Industry companies and groups disagreed sharply on the best way for the FCC to open the 12.7 GHz band for other users, and whether it should be offered for exclusive-use licenses or be the next big sharing band. Band incumbents urged caution. Comments were due Monday and posted Tuesday in docket 22-352. The FCC approved a notice of inquiry in October on what others call the 13 GHz band (see 2210270046).

Representatives of the Edison Electric Institute, the National Rural Electric Cooperative Association, the American Public Power Association and the Utilities Technology Council urged the FCC to focus on real-world tests of potential 6 GHz interference, in a call with an aide to FCC Chairwoman Jessica Rosenworcel. The advocacy is consistent with the long-term focus of utilities on the need for testing (see 2211030066). “The Commission has a critical role to play in supporting such testing, which must be conducted in a collaborative, transparent and inclusive manner,” said a filing posted Monday in docket 18-295. “Although simulations do play an important part in assessing the interference potential of unlicensed 6 GHz operations, the Commission should also recognize the accuracy of real-world interference testing in developing measurements from actual deployments,” the groups said. “Underlying inputs and the algorithms” used in simulations also “need to be disclosed so that they are repeatable and transparent,” they said.

Citing a CableLabs analysis, NCTA said the power spectral density limit for 6 GHz low-power indoor access points floated in the 6 GHz Further NPRM isn't a big risk of causing harmful interference to incumbent fixed service links. It said in docket 18-295 Tuesday the analysis confirms its assertion that radio local area network power is only one factor affecting FS links, and not nearly as big a factor as link fading.

The FCC Office of Engineering and Technology appears to be taking a relatively conservative approach to interference mitigation in the 6 GHz band as it works through issues raised in an April 2020 Further NPRM (see 2004230059), industry officials told us. Apple and Apple/Qualcomm met with OET in recent days on the Monte Carlo simulations the tech companies are relying on to justify very-low power (VLP) operations in 6 GHz at the 14 dBm power levels proposed in the FNPRM.

Representatives from Miami-Dade County and APCO asked for help from the FCC, alleging interference in the 6 GHz band is keeping the county from using a new communications system. “Miami-Dade cannot fully utilize its new 6 GHz microwave system for the life-safety communications it was designed for until the interference is resolved,” said a filing posted Tuesday in docket 18-295. Officials met with staff from the Enforcement and Public Safety bureaus. An investigation tied the interference to part 15 devices used in an enterprise system managed by CitySpan, the filing said: “Interference … was causing a significant increase in noise floor and reduction in receiver threshold for the microwave links impacted. Identifying the source of interference was particularly difficult because the device’s frequency hopping made the interference inconsistent.” San Francisco-based CitySpan didn’t comment.

Bluetooth SIG announced a specification development project to define the operation of Bluetooth Low Energy in additional unlicensed mid-band spectrum, including the 6 GHz frequency band. “Expanding into the 6 GHz spectrum band will ensure the community can continue to make the enhancements necessary to pave the way for the next twenty years of Bluetooth innovation,” said Bluetooth SIG CEO Mark Powell Wednesday. The Wi-Fi Alliance “looks forward to collaborating with the Bluetooth SIG to ensure our successful co-existence in the band,” said Wi-Fi Alliance CEO Kevin Robinson.

Apple representatives spoke with FCC Office of Engineering and Technology staff about technical problems, including radio local access network/fixed service interference in the 6 GHz band, said a filing posted Wednesday in docket 18-295. The meeting last week came three days after a similar meeting Apple and Qualcomm had with OET staff (see 2211100045). “We discussed methodologies for probability analyses used to assess RLAN/FS interactions, including an overview of the structure and interpretation of Monte Carlo analyses; the analytic advantages of Monte Carlo analyses for the study of interference probabilities over large geographic areas; and the differences between the methodology employed” in tests in the E.U., and in models by RKF and CableLabs in the U.S., Apple said.

Qualcomm representatives met with FCC Office of Engineering and Technology staff about the company’s geolocation technologies for standard power devices used in the 6 GHz band and how they will “operate in conjunction with an Automated Frequency Coordination system,” said a filing posted Monday in docket 18-295. OET recently conditionally approved AFC systems in the band, subject to testing (see 2211040055).

Apple and Qualcomm representatives met with FCC Office of Engineering and Technology staff to discuss “the parameters that underlie probability analyses assessing” radio local access network and fixed service “interactions” in the 6 GHz band. The discussion noted “the importance of including parameters accounting for far-field loss, different bandwidths, different power-levels, instantaneously transmitting devices, propagation loss, RLAN and FS height, transmit power control, antenna patterns, polarization mismatch, feeder loss, and FS noise,” said a filing posted Thursday in docket 18-295. The companies cited “differences in the probability analyses already on the record,” including analyses by RKF, the EU and CableLabs, the filing said.

Southern Co. urged continuing caution as the FCC considers approving automated frequency coordination providers in the 6 GHz band. The agency issued a public notice last week (see 2211030066). Some proposed AFC providers expect required tests to be completed by early next year (see 2211040055). Southern officials met with aides to Chairwoman Jessica Rosenworcel and Commissioner Geoffrey Starks, said a filing posted Wednesday in docket 18-295. Southern asked the FCC to require broader tests using Wi-Fi 6E systems available at the University of Michigan. “Southern noted the particular value of collecting data on current Wi-Fi operations to the successful development and implementation” of AFC, the company said. Southern “remains very concerned about the potential for harmful interference to licensed 6 GHz systems that support critical electric utility and public safety operations and the potential consequences of any disruptions in public safety communications or in utilities’ ability to monitor and control the electric grid,” the filing said: “Southern appreciates the urgency of making additional unlicensed spectrum available for use but urged the Commission not to rush and to take the time needed to ensure the effectiveness of AFC in supporting unlicensed use and protecting incumbent operations in the band.” The Wi-Fi Alliance in a call with an aide to Rosenworcel urged action. The FCC should finalize “procedures for obtaining certification for 6 GHz standard power devices” and issue “as soon as possible, the further Public Notices contemplated by the AFC Conditional Approval Public Notice that will provide additional details on AFC testing protocols,” the alliance said.