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Wireless Networking

FCC Bars Lightsquared From Using Airwaves 178

Posted by Unknown Lamer
from the lightsquared-disputes-laws-of-physics dept.
New submitter mc6809e writes with news that Lightsquared might have just been killed. From the article: "A proposed wireless broadband network that would provide voice and Internet service using airwaves once reserved for satellite-telephone transmissions should be shelved because it interferes with GPS technology, the Federal Communications Commission said Tuesday. The news appears to squash the near-term hopes for the network pushed by LightSquared, a Virginia company that is majority-owned by Philip Falcone, a New York hedge fund manager." LightSquared, naturally, continues to deny that the interference is real.
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FCC Bars Lightsquared From Using Airwaves

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  • by neokushan (932374)

    It's my understanding* that Lightsquared's equipment was never the issue, but rather the GPS equipment that got interference were just poorly designed. If the GPS equipment was held to the standards it should have been, Lightsquared's equipment wouldn't have interfered. Yet Lightsquared are the ones being shafted, simply because GPS is "too important". Really, the FCC and/or the GPS equipment manufacturer should be the ones being penalised. FCC beucase it's their job to look after this sort of thing and the

    • by Anon E. Muss (808473) on Wednesday February 15, 2012 @10:09AM (#39043817)

      Really, the FCC and/or the GPS equipment manufacturer should be the ones being penalised.

      As a practical matter, there's no way to do that. If you allow Lightspeed to operate, you penalize the USERS of the (allegedly) badly designed GPS devices. It does suck to be Lightspeed, because GPS really is much more important than them.

      • by smpoole7 (1467717) on Wednesday February 15, 2012 @10:36AM (#39044157) Homepage

        > you penalize the USERS of the (allegedly) badly designed GPS devices

        I maintain a 50,000 watt AM and two 100,000 watt FMs, and we get interference complaints all the time. The only fair rule for EVERYONE involved is to say, "as long as I'm following the terms of my license, and I'm SURE that my transmitter isn't putting out unwanted products, there's nothing I can do."

        I'm friendly; I offer tips and suggest filters; I help if I can. But there's really not much I can do if they have a cheap radio. Am I "penalizing" them for buying a $20 table radio from WalMart? I don't think so.

        You say "allegedly," but believe me, some of the cheap Chinese junk (albeit with good-sounding American brand names) being sold now isn't worth the money to crush and melt it. I would be astonished if the same isn't true of GPS equipment.

        • by Megane (129182) on Wednesday February 15, 2012 @11:07AM (#39044541) Homepage

          And what if someone decided to operate a station on an adjacent frequency channel, with 10 megawatts of power? Or even half a channel over? (Rules? What rules? We just want a little variance in the rules!) Then suddenly people trying to receive your station get interference because the channel separation rules weren't designed for that kind of power on adjacent channels? The problem isn't "badly designed GPS devices", it's that this is a band which was allocated specifically for the purpose of satellite communication, which is by its very nature rather low-powered to begin with.

          I'm almost surprised it took this long, except I'm sure there has been some ohbummer-related political interference going on behind the scenes. And it's probably still going on even now.

        • by farnz (625056) <slashdot AT farnz DOT org DOT uk> on Wednesday February 15, 2012 @11:32AM (#39044901) Homepage Journal

          And that's where the debate lies. LightSquared's license permits them two uses of the frequencies licensed:

          1. For satellite to earth communication, provided they ensure that the transmissions from the satellite do not leak out of their licensed bands.
          2. As a later waiver, made after the spectrum was initially licensed: For earth to earth and earth to space communication, provided that they ensure that their earth-based transmitters do not interfere with earth-based receivers designed to pick up satellite to earth transmissions in neighbouring bands.

          LightSquared's argument is that they have met the second term of their license if they ensure that their earth-based transmitters do not leak out of their licensed bands, even if they interfere with licensed users of neighbouring bands; note that the FCC has been clear that one way to meet the second requirement is to replace receivers of the neighbouring bands with ones that cope with your interference, an option LS has rejected as impractical, as they cannot find affordable receivers that have both the GPS abilities of the receivers they're replacing and better rejection of LS's signals.

