Optical Communication and Networks Essay Example | Topics and Well Written Essays - 3000 words

Optical Communication and Networks - Essay Example The concept of wavelength division multiplexing (WDM) and DWDM has also been introduced. Finally, the latest trends in optical communication and networks are briefly explained. Optical communication system is similar to any kind of communication system, as far as the basics are concerned. The major difference in optical and other communication models is the additional requirement of a source (for conversion of signal from electrical to optical domain), receiver (for conversion from optical to electrical domain) and use of fibre as media in place of conventional copper wire or microwave. The use of glass fibre or optical fibre features a number of advantages that make it a formidable media, in comparison to others. One of the most important assets of optical communication is the availability of enormous potential bandwidth to the tune of hundreds of GHz. The potential cannot be fully harnessed owing to electrical domain limitation. However, technologies like WDM or DWDM are evolving to optimize the available bandwidth usage. Being fabricated from glass, the fibre does no have earth loop or interface problem as are evident in electrical media. The optical communication is immune to interference from radio frequency and electromagnetic radiations or EMP (electromagnetic pulses) as they act as dielectric waveguides. There are practically insignificant radiations from fibre which enhance security of signal in a communication system. Other advantages include low weight, small size, flexible, reliable, easily maintainable, low transmission losses and cost effective. The requirement for capacity is increasing at a fast rate in the present day networks. Growth of worldwide web and Internet are the primary causes for this increase. Every four to six months, the need is almost doubling. Available broadband access technologies like Digital subscriber line (DSL), cable modems etc. provide bandwidths of 1Mbps and 28 to 56 kbps per user, respectively. With online businesses company networks with their distant locations and the clients, the bandwidth requirement is will soon rise to level where, the only solution would remain to switch to optical networks. Optical networks can be broadly divided into two generations. The first generation optical networks were solely used to enhance capacity to stand alone communication links while; the second-generation networks encompass the issues of routing and switching. In the subsequent paragraphs we will discuss optical communication and networks with reference to the various components and devices in greater details. We shall initially cover the basic theory behind transmission, attenuation and distortion of optical signal in the fibre. Optical Transmission Basics Optical fibre acts as a cylindrical waveguide with an inner core and outer cladding of differing refractive index as shown in Figure 1, core refractive index being greater than clad refractive index. The light traverses in the core as well as in the cladding. To illustrate the transmission of light, let's consider ray theory. Figure 1: Structure of optical fibre (adopted from Senior, John M.) The refractive index of

Emerging global governance Research Paper Example | Topics and Well Written Essays - 1000 words

Emerging global governance - Research Paper Example A child who is defined as person of age below 18 years is entitled to healthcare, free education, adequate nutrition, freedom from violence, abuse, exploitation and leisure and recreation (Verhellen, 66). The CRC originated from the Geneva declaration o 1924 which according to Verhellen (64) is the first international human rights instrument dealing with children rights. Before then, various organizations like ILO have made efforts to improve the well-being of children by setting minimum employment age for children to avoid abuse and exploitation. The Geneva declaration was made after the First World War to deal with the plight of children and remove them from deplorable situations. The declaration had a preamble and five aims referred as â€Å"Declaration of the rights of the child.† Under this declaration, a child was entitled to receive relief first in times of distress, protection from any form of exploitation, to be fed and sheltered and to develop normally materially and spiritually. This is the obligation of parents or adults. More declarations concerned with children issues continued to emerge. The declaration was reconfirmed by the League of Nations General Assembly ( UNICEF, 2011). Another Declaration which forms the basis for CRC is the declaration on the rights of the child in 1959. Whereas Geneva declaration focused on social and economic needs, the 1959 declaration focused on families, right to name and nationality and need for love among other issues. It had a preamble and based on 10 principles hence it was more complex than Geneva declaration. It touched on issues such as non-discrimination, name and nationality, education, opportunity for development and enjoyment of social security benefits among others (Verhellen, 66). The 1989 convention was a culmination of various human rights instruments developed over the years and its work began during the 20th