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How The FCC Plans To Destroy GPS – A Simple Explanation

166 points by bwsd 16y ago

rit 16y ago
While an interesting article which does a good job of breaking down the technical details AND citing industry, it doesn't seem to me the FCC is "Planning to destroy GPS". This sounds a lot more like the FCC not entirely understanding the ramifications of what they approved and/or a company trying to take advantage of licensing loopholes which have unforeseen consequences. Yes, the FCC fucked up here but it isn't time to bring out the tin foil hats yet.
- InclinedPlane 16y ago
  This isn't just a clerical error, this is the very reason the FCC exists at all. This would be like the FDA accidentally approving a new drug that gave everyone in a 1 block radius cancer.
  - lukeschlather 16y ago
    Not at all. It's like the FDA approving a drug with a 100 mg /day dose, and a company rolling out a plan for 200 mg /day dose, and trying to convince the FDA that 200 mg is safe. Unless they actually get approval for 200 mg, they're not going to be able to ship.
    - roc 16y ago
      And continuing the metaphor: having the FDA say "If your self-funded trials say it's Ok, then we're satisfied". The funny part is, some times, that's how the FDA does work. That's how we wound up with all those depression drugs that were only as effective as a placebo.
mih 16y ago
Would this affect the upcoming Galileo platform too? Does it use similar frequencies?
- oigftrgtyh 16y ago
  Yes if you could actually get Galileo receivers ! Galileo changed the frequency to be slightly different to GPS to allow selectively blocking one or the other - but it's still close enough for this to interfere.
riordan 16y ago
Meanwhile, the FCC's enforcement chief just put out a press release decrying cell/GPS jammers saying they "create safety risks". http://www.fcc.gov/Daily_Releases/Daily_Business/2011/db0209/DOC-304575A1.pdf http://www.fcc.gov/Daily_Releases/Daily_Business/2011/db0209...
- derleth 16y ago
  Well, they do: Doctors and other medical professionals have come to rely on cell phones to be notified of emergencies quickly enough to save lives. If they are blocked, there's a realistic chance lives will be lost for no good reason. (I've never heard of a good reason to block cell phone transmissions. It always seems to come down to trying to enforce some vision of politeness via technical means, which doesn't take considerate cell phone usage into account at all.)
  - X-Istence 16y ago
    This is why it should be possible for theatres and the like to set up alternate base stations that cell phones connect to, this way 911 calls and text messages incoming may still be delivered but no incoming/outgoing calls may be connected.
    - derleth 16y ago
      In the scenario I'm describing, the doctor is going to the theater when they get a call from the hospital saying there's someone there who needs their skill. (It's actually in their contract that, while they're on-call, they have to remain within a certain amount of travel time from the hospital so they can get there in time. This does affect home purchases.) If their cell phone is blocked, the call is missed and someone may very well die. You could (presumably) attempt to fix this with technology. It might even work for a while, but when it breaks, someone could very easily die. And they'd have died of someone else's dislike for cell phones, which is not a good reason.
machrider 16y ago
Doesn't the military still rely heavily on GPS? I have a hard time believing they'd tolerate any kind of interference with such a crucial system.
- oigftrgtyh 16y ago
  Yes - without it's operation many senior members of staff would be forced to learn map reading to find their way around Washington (or at least their drivers would)
- hcurtiss 16y ago
  I believe M-code also operates on 1227.6 (L2). According to wikipedia, they do still use 1575.42 (L1). http://en.wikipedia.org/wiki/GPS_signals#Frequencies_used_by_GPS http://en.wikipedia.org/wiki/GPS_signals#Frequencies_used_by...
Kadin 16y ago
