AT&T claims it achieved a long distance world record top speed of 1.6Tb/s over a single wavelength across 296 km of its long haul fiber optic network (spanning Newark, New Jersey to Philadelphia, Pennsylvania). That is four times faster than its current top speed of 400Gb/s per wavelength!
The 1.6Tb/s wavelength carried two IEEE 802.3df-2024 standard-based 800 Gigabit Ethernet end-to-end circuits, an industry first. It is a full, uninterrupted data path utilizing a single light frequency across the entire fiber length between two endpoints. The single-carrier 1.6 Tb/s wavelength was transported alongside existing live customer traffic on 100Gb/s and 400Gb/s wavelengths.
Open-sourced white box switches were the network equipment used during the trial. The white boxes are designed using the Broadcom Jericho3 packet processor chip and can provide up to 18 x 800G network interface ports all within a 2RU platform. The (Israel based) DriveNets Network Cloud software-based solution is hardware-agnostic and runs open APIs on the white boxes to perform data and control plane functions, including routing at 800G. The use of white boxes and the disaggregation of the hardware and software control costs and facilitate faster innovation.
The two 800GbE signals from the white box were multiplexed to 1.6 Tb/s in Ciena’s WaveLogic 6 Extreme coherent optical transponder, which is the first coherent optical solution to use a 200Gbaud design and 3nm coherent DSP ASIC and to reach speeds up to 1.6 Tb/s on a single carrier. The WL6e technology reduces the space and power per transmitted bit by 50% compared to current 800G transponders. This trial is the first to demonstrate WL6e at 1.6Tb/s with standards compliant 800GbE clients.
In the Newark and Philadelphia offices, 800G DR8 pluggable transceivers from Coherent were installed in the white box router and WL6e transponder to create the cross-office connectivity between the packet and optical technologies. And 800GbE client signals, provided by Keysight’s AresOne-M 800GE testset, fed the white box through additional pairs of 800G DR8 pluggable client optics, allowing verification of end-to-end performance of the two 800GbE services from Newark to Philadelphia.
Quotes:
“Traffic on AT&T’s network continues to increase as consumers are using more connected devices,” said Mike Satterlee, vice president, Network Infrastructure and Services, AT&T. “We anticipate network traffic growth to double by 2028 and 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.”
“This groundbreaking achievement with AT&T adds to a growing list of Ciena industry-firsts that push the boundaries of optical network speed and capacity,” said Dino DiPerna, senior vice president, Global Research and Development, Ciena. “Ciena’s WaveLogic 6 coherent optics will support AT&T’s next gen converged optical network and efforts to build a cloud-based and AI-ready network with greater scale, flexibility and efficiency.”
Verizon’s 1.6Tb/s on Metro Fiber Network:
AT&T’s announcement comes just a few months after arch-rival Verizon announced a 1.6 Tb/s milestone of its own. Verizon also, working with Ciena, achieved that peak speed on a single wavelength, but on its metro fiber (not long distance) network. Verizon is mainly looking to advance through M&A. Its proposed acquisition of Frontier Communications is still pending, with some Frontier shareholders insisting that the US$20 billion price tag undervalues the operator.
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AT&T has spent the past six months demonstrating that it aims to build its way to fiber domination. It rolled out fiber to around 600,000 premises in the 4th quarter of last year, taking its total fiber footprint to 28.9 million locations; it is shooting for 50 million by the end of 2029.
References:
https://about.att.com/story/2025/data-transport.html
https://www.business.att.com/products/wavelength-services.html
https://www.telecoms.com/fibre/at-t-touts-1-6-tbps-fibre-speed-milestone-as-us-battle-continues