NCT5 Flashcards
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
If start and stop bits are included with Asynchronous Communications, then how many bits are in a byte?
10
74
ADC
Analog to Digital Conversion
75
DAC
Digital to Analog Conversion
76
A continuously varying signal with an unlimited number of possible values of amplitude and frequency.
Analog Signal
77
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
78
3 steps of basic ADC
SamplingQuantizationEncoding
79
The "Measuring" of the analog signal at specific intervals.
Sampling
80
The assigning of a specific value to each of the samples
Quantization
81
The process by which Quantized values are converted into a data or bit stream
Encoding
82
ASK
Amplitude Shift Keying
83
FSK
Frequency Shift Keying
84
QPSK
Quadrature Phase Shift Keying
85
QAM
Quadrature Amplitude Modulation
86
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
87
Data transmission scheme wherein the carrier is shifted in amplitude
Amplitude Shift Keying (ASK)
88
The carrier frequency is shifted to represent the difference between a one and a zero
Frequency Shift Keying (FSK)
89
The position on a waveform cycle at a specific point in time. One cycle is defined as 360 degrees of this
Phase
90
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)
91
BPSK
BiPhase Shift Keying
92
In QPSK, what does "I" stand for?
In-Phase
93
In QPSK, what does "Q" Stand for?
Quadrature - shifted 90* or one quarter of a cycle
94
A graphic depiction of the four phase states of a Quadrature Phase Shift Key signal.
Constellation Diagram
95
What is the bandwidth of QPSK in a 6MHz bandwidth?
10 Mb/s
96
Digital modulation scheme that changes the phase and the amplitude.
Quadrature Amplitude Modulation (QAM)
97
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)
98
The digital equivalent to Signal-to-Noise
Modulation Error Ratio (MER)
99
A joined or connected group of devices
Network
100
A network of computers linked by cable within a building or office complex.
Local Area Network (LAN)
101
A network of multiple locations linked by cable withina city or campus
Metropolitan Area Network (MAN)
102
A network typically bigger than a city or metropolitan area.
Wide Area Network (WAN)
103
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
104
Consists of several star networks that have been linked together
Clustered Star
105
Topology where workstations are connected to the network through a common path
Bus
106
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
107
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
Ring
108
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
109
An extra bit added to help check if the data that isbeing transferred is correct
Parity Bit
110
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
111
Synchronizing bits used in synchronous transmission to maintain synchronization between transmitter and receiver.
Sync Bits
112
SNMP
Simple Network Management Protocol (SNMP)
113
NE
Network Elements
114
MIB
Management Information Base
115
A unique number assigned to a piece of equipmentused for identification purposes.
Media Access Control Address (MAC)
116
UTP
Unshielded Twisted Pair
117
signaling rate of 10BaseT
10 Mb/s
118
Signaling rate of 100BaseT
100 Mb/s
119
The designation for Ethernet over fiber optic cable, primarily for point-topoint links
10Base-F
120
This device works as a multiport signal repeater, broadcasting an incoming signal to all other ports on an ethernet network
Ethernet Hub
121
The four-part numeric address that is assigned to a computer or an account as an identification tool
Internet Protocol Address (IP)
122
DOCSIS
Data Over Cable Service Interface Specification
123
The Leading standard for cable modems
DOCSIS
124
Four devices that must be added to a system to offer high-speed internet
CMTS (Cable Modem Termination System)CM (Cable Modem)ServersNoise Filters
125
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)
126
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)
127
The collection of computers accessed through the Internet. Uses a hypertext based system for finding andaccessing its resources.
WWW (World Wide Web)
128
Four Items that a CMTS manages
Time SlotsContention SlotsModem DataTransmit Levels
129
Each cable modem is assigned one of these by the CMTS and only one modem is allowed to transmit during this.
Time Slot
130
These slots are usually used for short data transmissions such as a request for an additional number of reserved time slots
Contention Slots
131
The signal level that the CMTS wants to "See"
0dBmV
132
A PC on a LAN from which information or applications are requested.
Client/Server
133
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)
134
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
135
Four of the most common servers found in a braodband network
DHCPTODTFTPProxy
136
This server sets up the MAC and IP addresses for the cable modem.
