- Author, Chris Baraniuk
- Role, Technology journalist
As far as computer updates go, this was about as stressful as it gets.
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 on a black background appeared on a screen in front of them. It had worked. “There were high fives,” recalls Joachim Opdenakker of SURF, a Dutch IT association that works for educational and research institutions. “It was super cool to see.”
He and his colleague Edwin Verheul had just established a new data link between the LHC in Switzerland and the data storage sites in the Netherlands.
A data link that could reach speeds of 800 gigabits per second (Gbps), more than 11,000 times the average speed of a UK home network. The idea is to improve scientists’ access to the results of LHC experiments.
A subsequent test in March, using special equipment loaned by Nokia, proved that the desired speeds were achievable.
“This transponder that Nokia uses is like a celebrity,” Verheul says, explaining that the kit is reserved in advance for use at different locations. “We had a short time to do tests. If you have to postpone for a week, the transponder is lost.”
This amount of bandwidth, approaching a terabit per second, is extremely fast, but some submarine cables are even a few hundred times faster: they use multiple strands of fiber to achieve such speeds.
Image source, Nokia and Surf
In labs around the world, networking experts are developing fibre optic systems that can transmit data even faster. They are achieving extraordinary speeds of several petabits per second (Pbps) – 300 million times the average broadband connection in a UK home.
It’s so fast that it’s hard to imagine how people will use this bandwidth in the future. But engineers are wasting no time in proving that it’s possible. And they want to go faster.
The duplex cable (with conductors that send or receive) connecting CERN to the data centres in the Netherlands is nearly 1,650 km long, from Geneva to Paris, then Brussels and finally Amsterdam. Part of the challenge in reaching 800 Gbps was transmitting light pulses over such a long distance. “Because of the distance, the power levels of this light decrease, so you have to amplify it at different points,” Opdenakker explains.
Every time a tiny subatomic particle collides with another during an LHC experiment, the impact generates staggering volumes of data: about one petabyte per second. That’s enough to fill 220,000 DVDs.
The LHC has been optimized for storage and study, but it still requires significant bandwidth. In addition, 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,” said James Watt, senior vice president and general manager of optical networks at Nokia.
But the time when 800 Gbps feels slow may be coming soon. In November, a team of Japanese researchers broke the world record for data transmission speeds by achieving an astonishing 22.9 Pbps. That’s enough bandwidth to deliver a Netflix stream to every person on the planet, and a few billion more, says Chigo Okonkwo of Eindhoven University of Technology, who was involved in the work.
In this case, a meaningless but enormous pseudo-random data stream was transmitted over 13km of spiral fibre optic cable in a laboratory. Dr Okonkwo explains that the integrity of the data is analysed after the transfer to confirm that it was sent as quickly as expected without accumulating too many errors.
He also adds that the system he and his colleagues used relied on multiple conductors, a total of 19 conductors in a fiber optic cable. This is a new type of cable, different from the standard cables that connect many homes to the Internet.
But old optical fibres are expensive to dig up and replace. It makes sense to extend their lifespan, says Wladek Forysiak of Aston University in the UK. He and his colleagues recently achieved speeds of around 402 terabits per second (Tbps) over a 50km-long optical fibre with a single core. That’s around 5.7 million times faster than the average UK home broadband connection.
“I think this is a world first, we don’t know of any better results than this,” says Professor Forysiak. Their technique involves using more wavelengths of light than usual to transmit data over an optical line.
To do this, they use alternative forms of electronic equipment that send and receive signals via fiber optic cables, but such a setup could be easier to install 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 have to avoid any scenario where the network goes down,” Creaner says.
Dr. Okonkwo adds that training AI will increasingly require moving huge data sets. The faster this can be done, the better, he says.
And Ian Phillips, who works alongside Professor Forysiak, says bandwidth tends to find applications once it’s available: “Humanity finds a way to consume it.”
Image source, TeleGeography
Although several petabits per second is well beyond the current needs of Web users, Lane Burdette, a research analyst at TeleGeography, a telecommunications market research firm, says it’s striking how quickly demand for bandwidth is growing — currently, about 30 percent year over year on transatlantic fiber-optic cables.
Content delivery – social media, cloud services, video streaming – consumes far more bandwidth than it used to, she notes: “In the early 2010s, it was about 15% of international bandwidth. Now it’s three-quarters, or 75%. It’s absolutely huge.”
Andrew Kernahan, public affairs manager at the Internet Service Providers Association, says most home users can now access speeds in the gigabit per second range.
However, only a third of broadband subscribers have signed up for the technology. There is no major application that really requires it yet, Kernahan says. That could change as more and more TV shows are consumed over the Internet, for example.
“There’s definitely a challenge in getting the message out and making people aware of what they can do with the infrastructure,” he says.