The long awaited C-Band 5G rollout has been off to a rocky start.
The deployment of C-Band spectrum, which wireless carriers have praised as the key to wider 5G accessibility and faster network speeds, has been marred by controversy over safety concerns and delays. Telecom companies and aviation experts are still butting heads over whether the latest flavor of 5G and air travel can safely co-exist, a fight which has grounded flights and inevitably pissed off airlines.
Here’s a breakdown of the battle over 5G.
What is the matter with 5G?
The Federal Aviation Administration and several airlines say that the use of C-Band frequencies for 5G will interfere with airplane altimeters, devices used to monitor a plane’s altitude and distance from other objects in low-visibility conditions. This is mainly because these systems operate in close proximity to the C-Band frequency, posing a risk of signal interference. In a worst-case scenario, the altimeters could indicate an incorrect altitude, and offer no signal that the device was malfunctioning. In some cases, this altimeter data feeds into other control systems, potentially causing other knock-on effects.
The FCC approved the C-Band 5G rollout in 2020, saying that two years of technical analysis brought them to the conclusion that potential interference was a non-issue. The FAA obviously disagrees. This sparked a public, months-long feud between some of the biggest companies in the world and one of the most powerful agencies in the U.S. government.
Who's fighting with whom?
Verizon and AT&T have made some of the biggest bets on C-Band spectrum, spending more than $70 billion combined for licenses at an FCC auction in late February. The spectrum they bought has a longer range than the mmWave spectrum, which mainly serves cities and venues, and is much faster than the long-range low-band 5G spectrum. Verizon spent more than $45.5 billion for around 3,500 of those licenses, and AT&T snagged more than 1,600 licenses for $23.4 billion.
Their opposition is the FAA and major airlines, which have feared that 5G signals could pose safety threats to planes landing in low-visibility weather conditions.
Why is this happening now?
The FCC and the FAA were not on the same page about the risks posed by C-Band 5G.
Back in 2020, the FCC decided to free up the C-Band spectrum for 5G. It had previously been utilized in part by satellite companies, but the agency decided to relocate them in the interest of advancing 5G wireless capabilities. The FCC also concluded that “the limits we set for the 3.7 GHz Service are sufficient to protect aeronautical services in the 4.2-4.4 GHz band.” It pointed to the fact that France, Germany and Austria had already started making their own arrangements for C-Band 5G, with no worries about airports or aviation. In other words: They assured everyone this whole airline issue wouldn’t happen.
It turns out the airline industry’s penchant for delaying things extends to the agency that regulates it. The FAA waited until Nov. 2, 2021 — a little over a month away from the scheduled C-Band deployment — to issue a Special Airworthiness Information Bulletin requesting that airline manufacturers test their radio equipment ahead of the scheduled Dec. 5 deployment of C-Band 5G. They (rather optimistically) hoped that the companies would be able to assess the safety risks in that time frame. When that didn’t happen, the FAA had to pull the emergency lever and request a delay.
So, what’s the status of the rollout?
Three words: delays, delays, delays. Here’s a rough timeline of what’s happened so far:
Nov. 2, 2021: The FAA issued its bulletin requesting that airline manufacturers test their radio equipment ahead of the scheduled Dec. 5 deployment of C-Band 5G. In a little over a month, they wanted these companies to “voluntarily provide to federal authorities specific information related to altimeter design and functionality, specifics on deployment and usage of radio altimeters in aircraft, and that they test and assess their equipment in conjunction with federal authorities.”
Nov. 4, 2021: AT&T and Verizon agreed to a voluntary delay to give the FAA more time to address signal interference concerns. This shifted the anticipated deployment date from Dec. 5, 2021 to Jan. 5, 2022.
Dec. 31, 2021: Transportation Secretary Pete Buttigieg and FAA Administrator Steve Dickson sent a letter to the CEOs of the telecom giants requesting a further delay. They set a goal for full deployment of C-Band 5G by the end of March, “barring unforeseen technical challenges or new safety concerns.”
Jan. 2, 2022: Verizon and AT&T denied the request. They said the concerns over signal interference were unwarranted. Nevertheless, they offered to adapt the same C-Band exclusion zones utilized in France, which the companies called “one of the most conservative [approaches] in the world.”
Jan. 3, 2022: The wireless carriers changed course and agreed to another two-week postponement.
Jan. 16, 2022: The FAA announced that it cleared “an estimated 45 percent of the U.S. commercial fleet to perform low-visibility landings at many of the airports where 5G C-band will be deployed on Jan. 19.”
Jan. 17, 2022: Executives representing major U.S. airlines sent a dire warning to senior government officials. They wrote in a letter: “Immediate intervention is needed to avoid significant operational disruption to air passengers, shippers, supply chain and delivery of needed medical supplies.” This time, rather than request another full delay of C-Band deployment, they asked that “5G be implemented everywhere in the country except within the approximate 2 miles (3.2 km) of airport runways.”
Jan. 18, 2022: AT&T and Verizon agreed to a voluntary third delay of full C-Band 5G deployment. This time, however, they only limited C-Band 5G signals near select runways. President Biden claimed this concession would still allow “more than 90 percent of wireless tower deployment to occur as scheduled.”
Jan. 19, 2022: Emirates, Japan Airlines and Air India canceled a select few international flights set to land in the U.S. due to concerns that Boeing 777 hadn’t yet been cleared. The FAA then issued new approvals that cleared “an estimated 62 percent of the U.S. commercial fleet to perform low-visibility landings at airports where wireless companies deployed 5G C-band.”
What’s next?
The FAA announced on Jan. 28 that it had reached an agreement with Verizon and AT&T on how to expand 5G service while enabling more aircraft safely land at “key airports." Verizon and AT&T provided the FAA with precise data and locations of wireless transmitters, which the FAA used to “determine that it is possible to safely and more precisely map the size and shape of the areas around airports where 5G signals are mitigated.”
In other words, a solution appears to be on the way. Until then? “Passengers should check with their airlines for latest flight schedules."
Updated Jan. 28 with the latest from the FAA.
