Recognizing the growing needs of the UAS industry, the World Radiocommunication Conference established new international allocations for aeronautical use in the 960-1164 MHz portion of the L-Band in 2007 and the 5030-5091 MHz portion of the C-Band in 2012. In Section 374 of the FAA Reauthorization Act of 2018, Congress directed the FAA, NTIA, and FCC to consider whether UAS should be allowed to operate in those bands on an unlicensed, shared, or exclusive basis and to identify any barriers to use of the spectrum for UAS. Congress also asked the agencies to identify other spectrum bands that might be suitable for UAS. The FCC developed and recently published its report after a concluding a public comment cycle to inform the record.
5030-5091 MHz Band
The report states that the 5030-5091 MHz band offers “the current best option for a dedicated aeronautical band for UAS” because it is unencumbered and has the capacity to support UAS operations. There are, however, technical and regulatory issues that must be resolved, including: (i) whether the FCC should afford operators in the band flexibility regarding the types of services and applications offered, or if the UAS operations should be limited in terms of altitude or other factors; (ii) the potential implications of the band’s propagation characteristics; and (iii) the potential impact of UAS operations in the band on other operations. The report recommends that the Commission initiate a rulemaking proceeding in the near future to consider how best to allow UAS use of the 5030-5091 MHz band, in close collaboration with the FAA and NTIA.
The Commission noted that the FAA and private industry are already pursuing the development of technical standards for UAS operations in the band. RTCA, a standards development organization, plans to complete work on performance standards to support both radio line-of-sight and beyond-line-of-sight networked command-and-control operations for UAS by the end of 2020. The FAA previously released a Technical Standard Order with performance standards for UAS terrestrial non-networked control system radios in the 5040-5050 portion of the band.
At the FCC, the Aerospace Industries Association (AIA) filed a pending Petition for Rulemaking that proposes service rules to allow UAS command and control operations in the 5030-5091 MHz band. The public comments on the AIA petition showed significant support for the petition but highlighted areas of disagreement that would need to be resolved in the FCC’s rulemaking proceeding. The FCC report expresses optimism about the prospect of licensing UAS operations in this band.
The report also concludes that alternative frequencies licensed under flexible-use service rules are a promising option for UAS operations. The report suggests that beyond-visual-line-of-sight (BVLOS) and other UAS communications might even be realized earlier in some of these bands than in the 5030-5091 MHZ band. There are, however, technical challenges to deployment of UAS in these frequencies. These include varying technical and service rules, as well as concerns about the potential for harmful interference to non-UAS operations conducted over the commercial mobile networks that may end up serving UAS and to operations by other commercial mobile providers that use the same frequencies in neighboring geographic license areas. The report recommends that the FCC continue to review flexible-use bands and explore through public and private sector engagement whether its interference concerns can be mitigated through voluntary industry standards or private agreements. The FCC also acknowledges that regulatory measures may be necessary to bring UAS operations in these bands to fruition.
960-1164 MHz Band
After reviewing the record, the FCC concluded that extensive use of the 960-1164 MHz band for numerous critical aeronautical navigation systems currently limits the potential for UAS operations in there, although it will continue to study the interference and safety challenges involved.
Other UAS Opportunities
The FCC is considering other bands to enable UAS use as well. For example, AURA Network Systems filed a Request for Waiver on June 12, 2020, seeking the ability to provide data and by extension support UAS operations in the 450 MHz band. The FCC sought comment on the waiver request, which now awaits FCC action.
Authored by Lisa Ellman, Michele C. Farquhar, Ari Q. Fitzgerald, John Castle, Matthew J. Clark, and Ambia Harper