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Terahertz Wireless Chip Will Bring 30Gbps Networks 177

MrSeb writes "Rohm, a Japanese semiconductor company, has created a silicon chip and antenna that's currently capable of transmitting 1.5Gbps, with the potential to scale up to 30Gbps in the future. While this is a lot faster than anything currently on the market, the significant advance here is the reception and transmission of terahertz waves (300GHz to 3THz) using a chip and antenna that's just two centimeters long. Rohm says it will only cost $5 when it comes to market in a few years — a stark comparison to current terahertz gear that's both large and expensive. The problem with terahertz transmissions, though, is that it's highly directional — with a submillimeter wavelength, it's more like a laser than a signal. Terahertz waves might enable awesome device-to-device networks, but it isn't going to bring 30Gbps internet to a whole city block. More interestingly, submillimeter terahertz radiation is the next step up from the gigahertz radiation used in full-body millimeter wave scanners. Terahertz waves can not only see through clothing, but can also penetrate a few millimeters of skin."
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Terahertz Wireless Chip Will Bring 30Gbps Networks

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  • Build your own fully body scanner.
    • by ddd0004 ( 1984672 ) on Monday November 28, 2011 @12:21PM (#38191412)

      This could be very handy for searching for government implanted transmitters inside your own body. I look forward to a day when we can cast aside our crudely fashioned aluminum hats

    • Which part of "can penetrate a few millimeters of skin" is 'interesting' rather than 'scary'?

      • Re:Next mod... (Score:5, Informative)

        by Anonymous Coward on Monday November 28, 2011 @01:11PM (#38192008)

        Terahertz radiation is non-ionizing, unlike say X-Rays. This type of radiation is used in things like bomb detectors and to inspect explosives and other unstable compounds because it can penetrate a few millimeters but does not break down molecular bonds.

      • Medical diagnostics.
  • by masternerdguy ( 2468142 ) on Monday November 28, 2011 @12:10PM (#38191284)
    What can I do with 30 GiB/s? I'm trying to figure that out, give me some ideas.
    • Re: (Score:3, Funny)

      by mwfischer ( 1919758 )

      Run Windows Update and be done in about 15 minutes.

    • by Anonymous Coward on Monday November 28, 2011 @12:16PM (#38191350)

      Cook chicken, most likely

    • by Synerg1y ( 2169962 ) on Monday November 28, 2011 @12:17PM (#38191364)

      Share porn with your neighbor across the street at never before seen transfer speeds.

    • by Lord Lode ( 1290856 ) on Monday November 28, 2011 @12:36PM (#38191610)

      Indeed, 640K ought to be enough for everyone!

    • Re:The Future (Score:5, Interesting)

      by Anonymous Coward on Monday November 28, 2011 @12:41PM (#38191656)

      They said the same about broadband: "What could anyone possibly do with 20mbps? They barely use the 56k we give them!"

      Give them the bandwidth - they'll find a good use for it. I can see it being very useful in a small/medium server room - 30Gbps makes it a competitive LAN system. Having a bunch of wireless cards would be much easier than running all that cable, even if some manual aiming and orientation of antennas is necessary.

      I also imagine "the cloud" would benefit from this - even 1.5gbps is basically SATA speeds. Latency is higher, but the potential throughput gains are impressive. That may make it possible for "local storage" to be "operating system and cloud sync software", with everything being server-side somewhere. You and I may not join in (I don't like the privacy most of the cloud has), but many people don't give a shit about that.

      Gaming might also benefit. Current online gaming depends a lot on synchronizing things, then letting the clients do a lot of the calculation. Updating the position of falling objects is almost always client-side, with the server checking every once in a while. It's a major headache, code-wise. With a suitably massive pipe, it becomes unnecessary - just send the coordinates every frame.

      Or it makes video streaming work properly. Dealing with current streaming is rough on networks, as it needs to get there quickly. 30gbps to the home, and you can download an entire blu-ray, uncompressed, in two seconds. Latency can be looser - nobody's going to complain if it takes three seconds instead of two. There was an article on /. about that a couple months back.

