Meaning
Submarine communication cables are fibre-optic cables laid on or beneath the seabed to carry digital data between countries and continents.
They form the backbone of global communications, carrying internet traffic, cloud data, financial transactions, video calls and other international digital services.
How They Work
Modern submarine cables use optical fibres, where information is transmitted as pulses of light.
A typical network works as:
Data network → Cable Landing Station → Submarine fibre-optic cable → Overseas Landing Station → Foreign network
Signal repeaters are installed along long-distance cables to strengthen optical signals.
Cable Landing Stations
A Cable Landing Station (CLS) is the coastal facility where an international submarine cable connects with a country’s terrestrial telecom network.
It performs functions such as:
- receiving and transmitting international data;
- connecting submarine cables to domestic fibre networks;
- monitoring and maintaining cable systems.
In India, establishing and operating CLS facilities requires telecom authorisation and security clearance.
Why They Are Important
Submarine cables provide:
- very high bandwidth;
- relatively low latency;
- large-scale international connectivity;
- reliable transmission of enormous data volumes.
They are critical for:
- internet and telecom networks;
- banking and financial markets;
- cloud computing;
- data centres;
- defence communications;
- global digital trade.
Strategic Importance
Submarine cables are increasingly treated as critical information infrastructure.
Damage or disruption can affect:
- internet connectivity;
- international banking;
- government communication;
- cloud services;
- military and strategic networks.
Major threats include:
- ship anchors and fishing activity;
- earthquakes and undersea landslides;
- sabotage;
- espionage and cable tapping;
- geopolitical conflict.
Therefore, countries increasingly seek multiple cable routes and redundancy rather than dependence on a few corridors.
India’s Submarine Cable Network
India is connected to global cable networks mainly through landing stations on its eastern and western coasts, particularly around Mumbai and Chennai.
As of March 2026, several additional systems were being commissioned, including:
- India Europe Xpress (IEX)
- SEA-ME-WE-6
- 2Africa
- Raman Cable
Further systems such as the Wyasa Cable System, Indian Ocean Cable and WABAN Cable System were under planning.
Island Connectivity
India has also developed domestic submarine optical fibre links:
Chennai–Andaman & Nicobar Islands: about 2,312 km
Kochi–Lakshadweep Islands: about 1,869 km
These have significantly improved broadband, 4G/5G and other high-speed digital services in the islands.
Data Centre Dimension
Submarine cables and data centres are closely connected.
More international cables can provide:
- greater international bandwidth;
- lower latency;
- better redundancy;
- stronger connectivity for cloud services.
Therefore, development of new cable landing stations can help India emerge as a larger regional data-centre and digital-connectivity hub.
Geopolitical Dimension
Undersea cables increasingly form part of geopolitical competition because controlling or protecting digital infrastructure affects:
- economic security;
- intelligence;
- technological sovereignty;
- military resilience.
Their protection is therefore becoming an important component of maritime security.
Major Challenges for India
- concentration of several cables around a few landing locations;
- physical vulnerability to cable cuts;
- complex permissions for laying and repairing cables;
- need for geographically diversified landing stations;
- cybersecurity and surveillance risks;
- need for rapid repair capabilities.
TRAI has recommended reforms to simplify cable-landing regulations and improve resilience, including better coordination for protection of submarine cable routes.
