Fiber Flashcards
These two scientific properties allow light to travel inside of a specialized piece of glass know as fiber optics:
Refraction, Reflection
These active devices must be changed when transitioning a network fro sub-split to mid-split:
Amplifiers
To take full advantage of DOCSIS 3.1 upstream speeds, Comcast network needs to adopt this architecture:
High-Split
The history of of Fiber Optics goes back to as early as this:
1700’s
In this decade, Fiber Optic cable was improved and gained the capability to transmit light over long distances:
1960’s
In this year, John Tyndall demonstrate that light could be channeled through a curved stream of water:
1854
This individual first demonstrated that light could be channeled through a curved medium;
John Tyndall
This a process that confines light to an optical fiber:
TIR (Total Internal Reflection)
This process is the reflection of the total amount of incident light that occurs with large angles of incidence:
Total Internal Reflection - TIR
Light can travel through a stream of water and remain contained because air and water because this characteristic differs:
Index of Refraction
Light propagates inside the core of a fiber by this:
TIR Total Internal Reflection
This is the glass covering over the core of a fiber optic cable
Cladding
IoR
Index of Refraction
This term describes the imaginary line running perpendicular to the interface of of two materials:
The Normal
This is the angle between the incident ray and the normal:
The angle of Incidence
This is the angle between the refracted ray and the normal:
The angle of Refraction
Light traveling inside the core of a fiber optic cable strikes the cladding at this angle:
The angle of incidence
In order for fiber optic cable to cause TIR, This component is more dense than the cladding:
Core
These are the 4 types of dispersion in fiber optic signal:
Modal, Chromatic, Waveguide, polarization-mode
During process of manufacturing fiber optic cables, the process used to thicken the core of the fiber by adding a mixture of elements can cause this:
Intrinsic Loss
This is the spreading in time of an optical signal as it travels down the length of an optical fiber:
Dispersion
This form of dispersion is the most common in multimode-fiber optic systems:
Modal Dispersion
This is when the core of multimode fiber allows light to break up into many different “modes” or paths, with some modes reaching the far end of an optical fiber before others:
Modal Dispersion
This results from different wavelengths traveling through a fiber at different velocities, the intensity increases as the distance increases:
Chromatic Dispersion
This occurs because small amounts of light travels in the interface between the core and cladding:
Waveguide Dispersion
Light can be broken into a vertically polarized component and a horizontally polarized component. This occurs when these components travel through a optical fiber at different velocities:
Polarization-Mode Dispersion
Imperfections and impurities in optical fibers caused when making the structure of fiber will cause signal loss in these two forms:
Scattering and Absorption
This comes from changes in the density of a optical fiber and variations of the composition that occur during manufacturing:
Rayleigh Scattering or Double Rayleigh Scattering
These two optical wavelengths are used in the cable industry are because they are less affected by absorption than their neighbors on the spectrum:
1310nm and 1550nm
This is the term for signal loss inside fiber that is the result of installation methods:
Extrinsic Loss
This is when a fiber optic cable is visibly bent too sharply and will cause some of the light to hit the interface between the core and cladding that exceeds the critical angle:
Macrobend
This is a small irregularity in the core-to-cladding interface that cause reflections that allow the light to be refracted out of the core:
Microbend
In an HFC network with multiple active devices, a power supply along with a power inserter is used to introduce these two possible voltage levels into the hardline coax:
60 or 90 V
All Fiber Deep Designs must meet the max power consumption of this per fully configured node:
160 Watts
Each Fiber Deep node must have a minimum voltage of this :
50 V
This is a hardline coax connection that will bring AC power from one segment to another:
Power Bus
Power inserters have this many ports
3
This device connects the power supply to the hardline cable to power all the active devices:
Power inserter
This is the act of pulling power from one segment to provide power to another segment:
Power Bus
extends an uncontaminated section of cleaning material from the nozzle of the tool using an automatic reeling system
One Click
contains a powerful solvent cleaner that quickly and safely cleans the end face of fiber optic connectors, splices and ribbons.
Electro Wash Optic Cleaning Pen
A cassette style fiber optic connector cleaner system that use densely woven micro-fiber cleaning fabrics to remove harmful contaminants off of the ferrule end face
CLETOP
first step for installer measurement procedures should also start with inspection and verification of the cleanliness of the connectors and ports.
Fiber Inspection (Scope)
accurately measures optical power at simultaneous wavelengths, supporting measurements over burst mode transmissions.
Pon Power Meter or PPM
It can verify splice loss, measure length and find faults in fiber cable.
