Gloss over it (BH10-24-2018) Flashcards
data transmission scheme wherein the carrier is shifted in amplitude
ASK (amplitude shift keying)
a continuously varying signal with an unlimited number of possible values of amplitude and frequency
Analog signals
8 to 12 degree angled cut end
APC (angle polish connector)
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
asynchronous
the difference between transmitted and received power resulting from the loss through equipment, lines, or other transmission devices. usually expressed in dB
attenuation
a circuit that automatically adjusts the gain of an amplifier so that the output signal levels stay constant despite varying input levels
AGC (automatic gain control)
a high speed line or series of connections that forms a major pathway within a network
backbone
light that is reflected back to the source and contributes to the optical fiber loss
backscattered light
number of changed states that can occur per second
Baud
smallest unit of computerized dat
binary digit (bit)
constrained to have two states (on and off)
binary format
a set of bits that represent a single character
byte
a unit consisting of various hardware and software entities that acts as a hand off point between the HFC and internet
CMTS
a continuous wave frequency onto which information is modulated for transport
carrier frequency
the glass material surrounding the fiber core. has a lower refractive index and reflects the light back into the core
cladding
a device that scores and then breaks the optical fiber
cleaver
acrylic or plastic material applied over the cladding and core. protects the fiber and adds to its strength
coating
a clustering of beats 1.25 Mhz above the visual carriers
CSO (composite second order)
a form of interference or noise resulting from the mixing of all of the various carriers in a CATV network
CTB (composite triple beat)
a graphic depiction of the 4 phase states of a quadrature shift key signal
constellation diagram
the center of the fiber that carries the transmitted light
core
a steam of atomic nuclei that enters the earths atmosphere at speeds approaching that of light
cosmic rays
allows multiple wavelengths above and below a center wavelength to be carried on a single optical fiber
Dense Wave Division Multiplexing (DWDM)
a device that converts an amount of light to a power level
detector
discontinuous signal whose various states are discrete intervals apart
digital signal
device used to convert a analog signal to a digital signal
digitizer
separates and combines based on frequency
diplex filter
an analyzer setting that allows for testing modulated carriers
gated mode
one billion cycles per second
gigahertz
having or relating to a frequency below the audibility range of the human ear
infrasonic
noise caused by inherent instabilities within a laser
RIN (relative intensity noise)
the part of the packet that contains the data being sent
payload
an alternate feed used as a backup it contains the same info as the primary configuration but is routed in a different path
redundant
provision for connection to a device such as a tap, splitter, STB, or computer
Port
the square root of the sum of the squares of the amplitude of individual components of a function, such as frequency components of a signal
RMS (root means square)
3 most basic functions of any spectrum analyzer
frequency, span, amplitude
digital modulation wherein the frequency of the carrier is shifted
FSK (frequency shift keying)
cumulative effect of the return path distortions, they are added to the signal at carious locations in the HFC network
Funnel effect
method of joining 2 optical fibers of the same type using an elctrical arc to form a precision splice
fusion splicing
an analyzer setting that allows for testing modulated carriers
gated mode
analyzer feature that allows intrusive tests to be performed in a non-intrusive manner
gated testing
one billion cycles per second
gigahertz
device used to combine the channels for entry onto the cable or fiber optic transmitter
head end combiner
a facility between the headend and the customer that performs many of the functions of the head end.
Hubsite
the 4 part numeric address that is assigned to a computer or an account as an identification tool
internet protocol address (IP)
a device that generates a light source used in optical fiber communication
LASER
fibers are contained in a plasti tube much larger than the optical fibers. fibers can move freely within the tube
Loose tube
a temporary joining of 2 optical fibers of the same type using a plastic form to hold and lock the fibers together higher splice loss than fusion splic
mechanical splice
the process of varying the amplitude, frequency, or phase of a carrier to be instep with the instantaneous value of the modulating waveform
modulation
an electrical or optical process that combines several individual signals or wavelengths into a single carrier or path
multiplexing
one billionth of a meter
nanometer
specifications standard approved by the fcc in 1953 for commercial analog color TV broadcasting
NTSC (national television standards committee)
a computer circuit board installed in a computer so that the computer can be connected to a network. provides a dedicated, full-time connection to a network.
