It’s omnipresent yet finite, invisible but ambient. It’s the electromagnetic spectrum (EMS), a range of electromagnetic frequencies that radiate in wavelengths and photon energies to flip on lights, to beam voices through radios, to track threats with radar, to function in nearly any capacity in the contemporary world.
Each EMS frequency range avails itself to different uses. Lower frequencies are best for transmitting radio waves across long distances; taking X-rays is a common use for higher frequencies.
But spectrum space is limited: Multiple users can’t simultaneously occupy the same frequency in the same geographical location.
This physical reality has the U.S. Department of Defense (DOD) and the nation’s wireless telecom industry competing for air within the EMS—and Pentagon leaders are objecting strongly to tentative proposals for the military to cede or share part or even all its exclusive, dedicated swath of EMS frequencies.
1500 MHz Up for ‘Repurpose’
Because EMS space is finite, frequencies in the United States are apportioned, like they are across a radio dial, to commercial and government users, including the Pentagon, by the U.S. Federal Communications Commission (FCC).EMS use is then regulated by the U.S. Department of Commerce’s National Telecommunications & Information Administration (NTIA), which was commissioned by Congress in 2020 to study expanding frequencies for commercial use.
There are four thrusts to developing the plan, Mr. Davidson said, starting with improving long-range coordination between government agencies and the private sector, identifying 1500 megahertz (MHz) of spectrum for “repurposing,” leveraging technology to manage spectrum sharing, and developing workforce proficiencies.
The nation’s wireless telecom industry has been lobbying the FCC for years to open more EMS space as demand for consumer electronics expands exponentially.
Cellular Telephone Industries Association (CTIA) President/CEO Meredith Atwell Baker asked President Joe Biden in an April letter to make “at least 1500 MHz of mid-band spectrum available for licensed commercial use,” maintaining that expansion is necessary “for the United States to maintain its technological, economic, and national security edge against adversaries,” such as communist China.
“Expanding full-power commercial access to spectrum is also vital to maintaining U.S. global leadership in wireless,” the letter states. “Absent U.S. leadership in the global spectrum ecosystem, China and other ambitious nations will seize technological advantage by disproportionately shaping—and benefiting from—global 5G developments, 6G, and other technologies of the future.”
CTIA is among trade groups and associations advocating for “a spectrum pipeline” of frequencies now allocated to federal users, including the DOD, to be auctioned by the FCC to commercial buyers.
5G Changed Everything
For decades, the DOD has had unfettered, exclusive, and dedicated access to the 3100–3450 MHz S-Band swath of the EMS without competition for frequencies because there was relatively little demand for the mid-band spectrum.The military uses the 3.1–3.45 MHz range from the sea floor to space, from the Navy’s Aegis AN/SPY radars to the seniors inside an Air Force C-130. The frequencies guide air-, land- and sea-based radars; weapons, navigation, communications systems; and satellites.
There was little commercial telecommunications demand for 3GHz spectrum space because the first four generations of wireless technology could only access lower frequencies.
That changed with the 2018 advent of the fifth iteration of wireless technology—5G—that could access higher EMS frequencies as well as the mid- and low-range frequencies utilized by predecessor technologies.
Suddenly, the underutilized 3MHz range became the “Goldilocks spectrum.”
Before FCC’s EMS auction authority expired in 2023, it sold the 3.45 to 3.55 MHz range to U.S. telecom bidders in 2021 for $21 billon. U.S. wireless telecoms and other technology companies lobbying for more MHz range auctions appear willing to buy even more if presented with the opportunity.
Opening more EMS space for the commercial sector is necessary to accommodate the transition to 5G, which is expected to increase dramatically in coming years, groups such as CTIA insist.
According to the U.S. Government Accountability Office, the wireless industry used about 17 gigabytes of data per person in the United States in 2022. That will triple to 55 gigabytes in five years, GAO projects.
Telecommunications companies assert that the DOD’s lock on the 3.1–3.45 GHz range actually endangers national security by sustaining an outdated EMS management system, stifling technological advances, stymying enhancement of best practices, and giving a competitive advantage to potential adversaries.
Balancing Defense and Commerce
The DOD has acknowledged that some of its EMS systems may be out of date, as are some policies in incorporating 5G technologies across its 3.1–3.45 GHz range. While wary, it’s participating in NTIA’s study to expand commercial spectrum access, it assures.But Pentagon officials during 2023 budget hearings uniformly stressed that freeing up space on the EMS’s 3MHz range imposes unexpected costs and poses a national security risk that must be further scrutinized.
Among options being considered by the NTIA and the DOD is “vacating” frequency spans currently used by older Pentagon systems within the 3.1–3.45 GHz range when they are retired.
The NTIA and Pentagon are also examining the feasibility of 5G providers and the DOD “sharing the spectrum” in a way that balances national defense concerns with the burgeoning needs of the wireless industry.
