Subsea cables play an essential role in enabling the digital world we know today, but it’s important to consider that subsea cables predate the internet by well over a century. These cables are merely a transmission medium we’ve adapted to support various communications technologies over the years.
As we look toward the future, we must ask how subsea cables will continue to evolve to meet the changing requirements of the digital world. Even today, bandwidth is exploding to all-time highs. That’s why it’s no surprise that the volume of subsea cable construction is the highest it’s ever been in the 150-year history of the medium.
Major projects are bringing new capacity into emerging and high-growth markets such as Africa (2Africa, Equiano), the Middle East (Oman Australia Cable) and India (India-Asia-Xpress and India-Europe-Xpress), a major step toward closing the digital divide globally. However, even well-established subsea cable corridors are seeing new construction to keep up with growing demand.
For instance, the AMITIE cable in the transatlantic corridor is designed to offer high capacity and low-latency performance while also meeting environmental sustainability goals. In spite of offering 10x more capacity than older cable systems, AMITIE is forecast to use half the energy. This offers a glimpse into the future of subsea cables: All future projects must balance ever-growing demand for capacity with the sustainability targets of the organizations that will use that capacity.
In the Pacific, the Southern Cross NEXT cable provides additional capacity between Australia and the West Coast of the United States. It supplements existing transpacific routes such as the original Southern Cross Cable Network (SCCN) and the Hawaiki cable to provide redundancy and optimal traffic balancing.
Back when Equinix was founded 25 years ago, we commonly talked about intercontinental bandwidth in terms of megabits per second (Mbps). Now, it’s much more common to talk in terms of gigabits per second (Gbps). If we assume that global bandwidth will continue to double roughly every 18 months, we could soon be talking about terabits per second—or even petabits or exabits. Regardless of the vocabulary we end up using, one thing is certain: Data volumes will continue growing exponentially, and subsea cables must adapt to keep up.
Subsea cables will expand across regions
In the future, digital traffic will be much more widely distributed, a fact that seems likely to accelerate the subsea cable construction binge in regions across the world. The U.S. has traditionally been the center of the digital world. Parts of Europe and Asia-Pacific played a smaller role, while other regions originated very little traffic at all.
This has already begun to change. We’re seeing new subsea cable landings in one emerging market after another, including Africa, Latin America, the Middle East and Southeast Asia. These landing sites are the first step toward boosting the digital economy in those regions. Under the right set of circumstances—where service providers and governments come together to invest in downstream capacity—subsea cable growth can create a virtuous cycle. Ongoing digital growth will lead to even greater demand for bandwidth, which in turn will drive additional subsea cable projects.
Avoiding geopolitical hotspots is a major concern for many organizations, giving rise to alternative routes through the Asia-Pacific region. Markets such as Indonesia, Malaysia and Australia are poised to benefit from this trend. For instance, the Asia Connect Cable System (ACC-1) from Inligo Networks will connect the growth regions of Southeast Asia with Australia and the U.S. At Equinix, we’re also investing in this region: Within the last year, we’ve announced plans to build new data centers in Jakarta, Johor and Kuala Lumpur.
Subsea cables must offer sustainability and security
As enterprises and service providers continue to move and store exponentially larger volumes of data throughout the world, they must consider the sustainability and security impact of that data. For one thing, their customers will expect nothing less. For another, stricter regulations in different jurisdictions will likely force their hand.
From a sustainability perspective, colocation providers are pursuing innovations that will help make cleaner, more efficient data centers plentiful throughout the world. The next logical step is for service providers to come together to offer network segments that are certified to have a limited carbon footprint. This means that all elements of the network—including the subsea cables—need to be built using efficient design principles and powered using renewable energy. Customers will likely be willing to pay a premium for these accreditations, as it will allow them to stand behind their sustainability principles and get more visibility into their emissions to help with sustainability reporting.
Any organization that needs to move large volumes of data throughout the world must also consider the security of their data. Today’s subsea cables are an extension of the original internet infrastructure, which was always intended to be a shared transmission medium. The users of the early internet benefited from sharing the infrastructure costs, allowing them to achieve things that would have been cost-prohibitive acting alone. However, organizations also had to share the risks. The public nature of the internet gave rise to denial-of-service attacks and other nefarious exploits. As the internet grew larger and more sophisticated, these risks grew along with it.
