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Wireless Networking Hardware Technology

CSIRO Demonstrates Fastest Wireless Link Yet 94

Posted by CowboyNeal
from the sky-is-the-limit dept.
rob101 writes "The CSIRO yesterday demonstrated the world's 'fastest' wireless radio link by transmitting sixteen full quality DVD streams over a 250m link and only using a quarter of the available bandwidth. 'The CSIRO ICT Centre today announced that it has achieved over six gigabits per second over a point to point wireless connection with the highest efficiency (2.4bits/s/Hz) ever achieved for such a system.'" CSIRO hopes to double the speed of this connection in the future, pushing twelve gigabits a second.
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CSIRO Demonstrates Fastest Wireless Link Yet

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  • by quokkapox (847798) <quokkapox@gmail.com> on Friday December 08, 2006 @03:50AM (#17159412)
    You can pop your microwave popcorn by just holding it up between the router and the TV during the FBI warning.
    • Re: (Score:2, Funny)

      by feld (980784)
      try not to burn the butter this time
    • Re: (Score:3, Interesting)

      by imaginaryelf (862886)
      I know you're just joking, but to clear up a common misconception, your microwave oven operates at 2.5GHz, which is why it interferes with current wifi stuff.

      This technology operates at 85GHz, which is still in the microwave/radar band of the EM spectrum, so it's likely to interfere with radars.
      • I've got it! The whole thing is really a plot by the MPAA. They want to be able to conduct airstrikes on your house while you're watching your pirated movies, so the made a wireless technology that will jam your radar while seeming to make it easier to watch the movies. Clever bastards...
      • Indeed, most radars are still lower than that. The W band is home to some cloud-studying radars and not much else.
    • by dch24 (904899)
      Sounds like flamebait to me.
  • ...to get my new cellphone with the new network that uses this awesome technology!

    Only to realise that the extremely high frequency is ionizing my head, and to make and receive my calls I use up all of 1 hundredth of its power.

    That is progress indeed.
  • Terminology (Score:5, Funny)

    by nacturation (646836) <nacturation@@@gmail...com> on Friday December 08, 2006 @04:01AM (#17159454) Journal
    Sorry, I just don't understand this DVD streaming thing. Can someone translate this into Libraries of Congress per second?
     
    • Re: (Score:2, Informative)

      by Ryuu (742860)

      Can someone translate this into Libraries of Congress per second?
      Approximately 0.00003662109375 LOC/sec.
    • Re: (Score:3, Interesting)

      by BigZaphod (12942)
      Well, according to one page I found, the Library of Congress is (was?) around 10 Terabytes. Google says that equals 83,886,080 Megabits. Wikipedia says that DVD video can run at 9.8 Megabits/second using MPEG-2. So, my calculation is: (9.8 * 16) / 83886080 = 0.00000186920166 LOC/s. (Here's hoping I didn't make some stupid 2:30am math mistake here... :))
      • Re: (Score:2, Informative)

        by Ryuu (742860)
        Well, the result I found was 20 TB for the books (163840 gigabits) and they said in the article it was 6Gb/sec, so 6/163840=0.00003662109375 LOC/sec.
        • by BigZaphod (12942)
          That's the problem with LOC/s... it's a moving target. :-) It reminds me of the era when measurements were based off the king's physical body. Like, the length of his foot might be a "foot" until he got replaced by a different king. Etc.

          In any case, that 10TB number I found seemed a bit small and the page looked sort of old. So it's probably not very accurate - but that wasn't really the point. I hadn't looked at the article yet, either, and decided it'd be more fun to base it almost entirely on the b
      • by JohnFluxx (413620)
        Good grief, there's 3 answers so far and all use 2 significant figures for their data, yet quote the answer around 10 significant figures!
        • "...all use 2 significant figures for their data, yet quote the answer around 10 significant figures!"

          Which is why slide rules ought to be used in introductory science classes, not calculators. Slide rule use does two things: 1) enforces a basic understanding of significant figures, and 2) creates an ability to quickly calculate order of magnitude and therefore to quickly dismiss solutions that cannot possibly be correct.

          However, I suspect that the parent posters know all of the above, and that this is ju
        • by scdeimos (632778)
          How about 36.62 uLOC/sec?

          (Sure would be nice if ampersand-mu or ampersand-#956 worked on /.)
    • by 1310nm (687270)
      Well, they do have an EWS (Entire Works of Shakespeare) reference available in TFA for you - the earliest known bandwidth calculator, dating as far back as the Renaissance Period, when RFC 1149 was in its infancy.

