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Yet More Tests Show LightSquared Interference
Two Government Agencies Join Concerned Chorus
The other day we noted that John Deere had joined the growing number of companies concerned with LightSquared LTE technology's interference with GPS signals, providing data showing significant interference as far as twenty-two miles away from a tower. Now both the National Space-Based PNT Advisory Board and the National PNT Engineering Forum have released tests that also suggest serious problems, specifically noting interference in the higher portion of LightSquared's spectrum bands and minimal GPS interference in the lower portions of of the spectrum. According to the National PNT Engineering forum, the problems could be avoided by moving LightSquared's planned LTE service to a different frequency band, limiting the service to the lower chunks of L-band spectrum it owns -- and installing filters on GPS receivers to reject or limit LightSquared transmissions.
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FFH5
Premium Member
join:2002-03-03
Tavistock NJ

FFH5

Premium Member

FCC fell down on the job once again

»www.fiercewireless.com/s ··· urce=rss
quote:
Carlisle said that in 2005, the FCC removed the limit on the number of base stations that could be deployed using MSS spectrum, and made the power limit the one that LightSquared is using. Several members of the Advisory Board said that the wider GPS community and GPS users in general had not been properly informed of the changes by the FCC, which is why the arguments over potential GPS interference only began to percolate last year. Carlisle conceded that the kind of GPS interference testing being conducted now could have been done six years ago.
Just another instance where the FCC has fallen down on their prime job - managing spectrum and making sure their is no interference. Instead they spend all their time trying to keep their White House masters happy.
gorehound
join:2009-06-19
Portland, ME

gorehound

Member

Re: FCC fell down on the job once again

they are pawns of the industry with no balls

N3OGH
Yo Soy Col. "Bat" Guano
Premium Member
join:2003-11-11
Philly burbs

N3OGH to FFH5

Premium Member

to FFH5
"GPS operations below elevations of 2,000 feet would be unavailable over a large radius of metro" areas for aircraft."

Oh boy, that's going to make those low visibility GPS/WAAS approaches, um what's the adjective I'm hunting for here? Thrilling! Yes, that's it. Thrilling.

The FCC shouldn't even be allowing these tests. It's clear to anyone with a basic knowledge of receiver characteristics that this is a hair brained scheme from the start.

Hopefully, it dies the same death BPL did...

ropeguru
Premium Member
join:2001-01-25
Mechanicsville, VA

ropeguru

Premium Member

Why should I...

and installing filters on GPS receivers to reject or limit LightSquared transmissions.

Why should I have to purchase a filter for my GPS in order to fix their inteference?

fsdf4342342f
@thvilledigital.net

fsdf4342342f

Anon

Re: Why should I...

Well because ALL gps manufactures knew this was going to happen since 2003.

They could of easily put filters on all of there gps and there would not be a problem.

TamaraB
Question The Current Paradigm
Premium Member
join:2000-11-08
Da Bronx
·Verizon FiOS
Ubiquiti NSM5
Synology RT2600ac
Apple AirPort Extreme (2013)

1 recommendation

TamaraB

Premium Member

Re: Why should I...

said by fsdf4342342f :

Well because ALL gps manufactures knew this was going to happen since 2003.

They could of easily put filters on all of there gps and there would not be a problem.

That's not the problem. L band spectrum was allocated to Satellite communications ONLY, where power levels are extremely low, and was supposed to remain that way. All design criteria was based on this fact.

The FCC issued Lightsquared a waiver to operate terrestrial transmitters, having a whoppingly higher power level in an environment in which it was never supposed to be allowed. Spurious emissions occur in all RF transmissions, and are LOW compared to the primary frequency, but when you start allowing high power transmitters to operate in what was supposed to be an extremely low-power band, those spurious signals become significant.

The FCC needs to pull the waiver, and never again allow this sort of thing to happen. Lightsquared needs to run their operations in a spectrum allocated for terrestrial use.

