Quizzes Chp 1 To 7 Datacomm

Front 1

CHAPTER 1

Back 1

CHAPTER 1

Front 2

A local area network (LAN) is defined by _______________.

Back 2

the geometric size of the network

Front 3

The largest geographic area a wide area network (WAN) can span is _______________.

Back 3

the world

Front 4

A proposed standard is elevated to ________ standard status after at least two successful tries.

Back 4

draft

Front 5

Which of the following is not one of the components of a data communication system?

Back 5

A)Message

B)Sender

C)Medium

D)All of the choices are correct

Front 6

List characteristics of a data communication system?

Back 6

A)Delivery

B)Accuracy

C)Jitter

Front 7

Data can flow only in one direction all of the times in a _________ mode.

Back 7

simplex

Front 8

Data can flow only in both direction all of the times in a _________ mode.

Back 8

full-duplex

Front 9

List network criterias

Back 9

A)Performance

B)Reliability

C)Security

Front 10

In a _____________ communication, the media needs to be shared between devices.

Back 10

multipoint

Front 11

In a _____________ communication, the media is dedicated.

Back 11

point-to-point

Front 12

In a fully connected mesh topology with six computers, we need ________ links.

Back 12

15

Front 13

In a star topology with six computers, we need ________ links.

Back 13

6

Front 14

An RFC is labeled ________ if it must be implemented by all Internet systems.

Back 14

required

Front 15

_______ was formed to connect universities with no defense ties.

Back 15

CSNET

Front 16

Currently _______ is responsible for the management of Internet domain names and addresses.

Back 16

ICANN

Front 17

CHAPTER 2

Back 17

CHAPTER 2

Front 18

The TCP/IP protocol suite consists of _______ layers.

Back 18

5 layers

Front 19

A router is involved in ____________ layers of the TCP/IP protocol suite.

Back 19

3

Front 20

A link-layer switch is involved in ______________ layers of the TCP/IP protocol suite.

Back 20

2

Front 21

In the TCP/IP protocol suite, which of the following is an application layer protocol?

Back 21

A)The User Datagram Protocol (UDP)

B)The Internet Protocol (IP)

C)The File Transfer Protocol (FTP)

D)The Transmission Control Protocol (TCP)

Front 22

In the TCP/IP protocol suite, which of the following is a transport-layer protocol?

Back 22

The Transmission Control Protocol (TCP)

Front 23

In the TCP/IP protocol suite, which of the following is a network layer protocol?

Back 23

The Internet Protocol (IP)

Front 24

The transport-layer packet in the TCP/IP protocol suite is called _______________.

Back 24

a segment or a user datagram

Front 25

In the TCP/IP protocol suite, the ______ layer is responsible for moving frames from one hop (node) to the next.

Back 25

data-link layer

Front 26

In the TCP/IP protocol suite, the physical layer is concerned with the movement of _______ over the physical medium.

Back 26

bits

Front 27

In the TCP/IP protocol suite, a port number is the identifier at the____________.

Back 27

transport layer

Front 28

In the TCP/IP protocol suite, a logical address is the identifier at the _______________.

Back 28

network layer

Front 29

The_________ layer is responsible for the delivery of a message from one process to another.

Back 29

transport layer

Front 30

The Internet Protocol (IP) is ________ protocol.

Back 30

an unreliable

Front 31

The application layer in the TCP/IP protocol suite is usually considered to be the combination of ________layers in the OSI model.

Back 31

application, presentation, and session

Front 32

In TCP/IP, a message at the application layer is encapsulated in a packet at the ________ layer.

Back 32

transport

Front 33

In TCP/IP, a message belonging to the network layer is decapsulated from a packet at the ________ layer.

Back 33

data-link layer

Front 34

In TCP/IP, a message belonging to the transport layer is decapsulated from a packet at the ________ layer.

Back 34

network

Front 35

In TCP/IP, a logical connection between an entity at the network layer can be made with another entity at the ________ layer.

Back 35

network

Front 36

In TCP/IP, a logical connection between an entity at the data-link layer can be made with another entity at the ________ layer.

Back 36

data-link

Front 37

In TCP/IP, a packet at the third layer carries data belonging to the ________ layer and the header belonging to the _________ layer.

Back 37

fourth; third

Front 38

CHAPTER 3 Quiz Questions

Back 38

CHAPTER 3 Quiz Questions

Front 39

In a frequency-domain plot, the horizontal axis measures the ________.

Back 39

frequency

Front 40

In a time-domain plot, the horizontal axis is a measure of ________.

Back 40

time

Front 41

_______ data are continuous and take continuous values.

Back 41

Analog

Front 42

_______ data have discrete states and take discrete values.

Back 42

Digital

Front 43

_____ signals have an infinite number of values in a time interval.

Back 43

Analog

Front 44

_______ signals can have only a limited number of values in a time interval.

Back 44

Digital

Front 45

Frequency and period are ______.

