CT5 Flashcards
(2104 cards)
1
Q
The topology where signals originate in the headend andare transmitted long distances via trunk cables
A
Tree and Branch
2
Q
A network architecture that typically uses fiber optic cables to bring signals to selected areas of the system called nodes
A
Hybrid Fiber-Coax (HFC)
3
Q
Bi-annual tests, performed in the headend and at a number of end-of-line location
A
FCC Proof-of-Performance
4
Q
The cumulative effect of return path distortions they are added to the signal at various locations in the coaxial portion of the network.
A
Funnel Effect
5
Q
Specifications standards approved by the FCC in 1953for commercial analog color TV broadcasting.
A
National Television Standards Committee (NTSC)
6
Q
a portion of the electromagnetic spectrum whose frequencies are well suited for transmitting and receiving Telecommunications signals through the air.
A
Radio Frequency (RF) Spectrum
7
Q
Signals that flow downstream, from the headend to the network.
A
Forwards (Downstream) Signals
8
Q
Signals that flow in the upstream direction, from customer to headend
A
Revers (upstream) Signals
9
Q
Device that separates or combines based on frequency.
A
Diplex Filter
10
Q
typical cutoff frequency for a sub-split diplex filter
A
About 50 MHz
11
Q
The three major concerns/ limitations of the tree andbranch architecture are:
A
BandwidthImpairmentsDependency on Power
12
Q
The lowest possible power level determined by the thermal noise generated within the electrical componentsbeing tested
A
Noise Floor
13
Q
The highest power level (amplitude) reached by a carrier
A
Peak
14
Q
A clustering of beats 1.25 MHz above the visual carriers in a CATV network
A
Composite Second Order (CSO)
15
Q
A form of interference or noise resulting from the mixingof all of the various carriers in a CATV network
A
Composite Triple Beat (CTB)
16
Q
Two major types of distortions that are typically associated with CATV
A
Composite Second Order (CSO) and Composite Triple Beat (CTB)
17
Q
The 6 benefits of implementing fiber optics in broadband networks
A
Enhances Picture QualityIncreased ReliabilityDecreased cost of system maintenanceCost effective system bandwidth upgradesCost means of system upgrade requiring a complete change our of electronicsSmall segmented areas allow greater return path functionality
18
Q
Having or relating to a frequency below the audibility range of the human ear.
A
Infrasonic
19
Q
A stream of atomic nuclei that enter the earth’s atmosphere from outer space at speeds approaching that of light
A
Cosmic Rays
20
Q
Frequency range of satellite systems
A
4GHz to 13GHz
21
Q
The wavelengths most commonly used by the CATVindustry
A
1310nm and 1550nm
22
Q
The type of fiber optic cable that the broadband industry uses
A
Single Mode Fiber
23
Q
The process of combining multiple carriers onto a single medium
A
Multiplexing
24
Q
Width of the Fiber optic core
A
8-10um
25
Width of the fiber optic cladding
125um
26
Width of the fiber optic coating
250um
27
Combines multiple optical signals in order to amplify them as a group and transported over a single fiber
Wave Division Multiplexing (WDM)
28
Allows multiple wavelengths above and below a centerwavelength to be carried on a single optical fiber.
Dense Wave Division Multiplexing (DWDM)
29
Three parts of the optical link
Fiber Optic CableTransmitter (Laser)Receiver (Node)
30
Individual fibers are bundled and then placed into these to reduce the possibility of damage
Buffer Tubes
31
This diode changes the RF signals to pulsesof light and then transmits them onto an optical fiber
Semiconductor Laser Diode
32
The Three types of optical transmitters that are typically used in broadband HFC Network
Fabry-Perot (F-P)Distributed Feedback (DFB)Yttrium-Aluminum-Garnet (YAG)
33
YAG
Yttrium-Aluminum-Garnet
34
DFB
Distributed Feedback
35
F-P
Fabry-Perot
36
A spare fiber installed during the construction of the network that was reserved for future use.
Dark Fiber
37
Three advantages of trunk reduction
Shorter CascadesFewer/smaller outages due to segmenting the system into smaller areasImproved picture Quality
38
FTTF
Fiber to the Feeder
39
Advantages of FTTF
Shorter CascadesFewer/smaller outages due to segmenting the system intosmaller areas.Increased Bandwidth
40
FTTC
Fiber to the Curb
41
PON
Passive Optical Network
42
Consists of a transmitter at the Headend and a receiver near the subscriber. Requires a power supply near the node but all other actives have been removed
FTTC PON
43
4 advantages of FTTC
No active devices after nodeNo CascadeFewer/smaller outages due to segmenting the system intovery small areasIncreased Bandwidth
44
A fiber-based network which uses passive splitters todeliver signals to multiple locations
Passive Optical Network (PON)
45
FTTH
Fiber to the Home
46
6 advantages of FTTH
Passive networkSingle fiber is dedicated to each subscriberFeatures local battery backup, no large remote power supplies are required.No exterior active devicesNo CascadesIncreased Bandwidth
47
This will ALWAYS be considered the "Backbone" in an HFC Network
The Fiber Network
48
A high-speed line or series of connections that forms a major pathway within a network
Backbone
49
The duplication of certain pieces and/or portions of thenetwork.
Redundancy
50
Comcast's goal for network reliability
"four-nines" or 99.99%
51
A network architecture where nodes, hubs, or headendsmay be connected with fiber optic cables to provideredundancy or increase services
Ring Architecture
52
Builds upon ring technology by adding a second (redundant) ring connecting the nodes to the headend. The second ring typically takes a different path
Ring within a Ring
53
A facility between the headend and the customer that performs many of the functions of a headend
Hubsite
54
Similar in function to a hubsite, but serving fewer customers
Optical Transition Node (OTN)
55
Usually a passive device such as a splitter or directional coupler used to combine radio frequency signals from one source with those from another
RF Combiner
56
Usually a passive device that divides a signal into two equal paths. It may be found on trunk, feeder, or drop cable.
RF Splitter
57
Device used to combine the channels for entry onto the cable or fiber optic transmitter
Headend Combiner
58
The difference, in dB, of a signal level, injected into one output port, and the measured level of that same signal on another output port, with the input port properly terminated.
Port-to-port isolation
59
Obtained by measuring the attenuation between the two output ports (A and B) when the common port (input port) is terminated in the correct value of impedance. An RF generator signal is applied to port A and an RF voltmeter reading is taken at Port B.
Isolation
60
Provision for connection to a device such as a tap, splitter, set-top box or computer
Port
61
Used to combine all of the signals to be carried over the cable system into a single medium (cable) for routing to the laser transmitters that are feeding the optical nodes in the system
Headend Combining Network
62
A measurement of the reflected signal compared to that of the incident signal
Return Loss
63
Device used to divide or combine light carriers on fiber optic cables.
Optical Splitter
64
A discontinuous signal whose various states are discrete intervals apart.
Digital Signal
65
Device used to convert an analog signal to a digital signal.
Digitizer
66
takes an amplitude measurement of the waveform at fixed intervals of time, and converts them to a binary number
Digitizer
67
The smallest unit of computerized data. Bits are defined as single characters of 0 or 1. Bandwidth is usually measured in bits-persecond.
Binary Digit (Bit)
68
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.
Byte
69
The number of changed states that can occur per second.
Baud
70
The value of "On" in a binary system
"1"
71
The value of "Off" in a Binary system
"0"
72
How many bits are in a "Nibble"?
4
73
In ASCII #5 alphabet, how man bits are in a byte?
7
74
If start and stop bits are included with Asynchronous Communications, then how many bits are in a byte?
10
75
ADC
Analog to Digital Conversion
76
DAC
Digital to Analog Conversion
77
A continuously varying signal with an unlimited number of possible values of amplitude and frequency.
Analog Signal
78
a non-continuous signal or carrier that changes its output in discreetly timed steps of voltage level and/or phase that can represent numerical values or other information
Digital Transmission
79
3 steps of basic ADC
SamplingQuantizationEncoding
80
The "Measuring" of the analog signal at specific intervals.
Sampling
81
The assigning of a specific value to each of the samples
Quantization
82
The process by which Quantized values are converted into a data or bit stream
Encoding
83
ASK
Amplitude Shift Keying
84
FSK
Frequency Shift Keying
85
QPSK
Quadrature Phase Shift Keying
86
QAM
Quadrature Amplitude Modulation
87
The process of varying the amplitude, frequency, or phase of a carrier to be in step with the instantaneous value of the modulating waveform
Modulation
88
Data transmission scheme wherein the carrier is shifted in amplitude
Amplitude Shift Keying (ASK)
89
The carrier frequency is shifted to represent the difference between a one and a zero
Frequency Shift Keying (FSK)
90
The position on a waveform cycle at a specific point in time. One cycle is defined as 360 degrees of this
Phase
91
Digital modulation scheme wherein the carrier is shifted in 90 degree steps. There are four possible phase states and the magnitude is constant.
Quadrature Phase Shift Keying (QPSK)
92
BPSK
BiPhase Shift Keying
93
In QPSK, what does "I" stand for?
In-Phase
94
In QPSK, what does "Q" Stand for?
Quadrature - shifted 90* or one quarter of a cycle
95
A graphic depiction of the four phase states of a Quadrature Phase Shift Key signal.
Constellation Diagram
96
What is the bandwidth of QPSK in a 6MHz bandwidth?
10 Mb/s
97
Digital modulation scheme that changes the phase and the amplitude.
Quadrature Amplitude Modulation (QAM)
98
a digital transmission technology that splits the frequency band into a number of channels. The channels are each assigned a specific time slot, so that several transmissions can share a single channel without interfering with one another
Time Division Multiple Access (TDMA)
99
The digital equivalent to Signal-to-Noise
Modulation Error Ratio (MER)
100
A joined or connected group of devices
Network
101
A network of computers linked by cable within a building or office complex.
Local Area Network (LAN)
102
A network of multiple locations linked by cable withina city or campus
Metropolitan Area Network (MAN)
103
A network typically bigger than a city or metropolitan area.
Wide Area Network (WAN)
104
A data network connects each of its endpoints to the network with a single link. A central device (hub) is used to aggregate and distribute data traffic to all endpoints and/or other central points in what’s referred to as a clustered star.
Star
105
Consists of several star networks that have been linked together
Clustered Star
106
Topology where workstations are connected to the network through a common path
Bus
107
A topology in which a data frame is passed around. As it arrives at an endpoint, the endpoint can either pass it along to the next endpoint or attach information to be sent to a destination
Token Ring
108
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
Ring
109
A method of data transmission that allows characters to be sent at irregular intervals by preceding each character with a 0 and by ending each character with a 1. This is referred to as start (0) and stop bits (1). It is the method, which most PCs use to communicate with each other and mainframes
Asynchronous Transmission
110
An extra bit added to help check if the data that isbeing transferred is correct
Parity Bit
111
The condition that occurs when two events happen in a specific time relationship with each other and both are under control of a master clock. Characters are spaced by time, not by start and stop bits.
Synchronous Transmission
112
Synchronizing bits used in synchronous transmission to maintain synchronization between transmitter and receiver.
Sync Bits
113
SNMP
Simple Network Management Protocol (SNMP)
114
NE
Network Elements
115
MIB
Management Information Base
116
A unique number assigned to a piece of equipmentused for identification purposes.
Media Access Control Address (MAC)
117
UTP
Unshielded Twisted Pair
118
signaling rate of 10BaseT
10 Mb/s
119
Signaling rate of 100BaseT
100 Mb/s
120
The designation for Ethernet over fiber optic cable, primarily for point-topoint links
10Base-F
121
Ethernet resides in what layers of the OSI model?
The 2 lowest levels (layers)
122
This device works as a multiport signal repeater, broadcasting an incoming signal to all other ports on an ethernet network
Ethernet Hub
123
The four-part numeric address that is assigned to a computer or an account as an identification tool
Internet Protocol Address (IP)
124
IEEE MAC Protocol for Hybrid Fiber-Coax Networks; standard for data communicatons over a cable network
802.14
125
The Four original partners of MCNS (Multimedia Cable Network Partners Ltd.)
Comcast, Cox, TCI and Time Warner
126
The three companies that joined MCNS in late 1996
Media One, Rogers Cablevision and CableLabs
127
DOCSIS
Data Over Cable Service Interface Specification
128
When was DOCSIS 1.0 released? (Month & Year)
Mar-97
129
The Leading standard for cable modems
DOCSIS
130
Four devices that must be added to a system to offer high-speed internet
CMTS (Cable Modem Termination System)CM (Cable Modem)ServersNoise Filters
131
A unit consisting of various hardware and software entities that acts as the hand-off point between the RF based HFC network and other networks such as theInternet and the PSTN.
CMTS (Cable Modem Termination System)
132
Used to terminate, manage and translate high-speed Internet sessions between cable modems in a LAN and other devices in a WAN.
CMTS (Cable Modem Termination System)
133
The collection of computers accessed through the Internet. Uses a hypertext based system for finding andaccessing its resources.
WWW (World Wide Web)
134
Four Items that a CMTS manages
Time SlotsContention SlotsModem DataTransmit Levels
135
Each cable modem is assigned one of these by the CMTS and only one modem is allowed to transmit during this.
Time Slot
136
These slots are usually used for short data transmissions such as a request for an additional number of reserved time slots
Contention Slots
137
The signal level that the CMTS wants to "See"
0dBmV
138
A PC on a LAN from which information or applications are requested.
Client/Server
139
A computer circuit board (card) installed in a computer so that the computer can be connected to a network. Provide a dedicated, full-time connection to a network.
NIC (Network Interface Card)
140
Why is it called a cable "Modem"?
When they transmit data they "MOdulate" the data onto a carrier, then receive data and "DEModulate" it from the carrier and send it on to the computer
141
Four of the most common servers found in a braodband network
DHCPTODTFTPProxy
142
This server sets up the MAC and IP addresses for the cable modem.
DHCP Server(Dynamic Host Configuration Protocol)
143
This server sets up a common clock between the CM and the CMTS
TOD Server(Time of Day)
144
This server allows non-protected file transfers, such as aconfiguration file for a modem.
TFTP Server(Trivial File Transfer Protocol)
145
These servers store commonly used (or contractually stored) data. A network may have a series of these servers located in different places.
Proxy Server
146
The two types of noise filters
High Pass FilterNotch Filter
147
These types of filters only allow signals above 50MHz to pass through the filter
High Pass Filter
148
In addition to letting everything above 50 MHz to pass, this filter allows a small spectrum below 50 MHz to pass
Notch Filter
149
The process of setting up the connection between theCMTS and the cable modem, where transmit levels andfrequency are determined.
Ranged
150
A switch or collection of switches connecting multiple networks
POP (Point of Presence)
151
The point of access into theInternet.
NAP(Network Access Point)
152
The company who provides access to the Internet and the World Wide Web, who usually also provides corefeatures such as e-mail.
ISPInternet Service Provider
153
The local, long-distance and internationalphone system in use today
PSTN(Public Switched Telephone Network)
154
This device in the Headend controls the operation of CDV.
HDT(Host Digital Terminal)
155
Three major components of the Host Digital Terminal
Access Bandwidth Manager ShelfModem ShelfSpectrum Manager Shelf
156
This Shelf provides the connection between the Network Interface Unit (NIU) and the switch, or more simply, the connection between the HDT and the LEC
ABM(Access Bandwidth Manager)
157
The point of demarcation between the network and the customer. It contains the modem necessary for telephony over a cable network.
NIU(Network Interface Device)
158
The device that opens or breaks the circuit path in a telephone call. This device looks at the incoming data to determine where the data should get routed.
Switch
159
The local phone company is also known as what?
LEC(Local Exchange Carrier
160
Shelf on the HDT (Host Digital Terminal) that converts the digital telephone signals into digital signals that are then modulated onto an RF carrier to be transmitted over the HFC Network.
Modem Shelf
161
This shelf on the HDT (Host Digital Terminal) monitors the RF spectrum allocated for telephone services over the HFC network. If problems are detected, it can switch the data transmission (telephone call) to another frequency.
Spectrum Manager
162
How many subscriber telephone lines can an NIU Handle?
4
163
LPSU
Local Power Supply Unit
164
The process of setting up the connection between the HDT and the NIU, where transmit levels and frequency are determined.
Marshalled
165
Modulating technique that interweaves multiple conversations, based on time.
TDMA(Time Division Multiple Access)
166
The number of the person that youare trying to call.
Terminating Number
167
The phone company of the person you are trying to call.
Terminating LEC
168
The “local” phone office where the subscriber’s lines are connected to the switching equipment.
Central Office
169
What is "7" equal to in binary?
111
170
64 QAM has how many phase angles?
52
171
16 QAM has how many phase angles?
10
172
The distance between two points of like phasein a wave.
Wavelength
173
A card made up of material similar to photographic film that changes colors when exposed to light.
Photosensitive Card
174
ANSI Laser standard that separates lasers into various classes that take into consideration the operating wavelength, output power level and whether the laser operates as a continuous or pulsed light output
Z-136
175
Four nines works out to how many minutes of down time per month?
4.5 minutes
176
loss of service to ourcustomers due to a fault in thedelivery network.
Outage
177
Minimum telephone service to assure a contact in case of an emergency.
Lifeline
178
FCC Standards CFR 47, Part 76.605(a)(1-12)
Proof-of-performance (POP) test
179
A continuous wave (CW) frequency onto which information is modulated for transport.
Carrier Frequency
180
Maximum Bandwidth of 256QAM
42.88Mbps
181
How long must POP tests be kept at the local office?
minimum of 5 years
182
how many test points are required for 1,000 to 12,500 customers?
6
183
How many test points are required for each additional 12,500 customers?
1
184
Channel requirements for POP testing (amount)
4 channels plus one additional channel for every 100 MHz.
185
In a cable system with an upper frequency at 750 MHz, how many test channels must be used?
11 Channels
186
All channels must be tested during these 3 tests.
Video Carrier Level, Audio Carrier Level, Video Carrier Level Stability Test
187
Only one Channel needs to be tested during this non-frequency specific test
Hum Modulation
188
How many digital channels must be tested on an all digital system with an upper frequency of 862MHz?
0, digital channels are not included and are not tested.
189
The amount of channels during these tests are based solely on the highest operating frequency
Video-Audio Carrier Frequency SeparationIn-Channel ResponseCarrier to NoiseCoherent Disturbances Tests
190
This test must be performed twice a year, once during the coldest months and again during the warmest (Jan-Feb and Jul-Aug respectively)
Video Carrier Level Stability (24-hour) test
191
This POP test must be performed every three years
Color Performance test
192
A circuit that automaticallyadjusts the gain of an amplifier sothat the output signal levels stayconstant despite varying inputlevels.
Automatic Gain Control (AGC)
193
a spectrumanalyzer feature that allows theuser to make otherwise intrusiveFCC POP tests in a non-intrusivemanner.
Gated Testing
194
When planning POP tests, these four things need to be considered
Test timesChannels and programming affected by testingTest lengthsAbility to perform non-intrusive gated testing
195
This test is usually performed by a Headend tech rather than a System Tech
Color Performance
196
What would a Discrepancy statement include?
Explain all possible misinterpreted fails, such as test point relocation, added channels, encoding issues and so on.
197
POP measurements are to be taken at what location?
Input to the subscriber terminal
198
EIA
Electronic Industry Association
199
What must an operator do in order to pass the receivability test?
Submit documentation showing that their channel lineup conforms to the EIA Channel allocation plan
200
What does the Audio Carrier Frequency Test ensure
That the audio carrier frequency for each channel must be 4.5MHz above the video carrier frequency, +/- 5kHz
201
Where is the Audio Carrier Frequency test performed at?
The Headend as well as the field test points
202
How many times a year is the Audio Carrier Frequency test performed?
Twice annually
203
What type of set-top box can alter the Audio Carrier Frequency?
Baseband set-top boxes (as opposed to non-baseband)
204
What six measurements are taken during the 24-hour test?
Minimum Visual Signal LevelVisual Signal changeAdjacent Visual SignalAny Other Visual Signal in BandwidthVisual Carrier LevelAudio Carrier Level
205
The six measurements that are taken during the 24-hour test are performed on what channels?
All NTSC Channels at each test point location
206
What is the Minimum Visual Signal Level allowed at the end of a 30-meter (100') cable drop that is connected to the subscriber tap?
1.41mV across an internal impedance of 75 ohms (+3dBmV(CT 5-3-22)
207
The square root of the sum ofthe squares of the amplitudes ofindividual components of afunction, such as the frequencycomponents of a signal.
Root Mean Square (RMS)
208
Maximum variation of each channel within any six-month period at the end of a 30-meter drop cable
8dB
209
Adjacent Visual Signal deviation of the visual signal level of any visual carrier within a 6MHz nominal frequency separation
3dB
210
What is the maximum "spread" or deviation among ALL channel levels in a 300MHz cable system and what is the incremental increase
10dB1db per 100MHz
211
At what level must the aural signal be maintained in association with the visual signal level?
between 10dB and 17dB below the visual signal level
212
At what level must the aural signal be maintained in association with the visual signal level on a baseband converter.
between 6.5dB and 17dB below the visual signal level.
213
In a 24-hour test, how many times must the signal level be checked?
four times
214
What are the time intervals of the 24-hour test?
5 to 7 hours
215
at what frequency is the In-Channel Response test performed?
.75MHz to 5Mhz above the lower frequency boundary of the cable channel under test
216
What is the FCC In-Channel Response requirement?
+/-2dB or 4dB peak-to-valley
217
To perform this test, a signal must be inserted on the channel, either by the headend technician or by other means
In-Channel Response Test
218
FCC Requirement for C/N
43dB at each test point
219
What are the three type of coherent disturbances?
Composite Second Order (CSO)Composite Triple Beat (CTB)Other interfering signals (i.e. Ingress)
220
What is the FCC requirement for Coherent Disturbances?
51dB below the desired carrier level for STD plans and 47dB in IRC and HRC systems
221
The goal of this test is to find the worst beat or interfering signal, regardless of it's type
Coherent Disturbances Test
222
FCC requirement for isolation
18dB
223
Because the FCC allows you to submit manufacturers specifications to prove compliance, you rarely need to perform this test:
Terminal Isolation Test
224
FCC requirement for Hum Modulation
less that 3% of the video carrier level.
225
Where is the Hum Modulation test done?
the end of a 30m or 100' drop
226
how many channels is the Hum Modulation test performed on?
One channel per test point
227
How many channels is the Coherent Disturbance test performed on?
Dependent on highest frequency
228
What are the three Color Performance tests?
Chrominance to Luminance Delay InequalityDifferential GainDifferential Phase
229
FCC Spec for Chrominance to Luminance Delay test
Within 170 nanoseconds
230
FCC Spec for Differential Gain
Within +/-20%
231
FCC Spec for Differential Phase
Within +/-10 degrees
232
Who usually performs the color performance tests?
The Headend Technician
233
How many channels are recommended to be tested during the Color Performance test?
All NTSC or similar channels
234
How often are the Color Performance Test performed?
once every three years
235
Allowable signal leakage level below 54MHz
Up to 15uV/m @ 30m
236
Allowable signal leakage level between 54MHz and 216 MHz
up to 20uV/m @ 3m
237
Allowable signal leakage above 216MHz
up to 15uV/m @30m
238
The two types of leakage monitoring frequency.
Continuous MonitoringQuarterly Monitoring
239
Two types of annual leakage monitoring methods
Ground BasedFlyover
240
What is the minimum cable strand sample allowed during a ground based leakage measurement?
75%
241
What leaks are included in the CLI calculation?
All leaks 50uV or greater
242
what is the elevation that a flyover is completed at? (in meters)
450m(1476')
243
Two requirements for monitoring of plant with a handheld signal leakage detector
-Must be properly calibrated to detect a leak of 20uV/m or greater @ 3m-Perform all measurements with a horizontally polarized dipole antenna, preferably located no more than 3m from the leak and 3m from the ground
244
What does a Spectrum Analyzer Display?
information in the amplitude (vertical) vs. frequency (horizontal) domain over the entire spectrum or portions of it.
245
comparable in certain respects, typically in a way that makes clearer the nature of the things compared.
Analogous
246
This filter has a bell-curved "shape," which it applies to all energy passing through it.
Resolution Bandwidth Filter (RBW)
247
This is a low-pass filter at the analyzer detector's output. This filter takes the RF energy associated with the video modulation on the carrier that has already passed through the RBW filter and the detector and smoothes it out
Video Bandwidth Filter (VBW)(CT 5-3-39)
248
The signal to an analyzer is injected here
RF Input
249
Used when accessing analyzer's gated mode, such as in the C/N POP test
TV Input Connector
250
The main setting and adjustment keys for the analyzer functions and the display. These keys are most often used in the analyzer's manual testing modes
Function Keys
251
Additional keys whose action changes depending on the selected analyzer mode or function. Most often used in the analyzer's automated testing modes
Softkeys
252
The principal keys useed in the analyzer's manual modes of operation. They represent the three most basic functions of any spectrum analyzer
Frequency, Span and Amplitude keys
253
Adjusts the value or amount for the selected function or measurement
Adjustment Knob
254
Adjust value or amount in incremental steps for the selected function or measurement
Step Key
255
Allows direct input of a specific value or amount for the selected function or measurement
Numeric Keypad
256
Sets the type of measurement unit, such as kHz or MHz, for the selected function or measurement
Measurement units' keys
257
Marker function and trace control keys
Access marker functions and set trace control functions such as display line, RBW and VBW
258
Sets analyzer modes, presets and stores or recalls analyzer trace
Mode select Key
259
Maximum input power of HP 8591C
+72dBmV
260
Maximum input power of Tektronix 2715
+69dBmV
261
This must be used when high input levels are required to the analyzer to avoid input overload
preselector
262
For the greatest accuracy, how should the carrier peak be adjusted?
To the analyzer's reference level (top of the display)
263
Three tests that can use gated mode on the HP 8591C
Carrier to NoiseCoherent Disturbances (CSO measurement only)In-Channel Response
264
# Comcast
The topology where signals originate in the headend andare transmitted long distances via trunk cables
Tree and Branch
265
# Comcast
A network architecture that typically uses fiber optic cables to bring signals to selected areas of the system called nodes
Hybrid Fiber-Coax (HFC)
266
# Comcast
Bi-annual tests, performed in the headend and at a number of end-of-line location
FCC Proof-of-Performance
267
# Comcast
The cumulative effect of return path distortions they are added to the signal at various locations in the coaxial portion of the network.
Funnel Effect
268
# Comcast
Specifications standards approved by the FCC in 1953for commercial analog color TV broadcasting.
National Television Standards Committee (NTSC)
269
# Comcast
a portion of the electromagnetic spectrum whose frequencies are well suited for transmitting and receiving Telecommunications signals through the air.
Radio Frequency (RF) Spectrum
270
# Comcast
Signals that flow downstream, from the headend to the network.
Forwards (Downstream) Signals
271
# Comcast
Signals that flow in the upstream direction, from customer to headend
Revers (upstream) Signals
272
# Comcast
Device that separates or combines based on frequency.
Diplex Filter
273
# Comcast
typical cutoff frequency for a sub-split diplex filter
About 50 MHz
274
# Comcast
The three major concerns/ limitations of the tree andbranch architecture are:
BandwidthImpairmentsDependency on Power
275
# Comcast
The lowest possible power level determined by the thermal noise generated within the electrical componentsbeing tested
Noise Floor
276
# Comcast
The highest power level (amplitude) reached by a carrier
Peak
277
# Comcast
A clustering of beats 1.25 MHz above the visual carriers in a CATV network
Composite Second Order (CSO)
278
# Comcast
A form of interference or noise resulting from the mixingof all of the various carriers in a CATV network
Composite Triple Beat (CTB)
279
# Comcast
Two major types of distortions that are typically associated with CATV
Composite Second Order (CSO) and Composite Triple Beat (CTB)
280
# Comcast
The 6 benefits of implementing fiber optics in broadband networks
Enhances Picture QualityIncreased ReliabilityDecreased cost of system maintenanceCost effective system bandwidth upgradesCost means of system upgrade requiring a complete change our of electronicsSmall segmented areas allow greater return path functionality
281
# Comcast
Having or relating to a frequency below the audibility range of the human ear.
Infrasonic
282
# Comcast
A stream of atomic nuclei that enter the earth’s atmosphere from outer space at speeds approaching that of light
Cosmic Rays
283
# Comcast
Frequency range of satellite systems
4GHz to 13GHz
284
# Comcast
The wavelengths most commonly used by the CATVindustry
1310nm and 1550nm
285
# Comcast
The type of fiber optic cable that the broadband industry uses
Single Mode Fiber
286
# Comcast
The process of combining multiple carriers onto a single medium
Multiplexing
287
# Comcast
Width of the Fiber optic core
8-10um
288
# Comcast
Width of the fiber optic cladding
125um
289
# Comcast
Width of the fiber optic coating
250um
290
# Comcast
Combines multiple optical signals in order to amplify them as a group and transported over a single fiber
Wave Division Multiplexing (WDM)
291
# Comcast
Allows multiple wavelengths above and below a centerwavelength to be carried on a single optical fiber.
