation employed is amplitude shift keying.

    Its land is mostly mountainous, and its chief export is beans.

  36. Is 120 GHz even regulated? by Anonymous Coward · · Score: 2, Insightful

    As far as I know, 120 GHz is the highest frequency regulated in the U.K.

    Does that mean that an unlicensed 200 GHz transmitter would be legal?

  37. Gosh by jeti · · Score: 2

    At that speed, I could use up my server bandwidth in 8 seconds.

  38. How's the view from that Ivory tower? by djrogers · · Score: 2

    Sheesh, elitist much? Your misguided opinion on this subject have been proven wrong more times than I care to demonstrate, but let me try anyway... I remember 'back in the day' being able to buy NICs that encrypted ethernet traffic. Never actually saw one, amongst the thousands of NICs I installed, purchased, or ran across, but they were there.

    Nobody refused to buy an HP/UX box, or a Sun E2k because their NICs were'nt 'secure', and nobody ripped out all of their 10Mb Ethernet infrasructure for the cause of security either.

    What caused organizations to pull out all of their old NICs though? Speed. It will always be speed. What kind of world do you live in where you think that 2x as many wireless nodes would be sold if they were 'more secure'? I sell them for a living, and nobody I work with is worried about security. I'd love it if they were so I could sell our IPSEC solution to them as well, but...

    Sometimes I'm amazed at how out of touch with the real world us geek types can get...

    --
    Think outside the... Hey, where'd the friggin' box go?
  39. Lame by Grape+Shasta · · Score: 2

    "NTT... has developed a wireless communications that..."

    Society has also developed a grammaticals that communicate helps. Try it, you should.

    --

    "I am a cipher, a cipher, wrapped in an enigma, smothered in secret sauce" -Jimmy James
  40. Re:Doesn't anyone read the article before posting? by Muad'Dave · · Score: 3, Informative

    Yes, we do. Do you? It uses optical means to generate the 120 GHz RF inside each unit, NOT BETWEEN THE BOXES.

    Obligatory nit: Optical is RF. Just really high in frequency (THz).

    --
    Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
  41. 1.5 Gigs per second? Average vs max? by phorm · · Score: 2

    non-compressed HDTV-quality (1.5Gbps)

    Is this right? Did I see Gigabit per second? I assume that it's actually 1.5Mbps?

    Regardless, am I the only one who gets scared when a company says "max" or "up to." How about a average/nominal rating, so that we can see what most users get on a normal day, as opposed to every-second-sunday-when-the-moon-is-full. On a lot of devices, max rating is crap, as it rarely indicates the transfer speed achieved in most cases.

    1. Re:1.5 Gigs per second? Average vs max? by TheSync · · Score: 2

      Yes, uncompressed HD (HDSDI) is 1.485 Gbps. It is either progressive scan 60 fps, 1280x720 or interlaced 30 fps, 1920x1080, both at 20 bits per sample.

      What you receive on HD television sets is this signal compressed using MPEG-2 down to 19.34 Mbps. And yes, in scenes with lots of independently moving things, there are visible artifacts.

      Reed-Solomon and Trellis coding are added to provide some forward error correction. This increases the transmission bandwidth to 32.38 Mbps.

      In the US, the 32.38 Mbps signal is transmitted using 8VSB (vestigial sideband) modulation, 3 bits per symbol at a rate of 10.76 Msps, Nyquist filtered to take up 5.38 MHz, which fits into a 6 MHz television channel.

  42. 120GHz unused? by jnik · · Score: 3, Informative

    I couldn't find anything on what exactly is the centre frequency for this, but around 120GHz is certainly allocated and in use--119.98-120.02 to ham use and 101-120 GHz to radio astronomy (search for intentional extraterrestrial emission). Perhaps they mean "previously unused for wireless computer communication"?

  43. AOL's new slogan: "You've got cancer!" by Diesel+Dave · · Score: 2, Funny

    120GHz? Not anywhere near me, thank you. 2 and 5 GHz worry me enough as it is.

  44. It's true by slick3 · · Score: 2, Informative

    Many birds can "feel" radar pulses, and their typical response is to fold their wings and fall. One effect of this is the fact that, if there are birds in the vicinity of an airport, pilots are encouraged to turn on their aircraft's radar to avoid birdstrikes on takeoff.

  45. Isn't Less More? by mmol_6453 · · Score: 3, Insightful

    Don't you generally want to send more data over less bandwidth?

    Failing the "more data" point, I'd like to see a lot less bandwidth used, just to accomodate the artificial "crowding" of the spectrum. At this point, 10Gbps isn't very useful yet.

    I mean, look, people! You're talking about 1.7 GHz/bit. To put that in comparison, think of extreme environments. If a deep-space probe developer only had a 17Hz signal, would you want to get only 1 bit per second, instead of the theoretically possible 8 bits per second? (IIRC, the theoretical limit for data transfer on a specific RF wavelength is freq/2. Any more, and you can't tell signal from noise without something as redundant as a UPS address stamp.)

    I know this sounds like a "640k is all you'll need"-type-argument, but why not use a smaller bandwidth, and allow for multiple independant channels? If you need additional data transfer, you could use channel bonding.

    This'll especially help wireless providers, who have to relay their signal from tower to tower without hitting the tower-after-the-next with a poorer signal. (Signals will travel beyond the horizon, but not very reliably.) Currently, they use polarization of their signal.

    --
    What's this Submit thingy do?
    1. Re:Isn't Less More? by afidel · · Score: 2

      No that's 1.7Hz/bit 17Ghz/10Gbps which is not too bad considering the high frequencies and current high frequency tech. Also you can pack a lot more then 2 bits of info per wavelength, look at the P4 bus it's quad pumped aka 4 bits per wave.

      --
      There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
    2. Re:Isn't Less More? by rcw-home · · Score: 2
      IIRC, the theoretical limit for data transfer on a specific RF wavelength is freq/2.

      False. It's actually dependant on bandwidth and signal-to-noise ratio. See Shannon's Law.