This is like allowing an elephant to roam around in a china shop, and thinking he won't break anything, even if he is a well behaved and docile elephant. The elephant needs to be kept in the zoo, and only dainty people allowed in the china shop.

Bob
rlharris02
join:2009-02-06

rlharris02

Member

Re: Why should I...

Things change and the usage of freq does as well.

If the gps companys work out these issues years ago this would not be a problem.

Yes, filters will work to solve the problem and all of the gps companies know this.
PDXPLT
join:2003-12-04
Banks, OR

PDXPLT to ropeguru

Member

to ropeguru
said by ropeguru:

and installing filters on GPS receivers to reject or limit LightSquared transmissions.

Why should I have to purchase a filter for my GPS in order to fix their inteference?

Because your cheap-ass GPS receiver is receiving signals from outside the GPS band; i.e., from the band allocated to Lightsquared. Lightsquared does not operate in the GPS band and is not interfering with GPS signals; it's GPS receivers that are receiving non-GPS band signals and are crying foul.

iLive4Fusion
Premium Member
join:2006-07-13

iLive4Fusion

Premium Member

Re: Why should I...

said by PDXPLT:

said by ropeguru:

and installing filters on GPS receivers to reject or limit LightSquared transmissions.

Why should I have to purchase a filter for my GPS in order to fix their inteference?

Because your cheap-ass GPS receiver is receiving signals from outside the GPS band; i.e., from the band allocated to Lightsquared. Lightsquared does not operate in the GPS band and is not interfering with GPS signals; it's GPS receivers that are receiving non-GPS band signals and are crying foul.

Just like those "Cheap Ass" multi-million dollar trunked Public Safety radio equipment was receiving interference from iDEN before the rebanding? Sounds more like an FCC mismanagement issue.
captnk
join:2001-03-07
Valparaiso, IN

captnk

Member

filter

How do you put a filter on a device with an internal antenna?

norbert26
Premium Member
join:2010-08-10
Warwick, RI

norbert26

Premium Member

Re: filter

said by captnk:

How do you put a filter on a device with an internal antenna?

you throw it in the landfill and buy a new one .

firephoto
Truth and reality matters
Premium Member
join:2003-03-18
Brewster, WA

firephoto

Premium Member

Re: filter

said by norbert26:

said by captnk:

How do you put a filter on a device with an internal antenna?

you throw it in the landfill and buy a new one .

"Thank you for shopping at Walmart. "
captnk
join:2001-03-07
Valparaiso, IN

captnk

Member

Re: filter

Does that include every cellphone with a GPS including my Droid?

FFH5
Premium Member
join:2002-03-03
Tavistock NJ

FFH5 to captnk

Premium Member

to captnk
said by captnk:

How do you put a filter on a device with an internal antenna?

And all those cars with built-in Nav systems are screwed. Somehow I doubt that a whole unit replacement will be something most car owners will want to pay for. Trash the built-in and buy a new portable that works with the new filters Lightsquared will force on consumer devices.
rlharris02
join:2009-02-06

rlharris02

Member

Re: filter

No one is forcing anything all of the GPS companys had years to fix there products.

iLive4Fusion
Premium Member
join:2006-07-13

iLive4Fusion

Premium Member

Re: filter

said by rlharris02:

No one is forcing anything all of the GPS companys had years to fix there products.

Well it's too late for that, and it's not going to be allowed to operate if it keeps interfering with E911 system's. Look's like Sprint going to have to build their own 4G for once.
HIPAR
join:2005-11-10
Tannersville, PA

1 recommendation

HIPAR

Member

Lets be practical

Cut this put a filter on crap. Our personal GPSs aren't the real issue. It's those aircraft GPS receivers worth tens of thousands of dollars that are already filtered as required to meet their operational requirements that are a real issue.

I don't care how history is being spun. For practical reasons, Lightsquared can't be allowed to trash GPS.

--- CHAS

JigglyWiggly
join:2009-07-12
Pleasanton, CA

JigglyWiggly

Member

Re: Lets be practical

This isn't really light squared's fault. Filters should just be put on GPS devices, or some shit.