Dense Wave Division Multiplexing (DWDM)
292
# Comcast
Three parts of the optical link
Fiber Optic CableTransmitter (Laser)Receiver (Node)
293
# Comcast
Individual fibers are bundled and then placed into these to reduce the possibility of damage
Buffer Tubes
294
# Comcast
This diode changes the RF signals to pulsesof light and then transmits them onto an optical fiber
Semiconductor Laser Diode
295
# Comcast
The Three types of optical transmitters that are typically used in broadband HFC Network
Fabry-Perot (F-P)Distributed Feedback (DFB)Yttrium-Aluminum-Garnet (YAG)
296
# Comcast
YAG
Yttrium-Aluminum-Garnet
297
# Comcast
DFB
Distributed Feedback
298
# Comcast
F-P
Fabry-Perot
299
# Comcast
A spare fiber installed during the construction of the network that was reserved for future use.
Dark Fiber
300
# Comcast
Three advantages of trunk reduction
Shorter CascadesFewer/smaller outages due to segmenting the system into smaller areasImproved picture Quality
301
# Comcast
FTTF
Fiber to the Feeder
302
# Comcast
Advantages of FTTF
Shorter CascadesFewer/smaller outages due to segmenting the system intosmaller areas.Increased Bandwidth
303
# Comcast
FTTC
Fiber to the Curb
304
# Comcast
PON
Passive Optical Network
305
# Comcast
Consists of a transmitter at the Headend and a receiver near the subscriber. Requires a power supply near the node but all other actives have been removed
FTTC PON
306
# Comcast
4 advantages of FTTC
No active devices after nodeNo CascadeFewer/smaller outages due to segmenting the system intovery small areasIncreased Bandwidth
307
# Comcast
A fiber-based network which uses passive splitters todeliver signals to multiple locations
Passive Optical Network (PON)
308
# Comcast
FTTH
Fiber to the Home
309
# Comcast
6 advantages of FTTH
Passive networkSingle fiber is dedicated to each subscriberFeatures local battery backup, no large remote power supplies are required.No exterior active devicesNo CascadesIncreased Bandwidth
310
# Comcast
This will ALWAYS be considered the "Backbone" in an HFC Network
The Fiber Network
311
# Comcast
A high-speed line or series of connections that forms a major pathway within a network
Backbone
312
# Comcast
The duplication of certain pieces and/or portions of thenetwork.
Redundancy
313
# Comcast
Comcast's goal for network reliability
"four-nines" or 99.99%
314
# Comcast
A network architecture where nodes, hubs, or headendsmay be connected with fiber optic cables to provideredundancy or increase services
Ring Architecture
315
# Comcast
Builds upon ring technology by adding a second (redundant) ring connecting the nodes to the headend. The second ring typically takes a different path
Ring within a Ring
316
# Comcast
A facility between the headend and the customer that performs many of the functions of a headend
Hubsite
317
# Comcast
Similar in function to a hubsite, but serving fewer customers
Optical Transition Node (OTN)
318
# Comcast
Usually a passive device such as a splitter or directional coupler used to combine radio frequency signals from one source with those from another
RF Combiner
319
# Comcast
Usually a passive device that divides a signal into two equal paths. It may be found on trunk, feeder, or drop cable.
RF Splitter
320
# Comcast
Device used to combine the channels for entry onto the cable or fiber optic transmitter
Headend Combiner
321
# Comcast
The difference, in dB, of a signal level, injected into one output port, and the measured level of that same signal on another output port, with the input port properly terminated.
Port-to-port isolation
322
# Comcast
Obtained by measuring the attenuation between the two output ports (A and B) when the common port (input port) is terminated in the correct value of impedance. An RF generator signal is applied to port A and an RF voltmeter reading is taken at Port B.
Isolation
323
# Comcast
Provision for connection to a device such as a tap, splitter, set-top box or computer
Port
324
# Comcast
Used to combine all of the signals to be carried over the cable system into a single medium (cable) for routing to the laser transmitters that are feeding the optical nodes in the system
Headend Combining Network
325
# Comcast
A measurement of the reflected signal compared to that of the incident signal
Return Loss
326
# Comcast
Device used to divide or combine light carriers on fiber optic cables.
Optical Splitter
327
# Comcast
A discontinuous signal whose various states are discrete intervals apart.
Digital Signal
328
# Comcast
Device used to convert an analog signal to a digital signal.
Digitizer
329
# Comcast
takes an amplitude measurement of the waveform at fixed intervals of time, and converts them to a binary number
Digitizer
330
# Comcast
The smallest unit of computerized data. Bits are defined as single characters of 0 or 1. Bandwidth is usually measured in bits-persecond.
Binary Digit (Bit)
331
# Comcast
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.
Byte
332
# Comcast
The number of changed states that can occur per second.
Baud
333
# Comcast
The value of "On" in a binary system
"1"
334
# Comcast
The value of "Off" in a Binary system
"0"
335
# Comcast
How many bits are in a "Nibble"?
4
336
# Comcast
In ASCII #5 alphabet, how man bits are in a byte?
7
337
# Comcast
If start and stop bits are included with Asynchronous Communications, then how many bits are in a byte?
10
338
# Comcast
ADC
Analog to Digital Conversion
339
# Comcast
DAC
Digital to Analog Conversion
340
# Comcast
A continuously varying signal with an unlimited number of possible values of amplitude and frequency.
Analog Signal
341
# Comcast
a non-continuous signal or carrier that changes its output in discreetly timed steps of voltage level and/or phase that can represent numerical values or other information
Digital Transmission
342
# Comcast
3 steps of basic ADC
SamplingQuantizationEncoding
343
# Comcast
The "Measuring" of the analog signal at specific intervals.
Sampling
344
# Comcast
The assigning of a specific value to each of the samples
Quantization
345
# Comcast
The process by which Quantized values are converted into a data or bit stream
Encoding
346
# Comcast
ASK
Amplitude Shift Keying
347
# Comcast
FSK
Frequency Shift Keying
348
# Comcast
QPSK
Quadrature Phase Shift Keying
349
# Comcast
QAM
Quadrature Amplitude Modulation
350
# Comcast
The process of varying the amplitude, frequency, or phase of a carrier to be in step with the instantaneous value of the modulating waveform
Modulation
351
# Comcast
Data transmission scheme wherein the carrier is shifted in amplitude
Amplitude Shift Keying (ASK)
352
# Comcast
The carrier frequency is shifted to represent the difference between a one and a zero
Frequency Shift Keying (FSK)
353
# Comcast
The position on a waveform cycle at a specific point in time. One cycle is defined as 360 degrees of this
Phase
354
# Comcast
Digital modulation scheme wherein the carrier is shifted in 90 degree steps. There are four possible phase states and the magnitude is constant.
Quadrature Phase Shift Keying (QPSK)
355
# Comcast
BPSK
BiPhase Shift Keying
356
# Comcast
In QPSK, what does "I" stand for?
In-Phase
357
# Comcast
In QPSK, what does "Q" Stand for?
Quadrature - shifted 90* or one quarter of a cycle
358
# Comcast
A graphic depiction of the four phase states of a Quadrature Phase Shift Key signal.
Constellation Diagram
359
# Comcast
What is the bandwidth of QPSK in a 6MHz bandwidth?
10 Mb/s
360
# Comcast
Digital modulation scheme that changes the phase and the amplitude.
Quadrature Amplitude Modulation (QAM)
361
# Comcast
a digital transmission technology that splits the frequency band into a number of channels. The channels are each assigned a specific time slot, so that several transmissions can share a single channel without interfering with one another
Time Division Multiple Access (TDMA)
362
# Comcast
The digital equivalent to Signal-to-Noise
Modulation Error Ratio (MER)
363
# Comcast
A joined or connected group of devices
Network
364
# Comcast
A network of computers linked by cable within a building or office complex.
Local Area Network (LAN)
365
# Comcast
A network of multiple locations linked by cable withina city or campus
Metropolitan Area Network (MAN)
366
# Comcast
A network typically bigger than a city or metropolitan area.
Wide Area Network (WAN)
367
# Comcast
A data network connects each of its endpoints to the network with a single link. A central device (hub) is used to aggregate and distribute data traffic to all endpoints and/or other central points in what’s referred to as a clustered star.
Star
368
# Comcast
Consists of several star networks that have been linked together
Clustered Star
369
# Comcast
Topology where workstations are connected to the network through a common path
Bus
370
# Comcast
A topology in which a data frame is passed around. As it arrives at an endpoint, the endpoint can either pass it along to the next endpoint or attach information to be sent to a destination
Token Ring
371
# Comcast
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
Ring
372
# Comcast
A method of data transmission that allows characters to be sent at irregular intervals by preceding each character with a 0 and by ending each character with a 1. This is referred to as start (0) and stop bits (1). It is the method, which most PCs use to communicate with each other and mainframes
Asynchronous Transmission
373
# Comcast
An extra bit added to help check if the data that isbeing transferred is correct
Parity Bit
374
# Comcast
The condition that occurs when two events happen in a specific time relationship with each other and both are under control of a master clock. Characters are spaced by time, not by start and stop bits.
Synchronous Transmission
375
# Comcast
Synchronizing bits used in synchronous transmission to maintain synchronization between transmitter and receiver.
Sync Bits
376
# Comcast
SNMP
Simple Network Management Protocol (SNMP)
377
# Comcast
NE
Network Elements
378
# Comcast
MIB
Management Information Base
379
# Comcast
A unique number assigned to a piece of equipmentused for identification purposes.
Media Access Control Address (MAC)
380
# Comcast
UTP
Unshielded Twisted Pair
381
# Comcast
signaling rate of 10BaseT
10 Mb/s
382
# Comcast
Signaling rate of 100BaseT
100 Mb/s
383
# Comcast
The designation for Ethernet over fiber optic cable, primarily for point-topoint links
10Base-F
384
# Comcast
Ethernet resides in what layers of the OSI model?
The 2 lowest levels (layers)
385
# Comcast
This device works as a multiport signal repeater, broadcasting an incoming signal to all other ports on an ethernet network
Ethernet Hub
386
# Comcast
The four-part numeric address that is assigned to a computer or an account as an identification tool
Internet Protocol Address (IP)
387
# Comcast
IEEE MAC Protocol for Hybrid Fiber-Coax Networks; standard for data communicatons over a cable network
802.14
388
# Comcast
The Four original partners of MCNS (Multimedia Cable Network Partners Ltd.)
Comcast, Cox, TCI and Time Warner
389
# Comcast
The three companies that joined MCNS in late 1996
Media One, Rogers Cablevision and CableLabs
390
# Comcast
DOCSIS
Data Over Cable Service Interface Specification
391
# Comcast
When was DOCSIS 1.0 released? (Month & Year)
Mar-97
392
# Comcast
The Leading standard for cable modems
DOCSIS
393
# Comcast
Four devices that must be added to a system to offer high-speed internet
CMTS (Cable Modem Termination System)CM (Cable Modem)ServersNoise Filters
394
# Comcast
A unit consisting of various hardware and software entities that acts as the hand-off point between the RF based HFC network and other networks such as theInternet and the PSTN.
CMTS (Cable Modem Termination System)
395
# Comcast
Used to terminate, manage and translate high-speed Internet sessions between cable modems in a LAN and other devices in a WAN.
CMTS (Cable Modem Termination System)
396
# Comcast
The collection of computers accessed through the Internet. Uses a hypertext based system for finding andaccessing its resources.
WWW (World Wide Web)
397
# Comcast
Four Items that a CMTS manages
Time SlotsContention SlotsModem DataTransmit Levels
398
# Comcast
Each cable modem is assigned one of these by the CMTS and only one modem is allowed to transmit during this.
Time Slot
399
# Comcast
These slots are usually used for short data transmissions such as a request for an additional number of reserved time slots
Contention Slots
400
# Comcast
The signal level that the CMTS wants to "See"
0dBmV
401
# Comcast
A PC on a LAN from which information or applications are requested.
Client/Server
402
# Comcast
A computer circuit board (card) installed in a computer so that the computer can be connected to a network. Provide a dedicated, full-time connection to a network.
NIC (Network Interface Card)
403
# Comcast
Why is it called a cable "Modem"?
When they transmit data they "MOdulate" the data onto a carrier, then receive data and "DEModulate" it from the carrier and send it on to the computer
404
# Comcast
Four of the most common servers found in a braodband network
DHCPTODTFTPProxy
405
# Comcast
This server sets up the MAC and IP addresses for the cable modem.
DHCP Server(Dynamic Host Configuration Protocol)
406
# Comcast
This server sets up a common clock between the CM and the CMTS
TOD Server(Time of Day)
407
# Comcast
This server allows non-protected file transfers, such as aconfiguration file for a modem.
TFTP Server(Trivial File Transfer Protocol)
408
# Comcast
These servers store commonly used (or contractually stored) data. A network may have a series of these servers located in different places.
Proxy Server
409
# Comcast
The two types of noise filters
High Pass FilterNotch Filter
410
# Comcast
These types of filters only allow signals above 50MHz to pass through the filter
High Pass Filter
411
# Comcast
In addition to letting everything above 50 MHz to pass, this filter allows a small spectrum below 50 MHz to pass
Notch Filter
412
# Comcast
The process of setting up the connection between theCMTS and the cable modem, where transmit levels andfrequency are determined.
Ranged
413
# Comcast
A switch or collection of switches connecting multiple networks
POP (Point of Presence)
414
# Comcast
The point of access into theInternet.
NAP(Network Access Point)
415
# Comcast
The company who provides access to the Internet and the World Wide Web, who usually also provides corefeatures such as e-mail.
ISPInternet Service Provider
416
# Comcast
The local, long-distance and internationalphone system in use today
PSTN(Public Switched Telephone Network)
417
# Comcast
This device in the Headend controls the operation of CDV.
HDT(Host Digital Terminal)
418
# Comcast
Three major components of the Host Digital Terminal
Access Bandwidth Manager ShelfModem ShelfSpectrum Manager Shelf
419
# Comcast
This Shelf provides the connection between the Network Interface Unit (NIU) and the switch, or more simply, the connection between the HDT and the LEC
ABM(Access Bandwidth Manager)
420
# Comcast
The point of demarcation between the network and the customer. It contains the modem necessary for telephony over a cable network.
NIU(Network Interface Device)
421
# Comcast
The device that opens or breaks the circuit path in a telephone call. This device looks at the incoming data to determine where the data should get routed.
Switch
422
# Comcast
The local phone company is also known as what?
LEC(Local Exchange Carrier
423
# Comcast
Shelf on the HDT (Host Digital Terminal) that converts the digital telephone signals into digital signals that are then modulated onto an RF carrier to be transmitted over the HFC Network.
Modem Shelf
424
# Comcast
This shelf on the HDT (Host Digital Terminal) monitors the RF spectrum allocated for telephone services over the HFC network. If problems are detected, it can switch the data transmission (telephone call) to another frequency.
Spectrum Manager
425
# Comcast
How many subscriber telephone lines can an NIU Handle?
4
426
# Comcast
LPSU
Local Power Supply Unit
427
# Comcast
The process of setting up the connection between the HDT and the NIU, where transmit levels and frequency are determined.
Marshalled
428
# Comcast
Modulating technique that interweaves multiple conversations, based on time.
TDMA(Time Division Multiple Access)
429
# Comcast
The number of the person that youare trying to call.
Terminating Number
430
# Comcast
The phone company of the person you are trying to call.
Terminating LEC
431
# Comcast
The “local” phone office where the subscriber’s lines are connected to the switching equipment.
Central Office
432
# Comcast
What is "7" equal to in binary?
111
433
# Comcast
64 QAM has how many phase angles?
52
434
# Comcast
16 QAM has how many phase angles?
10
435
# Comcast
The distance between two points of like phasein a wave.
Wavelength
436
# Comcast
A card made up of material similar to photographic film that changes colors when exposed to light.
Photosensitive Card
437
# Comcast
ANSI Laser standard that separates lasers into various classes that take into consideration the operating wavelength, output power level and whether the laser operates as a continuous or pulsed light output
Z-136
438
# Comcast
Four nines works out to how many minutes of down time per month?
4.5 minutes
439
# Comcast
loss of service to ourcustomers due to a fault in thedelivery network.
Outage
440
# Comcast
Minimum telephone service to assure a contact in case of an emergency.
Lifeline
441
# Comcast
FCC Standards CFR 47, Part 76.605(a)(1-12)
Proof-of-performance (POP) test
442
# Comcast
A continuous wave (CW) frequency onto which information is modulated for transport.
Carrier Frequency
443
# Comcast
Maximum Bandwidth of 256QAM
42.88Mbps
444
# Comcast
How long must POP tests be kept at the local office?
minimum of 5 years
445
# Comcast
how many test points are required for 1,000 to 12,500 customers?
6
446
# Comcast
How many test points are required for each additional 12,500 customers?
1
447
# Comcast
Channel requirements for POP testing (amount)
4 channels plus one additional channel for every 100 MHz.
448
# Comcast
In a cable system with an upper frequency at 750 MHz, how many test channels must be used?
11 Channels
449
# Comcast
All channels must be tested during these 3 tests.
Video Carrier Level, Audio Carrier Level, Video Carrier Level Stability Test
450
# Comcast
Only one Channel needs to be tested during this non-frequency specific test
Hum Modulation
451
# Comcast
How many digital channels must be tested on an all digital system with an upper frequency of 862MHz?
0, digital channels are not included and are not tested.
452
# Comcast
The amount of channels during these tests are based solely on the highest operating frequency
Video-Audio Carrier Frequency SeparationIn-Channel ResponseCarrier to NoiseCoherent Disturbances Tests
453
# Comcast
This test must be performed twice a year, once during the coldest months and again during the warmest (Jan-Feb and Jul-Aug respectively)
Video Carrier Level Stability (24-hour) test
454
# Comcast
This POP test must be performed every three years
Color Performance test
455
# Comcast
A circuit that automaticallyadjusts the gain of an amplifier sothat the output signal levels stayconstant despite varying inputlevels.
Automatic Gain Control (AGC)
456
# Comcast
a spectrumanalyzer feature that allows theuser to make otherwise intrusiveFCC POP tests in a non-intrusivemanner.
Gated Testing
457
# Comcast
When planning POP tests, these four things need to be considered
Test timesChannels and programming affected by testingTest lengthsAbility to perform non-intrusive gated testing
458
# Comcast
This test is usually performed by a Headend tech rather than a System Tech
Color Performance
459
# Comcast
What would a Discrepancy statement include?
Explain all possible misinterpreted fails, such as test point relocation, added channels, encoding issues and so on.
460
# Comcast
POP measurements are to be taken at what location?
Input to the subscriber terminal
461
# Comcast
EIA
Electronic Industry Association
462
# Comcast
What must an operator do in order to pass the receivability test?
Submit documentation showing that their channel lineup conforms to the EIA Channel allocation plan
463
# Comcast
What does the Audio Carrier Frequency Test ensure
That the audio carrier frequency for each channel must be 4.5MHz above the video carrier frequency, +/- 5kHz
464
# Comcast
Where is the Audio Carrier Frequency test performed at?
The Headend as well as the field test points
465
# Comcast
How many times a year is the Audio Carrier Frequency test performed?
Twice annually
466
# Comcast
What type of set-top box can alter the Audio Carrier Frequency?
Baseband set-top boxes (as opposed to non-baseband)
467
# Comcast
What six measurements are taken during the 24-hour test?
Minimum Visual Signal LevelVisual Signal changeAdjacent Visual SignalAny Other Visual Signal in BandwidthVisual Carrier LevelAudio Carrier Level
468
# Comcast
The six measurements that are taken during the 24-hour test are performed on what channels?
All NTSC Channels at each test point location
469
# Comcast
What is the Minimum Visual Signal Level allowed at the end of a 30-meter (100') cable drop that is connected to the subscriber tap?
1.41mV across an internal impedance of 75 ohms (+3dBmV(CT 5-3-22)
470
# Comcast
The square root of the sum ofthe squares of the amplitudes ofindividual components of afunction, such as the frequencycomponents of a signal.
Root Mean Square (RMS)
471
# Comcast
Maximum variation of each channel within any six-month period at the end of a 30-meter drop cable
8dB
472
# Comcast
Adjacent Visual Signal deviation of the visual signal level of any visual carrier within a 6MHz nominal frequency separation
3dB
473
# Comcast
What is the maximum "spread" or deviation among ALL channel levels in a 300MHz cable system and what is the incremental increase
10dB1db per 100MHz
474
# Comcast
At what level must the aural signal be maintained in association with the visual signal level?
between 10dB and 17dB below the visual signal level
475
# Comcast
At what level must the aural signal be maintained in association with the visual signal level on a baseband converter.
between 6.5dB and 17dB below the visual signal level.
476
# Comcast
In a 24-hour test, how many times must the signal level be checked?
four times
477
# Comcast
What are the time intervals of the 24-hour test?
5 to 7 hours
478
# Comcast
at what frequency is the In-Channel Response test performed?
.75MHz to 5Mhz above the lower frequency boundary of the cable channel under test
479
# Comcast
What is the FCC In-Channel Response requirement?
+/-2dB or 4dB peak-to-valley
480
# Comcast
To perform this test, a signal must be inserted on the channel, either by the headend technician or by other means
In-Channel Response Test
481
# Comcast
FCC Requirement for C/N
43dB at each test point
482
# Comcast
What are the three type of coherent disturbances?
Composite Second Order (CSO)Composite Triple Beat (CTB)Other interfering signals (i.e. Ingress)
483
# Comcast
What is the FCC requirement for Coherent Disturbances?
51dB below the desired carrier level for STD plans and 47dB in IRC and HRC systems
484
# Comcast
The goal of this test is to find the worst beat or interfering signal, regardless of it's type
Coherent Disturbances Test
485
# Comcast
FCC requirement for isolation
18dB
486
# Comcast
Because the FCC allows you to submit manufacturers specifications to prove compliance, you rarely need to perform this test:
Terminal Isolation Test
487
# Comcast
FCC requirement for Hum Modulation
less that 3% of the video carrier level.
488
# Comcast
Where is the Hum Modulation test done?
the end of a 30m or 100' drop
489
# Comcast
how many channels is the Hum Modulation test performed on?
One channel per test point
490
# Comcast
How many channels is the Coherent Disturbance test performed on?
Dependent on highest frequency
491
# Comcast
What are the three Color Performance tests?
Chrominance to Luminance Delay InequalityDifferential GainDifferential Phase
492
# Comcast
FCC Spec for Chrominance to Luminance Delay test
Within 170 nanoseconds
493
# Comcast
FCC Spec for Differential Gain
Within +/-20%
494
# Comcast
FCC Spec for Differential Phase
Within +/-10 degrees
495
# Comcast
Who usually performs the color performance tests?
The Headend Technician
496
# Comcast
How many channels are recommended to be tested during the Color Performance test?
All NTSC or similar channels
497
# Comcast
How often are the Color Performance Test performed?
once every three years
498
# Comcast
Allowable signal leakage level below 54MHz
Up to 15uV/m @ 30m
499
# Comcast
Allowable signal leakage level between 54MHz and 216 MHz
up to 20uV/m @ 3m
500
# Comcast
Allowable signal leakage above 216MHz
up to 15uV/m @30m
501
# Comcast
The two types of leakage monitoring frequency.
Continuous MonitoringQuarterly Monitoring
502
# Comcast
Two types of annual leakage monitoring methods
Ground BasedFlyover
503
# Comcast
What is the minimum cable strand sample allowed during a ground based leakage measurement?
75%
504
# Comcast
What leaks are included in the CLI calculation?
All leaks 50uV or greater
505
# Comcast
what is the elevation that a flyover is completed at? (in meters)
450m(1476')
506
# Comcast
Two requirements for monitoring of plant with a handheld signal leakage detector
-Must be properly calibrated to detect a leak of 20uV/m or greater @ 3m-Perform all measurements with a horizontally polarized dipole antenna, preferably located no more than 3m from the leak and 3m from the ground
507
# Comcast
What does a Spectrum Analyzer Display?
information in the amplitude (vertical) vs. frequency (horizontal) domain over the entire spectrum or portions of it.
508
# Comcast
comparable in certain respects, typically in a way that makes clearer the nature of the things compared.
Analogous
509
# Comcast
This filter has a bell-curved "shape," which it applies to all energy passing through it.
Resolution Bandwidth Filter (RBW)
510
# Comcast
This is a low-pass filter at the analyzer detector's output. This filter takes the RF energy associated with the video modulation on the carrier that has already passed through the RBW filter and the detector and smoothes it out
Video Bandwidth Filter (VBW)(CT 5-3-39)
511
# Comcast
The signal to an analyzer is injected here
RF Input
512
# Comcast
Used when accessing analyzer's gated mode, such as in the C/N POP test
TV Input Connector
513
# Comcast
The main setting and adjustment keys for the analyzer functions and the display. These keys are most often used in the analyzer's manual testing modes
Function Keys
514
# Comcast
Additional keys whose action changes depending on the selected analyzer mode or function. Most often used in the analyzer's automated testing modes
Softkeys
515
# Comcast
The principal keys useed in the analyzer's manual modes of operation. They represent the three most basic functions of any spectrum analyzer
Frequency, Span and Amplitude keys
516
# Comcast
Adjusts the value or amount for the selected function or measurement
Adjustment Knob
517
# Comcast
Adjust value or amount in incremental steps for the selected function or measurement
Step Key
518
# Comcast
Allows direct input of a specific value or amount for the selected function or measurement
Numeric Keypad
519
# Comcast
Sets the type of measurement unit, such as kHz or MHz, for the selected function or measurement
Measurement units' keys
520
# Comcast
Marker function and trace control keys
Access marker functions and set trace control functions such as display line, RBW and VBW
521
# Comcast
Sets analyzer modes, presets and stores or recalls analyzer trace
Mode select Key
522
# Comcast
Maximum input power of HP 8591C
+72dBmV
523
# Comcast
Maximum input power of Tektronix 2715
+69dBmV
524
# Comcast
This must be used when high input levels are required to the analyzer to avoid input overload
preselector
525
# Comcast
For the greatest accuracy, how should the carrier peak be adjusted?
To the analyzer's reference level (top of the display)
526
# Comcast
Three tests that can use gated mode on the HP 8591C
Carrier to NoiseCoherent Disturbances (CSO measurement only)In-Channel Response
527
# Comcast
The topology where signals originate in the headend andare transmitted long distances via trunk cables
Tree and Branch
528
# Comcast
A network architecture that typically uses fiber optic cables to bring signals to selected areas of the system called nodes
Hybrid Fiber-Coax (HFC)
529
# Comcast
Bi-annual tests, performed in the headend and at a number of end-of-line location
FCC Proof-of-Performance
530
# Comcast
The cumulative effect of return path distortions they are added to the signal at various locations in the coaxial portion of the network.
Funnel Effect
531
# Comcast
Specifications standards approved by the FCC in 1953for commercial analog color TV broadcasting.
National Television Standards Committee (NTSC)
532
# Comcast
a portion of the electromagnetic spectrum whose frequencies are well suited for transmitting and receiving Telecommunications signals through the air.
Radio Frequency (RF) Spectrum
533
# Comcast
Signals that flow downstream, from the headend to the network.
Forwards (Downstream) Signals
534
# Comcast
Signals that flow in the upstream direction, from customer to headend
Revers (upstream) Signals
535
# Comcast
Device that separates or combines based on frequency.
Diplex Filter
536
# Comcast
typical cutoff frequency for a sub-split diplex filter
About 50 MHz
537
# Comcast
The three major concerns/ limitations of the tree andbranch architecture are:
BandwidthImpairmentsDependency on Power
538
# Comcast
The lowest possible power level determined by the thermal noise generated within the electrical componentsbeing tested
Noise Floor
539
# Comcast
The highest power level (amplitude) reached by a carrier
Peak
540
# Comcast
A clustering of beats 1.25 MHz above the visual carriers in a CATV network
Composite Second Order (CSO)
541
# Comcast
A form of interference or noise resulting from the mixingof all of the various carriers in a CATV network
Composite Triple Beat (CTB)
542
# Comcast
Two major types of distortions that are typically associated with CATV
Composite Second Order (CSO) and Composite Triple Beat (CTB)
543
# Comcast
The 6 benefits of implementing fiber optics in broadband networks
Enhances Picture QualityIncreased ReliabilityDecreased cost of system maintenanceCost effective system bandwidth upgradesCost means of system upgrade requiring a complete change our of electronicsSmall segmented areas allow greater return path functionality
544
# Comcast
Having or relating to a frequency below the audibility range of the human ear.
