AT&T’s 5G network utilization and build is making significant progress as the carrier continues to invest heavily into its core network plans.

Chris Sambar, Network EVP at AT&T, in a press briefing this week tied to the carrier’s latest earnings release, explained the carrier is supporting commercial customers on its 5G standalone (SA) network core. This would align with more vocal news from rivals T-Mobile US and Verizon on their 5G SA use.

“We haven't made a big splash about standalone core, but we have a standalone core deployed, and we do have commercial users on it, and we're slowly moving more commercial users onto it,” Sambar said. “We're marching down the road on standalone core just like everyone else is, and I think everyone is in the place where we need to have it well distributed. We've already done that with non-standalone because [of] the architecture we used there – we were at the forefront of that – so our standalone core will follow in the same locations.”

Sambar added that the carrier will be using “a lot of the same infrastructure” between its SA and non-standalone (NSA) core. This ties back to AT&T’s extensive SDN push that began nearly a decade ago and has resulted in the carrier running its 5G network as a cloud-native function.

Sambar also clarified that the carrier’s recently announced edge zones expansion is currently riding on its 5G NSA core, but that it has “standalone 5G in mind.”

“They will evolve to standalone 5G as we increase the reach of the standalone 5G core,” Sambar said.

Commercial 5G NSA networks rely on an operator’s legacy 4G LTE core for base processing and routing. A 5G SA core, which consists of the user plane, control plane, and shared data layer network functions, allows operators to deliver a more resilient core network and support highly-touted 5G services like network slicing, automation, orchestration, and mobile edge computing (MEC).

AT&T’s 5G SA plans have lagged behind rivals. The carrier initially planned to launch its 5G SA core in 2020, but pushed those plans due to technology maturity. A company executive recently noted that AT&T was continuing to test the technology in lab environments.

“We’ve always said we’re going to deploy this 5G when the ecosystem is ready,” Marachel Knight, SVP of technology and planning operations at AT&T Communications, said during a fireside chat at the recent ConnectX event. “Are there devices there to take advantage of that? So, it’s a very methodical approach for us.”

T-Mobile US was the world’s first, launching its 5G SA core in mid-2020, and just beating out SK Telecom. T-Mobile US has since expanded that SA network to support voice traffic.

Dish launched its multivendor, greenfield 5G SA core network and commercial service in June.

Verizon more recently began moving commercial traffic to its cloud-native 5G SA core network following extensive delays.

During its earnings call, AT&T executives also touted the carrier’s progress in bolstering its current 5G network with its C-Band spectrum assets. This is spectrum in the 3.7 GHz-4 GHz band the carrier spent $23.4 billion on during the Federal Communications Commission (FCC) auction.

AT&T CEO John Stankey raised the carrier’s year-end coverage target from 100 million potential customers to more than 130 million potential customers, or “nearly double our expectations when we entered the year.”

That increase was helped by a lot of initial uncertainty surrounding potential interference issues with the C-Band spectrum. AT&T and Verizon, which spent more than $45 billion on C-Band spectrum, were forced to delay the deployment of that spectrum due to potential interference with some radio altimeters.

Sambar also explained that AT&T was able to shore up supply chain concerns on equipment and that the carrier made “some architectural changes” that have allowed the carrier to squeeze better coverage out of its C-Band deployment. He noted some of that was tied to the massive multiple-input, multiple-output (MIMO) radios, but did not want to provide specific details.

“I'd love to tell you, but I don't want to give away the secrets because I think we have a better network than our competitors, and I don't want them to know how we build it,” Sambar said.