DHCP Server(Dynamic Host Configuration Protocol)
137
This server sets up a common clock between the CM and the CMTS
TOD Server(Time of Day)
138
This server allows non-protected file transfers, such as aconfiguration file for a modem.
TFTP Server(Trivial File Transfer Protocol)
139
These servers store commonly used (or contractually stored) data. A network may have a series of these servers located in different places.
Proxy Server
140
The two types of noise filters
High Pass FilterNotch Filter
141
These types of filters only allow signals above 50MHz to pass through the filter
High Pass Filter
142
In addition to letting everything above 50 MHz to pass, this filter allows a small spectrum below 50 MHz to pass
Notch Filter
143
The process of setting up the connection between theCMTS and the cable modem, where transmit levels andfrequency are determined.
Ranged
144
A switch or collection of switches connecting multiple networks
POP (Point of Presence)
145
The point of access into theInternet.
NAP(Network Access Point)
146
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
147
What is "7" equal to in binary?
111
148
64 QAM has how many phase angles?
52
149
16 QAM has how many phase angles?
10
150
The distance between two points of like phasein a wave.
Wavelength
151
A card made up of material similar to photographic film that changes colors when exposed to light.
Photosensitive Card
152
loss of service to ourcustomers due to a fault in thedelivery network.
Outage
153
A continuous wave (CW) frequency onto which information is modulated for transport.
Carrier Frequency
154
Maximum Bandwidth of 256QAM
42.88Mbps
155
How long must POP tests be kept at the local office?
minimum of 5 years
156
A circuit that automaticallyadjusts the gain of an amplifier sothat the output signal levels stayconstant despite varying inputlevels.
Automatic Gain Control (AGC)
157
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)
158
What are the three type of coherent disturbances?
Composite Second Order (CSO)Composite Triple Beat (CTB)Other interfering signals (i.e. Ingress)
159
Allowable signal leakage level below 54MHz
Up to 15uV/m @ 30m
160
Allowable signal leakage level between 54MHz and 216 MHz
up to 20uV/m @ 3m
161
Allowable signal leakage above 216MHz
up to 15uV/m @30m
162
Two types of annual leakage monitoring methods
Ground BasedFlyover
163
What does a Spectrum Analyzer Display?
information in the amplitude (vertical) vs. frequency (horizontal) domain over the entire spectrum or portions of it.
164
Counteracts Horizontal forces placed on poles by the strand and cable
Guy & Anchor
165
Connects pole hardware to the anchor
Guy
166
Transfers horizontal stress from the pole to the ground
Anchor
167
Conduit pipe is usually made from
PVC
168
Allows strand to be pulled in only one direction
Strand Brake
169
Prevents unwanted payoff from the Reel
Reel Brake
170
A portable bonding method used in the stationary reel method
Traveling ground
171
Strand and cable should pay-off the _______ of the reel
Top
172
Measures pulling tension on the cable
Dynamometer
173
Ensures cables are not over tensioned
Breakaway Swivel
174
Minimizes drag on the cables in the corners & ensures that minimum bending radius is not exceeded
Corner Block
175
Tension in the cable caused by the mass of the cable & reel brake
Tail Loading
176
Cable spans______ and greater require two expansion loops
250'
177
Expansion loops should be formed on the ______ side of the pole
output
178
Double lashing is done in these three scenarios
1) two or more cables2) trunk cables3) Street and RR Crossing
179
How deep is warning tape buried?
12 inches
180
When doing a figure eight with fiber, how far apart should the cones be placed?
10-15 paces
181
Clearance for communications lines above roads, streets or alleys
15.5 ft
182
EDFA
Erbium-Doped Fiber Amplifier
183
Similar to loose tube, this type of cable has ribbons that are contained in buffer tubes
Ribbon Stranded
184
A card made up of material similar to photographic film that changes colors when exposed to light
Photosensitive Card
185
The wavelength range of visible light
390nm to 780nm
186
OCEF
Optical Cable Entry Facility
187
What is the formula to convert dB to mW?
mW = 10(dB/10)
188
The two means of splicing fiber optic cable
Fusion SplicingMechanical Splicing
189
APC
Angle Polish Connector
190
Monitoring Center for high-speed data and telephony. Technical customer service calls are escalated here for investigation and network troubleshooting
Network Operation Center (NOC)
191
Generated during the node certification showing the fiber performance when first activated. It is a document used to compare old test results to new test results
Node Birth Certificate.
