Fiber Installation and Activation
Which answer best describes network topology?
It's a sub-layer of network architecture that describes the physical and logical configuration of connected elements between the signal source and the network termination elements.
Why are laser diodes most effective when coupled to single mode fiber?
Its high coupled power, directionality, and speed.
What is a design option for a broadband cable network to maximize the use of its optical fiber resources?
Leasing spare fibers.
When preparing fiber-optic cable for connection to a patch panel, how much buffer tube and fiber slack should be provided?
Leave enough slack in the buffer tubes to allow the splice trays to reach the splicing equipment and enough fiber slack to store on individual trays for later additions, moves, and changes.
Which of the following statements about local ad insertion is true?
Local ad insertion is performed usually by a video server.
Which type of fiber-optic cable provides the most stable transport characteristics and additional protection from stresses caused by macrobends and microbends?
Loose-tube cable.
What are some advantages of using flexible conduit?
Low coefficient of friction (COF) and the capability to bend around corners and obstructions with minimal splices.
What step should be performed at the beginning of every fusion splicing operation?
Make a number of test splices to set up the fusion splicer and to verify the instrument's settings and calibration for both the environment and the type of fiber to be spliced.
What are the primary causes of intrinsic loss in single-mode fiber?
Material absorption and Rayleigh scattering.
Chromatic dispersion is a combination of which two dispersions?
Material and wave-guide dispersion.
The National Electrical Safety Code (NESC) provides guidelines concerning which portion of the fiber-optic cable network?
Minimum safety clearances between different conductors of overhead and underground electric supply and communications lines.
Eliminating pulling lines using high air speed blowing (HASB) can achieve how much of a cost savings over conventional pulling techniques?
More than 40%.
A type of optical fiber with large core diameters which allow multiple modes, or paths, upon which the optical signal travels is known as what?
Multi - Mode Fiber
What does the amplification process in an avalanche photodiode (APD) introduce into the electrical output of an optical detector?
Noise
What are the factors that contribute to an optical receiver's sensitivity?
Noise, responsivity, response time, linear response, back reflection, and optical detector material.
What happens if the optical signal exceeds the maximum specified input power into a photodetector?
Nonlinear operation resulting in distortion, data errors, and signal loss.
Which element of a passive optical network (PON) consists of a downstream (forward path) optical transmitter, an upstream (return path) receiver, and a multiplexer/demultiplexer?
Optical line terminal (OLT).
Which component of an optical modulation system contains an optical detector and a demodulator?
Optical receiver.
Which component of a digital optical network is used to receive digital modulation light waves and convert them to an electrical signal?
Optical transponder.
What benefits were realized using fiber for the cascade reduction of RF trunk amplifiers?
Outage reduction and improved picture quality.
What is a benefit of using a point-to-point (P2P) topology instead of a point-to-multipoint (P2MP) topology?
P2P topologies are more stable than P2MP topologies.
Which of these items should be identified on a route map?
Parks.
Which layer of a synchronous optical network (SONET) maps the signals into a synchronous payload envelope (SPE)?
Path
What are two types of optical detector used in fiber-optic networks?
Positive-Intrinsic-Negative diode (PIN) & Avalanche Photo Diode (APD)
Which statement about pigtails used for optical fiber terminations is true?
Prior to splicing, pigtails should be labeled to correspond with the correct color code and patch panel designation
What is it about radio frequency over glass (RFoG) that made broadband cable operators envision using it to make a seamless transition from the legacy hybrid fiber/coax (HFC) architecture over to a gigabit-capable passive optical network (GPON) or Ethernet passive optical network (EPON)?
RFoG can operate in parallel with GPON or EPON, operating independent of the PON communications protocols and data rates.
In fiber-optic terminology, what is "window" ?
Refers to a center optical wavelength, as well as a range of wavelengths on either side of the center wavelength
In an optical network, what is reflectance?
Reflectance is the reflected light from a single Fresnel reflection event.
