- AT&T took a 1.6 Tbps carrier wavelength out for a test run across its fiber network
- The trial, which used Ciena’s coherent optics, will help AT&T prepare its network for AI and other bandwidth-intensive applications in the future
- The wavelength services market is running hot right now due to demand for AI applications, according to Vertical Systems Group
Telcos have their work cut out for them preparing to handle rising traffic from AI applications, cloud computing, streaming and more. AT&T, which notched a new 1.6 Tbps single carrier wavelength trial under its belt, claimed its network is one step closer to getting there.
Here's the lowdown: AT&T ran a wavelength that carried two 800 Gigabit Ethernet circuits across 296 kilometers of its commercial long-distance fiber network, creating "a full, uninterrupted data path utilizing a single light frequency across the entire fiber length between two points.” Practically speaking, this means AT&T can brace itself for the incoming barrage of network traffic, which is set to double by 2028, according to Mike Satterlee, AT&T’s VP of Network Infrastructure and Services.
“The technologies demonstrated in this trial will play a key role in AT&T’s continued efforts to keep up with increasing customer demand to send data, watch videos, and use streaming services,” Satterlee stated.
One key point is that AT&T's trial took place “with other customers’ live traffic alongside it,” said Dell’Oro Group analyst Jimmy Yu. The 296-kilometer benchmark is also important, as it gets “harder and harder to increase the span length as the wavelength speed goes up,” he told Fierce. AT&T got the job done using Ciena’s WaveLogic 6 Extreme coherent optical transponder.
“As a reminder, Ciena is the first supplier of coherent 1.6 Tbps-capable transponders,” Yu said. “Previous to this, the highest speed was 1.2 Tbps.”
Ciena is no stranger to telcos and their AI ambitions, with Lumen being the most recent customer win. In Lumen’s case, the company wants to employ WaveLogic 6 to feed hyperscaler hunger for AI bandwidth. Verizon, which recently launched its AI Connect portfolio, has also trialed WaveLogic 6 to see how fast it could transmit data in a live fiber network.
It's only a “matter of time” before we see widespread deployments of 1.6 Tbps coherent technology, according to Jabulani Dhliwayo, founder and technical director at Fiberguide, a company that provides training for optical communications professionals.
A single 1.6 Tbps wavelength has a reduced hardware footprint and consumes less power than optical networking configurations that use multiple wavelengths, Dhliwayo said on LinkedIn. But he did caution achieving 1.6 Tbps in coherent optical systems requires "a careful management of trade-offs between competing technologies such as modulation complexity and baud rate."
The rising tide
AT&T’s 1.6 Tbps test run is also indicative of the rise in demand for wavelength services. The operator, along with Lumen, Zayo, Verizon and Crown Castle were the top five providers in the U.S. wavelength services market in 2024, per data from Vertical Systems Group.
As expected, AI applications are a “major purchase driver” for 100+ Gbps wavelength orders, the firm said. Hyperscalers, financial institutions, media companies and others are buying specifically 400 Gbps services to meet their connectivity needs.
“Double digit annual growth is projected for 100 Gbps and higher speed wavelength circuits through 2028,” said VSG Principal Rick Malone.