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  • Varun Rao

The Cloud beneath our feet

by Varun Rao, Rahul Rao and Yasir Aheer


  • Over 97% of internet traffic is transmitted through physical fibre-optic cables.

  • There are over 200 cable failures every year, but redundancy generally ensures uninterrupted connectivity.

  • Most cable damage occurs due to accidents caused by humans, but they are vulnerable to deliberate attacks.

  • A new age Space Race is putting satellites into orbit at a faster rate than ever before to provide satellite internet connectivity.

  • If today’s space pioneers have their way, mega-constellations of hundreds or thousands of satellites will usher in an era of true global connectivity.


In 2019, the island nation of Tonga was hit by a near total blackout of internet and mobile services, bringing the country’s internet life to a standstill. It was a sobering reminder of the all pervasive influence of the digital age. Bizarrely, this event was believed to have been caused by a ship operating in a restricted area. How could one errant ship captain cause an event of such staggering proportions simply by accident?

In a world where our doorbells, headphones and printers are wireless, it may surprise readers to read that over 97% of internet traffic is transmitted through physical fibre-optic cables, laid on the sea bed.

Each undersea cable consists of between 4 and 200 optical fibres, each of which can transmit about 400GB per second. There are approximately 1.2 million km worth of undersea cables currently in operation, a spider’s web of 0s and 1s crisscrossing the Earth carrying an estimated $10 trillion of financial transfers, and over 1 sextillion bytes of data every day. Most cables are no thicker than a garden hose, an astonishing fact given they transmit data at the rate of terabytes per second.

Worryingly, these cables are largely protected only by the sheer vastness of the ocean (a topic we’ve explored previously). Given how tenuous this safeguarding is, it is unsurprising that there are over 200 cable failures every year. Most people are oblivious to cable damage incidents because providers, mostly Internet giants like Google, Facebook, Amazon and Microsoft, have deliberately built redundancy into their systems, meaning that most countries are serviced by multiple cables. In the event that one cable suffers a failure, internet traffic is seamlessly re-routed to the existing intact cables, if there are any. However, a total of 19 countries rely on a single cable to provide them internet, including Kazakhstan, Azerbaijan, Togo and Sierra Leone. While countries like the US, UK and Japan are supported by 91, 54 and 26 cables respectively, over 5% of the world’s population live in countries supported by only two cables. As island nations, Australia and New Zealand are particularly vulnerable in this respect, the latter being supported by just three cables.

The majority of cable failures each year are inadvertently caused by humans, rather than natural causes. The aforementioned blackout in Tonga was apparently caused by a ships’ anchor damaging an undersea cable. Eight cables were damaged during an earthquake in 2006, causing internet outages in Taiwan, Hong Kong, China, Japan, Korea and the Philippines. When ships accidentally severed cables in the Mediterranean in 2008, 80% of the connectivity between Europe and the Middle East was knocked out in a matter of hours. In 2017, Australians were warned about slow internet speeds due to cable damage caused by typhoons. In 2018, the entire country of Mauritania was forced offline when a fishing trawler damaged an important cable link to Europe. 28 million Yemenis suffered a similar fate in January 2020, when a single cable was severed.

That’s just accidental breakages. There remains the terrifying possibility of deliberate attacks by unfriendly agents. We’ve previously expounded on the dangers of confidential messages being decrypted by hostile actors. What better avenue for this manner of espionage than poorly guarded optic fibres strung out in the vastness of the ocean, far from prying eyes? Far more terrifying is the prospect of a complete loss of internet connectivity for entire countries, crippling economies and causing massive social unrest.

The cables are also vulnerable to attack, bizarrely enough, from sharks. Given that sharks are so ancient they reportedly predate trees, it is ironic that one of the newest inventions on Earth, the internet, is vulnerable to one of the oldest. It appears that the truth is once again stranger than, or at least as strange as, fiction - in the comedy The IT Crowd, technically incompetent IT Manager Jen Barber is convinced the “Internet” in fact lives inside a small black box*.

So why do we use physical undersea cables, with all the attendant risks, when we could use satellite communications instead? Simply put, because fibre-optic cables use light to transmit information, they are both faster and cheaper to use for the mind boggling scale of internet traffic. Rather surprisingly, given the discussion above, the standard measure of cable downtime is measured in a mere seconds per year, indicating their reliability in adverse conditions. And of course, repairs are far easier to undertake on the seabed than in Earth orbit.

Is the future in the skies?

Although the first Space Race was aimed at setting foot on the Moon (a swashbuckling story we’ve covered here), of late focus has shifted to launching satellites into Earth orbit. As a result, there are now over 2600 satellites in orbit, with 180 belonging to SpaceX specifically to provide internet services.

Looking ahead, satellite internet would offer the next quantum leap in internet accessibility, while potentially sidestepping some of the intractable issues faced by undersea cables. Remarkably, the development of geostationary satellite communication was heavily influenced by a 1945 publication by the prescient sci-fi author Arthur C. Clarke, a full 20 years before the first commercial example was launched.

At current speeds, satellite connectivity is not a feasible option for high-volume data transfers, such as video games or videoconferencing, and all the usual problems apply - limited bandwidth, slow speeds, high latency and data limitations. However, for some rural areas this is the only method of getting online. In Australia for example, people in remote areas rely on the NBN Sky Muster Plus satellite service, limitations notwithstanding.

Recent advances have helped. The cost to build and launch satellites has dropped significantly (also here) over the past few years. Over 46 thousand satellites are projected to be launched in the next few years, more than five times the number of objects ever launched into space in mankind’s history. Some have even gone so far as to call this the new-age Space Race. Tesla’s Starlink project is the most ambitious of these projects, with 120 satellites currently in orbit (a number they hope will rise to 12,000). The target is to offer satellite services in the USA and Canada by the end of 2020.

Will the cloud of the future truly be in the skies? If today’s space pioneers have their way, mega-constellations of hundreds or thousands of satellites will usher in an era of true global connectivity. This will likely mean significantly better connectivity for ships and airplanes, remote IoT applications, and rural areas. Given that the UN recently declared access to the internet to be a basic human right, it’s about time.

*Credit to Michelle Isaac for this key cultural reference.




Disclaimer: This article is based on our personal opinion and does not reflect or represent any organisation that we might be associated with.


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