Infrasonic
545
# Comcast
A stream of atomic nuclei that enter the earth’s atmosphere from outer space at speeds approaching that of light
Cosmic Rays
546
# Comcast
Frequency range of satellite systems
4GHz to 13GHz
547
# Comcast
The wavelengths most commonly used by the CATVindustry
1310nm and 1550nm
548
# Comcast
The type of fiber optic cable that the broadband industry uses
Single Mode Fiber
549
# Comcast
The process of combining multiple carriers onto a single medium
Multiplexing
550
# Comcast
Width of the Fiber optic core
8-10um
551
# Comcast
Width of the fiber optic cladding
125um
552
# Comcast
Width of the fiber optic coating
250um
553
# Comcast
Combines multiple optical signals in order to amplify them as a group and transported over a single fiber
Wave Division Multiplexing (WDM)
554
# Comcast
Allows multiple wavelengths above and below a centerwavelength to be carried on a single optical fiber.
Dense Wave Division Multiplexing (DWDM)
555
# Comcast
Three parts of the optical link
Fiber Optic CableTransmitter (Laser)Receiver (Node)
556
# Comcast
Individual fibers are bundled and then placed into these to reduce the possibility of damage
Buffer Tubes
557
# Comcast
This diode changes the RF signals to pulsesof light and then transmits them onto an optical fiber
Semiconductor Laser Diode
558
# Comcast
The Three types of optical transmitters that are typically used in broadband HFC Network
Fabry-Perot (F-P)Distributed Feedback (DFB)Yttrium-Aluminum-Garnet (YAG)
559
# Comcast
YAG
Yttrium-Aluminum-Garnet
560
# Comcast
DFB
Distributed Feedback
561
# Comcast
F-P
Fabry-Perot
562
# Comcast
A spare fiber installed during the construction of the network that was reserved for future use.
Dark Fiber
563
# Comcast
Three advantages of trunk reduction
Shorter CascadesFewer/smaller outages due to segmenting the system into smaller areasImproved picture Quality
564
# Comcast
FTTF
Fiber to the Feeder
565
# Comcast
Advantages of FTTF
Shorter CascadesFewer/smaller outages due to segmenting the system intosmaller areas.Increased Bandwidth
566
# Comcast
FTTC
Fiber to the Curb
567
# Comcast
PON
Passive Optical Network
568
# Comcast
Consists of a transmitter at the Headend and a receiver near the subscriber. Requires a power supply near the node but all other actives have been removed
FTTC PON
569
# Comcast
4 advantages of FTTC
No active devices after nodeNo CascadeFewer/smaller outages due to segmenting the system intovery small areasIncreased Bandwidth
570
# Comcast
A fiber-based network which uses passive splitters todeliver signals to multiple locations
Passive Optical Network (PON)
571
# Comcast
FTTH
Fiber to the Home
572
# Comcast
6 advantages of FTTH
Passive networkSingle fiber is dedicated to each subscriberFeatures local battery backup, no large remote power supplies are required.No exterior active devicesNo CascadesIncreased Bandwidth
573
# Comcast
This will ALWAYS be considered the "Backbone" in an HFC Network
The Fiber Network
574
# Comcast
A high-speed line or series of connections that forms a major pathway within a network
Backbone
575
# Comcast
The duplication of certain pieces and/or portions of thenetwork.
Redundancy
576
# Comcast
Comcast's goal for network reliability
"four-nines" or 99.99%
577
# Comcast
A network architecture where nodes, hubs, or headendsmay be connected with fiber optic cables to provideredundancy or increase services
Ring Architecture
578
# Comcast
Builds upon ring technology by adding a second (redundant) ring connecting the nodes to the headend. The second ring typically takes a different path
Ring within a Ring
579
# Comcast
A facility between the headend and the customer that performs many of the functions of a headend
Hubsite
580
# Comcast
Similar in function to a hubsite, but serving fewer customers
Optical Transition Node (OTN)
581
# Comcast
Usually a passive device such as a splitter or directional coupler used to combine radio frequency signals from one source with those from another
RF Combiner
582
# Comcast
Usually a passive device that divides a signal into two equal paths. It may be found on trunk, feeder, or drop cable.
RF Splitter
583
# Comcast
Device used to combine the channels for entry onto the cable or fiber optic transmitter
Headend Combiner
584
# Comcast
The difference, in dB, of a signal level, injected into one output port, and the measured level of that same signal on another output port, with the input port properly terminated.
Port-to-port isolation
585
# Comcast
Obtained by measuring the attenuation between the two output ports (A and B) when the common port (input port) is terminated in the correct value of impedance. An RF generator signal is applied to port A and an RF voltmeter reading is taken at Port B.
Isolation
586
# Comcast
Provision for connection to a device such as a tap, splitter, set-top box or computer
Port
587
# Comcast
Used to combine all of the signals to be carried over the cable system into a single medium (cable) for routing to the laser transmitters that are feeding the optical nodes in the system
Headend Combining Network
588
# Comcast
A measurement of the reflected signal compared to that of the incident signal
Return Loss
589
# Comcast
Device used to divide or combine light carriers on fiber optic cables.
Optical Splitter
590
# Comcast
A discontinuous signal whose various states are discrete intervals apart.
Digital Signal
591
# Comcast
Device used to convert an analog signal to a digital signal.
Digitizer
592
# Comcast
takes an amplitude measurement of the waveform at fixed intervals of time, and converts them to a binary number
Digitizer
593
# Comcast
The smallest unit of computerized data. Bits are defined as single characters of 0 or 1. Bandwidth is usually measured in bits-persecond.
Binary Digit (Bit)
594
# Comcast
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.
Byte
595
# Comcast
The number of changed states that can occur per second.
Baud
596
# Comcast
The value of "On" in a binary system
"1"
597
# Comcast
The value of "Off" in a Binary system
"0"
598
# Comcast
How many bits are in a "Nibble"?
4
599
# Comcast
In ASCII #5 alphabet, how man bits are in a byte?
7
600
# Comcast
If start and stop bits are included with Asynchronous Communications, then how many bits are in a byte?
10
601
# Comcast
ADC
Analog to Digital Conversion
602
# Comcast
DAC
Digital to Analog Conversion
603
# Comcast
A continuously varying signal with an unlimited number of possible values of amplitude and frequency.
Analog Signal
604
# Comcast
a non-continuous signal or carrier that changes its output in discreetly timed steps of voltage level and/or phase that can represent numerical values or other information
Digital Transmission
605
# Comcast
3 steps of basic ADC
SamplingQuantizationEncoding
606
# Comcast
The "Measuring" of the analog signal at specific intervals.
Sampling
607
# Comcast
The assigning of a specific value to each of the samples
Quantization
608
# Comcast
The process by which Quantized values are converted into a data or bit stream
Encoding
609
# Comcast
ASK
Amplitude Shift Keying
610
# Comcast
FSK
Frequency Shift Keying
611
# Comcast
QPSK
Quadrature Phase Shift Keying
612
# Comcast
QAM
Quadrature Amplitude Modulation
613
# Comcast
The process of varying the amplitude, frequency, or phase of a carrier to be in step with the instantaneous value of the modulating waveform
Modulation
614
# Comcast
Data transmission scheme wherein the carrier is shifted in amplitude
Amplitude Shift Keying (ASK)
615
# Comcast
The carrier frequency is shifted to represent the difference between a one and a zero
Frequency Shift Keying (FSK)
616
# Comcast
The position on a waveform cycle at a specific point in time. One cycle is defined as 360 degrees of this
Phase
617
# Comcast
Digital modulation scheme wherein the carrier is shifted in 90 degree steps. There are four possible phase states and the magnitude is constant.
Quadrature Phase Shift Keying (QPSK)
618
# Comcast
BPSK
BiPhase Shift Keying
619
# Comcast
In QPSK, what does "I" stand for?
In-Phase
620
# Comcast
In QPSK, what does "Q" Stand for?
Quadrature - shifted 90* or one quarter of a cycle
621
# Comcast
A graphic depiction of the four phase states of a Quadrature Phase Shift Key signal.
Constellation Diagram
622
# Comcast
What is the bandwidth of QPSK in a 6MHz bandwidth?
10 Mb/s
623
# Comcast
Digital modulation scheme that changes the phase and the amplitude.
Quadrature Amplitude Modulation (QAM)
624
# Comcast
a digital transmission technology that splits the frequency band into a number of channels. The channels are each assigned a specific time slot, so that several transmissions can share a single channel without interfering with one another
Time Division Multiple Access (TDMA)
625
# Comcast
The digital equivalent to Signal-to-Noise
Modulation Error Ratio (MER)
626
# Comcast
A joined or connected group of devices
Network
627
# Comcast
A network of computers linked by cable within a building or office complex.
Local Area Network (LAN)
628
# Comcast
A network of multiple locations linked by cable withina city or campus
Metropolitan Area Network (MAN)
629
# Comcast
A network typically bigger than a city or metropolitan area.
Wide Area Network (WAN)
630
# Comcast
A data network connects each of its endpoints to the network with a single link. A central device (hub) is used to aggregate and distribute data traffic to all endpoints and/or other central points in what’s referred to as a clustered star.
Star
631
# Comcast
Consists of several star networks that have been linked together
Clustered Star
632
# Comcast
Topology where workstations are connected to the network through a common path
Bus
633
# Comcast
A topology in which a data frame is passed around. As it arrives at an endpoint, the endpoint can either pass it along to the next endpoint or attach information to be sent to a destination
Token Ring
634
# Comcast
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
Ring
635
# Comcast
A method of data transmission that allows characters to be sent at irregular intervals by preceding each character with a 0 and by ending each character with a 1. This is referred to as start (0) and stop bits (1). It is the method, which most PCs use to communicate with each other and mainframes
Asynchronous Transmission
636
# Comcast
An extra bit added to help check if the data that isbeing transferred is correct
Parity Bit
637
# Comcast
The condition that occurs when two events happen in a specific time relationship with each other and both are under control of a master clock. Characters are spaced by time, not by start and stop bits.
Synchronous Transmission
638
# Comcast
Synchronizing bits used in synchronous transmission to maintain synchronization between transmitter and receiver.
Sync Bits
639
# Comcast
SNMP
Simple Network Management Protocol (SNMP)
640
# Comcast
NE
Network Elements
641
# Comcast
MIB
Management Information Base
642
# Comcast
A unique number assigned to a piece of equipmentused for identification purposes.
Media Access Control Address (MAC)
643
# Comcast
UTP
Unshielded Twisted Pair
644
# Comcast
signaling rate of 10BaseT
10 Mb/s
645
# Comcast
Signaling rate of 100BaseT
100 Mb/s
646
# Comcast
The designation for Ethernet over fiber optic cable, primarily for point-topoint links
10Base-F
647
# Comcast
Ethernet resides in what layers of the OSI model?
The 2 lowest levels (layers)
648
# Comcast
This device works as a multiport signal repeater, broadcasting an incoming signal to all other ports on an ethernet network
Ethernet Hub
649
# Comcast
The four-part numeric address that is assigned to a computer or an account as an identification tool
Internet Protocol Address (IP)
650
# Comcast
IEEE MAC Protocol for Hybrid Fiber-Coax Networks; standard for data communicatons over a cable network
802.14
651
# Comcast
The Four original partners of MCNS (Multimedia Cable Network Partners Ltd.)
Comcast, Cox, TCI and Time Warner
652
# Comcast
The three companies that joined MCNS in late 1996
Media One, Rogers Cablevision and CableLabs
653
# Comcast
DOCSIS
Data Over Cable Service Interface Specification
654
# Comcast
When was DOCSIS 1.0 released? (Month & Year)
Mar-97
655
# Comcast
The Leading standard for cable modems
DOCSIS
656
# Comcast
Four devices that must be added to a system to offer high-speed internet
CMTS (Cable Modem Termination System)CM (Cable Modem)ServersNoise Filters
657
# Comcast
A unit consisting of various hardware and software entities that acts as the hand-off point between the RF based HFC network and other networks such as theInternet and the PSTN.
CMTS (Cable Modem Termination System)
658
# Comcast
Used to terminate, manage and translate high-speed Internet sessions between cable modems in a LAN and other devices in a WAN.
CMTS (Cable Modem Termination System)
659
# Comcast
The collection of computers accessed through the Internet. Uses a hypertext based system for finding andaccessing its resources.
WWW (World Wide Web)
660
# Comcast
Four Items that a CMTS manages
Time SlotsContention SlotsModem DataTransmit Levels
661
# Comcast
Each cable modem is assigned one of these by the CMTS and only one modem is allowed to transmit during this.
Time Slot
662
# Comcast
These slots are usually used for short data transmissions such as a request for an additional number of reserved time slots
Contention Slots
663
# Comcast
The signal level that the CMTS wants to "See"
0dBmV
664
# Comcast
A PC on a LAN from which information or applications are requested.
Client/Server
665
# Comcast
A computer circuit board (card) installed in a computer so that the computer can be connected to a network. Provide a dedicated, full-time connection to a network.
NIC (Network Interface Card)
666
# Comcast
Why is it called a cable "Modem"?
When they transmit data they "MOdulate" the data onto a carrier, then receive data and "DEModulate" it from the carrier and send it on to the computer
667
# Comcast
Four of the most common servers found in a braodband network
DHCPTODTFTPProxy
668
# Comcast
This server sets up the MAC and IP addresses for the cable modem.
DHCP Server(Dynamic Host Configuration Protocol)
669
# Comcast
This server sets up a common clock between the CM and the CMTS
TOD Server(Time of Day)
670
# Comcast
This server allows non-protected file transfers, such as aconfiguration file for a modem.
TFTP Server(Trivial File Transfer Protocol)
671
# Comcast
These servers store commonly used (or contractually stored) data. A network may have a series of these servers located in different places.
Proxy Server
672
# Comcast
The two types of noise filters
High Pass FilterNotch Filter
673
# Comcast
These types of filters only allow signals above 50MHz to pass through the filter
High Pass Filter
674
# Comcast
In addition to letting everything above 50 MHz to pass, this filter allows a small spectrum below 50 MHz to pass
Notch Filter
675
# Comcast
The process of setting up the connection between theCMTS and the cable modem, where transmit levels andfrequency are determined.
Ranged
676
# Comcast
A switch or collection of switches connecting multiple networks
POP (Point of Presence)
677
# Comcast
The point of access into theInternet.
NAP(Network Access Point)
678
# Comcast
The company who provides access to the Internet and the World Wide Web, who usually also provides corefeatures such as e-mail.
ISPInternet Service Provider
679
# Comcast
The local, long-distance and internationalphone system in use today
PSTN(Public Switched Telephone Network)
680
# Comcast
This device in the Headend controls the operation of CDV.
HDT(Host Digital Terminal)
681
# Comcast
Three major components of the Host Digital Terminal
Access Bandwidth Manager ShelfModem ShelfSpectrum Manager Shelf
682
# Comcast
This Shelf provides the connection between the Network Interface Unit (NIU) and the switch, or more simply, the connection between the HDT and the LEC
ABM(Access Bandwidth Manager)
683
# Comcast
The point of demarcation between the network and the customer. It contains the modem necessary for telephony over a cable network.
NIU(Network Interface Device)
684
# Comcast
The device that opens or breaks the circuit path in a telephone call. This device looks at the incoming data to determine where the data should get routed.
Switch
685
# Comcast
The local phone company is also known as what?
LEC(Local Exchange Carrier
686
# Comcast
Shelf on the HDT (Host Digital Terminal) that converts the digital telephone signals into digital signals that are then modulated onto an RF carrier to be transmitted over the HFC Network.
Modem Shelf
687
# Comcast
This shelf on the HDT (Host Digital Terminal) monitors the RF spectrum allocated for telephone services over the HFC network. If problems are detected, it can switch the data transmission (telephone call) to another frequency.
Spectrum Manager
688
# Comcast
How many subscriber telephone lines can an NIU Handle?
4
689
# Comcast
LPSU
Local Power Supply Unit
690
# Comcast
The process of setting up the connection between the HDT and the NIU, where transmit levels and frequency are determined.
Marshalled
691
# Comcast
Modulating technique that interweaves multiple conversations, based on time.
TDMA(Time Division Multiple Access)
692
# Comcast
The number of the person that youare trying to call.
Terminating Number
693
# Comcast
The phone company of the person you are trying to call.
Terminating LEC
694
# Comcast
The “local” phone office where the subscriber’s lines are connected to the switching equipment.
Central Office
695
# Comcast
What is "7" equal to in binary?
111
696
# Comcast
64 QAM has how many phase angles?
52
697
# Comcast
16 QAM has how many phase angles?
10
698
# Comcast
The distance between two points of like phasein a wave.
Wavelength
699
# Comcast
A card made up of material similar to photographic film that changes colors when exposed to light.
Photosensitive Card
700
# Comcast
ANSI Laser standard that separates lasers into various classes that take into consideration the operating wavelength, output power level and whether the laser operates as a continuous or pulsed light output
Z-136
701
# Comcast
Four nines works out to how many minutes of down time per month?
4.5 minutes
702
# Comcast
loss of service to ourcustomers due to a fault in thedelivery network.
Outage
703
# Comcast
Minimum telephone service to assure a contact in case of an emergency.
Lifeline
704
# Comcast
FCC Standards CFR 47, Part 76.605(a)(1-12)
Proof-of-performance (POP) test
705
# Comcast
A continuous wave (CW) frequency onto which information is modulated for transport.
Carrier Frequency
706
# Comcast
Maximum Bandwidth of 256QAM
42.88Mbps
707
# Comcast
How long must POP tests be kept at the local office?
minimum of 5 years
708
# Comcast
how many test points are required for 1,000 to 12,500 customers?
6
709
# Comcast
How many test points are required for each additional 12,500 customers?
1
710
# Comcast
Channel requirements for POP testing (amount)
4 channels plus one additional channel for every 100 MHz.
711
# Comcast
In a cable system with an upper frequency at 750 MHz, how many test channels must be used?
11 Channels
712
# Comcast
All channels must be tested during these 3 tests.
Video Carrier Level, Audio Carrier Level, Video Carrier Level Stability Test
713
# Comcast
Only one Channel needs to be tested during this non-frequency specific test
Hum Modulation
714
# Comcast
How many digital channels must be tested on an all digital system with an upper frequency of 862MHz?
0, digital channels are not included and are not tested.
715
# Comcast
The amount of channels during these tests are based solely on the highest operating frequency
Video-Audio Carrier Frequency SeparationIn-Channel ResponseCarrier to NoiseCoherent Disturbances Tests
716
# Comcast
This test must be performed twice a year, once during the coldest months and again during the warmest (Jan-Feb and Jul-Aug respectively)
Video Carrier Level Stability (24-hour) test
717
# Comcast
This POP test must be performed every three years
Color Performance test
718
# Comcast
A circuit that automaticallyadjusts the gain of an amplifier sothat the output signal levels stayconstant despite varying inputlevels.
Automatic Gain Control (AGC)
719
# Comcast
a spectrumanalyzer feature that allows theuser to make otherwise intrusiveFCC POP tests in a non-intrusivemanner.
Gated Testing
720
# Comcast
When planning POP tests, these four things need to be considered
Test timesChannels and programming affected by testingTest lengthsAbility to perform non-intrusive gated testing
721
# Comcast
This test is usually performed by a Headend tech rather than a System Tech
Color Performance
722
# Comcast
What would a Discrepancy statement include?
Explain all possible misinterpreted fails, such as test point relocation, added channels, encoding issues and so on.
723
# Comcast
POP measurements are to be taken at what location?
Input to the subscriber terminal
724
# Comcast
EIA
Electronic Industry Association
725
# Comcast
What must an operator do in order to pass the receivability test?
Submit documentation showing that their channel lineup conforms to the EIA Channel allocation plan
726
# Comcast
What does the Audio Carrier Frequency Test ensure
That the audio carrier frequency for each channel must be 4.5MHz above the video carrier frequency, +/- 5kHz
727
# Comcast
Where is the Audio Carrier Frequency test performed at?
The Headend as well as the field test points
728
# Comcast
How many times a year is the Audio Carrier Frequency test performed?
Twice annually
729
# Comcast
What type of set-top box can alter the Audio Carrier Frequency?
Baseband set-top boxes (as opposed to non-baseband)
730
# Comcast
What six measurements are taken during the 24-hour test?
Minimum Visual Signal LevelVisual Signal changeAdjacent Visual SignalAny Other Visual Signal in BandwidthVisual Carrier LevelAudio Carrier Level
731
# Comcast
The six measurements that are taken during the 24-hour test are performed on what channels?
All NTSC Channels at each test point location
732
# Comcast
What is the Minimum Visual Signal Level allowed at the end of a 30-meter (100') cable drop that is connected to the subscriber tap?
1.41mV across an internal impedance of 75 ohms (+3dBmV(CT 5-3-22)
733
# Comcast
The square root of the sum ofthe squares of the amplitudes ofindividual components of afunction, such as the frequencycomponents of a signal.
Root Mean Square (RMS)
734
# Comcast
Maximum variation of each channel within any six-month period at the end of a 30-meter drop cable
8dB
735
# Comcast
Adjacent Visual Signal deviation of the visual signal level of any visual carrier within a 6MHz nominal frequency separation
3dB
736
# Comcast
What is the maximum "spread" or deviation among ALL channel levels in a 300MHz cable system and what is the incremental increase
10dB1db per 100MHz
737
# Comcast
At what level must the aural signal be maintained in association with the visual signal level?
between 10dB and 17dB below the visual signal level
738
# Comcast
At what level must the aural signal be maintained in association with the visual signal level on a baseband converter.
between 6.5dB and 17dB below the visual signal level.
739
# Comcast
In a 24-hour test, how many times must the signal level be checked?
four times
740
# Comcast
What are the time intervals of the 24-hour test?
5 to 7 hours
741
# Comcast
at what frequency is the In-Channel Response test performed?
.75MHz to 5Mhz above the lower frequency boundary of the cable channel under test
742
# Comcast
What is the FCC In-Channel Response requirement?
+/-2dB or 4dB peak-to-valley
743
# Comcast
To perform this test, a signal must be inserted on the channel, either by the headend technician or by other means
In-Channel Response Test
744
# Comcast
FCC Requirement for C/N
43dB at each test point
745
# Comcast
What are the three type of coherent disturbances?
Composite Second Order (CSO)Composite Triple Beat (CTB)Other interfering signals (i.e. Ingress)
746
# Comcast
What is the FCC requirement for Coherent Disturbances?
51dB below the desired carrier level for STD plans and 47dB in IRC and HRC systems
747
# Comcast
The goal of this test is to find the worst beat or interfering signal, regardless of it's type
Coherent Disturbances Test
748
# Comcast
FCC requirement for isolation
18dB
749
# Comcast
Because the FCC allows you to submit manufacturers specifications to prove compliance, you rarely need to perform this test:
Terminal Isolation Test
750
# Comcast
FCC requirement for Hum Modulation
less that 3% of the video carrier level.
751
# Comcast
Where is the Hum Modulation test done?
the end of a 30m or 100' drop
752
# Comcast
how many channels is the Hum Modulation test performed on?
One channel per test point
753
# Comcast
How many channels is the Coherent Disturbance test performed on?
Dependent on highest frequency
754
# Comcast
What are the three Color Performance tests?
Chrominance to Luminance Delay InequalityDifferential GainDifferential Phase
755
# Comcast
FCC Spec for Chrominance to Luminance Delay test
Within 170 nanoseconds
756
# Comcast
FCC Spec for Differential Gain
Within +/-20%
757
# Comcast
FCC Spec for Differential Phase
Within +/-10 degrees
758
# Comcast
Who usually performs the color performance tests?
The Headend Technician
759
# Comcast
How many channels are recommended to be tested during the Color Performance test?
All NTSC or similar channels
760
# Comcast
How often are the Color Performance Test performed?
once every three years
761
# Comcast
Allowable signal leakage level below 54MHz
Up to 15uV/m @ 30m
762
# Comcast
Allowable signal leakage level between 54MHz and 216 MHz
up to 20uV/m @ 3m
763
# Comcast
Allowable signal leakage above 216MHz
up to 15uV/m @30m
764
# Comcast
The two types of leakage monitoring frequency.
Continuous MonitoringQuarterly Monitoring
765
# Comcast
Two types of annual leakage monitoring methods
Ground BasedFlyover
766
# Comcast
What is the minimum cable strand sample allowed during a ground based leakage measurement?
75%
767
# Comcast
What leaks are included in the CLI calculation?
All leaks 50uV or greater
768
# Comcast
what is the elevation that a flyover is completed at? (in meters)
450m(1476')
769
# Comcast
Two requirements for monitoring of plant with a handheld signal leakage detector
-Must be properly calibrated to detect a leak of 20uV/m or greater @ 3m-Perform all measurements with a horizontally polarized dipole antenna, preferably located no more than 3m from the leak and 3m from the ground
770
# Comcast
What does a Spectrum Analyzer Display?
information in the amplitude (vertical) vs. frequency (horizontal) domain over the entire spectrum or portions of it.
771
# Comcast
comparable in certain respects, typically in a way that makes clearer the nature of the things compared.
Analogous
772
# Comcast
This filter has a bell-curved "shape," which it applies to all energy passing through it.
Resolution Bandwidth Filter (RBW)
773
# Comcast
This is a low-pass filter at the analyzer detector's output. This filter takes the RF energy associated with the video modulation on the carrier that has already passed through the RBW filter and the detector and smoothes it out
Video Bandwidth Filter (VBW)(CT 5-3-39)
774
# Comcast
The signal to an analyzer is injected here
RF Input
775
# Comcast
Used when accessing analyzer's gated mode, such as in the C/N POP test
TV Input Connector
776
# Comcast
The main setting and adjustment keys for the analyzer functions and the display. These keys are most often used in the analyzer's manual testing modes
Function Keys
777
# Comcast
Additional keys whose action changes depending on the selected analyzer mode or function. Most often used in the analyzer's automated testing modes
Softkeys
778
# Comcast
The principal keys useed in the analyzer's manual modes of operation. They represent the three most basic functions of any spectrum analyzer
Frequency, Span and Amplitude keys
779
# Comcast
Adjusts the value or amount for the selected function or measurement
Adjustment Knob
780
# Comcast
Adjust value or amount in incremental steps for the selected function or measurement
Step Key
781
# Comcast
Allows direct input of a specific value or amount for the selected function or measurement
Numeric Keypad
782
# Comcast
Sets the type of measurement unit, such as kHz or MHz, for the selected function or measurement
Measurement units' keys
783
# Comcast
Marker function and trace control keys
Access marker functions and set trace control functions such as display line, RBW and VBW
784
# Comcast
Sets analyzer modes, presets and stores or recalls analyzer trace
Mode select Key
785
# Comcast
Maximum input power of HP 8591C
+72dBmV
786
# Comcast
Maximum input power of Tektronix 2715
+69dBmV
787
# Comcast
This must be used when high input levels are required to the analyzer to avoid input overload
preselector
788
# Comcast
For the greatest accuracy, how should the carrier peak be adjusted?
To the analyzer's reference level (top of the display)
789
# Comcast
Three tests that can use gated mode on the HP 8591C
Carrier to NoiseCoherent Disturbances (CSO measurement only)In-Channel Response
790
# Comcast
The topology where signals originate in the headend andare transmitted long distances via trunk cables
Tree and Branch
791
# Comcast
A network architecture that typically uses fiber optic cables to bring signals to selected areas of the system called nodes
Hybrid Fiber-Coax (HFC)
792
# Comcast
Bi-annual tests, performed in the headend and at a number of end-of-line location
FCC Proof-of-Performance
793
# Comcast
The cumulative effect of return path distortions they are added to the signal at various locations in the coaxial portion of the network.
Funnel Effect
794
# Comcast
Specifications standards approved by the FCC in 1953for commercial analog color TV broadcasting.
National Television Standards Committee (NTSC)
795
# Comcast
a portion of the electromagnetic spectrum whose frequencies are well suited for transmitting and receiving Telecommunications signals through the air.
Radio Frequency (RF) Spectrum
796
# Comcast
Signals that flow downstream, from the headend to the network.
Forwards (Downstream) Signals
797
# Comcast
Signals that flow in the upstream direction, from customer to headend
Revers (upstream) Signals
798
# Comcast
Device that separates or combines based on frequency.
Diplex Filter
799
# Comcast
typical cutoff frequency for a sub-split diplex filter
About 50 MHz
800
# Comcast
The three major concerns/ limitations of the tree andbranch architecture are:
BandwidthImpairmentsDependency on Power
801
# Comcast
The lowest possible power level determined by the thermal noise generated within the electrical componentsbeing tested
Noise Floor
802
# Comcast
The highest power level (amplitude) reached by a carrier
Peak
803
# Comcast
A clustering of beats 1.25 MHz above the visual carriers in a CATV network
Composite Second Order (CSO)
804
# Comcast
A form of interference or noise resulting from the mixingof all of the various carriers in a CATV network
Composite Triple Beat (CTB)
805
# Comcast
Two major types of distortions that are typically associated with CATV
Composite Second Order (CSO) and Composite Triple Beat (CTB)
806
# Comcast
The 6 benefits of implementing fiber optics in broadband networks
Enhances Picture QualityIncreased ReliabilityDecreased cost of system maintenanceCost effective system bandwidth upgradesCost means of system upgrade requiring a complete change our of electronicsSmall segmented areas allow greater return path functionality
807
# Comcast
Having or relating to a frequency below the audibility range of the human ear.
