ct3 week 2 Flashcards
1
Q
a feature in Scout that shows the presence (or absence of) faults called linear distortions in the RF portion of the return path
A
Scout Flux
2
Q
a technology that encodes, compresses, and decodes video and audio so we can pack multiple programs in the same space as we used to carry one TV station
A
MPEG2
3
Q
The Wifi password on all XM meters
A
defaultkey
4
Q
VOM
A
Volt Ohm Meter
5
Q
A test instrument used to measure AC and DC voltage, current, and resistance in ohms
A
Volt Ohm Meter (VOM)
6
Q
Passage of signal intended to remain within the cable into the outside world
A
Egress
7
Q
Name 3 of the 6 test you can do on the Polarity Tester
A
Open Ground, Open Neutral, Open Hot, Hot & Ground Reversed, Hot & Neutral Reversed, Correct polarity
8
Q
The CATV frequency spectrum is between
A
5 and 1002 MHz
9
Q
With this app you can pay your bill, manage appointments, view or edit your WiFi Network name or password, and troubleshoot your devices. No Lines. No Waiting
A
Xfinity My Account
10
Q
Constant power adjustment messages between the CMTS and the device
A
Compression
11
Q
This happens when any downstream or upstream channel is impaired and the device stops using them
A
Partial Bonding
12
Q
Maximum upstream before PHT fail
A
54 dBmV
13
Q
Minimum DSSNR level before PHT fail
A
33 dB
14
Q
Maximum downstream before PHT fail
A
12 dBmV
15
Q
Minimum downstream before PHT fail
A
-10 dBmV
16
Q
Minimum upstream before PHT fail
A
25 dBmV
17
Q
a measurement of how consistent the signal response is from the beginning to the end of the channel space
A
In-Channel Frequency Response (ICFR)
18
Q
a software application designed in response to a need for a simple and consistent way to proactively communicate information about the network’s health
A
Watchtower
19
Q
Formula for cable loss
A
Cable loss = Footage x Cable loss per foot
20
Q
Formula for total loss
A
Total loss = Cable loss + Passive loss
21
Q
Formula for Expected Level
A
Expected Level = Starting level – Total loss
22
Q
For a series-6 cable at 54 MHz, the attenuation is
A
2 dB per 100 feet
23
Q
For a series-6 cable at 750 MHz, the attenuation is
A
6 dB per 100 feet
24
Q
For a 2-way splitter, the signal loss is
A
4 dB
25
For a 4-way splitter, the signal loss is
8 dB
26
For an 8-way splitter, the signal loss is
12 dB
27
The difference between transmitted and received power resulting from the loss through equipment, lines, or other transmission devices; usually expressed in decibels
Attenuation
28
A cable television system's master control operation where signals are received and delivered on various cable system channels
Headend
29
The process of converting data into a coded form (ciphertext) to prevent it from being read and understood by an unauthorized party
Encryption
30
DRM
Digital Rights Management
31
HDCP
High-bandwidth Digital Content Protection
32
Signal security can be applied at these 3 locations
Headend, Tap, and Set-top box
33
The process of converting data into a coded form (ciphertext) to prevent it from being read and understood by an unauthorized party.
Encryption
34
What are the two types of traps/filters
Positive and Negative
35
Type of trap that block a channel or channels from being received by a cable TV customer
Negative
36
Type of trap that removes an interfering carrier from a channel that a customer wants to receive
Positive
37
DRM
Digital Rights Management
38
HDCP
High-bandwidth Digital Content Protection
39
What are the two common content protection measures
DRM and HDCP
40
Any technology used to protect the interests of owners of content and services (such as copyright owners).
Digital Rights Management (DRM)
41
A specification developed for protecting digital entertainment content that travels over HDMI cables
High-bandwidth Digital Content Protection (HDCP)
42
Front-line employee that answers customer telephone calls, or works at a Service Center. Formerly referred to as a "call rep."
Customer Account Executive (CAE)
43
A mandate by the Federal Communications Commission which requires cable operators only deploy digital set-top boxes that have a PC card slot for a multichannel CableCARD to decrypt channels
Separable Security
44
A removable security card available from cable TV providers, translates encrypted signals on the Comcast network
CableCARD
45
What date did the FCC begin requiring service providers to make CableCARDs available
July 1st, 2004
46
OES requires a jumper to be installed if the trap exceeds this length
The length of a locking terminator
47
What is the frequency range of RF signals
5-1002 MHz
48
electromagnetic wave used to transport information from one point to another
Radio Frequency (RF)
49
the basic example of a signal that can be generated, transmitted, and received with RF equipment.
Sine wave
50
RF is characterized by what three elements
Wavelength, Frequency, and Amplitude
51
an electromagnetic signal above the audio and below the infrared frequencies.
Radio Frequency (RF)
52
the distance between two consecutive peaks or troughs of a waveform
Wavelength
53
defined as the space occupied by one complete cycle of a wave.
Wavelength
54
If the frequency of a signal increases, what happens to the wavelength
It becomes shorter
55
difference between a signal’s maximum or minimum value during one cycle and usually indicates signal strength or intensity.
Amplitude
56
What is Amplitude measured in
Volts
57
the number of times a signal goes through a complete cycle
Frequency
58
What is frequency measured in
Hertz
59
What is an unwanted alteration of the original shape of a signal called?
Signal Distortion
60
A range of wavelengths of electromagnetic emission.