192
The diameter of the glass cladding
125 microns
193
A device that scores then breaks the optical fiber to prepare it for splicing
Cleaver
194
Radiated light created in the same direction at the same time
Coherent Light
195
Where the connector end of the pigtail is connected to the laser. Provides a neat and orderly method of managing the patch cords.
Patch Panel
196
The two ways a fusion splicer lines up the fiber ends in order to get the best possible splice.
Local Injection and Detection (LID)Profile Alignment
197
SC
Standard Connector
198
Silicon photodiodes are sensitive to light in the range of
400 to 1000nm
199
What is Comcast's maximum allowed loss through a fusion splice?
0.05dB
200
The ideal optical power level at a receiver input is
0dBm
201
The ratio of the velocity of light of two mediums of optical glass
Refractive Index
202
UPC
Ultra Polish Connector
203
Most light generated by lasers for telecommunications exist in this light band
Infrared band
204
Theoretically, how many wavelengths can be carried on a single fiber using DWDM?
2 to 128
205
A device used to test for dicontinuities (impedance mismatches) on coaxial cables
Time Domain Reflectometer (TDR)
206
Used to detect light from an optical fiber and convert the light to an electrical source
Photodiode
207
A jumper cable for optical connectors
Pigtail
208
This laser generates only one wavelength at it's output
Distributive Feedback Laser (DFB)
209
The ratio of the velocity of light of two mediums of optical glass
Refractive Index
210
Enables different wavelengths to be carried on a single optical fiber
WDM (Wave Division Multiplexing)
211
List the 5 laser classes
Class 1Class 2/2AClass 3AClass 3BClass 4
212
Typical loss (in dB) of a fiber connector
0.5dB
213
A device used to wrap and store excess fiber optic cable in an aerial location
Snowshoe
214
Two types of fiber amplifiers
EDFA (Erbium-Doped Fiber Amplifier)YEDFA (Ytterbium Erbium-Doped Fiber Amplifier)
215
Formula to convert mW to dBm
dBm = 10log(mW)
216
An electronic or optical process that combines several individual signals or wavelengths into a single carrier or path.
Multiplexing
217
Type of cable consisting of larger buffer tubes with the fibers inside, surrounded by fiberglass water block tape, armor, two steel strength members and a jacket
Unitube
218
a trillion Hertz or 1,000 gighertz
Terahertz
219
Similar to loose tube, this type of cable consists of buffer tubes surrounded by a fiberglass wrap and two steel strength members on each side molded into the jacket.
Flex Tube
220
The most basic laser and consists of two pieces of semiconductor material with an active layer between them
Fabry-Perot Laser
221
Central data point communicating with endpoints of a network. All data communications must flow through the central point.
Star
222
Test equipment used to visually see the losses, breaks and distance measurements in an optical fiber
OTDR (Optical Time Domain Reflectometer)
223
Fiber loss is expressed in this manner
dB/km (decibels per kilometer)
224
A network of devices connected together in a circular communication link
Ring
225
A board for making optical connections consisting of sleeves used to line up two connectors
Patch Panel
226
Used to measure transmitter outputs and receiver inputs
Optical Power Meter
227
Allows multiple wavelengths above and below a center wavelength to be carried on a single optical fiber
DWDM (Dense Wave Division Multiplexing)
228
Output of a YEDFA
22dBm
229
How far back should the fibers be stripped?
1-1/2 to 2 inches
230
Typical loss (in dB) of a mechanical splice
0.25dB
231
Allows only a single mode of light to propagate through the fiber core
Single Mode Fiber
232
Light that is reflected back to the source and contributes to the optical fiber loss
Backscattered Light
233
A special optical fiber connector used in gigabit Ethernet Devices that uses fibers in pairs with LC and/or SC.
LCSC
234
A connection point in a cable system where a fiber enters a neighborhood and the optical signal is converted to an electrical signal
Node
235
How many feet is equal to 1km
3300 ft
236
Is a water-resistant enclosure that is intended for storing trays of optical fiber splices between incoming outside plant fiber cables and the inside fiber cables going to the fiber patch panels.
