Spectrum rules and policies for the operation of unmanned aircraft systems: A look at the FCC’s latest Notice of Proposed Rulemaking
On January 4, 2023, the FCC released a notice of proposed rulemaking (NPRM) addressing the spectrum rules and policies for the operation of unmanned aircraft systems (UAS), otherwise known as drones. Public comments and reply comments to the NPRM will be due 30 days and 60 days, respectively, from the document’s publication in the Federal Register, which has not yet occurred. Based on past experience, we expect the comment deadlines to fall in the mid-March and mid-April timeframes.
The 5030-5091 MHz band is allocated domestically for UAS control, non-payload communications (CNPC), consistent with international allocations. This proceeding is intended primarily to develop the technical and operational service rules to allow access to this spectrum band.
However, the FCC made clear that it does not intend to mandate that all UAS CNPC occur exclusively in the 5030-5091 MHz band and that other licensed bands, including the flexible-use bands where mobile networks are already deployed as well as the 450 MHz General Aviation Air-Ground band, are being explored as platforms for UAS operations. To that end, the NPRM also addresses airborne use of flexible-use spectrum allocations used primarily for terrestrial mobile services.
I. UAS communications in the 5030-5091 MHz band
The NPRM identifies two UAS use cases for purposes of determining the appropriate band plan and service rules: (1) non-networked access (NNA), for operations within radio-line-of-sight of the UAS operator; and (2) network-supported service (NSS) operations which rely on network infrastructure to go beyond radio-line-of-sight of the operator. The NPRM proposes to dedicate at least 10 MHz of the band for NNA and seeks comment on how best to structure the band between NNA and NSS operations.
For NNA operations, access to the band would be managed by one or more dynamic frequency management systems (DFMS). The DFMS would assign, through an automated process, frequencies for temporary use in a particular geographic area and time period in support of the operator’s submitted flight plan. The notice seeks comment on the requirements and responsibilities for both the DMFS system(s) and its administrator(s).
The NPRM proposes that only CNPC traffic would be permitted but seeks comment on other approaches such as restricting NNA to CNPC while permitting NSS licensees to also transmit UAS payload communications.
NNA operations would be authorized on a “licensed-by-rule” basis for both aircraft and ground stations. Operators would not be required to apply for individual spectrum licenses. Instead, parties using rule-compliant stations and operating in compliance with the rules would only need to obtain the requisite temporary frequency assignment from a DFMS in order to transmit in the band in the requested location, frequency, and timeframe. The FCC seeks comment on the necessary technical requirements for NNA operations, which would include FCC equipment authorization.
NSS spectrum blocks would be licensed for exclusive use on a geographic area basis. The NPRM seeks comment on the appropriate geographic license areas, license terms, performance (build-out) requirements, and technical standards. In the event that mutually exclusive license applications are received, the FCC proposes to assign these exclusive-use licenses through a system of competitive bidding (eg, spectrum auctions).
II. Airborne use of flexible-use spectrum
The NPRM notes that the use of flexible-use spectrum and existing networks as platforms for UAS offers promise because they provide significant coverage with low latency, high throughput, and dedicated and secure communications. But such networks were not designed for UAS use and the integration of UAS into terrestrial mobile networks may not be a seamless transition as terrestrial mobile service rules generally do not consider airborne use or whether there is the potential for increased interference if UAS are introduced.
The rules for flexible-use spectrum are varied – some bands expressly prohibit airborne use while other are silent on airborne operation. Parts 22 and 96 explicitly prohibit airborne use of Cellular Radiotelephone Service and CBRS spectrum while the Table of Frequency Allocations prohibits aeronautical mobile use for several other spectrum bands, including all or portions of the 1670-1675 MHz, 1.4 GHz, 2.3 GHz, and 3.7 GHz bands.
The FCC seeks comment on the spectrum bands that might be utilized for UAS, as well as the spectrum bands that would not be suitable for such operation (eg, frequency bands with co-channel or adjacent channel services that require protection).
III. Licensing UAS operators for VHF communications
The NPRM proposes to provide UAS operators access to aeronautical VHF frequencies in order to communicate with air traffic control facilities when required by the FAA.
Learn more about the implications of this NPRM by contacting any of the authors.