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Jared Nationals > Cable Theory 102/201 > Flashcards

Cable Theory 102/201 Flashcards

1
Q

RF

A

Radio Frequency

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2
Q

Defined as the physical length of one cycle of the voltage waveform.

A

Wavelength

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3
Q

In free space, a RF that is a very high frequency AC Waveform, travels at what speed

A

Speed of Light

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4
Q

Mandates certain frequency levels for various types of communication

A

FCC

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5
Q

a set list of frequencies at which channels transmit; can be analog, digital, or data

A

Channel Plans

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6
Q

A cable transmission can be transmitted and received in either of these formats

A

analog or digital

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7
Q

an analog signal is a what type of waveform?

A

continuous waveform

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8
Q

a digital signal has two discrete values that are often expressed as what

A

0 and 1

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9
Q

The degradation in analog transmission affects the amount of fine detail here

A

the picture quality

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10
Q

The height of the radio wave is also called this

A

amplitude

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11
Q

The height(amplitude) of the radio wave represents various aspects of the broadcast such as these two things

A

color and brightness

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12
Q

AM

A

Amplitude Modulation

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13
Q

PM

A

Phase Modulation

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14
Q

FM

A

Frequency Modulation

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15
Q

(AM) Amplitude Modulation is used for this

A

Video

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16
Q

(PM) Phase Modulation is used for this

A

Color

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17
Q

(FM) Frequency Modulation is used for this

A

Audio

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18
Q

Can be compressed and/or Encoded, Unlimited copying or regeneration, Allows error checking, Easily stored and retrieved, Less loss of quality over distance, No noise or distortion accumulation, High immunity to interference. Are all advantages of what?

A

digital broadcasting

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19
Q

the signal format by which digital cable channels are encoded and transmitted via cable

A

QAM or Quadrature Amplitude Modulation

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20
Q

works by modulating the amplitude of two incoming carrier waves to one RF carrier wave, thus doubling the effective bandwidth

A

QAM or Quadrature Amplitude Modulation

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21
Q

For a customer to receive a QAM signal, the signal must be what

A

Demodulated

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22
Q

The effect of moving electrons provides this, that powers lights, radios, televisions, and appliances in most homes around the world

A

AC or Alternating Current

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23
Q

The human voice produces what type of waveform at different frequencies

A

AC Waveforms

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24
Q

HFC power supplies transform AC waveforms into this

A

Quasi Square AC Waveforms

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25
Q

Four common types of waveforms you’ll encounter in telecommunications are

A

Sine, Square, Quasi-square, Saw Tooth

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26
Q

on an ac waveform. this is Usually represented on the vertical axis

A

Current

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27
Q

a graphic display which shows the flow of current over an elapse of time

A

AC Waveforms

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28
Q

shown in the waveform above the horizontal axis

A

Positive polarity

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29
Q

shown in the waveform below the horizontal axis

A

Negative polarity

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30
Q

The relationship of an AC waveform displayed as a graph

A

Current or Voltage, and Elapsed Time

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31
Q

This is the type of waveform that powers your power supplies, home appliances, and the television channels that carry program information to your customers’ homes

A

Sine

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32
Q

This waveform is often found within the switching regulator DC output power supplies in amplifiers.

A

Square

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33
Q

A CATV power supply without a load produces this waveform that combines a non linear increase and decrease of current with an extended maximum positive and negative peak value

A

Quasi Square

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34
Q

this is the waveform that is typically used to drive the horizontal trace on a spectrum analyzer

A

Sawtooth

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35
Q

defined as one complete sine wave

A

Cycle

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36
Q

the number of cycles of an AC waveform that occur in one second and is measured in hertz

A

Frequency

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37
Q

CPS

A

Cycles per second

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38
Q

Hz

A

Hertz

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39
Q

T

A

Period

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40
Q

the amount of time it takes a waveform to complete 1 cycle

A

Period

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41
Q

The peak value of an AC waveform is also known as this

A

Amplitude

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42
Q

Random, Fluctuating signals on the network not part of the channels,audio/video or data carriers

A

Noise

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43
Q

Unwanted outside signal entering or exiting the coaxial cable through cracks, breaks, loose connectors, and poorly shielded drops

A

Ingress/Egress

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44
Q

Three signals combining to create a distortion

A

Composite Triple Beat (CTB)

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45
Q

When two or more carries encounter a non linear device, such as a loose connection where some oxidation has occurred

A

Common Path Distortions (CPD)

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46
Q

Two signals combining to create a distortion. occur at .75 MHz and 1.25 MHz above and below the desired carrier frequency

A

Composite Second Order (CSO)

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47
Q

The introduction of outside signal into the HFC Network

A

Ingress

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48
Q

This can hamper digital signals, cause noise, and picture ghosting.

