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Recent developments
Words and word combinations:
Replacing – заменяя
carrying messages – переносящий сообщения
subscribing – абонент
a wide range – круг, область
In the late 1970’s, telephone companies began replacing coaxial cables with fiber-optic cables. The first long-distance fiber-optic cable was completed in 1983. This cable carries telephone conversations between New York City and Washington, D.C. Fiber-optic cables began carrying messages between the United States and Europe in 1988 and between the United States and Japan in 1989.
Cable television, which began in the 1950’s, became popular during the early 1980’s many people began subscribing to cable television because it offers a wide range of special programs.
Exercises:
1. Give Russian equivalents of the following phrases:
Replacing coaxial cables with fiber-optic cables; carries telephone conversations; became popular, special programs.
2. Say if the following sentences are true or false.
1. In the late 1980’s, telephone companies began replacing coaxial cables with fiber-optic cables. 2. Fiber-optic cables began carrying messages between the United States and Europe in 1980 and between the United States and Japan in 1989. 3. Cable television, which began in the 1950’s, didn’t become popular during the early 1980’s
Retell the text.
Text 8
Types of cables
Words and word combinations:
Conductors – проводники
copper – медь
damage – повреждение
interference – помехи
multiconductor – много проводниковый
sheath – обшивка
to mount – монтировать, устанавливать
burying cable – зарытый в землю кабель
harsh weather – суровый климат
underwater cables – подводный кабель
to withstand – противостоять
frequency – частота
Most communications cables consist of conductors (metal wires that carry electric current) and insulation. Metals commonly used to make conductors include copper and aluminum. Insulation holds the electricity in the conductors and protects the conductors from damage. Insulation also helps prevent interference.
Interference occurs when a conductor picks up stray electricity from other conductors or from the air. Insulation is made from such multiconductor materials as plastic and paper pulp.
Simple cables are made up of a single pair of insulated wires twisted together. Multiconductor cables, such as telephone lines, contain hundreds- or even thousands- of conductors bound together. In many cases, multiconductor cables are enclosed in a heavy sheath made up of several layers of aluminum or plastic. Some thick cables also contain steel wire provide strength.
Communication Cables Electric Power Cables Connectors
Fiber- Coaxial Multi- Submarine Household Above- Underground Ribbon Television
optic conductor ground
Communication cables are laid underground and along the ocean floor, or they are mounted on poles. Burying cable protects it from harsh weather and keeps the land aboveground uncluttered. As a result, few new communications cables are strung aboveground today. Underwater cables serve as a communications link between continents. These underwater cables need tough outer coverings so that they can withstand strong ocean currents.
Most cables are designed to carry more than one message at a time. For example, a process called carrier transmission enables two pairs of wires to transmit as many as 96 telephone conversations simultaneously. Each conversation is carried by an electric current vibrating at a different frequency (number of cycles per second) so that the individual signals do not interfere with one another. Electronic filters at each end of the cable sort out the various conversations.
Engineers have developed two kinds of cables that can carry especially large quantities of messages at once. They are (1) coaxial cables and (2) fiber-optic cables.
Exercises:
1. Give Russian equivalents of the following phrases:
Conductors include copper; protects the conductors from damage; multiconductor materials; a single pair of insulated wires; a heavy sheath; tough outer coverings.
2. Say if the following sentences are true or false.
1. Metals commonly didn’t use to make conductors include copper and aluminum. 2. Interference occurs when a conductor picks up stray electricity from other conductors or from the air. 3. Simple cables aren’t made up of a single pair of insulated wires twisted together. 4. Communication cables are laid underground and along the ocean floor, or they are mounted on poles. 5. Most cables aren’t designed to carry more than one message at a time.
3. Insert missing words, use the text’s vocabulary:
1. Most communications cables consist of … (metal wires that carry electric current) and insulation. 2. Insulation is made from such … materials as plastic and paper pulp. 3. Burying cable protects it from … weather and keeps the land aboveground uncluttered. 4. These underwater cables need tough outer coverings so that they can … strong ocean currents. 5. Electronic … at each end of the cable sort out the various conversations.
