More satellite spectrum struggles

The space industry is used to battles over radiofrequency spectrum. Usually they play out on the international stage, such as at last year’s World Radio Communication Conference, or among companies seeking licenses from the U.S. Federal Communications Commission. But another spectrum debate could, in effect, pit one federal agency against another.

On one side of the debate is the FCC and the National Telecommunications and Information Administration (NTIA), the agency that manages the federal government’s use of spectrum. The Obama administration asked NTIA and FCC to work together to free up 500 megahertz of spectrum by 2020 for wireless broadband use. That involves, in some cases, relocating government users or developing “sharing arrangements” between commercial and government users.

The NTIA and FCC are about halfway to that goal, said Paige Atkins, associate administrator of the Office of Spectrum Management at NTIA, during a panel discussion on Capitol Hill May 25. While the agencies are on track to reach their goal of 500 megahertz by 2020, it won’t be easy, she warned. “We’ve moved the easy systems,” she said. “Spectrum sharing is really essential to our future.”

One of the spectrum bands being considered for sharing is a relatively small band, between 1,675 and 1,680 megahertz. That’s causing concern at the National Oceanic and Atmospheric Administration, and among those who use NOAA satellite weather data, since NOAA satellites use that band to broadcast data.

Mark Paese, deputy assistant administrator for satellite and information services at NOAA, said there have already been cases of terrestrial interference with satellite broadcasts. On three separate occasions last year, interference disrupted reception of geostationary weather satellite images at a ground station at Wallops Island, Virginia. That interference, he said, was traced to an unnamed commercial operator in an adjacent band, broadcasting more than 300 kilometers away.

Paese argued such interference could become more commonplace if NOAA satellites had to share the band with commercial users. “The operational impacts could be weather forecasting nationwide,” he said, as well as to industries like shipping and airlines that rely on direct access to that data.

That issue could come to a head soon. In April, the FCC issued a call for comments on a request by one company, Ligado, who is seeking permission to share that band with NOAA (Ligado is formerly known as LightSquared, who previously battled over spectrum near that used by navigation satellites). Comments are due to the FCC by June 21, although it’s not clear when, or if, the FCC will decide to move ahead with a formal rulemaking process to share that spectrum.

Even if the FCC and NTIA decide to keep that band protected, there are likely to be conflicts in the future between space and terrestrial systems for scarce spectrum, either involving companies versus the government, or pitting government agencies against one another.

Spectrum reserved for satellite services are “prime for development,” said Scott Pace, director of the Space Policy Institute at George Washington University, since those bands are relatively clean and globally coordinated. As the demand for wireless broadband grows, that makes those bands particularly vulnerable to sharing with terrestrial services. And that sharing could be technically difficult, despite promises made by agencies for sharing on a non-interference basis.

“Policy and politics are important,” Pace said, “but electronics and radio waves don’t care.”