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Flashcards in Telephone Instruments & Signals Deck (61):
1

The process of conveying information from one place to another

Communication

2

A long distance communications;
‘tele’ Greek word for distant or afar

Telecommunication

3

One of the most remarkable devices ever invented

Telephone

4

Anyone who uses a telephone or data modem on a telephone circuit is part of a global communications network called __

Public telephone network or PTN

5

The PTN is comprised of several vry large corp. and hundreds of smaller independent companies referred to as _____

Telco

6

Inventor of telephone

Alexander Graham Bell and Thomas A Watson

7

Referred to as the Bell Telephone System or "Ma Bell"

AT&T –American Telephone & Telegraph Company

8

World's most complicated machine

Bell System

9

Simplest and most straightforward form of telephone service

POTS – Plain Old Telephone Service

10

Most fundamental component of a telephone circuit

Local Loop

11

Provides the means to connect telephone set of the subscriber’s location to the closest telephone office

Subscriber Loop

12

Telephone office also called ___

end office
local exchange
central office

13

Enables the subscriber to access the PTN once in the central office

electronic switching system (ESS)

14

An apparatus for reproducing sound, especially that of the human voice (speech) at a great distance by means of electricity; consisting of transmitting & receiving instruments connected by a line or wire which conveys the electric current

Telephone

15

Simple analog transceiver designed for converting speech of acoustical signals to electrical signals

Basic Telephone Set

16

First telephone set that combined a transmitter and receiver into single handheld unit

Butterstamp Telephone (1878)

17

Introduced by western electric company also called the bell system

Rotary Dial Telephone

18

Is called a 2500-type telephone circuit

Touch-tone Telephone

19

Quality of transmission over a telephone connection depends on ___

received volume

Frequency response of the telephone circuit

Degree of the interference

20

Wires on the local loop

Tip (ground) and Ring (-48 Vdc)

21

Third wire to be used in a local loop is called ____

Sleeve

22

A dc voltage is used rather than ac because:

1. to prevent power supply hum
2. to allow service to continue in the event of a power outage
3. people are afraid of ac

23

the only voltage required for the operation of a standard telephone

48 Vdc

24

An Electronic oscilllator used to alert the destination party of the incoming calls

Ringer Circuit

25

Sometimes called switch hook; Simple single throw-double-pole STDP switch

On/Off Hook Circuit

26

Placed across the ‘tip’ and ‘ring’

On/Off Hook Circuit

27

idle, open switch

On Hook

28

in use, closed switch

Off Hook

29

Combination of passive components (resistors & capacitors)

Use to regulate the amplitude & frequency response of the voice signals

Equalizer circuit

30

Receiver for the telephone

Speaker

31

Converts electrical signals received from the local loop to acoustical signals (sound waves)

Speaker

32

Transmitter for the telephone

Microphone

33

Converts acoustical signals in the form of sound pressure waves from the caller to electrical signals

Microphone

34

Also called Hybrid coil or duplex coil

Hybrid network

35

A Special balanced transformer used to convert 2-wire (local loop) circuit into 4-wire (telephone set) circuit

Hybrid network

36

Enables the subscriber to output signals representing digits

Dialing Circuit

37

Are acknowledgement & status signals that ensure the processes necessary to set-up and terminate a telephone call are completed in an orderly & timely manner

Call Progress Tones & Signals

38

exchange of signaling message over local loops between stations & tel. company switching machines

Station signaling

39

exchange of signaling message bet. switching machines

Interoffice signaling

40

Indicate request for service

Alerting Signals

41

Provide call status information

Supervising Signals

42

Provide information in the form of announcement

Controlling Signals

43

Provide routing information (calling & called numbers)

Addressing Signals

44

is an audible signal comprised of 2 frequencies – 350 & 440Hz

Dial Tone

45

Each digit is represented by the linear addition of two frequencies

Dual tone multifrequency tones (touch tones)

46

Used to transfer digits & control signals between telephone sets & local switching machines

Dual tone multifrequency tones (touch tones)

47

Combination of two frequencies that fall within the same speech BW so that they can be propagated over the same circuits as voice (in-band signaling)

Multifrequency tones

48

Used to transfer digits and control signals between switching machines

Multifrequency tones

49

Used to indicate the beginning of a sequence of MF digits

KP

50

used to indicate the end sequence of dialed digits

ST

51

Sent from the switching machine back to the calling station whenever the called tel # is off hook

0.5s ON, 0.5s OFF

Station Busy

52

Congestion tone or no circuit available tone

0.2s ON, 0.3s OFF

Equipment Busy

53

20 Hz, 90 Vrms
‘on’ for 2 sec
‘off’ for 4 sec

Ringing Signal

54

440 Hz & 480 Hz
‘on’ for 2 sec
‘off’ for 4 sec

Ring Back

55

Non-Essential Signaling & Call Progress Tones

- Call waiting tones
- Hold
- Stutter dial tone (for voice mail)
- Calling card service tone
- Intrusion tones

56

Sound in motion

Speech

57

Acoustic waves or ___ have no electrical component

Sound waves

58

Is an apparatus that creates an exact likeness of sound waves with an electric current

Telephone Set

59

Is a series of telephone connection interfaces (receptacle and plug) that are registered with the US federal communications commission (FCC).

RJ or Registered Jacks

60

Is a method originally used to transfer digits from a telephone set to the local switch. Also called rotary dial pulsing

Dial Pulses

61

Occurs whenever the system is overloaded and more calls are being placed than can be completed

Blocking