4. Translate these sentences into your native language:
Insulation holds the electricity in the conductors and protects the conductors from damage. 2. Insulation is made from such multiconductor materials as plastic and paper pulp. 3. In many cases, multiconductor cables are enclosed in a heavy sheath made up of several layers of aluminum or plastic. 4. Communication cables are laid underground and along the ocean floor, or they are mounted on poles. 5. Engineers have developed two kinds of cables that can carry especially large quantities of messages at once.
Retell the text.
Text 9
Coaxial cables
Words and word combinations:
Coaxial cables – коаксиальный кабель
flexible metal tube – гибкая металлическая трубка
rigid – негнущийся, негибкий
axis – ось
outer conductor – внешний проводник
repeaters – трансляционный усилитель
amplifiers – усилители
electronic devices – электронные приборы
transistors – транзистор
long-distance calls – междугородний, международный звонок
variety of special features – разнообразные специальные свойства
communications medium – средства связи
Coaxial cables (also called shielded cable) are made up of two conductors. The outer conductor is a rigid or flexible metal tube, and the inner conductor is a wire running through its center. Insulation holds the wire in place. The tube and the wire have the same axis (center) and are therefore called coaxial. A typical coaxial cable has about the same diameter as a pencil, and as many as 22 cables may be bundled together to make a larger cable.
A coaxial cable’s outer conductor shields the electric signals it carries from outside inter-ference and helps pre-vent the signals from escaping. In addition, special amplifiers called repeaters are insulated at various points along many coaxial cable systems to strengthen the signals. These amplifiers help prevent cable loss. Cable loss is the gradual weakening of signals as they travel along the cable. Repeaters consist of such electronic devices as transistors.
Many telephone calls, especially long-distance calls, travel over coaxial cables. When used for telephone conversations, coaxial work in pairs. One coaxial carries signals in one direction, while the other handles signals from the other direction. A pair of coaxial may handle as many as 13,200 telephone conversations at once.
Cable television systems use coaxial cables to transmit TV programs. A single cable can carry as many as 100 television signals at once. As a result, cable TV systems can transmit regular network programs as well as a variety of special features. Coaxial cables are most often used as the primary communications medium for locally connected networks in which all computer communication is within a limited geographic area, such as in the same building.
Exercises:
1. Give Russian equivalents of the following phrases:
Coaxial cables; a rigid or flexible metal tube; the same diameter as a pencil; shields the electric signals; to strengthen the signals; cable loss; carries signals in one direction; locally connected networks.
2. Say if the following sentences are true or false.
1. The outer conductor isn’t a rigid or flexible metal tube, and the inner conductor is a wire running through its center. 2. Cable loss is the gradual weakening of signals as they travel along the cable. 3. Repeaters don’t consist of such electronic devices as transistors. 4. Many telephone calls, especially long-distance calls, travel over coaxial cables. 5. Cable television systems don’t use coaxial cables to transmit TV programs.
3. Insert missing words, use the text’s vocabulary:
1. Insulation … the wire in place. 2. A coaxial cable’s outer conductor shields the … … it carries from outside interference and helps prevent the signals from escaping. 3. Many … calls, especially long-distance calls, travel over coaxial cables. 4. As a result, cable TV systems can … regular network programs as well as a variety of special features. 5. Repeaters consist of such electronic devices as … .
4. Translate these sentences into your native language:
1.Coaxial cables (also called shielded cable) are made up of two conductors. 2. A typical coaxial able has about the same diameter as a pencil, and as many as 22 cables may be bundled together to make a larger cable. 3. A pair of coaxials may handle as many as 13,200 telephone conversations at once. 4. A single cable can carry as many as 100 television signals at once. 5. Coaxial cables are most often used as the primary communications medium for locally connected networks in which all computer communication is within a limited geographic area, such as in the same building.
Retell the text.
