Md Jahedul Islam

Today our public life cannot be imagined without the Internet. The submarine cable works to deliver this internet to us. The most important thing for the current generation is the mutual communication system. Due to the availability of modern technology the distance gap has reduced. Communicating instantly through messaging, phone calls, video calls. Optical fiber plays a major role in this accessibility of communication technology. Optical fiber utilizes the technology of total internal reflection of light to transmit light or light signals instead of electrical signals using laser beams for data exchange.

At the same time this optical fiber technology has the ability to send electricity and signals. There are multiple submarine cables worldwide. Which have connected from one country to another country, from one continent to another continent and the whole world. The " Sub" means below and "Marine" means sea.

That is submarine cable refers to the cable located under the sea. Currently ninety-nine percent of the world's total Internet traffic is dependent on submarine cables. Submarine (undersea) optical fiber cable is also known as submarine communication cable. Submarine fiber optic cable system is mainly used to connect fiber optic cable and internet. Seawater can prevent interference from external light and magnetic waves. Therefore submarine cables have a high signal-to-noise ratio. Submarine optical cable communication has no time delay. The basic structure of submarine optical cable is polyethylene layer, polyester resin or asphalt layer, steel strand layer, aluminum waterproof layer, polycarbonate layer, copper or aluminum tube, paraffin, alkane layer, optical fiber bundle, etc.

A single submarine cable can remain intact for twenty to twenty-five years. Whereas artificial satellites typically run out of fuel in 10 to 15 years. Meanwhile the cables under the sea have to withstand the enormous water pressure. Besides there is fear of its damage due to the attack of various marine animals and natural calamities. They can even be damaged by ship anchors. They are made with eight layers to protect them from any kind of damage. Seven of them act as safety layers.

The innermost layer works for data transmission through optical fiber. Laying submarine cable under the sea is one of the most difficult tasks in the world. Some special types of ships work for this. There are currently more than four hundred and six submarine cables in the world. which are spread over more than twelve lakh kilometers. The submarine optical cable system is mainly divided into two parts. They are called coastal equipment and underwater equipment.

Shore-based equipment collects and transmits communication services such as voice, images and data. Underwater equipment performs the functions of processing, transmitting and receiving communication signals. Meanwhile, underwater equipment is divided into three categories. The first is the submarine fiber optic cable. The second is the repeater and the third i.e. the last is the branch unit.

Among them submarine fiber optic cable is the most important and the most vulnerable part. Submarine optical cable is strong in structure and light metal is used in the material. Optical cables are deployed in deep-sea and shallow-sea according to different marine environment and water depth. Today submarine cables are widely recognized as the best means of communication around the world.

If someone pulls out a submarine cable and adds optical fiber, data can be stolen. A fight can damage fiber optic cables. So submarine cables need to be maintained for safety. Submarine fiber optic cable has many advantages when compared to terrestrial fiber optic cable. Optical fiber can transport large amounts of data over long distances in a much shorter time. Among the many other advantages of optical fiber, it is worth noting that the data transmission in this system is free from electro-magnetic effects, as well as less loss of data.

Submarine optical cable is designed in such a way that the optical fiber is not affected by external forces and environment. It is also designed in such a way that the submarine can adapt to the environment of stress, friction, erosion, biology, etc. The submarine cable project is recognized as a complex and difficult large-scale project by countries around the world. Natural disasters such as earthquakes and tsunamis often cause submarine cables to break due to force.

There are also various man-made factors that cause the disconnection of submarine optical cables. Once the cable is disconnected, it has a huge impact on international communications. The resulting damage is irreparable. Submarine optical cables are usually buried 1-2 meters below the seabed. Meanwhile, the sea floor is not flat everywhere. Optical cables inevitably become exposed at times. Fiber optic cables can be damaged when fishing boats are anchored or trawls are used for fishing.

So robust technology is put in place to protect and improve submarine optical cables. If due to the inevitable accident then a submarine optical fiber junction is damaged or torn. That time the first step in the repair work is to find the breakpoint.

Submarine cable engineers find the approximate location of breakpoints through telephone and Internet outages. Since then advanced technology has been used through ships and artificial intelligence robots for repairs as needed. Optical fiber has played a very profound role in the development of communication technology in a short period of time and promoted the revolution of human science and technology. Optical fiber technology has come a long way since its inception. Currently optical fiber communication technology is widely used not only in the communication industry but also in the power industry, military field, and many other fields.

The writer is a Network Technician (ICT Cell) Jagannath University, Dhaka.