OCEF (Optical Cable Entry Facility)
237
This cable configuration is the same as unitube, except fibers are arranged side by side
Ribbon
238
FC
Ferruled Connector
239
Attenuation of the wavelength 1310nm per kilometer
.35 dB/km
240
Method of joining two optical fibers of the same type using an electrical arc to form a precision splice
Fusion Splice
241
YEDFA
Ytterbium Erbium-Doped Fiber Amplifier
242
The twelve fiber and buffer tube colors in order:
* Blue
* Orange
* Green
* Brown
* Slate
* White
* Red
* Black
* Yellow
* Violet
* Rose
* Aqua
243
The three most important procedures to insure a good splice
Proper CleaningProper CleaveControlled Break
244
This is the sum of all the losses associated with a fiber link between the optical fiber transmitter and the optical fiber receiver
Loss Budget
245
5 types of fiber connections
FC (Ferruled Connector)SC (Standard Connector)UPC (Ultra Polish Connector)APC (Angle Polish Connector)LCSC
246
Output gain of an EDFA
Over 40dB Possible
247
Used to visually see the losses, breaks and distance measurements in an optical fiber link
OTDR (Optical Time Domain Reflectometer)
248
One billion cycles per second or 1 billion Hertz
Gigahertz
249
In DWDM, the wavelengths are this far apart
0.8nm or 100GHz
250
Attenuation of the wavelength 1550nm per kilometer
.25 dB/km
251
Color-Coded tubes that house and protect the optical fibers within a fiber optic cable.
Buffer Tubes
252
A method used to lock and mark one end of a line in order to allow someone to safely work on the other end
Lockout Tag-out
253
Typical loss (in dB) of a fusion splice
0.1dB
254
The distance that cannot be seen by the OTDR because the initial pulse doesn't create enough backscattered light and "hides" the first several hundred feet of cable.
Dead Zone
255
The preferred method of fiber optic splicing
Fusion Splicing
256
This type of fiber optic cable consists of a single strength member in the center surrounded by color-coded buffer tubers, which contain fibers that are also color-coded.
Loose Tube
257
A temporary joining of two optical fibers of the same type using a plastic form to hold and lock fibers together.
Mechanical Splice
258
The gel from buffer tubes should be cleaned with what?
Isopropyl Alcohol that is at least 90% pure
259
To prevent stress on the fiber, cable manufacturers put about 1% more fiber in the cable than the length of the cable itself, to allow for some stretch. What is this called?
Lay Loss Factor
260
Used to locate faults in jumpers and pigtails
Visible fault locator
261
A Photodiode used to detect light from an optical fiber and converts the light to an electrical source
PIN Diode
262
The interface between the Headend (Hub) and the RF Plant.
Node
263
Optical fiber with erbium, a rare earth material, added to the glass during the manufacturing process, to give fiber useful properties when properly lased
Doping
264
Attaches optical fiber from the device to an optical connector
Pigtail
265
The difference between transmitted and received power resulting from the loss through equipment, lines, or other transmission devices; usually expressed in decibels
Attenuation
266
The diameter of the fiber optic coating
250 microns
267
Allows many modes of light to propagate through the core.
Multi-Mode Fiber
268
Name the 5 most common fiber optic cable arrangements
Loose TubeFlex TubeUnitubeRibbonRibbon Stranded
269
A cabinet or rack that houses the splices of the outside plant fiber to the inside headend, node or OTN fiber.
Splice Panel
270
The diameter range of the fiber optic core
8 to 10 micron
271
Extra fiber connected to the OTDR to make up for the dead zone.
Launch Cable
272
What does LASER stand for?
Light Amplification by the Stimulated Emission of Radiation
273
Optical splitter loss is based on _________
Percentages
274
Fiber amplifier that provides the greatest output gain
YEDFA (Ytterbium Erbium-Doped Fiber Amplifier)
275
Advantage of InGaAs over Ge detectors.
InGaAs are less noisy and allow measurements down to -65dBm.
276
Fibers are contained in a plastic tube much larger than the optical fibers. The fibers can move freely within the tube.
