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DoD Dreams of Efficient Spectrum Usage

Posted by michael on from the spectrum-spectrum-everywhere-and-nary-a-drop-to-drink dept.

Unstrung writes "US Military research agency DARPA is sick of all those static-filled cellphone calls and dropped connections too. The shadowy eggheads are working on a way of using the bandwidth available today more efficiently."

49 of 135 comments (clear)

  1. this just in... by red_five_standing_by · · Score: 5, Funny

    DoD reports that they have fortified the radio spectrum with "stuff" for more "goodness." They declined further comment.

  2. Doubt it. by smittyoneeach · · Score: 5, Funny

    After ten years active duty, and one in the Reserves, I can attest that the DOD has few, if any, dreams of efficiency. Keep trying.

    --
    Get thee glass eyes, and, like a scurvy politician, seem to see things thou dost not.--King Lear
    1. Re:Doubt it. by PD · · Score: 5, Insightful

      Let me shorten that down a bit for you:

      The efficiency isn't about money, it's about efficiently destroying the enemy, weighed against the expense of our own soldier's lives.

      --
      If tits were wings it'd be flying around.
    2. Re:Doubt it. by ahfoo · · Score: 2

      Yeah, sounds like a shell game to me.
      If more efficient spectrum use is really the goal then all they have to do is go visit their friends in the Department of Commerce who are trying to force the FCC to restrict 802.11a to indoor use only. I think it's safe to assume that the current administration is decidedly anti-wireless for some mysterious reason probably related to --cough-- national security. That's probably why Taiwan already has such restrictions. It certainly wouldn't have anything to do with protecting monopoly telecom interests.

    3. Re:Doubt it. by smittyoneeach · · Score: 2

      Consider the A-12 Avenger. Prosecution yawns.

      --
      Get thee glass eyes, and, like a scurvy politician, seem to see things thou dost not.--King Lear
  3. DOD, DARPA and Inovation by haz-mat · · Score: 4, Interesting

    The DOD and DARPA have a long history of bringing about technical innnovation, regardless of how slowly it comes into actual being, the very medium we are using (or abusing) right now is a result of that... unfortunately given the fact that i am at "work" right now, i can attest that they are not interested in efficency, mine is dropping like a rock... TGIF

    1. Re:DOD, DARPA and Inovation by i_am_pi · · Score: 2, Informative

      They're the one's that implemented TCP/IP, and that's still in use today.

      I wonder if that's what'll happen with cell phones: people running their own Cell providers, just like TCP/IP services today.

      Pi

    2. Re:DOD, DARPA and Inovation by craw · · Score: 4, Funny

      The role that DARPA played in the "early" days of computing is often overlooked. DARPA funded the initial prototype development of something called the Stanford University Network workstation. IIRC, a guy by the name of Joy at UCB also received DARPA funding to enhance some of the capabilites of a "new" OS called UNIX. Eventually, the two efforts joined forces and produced a commercial product.

      RISC technology was pushed forward by DARPA. One effort eventually led to MIPS. Another effort led to the development of the RISC I and RISC II. This technology was licenced to Sun Microsystems, and eventually evolved into a more scalable architecture. I believe that this had some modest commercial success.

      Warp and the Connection Machine were the result of DARPA funded efforts to push forward and test the capabilites of massively parallel computers. These were technnological wonders, but did not achieve commercial success. At least, one of these was featured in a very successful motion picture. Furthermore, thanks to MIPS, probably the geekiest line in motion picture history was spoken, "This is a UNIX system. I know this."

      I would also have to speculate that a there are numerous computer industry leaders that had RA's in grad school via DARPA funding.

  4. Well. by Krapangor · · Score: 3, Insightful
    As far as I understood the article is that some dude got a research grant and the guy at the DoD thinks that he might get results eventually.
    This is nothing very expectional.
    People in research always get some grants and think that they'll get some results in some time.
    But often they get only one result: Is doesn't work. Or it does the same as the old stuff but more expensive.

    If often wonder if anyone has tried to get a grant for "the development of a disc-shaped flying object" yet.

