FAA identifies airports set for 5G C-band buffer zones

The Federal Aviation Administration (FAA) on Friday disclosed a list of 50 airports where 5G “buffer zones” will be put in place once AT&T and Verizon turn on C-band spectrum later this month.

In a January 7 statement the FAA said carriers “agreed to turn off transmitters and make other adjustments near these airports for six months to minimize potential 5G interference with sensitive aircraft instruments used in low-visibility landings.”

The exclusion zones around certain airports would reduce 5G C-band signal levels by at least 10 times on the runway or during the last mile of final approach and the first mile after takeoff, according to an AT&T spokesperson, which the carriers had proposed and outlined in a January 2 letter to the U.S. Department of Transportation and FAA.

Days before a planned January 5 C-band deployment AT&T and Verizon had agreed to another delay, pushing C-band deployments out an additional two weeks to January 19. That came after the FAA stepped up warnings of imminent disruptions to air travel from flight delays if a resolution wasn’t reached and the operators offered up their own proposal to alleviate the agency and aviation concerns about issues with 5G service and older radio altimeters operating in the 4.2 GHz band.

RELATED: AT&T, Verizon agree to delay C-band launch – again

Verizon and AT&T both won 3.7 GHz C-band spectrum at the FCC auction that brought in more than $80 billion.

In selecting 50 airports, the FAA said it sought input from the aviation community, factoring in traffic volume, the number of low-visibility days and geographic location as part of the selection process.

The first 100 MHz tranche of C-band spectrum available (of which Verizon bought 60 MHz and AT&T acquired 40 MHz) is set to be deployed in 46 major markets, called partial economic areas (PEAs). Airport hubs in locations like New York, Los Angeles, Chicago, Miami, Dallas are among those on the FAA’s 5G buffer zone list. Airports that don’t currently have the ability to allow low-visibility landings and airports not in the initial C-band launch markets aren’t on the list.

“The FAA continues to work with the aerospace manufacturers and wireless companies to make sure 5G is safely deployed and to limit the risk of flight disruptions at all airports,” the FAA said.

RELATED: Verizon’s Malady on C-band: It’s a game changer

AT&T and Verizon on January 2 offered a proposal to adopt new mitigations until July 5 that modeled exclusion zones in France where C-band has already been deployed. At the time, the FAA said “while U.S. standards and operating environments are unique, we believe this could substantially reduce the disruptions to air operations” and that they would be in place for six months around 50 airports with the greatest impact.

In the last week Verizon has made clear it’s committed to launching C-band service on January 19 and expects to immediately cover 100 million people with the new mid-band spectrum for its 5G Ultra Wideband service.

Adam Koeppe, Verizon SVP of technology, planning and operations, spoke to FierceWireless last week after the carriers agreed to give the FAA two more weeks before turning on C-band. Asked about the proposed mitigations around airports modeling France and what it means for coverage, he acknowledged “there certainly is an impact” but declined to quantify further.

“In the vast majority of cases, we’re talking about limiting power at certain locations around airport runways, still a bit of work in progress with the FAA and the FCC and we’ll react accordingly as needed,” Koeppe said on January 4.

RELATED: AT&T, Verizon agree to C-band power limitations for 6 months

As for the reference to France, he noted that the country already has C-band infrastructure transmitting with a set of restrictions around airports where American planes fly in and out of without issues.

“Taking the mitigation elements we already agreed to, aligning them with what’s being done in France where American planes fly every single day seemed a fairly straight forward way to show the FAA that we’re certainly committed to aviation safety and we’ll do anything to ensure that safety,” Koeppe said.

Importantly, he highlighted that in terms of overall network design, traditionally there’s not a ton of infrastructure right next to runways. In that sense, he said most airport coverage is around in-building systems that will be getting millimeter wave anyway. For initial C-band deployments Verizon has said it's focused on macro sites that overlay its existing LTE network. Outdoors, Koeppe pointed out that Verizon already has a broad cellular footprint around airport locations with its current network and said the carrier can overcome any kind of C-band coverage impact that mitigations might have with other solutions, if needed.

RELATED: Despite delays, Verizon to hit 100M C-band coverage target this month

“Being able to work through the mitigation aspects with the agencies and ensure we can still put an incredible product in front of 100 million customers is something we’ve been working on really since the FAA brought these issues up and we feel great about our launch plans how this product is going to perform in the market,” Koeppe said last week.

One group not satisfied with the FAA’s list of priority airports is the Airports Council International – North America (ACI-NA), a trade association representing airports in the U.S. and Canada.

In a Friday statement, ACI-NA President and CEO Kevin Burke responded to the FAA list, saying it creates winners and losers in the airport community.  

“The list of airports put forward by the FAA is largely irrelevant because the entire aviation system is about to be adversely impacted by this poorly planned and coordinated expansion of 5G service in and around airports,” Burke stated, adding that the short-term fix doesn’t address uncertainties about potentially impacts of 5G on some low-visibility approaches. “This so-called fix will create winners and losers within the airport community, and the entire aviation system will suffer under the terms of this deal.”