Spectrum Sharing Model Gaining Ground

An innovative spectrum sharing model in the 3.5 GHz Citizens Broadband Radio Service (CBRS) band is coming closer to reality, NTIA senior spectrum advisor Derek Khlopin reported at the CBRS Alliance annual meeting in Charlotte, N.C. this week.

Since this band was initially targeted as a candidate to make available for commercial use nearly a decade ago, NTIA has engaged closely with the Department of Defense and the Federal Communications Commission (FCC) to bring the idea to fruition. The 3.5 GHz band affords an excellent mix of capacity and coverage capabilities, defining characteristics of mid-band spectrum,  making the band appealing for future 5G deployment.

NTIA’s engineers and scientists in the Office of Spectrum Management and the Institute for Telecommunication Sciences (ITS) in Boulder, Colorado, have worked closely through each stage of development with their counterparts in government and the private sector. From shrinking exclusion zones into smaller protection zones to designing the concept of dynamic protection areas (DPAs) to assisting the FCC in certifying the components of the spectrum sharing mechanism, it has been a long, complex process, but the light at the end of the tunnel is getting brighter by the day.

This week brought news on two important, interrelated fronts. On Monday, in coordination with NTIA and DOD, the FCC approved the Environmental Sensing Capabilities (ESC) of three vendors following application updates that reflect conformance testing performed by ITS. (See our related post on how ESCs work).

Meanwhile, NTIA this week has wrapped up the laboratory testing stage of its examination of the systems of five Spectrum Access System (SAS) vendors. The SAS manages parameters that commercial spectrum systems will rely upon.  ITS will then begin writing test reports for submission to the FCC, likely in June.

These milestones give momentum to development of the 3.5 GHz band, which affords an excellent mix of capacity and coverage capabilities, defining characteristics of mid-band spectrum. The CBRS Alliance has initiated work to develop specifications to support 5G deployments in the band.

Combined with the FCC's pursuit of repurposing C-Band spectrum above the band and NTIA and the DOD's examination of whether spectrum could be made available at 3450-3550 MHz, these developments mean the U.S. will be well positioned to put key mid-band spectrum into the market to support U.S. leadership in 5G and the technology industries of the future.