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5G jamming GPS and radio altimeters

https://www.aopa.org/news-and-media/all-news/2020/may/07/protecting-gps-senators-grill-officials-on-ligado-network-plan

Just read this and wonder if anyone else has seen it and would care to comment? I have insufficient knowledge of radio to understand if there really is any possibility of these signals affecting GPS.

UK, United Kingdom

There’s not enough detail in there to know. It just says it’s L band, which is 500MHz to 1.5GHz. GPS also operates in the L band, but so do a lot of other things, including things like the amateur 23cm band (where in the USA, an amateur is free to transmit at 1500w of power, which is quite a lot).

The main issue is that if the service is harmonically related to a GPS signal (e.g. if it’s say 1/3rd or 1/2 the frequency of one of the GPS signals), and it’s strong, then the harmonics can be a problem (see issues with certain air band frequencies, their harmonics, and an aircraft’s on-board GPS).

Last Edited by alioth at 09 May 08:42
Andreas IOM

A firm called Lightsquared planned a network in the US with permission to use frequencies which conflicted with GPS. They were stopped.
So they’ve changed their name, but not the frequencies, and are trying again.

Last Edited by Maoraigh at 09 May 21:24
Maoraigh
EGPE, United Kingdom

The FCC is just a corrupt puppet for industry under this administration.

Kent, UK

A firm called Lightsquared planned a network in the US with permission to use frequencies which conflicted with GPS. They were stopped.
So they’ve changed their name, but not the frequencies, and are trying again.

And the same thing comes around

Administrator
Shoreham EGKA, United Kingdom
Administrator
Shoreham EGKA, United Kingdom

Radio altimeter jamming

It’s going to be good money for somebody to rip out all that expensive kit and replace it with even more expensive immune kit

Administrator
Shoreham EGKA, United Kingdom

Are there really radio altimeters out there with such a poor RF front end they’ll get de-sensed by signals that are (a) not harmonically related (b) over 200MHz away? (I guess some ancient kit might be)

Andreas IOM

Radio altimeters affected by wireless broadband networks in the 3700-3980 MHz bands

PDF

For the past 15 years, the 3 GHz band globally has been the subject of harmonization activity for mobile broadband, both at the International Telecommunication Union and within regional groups. A number of countries already have allocated and assigned spectrum for wireless deployments in the 3 GHz range and additional countries are following suit. Many countries around the world are already deploying wireless networks in the bands from 3300-4200 MHz; some countries have implemented temporary technical, regulatory and operational mitigations, including temporary proximity and power restrictions, on wireless broadband networks operating in bands ranging from 3700-4200 MHz. There have not yet been proven reports of harmful interference due to wireless broadband operations internationally, although this issue is continuing to be studied. In the United States, there has been wireless broadband deployment in the 3.65-3.7 GHz band since 2007. The FCC started a proceeding to authorize mobile broadband service in the 3.55-3.7 GHz band in December 2012 and adopted final rules in April 2015 and October 2018. Commercial deployment started in September 2019, with no known issues for altimeters to date.

Where are these 3.7-3.9GHz networks and what are they?

Administrator
Shoreham EGKA, United Kingdom

It’s related to 5G network using the 3.7-3.9GHz band.

ENVA, Norway
18 Posts
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