US telecommunications companies and air carriers have been fighting for weeks over the potential impact of 5G wireless services on aircraft safety. Elsewhere in the world, this issue has not been the subject of such intense public debate. That's why US phone operators Verizon and AT&T have very reluctantly agreed to delay the rollout of 5G wireless service by another 14 days.

• Why 5G could be a problem

The US government in early 2021 auctioned off for about 80 billion dollars the C-band (3.7-3.98 GHz frequencies) for 5G service intended for mobile phone companies. In the airline industry, altimeters operate on 4.2-4.4 GHz frequencies, so some manufacturers in the aviation industry and the Federal Aviation Administration (Faa) are concerned that the buffer between frequencies is too small, such that it could cause interference with aircraft instrumentation. This could cause problems during landing, especially if dangerous windshear currents are present. 

• Why frequency band is so important

Telecommunications operators want to operate at very high frequencies because the higher the spectrum power, the faster the service. So they want to get the most value out of 5G wireless internet service. So, in the US from now on there will be much more traffic in the C-band spectrum.

• The situation in other countries

In 2019, the European Union set standards for the mid-range 5G frequency band in the 3.4-3.8 GHz range that were auctioned off to the 27 member States. The European Aviation Safety Agency (Easa) in mid-December, commenting on the US dispute, said that so far "no risk of dangerous interference has been identified". As of 2019 in South Korea, the 5G mobile communication frequency is in the 3.42-3.7 GHz band, and since then there have been no reports of interference with radio waves from commercial mobile telephony. However, Faa officials pointed out that in France there is a larger buffer between commercial frequencies (3.6-3.8 GHz) and the spectrum used used for radio altimeters (4.2-4.4 GHz) than in the United States. 

On the same subject see also the article published by AVIONEWS.