Tuesday, September 24, 2019
Electrical Engineering in Telecommunications Essay
Electrical Engineering in Telecommunications - Essay Example The next step is for telecommunication engineers to outline a transmission and reception of the transmitted information. In designing the transmitters and receivers, the engineers have to factor in the power consumption especially of the transmitters since a weak signal will due to low or insufficient power will be susceptible to corruption by noise so that the sent information is received as jumbled or incoherent. Looked at simplistically, two telephone handsets connected together need a battery in between to provide the electrical signal to transmit voice signals as depicted below; d1 d2 Handset Battery Handset D Fig 1: Simple telecommunication connection In the above diagram signal will be transmitted a total distance D. d1 and d2 are the distances of each handset to the battery. Now D in practice can be a very long distance, for which certain factors determine this distance which are attenuation and IR drop that limits the voltage across the transmitter. The common 19 gauge wire has a 30 km limit which is also affected by the quality of the handsets. To increase the length of D, we can either increase the voltage of the power source (battery) or we can install amplifiers along D to solve the attenuation problem [2]. The above diagram however is limited to just two people communicating; in real life hundreds or even thousands of people communicate in a telecommunication network not just two people. This makes signalling a more complex problem so that a telecommunication network type must be adopted. These can be a start topology, a mesh topology or many single start topologies connected together to form a network. Adding more users (subscribers) to a network over long distances will raise the cost of the network as many amplifiers and more power sources will be needed, a better solution is therefore needed. Only the most basic telecommunication systems require a power system on site. Telecommunication systems require a prime power source such as a mains elec tricity supply from a grid or a generator for sites in areas where there is no electric grid coverage and a standby power source should also be availed in case there are extended interruptions to the primary power source with a means to protect the equipment for instance against lightning or surges. Telecommunication systems utilize Direct Current (DC) power which can be low current power of 24 or 48 volts dc or complex systems used at exchanges. A telecommunications DC power system consists of a rectifier system, battery system, charge and discharge buses, primary and secondary distribution systems and a voltage conversions system which work together to power a telecommunications network whether the old telephone lines (twisted copper pair), fibre optic, voice over internet protocol or wireless (radio). Rectifiers convert Alternating Current (AC) to DC and are the major supply of power used for a telecommunication system. A rectifier also provides extra power to overcome the intern al resistance of a battery before charging commences and it recharges the battery when AC power supply is restored after an interruption. The Battery stores charge to power components especially when there is no AC power and ensures there is constant power to the loads so break in communication occurs. It is constantly connected directly to the discharge bus so no interruption occurs
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