Ugh, c'mon, people. The FCC isn't planning to destroy GPS. I hate the FCC as much as the next guy on the Internet, but that's too ridiculous for consideration. What they're trying to do is balance the legitimate right that one user has to a piece of spectrum, with the legitimate right that a lot of users have to some that's adjacent. They'd be looking at nothing but an endless series of lawsuits if they told LightSquared that they couldn't use their spectrum (which they have a license to), particularly since LightSquared has a proposal which -- yes, on paper, but what's on paper matters -- says they'll not interfere with GPS. It looks much more like the FCC is giving LightSquared an opportunity, either to show that they can make the system workable, or to come up with enough rope to hang themselves, one way or the other. If LightSquared can't resolve the interference issues, then the FCC will have a much better case for an enforcement action than they currently do. (Although an enforcement action might require a rule change, because it's not clear that they would actually be in violation of the rules; front-end overload is typically the receiver's problem, not the transmitter's.) I'm all for spectrum users being vigilant, and perhaps GPS users need an organization analogous to the ARRL (which protects the Amateur Radio spectrum, and successfully defeated the shitty BPL implementations that were kicking around a few years ago) to nip these things in the bud. But the conspiracy-theorizing is a bit rich.
- oigftrgtyh 16y ago
  Has the FCC ever bothered to actually go after people that abuse bits of the spectrum? Wardrobe malfunctions they are right on top of - but anything that requires technical knowledge seems to escape them. GPS does have a group that protects it's users - I believe it's called the USAF.
  - trafficlight 16y ago
    A few years back, a local WISP (in Montana) was shutdown because they were breaking the Part 15 power rule in several markets. Their custom made radios were putting out over 5 watts EIRP, when the maximum legal limit is 1 watt. It took the FCC several years to get out here, but they did do it.
  - kpeel 16y ago
iwwr 16y ago
Google cache link: http://webcache.googleusercontent.com/search?q=cache:I2iCQGcQ3YUJ:freegeographytools.com/2011/how-the-fcc-plans-to-destroy-gps-a-simple-explanation+http://freegeographytools.com/2011/how-the-fcc-plans-to-destroy-gps-a-simple-explanation http://webcache.googleusercontent.com/search?q=cache:I2iCQGc...
marshray 16y ago
It's possible the LightSquared transmitters will be far more directional than the Garmin test gives them credit for. They may not run full power all the time anyway. Regardless, it's generally the responsibility of the receiver to ignore signals in another part of the same band, and this is a different band entirely. Perhaps some receivers are built as cheaply as possible and don't have the best filters. If they all break, well, their customers should know not to trust that brand again. Any other policy amounts to no one ever being able to establish new radio service on its own part of the spectrum, on the theory that some other defective other equipment might fall over. Personally, I think it's far more interesting the prospect of having a network of 20,000 steerable-beam transmitters approved for 15KW ERP each at 1.5GHz. 300MW is about half the output of a typical electrical power plant. If those were networked that could make one hell of an antisatellite weapon, phased-array radar illuminator, or maybe even an SDI-type directed energy weapon. If the military isn't behind this, well they should be. <conspiracy theory>Maybe that's why the FCC is fast tracking it so much.</conspiracy theory>
- jbri 16y ago
  It's the responsibility of the receiver to ignore signals transmitted at appropriate power levels, yes. The receiver is not required to be overengineered to cope with transmissions vastly more powerful than expected - that's why limits on broadcast power exist in the first place.
  - marshray 16y ago
    OK I see it now. It looks like everything in that adjacent band had previously been designated space-to-earth. I suppose it would be reasonable for an engineer to assume a receiver is not going to end up within a few KM of a 15 KW transmitter at those frequencies.
    - X-Istence 16y ago
      At high power you can overpower adjacent frequencies wether you have good band filtering on it or not. For example a 2 Watt FM transmitter at 100 Mhz can easily overpower radio's tuned to 95 Mhz just because of its power, even with the appropriate filtering.
wickedchicken 16y ago
I thought GPS was spread spectrum which would make it resistant to these kinds of interference? After all, GPS satellites broadcast at the same frequency as each other, that's the genius of how GPS works.
- X-Istence 16y ago