Today, virtual network solutions offer a happy medium: the security of a private network without the high cost of building private network infrastructure. Virtual networking will make it easier for organizations to move large volumes of data securely, without even having to consider the underlying subsea cables that make it all possible. The subsea cables of the future will need to offer a mix of high capacity and reliability to support these solutions, so that users will be able to get the always-on experience that they expect.
Subsea cables will be augmented by other transmission media
In spite of the security benefits that virtual networks offer, there’s no avoiding the fact that subsea cables represent a point of vulnerability. In addition to increased capacity, future cable systems will also offer greater visibility and reliability. Already, smart cable technology is helping cable operators detect outages caused by acts of sabotage or natural disasters. Using massive amounts of data from connected sensors, operators can locate the problem, identify when it occurred and respond quickly to minimize disruption. In the future, we’ll be able to leverage hundreds of these smart cables simultaneously, giving us a much better understanding of what’s happening across the globe at any one time.
Ensuring cable reliability will become even more important as we continue to see extreme weather patterns caused by climate change. More severe weather logically means more potential for damage to subsea cable systems. This is happening at the same time that geopolitical conflict and expanding territorial claims in international waters are making it more difficult and time-consuming to repair cable systems after they’ve been damaged.
For these reasons and more, we’ll likely need to use subsea cables alongside other transmission media that can offer greater security and reliability. For instance, optical transmission via laser systems offers a natural encryption wrapper. You can’t intercept a beam of light; therefore, you can’t intercept optical traffic.
These laser systems will become increasingly important as we start to reach the theoretical limits of how quickly we can transmit traffic over traditional fiber technology—a concept known as Shannon’s Law. If we reach this point sooner than expected, optical communications will help pick up the slack, allowing us to continue moving ever-larger volumes of data faster and more efficiently. As long as we can continue to amplify laser signals, we’ll theoretically have a line of sight to anywhere in the universe.
Of course, optical communications will rely on advanced satellite infrastructure; just like with subsea cables, we’ll no doubt see these satellite constellations grow more numerous and advanced in the years to come. In addition, we’ll have to overcome many of the same challenges we face with subsea cables today. For one thing, we’ll need repeaters in space to help relay optical signals over very long distances. In addition, we’ll need some degree of international cooperation to make satellite communications work well on a global scale. Getting that cooperation won’t be easy, especially given recent geopolitical trends.
In addition, pollution and sustainable use of raw materials will be an area of concern for the satellite industry. Low-Earth orbit satellites have operational lifespans as low as five years, meaning that they need to be replaced more often than subsea cables. Combine this with the fact that about 15% of all satellite launches fail, and we have good reason to believe that space junk will become a growing problem over the next several decades. We can expect to see increased legislation around this issue, along with an emerging niche industry of companies that help operators deorbit their satellites after they reach end of life.
Prepare yourself for whatever the future may offer
We can’t know for sure exactly what will happen in the future. However, we feel confident that data volumes will continue to grow, and that transmission media—be they subsea cables, communications satellites or something new altogether—will grow to help meet that demand.
Regardless of what happens next, you’ll need a future-looking digital infrastructure partner to help you capitalize on the opportunities and navigate the challenges. This is where Equinix can help. Equinix IBX® data centers are located in 70+ metros worldwide, many of them key subsea cable landing sites. As global bandwidth continues to become more widely available, ecosystem partners are gathering on Platform Equinix® to turn that bandwidth into collaboration and innovation opportunities.
To learn more, read the Global Interconnection Index (GXI) 2023 report. The GXI, a market study published by Equinix, examines how suppliers and industry partners are helping one another pursue their digital transformation priorities by interconnecting inside vendor-neutral colocation data centers.
 “Building AMITIE, an eco-friendly transatlantic cable,” Orange International Carriers, February 2, 2023.
 Aaron C. Boley and Michael Byers, “Satellite mega-constellations create risks in Low Earth Orbit, the atmosphere and on Earth,” Scientific Reports, May 20, 2021.