Wi-Fi Exhaustion Seen Raising Questions for IoT's Future; Rosenworcel Concerned

FCC Commissioner Jessica Rosenworcel, who wasn’t at CES this year because of the FCC shutdown, said she had similar concerns when on the convention floor in previous years. “I walk around the floor and everyone says, ‘Mobile, mobile, mobile,’” Rosenworcel told us. “I think, wireless, wireless, wireless. Where is the spectrum coming from? … Our unlicensed bands are going to be so crowded.” Rosenworcel noted unlicensed contributes billions of dollars yearly to economic growth: “Let’s figure how we can have more of it.” Both the 5.9 GHz and 6 GHz band offer potential, she said. “Let’s get to it. Let's make it happen."

Commissioners voted 4-0 in October to launch an NPRM on opening the 6 GHz band (see 1810230038). FCC Chairman Ajit Pai is expected to circulate a Further NPRM on Wi-Fi in 5.9 GHz (see 1811140061). Some hope unlicensed use of the 3.5 GHz citizens broadband radio service band could start this summer (see 1901150043).

“To provide 5G and the next-generation of Wi-Fi services, we’re strongly behind the FCC opening up the 6 GHz band, which provides 1.2 GHz" for unlicensed uses, said John Kuzin, Qualcomm regulatory counsel. “Hopefully, the FCC will move forward later this year" with an order. The band will be used for everything, from generations of Wi-Fi to come to 5G-unlicensed and licensed assistance access, he noted. “You name it.”

“Spectrum capacity is limited and the Wi-Fi Alliance urges FCC to move expeditiously on the 6 GHz proceeding,” wrote Alex Roytblat, senior director-regulatory affairs. “Users’ increasing reliance on Wi-Fi as their primary means for internet connectivity will soon exceed the capacity of available spectrum to deliver the expected experience for demanding applications such as mobile offload in congested indoor environments or distribution of 4K video.” He said unlicensed frequency availability hasn't kept pace with Wi-Fi demand. An alliance-commission study last year said the Wi-Fi ecosystem may require up to 1,500 MHz of additional mid-band spectrum by 2025 to sustain the projected growth in demand, he noted.

Michael Calabrese, director of the Wireless Future Program at New America, agreed Wi-Fi exhaustion is a concern. In 2013, the FCC initiated an NPRM proposing to make up to 750 contiguous MHz across the 5 GHz band available for Wi-Fi, he said. UNII-1 and UNII-3, are available, he said: “But the two other segments stalled.” DOD and NTIA “nixed unlicensed sharing” in UNII-2b, and, for the 5.9 GHz band, “we continue to debate.” Congestion is a problem in high-use areas, including multi-user homes and offices, Calabrese said. “There’s simply not enough capacity.” Superfast, next-generation Wi-Fi 6 requires channels as wide as 160 MHz and in all mid-band Wi-Fi allocations, there's one 80 MHz channel “and nothing larger,” he said.

The main Wi-Fi bands are becoming less useful in areas where lots of devices are deployed, whether smart light bulbs and meters or Wi-Fi routers, said Claude Aiken, president of the Wireless ISP Association. “WISPs are adept at using multiple tools in their toolkits” and need unlicensed, lightly licensed and licensed spectrum “that is accessible to the small rural entrepreneur,” he said.

Others question the projected needs. Wi-Fi bands are low power and need only enough bandwidth to serve devices within a 200-foot radius, said Richard Bennett, network architect. Zigbee and Z-wave "operate in 900 MHz at even lower power,” he said. While Wi-Fi video cameras can impose the most demand on unlicensed spectrum, permanent camera installations tend to use powered Ethernet, he said: “We have more than enough unlicensed available for current needs, and advanced technologies such as Wi-Fi 6 and Bluetooth 5 will serve future applications more efficiently in existing bands.”

Congestion from a growing number of devices using the same frequency swaths is a “growing concern” and “one of the main justifications for the current proceeding to have unlicensed in 6 GHz,” said Joe Kane, tech policy fellow at the R Street Institute. “I get a little concerned when people make the argument that congestion means demand is high, and therefore we should designate more spectrum for unlicensed use,” Kane said. “This is exactly what we would expect to happen when an unpriced resource experiences a tragedy of the commons. There's little incentive to economize, so the resource is quickly depleted.” More unlicensed wouldn’t be bad, but the main need is for technical rules and limitations to mitigate interference, he said.