Under a tentative “dynamic spectrum sharing” concept still being fleshed out, instead of dedicating an EMS frequency to a single “incumbent,” multiple users can access and use the same frequency bands by “optimizing spectrum use” in calibration with geography, time, and the frequency itself.
The concept would need joint technology upgrades, deconfliction paradigms, and complex legal agreements that could take years to orchestrate, although some preliminary efforts to test the arrangement’s viability are being staged by several military branches, Mr. Sherman said.
Industry proponents of the sharing concept say that communications would stay secure because the 5G network is reinforced by zero-trust architecture—a cybersecurity framework that requires all users and data to be authenticated and approved after every digital interaction.
Mr. Sherman said the DOD’s America’s Mid-Band Initiative Team (AMBIT) offered shared spectrum space to commercial users between the 3.45–3.55 GHz frequencies before the FCC auctioned it for $21 billion in 2021.
He said the DOD has launched an Emerging Mid-Band Radar Spectrum Sharing program that’s opening some frequencies to commercial use while still performing its military duty.
To some, the Pentagon’s sudden interest in sharing some EMS frequencies is an attempt to stave off the inevitable loss of some of its range to commercial development.
Mr. Sherman said the DOD considers it critical to retain access to the complete 3100–3450 MHz portion of the EMS and will not consent to “giving up entirely” any of that range.
‘Vacating the 3100–3450 MHz band would take decades and would cost the DOD billions of dollars. But sharing offers us a way ahead out of this and we’ve proven we can do this,“ he said. ”We can make sharing work in collaboration with [industry] and with our interagency partners.
“As I said during my confirmation hearing last fall, sharing of the spectrum space must be our watchword.”
Vacating ‘Off The Table’
During 2023 congressional budget hearings, Pentagon leaders uniformly opposed ceding any DOD spectrum space; questioned the costs, timelines, and security implications of sharing EMS frequencies; and identified numerous technical issues that would bedevil operations now conducted via exclusive access to the EMS’s 3MHz range.In an April hearing before the Senate Armed Services Committee (SASC), then-Marine Corps Commandant Gen. David Berger said that many military systems are specifically designed to optimize at specific 3MHz EMS frequencies.
“If that access is lost, then the very reason you pick that part of the band of the spectrum for a radar, for electronic warfare, for a training system—all that is lost to us,” he said.
Like many existing systems, new technologies are also designed to operate on the 3MHz S-band, Chief of Space Operations Gen. Chance Saltzman told the SASC in a May hearing.
Among them is the Space Force’s Deep Space Advanced Radar Capability, he said.
“If we were not able to use that piece of spectrum, not only would we lose the time that we have already invested in as much as several hundred million dollars that we have already put into development,” Gen. Saltzman said, “but it would also mean that we have to use a different portion of the electromagnetic spectrum which isn’t as capable in determining and discriminating capabilities in deep space.”
Gen. Berger said the adjustments required to share some EMS frequencies while shifting operations to others could take up to five years.
Secretary of the Navy Carlos Del Toro told senators in a later hearing that it would cost an estimated $250 billion to relocate the Navy’s systems to a different spectrum band if the frequencies now used were auctioned or shared.
“So, I am really fearful of the secondary consequences that some of these decisions could actually lead us to,” he said.
The DOD maintains that it’s also still developing its own 5G programming plans and is prudently hesitant to cede or share EMS frequency space “without a plan to reacquire it or get new technology to make up for the loss.”
During his July Senate confirmation hearing to be the next chairman of the Joint Chiefs of Staff, Air Force Gen. Charles “CQ” Brown said the Pentagon’s “'Joint War-Fighting Concept’ emphasizes the importance of the electromagnetic spectrum” and is stepping up training because, right now, “against our most advanced adversaries, the Joint Force would likely face challenges protecting itself from electromagnetic attack.”
He offered two reasons for that.
“Over the past few decades, the Joint Force has lost some muscle memory defending against electromagnetic attack by conducting operations within a permissive electromagnetic spectrum,” Gen. Brown said, referring to the 3100–3450 MHz band exclusively dedicated to the DOD for years.
“Over the same period,” he continued, “operations within this spectrum have changed significantly while our most advanced adversaries have done their best to rapidly evolve.”
It’s a quandary, Gen. Brown conceded, telling senators that while “the spectrum is a vital asset in the conduct of electronic warfare, I recognize that spectrum is a precious resource and [vital for] our national economic prosperity and position as a global leader in technology innovation.”
He pledged that the Pentagon would contribute to “efforts to preserve and develop spectrum as a vital national resource.”
“We must ensure, first and foremost, that we preserve and protect our vital national security and operational readiness equities,” he added.
DOD will wait for NTIA to publish its study in December, Gen. Brown said. But he made it clear that there are some things the Pentagon won’t negotiate.
“Vacating this band is not an option,” he said. “Proposals for DOD to share or vacate the S-Band may result in setting the DOD back several decades, compared to near-peer adversary nations, and result in significant financial costs.”