Back 45

inverse of each other

Front 46

________is the rate of change with respect to time.

Back 46

Frequency

Front 47

_______ describes the position of the waveform relative to time 0.

Back 47

Phase

Front 48

A simple sine wave can be represented by one single spike in the _____ domain.

*

Back 48

frequency

Front 49

As frequency increases, the period ________.

Back 49

decreases

Front 50

________ is a type of transmission impairment in which the signal loses strength due to the resistance of the transmission medium.

Back 50

Attenuation

Front 51

________ is a type of transmission impairment in which the signal loses strength due to the different propagation speeds of each frequency that makes up the signal.

Back 51

Distortion

Front 52

________ is a type of transmission impairment in which an outside source such as crosstalk corrupts a signal.

Back 52

Noise

Front 53

When propagation speed is multiplied by propagation time, we get the ________.

Back 53

distance a signal or bit has traveled

Front 54

Baseband transmission of a digital signal is possible only if we have a ____ channel.

Back 54

low-pass

Front 55

If the available channel is a ____ channel, we cannot send a digital signal directly to the channel.

Back 55

bandpass

Front 56

For a ______ channel, the Nyquist bit rate formula defines the theoretical maximum bit rate.

Back 56

noiseless

bitrate = 2 x bandwidth x log(2,L)

Front 57

For a ______ channel, we need to use the Shannon capacity to find the maximum bit rate.

Back 57

shannon

capacity = bandwidth x log(2,1+SNR)

Front 58

_________ can impair a signal.

Back 58

A)Attenuation

B)Distortion

C)Noise

Front 59

The _________ product defines the number of bits that can fill the link.

Back 59

bandwidth-delay

Front 60

CHAPTER 4

Back 60

CHAPTER 4

Front 61

Polar and bipolar encoding are types of _______ coding.

Back 61

line

Front 62

___________ conversion involves three techniques: line coding, block coding, and scrambling.

Back 62

Digital-to-digital

Front 63

In ______ schemes, the voltage level oscillates between a positive and a negative value although it may remain at zero level between the two values.

Back 63

polar

Front 64

In _____, the level of the voltage determines the value of the bit.

Back 64

NRZ-L

Front 65

In ______, the change or lack of change in the level of the voltage determines the value of the bit.

Back 65

NRZ-I

Front 66

The idea of RZ and the idea of NRZ-L are combined into the ________ scheme.

Back 66

Manchester

Front 67

The idea of RZ and the idea of NRZ-I are combined into the ________ scheme.

Back 67

differential Manchester

Front 68

In Manchester and differential Manchester encoding, the transition at the middle of the bit is used for __________.

Back 68

synchronization

Front 69

In _______encoding, we use three levels: positive, zero, and negative.

Back 69

bipolar

Front 70

The _____ scheme uses data patterns of size 2 and encodes the 2-bit patterns as one signal element belonging to a four-level signal.

Back 70

2B1Q

Front 71

_______ encoding has a transition at the middle of each bit.

Back 71

A)RZ

B)Manchester

C)Differential Manchester

Front 72

_______ encoding has a transition at the beginning of each 0 bit.

Back 72

Differential Manchester

Front 73

Which of the following encoding methods does not provide for synchronization?

Back 73

NRZ-L

Front 74

Which encoding method uses alternating positive and negative values for 1s?

Back 74

NRZ-I

Front 75

Block coding can help in _______ and _________ at the receiver.

Back 75

synchronization and error detection

Front 76

________ is the process of converting digital data to a digital signal.

Back 76

A)Block coding

B)Line coding

C)Scrambling

Front 77

_______ provides redundancy to ensure synchronization and inherent error detection.

Back 77

Block coding

Front 78

________ is normally referred to as mB/nB coding; it replaces each m-bit group with an n-bit group.

Back 78

Block coding

Front 79

________ provides synchronization without increasing the number of bits.

Back 79

Scrambling

Front 80

Two common scrambling techniques are ________.

Back 80

B8ZS and HDB3

Front 81

PCM is an example of _______ conversion.

Back 81

analog-to-digital

Front 82

The most common technique to change an analog signal to digital data is called __________.

Back 82

PCM

Front 83

The first step in PCM is ________.

Back 83

sampling

Front 84

______ finds the value of the signal amplitude for each sample; ____ finds the change from the previous sample.

Back 84

PCM; DM

Front 85

CHAPTER 5

Front 86

ASK, PSK, FSK, and QAM are examples of ________ conversion.

Back 86

digital-to-analog

Front 87

AM, FM, and PM are examples of ________ conversion.

Back 87

analog-to-analog

Front 88

In QAM, both ________ of a carrier frequency are varied.

Back 88

amplitude and phase

Front 89

In ________, the amplitude of the carrier signal is varied to create signal elements. Both frequency and phase remain constant.

Back 89

ASK

Front 90

In _________, the frequency of the carrier signal is varied to represent data. Both peak amplitude and phase remain constant.