Loose Tube
277
A photo diode used to detect light from an optical fiber and convert the light to an electrical source
PIN Diode
278
The topology where signals originate in the headend andare transmitted long distances via trunk cables
Tree and Branch
279
A network architecture that typically uses fiber optic cables to bring signals to selected areas of the system called nodes
Hybrid Fiber-Coax (HFC)
280
Bi-annual tests, performed in the headend and at a number of end-of-line location
FCC Proof-of-Performance
281
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
282
Specifications standards approved by the FCC in 1953for commercial analog color TV broadcasting.
National Television Standards Committee (NTSC)
283
a portion of the electromagnetic spectrum whose frequencies are well suited for transmitting and receiving Telecommunications signals through the air.
Radio Frequency (RF) Spectrum
284
Signals that flow downstream, from the headend to the network.
Forwards (Downstream) Signals
285
Signals that flow in the upstream direction, from customer to headend
Revers (upstream) Signals
286
Device that separates or combines based on frequency.
Diplex Filter
287
typical cutoff frequency for a sub-split diplex filter
About 50 MHz
288
The three major concerns/ limitations of the tree andbranch architecture are:
BandwidthImpairmentsDependency on Power
289
The lowest possible power level determined by the thermal noise generated within the electrical componentsbeing tested
Noise Floor
290
The highest power level (amplitude) reached by a carrier
Peak
291
A clustering of beats 1.25 MHz above the visual carriers in a CATV network
Composite Second Order (CSO)
292
A form of interference or noise resulting from the mixingof all of the various carriers in a CATV network
Composite Triple Beat (CTB)
293
Two major types of distortions that are typically associated with CATV
Composite Second Order (CSO) and Composite Triple Beat (CTB)
294
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
295
Having or relating to a frequency below the audibility range of the human ear.
Infrasonic
296
A stream of atomic nuclei that enter the earth’s atmosphere from outer space at speeds approaching that of light
Cosmic Rays
297
Frequency range of satellite systems
4GHz to 13GHz
298
The wavelengths most commonly used by the CATVindustry
1310nm and 1550nm
299
The type of fiber optic cable that the broadband industry uses
Single Mode Fiber
300
The process of combining multiple carriers onto a single medium
Multiplexing
301
Width of the Fiber optic core
8-10um
302
Width of the fiber optic cladding
125um
303
Width of the fiber optic coating
250um
304
Combines multiple optical signals in order to amplify them as a group and transported over a single fiber
Wave Division Multiplexing (WDM)
305
Allows multiple wavelengths above and below a centerwavelength to be carried on a single optical fiber.
Dense Wave Division Multiplexing (DWDM)
306
Three parts of the optical link
Fiber Optic CableTransmitter (Laser)Receiver (Node)
307
Individual fibers are bundled and then placed into these to reduce the possibility of damage
Buffer Tubes
308
This diode changes the RF signals to pulsesof light and then transmits them onto an optical fiber
Semiconductor Laser Diode
309
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)
310
YAG
Yttrium-Aluminum-Garnet
311
DFB
Distributed Feedback
312
F-P
Fabry-Perot
313
A spare fiber installed during the construction of the network that was reserved for future use.
Dark Fiber
314
Three advantages of trunk reduction
Shorter CascadesFewer/smaller outages due to segmenting the system into smaller areasImproved picture Quality
315
FTTF
Fiber to the Feeder
316
Advantages of FTTF
Shorter CascadesFewer/smaller outages due to segmenting the system intosmaller areas.Increased Bandwidth
317
FTTC
Fiber to the Curb
318
PON
Passive Optical Network
319
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
320
4 advantages of FTTC
No active devices after nodeNo CascadeFewer/smaller outages due to segmenting the system intovery small areasIncreased Bandwidth
321
A fiber-based network which uses passive splitters todeliver signals to multiple locations
Passive Optical Network (PON)
322
FTTH
Fiber to the Home
323
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
324
This will ALWAYS be considered the "Backbone" in an HFC Network
The Fiber Network
325
A high-speed line or series of connections that forms a major pathway within a network
Backbone
326
The duplication of certain pieces and/or portions of thenetwork.
Redundancy
327
Comcast's goal for network reliability
"four-nines" or 99.99%
328
A network architecture where nodes, hubs, or headendsmay be connected with fiber optic cables to provideredundancy or increase services
Ring Architecture
329
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
330
A facility between the headend and the customer that performs many of the functions of a headend
Hubsite
331
Similar in function to a hubsite, but serving fewer customers
Optical Transition Node (OTN)
332
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
333
Usually a passive device that divides a signal into two equal paths. It may be found on trunk, feeder, or drop cable.
