Fiber Install and Activation Questions and Correct Answers

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Fiber Install and Activation
Questions and Correct Answers

Question: Which standards organization is considered to be the creator
of the worlds' most recognized communications standards, known as
"recommendations"?
Answer: The International Telecommunications Union (ITU)


Question: In which component in a fiber-optics communication system
do changes to the intensity of the optical signal occur?
Answer: The optical transmitter


Question: What is a drawback of using Fabry-Perot (F-P)lasers in high-
speed data (HSD) networks?
Answer: The emission of a number of discrete wavelengths or side modes.


Question: Why are laser diodes most effective when coupled to
singlemode fiber?
Answer: Its high coupled power, directionality, and speed.


Question: What are the factors that contribute to an optical receiver's
sensitivity?
Answer: Noise, responsivity, response time, linear response, back
reflection, optical detector.


Question: What is a positive-intrinsic-negative (PIN) diode?
Answer: 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.




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Question: What does the amplification process in an avalanche
photodiode (APD) introduce into the electrical output of an optical
detector?
Answer: Noise


Question: What function does the detector in an optical receiver
perform?
Answer: Conversion of an optical carrier to an electrical signal, and
demodulation of the modulated optical carrier.


Question: What happens if the optical signal exceeds the maximum
specified input power into a photodetector?
Answer: Nonlinear operation resulting in distortion, data errors, and
signal loss.


Question: What is a characteristic of light in a laser beam?
Answer: The laser beam consists of a limited range of wavelengths
(monochromatic), with all light waves in phase (coherent light).


Question: Monitoring the status of optical nodes
Answer: Involves the use of a node transponder that continuously
monitors a number of critical functions.


Question: Digital return path transmissions
Answer: Use dense wavelength division multiplexing (DWDM) digital
return transmitters in hub-to-headend architectures.


Question: What is channel bonding?
Answer: A 3.0 revision to DOCSIS that significantly increases upstream
and downstream transport data rates.


Question: What is MPEG?
Answer: A universally accepted standard for digital television, first
released in 1992.



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Question: Which of the following is true about optical nodes?
Answer: They contain four main sections: the optical receiver, the RF
amplifier module, the reverse optical transmitter, and the DC power
supply.


Question: Internet protocol telephony systems in broadband cable
networks
Answer: Require a call management server, media gateway, signaling
gateway, billing system, and CMTS.


Question: In a centralized server video-on-demand architecture
Answer: The number of servers needed for video content storage is
smaller than in the distributed server architecture.


Question: Which of the following statements about local ad insertion is
true?
Answer: Local ad insertion is performed usually by a video server.


Question: In regard to providing high-speed data service,
Answer: The CMTS can provide a data transfer rate up to 38 Mbps, using
256-QAM in a single 6Mhz channel.


Question: Which of the following is true about the SONET transmission
standard?
Answer: SONET is the North American standard used for telephony
applications.


Question: Why was the zero-dispersion point in single-mode fiber
moved to 1,550 nm?
Answer: To take advantage of the low intrinsic absorption and lower
attenuation at 1550 nm in single-mode fiber


Question: What type of single-mode fiber is intended for fiber-to-the-
home installations?

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