ROC III Part 1

What topology do most FTTx (Fiber-to-the-x) networks use, requiring greater fiber color code management in documentation?

P2MP Point-to-multipoint

Improper use of nylon tie wraps can cause what problem?

Microbends

What are the potential sources of problems in aerial installations?

Tree growth, physical damage, pole attachment problems, and improper sag and loading considerations.

During the installation of fiber-optic cable, what does damage to the cable jacket cause?

Moisture travels into the cable.

A fiber-optic network maintenance plan should be developed with which of the following in mind?

Compiling the physical document must become the responsibility of an identifiable position or organization.

What is the best way to prevent problems in outside fiber-optic splice enclosures?

The outer jacket and the internal cable structures must be secured individually to protect the closure and splice trays from the effects of expansion and contraction.

What documentation changes should occur as changes are introduced to a fiber-optic network?

Documentation must be updated to reflect the new configuration and performance data.

In locating a fault in the link, the transmitter to the _________should be tested.

Patch panel

What should be reviewed and updated immediately following each maintenance cycle?

Maintenance posture

During the periodic check and resupply, what should be done with the optical power meters?

Check the calibration dates and perform calibrations as needed

What type of interface is common on new-generation optical power meters?

A USB

Optical power meters used for testing FTTx installations operating downstream from the headend should be calibrated for which wavelengths?

1490, 1550, and 1577 nm

Besides a stabilized light source, an enhanced optical power meter, and an optical talk set, what else do optical loss test sets include in their combined features?

An ORL (Optical return loss) Meter

What do most optical power meters require in order to verify accuracy of the transmit and receive power measurements?

Annual calibration that is traceable to the NIST

What must be done first when measuring end-to-end attenuation using the optical power meter?

The light source and optical power meter must be referenced together before taking measurements.

What do most models of laser light sources use as operational status indicators?

Controls for turning the light source on and off, selecting the laser wavelength for testing, and selecting the modulation signals; display indicators for the selected wavelength, mode of operation, battery status, and power source.

What occurs when a laser light source is used with an optical fiber identifier to test fibers?

A 2-kHz modulation provides a test signal allowing the fiber under test to be detected by the optical fiber identifier.

Besides determining whether the light is on fiber and the light is modulated and carrying traffic, what does is the third function the optical fiber identifiers determine?

The direction from which the light is coming.

Which of the following statements is accurate regarding laser light source specifications?

Standard environmental specifications for laser light sources range from 13°F to 130°F for operating temperatures and –19°F to 158°F for storage temperatures

What are the main functions of an optical fiber identifier?

Detecting whether light is on the fiber, checking if the light is modulated, and identifying the direction of light.

What visually represents the optical fiber's attenuation characteristics and the OTDR setup?

The waveform.

What are the most common single-mode wavelengths used by OTDR?

1310 nm and 1550 nm.

Which class of optical transmitters is the safest for the human eye?

Class 1.

What is unique to a fiber break locator?

It is the least expensive type of OTDR

Which of the following is an additional option for a full-feature OTDR:

DWDM

Which of the following is true regarding reflections in an optical fiber?

• As light passes through two materials with different refraction indexes, the small portion of reflected light is called an incident reflection.

• Fresnel reflection does not occur at the end of the optical fiber with a subtle glass-to-air surface.

• Microscopic density fluctuations, impurities, and structural imperfections in the fiber cause Rayleigh scattering.

• The backscatter scattering and absorption effects subtract from the attenuation of the optical fiber.

What is an RTU characteristic?

It monitors optical fiber from the headend or other key points in a network.

What do OTDR displays and controls encompass?

Task options, which include range, pulse width, wavelength, measuring mode, backscatter coefficient, and index of refraction.

What happens if the OTDR pulse width is set too long?

Events can be missed or combined.

The refractive index is calculated by what formula?

Divide the speed of light in a vacuum by the speed of light through an optical fiber.

What is ORL?

The sum of all Fresnel reflections and the fiber's Rayleigh backscatter.

Which wavelength is the most sensitive to macrobends and microbends and has been specified by standards groups for testing and monitoring fiber-optic spans?

The 1625-nm wavelength is the most sensitive for microbend and macrobend detection.

Which type of fiber-optic cable has a connector on both ends?

Jumper.

Which of the following is true when programming an OTDR?

Configuration settings include refraction index, pulse width, range, wavelength, dead zone, event dead zone, masking, noise floor, and loss variables.

Which of the following is true regarding OTDR terminology?

Acceptance testing consists of checking two-point attenuation, comparing the refractive index to the physical cable length, and zooming in to place markers correctly.

What steps are used for connecting a bare optical fiber to an OTDR for acceptance and post-installation tests using a mechanical splice and pigtail?

Clean the connector end of the pigtail, connect the pigtail connector's cleaned end to the OTDR, then connect the bare end of the pigtail to a mechanical fiber splice.

Which of the following statements correctly summarizes the role of pulse width in an OTDR measurement process?

A shorter pulse width reduces the dynamic range, thus limiting the OTDR's ability to measure longer distances.

What is the best course of action for the OTDR operator when the distance measurement for a fiber strand doesn't match the sequential distance markings outside the cable jacket?

Adjust the factory refractive index settings on the OTDR to settings that match the cable jacket's sequential markings.

What is the difference between a reflectance measurement and an ORL measurement with an OTDR?

A reflectance measurement measures an individual component, and an ORL measurement measures the sum of all components.

When cleaning the optical port of an OTDR, which connector port requires using a 1.25 mm cleaner?

LC (Lucent connector).

What is the purpose of the Fiber-optic acceptance test?

To make sure that the optical cable that has been ordered and received matches the order's optical and physical requirements.

What should be done when performing an optical fiber acceptance test?

Organize the fibers by color, per the TIA-598A standard

Which of the following is true when choosing the appropriate optical measurement for post-installation fiber-optic span tests?

Test includes, splice loss, attenuation measurements of fiber segments, component reflectance, optical splitters, accumulated loss, dual wavelength testing, bi-directional testing and pass/fail analysis.

When testing a fiber-optic splitter with an OTDR, what would cause all the splitter output ports to look the same on the OTDR's display?

An equal percentage fiber-optic splitter with all the same drop lengths

In reflective signatures, what causes Fresnel reflections?

Light energy that is reflected back toward the source when light encounters an interface.

Which OTDR configuration setting must always exceed the span length under test?

Range

How can an OTDR operator compare an old fiber trace with a new one?

By overlaying a new trace on top of a previously saved trace.

What fiber length should be encased in a dead zone box according to industry standards?

At least 20x times the length of the OTDR shortest pulse width.

What is the commonly accepted value of a splice?

-0.1dB

What results when 2 fiber strands with dissimilar cores are fusion spliced together?

The increased backscatter in the fiber with the large core is detected by the OTDR and displayed as a gain signature.