Английский язык в сфере компьютерных и телекоммуникационных технологий (стр. 11 )

Radio broadcast – Before the advent of television, commercial radio broadcasts included news and music, dramas, comedies, variety shows, and many other forms of entertainment.

VHF AM 3 MHz to 30 MHz. narrowband FM INMARSAT and Iridium geosynchronous satellites 66 Low Earth Orbit satellites 4.5 MHz in the NTSC system a vestigial sideband heating of objects microgravity environments radiation pressure radio remote control energy  autarkic radio technology Starwisp

Text V

Communications Satellites

EXERCISE 1

Read and translate the text. Insert necessary word combinations that are given into the gapped sentences of the text:

Communications satellites provide a means of ____ all over the globe, without the need for a network of wires and cables. They ___ Earth at a speed that enables them to stay above the same place on Earth at all times. This type of orbit is called geostationary or geosynchronous orbit because the satellite’s orbital speed operates in synchronicity with Earth’s ___. The satellites ___ transmissions from Earth and transmit them back to numerous Earth station receivers scattered within the receiving coverage area of the satellite. This relay function makes it ___ for satellites to operate as "bent pipes"—that is, wireless transfer stations for point-to-point and point-to-multipoint munications satellites are used by ___ to transmit signals across great distances. Ship, airplane, and land navigators also receive signals from ___ to determine geographic positions.

(Receive, satellites, orbit, transmitting telecommunications, rotation, telephone and television companies, possible)

EXERCISE 2

Answer the questions. Add information from the text to your answer.

What are the primary means for telephone connections? What do you know about the coaxial cable? For what purpose does the coaxial cable network include amplifiers? What do fiber-optic cables use for transmission? What are the advantages of fiber-optic technology? What cables do new improvements promise for future? How and for what purpose do radio waves travel? What types of modulation can radio waves receive? Why do microwaves can transmit larger amounts of data more efficiently then radio waves? What are the characteristics of microwaves? When are communications satellites used? Why is this type of communication more efficient?

UNIT IV

TELECOMMUNICATIONS SYSTEMS

EXERCISE 1

Read and translate the text. Speak about the systems that you use in your everyday life.

Individual people, businesses, and governments use many different types of telecommunications systems. Some systems, such as the telephone system, use a network of cables, wires, and switching stations for point-to-point communication. Other systems, such as radio and television, broadcast radio signals over the air that can be received by anyone who has a device to receive them. Some systems make use of several types of media to complete a transmission. For example, a telephone call may travel by means of copper wire, fiber-optic cable, and radio waves as the call is sent from sender to receiver. All telecommunications systems are constantly evolving as telecommunications technology improves. Many recent improvements, for example, offer high-speed broadband connections that are needed to send multimedia information over the Internet.

EXERCISE 2

Look through the words below and practice in pronunciation.

switchingstation –1) (электрическая) подстанция; 2) коммутационный [переключательный]  пункт; 3) коммутационная телефонная станция;

makeuse – воспользоваться

evolve - эволюционировать, развиваться

broadband - широкополосная сеть ( технология, способная обеспечить одновременную передачу голоса, данных, видео; обычно это осуществляется путем мультиплексирования с разделением частот )

span - простираться, распространяться

Text I

Telegraph

EXERCISE 1

Read the text carefully and fill in the gap the missing information that is given in brackets.

(spanned, radio, message, numerous cities, wireline and wireless, company)

Telegraph services use both ____ media for transmissions. Soon after the introduction of the telegraph in 1844, telegraph wires ____ the country. Telegraph companies maintained a system of wires and offices located in _____. A ___ sent by telegraph was called a telegram. Telegrams were printed on paper and delivered to the receiving party by the telegraph _____. With the invention of the ____ in the early 1900s, telegraph signals could also be sent by radio waves. Wireless telegraphy made it practical for oceangoing ships as well as aircraft to stay in constant contact with land-based stations.

EXERCISE 2

Read and translate the information from the history of telegraph and make up the summary of it.

