Faster 5G Spectrum from AT&T and Verizon Won’t Be Coming Until Next Year

The FAA is still concerned they could interfere with aircraft systems
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It looks like Verizon and AT&T may have to wait a little while longer before they can roll out the faster 5G spectrum they spent billions of dollars to acquire earlier this year.

The two carriers had been poised to launch their new mid-range “C-band” spectrum as soon as December 5, which would have delivered considerably faster 5G speeds for users of the newest 5G smartphones, including the iPhone 12 and iPhone 13. But, unfortunately, it looks like the Federal Aviation Administration (FAA) has called a halt to the planned deployments.

According to The Wall Street Journal (via Apple News+), the FAA is concerned about potential interference with important cockpit safety systems and has asked the carriers to delay the rollout of the new 5G frequency bands to provide more time to address these concerns.

This isn’t the first time FAA officials have raised this issue. Last year, the head of the FAA and a top-level official as the U.S. Department of Transportation, called on the FCC to pause the sale of the new spectrum until the relevant aviation-related safety concerns could be properly studied and addressed.

For their part, both AT&T and Verizon have voluntarily agreed to delay their rollouts until January 5 in response to the FAA’s concerns, although they also deny any claims that the proposed signals present a danger to aviation.

The Spectrum in Question

Earlier this year, the FCC proceeded with its auction for the new C-band spectrum, the bulk of which was gobbled up by Verizon for a record-breaking $45 billion. This newly available spectrum operates in the range of 3.7–3.98GHz, frequencies previously unused by cellular carriers.

While these frequencies don’t actually overlap with those used by aircraft equipment, which operates just above them in the low 4GHz spectrum, they’re a bit too close for comfort. This has many aviation experts concerned that 5G towers using the new spectrum could interfere with important pieces of aviation safety equipment that help pilots land in poor weather.

For example, most commercial aircraft use radar altimeters to determine how high the plane is above the ground. These are crucial in inclement weather, where traditional barometric altimeters can be unreliable. Most of the radar altimeters used by modern military, commercial, and even civil aircrafts operated in the low 4GHz frequency range.

As Interesting Engineering explained in an article last December, a high number of signals operating in frequency ranges that are close to each other can result in a phenomenon known as “bandwidth pollution.” Much like how “light pollution” makes it hard to see the stars at night when you’re close to a well-lit city, a large number of radio signals in one frequency band can “bleed through” into neighboring frequencies.

This was also backed up by a research paper published last year by the RTCA, an independent standards development organization that works with the FAA to study and analyze technical advances in aviation. The RTCA showed evidence that a concentration of 5G telecommunications in the 3.7–3.98GHz spectrum could risk causing “harmful interference” to radar altimeters.

The FCC has pointedly disagreed with these studies, claiming that the 0.2GHz “buffer” in between the C-band spectrum and those used by aviation equipment is more than sufficient to avoid any possibility of interference, placing the two government agencies at loggerheads.

Faced with few other alternatives after the FCC went ahead and auctioned off the disputed spectrum, the FAA has instead been working on issuing official mandates to pilots and airlines, warning them about potential interference with cockpit safety systems.

The mandate would limit pilots’ use of certain automated cockpit systems, which aviation industry officials note could disrupt passengers and cargo flights in the 46 metropolitan areas where the C-band 5G towers will be located, resulting in increased flight delays and other related problems.

The FCC, which has come under new leadership since the original controversy, has issued a joint statement with the FAA confirming the voluntary pause and said they would work closely with both AT&T and Verizon to ensure all the relevant concerns are addressed.

Verizon has emphasized that it is postponing its C-band rollout purely “in the spirit of good faith” but insists that the FAA’s concerns are groundless. The carrier says it remains on track to bring C-band 5G services to 100 million Americans in early 2022.

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.


AT&T was a bit more circumspect in its response, noting that it will work with the FCC and FAA to understand the FAA’s concerns.

It is critical that these discussions be informed by the science and the data. That is the only path to enabling experts and engineers to assess whether any legitimate coexistence issues exist.


Although T-Mobile also acquired some C-band spectrum license in the auction earlier this year, it doesn’t plan to use it until late 2023 and hence has no skin in the current game. The “Uncarrier” is also in far less of a hurry to roll out this new spectrum, as it already has the benefit of all the 2.5GHz mid-range spectrum that it inherited when it merged with Sprint last year.

What This Means for You

To be clear, none of this discussion pertains to the use of your iPhone. While there was once a time when cellular phones could potentially cause interference with aircraft instruments, that hasn’t actually been the case for years, and 5G doesn’t change that in any way. Moreover, the FAA has said nothing at all about consumer cellphones, and it’s not expected to do so.

Put simply, it’s not individual 5G iPhones that are at issue here, but rather the 5G towers located outside the aircraft. These operate at considerably higher power levels than the iPhone in your pocket ever could, and they’re already handling signals from hundreds, or even thousands, of users on the ground. So even if you were actively using your 5G iPhone, anything it’s going to add to the mix is like a drop in the ocean.

The biggest issue with this delay for consumers is simply that those on Verizon and AT&T may have to wait a bit longer before they can take advantage of the faster speeds that both carriers are promising. At this point, unless you’re fortunate enough to operate within a couple of blocks of an ultra-fast mmWave cell, you’re likely getting pretty lousy 5G speeds.

This is because both AT&T and Verizon have had to piggyback their 5G signals on their existing 4G LTE frequencies, creating a scenario where most Verizon and AT&T users are better off just keeping 5G switched off and using the 4G LTE network instead.

The new C-band spectrum promises to fix this by opening up a whole new range of frequencies that aren’t being used by anything else, providing an open field for 5G communications where they won’t have to deal with all the 4G LTE traffic getting in the way.

These frequencies are already in use in several other countries, hence they’re already supported by the iPhone 12 and iPhone 13. This means that when these frequencies do get rolled out on Verizon and AT&T’s towers, you should be able to take advantage of the faster 5G speeds right away.

Fortunately, it doesn’t look like you’ll have to wait too long. Both Verizon and AT&T have only promised to delay their rollouts by a month, pushing them to January 5.

While it’s possible it could delay them further, it’s important to keep in mind that the FAA doesn’t have the authority to order them to stop, at least not on its own. That responsibility lies solely with the FCC, and while the communications regulator appears to be more willing to listen to the FAA’s case this time around, it’s unlikely to halt the rollouts without incontrovertible evidence of a serious problem.

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