  By the time the GPS signal reaches earth it is at a very low power, think milliwatts. Lets think of it as you trying to eavesdrop on a meeting. You have your ear pressed on a big thick wooden door that lets very little sound through, you are attempting to hear so you have everything around you very quiet and try your best to hear that very faint sound of your boss talking about the companies plan to fire everyone. Now your co-worker just a cubicle down is on the phone and instead of keeping it down is talking very loudly. It doesn't matter how hard you try to listen for the sound from inside the meeting all you can hear is your co-worker. Now think of your boss in the meeting as the GPS satellites and your co-worker as this new company. Unfortunately when it comes to transmitting power, the more you have of it the more likely you are to overpower other signals. This is the same issue that FM transmitters have as mentioned in the article. Unless we put better band filters on GPS devices and attempt to filter out a very high power signal GPS is going to get lost in the signal that is being transmitted from the ground.
  - derobert 16y ago
    GPS signal strength at Earth's surface is -130dBmW, so that'd be attowatts... A GPS satellite capable of 0dBmW would be truly scary; it'd have about a petawatt of electrical supply. See, e.g., http://gpsinformation.net/main/gpspower.htm http://gpsinformation.net/main/gpspower.htm
fuzzmeister 16y ago
Has the FAA said anything about this? I would hope that they would be concerned about the impact on aviation GPS.
crikli 16y ago
I'm a licensed (technically "certificated") private pilot and this is article is bullocks. Aviation, both general and commercial, relies increasingly on GPS integrated avionics to navigate the rigidly defined airspace that instrument rated pilots refer to as "the system." GPS has become so prevalent that the decades old method of navigation using VOR (VHF omnidirectional frequency) radials is going the way of that which came before it, ADF ("Automatic" Direction Finder). Even the smelly old 1965 Piper Cherokee I fly sometimes has a Garmin GPS unit in it. The guy that taught me to fly has a 1947 Cessna 140 with a GPS unit. It's become ubiquitous in general aviation and is a de-facto requirement in commercial aviation. GPS isn't going anywhere because it's too crucial to one of the major facets of the national transportation system.
- marshray 16y ago
  Perhaps you can explain why the FCC is granting this license/waiver even in the face of vehement opposition from a broad collection of GPS manufacturers and aviation groups? http://licensing.fcc.gov/cgi-bin/ws.exe/prod/ib/forms/reports/related_filing.hts?f_key=-216679&f_number=SATMOD2010111800239 http://licensing.fcc.gov/cgi-bin/ws.exe/prod/ib/forms/report...
  - crikli 16y ago
    The opposition was vehement, yes, but limited to strongly worded letters from (mostly) small general aviation companies. No Boeings, no American Airlines, no 'big guns' with be-suited lawyers to make the FCC wake up and smell the jet fuel. Wait until a couple airliners go missed on RNAV GPS approaches in low IFR conditions (visibility < 1 mile or cloud ceilings at less than 500 feet). The airlines will raise hell, the FAA will get involved and that'll be all she wrote.
    - marshray 16y ago
      I think this company is a customer of Boeing's. Boeing builds their satellites. As for the airlines, they are so heavily regulated that they might think twice about filing official comments on stuff like this without permission. No doubt FAA and FCC are talking about this even if it's not official. Their offices are only a few blocks away.
jrockway 16y ago
I'm looking forward to a VOR/DME receiver in my phone to make up for the loss of GPS.
Dramatize 16y ago
That site looks pretty spammy. You sure this isn't just an attempt to build links?
jcr 16y ago
(sigh) The article was written by an alarmist moron trying to push his own agenda, and most likely, pushing it for his own profit. The only real problem is GPS equipment manufacturers intentionally cut corners and costs by FAILING to implement proper bandpass filters. When the LightSquared towers get turned on, and customers who bought incorrectly designed garbage from the likes of Garmin, the result will be simple: The equipment makers will get sued in massive class action law suits for selling broken equipment. And yes, the manufacturers deserved to be sued for cutting corners on bandpass filters and selling junk since THEY HAVE ALWAYS KNOWN the adjacent spectrum frequencies could be used at any time.

