In Win for Wi-Fi Industry, FCC Approves Launch of 6 GHz AFCs

OET cleared the applications to operate AFC systems submitted by Broadcom, Qualcomm, Federated Wireless, Sony, Comsearch, the Wi-Fi Alliance and the Wireless Broadband Alliance (WBA). It also sought comment by March 15 on C3Spectra’s AFC proposal, in docket 21-352.

The seven AFC systems “have undergone a rigorous testing program, as directed by OET, which included both lab testing and a public trial,” OET said: “The results from this testing indicate that these … systems operate in conformance with the Commission’s 6 GHz band (5.925-7.125 GHz) unlicensed rules, which are designed to prevent harmful interference from standard power access devices and fixed client devices to licensed microwave receivers and certain radio astronomy observatories in the 6 GHz band.” The companies can now manage spectrum in two parts of the band -- 5.925-6.425 and 6.525-6.875 GHz.

OET conditioned the approvals on the operators working together “to create a process for receiving and addressing complaints of potential interference.” OET said that process is important “given the obligation that unlicensed devices not cause harmful interference to licensed operations.” OET required the process to be in place by April 23.

The approvals “mark a major milestone for widespread deployment of unlicensed operations in the 6 GHz spectrum band and for the unlicensed ecosystem overall,” said FCC Chief Engineer Ron Repasi.

The approval solidifies the FCC’s commitment “to unlocking the full potential of the 6 GHz band for unlicensed technology, playing a huge role in bridging the digital divide and enabling enhanced outdoor operations,” Chris Szymanski, Broadcom director-product marketing and technology strategy, wrote in a Friday blog post. “With Standard Power Wi-Fi, wireless devices can now transmit indoors and outdoors and at up to 63 times higher power than their Low Power Indoors … counterparts.”

The WBA has been working with its members for more than four years "to see its vision for combining Wi-Fi 6E, 7 and 6 GHz AFC become a reality, as AFC is a critical component for the use of standard power on 6 GHz,” WBA President Tiago Rodrigues wrote in an email.

The approvals are “a significant milestone for the 6 GHz Wi-Fi ecosystem that will maintain U.S. momentum in wireless connectivity and innovation,” emailed Alex Roytblat, Wi-Fi Alliance vice president-regulatory affairs.

OET launched a process for approving the AFC operators last August, months later than expected (see 2308250061). Some 6 GHz advocates had hoped operations could have started a year ago. The FCC issued a public notice requesting proposals from prospective AFC system operators in September 2021 (see 2109290040).

After the proposed AFC operators filed reports on their public tests, the Electric Power Research Institute raised numerous challenges (see 2401190036). AT&T has also challenged some data points, but the operators addressed most of its concerns. EPRI and AT&T didn’t comment Friday.

The use of AFCs remains controversial. AT&T in December urged the FCC to condition approval on the willingness of the system operators to “work within inter-industry groups to collaborate on implementation decisions affecting AFC System calculations.”

The Enterprise Wireless Alliance “trusts the FCC is correct that the challenges made during the testing process have all been resolved,” EWA President Robin Cohen told us. EWA supports AT&T’s recommendation “that an inter-industry organization develop standardized implementations for the propagation models to ensure consistent results among AFCs,” she said. The group expects the FCC “to monitor developments in this area carefully and to make changes as appropriate to ensure protection for incumbent systems,” she said.

“We're particularly encouraged by the OET's emphasis on collaboration among AFC operators to address potential interference concerns,” emailed a spokesperson for the Edison Electric Institute, which has raised broader 6 GHz concerns. “This is crucial -- unlicensed devices must operate without disrupting licensed operations, and a collaborative approach is key to achieving that,” the spokesperson said.

The U.S. made preservation of the 6 GHz band for unlicensed use its top focus during last year’s World Radiocommunication Conference (see 2401220066). China has pushed to have the band harmonized for 5G and 6G.

“Much of the world has taken a different approach to 6 GHz, and the long delays in the U.S. don't really make our framework more appealing on the international stage,” said Joe Kane, Information Technology and Innovation Foundation director-broadband and spectrum policy. “Once we see how the technology works, it could be a foundation for more efficient spectrum sharing in the future,” he said.

It has become increasingly important for the FCC to show manufacturers and the world in general that the commission “still has confidence in its previous engineering analysis, and it genuinely intends to allow outdoor use of the 6 GHz band,” despite the success of indoor use for Wi-Fi 6E, said Public Knowledge Senior Vice President Harold Feld. “The long delay in moving forward on outdoor use has created a drop-off in the enthusiasm of equipment developers to develop new outdoor equipment for the band,” but the latest action “should restore confidence that OET stands by its prior analysis that controlled outdoor use will not cause harmful interference,” he said.