RF Splitter
334
Device used to combine the channels for entry onto the cable or fiber optic transmitter
Headend Combiner
335
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
336
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
337
Provision for connection to a device such as a tap, splitter, set-top box or computer
Port
338
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
339
A measurement of the reflected signal compared to that of the incident signal
Return Loss
340
Device used to divide or combine light carriers on fiber optic cables.
Optical Splitter
341
A discontinuous signal whose various states are discrete intervals apart.
Digital Signal
342
Device used to convert an analog signal to a digital signal.
Digitizer
343
takes an amplitude measurement of the waveform at fixed intervals of time, and converts them to a binary number
Digitizer
344
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)
345
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
346
The number of changed states that can occur per second.
Baud
347
The value of "On" in a binary system
"1"
348
The value of "Off" in a Binary system
"0"
349
How many bits are in a "Nibble"?
4
350
If start and stop bits are included with Asynchronous Communications, then how many bits are in a byte?
10
351
ADC
Analog to Digital Conversion
352
DAC
Digital to Analog Conversion
353
A continuously varying signal with an unlimited number of possible values of amplitude and frequency.
Analog Signal
354
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
355
3 steps of basic ADC
SamplingQuantizationEncoding
356
The "Measuring" of the analog signal at specific intervals.
Sampling
357
The assigning of a specific value to each of the samples
Quantization
358
The process by which Quantized values are converted into a data or bit stream
Encoding
359
ASK
Amplitude Shift Keying
360
FSK
Frequency Shift Keying
361
QPSK
Quadrature Phase Shift Keying
362
QAM
Quadrature Amplitude Modulation
363
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
364
Data transmission scheme wherein the carrier is shifted in amplitude
Amplitude Shift Keying (ASK)
365
The carrier frequency is shifted to represent the difference between a one and a zero
Frequency Shift Keying (FSK)
366
The position on a waveform cycle at a specific point in time. One cycle is defined as 360 degrees of this
Phase
367
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)
368
BPSK
BiPhase Shift Keying
369
In QPSK, what does "I" stand for?
In-Phase
370
In QPSK, what does "Q" Stand for?
Quadrature - shifted 90* or one quarter of a cycle
371
A graphic depiction of the four phase states of a Quadrature Phase Shift Key signal.
Constellation Diagram
372
What is the bandwidth of QPSK in a 6MHz bandwidth?
10 Mb/s
373
Digital modulation scheme that changes the phase and the amplitude.
Quadrature Amplitude Modulation (QAM)
374
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)
375
The digital equivalent to Signal-to-Noise
Modulation Error Ratio (MER)
376
A joined or connected group of devices
Network
377
A network of computers linked by cable within a building or office complex.
Local Area Network (LAN)
378
A network of multiple locations linked by cable withina city or campus
Metropolitan Area Network (MAN)
379
A network typically bigger than a city or metropolitan area.
Wide Area Network (WAN)
380
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
381
Consists of several star networks that have been linked together
Clustered Star
382
Topology where workstations are connected to the network through a common path
Bus
383
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
384
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
Ring
385
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
386
An extra bit added to help check if the data that isbeing transferred is correct
Parity Bit
387
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
388
Synchronizing bits used in synchronous transmission to maintain synchronization between transmitter and receiver.
Sync Bits
389
SNMP
Simple Network Management Protocol (SNMP)
390
NE
Network Elements
391
MIB
Management Information Base
392
A unique number assigned to a piece of equipmentused for identification purposes.
Media Access Control Address (MAC)
393
UTP
Unshielded Twisted Pair
394
signaling rate of 10BaseT
10 Mb/s
395
Signaling rate of 100BaseT
100 Mb/s
396
The designation for Ethernet over fiber optic cable, primarily for point-topoint links
10Base-F
397
This device works as a multiport signal repeater, broadcasting an incoming signal to all other ports on an ethernet network
Ethernet Hub
398
The four-part numeric address that is assigned to a computer or an account as an identification tool
Internet Protocol Address (IP)
399
DOCSIS
Data Over Cable Service Interface Specification
400
The Leading standard for cable modems
DOCSIS
401
Four devices that must be added to a system to offer high-speed internet
CMTS (Cable Modem Termination System)CM (Cable Modem)ServersNoise Filters
402
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)
403
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)
404
The collection of computers accessed through the Internet. Uses a hypertext based system for finding andaccessing its resources.
