Earlier this week Reuters reported that the Federal Aviation Administration (FAA) warned that 5G networks in the US, operating on C-Band spectrum (3.7-3.98GHz range), could interfere with aircraft altimeters.
Altimeters are instruments used to measure how far above the ground an airplane is travelling as well as used to facilitate automated landings and to help detect dangerous currents known as wind shear.
Altimeters operate in the 4.2-4.4GHz range, a fact that some say is too close for comfort and could suffer from interference from the 5G networks in and around airports, rendering a large number of aircrafts unusable.
"Transmission rules for the C-band were published in March 2020. At the 11th hour, the Federal Aviation Administration issued a cryptic safety alert, saying that while there is no evidence that 5G harms the operation of altimeters, that pilots should pay attention to their gauges," says John Strand, CEO of Strand Consulting.
"The FAA has based this entire dispute on a theoretical modelling of multiple worst-case scenarios with obsolete altimeters, not testing with the actual equipment used in modern aircraft or 5G networks. In fact, the FAA attests that it has no evidence of actual interference."
Strand goes on to suggest that the FAA is colluding with "various aviation trade associations" to "get the mobile industry to cough up $100 million or so to pay for altimeter upgrades" and that this also serves as suitable distraction from "from airlines’ poor performance and many regulatory shortcomings".
As of 18 January 2022, Verizon has confirmed that it is proceeding with its 5G launch, saying in a statement: "Tomorrow, Verizon will launch its 5G Ultra-Wideband network which will enable more than 90 million Americans to experience the transformative speed, reliability and power of this game-changing network on the go or in their homes or businesses."
"The Federal Aviation Administration and our nation’s airlines have not been able to fully resolve navigating 5G around airports, despite it being safe and fully operational in more than 40 other countries."
While AT&T commented that it was "…frustrated by the FAA’s inability to do what nearly 40 countries have done, which is to safely deploy 5G technology without disrupting aviation services, and we urge it do so in a timely manner", saying that regulators had "two years" to prepare for the start of 5G.
"We are launching our advanced 5G services everywhere else as planned with the temporary exception of this limited number of towers."
According to the FAA, it is the complex nature of US airspace as well as high safety standards that sets the US apart from the likes of France and Japan that have already begun deploying 5G and not faced such issues.
Specifically, 5G in other countries typically feature lower power levels, downward titled antennas to reduce potential interference, unique placement of antennas relative to airfields and chief among them different 5G frequencies to that used by aviation equipment.
(Source: FAA: 5G and Aviation Safety)
In Europe 5G typically operates in the 3.4 – 3.8GHz range, South Korea in the 3.42-3.7GHz and in Japan three bands have been designated for 5G and are 3.6GHz - 4.1GHz, 4.5GHz and 28GHz.
Strand adds that despite the fact that part of Japan's 5G network overlaps altimeters in the 4.0-4.2GHz range, " the Japanese report no problems to aviation" and "have solved their problem, or rather, they do not allow a fake problem to take root".
As we know, the higher the frequency in the spectrum, the faster the 5G service meaning global operators all aim to operate in higher frequencies.
Following this warning from the FAA back in December 2021, the CEOs of American Airlines, Delta Air Lines, United Airlines and Southwest Airlines among others called on the likes of AT&T and Verizon, to delay doing so in order for a solution to be found.
In a letter to the US wireless companies, the aviation community said that without an agreement in place it could "could potentially strand tens of thousands of Americans overseas" and cause "chaos" for US flights adding that "unless our major hubs are cleared to fly, the vast majority of the traveling and shipping public will essentially be grounded".
"The developments are a frustration to AT&T and Verizon which spent tens of billions of dollars last year to acquire crucial C-band spectrum and are losing ground to T-Mobile in the race to deploy 5G networks," commented Kester Mann, director of consumer and connectivity at CCS Insight
"The episode is causing some embarrassment for the US which is being weighed down by bureaucracy as regulators in other regions such as Europe voice no such concerns."
At the start of the year, AT&T and Verizon agreed to delay initial deployment by two weeks (with launch due to take place 19 January 2022), and to implement additional mitigations, to give the aviation industry time to find a solution and reduce the impact on commercial flights.
These include a list of no more than 50 priority airports provided by the aviation industry for proposed C-Band exclusion zone, information on base station locations and operating characteristics planned for Q1 2022 to be given to the FAA and for the 5G licensees to support the aviation industry in its assessment of individual altimeters and airport environments, to name a few.
"I want to thank Verizon and AT&T for agreeing to delay 5G deployment around key airports and to continue working with the Department of Transportation on safe 5G deployment at this limited set of locations," said President Joe Biden in an online statement.
"This agreement will avoid potentially devastating disruptions to passenger travel, cargo operations, and our economic recovery, while allowing more than 90 percent of wireless tower deployment to occur as scheduled."
