Text 1. Switching Technology. Switchboard

Introduction

Self-study of the student is aimed at individual fulfillment of academic assignments, generating cognitive interest, extending knowledge in the area of professional occupation through language-learning practice.

Term paper 1 (SSA – self-study assignment) consists in written translation of professionally-oriented texts with volume of no less than 3,000 symbols each, compiling a terminological glossary, and fulfillment of lexical and grammar assignments, and tasks for monitoring comprehension of the text, including writing of an abstract or a summary.

Generally, a term paper should be written in out-of class conditions, in accord with the suggested list of topics and the teacher’s assignments. One of the main tools for understanding the text content is its lexical and grammatical analysis which is applied while reading and checked in the process of fulfillment of the assignments.

Term paper assignments

1. Translate the text from English into Russian (volume – 3,000 symbols).

2. Compile a terminological glossary (no less than 20 items).

3. Fulfill the task on text comprehension.

4. Fulfill the tasks on vocabulary and grammar.

5. Write a summary.

Criteria for evaluating translation skills (professionally-oriented texts):

-volume of the material worked up;

- currency and relevance of the text (to the profile of the chosen discipline);

- logical sequencing and clear presentation;

- terminological style and grammar accuracy;

- abilities and skills of text analysis, generalizing, organization and delivery of factual information;

- argumentation, support and conclusion.

Work on the term paper (TP 1) starts on the first week of the semester, and the completed paper must be submitted by the end of the 5^th week.

The title page should be formatted according to the standard accepted in the University (consult the teacher).

It is also required to compile a student’s vocabulary book. The format may be free, or you can use the sample of a vocabulary log presented here.

Sample Vocabulary Log

While interpreting and translating terms (concepts, words and phrases) it is important to show their exact value and meaning in the particular text (the context).

It is preferable that all the work done by the student within the discipline “Professionally oriented English language for special purposes” should be reflected in a special folder (portfolio).

Unit 1

1.1 Read and translate the text. Use a dictionary to help you.

Text 1. Plain Old Telephone Service

The pair of wires going to the telephone transmitter and receiver constitutes a four-wire circuit. The transmitter sends a speech signal down the telephone line, and the receiver receives the signal from the central office. However, a two-wire local loop connects the telephone instrument and hence two-wire to four-wire conversion is needed within the telephone instrument. A center-tapped transformer, called a hybrid, accomplishes this conversion. The leakage current in the secondary receiver circuit depends on how well a balance network exactly matches the impedance of the telephone line. Since this balance network can never match the line perfectly, small amount of the received transmitted signal leaks into the receiver circuit, and the user hears one’s own speech, an effect known as sidetone. Actually, a small amount of sidetone is desirable because it makes the telephone seem live and natural, and thus the balance network is designed to allow an optimum amount of sidetone. Too much sidetone results in the user pulling the handset away from the head, which reduces the transmitted speech signal - an undesirable effect. The use of an induction coil to balance the electrical sidetone was patented in 1918 by G.A. Campbell, an AT&T research engineer. The induction coil has been replaced in modern telephones by a speech network that electronically cancels the sidetone leakage and performs the two-wire to four-wire conversion.

The telephone ringer is connected in parallel across the telephone line before

the switch hook’s contacts. Thomas Watson applied for the first ringer patent in 1878, and today’s electromechanical ringers have changed little since then. A hammer attached to an armature with a magnetic field strengthened by a permanent magnet moves in response to the ringer current loudly striking two bells. The high-impedance ringer was invented in 1890 by John J. Carty, a Bell engineer who had invented the two-wire local loop in 1881. A capacitor is placed on series with the ringer to prevent DC from flowing through it. The ringer signal consists of a short 2-s burst of a 75-V (rms), 20-Hz sine wave followed by 4 s of silence. Piezoelectric transducers and small loudspeakers are replacing electromechanical ringers in today’s telephones.

