NCT4/5 10-17-18BH 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
8-12 degree angled cut end
APC (angled polish connector)
allows characters to be sent at irregular intervals by preceding each character with a 0 and a 1 (start=0 stop=1) method used by most pc’s to communicate with each other and mainframes
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)
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 data
Binary digit (Bit)
constrained to have 2 states (on and off)
binary format
a set of bits that represent a single character
Byte
device that scores and then breaks the optial fiber
Cleaver
a clustering of beats 1.25Mhz above the visual carriers
CSO (composite 2nd 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 Phase Shift Key signal
constellation diagram
a stream of atomic nuclei that enters the earths atmosphere from outer space at speeds approaching that of light
cosmic rays
device that converts an amount of light to a power level
detector
separates or combines based on frequency
diplex filter
3 types of optical power meters
- silicon (si)
- Germanium (Ge)
- indium-gallium arsenide (InGAAs)
an extra bit added to help check if the data being transferred is correct
Parity Bit
used to detect light from an optical fiber and convert the light to an electrical source
Photodiode
provision for connection to a device such as a tap, splitter, stb, or computer
Port
an alternate feed used as a backup. contains the same info as the primary configuration but is routed in a different path
Redundant
the ratio of the velocity of light of 2 mediums of optical glass
Refractive index
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 head end, node, or OTN fiber
Splice Panel
noise caused by inherent instabilities within the laser
RIN (relative intensity noise)
the part of the packet that contains the data being sent
payload
YEDFA
ytterbium erbium doped fiber amplifier
distance between 2 points of like phase in a wave
wavelength
violet wavelength
455nM
blue wavelength
480nM
green wavelength
550nM
red wavelength
750nM
light escapes from the core into the cladding
macrobend
tiny kinks or nicks in the fiber that may be created in manufacturing or mishandling
microbend
directly encodes digital 1’s and 0’s as pulses of light
baseband digital modulation
varying the intensity of the light in direct proportion to the analog electrical signal that is applied to the optical transmitter
analog intensity modulation
spreading in time (t) of an optical signal as it travels through the fiber
dispersion
common dispersion in multi mode fiber
Modal dispersion
small amount of light travels through the interface between the core and cladding, this light travels faster than the light in the core
Waveguide dispersion
PMD
polarization mode dispersion
2 forms of attenuation in the fiber manufacturing process
scattering and absoption
light directed back to the input of the fiber
back scattering
angle of incidence greater than the critical angle creates
total internal reflection
loss of optical energy due to the imperfections in the fiber
scattering
MPEG format compresses video information by reducing
temporal redundancies
spatial redundancies
2 types of cipher algorithms
symmetric key
asymmetric key
2 common forms of multiplexing
time division
statistical (DVB standard, statmux)
redundant information in a single frame
temporal redundancies
redundant information spanning multiple frames
spatial redundancies
3 signs of a failing diplex filter
drifting
roll off
phase delay
common causes of micro reflections
damaged or missing terminators water filled taps kinked or damaged cables damaged splitters cpe
NCPdb
node combining plan database
name 4 linear distortions
micro reflections amplitude ripple group delay jitter notches
FM radio freq allocation
88-108Mhz
UHF ch 14-83 freq allocation
470-890 Mhz
VHF ch 7-13 freq allocation
174-216 Mhz
cellphone freq allocation
824.040-848.970 Mhz