    --
    Owner of a Mensa membership card.
  5. Re: Doubt it by Oztun · · Score: 2

    They developed the routing system and it works very well. However he is one of three people working for them and "dissing" them thus far. I think a lot has changed with all companies and government agencies since the 60's.

  6. GSM by Zephy · · Score: 5, Insightful

    Why not just convert everything to GSM? it works fine for the rest of the world. You never get static (digital transmission), and the call drop rate is a lot lower than analogue

    1. Re:GSM by kevin+lyda · · Score: 2, Troll

      yeah, those advantages plus the fact that i can use my gsm phone pretty much anywhere in the world except america. actually that works out well, 90% of americans don't have passports, and you'd have to be nuts to visit america as a non-citizen since you have no rights.

      --
      US Citizen living abroad? Register to vote!
    2. Re:GSM by forehead · · Score: 2, Offtopic

      you'd have to be nuts to visit america as a non-citizen since you have no rights.

      The almost trollish nature of your comment begs the question, What are the rights of non-citizens in other (non-US) countries? In the US, the constitution guaraneets certain rights for US citizens. The same rights do not necessarily apply to "outsiders".

      --
      --
    3. Re:GSM by funky+womble · · Score: 3, Insightful
      Errm, don't you mean that US cellular industry would rather use an incompatible system to help protect it's native manufacturers from higher levels of competition from international manufacturers?

      I don't see many countries converting GSM to CDMA... maybe some of the 3G protocols are CDMA, but that's adding to the GSM networks already in place, certainly not replacing them anytime soon.

      And I don't think the existing US cellular infrastructure is really on a par with what's planned for 3G. A lot of changes will be needed, whatever the current tech.

      There's quite a difference between GSM and MS: GSM does what it's supposed to, and works pretty damn well. You tried taking a CDMA phone to a different country lately?

      Sure, there are advantages with CDMA. Better range, for example, though that's less important for more densely-populated parts of the world (and analogue probably still has the edge). But GSM has advantages too - well-established packet data, SIMs, global roaming...

      If CDMA has won, how come GSM is expanding so much in the US?

    4. Re:GSM by Moridineas · · Score: 3, Interesting

      Ok, I'm going to totally ignore your cell phone bashing which I'm sure others can refute better than I. However I have to make a point with the test of your message.

      You say that "90% of americans don't have passports". Let's check the data--I couldn't find anywhere a specific mention of how many passports in total are issued at any one time. however I could find press releases such as this one:

      http://secretary.state.gov/www/briefings/stateme nt s/970919.html

      Which state that:
      -In 1997 a record number of 6 million passports were issued
      -each year 40 million americas go abroad
      -in 1996 5.7 million passports were issued
      -each year since 1992 has seen more passports issued in 1992, in which 3.5 million passports were issed.

      So, we can assume that 40 million passports is the absolute floor number of possible passports. Also take note that many people who travel to other countries (Canada for instance, one of our two langbased neighbors in the US. Actually I just checked, and a border crossing into Mexico doesn't require a passport either) don't always have passports--I got into canada with a driver's license. So all those "international" travellers (of which there are a large number! don't always get passports).

      Also let's assume that since not everyone who has a passport goes broad every-year (and thus won't be represented in above 40M) that there are 30M who have passports sitting in a box at home. So we have a conservative number of 70M people with passports (I'm guessing the 30M is an under-representation).

      Also, on the web I read that around 16M people from the US visit Mexico every year. I couldn't find a number for Canada, but I'd bet it's similar. So right there we have 40M going abroad, and 30M going to other North American countries. That number alone is practically the population of Germany!! But anyway, disregarding Canada+Mexico (and also Alaska,Hawaii, smaller US islands etc, options most European nations don't have) somewhere around 1/4 of the population (population is around 270M) has a passport by my estimation, and enough people to roughly equal the population of Germany visit another country. And you're complaining about this why??

      This is just fud, fud, fud, us bashing.

