AT&T expects to complete 80% of FirstNet next year, as well as nationwide 5G on spectrum below 6 GHz
AT&T expects to complete 80% of its contracted FirstNet deployment for 700 MHz Band 14 spectrum next fall, and the FirstNet effort is helping the carrier realize its 5G vision on sub-6 GHz spectrum, a company official said last week.
“FirstNet is a huge opportunity for us, and—quite frankly—it’s also a mission,” Scott Mair, AT&T’s president of operations, said during a session at the Cowen and Company Technology, Media and Telecom Conference. “I say that it’s a mission, because it’s like nothing I’ve ever seen inside of AT&T. When we’re serving first responders who are taking care of people at their most critical time of need, it has a higher level of importance.”
AT&T is responsible for building and maintaining the FirstNet nationwide public-safety broadband network (NPSBN), including the deployment of LTE on the 20 MHz of Band 14 spectrum that is licensed to the FirstNet Authority. AT&T is required to meet certain buildout thresholds—in both urban and rural locations—to earn payouts that are expected to total $6.5 billion when the contracted deployment is finished.
Mair reiterated previous statements from AT&T officials that the 60% buildout target for FirstNet is “well on track” to be completed this fall, about six months ahead of the contract deadline of March 2020. The next buildout threshold—marking 80% of the FirstNet build—also will be finished early, he said.
“That next goal is March of 2021,” Mair said. “We’ll complete that in advance of that, by more than six months.”
When asked whether AT&T could finish all of its FirstNet deployment next year, Mair declined to speculate.
“I’m not ready to say [AT&T will complete the FirstNet build] by the end of 2020. It’s a five-year contract, and we’re in year 2,” he said. “I have high confidence that we’re going to finish that build early, but I’m not ready to commit that it’s going to be 2020.”
AT&T deployment strategy calls for crews installing equipment to support Band 14 operation while also deploying gear for operations in the WCS and AWS-3 bands, which company officials have said will boost the carrier’s spectral capacity by 50%. This is being done at a “majority” of AT&T’s estimated 70,000 macro site and is making a noticeable difference in system performance, Mair said, noting the most recent network test results published by Ookla
“The FirstNet network was the fastest network in the U.S. and 25% faster than any commercial network.” Mair said. “That’s a pretty good statement about the capability that we’re putting out there for our first-responder community.
Such network performance is the result of AT&T’s efforts to deploy the new spectrum swaths and utilize carrier-aggregation technology, which lets network operators virtually utilize disparate spectrum bands in a coordinated manner to achieve greater data throughput, according to Mair.
“When we’re touching the tower, we’re putting up the WCS and AWS spectrum with Band 14,” Mair said. “With carrier aggregation, I can then stitch that together logically and provide much greater speeds. We’re doing four-way carrier aggregation today, and we’re going to five-way and six-way [carrier aggregation] in the near future.
“So, touching the tower with FirstNet is really an entrée into enhancing our LTE network, and we’re seeing the results of it.”
These FirstNet deployment initiatives also are designed to help AT&T provide 5G coverage on its spectrum below 6 GHz, Mair said. The new equipment being deployed on macro towers is software-upgradeable, so cell sites that support 5G Evolution—AT&T’s term for LTE Advanced capability—can quickly be transitioned to 5G with a software upgrade.
“At this time next year, we’ll have nationwide coverage of 5G on a macro tower, backed up by our 5G Evolution LTE Advanced capability on those same towers,” Mair said. “We define nationwide as basically greater than 200 million POPs.”
Mair noted that the performance that users will experience from the 5G service from the sub-6 GHz spectrum deployment will differ significantly from the carrier’s 5G+ service that will leverage millimeter-wave airwaves of 24 GHz and higher.
These millimeter-wave 5G systems utilize enormous amounts of spectrum, so they can deliver tremendous data throughput, Mair said.
“When it’s there, it’s 1 GB/s-plus speeds,” he said. “We recently—through a software upgrade—tested over 2 GB/s speeds using millimeter-wave 5G, so it’s a really lightning-fast capability.”
However, the poor propagation characteristics of millimeter-wave spectrum means that the 5G signals only travel 200 to 300 meters, Mair said. As a result, AT&T will have to install many small cells to provide 5G+ performance in the same coverage as a macro site, he said.
“It’s a very different build model from the traditional macro tower,” Mair said. “A small cell is different, because it’s generally not mounted on a tower. Generally, it’s on light poles, telephone poles or sides of buildings. In order to do that, you’re working with different people.
“So, there’s a new ecosystem that is being built for small cells. What is really different is that—with a small cell—I’ll have to work very closely with cities for permitting and approvals of the city for that infrastructure for city streetlights or telephone poles. Typically, when I was putting something on a macro tower, I largely didn’t have to interface with the city.”
This approach is “immature” and is “a slow process” now, but Mair said he is optimistic about the progress being made within cities. However, Mair cautioned that city officials and consumers should not expect AT&T to blanket their jurisdictions with 5G+ millimeter-wave service.
“It is a different deployment,” Mair said. “With small cells, we’ve largely been using a capacity trigger as a way to say where we’re going to put small cells. We’re putting them in in different locations.”
“It’s a different deployment, because it’s not really a coverage layer. Small cells are going to be in smaller areas, I think, initially. Over time, it will grow a bit.”
AT&T’s small-cell deployments will be built with a centralized radio access network (C-RAN) architecture, according to Mair.
“C-RAN is the architecture; its called centralized radio access network, but the node at the end is a small cell—we use the terms interchangeably,” Mair said. “If you think about a cell tower, you’ve got a radio at the top with a baseband unit, and you’ve got the brains of tower at the bottom. Take that vertical architecture and turn it on its side. Now, I’m putting the baseband unit, or the brains of my small-cell deployment, in a central location—think about a technical office or a data center—and I’m extending fiber out from this central location to all of these small cells out in the city. Fronthaul is the fiber portion.
“What’s really nice about [C-RAN] is that—if I have 500 small cells attached to the centralized unit—when I do a software upgrade, I’m upgrading 500 small cells all at the same time. It’s very efficient, from an upgradeability standpoint. Small cells will continue to [be] built out in the city, based upon that centralized hubbing architecture.”