        • The thing is that terms of Lightspeed's license is that they demonstrate that they do not interfere with those GPS devices.
          If those complaints came from people who had bought those radios before you got those licenses and your license stipulated that you not interfere with their reception of other radio stations then your situation would be different.
        • by CompMD (522020) on Wednesday February 15, 2012 @12:35PM (#39045655)

          You understand radio a bit it seems. Here's what you're ignoring though, so follow me here: a high-precision GPS receiver must pick up signal at -165 dBm. This is right about at the noise floor. Its incredibly easy to cause interference with a receiver that must operate with these conditions, and incredibly difficult to design a filter that would actually be useful. You're talking about transmitters with 10^5 W output interfering with other transmitters in the same class. Its apples and oranges.

        • by sjames (1099) on Wednesday February 15, 2012 @01:22PM (#39046311) Homepage

          I'll bet you're not operating a terrestrial transmitter in a band that is restricted to satellite downlink are you? If you did, you would be shut down, and rightfully so.

          The GPS gear was designed to operate adequately within the environment the FCC promised they would be in. LS begged the FCC to go back on that promise and was given every chance to demonstrate that it wouldn't cause a problem for any existing application. They failed to prove their case. End of story. Note that the FCC was under no obligation to even give them a chance to prove their case, they were entitled to just give them a flat NO.

    • by ZaMoose (24734) on Wednesday February 15, 2012 @10:10AM (#39043825)

      The last time /. discussed this, it was pointed out that the spectrum L^2 was aiming for was intended for low-power satellite signals and was never intended to be used for (relatively) powerful ground stations. They were essentially trying to buy spectrum on-the-cheap and then repurpose it in a way that was virtually guaranteed to interfere with adjacent spectrum. So, while GPS devices could certainly be better-designed, this was more an incident of L^2 trying to abuse the system.

      Physics, alas, makes for a harsh mistress.

      • Re: (Score:2, Funny)

        by Anonymous Coward

        Physics, alas, makes for a harsh mistress.

        Yeah, but that's because Physics is a old, hairy dude.

        • Physics, alas, makes for a harsh mistress.

          Yeah, but that's because Physics is a old, hairy dude.

          ?

          Physics has to be a really curvy woman.

      • by poetmatt (793785)

        Yes, lightsquared was taking advantage of the system. Absolutely. While it's not ethical, that kind of crap is pretty much legal in the states.

        so it becomes a competitive question here - why aren't GPS devices better designed? why isn't L2 trying to avoid neighboring spectrum? etc. It's no longer "L2's fault" but both - to imply L2 when you acknowledge both have an issue (manufacturing to specs should be regulated by the FCC and isn't, yet FCC is regulating Lightsquared) is to focus on one side of the issue

        • by Zcar (756484) on Wednesday February 15, 2012 @11:21AM (#39044759)

          so it becomes a competitive question here - why aren't GPS devices better designed?

          Because they were engineered with the constraints of their band in mind. If the rules of the band are such that you don't need to worry about a powerful signal on an adjacent frequency, designing a filter to deal with such an adjacent signal is unnecessary expense.

      • by Deadstick (535032) on Wednesday February 15, 2012 @11:34AM (#39044917)

        L2 made one big mistake. Stepping on a lot of toes? No biggie, happens all the time. Stepping on toes that are in a building with five sides? Might want to think about that.

        • i wonder what are the nearest .mil bases to lightsquareds headquarters??

          Oh gee im sorry but we seem to have had a navigation error

    • According to this article: [sail-world.com]

      One of the MSS (mobile satellite service) bands involved is just below the GPS L1 band used by commercial GPS units. The FCC has authorized use of this band for terrestrial cellular services since 2003 .

      Now there is some dispute about details of the early FCC decisions and how many base stations were allowed under them, but it is clear that base stations were allowed next to the GPS band since 2003 and that the civil GPS supplier community paid little attention to the fact that G

      • by tixxit (1107127) on Wednesday February 15, 2012 @10:51AM (#39044347)

        According to the actual 2003 decision by the FCC:

        Today we decide to permit flexibility in the delivery of communications by Mobile Satellite Service (MSS) providers [cut]. Specifically, we permit MSS licensees to integrate ancillary terrestrial components (ATCs) into their MSS networks

        ...

