There is an ongoing battle between US wireless operators Verizon Communications and AT&T and the aviation industry that is threatening to derail the wireless operators’ plans to expand their 5G services to more customers and compete effectively in the wireless market.

Verizon and AT&T plan to use C-band spectrum to plug coverage gaps in their existing 5G networks. These gaps fall between the operators’ millimeter-wave spectrum, which provides high data speeds, but only for a short distance, and their low-band 5G spectrum, which provides coverage over a greater distance, but the network speeds are not much better than 4G.

However, aviation and airline officials do not want the wireless operators to use C-band spectrum for 5G because they fear it will potentially interfere with altimeter instruments that are used by airplanes and could cause problems with takeoffs and landings.

This dilemma comes at a particularly difficult time for Verizon and AT&T as the two companies are facing increasing pressure from T-Mobile, which already has deployed its 5G network in its 2.5 GHz mid-band spectrum and can offer more than 200 million people in the US a 5G network that is much faster than 4G.

In Opensignal’s USA 5G Experience Report October 2021, the company said that T-Mobile customers experienced the best 5G availability of any US operator, which means that customers spend more time connected to 5G and receive the benefits of 5G speeds. Specifically, Opensignal said that its T-Mobile users spent 34.7% of their time on an active 5G connection compared to AT&T users, which only had a 5G connection 16.4% of the time. Verizon users, meanwhile, only spent 9.7% of their time on a 5G connection.

Delays and More Delays

AT&T and Verizon planned to strengthen their 5G networks by using C-band spectrum starting December 5, 2021. However, at the request of the Federal Aviation Association (FAA), the operators delayed the launch for a month so that all parties could figure out what precautions, if any, were needed.

But just before the new January 5 launch date, US Transportation Secretary Pete Buttigieg wrote a letter to AT&T and Verizon requesting an additional two-week launch delay, saying that, without it, he feared there would be widespread air traffic disruptions.

The chief executive officers (CEOs) of AT&T and Verizon initially rebuffed Buttigieg’s request for more time and instead offered to adopt exclusion zones that would reduce C-band spectrum transmissions around runways and the last mile of takeoff and final approach. AT&T and Verizon said that this strategy has been successfully used in France and proves that aviation altimeters and 5G C-band services can coexist. However, the companies later agreed to Buttigieg’s two-week delay and are now planning to launch on January 19.

Speaking at Citi’s Apps Economy Conference on January 5, Kyle Malady, executive vice president (EVP) and chief technology officer (CTO) of Verizon, said that this last agreement is final and that Verizon will be turning on its C-band 5G network on January 19. “We have access to that spectrum and legal rights to that spectrum,” he said. “We have offered what we think is reasonable mitigation. It follows the rules that other countries have done.” Malady added that, on January 19, the company will provide C-band coverage to approximately 100 million people, but it will not turn on its C-band network around any airports.

John Stankey, CEO of AT&T, who also spoke at Citi’s Apps Economy Conference also emphasized the importance of deploying 5G in the C-band; however, he said that the recent C-band delays to accommodate the aviation industry are not going to be a big deal in the long run. He added that it is more important to provide strong 5G support for customers.

The C-band Dilemma

The reason the C-band spectrum is creating problems for wireless operators is that the aviation industry says that the C-band 5G signals, which are in the 3.7GHz to 3.98GHz frequency range, may interfere with aviation equipment, such as altimeters that use the 4.2GHz to 4.4GHz spectrum.

However, the wireless industry says that the Federal Communications Commission (FCC), which addressed this issue in its March 2020 order on the C-band, found that the spectrum separation between the C-band 5G signals and the altimeters are adequate. In addition, the wireless industry lobbying group CTIA has said that there are already many countries around the world, including Australia, China, France, South Korea and the United Kingdom, that use C-band spectrum for 5G and do not have interference problems with airplanes.

Of course, Verizon and AT&T are particularly upset over this development, as they have already spent billions on costly C-band licenses in the FCC’s C-band spectrum auction that concluded in 2020. The auction raised more than $80 billion for the government, and Verizon paid $45.4 billion for its licenses and AT&T paid $23.4 billion for its licenses. T-Mobile also participated in the C-band auction, paying $9.3 billion for its licenses, but the company already has a strong 5G network in the mid-band spectrum range (where the C-band spectrum is), so it is under less pressure to deploy 5G in the C-band.

Author Information

Sue Marek

Sue is a Denver-based freelance technology journalist, editor and analyst with expertise writing about topics like 5G communications, cloud-native networking, edge computing, and more. She can cut through industry jargon and explain complex technology concepts to both non-engineers and business decision makers.

Previously she had served as the editor-in-chief at SDxCentral, covering news and information related to the software defined networking market. Before that, she served as the editor-in-chief of FierceWireless, which covers cellular, satellite and other telecommunications technologies and markets.

As an expert in her covered areas, Sue is a frequent speaker at technology industry events and has moderated panels for the Consumer Electronics Show, the Competitive Carriers’ Show, The Wireless Infrastructure Show, 5G North America, DC 5G, Interop, and more.

Sue Holds a Bachelor of Science in Journalism from University of Colorado, Boulder.