Submarine Cable Network

Submarine Cable Network: How Continents Stay Connected

When you browse a website, stream a video, or make an international call, much of that data travels under the ocean on submarine cables. These cables are laid on specialized ships, like the modern René Desartes operated by France Telecom Marine. They carry communication signals between land stations across oceans and seas, forming the backbone of global Internet and telephone networks.

The history of submarine cables is fascinating. The first cables carried telegraph messages. Later, they carried telephone traffic, and today they transmit vast amounts of data using fiber optic technology. Modern cables are about 69 millimeters in diameter and weigh roughly 10 kilograms per meter, though deeper waters often use thinner, lighter cables for easier installation. Since 2010, submarine cables have connected every continent except Antarctica.

A typical submarine cable has multiple protective layers to ensure reliability:

1. Polyethylene

2. Mylar tape

3. Stranded steel wires

4. Aluminum water barrier

5. Polycarbonate

6. Copper or aluminum tube

7. Petroleum jelly

8. Optical fibers

These layers protect the delicate optical fibers that carry digital traffic. Modern cables transmit telephone, Internet, and personal data at incredibly high speeds. A multi terabit cable system can handle terabits per second, while satellite links usually offer only about 1,000 megabits per second and have higher latency.

fig: image Source:  https://www.submarinecablemap.com/

Submarine cables are expensive. Building a transoceanic, multi-terabit system can cost hundreds of millions of dollars. Because of their cost and value, both private companies and governments closely monitor and regulate them. In many regions, agencies like ACMA oversee projects related to new cable installations.

Reliability is another strength. Multiple routes ensure that if one cable is damaged, traffic can reroute, minimizing disruption. This is crucial not just for civilian Internet users but also for the military. For instance, the US military relies on submarine cables to transmit data from conflict zones to commanders. Any interruption during high-stakes operations can have serious consequences.

Submarine cables are the silent champions of modern communication. They carry enormous amounts of data across oceans, connect continents, and keep global digital life running smoothly.

Explain the importance of Submarine Cable applicable for landlocked countries such as Nepal 2082 Shrawan (Back)

Even though Nepal is landlocked and doesn’t have its own coastline, submarine cables still directly affect your Internet and global connectivity. Most of the world’s international data: emails, video calls, streaming, online banking, travels across oceans through these fiber optic cables. For Nepal, the country connects to the global Internet via neighboring countries’ submarine cable landing points, usually through India or China.

This connection is crucial for several reasons:

1. High-Speed International Internet
   Without access to submarine cables, Nepal would rely more on satellites or older terrestrial links, which are slower and less reliable. Fiber optic submarine connections dramatically improve speed, reduce latency, and allow high bandwidth services like video conferencing, cloud computing, and e-commerce.

2. Economic Growth and Digital Trade
   Landlocked countries often face geographic limitations for trade. Submarine cables help overcome digital barriers, letting Nepalese businesses participate in global e-commerce, offer IT services, and access international markets without physical transport constraints.

3. Reliable Communication for Critical Services
   Hospitals, banks, government agencies, and educational institutions rely on consistent international connectivity. Submarine cables ensure these services can communicate securely and without interruptions, which satellites alone cannot guarantee.

4. Disaster Resilience and Redundancy
   Modern submarine networks often have multiple routes. If one connection fails, data can be rerouted through another path. For Nepal, this redundancy is critical in maintaining Internet access during natural disasters or network outages.

FAQ

Q1: What is a submarine cable network?
A: It’s an undersea system of fiber optic cables that transmit data between continents, supporting Internet, telephone, and other digital communication.

Q2: How are submarine cables protected?
A: They have multiple layers, including polyethylene, steel wires, water barriers, and optical fibers, to prevent damage and ensure reliability.

Q3: Why are submarine cables faster than satellites?
A: They transmit data directly through fiber optics, providing terabits per second of capacity with much lower latency than satellite connections.

Q4: How expensive is it to build a submarine cable?
A: A typical transoceanic multi-terabit system can cost hundreds of millions of dollars.

Q5: Who regulates submarine cable projects?
A: Regulatory bodies like ACMA oversee the planning and installation of new submarine cables.

Q6: Why are submarine cables important for the military?
A: They carry critical data from conflict areas to command centers, and any disruption can impact military operations.

2079 Chaitra (Regular): Compare the optical backbone with marine cables.

Feature	Optical Fiber (Terrestrial Backbone)	Submarine / Marine Cable
Medium	Fiber optic strands installed underground or in buildings	Fiber optic strands laid on the seabed between continents
Distance Coverage	Local, regional, or national networks	Intercontinental, global connectivity
Installation Cost	Moderate to high, depending on terrain	Extremely high; can cost hundreds of millions of dollars per cable
Deployment Speed	Faster on land (depending on permits and terrain)	Slow; requires specialized ships and planning
Maintenance	Easier; technicians can access cables directly	Difficult; requires ships and deep-sea equipment; repairs take longer
Latency	Very low; ideal for real-time applications	Slightly higher due to long distances, but still low for bulk data
Capacity / Bandwidth	High; scalable with modern fiber technology	Extremely high; multi-terabit capacity per cable
Reliability	Vulnerable to natural disasters like earthquakes or construction damage	Highly reliable if multiple routes exist; rare interruptions
Suitability	Ideal for connecting cities, campuses, corporate networks	Essential for international Internet, connecting landlocked regions indirectly
Use Case Example	Corporate backbone, city-wide networks, WANs	International Internet traffic, cloud service access, global communications

Links:

• Fiber Optic Backbone Networks