    5. Re:GSM by mesocyclone · · Score: 3, Informative

      Next generation GSM uses CDMA. Period.

      CDMA proved itself technologically superior to TDMA. It allows more users in the same piece of space/bandwidth than TDMA does.

      "Better Range" is not an advantage of CDMA. The advantage is better spectral efficiency. I think it may also be more resistant to multipath, but I am not sure. Certainly WCDMA will be.

      Market forces and regulation, of course, distort how this affects what people actually have. Compatibility is in fact very important, which is why GSM provides, today, superior service in *that* particular regard. I am not sure why GSM is expanding so fast in the US, but I would bet it is to take advantage of the vast variety of GSM phones due to its superior compatibility. Also, due to the spectacular collapse of share values in telecom companies (partly caused by their grossly overbidding for bandwidth sold by greedy governments), the next generation (3 G wireless) has been delayed... perhaps for a long time.

      Today, the US has in inferior system due to its lack of compatibility and resultant duplication of resources. You might say that US users are suffering from the regulatory decision that allowed mankind to realize the benefits of CDMA in the future!

      The multiple standards had nothing to do with the us "protecting its native manufacturers." You may have noticed that if that was the goal, it failed! The multiple standardsd were due to a regulatory philosophy of reducing the standardization ordered by the government. The FCC decided to regulate based on spectral efficiency, rather than specific technical specifications. Both TDMA and CDMA met the initial requiremens, and the US thus has two kinds of TDMA (GSM and US) and CDMA. The choice was made completely by the providers. A provider could choose whatever standard he desired, as long as it met the FCC's spectral efficiency standards (and related things such as tolerance of out of band interference, etc). The result is this very frustrating hodge podge of systems. In the short run, it certainly provides on benefit to US telecom providers: it reduces churn - it makes it harder for a consumer to change providers. In the long run, I think it will hurt them, because various applications (such as instant messaging, etc) will not appear as quickly or be as ubiquitous as they are in GSM countries.

      BTW... the US is not the only country with multiple standards. Japan also has at least two.

      Frankly, I wish the French or some other country had done the experiment so we in the US could have a single standard... but that's not how it worked out. We are the guinea pigs.

      CDMA, btw, was invented by the president of Qualcomm, and would never have made it as a standard without this competitive build-out. In general, the "established" carriers took the proven approach - TDMA. Others took the gamble of the unproven technology (CDMA). CDMA is so bizarre that it was not really possible to predict it's bandwidth efficiency without large scale builds.

      BTW... from a technical standpoint, CDMA is a very elegant way to do things. Basically, one takes a high rate pseudo-random bit sequence and multiplies the data stream (at a slower bit rate) by it. One transmits the result, perhaps after shifting the frequency.

      The receiver has a synchronized pseudo-random bit sequence, and inverts the transform by multiplying the received RF signal (mixing) by it, and out of a loss pass filter appears the original data (audio) stream.It is a form of Direct Sequence Spread Spectrum technology.

      Pretty cool - nice an isomorphic - with pseudorandom. I love it! I've loved DSS for years.

      Interfering signals in the same bandwidth are multiplied, of course, by the same bit stream. But since it is pseudorandom, and the interfering signals are not correlated to it, they appear as broadband noise to the receiver. With techniques like this, you can also hide a signal so it is not detectable except by a receiver with the synchronized code. This stuff was first used for military secure and LPD (Low Probability of Detection) systems. The original inventor was the 1940's actress Heddy Lamar, who invented a system which multiplied music from a phonograph by audio (and recovered it by the same process). This was used to allow Roosevelt and Churchill to communicate over short wave radio without being deciphered.

      --

      The only good weather is bad weather.

    6. Re:GSM by TRACK-YOUR-POSITION · · Score: 2
      Hmm, this America suffering incompatibility for the sake of the world has a comparison to the health care sphere. Many countries have smaller price ceilings on their drugs than America (er...maybe America doesn't have any at all, for all I know). Thus drug companies pay the upfront costs to research new medications to sell to Americans. However, once the drugs are designed, they still sell them in foreign countries at the lower prices, because the marginal cost of making more medicine is lower than the price ceiling. It's concievable that if America put price ceilings on it's medicines, the state of the entire world's medicine would be hindered, even though American consumers might benefit.