Beginning in the mid-1800s, the telegraph delivered the first intercity, transcontinental, and transoceanic messages in the world. The telegraph revolutionized the way people communicated by providing messages faster than any other means provided at the time. American art professor Samuel F. B. Morse pursued an interest in electromagnetism to create a practical electromagnetic telegraph in 1837. Morse partnered with Alfred Vail and was able to commercialize the technology with financial support from the U. S. government. In 1843 Morse built a demonstration telegraph link between Washington, D. C., and Baltimore, Maryland. On May 24, 1844, the network was inaugurated for commercial use with the message, "What hath God wrought!"

Telegraph use quickly spread; the first transcontinental link was completed in 1861 between San Francisco, California, and Washington, D. C. Railroad companies and newspapers were the first major telegraphy users. Telegraph lines were constructed parallel to railroad beds. Telegraphy helped the railroads manage traffic and allowed news organizations to distribute stories quickly to local newspapers. Within a few years, several telegraph companies were in operation, each with its own network of telegraph wires. Consolidation occurred in the telegraph industry (as it has in numerous telecommunications industries), and by the 1870s the Western Union Telegraph Company emerged as the dominant operator.

Text II

Telephone, Teletype, Telex, and Facsimile Transmission

EXERCISE 1

Read the text and underline the best word in each set. Make up the translation of the text.

The telephone network also uses both wireline and wireless methods to 1(deliver, bring, carry) voice communications between people, and data communications between computers and people or other computers. The part of the telephone network that currently serves individual residences and many businesses operates in an analog mode, uses copper wires, and relays electronic 2(alarm, signals, signs) that are continuous, such as the human voice. Digital transmission via fiber-optic cables is now used in some sections of the telephone network that send large amounts of 3(calls, rings, bells) over long distances. However, since the rest of the telephone system is still analog, these digital signals must be converted back to analog before they 4(come, reach, achieve) users. The telephone network is stable and reliable, because it uses 5(his, its, it) own wire system that is powered by low-voltage direct current from the telephone company. Telephone networks modulate 6(voice, music, sound) communications over these wires. A 7(difficult, hard, complex) system of network switches maintains the telephone links between callers. Telephone networks also use microwave relay stations to send calls from place to place on the 8(land, ground, earth). Satellites are used by telephone networks to transmit telephone calls 9(along, through, across) countries and oceans.

EXERCISE 2

Retell this information close to the text.

EXERCISE 3

Study this information and make up the questions in the form of a plan to the text. Retell it.

Teletype, telex, and facsimile transmission are all methods for transmitting text rather than sounds. These text delivery systems evolved from the telegraph. Teletype and telex systems still exist, but they have been largely replaced by facsimile machines, which are inexpensive and better able to operate over the existing telephone network. The Internet increasingly provides an even more inexpensive and convenient option. The Teletype, essentially a printing telegraph, is primarily a point-to-multipoint system for sending text. The Teletype converts the same pulses used by telegraphs into letters and numbers, and then prints out readable text. It was often used by news media organizations to provide newspaper stories and stock market data to subscribers. Telex is primarily a point-to-point system that uses a keyboard to transmit typed text over telephone lines to similar terminals situated at individual company locations.

Facsimile transmission now provides a cheaper and easier way to transmit text and graphics over distances. Fax machines contain an optical scanner that converts text and graphics into digital, or machine-readable, codes. This coded information is sent over ordinary analog telephone lines through the use of a modem included in the fax machine. The receiving fax machine’s modem demodulates the signal and sends it to a printer also contained in the fax machine.

Text III

Radio and Television

EXERCISE 1

Read and translate the text.

Radios transmit and receive communications at various preset frequencies. Radio waves carry the signals heard on AM and FM radio, as well as the signals seen on a television set receiving broadcasts from an antenna. Radio is used mostly as a public medium, sending commercial broadcasts from a transmitter to anyone with a radio receiver within its range, so it is known as a point-to-multipoint medium. However, radio can also be used for private point-to-point transmissions. Two-way radios, cordless telephones, and cellular radiotelephones are common examples of transceivers, which are devices that can both transmit and receive point-to-point messages.