The public switched network can be used to transmit and switch any signal that remains within its baseband, namely, about 4 kHz. Thus, devices other than just a telephone network can be used on the telephone network. The recent success of facsimile is one example; modems operating at speeds of 28.8 kb/s are another.

(From A. Michael Noll. The Communications

Handbook. CRC Press Inc., 1997)

Vocabulary

1.2Compile the vocabulary (term) log as shown in the preface (part of speech, definition, translation, synonyms and antonyms if possible, example of use). Words (concepts) are given below.

Impedance; baseband; piezoelectric transducer; capacitor; leakage current; facsimile; sidetone; induction coil; Vrms; handset; center-tapped transformer; receiver circuit; public switched network; conversion; in series.

Grammar

Sometimes a noun modifies another noun and functions as an adjective (an attributive noun). Example: balance network, sports car.

1.3 In the text, find, write out and translate phrases (word combinations)

where nouns are used as attributes.

1.4 Choose the necessary tense form of the verb in brackets:

1) Development in the field of telecommunications (is/ was/ has been, had been) very rapid in recent years.

2) The reliability of the network (depends/ is depended/ has depended/is depending) on the ability of the optical cross-connect system to reconfigure.

3) The global telecommunications network is the largest and most complex technical system that man (created/is creating/ has created/had created).

4) The basic principles of diversity (have been known/are known/have known/had been known) since 1927 when the first experiments in space diversity were reported.

5) The high-frequency quantization noise in the receive channel must (remove/be removed/have been removed/be removing) by the digital decimation filters.

6) Today the rate of change and innovation in the telecommunications industry (accelerates/has accelerated/ is accelerating/is accelerated) at a breakneck pace.

7) The first ringer patent (applied /was applied/had applied/ had been applied) for in 1878, and today’s electromechanical ringers (have changed/changed/are changing/change) little since then.

8) The special code (contains/contain/is containing/has contained) pulses facilitating synchronization even when the original data has a long string of zeros.

Comprehention Check

1.5 Answer the following questions:

1) What constitutes a four-wire circuit? 2) What does a transmitter send down the telephone line? 3) How is a center-tapped transformer called? 4) What does the leakage current in the secondary receiver circuit depend on? 5) Why does a small amount of the received transmitted signal leak into the receiver circuit? 6) What does a sidetone mean? 7) Why is a small amount of sidetone desirable? 8) What does too much sidetone result in? 9) When was the use of an induction coil to balance the electrical sidetone patented? 10) Who was it patented by? 11) What has the induction coil been replaced in modern telephones by? 12) What is the functioning principle of a speech network? 13) How is the telephone ringer connected? 14) Have today’s electromechanical ringers changed little or much since 1878? 15) What is a hammer attached to? 16) Who was the high-impedance ringer invented by? When? 17) Why is a capacitor placed in series with the ringer? 18) What does a ringer signal consist of? 19) What is replacing electromechanical ringers in today’s telephones? 20) What can the public switched network be used for? Why?

Developing Language Skills

1.6 Complete the sentences with the correct preposition (by, in, of, at) :

1) A hammer moves …… response to the ringer current loudly striking two bells.

2) The induction coil has been replaced in modern telephones …… a speech network.

3) Analog multiplexing is today obsolete …… telephony.

4) Long-distance transmission systems and local carrier systems utilize separate paths…… each direction of transmission.

5) The ringer signal consists …… a short 2-s burst of a 75 V.

6) An echo canceller is required …… each end of the transmission circuit.

1.7 Ask questions so that the sentences given below were the answers:

1) Each baseband telephone channel was shifted in frequency to its own unique kHz channel.

2) Today’s fiber strands each carry a few gigabits per second.

3) A speech network performs the two-wire to four-wire conversion.

4) The transmission media and systems have progressed over the decades.

5) Today’s transmission medium of choice is optical fiber utilizing digital, time-division multiplexing of the voice circuits.

