Several international airlines recently canceled flights into certain US airports because of concerns about the use of 5G mobile communication technology.
The Federal Aviation Administration and aviation bosses warned about the potential problem of 5G masts around airports.
How could 5G interfere with planes? Can the problem be fixed? Let's look at it.
5G is the fifth generation of mobile phone technology and is being deployed in several countries around the world. It could offer network speeds up to 100 times faster than what we have experienced with 4G.
To ensure high speeds with the widest possible coverage, AT&T and Verizon had planned to generate 5G internet using something called C-band frequencies, a type of radio frequencies between 3.7 and 3.98 gigahertz.
Modern aircraft measure altitude using these frequencies. An important piece of an aircraft's equipment, called a radio altimeter, operates on C-band frequencies.
When visibility is poor and the airport is surrounded by high mountains, pilots rely on radio altimeters to land the plane safely.
The radio waves from 5G towers near airports could cause interference, due to the narrow gap between the frequencies of the 5G and the radio altimeters. People using 5G on their phones could damage the radio altimeter.
If this happens for a while, it could mean the pilot doesn't get the correct information. The US Federal Aviation Administration raised concerns about this.
Other countries that are rolling out 5G are using frequencies that are close to radio altimeters without any reported problems. In the UK, 5G goes up to 4 GHz. The risk is reduced by having no mountains around airports.
Some countries operate their 5G on a different Frequency than the aircraft equipment. 5G goes up to 3.8 GHz in the European Union. This could be a good option for US airports.
The best option would be to use a much higher band for 5G, such as 24 GHz to 47 GHz. The coverage area of each cell will be less than at these frequencies, so you would need more towers.
There is an option to reduce the signal strength from the towers around airports, which has been done in France and Canada. The signal strength is not measured in GHz but in decibels, so limiting the signal power can reduce interference with neighboring bands.
The range of radio altimeters could be adjusted. It would take a long time and probably be very resource intensive for the aviation industry.
We need to take any possible risks very seriously, as the risk of an in-flight complication due to 5G interference may be very low.
Delaying the roll out of 5G masts near US airports is a good option while the relevant authorities determine the safest way forward.
The Director of the Telecommunications Engineering Research Group is Sufian Yousef.
This article is free to use under a Creative Commons license. The original article is worth a read.