Subsea Cables & Internet Infrastructure

Despite what we think, telecom wholesale service is not really a tech industry, at least not in leadership. Engineers, scientists, technicians, mathematicians, and computer scientists lead the real tech companies. Google is an excellent example. Sergey Brin and Steve Paige, two Stanford educated computer scientists, founded the company. German companies almost always select mechanical engineers to lead them. Obviously there will be cases of generalists who do quite well. Bjarni Thorvardarson was not a STEM graduate, but he has a critical, yet open mind and led Hibernia out of bankruptcy to a $610 million sale sale to GTT. He accepted a sales force initially composed of four sales contractors who had no salaries, but received 10% of net revenue, (gross revenue minus third party network costs), used a contract manager to handle standard NSA and MSA negotiations as opposed to a lawyer, and took the daring step of building the new, ultra-low latency Express cable in an era o...

EXA has deployed G.652d fibre across much of its European backbone with the important routes receiving priority. Chart below shows the paths that have been upgraded. EXA's western European network consists largely of the Interoute assets plus a Bulgarian company that had fibre and conduit into Turkey. It is a highly dense network that gives EXA's Atlantic cables and Trans-Atlantic capacity (it owns a fibre pair on Dunant as well as some capacity on Amitié and other cables) the ability to deliver traffic from Chicago and Equinix all the way to Instanbul. This dense footprint allows to deliver traffic at lower costs then its main competitor, Telxius. The carrier has the same basic reasons to upgrade as EUNetworks, namely fibre depletion, hyperscaler demand for long haul dark fibre, and the improved performance of modern fibre with less bending and linear attenuation. Its marketing emphasizes that it is deploying G.652d fibre, but I believe this is just marketing to reassure pot...

With most European long haul fibre having been deployed in the 1998-2002 periods, it is not surprising that after 20 years that carrier upgrades were in the cards. There are several reasons. One is fibre exhaustion. Secondly, although fibre itself does not rapidly depreciate because glass is highly stable, technology has evolved. For one, the optimal ILA spacing has sharply increased due to the advent of ultra-low loss fibre, which has attenuation of .2 dB or even less per kilometer. Since most repeater huts are old, replacing closely spaced old ILAs with new, more widely spaced facilities lowers power and equipment costs long term. With fewer ILAs, less can go wrong. There were other factors as well driving EUNetworks' upgrade decision. Although old fibre is generally in remarkably good shape, there are often problems at joints. At these locations, the fibre pairs must be removed from the cable for splicing. Moisture often penetrates these joint enclosures. It attacks and erodes t...

During most of my telecom career terrestrial long haul fibre was synonymous with the ITU's G652 standard. This is single mode optical fibre that has zero chromatic dispersion at the 1310 nanometer wavelength and good wavelength performance in the 1260 to 1625 nanometer range. This include the O, E, S and workhorse C bands. G.652d fibre quickly became the de facto standard for long haul terrestrial fibre optic networks. The G.652 standard was introduced in 1984. Its motivation was a dual purpose optical fibre suitable for data centers and long haul. Most optical equipment for internal data center traffic transmitted in the O band, which ranges from 1260 to 1390 nanometers. But long haul traffic faces significant attenuation as distances grow. This required repeaters, another source of capex and opex expense. It was already known that attenuation or the diminishing of light's intensity was minimized in glass at 1550 nanometers. The versatility of the G.652 standard made it hugel...

I An optical fibre has three structural components. The glass core transmits the light. It is the optical highway that the light travels. If the light is single mode, the core is 8.3 microns. A single mode fibre can be thought of as a single lane road. If the light is multi-mode, the core is 50 or 62.5 microns.  The 125 micron cladding is also glass. It is made ofglass that keeps the core glass from leaking light as long as the angle of incidence is not too big. The buffer consists of a hard and soft layer of plastic, often urethane acrylate. The soft layer surrounds the cladding and cushions it. The hard layer prevents abrasion. For a more complete explanation, click on https://learn.aflglobal.com/home/the-basic-structure-of-optical-fiber. II Modes of Optical Strands A single mode strand has one path. Think of it as a straight path down which the light travels. To keep the path straight the diameter is relatively small at 8.3 microns. Multimode glass allows the glass to trave...

Juno is the Queen of the Olympian gods in Roman Mythology. This 20 fibre pair cable has design capacity of 320 Tbps, which makes it the highest capacity subsea network to connect the US to Asia. It lands at Grover Beach, California, and also has Japanese landings at Shima and Minami-Boso. NTT is the project's main backer and owner. The carrier clearly felt that two Japanese branches along with three cable landing stations (Softbank Maruyama, NTT Shima, and NTT Minami-Boso) would significantly improve resiliency given Japan's reputation for earthquakes and other natural disasters such as tsunamis. As is usual for a NTT project, it created a standalone company known as SerenJuno in which it has majority ownership to minimize risk. This way any misfortunes would not result in the parent company having financial liabilities. NTT is also extremely reserved about revealing capacity owners on the system. I have learned that PCCW is on the system. Details Ownership: NTT and Mitsui. Cap...

 1. Damage to cables is often the result of a cascade of events. For example, the 2006 Taiwan Earthquake pushed coastal sediments down a steep slope and triggered a massive landslide that traversed over a hundred kilometers. In many cases snapping deep sea cables like they were toothpicks. The sediment build up is due to Taiwan's heavy rains that carry eroded soil to the sea. 2. Lots of subsea faults arise from events that unfold over years such as deep sea abrasion of the outer sheaths of a cable. A cable may rub against a rough surface on the ocean floor for years until the polyethylene layer and the wound steel strands are removed and water hits the copper power conductor. 3. Another interesting example is the Congo Canyon where the Congo river deposits sediments offshore that high spring tides or flooding push down the undersea canyon and crush subsea cables. 4. Volcanoes during discharges have buried cables in molten lava. Also pose a danger to cable landing stations and terre...