IT Advance DOCSIS 3.1 Question and
answers verified to pass
What over-the-top (OTT) delivered content could cause the current broadband
network data rates to become inadequate? - correct answers Ultra-high
definition TV (UHDTV) content
Which elements of a hybrid fiber/coax (HFC) network are most likely to cause
a service outage because of component failure or loss of power? - correct
answers Amplifiers.
Under equal network conditions, what advantage does low-density parity-
check (LDPC) forward error correction (FEC) coding have over Reed-
Solomon (RS) coding? - correct answers LDPC is able to correct errors at
orders of modulation that are higher than that of RS coding.
What was the motivation for the conception of the converged cable access
platform (CCAP)? - correct answers To combine digital television (DTV) and
DOCSIS operations from a common unified platform.
In the DOCSIS architecture, what performs the back office tasks that
provision, configure, and manage cable modem operations? - correct answers
The Operational Support Systems (OSS).
What are the responsibilities of the Physical Layer (Layer 1) in the Open
Systems Interconnection (OSI) reference model and DOCSIS? - correct
answers Transmission stream of data bits.
Because they use different transmission and coding schemes, the DOCSIS
3.1 Physical (PHY) Layer is incompatible with the PHY Layer of previous
DOCSIS versions. How does DOCSIS 3.1 comply with the requirement of
, compatibility with previous DOCSIS versions? - correct answers DOCSIS 3.1
has two PHY Layers, one for previous DOCSIS versions and another for
DOCSIS 3.1. Both Layers can operate simultaneously or individually.
The DOCSIS MAC and Upper Layer Protocols Interface (MULPI) specification
extends through which layers of the Open Systems Interconnection (OSI)
reference model? - correct answers Layer 2 through Layer 7.
What is defined in DOCSIS 3.1 that strengthens the security of cable modem
authentication and secures software download features? - correct answers A
new certificate public key infrastructure (PKI).
In modular cable modem termination system (M-CMTS) architecture, what
automatically compensates for cable length and ensures that the M-CMTS
clients have the same sense of time and frequency? - correct answers The
DOCSIS Timing Interface (DTI) server.
Where does the modem, operating in DOCSIS 3.1 mode, tune to receive data
when the downstream contains an orthogonal frequency division multiplexing
(OFDM) channel and single carrier-quadrature amplitude modulation (SC-
QAM) channels? - correct answers The modem tunes to the OFDM channel
and the SC-QAM channels, and receives data on both.
What is used in orthogonal frequency division multiplexing (OFDM) to
transform the serial data stream from the time domain to multiple subcarriers
in the frequency domain? - correct answers Fast Fourier transform (FFT)
algorithms compute the discrete Fourier transform (DFT).
What is the purpose of the cyclic prefix (CP)? - correct answers To
compensate for micro-reflections in the transmission path by providing a
protective interval between successive orthogonal frequency division
multiplexing (OFDM) symbols.
answers verified to pass
What over-the-top (OTT) delivered content could cause the current broadband
network data rates to become inadequate? - correct answers Ultra-high
definition TV (UHDTV) content
Which elements of a hybrid fiber/coax (HFC) network are most likely to cause
a service outage because of component failure or loss of power? - correct
answers Amplifiers.
Under equal network conditions, what advantage does low-density parity-
check (LDPC) forward error correction (FEC) coding have over Reed-
Solomon (RS) coding? - correct answers LDPC is able to correct errors at
orders of modulation that are higher than that of RS coding.
What was the motivation for the conception of the converged cable access
platform (CCAP)? - correct answers To combine digital television (DTV) and
DOCSIS operations from a common unified platform.
In the DOCSIS architecture, what performs the back office tasks that
provision, configure, and manage cable modem operations? - correct answers
The Operational Support Systems (OSS).
What are the responsibilities of the Physical Layer (Layer 1) in the Open
Systems Interconnection (OSI) reference model and DOCSIS? - correct
answers Transmission stream of data bits.
Because they use different transmission and coding schemes, the DOCSIS
3.1 Physical (PHY) Layer is incompatible with the PHY Layer of previous
DOCSIS versions. How does DOCSIS 3.1 comply with the requirement of
, compatibility with previous DOCSIS versions? - correct answers DOCSIS 3.1
has two PHY Layers, one for previous DOCSIS versions and another for
DOCSIS 3.1. Both Layers can operate simultaneously or individually.
The DOCSIS MAC and Upper Layer Protocols Interface (MULPI) specification
extends through which layers of the Open Systems Interconnection (OSI)
reference model? - correct answers Layer 2 through Layer 7.
What is defined in DOCSIS 3.1 that strengthens the security of cable modem
authentication and secures software download features? - correct answers A
new certificate public key infrastructure (PKI).
In modular cable modem termination system (M-CMTS) architecture, what
automatically compensates for cable length and ensures that the M-CMTS
clients have the same sense of time and frequency? - correct answers The
DOCSIS Timing Interface (DTI) server.
Where does the modem, operating in DOCSIS 3.1 mode, tune to receive data
when the downstream contains an orthogonal frequency division multiplexing
(OFDM) channel and single carrier-quadrature amplitude modulation (SC-
QAM) channels? - correct answers The modem tunes to the OFDM channel
and the SC-QAM channels, and receives data on both.
What is used in orthogonal frequency division multiplexing (OFDM) to
transform the serial data stream from the time domain to multiple subcarriers
in the frequency domain? - correct answers Fast Fourier transform (FFT)
algorithms compute the discrete Fourier transform (DFT).
What is the purpose of the cyclic prefix (CP)? - correct answers To
compensate for micro-reflections in the transmission path by providing a
protective interval between successive orthogonal frequency division
multiplexing (OFDM) symbols.