Infrasonic
808
# Comcast
A stream of atomic nuclei that enter the earth’s atmosphere from outer space at speeds approaching that of light
Cosmic Rays
809
# Comcast
Frequency range of satellite systems
4GHz to 13GHz
810
# Comcast
The wavelengths most commonly used by the CATVindustry
1310nm and 1550nm
811
# Comcast
The type of fiber optic cable that the broadband industry uses
Single Mode Fiber
812
# Comcast
The process of combining multiple carriers onto a single medium
Multiplexing
813
# Comcast
Width of the Fiber optic core
8-10um
814
# Comcast
Width of the fiber optic cladding
125um
815
# Comcast
Width of the fiber optic coating
250um
816
# Comcast
Combines multiple optical signals in order to amplify them as a group and transported over a single fiber
Wave Division Multiplexing (WDM)
817
# Comcast
Allows multiple wavelengths above and below a centerwavelength to be carried on a single optical fiber.
Dense Wave Division Multiplexing (DWDM)
818
# Comcast
Three parts of the optical link
Fiber Optic CableTransmitter (Laser)Receiver (Node)
819
# Comcast
Individual fibers are bundled and then placed into these to reduce the possibility of damage
Buffer Tubes
820
# Comcast
This diode changes the RF signals to pulsesof light and then transmits them onto an optical fiber
Semiconductor Laser Diode
821
# Comcast
The Three types of optical transmitters that are typically used in broadband HFC Network
Fabry-Perot (F-P)Distributed Feedback (DFB)Yttrium-Aluminum-Garnet (YAG)
822
# Comcast
YAG
Yttrium-Aluminum-Garnet
823
# Comcast
DFB
Distributed Feedback
824
# Comcast
F-P
Fabry-Perot
825
# Comcast
A spare fiber installed during the construction of the network that was reserved for future use.
Dark Fiber
826
# Comcast
Three advantages of trunk reduction
Shorter CascadesFewer/smaller outages due to segmenting the system into smaller areasImproved picture Quality
827
# Comcast
FTTF
Fiber to the Feeder
828
# Comcast
Advantages of FTTF
Shorter CascadesFewer/smaller outages due to segmenting the system intosmaller areas.Increased Bandwidth
829
# Comcast
FTTC
Fiber to the Curb
830
# Comcast
PON
Passive Optical Network
831
# Comcast
Consists of a transmitter at the Headend and a receiver near the subscriber. Requires a power supply near the node but all other actives have been removed
FTTC PON
832
# Comcast
4 advantages of FTTC
No active devices after nodeNo CascadeFewer/smaller outages due to segmenting the system intovery small areasIncreased Bandwidth
833
# Comcast
A fiber-based network which uses passive splitters todeliver signals to multiple locations
Passive Optical Network (PON)
834
# Comcast
FTTH
Fiber to the Home
835
# Comcast
6 advantages of FTTH
Passive networkSingle fiber is dedicated to each subscriberFeatures local battery backup, no large remote power supplies are required.No exterior active devicesNo CascadesIncreased Bandwidth
836
# Comcast
This will ALWAYS be considered the "Backbone" in an HFC Network
The Fiber Network
837
# Comcast
A high-speed line or series of connections that forms a major pathway within a network
Backbone
838
# Comcast
The duplication of certain pieces and/or portions of thenetwork.
Redundancy
839
# Comcast
Comcast's goal for network reliability
"four-nines" or 99.99%
840
# Comcast
A network architecture where nodes, hubs, or headendsmay be connected with fiber optic cables to provideredundancy or increase services
Ring Architecture
841
# Comcast
Builds upon ring technology by adding a second (redundant) ring connecting the nodes to the headend. The second ring typically takes a different path
Ring within a Ring
842
# Comcast
A facility between the headend and the customer that performs many of the functions of a headend
Hubsite
843
# Comcast
Similar in function to a hubsite, but serving fewer customers
Optical Transition Node (OTN)
844
# Comcast
Usually a passive device such as a splitter or directional coupler used to combine radio frequency signals from one source with those from another
RF Combiner
845
# Comcast
Usually a passive device that divides a signal into two equal paths. It may be found on trunk, feeder, or drop cable.
RF Splitter
846
# Comcast
Device used to combine the channels for entry onto the cable or fiber optic transmitter
Headend Combiner
847
# Comcast
The difference, in dB, of a signal level, injected into one output port, and the measured level of that same signal on another output port, with the input port properly terminated.
Port-to-port isolation
848
# Comcast
Obtained by measuring the attenuation between the two output ports (A and B) when the common port (input port) is terminated in the correct value of impedance. An RF generator signal is applied to port A and an RF voltmeter reading is taken at Port B.
Isolation
849
# Comcast
Provision for connection to a device such as a tap, splitter, set-top box or computer
Port
850
# Comcast
Used to combine all of the signals to be carried over the cable system into a single medium (cable) for routing to the laser transmitters that are feeding the optical nodes in the system
Headend Combining Network
851
# Comcast
A measurement of the reflected signal compared to that of the incident signal
Return Loss
852
# Comcast
Device used to divide or combine light carriers on fiber optic cables.
Optical Splitter
853
# Comcast
A discontinuous signal whose various states are discrete intervals apart.
Digital Signal
854
# Comcast
Device used to convert an analog signal to a digital signal.
Digitizer
855
# Comcast
takes an amplitude measurement of the waveform at fixed intervals of time, and converts them to a binary number
Digitizer
856
# Comcast
The smallest unit of computerized data. Bits are defined as single characters of 0 or 1. Bandwidth is usually measured in bits-persecond.
Binary Digit (Bit)
857
# Comcast
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.
Byte
858
# Comcast
The number of changed states that can occur per second.
Baud
859
# Comcast
The value of "On" in a binary system
"1"
860
# Comcast
The value of "Off" in a Binary system
"0"
861
# Comcast
How many bits are in a "Nibble"?
4
862
# Comcast
In ASCII #5 alphabet, how man bits are in a byte?
7
863
# Comcast
If start and stop bits are included with Asynchronous Communications, then how many bits are in a byte?
10
864
# Comcast
ADC
Analog to Digital Conversion
865
# Comcast
DAC
Digital to Analog Conversion
866
# Comcast
A continuously varying signal with an unlimited number of possible values of amplitude and frequency.
Analog Signal
867
# Comcast
a non-continuous signal or carrier that changes its output in discreetly timed steps of voltage level and/or phase that can represent numerical values or other information
Digital Transmission
868
# Comcast
3 steps of basic ADC
SamplingQuantizationEncoding
869
# Comcast
The "Measuring" of the analog signal at specific intervals.
Sampling
870
# Comcast
The assigning of a specific value to each of the samples
Quantization
871
# Comcast
The process by which Quantized values are converted into a data or bit stream
Encoding
872
# Comcast
ASK
Amplitude Shift Keying
873
# Comcast
FSK
Frequency Shift Keying
874
# Comcast
QPSK
Quadrature Phase Shift Keying
875
# Comcast
QAM
Quadrature Amplitude Modulation
876
# Comcast
The process of varying the amplitude, frequency, or phase of a carrier to be in step with the instantaneous value of the modulating waveform
Modulation
877
# Comcast
Data transmission scheme wherein the carrier is shifted in amplitude
Amplitude Shift Keying (ASK)
878
# Comcast
The carrier frequency is shifted to represent the difference between a one and a zero
Frequency Shift Keying (FSK)
879
# Comcast
The position on a waveform cycle at a specific point in time. One cycle is defined as 360 degrees of this
Phase
880
# Comcast
Digital modulation scheme wherein the carrier is shifted in 90 degree steps. There are four possible phase states and the magnitude is constant.
Quadrature Phase Shift Keying (QPSK)
881
# Comcast
BPSK
BiPhase Shift Keying
882
# Comcast
In QPSK, what does "I" stand for?
In-Phase
883
# Comcast
In QPSK, what does "Q" Stand for?
Quadrature - shifted 90* or one quarter of a cycle
884
# Comcast
A graphic depiction of the four phase states of a Quadrature Phase Shift Key signal.
Constellation Diagram
885
# Comcast
What is the bandwidth of QPSK in a 6MHz bandwidth?
10 Mb/s
886
# Comcast
Digital modulation scheme that changes the phase and the amplitude.
Quadrature Amplitude Modulation (QAM)
887
# Comcast
a digital transmission technology that splits the frequency band into a number of channels. The channels are each assigned a specific time slot, so that several transmissions can share a single channel without interfering with one another
Time Division Multiple Access (TDMA)
888
# Comcast
The digital equivalent to Signal-to-Noise
Modulation Error Ratio (MER)
889
# Comcast
A joined or connected group of devices
Network
890
# Comcast
A network of computers linked by cable within a building or office complex.
Local Area Network (LAN)
891
# Comcast
A network of multiple locations linked by cable withina city or campus
Metropolitan Area Network (MAN)
892
# Comcast
A network typically bigger than a city or metropolitan area.
Wide Area Network (WAN)
893
# Comcast
A data network connects each of its endpoints to the network with a single link. A central device (hub) is used to aggregate and distribute data traffic to all endpoints and/or other central points in what’s referred to as a clustered star.
Star
894
# Comcast
Consists of several star networks that have been linked together
Clustered Star
895
# Comcast
Topology where workstations are connected to the network through a common path
Bus
896
# Comcast
A topology in which a data frame is passed around. As it arrives at an endpoint, the endpoint can either pass it along to the next endpoint or attach information to be sent to a destination
Token Ring
897
# Comcast
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
Ring
898
# Comcast
A method of data transmission that allows characters to be sent at irregular intervals by preceding each character with a 0 and by ending each character with a 1. This is referred to as start (0) and stop bits (1). It is the method, which most PCs use to communicate with each other and mainframes
Asynchronous Transmission
899
# Comcast
An extra bit added to help check if the data that isbeing transferred is correct
Parity Bit
900
# Comcast
The condition that occurs when two events happen in a specific time relationship with each other and both are under control of a master clock. Characters are spaced by time, not by start and stop bits.
Synchronous Transmission
901
# Comcast
Synchronizing bits used in synchronous transmission to maintain synchronization between transmitter and receiver.
Sync Bits
902
# Comcast
SNMP
Simple Network Management Protocol (SNMP)
903
# Comcast
NE
Network Elements
904
# Comcast
MIB
Management Information Base
905
# Comcast
A unique number assigned to a piece of equipmentused for identification purposes.
Media Access Control Address (MAC)
906
# Comcast
UTP
Unshielded Twisted Pair
907
# Comcast
signaling rate of 10BaseT
10 Mb/s
908
# Comcast
Signaling rate of 100BaseT
100 Mb/s
909
# Comcast
The designation for Ethernet over fiber optic cable, primarily for point-topoint links
10Base-F
910
# Comcast
Ethernet resides in what layers of the OSI model?
The 2 lowest levels (layers)
911
# Comcast
This device works as a multiport signal repeater, broadcasting an incoming signal to all other ports on an ethernet network
Ethernet Hub
912
# Comcast
The four-part numeric address that is assigned to a computer or an account as an identification tool
Internet Protocol Address (IP)
913
# Comcast
IEEE MAC Protocol for Hybrid Fiber-Coax Networks; standard for data communicatons over a cable network
802.14
914
# Comcast
The Four original partners of MCNS (Multimedia Cable Network Partners Ltd.)
Comcast, Cox, TCI and Time Warner
915
# Comcast
The three companies that joined MCNS in late 1996
Media One, Rogers Cablevision and CableLabs
916
# Comcast
DOCSIS
Data Over Cable Service Interface Specification
917
# Comcast
When was DOCSIS 1.0 released? (Month & Year)
Mar-97
918
# Comcast
The Leading standard for cable modems
DOCSIS
919
# Comcast
Four devices that must be added to a system to offer high-speed internet
CMTS (Cable Modem Termination System)CM (Cable Modem)ServersNoise Filters
920
# Comcast
A unit consisting of various hardware and software entities that acts as the hand-off point between the RF based HFC network and other networks such as theInternet and the PSTN.
CMTS (Cable Modem Termination System)
921
# Comcast
Used to terminate, manage and translate high-speed Internet sessions between cable modems in a LAN and other devices in a WAN.
CMTS (Cable Modem Termination System)
922
# Comcast
The collection of computers accessed through the Internet. Uses a hypertext based system for finding andaccessing its resources.
WWW (World Wide Web)
923
# Comcast
Four Items that a CMTS manages
Time SlotsContention SlotsModem DataTransmit Levels
924
# Comcast
Each cable modem is assigned one of these by the CMTS and only one modem is allowed to transmit during this.
Time Slot
925
# Comcast
These slots are usually used for short data transmissions such as a request for an additional number of reserved time slots
Contention Slots
926
# Comcast
The signal level that the CMTS wants to "See"
0dBmV
927
# Comcast
A PC on a LAN from which information or applications are requested.
Client/Server
928
# Comcast
A computer circuit board (card) installed in a computer so that the computer can be connected to a network. Provide a dedicated, full-time connection to a network.
NIC (Network Interface Card)
929
# Comcast
Why is it called a cable "Modem"?
When they transmit data they "MOdulate" the data onto a carrier, then receive data and "DEModulate" it from the carrier and send it on to the computer
930
# Comcast
Four of the most common servers found in a braodband network
DHCPTODTFTPProxy
931
# Comcast
This server sets up the MAC and IP addresses for the cable modem.
DHCP Server(Dynamic Host Configuration Protocol)
932
# Comcast
This server sets up a common clock between the CM and the CMTS
TOD Server(Time of Day)
933
# Comcast
This server allows non-protected file transfers, such as aconfiguration file for a modem.
TFTP Server(Trivial File Transfer Protocol)
934
# Comcast
These servers store commonly used (or contractually stored) data. A network may have a series of these servers located in different places.
Proxy Server
935
# Comcast
The two types of noise filters
High Pass FilterNotch Filter
936
# Comcast
These types of filters only allow signals above 50MHz to pass through the filter
High Pass Filter
937
# Comcast
In addition to letting everything above 50 MHz to pass, this filter allows a small spectrum below 50 MHz to pass
Notch Filter
938
# Comcast
The process of setting up the connection between theCMTS and the cable modem, where transmit levels andfrequency are determined.
Ranged
939
# Comcast
A switch or collection of switches connecting multiple networks
POP (Point of Presence)
940
# Comcast
The point of access into theInternet.
NAP(Network Access Point)
941
# Comcast
The company who provides access to the Internet and the World Wide Web, who usually also provides corefeatures such as e-mail.
ISPInternet Service Provider
942
# Comcast
The local, long-distance and internationalphone system in use today
PSTN(Public Switched Telephone Network)
943
# Comcast
This device in the Headend controls the operation of CDV.
HDT(Host Digital Terminal)
944
# Comcast
Three major components of the Host Digital Terminal
Access Bandwidth Manager ShelfModem ShelfSpectrum Manager Shelf
945
# Comcast
This Shelf provides the connection between the Network Interface Unit (NIU) and the switch, or more simply, the connection between the HDT and the LEC
ABM(Access Bandwidth Manager)
946
# Comcast
The point of demarcation between the network and the customer. It contains the modem necessary for telephony over a cable network.
NIU(Network Interface Device)
947
# Comcast
The device that opens or breaks the circuit path in a telephone call. This device looks at the incoming data to determine where the data should get routed.
Switch
948
# Comcast
The local phone company is also known as what?
LEC(Local Exchange Carrier
949
# Comcast
Shelf on the HDT (Host Digital Terminal) that converts the digital telephone signals into digital signals that are then modulated onto an RF carrier to be transmitted over the HFC Network.
Modem Shelf
950
# Comcast
This shelf on the HDT (Host Digital Terminal) monitors the RF spectrum allocated for telephone services over the HFC network. If problems are detected, it can switch the data transmission (telephone call) to another frequency.
Spectrum Manager
951
# Comcast
How many subscriber telephone lines can an NIU Handle?
4
952
# Comcast
LPSU
Local Power Supply Unit
953
# Comcast
The process of setting up the connection between the HDT and the NIU, where transmit levels and frequency are determined.
Marshalled
954
# Comcast
Modulating technique that interweaves multiple conversations, based on time.
TDMA(Time Division Multiple Access)
955
# Comcast
The number of the person that youare trying to call.
Terminating Number
956
# Comcast
The phone company of the person you are trying to call.
Terminating LEC
957
# Comcast
The “local” phone office where the subscriber’s lines are connected to the switching equipment.
Central Office
958
# Comcast
What is "7" equal to in binary?
111
959
# Comcast
64 QAM has how many phase angles?
52
960
# Comcast
16 QAM has how many phase angles?
10
961
# Comcast
The distance between two points of like phasein a wave.
Wavelength
962
# Comcast
A card made up of material similar to photographic film that changes colors when exposed to light.
Photosensitive Card
963
# Comcast
ANSI Laser standard that separates lasers into various classes that take into consideration the operating wavelength, output power level and whether the laser operates as a continuous or pulsed light output
Z-136
964
# Comcast
Four nines works out to how many minutes of down time per month?
4.5 minutes
965
# Comcast
loss of service to ourcustomers due to a fault in thedelivery network.
Outage
966
# Comcast
Minimum telephone service to assure a contact in case of an emergency.
Lifeline
967
# Comcast
FCC Standards CFR 47, Part 76.605(a)(1-12)
Proof-of-performance (POP) test
968
# Comcast
A continuous wave (CW) frequency onto which information is modulated for transport.
Carrier Frequency
969
# Comcast
Maximum Bandwidth of 256QAM
42.88Mbps
970
# Comcast
How long must POP tests be kept at the local office?
minimum of 5 years
971
# Comcast
how many test points are required for 1,000 to 12,500 customers?
6
972
# Comcast
How many test points are required for each additional 12,500 customers?
1
973
# Comcast
Channel requirements for POP testing (amount)
4 channels plus one additional channel for every 100 MHz.
974
# Comcast
In a cable system with an upper frequency at 750 MHz, how many test channels must be used?
11 Channels
975
# Comcast
All channels must be tested during these 3 tests.
Video Carrier Level, Audio Carrier Level, Video Carrier Level Stability Test
976
# Comcast
Only one Channel needs to be tested during this non-frequency specific test
Hum Modulation
977
# Comcast
How many digital channels must be tested on an all digital system with an upper frequency of 862MHz?
0, digital channels are not included and are not tested.
978
# Comcast
The amount of channels during these tests are based solely on the highest operating frequency
Video-Audio Carrier Frequency SeparationIn-Channel ResponseCarrier to NoiseCoherent Disturbances Tests
979
# Comcast
This test must be performed twice a year, once during the coldest months and again during the warmest (Jan-Feb and Jul-Aug respectively)
Video Carrier Level Stability (24-hour) test
980
# Comcast
This POP test must be performed every three years
Color Performance test
981
# Comcast
A circuit that automaticallyadjusts the gain of an amplifier sothat the output signal levels stayconstant despite varying inputlevels.
Automatic Gain Control (AGC)
982
# Comcast
a spectrumanalyzer feature that allows theuser to make otherwise intrusiveFCC POP tests in a non-intrusivemanner.
Gated Testing
983
# Comcast
When planning POP tests, these four things need to be considered
Test timesChannels and programming affected by testingTest lengthsAbility to perform non-intrusive gated testing
984
# Comcast
This test is usually performed by a Headend tech rather than a System Tech
Color Performance
985
# Comcast
What would a Discrepancy statement include?
Explain all possible misinterpreted fails, such as test point relocation, added channels, encoding issues and so on.
986
# Comcast
POP measurements are to be taken at what location?
Input to the subscriber terminal
987
# Comcast
EIA
Electronic Industry Association
988
# Comcast
What must an operator do in order to pass the receivability test?
Submit documentation showing that their channel lineup conforms to the EIA Channel allocation plan
989
# Comcast
What does the Audio Carrier Frequency Test ensure
That the audio carrier frequency for each channel must be 4.5MHz above the video carrier frequency, +/- 5kHz
990
# Comcast
Where is the Audio Carrier Frequency test performed at?
The Headend as well as the field test points
991
# Comcast
How many times a year is the Audio Carrier Frequency test performed?
Twice annually
992
# Comcast
What type of set-top box can alter the Audio Carrier Frequency?
Baseband set-top boxes (as opposed to non-baseband)
993
# Comcast
What six measurements are taken during the 24-hour test?
Minimum Visual Signal LevelVisual Signal changeAdjacent Visual SignalAny Other Visual Signal in BandwidthVisual Carrier LevelAudio Carrier Level
994
# Comcast
The six measurements that are taken during the 24-hour test are performed on what channels?
All NTSC Channels at each test point location
995
# Comcast
What is the Minimum Visual Signal Level allowed at the end of a 30-meter (100') cable drop that is connected to the subscriber tap?
1.41mV across an internal impedance of 75 ohms (+3dBmV(CT 5-3-22)
996
# Comcast
The square root of the sum ofthe squares of the amplitudes ofindividual components of afunction, such as the frequencycomponents of a signal.
Root Mean Square (RMS)
997
# Comcast
Maximum variation of each channel within any six-month period at the end of a 30-meter drop cable
8dB
998
# Comcast
Adjacent Visual Signal deviation of the visual signal level of any visual carrier within a 6MHz nominal frequency separation
3dB
999
# Comcast
What is the maximum "spread" or deviation among ALL channel levels in a 300MHz cable system and what is the incremental increase
10dB1db per 100MHz
1000
# Comcast
At what level must the aural signal be maintained in association with the visual signal level?
between 10dB and 17dB below the visual signal level
1001
# Comcast
At what level must the aural signal be maintained in association with the visual signal level on a baseband converter.
between 6.5dB and 17dB below the visual signal level.
1002
# Comcast
In a 24-hour test, how many times must the signal level be checked?
four times
1003
# Comcast
What are the time intervals of the 24-hour test?
5 to 7 hours
1004
# Comcast
at what frequency is the In-Channel Response test performed?
.75MHz to 5Mhz above the lower frequency boundary of the cable channel under test
1005
# Comcast
What is the FCC In-Channel Response requirement?
+/-2dB or 4dB peak-to-valley
1006
# Comcast
To perform this test, a signal must be inserted on the channel, either by the headend technician or by other means
In-Channel Response Test
1007
# Comcast
FCC Requirement for C/N
43dB at each test point
1008
# Comcast
What are the three type of coherent disturbances?
Composite Second Order (CSO)Composite Triple Beat (CTB)Other interfering signals (i.e. Ingress)
1009
# Comcast
What is the FCC requirement for Coherent Disturbances?
51dB below the desired carrier level for STD plans and 47dB in IRC and HRC systems
1010
# Comcast
The goal of this test is to find the worst beat or interfering signal, regardless of it's type
Coherent Disturbances Test
1011
# Comcast
FCC requirement for isolation
18dB
1012
# Comcast
Because the FCC allows you to submit manufacturers specifications to prove compliance, you rarely need to perform this test:
Terminal Isolation Test
1013
# Comcast
FCC requirement for Hum Modulation
less that 3% of the video carrier level.
1014
# Comcast
Where is the Hum Modulation test done?
the end of a 30m or 100' drop
1015
# Comcast
how many channels is the Hum Modulation test performed on?
One channel per test point
1016
# Comcast
How many channels is the Coherent Disturbance test performed on?
Dependent on highest frequency
1017
# Comcast
What are the three Color Performance tests?
Chrominance to Luminance Delay InequalityDifferential GainDifferential Phase
1018
# Comcast
FCC Spec for Chrominance to Luminance Delay test
Within 170 nanoseconds
1019
# Comcast
FCC Spec for Differential Gain
Within +/-20%
1020
# Comcast
FCC Spec for Differential Phase
Within +/-10 degrees
1021
# Comcast
Who usually performs the color performance tests?
The Headend Technician
1022
# Comcast
How many channels are recommended to be tested during the Color Performance test?
All NTSC or similar channels
1023
# Comcast
How often are the Color Performance Test performed?
once every three years
1024
# Comcast
Allowable signal leakage level below 54MHz
Up to 15uV/m @ 30m
1025
# Comcast
Allowable signal leakage level between 54MHz and 216 MHz
up to 20uV/m @ 3m
1026
# Comcast
Allowable signal leakage above 216MHz
up to 15uV/m @30m
1027
# Comcast
The two types of leakage monitoring frequency.
Continuous MonitoringQuarterly Monitoring
1028
# Comcast
Two types of annual leakage monitoring methods
Ground BasedFlyover
1029
# Comcast
What is the minimum cable strand sample allowed during a ground based leakage measurement?
75%
1030
# Comcast
What leaks are included in the CLI calculation?
All leaks 50uV or greater
1031
# Comcast
what is the elevation that a flyover is completed at? (in meters)
450m(1476')
1032
# Comcast
Two requirements for monitoring of plant with a handheld signal leakage detector
-Must be properly calibrated to detect a leak of 20uV/m or greater @ 3m-Perform all measurements with a horizontally polarized dipole antenna, preferably located no more than 3m from the leak and 3m from the ground
1033
# Comcast
What does a Spectrum Analyzer Display?
information in the amplitude (vertical) vs. frequency (horizontal) domain over the entire spectrum or portions of it.
1034
# Comcast
comparable in certain respects, typically in a way that makes clearer the nature of the things compared.
Analogous
1035
# Comcast
This filter has a bell-curved "shape," which it applies to all energy passing through it.
Resolution Bandwidth Filter (RBW)
1036
# Comcast
This is a low-pass filter at the analyzer detector's output. This filter takes the RF energy associated with the video modulation on the carrier that has already passed through the RBW filter and the detector and smoothes it out
Video Bandwidth Filter (VBW)(CT 5-3-39)
1037
# Comcast
The signal to an analyzer is injected here
RF Input
1038
# Comcast
Used when accessing analyzer's gated mode, such as in the C/N POP test
TV Input Connector
1039
# Comcast
The main setting and adjustment keys for the analyzer functions and the display. These keys are most often used in the analyzer's manual testing modes
Function Keys
1040
# Comcast
Additional keys whose action changes depending on the selected analyzer mode or function. Most often used in the analyzer's automated testing modes
Softkeys
1041
# Comcast
The principal keys useed in the analyzer's manual modes of operation. They represent the three most basic functions of any spectrum analyzer
Frequency, Span and Amplitude keys
1042
# Comcast
Adjusts the value or amount for the selected function or measurement
Adjustment Knob
1043
# Comcast
Adjust value or amount in incremental steps for the selected function or measurement
Step Key
1044
# Comcast
Allows direct input of a specific value or amount for the selected function or measurement
Numeric Keypad
1045
# Comcast
Sets the type of measurement unit, such as kHz or MHz, for the selected function or measurement
Measurement units' keys
1046
# Comcast
Marker function and trace control keys
Access marker functions and set trace control functions such as display line, RBW and VBW
1047
# Comcast
Sets analyzer modes, presets and stores or recalls analyzer trace
Mode select Key
1048
# Comcast
Maximum input power of HP 8591C
+72dBmV
1049
# Comcast
Maximum input power of Tektronix 2715
+69dBmV
1050
# Comcast
This must be used when high input levels are required to the analyzer to avoid input overload
preselector
1051
# Comcast
For the greatest accuracy, how should the carrier peak be adjusted?
To the analyzer's reference level (top of the display)
1052
# Comcast
Three tests that can use gated mode on the HP 8591C
Carrier to NoiseCoherent Disturbances (CSO measurement only)In-Channel Response
1053
# Comcast
The topology where signals originate in the headend andare transmitted long distances via trunk cables
Tree and Branch
1054
# Comcast
A network architecture that typically uses fiber optic cables to bring signals to selected areas of the system called nodes
Hybrid Fiber-Coax (HFC)
1055
# Comcast
Bi-annual tests, performed in the headend and at a number of end-of-line location
FCC Proof-of-Performance
1056
# Comcast
The cumulative effect of return path distortions they are added to the signal at various locations in the coaxial portion of the network.
Funnel Effect
1057
# Comcast
Specifications standards approved by the FCC in 1953for commercial analog color TV broadcasting.
National Television Standards Committee (NTSC)
1058
# Comcast
a portion of the electromagnetic spectrum whose frequencies are well suited for transmitting and receiving Telecommunications signals through the air.
Radio Frequency (RF) Spectrum
1059
# Comcast
Signals that flow downstream, from the headend to the network.
Forwards (Downstream) Signals
1060
# Comcast
Signals that flow in the upstream direction, from customer to headend
Revers (upstream) Signals
1061
# Comcast
Device that separates or combines based on frequency.
