5 ms·

Researchers have achieved wireless speeds of 1 Tb per second

59 points by ddispaltro 12y ago

jklontz 12y ago
For reference, current DDR4 RAM to CPU is ~0.5 Tb/s [0]. [0] http://ark.intel.com/products/81059/Intel-Xeon-Processor-E5-2697-v3-35M-Cache-2_60-GHz http://ark.intel.com/products/81059/Intel-Xeon-Processor-E5-... (see "Max Memory Bandwidth")
- sak 12y ago
  Usually you don't have to share your memory bandwidth with others nearby.
  - mentat 12y ago
    Doing so within a rack might be quite handy.
imaginenore 12y ago
2.56 Tb/s in 2012: http://spectrum.ieee.org/tech-talk/telecom/wireless/twisted-light-leads-to-256-tbs-link http://spectrum.ieee.org/tech-talk/telecom/wireless/twisted-...
- hristov 12y ago
  Yeah but this is optical, not radio. Optical transmission may technically be wireless (such as for laser communications) but this is usually too unreliable for ordinary communications. Thus, optical is most often wired, as in fiber optic.
hristov 12y ago
This does not mean much until we learn how much spectrum they used. We need more efficient use of spectrum not raw download speeds.
- ArkyBeagle 12y ago
  This claims 100MHz bandwidth: http://www.ispreview.co.uk/index.php/2015/02/university-of-surrey-claims-1tbps-speed-over-future-5g-mobile-tech.html http://www.ispreview.co.uk/index.php/2015/02/university-of-s...
  - japhyr 12y ago
    Is that good or bad?
    - ArkyBeagle 12y ago
      It's 100 times a Bluetooth channel. So for deployment, that rounds down to "bad". It might makes sense for tightly controlled point-to-point.
    - wmf 12y ago
      100 MHz is a lot. It's wider than the entire 2.4 GHz band and each cellular carrier has less than 100 MHz of spectrum. http://www.fiercewireless.com/special-reports/how-much-lte-spectrum-do-verizon-att-sprint-and-t-mobile-have-and-where http://www.fiercewireless.com/special-reports/how-much-lte-s...
  - jpmattia 12y ago
    Not really, according to the update the entire result is sim. From your link: > According to Tafazolli, the new class of Detector (a completely new approach) was tested through computer simulations (these simulated a real mobile/wireless environment) and were found to achieve the 1Tbps rate claimed. In our view that’s quite a bit different from conducting a practical test. It doesn't look like there was any actual lab result.
    - ArkyBeagle 12y ago
      Argpfhh! I didn't scroll down to the update. I just saw "measured at" and took them at their word. So vapor again. sigh. At least until they actually measure it. Good eye, sir.
DiabloD3 12y ago
This test is largely bunk. Its over 100 feet, in direct line of sight, using a client device that is a test device built exclusively for this (as in, it is not a phone nor a laptop nor anything small and underpowered like that). They say "5G speeds" but neglect to tell you this is not done using LTE or Wimax (the only two protocols that ITU-R recognizes for 4G; 5G will use descendents of these as they are designed for many generation forwards and backwards compatibility in mind).
- wyager 12y ago
  Well, duh. This is obviously not a production device. Nothing about the title leads us to believe that this is a production device. You generally have to achieve breakthroughs in lab settings before you can achieve them in real-world settings. 1Tbps is well beyond anything we have in production today.
  - DiabloD3 12y ago
    Well, it also fails to claim what it can do over distance. Like, LTE-Advanced with high order antennas (supports up to like 32x32 MIMO, but lets for this example say 8x8) could do 100mbit/sec within a 25 mile sphere around the tower using a fixed install (ie, home internet router), according to some stuff I've read. This is technology we have now that could be used to deploy the last mile solution that'd work in many communities, yet we're not deploying it, but we're working on new tech to replace tech we're not even using (possibly just "yet", possibly forever).
z3t4 12y ago
Wouldn't there be a noise problem when all signals are broadcasted as in radio transmission!? Unless you point it like with a laser or microwave. I would be hesitant putting a 1TB/s uplink next to my head. :P
- SigmundA 12y ago
  Yet you walk around outside in 428-750 terahertz radiation at 120 watts per square meter without ill effect (mostly).
  - bjornsing 12y ago
    120 W? I thought sunlight was more like 1 kW (but perhaps not much of it in 428-750 terahertz?).
dustingetz 12y ago
What could we do with this kind of bandwidth? I can't even imagine.
- Dylan16807 12y ago
  Well first off you can serve thousands of phones with attenuated signals with reasonable speed. Also I guess you can run at SSD speeds over local wireless. Things like wireless monitors/TV are already doable.
paulsutter 12y ago
TL/DR: Simulating a low noise environment is lot easier than finding one in the real world. And that's not news. Researchers simulated a 1Tb/s transfer rate within a 100Mhz channel. Shannon's limit[1] explains how: set the noise term arbitrarily small, and your transfer rate can be arbitrarily large. Bandwidth is popularly misunderstood to be some fixed range of spectrum, as if signals outside the range are attenuated to zero. But you can't attenuate a signal to zero. "Bandwidth" is measured[2] as the range over which attenuation is less than (say) 3db. If not for noise, you could utilize a limited-bandwidth channel as if it had infinite bandwidth merely by amplifying frequencies outside the range in the exact proportion they are attenuated. But every real system has noise. Overcoming this noise is the challenge of high speed transfers. There's no indication these "researchers" have accomplished anything whatsoever. [1] http://en.wikipedia.org/wiki/Noisy-channel_coding_theorem http://en.wikipedia.org/wiki/Noisy-channel_coding_theorem [2] http://en.wikipedia.org/wiki/Cutoff_frequency http://en.wikipedia.org/wiki/Cutoff_frequency
- frozenport 12y ago
  >>by amplifying frequencies outside the range in the exact proportion they are attenuated. This is true in the sense you know a function everywhere if you can expand it for example using the Taylor series with inifnite terms. This is not true for discrete data which is limited by the niquist rate and the DTFT of the data will clearly repeat, meaning you literally can't get at higher frequencies to amplify. See the following figure, notice how higher frequencies are lower frequencies repeated: http://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/ReconstructFilter.png/400px-ReconstructFilter.png http://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Rec... >>But every real system has noise. Indeed, but in many channels there are physical limitations on the propagation which is slightly different then noise....
  - paulsutter 12y ago
    I'm not sure what you mean - any real world test wouldn't be a discrete signal. And yes, real physical channels are imperfect in other ways, for example not perfectly linear, etc. Could you dig into that a little? You think these effects are more significant than noise? Love to hear about it.

