What are Undersea Cables?

Context: Bharti Airtel has landed the 2Africa Pearls submarine cable in Mumbai in partnership with Saudi Arabia based digital infrastructure provider center3 and Facebook parent Meta. This will add 100 Tbps (terabits per second) capacity to India’s international bandwidth.

Undersea Cables

• Undersea cables (or submarine communications cables) are fiber-optic cables laid on the ocean floor, and used to transmit data between continents. These cables are the backbone of the global internet, carrying the bulk of international communications. Around 90% of data, 80% of world trade, and about $10 trillion of financial transactions, as well as secure government information, move through these cables.
• Fiber-optic cables transmit data at the speed of light enabling Tbps capacity of data transfer, which is the fastest and most reliable method of data transfer available today, and can support thousands of telecom users.

Optical Fibres:  

• Thin, flexible and transparent fibre made of glass (high quality silica) or plastic. 
• It is used to transmit information, such as text, images, videos, etc. encoded as digital information or electromagnetic waves/light pulses almost at the speed of light.

• Optical fibres utilise the phenomenon of total internal reflection for transmission across long distances with minimal loss of signal quality (low signal attenuation). 
• Optical waves have high bandwidth, thus allowing a high data-transmission rate up to several hundred Gbps (gigabits per second of capacity) in a single fibre. 
• The fibers are bundled and encased in protective layers designed to withstand the harsh undersea environment, including pressure, wear and potential damage from fishing activities. 
• Along the route, repeaters are installed at intervals to amplify the optical signal and ensure data can travel long distances without degradation.
• Optical Fibre cables are immune to electromagnetic interference, and less sensitive to external perturbations such as lightning and bad weather, unlike copper cables.

India’s Undersea Cable Infrastructure

• India currently has 17 international cable systems, connecting to global networks with two major hubs of cable landing sites: Mumbai and Chennai.
• India also has two domestic cable systems:
  • Chennai Andaman and Nicobar Islands (CANI) cable to provide high-speed connectivity to the islands. 
  • Kochi Lakshadweep Islands project. 
• In 2025, three major subsea cable systems—2Africa Pearls, India-Asia-Express (IAX), and India-Europe-Express (IEX)— are projected to quadruple India's internet capacity. These cables will connect India to Europe, Africa, and Southeast Asia. 

Risks Surrounding Undersea Cable Deployment in India

• Strategic risks: 95% of undersea cables pass through just a single 6 km wide area on the Juhu-Versova beach in Mumbai. India's reliance on a few key landing sites creates a single point of failure. 
• Inadequate Infrastructure:
  • About 20% of global internet traffic is consumed or generated in India. To support that, India has only about 3% of global subsea cables. India has just 17 undersea cables, way fewer than even Singapore. 
  • At least 11 of India's cables are at the end of their average 25-year life today. (A  transoceanic cable system takes at least 5 years to build).
  • India does not have the requisite subsea cable repair ships and cable storage depot capacity. Consequently, India depends on foreign repair vessels with long permission processes for them to begin work in Indian waters.
• Vulnerability due to global chokepoints: Most subsea cable routes follow strategic maritime  trade routes (choke points). E.g., If there is a disruption at the Red Sea, it would bring down 25% of India’s Internet. 
• Regulatory Issues: Around 51 different permissions are needed to land a single cable. Involves approvals from departments such as: Telecom, Home Ministry, Environment Ministry, Fisheries, and local bodies. This bureaucratic red tape delays infrastructure rollout and deters global investors.

Way Forward: Bolster India’s Subsea Cable Infrastructure

• Regulatory reforms: Simplify the permissions process through a single-window clearance mechanism. Encourage faster approvals for cable laying and foreign vessel entry for repairs.
• Infrastructure diversification: Build more landing points outside Mumbai and Chennai (E.g., Gujarat, Odisha, Andhra Pradesh) to reduce concentration risk. Establish alternative routes that do not rely on high-risk regions like the Red Sea.
• Domestic capabilities: Invest in India-owned cable repair ships and cable storage depots to reduce dependence on foreign repair vessels.
• Strategic planning: Proactively commission cable capacity years in advance to match India’s fast-growing data consumption and Focus on secure corridors that avoid geopolitical hotspots.

Also Read: New cables to enhance India's Internet Connectivity 

India is at a critical juncture — with its digital economy booming, the demand for robust and redundant global connectivity is greater than ever. India needs reforms to bolster India’s submarine telecommunication cables which are the backbone of global communication.