Astronomers Urge More Protection for Radioastronomy in 42 GHz Band

The National Academy of Sciences, through its Committee on Radio Frequencies (CORF), urged the FCC to provide more certainty on radioastronomy service (RAS) use of the 42 GHz band, in response to an NPRM on sharing the band (see 2308310053). The comments were posted Friday in docket 23-158. “As the Commission has recognized throughout … radio astronomy is a vitally important tool used by scientists to study the universe,” CORF said. The commission proposes that RAS observations be protected, but “it does not propose a means for doing so,” the committee said: “At 42 GHz, terrain shielding can provide effective protection to an RAS observatory. However, this shielding is highly dependent on the details of the surrounding topography and the nature of a prospective active service deployment. Thus … coordination requires the use of terrain elevation data combined with an irregular terrain propagation model.” In another filing, Qualcomm said its long-standing proposal for licensed sharing in the 37 GHz band (see 2104280038) could also work in 42 GHz. “Qualcomm’s technology-based sensing proposal enables licensed sharing of the entire band in the same location, at the same time, and on the same exact frequencies, by taking advantage of synchronized access, energy measurements, and the highly directional nature of millimeter wave communications,” the company said. The Wireless ISP Association opposed the Qualcomm model, which was mentioned in the 42 GHz NPRM. “The approach Qualcomm offers would require users to shut down for a given period of time, deploy sensing capability to detect other transmitters, and then transmit only where there would be no predicted harmful interference,” WISPA said: “It would be difficult, if not impossible, for licensees to build a business model under this narrow approach when consumers need real-time access to connectivity.”