A

Ingress

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49
Q

Minimum acceptable ingress at 5-18MHz

A

-20 dBc

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50
Q

Minimum acceptable ingress at 18-42MHz

A

-30 dBc

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51
Q

Sources of RF interference fall into these two categories

A

intentional and unintentional

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52
Q

List 4 of the 12 Intentional sources of RF interference are

A

AM, Shortwave, FM and Tv broadcast transmitters; Remote controls; Cell phones; Taxi, police and aircraft radios; Microwave ovens; Motion Sensors; Radar systems

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53
Q

Unintentional RF sources are most commonly devices that produce a what

A

Electrical spark

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54
Q

3 Common sparking sources include what

A

Electric welders, Brush-type motors, Relays and switches

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55
Q

This is inevitable and occurs in every system

A

Noise

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56
Q

The conversion of an analog signal into a digital signal to improve signal quality by reducing interference.

A

Digital Conversion

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57
Q

The process of compressing digital video to reduce the bandwidth required

A

Digital Compression

58
Q

The modulation scheme by which digital cable channels are encoded so they can be transmitted via cable

A

QAM Modulation

59
Q

measuring the quality of a digital signal so it can be maintained within a desirable range

A

Digital Signal Quality

60
Q

Can interfere with an analog signal and reduce its clarity

A

Thermal Noise

61
Q

This type of bit are regenerated rather than amplified.

A

Digital bits

62
Q

As long as the signal is received and read before its level cannot be properly recognized, transmission distance is this

A

virtually unlimited

63
Q

The process of converting an analog signal into a digital signal is called this

A

analog to digital conversion

64
Q

ADC

A

analog to digital conversion

65
Q

Basic steps of the ADC process

A

Sampling, Quantization, Encoding

66
Q

Process used to reduce the bandwidth required for video

A

Digital Compression

67
Q

In digital compression the video frames are split into these two types

A

Key and Predictive

68
Q

Key video frame type is comprised of this information

A

static information

69
Q

Predictive video frame type is comprised of this information

A

information that changes from frame to frame

70
Q

a device or software that enables compression or decompression to take place

A

video codec

71
Q

QAM

A

Quadrature Amplitude Modulation

72
Q

the signal format by which digital cable channels are encoded so they can be transmitted via cable

A

Quadrature Amplitude Modulation or QAM

73
Q

Works by modulating the amplitude of two incoming carrier waves to one rf carrier wave

A

Quadrature Amplitude Modulation or QAM

74
Q

Five primary indicators available to assist in measuring signal quality

A

Constellation diagram, Modulation Error Ratio (MER), Bit Error Rate (BER), Forward Error Correction (FEC), QAM ingress

75
Q

Measures incoming signal quality by providing a graphical representation of the signal within a box

A

Constellation diagram

76
Q

In perfect data transmission conditions, each bit of an incoming signal appears as what in the constellation diagram

A

a dot in the center of each box

77
Q

In less than perfect data transmission conditions, each bit of an incoming signal appears as what in the constellation diagram

A

toward an outer edge of each box

78
Q

in constellation diagrams, this indicates that a signal disturbance is causing an error in the bit rate

A

signal appears toward an outer edge of each box

79
Q

These two things can cause a bit error

A

Noise and Ingress

80
Q

MER

A

Modulation Error Rate

81
Q

a measure of signal quality (in dB)

A

Modulation Error Rate or MER

82
Q

A determination of how much margin the system has before failure

A

Modulation Error Rate or MER

83
Q

the ratio of average symbol power to average error power

A

Modulation Error Rate or MER

84
Q

An acceptable MER for a 256 QAM channel measured at the STB or Modem is what

A

35dB

85
Q

BER

A

Bit Error Rate

86
Q

A ratio of errored bits compared to the total number of bits received in one second of time

A

Bit Error Rate or BER

87
Q

Occurs when, due to a distorted signal, an incorrect decision is made

A

Bit error

88
Q

Ideal BER of a 256 QAM channel of 40Mbps

A

1.0E-09 (1 error per one billion bits)

89
Q

Theoretical perfect BER

A

0.0E- 00

90
Q

FEC

A

Forward Error Correction

91
Q

A system of error control for data transmission where the transmitting device adds additional data to a signal in order to detect errors

A

Forward Error Correction or FEC

92
Q

Many FEC codecs can also generate this

A

Bit Error Rate signal

93
Q

Located in the area of 32dB

A

the MER Cliff

94
Q

To ensure the highest quality digital services, technicians should confirm MER values are reading at this

A

35dB

95
Q

Any impairment in the customers drop system will be reflected in this signal quality measurement