166 points by bwsd 16y ago

rit 16y ago

While an interesting article which does a good job of breaking down the technical details AND citing industry, it doesn't seem to me the FCC is "Planning to destroy GPS". This sounds a lot more like the FCC not entirely understanding the ramifications of what they approved and/or a company trying to take advantage of licensing loopholes which have unforeseen consequences. Yes, the FCC fucked up here but it isn't time to bring out the tin foil hats yet.

InclinedPlane 16y ago
This isn't just a clerical error, this is the very reason the FCC exists at all. This would be like the FDA accidentally approving a new drug that gave everyone in a 1 block radius cancer.
- lukeschlather 16y ago
  Not at all. It's like the FDA approving a drug with a 100 mg /day dose, and a company rolling out a plan for 200 mg /day dose, and trying to convince the FDA that 200 mg is safe. Unless they actually get approval for 200 mg, they're not going to be able to ship.
  - roc 16y ago
    And continuing the metaphor: having the FDA say "If your self-funded trials say it's Ok, then we're satisfied". The funny part is, some times, that's how the FDA does work. That's how we wound up with all those depression drugs that were only as effective as a placebo.

mih 16y ago

Would this affect the upcoming Galileo platform too? Does it use similar frequencies?

oigftrgtyh 16y ago
Yes if you could actually get Galileo receivers ! Galileo changed the frequency to be slightly different to GPS to allow selectively blocking one or the other - but it's still close enough for this to interfere.

riordan 16y ago

Meanwhile, the FCC's enforcement chief just put out a press release decrying cell/GPS jammers saying they "create safety risks". http://www.fcc.gov/Daily_Releases/Daily_Business/2011/db0209/DOC-304575A1.pdf http://www.fcc.gov/Daily_Releases/Daily_Business/2011/db0209...

derleth 16y ago
Well, they do: Doctors and other medical professionals have come to rely on cell phones to be notified of emergencies quickly enough to save lives. If they are blocked, there's a realistic chance lives will be lost for no good reason. (I've never heard of a good reason to block cell phone transmissions. It always seems to come down to trying to enforce some vision of politeness via technical means, which doesn't take considerate cell phone usage into account at all.)
- X-Istence 16y ago
  This is why it should be possible for theatres and the like to set up alternate base stations that cell phones connect to, this way 911 calls and text messages incoming may still be delivered but no incoming/outgoing calls may be connected.
  - derleth 16y ago
    In the scenario I'm describing, the doctor is going to the theater when they get a call from the hospital saying there's someone there who needs their skill. (It's actually in their contract that, while they're on-call, they have to remain within a certain amount of travel time from the hospital so they can get there in time. This does affect home purchases.) If their cell phone is blocked, the call is missed and someone may very well die. You could (presumably) attempt to fix this with technology. It might even work for a while, but when it breaks, someone could very easily die. And they'd have died of someone else's dislike for cell phones, which is not a good reason.

machrider 16y ago

Doesn't the military still rely heavily on GPS? I have a hard time believing they'd tolerate any kind of interference with such a crucial system.

oigftrgtyh 16y ago
Yes - without it's operation many senior members of staff would be forced to learn map reading to find their way around Washington (or at least their drivers would)
hcurtiss 16y ago
I believe M-code also operates on 1227.6 (L2). According to wikipedia, they do still use 1575.42 (L1). http://en.wikipedia.org/wiki/GPS_signals#Frequencies_used_by_GPS http://en.wikipedia.org/wiki/GPS_signals#Frequencies_used_by...

