FCC Finalizes Rules for Commercial Use of the 3.5 GHz Band

The Federal Communications Commission (“FCC”) has released a Second Report and Order containing the final rules governing the Citizens Broadband Radio Service (“CBRS”) in the 3550-3700 MHz (“3.5 GHz”) band. These rules, which allow commercial shared use of 150 MHz of 3.5 GHz spectrum, are certain to speed the implementation of small cell and distributed antenna system (“DAS”) technologies.  As these technologies are instrumental in the Internet of Things (“IoT”) industry, smart buildings, smart homes, and smart cities will grow exponentially in the coming years as the 3.5 GHz spectrum increases capacity and extends coverage of wireless services.

The original rules, released in an April 2015 Report and Order, delineated three tiers of 3.5 GHz operations: (1) incumbents (federal users and fixed satellite service (“FSS”) operators); (2) Priority Access (“PA”) licensees who will bid for small census tract licenses in upcoming auctions; and (3) General Authorized Access (“GAA”) operators, who will have access to 80 MHz of unlicensed spectrum in the 3.5 GHz band.   CBRS encompasses the PA and GAA portions of the 3.5 GHz spectrum.

Commercial Benefits of the New Rules and Policies

In the Second Report and Order, the FCC reaffirmed the regulatory approach adopted in the original Report and Order.[1]  But, the FCC made some important rule/policy adjustments, based on issues addressed in Petitions for Reconsideration of the Report and Order, and public comments solicited by the FCC in a Further Notice of Propose Rulemaking. Most of the new rules and policies are summarized herein.[2]

The new rules will not only make access to the 3.5 GHz spectrum easier, they will permit more efficient and profitable use of it by PA licensees and GAA operators.  Equipment manufacturers will also benefit, as the FCC has liberalized equipment interference response time, increased power limits, and permitted an alternative RF emissions testing methodology.                            

Auction Exemption for Rural PA Licenses

The original rules provided that all PA Licenses (“PALs”) are to be distributed via auction when mutual exclusivity exists.  In other words, when multiple applicants apply to bid on more PALs than exist in a given census tract, the PALs will be subject to competitive bidding.  In cases where no mutual exclusivity exists, the FCC will cancel the auction for that area and assign the subject spectrum for GAA use.

The FCC, in an attempt to provide more incentive for broadband coverage in rural areas, modified its auction rules to allow for the assignment of a PAL without an auction in rural areas when there is only one applicant for a PAL. A rural area is defined a census tract not located within or overlapping a town with more than 20,000 people or an urbanized area adjacent to a city that has more than 50,000 inhabitants.

CBRS Equipment Response Time Increase

The FCC requires that transmission equipment with specific, standardized capabilities be employed by CBRS operators for use in the 3.5 GHz band.   The FCC defines this equipment as Citizens Broadband Service Device (“CBSD”). There are two types of CBDSs:  Category A (lower power CBSD) and Category B (higher power CBSD which may only be used outdoors).

Under the original rules a CBSD must, within 60 seconds of receiving a command from a Spectrum Access System (“SAS” - a highly automated frequency coordinator) that a signal from a federal system is in a given area: (A) cease transmission, (B) move to another frequency range, or (C) change its power level.  Acknowledging comments asserting that 60 seconds is too short a time for operators to effectively re-configure their networks in response to reported interference, the FCC increased the reconfiguration timeframe to 300 seconds.

Power Limit Increase for CBRS Equipment

Acknowledging comments that additional flexibility for CBSDs would promote 3.5 GHz deployment, the FCC agreed to liberalize the power limits imposed in the original rules. Specifically, the FCC: (1) eliminated the previously-imposed conducted power limits for all CBSDs; and (2) increased the maximum allowable equivalent isotropically radiated power (“EIRP”) for non-rural Category B CBSDs from 40 dBm/10 MHz to 47 dBm/10 MHZ.  This EIRP increase makes the power levels for rural and non-rural deployments identical.              

