Fundamentals of Networking and Data Communications International Edition 7th Edition Curt White-Test Bank
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Sample Test
Chapter 3: Conducted and Wireless Media
TRUE/FALSE
1. Category
1 twisted pair wire is not recommended for transmitting megabits of computer
data.
ANS:
T
PTS:
1
REF: 65
2. Category
1 wire is susceptible to experiencing noise and signal attenuation.
ANS:
T
PTS: 1
REF: 65
3. Category
1 twisted pair wire produces less noise and signal attenuation than Category 2.
ANS:
F
PTS:
1
REF: 65
4. Much
of the Category 3 wire sold today is used for new computer network
installations.
ANS:
F
PTS:
1
REF: 66
5. Category
5 twisted pair has a higher number of twists per inch than the Category 1 to 4
wires.
ANS:
T
PTS: 1
REF: 66
6. Category
1 through 7 twisted pair wires can be purchased only as unshielded twisted
pair.
ANS:
F
PTS:
1
REF: 67
7. The
braided metal shield is very good at blocking electromagnetic signals from
entering the cable and producing noise.
ANS:
T
PTS:
1
REF: 67
8. A
fairly common application for baseband coaxial used to be the interconnection
of hubs within a local area network.
ANS: T
PTS:
1
REF: 69
9. Thin
coaxial cable typically carries broadband signals.
ANS:
F
PTS:
1
REF: 69
10.
Thick coaxial cable has limited noise isolation and typically
carries baseband signals.
ANS:
F
PTS:
1
REF: 69
11.
Electromagnetic interference can be reduced with proper
shielding, but it cannot be completely avoided unless you use fiber-optic
cable.
ANS:
T
PTS:
1
REF: 70
12.
Fiber-optic cable cannot generate nor be disrupted by
electromagnetic interference.
ANS:
T
PTS:
1
REF: 71
13.
Light traveling through air experiences little resistance.
ANS:
T
PTS:
1
REF: 71
14.
It is estimated that in the future, photonic fibers will have
transmission speeds and distances at least 10 times that of current fiber-optic
cable.
ANS:
T
PTS:
1
REF: 73
15.
Single-mode fiber-optic cable is labeled 62.5/125 cable.
ANS:
F
PTS:
1
REF: 73
16.
Wireless transmissions generally do not have to deal with
right-of-way issues.
ANS:
T
PTS:
1
REF: 75
17.
Businesses can use terrestrial microwave to implement
telecommunications systems between corporate buildings.
ANS:
T
PTS:
1
REF: 76
18.
Microwave transmissions follow the curvature of the Earth.
ANS:
F
PTS:
1
REF: 76
19.
One way of categorizing satellite systems is by how far the
satellite is from the Earth.
ANS:
T
PTS: 1
REF: 78
20.
The advantage to being closer to Earth is that the satellite
must continuously circle the Earth to remain in orbit.
ANS:
F
PTS:
1
REF: 78
21.
Satellites that are always over the same point on Earth can be
used for long periods of high-speed data transfers.
ANS:
T
PTS:
1
REF: 80
22.
At the end of the twentieth century, there were approximately
3000 LEO satellites.
ANS:
F
PTS:
1
REF: 78
23.
At the end of the twentieth century, approximately 105 MEO
satellites were orbiting the Earth.
ANS:
F
PTS:
1
REF: 78
24.
Geosynchronous-Earth-orbit satellites are most commonly used for
signal relays for broadcast, cable, and direct television.
ANS:
T
PTS:
1
REF: 80
25.
Four basic generations of cellular telephone systems currently exist.
ANS:
T
PTS:
1
REF: 81
26.
Because each cell uses low-power transmissions, it is not likely
that a transmission within one particular cell will interfere with a
transmission in another cell.
ANS: T
PTS:
1
REF: 81
27.
AMPS and D-AMPS technologies generally offer a clearer signal
than all PCS technologies.
