The FCC is seeking comment on issues involving expanded use of various radar applications in the 76-81 GHz band, which Amateur Radio shares with other services. The band 77.5-78 GHz is allocated to the Amateur and Amateur Satellite services on a primary basis, and to the Radio Astronomy and Space Research services on a secondary basis.

“We undertake this proceeding to expand the available spectrum for radar operations in the 76-81 GHz band,” the FCC said in a detailed Notice of Proposed Rulemaking and Reconsideration Order (NPRM&RO), released February 5 in ET Docket 15-26. The Commission said the proposals include allocation changes as well as provisions “to ensure that new and incumbent operations can share the available frequencies in the band.”

The FCC NPRM&RO is in response to a Petition for Rulemaking (RM-11666) filed in 2012 by Robert Bosch LLC and to two petitions for reconsideration of the Commission’s 2012 Report and Order (R&O) addressing vehicular radar systems in the 76-77 GHz band. ET 15-26 incorporates earlier proceedings.

Among many issues, the FCC seeks comment on the possibility of reallocating the Amateur Radio and Amateur Satellite services from 76-81 GHz, and it asks for suggestions on “alternative spectrum that we might make available in this general region.”

Bosch’s 2012 Petition sought to modify the FCC’s Part 15 rules to expand the operation of unlicensed vehicular radar systems from 76-77 GHz to the 76-81 GHz band to develop short-range radar (SRR) applications. The Bosch petition received “general support from the automotive industry,” the Commission said.

In its petition, Bosch said that it anticipated no interference issues between Amateur Radio operations and vehicular radar operations at 77-81 GHz. “It notes that it is unconvinced after several meetings with the technical staff of ARRL that there is any ‘significant incompatibility,’” the FCC NPRM&RO recounted, “and describes how amateur operations in the band ‘tend to be largely experimental, occurring in geographic areas such as mountaintops and other rural areas where motor vehicle operation is not typical.’”

The FCC noted, however, that it “has previously recognized evidence of potential interference conflicts” between Amateur Radio and vehicular radar systems in the 76-77 GHz band, and believes the potential for “similar compatibility issues” could exist above 77 GHz. More than 10 years ago the FCC suspended Amateur Radio and Amateur Satellite operation in the 76-77 GHz segment and recently extended the suspension.

“Our goal is to adopt rules that address amateur use, including Amateur Satellite use, within the 76-81 GHz band in a comprehensive and consistent manner,” the FCC asserted.

The FCC said that to the extent commenters believe Amateur Radio can continue to use the 4 millimeter band, it seeks comments on “what additional rule modifications we would have to adopt to realize successful shared use of the entire band.” One possibility the FCC raised was altering current amateur power limits in that portion of the spectrum. The Commission said it also wants to “develop a record on the types of amateur use, and the extent of such use, that is currently undertaken” at 4 millimeters.

The ARRL plans to comment in the FCC proceeding.