Big 5G Event speakers outline 6G spectrum, business-case challenges in the wake of lagging 5G profits

AUSTIN—Telecom experts already are working to develop a 6G standard, but little tangible progress has been made as the industry wrestles with myriad challenges, including a lack of easily identifiable spectrum in the U.S. and whether a business model will emerge that is more profitable than 5G has been to date.

These were just some of the notions shared by speakers during the 6G pre-conference event conducted Monday in conjunction with the Big 5G Event powered by Light Reading, an Informa sister property to IWCE’s Urgent Communications.

Speakers noted that the next standardized generation of commercial wireless communications will be dubbed 6G and that the 3GPP standards body has declared that 6G will begin with the implementation of the Release 20 standard during the next several years, but little else has been decided about 6G.

Ideas about what 6G could be were plentiful and varied during the day’s sessions, ranging from an incremental “evolution” of the existing 5G standard to enabling “revolutionary” functionality that supports the leveraging of artificial intelligence (AI) to both optimize operating networks and much-desired applications.

But the challenges associated with 6G also are numerous, beginning with a fundamental tenet of all wireless communications: identifying the airwaves that will be used to transmit packets. With the World Radiocommunications Conference (WRC) 2023 set to begin in November, identifying spectrum for 6G in the U.S. is proving to be difficult, according to Andrew Thiessen, chair of the Spectrum Working Group for the Next G Alliance.

“I would say that the work that my working group has been doing had been trudging right along quite well, right until we actually got to the part of a deliverable where we were looking at what spectrum is actually relevant to 6G,” Thiessen said during a panel examining 6G spectrum options.

“The moment we got to that point, what we started to see was that everybody’s differing equities started to play a role in their independent opinions about every single piece of spectrum that would be suitable for 6G.”

Indeed, much of the U.S. spectrum that has been introduced into the commercial space previously was licensed to the federal government—notably, the U.S. military. However, federal lawmakers and military officials recently have been outspoken in expressing concerns that continuing such a trend could hamper critical defense objectives.

When asked about which spectrum the U.S. would recommend that the WRC identify for 6G, Thiessen said many bands have been considered but expressed doubt that large contiguous swaths would be available.

“What I can say is that the number of different spectrum bands that are being explored range from mid-band to …. terahertz [spectrum], so it’s all over the map,” Thiessen said.

“When you think about 6G, one of the challenges is the lack of contiguous spectrum. Even if you look at sub-terahertz spectrum—where there’s lot of spectrum available—it’s not lots of contiguous spectrum. Even if we do carrier aggregation and lots of other tricks in the book to try to engineer around some of those problems, it doesn’t really get to the efficiency—the massive amounts of contiguous spectrum—that people really like when it comes to these Gs.”

One audience member asked about spectrum between 7.125 GHz and 8.5 GHz, describing it as one of the “golden bands” for 6G. Derek Khlopin, NTIA’s deputy associate administrator for spectrum planning and policy, acknowledged the telecom industry’s interest in the spectrum but noted that it also has challenges.

“We certainly are aware that there’s been interest in the 7 GHz band for several years from industry,” Khlopin said. “It is a very complicated band. We have taken some looks at it, along with our federal-agency partners. There are a lot of disparate systems in there, including some non-federal [networks], as well.

“There’s everything from microwave to airborne—all kinds of systems—and obviously things we can’t talk about. There’s a lot there, but we’re certainly aware of the industry interest there. There are a number of bands [that are candidates for 6G use], with that being one of them.”

Thiessen echoed this sentiment and questioned whether carriers would want to build a network primarily on that spectrum, even if it could be made available.

“I think it’s a prime band that everyone is looking at, but also consider the propagation characteristics and the densification of networks [necessary when] deploying from 7 GHz to 8 GHz,” Thiessen said. “It’s going to cost a whole lot of money where our operators are already leveraged to the gills when it comes to their books. Where are they going to come up with the money to build a RAN to support that?”

Such economic concerns are particularly important at the moment, because U.S. carriers spent more than $100 billion on spectrum and infrastructure for 5G with a relatively small increase in revenues from the investment. Identifying a clear business case for 5G and 6G will be crucial to success—and it may not be the typical carrier-consumer relationship that has driven previous generations of commercial wireless standards, Thiessen said.

“I think one of the things we’re going to see with 5G—when we actually start to see real money made—is an evolution of the device ecosystem, where a lot of the value of 5G is going to be on the device side, and it’s not going to be smartphones,” Thiessen said. “It’s going to be other stuff—sensors … buying a 5G-enabled drone for beyond-line-of-sight flying, that type of stuff.

“I think we’re going to see a massive increase in the number of types of devices that could be on this network, and they’re not necessarily going to be a bunch of high-bandwidth devices. If we take the massive IoT space [as an example], it’s probably going to be a bunch of low-bit-rate stuff, which are going to cause massive [packet] overhead issues.”

With this in mind, it may be that massive swaths of contiguous spectrum may not be needed for 6G, according to Thiessen.

“I don’t know if having 400 MHz swaths is necessarily a solution for our mobile network operators to do anything other than ENBB again,” he said. “And I still don’t have an application on my phone that cares whether it’s 4G or 5G—I can’t get 8K video, 4K video or anything else better, for that matter [using 5G].”