Testing/Emission Power Measurements

The original rules required that when CBSDs are tested for compliance with the RF emissions rules, the emission power measurements must be performed with a peak detector in maximum hold. After considering comments that requiring devices to be tested in such a manner was a poor representation of actual interference impact, which could effectively prevent deployment, the FCC concluded that emissions measurements may be performed using either root-mean-square (“RMS”) detection, which calculates  “average loudness” of a signal, or peak detection.

“Use” of PA Frequencies Defined

Under the FCC’s rules, when a PAL has not been issued for a given census tract or the spectrum is not in use by a PA licensee, the SAS will automatically make the spectrum available for GAA use. The term “use” was not previously defined. The FCC has decided on a two-pronged approach to determining “use” by a PA licensee.

First, PA licensees may self-report to the SAS their “PAL Protection Areas” on the basis of their actual network deployment.  Second, to establish a consistent objective maximum PAL Protection Area, an SAS will use a consistent model to define a default -96 dBm/10 MHz protection contour.

The FCC encourages PA licensees to work with the SAS to restrict their PAL Protection areas to less than the above-described default protection contour. The idea is that more spectrum will be available for other users, which will in turn permit licensees to lease more spectrum, as described below. PA licensees may freely alter their reported PAL Protection Areas during their license terms by reporting such changes to the SAS.

Spectrum Leasing Permitted

The FCC has settled on “light touch” spectrum manager leasing rules for PA licensees. Specifically, a PA licensee may lease any portion of its census tract geographic area for any bandwidth for any period of time within the scope of the PAL but outside of its PAL Protection Area.

The basic procedure requires: (1) the licensee and lessee must complete an FCC Form 608 through the FCC’s database; (2) the lessee must certify that it meets the basic FCC requirements to hold a license; (3) the licensee must notify the SAS of the leasing arrangement (providing a substantial amount of information); and (4) the SAS must be able to confirm that (a) the lessee provided the required certification to the FCC, (b) the lease will not violate the 40 MHz spectrum aggregation limit for the specific census tract, and (c) the lease area is within the licensee’s service area, but outside of its PAL Protection Area.


This article provides a high-level general overview of the new rules pertinent to use of the 3.5 GHz spectrum band. The overall regulatory regime for 3.5 GHz is very complex, and potential service providers wishing to utilize this band are well advised to contact an experienced consultant or attorney for advice on how to obtain authorization and remain in compliance with the FCC’s rules.

If you would like further information, please contact IoT Attorney, Ronald E. Quirk, Jr., at [email protected] or 703-714-1305.

Ronald E. Quirk, Jr. is Head of The CommLaw Group’s Internet of Things Practice Group.  Mr. Quirk focuses his practice primarily on federal, state and international telecommunications regulation and policy, with a particular expertise in assisting clients navigate the complex labyrinths of radiofrequency (“RF”) equipment authorization, licensed and unlicensed spectrum allocation, and enforcement processes in the U.S. and around the world.  Mr. Quirk also counsels clients on a variety of legal and regulatory matters, including:  spectrum allocation & leasing, public safety communications; wireless licensing, policy and regulatory issues;  experimental licensing; privacy; VoIP policy and state regulation; satellite regulation; and state and federal Universal Service requirements and project funding through Universal Service programs.


Disclaimer: This article is intended for informational purposes only and is not for the purpose of providing legal advice. You should not act upon the information in this article without seeking professional counsel.


© 2016 Marashlian & Donahue PLLC.   All rights reserved.


[1] The author has published detailed articles concerning the entire 3.5 GHz regulatory regime and business opportunities offered by this spectrum band.   Those articles are available via The CommLaw Group’s website or upon request to the author. 

[2] The FCC also promulgated new rules for the protection of FSS earth station licensees.  Those rules are beyond the scope of this article.  If you would like information concerning the new FSS protection rules, please contact the author.

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