Kadin 16y ago

Ugh, c'mon, people. The FCC isn't planning to destroy GPS. I hate the FCC as much as the next guy on the Internet, but that's too ridiculous for consideration. What they're trying to do is balance the legitimate right that one user has to a piece of spectrum, with the legitimate right that a lot of users have to some that's adjacent. They'd be looking at nothing but an endless series of lawsuits if they told LightSquared that they couldn't use their spectrum (which they have a license to), particularly since LightSquared has a proposal which -- yes, on paper, but what's on paper matters -- says they'll not interfere with GPS. It looks much more like the FCC is giving LightSquared an opportunity, either to show that they can make the system workable, or to come up with enough rope to hang themselves, one way or the other. If LightSquared can't resolve the interference issues, then the FCC will have a much better case for an enforcement action than they currently do. (Although an enforcement action might require a rule change, because it's not clear that they would actually be in violation of the rules; front-end overload is typically the receiver's problem, not the transmitter's.) I'm all for spectrum users being vigilant, and perhaps GPS users need an organization analogous to the ARRL (which protects the Amateur Radio spectrum, and successfully defeated the shitty BPL implementations that were kicking around a few years ago) to nip these things in the bud. But the conspiracy-theorizing is a bit rich.

oigftrgtyh 16y ago
Has the FCC ever bothered to actually go after people that abuse bits of the spectrum? Wardrobe malfunctions they are right on top of - but anything that requires technical knowledge seems to escape them. GPS does have a group that protects it's users - I believe it's called the USAF.
- trafficlight 16y ago
  A few years back, a local WISP (in Montana) was shutdown because they were breaking the Part 15 power rule in several markets. Their custom made radios were putting out over 5 watts EIRP, when the maximum legal limit is 1 watt. It took the FCC several years to get out here, but they did do it.
- kpeel 16y ago

iwwr 16y ago

Google cache link: http://webcache.googleusercontent.com/search?q=cache:I2iCQGcQ3YUJ:freegeographytools.com/2011/how-the-fcc-plans-to-destroy-gps-a-simple-explanation+http://freegeographytools.com/2011/how-the-fcc-plans-to-destroy-gps-a-simple-explanation http://webcache.googleusercontent.com/search?q=cache:I2iCQGc...

marshray 16y ago

It's possible the LightSquared transmitters will be far more directional than the Garmin test gives them credit for. They may not run full power all the time anyway. Regardless, it's generally the responsibility of the receiver to ignore signals in another part of the same band, and this is a different band entirely. Perhaps some receivers are built as cheaply as possible and don't have the best filters. If they all break, well, their customers should know not to trust that brand again. Any other policy amounts to no one ever being able to establish new radio service on its own part of the spectrum, on the theory that some other defective other equipment might fall over. Personally, I think it's far more interesting the prospect of having a network of 20,000 steerable-beam transmitters approved for 15KW ERP each at 1.5GHz. 300MW is about half the output of a typical electrical power plant. If those were networked that could make one hell of an antisatellite weapon, phased-array radar illuminator, or maybe even an SDI-type directed energy weapon. If the military isn't behind this, well they should be. <conspiracy theory>Maybe that's why the FCC is fast tracking it so much.</conspiracy theory>

jbri 16y ago
It's the responsibility of the receiver to ignore signals transmitted at appropriate power levels, yes. The receiver is not required to be overengineered to cope with transmissions vastly more powerful than expected - that's why limits on broadcast power exist in the first place.
- marshray 16y ago
  OK I see it now. It looks like everything in that adjacent band had previously been designated space-to-earth. I suppose it would be reasonable for an engineer to assume a receiver is not going to end up within a few KM of a 15 KW transmitter at those frequencies.
  - X-Istence 16y ago
    At high power you can overpower adjacent frequencies wether you have good band filtering on it or not. For example a 2 Watt FM transmitter at 100 Mhz can easily overpower radio's tuned to 95 Mhz just because of its power, even with the appropriate filtering.

wickedchicken 16y ago

I thought GPS was spread spectrum which would make it resistant to these kinds of interference? After all, GPS satellites broadcast at the same frequency as each other, that's the genius of how GPS works.

