Terms - Blake - LE 1 Flashcards Preview

Telephony > Terms - Blake - LE 1 > Flashcards

Flashcards in Terms - Blake - LE 1 Deck (35):
1

method of providing high-speed data transmission on twisted-pair telephone loops by
using high-frequency carriers

Asymmetrical Digital Subscriber Line (ADSL)

2

in ISDN, channels that carry subscriber communication (voice or data or both)

B (bearer) channels

3

use of bits that normally carry payload information for
other purposes, such as controlling the communication system

bit robbing

4

addition of bits to a bitstream to compensate for timing
variations

bit stuffing

5

failure to connect a telephone call because of lack of
system capacity

call blocking

6

switch in a telephone system that connects to local
subscriber lines

central office

7

communication system in which a dedicated channel is set up between parties for the duration of the communication

circuit-switched network

8

use of a separate signaling channel in a
telephone system, so that voice channels do not have to carry signaling information

common-channel signaling

9

interference between two signals multiplexed into the same channel

crosstalk

10

in ISDN, a communication channel used for setting up
calls and not for user communication

D (data) channel

11

signaling using combinations
of two audio tones transmitted on the voice channel

dual-tone multi-frequency (DTMF) dialing

12

use of optical fiber for telephone connections to
individual customers

fiber-in-the-loop (FITL)

13

a specialized transformer (or its electronic equivalent) that
allows telephone voice signals to travel in both directions
simultaneously on a single twisted-pair loop

hybrid coil

14

control signals sent in a voice channel at voice frequencies

in-band signals

15

control signals using the same channel as a voice signal

in-channel signals

16

telephone system using
digital local loops for both voice and data, with the codec in the
telephone equipment

integrated services digital network (ISDN)

17

addition of bits to a digital signal to compensate for
differences in clock rates; informally known as bit stuffing

justification

18

in a telephone system, the area
controlled by one central office switch

local access and transport area (LATA)

19

a small data network, usually confined to a building
or cluster of buildings

LAN or local area network

20

in a telephone system, the wiring from the central office to an individual customer

local loop

21

in telephone signaling, a control signal that is outside the
voice frequency range

out-of-band

22

a communication system that works using data
divided into relatively short transmissions called packets; these are routed through the system without requiring a long-term connection between sender and receiver

packet-switched network

23

place where one telephone network connects to
another

point of presence (POP)

24

small telephone switch located on customer premises

private branch exchange (PBX)

25

the ordinary public wireline
phone system

public switched telephone system (PSTN)

26

in telephony, a signal generated at the central office and
sent to the originating telephone to indicate that the destination telephone is ringing

ringback signal

27

in telephony, the presence in the receiver of sounds picked up by the transmitter of the same telephone

sidetone

28

system used in telephony which transmits
all call setup information on a packet-data network that is separate from the voice channels used for telephone conversations

signaling system seven (SS7)

29

telephone switch that connects only to other switches,
and not to individual customers

tandem office

30

transmission line carrying many signals, either on multiple
pairs or multiplexed together on a single twisted-pair, coaxial cable, or optical fiber

trunk lines

31

The single twisted-pair local loop is required to carry both sides of the conversation simultaneously, providing full-duplex communication.

Two-wire System

32

The rest of the network uses separate transmission
paths for each direction, a topology called a ___

four-wire system

33

Deliberately unbalancing the circuit allows a small portion of the transmitter signal to reach the receiver, creating a ___ that lets the user know
the line is active and hear what is being transmitted.

sidetone

34

results in a very slight degradation of voice signal quality; for instance, the
signal-to-noise ratio is reduced by about two decibels

bit robbing

35

extra bits called ____ which
are added during multiplexing to compensate for differences between the clock rates of the tributaries and the multiplexer

stuff bits