Subsea Cables & Internet Infrastructure

In a recent interview META subsea engineers suggested their next project would be a 1 Petabit Trans-Atlantic cable. They pointed to three possible ways of accomplishing it: multicore fibre, use of the C and L spectrum bands, and 50 fibre pair SDM. Pros and Cons 1. Multicore is subject to cross talk. Right now the only multicore cable is the Taiwan-Phillipines-US cable scheduled to go live this year. A Google project with NEC as the vendor, it has two cores per fibre strand and 26 Tbps total per fibre strand or 13 Tbps per core. The challenge is cross talk. The light spills from one core to the other and vice versa. Obviously this distorts the signals and at high transmission rates the distortions become greater and greater and the signal-to-noise ratio disintegrates. The advantage of multicore fibre is that no redesigning of the optical amplifiers is required. Since everyone acknowledges that SDM alone is unlikely to surpass the half terabit mark, Google is obviously interested in mult...

Facebook engineers during an interview on the Waterworth project provided details about their next big project. 1. Facebook is planning to build the first one petabit per second Atlantic cable. No details yet available on end points. Given traffic flows it is most likely to directly connect Continental Europe and the US. 2. META engineering is looking at three options to achieve one petabit per second throughput. A. Using both the C and L spectrum. This would effectively double the bandwidth. B. Cable will definitely be SDM (spatial division multiplexing). Strong likelihood that will be 48 pairs. C. Another possibility is two core optical fibre in order to double the bandwidth per pair. 3. I believe the most likely option is using C and L bandwidth. Arelion has incorporated L band spectrum into its DWDM Layer 1 service between Atlanta data centers and Ashburn Equinix using Infinera gear. Colt and Sparkle have used the L band on terrestrial routes. Most DWDM equipment today offers both ...

I predicted a couple months ago that EXA was consolidating the Atlantic and would purchase Aqua Comms, which has been struggling, and whose estimated value was written down by its former owner, an infrastructure fund. An financial disclosure indicates that the buy price is a mere $54 million for all of Aqua Comms' assets. That $54 million includes the the four fibre pair AEC1, two fibre pairs on AEC2, which is a consortium project, and two Irish Sea cables. That's not very good. In fact, it is terrible. The price is probably 15% of of construction costs. It's a great contrarian EXA move because EXA can absorb the company's assets, but fire 99% of the employees. So the revenue should improve the bottom line. Aqua Comms illustrate how a lot of venture capitalists are bullish on telecom infrastructure without really understanding the challenges of making it successful (they should hire me for a lot of money to educate them). 😃 So what went wrong? Poor operational performa...

Amazon Ireland has applied for a maritime usage license to land a planned cable connecting Ireland to the United States. It is considering landing the cable near Castlefreke on Ireland's Southeast Coast in County Cork along a stretch of beach called the Strand. Amazon has made no public announcement so far. Here is the filed application . I discovered this when I came across a local Irish newspaper that mentioned that Amazon was looking at a nearby beach for a cable landing. I then did a Google search and found the filing. All these filings are posted online and they are 'leading indicators' as economists would say of what is going to happen.  No Trans-Atlantic subsea cables currently land on Ireland's South Coast other than EXA's Express and that is part of the reason that Amazon finds it so appealing. Such a cable would be physically diverse at least on the terrestrial side to the Irish Sea and older Atlantic cables like Hibernia North and South and AC1. I can nev...

Like Firmina Anjana uses the Myrtle Beach CLS (DC Blox is the owner) for its US landing and is an extremely high capacity spatial division multiplexing cable with 24 fibre pairs. Design throughput is 480 Tbps. It is also a hyperscaler cable, a Meta project. The European landing is at Santander, Spain with Telxius providing the CLS. The name Anjana is a mystery to me. I assumed it was a Spanish name, but Anjana is also an Asian Indian female name that means complete and worthy.  Notable features include ***Record holder for highest capacity Trans-Atlantic cable at a half petabit day one. Note this is design capacity. It will undoubtedly be upgraded to even higher levels down the road. How much depends on coherent optics progress. ***Uses aluminum to conduct power. This works better than copper because it is lighter weight and less expensive. By using a slightly greater diameter aluminum can maintain the same voltage draw down as copper. ***Meta is landing the cable itself in US wate...

Most Layer 1 bandwidth buyers focus their efforts on EXA's three Hibernia Atlantic cables, Aquacoms' AEC-1 and AEC-2 assets, and Marea and Dunant. As a group, those subsea networks probably account for 80% of wavelength transactions across the Pond. Two lesser well known alternatives are Amitié and Grace Hopper. Amitié means friendship in French. Not surprisingly, it connects Boston via a Lynn, Massachusetts landing at a Hibernia CLS to Bordeaux, France. This spatial division multiplexing 16 fibre pair main trunk cable is a Meta project. Meta owns 80% of the network capacity with the balance held by the minority partners of Orange, Vodafone, and Aquacoms. To be more precise, Amitié branches in the Eastern Atlantic to the UK and France. Twelve fibre pairs land at Bude, Cornwall, and sixteen pairs at the Orange La Porge CLS, a short distance from Bordeaux. Note that 16 pairs land in the US, but a total of 28 on the European side. The branching unit is using optical switching to ...

I n 2005 there were 7 high c apacity Trans- Atl antic subsea fibre optic networks connecting North  Americ a to Europe. Flag had two cables, Hibernia  Atl antic two as well, Level3 owned the Yellow cable, Global Crossing had  AC1, the PTTs owned TAT-14,  and  Apollo h ad two. In most cases the cables landed in either Ireland or the UK with most traffic destined for downtown London telecom hotels like the various partitions of Telehouse London (East & North at that time). London was Europe's key telecom hub. The other two important hubs were Frankfurt and  Amsterd am.  At the time Teli a Carrier was buying 10G waves 60 Hudson to Telehouse East for $38K a month. But that did not last long.  There was chronic excess capacity due to zombie subsea cables. In most industries if rates of return are depressed, firms exit the industry with their assets sold to be used in other sectors. Consequently, the in...

EXA has emerged as the dominant player on the Atlantic routes. Its original subsea network consisted of the the highly diverse North and South Hibernia cables complemented by the much faster and younger Express cable.  North EXA cable was RFS 2001. It connects London & New York via landings highly diverse to its competitors. North lands in Canada at Halifax and at Southport, UK. In contrast, most Atlantic cables land near New York City and in Cornwall near Bude. North's diversity makes it an excellent choice for network planners focusing on resiliency. Obviously, the cable's latency is high, but that is generally the tradeoff one must accept to achieve physical diversity. I think the RTD 60 Hudson/Telehouse London is probably 76 ms. dfs South EXA cable was also RFS 2001. It lands at the same CLS as North on both sides of the Atlantic. I believe the latency is slightly higher.  Express was built much later (RFS 2015). It is designed to be the lowest latency path f...