Wired to a fast-track world

The world is getting smaller by the day with information passing around at lightning speed. However, as more and more information is passed, the need for better telecommunication infrastructure to keep up with the increasing demand becomes an urgent necessity. Installation of optical fibre networks are being stressed upon the world over as the currently most viable solution. Installations in Bangladesh have already begun and its appropriateness to Bangladesh’s needs is being widely talked about. Inspite of so much talk about fibre optics, many may have questions about the very basics of fibre optics. Many of us must have already seen a fibre optic wire in our homes, but not identified it. Sometime around the 90s, a particular type of showpiece had started becoming increasingly popular in homes of Bangladesh. These showpieces had a mass of hair-like white plastic wires coming out of a golden coloured sphere and only the ends of these wires would light up when the showpiece was plugged in and switched on. Why am I reminiscing about a showpiece in the Star Tech section? My point here is that each of these wires were actually a single strand of optical fibre.
An optical fibre is a glass or plastic fibre that carries light along its length. At the very core of this technology is a principle of light called Total Internal Reflection – a conept that ensures that light passed through the wire from one end comes out as it is, without loss, through the other end. Through this property, light is guided from one end of the wire to the other, without any kind of leakage in between. Optical fibres are widely used in fibre-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communications. Fibres are used instead of metal wires because signals travel along them with less loss, and they are also immune to electromagnetic interference.
Optical fibre can be used as a medium for telecommunication and networking because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because light propagates through the fibre with little attenuation (loss) compared to electrical cables. This allows long distances to be spanned with few repeaters. Fibre is also immune to electrical interference; there is no cross-talk between signals in different cables and no pickup of environmental noise. Non-armored fibre cables do not conduct electricity, which makes fibre a good solution for protecting communications equipment located in high voltage environments such as power generation. Wiretapping is more difficult compared to electrical connections, and there are concentric dual core fibres that are said to be tap-proof.
In a fibre optic cable, the cladding is usually coated with a tough resin buffer layer, which may be further surrounded by a jacket layer, usually plastic. These layers add strength to the fibre but do not contribute to its optical wave guide properties. Rigid fibre assemblies sometimes put light-absorbing ("dark") glass between the fibres, to prevent light that leaks out of one fibre from entering another. This reduces cross-talk between the fibres.
Underwater cables for communications have a relatively long history. The first transatlantic cable was laid as early as 1858. It was used for telegraphy and transmitted less than a few words per minute. By the end of that decade high capacity optical fibre cables were laid under the Atlantic Ocean (TAT-8) and the Pacific Ocean (TPC-3) respectively. These formed part of the so-called first generation digital lightwave systems. The second and third generation cables have extended digital connectivity to the South Pacific, South East Asia and other points. Two of such global submarine cable networks that are in the vicinity of Bangladesh are the “South East Asia, Middle East and Western Europe (SEA-ME-WE)” and the “Fibre Link Around the Globe (FLAG)” long haul backbones respectively.
Establishment of fibre optic links in Bangladesh began in 1986, along with the installation of new digital switches. Starting with the optical fibre link between Dhaka’s Maghbazar and Gulshan telephone exchanges, all intra-city inter-exchange connections are now established through short distance fibre optic links. Moreover, to cater for the increasing international traffic, Bangladesh, having missed out on a similar opportunity earlier, has finally joined the SEA-ME-WE-4 submarine cable network consortium. The 10Gbs bandwidth of this network is expected to serve Bangladesh’s needs for a long time to come.
GrameenPhone had leased dark fibres from the Bangladesh Railway to serve as the backbone for their domestic mobile phone communication network. In 2008, they took the initiative to increase the strength of their transmission network by upgrading a major portion of the leased Network from a composite cable network of single-pair fibre to 24-pair fibre and 10-pair copper cable network to support the requirements of Grameenphone and Bangladesh Railway simultaneously.
Banglalink, the second largest operator of the country, has also established a nationwide fibre optic network of 1920km with the longest submarine cable which lies under the river Padma. They have two strong ring cycles in Khulna-Rajshahi region including Dhaka to ensure quality and uninterrupted service for its subscribers.
Thus, installation and upgrade of optical fibre networks can help a developing country like Bangladesh be at par with global trends and latest information by providing a better and more reliable telecommunication system.