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While the deployment of new frequency bands should normally take place in the United States on January 19, a dozen carriers are asking the American government for a new postponement for the installation of powerful relay antennas in the immediate vicinity of the tarmacs. Interview.
US airlines fear that the deployment of new services from the communications giants will bring chaos to the skies. The aviation safety agency, the FAA, seeks to allay these concerns, without announcing concrete measures. US carriers are right to be concerned, says Xavier Tytelman, aviation consultant for Aviation NXT.
RFI: 3.7-3.8 GHz frequency bands were allocated in particular to AT&T and Verizon in February 2021 following a call for tenders worth several tens of billions of dollars. Since then, American carriers have continued to highlight possible interference with the two aircraft on-board instruments. What concrete problems might arise?
Xavier Tytelman: When a plane lands at an airport where there is no visibility, it is obliged to use precision guidance systems, and in particular a device called a radiosonde which allows its altitude to be determined by using a sort of downward facing radar. In other words, we “radarise” the ground. 5G, for certain frequency bands, uses the same frequency as radiosondes. And therefore potentially, it might disrupt certain approaches. However, these cases are very rare.
The problem is that in the United States a lot of frequency bands have been assigned to a lot of different operators, including those that are normally used by aircraft devices. As a result, what the American airlines are asking for is either to adapt the frequencies which are allocated to the various 5G holders, or to reduce the power of the transmitters which would be installed around the airports so as not to disturb the machines. Knowing that in any case it will cost a lot of money, either to the airlines if they had to modify all their boxes, or to the mobile telephone operators. The situation is complex and results from a lack of anticipation on the part of the American government.
► Read also: 5G/air: the new deadline requested by the American authorities refused by the operators
South Korea began marketing its first 5G networks in 2019. Three national operators, SK Telecom, KT and 3 LG Uplus participated in the frequency band allocation auctions. The country has 20 million 5G users. Users not always happy because of the insufficient quality of the network or the high price. But what regarding airplanes?
Inevitably, when you have a lot of frequency band applicants in 5G, you can’t put them all on the same tapes. To the point that some of these bands can approach those used by aircraft devices. And that is the problem of the United States which has a lot of mobile operators, but also a lot of old planes [aux États-Unis, les enchères 5G ont attiré 57 enchérisseurs potentiels qui ont déboursé quelques 76,5 milliards de dollars. Certaines entreprises, telles que Verizon, AT&T, Dish et Comcast, se sont endettées pour acquérir leurs précieuses bandes de fréquences 5G, ndlr]. In South Korea, they anticipated the problem and there was no interference there.
► To listen and read also: 5G, dawn of a new industrial revolution
And in France, was the problem anticipated ?
The Directorate General of Civil Aviation, the DGAC, has from the outset requested that on approaches to airports, 5G networks be of lower power than the maximum potential. The objective is that planes do not receive the signal from 5G which is stronger than the signal from their own radiosondes. So, yes, there was in France an anticipation to avoid there being the slightest problem. And a priori, the certification has gone without a hitch so far.
But I assure you, the planes always have two to three hours of fuel to change, if necessary, airport in order to land. The problem is that the bifurcation potentially disrupts 200,000 to 300,000 people who see their flights canceled, delayed, and this obviously costs a fortune.
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