      It's a strange world we live in.

    7. Re:GSM by mesocyclone · · Score: 2

      Yes. I considered tossing in that situation, because it is analogous.

      And you are quite right. Adding prescriptions to Medicare will probably result in price controls, which will greatly slow the world-wide progress in medication research.

      Of course, that doesn't stop me from driving to Mexico to buy prescription drugs occasionally :-)

      --

      The only good weather is bad weather.

    8. Re:GSM by Cato · · Score: 3, Informative

      GSM is not going to go away! Those GSM operators who have a 3G license (about 100 of them, out of hundreds of GSM operators) will deploy overlay UMTS/W-CDMA networks, but an absolutely critical feature of these networks and any 3G phones will be seamless roaming to GSM.

      GSM has over 70% of the world market, and UMTS (or CDMA2000 1x etc) will not have anything like universal coverage for a long time... CDMA is more spectrum-efficient than GSM, but GSM is going to stay around particularly in rural areas where large cells are important and 3G won't have that sort of coverage. CDMA2000 1x is an easy upgrade from cdmaOne, but going to 1xEV-DO/DV (the true 3G versions) will be a similarly expensive operation.

      GSM was decreed by the European standards bodies, but it has been an incredible success - you can use GSM phones in almost every country in the world, on over 400 networks. Call quality is great, coverage is good wherever I've been (including parts of India), and you have universal services such as short message service (text messaging).

    9. Re:GSM by Cato · · Score: 2

      This is simply wrong - last time this came up on Slashdot, someone produced stats showing that Finland has a lower population density than the US, and of course it uses GSM quite successfully.

    10. Re:GSM by TheSync · · Score: 2

      It's concievable that if America put price ceilings on it's medicines, the state of the entire world's medicine would be hindered

      This is happening right now. Once $200 billion in Federal benefits are given US seniors, the next step will be Federal ceilings on drug prices (this is what has happened in every other country). Maine and Vermont are already looking into drug price ceilings.

      check this out

    11. Re:GSM by Moridineas · · Score: 2

      http://www.cia.gov/cia/publications/factbook/

      Population is 278M.

      And as for a military tribunal, unless you're a terrorist, plotting death and destruction you have nothing to worry about.

    12. Re:GSM by alexburke · · Score: 3

      CDMA, btw, was invented by the president of Qualcomm

      At no time did Hedy Lamarr hold a position at Qualcomm...

    13. Re:GSM by mesocyclone · · Score: 2

      Good point. I mis-typed. I meant spread spectrum.

      --

      The only good weather is bad weather.

    14. Re:GSM by Ben+Hutchings · · Score: 2

      Hedy Lamarr invented frequency-hopping, not CDMA.

  7. Interference Problems by Detritus · · Score: 5, Funny

    Give me a couple of RDF (radio direction finding) stations and an 8" howitzer and I will eliminate all of your interference and congestion problems.

    --
    Mea navis aericumbens anguillis abundat
  8. Sounds a bit like DAMA... by srvivn21 · · Score: 2

    Bringing to terrestrial communications what satellite comms have had for years: Demand Assigned Multiple Access. The article is a bit short on technical details, but it sounds like a very similar concept.

    1. Re:Sounds a bit like DAMA... by Beryllium+Sphere(tm) · · Score: 2

      Also sound a little like a trunked radio system, the kind your local police and fire departments quite likely use. When your local emergency worker presses the push-to-talk button, the radio politely asks a central server to assign it a frequency.

      The article is *really* short on technical details, and even confuses directionality with frequency assignment.

  9. BUZZWORD ALERT! BUZZWORD ALERT! by Dthoma · · Score: 3, Funny
    "These demonstrations will include demonstrating a low power/wideband spectrum sensor, time/frequency agile waveforms, and dynamic spectrum access and control."

    For all we know, this project description might actually MEAN something.