59 points by ddispaltro 12y ago

For reference, current DDR4 RAM to CPU is ~0.5 Tb/s [0]. [0] http://ark.intel.com/products/81059/Intel-Xeon-Processor-E5-2697-v3-35M-Cache-2_60-GHz http://ark.intel.com/products/81059/Intel-Xeon-Processor-E5-... (see "Max Memory Bandwidth")

sak 12y ago
Usually you don't have to share your memory bandwidth with others nearby.
- mentat 12y ago
  Doing so within a rack might be quite handy.

imaginenore 12y ago

2.56 Tb/s in 2012: http://spectrum.ieee.org/tech-talk/telecom/wireless/twisted-light-leads-to-256-tbs-link http://spectrum.ieee.org/tech-talk/telecom/wireless/twisted-...

hristov 12y ago
Yeah but this is optical, not radio. Optical transmission may technically be wireless (such as for laser communications) but this is usually too unreliable for ordinary communications. Thus, optical is most often wired, as in fiber optic.

hristov 12y ago

This does not mean much until we learn how much spectrum they used. We need more efficient use of spectrum not raw download speeds.

ArkyBeagle 12y ago
This claims 100MHz bandwidth: http://www.ispreview.co.uk/index.php/2015/02/university-of-surrey-claims-1tbps-speed-over-future-5g-mobile-tech.html http://www.ispreview.co.uk/index.php/2015/02/university-of-s...
- japhyr 12y ago
  Is that good or bad?
  - ArkyBeagle 12y ago
    It's 100 times a Bluetooth channel. So for deployment, that rounds down to "bad". It might makes sense for tightly controlled point-to-point.
  - wmf 12y ago
    100 MHz is a lot. It's wider than the entire 2.4 GHz band and each cellular carrier has less than 100 MHz of spectrum. http://www.fiercewireless.com/special-reports/how-much-lte-spectrum-do-verizon-att-sprint-and-t-mobile-have-and-where http://www.fiercewireless.com/special-reports/how-much-lte-s...
- jpmattia 12y ago
  Not really, according to the update the entire result is sim. From your link: > According to Tafazolli, the new class of Detector (a completely new approach) was tested through computer simulations (these simulated a real mobile/wireless environment) and were found to achieve the 1Tbps rate claimed. In our view that’s quite a bit different from conducting a practical test. It doesn't look like there was any actual lab result.
  - ArkyBeagle 12y ago
    Argpfhh! I didn't scroll down to the update. I just saw "measured at" and took them at their word. So vapor again. sigh. At least until they actually measure it. Good eye, sir.

