New Delhi: With at least ten leading US airlines saying the new 5G technology could result in major operational disruptions and cause thousands of flights to be delayed, US mobile networks AT&T and Verizon are learnt to have decided to postpone the expansion of their 5G service at some airports.
After two earlier delays, the service was to begin operations in more places on Wednesday, BBC reported.
On Tuesday, American Airlines Chief Operating Officer David Seymour told employees the entire US airline industry was facing “major disruption” as new technology was activated.
"Until a long-term technical solution is developed and implemented and as long as 5G is deployed, we anticipate we’ll experience delays, diversions and cancellations that are well beyond our control," he said in a note to employees, according to a Reuters report.
In early 2021, the US authorities auctioned mid-range 5G bandwidth to mobile phone companies in the 3.7-3.98 GHz range on the C band spectrum, for about $80 billion.
These frequencies are close to the ones radio altimeters on aeroplanes use.
On Wednesday, Air India cancelled eight flights on the India-US routes due to the deployment of 5G internet, which it said could interfere with navigation systems of aircraft.
Arun Kumar, head of the Directorate General of Civil Aviation, said the Indian aviation regulator is working "in close coordination with our carriers to overcome the situation", PTI reported.
Why Are Airlines Worried And How Serious Is The Risk?
The RTCA, a US organisation that produces technical guidance on aviation issues, had published a report in late 2020, before the 5G spectrum was auctioned, warning of the possibility of "catastrophic failures leading to multiple fatalities, in the absence of appropriate mitigations".
The US Federal Aviation Administration (FAA) later warned that the 5G technology could interfere with instruments such as altimeters. It said the interference could make it difficult to slow down a plane on landing, resulting in it veering off the runway.
Altimeters operate in the 4.2-4.4 GHz range, close to the auctioned frequencies, and that is the cause for concern.
It is the altimeters that measure how far above the ground a plane is flying, and also provide data for aeroplane safety and navigation systems. Altimeter readouts are used to facilitate automated landings, and they help detect wind shear that are dangerous currents, according to a Reuters report.
United Airlines CEO Scott Kirby said in December the FAA's 5G directives would bar the use of radio altimeters at about 40 of the most prominent US airports.
US airlines have said this could disrupt up to 4 per cent of daily flights.
Why Telecom Operators Want Higher Frequency
Telecom service providers want to operate at higher frequencies so they tap the full potential of 5G. The speed of a telecom service depends on how high the frequency is on the spectrum.
While Verizon and AT&T mobile networks have now decided to postpone rollout of the 5G service, they had earlier argued that C band 5G had been deployed in about 40 other countries without interference issues with aviation, the Reuters report said.
France has buffer zones around airports to reduce interference risks, and the networks agreed to put similar arrangements in place at 50 US airports for six months, according to the report.
Verizon and AT&T have now decided to not switch on some 5G masts while talks continue for a permanent solution, BBC reported.
This, it said, should reduce the possibility of interference with systems onboard planes. President Joe Biden said in a statement the delay would affect about 10 per cent of the 5G masts involved in the expansion of the technology.
How Are Other Countries Dealing With This?
Not all countries are rolling out 5G in the same manner.
In 2019, according to reports, the European Union decided that mobile networks will operate at mid-range frequencies in a 3.4-3.8 GHz range — lower than those the US operators are planning to use.
The bandwidth has been in use in many of the 27 EU member states without any issue, said the Reuters report quoted above.
Some countries have also taken other steps to reduce possible risks of interference.
In France, for example, the ‘buffer zones’ around airports restrict 5G signals, with antennas tilted downwards to prevent any possible interference, the BBC report said.
In South Korea, where 5G services were commercialised in April 2019, the 5G mobile communication frequency is 3.42-3.7 GHz band. The Reuters report said there has been no report of interference with the radio waves since.
"Wireless carriers in nearly 40 countries throughout Europe and Asia now use the C band for 5G, with no reported effects on radio altimeters that operate in the same internationally designated 4.2-4.4 GHz band," the report quoted CTIA, a US wireless trade group, as saying in a filing with the Federal Communications Commission.