ESAT Forouzan - Chapter 9: High Speed Digital Access

Question 1

____ has a higher transmission rate in the downstream direction than in the upstream direction.
a. VDSL
b. ADSL
c. SDSL
d. (a) and (b)

Answer 1

d. (a) and (b)

Question 2

_____ is suitable for businesses that require comparable upstream and downstream data rates.
a. VDSL
b. ADSL
c. SDSL
d. (a) and (b)

Answer 2

c. SDSL

Question 3

_____ limit the bandwidth of the local loop to 4 KHz.
a. Fiber Nodes
b. Filters
c. Repeaters
d. Hubs

Answer 3

b. Filters

Question 4

DMT is a modulation technique that combines elements of _____ and _____.
a. FDM; TDM
b. QDM; QAM
c. FDM; QAM
d. PSK; FSK

Answer 4

c. FDM; QAM

Question 5

The largest portion of the bandwidth for ADSL carries _____.
a. Voice Communication
b. Upstream data
c. Downstream data
d. Control data

Answer 5

c. Downstream data

Question 6

The actual bit rate of ADSL downstream data is _____.
a. 64 Kbps to 1 Mbps
b. 6 to 30 Kbps
c. 31 Kbps to 225 Mbps
d. 500 Kbps to 8 Mbps

Answer 6

d. 500 Kbps to 8 Mbps

Question 7

_____ is a device at the telephone company site that can packetize data to be sent to the ISP Server.
a. A DSLAM
b. An ADSL modem
c. A filter
d. A splitter

Answer 7

a. A DSLAM

Question 8

______ was designed as an alternative to the T-1 line.
a. VSL
b. ADSL
c. SDSL
d. HDSL

Answer 8

d. HDSL

Question 9

HDSL encodes data using _______
a. 4B/5B
b. 2B1Q
c. 1B2Q
d. 6B/8T

Answer 9

b. 2B1Q

Question 10

_____ encoded signal is more susceptible to attenuation than _____ encoded signal.
a. An AMI; a 2B2Q
b. A 2B1Q; an AMI
c. An AMI; a 2B1Q
d. None of the above

Answer 10

c. An AMI; a 2B1Q

Question 11

Another name for the cable TV office is the _____.
a. Splitter
b. Fiber node
c. Combiner
d. Head end

Answer 11

d. Head end

Question 12

A traditional Cable TV network transmits signals _____.
a. Upstream
b. Downstream
c. Upstream and Downstream
d. None of the above

Answer 12

b. Downstream

Question 13

An HFC network uses _____ as the medium from the switch to the fiber node.
a. Optical Fiber
b. Coaxial Cable
c. UTP
d. STP

Answer 13

a. Optical Fiber

Question 14

In an HFC network, the distribution hub handles the _____ of signals.
a. Modulation
b. Distribution
c. Splitting
d. (a) and (b)

Answer 14

d. (a) and (b)

Question 15

A TV channel in an HFC network needs a _____- MHz bandwidth.
a. 6
b. 100
c. 250
d. 369

Answer 15

a. 6

Question 16

_____ data go from the subscriber to the Internet.
a. Upstream
b. Downstream
c. Midstream
d. None of the above

Answer 16

a. Upstream

Question 17

In an HFC network, the upstream are modulated using the _____ modulation technique.
a. QAM
b. QPSK
c. PCM
d. ASK

Answer 17

b. QPSK

Question 18

The standard for data transmission over an HFC network is called _____.
a. MCNS
b. DOCSIS
c. CMTS
d. ADSL

Answer 18

b. DOCSIS

Question 19

The _____ is an HFC network device installed inside the distribution hub that receives data from the Internet and passes them to the combiner.
a. CM
b. CMTS
c. DOCSIS
d. MCNS

Answer 19

b. CMTS

Question 20

SONET is a standard for _____ networks.
a. Twisted-pair cable
b. Coaxial Cable
c. Ethernet
d. Fiber-Optic cable

Answer 20

d. Fiber-Optic cable

Question 21

SONET in an acronym for _____ Network.
a. Synchronous Optical
b. Standard Optical
c. Symmetric Open
d. Standard Open

Answer 21

a. Synchronous Optical

Question 22

In a SONET system, _____ can remove signals from a path.
a. An STS multiplier
b. A regenerator
c. An Add/Drop multiplier
d. A repeater

Answer 22

c. An Add/Drop multiplier

Question 23

The synchronous payload envelope of an STS-1 frame contains _____.
a. Pointers
b. User data
c. Overhead
d. (b) and (c)

Answer 23

d. (b) and (c)