The fastest data in the world

As far as IT upgrades go, this was one of the most stressful things you can experience.

In February, deep in a warehouse at CERN, the Swiss home of the Large Hadron Collider (LHC), the world’s largest scientific experiment, two network engineers held their breath and pressed a button.

Suddenly, text appeared on a black background on a screen in front of them. It had worked. “There was a moment of joy,” recalls Joachim Opdenakker of SURF, a Dutch IT association working for educational and research institutions. “It was great to see it.”

He and his colleague Edwin Verheul had just established a new data link between the LHC in Switzerland and data storage sites in the Netherlands.

A data link that could reach speeds of 800 gigabits per second (Gbps), or more than 11,000 times the average UK home broadband speed. The idea is to improve scientists’ access to the results of LHC experiments.

A subsequent test in March, using special equipment loaned by Nokia, showed that the desired speeds could be achieved.

“This transponder that Nokia uses is like a celebrity,” says Verheul, explaining that the equipment is reserved in advance for use in various locations. “We had a limited time to test. If you have to postpone it for a week, the transponder is gone.”

This amount of bandwidth, close to a terabit per second, is extremely fast, but some undersea cables are even hundreds of times faster – they use multiple strands of fibre to achieve such speeds.

In laboratories around the world, network experts are creating fibre optic systems capable of transmitting data at ever faster speeds. They are achieving extraordinary speeds of many petabits per second (Pbps), or 300 million times the average UK home broadband connection.

It’s so fast that we can hardly imagine how that bandwidth will be used in the future. But engineers are wasting no time in proving that it’s possible and they just want to go faster.

The duplex cable (with cores that send or receive signals) running from CERN to data centres in the Netherlands is just under 1,650km (1,025 miles) long and snakes from Geneva to Paris, then Brussels and finally Amsterdam. Part of the challenge in reaching 800Gbps was sending pulses of light over such a long distance. “Because of the distance, the power levels of that light decrease, so you have to amplify it in different places,” Opdenakker explains.

Every time a tiny subatomic particle collides with another during experiments at the LHC, the impact generates staggering volumes of data: about a petabyte per second. That’s enough to fill 220,000 DVDs.

Although it is a simpler technology for storage and study purposes, it still requires a lot of bandwidth. And with an upgrade planned for 2029, the LHC is expected to produce even more scientific data than it does today.

“The upgrade increases the number of collisions by at least a factor of five,” says James Watt, senior vice president and general manager of optical networks at Nokia.

The time when 800 Gbps will seem slow may not be far off, however. In November, a team of researchers in Japan broke the world record for data transmission speeds by achieving a staggering 22.9 Pbps. That’s enough bandwidth to power every person on the planet, and then a couple billion more, with a Netflix streaming service, says Chigo Okonkwo of Eindhoven University of Technology, who was involved in the work.

In this case, a huge but insignificant stream of pseudo-random data was transmitted along 13km of coiled fibre optic cable in a laboratory. Dr Okonkwo explains that the integrity of the data is analysed after transfer to confirm that it was sent as quickly as reported without accumulating too many errors.

He also adds that the system he and his colleagues used was based on multiple cores – a total of 19 cores inside a fibre cable. This is a new type of cable, different from the standard cables that connect many people’s homes to the internet.

But ripping out and replacing old fibres is expensive. According to Wladek Forysiak of Aston University in the UK, it helps to extend their lifespan. He and his colleagues recently achieved speeds of around 402 terabits per second (Tbps) along a 50km-long optical fibre with a single core. That’s about 5.7 million times faster than the average UK home broadband connection.

“I think it’s the best in the world, we don’t know of any better results than that,” says Professor Forysiak. His technique is based on using more wavelengths of light than usual when transmitting data over an optical line.

Alternative forms of electronic equipment that send and receive signals over fibre optic cables are used, but such an installation could be simpler than replacing thousands of miles of the cable itself.

But reliability may be even more important than speed for some applications. “For remote robotic surgery over 3,000 miles… you absolutely don’t want a situation where the network goes down,” Creaner says.

Dr Okonkwo adds that training AI will increasingly require moving huge data sets around. The faster this can be done, the better, he argues.

And Ian Phillips, who works alongside Professor Forysiak, says bandwidth tends to find applications once it is available: “Humanity finds a way to consume it.”

Although several petabits per second is far above the current needs of Internet users, Lane Burdette, a research analyst at TeleGeography, a telecommunications market research firm, says it’s surprising how fast demand for bandwidth is growing — currently about 30% a year over transatlantic fiber-optic cables.

Content delivery – social media, cloud services, video streaming – is consuming far more bandwidth than it used to, he notes: “In the early 2010s, it accounted for about 15% of international bandwidth. Now it accounts for three-quarters, 75%. It’s absolutely huge.”

Andrew Kernahan, head of public affairs for the Internet Service Providers Association, says most home users can now access gigabit-per-second speeds.

However, only a third of broadband customers are signing up for the technology. There is currently no “major application” that really requires it, says Kernahan. That could change as more and more television is consumed over the Internet, for example.

“It is certainly a challenge to spread the message and make people more aware of what they can do with infrastructure,” he says.