The Federal Communications Commission (FCC) is considering rules to enable wireless communications for drones (or unmanned aircraft (UAS)) operating in the 5030-5091 MHz spectrum band and is seeking comment on whether the FCC should take other measures to facilitate drone use on a flexible use wireless network.
According to Chairwoman Jessica Rosenworcel, “it is past time” the FCC assesses the availability of wireless communications resources for the “increasingly important remote-piloted aircraft activity we rely on,” noting critical services being supported by drones today and the potential of this evolving technology.
FCC Commissioner Geoffrey Starks also supported the FCC’s forward-looking proceeding, pointing out that UAS technologies already aid in disaster relief, protect critical infrastructure, enhance smart applications and precision agriculture, improve public safety, and even help make construction safer and more efficient. He supported exploring 5G as a UAS platform and the broader use of cellular bands for drone applications.
These rules will affect UAS manufacturers, service providers, operators, and other stakeholders in the UAS market. The FCC will accept initial input to its Notice of Proposed Rulemaking (NPRM) in comments by March 9 and reply comments by April 10, 2023.
BACKGROUND
Currently, no spectrum is licensed in the United States exclusively for UAS communications, and operators have generally relied on unlicensed low-power wireless operations or experimental licenses to support communications for UAS operations.
In 2012, the FCC allocated the 5030 – 5091 MHz band to the aeronautical mobile (route) service (AM(R)S) on a primary basis to support terrestrial control links for UAS but did not adopt any rules to license or govern UAS services deferring to future proceeding to develop “[t]echnical and operational rules relating to altitude, weight, or other requirements.” Following industry requests to move ahead and further FCC’s study and collaboration with the FAA, the National Telecommunications and Information Administration (NTIA), and the Department of Transportation, the FCC’s NPRM proposes an incremental approach to regulating UAS operation to support drone innovation and ensure robust, reliable, and safe UAS deployments.
REQUEST FOR COMMENT
The FCC’s lengthy (89 page) NPRM proposes multiple detailed technical and operational rules or UAS communications primarily on the following topics.
Service Rules for the 5030-5091 MHz Band
The NPRM explicitly states that the FCC does not intend to mandate that all UAS control-and-nonpayload communications (CNPC) occur exclusively in the 5030-5091 MHz band; instead, 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.
The NPRM identifies two UAS use cases: (1) Non-Network Access (NNA), generally operated within radio line-of-sight of the operator and (2) Network-Supported Service (NSS), generally operated beyond radio line-of-sight using network infrastructure. Under the proposed rules, the 5030-5091 MHz band would be partitioned to support both use cases, with five megahertz blocks at the bottom (5030-5035 MHz) and top (5086-5091 MHz) of the band for NNA use.
The FCC seeks comment on whether NSS operations should also receive a dedicated spectrum block (and the appropriate spectrum block size), whether such operations should be conducted on any available spectrum in the band, and whether the spectrum block dedicated for NSS use should also allow for opportunistic use by NNA. The FCC also considers making a spectrum block available for temporary, opportunistic access by both NNA and NSS licensees.
Figure 1 - Proposed Use of the 5030-5091 MHz Band
The NPRM clarifies that FCC is also open to considering alternative approaches to allocating the 5030-5091 MHz band for the support of UAS and welcomes recommendations from outside parties on this aspect.
Dynamic Frequency Management System
The NPRM proposes that access to the band be managed by one or more dynamic frequency management systems (DFMS) and contemplates that each DFMS be managed by a private third-party DFMS administrator. The NPRM proposes permitting more than one DFMS, each providing access to frequencies nationwide, and requiring coordination and communication between them to ensure that the assignments of one DFMS are consistent with the assignments of the others. Based on its past successful experiences with automated dynamic frequency management systems in other bands (e.g., the Spectrum Access System that was adopted in the 3.55-3.7 GHz band), the FCC tentatively concludes that the DFMS approach is feasible and practical.
However, the FCC acknowledged the many unique challenges of ensuring appropriate protection and reliability for all authorized UAS operations in the band, which could involve highly diverse and evolving operations with different risk profiles, altitudes, flight speeds, and spectrum needs in a shared spectrum environment, and could potentially involve the need for mid-flight alterations to flight plans and other operational complications. The NPRM accordingly seeks comment on the appropriate regulatory framework to establish for a DFMS, including the requirements and responsibilities of a DFMS administrator.
Similar to the 3.5 GHz rules, the FCC proposes authorizing the administrator of a DFMS to charge reasonable fees for its provision of services, including registration and channel assignment services, and permitting parties to petition the FCC to review fees and require changes. The NPRM also asks whether the process for selecting the DFMS administrators should be modeled on the 3.5 GHz SAS approval process.
