How is the world keeping up with the explosive growth in data driven by artificial intelligence (AI), 5G, and cloud technologies? The answer lies beneath the oceans. The surge in data consumption has significantly increased the need for robust and far-reaching subsea cable systems.
As a result, the global submarine cable market is experiencing rapid growth, with ongoing investments and strategic initiatives playing a crucial role in meeting the digital age’s demands and ensuring the resilience of global communications infrastructure.
Architecture
The physical and logical design of subsea systems shapes performance by determining their capacity, flexibility, and longevity. Some key architectural considerations include:
- Fiber Pair Count: To boost both capacity and redundancy, modern subsea cables are now being built with numerous fiber pairs. A prime example is Meta’s Anjana cable, launched in 2024, which stands out as one of the highest-capacity transatlantic cables ever deployed with a total capacity of 480 Tbps.
- Repeater Spacing: Optimizing the distance between repeaters ensures signal integrity over vast distances. The Equiano cable, connecting Portugal to South Africa, utilizes space division multiplexing (SDM) technology to enhance performance and flexibility.
- Branching Units: These allow cables to split and connect multiple destinations, increasing network reach and flexibility. The 2Africa cable, set to be the world’s longest subsea cable at 45,000 km, will incorporate multiple branching units, connecting 33 countries across Africa, the Middle East, and Europe.
- Open vs. Closed Systems: Open cable systems encourage interoperability by enabling multiple vendors to integrate their own equipment, driving innovation and lowering overall costs. Another example is the Asia-Africa-Europe 1 (AAE-1) cable, which includes key landing points in the Middle East and supports shared infrastructure and open access among a broad range of stakeholders.
- Data Center and Cloud Compatibility: Ensuring seamless integration with terrestrial networks and cloud infrastructures is essential for efficient data transmission. The Oman Australia Cable (OAC), operational since 2022, connects Muscat and Perth, integrating with Equinix data centers to provide direct links between the Middle East and Australia, enhancing cloud service accessibility.
Agreements
No cable system can be built alone. The successful deployment and operation of subsea cables hinges on strategic agreements and regulatory compliance. Some recent examples are:
- Consortium vs. Private Ownership: In April 2025, a consortium reached an agreement to acquire Sparkle for EUR 700 million, including debt. The move highlights the strategic value of consortium models in sharing costs and risks among stakeholders while safeguarding national interests.
Conversely, private ownership models offer greater control and faster decision-making. Google has invested in privately-owned subsea cables like Dunant and Equiano, enhancing its global network infrastructure and service delivery capabilities.
- Regulatory and Cross-Border Landing Rights: Securing permissions to land cables in different jurisdictions involves navigating complex legal and geopolitical landscapes. The 2Africa cable project required extensive coordination with multiple national regulators to obtain landing rights.
- Service-Level Agreements (SLAs): Establishing clear SLAs with partners and clients ensures accountability and sets performance expectations. In 2023, Prysmian Group signed a major SLA with TenneT, the German-Dutch transmission system operator, to provide inspection, maintenance, and repair services for approximately 4,000 km of TenneT’s submarine cable systems in the North Sea.
Analytics
Advanced analytics play a vital role in monitoring and enhancing the performance of subsea cable systems. Several real-world applications have demonstrated the effectiveness of these analytical practices:
- Real-Time Network Monitoring: Distributed acoustic sensing (DAS) has emerged as a crucial technology for real-time monitoring of subsea cables. By detecting disturbances in fiber optic signals caused by vibrations or temperature changes, DAS can identify potential threats such as undersea drones, vessels dragging anchors, or divers near cables.
Additionally, in early 2025, maritime AI firm, Windward, introduced an AI-driven solution specifically designed to monitor subsea cables. By leveraging historical data, behavioral trends, and predictive analytics, the system delivers a comprehensive assessment of potential risks to undersea infrastructure.
- Predictive Maintenance: Utilizing machine learning (ML) algorithms to predict potential failures enables proactive maintenance, reducing downtime. A 2024 study revealed that the Random Forest model achieved the highest accuracy in predicting true failures, reinforcing the financial and operational benefits of predictive maintenance.
Moreover, in December 2024, Yokogawa Electric Corporation unveiled its advanced solution that uses fiber optic temperature sensors to provide continuous monitoring of subsea cable temperatures. Consequently, the OpreX™ Subsea Power Cable Monitoring system is enabling condition-based maintenance and significantly lowering the costs tied to inspections and unplanned repairs.
- Capacity Planning and Route Optimization: Analyzing traffic patterns aids in efficient capacity allocation and optimal routing of data. In 2024, a study compared three automated path-planning algorithms—Dijkstra-based algorithm (DBA), fast marching method (FMM), and a great circle-based method—for undersea cable route planning. The research provided a comprehensive comparison method for evaluating multiple algorithms, assisting in assessing optimal solutions for cable route planning.
Assurance
Assurance encompasses the measures taken to protect subsea cable systems from various threats and to ensure compliance with environmental standards. Key assurance strategies include:
- Cybersecurity Measures: Protecting cables from cyber threats is critical, given their role in global communications infrastructure. The North Atlantic Treaty Organization (NATO) has enhanced measures to protect Europe’s critical infrastructure from suspected sabotage by Russia and China, following incidents of data cable breakages in Sweden, Finland, and other locations. A maritime exercise referred to as Freezing Winds, involving underwater drones and minesweeper ships, is underway to enhance monitoring capabilities.
- Redundancy and Disaster Recovery Plans: Implementing alternative routes and recovery protocols is significant in maintaining service continuity during disruptions. This was observed during the 2024 Estlink 2 incident, where damage to the submarine power cable between Finland and Estonia also disrupted four internet connections. Restoring the link required meticulous planning and the deployment of a specialized vessel to install a new one-kilometer section of cable along the seabed.
In response to such incidents, NATO has initiated the ‘Baltic Sentry’ mission to enhance surveillance and protection measures for undersea cables in the Baltic Sea. This mission involves deploying military assets to monitor and deter potential threats, while intelligence agencies continue to investigate the causes of recent damages.
- Environmental Impact Mitigation: Conducting environmental impact assessments (EIAs) and adhering to regulations minimizes the ecological footprint of cable installations. By powering cable landing stations with renewable energy and improving energy efficiency, Equinix aims to lower the carbon footprint of the global subsea cable network.
In the Maldives, Ocean Connect Maldives (OCM) has taken proactive measures to mitigate the impact of environmental hazards. By choosing to land their subsea cable on Hulhumalé, an island entirely built on artificial land with an average height of 2 meters above sea level, OCM reduces the risk of potential damage due to rising sea levels and coastal erosion.
Conclusion
The evolution of subsea cable systems is a testament to the synergy of innovative architecture, strategic agreements, advanced analytics, and robust assurance measures.
As the digital landscape continues to expand, embracing these four pillars is crucial for building resilient and future-ready subsea networks.
