Cisco, and Microsoft Demonstrate 800G Transport on the Amitié Transatlantic Communications Cable
By Sean Buckley, Lightwave Online
February 13, 2024
Cisco completed a trial to transmit 800 Gbps on the Amitié transatlantic communications cable, which runs 6,234 kilometers from Boston, Massachusetts, to Bordeaux, France.
Amitié's network features 16 fiber pairs, each with 23 Tbps capacity, went live in October 2023.
The trial leveraged the Cisco NCS 1014 platform enabled by Acacia’s Coherent Interconnect Module 8 (CIM 8), powered by its Jannu digital signal processor and advanced silicon photonics.
Both products are available today and actively deployed in multiple networks.
Addressing AI growth
This cable is focused on addressing the continued growth of the cloud and the explosion of AI services that is driving the need for greater subsea network capacity, which requires advanced coherent transmission systems that support higher performance. This trial targeted improvements in subsea transmission to provide increased performance and capacity.
According to Cisco, the trial exceeded what it claimed was any industry performance with DWDM 800G in a 150GHz channel spacing, equivalent to a spectrum efficiency of 5.33bit/s/Hz and a maximum spectral efficiency of 5.6bit/s/Hz.
Additionally, 600G was transmitted over 12,469 kilometers for a trans-Atlantic loopback configuration. This is the first time a 140Gbaud single carrier signal was demonstrated life, and it is the longest distance ever reported at single carrier 600G DWDM transmission on an SDM cable.
The Amitié cable, a transatlantic submarine cable connecting the US, UK, and France, is now part of Microsoft’s global network supporting all Microsoft services.
Showcasing Space Division Multiplexing (SDM)
One of the unique elements of the Amitié cable is that it features Space Division Multiplexing (SDM) technology.
SDM's benefit in a submarine cable is that it can increase cable cores and overall capacity.
It can achieve this by combining multiple fiber cables into a bundle to realize space division multiplexing or realize space division multiplexing in the same fiber cable.