Internet protocol (IP) telephony systems in broadband cable networks
Require a call management server, media gateway, signaling gateway, billing system, and cable modem termination system (CMTS).
How are optical splices secured in a splice tray?
Retaining clips hold optical splices in place in a splice tray.
What is a consideration for the use of ribbon fiber?
Ribbon fiber requires different tools and equipment to perform splicing.
Which type of network topology allows troubleshooting a problem or switching around the problem to be accomplished easily from the central hub?
Ring
Which type of network topology has been focused primarily on alternative routing around cities and industrial areas?
Ring
Which of the following is true about the synchronous optical network (SONET) transmission standard?
SONET is the North American standard used for telephony applications.
When installing fiber-optic cable over coaxial cable, what should be done at the coaxial cable expansion loops?
Secure the fiber-optic cable to the strand across the coaxial cable expansion loops using plastic cable ties or support straps.
Which category of fiber-optic cable design typically uses some variation of the star topology?
Signal distribution
What is the Fiber-optic cable term for optical transport that is restricted to one path (mode) for light propagation through the core of an optical fiber?
Single Mode Fiber
In what applications is a splice closure used?
Splice closures are used to protect optical fibers and splices against a full range of environmental changes in aerial installations or below ground in vaults.
What is the purpose of splice trays inside splice closures?
Splice trays are designed to provide protection for mechanical splices, fusion splice protectors, and optical splitters as well as provide storage for the required fiber slack.
What is used in outside plant fiber-optic cable to protect and isolate the optical fibers from stress
Strength members and buffer tubes.
Since they provide the same functions, what is the primary difference between the fiber distribution hub (FDH) and fiber access terminal (FAT)?.
The FAT is typically easier to install and has lower fiber counts than the FDH.
What type of single-mode fiber is intended for fiber-to-the-home (FTTH) installations?
The ITU-T G.657 bend-insensitive fiber (BIF).
Which standards organization is considered to be the creator of the world's most recognized communications standards, known as "recommendations?"
The International Telecommunication Union (ITU).
What are the two accepted methods for pulling fiber-optic cable off the cable reel as part of an aerial installation?
The back-pull method and the drive-off method.
How should the buffer tubes be secured in the closure?
The buffer tubes should be secured with tie wraps so that there is no movement of the optical fibers inside the buffer tube.
What is a concern when aerial fiber-optic cable is installed between poles, even though there are no high-voltage power lines?
The buildup of lethal amounts of static electricity on the fiber-optic cable that can discharge through a person on a ladder or some other conductor connected to ground.
In regard to providing high-speed data (HSD) service,
The cable modem termination system (CMTS) can provide a data transfer rate up to 38 Mbps, using 256-QAM in a single 6 MHz channel.
What is one process that has to happen before digital modulation can occur in an optical transmitter?
The data must be encoded.
The phenomenon, total internal reflection, is what enables an optical fiber to guide light. What characteristic of optical fiber causes total internal reflection?
The difference in refractive indexes, between cladding and core, causes light to be reflected off the cladding and back into the core along the optical fiber.
If tight-buffered distribution fiber-optic cable is installed between the master splice panel in an optical entrance enclosure (OEE) and a rack-mounted fiber-optic distribution panel, where in the facility must the distribution panel be located?
The distribution panel must be located within 15 meters (50 feet) of the entrance to the building since the distribution cable does not comply with indoor code requirements for riser or plenum installations.
What is a drawback of using Fabry-Perot (F-P) lasers in high-speed data (HSD) networks?
The emission of a number of discrete wavelengths or side modes.
What are the two critical elements that align the optical fibers in a connection?
The ferrules and the mating adapter.
Which type of fusion splicer is ideal for fiber-to-the-x (FTTx) splicing?
The fixed V-groove splicer.
What is one advantage and one disadvantage of single-mode fiber with a large mode field diameter (MFD)?
The larger the MFD, the easier it is to splice and connectorize the fiber, although it becomes more sensitive to bending losses.
What is a characteristic of light in a laser beam?