ANS:
F
PTS:
1
REF: 84
28.
IEEE 802.16a is a revision of the 802.16 standard that provides
a high-speed connection for slowly moving devices.
ANS:
F
PTS:
1
REF: 87
29.
Data transmission speed is the number of bits per second that
can be transmitted.
ANS:
T
PTS:
1
REF: 93
30.
ZigBee is a form of wireless technology used within buildings.
ANS:
T
PTS:
1
REF: 88
31.
ZigBee is capable of transmitting signals for up to one mile.
ANS: F
PTS:
1
REF: 88
MULTIPLE CHOICE
1. A
current or signal in one wire can produce an unwanted current or signal, called
____, in a second wire.
|
a. |
current-talk |
c. |
crosstalk |
|
b. |
signal-talk |
d. |
crossover |
ANS:
C
PTS:
1
REF: 65
2. ____
twisted pair is the least quality twisted pair wire that should be used in a
data/voice application.
|
a. |
Category 1 |
c. |
Category 5 |
|
b. |
Category 3 |
d. |
Category 7 |
ANS: C
PTS:
1
REF: 65
3. ____
twisted pair wire is used in environments that have a noticeable amount of
electromagnetic interference.
|
a. |
Shielded |
c. |
Super |
|
b. |
Congealed |
d. |
Dilithium |
ANS: A
PTS:
1
REF: 65
4. ____
is the designation for a digital telephone circuit that transmits voice or data
at 1.544 Mbps.
|
a. |
ISDN |
c. |
VSAT |
|
b. |
T-1 |
d. |
T-32 |
ANS:
B
PTS: 1
REF: 65
5. ____
twisted pair was designed to transmit 10 Mbps of data over a local area network
for distances up to 100 meters (328 feet).
|
a. |
Category 2 |
c. |
Category 5 |
|
b. |
Category 3 |
d. |
Category 6 |
ANS: B
PTS:
1
REF: 66
6. Category
5e twisted pair can run farther than 100 meters from its source to its final
destination, as long as the signal is regenerated at least every ____ meters.
|
a. |
20 |
c. |
75 |
|
b. |
50 |
d. |
100 |
ANS:
D
PTS:
1
REF: 66
7. ____
twisted pair was designed to transmit 20 Mbps of data for distances up to 100
meters.
|
a. |
Category 1 |
c. |
Category 4 |
|
b. |
Category 3 |
d. |
Category 5 |
ANS: C
PTS:
1
REF: 66
8. ____
twisted pair is designed to support data transmission with signals as high as
200 MHz for 100 meters.
|
a. |
Category 6 |
c. |
Category 7a |
|
b. |
Category 7 |
d. |
Category 7e |
ANS: A
PTS:
1
REF: 66
9. In
a(n) ____ none of the wires is wrapped with a metal foil or braid.
|
a. |
shielded twisted pair (STP) |
c. |
CAT 4 twisted pair |
|
b. |
unshielded twisted pair (UTP) |
d. |
CAT 7 twisted pair |
ANS: B
PTS:
1
REF: 67
10.
____ is a form in which a shield is wrapped around each wire
individually, around all the wires together, or both.
|
a. |
Shielded twisted pair (STP) |
c. |
CAT 2 twisted pair |
|
b. |
Unshielded twisted pair (UTP) |
d. |
CAT 5 twisted pair |
ANS:
A
PTS:
1
REF: 67
11.
Because of its good shielding properties, ____ is good at
carrying analog signals with a wide range of frequencies.
|
a. |
CAT 1 wire |
c. |
copper wire |
|
b. |
CAT 2 wire |
d. |
coaxial cable |
ANS:
D
PTS:
1
REF: 69
12.
____ technology uses digital signaling in which the cable
carries only one channel of digital data.
|
a. |
Broadband coaxial |
c. |
Baseband coaxial |
|
b. |
CAT 7 |
d. |
Fiber optic |
ANS:
C
PTS:
1
REF: 69
13.
