5G advancement requires transferring spectrum authority from the DOD to the telecom industry. That leaves it vulnerable AND takes too long.

For decades, the Department of Defense has had relatively unquestioned access to a large portion of the electromagnetic spectrum — a critical resource that enables capabilities like radars, satellite communications and navigation systems.

However, a number of leaders at the Pentagon concerned that access may soon be taken away.

“That part of the spectrum is where we have many of our capabilities across the Joint Force,” Air Force Chief of Staff Gen. Charles “CQ” Brown said in July during his confirmation hearing to be the next chairman of the Joint Chiefs of Staff. “If we had to vacate that, we’d lose that capability and we’d have to figure out how now to regain that capability, and that will take time and cost money.”

Brown’s comments to the Senate Armed Services Committee were echoed by numerous Pentagon officials throughout this year’s budget hearing process. They represent one side of a yearslong battle between the Defense Department and the commercial telecommunications industry over access to the 3.1-3.45 GHz S-band.

That portion has been solely designated to the Defense Department for decades. But telecommunications companies are arguing that obtaining access to it is crucial for them to meet a rising demand for 5G wireless technology.

The National Telecommunications and Information Administration (NTIA) is on the cusp of releasing a highly anticipated congressionally mandated study — which the Pentagon participated in — discussing potential impacts to the department if it had to give up parts of the spectrum to commercial companies. The study is also examining the feasibility of both 5G providers and the Defense Department sharing the spectrum, requiring additional technical and scheduling agreements between both parties.

However, experts told DefenseScoop the conflict is symptomatic of an outdated spectrum management system plagued by policy, legal and technological guardrails. At the same time, freeing up spectrum for commercial use could be considered a national security interest.

“Even a relatively short time ago, 20-30 years ago, the military could command part of the spectrum and not have to compete, but that’s no longer the case,” Joseph Kirschbaum, director of defense capabilities and management at the Government Accountability Office, told DefenseScoop in an interview. “We are well past that where the military can own and operate everything with impunity. The commercial world is knocking at their door in every single area.”

The ‘Goldilocks spectrum’

The electromagnetic spectrum is a range of frequencies or wavelengths on which energy and information are transmitted. Each frequency range, ranging from high to low, has different use cases — lower frequencies are often used for transmitting radio waves across long distances, while higher frequencies are used in X-rays.

But while the spectrum exists all around us, it is not an infinite resource. Multiple users aren’t able to simultaneously use the same frequencies in the same geographical location without running into interference and impeding their respective operations.

To avoid overlap, portions of the spectrum are allocated to the commercial industry by the Federal Communications Commission (FCC) in the United States, while the NTIA, an agency under the Commerce Department, regulates government spectrum use — including the Department of Defense’s portion in the 3GHz range. Typically, the FCC holds auctions where specific stakeholders can bid to purchase certain bands.

“Before 1990, they were offering spectrum like taxi cabs. There wasn’t a lot of demand for it, and so DOD and other federal agencies got used to having these big sprawling allocations of the spectrum, and they didn’t really feel any incentive to modernize or upgrade their equipment to be more officiant,” said Jim Lewis, director of the Strategic Technologies Program at the the Center for Strategic and International Studies.

Considered mid-band spectrum, the 3.1-3.45 GHz range is largely used for the Pentagon’s air-, land- and sea-based radars, weapons systems and other electronics — such as the Navy’s Aegis AN/SPY radars and the stationkeeping equipment on Air Force C-130 aircraft.

Because of its incumbent access, then-Commandant of the Marine Corps David Berger told senators that many of the U.S. military’s systems were specifically designed to optimize those frequencies.

“We had access to that when the requirements were developed, that is why we went with that weapon system,” Berger said during an April SASC hearing. “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.”

New technologies are being developed to operate via the S-band, as well. During a separate congressional budget hearing in May, Chief of Space Operations Gen. Chance Saltzman told SASC lawmakers that the Space Force’s Deep Space Advanced Radar Capability (DARC) will use that part of the spectrum.

“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, 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,” Saltzman said.

Paul Challoner, vice president of network product solutions at Ericsson North America, explained that the commercial telecommunications industry was largely uninterested in the 3GHz spectrum range for many years, mainly because previous generations of wireless technology could only access lower frequencies.

Then 5G came along in 2018. The latest generation is able to harness more of the spectrum than previous iterations and the characteristics of 3GHz frequencies are ideal for hosting ubiquitous, wireless connectivity, Challoner said.

“We call it the ‘Goldilocks spectrum,’” he told DefenseScoop. “It’s not too high, not too low, it’s just perfect.”

While other nations have primarily been focusing 5G development in the 3GHz spectrum, the United States has been slow to allocate it for commercial use, he noted. Much of that is due to the Pentagon’s hold over that portion and its apprehension to relocate so that commercial users could access it.

A C-130J Super Hercules assigned to the 19th Airlift Wing, Little Rock Air Force Base, Arkansas, takes off in support of Razor Talon 2023 at Seymour Johnson Air Force Base, North Carolina, July 24, 2023. (U.S. Air Force photo by Airman 1st Class Rebecca Sirimarco-Lang)

“What DOD is finding is they have been operating in an area of the spectrum that has not been contested before, and now it is becoming contested,” Kirschbaum said. “So then now their choices are [to] put up the walls and wall that off, which from a governance and legal perspective may not be possible, or they have to take a technical solution, which will require some technical adaptation.”

At the same time, Kirschbaum noted the Defense Department is also in the process of developing its own use cases for 5G technology and may be hesitant to give up that spectrum without a plan to reacquire it or get new technology to make up for the loss.

A Pentagon official told DefenseScoop that if the department had to vacate a range of the spectrum, it would require the military to completely redesign their systems from the ground up so that they are able to operate using different frequencies on the electromagnetic spectrum.

“Oftentimes that different frequency range may be less ideal for the needs of any particular mission, as different areas of the electromagnetic spectrum have various strengths and weaknesses in supporting different missions,” the official said. For example, frequencies higher than 3GHz can send more data at higher resolutions but are more sensitive to interference from buildings and weather effects, they added.

Depending on the scope of the required modifications or replacements, it could take anywhere from “3 to 5 years or longer” to implement the change, then field and operationally accept modifications, they said.

Advertisement

In addition to time, Secretary of the Navy Carlos Del Toro told SASC lawmakers it would take an estimated $250 billion to relocate just the Department of the Navy’s systems to a different spectrum band.

“So, I am really fearful of the secondary consequences that some of these decisions could actually lead us to,” he said.