6) The balance network is designed to allow an optimum amount of sidetone to make the telephone seem live and natural.

7) A number of fiber strands are usually placed together in a single cable.

8) No, the hybrids can not match perfectly the transmission characteristics of each and every local loop.

1.8 Read the following text, guess or suggest a title to it, and write a summary (approximately 7 sentences).

Text 2. ___________________

This term 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 organizations 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?

1.9 Make up 10 questions to text 2.

Unit 2

2.1 Read and translate the text. Use a dictionary to help you.

Text 1. Switching Technology. Switchboard

In the old days, one telephone was connected to another telephone at

switchboards operated by humans. A switchboard(also called a manual exchange) was a device used to connect a group of telephones manually to one another or to an outside connection, within and between telephone exchanges or private branch exchanges (PBXs). The user was typically known as an operator. The human operators used cords with plugs at each end to make the connections. Each plug had a tip and a ring about the tip to create the electric circuit to carry the signals. A sleeve was used for signaling purposes to indicate whether a circuit was in use. Each human operator could reach as many as 10,000 jacks. Public manual exchanges disappeared during the last half of the 20th century, leaving a few PBXs working in offices and hotels as manual branch exchanges.

The electromechanical automatic telephone exchange, invented by Almon

Strowger in 1888, gradually replaced manual switchboards in central telephone

exchanges.

Manual PBXs have also for the most part been replaced by more sophisticated devices or even personal computers, which give the operator access to an abundance of features. In modern businesses, a PBX often has an attendant console for the operator, or an auto-attendant avoiding the operator entirely.

The switchboard is usually designed to accommodate the operator to sit facing it. It has a high backpanel which consists of rows of jacks, each jack designated and wired as a local extension of the switchboard (which serves an individual subscriber) or as an incoming or outgoing trunk line. The jack is also associated with a lamp. When a call is received, a jack lamp lights up on the back panel and the operator responds by placing the rear cord into the jack and throwing the front key forward.

As telephone exchanges were converted to automatic, or direct dial service,

switchboards remained in use for specialized purposes. Before the advent of direct dialed long distance calls, a subscriber would need to contact the long-distance operator in order to place a call. In large cities, there was often a special number, such as 1-1-2 or 2-1-1, which would ring the long-distance operator directly. Elsewhere, the subscriber would ask the local operator to ring the long-distance operator.

Calls can be connected by physically connecting wires to create an electrical path, a technique called space switching. With space switching, individual telephone circuits are connected physically to each other by some form of electromechanical or electronic switch. Calls can also be connected by reordering the time sequence of digitized samples, a technique called time switching. Modern digital switching systems frequently utilize both techniques in the switching network.

The switching network in today's switching systems is completely digital.

Telephone signals either arrive in digital or are converted to digital. The digital signals are then switched, usually using a combination of electronic space switching along with time switching of the sequence of digitized samples. The space switches are shared by a number of digital calls connecting each of them for short durations while a small number of bits in each sample are transferred.

Vocabulary

2.2 Compile the vocabulary (term) log as shown in the preface (part of speech, definition, translation, synonyms and antonyms if possible, example of use). Words (concepts) are given below.

A switchboard; exchange; digitized; gradually; sophisticated; subscriber; abundance; to accommodate; a jack; a sleeve; (local) extension; plug; console; space switching; convert.

2.3 Find in the text and suggest English equivalents for the following:

АТС; учрежденческая телефонная станция с исходящей и входящей связью (УПАТС); ручной коммутатор каналов; внутренняя телефонная станция с внешними линиями связи; заменять; сложные устройства; обеспечивать доступ к; клеммное гнездо; патрубок; местный добавочный номер; междугородние звонки; коммутация с пространственным разделением каналов; коммутация с разделением по времени; оцифрованные образцы.