Multi-Stakeholder Group to Develop UAS
The NPRM considers a possible role for a multi-stakeholder group to help develop the requirements and processes applicable to the DFMSs, in addition to study standards and interference issues associated with UAS operations in the band. If there is a role for such a multi-stakeholder group, the NPRM seeks comment on the appropriate extent of that role and the responsibilities, including, for example, developing consensus standards and recommendations to one or more of the stakeholder agencies.
Permissible Services
The FCC asks whether it should explicitly define covered categories of communications, such as (1) telecommands to the unmanned aircraft; (2) telemetry from the unmanned aircraft that is relied upon for flight guidance or other flight safety-related purposes, such as geofencing to protect sensitive areas; (3) transmissions related to detect-and-avoid operations; (4) video transmissions from the unmanned aircraft relied upon for flight guidance or other flight safety-related purposes; (5) air traffic control communications relayed via the unmanned aircraft; and (6) remote identification transmissions.
The NPRM also highlights two potential distinctions between NNA and NSS operations. First, NSS operations will require deployment of networks that will require a very substantial investment, in contrast to NNA operations that can occur without any network deployment. Second, network technologies may be better positioned than direct-link systems to implement a successful prioritization of CNPC. The NPRM seeks comment on whether NNA operations should be restricted to CNPC but NSS licensees permitted on a broader scope, such as a scope permitting UAS payload communications or permitting both UAS and non-UAS payload communications.
Licensing Rules
For licensing rules associated with NNA service, the NPRM seeks comment on whether the FCC should adopt a licensed-by-rule authorization in anticipation of a large number of operators seeking temporary use of the band. The NPRM explains that Section 307(e) of the Communications Act authorizes the FCC to adopt a licensed-by-rule approach for certain specific categories of services and the FCC tentatively finds that licensing by rule of NNA stations would serve public interest, convenience, and necessity. The NPRM also notes that NTIA’s recommendation is to require the applicant to certify that it has FAA remote pilot certification or, in the case of an organization, certify that it will only use qualified individuals for its UAS operations. However, if the NPRM’s proposed licensed-by-rule model is adopted, UAS operators will not be required to make the proposed certification. In other words, UAS operators using rule-compliant stations and operating in compliance with the rules would only need to obtain the requisite temporary frequency assignment from the DFMS in order to transmit in the band in the requested location, frequency, and timeframe and not be required to ensure FAA remote pilot certification.
The NPRM also seeks comment on licensing rules for NSS operation. There, the NPRM proposes to license NSS spectrum blocks in the 5030-5091 MHz band for exclusive use on a geographic area basis. The NPRM explains that geographic area licensing will promote expedited assignment of licenses and can utilize competitive bidding when mutually exclusive applications are received. The NPRM additionally seeks comment on performance (or network build-out or coverage) requirements for NSS licenses. Notably, the NPRM queries whether any NSS license holders be considered as “holding a “common carrier[,] aeronautical en route or aeronautical fixed radio station license” and, if so, how any foreign-ownership holdings should be evaluated.
Under the proposed rules, NSS licenses would be issued for an initial 15-year term, with subsequent 10-year terms. In the case of mutually exclusive applications, the NPRM proposes using a competitive bidding system to assign exclusive-use licenses.
Equipment Authorization Rules
To ensure reliable and safe equipment for use in the 5030-5091 MHz band, the NPRM proposes imposing equipment authorization requirements similar to those under Sections 87.145 and 87.147 of the FCC’s rules to all equipment intended for use in the 5030-5091 MHz band. 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
The NPRM recognizes that there is considerable interest in the use of flexible-use spectrum and existing networks as platforms for UAS because they provide “significant coverage with low latency, high throughput, and dedicated and secure communications.” However, the integration of UAS into the existing terrestrial mobile networks may not be a seamless transition, as the existing rules generally do not consider airborne use (for example, the Table of Frequency Allocations precludes aeronautical mobile use for all or portions of the 1670-1675 MHz, 1.4 GHz, 2.3 GHz, and 3.7 GHz bands, while other flexible-use bands are silent regarding airborne operations). The NPRM seeks comment on the necessary regulatory solutions to facilitate and encourage the use of a flexible-use spectrum.
Licensing UAS Operators for Aeronautical Very-High-Frequency Communications
The NPRM additionally contemplates requiring that UAS operators obtain a formal license to ensure compliance with current airspace law. As the FCC explained, the aeronautical very-high-frequency (VHF) band (117.975 MHz -137 MHz) is currently used by aviation for air traffic control and advisory communications, among other aviation-safety purposes. UAS operators requesting the use of the aeronautical VHF band are currently authorized by special temporary authority on a case-by-case basis.
Due to the potential exponential growth of the UAS fleet, the NPRM does not propose a licensed-by-rule approach to operators’ stations in the VHF band. Rather, operators would be required to file a license application with the FCC for an individual license covering their VHF station. This would permit operators to communicate with air traffic control and other aircraft within the spectrum band. The NPRM seeks comment on the several proposed licensing mechanisms designed to address the growing concerns of the UAS operations in the VHF band.
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