Spectrum
61
Regulatory responsibility for the radio spectrum is divided between these two administrations
Federal Communications Commission (FCC) and National Telecommunications and Information Administration (NTIA)
62
NTIA
National Telecommunications and Information Administration
63
Forward path frequency range for legacy systems
54-1002 MHz
64
Return path frequency range for legacy systems
5-42 MHz
65
Forward path frequency range for mid-split systems
85 MHz - 1.2 GHz
66
Return path frequency range for mid-split systems
5-85 MHz
67
passive and active equipment in a Mid-Split system must be designed to operate in this frequency range
5-1,675 MHz
68
Comcast uses MoCA at this frequency range
1125-1625 MHz
69
used to express a ratio between two signal power levels, i.e., the loss of signal through a splitter.
dB
70
Absolute signal power that describes the signal at a specific location
dBmV
71
1 millivolt across 75 Ohms is equal to this
0 dBmV
72
A telephones signal strength used to be measured in this
Bels
73
How many decibels are in a Bel?
10
74
A cable signal can be transmitted and received in these two formats?
Analog and Digital
75
What are the 3 different carrier parts that make up the analog waveform?
video, audio, and color
76
The number of frequency and amplitude variations in an analog waveform
infinite
77
Changing the characteristics of a wave is known as this:
Modulation
78
process of encoding a simple radio wave, also known as the carrier wave, with data.
Modulation
79
The modulation technique that Comcast uses to encode digital cable channels is called
Quadrature Amplitude Modulation (QAM)
80
modulates the amplitude of two incoming carrier waves (I signal and Q signal) to one RF carrier wave.
Quadrature Amplitude Modulation (QAM)
81
Two examples of devices that demodulate a QAM signal
Set-top boxes and cable modems
82
refers to reducing the number of bits required to carry information (such as digital video images) by removing the redundant bits in the data.
Digital Compression
83
MPEG
Moving Picture Experts Group
84
the name of a family of standards used for coding audio-visual information in a digital compressed format.
Moving Picture Experts Group MPEG
85
MPEG method splits the signal into these three types of encoded pictures:
Key Frames (I), Predictive frames (P), and Bi-Directional Frames (B)
86
Pictures which contain all the information to be transmitted and serve as a reference point
Key Frames (I)
87
Pictures which carry information about which pixels change in relation to the i-frame
Predictive Frames (P)
88
Pictures which carry information about which pixels change in relation to the i-frame for transmitted and to-be-transmitted frames
Bi-directional frames (B)
89
The collection of frames to be transmitted in one unit of time is called what?
Picture Group
90
A list of channel numbers and their associated stations for a particular headend
Channel Map
91
Is the difference between transmitted and received power resulting from the loss through equipment, lines, passive devices, or other transmission devices.
Attenuation
92
What are the 5 factors that affect attenuation?
Frequency, Temperature, Dielectric, Center conductor diameter, Cable length
93
Passage of an outside signal into the cable; can result in noise and disruption of the desired signal.
Ingress
94
Passage of signal intended to remain within the cable into the outside world
Egress
95
a figure of merit derived mathematically from the number and severity of signal leaks in a cable system.
Cumulative Leakage Index
96
According to FCC, leakage should not exceed 20 microvolts per meter at 3 meters between these frequencies
54-216 MHz
97
fcc leakage limits over 216mhz
no more than 15 microvolts per meter at 30 meters
98
fcc leakage limits at less than 54mhz
no more than 15 microvolts per meter at 30 meters
99
fcc leakage limits between 54-216 mhz
no more than 20 microvolts per meter at 3 meters
100
According to FCC, leakage should not exceed 15 microvolts per meter at 30 meter at these frequencies
0-54 MHz and above 216 MHz
101
a condition where external frequencies or interfering signals leak into the cable network, and is more prominent in lower frequencies.
Ingress
102
defined as random, fluctuating signals on the network, which are not part of the channel’s audio/video or data carriers.
Noise
103
A form of low frequency electromagnetic interference, which can affect a customer’s service
Hum
104
It is the amplitude distortion of a signal caused by the modulation of the signal by components of the power line frequency.
Hum
105
Displayed as black horizontal bars progressing up the TV
Hum
106
The frequency cycle in which hum creates one black horizontal bar
60Hz
107
a measure of how well symbols can be differentiated from the random noise, distortion, or interference accumulated within a 6 MHz channel
Modulation Error Ratio (MER)
108
a direct indication of the fidelity of the transportation medium and determines how much margin the system has before failure.
Modulation Error Ratio (MER)
109
the rate of errored bits compared to the total number of bits received in one second of time.
Bit Error Rate (BER)
110
What is the ideal BER of a 256 QAM channel
1xE-9
111
a system of error control for data transmission, where the transmitting device adds additional data to a signal in order to detect errors
Forward Error Correction (FEC)
112
MER
Modulation Error Ratio
113
BER
Bit Error Rate
114
defined as the ratio of signal power to the noise power and is expressed in dB.
Signal-to-Noise Ratio (SNR)
115
SNR
Signal-to-Noise Ratio
116
This digital processing technique makes channel mapping possible
Modulation
117
Frequency range: Broadcasting TV Channels 2-4
54-72 MHz
118
Frequency range: Broadcasting TV channels 5-6
76-88 MHz
119
Frequency range: Radio Astronomy
73-74.6 MHz
120
Frequency range: Aeronautical radionavigation
74.8-75.2 MHz
121
What 2 frequencies do we use when using cable math with the rule of thumb
54 MHz and 750 MHz
122
The difference between transmitted and received power resulting from the loss through equipment, lines, or other transmission devices; usually expressed in decibels.
Attenuation
