Verizon CTO Yago Tenorio laments the way 5G technology has evolved but hopes the industry can learn from past mistakes as it works toward 6G.

Tenorio took his position during a keynote at this week’s Brooklyn 6G Summit, pointing to several issues that continue to plague 5G, including a particular angle on spectrum alignment that has impacted the transition from non-standalone (NSA) to standalone (SA) network cores.

This issue involves an initial compromise made by the 3GPP industry standards body that provided a dual path toward deploying 5G networks. The NSA path allowed operators to stand up a 5G core as an appendage to a legacy 4G LTE core, while the SA path was a straight move to a strict 5G core running the network.

A 5G NSA deployment allowed operators to tap some of the radio spectrum efficiency gains from the 5G standard, but did not allow for them to tap deeper network management opportunities like network slicing that could support new revenue streams.

Tenorio explained that the move “was a necessary evil, it was the right decision … but we’re still paying for it.”

The payment has been that operators selecting the NSA path, which was most of the early movers toward 5G, have been stuck aligning their spectrum assets between two different network cores. Operators needed to maintain a strong spectrum position for their 4G LTE network and core because most of their customers remained on those networks, which limited how much spectrum they could then allocate to a 5G SA network.

“When you are an operator, you are migrating your customers from NSA to SA, because of the way we designed the system, the performance they experience goes backwards,” Tenorio said of the impact. “You can no [longer] aggregate the 4G capacity. You just lose it. If you have bands dedicated to 4G they will not aggregate anymore with a 5G SA one, you can only aggregate 5G carriers, but you need to wait until you have enough people with 5G SA devices.”

Verizon attempted to use dynamic spectrum sharing (DSS) technology to bridge that gap, but those efforts did not provide the expected performance benefits. This proved especially challenging in terms of getting the DSS technology to work between network equipment vendors.

Tenorio did note that 5G NSA was “the right start to fast track 5G,” but that the industry did not follow up with the correct technical implementation support for NSA to seamlessly integrate with SA.

“It's true that it would have complicated the system even more,” Tenorio said of those potential 5G NSA technical implementations, adding that “at least it would have provided accretive capacity.”

Tenorio added that the industry cannot make the same mistake with 6G. That means the generational jump will need to support spectrum aggregation “all the way up,” and that 6G should use an “evolution” of the 5G core and “new radio” (NR) technology to make the upgrade to 6G easier for operators.

Tenorio did note that this 5G radio re-use would be based on open radio access network (RAN) infrastructure.

“Open RAN and the value of open RAN, that should be a given on 6G,” Tenorio said. “It's been the discussion, the topic. Yes, no, when? I think on 6G it’s obvious. It needs to be natively built with open interfaces and off-the-shelf servers. It's just a no brainer.”

Open RAN has slowly started to gain traction in the market, with analysts expecting investments to ramp toward the end of the decade.

6G is not a race … or is it?

Tenorio also asked that 6G not be a “race for the icon” in reference to past technology generations that have seen operators engage a “G” icon on a user’s device despite that connection not actually conforming to that technology standard.

“If it means nothing to the customer, why would we do that?” Tenorio asked. “Let's just have a smooth upgrade and works on what matters and what matters to the customer.”

However, that request came just weeks after Verizon unveiled its boldly named 6G Innovation Forum with partners Ericsson, Samsung, Nokia, Meta, and Qualcomm. That group has tasked itself with the heady goal of establishing “an open, diversified, and resilient 6G ecosystem and develop foundational 6G technologies while ensuring global alignment."

Tenorio at that time explained to SDxCentral that he views use cases as being central in driving the 6G development path.

“This time around, we want to design a 6G system with a set of use cases in mind, so that it comes to solve some problems, pressing problems, and enable some things that you cannot do today,” Tenorio said.

Verizon’s move echoed its controversial decision 10 years ago to form the 5G Technology Forum, which had a similar goal of steering 5G technology standards. Tenorio told SDxCental that the carrier this time wants to avoid that previous path.

“That's not something that we want to do this time,” Tenorio said, adding, “We want to stay within standards, similarities straight away. We want to be first, same as last time. So that's one of the purposes, why we're doing this, and why this is important.”

Toward that end, Tenorio also noted that the 6G Innovation Forum would be open to other parties.

“I mean, we already have a number of companies reaching out as a result of the announcement … that they are interested to understand more the purpose and consider a participation,” Tenorio said of the initiative. “And that's super good to hear. The more the merrier in general, as long as we keep it focused on the target.”

Tenorio did add that this “more” does not necessarily include Verizon’s direct rivals.

“That's a very interesting one that we have considered,” Tenorio said of potential inclusion of other operators. “I think there is one contention point here, which is one part of the purpose, we want to be first in the world. So how is that compatible with having others? Can we ask them to withdraw from that ambition? That’s probably not fair. I know it sounds a lot, self-centered and selfish, but if the purpose is to be first, we may have to go it alone.”