Comprehension Check

2.4 Answer the following questions:

1) How was one telephone connected to another? 2) What was a switchboard? 3) Who was typically known as an operator? 4) What did each plug have? 5) What was a sleeve used for? 6) How many jacks could each operator reach? 7) When did PBXs disappear? 8) Who invented the electromechanical automatic telephone exchange? 9) What have manual PBXs been replaced by? 10) What do modern PBXs often have? 11) How is the switch board usually designed? 12) What is each jack also associated with? 13) What happens when a call is received? 14) What would a subscriber need to do? 15) How can calls be connected? 16) What can you say about modern digital switching systems? 17) Is the switching network in today's switching systems completely digital?

2.5 Translate the following words and word combinations.

In the old days, to be connected to, operated by, manually, to connect, within and between, telephone exchange, typically, to use cords, an operator, a plug, a tip, to create the electric circuit, a sleeve, to indicate, a circuit, to be in use, gradually, sophisticated devices, an access, features, a console, backpanel, jacks, to convert to, advent, direct-dialed long distance calls, to place a call, a subscriber, to connect wires, to create an electric path, space switching, time switching, by reordering, to utilize, completely, digital signals, to transfer.

Developing Language Skills

2.6 Translate the following sentences into English. Use a dictionary:

1) Алман Строуджер изобрёл автоматический телефонный коммутатор декадно-шагового типа ёмкостью до 99 абонентов.

2) АТС – устройство, автоматически передающее сигнал вызова от одного телефонного аппарата к другому.

3) Аналоговый сигнал оцифровывается в абонентском комплекте и передаётся внутри АТС и между АТС в цифровом виде, что гарантирует отсутствие затухания и минимальное число помех независимо от длины пути между АТС.

4) В цифровых АТС (IP-PBX) используется не коммутация каналов, а коммутация пакетов, и транспортом является протокол IP.

5) IP-АТС осуществляют коммутацию устройств IP-телефонии (VoIP).

2.7 Complete the following sentences using parts from the right hand column. Translate them.

1. Touchtone is also known as a) their functionality from the basic

black, rotary-dial phones of the past.

2. The telephone receiver is a b) receives the signal from the central

small loudspeaker using office.

3. Filters are used at the c) dual-tone multifrequency dialing.

switching machine at the central

office to detect

4. The leakage current in the d) a permanent magnet, coil of wire

secondary receiver circuit depends and metal diaphragm.

on how well a balance network

exactly matches

5. Telephone instruments e) the impedance of the telephone line.

have progressed greatly in

6. The transmitter sends a f) the frequencies of the tones and

speech signal down the telephone thus decode the dialed digits.

line, and the receiver

2.8 Read the following text, guess or suggest a title to it, and write a summary (approximately 7 sentences).

Text 2____________________

The Global Positioning System (GPS) is a satellite-based navigation system made up of a network of 24 satellites placed into orbit by the U.S. Department of Defense. GPS was originally intended for military applications, but in the 1980s, the government made the system available for civilian use. GPS works in any weather conditions, anywhere in the world, 24 hours a day. There are no subscription fees or setup charges to use GPS.

GPS satellites circle the earth twice a day in a very precise orbit and transmit signal information to earth. GPS receivers take this information and use triangulation to calculate the user's exact location. Essentially, the GPS receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. Now, with distance measurements from a few more satellites, the receiver can determine the user's position and display it on the unit's electronic map.

A GPS receiver must be locked on to the signal of at least three satellites to calculate a 2D position (latitude and longitude) and track movement. With four or more satellites in view, the receiver can determine the user's 3D position (latitude, longitude and altitude). Once the user's position has been determined, the GPS unit can calculate other information, such as speed, bearing, track, trip distance, distance to destination, sunrise and sunset time and more.

Today's GPS receivers are extremely accurate, thanks to their parallel multi-channel design. Garmin's 12 parallel channel receivers are quick to lock onto satellites when first turned on and they maintain strong locks, even in dense foliage or urban settings with tall buildings. Certain atmospheric factors and other sources of error can affect the accuracy of GPS receivers. Garmin’s GPS receivers are accurate to within 15 meters on average.

