МУ РЭТ. Unit Telecommunications. Basic Concepts
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Introduction These methodical and practical guidelines intended for 2-3-year students are prepared in compliance with the Course syllabus and designed to help the learners develop professional language skills and competences. There will be no attempt to replace the content of themes and topics of the major specialties, but make it easier for future specialists to deal with foreign sources and partners, thus, use the English language in order to enhance their professional growth, to boost career development and always enjoy unlimited worldwide information resources and opportunities. Much will depend on the students’ ability to work independently. Undoubtedly, there will be numerous textbooks, special teaching aids and recommendations, but real-life up-to-date information will always remain indispensable. Unfortunately, we have to admit the fact, that the subject material of the present guide is rather limited, narrowed to quite a few topics, related, however, to the basic concepts of telecommunication systems, networks and convergence in telecoms and IT. Unit 1. Telecommunications. Basic Concepts Start-up 1.1 In pairs or small groups, discuss and suggest suitable answers to the following questions: - What general problems can be solved with the help of computer networks? - What types of computer networks do you know? - What are communication protocols designed for? Text A. Telecommunications (1) The term “telecommunications” refers to the transmission of information over long distances using the telephone system, radio, TV satellite or computer links. Examples are two people speaking on the phone, a sales department sending a fax to a client or someone reading the teletext pages on TV. But in the modern world, telecommunications mainly means transferring information from one PC to another via modem and phone lines (or fiber-optic cables). The global telecommunications network is the largest and most complex technical system that man has created. It makes up a substantial part of a country's infrastructure and is vital to the development of the country. Development in the field of telecommunications has been very rapid in recent years. By telecommunications we mean here all processes that render it possible to transfer voice, data and video with the help of some form of electromagnetic system, including optical transfer methods. This rapid development points to new demands on knowledge and competence for everyone who takes an active part in modern telecommunications. Today the rate of change and innovation in the telecommunications industry is accelerating at a breakneck pace. New telecommunications technology enables companies to interface directly with their customers wherever on the globe they happen to be. The coming convergence of voice, data, and video technologies means that the media, entertainment, computer, and telecommunications organisations are all going to be merging and interoperating their activities. Even something so small as an individual strand of optical fiber today has the capacity to carry million television channels simultaneously. How will telecommunications technology evolve and with what impact in the coming years? 1.2 In text A find synonyms or equivalents for the following words and expressions. Computer connections; transmission; make it possible; excessive speed; clients; coming closer (about services); occurring at the same time. 1.3 Find equivalents for the following Russian words and expressions. Слияние (организаций); передача информации; стремительное развитие; взаимодействовать с клиентами напрямую. 1.4 Due to the new telecommunications technology companies do not need to cooperate with their clients directly (True or False?). 1.5 Find and present to the group information supporting the idea that “The global telecommunication network is vital to the development of the country”. A two-three minute presentation will be welcomed and result in additional assessment points. 1.6 Read text B and give headings to the paragraphs. Text B. Telecommunications (2) 1. ____________________________ Telecommunication is the transmission of signals over a distance for the purpose of communication. In modern times, this process almost always involves the sending of electromagnetic waves by electronic transmitters but in earlier years it may have involved the use of smoke signals, drums or semaphore. Today, telecommunication is widespread and devices that assist the process, such as television, radio and telephone, are common in many parts of the world. There is also a vast array1 of networks that connect these devices, including computer networks, public telephone networks, radio networks and television networks. Computer communication across the Internet, such as e-mail and instant messaging, is just one of many examples of telecommunication. 2. ____________________________ Telecommunication systems are generally designed by telecommunication engineers. Major contributors to the field of telecommunications include Alexander Bell who invented the telephone, John Logie Baird who invented the mechanical television and Guglielmo Marconi who first demonstrated transatlantic radio communication. In recent times, optical fiber has radically improved the bandwidth available for intercontinental communication, helping to facilitate a faster and richer Internet experience. And, digital television has eliminated effects such as snowy pictures and ghosting. Telecommunication remains an important part of the world economy and the telecommunication industry's revenue has been placed at just under 3% of the gross world product. 