      I always wondered why the rate of DVDs / t is used as a way of conveying bandwidth developments to the public. It's kind of a tease, as though there will be some point at which it will be legal to stream DVD-quality video in some way without giving up all your rights or paying more for the righ
      • How about a wireless TV cable, between your set-top box/DVD player and your TV(s).

        The MPAA may ask that this link be heavily encrypted, but it will make a nice CS hobby project in trying to decrypt it.
  • Ugh! (Score:1, Interesting)

    by lordvalrole (886029)
    I swear, none of this technology ever sees the light of day to the public. It is just astounding on how much bullshit that goes around in this country because of big business models. Something amazing like this should be rolled out everywhere. Even if this stuff costs a crap load atleast it is better spent on the public than a shitty ass war. It is nice to know US tax dollars go out the window where it could be actually funding programs like this and help roll out this tech. to communities. We have such
    • Re: (Score:3, Insightful)

      by Anonymous Coward
      I assume that you're speaking in general, but I would like to point out that the CSIRO (Commonwealth Serum and Industrial Research Organisation) is throwing Australian -- not US -- taxpayer's dollars out the window.
      • Re: (Score:1, Informative)

        by Anonymous Coward
        CSIRO == Commonwealth Scientific and Industrial Research Organisation,.. and it does really good work, and provides more than the average bang for the buck. If only US companies would pay for using patented technologies the CSIRO develops Australia would have an even greater return on investment, or even more practical research to aid industry in Australia, and in turn the world.
      • Re:Ugh! (Score:4, Interesting)

        by TapeCutter (624760) on Friday December 08, 2006 @08:48AM (#17160738) Journal
        Radio comms has been a productive area of reasearch at CSIRO for decades. Politicians who ignore them are the ones who waste MY tax dollars. There are many examples that defend the CSIRO's enviable reputation for genuine science without political "fear or favour", ie a "model public service" (as opposed to the non-existant "perfected public service" or the ever present "public propoganda service").

        To give an example of just one "public service": The CSIRO were the first to demonstrate to the world that radiation from atmoshperic testing of nukes was ending up as plutonium and other RA trace elements in childrens bones (MY bones considering the era). They found out by starting with an agricultural study into sheep near an Australian test site run by the Brit's and found the bombs were adding to a rapidly growing planet wide "haze" of radioactive dust.

        Obviously they were not popular with the politicians of the day when their extrodinary claim was promptly backed with extrodinary evidence.
    • Re:Ugh! (Score:5, Informative)

      by phrasebook (740834) on Friday December 08, 2006 @04:19AM (#17159570)
      CSIRO is Australian.

      Your country does indeed take this sort of technology, and doesn't like to honour the patents [slashdot.org] on it either! So stop complaining.

    • by desplesda (742182)
      CSIRO is an Australian research organisation. The US government has nothing to do with it, and your tax dollars are not involved.
    • Re: (Score:2, Informative)

      by Anonymous Coward
      Actually, the reason you won't have that at home is that it operates at 85 GHz, so it's only useful for line of sight communication. Think next-generation microwave towers, not WLAN.
    • Like everyone else has said CSIRO is The Aussie science agency (capital 'T' since many countries have multiple agencies). However since I support my tax dollars going to CSIRO I wondered how many $ are going there? A quick check on the site supports their reputation for transparency and provides some numbers.

      Total Income (including tax $'s): $929M Income from tax $'s: $250M ($12.50 per Aussie) Total expenditure: $947M Total Equity: $1126M

      Not everyone is a taxpayer and many taxpayers would rather spend
  • by pingbot (1037186) on Friday December 08, 2006 @04:12AM (#17159530)
    Remember this the Australian Government research organisation that has been defending there early 802.11a/g wireless patents against some mighty companies corps who want to avoid paying there dues http://www.theage.com.au/news/wireless--broadband/ csiro-wins-landmark-legal-battle/2006/11/15/116326 6614119.html [theage.com.au].

    Heartening to know the licence fees are not just going to the lawyers (something they have received some flack for in Aus), but getting invested in more research. More power to them I say.
    • Re: (Score:2, Interesting)

      by AlanS2002 (580378)
      It's also a extremely good counter example to the small government argument that the private sector can always do anything better/more efficiently.
    • by cperciva (102828)
      This isn't really an example of patents working: The idea behind patents is that a guaranteed monopoly will encourage people to do and publish research, not to provide funding to people who have done good research in the hope that they will continue to do more good research.