____ technology typically transmits analog signals and is
capable of supporting multiple channels of data simultaneously.
|
a. |
Broadband coaxial |
c. |
Baseband coaxial |
|
b. |
CAT 7 |
d. |
Fiber optic |
ANS:
A
PTS:
1
REF: 69
14.
____ cable ranges in size from approximately 6 to 10 mm or more
(1/4 to 3/8 inch) in diameter.
|
a. |
Thin coaxial |
c. |
CAT 2 |
|
b. |
Thick coaxial |
d. |
CAT 3 |
ANS:
B
PTS:
1
REF: 69
15.
____ cable is approximately 4 mm (less than 1/4 inch) in
diameter.
|
a. |
CAT 2 |
c. |
Thin coaxial |
|
b. |
Thick coaxial |
d. |
CAT 3 |
ANS: C
PTS:
1
REF: 69
16.
____ cable contains, as the name implies, a single copper wire
in the center of the cable.
|
a. |
Braided coaxial |
c. |
thin-stranded coaxial |
|
b. |
Fiber optic |
d. |
Single-stranded coaxial |
ANS: D
PTS:
1
REF: 69
17.
____ cable is a thin glass cable, a little thicker than a human
hair, surrounded by a plastic coating.
|
a. |
Single-stranded coaxial |
c. |
Braided coaxial |
|
b. |
Fiber-optic |
d. |
CAT 7 |
ANS: B
PTS:
1
REF: 71
18.
____ cable is virtually impossible to wiretap.
|
a. |
CAT 1 |
c. |
Thick coaxial |
|
b. |
Single-stranded coaxial |
d. |
Fiber-optic |
ANS:
D
PTS:
1
REF: 71
19.
As the length of a glass cable grows, the light signal
attenuates due to reflection and ____.
|
a. |
EMI |
c. |
refraction |
|
b. |
RFI |
d. |
friction |
ANS:
C
PTS:
1
REF: 73
20.
The ____ cable is similar to fiber-optic cable in that it is as
thin as a hair and transparent. The big difference, however, is that this new
cable is full of holes.
|
a. |
photonic fiber |
c. |
thick coaxial |
|
b. |
single-stranded coaxial |
d. |
thin coaxial |
ANS:
A
PTS: 1
REF: 73
21.
When a light signal inside the cable bounces off the cable wall
and back into the cable, this is called ____.
|
a. |
refraction |
c. |
blinking |
|
b. |
reflection |
d. |
friction |
ANS:
B
PTS: 1
REF: 73
22.
____ transmission requires the use of a very thin fiber-optic
cable and a very focused light source, such as a laser.
|
a. |
Multimode |
c. |
Single-mode |
|
b. |
Reflection |
d. |
Refraction |
ANS: C
PTS:
1
REF: 73
23.
____ transmission uses a slightly thicker fiber cable and an
unfocused light source, such as an LED.
|
a. |
Multimode |
c. |
Single-mode |
|
b. |
Reflection |
d. |
Refraction |
ANS: A
PTS:
1
REF: 73
24.
____ transmission systems transmit tightly focused beams of
radio signals from one ground-based microwave transmission antenna to another.
|
a. |
Satellite |
c. |
Downlink |
|
b. |
Cellular |
d. |
Terrestrial microwave |
ANS:
D
PTS:
1
REF: 76
25.
____ transmission means that to receive and transmit a signal,
each antenna must be in sight of the next antenna.
|
a. |
Uplink |
c. |
Line-of-sight |
|
b. |
Omnidirectional |
d. |
Downlink |
ANS:
C
PTS:
1
REF: 77
26.
The typical maximum distance between microwave towers is roughly
____ to 30 miles.
|
a. |
3 |
c. |
8 |
|
b. |
6 |
d. |
15 |
ANS:
D
PTS: 1
REF: 77
27.