WWW (World Wide Web)
405
Four Items that a CMTS manages
Time SlotsContention SlotsModem DataTransmit Levels
406
Each cable modem is assigned one of these by the CMTS and only one modem is allowed to transmit during this.
Time Slot
407
These slots are usually used for short data transmissions such as a request for an additional number of reserved time slots
Contention Slots
408
The signal level that the CMTS wants to "See"
0dBmV
409
A PC on a LAN from which information or applications are requested.
Client/Server
410
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)
411
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
412
Four of the most common servers found in a braodband network
DHCPTODTFTPProxy
413
This server sets up the MAC and IP addresses for the cable modem.
DHCP Server(Dynamic Host Configuration Protocol)
414
This server sets up a common clock between the CM and the CMTS
TOD Server(Time of Day)
415
This server allows non-protected file transfers, such as aconfiguration file for a modem.
TFTP Server(Trivial File Transfer Protocol)
416
These servers store commonly used (or contractually stored) data. A network may have a series of these servers located in different places.
Proxy Server
417
The two types of noise filters
High Pass FilterNotch Filter
418
These types of filters only allow signals above 50MHz to pass through the filter
High Pass Filter
419
In addition to letting everything above 50 MHz to pass, this filter allows a small spectrum below 50 MHz to pass
Notch Filter
420
The process of setting up the connection between theCMTS and the cable modem, where transmit levels andfrequency are determined.
Ranged
421
A switch or collection of switches connecting multiple networks
POP (Point of Presence)
422
The point of access into theInternet.
NAP(Network Access Point)
423
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
424
The local, long-distance and internationalphone system in use today
PSTN(Public Switched Telephone Network)
425
This device in the Headend controls the operation of CDV.
HDT(Host Digital Terminal)
426
What is "7" equal to in binary?
0111
427
64 QAM has how many phase angles?
52
428
16 QAM has how many phase angles?
10
429
The distance between two points of like phasein a wave.
Wavelength
430
A card made up of material similar to photographic film that changes colors when exposed to light.
Photosensitive Card
431
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
432
loss of service to ourcustomers due to a fault in thedelivery network.
Outage
433
A continuous wave (CW) frequency onto which information is modulated for transport.
Carrier Frequency
434
Maximum Bandwidth of 256QAM
42.88Mbps
435
How long must POP tests be kept at the local office?
minimum of 5 years
436
A circuit that automaticallyadjusts the gain of an amplifier sothat the output signal levels stayconstant despite varying inputlevels.
Automatic Gain Control (AGC)
437
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)
438
What are the three type of coherent disturbances?
Composite Second Order (CSO)Composite Triple Beat (CTB)Other interfering signals (i.e. Ingress)
439
FCC requirement for isolation
18dB
440
Allowable signal leakage level below 54MHz
Up to 15uV/m @ 30m
441
Allowable signal leakage level between 54MHz and 216 MHz
up to 20uV/m @ 3m
442
Allowable signal leakage above 216MHz
up to 15uV/m @30m
443
The two types of leakage monitoring frequency.
Continuous MonitoringQuarterly Monitoring
444
Two types of annual leakage monitoring methods
Ground BasedFlyover
445
What leaks are included in the CLI calculation?
All leaks 50uV or greater
446
what is the elevation that a flyover is completed at? (in meters)
450m(1476')
447
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
448
What does a Spectrum Analyzer Display?
information in the amplitude (vertical) vs. frequency (horizontal) domain over the entire spectrum or portions of it.
449
comparable in certain respects, typically in a way that makes clearer the nature of the things compared.
Analogous
450
states that in order to obtain an accurate recreation of a signal, it must be sampled at a rate of at least twice the highest frequency
Nyquist's Rule
451
In identifying utility locate colors, What colors represent power, telecommunications, and water?
Red, Orange, and Blue
452
How many feet should a ladder be angled per 4 feet of height?
1 foot
453
When a ladder is extended to 20 feet, how far from the base of the pole should its feet be positioned?
5 feet
