Wireless carriers AT&T and Verizon will have to wait another month to deploy their new {C- Band} 5G frequencies, The Wall Street Journal reports. Both carriers had their sights set on a December 5 rollout, but will now do so on January 5.
Why are AT&T and Verizon delaying their 5G rollouts?
Verizon and AT&T announced that they would delay their scheduled 5G deployment so they could work with the Federal Aviation Administration (FAA) to address concerns about potential interference with airplanes’ key cockpit safety systems. The carriers’ delay is a response to regulators’ warnings, but at the same time they dispute claims that their 5G signals would create any interference or represent a danger.
The FAA was preparing to hand out official mandates that would limit pilots’ use of certain automated cockpit systems like ones that assist landings in inclement weather, The Wall Street Journal reports. The limits are deigned to avoid potential interference from wireless towers on the ground that would be transmitting new 5G signals. These limits could disrupt both passenger and cargo flights in the nearly 50 metropolitan areas were towers are located, according to aviation industry officials.
“Aviation safety and technology leadership are national priorities, and with today’s announcement these companies have demonstrated their commitment to both,” the FAA and Federal Communications Commission (FCC) said in statement.
Both agencies said they would continue working together to ensure the U.S. keeps pace with the rest of the world regarding the latest communications technologies, without any unnecessary delays.
Meanwhile, telecom industry officials aren’t convinced that additional safeguards are necessary, however. They’ve pointed to evidence that shows that proposed 5G signals would not interfere with flight equipment. For example, wireless carriers in other countries are currently using some of the wireless frequencies in question without issue.
CTIA, a trade group that represents the wireless industry, also noted that active 5G networks using the same spectrum band works safely in 40 countries, Bloomberg reports. The group said that the agencies across the globe have studied this issue, including the FCC.
“5G networks using C-band spectrum operate safely and without causing harmful interference to aviation equipment,” the group said in a statement. “C-band spectrum is critical to delivering 5G service in communities large and small across the country, ensuring all Americans benefit from these next generation networks. Any delay in activating this spectrum risks America’s competitiveness and jeopardizes our ability to ensure global 5G leadership.”
Verizon and AT&T’s current cooperation with the federal agencies is not an admission that it agrees with them. Verizon said it postponed its 5G deployment “in the spirt of good faith”, but still plans to bring 5G services over C-band to 100 million Americans by early next year.
“We appreciate the FCC’s work in its discussions with the FAA and others to ensure a data-driven analysis that will again demonstrate that 5G operations in this band pose no risk to flight safety,” a Verizon spokesman said in a statement.
Meanwhile, AT&T said it also plans to work with the FAA and FCC to understand the FAA’s concerns.
“It is critical that these discussions be informed by the science and the data,” AT&T said. “That is the only path to enabling experts and engineers to assess whether any legitimate coexistence issues exist.”
Why does the FAA believe 5G could interfere with airplane equipment?
C-band spectrum, the frequency where 5G would run over, covers a section of radio frequencies measured between 3.7 and 4.2 gigahertz. Some airplane equipment operates in neighboring frequencies, between 4.2 and 4.4 GHz. The FAA recently sent a special bulletin to pilots, airlines and aerospace manufacturers to warn them of the potential for 5G interference.
The FCC created rules for C-band spectrum use last year. After the agency reviewed the impact the spectrum could have on aviation, it created a “guard band” to create some distance between cellular and flight use. However, aviation industry groups are warning federal officials about what they see as potential safety implications from the new 5G service, as well as the potential economic fallout, The Wall Street Journal reports. Additionally, a coalition of aviation groups were expected to make a presentation to White House officials that would warn that these potential FAA restrictions could lead to airports or regions being shut down as passengers deal with flight cancellations and delays.
The FAA and FCC have gone back and forth over the potential 5G interference issue for months, despite the fact that the plan to use the spectrum for cellular networks goes back several years. The FAA has requested specific data about 5G towers’ locations, power and angles to determine whether they could interfere with planes’ glide paths on final approach.
“At this time, the FAA has no way of determining which airports or areas within the U.S. have or will have 5G base stations or other devices that could provide interference with airplane systems,” the FAA’s directive draft said. The draft also said that this type of interference “could lead to loss of continued safe flight and landing.”
What else could 5G interfere with?
As it turns out, it’s not just aviation equipment that some people are worried about 5G interfering with. Some meteorologists have expressed concerns that increasing the 5G cellular network could interfere with satellite observations, which could make weather forecasts less effective, according to KUSA in Denver. The reasoning is the Earth’s atmosphere emits radio waves naturally and satellite sensors pick up those waves and translate them into weather data such as temperature and water vapor. Those radio waves travel on faint and specific frequencies.