Airplanes and stuff already have filters don't they? So what's the prob?
KKaWing
join:2007-06-14

KKaWing

Member

Re: Lets be practical

Problem is even with the filters being slightly off in an aircraft setting would cause you to fly into something. Unless you want ATCs to revert to the old ways and funnel everyone into even tighter airways with increased separation which leads to even more delays...
HIPAR
join:2005-11-10
Tannersville, PA

HIPAR to JigglyWiggly

Member

to JigglyWiggly
Please reread what I said. Let me try to say it in another way.

Lightsquared doesn't need to get past us and our cell phones or car navigators to operate. They need to get past the FAA. And there's the problem .. aircraft GPS is not cheap consumer class junk. The receivers are engineered to the most stringent standards. They are certified internationally for Safety of Life operations. They are already OPTIMIZED for their purpose and cannot be modified to operate in the proposed Lightsquared electromagnetic environment. There are 150,000 (plus) avionics receivers in service that will become useless.

I don't care whose 'fault' this is. There's no justice involved. Lightsquared cannot be allowed to trash installed equipments that's forming the basis for the next generation air traffic control system. That's just not practical.
rahvin112
join:2002-05-24
Sandy, UT

rahvin112

Member

Re: Lets be practical

Don't disregard the rest of the market and only consider the FAA. Yes there will be a major reduction in air flights and a corresponding massive increase in fares as the airlines lose 20% of flights and that's a serious issue. But there are several billion GPS receivers out there at would need to be trashed. I'm sure the CE industry would love that but telling everyone in the US they need to buy a new phone, vehicular GPS and basically replace every device in their homes that need GPS is not an insignificant request.

Add in the construction and surveying industry where there are probably several hundred billion dollars worth of high precision GPS equipment that would need to be trashed, the farming GPS systems that make large industrial scale farming operations possible that John Deere is complaining about and the hundreds of other industries that are now dependent on the signals along with the militaries ability to defend this nation and you aren't talking about a simple fix.

Regardless if this has been known about for 7 years, the FCC had the ability to test all these devices sold over the last 7 years to ensure they were compliant with interference. But either way, that doesn't excuse the fact that GPS receivers have been sold for several decades and even if you had filters on every GPS system in the last 7 years you are still talking about throwing out billions of dollars worth of existing equipment. And contrary to the statements on here I don't believe filters would solve this problem. There is a serious interference being generated with the Doppler effect the high precision GPS units use to increase their precision. That isn't something that filters can solve because they would simply filter out the Doppler effect thereby eliminating the high precision environment. Lightsquared trials should be canceled unless they can demonstrate a technology to get rid of the interference.

Unlike others I believe LightSquared should have been allowed the trial to demonstrate if they could avoid interference. The technology of RF has increased dramatically due to cellular research and it's still possible they might find a solution to the problem that doesn't involve throwing out every GPS receiver in the US. But if they can't demonstrate that they can solve the interference then the trials should be shut down and the temporary approval revoked. If the trials continue without the interference being addressed, personally I would like the Military to make a statement that any Lightsquared tower that is jamming GPS will get a precision guided munition dropped on it.

I simply can't believe anyone would think it's OK to suggest that every GPS device in the US would need to be replaced so some company can offer cellular service in a band that was never supposed to be for terrestrial use. Unless Lightsquared wants to pay for all those GPS receivers that is, but they better be prepared to come up with more money than they can imagine.

smackdabr
@gci.net

smackdabr

Anon

gps for timing?

I wonder if their LTE eqipment or backhaul is using GPS as a timing source. Its kind of ironic that the most accurate broadly used timing source for telecom equipment is GPS. Timing is everything and nothing will work without it being accurate.