____ transmission systems are similar to terrestrial microwave
systems except that the signal travels from a ground station on Earth to a
satellite and back to another ground station on Earth.
|
a. |
Satellite microwave |
c. |
Downlink |
|
b. |
Cellular |
d. |
Terrestrial microwave |
ANS:
A
PTS:
1
REF: 77
28.
The closer a satellite is to the Earth, the shorter the times
required to send data to the satellite, that is, to ____.
|
a. |
downlink |
c. |
download |
|
b. |
uplink |
d. |
send down |
ANS:
B
PTS:
1
REF: 77
29.
The transmission time from when a signal first leaves a
satellite and then arrives at a ground station is called ____.
|
a. |
propagation delay |
c. |
uplink |
|
b. |
downlink |
d. |
upload |
ANS:
A
PTS:
1
REF: 77
30.
____ satellites are closest to the Earth.
|
a. |
Low-Earth-orbit (LEO) |
c. |
Geosynchronous-Earth-orbit (GEO) |
|
b. |
Middle-Earth-orbit (MEO) |
d. |
Highly-elliptical-Earth-orbit (HEO) |
ANS:
A
PTS:
1
REF: 78
31.
____ satellites can be found roughly 1000 to 3000 miles from the
Earth.
|
a. |
Low-Earth-orbit (LEO) |
c. |
Geosynchronous-Earth-orbit (GEO) |
|
b. |
Middle-Earth-orbit (MEO) |
d. |
Highly-elliptical-Earth-orbit (HEO) |
ANS:
B
PTS:
1
REF: 78
32.
A satellite system that has unique properties is the ____
satellite, which is used by governments for spying and by scientific agencies
for observing celestial bodies.
|
a. |
Low-Earth-orbit (LEO) |
c. |
Geosynchronous-Earth-orbit (GEO) |
|
b. |
Middle-Earth-orbit (MEO) |
d. |
Highly-elliptical-Earth-orbit (HEO) |
ANS: D
PTS:
1
REF: 78
33.
Cells, in a cellular telephone system, can range in size from
one-half mile in radius to ____ miles in radius.
|
a. |
25 |
c. |
50 |
|
b. |
35 |
d. |
70 |
ANS:
C
PTS: 1
REF: 82
34.
____ was the first-generation cellular telephone system.
|
a. |
Personal Communications Services (PCS) |
|
b. |
Time Division Multiple Access (TDMA) |
|
c. |
Advanced Mobile Phone Service (AMPS) |
|
d. |
Global System for Mobile (GSM) Communications |
ANS:
C
PTS:
1
REF: 84
35.
The ____ system is an example of a single-user Earth station
satellite system with its own ground station and a small antenna (two to six
feet across).
|
a. |
T1 |
c. |
VSAT |
|
b. |
LEO |
d. |
SAT-V |
ANS:
C
PTS:
1
REF: 79
36.
The first PCS technology used a form of time division
multiplexing called ____.
|
a. |
Code Division Multiple Access (CDMA) |
|
b. |
Time Division Multiple Access (TDMA) |
|
c. |
Global System for Mobile (GSM)
Communications |
|
d. |
Digital-Advanced Mobile Phone Service
(D-AMPS) |
ANS:
B
PTS:
1
REF: 85
37.
The third PCS technology was ____ and used a different form of
time division multiple access technology.
|
a. |
Global System for Mobile (GSM)
Communications |
|
b. |
Time Division Multiple Access (TDMA) |
|
c. |
Code Division Multiple Access (CDMA) |
|
d. |
Digital-Advanced Mobile Phone Service
(D-AMPS) |
ANS:
A
PTS: 1
REF: 85
38.
____ is a broadband wireless transmission technology that is
based upon a series of IEEE standards.
|
a. |
WiFi |
c. |
IrDA |
|
b. |
Bluetooth |
d. |
WiMAX |
ANS:
D
PTS:
1
REF: 85
39.