The laser beam consists of a limited range of wavelengths (monochromatic), with all light waves in phase (coherent light).
What is a local loop?
The local loop refers to the twisted-pair copper wire network within an area of a city.
What designation has been given to optical fibers that are used to connect the master headend with the primary hub?
The master headend and primary hubs are connected using primary ring fibers.
In underground installations, what are two recommended techniques that prevent the pulling tension through the conduit from exceeding the pulling tension specification of the fiber-optic cable?
The midpoint pull and the intermediate pull.
In a centralized server video-on-demand (VOD) architecture,
The number of servers needed for video content storage is smaller than in the distributed server architecture.
What is true of the following types of uninterruptible power supplies (UPS)?
The offline type routes incoming power directly to connected devices and switches to battery backup during a power interruption.
What occurs in the wavelength division multiplexing (WDM) process?
The optical output from multiple lasers operating at different wavelengths is combined and transported over a single, common optical fiber.
In which component in a fiber-optics communication system do changes to the intensity of the optical signal occur?
The optical transmitter.
Which fusion splicer alignment method uses a camera to align the optical fibers before splicing?
The profile alignment system (PAS) method.
The quality and attenuation value of a mechanical splice of optical fibers is dependent on which tool during the preparation process?
The quality and attenuation value of the mechanical splice of optical fibers is dependent on the quality of the cleaving tool.
When working on a ladder, which rungs are forbidden for standing?
The top two rungs of any ladder.
When installing aerial fiber-optic cable employing the back-pull method, how should the cable trailer be positioned in order to keep the cable from rubbing on the pole or cable reel when pulled?
The trailer should be positioned in line with the strand and at least twice the distance from the pole as the height from the ground to the set-up chute.
The frame structure of a synchronous transport signal (STS) is divided into two parts. What are they?
The transport overhead, which contains the section and line layers, and the synchronous payload envelope, which contains the path overhead and the payload data.
How is the high air speed blowing (HASB) method of installing fiber-optic cable in conduit different from other methods?
There is no need for a pulling rope in the conduit before the cable is installed
What is true of online uninterruptible power supply (UPS) systems?
They are recommended for commercial applications such as data centers and telecommunications operations.
Which of the following is true about optical nodes?
They contain four main sections: the optical receiver, the RF amplifier module, the reverse optical transmitter, and the DC power supply.
How do technicians know the specific type of single-mode fiber used in a particular project?
They have read the project's specification records.
Why is -48 VDC (volts of direct current) with a positive ground used by the telecommunications industry?
This reverse polarity is a means of mitigating electrolytic corrosion on the outside plant.
What is an option available on most optical nodes for connecting to the power supply?
Through a power cable that is connected from the power supply directly to the power port of the node.
When preparing a fiber-optic cable for splicing, what is the purpose of removing approximately 2.5 cm (1 inch) of jacket and any armor that is present, from the end of the cable?
To access the cable's rip cord and to check the cutting depth of the knife or ringing tool.
What is the core objective of the Data Over Cable Service Interface Specification (DOCSIS) Provisioning of Ethernet passive optical network (EPON), or DPoE, access architecture?
To make the EPON elements appear and operate as DOCSIS elements to the existing DOCSIS-based back office provisioning operations.
When splicing fiber-optic cable, why is it a good safety practice to clean off fiber strippers and other hand tools after each use?
To prevent the accidental transfer of fiber debris or fiber chips onto clean hands.
Why are backup AC generators included in many commercial AC uninterruptible power supply (UPS) and DC power systems?
To provide AC power in the event of a prolonged utility power interruption
Why was the zero-dispersion point in single-mode fiber moved to 1,550 nm?
To take advantage of the low intrinsic absorption and lower attenuation at 1,550 nm in single-mode fiber.
When preparing a splice closure, what should be done with the fiberglass rod strength member that runs down the center of loose-tube fiber-optic cable?
Trim the strength member back for convenience, but leave it long enough to be tightly clamped to a strain-relief lug in the closure.