Transmaster
Don't Blame Me I Voted For Bill and Opus
join:2001-06-20
Cheyenne, WY

Transmaster

Member

God What a bunch of Noobs

I see with some notable exceptions people who are clueless when it come to weak signal reception especially in the frequencies GPS uses. Filters will not work any band pass filter used will reduce the sensitivity of a pocket GPS unit this might be the difference between being able to report the position of a person located in a rural area who is injured and either his phone is unable to report his position or the rescue worker will be unable to report his position when a victim is found. This is BPL all over again. A bunch of people who could careless about how a frequency band is used all they care about is being able to tweet their sweeties.
HIPAR
join:2005-11-10
Tannersville, PA

HIPAR to smackdabr

Member

to smackdabr

Re: gps for timing?

There are methods proposed to synchronize a network via timing packets sent through the ground infrastructure.

(symmetricom)

--- CHAS

WHT
join:2010-03-26
Rosston, TX

WHT

Member

The Goal Posts Got Moved

Yes, the GPS community knew there was a potential for interference, they also knew FCC rules didn't allow terrestrial use. They built a GPS culture based on that spectrum use assumption. And the comes along the FCC granting a waiver to their rules - the goal posts were moved.

The carriers that spent billions of dollars on the spectrum auctions must be having a cow over this....BUT you don't see AT&T, Verizon, et al anguishing over this. That leads to the question, why? Could it be it's an untapped resource for backhauls?
jfmezei
Premium Member
join:2007-01-03
Pointe-Claire, QC

jfmezei

Premium Member

Current GPS apps rely on accuracy. Can't mess with it.

When Bill Clinton ordered the military to stop Selective Availability (purposeful degrading of GPS accuracy), the GPS industry grew by leaps and bounds due to all the new applications (such as car GPS) that were now possible.

Allowing interference in the GPS bands is akin to re-instating SA and making a whole bunch of GPS applications no longer trustable.

If you will expect everyone to update their GPS units, then Lighsquared should be told to wait 5 to 10 years before it can light up its towers to give people time to upgrade.

But it only takes one care with unupgraded GPS to cause an accident in a city because the car drive was told to turn left into a one way street instead of waiting 200m further to turn into the right street.

kerriskandie
join:2001-10-09
Coram, NY

kerriskandie

Member

Re: Current GPS apps rely on accuracy. Can't mess with it.

...and then I WILL own LightSquared???
Cool....................
tmc8080
join:2004-04-24
Brooklyn, NY

tmc8080

Member

how bad really?

Is this any worse than Broadband over Powerlines (BPL)?

Transmaster
Don't Blame Me I Voted For Bill and Opus
join:2001-06-20
Cheyenne, WY

Transmaster

Member

Re: how bad really?

said by tmc8080:

Is this any worse than Broadband over Powerlines (BPL)?

The Arguments for it are sure the same. There equipment is old, they need to get a life, things change, we need _______ (fill in the blank) Bla-Bla-Bla. So what if an Air Ambulance fails to find accident scene and a victim dies because of the delay, who cares if a 911 call from a wireless phone that normally can report it's position can't and a child calling for help disappears. A team of hotshot wildfire fighters dies because the Fire boss looses track of where they are and does not get them out of a dangerous area in time. No it is more important for people to be able to "Weiner" over their smart phones no matter where they are.
scubatime
join:2011-06-14
New Orleans, LA

scubatime

Member

GPS interference

I don't get the LTE GPS interference. The military uses GPS for weapons targeting and they are not going to give this up at any cost.
UncleDave
join:2009-01-08
Florissant, CO

UncleDave

Member

Re: GPS interference

I have just completed a trip from Colorado Springs to Bolder CO. Going through Denver on I 25, about a mile South of the Mile High Stadium my GPS lost it's mind. I can see problems in the country where it really does not matter, but in the middle of a major city? Driving a 55, and loss of navigation is a little disconcerting. Sort of like having the engine go wide open, or the Breaks fail. Been there, and done it. I have seen this in a post someplace. Would be nice to be able to report this, but to whom? I have tried to report things to the National Highway Traffic Safety, and was told to wait until some one dies, and then call.

DHLawry@gmail.com