Band Plan and Spectrum Assignment
The proposed rules would make available for UAS use licensed spectrum that would provide interference protection for control-and-non-payload communications (CNPC) links. (UAS currently operate on unlicensed, unprotected spectrum.) UAS generally operate within radio line-of-sight of the operator, called Non-Network Access (NNA), or beyond radio line-of-sight using network infrastructure, called Network-Supported Service (NSS). Under the proposed rules, the 5030-5091 MHz band would be partitioned to support both service types, with 10 megahertz dedicated to NNA operations. The FCC asks whether NSS operations should also receive a dedicated spectrum block or whether such operations should be conducted on any available spectrum in the band. The FCC also considers making a spectrum block available for opportunistic use by both NNA and NSS licensees.
To coordinate band sharing, the Commission proposes employing a dynamic frequency management system (DFMS) managed by a third party. The DFMS would assign temporary use of spectrum in a particular geographic area, giving the operator exclusive and protected use of that spectrum for a certain time period. The FCC seeks comment on a DFMS framework and administrator responsibilities, and proposes authorizing the DFMS administrator to charge reasonable fees for its services. The FCC seeks comment on how to administer fees and how to choose a DFMS administrator. Recognizing that UAS operations implicate interested parties across different industries, the Commission sees a possible role for a multi-stakeholder group to help develop the requirements and processes applicable to the DFMS. The group may advise on standards and interference issues associated with UAS operations in the band and address aviation-specific considerations.
FAA Coordination
Under current FAA rules, UAS are permitted to operate in uncontrolled airspace below 400 feet above ground level without specific authorization. Flights in controlled airspace above 400 feet above ground level must generally be coordinated with air traffic control. With UAS potentially sharing controlled airspace, the Commission seeks comment on whether and how frequency assignments should be coordinated with airspace authorization for low altitude, high altitude, and departure and arrival operations.
Scope of Permissible Services
The Commission added an aeronautical mobile (route) service (AM(R)S) allocation in the 5030-5091 MHz band to support UAS communications. AM(R)S is reserved exclusively for communications relating to the safety and regularity of flight, primarily along national or international civil air routes. The FCC proposes to permit only CNPC and to define CNPC as any UAS transmission that is sent to or from the unmanned aircraft (UA) component of the UAS and that supports the safety or regularity of flight.
Licensing and Eligibility
For NNA operations, the Commission proposes a licensed-by-rule authorization for aircraft and ground stations in the band. Operators would not be required to apply for individual spectrum licenses for themselves or their mobile or ground stations to conduct NNA operations in the band. Instead, parties operating in compliance with the rules would only need to obtain a temporary frequency assignment from the DFMS.
Under the proposed rules, any entity would be eligible to apply for a 5030-5091 MHz NSS license, unless the applicant is precluded from holding a license by Section 310 of the Communications Act or is barred under 47 U.S.C. § 1404 from participating in auctions. Licenses would be issued for an initial 15-year term, with subsequent 10-year terms. In the case of mutually exclusive applications, the FCC proposes using a competitive bidding system to assign exclusive-use licenses.
NTIA recommends that license eligibility should require the applicant to certify that it has FAA remote pilot certification or, for an organization, certify that it will only use qualified individuals for its UAS operations.
Equipment Authorization
To ensure reliable and safe equipment in the new band, the FCC proposes equipment authorization requirements similar to those under sections 87.145 and 87.147 of its rules. Section 87.145 requires that each transmitter be certified for use in the relevant service. Section 87.147 establishes a specific equipment authorization process, which requires coordination with the FAA.
Airborne Flexible-Use Spectrum Use
Recognizing uncertainty about the potential interference impacts of UAS use, the FCC asks for comment on the adequacy of current rules to ensure coexistence of existing terrestrial wireless networks and UAS.
Spectrum Rights
Because the Commission’s rules largely presume that wireless networks are terrestrial, the Commission has never explicitly stated what it believes to be the vertical limit of a licensee’s spectrum rights, leaving a question as to the upper limit of license areas and the protections associated with these geographic markets. In the UA context, operation within one license area can potentially affect and be affected by connecting to base stations located inside another license area. Commission policies cause tension by dictating that a license generally provides the licensee exclusive use of the spectrum within its licensed market area and that mobile devices operate under the authority of the licensee whose transmitter is providing service, so final rules must address how and under what circumstances a licensee can enforce its license rights. To this end, the FCC asks whether it should identify a vertical limit at which flexible-use licenses may be used to support UAS on an exclusive or primary basis; any use beyond this limit would be non-primary and would have to accept interference from primary users of the spectrum.
