NCTI Troubleshooting Advanced Services Revised
Questions With 100% Verified Solutions
Although off-network programming is not the responsibility of a cable operator, -
ANSWER A) A technician needs to understand that customers viewing video through
the Internet may report problems with a video program that has not been scrutinized by
the cable operator.
The digital artifacts referred to as blockiness, blurring, mosquito noise, and contour
represent - ANSWER B) Digital video artifacts originating in the cable distribution
network, which may be resolved by replacing faulty coax.
Tiling, missing audio, and frozen picture are examples of artifacts that - ANSWER A)
Are likely under the control of the technician in the hybrid fiber/coax (HFC) network or at
the customer premises.
The poor quality of analog programming displayed on a digital TV set, a common
complaint of customers, can be caused by - ANSWER D) Image rescaling that standard
definition TV (SDTV) analog programs require to be displayed on a 1080p resolution
display.
The digital video artifacts of loss of lip sync and smearing are associated with -
ANSWER A) The types of artifacts generally found at the customer premises due to
timing delay and frame rate, respectively.
One of the first things a technician needs to address in troubleshooting issues with
digital video quality is - ANSWER B) Identify the problem by asking the customer to
describe the problem and whether or not it is intermittent or constant.
One of the last things a technician does when following a process for troubleshooting
and resolving problems with digital video quality is - ANSWER D) Verify the problem is
resolved by taking measurements to confirm the resolution and ensuring the resolution
did not introduce new problems.
When a viewer receives a "Channel not available, try again later" message, the
probable cause is - ANSWER There is insufficient bandwidth from the headend to the
hub to accommodate the data stream for the requested channel.
If a customer reports that a program's audio plays but there is no video display, the
recommended actions are - ANSWER C) Check if any cables are disconnected, make
sure the TV set is properly configured, and check to see if the TV is on (if audio runs
, through a different system such as surround sound).
A logical progression of events for resolving a customer's report of digital video artifacts
on various channels could include - ANSWER C) Analyzing the problem further to get a
more narrow definition of the issue before trying to diagnose the symptoms of the
problem.
In working through a flowchart for the six-step process of troubleshooting a report of
tiling by a single customer, one of the first questions asked should be - ANSWER D) Are
there similar complaints from other customers?
Modulation error ratio (MER) is an indicator of digital modulation signal quality. For
error-free reception and adequate margin, what should be the minimum MER reading
for a 256-QAM (quadrature amplitude modulation) signal? - ANSWER B) = 32 dB.
Bit error rate (BER) is one of the measurements a technician uses to determine how
well the network is operating. What is an acceptable post-BER at the end of the drop? -
ANSWER A) <1.0E-9.
Coherent interference causes the constellation display to look like a series of small
donuts. What is one cause of coherent interference? - ANSWER A) In-channel ingress.
What information about the digital carrier can be learned by accessing the adaptive
equalizer function of the digital signal analyzer? - ANSWER A) How much the adaptive
equalizer has to compensate for linear distortions of the digital carrier.
When you use a digital signal analyzer to examine a digital signal, one of the values you
should check is the symbol rate. What should the symbol rate setting be for a 256-QAM
signal specified by the International Telecommunication Union (ITU) in ITU-T J.83
Annex B? - ANSWER D) 5.360537 megasymbols per second (MS/s).
Many cable operators have a drop certification program and require measurements
using a digital signal analyzer with minimum and maximum criteria programmed into the
instrument. Why should the technician recognize and understand which channels are
being measured when automated measurements are being performed by the digital
signal analyzer? - ANSWER B) To save measurement time, some cable operators
perform automated measurements on a sample of channels which can result in
problems going undetected in unmeasured channels.
You have a cable modem analyzer and you want to replace the cable modem to
determine whether the modem is bad. How should the modem analyzer be connected
to replace the modem? - ANSWER D) An Ethernet cable is connected from the cable
modem analyzer to the customer's computer, and the RF drop input cable is connected
to the cable modem analyzer.