      • by Lennie ( 16154 )

        A lot of systems already support 10 Gbps Ethernet on UTP and fibre. 40 and 100 Gbps Ethernet is coming.

        At 10 Gbps, iSCSI is already faster, cheaper and even lower latency than most 8 Gbps FibreChannel solutions, pushing FibreChannel even more into the highend niche markets it already is.

        After the fairly new SATA 6 Gbit/s, it looks like SATA Express is will be connected directly to the PCI Express bus without needing a SATA controller.

        This 30 Gbps wireless stuff is probably only useful for point-to-point and

        • Yes, there's already 10+Gbps ethernet stuff. But that's honestly overkill for a lot of small/medium businesses' servers. Even 10Gbps is sort of overkill going to an Exchange server for 100 people. Few companies would pay extra to get 100GE to everything unless it actually benefits something.

          Many companies, however, would pay a little extra to cut down on cable nests. Easier maintenance, easier expandability... those all serve business purposes. Bosses like to hear "this investment will cost $X, and save us

          • 10 GbE is currently used broadly by large data movers as outputs from there servers. Many "cache nodes" in todays large CDN's (akamai, level 3) run multiple 10GbE interfaces. 40GbE and 100GbE are only currently used on backbone routers to upgrade capacity.
          • by Lennie ( 16154 )

            A lot have replaced 4 or more 1 Gbps with one 10 Gbps on the vmware/whatever-virt. servers.

    • Re:The Future (Score:5, Informative)

      by poetmatt ( 793785 ) on Monday November 28, 2011 @01:17PM (#38192102) Journal

      apparently nothing, because higher frequencies have horrible ranges. This stuff might work at ridiculously short range, but also won't be able to penetrate through anything which would enable it to work anywhere significant. Look at how tough even the 2.4ghz stuff like wireless devices can barely even penetrate a few walls, and now we're talking terahertz?

      Long story short, nothing, because this product will never even give you 1.5Gbps.

      • What about reflection? Just because they can't go through the wall doesn't mean they can't reflect off the other wall and through the door.

        • by Rich0 ( 548339 )

          I think that absorption is a problem when you get even into the 100GHz range or so. The atmosphere is relatively transparent to radiation below a few GHz, and to the range that contains visible light (probably the reason we can see that range), but it is fairly opaque to everything else.

          Water and oxygen and various other molecules absorb energy across a huge range of the spectrum. That's why telescopes outside of the more traditional radio and visible wavelengths need to be located at high altitude.

        • what part of "you'll be lucky if the signal can travel 1 centimeter" makes you think that reflecting off of anything would matter? I don't mean this as an insult towards you, just a matter of practicality. It wouldn't work.

          This could have use in the same way that body scanners work, or the concept of a wireless connection from hardware to hardware - think of those "stone" chargers where you just drop the phone on top of it, but instead being able to just put a graphics card on top to have it connect to your

          • Well lets put it this way.

            Your lamp, even if you block sight of it with your hand, you can still see the light it gives off, no? And if it was modulated (eg switched on and off) you would still see this, even though you have no line of sight? EM works the same way.

            And the range is not only a handful of centimeters. The air doesn't absorb it THAT much...

            • Here's an example of long range: FM frequencies, which go hundreds of miles. How low is the frequency? in the 88-> 175 megahertz range. Lower ranges work better.
              Here's an example of short range: bluetooth, which can go up to 130 meters or so if I recall correctly. Bluetooth is in the gigahertz range.

              I think you are possibly conflating radiation/emission and frequency itself - while they have things in common, they are not the same.

              The "range" of the frequencies is theoretically infinite. It doesn't mean

              • Different frequencies are absorbed by the 'air' to different amounts - I do realize this. I also realize that ionization of the air changes this. This is why sky-wave propagation changes throughout the day/night cycle.

                I don't know the relationship between frequency and absorption though. I imagine there's a handy graph showing it at some normal density, humidity, and temperature, though?

    • by fred fleenblat ( 463628 ) on Monday November 28, 2011 @02:27PM (#38192894) Homepage

      You can run through your comcast monthly bandwidth cap in 8.3 seconds.