____ systems transmit data over a wide range of frequencies
rather than limiting transmissions to a narrow, fixed band of frequencies.
|
a. |
WiFi |
c. |
Ultra-wideband |
|
b. |
Bluetooth |
d. |
Free space optics |
ANS:
C
PTS: 1
REF: 88
40.
____ systems are good at sending low-speed signals over short to
medium distances.
|
a. |
Microwave |
c. |
WiFi |
|
b. |
Satellite |
d. |
ZigBee |
ANS:
D
PTS:
1
REF: 88
41.
The popular GPS devices that people use to find directions while
driving use which type of satellite system?
|
a. |
LEO |
c. |
GEO |
|
b. |
MEO |
d. |
HEO |
ANS:
B
PTS:
1
REF: 80
42.
Which type of satellite remains located over the same point of
earth at all times?
|
a. |
LEO |
c. |
GEO |
|
b. |
MEO |
d. |
HEO |
ANS:
C
PTS:
1
REF: 80
COMPLETION
1. ____________________
wire comes as two or more pairs of single-conductor copper wires that have been
twisted around each other.
ANS: Twisted pair
PTS:
1
REF: 64
2. ____________________
twisted pair is designed to carry analog voice or digital data at low speeds
(less than or equal to 9600 bps) and is now obsolete.
ANS:
Category 1
CAT 1
PTS:
1
REF: 65
3. A(n)
____________________ is a device that generates a new signal by creating an
exact replica of the original signal.
ANS: repeater
PTS:
1
REF: 65
4. ____________________
twisted pair was designed to transmit 100 Mbps of data for distances up to 100
meters.
ANS:
Category 5
CAT 5
PTS:
1
REF: 66
5. ____________________
wire is designed to support 600 MHz of bandwidth for 100 meters.
ANS:
Category 7
CAT 7
PTS:
1
REF: 66
6. ____________________
is the most common form of twisted pair.
ANS:
Unshielded twisted pair (UTP)
Unshielded twisted pair
UTP
PTS:
1
REF: 67
7. ____________________
cable, in its simplest form, is a single wire (usually copper) wrapped in a
foam insulation, surrounded by a braided metal shield, then covered in a
plastic jacket.
ANS: Coaxial
PTS:
1
REF: 69
8. Two
major coaxial cable technologies exist and are distinguished by the type of
signal each carries: baseband and ____________________.
ANS: broadband
PTS:
1
REF: 69
9. Coaxial
cable is available in a variety of thicknesses, with two primary physical
types: thick coaxial cable and ____________________ coaxial cable.
ANS: thin
PTS:
1
REF: 69
10.
____________________ cable is composed of many fine wires
twisted around each other, acting as a single conductor.
ANS: Braided coaxial
PTS:
1
REF: 70
11.
____________________ is the electronic distortion that a signal
passing through a metal wire experiences when a stray magnetic field passes
over it.
ANS: Electromagnetic interference
PTS:
1
REF: 70
12.
The ____________________ is the main connecting cable that runs
from one end of the installation to another.
ANS: backbone
PTS:
1
REF: 72
13.
When a light signal passes from the core of the cable into the
surrounding material, this is called ____________________.
ANS: refraction
PTS:
1
REF: 73
14.
Multimode fiber-optic cable is labeled ____________________
cable.
ANS: 62.5/125
PTS: 1
REF: 73
15.
____________________ is the legal capability of a business to
install a wire or cable across someone’s property.
ANS: Right-of-way
PTS:
1
REF: 74
16.
The two most common application areas of terrestrial microwave
are ____________________ and business intercommunication.
ANS: telephone communications
PTS:
1
REF: 76
17.
The closer a satellite is to the Earth, the shorter the times
required to receive data from the satellite, that is, to ____________________.
ANS: downlink
PTS:
1
REF: 77
18.
____________________ satellites can be found as close as 100
miles from the surface and as far as 1000 miles.
ANS:
Low-Earth-orbit (LEO)
Low-Earth-orbit
LEO
PTS:
1
REF: 78
19.
