AT&T earlier this week announced Indianapolis, Ind., is the latest city to benefit from its “5G Evolution” technology. But that term – “5G Evolution” – has become a bone of contention with industry rivals, who claim AT&T is deceptively rebranding what is essentially LTE-Advanced technology. AT&T’s defense to these criticisms has hitherto been the vague claim that the moniker is accurate because the technology lays the foundation for next generation technology. What that means, exactly, remained somewhat of a mystery. Until now.

Following the Indianapolis announcement, Wireless Week asked AT&T’s VP of RAN and Device Design Gordon Mansfield to shed more light on what AT&T means when it uses the phrase “5G Evolution.” He said it’s exactly what it sounds like.

“One of the things everyone has to keep in mind is that we’re not going to suddenly flip a switch and everything is 5G. That’s not realistic,” Mansfield commented. “There is an evolution that has to occur and that evolution requires many things so that as you evolve some other components of the network you can take full advantage of it with some of the LTE-Advanced and LTE-Pro capabilities.”

Mansfield noted one of the main changes AT&T is making along this path is evolving the topology of its network. Like its major rivals, AT&T is densifying its network ahead of 5G. But as part of that process, Mansfield said AT&T is also centralizing the RAN. This shift, he said, will allow the carrier to “very quickly and very cost effectively” evolve the centralized component of the network to virtualized capabilities down the line, just as it’s doing with the mobile core.

While work is well underway in terms of virtualizing the mobile core – more than a third of the carrier’s network is already software-based and AT&T is shooting to raise that figure to 55 percent by the end of 2017 – Mansfield explained virtualizing the RAN is more complex.

“We’re doing a lot of proof of concept work in that area,” he reported. “As quickly as the technology is ready then we’ll start that pivot. A lot of the work we’re doing right now is kind of a stepping stone. You’ve got to go build out the centers where you’re centralizing the capability, and once you’ve centralized it it makes it easier to virtualize it. So they go hand in hand.”

In turn, he added, virtualization will allow AT&T to upgrade its network to 3GPP’s 5G standards faster, which will help it meet its goal of introducing standards-based 5G as early as late next year.

Those densification efforts also go hand in hand with AT&T’s plans to launch License Assisted Access (LAA) technology on its network by the end of this year. Mansfield noted LAA power levels require short ranges, meaning the carrier has to densify to make deployments feasible.

Mansfield said AT&T is targeting areas of high traffic density for densification first, but noted the order of technology rollouts will hinge on “how easy or not” it is to get all the site acquisition, permitting, and construction work done.

“It’s not just the permitting aspect. That’s a big part of it, but it’s also the ability to go and construct and quickly get the transport,” he concluded. “You’ve not only got to build the radio infrastructure, but you’ve got to get the (fiber fronthaul or backhaul) to deliver on the higher speeds we’re targeting with this.”