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3550-3650 MHz

The Federal Communications Commission (FCC) created the Citizens Broadband Radio Service (CBRS) in the 3550-3650 MHz band in 2015. Since then, NTIA has worked closely with the FCC and the Department of Defense (DOD) to coordinate spectrum sharing among CBRS operators and existing federal users in the band. The sharing approach includes creating Dynamic Protection Areas to protect federal wireless operations from potentially harmful interference by new CBRS systems.

Transition Plans for 3550-3650 MHz Auction 

The FCC has announced plans for a CBRS spectrum auction in the 3550-3650 MHz band. The Commercial Spectrum Enhancement Act enables federal agencies to seek reimbursement for transition costs associated with an auction, and these plans must be made public no later than 120 days before the auction begins. NTIA provided initial estimates of sharing costs to the FCC in December 2019.  These estimated costs were reviewed by OMB and approved by Congress. The final transition plans are listed below.

  • DOD Office of the Chief Information Officer — xlsx | pdf
  • DOD Defense Spectrum Organization — xlsx | pdf
  • U.S. Air Force — xlsx | pdf
  • U.S. Army — xlsx | pdf
  • U.S. Navy and U.S. Marine Corps — xlsx | pdf

Additional Transition Information

  • Status of transition
    These files provide the Status of Transition
    for 3550-3650 MHz frequency
    assignments as of November 17, 2023 – xlsx | pdf – 

  • Agency Transition Plan Contact Information [--xlsx--|--pdf--]

Archived Transition Plans

Related content

Final Tests Completed on 3.5 GHz Spectrum Sharing Model

July 19, 2019

On Thursday, NTIA’s Institute for Telecommunication Sciences (ITS) released final test reports to commercial entities that participated in spectrum sharing testing on a model that would allow commercial and military use in the 3.5 GHz Citizens Broadband Radio Service (CBRS) band. The completed tests will drive progress toward initial commercial deployments in the band, prized for its excellent mix of capacity and coverage capabilities. With 4G LTE technology for the band available today, industry has already begun to develop specifications to support 5G deployments.

NTIA’s ITS oversaw rigorous testing, which included using a wide variety of scenarios and situations to test a Spectrum Access System’s (SAS) ability to manage CBRS devices while protecting incumbent federal and commercial operations in the 3.5 GHz band. The Federal Communications Commission anticipates relying on the test reports to certify that a SAS is complying with its rules.

Last year, ITS conducted the certification testing on Environmental Sensing Capability sensors for the CBRS band. The ESC sensors are intended to work with the SASs to enable dynamic sharing and were certified by the FCC in late April 2019. The completion of both the SAS and the ESC testing continues a 100-year tradition of ITS performing independent research and engineering in telecommunications to advance efficient spectrum use.

Spectrum Sharing Testing Reports Shared with SAS Administrators

June 25, 2019

NTIA’s engineering lab has shared Spectrum Access System (SAS) laboratory test reports with the commercial entities that participated in spectrum sharing testing at the Institute for Telecommunication Sciences. The reports are a critical part of advancing the sharing model in the Citizens Broadband Radio Service 3.5 GHz band.

The reports include a comprehensive analysis and interpretation of the test results to ensure accuracy and consistency. This work adds to already substantial work in progress in developing the 3.5 GHz band, which is prime mid-band spectrum that offers a mix of capacity and coverage capabilities. The SAS manages the environment where potential commercial spectrum systems will operate. The Federal Communications Commission anticipates relying on the test reports in certifying that an SAS is in compliance with its rules.

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