The ____________________ is a system of 24 satellites that were
launched by the U.S. Department of Defense and are used for identifying
locations on Earth.
ANS:
global positioning system (GPS)
global positioning system
GPS
PTS:
1
REF: 80
20.
____________________ satellites are found 22,300 miles from the
Earth and are always positioned over the same point on Earth.
ANS:
Geosynchronous-Earth-orbit (GEO)
Geosynchronous-Earth-orbit
GEO
PTS:
1
REF: 80
21.
____________________ is the digital equivalent of analog
cellular telephone service.
ANS:
Digital-Advanced Mobile Phone Service (D-AMPS)
Digital-Advanced Mobile Phone Service
D-AMPS
PTS: 1
REF: 81-82
22.
The second-generation PCS cell phone technology used both GSM
and ____________________ technology.
ANS:
Code Division Multiple Access (CDMA)
Code Division Multiple Access
CDMA
PTS:
1
REF: 85
23.
____________________ transmission is a special form of radio
transmission that uses a focused ray of light in the infrared frequency range
(1012 –1014 MHz).
ANS: Infrared
PTS:
1
REF: 88
24.
A(n) ____________________ system is one of the latest techniques
for delivering Internet services into homes and businesses.
ANS: broadband wireless
PTS:
1
REF: 85-86
25.
____________________ uses lasers, or, in some cases, infrared transmitting
devices, to transmit data between two buildings over short distances, like
across the street.
ANS: Free space optics
PTS:
1
REF: 88
ESSAY
1. Briefly
explain the characteristics of Category 5e twisted pair.
ANS:
Approved at the end of 1999, the specification for Category 5e
twisted pair is similar to Category 5’s in that this wire is also recommended
for transmissions of 100 Mbps (100 MHz) for 100 meters. Many companies are
producing Category 5e wire at 125 MHz for 100 meters. While the specifications
for the earlier Category 1 to 5 wires described only the individual wires, the
Category 5e specification indicates exactly four pairs of wires and provides
designations for the connectors on the ends of the wires, patch cords, and
other possible components that connect directly with a cable. Thus, as a more
detailed specification than Category 5, Category 5e can better support the
higher speeds of 100-Mbps (and higher) local area networks.
PTS:
1
REF: 66
2. Explain
when shielded twisted pair wire works better than unshielded twisted pair wire.
ANS:
If a twisted pair wire needs to go through walls, rooms, or
buildings where there is sufficient electromagnetic interference to cause
substantial noise problems, using shielded twisted pair can provide a higher
level of isolation from that interference than unshielded twisted pair wire,
and thus a lower level of errors. Electromagnetic interference is often
generated by large motors, such as those found in heating and cooling equipment
or manufacturing equipment. Even fluorescent light fixtures generate a
noticeable amount of electromagnetic interference. Large sources of power can
also generate damaging amounts of electromagnetic interference. Therefore, it
is generally not a good idea to strap twisted pair wiring to a power line that
runs through a room or through walls. Furthermore, even though Categories 3 to
6 shielded twisted pair have improved noise isolation, you cannot expect to
push them past the 100-meter limit. Finally, be prepared to pay a premium for
shielded twisted pair. It is not uncommon to spend an additional $1 per foot
for good-quality shielded twisted pair. In contrast, Category 5, 5e, and 6 UTP
often cost between $.10 and $.20 per foot.
PTS:
1
REF: 67
3. How
does a fiber-optic cable transmit data?
ANS:
A light source, called a photo diode, is placed at the
transmitting end and quickly switched on and off to produce light pulses. These
light pulses travel down the glass cable and are detected by an optic sensor
called a photo receptor on the receiving end. The light source can be either a
simple and inexpensive light-emitting diode (LED), such as those found in many
pocket calculators, or a more complex laser. The laser is much more expensive
than the LED, and it can produce much higher data transmission rates.
