system

Nothing to see here. This is just the FCC punting this rusty can of dogfood down the road a little bit. With the resignation of Ajit Pai last week, the commission is split 50-50 politically, so they did the least they had to, to get it off their agenda temporarily.

Spectrum interference is awfully hard to prove one way or the other without experimental data. But I suspect that the DoD has something to contribute here; they’ve been running NOTAMed GPS-denial tests for several years along the Atlantic coast and around various military installations.

The onus is on Legato to prove a negative. Given the wide range in quality of commercial GPS receivers, from IoT widgets to watches to phones to TSO’d panels, that’s going to be expensive. Let them spend their investment banker money (again) now that they don’t have any friends on Pennsylvania Ave. and maybe it will make the next round of angels think twice.

system

They ran (as Lightsquared/Phil Harbin) tests in the southwest at low power and disrupted GPS service at FL180 for 1400 nm. That’s what killed it the first time. We have RF propagation physics, and experimental proof the system cannot work. On one hand, it is the FCC’s fault: they should never have auctioned the guardbands off in the first place. Now, this ugly situation will float from bankruptcy to bankruptcy.

Do not underestimate the greed of an investment banker nor overestimate the length of their memories. Harbin thought he’d clean up when the spectrum auctioned off dirt cheap compared to legitimate, serviceable frequencies. Gifts were given to white house occupants an schmoozing was done in the early 2010 timeframe. He was allowed to proceed, and when it failed, suggested we put rf tanks the size of the airplanes on GPS receivers because they were “unlicensed” applications to block out their sideband transmissions. Now, Legato repeats history.

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system

This issue showcases – with sad clarity – how illogical, inefficient and political Governmental bureaucracies can be … and commonly are. GPS has become as important to every day living as the electrical, water and other essential infrastructures. We can no longer live without it. Just now – on ‘Modern Marvels’ – they’re showcasing GPS as one of the top 10 technological innovations of the last generation. So why we’d be seeing such ridiculously petty actions by multiple Agencies with different parochial interests is borderline criminal. And we the tax payers are paying these people handsome salaries … sigh!

Twenty + years ago, I bought an airplane with a Northstar LORAN installed. On the ferry home, I fell in love with it because I discovered it had two processors inside such that you could easily find a point in 2-D space with one box. I even bought some spares (not realizing LORAN was slated for shutdown). One model even had an auxiliary GPS option to increase accuracy and response time. At the time, GPS was coming out of its infancy becoming commonplace and trustworthy. The President had ordered SA turned off so the need for LAAS went away in favor of WAAS. Suddenly, some bean counting bureaucrats decided we didn’t need LORAN any longer. To save a few millions of dollars, a perfect backup to GPS was shut down. The Coast Guard realized it was a mistake and organized a coalition of people trying to save LORAN but it didn’t work. Suddenly, that wonderful box was a boat anchor weighing down my airplane when – for VFR flight, at least – it was perfectly usable. My point being that there was an emergency backup to GPS if nothing else. Now here we are just a few decades later and another Governmental Agency is betting the full house that there won’t be any interoperability or interference issues between these 5G and GPS technologies. Who’s on first? What’s on second? What’ll these people come up with next to prove how short sighted they really are?

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John_B

I can’t help but to recall a few years back, when I had a high-band commercial frequency for my business (152.900), that a paging service began to step all over our calls, effectively blocking us every time they transmitted. Turned out that their transmitter was drifting. I identified them, called them, and it got better - for a short time. After the fourth occurrence, I threatened FCC intervention, and the issue never returned. For me, it was an inconvenience. For navigation, that situation could become deadly. Just a thought.

system

Art,
You correctly identify the problem, IMO. The sale of the spectrum was an error.

You then go on to insult investment bankers. Was that reflexive, or is there more to the story? I’m in no habit of defending said group because as a group they’ve gone overboard, but in this case you admit they were ripped off.

I blame government. If you can’t set up a system for selling off the spectrum, and then deal with the mistakes you make within a DECADE, all the while playing CYA at the victim’s expense, you ought not be in the business of governing (and those bureaucrats are in business the second they realized they had a “career” rather than just a job).

bucc5062

I was under the impression that the back up to GPS for aviation was VOR:

" The FAA’s network of Distance Measuring Equipment (DME) NAVAIDs will provide a PBN-capable backup to GPS; however, for aircraft without scanning DME receivers (DD) or DD with Inertial Reference Unit aiding (DDI) equipment, the FAA will provide a conventional navigation backup service based on the VOR MON".

This is what happens at times with technology. You bank on one thing but the population or industries go another. One example, Beta vs VHS and let’s not get started on digital media changes.

Put it another way, I’d rather have the Government establish the standards for navigation and let private industry finds the means to exploit it then leave the whole thing to capitalism for in the latter you might find that the LORAN receiver you bought on the east coast may not have worked on the west (Yes that can happen, think geo-blocking on netflix).

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system

And what about ADS-B that everyone was forced to buy. If GPS signals get jammed due to this spectrum sale, it would make ADS-B inop, turning that equipment into boat anchors just like LORAN receivers. The FAA would be back to the previous radar surveillance system of traffic management.

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system

Justin … my point was that in the SPECIFIC airplane I had purchased (and many other people had similar installations then), I had a perfectly usable near GPS performance box installed that a bean counter turned obsolete despite a specific other branch of Government – the USCG – was trying to save. And “Inertial Reference Unit !” Are you kidding? Who with a Class I aircraft ever had that?

I’m perfectly aware that the current plan for a MON will likely work for a day or two if the GPS constellation was taken out but – long term – LORAN coulda been a backup. And lets not JUST think about aviation … what about ships?

system

Precisely, Matt !! Just imagine the havoc that will ensue if GPS signals become blocked. Elsewhere on Avweb this week, they’re talking about a municipal wastewater treatment facility’s instrumentation system causing local disruption at the adjacent airport. Now multiply that times … everything that depends upon GPS. The MON will only get the few IFR airplanes down safe … then what.