Diplex Filter
1062
# Comcast
typical cutoff frequency for a sub-split diplex filter
About 50 MHz
1063
# Comcast
The three major concerns/ limitations of the tree andbranch architecture are:
BandwidthImpairmentsDependency on Power
1064
# Comcast
The lowest possible power level determined by the thermal noise generated within the electrical componentsbeing tested
Noise Floor
1065
# Comcast
The highest power level (amplitude) reached by a carrier
Peak
1066
# Comcast
A clustering of beats 1.25 MHz above the visual carriers in a CATV network
Composite Second Order (CSO)
1067
# Comcast
A form of interference or noise resulting from the mixingof all of the various carriers in a CATV network
Composite Triple Beat (CTB)
1068
# Comcast
Two major types of distortions that are typically associated with CATV
Composite Second Order (CSO) and Composite Triple Beat (CTB)
1069
# Comcast
The 6 benefits of implementing fiber optics in broadband networks
Enhances Picture QualityIncreased ReliabilityDecreased cost of system maintenanceCost effective system bandwidth upgradesCost means of system upgrade requiring a complete change our of electronicsSmall segmented areas allow greater return path functionality
1070
# Comcast
Having or relating to a frequency below the audibility range of the human ear.
Infrasonic
1071
# Comcast
A stream of atomic nuclei that enter the earth’s atmosphere from outer space at speeds approaching that of light
Cosmic Rays
1072
# Comcast
Frequency range of satellite systems
4GHz to 13GHz
1073
# Comcast
The wavelengths most commonly used by the CATVindustry
1310nm and 1550nm
1074
# Comcast
The type of fiber optic cable that the broadband industry uses
Single Mode Fiber
1075
# Comcast
The process of combining multiple carriers onto a single medium
Multiplexing
1076
# Comcast
Width of the Fiber optic core
8-10um
1077
# Comcast
Width of the fiber optic cladding
125um
1078
# Comcast
Width of the fiber optic coating
250um
1079
# Comcast
Combines multiple optical signals in order to amplify them as a group and transported over a single fiber
Wave Division Multiplexing (WDM)
1080
# Comcast
Allows multiple wavelengths above and below a centerwavelength to be carried on a single optical fiber.
Dense Wave Division Multiplexing (DWDM)
1081
# Comcast
Three parts of the optical link
Fiber Optic CableTransmitter (Laser)Receiver (Node)
1082
# Comcast
Individual fibers are bundled and then placed into these to reduce the possibility of damage
Buffer Tubes
1083
# Comcast
This diode changes the RF signals to pulsesof light and then transmits them onto an optical fiber
Semiconductor Laser Diode
1084
# Comcast
The Three types of optical transmitters that are typically used in broadband HFC Network
Fabry-Perot (F-P)Distributed Feedback (DFB)Yttrium-Aluminum-Garnet (YAG)
1085
# Comcast
YAG
Yttrium-Aluminum-Garnet
1086
# Comcast
DFB
Distributed Feedback
1087
# Comcast
F-P
Fabry-Perot
1088
# Comcast
A spare fiber installed during the construction of the network that was reserved for future use.
Dark Fiber
1089
# Comcast
Three advantages of trunk reduction
Shorter CascadesFewer/smaller outages due to segmenting the system into smaller areasImproved picture Quality
1090
# Comcast
FTTF
Fiber to the Feeder
1091
# Comcast
Advantages of FTTF
Shorter CascadesFewer/smaller outages due to segmenting the system intosmaller areas.Increased Bandwidth
1092
# Comcast
FTTC
Fiber to the Curb
1093
# Comcast
PON
Passive Optical Network
1094
# Comcast
Consists of a transmitter at the Headend and a receiver near the subscriber. Requires a power supply near the node but all other actives have been removed
FTTC PON
1095
# Comcast
4 advantages of FTTC
No active devices after nodeNo CascadeFewer/smaller outages due to segmenting the system intovery small areasIncreased Bandwidth
1096
# Comcast
A fiber-based network which uses passive splitters todeliver signals to multiple locations
Passive Optical Network (PON)
1097
# Comcast
FTTH
Fiber to the Home
1098
# Comcast
6 advantages of FTTH
Passive networkSingle fiber is dedicated to each subscriberFeatures local battery backup, no large remote power supplies are required.No exterior active devicesNo CascadesIncreased Bandwidth
1099
# Comcast
This will ALWAYS be considered the "Backbone" in an HFC Network
The Fiber Network
1100
# Comcast
A high-speed line or series of connections that forms a major pathway within a network
Backbone
1101
# Comcast
The duplication of certain pieces and/or portions of thenetwork.
Redundancy
1102
# Comcast
Comcast's goal for network reliability
"four-nines" or 99.99%
1103
# Comcast
A network architecture where nodes, hubs, or headendsmay be connected with fiber optic cables to provideredundancy or increase services
Ring Architecture
1104
# Comcast
Builds upon ring technology by adding a second (redundant) ring connecting the nodes to the headend. The second ring typically takes a different path
Ring within a Ring
1105
# Comcast
A facility between the headend and the customer that performs many of the functions of a headend
Hubsite
1106
# Comcast
Similar in function to a hubsite, but serving fewer customers
Optical Transition Node (OTN)
1107
# Comcast
Usually a passive device such as a splitter or directional coupler used to combine radio frequency signals from one source with those from another
RF Combiner
1108
# Comcast
Usually a passive device that divides a signal into two equal paths. It may be found on trunk, feeder, or drop cable.
RF Splitter
1109
# Comcast
Device used to combine the channels for entry onto the cable or fiber optic transmitter
Headend Combiner
1110
# Comcast
The difference, in dB, of a signal level, injected into one output port, and the measured level of that same signal on another output port, with the input port properly terminated.
Port-to-port isolation
1111
# Comcast
Obtained by measuring the attenuation between the two output ports (A and B) when the common port (input port) is terminated in the correct value of impedance. An RF generator signal is applied to port A and an RF voltmeter reading is taken at Port B.
Isolation
1112
# Comcast
Provision for connection to a device such as a tap, splitter, set-top box or computer
Port
1113
# Comcast
Used to combine all of the signals to be carried over the cable system into a single medium (cable) for routing to the laser transmitters that are feeding the optical nodes in the system
Headend Combining Network
1114
# Comcast
A measurement of the reflected signal compared to that of the incident signal
Return Loss
1115
# Comcast
Device used to divide or combine light carriers on fiber optic cables.
Optical Splitter
1116
# Comcast
A discontinuous signal whose various states are discrete intervals apart.
Digital Signal
1117
# Comcast
Device used to convert an analog signal to a digital signal.
Digitizer
1118
# Comcast
takes an amplitude measurement of the waveform at fixed intervals of time, and converts them to a binary number
Digitizer
1119
# Comcast
The smallest unit of computerized data. Bits are defined as single characters of 0 or 1. Bandwidth is usually measured in bits-persecond.
Binary Digit (Bit)
1120
# Comcast
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.
Byte
1121
# Comcast
The number of changed states that can occur per second.
Baud
1122
# Comcast
The value of "On" in a binary system
"1"
1123
# Comcast
The value of "Off" in a Binary system
"0"
1124
# Comcast
How many bits are in a "Nibble"?
4
1125
# Comcast
In ASCII #5 alphabet, how man bits are in a byte?
7
1126
# Comcast
If start and stop bits are included with Asynchronous Communications, then how many bits are in a byte?
10
1127
# Comcast
ADC
Analog to Digital Conversion
1128
# Comcast
DAC
Digital to Analog Conversion
1129
# Comcast
A continuously varying signal with an unlimited number of possible values of amplitude and frequency.
Analog Signal
1130
# Comcast
a non-continuous signal or carrier that changes its output in discreetly timed steps of voltage level and/or phase that can represent numerical values or other information
Digital Transmission
1131
# Comcast
3 steps of basic ADC
SamplingQuantizationEncoding
1132
# Comcast
The "Measuring" of the analog signal at specific intervals.
Sampling
1133
# Comcast
The assigning of a specific value to each of the samples
Quantization
1134
# Comcast
The process by which Quantized values are converted into a data or bit stream
Encoding
1135
# Comcast
ASK
Amplitude Shift Keying
1136
# Comcast
FSK
Frequency Shift Keying
1137
# Comcast
QPSK
Quadrature Phase Shift Keying
1138
# Comcast
QAM
Quadrature Amplitude Modulation
1139
# Comcast
The process of varying the amplitude, frequency, or phase of a carrier to be in step with the instantaneous value of the modulating waveform
Modulation
1140
# Comcast
Data transmission scheme wherein the carrier is shifted in amplitude
Amplitude Shift Keying (ASK)
1141
# Comcast
The carrier frequency is shifted to represent the difference between a one and a zero
Frequency Shift Keying (FSK)
1142
# Comcast
The position on a waveform cycle at a specific point in time. One cycle is defined as 360 degrees of this
Phase
1143
# Comcast
Digital modulation scheme wherein the carrier is shifted in 90 degree steps. There are four possible phase states and the magnitude is constant.
Quadrature Phase Shift Keying (QPSK)
1144
# Comcast
BPSK
BiPhase Shift Keying
1145
# Comcast
In QPSK, what does "I" stand for?
In-Phase
1146
# Comcast
In QPSK, what does "Q" Stand for?
Quadrature - shifted 90* or one quarter of a cycle
1147
# Comcast
A graphic depiction of the four phase states of a Quadrature Phase Shift Key signal.
Constellation Diagram
1148
# Comcast
What is the bandwidth of QPSK in a 6MHz bandwidth?
10 Mb/s
1149
# Comcast
Digital modulation scheme that changes the phase and the amplitude.
Quadrature Amplitude Modulation (QAM)
1150
# Comcast
a digital transmission technology that splits the frequency band into a number of channels. The channels are each assigned a specific time slot, so that several transmissions can share a single channel without interfering with one another
Time Division Multiple Access (TDMA)
1151
# Comcast
The digital equivalent to Signal-to-Noise
Modulation Error Ratio (MER)
1152
# Comcast
A joined or connected group of devices
Network
1153
# Comcast
A network of computers linked by cable within a building or office complex.
Local Area Network (LAN)
1154
# Comcast
A network of multiple locations linked by cable withina city or campus
Metropolitan Area Network (MAN)
1155
# Comcast
A network typically bigger than a city or metropolitan area.
Wide Area Network (WAN)
1156
# Comcast
A data network connects each of its endpoints to the network with a single link. A central device (hub) is used to aggregate and distribute data traffic to all endpoints and/or other central points in what’s referred to as a clustered star.
Star
1157
# Comcast
Consists of several star networks that have been linked together
Clustered Star
1158
# Comcast
Topology where workstations are connected to the network through a common path
Bus
1159
# Comcast
A topology in which a data frame is passed around. As it arrives at an endpoint, the endpoint can either pass it along to the next endpoint or attach information to be sent to a destination
Token Ring
1160
# Comcast
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
Ring
1161
# Comcast
A method of data transmission that allows characters to be sent at irregular intervals by preceding each character with a 0 and by ending each character with a 1. This is referred to as start (0) and stop bits (1). It is the method, which most PCs use to communicate with each other and mainframes
Asynchronous Transmission
1162
# Comcast
An extra bit added to help check if the data that isbeing transferred is correct
Parity Bit
1163
# Comcast
The condition that occurs when two events happen in a specific time relationship with each other and both are under control of a master clock. Characters are spaced by time, not by start and stop bits.
Synchronous Transmission
1164
# Comcast
Synchronizing bits used in synchronous transmission to maintain synchronization between transmitter and receiver.
Sync Bits
1165
# Comcast
SNMP
Simple Network Management Protocol (SNMP)
1166
# Comcast
NE
Network Elements
1167
# Comcast
MIB
Management Information Base
1168
# Comcast
A unique number assigned to a piece of equipmentused for identification purposes.
Media Access Control Address (MAC)
1169
# Comcast
UTP
Unshielded Twisted Pair
1170
# Comcast
signaling rate of 10BaseT
10 Mb/s
1171
# Comcast
Signaling rate of 100BaseT
100 Mb/s
1172
# Comcast
The designation for Ethernet over fiber optic cable, primarily for point-topoint links
10Base-F
1173
# Comcast
Ethernet resides in what layers of the OSI model?
The 2 lowest levels (layers)
1174
# Comcast
This device works as a multiport signal repeater, broadcasting an incoming signal to all other ports on an ethernet network
Ethernet Hub
1175
# Comcast
The four-part numeric address that is assigned to a computer or an account as an identification tool
Internet Protocol Address (IP)
1176
# Comcast
IEEE MAC Protocol for Hybrid Fiber-Coax Networks; standard for data communicatons over a cable network
802.14
1177
# Comcast
The Four original partners of MCNS (Multimedia Cable Network Partners Ltd.)
Comcast, Cox, TCI and Time Warner
1178
# Comcast
The three companies that joined MCNS in late 1996
Media One, Rogers Cablevision and CableLabs
1179
# Comcast
DOCSIS
Data Over Cable Service Interface Specification
1180
# Comcast
When was DOCSIS 1.0 released? (Month & Year)
Mar-97
1181
# Comcast
The Leading standard for cable modems
DOCSIS
1182
# Comcast
Four devices that must be added to a system to offer high-speed internet
CMTS (Cable Modem Termination System)CM (Cable Modem)ServersNoise Filters
1183
# Comcast
A unit consisting of various hardware and software entities that acts as the hand-off point between the RF based HFC network and other networks such as theInternet and the PSTN.
CMTS (Cable Modem Termination System)
1184
# Comcast
Used to terminate, manage and translate high-speed Internet sessions between cable modems in a LAN and other devices in a WAN.
CMTS (Cable Modem Termination System)
1185
# Comcast
The collection of computers accessed through the Internet. Uses a hypertext based system for finding andaccessing its resources.
WWW (World Wide Web)
1186
# Comcast
Four Items that a CMTS manages
Time SlotsContention SlotsModem DataTransmit Levels
1187
# Comcast
Each cable modem is assigned one of these by the CMTS and only one modem is allowed to transmit during this.
Time Slot
1188
# Comcast
These slots are usually used for short data transmissions such as a request for an additional number of reserved time slots
Contention Slots
1189
# Comcast
The signal level that the CMTS wants to "See"
0dBmV
1190
# Comcast
A PC on a LAN from which information or applications are requested.
Client/Server
1191
# Comcast
A computer circuit board (card) installed in a computer so that the computer can be connected to a network. Provide a dedicated, full-time connection to a network.
NIC (Network Interface Card)
1192
# Comcast
Why is it called a cable "Modem"?
When they transmit data they "MOdulate" the data onto a carrier, then receive data and "DEModulate" it from the carrier and send it on to the computer
1193
# Comcast
Four of the most common servers found in a braodband network
DHCPTODTFTPProxy
1194
# Comcast
This server sets up the MAC and IP addresses for the cable modem.
DHCP Server(Dynamic Host Configuration Protocol)
1195
# Comcast
This server sets up a common clock between the CM and the CMTS
TOD Server(Time of Day)
1196
# Comcast
This server allows non-protected file transfers, such as aconfiguration file for a modem.
TFTP Server(Trivial File Transfer Protocol)
1197
# Comcast
These servers store commonly used (or contractually stored) data. A network may have a series of these servers located in different places.
Proxy Server
1198
# Comcast
The two types of noise filters
High Pass FilterNotch Filter
1199
# Comcast
These types of filters only allow signals above 50MHz to pass through the filter
High Pass Filter
1200
# Comcast
In addition to letting everything above 50 MHz to pass, this filter allows a small spectrum below 50 MHz to pass
Notch Filter
1201
# Comcast
The process of setting up the connection between theCMTS and the cable modem, where transmit levels andfrequency are determined.
Ranged
1202
# Comcast
A switch or collection of switches connecting multiple networks
POP (Point of Presence)
1203
# Comcast
The point of access into theInternet.
NAP(Network Access Point)
1204
# Comcast
The company who provides access to the Internet and the World Wide Web, who usually also provides corefeatures such as e-mail.
ISPInternet Service Provider
1205
# Comcast
The local, long-distance and internationalphone system in use today
PSTN(Public Switched Telephone Network)
1206
# Comcast
This device in the Headend controls the operation of CDV.
HDT(Host Digital Terminal)
1207
# Comcast
Three major components of the Host Digital Terminal
Access Bandwidth Manager ShelfModem ShelfSpectrum Manager Shelf
1208
# Comcast
This Shelf provides the connection between the Network Interface Unit (NIU) and the switch, or more simply, the connection between the HDT and the LEC
ABM(Access Bandwidth Manager)
1209
# Comcast
The point of demarcation between the network and the customer. It contains the modem necessary for telephony over a cable network.
NIU(Network Interface Device)
1210
# Comcast
The device that opens or breaks the circuit path in a telephone call. This device looks at the incoming data to determine where the data should get routed.
Switch
1211
# Comcast
The local phone company is also known as what?
LEC(Local Exchange Carrier
1212
# Comcast
Shelf on the HDT (Host Digital Terminal) that converts the digital telephone signals into digital signals that are then modulated onto an RF carrier to be transmitted over the HFC Network.
Modem Shelf
1213
# Comcast
This shelf on the HDT (Host Digital Terminal) monitors the RF spectrum allocated for telephone services over the HFC network. If problems are detected, it can switch the data transmission (telephone call) to another frequency.
Spectrum Manager
1214
# Comcast
How many subscriber telephone lines can an NIU Handle?
4
1215
# Comcast
LPSU
Local Power Supply Unit
1216
# Comcast
The process of setting up the connection between the HDT and the NIU, where transmit levels and frequency are determined.
Marshalled
1217
# Comcast
Modulating technique that interweaves multiple conversations, based on time.
TDMA(Time Division Multiple Access)
1218
# Comcast
The number of the person that youare trying to call.
Terminating Number
1219
# Comcast
The phone company of the person you are trying to call.
Terminating LEC
1220
# Comcast
The “local” phone office where the subscriber’s lines are connected to the switching equipment.
Central Office
1221
# Comcast
What is "7" equal to in binary?
111
1222
# Comcast
64 QAM has how many phase angles?
52
1223
# Comcast
16 QAM has how many phase angles?
10
1224
# Comcast
The distance between two points of like phasein a wave.
Wavelength
1225
# Comcast
A card made up of material similar to photographic film that changes colors when exposed to light.
Photosensitive Card
1226
# Comcast
ANSI Laser standard that separates lasers into various classes that take into consideration the operating wavelength, output power level and whether the laser operates as a continuous or pulsed light output
Z-136
1227
# Comcast
Four nines works out to how many minutes of down time per month?
4.5 minutes
1228
# Comcast
loss of service to ourcustomers due to a fault in thedelivery network.
Outage
1229
# Comcast
Minimum telephone service to assure a contact in case of an emergency.
Lifeline
1230
# Comcast
FCC Standards CFR 47, Part 76.605(a)(1-12)
Proof-of-performance (POP) test
1231
# Comcast
A continuous wave (CW) frequency onto which information is modulated for transport.
Carrier Frequency
1232
# Comcast
Maximum Bandwidth of 256QAM
42.88Mbps
1233
# Comcast
How long must POP tests be kept at the local office?
minimum of 5 years
1234
# Comcast
how many test points are required for 1,000 to 12,500 customers?
6
1235
# Comcast
How many test points are required for each additional 12,500 customers?
1
1236
# Comcast
Channel requirements for POP testing (amount)
4 channels plus one additional channel for every 100 MHz.
1237
# Comcast
In a cable system with an upper frequency at 750 MHz, how many test channels must be used?
11 Channels
1238
# Comcast
All channels must be tested during these 3 tests.
Video Carrier Level, Audio Carrier Level, Video Carrier Level Stability Test
1239
# Comcast
Only one Channel needs to be tested during this non-frequency specific test
Hum Modulation
1240
# Comcast
How many digital channels must be tested on an all digital system with an upper frequency of 862MHz?
0, digital channels are not included and are not tested.
1241
# Comcast
The amount of channels during these tests are based solely on the highest operating frequency
Video-Audio Carrier Frequency SeparationIn-Channel ResponseCarrier to NoiseCoherent Disturbances Tests
1242
# Comcast
This test must be performed twice a year, once during the coldest months and again during the warmest (Jan-Feb and Jul-Aug respectively)
Video Carrier Level Stability (24-hour) test
1243
# Comcast
This POP test must be performed every three years
Color Performance test
1244
# Comcast
A circuit that automaticallyadjusts the gain of an amplifier sothat the output signal levels stayconstant despite varying inputlevels.
Automatic Gain Control (AGC)
1245
# Comcast
a spectrumanalyzer feature that allows theuser to make otherwise intrusiveFCC POP tests in a non-intrusivemanner.
Gated Testing
1246
# Comcast
When planning POP tests, these four things need to be considered
Test timesChannels and programming affected by testingTest lengthsAbility to perform non-intrusive gated testing
1247
# Comcast
This test is usually performed by a Headend tech rather than a System Tech
Color Performance
1248
# Comcast
What would a Discrepancy statement include?
Explain all possible misinterpreted fails, such as test point relocation, added channels, encoding issues and so on.
1249
# Comcast
POP measurements are to be taken at what location?
Input to the subscriber terminal
1250
# Comcast
EIA
Electronic Industry Association
1251
# Comcast
What must an operator do in order to pass the receivability test?
Submit documentation showing that their channel lineup conforms to the EIA Channel allocation plan
1252
# Comcast
What does the Audio Carrier Frequency Test ensure
That the audio carrier frequency for each channel must be 4.5MHz above the video carrier frequency, +/- 5kHz
1253
# Comcast
Where is the Audio Carrier Frequency test performed at?
The Headend as well as the field test points
1254
# Comcast
How many times a year is the Audio Carrier Frequency test performed?
Twice annually
1255
# Comcast
What type of set-top box can alter the Audio Carrier Frequency?
Baseband set-top boxes (as opposed to non-baseband)
1256
# Comcast
What six measurements are taken during the 24-hour test?
Minimum Visual Signal LevelVisual Signal changeAdjacent Visual SignalAny Other Visual Signal in BandwidthVisual Carrier LevelAudio Carrier Level
1257
# Comcast
The six measurements that are taken during the 24-hour test are performed on what channels?
All NTSC Channels at each test point location
1258
# Comcast
What is the Minimum Visual Signal Level allowed at the end of a 30-meter (100') cable drop that is connected to the subscriber tap?
1.41mV across an internal impedance of 75 ohms (+3dBmV(CT 5-3-22)
1259
# Comcast
The square root of the sum ofthe squares of the amplitudes ofindividual components of afunction, such as the frequencycomponents of a signal.
Root Mean Square (RMS)
1260
# Comcast
Maximum variation of each channel within any six-month period at the end of a 30-meter drop cable
8dB
1261
# Comcast
Adjacent Visual Signal deviation of the visual signal level of any visual carrier within a 6MHz nominal frequency separation
3dB
1262
# Comcast
What is the maximum "spread" or deviation among ALL channel levels in a 300MHz cable system and what is the incremental increase
10dB1db per 100MHz
1263
# Comcast
At what level must the aural signal be maintained in association with the visual signal level?
between 10dB and 17dB below the visual signal level
1264
# Comcast
At what level must the aural signal be maintained in association with the visual signal level on a baseband converter.
between 6.5dB and 17dB below the visual signal level.
1265
# Comcast
In a 24-hour test, how many times must the signal level be checked?
four times
1266
# Comcast
What are the time intervals of the 24-hour test?
5 to 7 hours
1267
# Comcast
at what frequency is the In-Channel Response test performed?
.75MHz to 5Mhz above the lower frequency boundary of the cable channel under test
1268
# Comcast
What is the FCC In-Channel Response requirement?
+/-2dB or 4dB peak-to-valley
1269
# Comcast
To perform this test, a signal must be inserted on the channel, either by the headend technician or by other means
In-Channel Response Test
1270
# Comcast
FCC Requirement for C/N
43dB at each test point
1271
# Comcast
What are the three type of coherent disturbances?
Composite Second Order (CSO)Composite Triple Beat (CTB)Other interfering signals (i.e. Ingress)
1272
# Comcast
What is the FCC requirement for Coherent Disturbances?
51dB below the desired carrier level for STD plans and 47dB in IRC and HRC systems
1273
# Comcast
The goal of this test is to find the worst beat or interfering signal, regardless of it's type
Coherent Disturbances Test
1274
# Comcast
FCC requirement for isolation
18dB
1275
# Comcast
Because the FCC allows you to submit manufacturers specifications to prove compliance, you rarely need to perform this test:
Terminal Isolation Test
1276
# Comcast
FCC requirement for Hum Modulation
less that 3% of the video carrier level.
1277
# Comcast
Where is the Hum Modulation test done?
the end of a 30m or 100' drop
1278
# Comcast
how many channels is the Hum Modulation test performed on?
One channel per test point
1279
# Comcast
How many channels is the Coherent Disturbance test performed on?
Dependent on highest frequency
1280
# Comcast
What are the three Color Performance tests?
Chrominance to Luminance Delay InequalityDifferential GainDifferential Phase
1281
# Comcast
FCC Spec for Chrominance to Luminance Delay test
Within 170 nanoseconds
1282
# Comcast
FCC Spec for Differential Gain
Within +/-20%
1283
# Comcast
FCC Spec for Differential Phase
Within +/-10 degrees
1284
# Comcast
Who usually performs the color performance tests?
The Headend Technician
1285
# Comcast
How many channels are recommended to be tested during the Color Performance test?
All NTSC or similar channels
1286
# Comcast
How often are the Color Performance Test performed?
once every three years
1287
# Comcast
Allowable signal leakage level below 54MHz
Up to 15uV/m @ 30m
1288
# Comcast
Allowable signal leakage level between 54MHz and 216 MHz
up to 20uV/m @ 3m
1289
# Comcast
Allowable signal leakage above 216MHz
up to 15uV/m @30m
1290
# Comcast
The two types of leakage monitoring frequency.
Continuous MonitoringQuarterly Monitoring
1291
# Comcast
Two types of annual leakage monitoring methods
Ground BasedFlyover
1292
# Comcast
What is the minimum cable strand sample allowed during a ground based leakage measurement?
75%
1293
# Comcast
What leaks are included in the CLI calculation?
All leaks 50uV or greater
1294
# Comcast
what is the elevation that a flyover is completed at? (in meters)
450m(1476')
1295
# Comcast
Two requirements for monitoring of plant with a handheld signal leakage detector
-Must be properly calibrated to detect a leak of 20uV/m or greater @ 3m-Perform all measurements with a horizontally polarized dipole antenna, preferably located no more than 3m from the leak and 3m from the ground
1296
# Comcast
What does a Spectrum Analyzer Display?
information in the amplitude (vertical) vs. frequency (horizontal) domain over the entire spectrum or portions of it.
1297
# Comcast
comparable in certain respects, typically in a way that makes clearer the nature of the things compared.
Analogous
1298
# Comcast
This filter has a bell-curved "shape," which it applies to all energy passing through it.
Resolution Bandwidth Filter (RBW)
1299
# Comcast
This is a low-pass filter at the analyzer detector's output. This filter takes the RF energy associated with the video modulation on the carrier that has already passed through the RBW filter and the detector and smoothes it out
Video Bandwidth Filter (VBW)(CT 5-3-39)
1300
# Comcast
The signal to an analyzer is injected here
RF Input
1301
# Comcast
Used when accessing analyzer's gated mode, such as in the C/N POP test
TV Input Connector
1302
# Comcast
The main setting and adjustment keys for the analyzer functions and the display. These keys are most often used in the analyzer's manual testing modes
Function Keys
1303
# Comcast
Additional keys whose action changes depending on the selected analyzer mode or function. Most often used in the analyzer's automated testing modes
Softkeys
1304
# Comcast
The principal keys useed in the analyzer's manual modes of operation. They represent the three most basic functions of any spectrum analyzer
Frequency, Span and Amplitude keys
1305
# Comcast
Adjusts the value or amount for the selected function or measurement
Adjustment Knob
1306
# Comcast
Adjust value or amount in incremental steps for the selected function or measurement
Step Key
1307
# Comcast
Allows direct input of a specific value or amount for the selected function or measurement
Numeric Keypad
1308
# Comcast
Sets the type of measurement unit, such as kHz or MHz, for the selected function or measurement
Measurement units' keys
1309
# Comcast
Marker function and trace control keys
Access marker functions and set trace control functions such as display line, RBW and VBW
1310
# Comcast
Sets analyzer modes, presets and stores or recalls analyzer trace
Mode select Key
1311
# Comcast
Maximum input power of HP 8591C
+72dBmV
1312
# Comcast
Maximum input power of Tektronix 2715
+69dBmV
1313
# Comcast
This must be used when high input levels are required to the analyzer to avoid input overload
preselector
1314
# Comcast
For the greatest accuracy, how should the carrier peak be adjusted?