In a passive optical network (PON), which category of fiber-optic cable is routed from the headend into the optical distribution network (ODN)?
Trunk.
Typically, what is the first step to take when adjusting an optical receiver?
Turn on the optical receiver.
Digital return path transmissions
Use dense wavelength division multiplexing (DWDM) digital return transmitters in hub-to-headend architectures.
What is the ideal way for a broadband cable network designer to plan the replacement of coaxial cable with fiber-optic cable to shorten amplifier cascades?
Use the existing coaxial network infrastructure.
What is PacketCable and how is it used?
VoIP is based on the Data Over Cable Service Interface Specification standard that is used for the delivery of HSD service over an HFC network.
What does water do to the glass core of an optical fiber?
Water causes the glass core of the optical fiber to become opaque, which degrades the signal as it's transported through the fiber.
Explain how a digital return transmitter changes signals from analog to digital.
When a digital return transmitter changes signals from analog to digital, each input is processed through an A/D converter, which produces a digital stream from the analog signal information
When is it necessary to use the intermediate pull technique to install fiber-optic cable in conduit?
When the cable route has multiple 90° bends throughout.
What are the most common products that transfer contamination?
airborne contaminants, cable moisture repellent gels (used inside the buffer tubes), and the coating residue left from the removal of the 250 µm coatings from the 125 µm fiber.
What does a call management server provide?
call control and signaling related services for multimedia terminal adapters (MTA) and cable modem termination system (CMTS) gateways.
Name the three architectures used with video-on-demand in an HFC network
centralized, distributed, and hybrid server architectures.
What factors must be considered when designing high-speed optical circuits?
data rate, bandwidth requirements, and the dynamic range of the optical link.
when do most fiber splinters occur?
during preparation, stripping and cleaving
What is 8-VSB?
eight-level vestigial sideband modulation. It is the modulation method used for broadcast channels in the ATSC digital television standard, and the modulation that is used primarily in North America.
What do safety data sheets (SDS) cover?
identity of the substance, physical hazards, health hazards, and information regarding protective clothing required while using the substance.
What are two advantages of using a digital return path transmission system?
increased link distances, without a loss of performance and the amount of fiber required in the network can be greatly reduced when using DWDM digital return transmitters in hub-to-headend architectures.
What is a major benefit of using a scalable node?
it offers a wide variety of configuration options, which allows for future network upgrades
What is the function of a status monitoring node transponder?
monitors power supply voltages, transmitter/receiver status, and temperature, and it usually monitors a tamper switch mechanism.
What did synchronous optical network (SONET) define when it was initially proposed?
optical carrier data rates and interface standards that enabled international communications carriers to interconnect EXISTING fiber-optic transmission systems.
Describe the four main sections of a fiber-optic node.
optical receiver, RF amplifier module, reverse optical transmitter, DC power supply.
What are the three specific safety disciplines when working with optical fibers?
proper use of tools, safety eyewear, and the proper handling of chemicals.
What is the benefit of custom channel lineups for cable operators?
the ability to deliver specific programming content based on demographic needs or franchise requirements. Custom channel lineups also allow for tiered programming, which allows operators to charge for different levels of program services.
What does the dynamic range of an optical transmission link depend on?
the length of the link, receiver sensitivity, and the transmit power required to successfully recover the data at the other end
Describe the function of the cable modem termination system (CMTS) in the delivery of high-speed data service in an HFC network
transmits and receives digital signals over the HFC network and routes IP traffic to the Internet.
How are most surfaces designed in a splicing vehicle?
with good lighting and chemically resistant surfaces
Name and describe two key standards used for DWDM?
(1) ITU-T G.692, which defines digital systems, components, and optical interfaces for multi-channel systems with optical amplifiers; and (2) Telcordia-GR-1312-Core, which addresses generic requirements for optical amplifiers and proprietary DWDM systems
What is the purpose of grounding to earth?
(1) To protect against the adverse effects of lightning; (2) assist in the reduction of static; and (3) bring a zero-voltage reference to system components.