        We will authorize MSS ATC subject to conditions that ensure that the added terrestrial component remains ancillary to the principal MSS offering. We do not intend, nor will we permit, the terrestrial component to become a stand-alone service.

        That is, the decision was to let those offering mobile satellite services the ability to enhance their networks. This guy wanted to create a stand-alone cell phone network, which was explicitly not permitted in the 2003 decision.

    • by foo1752 (555890)

      I know that it is probably too much to ask, but if you had read some of the letter from the NTIA, they specifically mention that there are no performance standards for GPS equipment to be compared against. That is, no one ever told manufacturers of GPS equipment that they had to deal with so much interference in neighboring frequency bands. The result of this may be that some standards are developed, but that does nothing for the huge installed base of GPS receivers.

    • by FireFury03 (653718) <slashdot&nexusuk,org> on Wednesday February 15, 2012 @10:13AM (#39043887) Homepage

      It's my understanding* that Lightsquared's equipment was never the issue, but rather the GPS equipment that got interference were just poorly designed. If the GPS equipment was held to the standards it should have been, Lightsquared's equipment wouldn't have interfered. Yet Lightsquared are the ones being shafted, simply because GPS is "too important".

      That's not quite true. LS basically bought up a *satellite* band and tried to repurpose it for ground communications. It was then discovered that doing this caused some GPS equipment to malfunction. Whether or not you consider this GPS equipment to be "poorly designed", the fact remains that it was working absolutely fine for decades and LS's attempts to repurpose the ajacent band causes it to stop working. Expecting millions of GPS users to upgrade their GPS receivers just because LS wants to repurpose an existing band for a new use is ridiculous. On the other hand, if LS wants to buy shiny new GPS receivers for all these end-users...

      So no, LS isn't "being shafted" - they purchased a satellite band with the intention of using it for ground communications, rather than its existing use, badgered the FCC into letting them repurpose it and then cried when it was found that this repurposing wasn't compatable with millions of existing devices.

    • by heypete (60671) <pete@heypete.com> on Wednesday February 15, 2012 @10:14AM (#39043899) Homepage

      GPS receivers (and the filters in their electronics) were built with the assumption that neighboring frequencies would be used by other space-to-ground uses, and thus would have comparable signal strengths (that is, very low).

      Having ground-based stations blasting out signals that are brazillions of times more powerful than the weak space-to-ground signals on adjacent frequencies would overwhelm the relatively weak signal from GPS. Filters that can allow the weak GPS signals through while blocking out the immensely more powerful signals on neighboring frequencies would be bulky and expensive. Devices not equipped with those specialized filters (that is, essentially every GPS receiver ever made) would be screwed.

      I'm sure that if LightSquared wanted to use the frequencies they acquired for space-to-ground uses, the FCC would have very little trouble with it and the potential for interference with GPS would be essentially nil. Instead, LightSquared purchased (leased? I'm nowhere near an expert on this kind of thing.) these frequencies at a cheap price due to their being intended for space-to-ground use and was trying to change their classification to use them for ground-based transmitters (thus saving LightSquared tons of money acquiring spectrum). They gambled big and (rightfully) lost.

      Reliable GPS service is more important than the communication network LightSquared proposed, particularly in regards to safe navigation for aircraft and vessels.

      • Re: (Score:3, Interesting)

        by kaiser423 (828989)
        Don't forget that in response to LightSquared, DirectTV and pretty much every single company that owns satellite to ground spectrum was filing for similar waivers essentially re-purposing satellite communications to ground-base communications and creating the potential for satellite apocalypse as it becomes thousands of times harder to communicate with *all* satellites, effecting weather, hurricane, tsunami forecasting, early warning systems, satTV and radio, etc, etc. GPS/LightSquared was the proxy war fo
      • Having ground-based stations blasting out signals that are brazillions of times more powerful than the weak space-to-ground signals on adjacent frequencies would overwhelm the relatively weak signal from GPS.

