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AT&T will activate 5G standalone core when devices are ready


DENVER — AT&T currently has 277 million points of presence (PoPs) covered with its low-band spectrum, primarily its 850 MHz spectrum. And it is planning to have 200 million PoPs covered with its new C-band spectrum by the end of 2023. It uses mmWave spectrum on a more targeted basis at sports stadiums and other entertainment venues.


But aside from spectrum, what is AT&T’s roadmap to finish deploying 5G?

Speaking with Fierce Wireless today at the Wireless Infrastructure Association’s Connect(X) conference, Gordon Mansfield, AT&T’s VP of Mobility & Access Architecture, said the company is still waiting to activate its 5G standalone (SA) core. And the delay mainly relates to the device ecosystem.


For a carrier such as T-Mobile, its deployment of an SA 5G core may have been a priority related to its spectrum. But Mansfield said that for AT&T, “The SA 5G core really isn’t tied to any spectrum. It’s about maturity of the broader ecosystem.”


Specifically, he was referring to the device ecosystem of 5G phones and tablets. Apparently, the current devices on the market can handle the 5G network, but if they are constantly using a 5G SA network, that may impact device battery life.


“Device manufacturers don’t want to degrade the battery life,” said Mansfield. “They really care about their battery life. When you’re on non-standalone, you’re using LTE signaling protocols. For silicon, LTE is more efficient from a power-draw perspective.”


He said original equipment manufacturers (OEMs) prefer to stay on their older technology until the silicon in the phone can have the same power efficiency as existing phones.

Mansfield said new silicon is becoming available now to handle the power efficiency challenges. “You’ll start to see more SA capabilities deployed at more scale now as the device ecosystem starts to mature.”


Mansfield said there are three broad factors that impact the 5G environment. “First, you have to have the 5G radio environment, which we do,” he said. “Then you have to have the device. Then you need applications to take advantage. When you think about all that, the ecosystem is starting to mature, including the devices.”

Although more power-efficient silicon is coming and will deployed in new smartphones, Mansfield said the 5G-capable phones that people have purchased the last couple of years “still have a lot of runway.” Future 5G phones with the improved power efficiency, which will run on AT&T’s SA network, will make those people happy who use heavy applications on their devices such as cloud gaming. The news phones will also support more spectrum band combinations, which will free up the existing bands, used by older phones.


As of May, AT&T’s network supports 27 C-band compatible smartphones.


Mansfield said, “We have our SA core in our network from a maturity perspective, but enabling it in devices is the question. As we feel confident devices are performing well including battery management, we’ll begin to activate.”


Why does T-Mobile brag that it has deployed an SA 5G core?

T-Mobile announced in 2020 that its SA version of 5G was available nationwide, initially using its 600 MHz spectrum.


And in late 2021 T-Mobile said it was working on Voice over New Radio (VoNR) so that its 5G network will be able to handle voice calls as well as data.


From his perspective, Mansfield said T-Mobile needed to quickly deploy its SA 5G core because its LTE coverage on its AWS or PCS spectrum wasn’t very robust in rural areas. It deployed SA 5G on its 600 MHz spectrum to expand rural coverage. And now it needs VoNR so that voice calls have decent quality.


“They anchored 5G SA,” said Mansfield. “If they stayed on NSA their coverage would be limited because they’d have to be on LTE. Their move to SA was more about coverage than anything else. They need to rapidly move to VoNR. They have SA for data, but they need VoNR. It’s their Achilles Heel.”


Asked when AT&T plans to deploy VoNR, Mansfield said, “I don’t have a problem because I’ve already got good rural coverage.” He said AT&T’s timeline for VoNR is sometime next year — the same as when the device ecosystem matures.


Previously, Dave Bolan, research director at Dell’Oro Group, told Fierce Wireless that AT&T and Verizon may not have activated their SA 5G cores nationwide because they need the bandwidth of the C-band spectrum they’re deploying.


Bolan said, “CSPs have three choices for offering 5G: Dynamic spectrum sharing, 5G non-standalone and 5G SA. Only 5G SA requires the new 5G core, and many CSPs seem content for the time being to stick with DSS and 5G NSA.”


But Mansfield disagrees with that assessment. He said in AT&T’s case, it is using DSS, but that technology will work with both its NSA core and its SA 5G core.


He said the base station connects to both cores. And if a device is SA capable, it will connect to the SA 5G core.