What are the three basic components of all fiber-optic communications networks?
(1) an optical transmitter with a light source; (2) the optical fiber (3) an optical receiver with a photodetector.
What is the typical optical input level requirement for a digital return receiver?
-20 dbmv range
The 10G-EPON access architecture supports two data rates in the upstream. What are they?
1 Gbps and 10 Gbps.
What is one of the requirements that have been identified for next-generation access network architectures?
10 Gbps downstream data rate capacity.
Single -mode fiber-optic cable is optimized to transport which wavelengths?
1310 nm & 1550 nm
What is the minimum amount of slack that must be provided for splicing fiber-optic cable in underground installations?
15 meters on both the inbound and outbound span.
How many meters of slack cable are typically used in an aerial installation?
15-25 meters.
In networks transporting data rates that are higher than _____, Fabry-Perot (F-P) lasers are considered inadequate.
2.5 Gbps.
What is the maximum data rate the XG-PON1 (10G-PON) access architecture supports in the upstream?
2.5 Gbps.
What type of modulation is used to transport downstream data from the CMTS?
256 QAM
What is the minimum clearance in the middle of a cable span between the power's secondary conductor and the fiber-optic cable belonging to a broadband cable operator?
30 inches.
What window is exclusively used for multimode fiber?
850 nm
What are the four standard optical windows?
850 nm, 1,300 nm, 1,550 nm, and 1,625 nm.
What is one example of a stipulation in a franchise agreement that would affect network design?
A 100% fiber-optic network.
What is channel bonding?
A 3.0 revision to Data Over Cable Service Interface Specification (DOCSIS) that significantly increases upstream and downstream transport data rates.
What does a point-to-multipoint (P2MP) topology consist of?
A P2MP topology consists of a host element connected through a splitter or optical coupler to two or more receiving elements.
What can be attached to the pulling line to prevent the fiber-optic cable from twisting during installation?
A break-away swivel.
What are some prerequisites before performing a fusion splice of optical fibers?
A controlled environment such as a splicing van, trailer, or tent and a stable work surface that is large enough to accommodate the fusion splicer, tools, and the splice closure
Where would you expect to install a mid-entry splice in a fiber-optic cable network
A location where a select number of optical fibers need to be spliced, and the remaining buffer tubes and fibers remain untouched
What does the spectral width of a laser or Light Emitting Diode (LED) define?
A measurement for the band of wavelengths over which a laser light source emits its energy, generally measured in nanometers (Nm) between the half power points of an optical light sources maximum amplitude at the center frequency Full Width Half Maximum (FWHM)
What is required of mechanical splices used for acceptance testing?
A mechanical splice used for acceptance testing should be simple to use and reusable.
What is MPEG (Moving Picture Experts Group)?
A universally accepted standard for digital television, first released in 1992.
What is the primary difference between an avalanche photo-diode (APD) and a positive-intrinsic-negative (PIN) photo-diode?
APD require a higher voltage power supply and more complex circuitry
What is the difference between the fiber-to-the-node (FTTN) and fiber-to-the-curb (FTTC) topologies?
An FTTC is allowed a smaller number of RF amplifiers between the optical fiber and the customer premises.
What is an Erbium-doped fiber amplifier (EDFA)?
An optical amplifier that uses active erbium-doped fiber and a pump source (laser) to boost or amplify the optical signal?
What is a positive-intrinsic-negative (PIN) diode?
An optical detector with current flow that is linear to the intensity of light photons, with one electron/hole pair created for every absorbed photon until saturation.
Low coefficient of friction (COF) and the capability to bend around corners and obstructions with minimal splices.
An unused cable that is already installed in the conduit.
Where would you expect Fresnel reflections to occur in a fiber-optic network?
At connections and mechanical splices where the signal source is entering or exiting the cable
What happens to the dense wave division multiplexing (DWDM) signals at the primary hub locations in preparation for routing to digital receivers?