        Can I just say how much I like the term 'brazillion'? I'm going to start using now. Sorry to be OT. The rest of your argument is sound and I'd mod you up if I had the points today.

    • by msauve (701917) on Wednesday February 15, 2012 @10:14AM (#39043901)
      Not quite. The spectrum adjacent to GPS frequencies was authorized for for use with other satellite services, which obviously have a very low signal level. GPS receivers were designed with that in mind. That's not unreasonable, in the real world there's no such thing as a perfect filter with vertical skirts.

      Lightsquared "bought" this spectrum, much cheaper than similar spectrum allocated for terrestrial use. They then fast tracked a petition through the FCC to get authorized to use that spectrum terrestrially. The problem is, that produces much stronger signals than GPS receivers were designed to deal with.

      If Lightsquared were to use the spectrum as originally intended, there would be no issue. Instead, they want to have their cake, and eat it too, by paying for relatively low cost satellite spectrum, but using it for terrestrial transmitters.
    • by worip (1463581) on Wednesday February 15, 2012 @10:15AM (#39043927)
      Actually, the spectrum was never intended for terrestrial use at all. Lightsquared applied for an exemption to apply the spectrum for terrestrial use, but they had to prove that it did not intefere with GPS. Most RF engineers would have told you that they where doomed from the start to fail, as the physics does not allow you to do this. All RF equipment have to contend with a thing call adjacent channel rejection - i.e. whilst tuned to its own channel a device must reject inteference from channels adjacent to its own by using a bandpass filter. Bandpass filters are not perfect (i.e. it is not a brickwall) and some interference always leaks through. The specific issue here is that the terrestrial signal would have been so large compared to the signal received from the GPS sattelite that the bandpass filters would have been unable to suppress the signal in the adjacent channel. This is akin to someone shouting in your ear, while you are trying to listing to someone whispering 20meters away.
      • by shentino (1139071)

        Where GPS is a politically entrenched industry with the FCC in their pockets, which gives them a long leash to hog all the spectral elbow room they can get away with.

        GPS saw nothing but tumbleweeds, so it let itself go with lax filtering, and now it's "too big to fail" when LS shows up trying to move in next door.

        • Actually GPS knew there was a regulatory requirement for "nothing but tumbleweeds" and designed their systems according to said regulatory requirement. The adjacent spectrum was also marked for satellite transmission. There was no reason for GPS manufacturers to assume that suddenly there would be powerful terrestrial transmitters sitting next door, as they were told the adjacent frequency bands would be used for similar low power signals.

          Imagine you need to build a very loud factory. You go buy a parcel

        • What does this have to do with politics? GPS operates in a satellite band, and the surrounding traffic is also supposed to be satellite. It is perfectly proper for GPS makers to design their filters around their expectations for surrounding traffic. It would have just been needless complexity and expense for zero end-user benefit to design them tighter.

          If I build my house in the middle of nowhere surrounded by farmland, peace, and quiet, you can damn sure I'm going to protest when somebody tries to re-zo

        • by DeadCatX2 (950953)

          Some engineer did their homework. They decided to create a filter with the necessary -dB/octave roll-off needed to deal with the signals that could be expected in the real world.

          In the real world, signals of the power that LightSquared wants to use were illegal at the time the GPS device was manufactured. As in, violators go to federal pound-me-in-the-ass prison.

          So how, exactly, are their filters "lax", if they were designed to deal with the maximum power signals that were legal at the time of design?

    • by darkstar949 (697933) on Wednesday February 15, 2012 @10:18AM (#39043963)
      This has been coming up over on Ars Technica for awhile now and the explanation isn't so much that the GPS equipment is poorly designed but rather that Lighsquared is trying to use the spectrum in a way that it was not licensed to do so in. In short, the spectrum that they licensed is for low power satellite communications (i.e. GPS) and they want to use the same spectrum but to increase the power at which they broadcast it up to normal terrestrial levels. At that point the common analogy is that it is like trying to tell the color of a flashlight from a couple miles away: once you spot it you can tell when the color changes, but if someone comes along and places a high power search light next to it, the flashlight will drown out by the power of the other light source.