Fiber-optic cable is capable of transmitting data at over 100 Gbps (that’s 100
billion bits per second!) over several kilometers. Because many common local
area network installations use an LED source, however, real-world fiber-optic
transmissions are effectively limited to 10 gigabits for 300 meters.
PTS:
1
REF: 70-71
4. What
are the disadvantages of fiber-optic cables?
ANS:
Fiber-optic cable has two small but significant disadvantages.
First, due to the way the light source and photo receptor arrangement works,
light pulses can travel in one direction only. Thus, to support a two-way
transmission of data, two fiber-optic cables are necessary. For this reason,
most fiber-optic cable is sold with at least two (if not more) individual
strands of fiber bundled into a single package.
A second disadvantage of fiber-optic cable is its higher cost,
but this disadvantage is slowly disappearing. For example, it is now possible
to purchase bulk, general purpose duplex (two-strand) fiber-optic cable for
approximately $.50 per foot (as opposed to paying a few dollars per foot
several years ago), which is close to the price of many types of coaxial cable
and shielded twisted pair cable.
PTS:
1
REF: 71
5. What
are the main characteristics of the multiplexed Earth station satellite
topology?
ANS:
In a multiplexed Earth station satellite system, the ground
station accepts input from multiple sources and in some fashion interweaves the
data streams, either by assigning different frequencies to different signals or
by allowing different signals to take turns transmitting. How does this type of
satellite system satisfy the requests of users and assign time slots? Each user
could be asked in turn if he or she has data to transmit, but because so much
time could be lost by the asking process, this technique would not be
economically feasible. A first-come, first-served scenario, in which each user
competed with every other user, would also be an extremely inefficient design.
The technique that seems to work best for assigning access to multiplexed
satellite systems is a reservation system. In a reservation system, users place
a reservation for future time slots. When the reserved time slot arrives, the
user transmits his or her data on the system. Two types of reservation systems
exist: centralized reservation and distributed reservation. In a centralized
reservation system, all reservations go to a central location, and that site
handles the incoming requests. In a distributed reservation system, no central
site handles the reservations, but individual users come to some agreement on
the order of transmission.
PTS: 1
REF: 79
Chapter 5: Making Connections Efficient: Multiplexing and
Compression
TRUE/FALSE
1. Multiplexing
is a technique typically performed at the network access layer of the TCP/IP
protocol suite.
ANS: T
PTS:
1
REF: 122
2. One
way to make a connection between two devices more efficient is to compress the
data that transfers over the connection.
ANS:
T
PTS:
1
REF: 122
3. Frequency
division multiplexing is the latest multiplexing technique.
ANS:
F
PTS:
1
REF: 122
4. In
frequency division multiplexing, the combined signals are digital.
ANS: F
PTS:
1
REF: 123
5. Cell
phones are an example of dynamically assigned channels.
ANS:
T
PTS:
1
REF: 123
6. Time
division multiplexing (TDM) allows only one user at a time to transmit.
ANS:
T
PTS:
1
REF: 125
7. As
with a simple connection between one sending device and one receiving device,
maintaining synchronization across a multiplexed link is important.
ANS:
T
PTS:
1
REF: 126
8. The
T-1’s original purpose was to provide a high-speed connection between
AT&T’s switching centers.
ANS:
T
PTS:
1
REF: 127
9. The
T-1 system is a classic application of frequency division multiplexing.
ANS:
F
PTS:
1
REF: 127
10.
A T-1 system sends the equivalent of 24 voice grade telephone
lines over one line.
ANS:
T
PTS:
1
REF: 127
11.
A T-1 system continuously sends a signal, even if there is no
real data to transmit.
ANS:
T
PTS:
1
REF: 127
12.
SONET is a more modern term for the older T-1 system.
ANS: F
PTS:
1
REF: 128
13.
SDH was developed in Europe by ITU-T.
ANS:
T
PTS:
1
REF: 128
14.
SONET and SDH are able to multiplex varying speed streams of
data onto one fiber connection.