X-Istence 16y ago
By the time the GPS signal reaches earth it is at a very low power, think milliwatts. Lets think of it as you trying to eavesdrop on a meeting. You have your ear pressed on a big thick wooden door that lets very little sound through, you are attempting to hear so you have everything around you very quiet and try your best to hear that very faint sound of your boss talking about the companies plan to fire everyone. Now your co-worker just a cubicle down is on the phone and instead of keeping it down is talking very loudly. It doesn't matter how hard you try to listen for the sound from inside the meeting all you can hear is your co-worker. Now think of your boss in the meeting as the GPS satellites and your co-worker as this new company. Unfortunately when it comes to transmitting power, the more you have of it the more likely you are to overpower other signals. This is the same issue that FM transmitters have as mentioned in the article. Unless we put better band filters on GPS devices and attempt to filter out a very high power signal GPS is going to get lost in the signal that is being transmitted from the ground.
- derobert 16y ago
  GPS signal strength at Earth's surface is -130dBmW, so that'd be attowatts... A GPS satellite capable of 0dBmW would be truly scary; it'd have about a petawatt of electrical supply. See, e.g., http://gpsinformation.net/main/gpspower.htm http://gpsinformation.net/main/gpspower.htm

fuzzmeister 16y ago

Has the FAA said anything about this? I would hope that they would be concerned about the impact on aviation GPS.

crikli 16y ago

I'm a licensed (technically "certificated") private pilot and this is article is bullocks. Aviation, both general and commercial, relies increasingly on GPS integrated avionics to navigate the rigidly defined airspace that instrument rated pilots refer to as "the system." GPS has become so prevalent that the decades old method of navigation using VOR (VHF omnidirectional frequency) radials is going the way of that which came before it, ADF ("Automatic" Direction Finder). Even the smelly old 1965 Piper Cherokee I fly sometimes has a Garmin GPS unit in it. The guy that taught me to fly has a 1947 Cessna 140 with a GPS unit. It's become ubiquitous in general aviation and is a de-facto requirement in commercial aviation. GPS isn't going anywhere because it's too crucial to one of the major facets of the national transportation system.

marshray 16y ago
Perhaps you can explain why the FCC is granting this license/waiver even in the face of vehement opposition from a broad collection of GPS manufacturers and aviation groups? http://licensing.fcc.gov/cgi-bin/ws.exe/prod/ib/forms/reports/related_filing.hts?f_key=-216679&f_number=SATMOD2010111800239 http://licensing.fcc.gov/cgi-bin/ws.exe/prod/ib/forms/report...
- crikli 16y ago
  The opposition was vehement, yes, but limited to strongly worded letters from (mostly) small general aviation companies. No Boeings, no American Airlines, no 'big guns' with be-suited lawyers to make the FCC wake up and smell the jet fuel. Wait until a couple airliners go missed on RNAV GPS approaches in low IFR conditions (visibility < 1 mile or cloud ceilings at less than 500 feet). The airlines will raise hell, the FAA will get involved and that'll be all she wrote.
  - marshray 16y ago
    I think this company is a customer of Boeing's. Boeing builds their satellites. As for the airlines, they are so heavily regulated that they might think twice about filing official comments on stuff like this without permission. No doubt FAA and FCC are talking about this even if it's not official. Their offices are only a few blocks away.

jrockway 16y ago

I'm looking forward to a VOR/DME receiver in my phone to make up for the loss of GPS.

Dramatize 16y ago

That site looks pretty spammy. You sure this isn't just an attempt to build links?

jcr 16y ago

(sigh) The article was written by an alarmist moron trying to push his own agenda, and most likely, pushing it for his own profit. The only real problem is GPS equipment manufacturers intentionally cut corners and costs by FAILING to implement proper bandpass filters. When the LightSquared towers get turned on, and customers who bought incorrectly designed garbage from the likes of Garmin, the result will be simple: The equipment makers will get sued in massive class action law suits for selling broken equipment. And yes, the manufacturers deserved to be sued for cutting corners on bandpass filters and selling junk since THEY HAVE ALWAYS KNOWN the adjacent spectrum frequencies could be used at any time.