Like with any technology, it depends who is using it and how they use it. Parents who do use the technology to track their children may be invading their privacy, however in a situation where sometime does happen, it will give them comfort in knowing that there is a way to track them down. A similar situation that has been highly effective is used by the police. When people call 911 emergency the system is designed to identify where the caller is, enabling the police to act quick and effectively. Even though people say this technology has invaded privacy, I believe that any technology could be bad if used in the wrong hands. This technology has saved countless lives, helped with emergency's, made traveling easier, made buildings safer, and made life easier for many people. With all these benefits I believe that the Pros outweigh the Cons, and that the GPS system should be accepted and allowed to continually grow within our society.

2.9 Make up 10 questions to text 2.

Unit 3

3.1 Read and translate the text. Use a dictionary to help you.

Text 1. Switching Fabrics

There are two distinct principles employed in electronic switching systems. They are known as circuit switching and packet switching.

In circuit switching a dedicated path is selected, established, and utilized for the entire duration of a message session between a calling terminal and at least one selected called terminal. It usually has the capability of simultaneous transmission in both directions, known as duplex. Establishment of a channel through one or more switches in sequence is known as a connection. The process of requesting and establishing a connection is known as a call. The bandwidth associated with each service of a call is reserved for the duration of the service and dedicated to that call.

In telecommunication systems the most important element is the message. If there are only two terminals, one to originate and another to terminate message, no switching is required. When there are more than two terminals, unless messages are broadcast, switching is required to provide selective communication among a number of terminals. Generally privacy is required so that a message will be received by only the terminal for which the message is intended. Communication privacy requires that contention will be included in the selection process to insure privacy and that a message reaches only the selected terminal over the selected path. Selection and contention are basic to switching.

Contention for the selection of channels occurs only at the time when a connection is being established. If a complete path is not possible when requested, the calling terminal is usually requested or scheduled to try to establish the connection again later.

The function within a switch that provides paths for connections is known as the switch fabric. This term is relatively new. In the past it has been known as the switching network or the switching center network.

In circuit switches, a message may be sent only one way, directed only from one terminal to another. Or there may be interactive or two-way messages. For two way messages that occur in real time, circuit switching systems establish a path between two or more terminals exchanging messages.

Circuit switches are generally transparent to message content. However, to obtain efficiencies, circuit switching systems may remove or disconnect an established path in either or both directions during silent periods in the message and re-establish the circuit when the message information resumes.

This technique is sometimes referred to as virtual circuit switching. Virtual circuit switching assumes that there is no perceptible degradation of the message. This perception depends on the service quality expectations of users.

The combination of transmission, switching, and terminals form a telecommunications network. Where the nature of messages may not require real-time interaction, other forms of networks with different economic criteria for service quality and message delay may be employed. They may also be used where the network serves more than one type of telecommunications, for example, voice, data, and video.

In packet switching, messages are divided into segments or packets. These packets may be transmitted over different selected channels in a network. Each packet contains address information as well as other information regarding message treatment. Contention occurs for each packet at each switch. Most applications using packet switching are, traditionally at least, one way and not necessarily in real time; packets may be stored and delayed until the contention is resolved or the switch runs out of storage capacity. The memory used to store the packets is, for packet switching, the equivalent of the switching fabrics.

(Amos E. Joel Jr. Switching fabrics)

Vocabulary

3.2 Compile the vocabulary (term) log as shown in the preface (part of speech, definition, translation, synonyms and antonyms if possible, example of use). Words (concepts) are given below.

Switching fabric; distinct; circuit switching; packet switching; a dedicated path; session; to request; sequence; bandwidth; to originate; to terminate; to broadcast; technique

3.3 Find in the text and suggest English equivalents for the following:

Двунаправленные сообщения; получать; разъединять; возобновлять; подразделять на; попытка одновременного использования канала связи; планировать очередность обслуживания (в сети).