Optical Time Domain Reflectometer (OTDR)
The card will quickly visually indicate if an IR LED is producing light
Fiber Detector Card
Connects the OTDR to the link-under-test, discloses the insertion loss and reflectance of the near-end connection
OTDR launch cable
important in order to ensure the reliability and functionality of the final link
Proper cleaning of optical fiber
two methods of cleaning optical fiber
Wet and dry
Isopropyl alcohol purity %
0.9
Used to clean fiber in wet method
Lint free wipes, Isopropyl alcohol, lint free swabs or urethane foam heads
minimum magnification required for proper inspection to the degree needed for longer wavelength optical signals such as 1550 nm
400x
amount of slots a dry cleaner has with a cleaning tape underneath
2
Another method used to dry clean fiber
push pen
if not performed properly, can leave alcohol residue.
use of alcohol and lint-free wipes
What device will take the incoming coming fiber from the headend or hub site and distribute it to within 1000 feet from the customer?
Multiplexing Point
means by which light from an optical source is directed to a destination
optical fiber
Three basic components of optical fiber
Core, cladding, protective cover
Fiber with a large core that supports more than one mode
multimode fiber
Causes high loss by allowing light to escape from the core into the cladding of the fiber
Macrobend
Tool used to identify a macrobend by launching visible light down the optical fiber
Visual Fault Locator (VFL)
Name 3 of the 6 components of an optical fiber cable
Optical fiber, Buffer tube, Strength member, Water blocking elements, Armor, Jacket
A typical fiber bundle contains how many fibers
12
this device takes information in electrical form and encode that information onto an optical signal
Optical transmitters
two basic methods of encoding information onto an optical signal by varying the intensity of the light
baseband digital modulation and analog intensity modulation (AIM)
diretly 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
anilog intensity modulation
power link between two segments of a network
power bus
three major technologies that enable extension of fiber all the way to the customer premises
RFoG, EPON, GPON
uses analog intensity modulation to transport the RF signals over the optical fiber
Radio Frequency over Glass (RFoG)
tool used to examin optical fibers
video fiber scope
slightly adhesive, dark surface used when cutting or splicing fiber
tacky mat
One of the most common chemicals in use with fiber
alcohol
tool used to troubleshoot dirty connector, optical ports or bulkheads
video fiber inspection scope
tool used to troubleshoot low or high optical power issues
PON Power Meter (PPM)
tool used to troubleshoot total optical link health
Optical Time Domain Reflectometer (OTDR)
tool used to determine optical signal to noise ratio
Optical Spectrum Analyzer (OSA)
7 layers of the Open Systems Integration model
Physical, Data Link, Network, Transport, Session, Presentation, Application
Five steps for troubleshooting a service failure
Analyze, Isolate, Divide and conquer, resolve, confirm
The process of combining multiple signals by assigning each signal a unique frequency
frequency division multiplexing (FDM)
technique of using a single fiber to send upstream and downstream signals simultaneously while using a separate wavelenth for each direction
wavelength division multiplexing (WDM)
An architecture with no RF amplifiers after the node
Fiber Deep/ Node 0+
Process of moving the line card of the CMTS closer to the cable modems
Remote PHY
Name the 2 types of HFC powering architectures
distributed and centralized
minimum voltage needed in order for a Fiber Deep node to work
50 volts
approximate loss of a 32-way optical splitter
18 to 20 dB
approximate loss of a 64-way optical splitter
22 to 24 dB
approximate loss of a 128-way optical splitter
26 to 28 dB
three basic architectures that are used to distribute the optical signals in a FTTP system
centralized split, distributed split, distributed tap
RFoG
RF over Glass
EPON
Ethernet Passive Optical Network
FTTP
Fiber to the premises
GPON
Gigabit Passive Optical Network
FTTN
Fiber to the Node
This device converts the downstream optical signal to an electrical RF signal and converts the upstream RF signal into an optical signal
mini-node/micro-node
EDFA
Erbium Doped Fiber Amplifier
OBI
optical beat interference
Per wavelength what is maximum number of homes passed in a fiber deep system
128
If you have a 2-way optical splitter, what is the maximum distance to the node that is possible without the use of an EDFA
25km
If you have a 3-way optical splitter, what is the maximum distance to the node that is possible without the use of an EDFA
15km
If you have a 4-way optical splitter, what is the maximum distance to the node that is possible without the use of an EDFA