Text 10
Fiber optics
Words and word combinations:
Satellite systems – спутниковая система
next decade – следующее десятилетие
to revolutionize – произвести коренную ломку
low cost – низкая стоимость
high transmission volume – высокий объем передачи
low error rate – низкая норма ошибок
message security – надежная защита сообщений
huge sums of money – огромные суммы денег
signals are converted – сигналы превращаются
glass or plastic fibers – стеклянное или пластиковое волокно
equipment – оборудование
susceptible – чувствительный, восприимчивый
illegal data theft – нелегальная кража данных
to replace – заменять
satellite communications – спутниковая связь
Although satellite systems are expected to be the dominant communications medium for a long distance during the next decade, fiber optics technology is expected to revolutionize the communications industry because of its low cost, high transmission volume, low error rate, and a message security. Fiber optic cables are replacing copper wire as the major communications medium in building and cities; major communications companies are currently investing huge sums of money in fiber optics communications networks that can carry digital signals, thus increasing communications and capacity.
In fiber optics communications, signals are converted to light form and fired by laser in bursts through insulated, very thin (2,000ths of an inch) glass or plastic fibers. The pulses of light represent the ‘on’ state in electronic data representation and can occur nearly 1 billion times per second- nearly 1 billion bits can be communicated through a fiber optic cable per second. Equally important, fiber optic cables aren’t cumbersome in size: A fiber optic cable (insulated fibers bound together) that is only 1∕2 -inch thick is capable to supporting nearly 250,000 voice conversations at the same time (soon to be doubled to 500,000). However, since the data is communicated in the form of pulses of light, specialized communications equipment must be used.
Fiber-optic cables are not susceptible to electronic noise and so have much lower error rates than normal telephone wire and cable. In addition, their potential speed for data communications is up to 10,000 times faster than that of microwave and satellite systems. Fiber optics communications is also very resistant to illegal data theft, because it is almost impossible to tap into it to the data being transmitted- or to change it; in fact, it is currently being used by the Central Intelligence Agency.
AT& T has developed undersea optical fiber cables for transatlantic use in the belief that fiber optics will eventually replace satellite communications in terms of cost effectiveness and efficiency. The Japanese have already laid an underwater fiber optic cable. Sprint uses a fiber optics communications network laid along railroad rights-of-way in the United States that carries digital signals (analog voice signals are converted to digital signals at company switching stations).
Exercises:
1. Give Russian equivalents of the following phrases:
To be the dominant; the next decade, fiber optics technology; replacing copper wire; carry digital signals; lower error rates than normal telephone wire; the Central Intelligence Agency; cost effectiveness and efficiency; an underwater fiber optic cable
2. Say if the following sentences are true or false.
1. Although satellite systems aren’t expected to be the dominant communications medium for a long distance during the next decade. 2. Fiber optic cables are replacing copper wire as the major communications medium in building and cities. 3. However, since the data is communicated in the form of pulses of light, specialized communications equipment needn’t be used. 4. The Chinese have already laid an underwater fiber optic cable. 5. Fiber optics communications isn’t also very resistant to illegal data theft, because it isn’t almost impossible to tap into it to the data being transmitted- or to change it.
3. Insert missing words, use the text’s vocabulary:
1. Major communications companies are currently … … sums of money in fiber optics communications networks that can carry digital signals, thus increasing communications and capacity. 2. In fiber optics communications, signals are converted to … form and fired by laser in bursts through insulated. 3. Since the data is communicated in the form of pulses of light, specialized communications … must be used. 4. AT& T has developed … optical fiber cables for transatlantic use in the belief that fiber optics will eventually replace satellite communications in terms of cost effectiveness and efficiency. 5. Fiber optics … is also very resistant to illegal data theft.
4. Translate these sentences into your native language:
1. Although satellite systems are expected to be the dominant communications medium for a long distance during the next decade, fiber optics technology is expected to revolutionize the communications industry because of its low cost, high transmission volume, low error rate, and a message security. 2. Fiber-optic cables are not susceptible to electronic noise and so have much lower error rates than normal telephone wire and cable. 3. Sprint uses a fiber optics communications network laid along railroad rights-of-way in the United States that carries digital signals.
Retell the text.
Text 11