Defense IT

Slicing up the spectrum: DOD’s tough task

EHF Spectrum image

As Defense Department and other federal stakeholders struggle to divvy up precious electromagnetic spectrum, all sides agree on the need for closer government/industry collaboration along with investment in new "dynamic spectrum sharing" technologies.

The drawn-out process of moving DOD and other agencies off of "beachfront" spectrum and relocating them to other bands where they can still carry out their missions has been compared to "watching paint dry." But it is necessary: Vacated or shared spectrum will eventually be used to expand commercial broadband wireless services that are widely seen as engines of U.S. economic growth.

Finding a balance between national security and economic competitiveness remains a priority. Senior defense officials have acknowledged the need for spectrum reform while at the same time stressing the military's need for more bandwidth.

Spectrum sharing, either geographic or via new dynamic sharing technologies, appears to be a likely outcome of the protracted debate over how to reallocate frequencies. One thing seems certain: DOD, in the words of a senior Federal Communications Commission official, will have to share spectrum. "It needs to be a two-way street," said FCC chief engineer Julius Knapp.

After much delay, DOD finally released its Electromagnetic Spectrum Strategy in mid-February. "Together we must identify ways to make more spectrum available for commercial use, and find technologies that enhance spectrum sharing, all while improving how DOD accesses spectrum, where and when needed, to ensure mission success," CIO Teri Takai said in releasing the strategy on Feb. 20.

In a show of unity, a spectrum administrator for the Commerce Department's National Telecommunications and Information Administration praised the DOD plan for stressing "efficient, flexible and adaptable use of spectrum." Added NTIA's Karl Nebbia: "The longer-term spectrum needs for government agencies and industry alike can only be met through spectrum sharing, and we are looking for a top-to-bottom commitment from all stakeholders to make it happen."

Rather than relocating DOD and other agencies to other bands, spectrum sharing is increasingly seen as a faster, cheaper way to boost broadband wireless services while allowing DOD and other agencies to do their jobs. But observers note that technology tends to be offered as a panacea in intractable policy debates, particularly one in which industry has already made huge infrastructure investments.

"Technology always strikes me as the silver bullet in some ways for spectrum problems," noted James Lewis, director of the Strategic Technologies Program at the Washington-based Center for Strategic and International Studies. "We always say, 'Yeah, we'll fix it because we'll have a new technology'." But "you've got to invest in it if you want to get it."

According to Takai, DOD's strategy has three goals:

  • Improving military technologies that depend on spectrum, becoming more efficient, flexible and adaptable in how spectrum is used. Options include shifting some systems to less congested bands, adopting commercial products, and spectrum sharing.
  • Increasing the agility of DOD spectrum operations, starting with the acquisition process. "DOD spectrum-based operations must be able to move with and adjust to the spectrum environment as it changes," Takai said.
  • Playing a larger role "up front" in U.S. and international spectrum policy and regulatory decisions that also involve NTIA, the FCC, the White House Office of Science and Technology Policy and the Geneva-based International Telecommunication Union.

As with the wireless industry, senior DOD officials stress that spectrum demand is growing as new systems such as drones are deployed. DOD traffic is estimated to be growing by as much as 20 percent annually. "What does that mean? That means data is going to be the future," said Air Force Major Gen. Robert Wheeler, deputy CIO for C4 and information infrastructure capabilities. "More spectrum is going to be required or more efficient use of spectrum."

Wheeler pointed to dynamic spectrum sharing as one solution to maximizing bandwidth while ensuring priority access for the military. Such "spectral reconstruction" schemes might allow commercial access to little-used bands for, say, missile defense, with the assurance that DOD has priority in an emergency, Wheeler suggested.

Spectrum flexibility along with geographic and dynamic sharing technologies could eliminate current "spectral hogs" that currently retain exclusive use of valuable frequency bands, Wheeler said.

For industry's part, stakeholders are naturally enthusiastic about emerging technologies that would enable spectrum sharing, innovations that nevertheless have yet to face stiff market tests. Stacey Black, AT&T vice president for federal regulatory affairs, predicted that technologies such as software-defined radios could soon hit commercial markets. Software-defined radio allows transmitters and receivers that previously operated on fixed frequencies to change bands as a way, for example, to avoid interference.

"You're going to see more smart networks" based on software-defined radios that use spectrum more efficiently, Black predicted.

The DOD spectrum strategy may also help provide a measure of market certainty as commercial carriers continue to seek prime spectrum to deliver broadband wireless services through both auctions and dynamic sharing. Carriers are looking for the greatest economies of scale, AT&T's Black said. "If you can get [spectrum] bands that are harmonized globally, that makes it, for our device manufacturers, much [easier] to build devices that are affordable."

Takai said DOD's strategy represents the first step in a multiyear implementation plan. In releasing the strategy, she promised "timelines and detailed actions" for meeting Obama administration goals for freeing up at least 500 megahertz of spectrum for commercial use. Acknowledging the coming spectrum battles, she warned, "The process will be intense."

Beyond the strategy, DOD has so far released few details about its spectrum plans beyond an alternative proposal floated last year to either share with industry or vacate spectrum in the 1755-1850 megahertz band. The FCC is still considering the plan.

DOD officials also stressed that the spectrum strategy is an attempt to be "proactive" as they seek to balance national security with economic competitiveness. Wheeler said DOD must "make sure we doing the sharing piece correctly, [data] compression where necessary and vacating [spectrum] where necessary."

The FCC will try to serve as arbiter in the coming chess game over spectrum reform. The big challenge will be deciding where to relocate spectrum users in a way that promotes sharing. "All of the low-hanging fruit, and it wasn't so low to begin with, has been picked," warned the FCC's Knapp.

Like real estate, spectrum sharing depends largely on location and population density. Especially in large cities, Knapp added, "detailed analysis and testing" will be needed for efficient spectrum sharing.


About the Author

George Leopold is a contributing editor for Defense Systems and author of Calculated Risk: The Supersonic Life and Times of Gus Grissom."Connect with him on Twitter at @gleopold1.

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