To the analyzer's reference level (top of the display)
1315
# Comcast
Three tests that can use gated mode on the HP 8591C
Carrier to NoiseCoherent Disturbances (CSO measurement only)In-Channel Response
1316
# Comcast
The topology where signals originate in the headend andare transmitted long distances via trunk cables
Tree and Branch
1317
# Comcast
A network architecture that typically uses fiber optic cables to bring signals to selected areas of the system called nodes
Hybrid Fiber-Coax (HFC)
1318
# Comcast
Bi-annual tests, performed in the headend and at a number of end-of-line location
FCC Proof-of-Performance
1319
# Comcast
The cumulative effect of return path distortions they are added to the signal at various locations in the coaxial portion of the network.
Funnel Effect
1320
# Comcast
Specifications standards approved by the FCC in 1953for commercial analog color TV broadcasting.
National Television Standards Committee (NTSC)
1321
# Comcast
a portion of the electromagnetic spectrum whose frequencies are well suited for transmitting and receiving Telecommunications signals through the air.
Radio Frequency (RF) Spectrum
1322
# Comcast
Signals that flow downstream, from the headend to the network.
Forwards (Downstream) Signals
1323
# Comcast
Signals that flow in the upstream direction, from customer to headend
Revers (upstream) Signals
1324
# Comcast
Device that separates or combines based on frequency.
Diplex Filter
1325
# Comcast
typical cutoff frequency for a sub-split diplex filter
About 50 MHz
1326
# Comcast
The three major concerns/ limitations of the tree andbranch architecture are:
BandwidthImpairmentsDependency on Power
1327
# Comcast
The lowest possible power level determined by the thermal noise generated within the electrical componentsbeing tested
Noise Floor
1328
# Comcast
The highest power level (amplitude) reached by a carrier
Peak
1329
# Comcast
A clustering of beats 1.25 MHz above the visual carriers in a CATV network
Composite Second Order (CSO)
1330
# Comcast
A form of interference or noise resulting from the mixingof all of the various carriers in a CATV network
Composite Triple Beat (CTB)
1331
# Comcast
Two major types of distortions that are typically associated with CATV
Composite Second Order (CSO) and Composite Triple Beat (CTB)
1332
# Comcast
The 6 benefits of implementing fiber optics in broadband networks
Enhances Picture QualityIncreased ReliabilityDecreased cost of system maintenanceCost effective system bandwidth upgradesCost means of system upgrade requiring a complete change our of electronicsSmall segmented areas allow greater return path functionality
1333
# Comcast
Having or relating to a frequency below the audibility range of the human ear.
Infrasonic
1334
# Comcast
A stream of atomic nuclei that enter the earth’s atmosphere from outer space at speeds approaching that of light
Cosmic Rays
1335
# Comcast
Frequency range of satellite systems
4GHz to 13GHz
1336
# Comcast
The wavelengths most commonly used by the CATVindustry
1310nm and 1550nm
1337
# Comcast
The type of fiber optic cable that the broadband industry uses
Single Mode Fiber
1338
# Comcast
The process of combining multiple carriers onto a single medium
Multiplexing
1339
# Comcast
Width of the Fiber optic core
8-10um
1340
# Comcast
Width of the fiber optic cladding
125um
1341
# Comcast
Width of the fiber optic coating
250um
1342
# Comcast
Combines multiple optical signals in order to amplify them as a group and transported over a single fiber
Wave Division Multiplexing (WDM)
1343
# Comcast
Allows multiple wavelengths above and below a centerwavelength to be carried on a single optical fiber.
Dense Wave Division Multiplexing (DWDM)
1344
# Comcast
Three parts of the optical link
Fiber Optic CableTransmitter (Laser)Receiver (Node)
1345
# Comcast
Individual fibers are bundled and then placed into these to reduce the possibility of damage
Buffer Tubes
1346
# Comcast
This diode changes the RF signals to pulsesof light and then transmits them onto an optical fiber
Semiconductor Laser Diode
1347
# Comcast
The Three types of optical transmitters that are typically used in broadband HFC Network
Fabry-Perot (F-P)Distributed Feedback (DFB)Yttrium-Aluminum-Garnet (YAG)
1348
# Comcast
YAG
Yttrium-Aluminum-Garnet
1349
# Comcast
DFB
Distributed Feedback
1350
# Comcast
F-P
Fabry-Perot
1351
# Comcast
A spare fiber installed during the construction of the network that was reserved for future use.
Dark Fiber
1352
# Comcast
Three advantages of trunk reduction
Shorter CascadesFewer/smaller outages due to segmenting the system into smaller areasImproved picture Quality
1353
# Comcast
FTTF
Fiber to the Feeder
1354
# Comcast
Advantages of FTTF
Shorter CascadesFewer/smaller outages due to segmenting the system intosmaller areas.Increased Bandwidth
1355
# Comcast
FTTC
Fiber to the Curb
1356
# Comcast
PON
Passive Optical Network
1357
# Comcast
Consists of a transmitter at the Headend and a receiver near the subscriber. Requires a power supply near the node but all other actives have been removed
FTTC PON
1358
# Comcast
4 advantages of FTTC
No active devices after nodeNo CascadeFewer/smaller outages due to segmenting the system intovery small areasIncreased Bandwidth
1359
# Comcast
A fiber-based network which uses passive splitters todeliver signals to multiple locations
Passive Optical Network (PON)
1360
# Comcast
FTTH
Fiber to the Home
1361
# Comcast
6 advantages of FTTH
Passive networkSingle fiber is dedicated to each subscriberFeatures local battery backup, no large remote power supplies are required.No exterior active devicesNo CascadesIncreased Bandwidth
1362
# Comcast
This will ALWAYS be considered the "Backbone" in an HFC Network
The Fiber Network
1363
# Comcast
A high-speed line or series of connections that forms a major pathway within a network
Backbone
1364
# Comcast
The duplication of certain pieces and/or portions of thenetwork.
Redundancy
1365
# Comcast
Comcast's goal for network reliability
"four-nines" or 99.99%
1366
# Comcast
A network architecture where nodes, hubs, or headendsmay be connected with fiber optic cables to provideredundancy or increase services
Ring Architecture
1367
# Comcast
Builds upon ring technology by adding a second (redundant) ring connecting the nodes to the headend. The second ring typically takes a different path
Ring within a Ring
1368
# Comcast
A facility between the headend and the customer that performs many of the functions of a headend
Hubsite
1369
# Comcast
Similar in function to a hubsite, but serving fewer customers
Optical Transition Node (OTN)
1370
# Comcast
Usually a passive device such as a splitter or directional coupler used to combine radio frequency signals from one source with those from another
RF Combiner
1371
# Comcast
Usually a passive device that divides a signal into two equal paths. It may be found on trunk, feeder, or drop cable.
RF Splitter
1372
# Comcast
Device used to combine the channels for entry onto the cable or fiber optic transmitter
Headend Combiner
1373
# Comcast
The difference, in dB, of a signal level, injected into one output port, and the measured level of that same signal on another output port, with the input port properly terminated.
Port-to-port isolation
1374
# Comcast
Obtained by measuring the attenuation between the two output ports (A and B) when the common port (input port) is terminated in the correct value of impedance. An RF generator signal is applied to port A and an RF voltmeter reading is taken at Port B.
Isolation
1375
# Comcast
Provision for connection to a device such as a tap, splitter, set-top box or computer
Port
1376
# Comcast
Used to combine all of the signals to be carried over the cable system into a single medium (cable) for routing to the laser transmitters that are feeding the optical nodes in the system
Headend Combining Network
1377
# Comcast
A measurement of the reflected signal compared to that of the incident signal
Return Loss
1378
# Comcast
Device used to divide or combine light carriers on fiber optic cables.
Optical Splitter
1379
# Comcast
A discontinuous signal whose various states are discrete intervals apart.
Digital Signal
1380
# Comcast
Device used to convert an analog signal to a digital signal.
Digitizer
1381
# Comcast
takes an amplitude measurement of the waveform at fixed intervals of time, and converts them to a binary number
Digitizer
1382
# Comcast
The smallest unit of computerized data. Bits are defined as single characters of 0 or 1. Bandwidth is usually measured in bits-persecond.
Binary Digit (Bit)
1383
# Comcast
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.
Byte
1384
# Comcast
The number of changed states that can occur per second.
Baud
1385
# Comcast
The value of "On" in a binary system
"1"
1386
# Comcast
The value of "Off" in a Binary system
"0"
1387
# Comcast
How many bits are in a "Nibble"?
4
1388
# Comcast
In ASCII #5 alphabet, how man bits are in a byte?
7
1389
# Comcast
If start and stop bits are included with Asynchronous Communications, then how many bits are in a byte?
10
1390
# Comcast
ADC
Analog to Digital Conversion
1391
# Comcast
DAC
Digital to Analog Conversion
1392
# Comcast
A continuously varying signal with an unlimited number of possible values of amplitude and frequency.
Analog Signal
1393
# Comcast
a non-continuous signal or carrier that changes its output in discreetly timed steps of voltage level and/or phase that can represent numerical values or other information
Digital Transmission
1394
# Comcast
3 steps of basic ADC
SamplingQuantizationEncoding
1395
# Comcast
The "Measuring" of the analog signal at specific intervals.
Sampling
1396
# Comcast
The assigning of a specific value to each of the samples
Quantization
1397
# Comcast
The process by which Quantized values are converted into a data or bit stream
Encoding
1398
# Comcast
ASK
Amplitude Shift Keying
1399
# Comcast
FSK
Frequency Shift Keying
1400
# Comcast
QPSK
Quadrature Phase Shift Keying
1401
# Comcast
QAM
Quadrature Amplitude Modulation
1402
# Comcast
The process of varying the amplitude, frequency, or phase of a carrier to be in step with the instantaneous value of the modulating waveform
Modulation
1403
# Comcast
Data transmission scheme wherein the carrier is shifted in amplitude
Amplitude Shift Keying (ASK)
1404
# Comcast
The carrier frequency is shifted to represent the difference between a one and a zero
Frequency Shift Keying (FSK)
1405
# Comcast
The position on a waveform cycle at a specific point in time. One cycle is defined as 360 degrees of this
Phase
1406
# Comcast
Digital modulation scheme wherein the carrier is shifted in 90 degree steps. There are four possible phase states and the magnitude is constant.
Quadrature Phase Shift Keying (QPSK)
1407
# Comcast
BPSK
BiPhase Shift Keying
1408
# Comcast
In QPSK, what does "I" stand for?
In-Phase
1409
# Comcast
In QPSK, what does "Q" Stand for?
Quadrature - shifted 90* or one quarter of a cycle
1410
# Comcast
A graphic depiction of the four phase states of a Quadrature Phase Shift Key signal.
Constellation Diagram
1411
# Comcast
What is the bandwidth of QPSK in a 6MHz bandwidth?
10 Mb/s
1412
# Comcast
Digital modulation scheme that changes the phase and the amplitude.
Quadrature Amplitude Modulation (QAM)
1413
# Comcast
a digital transmission technology that splits the frequency band into a number of channels. The channels are each assigned a specific time slot, so that several transmissions can share a single channel without interfering with one another
Time Division Multiple Access (TDMA)
1414
# Comcast
The digital equivalent to Signal-to-Noise
Modulation Error Ratio (MER)
1415
# Comcast
A joined or connected group of devices
Network
1416
# Comcast
A network of computers linked by cable within a building or office complex.
Local Area Network (LAN)
1417
# Comcast
A network of multiple locations linked by cable withina city or campus
Metropolitan Area Network (MAN)
1418
# Comcast
A network typically bigger than a city or metropolitan area.
Wide Area Network (WAN)
1419
# Comcast
A data network connects each of its endpoints to the network with a single link. A central device (hub) is used to aggregate and distribute data traffic to all endpoints and/or other central points in what’s referred to as a clustered star.
Star
1420
# Comcast
Consists of several star networks that have been linked together
Clustered Star
1421
# Comcast
Topology where workstations are connected to the network through a common path
Bus
1422
# Comcast
A topology in which a data frame is passed around. As it arrives at an endpoint, the endpoint can either pass it along to the next endpoint or attach information to be sent to a destination
Token Ring
1423
# Comcast
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
Ring
1424
# Comcast
A method of data transmission that allows characters to be sent at irregular intervals by preceding each character with a 0 and by ending each character with a 1. This is referred to as start (0) and stop bits (1). It is the method, which most PCs use to communicate with each other and mainframes
Asynchronous Transmission
1425
# Comcast
An extra bit added to help check if the data that isbeing transferred is correct
Parity Bit
1426
# Comcast
The condition that occurs when two events happen in a specific time relationship with each other and both are under control of a master clock. Characters are spaced by time, not by start and stop bits.
Synchronous Transmission
1427
# Comcast
Synchronizing bits used in synchronous transmission to maintain synchronization between transmitter and receiver.
Sync Bits
1428
# Comcast
SNMP
Simple Network Management Protocol (SNMP)
1429
# Comcast
NE
Network Elements
1430
# Comcast
MIB
Management Information Base
1431
# Comcast
A unique number assigned to a piece of equipmentused for identification purposes.
Media Access Control Address (MAC)
1432
# Comcast
UTP
Unshielded Twisted Pair
1433
# Comcast
signaling rate of 10BaseT
10 Mb/s
1434
# Comcast
Signaling rate of 100BaseT
100 Mb/s
1435
# Comcast
The designation for Ethernet over fiber optic cable, primarily for point-topoint links
10Base-F
1436
# Comcast
Ethernet resides in what layers of the OSI model?
The 2 lowest levels (layers)
1437
# Comcast
This device works as a multiport signal repeater, broadcasting an incoming signal to all other ports on an ethernet network
Ethernet Hub
1438
# Comcast
The four-part numeric address that is assigned to a computer or an account as an identification tool
Internet Protocol Address (IP)
1439
# Comcast
IEEE MAC Protocol for Hybrid Fiber-Coax Networks; standard for data communicatons over a cable network
802.14
1440
# Comcast
The Four original partners of MCNS (Multimedia Cable Network Partners Ltd.)
Comcast, Cox, TCI and Time Warner
1441
# Comcast
The three companies that joined MCNS in late 1996
Media One, Rogers Cablevision and CableLabs
1442
# Comcast
DOCSIS
Data Over Cable Service Interface Specification
1443
# Comcast
When was DOCSIS 1.0 released? (Month & Year)
Mar-97
1444
# Comcast
The Leading standard for cable modems
DOCSIS
1445
# Comcast
Four devices that must be added to a system to offer high-speed internet
CMTS (Cable Modem Termination System)CM (Cable Modem)ServersNoise Filters
1446
# Comcast
A unit consisting of various hardware and software entities that acts as the hand-off point between the RF based HFC network and other networks such as theInternet and the PSTN.
CMTS (Cable Modem Termination System)
1447
# Comcast
Used to terminate, manage and translate high-speed Internet sessions between cable modems in a LAN and other devices in a WAN.
CMTS (Cable Modem Termination System)
1448
# Comcast
The collection of computers accessed through the Internet. Uses a hypertext based system for finding andaccessing its resources.
WWW (World Wide Web)
1449
# Comcast
Four Items that a CMTS manages
Time SlotsContention SlotsModem DataTransmit Levels
1450
# Comcast
Each cable modem is assigned one of these by the CMTS and only one modem is allowed to transmit during this.
Time Slot
1451
# Comcast
These slots are usually used for short data transmissions such as a request for an additional number of reserved time slots
Contention Slots
1452
# Comcast
The signal level that the CMTS wants to "See"
0dBmV
1453
# Comcast
A PC on a LAN from which information or applications are requested.
Client/Server
1454
# Comcast
A computer circuit board (card) installed in a computer so that the computer can be connected to a network. Provide a dedicated, full-time connection to a network.
NIC (Network Interface Card)
1455
# Comcast
Why is it called a cable "Modem"?
When they transmit data they "MOdulate" the data onto a carrier, then receive data and "DEModulate" it from the carrier and send it on to the computer
1456
# Comcast
Four of the most common servers found in a braodband network
DHCPTODTFTPProxy
1457
# Comcast
This server sets up the MAC and IP addresses for the cable modem.
DHCP Server(Dynamic Host Configuration Protocol)
1458
# Comcast
This server sets up a common clock between the CM and the CMTS
TOD Server(Time of Day)
1459
# Comcast
This server allows non-protected file transfers, such as aconfiguration file for a modem.
TFTP Server(Trivial File Transfer Protocol)
1460
# Comcast
These servers store commonly used (or contractually stored) data. A network may have a series of these servers located in different places.
Proxy Server
1461
# Comcast
The two types of noise filters
High Pass FilterNotch Filter
1462
# Comcast
These types of filters only allow signals above 50MHz to pass through the filter
High Pass Filter
1463
# Comcast
In addition to letting everything above 50 MHz to pass, this filter allows a small spectrum below 50 MHz to pass
Notch Filter
1464
# Comcast
The process of setting up the connection between theCMTS and the cable modem, where transmit levels andfrequency are determined.
Ranged
1465
# Comcast
A switch or collection of switches connecting multiple networks
POP (Point of Presence)
1466
# Comcast
The point of access into theInternet.
NAP(Network Access Point)
1467
# Comcast
The company who provides access to the Internet and the World Wide Web, who usually also provides corefeatures such as e-mail.
ISPInternet Service Provider
1468
# Comcast
The local, long-distance and internationalphone system in use today
PSTN(Public Switched Telephone Network)
1469
# Comcast
This device in the Headend controls the operation of CDV.
HDT(Host Digital Terminal)
1470
# Comcast
Three major components of the Host Digital Terminal
Access Bandwidth Manager ShelfModem ShelfSpectrum Manager Shelf
1471
# Comcast
This Shelf provides the connection between the Network Interface Unit (NIU) and the switch, or more simply, the connection between the HDT and the LEC
ABM(Access Bandwidth Manager)
1472
# Comcast
The point of demarcation between the network and the customer. It contains the modem necessary for telephony over a cable network.
NIU(Network Interface Device)
1473
# Comcast
The device that opens or breaks the circuit path in a telephone call. This device looks at the incoming data to determine where the data should get routed.
Switch
1474
# Comcast
The local phone company is also known as what?
LEC(Local Exchange Carrier
1475
# Comcast
Shelf on the HDT (Host Digital Terminal) that converts the digital telephone signals into digital signals that are then modulated onto an RF carrier to be transmitted over the HFC Network.
Modem Shelf
1476
# Comcast
This shelf on the HDT (Host Digital Terminal) monitors the RF spectrum allocated for telephone services over the HFC network. If problems are detected, it can switch the data transmission (telephone call) to another frequency.
Spectrum Manager
1477
# Comcast
How many subscriber telephone lines can an NIU Handle?
4
1478
# Comcast
LPSU
Local Power Supply Unit
1479
# Comcast
The process of setting up the connection between the HDT and the NIU, where transmit levels and frequency are determined.
Marshalled
1480
# Comcast
Modulating technique that interweaves multiple conversations, based on time.
TDMA(Time Division Multiple Access)
1481
# Comcast
The number of the person that youare trying to call.
Terminating Number
1482
# Comcast
The phone company of the person you are trying to call.
Terminating LEC
1483
# Comcast
The “local” phone office where the subscriber’s lines are connected to the switching equipment.
Central Office
1484
# Comcast
What is "7" equal to in binary?
111
1485
# Comcast
64 QAM has how many phase angles?
52
1486
# Comcast
16 QAM has how many phase angles?
10
1487
# Comcast
The distance between two points of like phasein a wave.
Wavelength
1488
# Comcast
A card made up of material similar to photographic film that changes colors when exposed to light.
Photosensitive Card
1489
# Comcast
ANSI Laser standard that separates lasers into various classes that take into consideration the operating wavelength, output power level and whether the laser operates as a continuous or pulsed light output
Z-136
1490
# Comcast
Four nines works out to how many minutes of down time per month?
4.5 minutes
1491
# Comcast
loss of service to ourcustomers due to a fault in thedelivery network.
Outage
1492
# Comcast
Minimum telephone service to assure a contact in case of an emergency.
Lifeline
1493
# Comcast
FCC Standards CFR 47, Part 76.605(a)(1-12)
Proof-of-performance (POP) test
1494
# Comcast
A continuous wave (CW) frequency onto which information is modulated for transport.
Carrier Frequency
1495
# Comcast
Maximum Bandwidth of 256QAM
42.88Mbps
1496
# Comcast
How long must POP tests be kept at the local office?
minimum of 5 years
1497
# Comcast
how many test points are required for 1,000 to 12,500 customers?
6
1498
# Comcast
How many test points are required for each additional 12,500 customers?
1
1499
# Comcast
Channel requirements for POP testing (amount)
4 channels plus one additional channel for every 100 MHz.
1500
# Comcast
In a cable system with an upper frequency at 750 MHz, how many test channels must be used?
11 Channels
1501
# Comcast
All channels must be tested during these 3 tests.
Video Carrier Level, Audio Carrier Level, Video Carrier Level Stability Test
1502
# Comcast
Only one Channel needs to be tested during this non-frequency specific test
Hum Modulation
1503
# Comcast
How many digital channels must be tested on an all digital system with an upper frequency of 862MHz?
0, digital channels are not included and are not tested.
1504
# Comcast
The amount of channels during these tests are based solely on the highest operating frequency
Video-Audio Carrier Frequency SeparationIn-Channel ResponseCarrier to NoiseCoherent Disturbances Tests
1505
# Comcast
This test must be performed twice a year, once during the coldest months and again during the warmest (Jan-Feb and Jul-Aug respectively)
Video Carrier Level Stability (24-hour) test
1506
# Comcast
This POP test must be performed every three years
Color Performance test
1507
# Comcast
A circuit that automaticallyadjusts the gain of an amplifier sothat the output signal levels stayconstant despite varying inputlevels.
Automatic Gain Control (AGC)
1508
# Comcast
a spectrumanalyzer feature that allows theuser to make otherwise intrusiveFCC POP tests in a non-intrusivemanner.
Gated Testing
1509
# Comcast
When planning POP tests, these four things need to be considered
Test timesChannels and programming affected by testingTest lengthsAbility to perform non-intrusive gated testing
1510
# Comcast
This test is usually performed by a Headend tech rather than a System Tech
Color Performance
1511
# Comcast
What would a Discrepancy statement include?
Explain all possible misinterpreted fails, such as test point relocation, added channels, encoding issues and so on.
1512
# Comcast
POP measurements are to be taken at what location?
Input to the subscriber terminal
1513
# Comcast
EIA
Electronic Industry Association
1514
# Comcast
What must an operator do in order to pass the receivability test?
Submit documentation showing that their channel lineup conforms to the EIA Channel allocation plan
1515
# Comcast
What does the Audio Carrier Frequency Test ensure
That the audio carrier frequency for each channel must be 4.5MHz above the video carrier frequency, +/- 5kHz
1516
# Comcast
Where is the Audio Carrier Frequency test performed at?
The Headend as well as the field test points
1517
# Comcast
How many times a year is the Audio Carrier Frequency test performed?
Twice annually
1518
# Comcast
What type of set-top box can alter the Audio Carrier Frequency?
Baseband set-top boxes (as opposed to non-baseband)
1519
# Comcast
What six measurements are taken during the 24-hour test?
Minimum Visual Signal LevelVisual Signal changeAdjacent Visual SignalAny Other Visual Signal in BandwidthVisual Carrier LevelAudio Carrier Level
1520
# Comcast
The six measurements that are taken during the 24-hour test are performed on what channels?
All NTSC Channels at each test point location
1521
# Comcast
What is the Minimum Visual Signal Level allowed at the end of a 30-meter (100') cable drop that is connected to the subscriber tap?
1.41mV across an internal impedance of 75 ohms (+3dBmV(CT 5-3-22)
1522
# Comcast
The square root of the sum ofthe squares of the amplitudes ofindividual components of afunction, such as the frequencycomponents of a signal.
Root Mean Square (RMS)
1523
# Comcast
Maximum variation of each channel within any six-month period at the end of a 30-meter drop cable
8dB
1524
# Comcast
Adjacent Visual Signal deviation of the visual signal level of any visual carrier within a 6MHz nominal frequency separation
3dB
1525
# Comcast
What is the maximum "spread" or deviation among ALL channel levels in a 300MHz cable system and what is the incremental increase
10dB1db per 100MHz
1526
# Comcast
At what level must the aural signal be maintained in association with the visual signal level?
between 10dB and 17dB below the visual signal level
1527
# Comcast
At what level must the aural signal be maintained in association with the visual signal level on a baseband converter.
between 6.5dB and 17dB below the visual signal level.
1528
# Comcast
In a 24-hour test, how many times must the signal level be checked?
four times
1529
# Comcast
What are the time intervals of the 24-hour test?
5 to 7 hours
1530
# Comcast
at what frequency is the In-Channel Response test performed?
.75MHz to 5Mhz above the lower frequency boundary of the cable channel under test
1531
# Comcast
What is the FCC In-Channel Response requirement?
+/-2dB or 4dB peak-to-valley
1532
# Comcast
To perform this test, a signal must be inserted on the channel, either by the headend technician or by other means
In-Channel Response Test
1533
# Comcast
FCC Requirement for C/N
43dB at each test point
1534
# Comcast
What are the three type of coherent disturbances?
Composite Second Order (CSO)Composite Triple Beat (CTB)Other interfering signals (i.e. Ingress)
1535
# Comcast
What is the FCC requirement for Coherent Disturbances?
51dB below the desired carrier level for STD plans and 47dB in IRC and HRC systems
1536
# Comcast
The goal of this test is to find the worst beat or interfering signal, regardless of it's type
Coherent Disturbances Test
1537
# Comcast
FCC requirement for isolation
18dB
1538
# Comcast
Because the FCC allows you to submit manufacturers specifications to prove compliance, you rarely need to perform this test:
Terminal Isolation Test
1539
# Comcast
FCC requirement for Hum Modulation
less that 3% of the video carrier level.
1540
# Comcast
Where is the Hum Modulation test done?
the end of a 30m or 100' drop
1541
# Comcast
how many channels is the Hum Modulation test performed on?
One channel per test point
1542
# Comcast
How many channels is the Coherent Disturbance test performed on?
Dependent on highest frequency
1543
# Comcast
What are the three Color Performance tests?
Chrominance to Luminance Delay InequalityDifferential GainDifferential Phase
1544
# Comcast
FCC Spec for Chrominance to Luminance Delay test
Within 170 nanoseconds
1545
# Comcast
FCC Spec for Differential Gain
Within +/-20%
1546
# Comcast
FCC Spec for Differential Phase
Within +/-10 degrees
1547
# Comcast
Who usually performs the color performance tests?
The Headend Technician
1548
# Comcast
How many channels are recommended to be tested during the Color Performance test?
All NTSC or similar channels
1549
# Comcast
How often are the Color Performance Test performed?
once every three years
1550
# Comcast
Allowable signal leakage level below 54MHz
Up to 15uV/m @ 30m
1551
# Comcast
Allowable signal leakage level between 54MHz and 216 MHz
up to 20uV/m @ 3m
1552
# Comcast
Allowable signal leakage above 216MHz
up to 15uV/m @30m
1553
# Comcast
The two types of leakage monitoring frequency.
Continuous MonitoringQuarterly Monitoring
1554
# Comcast
Two types of annual leakage monitoring methods
Ground BasedFlyover
1555
# Comcast
What is the minimum cable strand sample allowed during a ground based leakage measurement?
75%
1556
# Comcast
What leaks are included in the CLI calculation?
All leaks 50uV or greater
1557
# Comcast
what is the elevation that a flyover is completed at? (in meters)
450m(1476')
1558
# Comcast
Two requirements for monitoring of plant with a handheld signal leakage detector
-Must be properly calibrated to detect a leak of 20uV/m or greater @ 3m-Perform all measurements with a horizontally polarized dipole antenna, preferably located no more than 3m from the leak and 3m from the ground
1559
# Comcast
What does a Spectrum Analyzer Display?
information in the amplitude (vertical) vs. frequency (horizontal) domain over the entire spectrum or portions of it.
1560
# Comcast
comparable in certain respects, typically in a way that makes clearer the nature of the things compared.
Analogous
1561
# Comcast
This filter has a bell-curved "shape," which it applies to all energy passing through it.