      A better example of patents working would be if CSIRO said "we're doing this because we think we can make money by patenting it".
      • "A better example of patents working would be if CSIRO said "we're doing this because we think we can make money by patenting it"."

        They have been around for nearly a century, they have "lost" heaps by under-selling or giving patents away (particularly in the area of drug research). In the 80's there was a drive to get more "value" from their inventions and they are a bit wiser in that area now. However the CSIRO is still a "public service" (and a good one at that), similar to NASA and other US agencies i
    • Re: (Score:1, Interesting)

      by Anonymous Coward
      The irony is that the CSIRO is in the red on this one. So far their legal fees trying to defend the 802.11 patent substantially exceed their receipts. There is quite a bit of controversy with claims that the legal battle is draining research funds. Thus even this rare example is broken.
  • (2.4bits/s/Hz)
    bits per second per hertz? Wouldn't that just be bits?
    • Re:(2.4bits/s/Hz)? (Score:4, Informative)

      by John Miles (108215) on Friday December 08, 2006 @04:58AM (#17159744) Homepage Journal
      A "hertz" is a cycle per second, so what they're really saying is that they're getting 2.4 bits per cycle of the carrier. I agree that bits/sec/Hz is a ridiculous term for someone to have made up, but they would probably justify it by pointing out that there's not just one effective "carrier" in a modern modulation scheme.

      In any event 2.4 bits/s/Hz is nothing special, unless it applies to individual subcarriers in an OFDM-like scheme. 802.11g sends 54 MB/sec in a channel about 20 MHz wide, for a bandwidth efficiency of 2.7 bits/second/Hz. Sounds like they basically threw a metric assload of RF bandwidth at the problem (another technical term found in relatively-few EE textbooks).
      • Re: (Score:2, Informative)

        by squizzar (1031726)
        I might be wrong, radio comms stuff is not a strong area of mine, but I thought the intention of numbers such as these was to provide a view of the efficiency of the system. For example a QAM system gets 4 bits per cycle, 64-QAM gets, well, 64 (I think it's used in DVB broadcasts in the UK, don't know about elsewhere).

        As the amount of information per cycle goes up, the risk of noise and corruption increases, since they have a more significant effect on the signal. Seeing as there is usually a fixed freque
        • Re: (Score:1, Informative)

          by Anonymous Coward

          For example a QAM system gets 4 bits per cycle, 64-QAM gets, well, 64

          Not so fast, you're forgetting a logarithm (base 2) here: 1 bit gives 2 possible values, 2 bits give 4 distinct combinations etc...
          So QAM, using 4 distinct phases of the carrier transmits 2 bits per cycle. 64-QAM requires you to distinguish between 64 different possibilities for each cycle, and that gets you 6 bits. Whether it is actually possible to distinguish the different possibilities depends on the signal-to-noise ratio.

      • by cnettel (836611)
        802.11g is 54 Mbit, not 54 MB/s. Your calculation seems to be based on the latter. That means that this technology is a significant improvement, while not something ground-shattering. (And, for those wondering, this would also beat 802.11n, but the margin gets thinner.)
    • Re: (Score:2, Interesting)

      by GrizlyAdams (999280)
      Multiply the frequency of the channel being transmitted on by 2.4 and you get the bit rate. Supposing you were transmitting on 2.434 GHz you could get about 5.8 Gbit/s one way. at 85GHz thats 204 Gbit/s. Mind you this is not your actual sustainable data rate. You would likely be limited to 1/4th to 1/10th this by noise, packet overhead, latency issues, etc. A this kind of frequency anything getting in the line of site can kill your signal, of course, your signal can likely kill anything staying too long
      • Re: (Score:3, Informative)

        by Anonymous Coward
        No, not the frequency of the channel - the width of the channel.
        Look up the Shannon-Hartley theorem on Wikipedia for some context. It establishes the theoretical maximum capacity given the signal to noise ration and the width of the channel.
      • Re: (Score:1, Informative)

        by Anonymous Coward
        That's bits per second per Hertz of BANDWIDTH, not transmission frequency. Or at least it better be, because that's the only thing which makes any sense to consider (the carrier frequency has no bearing on the data rate).
      • No, no, no NO!!!! (Score:5, Informative)

        by Andy Dodd (701) <atd7@NosPaM.cornell.edu> on Friday December 08, 2006 @09:12AM (#17160864) Homepage
        God, I wish there were a -5 "Totally Wrong" moderation.

