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ARRL Asks FCC to Protect Amateur Radio Millimeter-Wave Bands


ARRL has asked the FCC to avoid authorizing developmental technologies in two Amateur Radio bands above 95 GHz that some radio amateurs may not be unaware of. The ARRL commented on May 2 in response to a Notice of Proposed Rule Making and Order (NPRM&O) in ET Docket 18-21, released in February. The so-called “Spectrum Horizons” proceeding seeks to make the bands above 95 GHz “more readily accessible for new innovative services and technologies.” ARRL said that, while it agrees that “regulatory flexibility is justified” in the millimeter-wave bands above 95 GHz, due to the extensive frequency re-use possibilities, the FCC ought to make two primary Amateur/Amateur Radio Satellite bands in that part of the spectrum unavailable for deployment of unlicensed Part 15 or Part 5 Experimental Spectrum Horizons devices. Amateur Radio has primary allocation status in the bands 134 – 136 GHz and 248 – 250 GHz, both shared with the Radio Astronomy Service, which is secondary.

“The amateur allocations require protection against increases in the noise floor due to aggregate radio frequency devices,” ARRL said. “The bands are used ubiquitously and unpredictably, typically, but not always, at high elevations for research and development purposes and propagation studies, for terrestrial point-to-point, satellite, and Earth-Moon-Earth communications experimentation.”

ARRL said it would oppose “any proposal to permit unlicensed devices or largely unregulated experimental operations” in the two primary Amateur Radio allocations in the range of spectrum the FCC is considering. “It is critical to preserve for Amateur Radio experimentation the current relatively quiet noise floor, and the positive RF environment that now exists in those two relatively small band segments,” ARRL told the FCC. The League’s comments noted that the secondary Radio Astronomy Service in those two bands also requires a quiet RF environment.

In strongly urging that the FCC not permit unlicensed Part 15 in either primary amateur band “under any circumstances,” ARRL pointed out that the FCC has no data concerning increases in the noise floor from potentially large numbers of unlicensed Part 15 devices in either band. Additionally, ARRL said, “There is no compelling need to include these two bands among those which might be made available for unlicensed devices and systems in this proceeding.”

ARRL said it also would oppose the authorization of Spectrum Horizons experimental authorizations in the two primary Amateur/Amateur Satellite allocations, operating under a new subpart for Spectrum Horizons Experimental Radio Licenses” in the spectrum at issue.

ARRL said it would be difficult for such applicants to make an accurate showing of non-interference in the two amateur allocations, “due to the variety and itinerant nature of Amateur Radio allocations.”

If the FCC should nonetheless decide to permit Spectrum Horizons experimental authorization applicants to apply for 134 – 136 GHz and 248 – 250 GHz, however, ARRL said applicants should have to “demonstrate convincingly” that no other suitable allocations are available, and that they coordinate their operations with ARRL when filing an application.

The omnibus NPRM&O includes consideration of a Petition for Rule Making (RM-11795) from Missouri radio amateur James Whedbee, N0ECN. He asked the FCC to adopt rules to permit the operation of unlicensed devices in the 95 – 1000 GHz range, by and large applying the same technical rules to those unlicensed operations as currently apply in the 57 – 71 GHz band.

Overall, the Commission is on the right track in this proceeding,” ARRL allowed. Opening the millimeter-wave bands to expanded unlicensed operation is not unreasonable. “Some, but not all, of the bands above 95 GHz can be removed from the Part 15 restricted band list in Section 15.205(a) of the Commission’s rules without significant concern,” ARRL concluded. “However, the Amateur Radio primary allocations at 134 – 136 GHz and 248 – 250 GHz, which are shared with radio astronomy, should be unavailable for either Part 15 operation or for other commercial development.”