NIC (network interface card)
the lowest possible power level determined by the thermal noise generated within the electrical components being tested
noise floor
in order to obtain an accurate recreation of a signal it must be sampled at a rate of at least the highest frequency
nyquists rule
an extremely thin flexible thread of pure cladding glass able to carry millions of times the information of a traditional copper wire and do it over greater distances
optical fiber
measurement based on the equivalent heating power of the light. measured in dBm
optical power
device used to test the optical power. it converts the amount of light present to a dBm level
optical power meter
3 types of optical power meters
Silicon (Si)
Germanium (Ge)
Indium-Gallium Arsenide (In-Ga-As)
found within the optical node or in the head end where information modulated onto the downstream and upstream light carriers are recovered
optical receiver
test equipment used to visually see the losses, breaks, and distance measurements in an optical link
OTDR (optical time domain reflectometer)
similar in function to a hubsite but serving fewer customers
OTN (optical transition node)
provides the means to modulate to RF carriers on to a coherent beam of light is then coupled to the fiber optic cables for routing to the systems fiber nodes or other optical receivers where carriers are recovered
Optical Transmitter
loss of service to our customers due to a fault in the delivery network
outage
an extra bit added to help check if the data being transferred is correct
parity bit
fiber based network which use passive splitters to deliver signals to multiple locations
PON (passive optical network)
a board for making optical connections consisting of sleeves used to line up 2 connectors
patch panel
the highest power level (amplitude) reached by a carrier
Peak
used to detect light from an optical fiber and convert the light to an electrical source
photo diode
attached optical fiber from the device to an optical connector
pigtail
a photo diode used to detect light from an optical fiber and converts the light to an electrical source
pin diode
a switch or collection of switches connecting multiple networks
POP (point of presence)
provision for connection to a device such as a tap, splitter, set top box or computer
Port
digital modulation scheme that changes the phase and the amplitude
QAM (Quadrature Amplitude Modulation)
the ratio of the velocity of light of 2 mediums of optical glass
Refractive index
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
the portion of the electromagnetic spectrum used to send and receive telecom signals over the air
RF spectrum
divides a signal into 2 equal paths
splitter
network architecture where nodes, hubs, or head ends may be connected with fiber optic cables to provide redundancy or increase services
Ring
required to “ring” the phone, typically between 70 and 90 volts at 17 to 20Hz
ringing voltage
the square root of the sum of the squares of the amplitude of individual components of a function, such as frequency components of a signal
RMS (root means square)
device used to wrap and store excess fiber in an aerial location
snowshoe
a cabinet or rack that houses the splices of the outside plant fiber to the inside headend, node or OTN fiber
Splice Panel
central data point communicating with end points of a network. all data communications must flow through the central point
Star
device that opens or breaks a circuit path in a telephone call. looks at the incoming data and determines where the data should get routed
Switch
used in synchronous transmissions to maintain synchronization between transmitter and receiver
sync bits
condition that occurs when 2 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 start/stop bits. fewer bits=less time to transmit
synchronous
used to test for impedance mismatches (discontinuities) on coaxial cable
TDR (time domain reflectometer)
1 trillion hertz
THz
modulating technique that interweaves multiple conversations based on time
TDMA (time division multiple access)
10log(average symbol power/average error power)
MER (dB)
cable loss + passive loss
total loss
starting level - total loss
expected level
amplitude vs. time
oscilliscope
amplitude vs. frequency
analyzer
percentage of light passed by each port
optical splitters
CMTS Modem = transmit levels
Long loop AGC
390nM-780nM
visible light
0 to 12 Hz
infrasonic
(8x10-21)
cosmic rays
4-13GHz
satellite
1271nM-1611nM
CWDM
digital carrier RMS/ noise floor RMS=
carrier to noise
errored bits vs. total bits per second
BER
10LOG(mw)
dBm
2ndLOG (dBm/10)
mW
20LOG (E(mv)/1) or 20LOG (E1(mv)/E2(mv))
dBmv
10LOG P1/P2 10 times the log10 power of p1/p2
dB