  • by Moheeheeko ( 1682914 ) on Monday November 28, 2011 @12:15PM (#38191342)
    ISPs will still throttle your ass to 55 Mbps
    • by ifrag ( 984323 )

      ISPs will still throttle your ass to 55 Mbps

      I'd be quite happy if I was only getting throttled down to 55 Mbps on downstream. For Comcast the 50 Mbps plan is almost the most extreme one you can get. Think I get throttled all the way down to something like 10/1.

  • by Nadaka ( 224565 ) on Monday November 28, 2011 @12:29PM (#38191500)

    Step into the Tear o' Hurts scanner citizen, if you choose not to you may instead choose to be violated by the TSA sanctioned probulation team currently on work release from a local for profit penitentiary.

  • by vlm ( 69642 ) on Monday November 28, 2011 @12:32PM (#38191542)

    Run it by a RF EE next time, or at least an advanced ham radio guy.

    using a chip and antenna that's just two centimeters long

    a stark comparison to current terahertz gear that's both large and expensive.

    with a submillimeter wavelength

    First of all its hard from a RF perspective to make stuff thats more than a 1/4 wavelength long. Obviously possible, but much harder. For example, I'm working on a K band transverter and one nightmare is standard SMA connectors resonate at 18 GHz or so, making them quite exciting to use. Yes I already know about the expensive and complicated and almost but not quite SMA compatible connectors I can use. Aside from connector and feedline issues, Its actually EASIER to make small stuff than large stuff at high frequencies / small wavelengths. Cable attenuation makes you put the whole RF works at the dish feedpoint above 50 GHz or so, if you want decent performance. The smaller it is, the lighter it is, more or less, making the mechanical engineering job simpler. Its not like 50 GHz amplifier dies are currently the size of dinner plates and will someday be the size of rice grains... they're already tiny. Ditto this chip. Also the silicon is cheap, the tools are expensive. A new ultrasonic wirebond machine must be worth, i donno, tens to hundreds of thousands of cheap MMIC dies? When you buy MMIC dies, its not like they're blowing lots of money on packaging... And thats before you hire the rare skilled labor to set up and operate and maintain the already expensive wire bonder. Wirebonding zero ohm resistors wouldn't really change the overall cost vs wirebonding some fancy dies because of the huge fixed and variable costs of the technology, so changing the die cost from ten dollars to ten cents isn't gonna help if the overall project cost due to R+D and manufacturing and test gear averages out to ten grand per active device...

    Secondly complete THZ systems are large and remain large and will probably always be "large". The internal chips are already small, and, frankly, relatively cheap. Antenna cannot be magically shrunk for same performance. Support gear like bias and main power regulators don't "know" they're powering microwave gear and should therefore be shrinking at a microwave pace. DSP processors don't "know" they're connected to a shrinking MMIC die and therefore they should be shrinking at a microwave pace. Support gear does shrink over time at the rate of normal support gear shrinkage, which isn't that fast. For example, not much has changed in the world of linear voltage regulators in the last 30 years... somewhat lower current references, MOS pass transistors instead of bipolar means lower voltage drop, um... thats about it?

    • Although the article claims to be talking about a silicon *transceiver* running at *300+GHz*, the graphics included in the article just have a planar horn antenna and a diode on an InP substrate all connected up to a SMA connector. A bit disappointing to be honest. No mention of whether they're using the diode as a detector or mixer (or both), but the pieces they are talking about appear to be a long ways away from an actual communication system.

      One of the big problems faced in reality will be getting eno

      • by vlm ( 69642 )

        And if they are using some high-harmonic mixing with that diode then they're probably not going to meet regulatory emission requirements

        subharmonic mixing is probably an analogy for what you're talking about, and yeah its a struggle to make that work. If you play games with waveguide between the mixer diodes and the antenna, which is a pretty decent high pass filter, and use some stubs, you can get great attenuation of the LO signal, but good luck cleaning up the images unless your IF is like 10 gigs.

