AT&T achieved symmetrical speeds of 20 Gbps in its production network in a trial of 25G technology from Nokia. Eddy Barker, AT&T AVP of Mobility and Access Architecture, told Fierce the test highlights the future-proof nature of the fiber network it is deploying and is the latest step toward the likely commercial deployment of the technology in a 2024 timeframe.
The operator has been working on 25G for some time. It signed on to the 25GS-PON Multi-Source Agreement (MSA) in March 2021 and Barker said it has been tinkering with the technology in its lab for “a while”. He said late last year AT&T tested the full 25 Gbps downstream speeds the technology enables but noted at that time the upstream speed was still asymmetrical at 10 Gbps.
Now that the ecosystem has matured a bit more AT&T decided to take its testing out to the field, running an experiment on the fiber infrastructure it is currently using to deliver commercial 2-gig and 5-gig services. Barker said its latest trial used the existing optical line terminals (OLTs) it has been deploying in its network since 2020 as well as the same Quillion chipset that’s in Nokia’s XGS-PON solution. It mixed in new photonics to enable the symmetrical capabilities it was seeking.
“We used that same fiber and then we actually turned up at some work centers the 25-gig symmetrical and tested it up to about 20 gigabits per second,” he said. “We actually combined that on the same fiber with our FiberWise technology, which is actually wave division multiplexing.”
According to Barker, a key takeaway from the trial is that AT&T is well-positioned to upgrade its existing fiber infrastructure for a minimal cost. He said electronics within the network typically make up around 20% to 25% of the deployment cost per home, with the bulk of the spend going toward the fiber itself and the labor to put it in the ground. The latter won’t need to be repeated to get to 25G.
“Our investment in fiber, which we’re targeting 30 million [locations] by 2025, is really very strategic,” he said. “This fiber infrastructure really has a huge potential lifespan. And we’re demonstrating that we can actually grow that as traffic grows, as services demand more bandwidth that we can sell and we can do it very nominally.”
In terms of when commercial deployment might follow, Barker said while the OLTs and photonics are ready it’s still waiting on the ecosystem to come out with gateway ONTs. That’s likely to happen by the end of this year or early 2023. During the rest of 2023, he added he expects to see more vendors beyond Nokia announcing 25G capabilities. Barker concluded there may be some early adoption of 25G in 2023, but it’s more likely that a steady flow of commercial deployments won’t happen until 2024.
AT&T is far from the only operator working on 25G. Belgian operator Proximus staked a claim in May 2021 as the first in the world to deploy the technology and Florida-based Hotwire Communications in December 2021 claimed to be the first in the U.S. to roll out 25G. Frontier Communications in the U.S., Bell Canada and U.K. operator BT are also trialing the technology.