Underwater Network Backbone: The Role of Submarine Cables in Maintaining Global Internet Connectivity
In the vast expanse of the world's oceans, a network of hidden connections lies beneath the waves, serving as the backbone of our global digital infrastructure. These are the undersea cables, the unsung heroes of the digital age.
These fibre-optic cables, also known as submarine or subsea cables, are laid on the ocean floor to transmit data between continents, carrying over 99% of international data traffic, including web browsing, streaming, phone calls, financial transactions, cloud computing, and more [1][4][5].
The cables consist of multiple layers of protective materials to withstand harsh underwater conditions such as high pressure, saltwater corrosion, and physical impacts. Inside, they use optical fibres that transmit data as pulses of light, allowing extremely fast and high-capacity communication [2]. A technology called Wavelength Division Multiplexing (WDM) is employed to multiply data capacity by sending multiple wavelengths (light channels) simultaneously through a single fibre, greatly increasing the volume of data transmitted across long distances without loss of quality [2].
At cable landing stations on shorelines, signals from the subsea cables are received, converted, and relayed inland through terrestrial networks, connecting global users to the undersea network [3]. This enables high-speed, low-latency communication between continents, vital for real-time applications like video conferencing, online gaming, stock trading, and international voice calls [2]. They are far more reliable and higher capacity than satellites, which suffer from higher latency and limited bandwidth [1].
Undersea cables support critical infrastructure for governments and businesses alike by facilitating secure communication, financial transactions, and cloud services that power modern economies [1][4]. They promote economic growth by expanding access to high-speed internet, especially in developing regions, thereby fostering innovation, education, employment, and inclusion [4].
However, given their strategic importance, these cables are also a point of concern for security against cyber threats, espionage, physical damage from natural events, or geopolitical conflicts [1]. Recent advancements in undersea cable technology have led to the development of cables with increased capacity and efficiency, such as the MAREA cable, a collaboration between Microsoft, Facebook, and Telxius, connecting Virginia Beach (USA) to Bilbao (Spain) over 4,000 miles and boasting a capacity of 160 terabits per second [6].
Companies and governments are investing heavily in expanding and upgrading the global undersea cable network. One exciting development is the use of quantum encryption for unparalleled security in data transmission [7]. Undersea cables today carry vast streams of data, having evolved from transmitting simple Morse code messages [8].
Cables are designed to lie flat on the seabed, allowing marine life to adapt and thrive around them. Some studies suggest that undersea cables can even serve as artificial reefs, providing habitats for various species [9]. Specialized teams work around the clock to ensure the integrity and functionality of undersea cables [10].
Undersea cables facilitate a seamless flow of information, making it possible for businesses to operate globally and individuals to access information instantaneously. It's essential to acknowledge the significance of undersea cables and the efforts of those who maintain them, as they are the lifelines of our digital world, ensuring that we remain connected, informed, and empowered.
References: [1] Submarine Cable Map, (2021), [2] Wavelength Division Multiplexing (WDM), (2021),
Research in the field of undersea cable technology continues to advance, focusing on enhancing capacity and security. For instance, the MAREA cable, a collaboration between Microsoft, Facebook, and Telxius, employs cutting-edge technology to transmit data at an astounding 160 terabits per second [6]. Additionally, recent developments in data-and-cloud-computing, such as quantum encryption, are being explored to ensure unparalleled security in the transmission of sensitive data across these ecosystems [7].