A

MER

96
Q

Allows the user to see signal interference, under a 64 or 256 QAM modulated signal, without turning the carrier off

A

QAM ingress

97
Q

Was designed for Best Effort Service and uses request/grant mechanisms to access upstream bandwidth

A

Docsis 1.0

98
Q

Uses Signal Quality of Service association per modem

A

Docsis 1.0

99
Q

Provides in-line 56-bit DES encryption/decryption to secure the privacy of the connection

A

Baseline Privacy

100
Q

Has capacity for symmetric and is interoperable and backwards compatible DOCSIS 1.x

A

Docsis 2.0

101
Q

Has more upstream capacity and reflects improved robustness against interference

A

Docsis 2.0

102
Q

DOCSIS

A

Data Over Cable Service Interface Specification

103
Q

Set of standards that defines how information is packaged and transported by coaxial cables

A

DOCSIS

104
Q

Four most notable enhancements in DOCSIS 3.0 over previous versions

A

Internet Protocol Version 6 (IPV6), Channel Bonding, Enhanced QOS, Increased data security

105
Q

The addresses in IPv6 are this long

A

128 bits

106
Q

IPv4 address is written in this

A

decimal,separated by periods

107
Q

IPv6 address is written in this

A

hexadecimal, separated by colons

108
Q

Can be used once in an IPv6 address to replace multiple fields of zeros

A

double colon (::)

109
Q

The typical throughput per 256 QAM DOCSIS channel

A

42.88Mbps

110
Q

When it is necessary to do this, be sure to take into account the size and modulation of your channel and multiply that number by the number of channels allocated to the data services

A

identify the size of your pipe

111
Q

Instructs to look for additional channels. combines multiple bandwidths, and enables the addition of channels

A

Channel Bonding

112
Q

MPEG

A

Moving Picture Experts Group

113
Q

Family of standards used for coding audiovisual information in a digitally compressed format

A

Moving Picture Experts Group (MPEG)

114
Q

The compression is done by storing information that is redundant, between successive images, in memory

A

Moving Picture Experts Group (MPEG)

115
Q

Enables all of the information of a TV signal to fit into as little bandwidth as possible, without changing the quality

A

Moving Picture Experts Group (MPEG)

116
Q

MPEG standard for video CDs

A

MPEG 1

117
Q

MPEG standard for DVD and HDTV

A

MPEG 2

118
Q

MPEG standard for Interactive TV, Video on cell phones, Internet Streaming

A

MPEG 4

119
Q

A MPEG video is a sequence of these three kinds of encoded pictures:

A

I, P, B pictures

120
Q

In a normal sequence of final video, there are 12 pictures, also known as

A

frames

121
Q

I- Picture

A

intra-coded picture

122
Q

single compressed picture that contains all the spatial information of a video picture

A

intra-coded picture (I-picture)

123
Q

GoP

A

Group of Pictures

124
Q

The starting and ending point in a GoP

A

I- Pictures

125
Q

All pictures before the next I-picture are called this

A

Group of Pictures (GoP)

126
Q

P-Pictures

A

Predicted Pictures

127
Q

Contain picture data that is compressed based on the nearest I or P-picture.

A

Predictive Pictures or P-pictures

128
Q

More highly compressed than I-pictures.

A

Predictive Pictures or P-pictures

129
Q

Macroblocks coded with forward prediction from previous I or P Pictures

A

Predictive Pictures or P-pictures

130
Q

B-Pictures

A

Bi-directional pictures

131
Q

Use both past and subsequent pictures as references for calculating compression data

A

Bi-directional pictures or B-Pictures

132
Q

Coded with forward/backward prediction from previous/next I or P references

A

Bi-directional pictures or B-Pictures

133
Q

May be coded with no prediction

A

Bi-directional pictures or B-Pictures

134
Q

There are three server network architectures for the implementation of Video on Demand services

A

Centralized Architecture, Distributed Architecture, Hybrid

135
Q

VOD

A

Video On Demand

136
Q

Network Server architecture that is implemented by first locating the servers channel modulation in a regional headend or hub

A

Centralized on Demand

137
Q

This Network Server architecture usually results in a reduction in the number and complexity of maintenance activities, centralizes hardware asset management, and lessens the number of locations requiring secure program content storage

A

Centralized on Demand

138
Q

Servers and content, or assets, are placed in most, if not all, headends and hubs of an HFC system in this Network Server architecture

A

Distributed on Demand

139
Q

Network Server architecture that is Used as a primary centralized server that links to locally distributed services.

A

Hybrid on Demand

140
Q

This Network Server architecture reduces demand on the backbone networks as well as on all servers

A

Hybrid on Demand

Jared Nationals (14 decks)

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