Wi-Fi Backers, Incumbents Hotly Contest FCC's 6 GHz Proposed Changes
Wi-Fi advocates and 6 GHz incumbents clashed on an FCC proposal that would expand parts of the 6 GHz band where new very-low power (VLP) devices can operate without coordination, beyond the initial 850 MHz commissioners approved last year (see 2310190054). The VLP rules took effect March 9. 6 GHz incumbents have lined up in opposition to further changes (see 2403270055).
The Further NPRM last year also proposed creating a geofenced variable power device class with higher power levels than VLP and expanding FCC authorization of direct client-to-client communication. The FCC already authorized VLP operations in 5.925-6.425 and 6.525-6.875 GHz and is considering 6.425-6.525 and 6.875-7.125 GHz as well.
Major tech companies asked the FCC to further liberalize the rules. The VLP rules “support a wide array of portable devices, including body-worn and augmented reality technologies,” the companies said in comments posted Thursday in docket 18-295: “The Commission’s decisions have placed the United States in a leadership position in the next generation of wireless innovation.”
“Numerous quantitative studies” in the record show that opening other parts of the 6 GHz band to VLP “will not create a significant risk of harmful interference” to fixed service, broadcast auxiliary services or cable TV relay service operations in the bands, said Apple, Broadcom, Google, Intel, Meta Platforms, Microsoft and Qualcomm. The companies also supported other FCC-proposed changes.
Yet, the VLP expansion is premature, countered AT&T: “The rules authorizing VLP devices are barely effective and the Commission, licensed users, and unlicensed operators should gain some practical experience with these new devices before further liberalization of the regulations.” The geofencing proposal would “effectively create an end-run around the Commission’s rules for Automated Frequency Coordination Systems and should not be adopted,” the carrier said.
VLP devices have “the potential to introduce a new generation of innovative wireless use cases to the consumer market,” said CTA: The devices “greatly benefit from low latency, high data rates, and high reliability for robust operations, especially in dense environments.” For widespread consumer adoption, “it is critical that the devices be able to utilize in the full 6 GHz band to operate at their highest potential performance levels without technological constraint,” CTA said.
The Wi-Fi Alliance supported the FCC's proposed changes. It said 6 GHz band use is gaining traction. “The Commission’s decisions have been transformative and mark the beginning of a new era for Wi-Fi,” the alliance said. It estimated that more than 473 million Wi-Fi 6E user devices, which use the band, and 94.6 million Wi-Fi 6E access points shipped last year. More than 233 million devices using the latest generation, Wi-Fi 7, are “expected to enter the market in 2024, growing to 2.1 billion devices by 2028.”
Letting VLP devices operate in two additional bands “will increase the overall spectrum capacity available for VLP applications and allow for seven contiguous 160 MHz and three contiguous 320 MHz channels,” the Dynamic Spectrum Alliance commented: “The larger channel sizes will allow VLP devices to operate with greater throughput and reduced latency. From a commercial standpoint, it is important for the Commission to have uniform limits for VLP devices across the entire 6 GHz band.”
Do No Harm
Others urged the FCC take a go-slow approach on revising the rules.
“A core principle of unlicensed operations is that they must not cause interference to licensed operations,” NAB said: “To date, nothing in the record … comes close to demonstrating that unlicensed operation across the entire 6 GHz band can avoid causing interference to mobile electronic newsgathering operations.” NAB acknowledged that in most cases VLP operation won’t pose a risk for ENG, but said “breaking news happens at times and places that defy ‘normal.’”
Sirius XM Radio noted that satellite digital audio radio service operations rely on 6.875–7.125 MHz, the U-NII-8 band. “Having just granted unlicensed interests access to the spectrum they requested in the U-NII-5 and U-NII-7 bands for outdoor, uncoordinated operation” of VLP devices, “why would the Commission simultaneously propose to allow use of U-NII-8 band spectrum for outdoor VLP operations that those interests had not requested and for which there is no demonstrated demand?” Sirius XM asked.
The company noted it provides the “entirety of its satellite-delivered content using 7.025-7.075 GHz uplink spectrum,” which it bought at auction and already faces interference. “Sirius XM has no margin to accept yet more interference, and adding the aggregate effect of potentially billions of outdoor VLP devices deployed anywhere in the nationwide receive beams of the Sirius XM satellites will materially degrade SDARS service quality.”
The Alliance for Automotive Innovation warned of potential risks for cellular vehicle-to-everything operations in the adjacent 5.9 GHz band. That group and the 5G Automotive Alliance said the commission’s -27 dB/MHz out-of-band emissions limit for VLP devices is insufficient to protect C-V2X.