Fiber Optics, Level 1

Réussis tes devoirs et examens dès maintenant avec Quizwiz!

What connector style is now specified in the latest 568 standard?

Any connector with a FOCIS document

Which reference method is required for TIA 568?

Any method as long as it is documented

The ? protects the fiber from harm.

Aramid fiber strength members, Jacket, Primary buffer coating

Which of the following fiber specifications is most important to the user and is an important factor in testing?

Attenuation

Which of the following communications systems typically use fiber-optic backbones?

CATV, Cell Phones, Internet, Telephones

Which type of dispersion affects single-mode fiber as well as multimode fiber?

Chromatic

Metropolitan networks can involve which of the following systems?

Closed-circuit television (CCTV) surveillance cameras, Educational systems, Emergency services, Traffic monitoring

Cables with metallic conductors as well as fiber are called ? .

Composite Cables

In an optical fiber, the light is transmitted through the ? .

Core

Single-mode transceivers use ? sources for their higher coupled power and bandwidth. (Choose all that apply.)

DFB Laser and F-P Laser

? of the cable plant is a necessary part of the design and installation process for a fiber-optic network that is often overlooked.

Documentation

Which is the most helpful information a worker can have when trying to troubleshoot a cabling network for restoration?

Documentation

Which one of the following performance requirements are not shared by connectors and splices?

Durability under repeated mating

Always keep ? on connectors when not connected to equipment or being tested.

Dust Caps

Fiber amplifiers and dense wavelength division multiplexers (DWDM) work in the ? wavelength range.

1,480-1,650

Ten dB corresponds to a factor of ? in power.

10

The minimum long-term bend radius of installed fiber-optic cable is usually specified as no less than ? .

10 times the cable diameter

Under pulling tension, the bend radius should not be less than ? .

20 times the cable diameter

How many methods are included in standards for setting the "0 dB" reference for loss testing?

3

The diameter of the core in OM2 and OM3 multimode fiber is how large?

50 Microns

What wavelengths are appropriate for use with multimode fiber?

850 and 1,300 nm

The loss of a multimode graded index fiber is greatest at ? .

850 nm

What is the core size of single-mode fiber?

9 microns

Factory terminations, such as those used for making patch cords, use which method of attaching the connector to the cable?

Epoxy / polish

The protective gear every voice/data/video (VDV) installer must always wear is ? .

Eye protection

Cables tested with an optical time domain reflectometer (OTDR) do not require insertion loss testing with a source and meter or optical loss test set (OLTS).

False

Connectors at each end of the cable plant should not be counted when calculating the cable plant loss.

False

Dangerous light from fiber-optic cables is bright and easily visible.

False

Discussions of which is better—copper, fiber, or wireless—are no longer relevant, as fiber is the only choice.

False

Light-emitting diodes (LEDs) have higher output power and bandwidth than lasers.

False

Telephone networks have been converted to fiber, including long distance and metropolitan networks, but fiber to the home (FTTH) is not yet feasible.

False

The first consideration for any network is choosing the proper fiber-optic cable type.

False

When upgrading cables in a telecom closet, old, abandoned cables can be cut back and placed above the drop ceiling.

False

The bandwidth and distance capability of optical fiber means that ? .

Fewer Cables are needed, fewer repeaters are needed, less maintenance is required, less power is consumed by the network.

Premises cables must be rated for ? to meet codes.

Fire retardance

Long distances mean fiber cable are spliced together, mostly by ? , because cables are not manufactured in lengths longer than about four to five kilometers.

Fusion Splicing

What is needed to get low loss from a prepolished/splice connector?

Good cleave

The first version of TIA/EIA 568 standard for premises cabling called for the use of which connector?

SC

The largest contributor to fiber attenuation is ? .

Scattering

On long pulls, at intermediate points, why do workers lay the cable in a "figure 8"?

To prevent it from twisting

All metal components of the cabling system installed in an equipment or telecom room must be grounded and bonded.

True

Any cable that contains metallic conductors must be properly grounded and bonded.

True

Besides causing attenuation, dirt particles can cause scratches on the polished fiber ends.

True

Fiber is used in long-distance phone networks because it is much cheaper than copper wire.

True

Fiber optics is used in cars to connect their electronic systems.

True

Fiber-optic links generally use two fibers for full duplex (bidirectional) links.

True

Fiber-optic network designers should have knowledge of electrical power systems and hardware as well as communications design.

True

In order to specify a fiber-optic cable properly, a worker needs to understand installation specifications as well as environmental specifications.

True

Industrial applications often use fiber-optics for its noise immunity rather than distance and bandwidth advantages.

True

It may be more cost effective for the fiber-optic cabling in many projects to be custom designed and made.

True

Most outside plant (OSP) installations are single-mode (SM) fiber.

True

Most single-mode (SM) field terminations are made by fusion splicing a factory-made pigtail onto the cable.

True

Optical fibers can transmit either analog or digital signals.

True

Single-mode fiber has a smaller core than multimode fiber.

True

Splicing is very rare in premises networks.

True

Testing a fiber-optic installation may require testing three times—testing the cable before installation, testing each segment as installed, and final testing of end-to-end loss.

True

The OTDR should never be used without a "launch cable," which is also called a "pulse suppressor".

True

The SC and LC connectors have different size ferrules and cannot be mated.

True

The biggest advantage of optical fiber is the fact it is the most cost effective means of transporting information.

True

Cables should always be pulled with ? to prevent damage.

the cable's strength members

The ? of a laser makes the effective bandwidth of multimode fiber higher than with LEDs.

Restricted Modal Launch

The design of cables of small size with very large fiber counts is usually ? .