3. ____________________________ The basic elements of a telecommunication system are: - a transmitter that takes information and converts it to a signal for transmission; - a transmission medium over which the signal is transmitted; - a receiver that receives and converts the signal back into usable information. For example, consider a radio broadcast. In this case the broadcast tower is the transmitter, the radio is the receiver and the transmission medium is free space. Often telecommunication systems are two-way and devices act as both a transmitter and receiver or transceiver. For example, a mobile phone is a transceiver. Telecommunication over a phone line is called point-to-point2 communication because it is between one transmitter and one receiver, telecommunication through radio broadcasts is called broadcast communication because it is between one powerful transmitter and numerous receivers. 4. ____________________________ Signals can either be analogue or digital. In an analogue signal, the signal is varied continuously with respect to the information. In a digital signal, the information is encoded as a set of discrete values. 5. ____________________________ The shaping of a signal to convey information is known as modulation. Modulation is a key concept in telecommunications and is frequently used to impose the information of one signal on another. Modulation is used to represent a digital message as an analogue waveform. This is known as keying and several keying techniques exist – these include phase-shift keying, amplitude-shift keying3 and minimum-shift keying4. Bluetooth, for example, uses phase-shift keying for exchanges between devices. Comments: 1) 1a vast array (of networks, technologies, etc.) – широкий спектр (сетей, технологий и пр.). 2) 2point-to-point– "точка-точка". Тип связи между устройствами в сети передачи данных (syn. monocast). 3) 3amplitude-shiftkeying– амплитудная манипуляция, АМн. 4) 4minimum-shiftkeying– манипуляция минимальным сдвигом, манипуляция с минимальным сдвигом. 1.7 Complete the chart with the key words from the text.
1.8 Match the terms with their definitions.
1.9 Underline the sentences that, in your opinion, contain the basic information and summarize the general ideas of the text. 1.10 Prepare a report and take part in the discussion on the topic “Uses of radio and communication”. Use any additional information you can find in other sources. Text C. Telecommunications: a brief historical review The first true telecommunications system using electrical signals to carry messages started in the 1840s with machine telegraphy. Samuel Morse first developed the telegraph in 1832 but it was not until the mid-1840s that the system was put into practical use - sending coded electrical messages (Morse Code) along the wires. The telegraph became a rapid success, its speed quickly outdating the Pony Express for long-distance communications. The next major step forward came in 1878 with the invention of the telephone by Bell. This enabled speech to be transported as electrical signals along wires and revolutionized personal communications. In 1886, Hertz verified experimentally that electrical energy could be radiated and thus proved the existence of electromagnetic wave. This opened the way for the free-space transmission of information without wires. This provided the basis for all radio and TV broadcasting. In 1901, Marconi established long-distance telegraph communication by transmitting between England and Canada. Although he did not realize it at the time, he achieved such long 20 distances by reflecting radio waves in the ionosphere (layers of ionized gases and electrons existing in the earth's upper atmosphere at heights of 50-500 km). This overcame the problem of transmitting round the earth from one side of the Atlantic to the other. With the discoveries of the diode and thermionic valve in the early part of the last century, advances were made in both receiver and transmitter design with an associated impact in telegraphy, telephony, and civil and military communications. Radio broadcasting soon followed, with powerful transmitters serving to communicate over wide areas. Television (TV) was first established in 1937. Radar (radio detection and ranging) was also developed from the 1930s and played a vital role in aircraft detection and navigation in World War II. As further advances in technology took place (e.g. the invention of the transistor in 1947 and the subsequent development of microelectronic integrated circuit technology), new applications became feasible, and new systems were developed. Data communications - the transmission of coded data (e.g. text, graphics, financial information) between 'intelligent' terminals and computers - was first established in the early 1950s using modems, equipment which enables the telephone network to convey data as well as speech. Other improvements in materials and devices also led to the transmission of information via cables. Much of today's long-distance telephone traffic is by submarine cable. The space race led to yet another means of long-distance communication, via fixed and mobile earth stations to satellites. Today, several hundred satellites orbit