“It says Iridium terminals “will experience harmful interference” within 2,401 feet of Ligado terminals.”
Not half a mile. Not twenty-four hundred feet. No, the problem is within 2,401 feet precisely. Watch your step.
If I were a bad guy I’d buy a bunch of 5G systems and put them by (2,401’) anything I didn’t want GPS bombs dropped on.
Sparky
Russ:
Did you notice the part that said:
DoD and interagency partners conducted testing to determine the impacts to GPS
(captures FCC Order 20-48’s authorized deployment). The tests demonstrated that
the proposed signal introduces harmful interference to critical national security
mission capabilities.
The terrestrial network authorized by FCC Order 20-48 will create unacceptable
harmful interference for DoD missions. The mitigation techniques and other
regulatory provisions in FCC Order 20-48 are insufficient to protect national security
missions.
Yeah, you were only reporting on the civil part, but it looks like some more work to do that is germane.
Best
Vince
Somehow, I’m not reassured that “critical national security mission capabilities” depend on systems that can so easily be trashed by incidental out of band transmissions. What will we do when the enemy infantryman fires up his $13.95 battery powered on-frequency pocket jammer?
Dear Russ: What did they say about high precision GPS systems used in farming? The problem with using RF guardbands is signal lobes harmonics will be present upband and down band and that is the reason these guardbands were established in the first place. Legado and its defunct predecessor, LightSquared demonstrated that same approach. Nothing has changed. Terrestrial Demonstration Testing done at 1/10th power in Las Vegas disrupted GPS air navigation for nearly 1000 miles at altitude then. What has Legado done differently from Lightsquared and how has it been tested? It is my understanding that the same issues remain, and it is unlikely that the physics of RF generation and propagation have markedly changed since Phil Harbin first gave big bucks to Obama to get the original and since rejected FCC waivers necessary to use the very cheap spectrum he bought which is now Legado networks after he was shut down. Perhaps a more in depth survey would be useful: Like perhaps calling Garmin, King and others for their data and comments?
The report did specifically mention agriculture as one of the applications affected.
Oh, joy. Just when technology is developed to precisely and accurately spry, map, and evaluate my crops, along comes corporate greed to mess it up! No transmitter issues just one signal frequency. There are harmonics above and below the actual target frequency. A good design has these harmonics at a much lower power than the main, but they exist nonetheless. Transmitters then utilize filters to attenuate those unwanted signals. But, again, nothing is perfect. Signal strength decreases with the square of the distance increase, so obviously towers at a significant distance are no issue. But they are growing out of the earth like weeds - a VZW tower (type yet unknown) just appeared about 1,000 yds from my home - direct line of view. I have had paging services of years gone by “tramp” on my commercial two-way system. Took over three months and several calls ( and a threat to involve the FCC) to rectify the issue. Let’s hope for the best, in a guarded way!