      Also, don't forget that radio signals aren't prefect pathways either and you can be broadcasting on one frequency and have it bleed over into another frequency. This is why radio stations and television channels are allocated in such a way that they aren't directly next to each other (think radio channel 100 and 100.1).

      So in summary, this isn't an equipment problem but a physics problem: making the equipment better isn't going to help the fact that the signal would be drown out if Lighsquared were to broadcast on a satellite channel at terrestrial power levels.
      • by fuzzyfuzzyfungus (1223518) on Wednesday February 15, 2012 @10:38AM (#39044179) Journal
        One wonders if Lightsquared thought that they had a good chance of pulling this off, either through technological optimism or confidence in their legal team(For whatever reason "Rural broadband!!!" appears to be the FCC's root password) or if this was some sort of long-odds/high-rewards gamble by the hedge fund chap...

        On the one hand, being able to convert a swath of satellite-to-ground spectrum into ground-ground spectrum would be crazy valuable, and likely result in some very nice returns. On the other, trying to go up against the now-firmly-entrenched users of GPS(ie. almost everybody) is a risky move indeed.

        Did they miscalculate the odds, or were they happy to take very bad odds for the possibility of extremely high returns?
      • by hamburger lady (218108) on Wednesday February 15, 2012 @10:40AM (#39044205)

        it's more like getting a permit to open a bar next door to an observatory but the city strictly requires you to keep your outdoor lighting to a minimum so as not to disturb the telescope next door. yet you still put up a huge neon sign and searchlight and when the observatory complains that your light pollution has ruined its ability to gather data, you say 'it's not my fault your telescope sucks'.

        • by Anonymous Coward

          http://www.archive.org/details/XMinus1_A [archive.org]

          It was done in 1950's pulp sci-fi. Casinos operated near observatory and the casino firework shows prevented observatory from taking good pictures. Casinos paid politicians, so the observatory was left in the cold. The observatory then started offering "readings based on the stars" for free to tourists, and started singling out a casino a week as "bad luck" for the tourist until that casino stopped the fireworks. It was a pretty good story 60 years ago and stands

    • by vlm (69642)

      rather the GPS equipment that got interference were just poorly designed. If the GPS equipment was held to the standards it should have been,

      Blatantly false. Ask your closest EE to run the numbers. The numbers are utterly insane. You need something like multiple superconducting resonant cavities to pull this off. IF you were willing to ten-tuple the size of your cellphone and include a liquid helium fill port and dewar then it'll work, just fine. At least the liq He dewar will stop the phone from physically heating up as you talk on it.

      Also they were very well designed to operate within and around a satellite to ground transmission band. P

    • For better or worse, it is generally the case that Legacy Systems Win.

      Outside of some limited consumer markets, or the occasional dramatic(and generally traumatic) forklift upgrade of some gigantic institutional system(usually still leaves a screen-scraper connected to the old system that everybody politely doesn't talk about hidden somewhere...), the clout of Stuff That Already Works is enormous compared to that of Stuff that Might Be Cool.

      If it were merely a matter of forcing Garmin into a class act
    • by RoboRay (735839)

      Your understanding is not correct. Had Lightsquared sought to use the satellite-only restricted band they bought for a satellite-based system, they would have been fine. Instead, they bought use of a satellite-only restricted band (which was cheap, because it's not useable for terrestrial-based transmitters, so nobody else really wanted it) and wanted to use it for a terrestrial-based system.

      ALL RF transmissions affect nearby bands, not just those the transmitter is intended to use. While it's trivial fo

    • by hairyfeet (841228)

      You seem to be missing the point that the ONLY reason LS was able to get this chunk of the spectrum in the first places was for SAT communications NOT ground, and if LS would have stuck to that frankly there wouldn't be a problem. Its not the fault of the FCC that LS decided they couldn't make a go of it in the business plan they had originally agreed to, they should have to sell the spectrum they bought to someone else or stick with the original agreement. Frankly it doesn't matter what the GPS OEMs did or

    • It is the opposite, kind of.

