Microsoft, NAB Find No Common Ground on TV White Spaces Rules
The FCC found no agreement between Microsoft and NAB on how often narrowband devices should have to check a database to operate in the TV white spaces (TVWS). In January, commissioners approved 4-0 an order requiring other devices to check the database at least once hourly. After NAB and Microsoft clashed as the order was before commissioners, the FCC decided to further explore the rules for narrowband IoT devices in a Further NPRM (see 2201270034). Wireless mic companies supported NAB.
Microsoft saw no need for the FCC to change the rule for narrowband white spaces devices, which allow a once daily database check. “This is the rule that applied for the more than six years that the ‘database push’ waiver for fixed and personal/portable WSDs was in effect without any reported incidents of harmful Interference,” Microsoft said, posted Monday in docket 14-165. The risks are minuscule, the company said: “These low power devices can only operate in areas with three contiguous White Spaces channels, limiting their operations to less populated areas where multiple channels are necessarily available for other operations. They are also subject to extremely strict duty cycle limits (they may transmit only for a total of 36 seconds per hour) and are only permitted to use a small fraction of a single White Spaces channel.”
The one-hour requirement “already represents a significant concession to the eternally nascent TVWS industry and is scarcely adequate to accommodate the needs of wireless microphones,” NAB countered. NAB urged the FCC to stop focusing on the white spaces and recognize it’s a failed experiment. “Microsoft has asked the Commission to dedicate a staggering level of resources to the promotion of TVWS technology; yet there are fewer TVWS devices operating in the United States now than a year ago, and only roughly a quarter as many as there were five years ago,” broadcasters said. NAB noted no corresponding FCC regulatory fees are charged: “Perversely, broadcasters are left paying part of the bill for a failed technology that does not benefit anyone, and least of all broadcasters.”
The check-in requirement is important for wireless mic users also in the spectrum, Sennheiser said. “An hourly recheck requirement is necessary to ensure that licensees and coequal users of the spectrum receive sufficient protection from interference from WSDs,” the company said: “Such devices should also cease operating within two hours if they are unable to contact a WSDs database.” Sennheiser disagreed with Microsoft about the potential risks. “Although narrowband WSDs have been touted as tools for agriculture, by rule, they are not restricted to rural areas, and device developers have continued to suggest utility in suburban and urban areas as well.”
“It is a core Commission policy that in the case of unlicensed devices attempting to share spectrum with licensed devices the onus for ensuring against harmful interference ought to be on the potential interferer,” Shure said. Absent the requirement, the FCC should restrict use of narrowband devices to rural areas, the mic maker said: “Microsoft, as the party requesting the extension of the once-a-day re-check interval, has repeatedly asserted that the major market for these narrowband WSDs will be in rural areas and to customers such as those in the precision agriculture industry.”
GE Healthcare asked the FCC to clarify that the rules don’t apply to medical devices using channel 37. “The FNPRM’s structure creates some ambiguity as to its scope,” GE said: “To reduce confusion, the Commission should clarify that any rules it adopts as a result of the FNPRM will apply only to narrowband and mobile white space devices operating in spectrum below 602 MHz.”