        Carrier frequency has nothing to do with how much information a channel can carry. Channel bandwidth (spectrum used on each side of the carrier frequency) is what matters.

        For example, a 6 MHz channel at 450 MHz and one at around 800 MHz have the exact same channel capacity (assuming that the SNR at the receiver is the same on each channel.)

        To be specific, the formula for maximum channel capacity of a communications channel is given by Shannon's Law:
        C = W log (1 + Eb/No), where Eb/No is the signal to noise ratio of the channel and W is the channel bandwidth.

        Maximum C for a given SNR and W (or minimum SNR for a given C and W) is not achievable in practice, but recent advances in error control coding techniques such as LDPC and turbo codes have allowed people to get to within just 1 dB of the minimum SNR for a few years. (And yes, this technology is in cell phones. If I recall correctly, turbo codes are used on some cell phone downlinks when transmitting image data that is not latency-sensitive. Unfortunately both turbo codes and LDPC both introduce pretty high latency to a communications system.

        2.4 bits/sec/Hz is nothing new. As others have pointed out, plenty of other systems have been doing this for quite some time.
        Cable modems - I believe the DOCSIS maximum limit is 36 Mbits/sec over a 6 MHz channel. 6 bits/sec/Hz - the nice thing about cable distribution is that the inverse square law goes bye bye and high SNRs are easily achievable.
        ATSC digital television - 8VSB provides 19.2 mbits/sec over a 6 MHz channel. Just over 3 bits/sec/Hz over relatively long free-space distances, although transmitter power is measured in kilowatts.

        There isn't really enough information to figure out exactly what they did, but it looks like the CSIRO people just threw a massive amount of channel bandwidth at the problem. 2.4 bits/sec/Hz means their SNR was not that high.

        BTW, yes, it IS true that at higher carrier frequencies, there is more free spectrum available to use wider channels, but there is no direct link between carrier frequency and channel capacity as you claim.
        • by expatriot (903070)
          To be fair, there is some relationship, so maybe it is only -3 Totally Wrong
          You can't have 2MHz of bandwidth on a 100Hz center frequency. It would be more correct to say in this case that the center frequency is somewhere around 1MHz.
          As you increase the information content by modulating the carrier, the channel bandwidth increases. The AM, FM, or phase modulation creates sidebands.
          The main reason higher carrier frequencies are used is so that it is easier to create large bandwidths. (I know that thi
          • by Andy Dodd (701)
            Well, I did mention that in my post - "BTW, yes, it IS true that at higher carrier frequencies, there is more free spectrum available to use wider channels, but there is no direct link between carrier frequency and channel capacity as you claim."

            In addition to there being more free spectrum, it's also true that many aspects of transmitter and receiver construction become more difficult as the ratio of bandwidth to carrier frequency increases. i.e. an antenna covering 1 GHz of bandwidth with a 2 GHz carrier
        • 2.4 bits/sec/Hz is nothing new

          Indeed, to digital communications people this is nothing special. Moreover: it is rather meaningless to say how many bits/s/Hz you get without any mention of distance, power or SNR (signal to noise ratio). I don't think the achievement has anything to do with clever modulation techniques, just with the large bandwidth emerging from just one transmitter. Just like a 1000 ton car consuming 1000 liters of fuel per km is no great technological achievement (in terms of theoretica

        • Like I said, I'm not an EE or HAM. I didn't even think about the channel bandwidth, thank you for pointing that out.
          If you managed to have a 2.5GHz channel bandwidth at 2.4bits/s/Hz that would be the ~6 gigabit/s they claimed as data throughput. At 85GHz that would be from 83.75GHz - 86.25GHz.
    • by Idbar (1034346)
      In a digital communication system you transmit symbols instead of bits, that is to take advantage of your bandwidth. For example, on your carrier of 2.4GHz you are allowed to use only a band of frequency, and you want to transmit the higher amount of data per second as possible, so you might thing about transmitting sinusoids of 128 different amplitudes (in the physical part) and that could represent 128 different symbols. You are not transmitting binary (only 2 amplitudes) and consequently, you have a more
  • This is old news - it was demonstrated (at least privately) two days ago, not yesterday!!!!

