In the earliest days of mobile phones, when they were like bricks and everyone still had a landline, people joked that any phone could be mobile if you had a long enough cord. It’s more than a little ironic that today everyone has a mobile, but global communications depend on cords thousands of kilometers long slung across ocean floors.
Submarine communications cables carry over 90 percent of data traffic between continents. They are the core of the internet backbone. Even if 5G meets its most optimistic latency and bandwidth goals, it will mean nothing if the backbone capacity isn’t there to move data globally. You can’t receive a 5G signal across the Atlantic no matter how much you wave your phone in the air. This is why there has been a surge in submarine comms cable projects over the past decade, one that has gone almost unnoticed amid the 5G buzz.
The Apollo program of the 19th century
Installing a physical cable across an ocean sounds like something that could only be possible with cutting-edge materials and engineering. In fact, it was first achieved 160 years ago with seven strands of copper wire wrapped in hardened tree sap.
In 1858, a British and a US warship met in the mid-Atlantic, spliced together two ends of the hundreds of tons of cable they each had on board and set off in opposite directions for home, paying the cable out behind them. Both ships made landfall a few weeks later and a 3,200 km-long telegraph line between Europe and the North America was opened.
The cable failed within a month, but it was a world-shaking technological achievement and proved a point. In 1866, a second attempt using improved cable (but still essentially copper wire wrapped in tree sap!) established a permanent connection.
You know how annoying it is when an ethernet cable slips down the back of your desk and you have to fumble around on the floor to find it? Now imagine you drop a cable in a 4 km-deep ocean and you have to retrieve it with a grappling hook from the deck of a pitching steam ship. That’s what engineers did in 1866 to recover a snapped cable and complete the second trans-Atlantic link.
Grow a backbone
Modern submarine cables consist of optical fibers sheathed in multiple protective layers, usually no more than 25 mm in diameter. The longest, the SEA-ME-WE 3, stretches over 39,000 km from Germany to Korea. In some places they lie on the ocean floor under 8 km of water.
Unsurprisingly, these cables are expensive to make and install. For much of their history, they were funded by governments and consortia of telecoms companies. In the last few years, however, this model has changed radically, with hyperscale cloud companies and large content providers now driving the biggest projects.
Google, Facebook, Microsoft, and Amazon have made major investments in submarine cable in the last five years, with much more planned. Google, for example, is currently building two across the Atlantic, another between the US and Chile, and a fourth between Hong Kong and Guam.
The technology that pushes data through the fiber is also bounding ahead. Google’s Dunant cable, stretching 6,400 km from North Virginia to the French coast, expects to achieve transmit speeds of 250 Terabits per second when it comes online in 2020. Contrast this with the 16 hours it took to send a 98-word telegram from Queen Victoria to US President James Buchannan over the 1858 cable.
When you have BigTech money, building your own internet backbone makes a lot of sense. Rather than rent capacity on connections built by telcos, these companies can route cables to minimize distance (and latency) between their own data centers. Competition from currently embryonic space-based networks, like SpaceX’s Starlink project, may make milliseconds critical.
It’s not what you know, it’s when you know
Considering the implications of 5G without thinking about the backbone network is like trying to understand cars without thinking about roads – one is meaningless without the other. Unfortunately, this doesn’t mean it’s uncommon.
The effective ban on US companies from using the 5G kit made by Chinese company Huawei is one such example. Whether the security concerns are justified or not, the idea of a US-only 5G network shining on a hilltop is a fantasy. Huawei is a massive investor in submarine cables. It may be banned from building or operating these cables on US soil, but data from US users will inevitably travel over Huawei-owned cables (and other networks) elsewhere in the world.
The speed and bandwidth of 5G on the edge of these networks will drive speed and capacity in the backbone (developments in fog computing not withstanding). Like flowing water, data will quickly find a way around political considerations.
The 1858 submarine cable failed in less than a month, but not before the British government had used it to send a message that saved £50,000 (a huge sum in the mid-19th century). At the outbreak of the Indian Mutiny the previous year, it had taken 40 days to receive a message in London requesting troops. When the uprising ended, it took a few hours for the British to send a trans-Atlantic telegram countermanding the very expensive embarkation of more reinforcements stationed in Canada. The value of data that enables individuals, enterprises, and governments to respond to distant events has driven technology for generations, and 5G will only sharpen that imperative.
Read more about the value 5G can bring to industry.
This blog is part 5 of a series of five written by Europe Chief Technology and Innovation Officer, Gunnar Menzel.
Missed the previous blogs? Read them here:
Part 1: Five new ways to think about 5G: The element of surprise
Part 2: Five new ways to think about 5G: In space, no one can hear your latency
Part 3: Five new ways to think about 5G: The speed trap
Part 4: Five new ways to think about 5G: Know your place