        Also like you said the power thing... subharmonic mixing is not known for efficiency, even with a crazy elaborate design covered with stub se

    • by Matheus ( 586080 )

      All that being said... if you would please just RTFS you'll get the following little tidbit: "using a chip and antenna that's just two centimeters long". Note the second half of that and-combo and your initial problem of "Antenna cannot be magically shrunk for same performance" seems to be what they've solved.

      IANAHFCD but I apparently can read...

      • by vlm ( 69642 )

        LOL... at "sub millimeter wavelengths" 2 cm is practically a longwire or a beverage antenna... 20, 30, 40 wavelengths long. Whatever they're doing, its pretty directive, and its never going to shrink, a 30 wavelength long sub millimeter band antenna is always going to be around 2 cm or so.

  • by AngryDeuce ( 2205124 ) on Monday November 28, 2011 @12:35PM (#38191584)

    All the wireless tech in the world doesn't seem to be able to stand up against saturation in the band.

    I say this, of course, as someone who lives in an apartment complex of 100's of units, all in close enough proximity that Wireless-N signals can be picked up pretty much anywhere in the complex from any users apartment. I had to forego wireless entirely and hard wire everything because every band was completely saturated with dozens of wireless networks. With the smart-switching shit that automatically looks for clean channels it's even worse; I've taken to illustrating the problem to friends at parties with the wifi scanner app on my phone, we all get a good laugh watching 10 networks bounce up and down the band constantly "Channel 1 is clean, quick, switch to channel 1! Shit, 9 other networks came with me...look, channel 3 is clean, quick, switch to channel 3! Fuck, they're following me! Channel 7 is clean, quick, switch to channel 7!!" all day long.

    The wireless band is becoming way over saturated. Now that we have cars with built in hotspots it's going to get even worse. We need some sort of fundamental shift in the way we do wireless networking, either that, or we need to greatly expand the band and the range between channels so that 30 devices can cohabitate the same frequency range without completely fucking up throughput.

    • As it's mentioned in the summary, the Terahertz frequencies are very directional, unlike the typical GHz stuff of wireless networks. So, instead of broadcasting for all the neighborhood you are transmitting more on a point to point fashion. Saturation is almost irrelevant in this scenario (as long as the signal dies off within the solar system).

      • Great, when there's one transmitter focused at one receiver. What happens when there's 20 transmitters sending to 20 receivers all within close proximity to each other? Wifi worked just fine for me 5 years ago when there was only as handful of people using it in my complex, now that everyone has wifi the service has become so degraded it's practically unusable for anyone that is trying to do more than surf the internet (and even that is a chore, requiring many page reloads sometimes to get the full page t

        • These higher frequencies are not only directional, but they don't penetrate walls. So if you can settle for needing near-line-of-sight within your apartment, you can be guaranteed no interference from neighbors.

          However, there may also be better ways to manage shared bandwidth, as you stated. Frankly, one solution is to sell slices of the spectrum to companies to manage autocratically and efficiently as they see fit. If there's a way to make more devices get more throughput on a limited spectrum by coo

    • I know it's traditional to skip reading the article, but the summary points out that this will be a directional-only signal. Directional signals generally don't have saturation problems, because they propagate (to simplify) in cones rather than spheres.

      • I understand that, so what happens when there's 15 cones propagating right next to each other? You know, kinda like how traditional wifi has exploded to the point where every goddamn thing in the world is a hotspot now?
    • In short: THz penetrates your T-shirt (airport scanners) but not any thin drywall.

      Roughly speaking for electromagnetic waves the higher the frequency the more light-like the radiation becomes. THz is close to infrared light, it will not penetrate much but can be used to transmit a lot of data because you can modulate it with a much higher frequency than standard 2.4 GHz wireless LAN. This comes at a price though, if a person walks through the line-of-sight between your notebook and the hypothetical THz wir

  • here in the future the 30Gbps wireless service is all seeing, all knowing, and spans across the city uninterrupted with a lemony fresh scent.