    Unfortunately I missed my only chance of slashdot fame by deciding to drink beer at our staff Christmas party rather than witness the demonstration. Oh well
    • by allrong (445675)
      It was quite impressive, though the heat generated by the demo PC's caused a few problems in a neighbouring server room. I also submitted the story yesterday (once the press release was made public) and it was rejected.
  • by jocks (56885) on Friday December 08, 2006 @06:43AM (#17160172) Homepage
    ....that will keep Windows Vista patched in real time!
  • by clickclickdrone (964164) on Friday December 08, 2006 @08:09AM (#17160556)
    Back in 1989 I had a 48Mb SCSI hard drive on my Atari ST. That loaded files at 350k/sec. That was fast back then.
    Now we have data going through the air at 6Gb/sec. It's all too easy to get used to the steady stream of new stuff but every now and then you need to stop, think about how much has changed in the last 15 years or so and think.. 'Wow!'
    • It's also all too easy to forget to close the bold tag and not bother to preview. Sheesh. God job it's Friday.
      • by Threni (635302)
        And easy to forget your units. "350k/sec". 350,000 what? bits? Bytes? Underpowered Amiga competitors?
  • by Xolom (989077) on Friday December 08, 2006 @08:12AM (#17160566)
    why don't they try using the rest?
    • Re: (Score:2, Funny)

      by Hanners1979 (959741)
      By the time they'd finished starting up the 16th DVD stream, the MPAA were hammering on the door...
    • by jmv (93421) on Friday December 08, 2006 @09:37AM (#17161088) Homepage
      Cost of the LCD screens. I'm not joking.
    • by sharkey (16670)
      Because the resulting 24Gbps would make their stated goal of reaching 12Gbps seem kind of pointless to fund.
    • I thought about that too. An RF channel isn't a perfect window in frequency. The further you put your information from the carrier frequency, the more distorted it becomes. This is mostly due to non-linear components. My guess is that the 3/4 of the bandwidth that they didn't use offers too much distortion or loss. Diminishing returns kicks in the further you get from the centre frequency. The marketing people would rather let the reader extrapolate the results. "Wow, if they used the whole bandwidth
    • I know you're just joking, but blah blah blah +5 insightful.
  • What's happening at a rate of "b:s:Hz"? "b:s", or bps, is a rate of data transmission. "b:Hz" is a rate of data processing, like the typical 0.5b:Hz CPU performance on a fixed clock. b:s:Hz sounds like the acceleration of bits on a clock, as if the last bit travels faster than the first after the system runs a while.

    Does this fiber have to warm up like my old B&W TV?
    • Re: (Score:1, Insightful)

      by Anonymous Coward
      Bits/second/Hertz is a measure of spectral efficiency [wikipedia.org].

      In other words, since they say their spectral efficiency is 2.4b/s/Hz and their link rate is 6 Gb/s, their system must use 2.5GHz of RF spectrum to accomplish that. The article says the system operates at 85GHz, so technically it probably emits energy along the entire range from 83.75GHz to 86.25GHz, assuming the bandwidth is centered at 85GHz.

      Also, this is wireless technology, not fiber, although that doesn't affect the above.
      • by Doc Ruby (173196)
        Ah, it's not Hz of actual cycles, it's Hz of literal bandwidth, simultaneously transmitted on multiple frequencies.

        Too bad. I'd love to see a physical example of bits per second per second, data acceleration. Especially traveling at the constant speed of light.
  • Pshaww.... (Score:3, Funny)

    by Quixote (154172) * on Friday December 08, 2006 @12:00PM (#17162854) Homepage Journal
    Not to rain on their parade, but bear with me:
    A DVD is 4.5GB (say). So 6Gb/s means a DVD can be transferred over the distance (250m) in 6 seconds.
    In my backpack, I can put a 100 DVDs (a spindle). Assume I'm not in shape and can't carry more. I can walk the 250m in just over 4 minnutes (at a leisurely pace of 1m/s).
    So if I carry my 100 DVDs the distance, I'll cover it in 250 seconds, which works out to a speed of 14.4 Gb/s, more than double of what these boffins are getting.

    Never underestimate the bandwidth of a backpack full of DVDs....

  • What one earth is the datarate of a "full quality DVD?". Why not use a datarate everyone knows like "Library of Congresses per half day"?
  • The article initially said:

    "Multi-gigabit links operate at speeds that leave current wireless networks far behind. For example the entire works of Shakespeare could be transmitted over this six gigabit link in under seven thousandths of a second or a full DVD movie in just over three quarters of a second."

    Oops. I think that the marketing people at a networking products company should get this kind of thing, above all else, correct. Especially when transmission speed is the focus of the announcement... :)

"Only the hypocrite is really rotten to the core." -- Hannah Arendt.

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