FIBER INSTALL AND ACTIVATION QUESTIONS AND
ANSWERS
Which standards organization is considered to be the creator of the worlds' most
recognized communications standards, known as "recommendations"? - Answers- The
International Telecommunications Union (ITU)
In which component in a fiber-optics communication system do changes to the intensity
of the optical signal occur? - Answers- The optical transmitter
What is a drawback of using Fabry-Perot (F-P)lasers in high-speed data (HSD)
networks? - Answers- The emission of a number of discrete wavelengths or side
modes.
Why are laser diodes most effective when coupled to singlemode fiber? - Answers- Its
high coupled power, directionality, and speed..
What happens if the optical signal exceeds the maximum specified input power into a
photodetector? - Answers- Nonlinear operation resulting in distortion, data errors, and
signal loss.
What is a characteristic of light in a laser beam? - Answers- The laser beam consists of
a limited range of wavelengths (monochromatic), with all light waves in phase (coherent
light).
Monitoring the status of optical nodes - Answers- Involves the use of a node
transponder that continuously monitors a number of critical functions.
Digital return path transmissions - Answers- Use dense wavelength division
multiplexing (DWDM) digital return transmitters in hub-to-headend architectures.
What is channel bonding? - Answers- A 3.0 revision to DOCSIS that significantly
increases upstream and downstream transport data rates.
What is MPEG? - Answers- A universally accepted standard for digital television, first
released in 1992.
Which of the following is true about optical nodes? - Answers- They contain four main
sections: the optical receiver, the RF amplifier module, the reverse optical transmitter,
and the DC power supply.
Internet protocol telephony systems in broadband cable networks - Answers- Require a
call management server, media gateway, signaling gateway, billing system, and CMTS.
, In a centralized server video-on-demand architecture - Answers- The number of servers
needed for video content storage is smaller than in the distributed server architecture.
Which of the following statements about local ad insertion is true? - Answers- Local ad
insertion is performed usually by a video server.
In regard to providing high-speed data service, - Answers- The CMTS can provide a
data transfer rate up to 38 Mbps, using 256-QAM in a single 6Mhz channel.
Which of the following is true about the SONET transmission standard? - Answers-
SONET is the North American standard used for telephony applications.
Why was the zero-dispersion point in single-mode fiber moved to 1,550 nm? - Answers-
To take advantage of the low intrinsic absorption and lower attenuation at 1550 nm in
single-mode fiber
What type of single-mode fiber is intended for fiber-to-the-home installations? -
Answers- The ITU-T G.657 bend-insensitive fiber (BIF)
What are the primary causes of intrinsic loss in single-mode fiber? - Answers- Material
absorption and Rayleigh scattering.
The phenomenon, total internal reflection, is what enables an optical fiber to guide light.
What characteristic of optical fiber causes total internal reflection? - Answers- 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.
What are the factors that contribute to an optical receiver's sensitivity? - Answers-
Noise, responsivity, response time, linear response, back reflection, optical detector.
What is a positive-intrinsic-negative (PIN) diode? - Answers- 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.
What does the amplification process in an avalanche photodiode (APD) introduce into
the electrical output of an optical detector? - Answers- Noise
What function does the detector in an optical receiver perform? - Answers- Conversion
of an optical carrier to an electrical signal, and demodulation of the modulated optical
carrier
Where would you expect Fresnel reflections to occur in a fiber-optic network? -
Answers- At connections and mechanical splices where the signal source is entering or
exiting the cable.
ANSWERS
Which standards organization is considered to be the creator of the worlds' most
recognized communications standards, known as "recommendations"? - Answers- The
International Telecommunications Union (ITU)
In which component in a fiber-optics communication system do changes to the intensity
of the optical signal occur? - Answers- The optical transmitter
What is a drawback of using Fabry-Perot (F-P)lasers in high-speed data (HSD)
networks? - Answers- The emission of a number of discrete wavelengths or side
modes.
Why are laser diodes most effective when coupled to singlemode fiber? - Answers- Its
high coupled power, directionality, and speed..
What happens if the optical signal exceeds the maximum specified input power into a
photodetector? - Answers- Nonlinear operation resulting in distortion, data errors, and
signal loss.
What is a characteristic of light in a laser beam? - Answers- The laser beam consists of
a limited range of wavelengths (monochromatic), with all light waves in phase (coherent
light).
Monitoring the status of optical nodes - Answers- Involves the use of a node
transponder that continuously monitors a number of critical functions.
Digital return path transmissions - Answers- Use dense wavelength division
multiplexing (DWDM) digital return transmitters in hub-to-headend architectures.
What is channel bonding? - Answers- A 3.0 revision to DOCSIS that significantly
increases upstream and downstream transport data rates.
What is MPEG? - Answers- A universally accepted standard for digital television, first
released in 1992.
Which of the following is true about optical nodes? - Answers- They contain four main
sections: the optical receiver, the RF amplifier module, the reverse optical transmitter,
and the DC power supply.
Internet protocol telephony systems in broadband cable networks - Answers- Require a
call management server, media gateway, signaling gateway, billing system, and CMTS.
, In a centralized server video-on-demand architecture - Answers- The number of servers
needed for video content storage is smaller than in the distributed server architecture.
Which of the following statements about local ad insertion is true? - Answers- Local ad
insertion is performed usually by a video server.
In regard to providing high-speed data service, - Answers- The CMTS can provide a
data transfer rate up to 38 Mbps, using 256-QAM in a single 6Mhz channel.
Which of the following is true about the SONET transmission standard? - Answers-
SONET is the North American standard used for telephony applications.
Why was the zero-dispersion point in single-mode fiber moved to 1,550 nm? - Answers-
To take advantage of the low intrinsic absorption and lower attenuation at 1550 nm in
single-mode fiber
What type of single-mode fiber is intended for fiber-to-the-home installations? -
Answers- The ITU-T G.657 bend-insensitive fiber (BIF)
What are the primary causes of intrinsic loss in single-mode fiber? - Answers- Material
absorption and Rayleigh scattering.
The phenomenon, total internal reflection, is what enables an optical fiber to guide light.
What characteristic of optical fiber causes total internal reflection? - Answers- 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.
What are the factors that contribute to an optical receiver's sensitivity? - Answers-
Noise, responsivity, response time, linear response, back reflection, optical detector.
What is a positive-intrinsic-negative (PIN) diode? - Answers- 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.
What does the amplification process in an avalanche photodiode (APD) introduce into
the electrical output of an optical detector? - Answers- Noise
What function does the detector in an optical receiver perform? - Answers- Conversion
of an optical carrier to an electrical signal, and demodulation of the modulated optical
carrier
Where would you expect Fresnel reflections to occur in a fiber-optic network? -
Answers- At connections and mechanical splices where the signal source is entering or
exiting the cable.