Ribbon Cable

The wavelength of light used for most fiber-optic systems is in the ? region and ? to the human eye.

infrared / invisible

Black polyethylene jackets are used on outdoor cables for ? .

sunlight and moisture resistance

The first requirement that must be considered for a new fiber-optic project is ? .

the customer's communications system requirements

Premises cables in local area network (LAN) backbones often contain ? .

Both Multimode and Single-Mode Fiber

A fiber stripper removes the ? of the fiber.

Buffer coating

Cables that contain both multimode and single-mode fibers are called ? .

Hybrid Cables

Long wavelength single-mode links at wavelengths in the range of 1,300-1,650 nanometer links must use ? detectors in the receiver for the best sensitivity performance.

InGaAs

Multimode graded-index glass fiber-optic cables are tested with ? sources at ? and ? wavelengths.

LED / 850- / 1,300-nm

Multimode transceivers use ? sources depending on their requirements for coupled power and bandwidth.

LED and VCSEL

What type of source is used for testing single-mode fibers?

Laser

Outside plant cabling can be installed by ? .

Pulling in underground in conduit, direct burial, aerial suspension

Which of the following are NOT necessary in a centralized fiber-optic cabling architecture?

Repeaters or Hubs

The design of cables for high pulling tension in outside plant installations is usually ? .

Loose Tube Cable

Copper networks can be converted to fiber optics using ? .

Media Converters

Rays of light transmitted in multimode fiber are called ? .

Modes

All underground or underwater cables are built to resist ? .

Moisture

The standard method of testing installed multimode cables in a cable plant is described in ? .

OFSTP-14

What test instrument(s) are used for insertion loss testing?

OLTS or light source and power meter

Most premises networks today should use ? multimode fiber, but backbone cables can contain ? fibers for future expansion.

OM3 / single-mode

Which fiber-optic test instrument uses backscattered light for measurements?

Optical time-domain reflectometer (OTDR)

Match the cable type to its proper designation.

Pg. 52-54

Match the following connectors to their proper identifier.

Pg. 66

Which fiber typically has the largest core?

Plastic Optical Fiber (POF)

Armored cable is used in outside plant installations to ? .

Prevent Rodent Damage

In an industrial environment, fiber is most often used to ? .

Prevent electromagnetic interference

? will facilitate installation, allow better planning for upgrades, and simplify testing.

Proper documentation

Short wavelength 850-nanometer links can use ? detectors in the receiver.

Silicon

The industry standard that covers structured cabling, both fiber and copper, is ? .

TIA-568

Multimode fiber systems operating at speeds of one gigabit per second or more use ? sources.

Vertical-cavity surface-emitting laser (VCSEL)

Single-mode (SM) fiber has ? light-carrying core than(as) multimode (MM) fiber.

a smaller

Outside plant cabling (OSP) can be installed by ? .

aerial suspension, direct burial, pulling in underground conduit

Fiber-optic network designers should have an in-depth knowledge of ? .

all applicable standards, codes, and any other local regulations / fiber-optic components and systems / installation processes

Loose tube cable requires a ? to terminate with connectors.

breakout kit

The advantage of a breakout cable over a distribution cable is ? .

the breakout cable can be installed and terminated without additional hardware for protection of the terminations

Cable ties used on fiber-optic cables ? .

can harm cables if too tight, so they should be hand tightened

Fiber-optic network design involves ? .

choosing appropriate cabling and media, determining the types of communications systems involved, planning the routes for all cabling or wireless

Both mechanical splices and prepolished/splice connectors require a good ? to have low loss.

cleave on the fiber being terminated

The difference between a fiber-optic connector and a splice is ? .

connectors are demountable, while splices are permanent

Optical power loss on any fiber in a cable is measured in ? .

dB

Cable plant loss should be estimated during the ? phase.

design

In premises applications, OTDRs are limited in usefulness by their ? .

distance resolution

Vertical cable runs should preferably be installed by ? .

dropping from above rather than pulling up

The protective gear every voice/data/video installer must always wear is ? .

eye protection

Reference cables must match the ? of the cables being tested.

fiber size and connector type

OTDRs are used in outside plant cables to ? .

find faults, measure length, verify splice loss

Information on the safety of chemicals used in fiber optics is ? .

in material safety data sheets (MSDS) supplied by manufacturers

No cable should be installed indoors unless it ? .

is UL listed for flame retardancy for National Electrical Code (NEC)

The total loss of the fiber in the cable plant is calculated by multiplying the attenuation coefficient of the fiber by the ? .

length

The fiberglass rod inside many fiber-optic cables is for ? .

limiting bend radius to preventing kinking

Physical contact (PC) polish on connectors is designed to reduce ? .

loss and reflectance

In single-mode connectors, ? is as important as low loss.

low reflectance

The diameter of an optical fiber is traditionally measured in ? .

microns (Micrometers)

Single-mode fiber has ? bandwidth than(as) multimode fiber.

more

All outdoor cables are specifically designed to ? .

prevent moisture damage to the fiber

Most building management systems use ? cabling.

proprietary copper

The principle of operation of OTDRs is similar to ? .

radar

Structured cabling installed to TIA-568 standards uses a ? cabling architecture.

star

To prevent the cable from twisting when pulling it, a worker should ? .

use a swivel eye


Ensembles d'études connexes

CS 2205 Web Programming 1 - Term 2, 2018-2019

View Set

What is ethics?/Teleology v. Deontology

View Set

Microeconomics First exam chapter 1

View Set

FINC314 (Investments) - Exam #1 Study Guide

View Set

Rules for safe use of hand tools.

View Set