Telecommunication Online [PDF]

Zitiervorschau

Telecommunication 1/Telecommunication occurs when the exchange of information between two or more entities (communication) includes the use of technology. Communication technology uses channels to transmit information (as electrical signals), either over a physical medium such as signal cables, or in the form of electromagnetic waves. The word is often used in its plural form, telecommunications, because it involves many different technologies. 2/Early means of communicating over a distance included visual signals, such as beacons, smoke signals,semaphore telegraphs,signal flags , and optical heliographs[7] Other examples of pre-modern long-distance communication included audio messages such as coded drumbeats, lung-blown horns, and loud whistles. Modern technologies for long-distance communication usually involve electrical and electromagnetic technologies, such as telegraph, telephone, and teleprinter,networks,radio,microwave transmission, fiber optics, and communications satellites. 3/A revolution in wireless communication began in the first decade of the 20th century with the pioneering developments in radio communications by Guglielmo Marconi, who won the Nobel Prize in Physics in 1909. Other highly notable pioneering inventors and developers in the field of electrical and electronic telecommunications include Charles Wheatstone and Samuel Morse (telegraph),Alexander Graham Bell (telephone),Edwin Armstrong, andLee de Forest (radio), as well as Vladimir K.Zworykin,John Logie Baird and Philo Farnsworth (television).

Telegraph and telephone 4/Sir Charles Wheatstone and Sir William Fothergill Cooke invented the electric telegraph in 1837. Also, the first commercial electrical telegraph is purported to have been constructed by Wheatstone and Cooke and opened on 9 April 1839.] Both inventors viewed their device as "an improvement to the existing electromagnetic telegraph" not as a new device. 5/Samuel Morse independently developed a version of the electrical telegraph that he unsuccessfully demonstrated on 2 September 1837. His code was an important advance over Wheatstone's signaling method. The first transatlantic telegraph cable was successfully completed on 27 July 1866, allowing transatlantic telecommunication for the first time. 6/The conventional telephone was invented independently by Alexander Bell and Elisha Gray in 1876.Antonia Meucci invented the first device that allowed the electrical transmission of voice over a line in 1849. However Meucci's device was of little practical value because it relied upon the electronic effect and thus required users to place the receiver in their mouth to "hear" what was being said. The first commercial telephone services were set-up in 1878 and 1879 on both sides of the Atlantic in the cities of New Haven and London. In the Middle Ages, chains of beacons were commonly used on hilltops as a means of relaying a signal. Beacon chains suffered the drawback that they could only pass a single bit of information, so the meaning of the message such as "the enemy has been sighted" had to be agreed upon in advance. One notable instance of their use was during the Spanish Armada, when a beacon chain relayed a signal from Plymouth to London.

In 1792, Claude Chappe, a French engineer, built the first fixed visual telegraphy system (or semaphore line) between Lille and Paris. However semaphore suffered from the need for skilled operators and expensive towers at intervals of ten to thirty kilometres (six to nineteen miles). As a result of competition from the electrical telegraph, the last commercial line was abandoned in 1880. A/True or false , justify your answers from the text 1)Telecommunication cannot occur without a signal cable(.....) 2)Early means of communication relied mainly on sound messages (.....) 3)Marconi was the first scientist to develop radio communication (.....) 4/Wheatstone and Cooke consider themselves as the inventors of the telegraph (....) 5/ Wheatstone ‘s signaling method outdid Samual Morse ‘s code (......) 6/ The electrophonic effect highlighted the practical side of Meucci’s device (....) 7/The electrical telegraph was so dominant that it could eliminate rivals(.....) B/Pick out words in the text meaning : a) Supposed :..............................para4

b) switching :.............................para6

C/Put the words between parentheses in the right tense or form , choose the right alternative Homing pigeons have 1/( occasion)................ been used through history by different cultures. Pigeon post is thought to have Persians roots and was used by the Romans to aid their military.Frontinus said thatJulius Caesar used pigeons 2/ (as ,like)............. messengers in his3/( conquer)..................... of Gaul . The 4/ (Greece)....................... also conveyed the names of the victors at the Olympic Games to various cities using homing pigeons. In the early 19th century, the Dutch 5/ ( govern)....................... used the system in Java and Sumatra. And in 1849, Paul Julius Reuter 6/ (start)........................ a pigeon service 7/( fly)............. stock prices between Aachen and Brussels, a service that 8/( operate)....................... for a year until the gap in the telegraph link 9/(be/ closed)............... In 1832, James Lindsay10/ (give)...................... a classroom demonstration of wireless telegraphy to his students. By 1854, he was able11/ ( demonstrate)............................. a transmission across the Firth of Tay from Dundee, Scotland to Woodhaven, a distance of two miles (3 km),12/( use)................ water as the transmission medium. In December 1901, Guglielmo Marconi 13/ (establish).......................... wireless communication between St.John’s,Newfoundland Canada14/ (and, to)............................ Podhu,Cornwall (England) , ( earn)................... him the 1909 Nobel Prize in physics which he 15/(share)......................... with Karl Braun) However small-scale radio communication already 16/

( demonstrate).............................. in 1893 by Nikola Tesla in a presentation to the National Electric Light 17/( Associate).............................. On 25 March 1925, D/Fill in the blanks with the right presposition Of, on, at, by , upon, to John Logie Baird was able ........ demonstrate the transmission .............. moving pictures....... the London department store Selfridges. Baird's device relied........... the Nipkow disk and thus became known as the mechanical television. It formed the basis................. experimental broadcasts done ............ the British Broadcasting Corporation beginning 30 September 1929. However, ......... most ........... the twentieth century televisions depended ........... the cathode ray tube invented ......... Karl Braun. The first version ........... such a television.............. show promise was produced ........... Philo Farnsworth and demonstrated........ his family ....... 7 September 1927.

E /Fill in the blanks with words from the list to complete the following conversation

 

A hold , busy , call ,waiting, wonder , strange , get , through , the net

Sydney:

Did you………….. Ben last night?

John:

Yes. I tried to get………….. of him last night, but it was so difficult to get……………...

Sydney:

That's ………... Maybe he was on ……………….

John:

That's probably it! No …………….. the line was ……. all the time! Maybe he ought to ……….. another line. 

Sydney:

Or he should get call-……………..

F/Fill in the blanks with words from the list Turn , thanks, cords, works ,wrong , connected,doesn’t,checked, outlet, didn’t ,from

Toubleshooting a computer problem

A: I'm having problems with my computer. B: What's …………… with it? A: For some reason it won't …………… on. B: Have you …………….the connections on your computer? A: What connections? B: There are ……… that connect your computer to a power ………... A: Will the cords keep it………… turning on? B: It won't turn on if the cords aren't …………….. A: I ………….. think of that. B: Try it and see if it …………….. A: I think that I will,……………….. B: It should work, but let me know if it ……………….