14km
If you have no optical splitter, what is the maximum distance to the node that is possible without the use of an EDFA
40km
sets the requirements for fiber connector quality
IEC 61300-3-35
Th 2 types of fiber inspection
Proactive and Reactive
visually inspecting fiber connectors at every stage of handling before mating them
Proactive inspection
visually inspecting fiber connectors after a problem is discovered, typically during troubleshooting
Reactive inspection
Name the 3 common FTTP connectors
SC/APC, LC/UPC, MPO
This fiber connector is used for R-ONU/ONU inputs and fiber splitters in the ODN
SC/APC connector
This fiber connector is used on a diplexer or return receiver module
MPO connector
This fiber connector is used for digital return path transmitter SFPs (Small Form factor plugable’s)
LC/UPC connector
This fiber connector is used for EPON ONUs
SC/UPC
This fiber connector is used for RFOG R-ONUs
SC/APC
These are the three common methods used to clean fibers
Dry Process, Wet Process, Combination Process
The most commonly used process for cleaning a new FTTP optical connection is
dry cleaning
Name the two types of splicing that exist in the cable industry
Mechanical and Fusion
A splice in which fibers are joined mechanically
Mechanical splice
is accomplished by the application of localized heat sufficient to fuse or melt two lengths of optical-fiber together forming a continuous, single fiber
Fusion splice
LID
Local Injection and Detection
PAS
Profile Alignment System
System System that projects an image allowing a fiber installer to view the fiber cores and manually or automatically bring the cores into alignment
Profile Alignment System (PAS)
Placed over the fiber prior to splicing
Heat-Shrink Sleeve
Used to hold splices in place and organize the fibers
Splice Tray
In a fiber deep architecture what device is used to increase the power of the optical signal
Erbium Doped Fiber Amplifier (EDFA)
Powers of 10 Formula
10 mW = 10 dBm
Name the 2 steps in a complete fusion cycle when fusion splicing fiber
Pre-fuse Phase and Fusion Phase
The ends of the fibers to be joined are separated, cleaned and softened by an electrical arc in this phase
Pre-fuse Phase
The ends of the fibers are manually or automatically brought together and longitudinally fed together while electrical current is applied to the electrodes during fusion in this phase
Fusion Phase
Typical loss value in a mechanical splice
0.2 to .25 dB
SC/APC
standard connector / angled physical contact
The defining equation for decibels
Power Ratio in dB = 10 x log10 (P1/P2)
the SCTE/ISBE standard for RFoG
SCTE/ISBE 174
R-ONU’s typically require a downstream input power level in this range
-6 to 0 dBm
For each change in optical loss of 1 dB, the RF output level will change by
2 dB
recommended maximum system loss for RFoG
25 dB
summarizes the power levels that will result in a network based on the transmit power levels and the losses in the network
power loss budget
Fiber Deep downstream wavelength
1550 nm
Fiber Deep upstream wavelength
1310 nm
EPON/GPON Downstream wavelength
1490 nm
EPON/GPON upstream wavelength
1310 nm
EPON/GPON (10 Gbps) Downstream wavelength
1577 nm
EPON/GPON (10 Gbps) upstream wavelength
1270 nm
the upstream wavelength for RFoG when overlayed with EPON
1310 nm
the standard upstream wavelength for RFoG
1610 nm
The downstream wavelength for RFoG
1550 nm
OSA
Optical Spectrum Analyzer
provides a visible light source that can be launched down the fiber
Visual Fault Locator (VFL)
ENS
Ethernet Network Service
MAN
Metropolitan Area Network
UNI
User-to-Network Interfaces
Ethernet Network Service is offered with these User-to-Network Interfaces (UNI)
10Mbps, 100Mbps, 1000Mbps, 10Gbps
Ethernet Network Service is offered with these Class of Service options
basic, priority, premium
Modulation used by EPON to transport the RF signals over optical fiber
Baseband Digital Modulation
Number of light intensities produced by an EPON optical transmitter
2
EPON device located at the customer premise that allows the CPE to communicate
Optical Network Unit (ONU)
Gives permission for an EPON ONU or ONT to transmit upstream
Optical Line Terminal (OLT)
BOGBSWRBYVRA
blue operators give better service, while running backwards you vomit right away
12 count fiber buffer tube fiber 1 color
blue
12 count fiber buffer tube fiber 2 color
orange
12 count fiber buffer tube fiber 3 color
green
12 count fiber buffer tube fiber 4 color
brown
12 count fiber buffer tube fiber 5 color
slate
12 count fiber buffer tube fiber 6 color
white
12 count fiber buffer tube fiber 7 color
red
12 count fiber buffer tube fiber 8 color
black
12 count fiber buffer tube fiber 9 color
yellow
12 count fiber buffer tube fiber 10 color
violet
12 count fiber buffer tube fiber 11 color
rose
12 count fiber buffer tube fiber 12 color
aqua