ANS:
T
PTS:
1
REF: 129
15.
The data rate of OC-3 is exactly thirty times the rate of OC-1.
ANS:
F
PTS:
1
REF: 129
16.
The STS multiplexor in a SONET network can accept electrical
signals from copper-based media.
ANS:
T
PTS:
1
REF: 129
17.
Both frequency division multiplexing and synchronous time
division multiplexing can waste unused transmission space.
ANS:
T
PTS:
1
REF: 130
18.
Wavelength division multiplexing (WDM) is, in essence, a time
division multiplexing technique.
ANS:
F
PTS:
1
REF: 131
19.
WDM supports multiple lambdas.
ANS:
T
PTS:
1
REF: 132
20.
Dense wavelength division multiplexing is an expensive way to
transmit signals from multiple devices due to the high number of differently
colored lasers required in one unit.
ANS: T
PTS:
1
REF: 132
21.
DSL is capable of achieving speeds into the millions of bits per
second.
ANS:
T
PTS:
1
REF: 133
22.
Code division multiplexing is based upon a class of modulation
techniques known as spread spectrum technology.
ANS:
T
PTS:
1
REF: 134
23.
The big advantage of frequency division multiplexing over
synchronous TDM is the lower noise due to the use of digital signals during
transmission.
ANS:
F
PTS:
1
REF: 136
24.
Synchronous time division multiplexing does not require as
high-speed a line as statistical time division multiplexing does.
ANS:
F
PTS: 1
REF: 136
25.
Code division multiplexing, while using a fairly wide bandwidth
of frequencies and a complex technology, is scalable like WDM.
ANS:
T
PTS:
1
REF: 136
26.
The basic way to perform compression is to look for some common
pattern in the data and replace each data pattern with a symbol or symbols that
will consume less space during transmission or storage.
ANS:
T
PTS:
1
REF: 137
27.
The Lempel-Ziv algorithm can be fairly effective in compressing
data.
ANS:
T
PTS:
1
REF: 139
28.
The human ear can hear sounds only within a certain range, which
for an average person is 10 Hz to 40 kHz (40,000 Hz).
ANS:
F
PTS:
1
REF: 140
29.
The MP3 encoder produces a data stream that has a much faster
data rate than that of conventional CD-quality music.
ANS:
F
PTS: 1
REF: 140
30.
A video device displays multiple (typically 30) frames per
second.
ANS:
T
PTS:
1
REF: 143
MULTIPLE CHOICE
1. Presently,
a medium can be divided in three basic ways: a division of ____, a division of
time, and a division of transmission codes.
|
a. |
frequencies |
c. |
wavelength |
|
b. |
amplitudes |
d. |
direction |
ANS:
A
PTS:
1
REF: 122
2. ____
is the assignment of nonoverlapping frequency ranges to each “user” of a
medium.
|
a. |
Time division multiplexing (TDM) |
c. |
Amplitude division multiplexing (ADM) |
|
b. |
Transmission code multiplexing (TCM) |
d. |
Frequency division multiplexing (FDM) |
ANS:
D
PTS: 1
REF: 122
3. To
allow multiple users to share a single medium, FDM assigns each user a separate
____.
|
a. |
time slot |
c. |
channel |
|
b. |
transmission code |
d. |
amplitude |
ANS:
C
PTS: 1
REF: 122
4. First-generation
cellular telephone systems allocated channels using frequency ranges within the
800 to ____ megahertz (MHz) spectrum.
|
a. |
830 |
c. |
930 |
|
b. |
900 |
d. |
960 |
ANS:
B
PTS: 1
REF: 123
5. The
device that is attached to the receiving end of the medium and splits off each
signal to deliver it to the appropriate receiver is called the second
multiplexor, or ____.
|
a. |
multiplexor |
c. |
splitxor |
|
b. |
endplexor |
d. |
demultiplexor |
ANS:
D
PTS:
1
REF: 124
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