A type of cable which is spread under the sea for the for the purpose of telecommunication service among different countries of the world is known as submarine communication cable. The submarine cable network is more efficient than a satellite network in terms of carrying data.
Development in the Optical Cables
Fiber Optic cable was invented in 1980 but it was brought into use in 1988. The first optical fiber was TAT-8; it comprised of two operational pairs and one back up pair. Earlier optic fiber cables had a single point to point connection. With the growth in submarine branching units, a single cable was able to serve more than one destination system. However modern cable systems comprise of self healing ring which helps it to improve its superfluous criterion. The more recent development in he self healing ring was the introduction of mesh networks. In this type of network fast switching devices are used which makes it possible to transfer services apathetic to the higher level protocols. The total carrying capacity of sub marine cables is terabits per second. The submarine cables were used initially for telegraphic transmission. It was later used for telephone communication however now it is used to transfer data. Modern submarine optical fiber cable is today the backbone of all internets.
The Structure of the Cable
The basic structure of the submarine communication cable consists of the polyethylene, Mylar tape, standard steel wires, aluminum water barriers, polycarbonate, copper aluminum tube, petroleum jelly and optical fibers. The first component used in making optical fiber is the polyethylene which is a type of plastic, containing long chain of monomer ethylene. Mylar tape is used for reflectivity and stability. A combination of standard steel wires is used in cables to make it durable. An aluminum barrier is used to protect cable from the damage inside the water. Aluminum is water resistant element. Polycarbonate is also used in submarine cables because this component is temperature resistant and provides optical functionality. A layer of petroleum jelly is often used because it is not soluble in water. Afterwards the optical fiber is protected in the covering of aluminum barriers. Hence the cable can withstand the changes in the temperature of the water and does not dissolve at all. While making the cable it is assured that it would work well because the damage would leave us deprived of any communication.
The early bandwidth dilemma was associated with the structure of the telegraphy cables. These cables were hard to use due to their fierce electric signals. The old cables does not comprise of nay amplifier. The distributed capacity and inductance largely distorted the telegraph pulses. Thus the data transfer rate was very slow hence the bandwidth was limited. The early cable design failed to understand the working of the electric charge hence was not recommended to use. Transatlantic cable took its place, however it faced the problem of short circuit when it was provided with a voltage of more than it can actually carry. Modern optical fiber repeaters are used to carry signals under the sea from one region to the other. This optical fiber is comprised of solid amplifier. The task of the amplifier is to rectify signal, control and error measurement mostly. The presence of the optical fiber cable and electrical conductors reduce the problem of bandwidth. Submarine cables are less prone to failure risks and carry more bandwidth per second. The fiber optical cables are laid under the sea nearly at 1m deep in sea. The submarine cables are still under the phase of development in order to achieve more bandwidth but the current bandwidth is also not less. It is about 5 GB per second.