How well protected are fiber-optic cables

The landing site of a submarine fiber-optic cable. (Internet photo)

The 2012 Olympics have come and gone, and millions of people around the world have followed the events on television. Yet much of Europe nearly missed out on it. Early July, workers renovating the town square of Steenkerke, a small Belgian village with only 400 inhabitants, uncovered a yellow cable, the use of which they did not know.

Luckily, they did some checking before cutting the cable – which actually carried all TV footage of the Olympic Games from London to Europe.

The inhabitants of Armenia were not so lucky in April last year, when a 75-year-old woman digging with a simple shovel next to a railway track in neighboring Georgia cut through a fiber optic cable and thus effectively cut off Armenia from the Internet (the cable in question is responsible for 90% of the country’s Internet access), as well as a large part of Georgia itself.

And, of course, Rwanda too has been the victim of such an incident, when in February a ship off the coast of Mombasa dropped its anchor and severed the Teams underseas fiber optic cable — one of three high-speed internet submarine cables that have arrived in the region since 2009. As a result, internet connections slowed down by 20% in Kenya, Rwanda, Burundi, Tanzania, Ethiopia and South Sudan’s capital, Juba, for about 14 days of reparation.

These three examples show that the cables that are the backbone of the world’s information system are rather vulnerable, and that some of them are quite crucial. So how well protected is Rwanda against such incidents? And how well protected are our cables?

First of all, there are three underseas cables that supply Rwanda (and the rest of EastAfrica). Seacom, the first to be up and running, links East Africa to Europe, India and South Africa; Teams links the region to the United Arab Emirates; and Eassy, which went live in July 2010, links countries along the East African coast. The landing stations that connect East Africa to the rest of the world are Kenya (entering Rwanda via Uganda) and Tanzania (entering Rwanda via Burundi).

A 75-year-old woman digging with a simple shovel next to a railway track in Georgia cut through a fiber optic cable and thus effectively cut off Armenia from the Internet.

Through Internet Service Providers (ISPs), Rwanda is connected to all the cables for the sake of preventing interruption of the services when one is broken or damaged – this is called “redundancy.” This is necessary because repairing a submarine cable is highly complex (see http://slate.me/RWw29j for a detailed explanation), and as the February cut showed, it can take a while to get it done.

BSC (the national backbone, with the widest coverage that touches every province of the country), depends on Seacom (through New Artel); MTN Rwanda’s fiber capacity depends on Eassy (80%) and Teams (20%), while Rwandatel (the shortest fiber of all) relies also on Seacom. This means that if there’s a problem with one of the cables, there will always be another ISP able to provide Internet access.

The ISPs can also provide back-up for their own systems, for example through satellite or, as in the case of MTN, by not placing all their bets on a single cable.

Secondly, there is also a fiber-optic cable network which has been laid in Rwanda since 2009. The simplest measure to protect them is, of course, to lay them underground, at around 1.5m deep.

However, as the cases above show, they can still be damaged by accident, or by a natural disaster. However, that much easier to repair than a submarine cable.

The most difficult part is in fact to locate the break, and even that is not complicated. Technicians use a device which is known as an optical time-domain reflectometer or OTDR, which works a bit like a radar – it sends a light pulse down to the cable, which will be reflected back to the device when it encounters break, giving them information about the distance.

After that, it is just a question of uncovering the cable and replacing the damaged part.

Posted by Eric Bright on Aug 13 2012. Filed under Other News, Technology, Weekly Highlights. You can follow any responses to this entry through the RSS 2.0. Both comments and pings are currently closed.