AT&T and Verizon have agreed to delay their roll-out of new C-band spectrum in order to give regulators more time to work on limiting potential interference for plane cockpit safety systems. The mobile operators agreed to delay the deployment on their 5G networks in the band for one month, until 5 January, according to a report in the Wall Street Journal.
The Federal Aviation Authority in the U.S. had previously expressed concerns about the use of the spectrum in the 3.7–3.98 GHz band, released by satellite operators, for mobile services. It is planning to issue official mandates as soon as this week that would limit pilots’ use of certain automated cockpit systems known as radio altimeters, according to government and industry officials familiar with the plans. Those restrictions aim to avoid potential interference from wireless towers on the ground transmitting new 5G signals.
The mobile industry has disputed the need for more safeguards, saying that available evidence does not show that the 5G signals would interfere with flight equipment. Carriers in other countries already use the wireless frequencies in question without problems. The FCC set its rules for use of the spectrum in early 2020 after reviewing the potential impact on aviation, creating a guard band as a buffer between the two uses. Some airplane equipment operates in nearby frequencies, between 4.2 and 4.4 GHz.
The Federal Communications Commission issued a statement with the FAA confirming the voluntary pause. The regulators will work together to ensure there are no undue delays to the process.
The delay represents a setback for AT&T and Verizon, which have been looking to capitalize on the mid-band spectrum to expand significantly their 5G coverage. Verizon said it postponed its rollout “in the spirit of good faith” and remained on track to bring 5G services over the C-band to 100 million Americans in early 2022.
In last week’s Story of the Week, we reported that the U.S. the aviation regulator was about to issue a warning regarding possible safety issues with 5G. Now, not only has the warning been issued, it has been heeded, with a decidedly negative impact on the country’s 5G rollout. The two top operators have agreed to a one-month delay in the launch of their C-band 5G spectrum, and that is truly an extraordinary development.
Hitting the pause button on a major industry-wide technological shift is serious enough, not to mention uncommon, but what makes this situation even more remarkable is that the objections come after another U.S. regulatory agency, the Federal Communications Commission, which supervises the mobile telecom industry, issued rules in 2020 for spectrum allocation that indicated that C-band 5G would not in fact pose a problem for radio altimeters. The disagreement between the FAA and the FCC on this point has resulted in the former prevailing, at least for the moment.
AT&T and Verizon say they are placing the rollout on hold simply out of good faith, not because they believe there is anything safe about their networks. However, even the perception of safety problems could have a chilling effect on development. Considering the gradual pace of the rollout and the fact that C-band is not the only frequency band used in 5G in the U.S., a one-month delay should not, in itself, have a major impact on the process in general. However, if that should stretch into a longer time for any reason, it could be quite bad for the operators, which have invested a great deal of capital in 5G and need it to support the growing demand for fast mobile internet, mainly due to streaming, gaming and other high-bandwidth services. Since the safety of the airlines is such a critical issue, the operators and the federal agencies need to come to an understanding as soon as possible so that 5G can continue to be rolled out in the United States.