Federal transportation officials want AT&T and Verizon to postpone their planned release of expanded 5G wireless services this week, citing fears of signal interference that they said could pose risks to flight safety. On Sunday, the wireless companies responded and said no.
In a letter sent on Friday, Transportation Secretary Pete Buttigieg and Steve Dickson, the head of the Federal Aviation Administration, asked the two wireless companies to delay their planned introduction, on Wednesday, of new 5G technology for a “short period” of up to two weeks.
Failing to reach a deal “will force the U.S. aviation sector to take steps to protect the safety of the traveling public,” the officials wrote. “These steps will result in widespread and unacceptable disruption as airplanes divert to other cities or flights are canceled, causing ripple effects throughout the U.S. air transportation system.”
On Sunday, AT&T and Verizon said they intended to proceed with their 5G expansion. The aviation industry had nearly two years to upgrade any equipment that might be affected by the new spectrum use, the companies said.
“Our two companies are deeply committed to public safety and national security, and fortunately, the question of whether 5G operations can safely coexist with aviation has long been settled,” John Stankey, the chief executive of AT&T, and Hans Vestberg, Verizon’s chief executive, wrote in a joint letter.
The fight could add to the turmoil that has been plaguing airlines and their passengers in the past week, as carriers battled bad winter weather and a coronavirus wave that thinned their staffing during a peak holiday travel period.
The wireless carriers previously agreed to a 30-day delay of their scheduled December debut of the 5G expansion. Federal officials said they wanted the additional delay to give them time to identify critical airports in need of a buffer zone to temporarily protect their operations.
Verizon and AT&T offered an alternate compromise: For six months, until early July, the companies said they would comply with a version of restrictions now in place in France, which would sharply limit the signals at issue around busy airport runways.
The 5G expansion is a major priority for the wireless carriers. Verizon and A&T collectively paid more than $70 billion last year at a government auction for access to the so-called C-band spectrum, which will bring their networks greater geographic reach and faster signals. The carriers have not yet said which areas will get the new services this week, or how many customers they will cover, but Verizon said last month that it expected its new spectrum to reach 100 million customers by March. AT&T has said it plans to reach at least 70 million people in the United States by the end of this year.
The showdown is also to some degree a fight between government regulators. The Federal Communications Commission has urged wireless carriers to expand their 5G networks, while the Federal Aviation Administration has sought to slow things down in response to airlines’ concerns.
On Saturday, Brendan Carr, a Republican F.C.C. commissioner appointed by President Donald J. Trump, tweeted about a letter he sent that day to Mr. Buttigieg criticizing the agency’s objections.
“Your request for the delay is not backed up by the science, engineering or law,” Mr. Carr wrote.
A spokeswoman for the F.A.A. said in a written statement that the agency was reviewing the wireless carriers’ letter.
“U.S. aviation safety standards will guide our next actions,” she said.