    --

    Note to M1-ers: a curt but otherwise insightful message is not "Flamebait" or "Troll".

  10. Personal Privacy... by Critical_ · · Score: 2, Interesting

    What people don't understand is that with the system used by Arraycomm allows better precision mapping of the wireless user. Sure, these days with our current cellular system we can triangulate a persons coordinates but this system could allows on-the-fly tracking since its built into the system. This is something for you privacy expertst to chew on.

    1. Re:Personal Privacy... by funky+womble · · Score: 2, Interesting
      Very easy with TDMA protocols, since timing is quite critical. The 'field engineer' menus on the average GSM phone will show the distance from the registered cell. All a network would have to do if there are multiple BSCs in range would be to bump from one to another and measure the response time on each to get a pretty accurate location.(Even with just two reachable in range you can tie down to one of two possible locations).

      Can be done with CDMA too but I suspect it's not so common (since unlike TDMA there are no timeslots to co-ordinate between different users).

      Pity the authorities don't make more use of this. If you ring the emergency services in the UK from a mobile phone, all the cellular operator passes on is the phone number you're calling from, not even the cell you're currently using. Could save a lot of time and trouble if they did.

      It's not all bad though. Location information can help prove you weren't somewhere just as easily as it can help prove you were somewhere!

      I don't think recording an _exact_ location is done as a matter of course, but it is common practice to keep track of the current registered cell (if only to save searching the whole network when there's an incoming call). In GSM the phones re-register periodically even if you don't switch cell so it's not uncommon to have the cell recorded every couple of hours.

  11. Isn't the military part of the problem? by Sanity · · Score: 2

    My understanding is that part of the problem in the US is that the military is hogging much of the radio spectrum, much more-so than the military in other countries.

    1. Re:Isn't the military part of the problem? by rossz · · Score: 2

      The U.S. military is also the military for a large number of other nations. Most of Europe could not field a decent army if their lives depended on it.

      --
      -- Will program for bandwidth
    2. Re:Isn't the military part of the problem? by Sanity · · Score: 2

      Europe doesn't maintain a large military because they don't need to, and if the US was smarter, they wouldn't need to waste their taxes on such things either. Hell, perhaps they might build a decent healthcare system instead. Which would you perfer?

  12. Spectrum Hogs by Detritus · · Score: 2

    You want to know is the biggest spectrum hog in the USA? The television broadcasting industry. We could recover huge amounts of spectrum if we killed over-the-air television distribution.

    --
    Mea navis aericumbens anguillis abundat
  13. frequency allocations by _ph1ux_ · · Score: 2

    I cant find a diagram showing how all the frequemcies are currently divided up. anyone havea link I can follow?

    We used to have a big poster of it on the wall at a VOIP company I worked at - know of an online version?

    1. Re:frequency allocations by mz001b · · Score: 5, Informative

      this link seems to actually work: http://www.ntia.doc.gov/osmhome/allochrt.html

    2. Re:frequency allocations by brer_rabbit · · Score: 2

      google image search found this one:

      http://www.jsc.mil/images/speccht.jpg

  14. Sounds interesting by hoytt · · Score: 2, Interesting

    So what they're trying to do if I understand it correctly is to get the location of the person using the mobile and only tansmit the signal in his direction, unlike the normal 360 degrees done by other systems. It sounds nice, if they can do it. It would mean a lot less 'un-needed' signals through the air. It's like using a satelite dish for an uplink to the satelite.

  15. Must be listening to George Gilder by John+Jorsett · · Score: 4, Insightful

    George Gilder has been talking about this for years. He gets your attention by making statements like, "available bandwidth is infinite." His basic point is that if the whole spectrum was available and if communicating entities continually adjusted their power levels and frequency to just what's necessary to communicate, the reuse of the spectrum could make it seem nearly infinite. I think he's probably right; I've seen some special radios designed on this principle, and their ability to communicate great distances with teensy power levels was nothing short of phenomenal.