“And those frequencies, which there are about a half a dozen of them, are a gift from nature and those are the only ones that work this way,” said Bill Mahoney, a meteorologist with the National Center for Atmospheric Research (NCAR).
Approximately 90% of the data that goes into computer forecast models comes from the information on those radio waves, according to Mahoney. Unfortunately for meteorologists, cell companies want to purchase these frequencies from the government. Such frequencies are in such high demand because they can carry data through barriers like vehicles and buildings, as well as support a lot more users. The government has already auctioned off frequencies that could impact weather forecasting, and the selloff doesn’t look like it’s ending anytime soon.
Carriers can only expand their 5G networks if they expand their range of frequencies. The frequencies being sold in the 24 GHz range are very close to the 23.8 GHz signal that water vapor emits, KUSA reports. Mahoney said he’s concerned that 5G cellular activity could bleed over and confuse weather satellites. The satellites could think the cell activity was water vapor, which in turn make one of weather forecasts’ most critical components unusable.
“If we lose the data from these passive channels, or it’s interfered with, we could send weather prediction skill back 30 years,” said Mahoney.
Mahoney and other scientists testified at a House Committee meeting in July in an effort to stop or at least delay the expansion.
“I’m optimistic that we’ll be able to protect these channels until sometime that maybe we have a solution that could be put in place,” Mahoney said.
While Mahoney wants 5G cellular network to be successful, he said he wants more time to study the impacts so that maybe the atmospheric science community could come up with alternative solutions.
“And we think the federal government should fund some additional research maybe using some of the funds from these frequency auctions,” he said. “So that we can get a better idea of what the problem space really is.”
Meteorologists’ concern about how 5G expansion could impact weather forecasts is not new. MIT physicist William Blackwell shared his concerns during a 2019 NPR interview.
“The sensors are extremely sensitive,” Blackwell said. “We’re trying to measure very small quantities on the order of a trillionth of a watt. So, any emission in the band from 23.6 to 24.0 (GHz), the sensors will measure some part of that. So, the question becomes, what levels of interference are tolerable?”
Why could 5G cause interference?
Concerns over 5G cellular networks interfering with airplane equipment, weather satellites and the like stem from spectrum proximity. The new 5G cell network’s coverage and capacity will mostly operate at 3.3 to 3.6 GHz, according to Sat Magazine. If that’s the case, there’s potential the network could interfere with the C-band satellite communication terminals that receive Space-to-Earth signals in the 3.4 to 4.2 GHz band.
Previously, satellite communication terminals operated in various frequency bands, including the C-band without any other terrestrial tech in the “neighborhood.” Whatever networks did exist, they were not widespread enough to cause interference concerns. That changed with 5G’s arrival. The fifth generation of wireless’ cell technology is expected to be very widespread and occupy the same spectrum.
“The 5G interference signals will be powerful enough to saturate the sensitive C-band satellite receiving systems, causing a potential for total loss of service,” Sat Magazine writes. “5G frequency bands fall in the C-band receive spectrum of 3.4 GHz to 4.2 GHz, the receiver of a C-band terminal operating at the same frequency as the 5G signal will face interference. Even if the satellite signals received by the C-band terminal are limited to 3.8 to 4.2 GHz, there is still a risk of 5G signal interference.”
Does T-Mobile 5G interfere with airplanes?
T-Mobile could be a beneficiary of Verizon and AT&T’s 5G deployment delay, Bloomberg reports. The carriers are already about a year behind T-Mobile when it comes to 5G network deployment, as it is not using airwaves that are not suspected of causing interference. The delay could help T-Mobile secure more 5G customers before its competitors improve their coverage, according to New Street Research analyst Blair Levin.
“A one-month delay will not have a material impact,” Levin wrote. “But the question remains whether the delay will continue to a point at which it will hurt Verizon and AT&T while benefiting T-Mobile.”
Meanwhile, Verizon and AT&T are likely anxious to get their 5G deployment going, not only to keep pace with T-Mobile, but because they spent $45 billion and $23 billion, respectively on C-band spectrum in a recent FCC auction. T-Mobile was not as active in that auction as it has a large amount of licenses in the 2.5 GHz range that’s clear of potential interference.
“This is a clear win for T-Mobile because delay keeps rivals from matching its airwaves holdings,” Walter Piecyk, an analyst with LightShed Partners LLC., said in a tweet.
The one-month delay will also give the FAA and FCC time to finish discussions about C-band spectrum, Verizon spokesman told Bloomberg.
“This will allow us to remain on track to bring the 5G services using the C-Band to 100 million Americans in early 2022,” Young said.