    Cancers however continue to elude us. We've taken to naming them after impressive sounding former presidents, or basing cartoon characters upon their loose interpretation. Incidentally, if you come across any historic manuscripts related to airport scanner safety, we would be quite interested.
    • by blueg3 ( 192743 )

      This is still below the ionization threshold, and so will not cause cancer at any appreciable rate.

      • by Instine ( 963303 )
        "and so will not cause cancer at any appreciable rate."
        But might it detect it?...
        • by blueg3 ( 192743 )

          The imaging depth for THz is shallow enough that it could only theoretically detect skin cancers. Whether or not that's even reasonable is outside my expertise, though.

          • by Instine ( 963303 )
            do you know what could penetrate deep enough? What is your expertise? I have an interest in the subject, but not much more.
            • by blueg3 ( 192743 )

              Well, a lot of lower-frequency radiation (sub-microwave) should, but they have long (> cm) wavelengths, and generally in imaging you have a hard time resolving anything less than the wavelength of the light you're using.

              I suppose the obvious answer is X-rays, since that's what they use, but that's ionizing. For a while people were working on visible-frequency imaging, but I don't really know how that turned out.

  • This could open up cheap land to space communication. This begs the question, "What is the cheapest way to send a home built satellite into a geosynchronous orbit"?

  • The problem with high frequency wireless networking is that more and more stuff becomes opaque as you increase the frequency. For Terahertz networks you're pretty much going to require a clear line of sight between you and the receiver. The directionality thing will be a big problem too, I'm sure some of us can remember setting up IR networks a few years ago (when laptops still had IR ports on them). Unless you're talking about fixed installations, Line of Sight is a big hurdle to adoption.

    In short:
  • by NixieBunny ( 859050 ) on Monday November 28, 2011 @01:26PM (#38192200) Homepage
    This article is basically nonsense. I work with folks who actually make terahertz radio equipment for radio astronomy. It seems like the last place in the spectrum you'd go to for anything practical. The technology is very primitive, since there has been little application for it, since the signals are quickly absorbed by water vapor in the atmosphere. My coworkers are currently in Antarctica to do some astronomy, because there's very little water in the air there.

    A stable local oscillator that puts out any useful amount of terahertz power is very difficult to make. You are lucky to get a few microwatts. The signals aren't quite as directional as a laser, but they're too directional to be of much use for the wireless networking that we are familiar with.

    There are optical ways of making signals at terahertz frequencies, which may hold more promise, but they're being used in only a few exotic applications, such as the ALMA interferometer array in Chile.
  • Three ad-heavy blogs deep, the best I'm able to find is a brief note in Electronics (AU) [electronicsnews.com.au] . It's not even clear if the device pictured is an emitter or a detector.

    Terahertz RF is essentially line of sight, and has roughly the propagation characteristics of light. This is not going to be useful for WiFi or cellular telephony. Imaging, though, may work. Here's a good paper [okstate.edu] on the subject. In the terahertz range, both RF and optical techniques are used; there are both antennas and lenses. The high end of t

    • Definitely could be useful for line-of-site backbones, though. Years ago I worked for a guy and we set up some of proprietary 2.4ghz bridges for just that purpose.

  • I can see it now. XXX websites dedicated to upskirt full body scan pr0n.

  • Seems to me you could quite easily use them to connect houses in an urban setting. Since they're cheap you could use one device for every home and since they're highly directional you could turn them off and on depending upon whether the homeowner wants to be connected (or has paid the bill). Put 15 or 20 in a central location and one at each house. This eliminates all the complexities of getting individual fiber to the houses, too.

  • As an IT nerd, I've used my fair share of 802.11g and 802.11n networks.
    802.11g I have never, ever seen more than 3.0MBytes/s sustained transfer rate about 24mbits.
    802.11n I've delt with mostly 300mbit equipment, the highest sustained and consistent speed I've seen is 10MBytes/s across a large transfer, the average I would say is 5 or 6 but I have seen a sustained 10 multiple times. NEVER faster, ever! That's 80mbits per second.

    On a 100mbit network, I've never seen a sustained speed of over 10 to 11MBytes/s

If I had only known, I would have been a locksmith. -- Albert Einstein