  16. What? Use CW? by AX.25 · · Score: 2, Insightful

    After all it is bandwidth efficient and is the most effective in low signal to noise ratio applications.

    --
    What is pirate software? Software for inventory of stolen treasure?
  17. Not backward compatible. by DraconPern · · Score: 3, Insightful

    This technology may be good for a spectrum where all the devices have the 'sharing' capability, but how are they going to make existing spectrum like the wireless network 'dynamic' without making everyone buy new equipment?

  18. July 26, 1947 by totallygeek · · Score: 3, Informative
    You know that it is the Department of Defense's birthday? It is also the first day of the CIA.

    --
    Click here or here.
  19. But that's the point :-) by billstewart · · Score: 3
    The military *does* like spending money on new toys, and Darpa's job is partly to design lots of new toys. So why was it you thought that "making everyone buy new equipment" was bad? :-)

    Cynicism aside, though, a lot of their existing communications tools are really expensive, and use old technology or newer technology that's made extra-complex to retain compatibility with older technology, and new equipment made with new commercially-viable parts can be *much* less expensive, often less expensive than maintaining existing equipment. For a computer example, compare the cost of buying a 1GHz 256M RAM 20GB disk machine today (about $400) with the cost of replacing fixing your 486 (which used different memory technology, EGA video, 5.25" disk drives, backup tape drives, no CDROMs, etc.) In some cases, the military does need militarized equipment (throwing radios around in trucks and dropping them off airplanes can be a bit rough), but often it's cheaper to buy 10 commercial units and have 8 of them break.

    --

    Bill Stewart
    New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
    1. Re:But that's the point :-) by billstewart · · Score: 2
      Also sucks to not be carrying the MIL-SPEC ruggedized 5-pound GPS unit that only 5% of the soldiers are carrying because they're expensive and clunky - much better to be carrying the small cheap commercial version, and if it breaks, maybe your buddy's is still working. And it sucks even worse to be the guy flying the expensive surveillance plane getting shot at instead of the guy remotely operating a bunch of cheap drones even if they get shot down more.

      And remember all those M-16s jamming all the time in Nam? The commercial gun that the Army started with when they developed it was apparently much less likely to jam, but by the time it got kluged up into a more military-looking gun, it jammed more.

      --

      Bill Stewart
      New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
  20. This may help that problem by billstewart · · Score: 2

    If this program gets anywhere, it can help the military retire a bunch of the old equipment that's hogging lots of that spectrum, and replace it with more flexible stuff that's less expensive, and can reduce the extent to which they're blocking development of new technologies (ultrawideband, etc.) that might interfere with their hogged spectrum.

    --

    Bill Stewart
    New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
  21. DARPA != DoD by Cato · · Score: 2

    The DoD no doubt wastes a vast amount of money - however that has very little to do with DARPA, which is a research agency funded by the DoD. Of course, ARPANET came from DARPA and was the essential precursor to the Internet. In any case, the DoD has good reason to use spectrum more efficiently - the less spectrum each person uses, the more people can communicate with high-bandwidth data in the same limited chunk of spectrum.

    Efficient spectrum usage is probably more useful for civilian use, though - imagine thousands of people trying to meet up with friends at a football match. Typically, cell phones don't work at all well in such huge densities - efficient spectrum would help in this scenario.

  22. GSM is not very spectrum efficient by Cato · · Score: 3, Informative

    GSM does not make very efficient use of spectrum - while it is very handy to be able to use my GSM phone almost everywhere in the world, most GSM operators are having to upgrade to the CDMA-based UMTS (aka W-CDMA) in order to use spectrum more efficiently.

    GSM works well, but suggesting it as a solution for spectrum efficiency is quite bizarre, particularly when cdmaOne (used by Sprint PCS and Verizon in the US) is more spectrum-efficient.

  23. Software radio by Cato · · Score: 2

    You will need new kit, but real soon now it should be possible to implement 'software radio', in which you can download new software to implement whatever new radio interface someone has dreamt up. May take a few years, but in the longer term you could just download a GSM or UMTS module to your cell phone before travelling to Europe.