Questions With 100% Verified Solutions
Although off-network programming is not the responsibility of a cable operator, -
ANSWER A) A technician needs to understand that customers viewing video through
the Internet may report problems with a video program that has not been scrutinized by
the cable operator.
The digital artifacts referred to as blockiness, blurring, mosquito noise, and contour
represent - ANSWER B) Digital video artifacts originating in the cable distribution
network, which may be resolved by replacing faulty coax.
Tiling, missing audio, and frozen picture are examples of artifacts that - ANSWER A)
Are likely under the control of the technician in the hybrid fiber/coax (HFC) network or at
the customer premises.
The poor quality of analog programming displayed on a digital TV set, a common
complaint of customers, can be caused by - ANSWER D) Image rescaling that standard
definition TV (SDTV) analog programs require to be displayed on a 1080p resolution
display.
The digital video artifacts of loss of lip sync and smearing are associated with -
ANSWER A) The types of artifacts generally found at the customer premises due to
timing delay and frame rate, respectively.
One of the first things a technician needs to address in troubleshooting issues with
digital video quality is - ANSWER B) Identify the problem by asking the customer to
describe the problem and whether or not it is intermittent or constant.
One of the last things a technician does when following a process for troubleshooting
and resolving problems with digital video quality is - ANSWER D) Verify the problem is
resolved by taking measurements to confirm the resolution and ensuring the resolution
did not introduce new problems.
When a viewer receives a "Channel not available, try again later" message, the
probable cause is - ANSWER There is insufficient bandwidth from the headend to the
hub to accommodate the data stream for the requested channel.
If a customer reports that a program's audio plays but there is no video display, the
recommended actions are - ANSWER C) Check if any cables are disconnected, make
sure the TV set is properly configured, and check to see if the TV is on (if audio runs
, through a different system such as surround sound).
A logical progression of events for resolving a customer's report of digital video artifacts
on various channels could include - ANSWER C) Analyzing the problem further to get a
more narrow definition of the issue before trying to diagnose the symptoms of the
problem.
In working through a flowchart for the six-step process of troubleshooting a report of
tiling by a single customer, one of the first questions asked should be - ANSWER D) Are
there similar complaints from other customers?
Modulation error ratio (MER) is an indicator of digital modulation signal quality. For
error-free reception and adequate margin, what should be the minimum MER reading
for a 256-QAM (quadrature amplitude modulation) signal? - ANSWER B) = 32 dB.
Bit error rate (BER) is one of the measurements a technician uses to determine how
well the network is operating. What is an acceptable post-BER at the end of the drop? -
ANSWER A) <1.0E-9.
Coherent interference causes the constellation display to look like a series of small
donuts. What is one cause of coherent interference? - ANSWER A) In-channel ingress.
What information about the digital carrier can be learned by accessing the adaptive
equalizer function of the digital signal analyzer? - ANSWER A) How much the adaptive
equalizer has to compensate for linear distortions of the digital carrier.
When you use a digital signal analyzer to examine a digital signal, one of the values you
should check is the symbol rate. What should the symbol rate setting be for a 256-QAM
signal specified by the International Telecommunication Union (ITU) in ITU-T J.83
Annex B? - ANSWER D) 5.360537 megasymbols per second (MS/s).
Many cable operators have a drop certification program and require measurements
using a digital signal analyzer with minimum and maximum criteria programmed into the
instrument. Why should the technician recognize and understand which channels are
being measured when automated measurements are being performed by the digital
signal analyzer? - ANSWER B) To save measurement time, some cable operators
perform automated measurements on a sample of channels which can result in
problems going undetected in unmeasured channels.
You have a cable modem analyzer and you want to replace the cable modem to
determine whether the modem is bad. How should the modem analyzer be connected
to replace the modem? - ANSWER D) An Ethernet cable is connected from the cable
modem analyzer to the customer's computer, and the RF drop input cable is connected
to the cable modem analyzer.