the earth, and satellite links provide all forms of communication and related services such as telephony, data, TV, navigation, meteorology, and surveillance. One of the very latest developments is the optical fiber cable - a tiny glass fiber which can be used to convey signal information by light pulses. Optical fiber cable with extremely low loss at low cost has now been developed with very high data-carrying capacity. Several thousands of telephone messages can be carried down a single fiber. Perhaps the greatest change which has occurred in the last decades is that from analogue to digital methods of information transmission. The very first commercially employed telecommunication system, telegraphy, was and still is a digital system. However, telephony, radio, and TV all started as analogue systems. Today, the general trend is strongly towards the digital, and now the vast majority of telecommunications systems are digital. Problems of noise and interference can be combated much more successfully in a digital system. The advances in microelectronics and the merging of communications with computers have led naturally to the digital transmission mode with its advantages of computer control, automatic error checking of signals, excellent memory storage, facilities for data, and intelligent terminals. The market need for vast quantities of information transmission and processing at very high speed can only be reliably catered for by using digital techniques. In fact, the most rapidly growing field is almost certainly in data communications employing high-speed digital techniques. 1.11 Translate the following sentences into Russian. a) Samuel Morse first developed the telegraph in 1832 but it was not until the mid-1840s that the system was put into practical use… b) Perhaps the greatest change which has occurred in the last decades is that from analogue to digital methods of information transmission. с) The market need for vast quantities of information transmission and processing at very high speed can only be reliably catered for by using digital techniques. 1.12 Find English equivalents of the following terms and phrases: Стационарные и подвижные наземные станции; это позволило передавать речь в виде электрических сигналов по проводам; малые потери при низкой стоимости; стационарные и подвижные наземные станции; в течение следующего десятилетия телевизионные системы станут, преимущественно, цифровыми; рыночные потребности в передаче больших объемов информации. 1.13 Answer the following questions: 1) What invention, according to the text, “revolutionized personal communication”? 2) What advances were the discoveries of the diode and thermionic valve followed by? 3) What are the advantages of the digital transmission mode? 4) What, according to the text, is the greatest change which has occurred in the last twenty years in methods of information transmission? 5) What advantages of digital transmission mode, besides excellent memory storage, were mentioned in the text? 1.14 Take brief notes from the text on the significance of the developments in telecommunications (Nineteenth century; 1901-1945; 1946-1980; 1980s on). 1.15 Read the following text and render the information in English. Text D. Что такое телекоммуникация (электросвязь) Телекоммуникацией принято считать прием и передачу звука, сигнала, текста, знака, письменного изображения по кабельной, проводной, магнитной, оптической, радио- и другим электромагнитным системам. Система технических средств, с помощью которой осуществляется телекоммуникация, называется сетью телекоммуникаций. Сами же технические средства телекоммуникаций это оборудование и машины, которые используются для обработки, передачи и приема сообщений телекоммуникаций. Каналы связи. Выделяют три основных разновидности каналов связи: симплексные — то есть допускающие передачу данных только в одном направлении, (например, в телевизионной и радиовещательной сетях); полудуплексные — то есть когда два узла связи соединены одним каналом, по которому информация передается попеременно то в одном направлении, то в противоположном (в информационно-справочных и запросно-ответных системах); дуплексные — позволяют передавать данные одновременно в двух направлениях за счет использования четырехпроводной линии связи (два провода для передачи, два других – для приема данных), или двух полос частот. По реализации каналы связи делятся на: беспроводные (радиосвязь); оптоволоконные; проводные. Спутниковые, естественно, относятся к беспроводным, т.е. к радиоканалам. 1.16 Answer these questions: 1) What are the basic parts of a telecommunication system? 2) What are the main types of data transmission media? 3) What are channels of communication and their main functions? 4) Why is the analog telecommunication system being replaced by the digital system? 1.17 Match the following words with their Russian equivalents: 1) стационарная (связь) a) fiber-optic 2) цифровая (связь) b) wireless 3) подвижная (связь) c) fixed 4) беспроводная (связь) d) discrete 5) наземный (ретранслятор) e) mobile 6) преобразовывать (сигналы) f) process 7) дискретные (сообщения) g) digital 8) ретранслятор h) convert 9) волоконно-оптическая (связь) i) ground-based 10) обрабатывать (сигнал) j) relay 1.18 Make up a list of terms you can find in the text. Translate them into English and write definitions. 1.19 Prepare a 2-3-minute presentation reflecting the history of modern-day communication technology in Kazakhstan. |