What is Submarine communications cable?

New Delhi, Aug 10: A submarine communications cable is a cable laid on the sea bed between land-based stations to carry telecommunication signals across stretches of ocean and sea.

The first submarine communications cables laid beginning in the 1850s carried telegraphy traffic, establishing the first instant telecommunications links between continents, such as the first transatlantic telegraph cable which became operational on 16 August 1858.

Subsequent generations of cables carried telephone traffic, then data communications traffic. Modern cables use optical fibre technology to carry digital data, which includes telephone, Internet and private data traffic.

Types of Submarine fiber cables:
There are two types of Submarine fibre cables: unrepeatered and repeatered.

Unrepeatered cables are preferred in short cable routes because it does not require repeaters, lowering costs; however, their maximum transmission distance is limited.

How Fibre optic cables are placed under the ocean?

Submarine cables are laid down by using specially-modified ships that carry the submarine cable on board and slowly lay it out on the seabed as per the plans given by the cable operator.

Importance of submarine cables
Currently 99 per cent of the data traffic that is crossing oceans is carried by undersea cables. The reliability of submarine cables is high, especially when (as noted above) multiple paths are available in the event of a cable break. Also, the total carrying capacity of submarine cables is in the terabits per second, while satellites typically offer only 1,000 megabits per second and display higher latency. However, a typical multi-terabit, transoceanic submarine cable system costs several hundred million dollars to construct.

As a result of these cables' cost and usefulness, they are highly valued not only by the corporations building and operating them for profit, but also by national governments. For instance, the Australian government considers its submarine cable systems to be "vital to the national economy".

Accordingly, the Australian Communications and Media Authority (ACMA) has created protection zones that restrict activities that could potentially damage cables linking Australia to the rest of the world. The ACMA also regulates all projects to install new submarine cables.
Submarine cables are important to the modern military as well as private enterprise.

The US military, for example, uses the submarine cable network for data transfer from conflict zones to command staff in the United States. Interruption of the cable network during intense operations could have direct consequences for the military on the ground.