Reliable Submarine Capacity

Why It Matters to Everyone

Ryan Wopschall and Simon Webster dive into the increasing need for capacity across the globe, and the implications on the cable industry. Ryan Wopschall and Simon Webster dive into the increasing need for capacity across the globe, and the implications on the cable industry.By Ryan Wopschall and Simon Webster
May 20, 2021


We all know what it feels like to suffer from intermittent coverage on our cellphone, or to experience unexplained dips in broadband speed at home.  At best, it may be a minor inconvenience, perhaps the difference between a successful video call and a frustrating experience for all.  On the other hand, the Internet pervades so much of modern life that it contributes significantly to business efficiency, innovation and a host of social benefits.  Some people go further, arguing that access to the Internet is a human right.  Whatever your view is on that, it is clear that network outages are more than just a nuisance – they can cause direct and significant economic damage.  As an example, a 2016 report commissioned by Submarine Cables UK and the UK’s Crown Estate1 estimated that the value of submarine telecom cables to the country’s economy was £62.8bn per year ($86.9bn).

Interruptions in service can occur at multiple points in the telecom network, but when a submarine telecom cable is impacted, the consequences can be extreme.  The data capacity carried by a single long-haul submarine telecom cable is now in the range of hundreds of terabits per second, traffic which includes data center replication, social media updates, financial transactions, gaming data, and of course international phone calls.

Nevertheless, incidents do occur – there are around 200 submarine cable faults around the world each year.  Where possible, much of the traffic is re-routed onto alternate cables installed on similar routes, under prior agreements between cable owners and other stakeholders.  Many of the world’s largest Internet technology companies have built three or four cables on important transoceanic routes to be protected in case a cable is cut or damaged.

Some coastal states however have yet to achieve that degree of resilience in their submarine network, and when those countries are hit by a cable outage, the whole population tends to suffer from poor connectivity and its economic consequences.  For many years, Bangladesh relied on the SEA-ME-WE-4 cable as its sole international submarine network connection, and during maintenance work on the system had to use terrestrial links through India to maintain fiber connectivity with the outside world.  This resulted in slow Internet speeds for most users, sometimes for periods of several days.


Demand for international capacity is continuing to soar.  TeleGeography’s 2021 Global Internet Map2 shows a 35% rise in international Internet capacity between 2019 and 2020.  That figure is not an exact proxy for cable capacity but is indicative of the trend.  Fundamental reasons for continued growth in submarine cable capacity include the following:

To continue reading the rest of this article, please read it in Issue 118 of the SubTel Forum Magazine on page 23 or you can find it here on our archive site here.