The Marea Subsea Cable: A Pioneer Of The Open Cable Model And New TransAtlantic Routing

Technology: Standard 100G wave coherent optics. Shorter repeater spacings to maximize per fibre pair throughput. 
Fibre Pairs: 8. 

Founding Fathers: Facebook and Microsoft

Consortium Members: Facebook, Microsoft, and Telxius. 

RFS: May, 2018. 

Route: Direct Ashburn Equinix to Spain. 

Landings: Virginia Beach, VA. Bilbao, Spain. 

Notable Features: First cable to directly link Ashburn Equinix to Europe. Also first cable to adopt the open cable system model where each consortium member selects their own submarine line termination gear and owns either fibre pairs or spectrum. 

Potential Throughput: 224 Tbps. 

Marea is the first cable to give the cold shoulder to New York City and the UK. It directly links Ashburn Equinix via a Virginia Beach landing to Continental Europe with a Spanish landing. The cable completely bypasses the UK and the Northeastern US. This reflected Ashburn Equinix' rising importance and the desire of network planners  to avoid NYC with its complex conduit systems and history of high profile terrorist attacks. It also reflected the desire of European telecom and political forces to be less dependent on the UK which had unwisely decided to leave the EU in 2016. Until Marea the majority of TransAtlantic telecom traffic traversed the UK to reach the rest of Europe. A bad situation in terms of resiliency, but also telecom sovereignty. 

Not only was Marea's route a first, but the cable's founding fathers, Facebook and Microsoft, decided to jettison the traditional consortium model where each member received a fixed percentage of a cable's lit capacity based on how much they invested. Instead, they replaced it with individual fibre ownership which meant that each consortium member could chose their own DWDM kit. It was the desire to escape the technological conformism of the traditional consortium that led Facebook and Microsoft to develop this new approach known as the open cable model. Part of the underlying rationale was that consortiums breed mediocrity because decisions require consensus in practice. Even in a majority voting set up consortiums tend to strive for unanimity which means that new ideas get swept under the rug. Status quo practice tends to prevail in such situations. Facebook and Microsoft partly recouped the construction expense by selling half of the 8 pair cable to Telxius who also took responsibility for operations. In turn, Telxius sold one of its 4 pairs to Amazon on an IRU basis. Subcom built the system which is a standard coherent optics cable pushed to the performance limit by smaller repeater spacings. 

Marea is really the pinnacle of the traditional coherent optics model where the aim is to maximize per pair throughput. It uses an ultra-low loss pure silica fibre core and smaller repeater spacings to increase per pair throughput. Note that smaller repeater spacings means more repeaters and hence much higher capex. Although the cable's intial design capacity was 180 Tbps or 23 Tbps per pair, field tests using Infinera's ICE6 optical engine show that the cable's aggregate output can be raised to 224 Tbps. 

Marea lands at the Telxius Bilbao cable station in Northern Spain. I am not a big fan of this landing because while ideal for Spain, French landings offer lower latency for traffic bound to France, Belgium, Netherlands, Germany, Switzerland, and Italy. The Spanish landing was a mistake in my opinion. It is worth noting that Marea customers are not stuck at Bilbao. Telxius can deliver their traffic to Madrid, Paris, and probably Marseille as well.