Back 90

FSK

Front 91

In ________, the phase of the carrier is varied to represent two or more different signal elements. Both peak amplitude and frequency remain constant.

Back 91

PSK

Front 92

Quadrature amplitude modulation (QAM) is a combination of ___________.

Back 92

ASK and PSK

Front 93

________ uses two carriers, one in-phase and the other quadrature.

Back 93

QAM

Front 94

How many carrier frequencies are used in BASK?

Back 94

1

Front 95

How many carrier frequencies are used in BFSK?

Back 95

2

Front 96

How many carrier frequencies are used in BPSK?

Back 96

1

Front 97

Which of the following is not an analog-to-analog conversion?

Back 97

QAM

Front 98

In _____ transmission, the carrier signal is modulated so that its amplitude varies with the changing amplitudes of the modulating signal.

Back 98

AM

Front 99

In the analog transmission of the digital signal, the baud rate is ___________ the bit rate.

Back 99

less than or equal to

Front 100

In ASK, the bandwidth is ________.

Back 100

equal or greater than signal rate

Front 101

With the same signal rate, the bandwidth of FSK is normally ___________ the bandwidth for ASK.

Back 101

greater than

Front 102

The bandwidth of an AM signal is ______________ the bandwidth of the original analog signal.

Back 102

two times

Front 103

In AM radio, the allocated bandwidth for each station is ___________ kHz.

Back 103

10

Front 104

In FM radio, the allocated bandwidth for each station is ___________ kHz.

Back 104

200

Front 105

CHAPTER 6

Front 106

Which multiplexing technique is used for analog signals?

Back 106

PDM

Front 107

Which multiplexing technique is used for digital signals?

Back 107

TDM

Front 108

Which multiplexing technique shifts each signal to a different carrier frequency?

Back 108

FDM

Front 109

Which multiplexing technique involves signals composed of light beams?

Back 109

WDM

Front 110

Which multiplexing technique shifts each signal to a different carrier frequency?

Back 110

FDM

Front 111

Which multiplexing technique involves signals composed of light beams?

Back 111

WDM

Front 112

________ is the set of techniques that allows the simultaneous transmission of multiple signals across a single data link.

Back 112

Multiplexing

Front 113

____ is designed to use the high bandwidth capability of fiber-optic cable.

Back 113

WDM

Front 114

______ is an analog multiplexing technique to combine optical signals.

Back 114

WDM

Front 115

_____ is a digital process that allows several connections to share the high bandwidth of a link.

Back 115

TDM

Front 116

We can divide ____ into two different schemes: synchronous or statistical.

Back 116

TDM

Front 117

In ________ TDM, each input connection has an allotment in the output even if it is not sending data.

Back 117

synchronous

Front 118

In ________ TDM, slots are dynamically allocated to improve bandwidth efficiency.

Back 118

statistical

Front 119

The _______ technique uses M different carrier frequencies that are modulated by the source signal. At one moment, the sign modulates one carrier frequency; at the next moment, the signal modulates another carrier frequency.

Back 119

FHSS

Front 120

The ______ technique expands the bandwidth of a signal by replacing each data bit with n bits using a spreading code.

Back 120

DSSS

Front 121

Groups, super groups, master groups, and jumbo groups are terms used in ______________.

Back 121

FDM

Front 122

Multilevel multiplexing is a strategy used in ___________.

Back 122

TDM

Front 123

Multislot allocation is a strategy used in ___________.

Back 123

TDM

Front 124

Frame synchronization is a strategy used in ___________.

Back 124

TDM

Front 125

A T-1 line uses ___________ frames.

Back 125

8000

Front 126

We need addressing mechanism in ___________ TDM.

Back 126

statistical

Front 127

CHAPTER 7

Front 128

Transmission media are usually categorized as _______.

Back 128

guided or unguided

Front 129

Transmission media lie below the _______ layer.

Back 129

physical

Front 130

_______ cable consists of an inner copper core and a second conducting outer sheath.

Back 130

Coaxial

Front 131

In fiber optics, the signal is _______ waves.

Back 131

light

Front 132

Which of the following is not a guided medium?

Back 132

atmosphere

Front 133

Twisting in a twisted-pair help reduce the __________.

Back 133

noise

Front 134

Noise in a coaxial cable is reduced by ___________________.

Back 134

the outer conductor

Front 135

UTP and STP are different implementations of ___________________ cable.

Back 135

twisted-pair

Front 136

RJ-45 is a type of connectors used in _________ cabling.

Back 136

twisted-pair

Front 137

RG rating is used in _________ cable.

Back 137

coaxial

Front 138

SC and TP are two types of connectors used in _________ cabling.

Back 138

fiber-optic

Front 139

The infrared wave has frequencies ________ microwave.

Back 139

below

Front 140

BNC is a type of connectors used in _________ cabling.

Back 140

coaxial