      Lightsquared's spectrum was meant for satellite, but wanted to use it as a primarily terrestrial communication spectrum. The GPS and Lightsquard's spectrums were setup assuming they were originating from satellites, and under those conditions shouldn't impede each other. GPS units, shoddy or not, were having trouble with bleed over from a signal far, far closer than ever intended to be.

      Lightsquard isn't blameless. They wanted to do similar to what they were accusing the GPS man

    • by neokushan (932374)

      Based on the additional comments, I stand very much corrected. Looks like this was a LS blunder after all.

    • by sjames (1099)

      No. Lightsquared knowingly bought a bit of low value spectrum that had a rather strong limitation placed on it. They knew about that limitation going in to the deal.

      They then tried to greatly expand the value of their spectrum by seeking a special exemption. They were given every chance to show that the restriction was unnecessary, but failed to do so. For that reason, the restriction stands.

      The GPS equipment designers designed for cost and performance knowing that that restriction was in place. They design

    • by garry_g (106621)

      Please read up on the issue ... the frequency L^2 purchased were always licensed for satellite-to-ground communication, which would have been fine for L^2 to do. But in order to get better coverage in dense areas like cities, they planed on putting up earth-based relay stations, which would have drowned out any adjacent frequency band ... I read a comparison somewhere where the regular communication was compared to a regular light bulb in orbit, say 100W ... while it's already hard to see by itself, now ima

    • by riverat1 (1048260)

      GPS uses a very low power signal from the orbiting satellites. Trying to add filters for the Lightsquared band to that would reduce the signal strength even more. Lightsquared's signals would have been terrestrial in origin and 100 times the signal strength of the the GPS signal. It's just not a workable combination.

  • by Anonymous Coward on Wednesday February 15, 2012 @10:08AM (#39043803)

    The FCC made a good and wise decision in this situation.

    It is unrealistic to expect the desires of a company which wants
    only to make money should override the safety of a public
    which depends increasingly on GPS.

  • by Tekfactory (937086) on Wednesday February 15, 2012 @10:12AM (#39043859) Homepage

    I mean if it gives you broadband, voice and blocks GPS guided missiles, what more could you want?

  • by vlm (69642) on Wednesday February 15, 2012 @10:16AM (#39043935)

    "A proposed wireless broadband network that would provide voice and Internet service using airwaves once reserved for satellite-telephone transmissions should be shelved because it interferes with GPS technology, the Federal Communications Commission said Tuesday

    That's a massive simplification. They sell mobile satellite internet, and have done so for a long time, and will do so into the indeterminate future, this has nothing to do with that.

    The LS idea was to provide a backend carrier to local on ground cellular providers for internet traffic. Same as your off the shelf 3G service you now "enjoy" but instead of your greedy provider paying AT&T (or whoever) for fiber to the cell phone tower, they'd use the satellite service.

    Except... they didn't have an allocation for their ground network. Hmm. What if we reuse the satellite freqs, yeah that'll work. Well, except that the would ruin/destroy/eliminate the possibility of anyone on the ground hearing the satellites without a huge dish or technically impossible filtering. OK no problemo we'll dump all our satellite customers and focus on the ground guys, and use the marketing for satellite "as if" we're not a ground 3G provider. Whoops that'll kill all the adjacent satellite services too. Oh Oh, GPS is adjacent.

    Well, so much for that bad idea.

    Note there is no reason that instead of paying AT&T for fiber to a cell tower in the middle of nowhere, LS can't provide slow and high latency service RIGHT NOW to that cell tower... this FCC bar only stops them from setting up their own tower and using the satellite freqs to set up something like a 3G service.

    The standard /. car analogy is this is kind of like getting rid of the SUV exception where hyper obese ultra low MPG passenger cars are permitted under the legal fiction they are classified as trucks not cars. That takes care of the analogy "why the F are they installing 100 watt ground transmitters on an allocation for satellite transmitters only?". Or maybe a better analogy is LS thought it would be fun to build a network of hydrogen fueling stations, and figured no one would have any problem if they used an off the shelf gasoline filling nozzle instead of a technically correct solution that would not result in an infinite number of burnout fires. That takes care of the analogy "why the F are they installing 100 watt ground transmitters right next to satellite receivers and even daydreaming that won't knock out the receivers".

