After 10 years, shared spectrum goes live

Almost a decade in the making, a frequency sharing program involving Defense Department spectrum and commercial users is open for business.

radio spectrum

The first vendors of a unique federal-commercial spectrum-sharing arrangement have been given the official go-ahead to provide services. Federal spectrum managers are pointing to the new arrangement as a model for things to come.

The Federal Communications Commission on Sept. 16 approved the first initial commercial deployments for Citizens Broadband Radio Service on the 150 MHz of spectrum in the 3.5-3.7 MHz range. CBRS users will share frequency allocations with incumbent Defense Department users' shipborne radar applications.

The commercial services from providers including AT&T, Boingo, Charter Communications and Verizon will leverage a three-tiered sharing model that gives incumbent DOD users priority access when needed as well as licensed and unlicensed access for commercial private and general access services.

The commercialized services will be sold by the vendors under umbrella "OnGo" branding for a variety of applications, from rural broadband connections, to enterprise in-building cellular coverage, to sports stadiums and private networks.

The approvals mark the first commercial applications for the CBRS spectrum since the FCC, the Commerce Department's National Telecommunications and Information Administration (NTIA) and DOD began planning to open the federal spectrum up for shared use in 2010.

The sharing arrangement, which gives DOD priority access to the top tier of the spectrum for Navy radar applications, is a model for federal agencies to consider for their own spectrum holdings as commercial demands on the limited wireless spectrum increase, FCC Commissioner Mike O'Rielly said at an OnGo kickoff event on Sept. 18 in Washington, D.C.

"Clearing spectrum should always be a goal. The dynamic sharing model has been created and can serve as a blueprint when sharing is the only option" in an increasingly cramped spectrum world, O'Rielly said.

The sharing process "wasn't always pretty," O'Rielly said. Thorny issues such as creating exclusion zones along coastlines to protect Navy radar applications had to be worked out, eventually being turned into smaller, tighter "protection zones" through collaboration of industry, NTIA and DOD teams.

"This dynamic sharing shows that spectrum owners can be protected, but also accommodate new users," O'Rielly said.

"The key to the success for other federal agencies working out spectrum-sharing arrangements is talking directly to industry guys," Frederick Moorefield, deputy CIO for Command, Control, Communications and Computers and Information Infrastructure Capabilities at the Defense Department, told FCW.

Moorefield headed up a team of DOD engineers and spectrum experts to work with industry over the years to develop a structure that would give the defense agencies access to their spectrum at 3.5MHz, but also allow an ecosystem of commercial services to develop alongside them.

DOD, he said, is working to develop new ways to forge ahead with other sharing arrangements, Moorefield said.

The FCC is considering other bandwidths for dynamic sharing, including the "C Band," directly adjacent to the CBRS band.

"This spectrum is crucial, because it could be combined with CBRS to provide the kind of large spectrum channel that could support 5G" services, O'Rielly said.