Read and translate the questions. Find answers to

Task 6

Read the text and find the endings of the following

Sentences in it.

Translate them into Russian.

1 Technically known as unshielded...

2. However, this іs the way...

3. These load coils...

4. For example, a drop wire...

5. Usually an outer insulating cover...

6. Whereas transmission over copper...

7. However, if a local loop...

8. The message is clear...

9. With single-mode fiber...

10. Most of the disruptions...

11. With microwave there is no...

ОДЕСЬКА НАЦІОНАЛЬНА АКАДЕМІЯ ЗВ‘ЯЗКУ

ім. О.С. ПОПОВА

ІНОЗЕМНА МОВА

МЕТОДИЧНА РОЗРОБКА

Technical Translation for students

Task 7

Read the text again and find the sentences where the following terms an used. Translate them into Russian, media, copper wire, cable, transmission, high-speed data transmission, load coils, data communications, customer premises, high frequency, coaxial cable, bandwidth, telephone channel, local loop, curb, multimode. single-mode, span, long-distance network, capacity, traffic, transmission medium, wireless system

Task8

Find all the abbreviations in the text. Give their meanings

Розробив викладач: Антипова О.Л.

TEXT 1

Telephony is the transmitting of speech over a con­siderable distance by means of electric current, using wires.

Telephone communication includes: 1) telephone sets to change sound energy into electric waves and back again; 2) transmission systems to carry electric waves over any

distance; and 3) switching systems to connect any two telephone sets.

Fig 1. Modern telephone set:

T - receiver with telephone and microphone,

D - disc, В - receiver and bell contact switch

Telephone is a device for reproducing sounds over con­siderable distances. A telephone set includes a transmit­ter and an electric network in addition to a receiver. The transmitter transmits sounds and a receiver receives them. The receiver includes a telephone and a micro­phone. Both the telephone and microphone are linked to a common circuit with an apparatus at the other end of the line.

fiber makes up the majority of today's long-distance network.

The tremendous capacity of fiber certainly makes for more efficient communications; however, placing so much traffic on a single strand makes for greater vulner­ability. Most of the disruptions in the long-distance net­work are a result of physical interruption of a fiber run. It is called backhoe fade.

Wireless communications is the final option asa transmission medium. This can take several forms: microwave, synchronous satellites, low-earth-orbit satel­lites, cellular, personal communications service (PCS), etc. Some of these will be described in more detail later. In every case, however, a wireless system obviates the need for a complex wired infrastructure. In the case of synchronous satellites, transmission can take place across oceans or deserts. With microwave there is no need to plant cable, and in mountainous territories this is a significant advantage. Cellular and PCS afford mobil­ity. There are advantages and disadvantages to each.

Figure 3. Optical Fiber Sizes

TEXT 2

Telephony is widely used in everyday life. By means of a telephone people communicate with each other at a dis­tance of thousands of kilometers. Thus a telephone is a very useful invention. Telephony enables us to transmit sound energy over long-length distances.

Fig.2 Transmitter

When speaking over a telephone, we press the receiver to our ear. We speak into the microphone or transmitter. The transmission of sounds over a distance is the transmission of oscillations. The frequency of the transmitted oscillations should be constant. The microphone or transmitter (Fig.2) consists of mi­crophone housing A, carbon chamber B, carbon dia­phragm C, carbon granules D, insulating spacer E, and conductor F.

The current passes through the diaphragm, carbon cham­ber and carbon granules. The sound pressure on the dia -

cable. Usually an outer insulating cover is applied to the overall cable - this has nothing to do with the carrying capacity of the cable. Because of the construction of the cable, obviously coaxial in nature, very high frequencies can be carried without leaking out. In fact, dozens of TV channels, each 6 MHz wide, can be carried on a single cable.

The fact that a coaxial cable - or coax - can sup­port a tremendous bandwidth has not been lost on the CATV folk. A leader of the CATV industry said, some years ago, " We have more bandwidth by accident than the telephone people have on purpose." Indeed, that is correct; piggybacking a telephone channel on a coax ca­ble is no challenge at all.

Fiber is the third transmission medium, and it is unquestionably the transmission medium of choice. Whereas transmission over copper utilizes frequencies in the megahertz range, transmission over fiber utilizes fre­quencies a million times higher. This is another way of saying that the predominant difference between electro­magnetic waves and light waves is the frequency. This difference, in turn, permits transmission speeds of im­mense magnitudes. Transmission speeds of as high as 9.9 Gbps have become commonplace in the industry to­day. At this speed, the entire fifteen-volume set of Ency­clopedia Britannica can be transmitted in well under one second.

Laying fiber on a per-mile basis still costs some­what more than laying copper. However, on a per-circuit basis there is no contest; fiber wins hands down. How­ever, if a local loop is being laid to a residence, there is little justification to installing fiber - there will never be a
need for more than one or two or three circuits. This re-

alization has led to a transition in our thinking.Shortly after the commercialization of fiber, we talked about fi-ber-to-the-home (FTTH). It was then realized that there was little need to install fiber for a final several hundred yards, so the industry shied away from fiber-to-the-curb (FTTC). In such a system, fiber would carry a plurality of channels to the " curb, " whereupon they would be bro­ken down and applied to the copper drop leading to the home. In many cases even this was overkill, and fiber-to-the-neighborhood (FTTN) is now being used. The mes­sage is clear: apply fiber when it is economical to do so, and otherwise rely on copper.

One final approach is being used in many areas, and it often proves workable. This is a combination of fiber and coax or, as it is known, hybrid fiber/coax (HFC). As we have seen, coax has a greater bandwidth than copper but a smaller one than fiber. Also, in some 60 percent of the homes in the United States, coax in the form of CATV goes to the home; tying fiber to coax for the final several hundred yards makes technological sense.

Fiber comes in several forms; the two predominant ones are multimode and single-mode (see Figure 3).
As can be seen, the total strand diameter for both is about 125 microns (a micron is a millionth of
a meter). How­ever, the glass that forms the core transmission medium is between 50 and 62.5 microns for the multimode fiber and about 8 to 10 microns for the single-mode fiber. One would think that the
multimode fiber would have a greater earning capacity; however, just the opposite is true. With single-mode fiber, only one ray or mode can travel down the strand, and this makes for a simpler job in regenerating the signal at points along the span. In fact, Single-mode

1. Practice the following words and word combina­tions from the text:

2).Translate the sentences:

1. Telephone communication includes...

- telephone sets.

- transmission system.

-switching systems.

2. Telephone sets...

- are commonly used.

- change sound energy into electric waves.

-include a number of elements.

3. Sounds are reproduced.,.
- by means of a - telephone set.
- over considerable distances.

4. The receiver includes...
- a telephone.

- both a telephone and a microphone.

Read and translate the questions. Find answers to

the questions in the text:

1. By what means is speech transmitted over a distance?

2. By what means are electric waves carried over a dis­tance? 3. By what means are two telephone sets connected? 4. What parts does a telephone set include? 5.What parts does a telephone receiver include? 6. What parts are linked to a common circuit? 7. What device is used for reproducing sounds over considerable distances?

should it vary? 6. How does the resistance of the gran­ules change? 7. How does the number of contacts change? 8. What parts does current pass through? 9. Does the sound pressure on the diaphragm vary? 10. What is the frequency of oscillations produced by sound waves?

Text3