Carriers Warn Against Excessive Limits on 24 GHz Band
Carriers need more spectrum and the 24 GHz band is important to deploying 5G, CTIA said in reply comments on a December NPRM examining changes to the rules. CTIA and other wireless industry commenters said the FCC should harmonize rules with decisions made during the World Radiocommunication Conference in 2019 but go no further.
“While policymakers’ focus is appropriately on the need for additional mid-band spectrum, access to high-band spectrum (such as the 24 GHz band) remains an important element of the broader spectrum approach,” CTIA said: “High-band spectrum provides dramatically higher speeds and capacity, which are key to realizing the full potential of 5G.”
Reactions have been mixed (see 2402280037). Replies were posted on Friday in docket 21-186.
Commissioners Brendan Carr and Nathan Simington dissented on the NPRM. Carr noted it asks questions for changes that go beyond decisions made at the WRC and argued that it’s bad policy to change the rules for a band years after licenses are sold at auction. The FCC sold 24 GHz licenses in a 2019 auction for a total of roughly $2 billion. AT&T was the top bidder -- winning 831 licenses in 383 markets with bids of $982.5 million. T-Mobile also went big, with $803.2 million for 1,346 licenses in 400 markets (see 1906030063).
The record in the proceeding shows widespread support for aligning the rules with decisions made at WRC-19, CTIA said. Commenters make clear that “going beyond the WRC-19 agreement is unnecessary to protect passive operations and would cause substantial harm to 24 GHz licensees.” CTIA noted that non-federal licensees and federal agencies have deployed nearly 40,000 point-to-point microwave links in the 21.2-23.6 GHz band adjacent to the 23.6-24 GHz passive band: “There is no indication that these operations have caused harmful interference to passive sensors in 23.6-24 GHz.”
WRC Resolution 750, which addressed the 24 GHz band, was “a carefully crafted, negotiated consensus” among International Telecommunication Union member states “on how to protect passive sensors in the 23.6-24.0 GHz band, while continuing to promote” 5G, AT&T said. The FCC should reject calls for stricter limits as unnecessary, the carrier said. While NTIA is open to stricter out-of-band emissions limits, the agency concedes “that adopting the limits in Resolution 750 would ‘minimize interference to passive sensors from new 5G broadband services’ and allow for continued operation of important federal missions,” AT&T said.
“There is no engineering evidence to support the Commission departing from the agreed outcome at WRC-19,” T-Mobile said. While the carrier agrees earth exploration satellite service sensors are important, “there has been no demonstration that the limits adopted at WRC-19 are not sufficient to protect them.” T-Mobile said the industry should comply with revised rules, especially since gear is different for the U.S. and European markets. In the U.S., the band consists of two non-contiguous band segments -- 24.25-24.45 and 24.75-25.25 GHz, T-Mobile explained. “In Europe, the 24 GHz band is contiguous and does not have the gap in the 24.45-24.75 GHz segment.”
Nokia agreed with earlier comments that limits should apply only to base and mobile stations and handsets and not small cells or other operations the rules allow (see 2402290074). Fixed operations “have considerably different equipment characteristics and deployments” compared to international mobile telecommunications “including highly directive antennas and transmissions in fixed directions, which minimize emissions in the direction of satellites,” Nokia said. “Only IMT stations were the subject of the WRC-19 studies” that led to the unwanted emissions limits in Resolution 750, the company said.