DiabloD3 12y ago

This test is largely bunk. Its over 100 feet, in direct line of sight, using a client device that is a test device built exclusively for this (as in, it is not a phone nor a laptop nor anything small and underpowered like that). They say "5G speeds" but neglect to tell you this is not done using LTE or Wimax (the only two protocols that ITU-R recognizes for 4G; 5G will use descendents of these as they are designed for many generation forwards and backwards compatibility in mind).

wyager 12y ago
Well, duh. This is obviously not a production device. Nothing about the title leads us to believe that this is a production device. You generally have to achieve breakthroughs in lab settings before you can achieve them in real-world settings. 1Tbps is well beyond anything we have in production today.
- DiabloD3 12y ago
  Well, it also fails to claim what it can do over distance. Like, LTE-Advanced with high order antennas (supports up to like 32x32 MIMO, but lets for this example say 8x8) could do 100mbit/sec within a 25 mile sphere around the tower using a fixed install (ie, home internet router), according to some stuff I've read. This is technology we have now that could be used to deploy the last mile solution that'd work in many communities, yet we're not deploying it, but we're working on new tech to replace tech we're not even using (possibly just "yet", possibly forever).

z3t4 12y ago

Wouldn't there be a noise problem when all signals are broadcasted as in radio transmission!? Unless you point it like with a laser or microwave. I would be hesitant putting a 1TB/s uplink next to my head. :P

SigmundA 12y ago
Yet you walk around outside in 428-750 terahertz radiation at 120 watts per square meter without ill effect (mostly).
- bjornsing 12y ago
  120 W? I thought sunlight was more like 1 kW (but perhaps not much of it in 428-750 terahertz?).

dustingetz 12y ago

What could we do with this kind of bandwidth? I can't even imagine.

Dylan16807 12y ago
Well first off you can serve thousands of phones with attenuated signals with reasonable speed. Also I guess you can run at SSD speeds over local wireless. Things like wireless monitors/TV are already doable.

paulsutter 12y ago

TL/DR: Simulating a low noise environment is lot easier than finding one in the real world. And that's not news. Researchers simulated a 1Tb/s transfer rate within a 100Mhz channel. Shannon's limit[1] explains how: set the noise term arbitrarily small, and your transfer rate can be arbitrarily large. Bandwidth is popularly misunderstood to be some fixed range of spectrum, as if signals outside the range are attenuated to zero. But you can't attenuate a signal to zero. "Bandwidth" is measured[2] as the range over which attenuation is less than (say) 3db. If not for noise, you could utilize a limited-bandwidth channel as if it had infinite bandwidth merely by amplifying frequencies outside the range in the exact proportion they are attenuated. But every real system has noise. Overcoming this noise is the challenge of high speed transfers. There's no indication these "researchers" have accomplished anything whatsoever. [1] http://en.wikipedia.org/wiki/Noisy-channel_coding_theorem http://en.wikipedia.org/wiki/Noisy-channel_coding_theorem [2] http://en.wikipedia.org/wiki/Cutoff_frequency http://en.wikipedia.org/wiki/Cutoff_frequency

frozenport 12y ago
>>by amplifying frequencies outside the range in the exact proportion they are attenuated. This is true in the sense you know a function everywhere if you can expand it for example using the Taylor series with inifnite terms. This is not true for discrete data which is limited by the niquist rate and the DTFT of the data will clearly repeat, meaning you literally can't get at higher frequencies to amplify. See the following figure, notice how higher frequencies are lower frequencies repeated: http://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/ReconstructFilter.png/400px-ReconstructFilter.png http://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Rec... >>But every real system has noise. Indeed, but in many channels there are physical limitations on the propagation which is slightly different then noise....
- paulsutter 12y ago
  I'm not sure what you mean - any real world test wouldn't be a discrete signal. And yes, real physical channels are imperfect in other ways, for example not perfectly linear, etc. Could you dig into that a little? You think these effects are more significant than noise? Love to hear about it.