  • Wasn't one of the stated goals of Lightsquared to help little companies compete with the big telcoms on the wireless broadband and mobile phone service fronts? If that's the case, I suspect way more was involved here than just GPS interference.

    • by CompMD (522020)

      Big telcoms? They are puny compared to who Lightsquared was really pissing off. Lightsquared was screwing with the primary user of GPS, which is the USAF, which has an arsenal of nuclear weapons. I think they are somewhat scarier (and more important) than Sprint.

  • Why am I surprised that some rich Wall St prick thinks like all other spoilt Wall St pricks, and thinks that they are exempt from the rules that everyone else is subjected to, and try and get one over everyone else so he can get even more obscenely rich than he is.

    I hope that prick Philip Falcone gets bankrupted for his hubris, and learns some morals and a little humility.

  • We do need to utilize these spectrums.

    I think what we have here is another example of why business and politics don't mix. Falcone tried to shmooze his way through the system by budding up to the administration and it backfired by creating enemies.

    I don't know if his tech is causing a problem or if it's all a big conspiracy to shut him down. It doesn't matter. He assumed he would pass inspection before the fact because he knew all the right people. He had made no preparation for rejection and that was stupi

  • by tsj5j (1159013) on Wednesday February 15, 2012 @10:26AM (#39044037)

    The article seems to gloss over the most critical point that breaks this deal, painting LightSquared as a victim in the process:

    LightSquared's spectrum (which was bought from another company) was for SATELLITE transmissions, not TERRESTRIAL.
    Satellite spectrums are much cheaper, but can't be used for terrestrial transmissions.
    LightSquared is in fact trying to cheap out by using a cheaper spectrum.

    Analogy:
    LightSquared tried to buy a plot of cheap residential land to start a chemical/manufacturing plant, which affects nearby residents.
    They should have bought a piece of commercial land that supports their requirements.

    More technically:
    Satellite signals are weak as they are sent from huge distances from satellites with limited power. To receive these signals, the receivers must be tuned to be sensitive to these signals. If LightSquare were to transmit terrestrially from the bordering spectrum (to pass through walls and what-have-you), the transmitted strength will be thousands of times stronger than the GPS signals, invariably causing interference with GPS signals. Even if GPSes are built with a filter (which they shouldn't need to, the nearby spectrums should also be weak signals!), it would be prohibitively expensive/unfeasible to filter the strong terrestrial signals.

    • by vlm (69642)

      Analogy:
      LightSquared tried to buy a plot of cheap residential land to start a chemical/manufacturing plant, which affects nearby residents.
      They should have bought a piece of commercial land that supports their requirements.

      /. car analogy: They bought property zoned for slot car racing tracks surrounded by residential. Then they said, forget this slot car stuff I'm building a full scale 1000 horsepower indy car / f1 / nascar track and they line up billions of bucks of investment for viewer stands, pork rind fryers, and network broadcast contracts. Then add a dose of blame the victim, those residents complaining about the full size race track being installed in a slot car zoned property should have known better when they mov

  • when space gets populated
  • The thing is GPS technology is in tons of random electronics. Since GPS satellites are essentially transmit their identification and an accurate time, GPS is used to keep time in everything from ATMs to our power grid to consumer "atomic" clocks.

    Cellphones also use GPS signals to triangulate their position on earth, so that they can connect to the nearest tower with minimal power. This is more FCC doing its real job, protecting everyone from this interference shit.
    • by Megane (129182)

      GPS is used to keep time in everything from ATMs to our power grid to consumer "atomic" clocks.

      WTF? WWV [wikipedia.org]

      And why the hell would ATMs need a radio signal to keep time?

      I am so facepalmed from that completely wrong statement that I'm going to need surgery to remove my hand from my face.

