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In 2015, the Commission adopted rules for shared commercial use of the 3550-3700 MHz band (3.5 GHz band). The Commission established the Citizens Broadband Radio Service (CBRS) and created a three-tiered access and authorization framework to accommodate shared federal and non-federal use of the band. Rules governing the Citizens Broadband Radio Service are found in Part 96 of the Commission’s rules.

Access and operations will be managed by an automated frequency coordinator, known as a Spectrum Access System (SAS). When managing spectrum access, SASs may incorporate information from an Environmental Sensing Capability (ESC), a sensor network that detects transmissions from Department of Defense radar systems and transmits that information to the SAS. Both SASs and ESCs must be approved by the Commission. SASs will coordinate operations between and among users in three tiers of authorization in the 3.5 GHz band: Incumbent Access, Priority Access, and General Authorized Access.

For more information about the history of 3.5 GHz band and Citizens Broadband Radio Service, search EDOCS or ECFS for Docket Numbers 12-354, 17-258, 15-319, and 19-244.


Tier 1 – Incumbent Access

Incumbent Access users include authorized federal users in the 3550-3700 MHz band, Fixed Satellite Service (space-to-Earth) earth stations in the 3600-3650 MHz band, and, for a finite period, grandfathered wireless broadband licensees in the 3650-3700 MHz band. Incumbent Access users receive protection against harmful interference from Priority Access Licensees and General Authorized Access users.

Tier 2 – Priority Access

The Priority Access tier consists of Priority Access Licenses (PALs) that will be licensed on a county-by-county basis through competitive bidding. Each PAL consists of a 10 megahertz channel within the 3550-3650 MHz band. PALs are 10-year renewable licenses. For purposes of the PAL service, counties are defined using the United States Census Bureau’s 2017 counties. Up to seven PALs may be licensed in any given county, subject to a four PAL channel aggregation cap for any licensee. PALs must meet a substantial performance requirement by the end of the initial license term. PALs must protect and accept interference from Incumbent Access users but receive protection from General Authorized Access users. Technical rules for PALs can be found in Subpart E of Part 96.

Interactive Map

Tier 3 – General Authorized Access (GAA)

The GAA tier is licensed-by-rule to permit open, flexible access to the band for the widest possible group of potential users. GAA users can operate throughout the 3550-3700 MHz band. GAA users must not cause harmful interference to Incumbent Access users or Priority Access Licensees and must accept interference from these users. GAA users also have no expectation of interference protection from other GAA users. Technical rules for GAA users can be found in Subpart E of Part 96.

Band Plan for 3.5 GHz Band

3.5 Band Plan


Secondary Markets for Priority Access Licenses

Partition & Disaggregation

Priority Access Licensees can partition and disaggregate their licenses. Priority Access Licensees may also partially assign or transfer their licenses. Holders of PALs may enter into de facto transfer leasing arrangements for a portion of their licensed spectrum.

Spectrum Manager Leasing and Light-Touch Leasing

Priority Access Licensees can engage in spectrum manager leasing for any bandwidth or duration of time within the terms of the license. An SAS Administrator may choose to accept leasing notifications and support leasing arrangements under a light-touch leasing procedure, as follows:

  • Lessees seeking to engage in light touch leasing will pre-certify with the FCC that they meet non-lease-specific eligibility and qualification criteria.
  • Priority Access Licensees will notify the SAS Administrator of leasing arrangements with pre-certified lessees.
  • The SAS Administrator will confirm the lessees meet the criteria in their pre-certification filings and the parties meet the lease-specific eligibility requirements. Priority Access Licensees are deemed to meet the certification requirements.  Prospective lessees may also certify their eligibility using the Universal Licensing System and FCC Form 608.
  • After the SAS Administrator’s confirmation, the lessees may immediately begin exercising the leased spectrum usage rights under the lease agreements.
  • On a daily basis, the SAS Administrator will provide the FCC with an electronic report of the leasing notifications. This will be done through an Application Programming Interface.

Priority Access Licensees and lessees may also enter into spectrum manager leases using the general 21-day notification procedure in ULS.  Regardless of whether the Priority Access Licensee and lessee enter into a spectrum manager lease via the light-touch notification process or the 21-day notification process, the Priority Access Licensee must notify an SAS Administrator before the lessee is permitted to operate.

Spectrum Access System

Automated frequency coordinators, known as Spectrum Access Systems (SASs), will facilitate sharing among the three tiers of authorized users in the 3.5 GHz band and authorize the use of PALs and GAA operations with information from an approved Environmental Sensing Capability (ESC) sensor.  Following Auction 105, SAS Administrators will assign channels to PALs.  The SASs will "assign geographically contiguous PALs held by the same Priority Access Licensee to the same channels in each geographic area" and "assign multiple channels held by the same Priority Access Licensee to contiguous frequencies within the same License Area," to the extent feasible. See 47 CFR 96.25.

SAS Administrators must be capable to receiving and responding to interference complaints from Fixed Satellite Service (FSS) earth station licensees in the 3600-3700 MHz band.  SAS Administrators are required to implement and enforce additional protection criteria for C-Band FSS earth stations used for telemetry, tracking, and control using the same methods used to protect in-band FSS earth stations.

SAS Administrators are prohibited from disclosing disaggregated Citizens Broadband Radio Device registration data to the public, except where such disclosure is authorized by the registrant or required by law.  SAS Administrators must make aggregated spectrum usage data for any particular area of interest available to the public.

The Wireless Telecommunications Bureau and Office of Engineering and Technology, in close consultation with the National Telecommunications and Information Administration and the Department of Defense, approved the following Spectrum Access Administrators for full scale commercial deployments:

  • Amdocs
  • Federated Wireless
  • Google
  • Sony
  • Key Bridge

Environmental Sensing Capability

An Environmental Sensing Capability (ESC) is a system that detects and communicates the presence of a signal from an Incumbent user to a SAS to facilitate shared spectrum access.  ESCs will detect federal frequency use in and adjacent to the 3.5 GHz band and transmit that information to the SASs.

The Wireless Telecommunications Bureau and Office of Engineering and Technology, in close consultation with the National Telecommunications and Information Administration and the Department of Defense, reviewed and approved the following four ESC Sensor Registrations:

  • CommScope
  • Federated Wireless, Inc.
  • Google
  • Key Bridge
Monday, April 3, 2023