Flights to the US were briefly disrupted over safety concerns after mobile service providers there rolled out fifth-generation (5G) cellular services.
The disruption led to 5G being painted as a villain, though it would facilitate faster cellular service than the existing 4G services.
Several airlines, including Air India, suspended several flights to the US fearing that the frequency of 5G signals would interfere with the frequencies of certain equipment, such as the altimeter, in aircraft.
Radio altimeters give data on height above ground for landing during inclement weather conditions, and it was feared that the 5G signals would interfere with its frequency.
Interestingly, flights to European countries which have 5G cellular services were not affected. India is set to launch 5G services in the country. Will the 5G roll out create the same problem as in the US? Why were European nations unaffected?
Before looking into other countries, it would be prudent to check how 5G rollout disrupted flight operations. The US Federal Aviation Administration (FAA) and other agencies warned that signals from 5G towers near the airports interfering with flights' radio frequencies might cause security issues while landing. The warning led to several airlines to suspend their flights to the US.
Considering the seriousness of the issue, US telecom firms AT&T and Verizon Communications on January 18 agreed to delay switching on the new towers near key airports.
The new 5G C-Band service in the US will be using frequencies of 3.7 to 3.8 gigahertz, whereas the radio altimeters' frequency is 4.2 to 4.4 gigahertz. It was suspected that the closer frequencies might interfere with each other, and affect the accurate reading of the aircraft's altitude, which could be of risk to the planes.
Altimeters send out short pulses of radio waves and capture them on rebound from the terrain. It measures the time taken for reflection to gauge the altitude of the aircraft while landing. Radar altimeter, which measures the distance between two aircraft to avoid collision, functions in a similar fashion. The radio altimeter helps in safe low-visibility, bad-weather landings.
FAA clears flights
Even as flights to the US were suspended, the FAA was busy inspecting the altimeters in each aircraft model to see if they would function properly if the 5G towers are switched on. After necessary checks, the agency cleared the operation of all Boeing 717, 737, 747, 757, 767, 777, 787 MD-10/-11; Airbus' A300, A310, A319, A220, A320, A321, A330, A34, A350, and A380.
Airlines, including Air India, resumed their US operations after getting the FAA clearance.
5G will not cause flight disruptions in India
The Telecom Authority of India (TRAI) and others have been maintaining that 5G launch would not disrupt flight movements in the country. The UN-recognised International Telecommunications Union-Asia-Pacific Telecommunity Foundation of India, too, have said that the 5G bands in India would not interfere with altimeters of civilian aircraft.
TRAI has announced that the 5G band frequency in India will be 3.3 to 3.67 gigahertz. Currently, various telecoms are conducting tests in 3.67 gigahertz. The altimeter frequency is 4.2 to 4.4 gigahertz, which has a difference of 530 megahertz from the 5G band. In the US, the difference was merely 220 megahertz.
Lessons from France
Other countries that have already switched to the 5G spectrum do not face problems similar to that of the US. The 5G functions at a lower frequency in the European Union compared to that of the US. Besides the higher frequency, the 5G in the US functions at a higher power level (1585 watts) than that of countries like France (631 watts).
Additionally, unlike in the US, the angles of 5G tower antennas are tilted downward in France to reduce potential interference with the aircraft equipment. France also has large airport buffer zones, providing protection during the final 96 seconds of the approaching flight, whereas the buffer zones in the US offer only 20 seconds of protection.
Small but powerful
The 5G towers cater to a smaller geographical area (small cell) compared to the existing ones which have a wider coverage. The 5G has a lesser latency and higher peak capacity than 4G. This would require the service provider to set up more mini towers. However, instead of installing new towers, the transmission equipment could be attached to existing electric poles and traffic signal posts, thereby helping to cut costs. The 5G towers are low-maintenance ones compared to 4G.
The mini telecom towers or small cells will have a range of 250 metres, and they require less power to operate. A strong network can be established with small cells put up on electric poles or signal posts that are closer to each other. Signals from the small cells will be equally strong in all areas. The mini towers will be linked to macro base stations (bigger towers).
Meanwhile, the Kerala State Electricity Board has expressed interest to be part of the 5G launch in Kerala. It has offered its electric poles to set up small cells.