The spectrum is different in Europe and might be one reason why there are fewer problems in Europe. And the aviation impact was taken into account. Deployment was more of a joint effort...

https://www.barrons.com/articles/5g-europe-airlines-51641398...

Europe Has 5G. Here Is Why It Hasn’t Messed Up the Airlines.

One thing is for sure: a green light for 5G in Europe doesn’t come from a lack of caution among regulators. After all, the European Union Aviation Safety Agency (EASA) last month warned about the potential risk of interference from 5G near airports—in the U.S.

The EASA said at the time that “no risk of unsafe interference has been identified in Europe.” Instead, the regulator cited the Federal Aviation Administration, which saw specific risk in the U.S. due to the implementation of potentially higher 5G ground station power emissions early this year.

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George Holmes, the chair and CEO of Resonant (RESN) a 5G industry player, told Barron’s that the difference between the U.S. and Europe stems from allocated frequencies for 5G, and their proximity to the defined band for altimeters.

Resonant is a Nasdaq-listed company that designs radio frequency filters, which are used to isolate signals from the right band while blocking unwanted noise from elsewhere in the radio spectrum. These filters are critical in 5G applications.

In the U.S., 5G is allocated to a range of between 3.7GHz and 3.98GHZ, which is closer to the 4.2GHz-4.4GHz frequency for altimeters than in Europe, which has allocated the 3.4GHz-3.8GHz range for 5G. Holmes said that in Europe altimeter filters will be better at stopping 5G signals, which will result in less potential interference.

https://edition.cnn.com/2022/01/19/business/5g-aviation-safe...

Europe rolled out 5G without hurting aviation. Here's how

Why is there a potential problem in the United States, but not Europe? It comes down to technical details.

Mobile phone companies in the United States are rolling out 5G service in a spectrum of radio waves with frequencies between 3.7 and 3.98 GHz. The companies paid the US government $81 billion in 2021 for the right to use those frequencies, known as the C-Band. But in Europe, 5G services use the slower 3.4 to 3.8 GHz range of spectrum.

The aviation industry is worried that US 5G service is too close to the spectrum used by radar altimeters, which is between 4.2 and 4.4 GHz. Europe does not face the same risk, according to the industry, because there is a much larger buffer between the spectrum used by radar altimeters and 5G.

What France did

There are other differences in how 5G is being rolled out, according to the US Federal Aviation Administration (FAA). Some countries are using lower power levels, restricting the placement of 5G antennas near airfields and requiring them to be tilted downward to limit potential interference with aircraft.

In France — cited by telecom carriers such as AT&T (T) and Verizon (VZ) as an example of 5G and aviation working seamlessly together — the height of a 5G antenna and the power of its signal determine how close it is allowed to a runway and the flight path of an aircraft, according to a technical note from France's National Frequency Agency (ANFR).

Antennas around 17 major French airports are also required to be tilted away from flight paths to minimize the risk of interference, the agency's director of spectrum planning and international affairs, Eric Fournier, told CNN.