      • by ruinevil (852677)
        No idea why ATMs need GPS, but... some went offline when the US Navy was playing with their jammer off the coast of San Diego, CA, USA. Link [newscientist.com]
      • by ruinevil (852677)
        Also Radio Clocks

        Nothing uses your silly 1950s technology, since shortwave receivers are vastly more expensive than GPS receivers due to economy of scale, and also less accurate. Welcome to the 21st century.
  • If the currently allocated bandwidth has proven to cause interference to other services, pick a different band of frequencies to use. They'll have to modify their equipment and I'm sure that will be expensive but if they have the capital to do it, I wouldn't rule them dead just yet.

    • The equipment design is the easy part; the problem is spectrum scarcity. LightSquared bought up a bunch of cheap satellite spectrum with the idea of using it for a vastly more valuable terrestrial network. While they DO have the capital to change their equipment to use a different band, they DON'T have the capital to actually purchase that band.

  • by thrich81 (1357561) on Wednesday February 15, 2012 @11:10AM (#39044595)

    Does it appear to anyone else that at least half the Lightspeed defenders must be paid shills for the company? Think about it -- GPS has been around for 20+ years and is considered a utility now, the facts of Lightspeed's purchase of the spectrum (only intended for satellite use) are not in question, and neither is the physics of humongously strong signals next to a band where the signals are below the noise floor. And, who gets all excited about some company's spectrum license unless have a vested interest -- it's not usually of much general interest. I'd like to be proved wrong so I can continue to trust he integrity of sites like /. but I'd say , "Reader beware".

    • Doh, where is the /. edit or delete function? Anyway, yes I meant, "Lightsquared". And I realize that this is sort of an ad hominem attack which is not what I really meant either, but my basic question remains.

    • Re: (Score:2, Interesting)

      by bill_mcgonigle (4333) *

      neither is the physics of humongously strong signals next to a band where the signals are below the noise floor

      Sometimes Slashdotters only see the technical arguments. Lightsquared has a somewhat-valid technical argument - if GPS receivers are intended to work on only one band they should take precautionary measures to reject potential interference from neighboring bands.

      But, this was never a problem before, so nobody who makes civilian GPS receivers bothered to do so (I presume milspec receivers have dece

      • Re: (Score:2, Informative)

        by Anonymous Coward

        Sometimes Slashdotters only see the technical arguments. Lightsquared has a somewhat-valid technical argument - if GPS receivers are intended to work on only one band they should take precautionary measures to reject potential interference from neighboring bands.

        That's not really a valid technical argument. The GPS receivers can very well reject the adjacent bands of relatively equal or slightly greater signal levels. LightSquared is essentially turning the technical details upside down by trying to use the band liscensed for non-terrstrial use for terrestial use.

        But, this was never a problem before, so nobody who makes civilian GPS receivers bothered to do so (I presume milspec receivers have decent filters).

        LightSquared interferance will actually have more impact on high precision devices. Those high precision devices need their high precision. Additional filtering for better sideband rejection can result in

      • by phliar (87116)

        Except that if you add the filtering to GPS receivers so they can reject that billions of times stronger Lightsquared signal in the adjacent band, there would be no GPS in your phone. In fact no handheld GPS receivers. Not to mention turning most of the installed base of GPS receivers into doorstops.

        The whole point is that satellite signals are really weak, so we put all the satellite frequencies together and keep terrestrial broadcasters out. That's also why satellite frequencies are cheaper than terrestri

        • add the filtering to GPS receivers so they can reject that billions of times stronger Lightsquared signal in the adjacent band, there would be no GPS in your phone

          So, it's not possible to filter out signals that narrowly? Or does some of the 'adjacent' RF inevitably leak over into the GPS bands?

  • ,quote>LightSquared, naturally, continues to deny that the interference is real.

    Cue the Interference Deniers in 3...2...1...

  • The FCC loves bribes [techdirt.com]. Of course Lightsquared's threat to the telecoms was going to fail. Any idiot could see that from the start.

    Anyone who threatens incumbent telecoms will be demonized as puppy kickers and grandmother harassers, guaranteed.

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