Resolution Bandwidth Filter (RBW)
1562
# Comcast
This is a low-pass filter at the analyzer detector's output. This filter takes the RF energy associated with the video modulation on the carrier that has already passed through the RBW filter and the detector and smoothes it out
Video Bandwidth Filter (VBW)(CT 5-3-39)
1563
# Comcast
The signal to an analyzer is injected here
RF Input
1564
# Comcast
Used when accessing analyzer's gated mode, such as in the C/N POP test
TV Input Connector
1565
# Comcast
The main setting and adjustment keys for the analyzer functions and the display. These keys are most often used in the analyzer's manual testing modes
Function Keys
1566
# Comcast
Additional keys whose action changes depending on the selected analyzer mode or function. Most often used in the analyzer's automated testing modes
Softkeys
1567
# Comcast
The principal keys useed in the analyzer's manual modes of operation. They represent the three most basic functions of any spectrum analyzer
Frequency, Span and Amplitude keys
1568
# Comcast
Adjusts the value or amount for the selected function or measurement
Adjustment Knob
1569
# Comcast
Adjust value or amount in incremental steps for the selected function or measurement
Step Key
1570
# Comcast
Allows direct input of a specific value or amount for the selected function or measurement
Numeric Keypad
1571
# Comcast
Sets the type of measurement unit, such as kHz or MHz, for the selected function or measurement
Measurement units' keys
1572
# Comcast
Marker function and trace control keys
Access marker functions and set trace control functions such as display line, RBW and VBW
1573
# Comcast
Sets analyzer modes, presets and stores or recalls analyzer trace
Mode select Key
1574
# Comcast
Maximum input power of HP 8591C
+72dBmV
1575
# Comcast
Maximum input power of Tektronix 2715
+69dBmV
1576
# Comcast
This must be used when high input levels are required to the analyzer to avoid input overload
preselector
1577
# Comcast
For the greatest accuracy, how should the carrier peak be adjusted?
To the analyzer's reference level (top of the display)
1578
# Comcast
Three tests that can use gated mode on the HP 8591C
Carrier to NoiseCoherent Disturbances (CSO measurement only)In-Channel Response
1579
# Comcast
The topology where signals originate in the headend andare transmitted long distances via trunk cables
Tree and Branch
1580
# Comcast
A network architecture that typically uses fiber optic cables to bring signals to selected areas of the system called nodes
Hybrid Fiber-Coax (HFC)
1581
# Comcast
Bi-annual tests, performed in the headend and at a number of end-of-line location
FCC Proof-of-Performance
1582
# Comcast
The cumulative effect of return path distortions they are added to the signal at various locations in the coaxial portion of the network.
Funnel Effect
1583
# Comcast
Specifications standards approved by the FCC in 1953for commercial analog color TV broadcasting.
National Television Standards Committee (NTSC)
1584
# Comcast
a portion of the electromagnetic spectrum whose frequencies are well suited for transmitting and receiving Telecommunications signals through the air.
Radio Frequency (RF) Spectrum
1585
# Comcast
Signals that flow downstream, from the headend to the network.
Forwards (Downstream) Signals
1586
# Comcast
Signals that flow in the upstream direction, from customer to headend
Revers (upstream) Signals
1587
# Comcast
Device that separates or combines based on frequency.
Diplex Filter
1588
# Comcast
typical cutoff frequency for a sub-split diplex filter
About 50 MHz
1589
# Comcast
The three major concerns/ limitations of the tree andbranch architecture are:
BandwidthImpairmentsDependency on Power
1590
# Comcast
The lowest possible power level determined by the thermal noise generated within the electrical componentsbeing tested
Noise Floor
1591
# Comcast
The highest power level (amplitude) reached by a carrier
Peak
1592
# Comcast
A clustering of beats 1.25 MHz above the visual carriers in a CATV network
Composite Second Order (CSO)
1593
# Comcast
A form of interference or noise resulting from the mixingof all of the various carriers in a CATV network
Composite Triple Beat (CTB)
1594
# Comcast
Two major types of distortions that are typically associated with CATV
Composite Second Order (CSO) and Composite Triple Beat (CTB)
1595
# Comcast
The 6 benefits of implementing fiber optics in broadband networks
Enhances Picture QualityIncreased ReliabilityDecreased cost of system maintenanceCost effective system bandwidth upgradesCost means of system upgrade requiring a complete change our of electronicsSmall segmented areas allow greater return path functionality
1596
# Comcast
Having or relating to a frequency below the audibility range of the human ear.
Infrasonic
1597
# Comcast
A stream of atomic nuclei that enter the earth’s atmosphere from outer space at speeds approaching that of light
Cosmic Rays
1598
# Comcast
Frequency range of satellite systems
4GHz to 13GHz
1599
# Comcast
The wavelengths most commonly used by the CATVindustry
1310nm and 1550nm
1600
# Comcast
The type of fiber optic cable that the broadband industry uses
Single Mode Fiber
1601
# Comcast
The process of combining multiple carriers onto a single medium
Multiplexing
1602
# Comcast
Width of the Fiber optic core
8-10um
1603
# Comcast
Width of the fiber optic cladding
125um
1604
# Comcast
Width of the fiber optic coating
250um
1605
# Comcast
Combines multiple optical signals in order to amplify them as a group and transported over a single fiber
Wave Division Multiplexing (WDM)
1606
# Comcast
Allows multiple wavelengths above and below a centerwavelength to be carried on a single optical fiber.
Dense Wave Division Multiplexing (DWDM)
1607
# Comcast
Three parts of the optical link
Fiber Optic CableTransmitter (Laser)Receiver (Node)
1608
# Comcast
Individual fibers are bundled and then placed into these to reduce the possibility of damage
Buffer Tubes
1609
# Comcast
This diode changes the RF signals to pulsesof light and then transmits them onto an optical fiber
Semiconductor Laser Diode
1610
# Comcast
The Three types of optical transmitters that are typically used in broadband HFC Network
Fabry-Perot (F-P)Distributed Feedback (DFB)Yttrium-Aluminum-Garnet (YAG)
1611
# Comcast
YAG
Yttrium-Aluminum-Garnet
1612
# Comcast
DFB
Distributed Feedback
1613
# Comcast
F-P
Fabry-Perot
1614
# Comcast
A spare fiber installed during the construction of the network that was reserved for future use.
Dark Fiber
1615
# Comcast
Three advantages of trunk reduction
Shorter CascadesFewer/smaller outages due to segmenting the system into smaller areasImproved picture Quality
1616
# Comcast
FTTF
Fiber to the Feeder
1617
# Comcast
Advantages of FTTF
Shorter CascadesFewer/smaller outages due to segmenting the system intosmaller areas.Increased Bandwidth
1618
# Comcast
FTTC
Fiber to the Curb
1619
# Comcast
PON
Passive Optical Network
1620
# Comcast
Consists of a transmitter at the Headend and a receiver near the subscriber. Requires a power supply near the node but all other actives have been removed
FTTC PON
1621
# Comcast
4 advantages of FTTC
No active devices after nodeNo CascadeFewer/smaller outages due to segmenting the system intovery small areasIncreased Bandwidth
1622
# Comcast
A fiber-based network which uses passive splitters todeliver signals to multiple locations
Passive Optical Network (PON)
1623
# Comcast
FTTH
Fiber to the Home
1624
# Comcast
6 advantages of FTTH
Passive networkSingle fiber is dedicated to each subscriberFeatures local battery backup, no large remote power supplies are required.No exterior active devicesNo CascadesIncreased Bandwidth
1625
# Comcast
This will ALWAYS be considered the "Backbone" in an HFC Network
The Fiber Network
1626
# Comcast
A high-speed line or series of connections that forms a major pathway within a network
Backbone
1627
# Comcast
The duplication of certain pieces and/or portions of thenetwork.
Redundancy
1628
# Comcast
Comcast's goal for network reliability
"four-nines" or 99.99%
1629
# Comcast
A network architecture where nodes, hubs, or headendsmay be connected with fiber optic cables to provideredundancy or increase services
Ring Architecture
1630
# Comcast
Builds upon ring technology by adding a second (redundant) ring connecting the nodes to the headend. The second ring typically takes a different path
Ring within a Ring
1631
# Comcast
A facility between the headend and the customer that performs many of the functions of a headend
Hubsite
1632
# Comcast
Similar in function to a hubsite, but serving fewer customers
Optical Transition Node (OTN)
1633
# Comcast
Usually a passive device such as a splitter or directional coupler used to combine radio frequency signals from one source with those from another
RF Combiner
1634
# Comcast
Usually a passive device that divides a signal into two equal paths. It may be found on trunk, feeder, or drop cable.
RF Splitter
1635
# Comcast
Device used to combine the channels for entry onto the cable or fiber optic transmitter
Headend Combiner
1636
# Comcast
The difference, in dB, of a signal level, injected into one output port, and the measured level of that same signal on another output port, with the input port properly terminated.
Port-to-port isolation
1637
# Comcast
Obtained by measuring the attenuation between the two output ports (A and B) when the common port (input port) is terminated in the correct value of impedance. An RF generator signal is applied to port A and an RF voltmeter reading is taken at Port B.
Isolation
1638
# Comcast
Provision for connection to a device such as a tap, splitter, set-top box or computer
Port
1639
# Comcast
Used to combine all of the signals to be carried over the cable system into a single medium (cable) for routing to the laser transmitters that are feeding the optical nodes in the system
Headend Combining Network
1640
# Comcast
A measurement of the reflected signal compared to that of the incident signal
Return Loss
1641
# Comcast
Device used to divide or combine light carriers on fiber optic cables.
Optical Splitter
1642
# Comcast
A discontinuous signal whose various states are discrete intervals apart.
Digital Signal
1643
# Comcast
Device used to convert an analog signal to a digital signal.
Digitizer
1644
# Comcast
takes an amplitude measurement of the waveform at fixed intervals of time, and converts them to a binary number
Digitizer
1645
# Comcast
The smallest unit of computerized data. Bits are defined as single characters of 0 or 1. Bandwidth is usually measured in bits-persecond.
Binary Digit (Bit)
1646
# Comcast
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.
Byte
1647
# Comcast
The number of changed states that can occur per second.
Baud
1648
# Comcast
The value of "On" in a binary system
"1"
1649
# Comcast
The value of "Off" in a Binary system
"0"
1650
# Comcast
How many bits are in a "Nibble"?
4
1651
# Comcast
In ASCII #5 alphabet, how man bits are in a byte?
7
1652
# Comcast
If start and stop bits are included with Asynchronous Communications, then how many bits are in a byte?
10
1653
# Comcast
ADC
Analog to Digital Conversion
1654
# Comcast
DAC
Digital to Analog Conversion
1655
# Comcast
A continuously varying signal with an unlimited number of possible values of amplitude and frequency.
Analog Signal
1656
# Comcast
a non-continuous signal or carrier that changes its output in discreetly timed steps of voltage level and/or phase that can represent numerical values or other information
Digital Transmission
1657
# Comcast
3 steps of basic ADC
SamplingQuantizationEncoding
1658
# Comcast
The "Measuring" of the analog signal at specific intervals.
Sampling
1659
# Comcast
The assigning of a specific value to each of the samples
Quantization
1660
# Comcast
The process by which Quantized values are converted into a data or bit stream
Encoding
1661
# Comcast
ASK
Amplitude Shift Keying
1662
# Comcast
FSK
Frequency Shift Keying
1663
# Comcast
QPSK
Quadrature Phase Shift Keying
1664
# Comcast
QAM
Quadrature Amplitude Modulation
1665
# Comcast
The process of varying the amplitude, frequency, or phase of a carrier to be in step with the instantaneous value of the modulating waveform
Modulation
1666
# Comcast
Data transmission scheme wherein the carrier is shifted in amplitude
Amplitude Shift Keying (ASK)
1667
# Comcast
The carrier frequency is shifted to represent the difference between a one and a zero
Frequency Shift Keying (FSK)
1668
# Comcast
The position on a waveform cycle at a specific point in time. One cycle is defined as 360 degrees of this
Phase
1669
# Comcast
Digital modulation scheme wherein the carrier is shifted in 90 degree steps. There are four possible phase states and the magnitude is constant.
Quadrature Phase Shift Keying (QPSK)
1670
# Comcast
BPSK
BiPhase Shift Keying
1671
# Comcast
In QPSK, what does "I" stand for?
In-Phase
1672
# Comcast
In QPSK, what does "Q" Stand for?
Quadrature - shifted 90* or one quarter of a cycle
1673
# Comcast
A graphic depiction of the four phase states of a Quadrature Phase Shift Key signal.
Constellation Diagram
1674
# Comcast
What is the bandwidth of QPSK in a 6MHz bandwidth?
10 Mb/s
1675
# Comcast
Digital modulation scheme that changes the phase and the amplitude.
Quadrature Amplitude Modulation (QAM)
1676
# Comcast
a digital transmission technology that splits the frequency band into a number of channels. The channels are each assigned a specific time slot, so that several transmissions can share a single channel without interfering with one another
Time Division Multiple Access (TDMA)
1677
# Comcast
The digital equivalent to Signal-to-Noise
Modulation Error Ratio (MER)
1678
# Comcast
A joined or connected group of devices
Network
1679
# Comcast
A network of computers linked by cable within a building or office complex.
Local Area Network (LAN)
1680
# Comcast
A network of multiple locations linked by cable withina city or campus
Metropolitan Area Network (MAN)
1681
# Comcast
A network typically bigger than a city or metropolitan area.
Wide Area Network (WAN)
1682
# Comcast
A data network connects each of its endpoints to the network with a single link. A central device (hub) is used to aggregate and distribute data traffic to all endpoints and/or other central points in what’s referred to as a clustered star.
Star
1683
# Comcast
Consists of several star networks that have been linked together
Clustered Star
1684
# Comcast
Topology where workstations are connected to the network through a common path
Bus
1685
# Comcast
A topology in which a data frame is passed around. As it arrives at an endpoint, the endpoint can either pass it along to the next endpoint or attach information to be sent to a destination
Token Ring
1686
# Comcast
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
Ring
1687
# Comcast
A method of data transmission that allows characters to be sent at irregular intervals by preceding each character with a 0 and by ending each character with a 1. This is referred to as start (0) and stop bits (1). It is the method, which most PCs use to communicate with each other and mainframes
Asynchronous Transmission
1688
# Comcast
An extra bit added to help check if the data that isbeing transferred is correct
Parity Bit
1689
# Comcast
The condition that occurs when two events happen in a specific time relationship with each other and both are under control of a master clock. Characters are spaced by time, not by start and stop bits.
Synchronous Transmission
1690
# Comcast
Synchronizing bits used in synchronous transmission to maintain synchronization between transmitter and receiver.
Sync Bits
1691
# Comcast
SNMP
Simple Network Management Protocol (SNMP)
1692
# Comcast
NE
Network Elements
1693
# Comcast
MIB
Management Information Base
1694
# Comcast
A unique number assigned to a piece of equipmentused for identification purposes.
Media Access Control Address (MAC)
1695
# Comcast
UTP
Unshielded Twisted Pair
1696
# Comcast
signaling rate of 10BaseT
10 Mb/s
1697
# Comcast
Signaling rate of 100BaseT
100 Mb/s
1698
# Comcast
The designation for Ethernet over fiber optic cable, primarily for point-topoint links
10Base-F
1699
# Comcast
Ethernet resides in what layers of the OSI model?
The 2 lowest levels (layers)
1700
# Comcast
This device works as a multiport signal repeater, broadcasting an incoming signal to all other ports on an ethernet network
Ethernet Hub
1701
# Comcast
The four-part numeric address that is assigned to a computer or an account as an identification tool
Internet Protocol Address (IP)
1702
# Comcast
IEEE MAC Protocol for Hybrid Fiber-Coax Networks; standard for data communicatons over a cable network
802.14
1703
# Comcast
The Four original partners of MCNS (Multimedia Cable Network Partners Ltd.)
Comcast, Cox, TCI and Time Warner
1704
# Comcast
The three companies that joined MCNS in late 1996
Media One, Rogers Cablevision and CableLabs
1705
# Comcast
DOCSIS
Data Over Cable Service Interface Specification
1706
# Comcast
When was DOCSIS 1.0 released? (Month & Year)
Mar-97
1707
# Comcast
The Leading standard for cable modems
DOCSIS
1708
# Comcast
Four devices that must be added to a system to offer high-speed internet
CMTS (Cable Modem Termination System)CM (Cable Modem)ServersNoise Filters
1709
# Comcast
A unit consisting of various hardware and software entities that acts as the hand-off point between the RF based HFC network and other networks such as theInternet and the PSTN.
CMTS (Cable Modem Termination System)
1710
# Comcast
Used to terminate, manage and translate high-speed Internet sessions between cable modems in a LAN and other devices in a WAN.
CMTS (Cable Modem Termination System)
1711
# Comcast
The collection of computers accessed through the Internet. Uses a hypertext based system for finding andaccessing its resources.
WWW (World Wide Web)
1712
# Comcast
Four Items that a CMTS manages
Time SlotsContention SlotsModem DataTransmit Levels
1713
# Comcast
Each cable modem is assigned one of these by the CMTS and only one modem is allowed to transmit during this.
Time Slot
1714
# Comcast
These slots are usually used for short data transmissions such as a request for an additional number of reserved time slots
Contention Slots
1715
# Comcast
The signal level that the CMTS wants to "See"
0dBmV
1716
# Comcast
A PC on a LAN from which information or applications are requested.
Client/Server
1717
# Comcast
A computer circuit board (card) installed in a computer so that the computer can be connected to a network. Provide a dedicated, full-time connection to a network.
NIC (Network Interface Card)
1718
# Comcast
Why is it called a cable "Modem"?
When they transmit data they "MOdulate" the data onto a carrier, then receive data and "DEModulate" it from the carrier and send it on to the computer
1719
# Comcast
Four of the most common servers found in a braodband network
DHCPTODTFTPProxy
1720
# Comcast
This server sets up the MAC and IP addresses for the cable modem.
DHCP Server(Dynamic Host Configuration Protocol)
1721
# Comcast
This server sets up a common clock between the CM and the CMTS
TOD Server(Time of Day)
1722
# Comcast
This server allows non-protected file transfers, such as aconfiguration file for a modem.
TFTP Server(Trivial File Transfer Protocol)
1723
# Comcast
These servers store commonly used (or contractually stored) data. A network may have a series of these servers located in different places.
Proxy Server
1724
# Comcast
The two types of noise filters
High Pass FilterNotch Filter
1725
# Comcast
These types of filters only allow signals above 50MHz to pass through the filter
High Pass Filter
1726
# Comcast
In addition to letting everything above 50 MHz to pass, this filter allows a small spectrum below 50 MHz to pass
Notch Filter
1727
# Comcast
The process of setting up the connection between theCMTS and the cable modem, where transmit levels andfrequency are determined.
Ranged
1728
# Comcast
A switch or collection of switches connecting multiple networks
POP (Point of Presence)
1729
# Comcast
The point of access into theInternet.
NAP(Network Access Point)
1730
# Comcast
The company who provides access to the Internet and the World Wide Web, who usually also provides corefeatures such as e-mail.
ISPInternet Service Provider
1731
# Comcast
The local, long-distance and internationalphone system in use today
PSTN(Public Switched Telephone Network)
1732
# Comcast
This device in the Headend controls the operation of CDV.
HDT(Host Digital Terminal)
1733
# Comcast
Three major components of the Host Digital Terminal
Access Bandwidth Manager ShelfModem ShelfSpectrum Manager Shelf
1734
# Comcast
This Shelf provides the connection between the Network Interface Unit (NIU) and the switch, or more simply, the connection between the HDT and the LEC
ABM(Access Bandwidth Manager)
1735
# Comcast
The point of demarcation between the network and the customer. It contains the modem necessary for telephony over a cable network.
NIU(Network Interface Device)
1736
# Comcast
The device that opens or breaks the circuit path in a telephone call. This device looks at the incoming data to determine where the data should get routed.
Switch
1737
# Comcast
The local phone company is also known as what?
LEC(Local Exchange Carrier
1738
# Comcast
Shelf on the HDT (Host Digital Terminal) that converts the digital telephone signals into digital signals that are then modulated onto an RF carrier to be transmitted over the HFC Network.
Modem Shelf
1739
# Comcast
This shelf on the HDT (Host Digital Terminal) monitors the RF spectrum allocated for telephone services over the HFC network. If problems are detected, it can switch the data transmission (telephone call) to another frequency.
Spectrum Manager
1740
# Comcast
How many subscriber telephone lines can an NIU Handle?
4
1741
# Comcast
LPSU
Local Power Supply Unit
1742
# Comcast
The process of setting up the connection between the HDT and the NIU, where transmit levels and frequency are determined.
Marshalled
1743
# Comcast
Modulating technique that interweaves multiple conversations, based on time.
TDMA(Time Division Multiple Access)
1744
# Comcast
The number of the person that youare trying to call.
Terminating Number
1745
# Comcast
The phone company of the person you are trying to call.
Terminating LEC
1746
# Comcast
The “local” phone office where the subscriber’s lines are connected to the switching equipment.
Central Office
1747
# Comcast
What is "7" equal to in binary?
111
1748
# Comcast
64 QAM has how many phase angles?
52
1749
# Comcast
16 QAM has how many phase angles?
10
1750
# Comcast
The distance between two points of like phasein a wave.
Wavelength
1751
# Comcast
A card made up of material similar to photographic film that changes colors when exposed to light.
Photosensitive Card
1752
# Comcast
ANSI Laser standard that separates lasers into various classes that take into consideration the operating wavelength, output power level and whether the laser operates as a continuous or pulsed light output
Z-136
1753
# Comcast
Four nines works out to how many minutes of down time per month?
4.5 minutes
1754
# Comcast
loss of service to ourcustomers due to a fault in thedelivery network.
Outage
1755
# Comcast
Minimum telephone service to assure a contact in case of an emergency.
Lifeline
1756
# Comcast
FCC Standards CFR 47, Part 76.605(a)(1-12)
Proof-of-performance (POP) test
1757
# Comcast
A continuous wave (CW) frequency onto which information is modulated for transport.
Carrier Frequency
1758
# Comcast
Maximum Bandwidth of 256QAM
42.88Mbps
1759
# Comcast
How long must POP tests be kept at the local office?
minimum of 5 years
1760
# Comcast
how many test points are required for 1,000 to 12,500 customers?
6
1761
# Comcast
How many test points are required for each additional 12,500 customers?
1
1762
# Comcast
Channel requirements for POP testing (amount)
4 channels plus one additional channel for every 100 MHz.
1763
# Comcast
In a cable system with an upper frequency at 750 MHz, how many test channels must be used?
11 Channels
1764
# Comcast
All channels must be tested during these 3 tests.
Video Carrier Level, Audio Carrier Level, Video Carrier Level Stability Test
1765
# Comcast
Only one Channel needs to be tested during this non-frequency specific test
Hum Modulation
1766
# Comcast
How many digital channels must be tested on an all digital system with an upper frequency of 862MHz?
0, digital channels are not included and are not tested.
1767
# Comcast
The amount of channels during these tests are based solely on the highest operating frequency
Video-Audio Carrier Frequency SeparationIn-Channel ResponseCarrier to NoiseCoherent Disturbances Tests
1768
# Comcast
This test must be performed twice a year, once during the coldest months and again during the warmest (Jan-Feb and Jul-Aug respectively)
Video Carrier Level Stability (24-hour) test
1769
# Comcast
This POP test must be performed every three years
Color Performance test
1770
# Comcast
A circuit that automaticallyadjusts the gain of an amplifier sothat the output signal levels stayconstant despite varying inputlevels.
Automatic Gain Control (AGC)
1771
# Comcast
a spectrumanalyzer feature that allows theuser to make otherwise intrusiveFCC POP tests in a non-intrusivemanner.
Gated Testing
1772
# Comcast
When planning POP tests, these four things need to be considered
Test timesChannels and programming affected by testingTest lengthsAbility to perform non-intrusive gated testing
1773
# Comcast
This test is usually performed by a Headend tech rather than a System Tech
Color Performance
1774
# Comcast
What would a Discrepancy statement include?
Explain all possible misinterpreted fails, such as test point relocation, added channels, encoding issues and so on.
1775
# Comcast
POP measurements are to be taken at what location?
Input to the subscriber terminal
1776
# Comcast
EIA
Electronic Industry Association
1777
# Comcast
What must an operator do in order to pass the receivability test?
Submit documentation showing that their channel lineup conforms to the EIA Channel allocation plan
1778
# Comcast
What does the Audio Carrier Frequency Test ensure
That the audio carrier frequency for each channel must be 4.5MHz above the video carrier frequency, +/- 5kHz
1779
# Comcast
Where is the Audio Carrier Frequency test performed at?
The Headend as well as the field test points
1780
# Comcast
How many times a year is the Audio Carrier Frequency test performed?
Twice annually
1781
# Comcast
What type of set-top box can alter the Audio Carrier Frequency?
Baseband set-top boxes (as opposed to non-baseband)
1782
# Comcast
What six measurements are taken during the 24-hour test?
Minimum Visual Signal LevelVisual Signal changeAdjacent Visual SignalAny Other Visual Signal in BandwidthVisual Carrier LevelAudio Carrier Level
1783
# Comcast
The six measurements that are taken during the 24-hour test are performed on what channels?
All NTSC Channels at each test point location
1784
# Comcast
What is the Minimum Visual Signal Level allowed at the end of a 30-meter (100') cable drop that is connected to the subscriber tap?
1.41mV across an internal impedance of 75 ohms (+3dBmV(CT 5-3-22)
1785
# Comcast
The square root of the sum ofthe squares of the amplitudes ofindividual components of afunction, such as the frequencycomponents of a signal.
Root Mean Square (RMS)
1786
# Comcast
Maximum variation of each channel within any six-month period at the end of a 30-meter drop cable
8dB
1787
# Comcast
Adjacent Visual Signal deviation of the visual signal level of any visual carrier within a 6MHz nominal frequency separation
3dB
1788
# Comcast
What is the maximum "spread" or deviation among ALL channel levels in a 300MHz cable system and what is the incremental increase
10dB1db per 100MHz
1789
# Comcast
At what level must the aural signal be maintained in association with the visual signal level?
between 10dB and 17dB below the visual signal level
1790
# Comcast
At what level must the aural signal be maintained in association with the visual signal level on a baseband converter.
between 6.5dB and 17dB below the visual signal level.
1791
# Comcast
In a 24-hour test, how many times must the signal level be checked?
four times
1792
# Comcast
What are the time intervals of the 24-hour test?
5 to 7 hours
1793
# Comcast
at what frequency is the In-Channel Response test performed?
.75MHz to 5Mhz above the lower frequency boundary of the cable channel under test
1794
# Comcast
What is the FCC In-Channel Response requirement?
+/-2dB or 4dB peak-to-valley
1795
# Comcast
To perform this test, a signal must be inserted on the channel, either by the headend technician or by other means
In-Channel Response Test
1796
# Comcast
FCC Requirement for C/N
43dB at each test point
1797
# Comcast
What are the three type of coherent disturbances?
Composite Second Order (CSO)Composite Triple Beat (CTB)Other interfering signals (i.e. Ingress)
1798
# Comcast
What is the FCC requirement for Coherent Disturbances?
51dB below the desired carrier level for STD plans and 47dB in IRC and HRC systems
1799
# Comcast
The goal of this test is to find the worst beat or interfering signal, regardless of it's type
Coherent Disturbances Test
1800
# Comcast
FCC requirement for isolation
18dB
1801
# Comcast
Because the FCC allows you to submit manufacturers specifications to prove compliance, you rarely need to perform this test:
Terminal Isolation Test
1802
# Comcast
FCC requirement for Hum Modulation
less that 3% of the video carrier level.
1803
# Comcast
Where is the Hum Modulation test done?
the end of a 30m or 100' drop
1804
# Comcast
how many channels is the Hum Modulation test performed on?
One channel per test point
1805
# Comcast
How many channels is the Coherent Disturbance test performed on?
Dependent on highest frequency
1806
# Comcast
What are the three Color Performance tests?
Chrominance to Luminance Delay InequalityDifferential GainDifferential Phase
1807
# Comcast
FCC Spec for Chrominance to Luminance Delay test
Within 170 nanoseconds
1808
# Comcast
FCC Spec for Differential Gain
Within +/-20%
1809
# Comcast
FCC Spec for Differential Phase
Within +/-10 degrees
1810
# Comcast
Who usually performs the color performance tests?
The Headend Technician
1811
# Comcast
How many channels are recommended to be tested during the Color Performance test?
All NTSC or similar channels
1812
# Comcast
How often are the Color Performance Test performed?
once every three years
1813
# Comcast
Allowable signal leakage level below 54MHz
Up to 15uV/m @ 30m
1814
# Comcast
Allowable signal leakage level between 54MHz and 216 MHz
up to 20uV/m @ 3m
1815
# Comcast
Allowable signal leakage above 216MHz
up to 15uV/m @30m
1816
# Comcast
The two types of leakage monitoring frequency.
Continuous MonitoringQuarterly Monitoring
1817
# Comcast
Two types of annual leakage monitoring methods
Ground BasedFlyover
1818
# Comcast
What is the minimum cable strand sample allowed during a ground based leakage measurement?
75%
1819
# Comcast
What leaks are included in the CLI calculation?