At the primary hub locations, the DWDM wavelengths are demultiplexed and routed to digital receivers, where the digital signals are converted back to the original video signals for modulation onto RF carriers. The RF carriers are combined to assemble a forward broadcast lineup.
Why are Velcro straps preferred over standard plastic tie wraps when bundling pigtails for storage in a splice panel?
Because Velcro straps are removable and can hold the pigtails together without placing undue strain on the optical fibers.
Why are the amplitude levels into an optical transmitter different between analog television and quadrature amplitude modulation (QAM) carriers?
Because analog carriers have a video sync pulse, which can be used to set amplitude. QAM carriers don't have a sync pulse; the average power of the carrier is used to adjust the QAM carrier's amplitude.
What is the wavelength allocation for video distribution (RF overlay) in broadband PON (BPON) access systems?
Between 1,550 and 1,560 nm
What is the purpose of buffer tubes in fiber-optic cable?
Buffer tubes protect and separate the optical fiber in smaller bundles.
How are the combined forward broadcast signals, including voice and data carriers, delivered to hubs and nodes?
By using 1,310 nm and 1,550 nm AM optical transmitters.
How should surface particulates usually be removed from optical connectors?
By using a compressed-air cleaner designed for optical connectors.
What is the benefit of coarse wavelength division multiplexing (CWDM) as compared to dense wavelength division multiplexing (DWDM)
CWDM is a lower cost version of DWDM because it uses less expensive components.
What are two critical factors for a successful installation of fiber-optic cable?
Cable pulling tension and cable bend radius
What is the disadvantage of long amplifier cascades used in some cable TV networks?
Cascading restricts how far cable TV signals could travel, primarily due to operating performance requirements and reliability of service.
What is one reason why broadband cable operators install fiber-optic cable in stages instead of changing the infrastructure all at once?
Changing the infrastructure all at once would cause too many service disruptions
What is an example of transport media in a telecommunications network?
Coaxial cable.
What type of electrical detection can improve the sensitivity of an optical reliever by as much as 20dB?
Coherent Detection
Which of these are concerns for radio frequency over glass (RFoG) and, fiber-to-the-x (FTTx) systems?
Consideration of how and who will provide AC power to the optical network terminal (ONT) at the customer premises.
What functions does the detector in an optical receiver perform?
Conversion of an optical carrier to an electrical signal, and demodulation of the modulated optical carrier.
An optical fiber consists of what three basic parts?
Core, Cladding, and Coating
What are the main elements of an optical transmitter?
Data encoder/modulator, electrical interface, laser, optical interface.
What are the main elements of an optical receiver?
Demodulator, electrical interface, optical detector, optical interface.
Which type of map contains node information?
Design Map
Which type of optical detection involves a photodiode that converts the light waves to an electrical signal that varies in proportion to intensity changes in the light waves?
Direct
What are the two methods used to modulate an optical carrier ?
Direct Modulation and Indirect Modulation
Which type of laser is ideal for analog, high speed digital, and optical multiplexing networks because of its high SNR (signal to noise ratio) and small spectral widths?
Distributed Feed Back (DFB) laser
What are the two common types of laser diodes used in fiber optic networks?
Distributed Feed Back (DFB) lasers and Fabry-Perot (F-P) lasers
Which type of star topology used in a passive optical network (PON) places the PON splitters into fiber access terminal (FAT) located deep in the network and closer to the customer premises than the centralized split?
Distributed star.
When activating a fiber-optic network, which acceptance-testing stage includes adjusting attenuation levels for the first time?
During equipment activation.
Coarse wavelength division multiplexing (CWDM) applications were expanded to include use in what band, where a large OH absorption loss occurred with older single-mode fibers?
E-band.
How is optimal sensitivity in an optical receiver obtained?
Efficient Coupling to the optical fiber to transfer the maximum amount of optical power from the optical fiber to the receiver.
Which type of optical amplifier produces no measurable distortion to the modulated light wave?
Erbium-doped fiber amplifiers (EDFA).