Grammar

3.4 Use the verbs in brackets in Present Simple Passive:

1) Establishment of a channel through one or more switches in sequence (know) as a connection.

2) These devices (expect) to be ready with these technologies in five upcoming years.

3) The plugs (associate) with flexible cords, several of which operate over a field of jacks that together constitute a fabric.

4) Circuit switching channels also (establish) on a schedule.

5) Crosspoints (assemble) in various ways to form switch fabrics.

6) Switch fabrics (organize) into divisions that are analogous to transmission multiplexing techniques.

7) The capacity of a frequency-division switch fabric (limit) by the bandwidth of the transmission medium divided by the bandwidth of each connection.

8) In packet switching, messages (divide) into segments or packets.

Comprehension Check

3.5 Answer the following questions:

1) How many distinct principles are there in electronic switching systems? 2)

What are they known as? 3) Which path is selected in circuit switching? 4) What capability does it have? 5) What is known as a connection? 6) What process is known as a call? 7) What is the most important element in telecommunication systems? 8) In which case no switching is required? 9) Why is switching required when there are more than two terminals, unless messages are broadcast? 10) What does communication privacy require? 11) What is basic to switching? 12) When does contention for the selection of channels occur? 13) What happens if a complete path is not possible when requested? 14) What is known as the switch fabric?

15) How may a message be sent in circuit switches? 16) What messages for do circuit switching systems establish a path between two or more terminals exchanging messages? 17) When may circuit switching systems remove or disconnect an established path? 18) Which technique is sometimes referred to as virtual circuit switching? 19) What forms a telecommunications network? 20) Where are messages divided into segments or packets? 21) May these packets be transmitted over different selected channels in a network? 22) What does each packet contain? 23) How long may packets be stored and delayed?

3.6 Read and translate the following word combinations:

Distinct principles, to be selected, at least, simultaneous transmission, in sequence, the process of requesting, for the duration, to provide selective communication, among a number of terminals, a complete path, relatively, to obtain efficiencies, during silent periods, virtual circuit switching, a user, real-time interaction, as well as, message treatment, to occur, to run out of storage capacity.

Developing Language Skills

3.7 Complete the following sentences:

1. The process of requesting and . . . . . . . is known as a call.

2) . . . . . . . are basic to switching.

3) In the past this term has been known as the switching network or . . . . . . .

4) In circuit switches, a message may be sent only . . . . . . . , directed from one terminal to another.

5) This technique is sometimes . . . . . . . virtual circuit switching.

6) In packet switching, messages are divided . . . . . . .

3.8 Read the following text, guess or suggest a title to it, and write a summary (approximately 7 sentences).

Text 2______________________

Convergence is creating new businesses and forcing existing businesses to adapt quickly or die. We are seeing the convergence of telecommunications, IT & Media; the convergence of fixed & mobile services and convergence at device level. All of these trends are creating new markets and making other equipment, products, services and even whole companies rapidly obsolete. For technology manufacturers or service providers, deciding which markets to base your future on becomes a challenge with serious consequences. Should ВТ or AT&T provide home TV services to replace their declining telephony revenues? Should Kodak integrate a mobile phone into its cameras or just give up?

Does Microsoft still need to sell boxed software when you can download applications onto a smart phone? Does everyone have to have a mobile offering or have no future? When the communication of voice is just another software application what do equipment manufacturers like Nortel or Alcatel-Lucent do? Google just does search, right? Collisions within the telecoms, IT and media sectors are occurring now on a daily basis. Like any busy crossroads, there are going to be near misses and head on crashes. As ever, the survivors will be the companies that understand their customers, and are agile enough to quickly respond to all this change.

3.9 Make up 10 questions of your own using the information in text 2.

Unit 4

4.1 Read and translate the text. Use a dictionary to help you.