All leaks 50uV or greater
1820
# Comcast
what is the elevation that a flyover is completed at? (in meters)
450m(1476')
1821
# Comcast
Two requirements for monitoring of plant with a handheld signal leakage detector
-Must be properly calibrated to detect a leak of 20uV/m or greater @ 3m-Perform all measurements with a horizontally polarized dipole antenna, preferably located no more than 3m from the leak and 3m from the ground
1822
# Comcast
What does a Spectrum Analyzer Display?
information in the amplitude (vertical) vs. frequency (horizontal) domain over the entire spectrum or portions of it.
1823
# Comcast
comparable in certain respects, typically in a way that makes clearer the nature of the things compared.
Analogous
1824
# Comcast
This filter has a bell-curved "shape," which it applies to all energy passing through it.
Resolution Bandwidth Filter (RBW)
1825
# Comcast
This is a low-pass filter at the analyzer detector's output. This filter takes the RF energy associated with the video modulation on the carrier that has already passed through the RBW filter and the detector and smoothes it out
Video Bandwidth Filter (VBW)(CT 5-3-39)
1826
# Comcast
The signal to an analyzer is injected here
RF Input
1827
# Comcast
Used when accessing analyzer's gated mode, such as in the C/N POP test
TV Input Connector
1828
# Comcast
The main setting and adjustment keys for the analyzer functions and the display. These keys are most often used in the analyzer's manual testing modes
Function Keys
1829
# Comcast
Additional keys whose action changes depending on the selected analyzer mode or function. Most often used in the analyzer's automated testing modes
Softkeys
1830
# Comcast
The principal keys useed in the analyzer's manual modes of operation. They represent the three most basic functions of any spectrum analyzer
Frequency, Span and Amplitude keys
1831
# Comcast
Adjusts the value or amount for the selected function or measurement
Adjustment Knob
1832
# Comcast
Adjust value or amount in incremental steps for the selected function or measurement
Step Key
1833
# Comcast
Allows direct input of a specific value or amount for the selected function or measurement
Numeric Keypad
1834
# Comcast
Sets the type of measurement unit, such as kHz or MHz, for the selected function or measurement
Measurement units' keys
1835
# Comcast
Marker function and trace control keys
Access marker functions and set trace control functions such as display line, RBW and VBW
1836
# Comcast
Sets analyzer modes, presets and stores or recalls analyzer trace
Mode select Key
1837
# Comcast
Maximum input power of HP 8591C
+72dBmV
1838
# Comcast
Maximum input power of Tektronix 2715
+69dBmV
1839
# Comcast
This must be used when high input levels are required to the analyzer to avoid input overload
preselector
1840
# Comcast
For the greatest accuracy, how should the carrier peak be adjusted?
To the analyzer's reference level (top of the display)
1841
# Comcast
Three tests that can use gated mode on the HP 8591C
Carrier to NoiseCoherent Disturbances (CSO measurement only)In-Channel Response
1842
The topology where signals originate in the headend andare transmitted long distances via trunk cables
Tree and Branch
1843
A network architecture that typically uses fiber optic cables to bring signals to selected areas of the system called nodes
Hybrid Fiber-Coax (HFC)
1844
Bi-annual tests, performed in the headend and at a number of end-of-line location
FCC Proof-of-Performance
1845
The cumulative effect of return path distortions they are added to the signal at various locations in the coaxial portion of the network.
Funnel Effect
1846
Specifications standards approved by the FCC in 1953for commercial analog color TV broadcasting.
National Television Standards Committee (NTSC)
1847
a portion of the electromagnetic spectrum whose frequencies are well suited for transmitting and receiving Telecommunications signals through the air.
Radio Frequency (RF) Spectrum
1848
Signals that flow downstream, from the headend to the network.
Forwards (Downstream) Signals
1849
Signals that flow in the upstream direction, from customer to headend
Revers (upstream) Signals
1850
Device that separates or combines based on frequency.
Diplex Filter
1851
typical cutoff frequency for a sub-split diplex filter
About 50 MHz
1852
The three major concerns/ limitations of the tree andbranch architecture are:
BandwidthImpairmentsDependency on Power
1853
The lowest possible power level determined by the thermal noise generated within the electrical componentsbeing tested
Noise Floor
1854
The highest power level (amplitude) reached by a carrier
Peak
1855
A clustering of beats 1.25 MHz above the visual carriers in a CATV network
Composite Second Order (CSO)
1856
A form of interference or noise resulting from the mixingof all of the various carriers in a CATV network
Composite Triple Beat (CTB)
1857
Two major types of distortions that are typically associated with CATV
Composite Second Order (CSO) and Composite Triple Beat (CTB)
1858
The 6 benefits of implementing fiber optics in broadband networks
Enhances Picture QualityIncreased ReliabilityDecreased cost of system maintenanceCost effective system bandwidth upgradesCost means of system upgrade requiring a complete change our of electronicsSmall segmented areas allow greater return path functionality
1859
Having or relating to a frequency below the audibility range of the human ear.
Infrasonic
1860
A stream of atomic nuclei that enter the earth’s atmosphere from outer space at speeds approaching that of light
Cosmic Rays
1861
Frequency range of satellite systems
4GHz to 13GHz
1862
The wavelengths most commonly used by the CATVindustry
1310nm and 1550nm
1863
The type of fiber optic cable that the broadband industry uses
Single Mode Fiber
1864
The process of combining multiple carriers onto a single medium
Multiplexing
1865
Width of the Fiber optic core
8-10um
1866
Width of the fiber optic cladding
125um
1867
Width of the fiber optic coating
250um
1868
Combines multiple optical signals in order to amplify them as a group and transported over a single fiber
Wave Division Multiplexing (WDM)
1869
Allows multiple wavelengths above and below a centerwavelength to be carried on a single optical fiber.
Dense Wave Division Multiplexing (DWDM)
1870
Three parts of the optical link
Fiber Optic CableTransmitter (Laser)Receiver (Node)
1871
Individual fibers are bundled and then placed into these to reduce the possibility of damage
Buffer Tubes
1872
This diode changes the RF signals to pulsesof light and then transmits them onto an optical fiber
Semiconductor Laser Diode
1873
The Three types of optical transmitters that are typically used in broadband HFC Network
Fabry-Perot (F-P)Distributed Feedback (DFB)Yttrium-Aluminum-Garnet (YAG)
1874
YAG
Yttrium-Aluminum-Garnet
1875
DFB
Distributed Feedback
1876
F-P
Fabry-Perot
1877
A spare fiber installed during the construction of the network that was reserved for future use.
Dark Fiber
1878
Three advantages of trunk reduction
Shorter CascadesFewer/smaller outages due to segmenting the system into smaller areasImproved picture Quality
1879
FTTF
Fiber to the Feeder
1880
Advantages of FTTF
Shorter CascadesFewer/smaller outages due to segmenting the system intosmaller areas.Increased Bandwidth
1881
FTTC
Fiber to the Curb
1882
PON
Passive Optical Network
1883
Consists of a transmitter at the Headend and a receiver near the subscriber. Requires a power supply near the node but all other actives have been removed
FTTC PON
1884
4 advantages of FTTC
No active devices after nodeNo CascadeFewer/smaller outages due to segmenting the system intovery small areasIncreased Bandwidth
1885
A fiber-based network which uses passive splitters todeliver signals to multiple locations
Passive Optical Network (PON)
1886
FTTH
Fiber to the Home
1887
6 advantages of FTTH
Passive networkSingle fiber is dedicated to each subscriberFeatures local battery backup, no large remote power supplies are required.No exterior active devicesNo CascadesIncreased Bandwidth
1888
This will ALWAYS be considered the "Backbone" in an HFC Network
The Fiber Network
1889
A high-speed line or series of connections that forms a major pathway within a network
Backbone
1890
The duplication of certain pieces and/or portions of thenetwork.
Redundancy
1891
Comcast's goal for network reliability
"four-nines" or 99.99%
1892
A network architecture where nodes, hubs, or headendsmay be connected with fiber optic cables to provideredundancy or increase services
Ring Architecture
1893
Builds upon ring technology by adding a second (redundant) ring connecting the nodes to the headend. The second ring typically takes a different path
Ring within a Ring
1894
A facility between the headend and the customer that performs many of the functions of a headend
Hubsite
1895
Similar in function to a hubsite, but serving fewer customers
Optical Transition Node (OTN)
1896
Usually a passive device such as a splitter or directional coupler used to combine radio frequency signals from one source with those from another
RF Combiner
1897
Usually a passive device that divides a signal into two equal paths. It may be found on trunk, feeder, or drop cable.
RF Splitter
1898
Device used to combine the channels for entry onto the cable or fiber optic transmitter
Headend Combiner
1899
The difference, in dB, of a signal level, injected into one output port, and the measured level of that same signal on another output port, with the input port properly terminated.
Port-to-port isolation
1900
Obtained by measuring the attenuation between the two output ports (A and B) when the common port (input port) is terminated in the correct value of impedance. An RF generator signal is applied to port A and an RF voltmeter reading is taken at Port B.
Isolation
1901
Provision for connection to a device such as a tap, splitter, set-top box or computer
Port
1902
Used to combine all of the signals to be carried over the cable system into a single medium (cable) for routing to the laser transmitters that are feeding the optical nodes in the system
Headend Combining Network
1903
A measurement of the reflected signal compared to that of the incident signal
Return Loss
1904
Device used to divide or combine light carriers on fiber optic cables.
Optical Splitter
1905
A discontinuous signal whose various states are discrete intervals apart.
Digital Signal
1906
Device used to convert an analog signal to a digital signal.
Digitizer
1907
takes an amplitude measurement of the waveform at fixed intervals of time, and converts them to a binary number
Digitizer
1908
The smallest unit of computerized data. Bits are defined as single characters of 0 or 1. Bandwidth is usually measured in bits-persecond.
Binary Digit (Bit)
1909
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.
Byte
1910
The number of changed states that can occur per second.
Baud
1911
The value of "On" in a binary system
"1"
1912
The value of "Off" in a Binary system
"0"
1913
How many bits are in a "Nibble"?
4
1914
In ASCII #5 alphabet, how man bits are in a byte?
7
1915
If start and stop bits are included with Asynchronous Communications, then how many bits are in a byte?
10
1916
ADC
Analog to Digital Conversion
1917
DAC
Digital to Analog Conversion
1918
A continuously varying signal with an unlimited number of possible values of amplitude and frequency.
Analog Signal
1919
a non-continuous signal or carrier that changes its output in discreetly timed steps of voltage level and/or phase that can represent numerical values or other information
Digital Transmission
1920
3 steps of basic ADC
SamplingQuantizationEncoding
1921
The "Measuring" of the analog signal at specific intervals.
Sampling
1922
The assigning of a specific value to each of the samples
Quantization
1923
The process by which Quantized values are converted into a data or bit stream
Encoding
1924
ASK
Amplitude Shift Keying
1925
FSK
Frequency Shift Keying
1926
QPSK
Quadrature Phase Shift Keying
1927
QAM
Quadrature Amplitude Modulation
1928
The process of varying the amplitude, frequency, or phase of a carrier to be in step with the instantaneous value of the modulating waveform
Modulation
1929
Data transmission scheme wherein the carrier is shifted in amplitude
Amplitude Shift Keying (ASK)
1930
The carrier frequency is shifted to represent the difference between a one and a zero
Frequency Shift Keying (FSK)
1931
The position on a waveform cycle at a specific point in time. One cycle is defined as 360 degrees of this
Phase
1932
Digital modulation scheme wherein the carrier is shifted in 90 degree steps. There are four possible phase states and the magnitude is constant.
Quadrature Phase Shift Keying (QPSK)
1933
BPSK
BiPhase Shift Keying
1934
In QPSK, what does "I" stand for?
In-Phase
1935
In QPSK, what does "Q" Stand for?
Quadrature - shifted 90* or one quarter of a cycle
1936
A graphic depiction of the four phase states of a Quadrature Phase Shift Key signal.
Constellation Diagram
1937
What is the bandwidth of QPSK in a 6MHz bandwidth?
10 Mb/s
1938
Digital modulation scheme that changes the phase and the amplitude.
Quadrature Amplitude Modulation (QAM)
1939
a digital transmission technology that splits the frequency band into a number of channels. The channels are each assigned a specific time slot, so that several transmissions can share a single channel without interfering with one another
Time Division Multiple Access (TDMA)
1940
The digital equivalent to Signal-to-Noise
Modulation Error Ratio (MER)
1941
A joined or connected group of devices
Network
1942
A network of computers linked by cable within a building or office complex.
Local Area Network (LAN)
1943
A network of multiple locations linked by cable withina city or campus
Metropolitan Area Network (MAN)
1944
A network typically bigger than a city or metropolitan area.
Wide Area Network (WAN)
1945
A data network connects each of its endpoints to the network with a single link. A central device (hub) is used to aggregate and distribute data traffic to all endpoints and/or other central points in what’s referred to as a clustered star.
Star
1946
Consists of several star networks that have been linked together
Clustered Star
1947
Topology where workstations are connected to the network through a common path
Bus
1948
A topology in which a data frame is passed around. As it arrives at an endpoint, the endpoint can either pass it along to the next endpoint or attach information to be sent to a destination
Token Ring
1949
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
Ring
1950
A method of data transmission that allows characters to be sent at irregular intervals by preceding each character with a 0 and by ending each character with a 1. This is referred to as start (0) and stop bits (1). It is the method, which most PCs use to communicate with each other and mainframes
Asynchronous Transmission
1951
An extra bit added to help check if the data that isbeing transferred is correct
Parity Bit
1952
The condition that occurs when two events happen in a specific time relationship with each other and both are under control of a master clock. Characters are spaced by time, not by start and stop bits.
Synchronous Transmission
1953
Synchronizing bits used in synchronous transmission to maintain synchronization between transmitter and receiver.
Sync Bits
1954
SNMP
Simple Network Management Protocol (SNMP)
1955
NE
Network Elements
1956
MIB
Management Information Base
1957
A unique number assigned to a piece of equipmentused for identification purposes.
Media Access Control Address (MAC)
1958
UTP
Unshielded Twisted Pair
1959
signaling rate of 10BaseT
10 Mb/s
1960
Signaling rate of 100BaseT
100 Mb/s
1961
The designation for Ethernet over fiber optic cable, primarily for point-topoint links
10Base-F
1962
Ethernet resides in what layers of the OSI model?
The 2 lowest levels (layers)
1963
This device works as a multiport signal repeater, broadcasting an incoming signal to all other ports on an ethernet network
Ethernet Hub
1964
The four-part numeric address that is assigned to a computer or an account as an identification tool
Internet Protocol Address (IP)
1965
IEEE MAC Protocol for Hybrid Fiber-Coax Networks; standard for data communicatons over a cable network
802.14
1966
The Four original partners of MCNS (Multimedia Cable Network Partners Ltd.)
Comcast, Cox, TCI and Time Warner
1967
The three companies that joined MCNS in late 1996
Media One, Rogers Cablevision and CableLabs
1968
DOCSIS
Data Over Cable Service Interface Specification
1969
When was DOCSIS 1.0 released? (Month & Year)
Mar-97
1970
The Leading standard for cable modems
DOCSIS
1971
Four devices that must be added to a system to offer high-speed internet
CMTS (Cable Modem Termination System)CM (Cable Modem)ServersNoise Filters
1972
A unit consisting of various hardware and software entities that acts as the hand-off point between the RF based HFC network and other networks such as theInternet and the PSTN.
CMTS (Cable Modem Termination System)
1973
Used to terminate, manage and translate high-speed Internet sessions between cable modems in a LAN and other devices in a WAN.
CMTS (Cable Modem Termination System)
1974
The collection of computers accessed through the Internet. Uses a hypertext based system for finding andaccessing its resources.
WWW (World Wide Web)
1975
Four Items that a CMTS manages
Time SlotsContention SlotsModem DataTransmit Levels
1976
Each cable modem is assigned one of these by the CMTS and only one modem is allowed to transmit during this.
Time Slot
1977
These slots are usually used for short data transmissions such as a request for an additional number of reserved time slots
Contention Slots
1978
The signal level that the CMTS wants to "See"
0dBmV
1979
A PC on a LAN from which information or applications are requested.
Client/Server
1980
A computer circuit board (card) installed in a computer so that the computer can be connected to a network. Provide a dedicated, full-time connection to a network.
NIC (Network Interface Card)
1981
Why is it called a cable "Modem"?
When they transmit data they "MOdulate" the data onto a carrier, then receive data and "DEModulate" it from the carrier and send it on to the computer
1982
Four of the most common servers found in a braodband network
DHCPTODTFTPProxy
1983
This server sets up the MAC and IP addresses for the cable modem.
DHCP Server(Dynamic Host Configuration Protocol)
1984
This server sets up a common clock between the CM and the CMTS
TOD Server(Time of Day)
1985
This server allows non-protected file transfers, such as aconfiguration file for a modem.
TFTP Server(Trivial File Transfer Protocol)
1986
These servers store commonly used (or contractually stored) data. A network may have a series of these servers located in different places.
Proxy Server
1987
The two types of noise filters
High Pass FilterNotch Filter
1988
These types of filters only allow signals above 50MHz to pass through the filter
High Pass Filter
1989
In addition to letting everything above 50 MHz to pass, this filter allows a small spectrum below 50 MHz to pass
Notch Filter
1990
The process of setting up the connection between theCMTS and the cable modem, where transmit levels andfrequency are determined.
Ranged
1991
A switch or collection of switches connecting multiple networks
POP (Point of Presence)
1992
The point of access into theInternet.
NAP(Network Access Point)
1993
The company who provides access to the Internet and the World Wide Web, who usually also provides corefeatures such as e-mail.
ISPInternet Service Provider
1994
The local, long-distance and internationalphone system in use today
PSTN(Public Switched Telephone Network)
1995
This device in the Headend controls the operation of CDV.
HDT(Host Digital Terminal)
1996
Three major components of the Host Digital Terminal
Access Bandwidth Manager ShelfModem ShelfSpectrum Manager Shelf
1997
This Shelf provides the connection between the Network Interface Unit (NIU) and the switch, or more simply, the connection between the HDT and the LEC
ABM(Access Bandwidth Manager)
1998
The point of demarcation between the network and the customer. It contains the modem necessary for telephony over a cable network.
NIU(Network Interface Device)
1999
The device that opens or breaks the circuit path in a telephone call. This device looks at the incoming data to determine where the data should get routed.
Switch
2000
The local phone company is also known as what?
LEC(Local Exchange Carrier
2001
Shelf on the HDT (Host Digital Terminal) that converts the digital telephone signals into digital signals that are then modulated onto an RF carrier to be transmitted over the HFC Network.
Modem Shelf
2002
This shelf on the HDT (Host Digital Terminal) monitors the RF spectrum allocated for telephone services over the HFC network. If problems are detected, it can switch the data transmission (telephone call) to another frequency.
Spectrum Manager
2003
How many subscriber telephone lines can an NIU Handle?
4
2004
LPSU
Local Power Supply Unit
2005
The process of setting up the connection between the HDT and the NIU, where transmit levels and frequency are determined.
Marshalled
2006
Modulating technique that interweaves multiple conversations, based on time.
TDMA(Time Division Multiple Access)
2007
The number of the person that youare trying to call.
Terminating Number
2008
The phone company of the person you are trying to call.
Terminating LEC
2009
The “local” phone office where the subscriber’s lines are connected to the switching equipment.
Central Office
2010
What is "7" equal to in binary?
111
2011
64 QAM has how many phase angles?
52
2012
16 QAM has how many phase angles?
10
2013
The distance between two points of like phasein a wave.
Wavelength
2014
A card made up of material similar to photographic film that changes colors when exposed to light.
Photosensitive Card
2015
ANSI Laser standard that separates lasers into various classes that take into consideration the operating wavelength, output power level and whether the laser operates as a continuous or pulsed light output
Z-136
2016
Four nines works out to how many minutes of down time per month?
4.5 minutes
2017
loss of service to ourcustomers due to a fault in thedelivery network.
Outage
2018
Minimum telephone service to assure a contact in case of an emergency.
Lifeline
2019
FCC Standards CFR 47, Part 76.605(a)(1-12)
Proof-of-performance (POP) test
2020
A continuous wave (CW) frequency onto which information is modulated for transport.
Carrier Frequency
2021
Maximum Bandwidth of 256QAM
42.88Mbps
2022
How long must POP tests be kept at the local office?
minimum of 5 years
2023
how many test points are required for 1,000 to 12,500 customers?
6
2024
How many test points are required for each additional 12,500 customers?
1
2025
Channel requirements for POP testing (amount)
4 channels plus one additional channel for every 100 MHz.
2026
In a cable system with an upper frequency at 750 MHz, how many test channels must be used?
11 Channels
2027
All channels must be tested during these 3 tests.
Video Carrier Level, Audio Carrier Level, Video Carrier Level Stability Test
2028
Only one Channel needs to be tested during this non-frequency specific test
Hum Modulation
2029
How many digital channels must be tested on an all digital system with an upper frequency of 862MHz?
0, digital channels are not included and are not tested.
2030
The amount of channels during these tests are based solely on the highest operating frequency
Video-Audio Carrier Frequency SeparationIn-Channel ResponseCarrier to NoiseCoherent Disturbances Tests
2031
This test must be performed twice a year, once during the coldest months and again during the warmest (Jan-Feb and Jul-Aug respectively)
Video Carrier Level Stability (24-hour) test
2032
This POP test must be performed every three years
Color Performance test
2033
A circuit that automaticallyadjusts the gain of an amplifier sothat the output signal levels stayconstant despite varying inputlevels.
Automatic Gain Control (AGC)
2034
a spectrumanalyzer feature that allows theuser to make otherwise intrusiveFCC POP tests in a non-intrusivemanner.
Gated Testing
2035
When planning POP tests, these four things need to be considered
Test timesChannels and programming affected by testingTest lengthsAbility to perform non-intrusive gated testing
2036
This test is usually performed by a Headend tech rather than a System Tech
Color Performance
2037
What would a Discrepancy statement include?
Explain all possible misinterpreted fails, such as test point relocation, added channels, encoding issues and so on.
2038
POP measurements are to be taken at what location?
Input to the subscriber terminal
2039
EIA
Electronic Industry Association
2040
What must an operator do in order to pass the receivability test?
Submit documentation showing that their channel lineup conforms to the EIA Channel allocation plan
2041
What does the Audio Carrier Frequency Test ensure
That the audio carrier frequency for each channel must be 4.5MHz above the video carrier frequency, +/- 5kHz
2042
Where is the Audio Carrier Frequency test performed at?
The Headend as well as the field test points
2043
How many times a year is the Audio Carrier Frequency test performed?
Twice annually
2044
What type of set-top box can alter the Audio Carrier Frequency?
Baseband set-top boxes (as opposed to non-baseband)
2045
What six measurements are taken during the 24-hour test?
Minimum Visual Signal LevelVisual Signal changeAdjacent Visual SignalAny Other Visual Signal in BandwidthVisual Carrier LevelAudio Carrier Level
2046
The six measurements that are taken during the 24-hour test are performed on what channels?
All NTSC Channels at each test point location
2047
What is the Minimum Visual Signal Level allowed at the end of a 30-meter (100') cable drop that is connected to the subscriber tap?
1.41mV across an internal impedance of 75 ohms (+3dBmV(CT 5-3-22)
2048
The square root of the sum ofthe squares of the amplitudes ofindividual components of afunction, such as the frequencycomponents of a signal.
Root Mean Square (RMS)
2049
Maximum variation of each channel within any six-month period at the end of a 30-meter drop cable
8dB
2050
Adjacent Visual Signal deviation of the visual signal level of any visual carrier within a 6MHz nominal frequency separation
3dB
2051
What is the maximum "spread" or deviation among ALL channel levels in a 300MHz cable system and what is the incremental increase
10dB1db per 100MHz
2052
At what level must the aural signal be maintained in association with the visual signal level?
between 10dB and 17dB below the visual signal level
2053
At what level must the aural signal be maintained in association with the visual signal level on a baseband converter.
between 6.5dB and 17dB below the visual signal level.
2054
In a 24-hour test, how many times must the signal level be checked?
four times
2055
What are the time intervals of the 24-hour test?
5 to 7 hours
2056
at what frequency is the In-Channel Response test performed?
.75MHz to 5Mhz above the lower frequency boundary of the cable channel under test
2057
What is the FCC In-Channel Response requirement?
+/-2dB or 4dB peak-to-valley
2058
To perform this test, a signal must be inserted on the channel, either by the headend technician or by other means
In-Channel Response Test
2059
FCC Requirement for C/N
43dB at each test point
2060
What are the three type of coherent disturbances?
Composite Second Order (CSO)Composite Triple Beat (CTB)Other interfering signals (i.e. Ingress)
2061
What is the FCC requirement for Coherent Disturbances?
51dB below the desired carrier level for STD plans and 47dB in IRC and HRC systems
2062
The goal of this test is to find the worst beat or interfering signal, regardless of it's type
Coherent Disturbances Test
2063
FCC requirement for isolation
18dB
2064
Because the FCC allows you to submit manufacturers specifications to prove compliance, you rarely need to perform this test:
Terminal Isolation Test
2065
FCC requirement for Hum Modulation
less that 3% of the video carrier level.
2066
Where is the Hum Modulation test done?
the end of a 30m or 100' drop
2067
how many channels is the Hum Modulation test performed on?
One channel per test point
2068
How many channels is the Coherent Disturbance test performed on?
Dependent on highest frequency
2069
What are the three Color Performance tests?
Chrominance to Luminance Delay InequalityDifferential GainDifferential Phase
2070
FCC Spec for Chrominance to Luminance Delay test
Within 170 nanoseconds
2071
FCC Spec for Differential Gain
Within +/-20%
2072
FCC Spec for Differential Phase
Within +/-10 degrees
2073
Who usually performs the color performance tests?
The Headend Technician
2074
How many channels are recommended to be tested during the Color Performance test?
All NTSC or similar channels
2075
How often are the Color Performance Test performed?
once every three years
2076
Allowable signal leakage level below 54MHz
Up to 15uV/m @ 30m
2077
Allowable signal leakage level between 54MHz and 216 MHz
up to 20uV/m @ 3m
2078
Allowable signal leakage above 216MHz
up to 15uV/m @30m
2079
The two types of leakage monitoring frequency.
Continuous MonitoringQuarterly Monitoring
2080
Two types of annual leakage monitoring methods
Ground BasedFlyover
2081
What is the minimum cable strand sample allowed during a ground based leakage measurement?
75%
2082
What leaks are included in the CLI calculation?
All leaks 50uV or greater
2083
what is the elevation that a flyover is completed at? (in meters)
450m(1476')
2084
Two requirements for monitoring of plant with a handheld signal leakage detector
-Must be properly calibrated to detect a leak of 20uV/m or greater @ 3m-Perform all measurements with a horizontally polarized dipole antenna, preferably located no more than 3m from the leak and 3m from the ground
2085
What does a Spectrum Analyzer Display?
information in the amplitude (vertical) vs. frequency (horizontal) domain over the entire spectrum or portions of it.
2086
comparable in certain respects, typically in a way that makes clearer the nature of the things compared.
Analogous
2087
This filter has a bell-curved "shape," which it applies to all energy passing through it.
Resolution Bandwidth Filter (RBW)
2088
This is a low-pass filter at the analyzer detector's output. This filter takes the RF energy associated with the video modulation on the carrier that has already passed through the RBW filter and the detector and smoothes it out
Video Bandwidth Filter (VBW)(CT 5-3-39)
2089
The signal to an analyzer is injected here
RF Input
2090
Used when accessing analyzer's gated mode, such as in the C/N POP test
TV Input Connector
2091
The main setting and adjustment keys for the analyzer functions and the display. These keys are most often used in the analyzer's manual testing modes
Function Keys
2092
Additional keys whose action changes depending on the selected analyzer mode or function. Most often used in the analyzer's automated testing modes
Softkeys
2093
The principal keys useed in the analyzer's manual modes of operation. They represent the three most basic functions of any spectrum analyzer
Frequency, Span and Amplitude keys
2094
Adjusts the value or amount for the selected function or measurement
Adjustment Knob
2095
Adjust value or amount in incremental steps for the selected function or measurement
Step Key
2096
Allows direct input of a specific value or amount for the selected function or measurement
Numeric Keypad
2097
Sets the type of measurement unit, such as kHz or MHz, for the selected function or measurement
Measurement units' keys
2098
Marker function and trace control keys
Access marker functions and set trace control functions such as display line, RBW and VBW
2099
Sets analyzer modes, presets and stores or recalls analyzer trace
Mode select Key
2100
Maximum input power of HP 8591C
+72dBmV
2101
Maximum input power of Tektronix 2715
+69dBmV
2102
This must be used when high input levels are required to the analyzer to avoid input overload
preselector
2103
For the greatest accuracy, how should the carrier peak be adjusted?
To the analyzer's reference level (top of the display)
2104
Three tests that can use gated mode on the HP 8591C
Carrier to NoiseCoherent Disturbances (CSO measurement only)In-Channel Response