Which type of passive optical network (PON) architecture was formed to develop a cost-effective, high-bandwidth, easy-to-provision solution for connecting businesses, schools, libraries, and customer local area networks to the public Internet.
Ethernet PON (EPON).
What information should always be included in fiber-optic network documentation?
Fiber assignments.
What characteristic of a fiber-optic cable enhances the security of signals being transported in the network?
Fiber optics are typically made of glass which is a dielectric material which is basically immune to EMI and RFI
What type of fiber-to-the-x (FTTx) topology does a passive optical network (PON) use to make a point-to-multipoint (P2MP) fiber-optic cable connection between the broadband cable headend and the customer premises?
Fiber-to-the-home (FTTH).
Why do many optical nodes accept two independent power supplies?
For redundant powering of the node
Besides protection, what else must the coating on an optical fiber do?
Function over a wide temperature range; be compatible with cable gels; adhere to the glass cladding over the lifetime of the cable; and be mechanically strippable for splicing operations
Which optical splitter package is similar in appearance and size to a standard fusion splice protector?
Fused biconical taper (FBT).
Which type of optical coupler provides the least amount of insertion loss?
Fused.
What do diameter differences between spliced fibers look like on an optical time domain reflectometer (OTDR)?
Gain in one direction and high loss in the opposite direction.
Which type of passive optical network (PON) access architecture replaced asynchronous PON (APON)?
Gigabit-capable PON (GPON).
Which architecture and topology today provides voice, video and data services to thousands of customers?
HFC architectures and redundant optical ring topologies
What is one element used in the transmission and reception of dense wavelength division multiplexing (DWDM)?
High-quality, temperature cooled distributed feedback lasers.
What telecommunication standard designation encompasses all things voice, video, and data?
ITU Telecommunications Standardization Sector ITU-T
In a hybrid fiber/coax (HFC) fiber optic node, what are common voltages produced by DC power supplies?
In a hybrid fiber/coax (HFC) fiber optic node, what are common voltages produced by DC power supplies?
When would a mid-entry splice in a fiber-optic network be used?
In a self-healing ring network that requires only two fibers to feed an optical fiber drop.
How are optical splitters used in the forward path?
In the forward path, optical splitters are used as passive branching devices that divide an optical signal across multiple output fibers.
What information is documented at fiber-optic slack and splice locations?
Incoming and outgoing sequential markings showing the cable's physical length
A technician is determining whether the optical power into an optical receiver is within the acceptable dynamic range. He finds that the optical power is too high, but the loss budget agrees with the design. What should he do to optimize the optical power in this situation?
Install an optical attenuator.
What should be done to prevent the buildup of lethal amounts of static electricity on long lengths of aerial fiber-optic cable?
Install grounding clamps, which connect the cable exterior and metallic messengers to a good solid ground at each pole site.
Select the answer that best completes this sentence: In analog modulation, the _____ of the light wave changes in _____ proportion to the _____ analog signal.
Intensity; direct; incoming
Which new approach to providing video uses video and audio compression technology over fiber-to-the-x (FTTx) standards to the customer?
Internet Protocol TV (IPTV) using video and audio compression technology and using FTTX standards for providing fiber connectivity at the location.
Monitoring the status of optical nodes
Involves the use of a node transponder that continuously monitors a number of critical functions.
Why might a technician who is troubleshooting an outage in an optical network want to refer to the network's as-built documentation?
Is dependent upon the load placed on the system.
Which of the following is true of a centralized power node?
It can provide sufficient power for a fiber-optic node, including outside plant amplifiers and customer premises network interface devices (NID) for telephony service.
What is the current standardized outside diameter (OD) of the cladding of single-mode fiber?
It is 125 µm, with an accuracy of ±1 µm.
Why is the positive -intrinsic - negative (PIN) photo-diode the most common type of photo-diode used in optical receivers?
It is relatively inexpensive and can be operated from a standard power supply.
What is digital modulation?
It is the interruption of light waves in a coded sequence.
In what type of installation is wide wavelength division multiplexing (WWDM) used?
It is used in passive optical networks.
