For anyone excited by what telecommunications technology can do, October 2024 saw the passing of a thrilling milestone.

On 29 October, a team of engineers from Colt and Ciena deployed transceivers at each end of the Grace Hopper transatlantic cable, instantly transforming its transmission potential.

Working in sync at the cable’s landing stations at Bellport, New York, and Bude, Cornwall, we plugged in the latest generation of Ciena coherent optics, WaveLogic^TM 6 Extreme, the foundation of Ciena’s GeoMesh Extreme submarine network solution.

The result was instantaneous: capacity on the Hopper cable leapt to 1.2 terabits per second per wavelength — equivalent to downloading 200 HD movies in one second. It was the first time transmission of 1Tb/s or higher had ever been achieved on a transatlantic subsea cable route.

A transformative moment for Colt and their customers

As technological breakthroughs go, the experience itself was anti-climactic — in a good way.

Colt and Ciena had been working toward it for a year, and when the day came, we essentially plugged in the WL6e equipment and it worked. For Colt, and for global B2B customers who rely on high-speed transatlantic connectivity, this was a transformative moment.

The capacity surge means Colt can not only meet soaring demand for transatlantic bandwidth, but also slash the power consumption and operating costs of its subsea network. It can also squeeze (much) more performance out of its existing subsea assets, thus improving sustainability and conserving capital.

I was very proud to have the opportunity to attend this milestone. Many thanks to the Colt and Ciena teams who made this possible.

Meeting demand for transatlantic capacity

Surpassing 1Tb/s is a timely achievement for Colt, because demand for transatlantic bandwidth is ramping up massively. TeleGeography predicts that global subsea traffic will grow to over 32 petabytes per second by 2030, up from 5,000 Tb/s in 2023 — a more than 550% increase.

TeleGeography Transport Networks Forecast Service report 3Q2024 shows that around three-quarters of that demand is coming from hyperscalers and content providers, for streaming content and emerging AI services that require low latency as well as high bandwidth. Omdia predicts that by 2030, nearly two-thirds of global network traffic will have an AI element.

Colt notes that an autonomous vehicle can generate 4TB of data per hour of driving, for example — data that must be processed in real time to ensure the vehicle makes the right driving decisions at the right time. Speed, capacity, and data center connectivity will be increasingly crucial to the way the world works, and subsea cables will play an important role.

Performance of WL6e sets Colt in a good position to meet this growing and diversifying demand, typically doubling the wavelength capacity of existing channels through the use of high-bandwidth electro-optics, high-speed converters, and smarter digital signal processing (DSP) algorithms.

The performance boost from WL6e means Colt can start offering customers bulk 100GbE and 400GbE services today, and be ready to offer 800GbE services as and when required. And because Colt’s transatlantic network is integrated with its terrestrial network, the performance gains will extend to Colt’s customers across the US, UK, and continental Europe.

Slashing power consumption and physical footprint

Colt and its customers don’t just benefit from increased speed and capacity. Revolutionary new silicon technology within WL6e means power consumption in the subsea network is cut in half.

Ciena has invested heavily in silicon innovation, reducing transistor size from 7nm to 3nm to fit more processing power on to the same semiconductor. That means the WL6e modem takes up the same amount of space as earlier generations of Ciena technology, while doubling capacity.

The result is a massive 50% power per bit reduction, delivering significant energy savings that will allow Colt to offer competitive services to customers on this popular transatlantic route.

That’s good news not only for Colt’s bottom line—and those of its customers—but also for its sustainability goals. A 50% reduction in power per bit will contribute significantly towards Colt’s target of cutting Scope 1, 2, and 3 emissions by 90% by 2045. It also makes Colt a sustainable choice in subsea connectivity for customers looking to decrease their own Scope 3 emissions.

The ability to unlock significantly more capacity per channel with WL6e also prolongs the life of Colt’s subsea assets. That provides Colt with a higher return on its investment strategy, which saw it acquire 10 subsea cables and 12 landing stations from Lumen EMEA in November 2023.

From 100G to 400G and 800G (and beyond) with no new investment in fibre

The flipside of squeezing more capacity out of existing cables with WL6e is that it removes or delays the need to deploy new cables.

As Keri Gilder, CEO of Colt told the Light Reading podcast: “The more bandwidth and capacity we can put over one fibre, the less systems we have to put into the sea over time.” The ability to deliver 400GbE, 800GbE and beyond with existing cables means that companies like Colt can meet tomorrow’s demand as well as today’s without laying new fibre.

Looking even further ahead, terabit transatlantic capacity will also help Colt to offer optical networking on demand to customers who need reliable and scalable high-speed connectivity, but not all the time. Optical wavelength connectivity will be essential for use cases like high-frequency trading, robotics, guided land/subsea vehicles, and global seismic analytics. Colt can draw on its high-speed subsea connectivity, powered by Ciena WL6e, as part of an overall optical-on-demand offering for emerging areas of demand.

A win-win for Colt, its customers and the planet

The WL6e addition at Colt’s Cornwall landing station reminded me of why I joined the networking industry in the first place, as a graduate engineer in 1987. I wanted to do cool things with new technologies that shape how the world connects.

Playing a small role in achieving the first-ever terabit transmission across the Atlantic was one of those cool things, and the opportunities it opens up are truly exciting.

Best of all, it shows that new optical technologies can meet current and future bandwidth demand while actively reducing the network’s environmental impact—a win-win for Colt, its customers and the planet.