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Showing posts with the label DWDM

The Subsea Fibre Optic Cable Class of 2027: Apricot

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Apricot is one of the most exciting Southeastern Asian cable projects to be RFS next year. In fact, it is the first subsea network to be truly physically diverse from the South China Sea. The 12 fibre pair main trunk's end points are Singapore and Tokyo, but the path completely bypasses the South China Sea by detouring through Indonesia and up the Philippines' East Coast. This increases latency, but makes Apricot the natural complement for any cable system like ADC or SJC2 that goes through the South China Sea. Obviously the latency is higher than the usual suspects, but most buyers need resilient networks to keep their jobs. Apricot lands in Singapore, Indonesia, the Philippines, Taiwan, Guam, and Japan. The cable system has military value as it links Taiwan to the Guam, the latter being the US military command center for the Western Pacific. Its routing around the South China Sea also makes it less vulnerable to sabotage. Design capacity was originally intended to be 211 Tbps...

Optical Subsea Amplification & The DWDM Revolution

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As noted in my previous post, optical amplification allow light signals to be boosted without being first decoded into a digital representation. Optical-electrical-optical conversions go away. Hence the computer necessary for OEO conversions disappears. This in turn sharply improves the amplifier's reliability and life span. It also eliminates the conversion delay so end-to-end latency is improved. Finally, no computer means less cost. But these benefits are really secondary. More importantly, the advent of optical amplifiers led to a quantum leap in bandwidth that can be attributed to two related developments. The first is that optical amplifiers impose no transmission limits on computer technology. This means that we can lay a cable in the water and then upgrade it at regular intervals as Moore's law improves the ability of computers to process optical signals. Nothing on the wet side changes. Indeed, the introduction of digital processing allowed 10G wave subsea cables like ...

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

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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 avo...