May 16, 2016The Federal Communications Commission (FCC) has released a Second Report and Order containing the final rules governing the Citizens Broadband Radio Service (CBRS) in the 3,550 to 3,700 MHz (3.5 GHz) band. These rules, which allow commercial shared use of 150 MHz of the 3.5 GHz spectrum, are certain to speed up the implementation of small cell and distributed antenna system (DAS) technologies.
These technologies are mainly used by cellular companies, large and small, to increase transmission capacity and extend their coverage. They are great for enabling in-building cellular coverage, but they work outdoors as well. Internet of Things and machine-to-machine technologies are placing a drain on available spectrum, and that drain is expected to increase sharply as IoT networks grow. Sufficient spectrum at all frequency ranges is needed to support the many forms of IoT technology. The wider availability of the 3.5 GHz spectrum increases capacity and extends coverage of wireless services, thereby providing new connectivity options for IoT applications in industry, smart buildings and homes, and smart-city infrastructure.
Additionally, wider access to the 3.5 GHz spectrum band is important because much of it will be unlicensed, meaning that entities that deploy small cells or DAS networks can provide in-building service economically, as they will not have to incur the costs of bidding for spectrum and paying the requisite licensing fees.
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 that will bid for small census tract licenses in upcoming auctions
3) General Authorized Access (GAA) operators that 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, but it made some important rule and policy adjustments.
The new rules will not only make use of the 3.5 GHz spectrum easier to access, but also 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 for which no mutual exclusivity exists, the FCC will cancel the auction for that area and assign the subject spectrum for GAA use.
To provide more incentive for broadband coverage in rural areas, the FCC modified its auction rules to allow for the assignment of a PAL without an auction in rural areas when there is only a single applicant for a PAL. A rural area is defined as a census tract not located within or overlapping a town containing 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 had 60 seconds to cease transmission, move to another frequency range or change its power level once it received a command from a Spectrum Access System (SAS) alerting it to a federal system emitting an interferring signal nearby. 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 eliminated the previously imposed conducted power limits for all CBSDs and 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, if 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 the following: the licensee and lessee must complete an FCC Form 608 through the FCC's database; the lessee must certify that it meets the basic FCC requirements to hold a license; the licensee must notify the SAS of the leasing arrangement (providing a substantial amount of information); and the SAS must be able to confirm that the lessee provided the required certification to the FCC, the lease will not violate the 40 MHz spectrum aggregation limit for the specific census tract, and the lease area is within the licensee's service area, but outside of its PAL Protection Area.
Ronald E. Quirk, Jr., the head of The CommLaw Group's Internet of Things Practice Group, focuses his practice on federal, state and international telecommunications regulation and policy, with a particular expertise in assisting clients in navigating the complex labyrinths of radio frequency equipment authorization, licensed and unlicensed spectrum allocation, and enforcement processes in the United States and around the world. If you have questions regarding use of the 3.5 GHz spectrum or seek advice on how to obtain authorization and remain in compliance with the FCC's rules, you may contact him at firstname.lastname@example.org or (703) 714-1305.
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.