Name: 
 

CS-320 Review 2



True/False
Indicate whether the statement is true or false.
 

 1. 

Category 1 twisted pair wire is not recommended for transmitting megabits of computer data.
 

 2. 

The braided metal shield is very good at blocking electromagnetic signals from entering the cable and producing noise.
 

 3. 

Electromagnetic interference can be reduced with proper shielding, but it cannot be completely avoided unless you use fiber-optic cable.
 

 4. 

Fiber-optic cable cannot generate nor be disrupted by electromagnetic interference.
 

 5. 

Light traveling through air experiences little resistance.
 

 6. 

Wireless transmissions generally do not have to deal with right-of-way issues.
 

 7. 

Businesses can use terrestrial microwave to implement telecommunications systems between corporate buildings.
 

 8. 

Microwave transmissions follow the curvature of the Earth.
 

 9. 

On occasion, a company will create a protocol that, while not an official standard, becomes so popular that other companies start using it.
 

 10. 

One of the latest interface standards is the RS-232 interface.
 

 11. 

USB is an example of a full-duplex connection.
 

 12. 

Examples of real-time applications usually include streaming voice, video, and music.
 

 13. 

If control simplicity is your primary goal, point-to-point connection of terminals is clearly superior to multipoint connections.
 

 14. 

Multiplexing is a technique typically performed at the network access layer of the TCP/IP protocol suite.
 

 15. 

Frequency division multiplexing is the latest multiplexing technique.
 

 16. 

In frequency division multiplexing, the combined signals are digital.
 

 17. 

Time division multiplexing (TDM) allows only one user at a time to transmit.
 

 18. 

A T-1 system sends the equivalent of 24 voice grade telephone lines over one line.
 

 19. 

Because white noise is relatively continuous, it can be reduced significantly but never completely eliminated.
 

 20. 

If the impulse spike interferes with an analog signal, removing it without affecting the original signal is extremely easy.
 

 21. 

If impulse noise interferes with a digital signal, often the original digital signal cannot be recognized and recovered.
 

 22. 

Noise is a problem for both analog and digital signals.
 

 23. 

Telephone signal crosstalk was a more common problem before telephone companies used fiber-optic cables and other well-shielded wires.
 

 24. 

TCP performs error detection at the end points of the connection.
 

 25. 

Simple parity can detect only an even number of erroneous bits per character.
 

 26. 

The CRC error-detection method treats the packet of data to be transmitted as a large polynomial.
 

 27. 

The CRC method catches almost 100% of errors.
 

 28. 

NAK represents a positive acknowledgment.
 

 29. 

In a stop-and-wait error control system, a receiver may acknowledge multiple packets with a single ACK.
 

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 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
 

 2. 

____ 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
 

 3. 

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
 

 4. 

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
 

 5. 

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
 

 6. 

____ 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
 

 7. 

____ cable is virtually impossible to wiretap.
a.
CAT 1
c.
Thick coaxial
b.
Single-stranded coaxial
d.
Fiber-optic
 

 8. 

As the length of a glass cable grows, the light signal attenuates due to reflection and ____.
a.
EMI
c.
refraction
b.
RFI
d.
friction
 

 9. 

The typical maximum distance between microwave towers is roughly ____ to 30 miles.
a.
3
c.
8
b.
6
d.
15
 

 10. 

____ 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
 

 11. 

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)
 

 12. 

The connection to a peripheral is often called the ____.
a.
USB
c.
FireWire
b.
interface
d.
EIA-232F
 

 13. 

A ____ connection is one in which both sender and receiver may transmit at the same time.
a.
full-duplex
c.
single-duplex
b.
half-duplex
d.
multi-duplex
 

 14. 

A(n) ____ is simply a high-speed connection to which multiple devices can attach.
a.
pin
c.
circuit
b.
bus
d.
interface
 

 15. 

Typically, impulse noise is a(n) ____ burst of energy.
a.
digital
c.
binary
b.
analog
d.
logical
 

 16. 

To minimize the effect of echo, a device called a(n) ____ can be attached to a line.
a.
echo suppressor
c.
amplifier
b.
repeater
d.
hub
 

 17. 

____ is not necessarily a form of error, but can indirectly lead to an increase in errors affecting the transmitted signal.
a.
Impulse noise
c.
Attenuation
b.
Crosstalk
d.
White noise
 

 18. 

Twisted pair Category 5e/6 cable should not be longer than the recommended 100-meter (300-foot) distance when it’s transmitting at ____ Mbps.
a.
100
c.
500
b.
250
d.
1000
 

 19. 

Longitudinal parity is sometimes called longitudinal redundancy check or ____ parity.
a.
vertical
c.
random
b.
horizontal
d.
binary
 

 20. 

CRC-____ is found in Ethernet LANs.
a.
5
c.
32
b.
12
d.
64
 

 21. 

____ cable is the medium least prone to generating errors.
a.
Fiber-optic
c.
Twisted-pair
b.
Coaxial
d.
Copper-based
 

 22. 

Under normal circumstances, the synchronous time division multiplexor maintains a simple ____ sampling order of the input devices.
a.
round-robin
c.
LIFO
b.
FIFO
d.
FILO
 

 23. 

In the 1960s, AT&T created a service known as ____, which multiplexed digital data and digitized voice onto a high-speed telephone line with a data rate of 1.544 megabits per second.
a.
ISDN
c.
SONET
b.
T-1
d.
SDH
 

 24. 

A ____ multiplexes 24 input channels together onto one high-speed telephone line.
a.
T-1 system
c.
SDH system
b.
SONET system
d.
congruent system
 

 25. 

____ multiplexes multiple data streams onto a single fiber-optic line.
a.
Statistical time division multiplexing (Stat TDM)
b.
Wavelength division multiplexing (WDM)
c.
Time division multiplexing (TDM)
d.
Channel division multiplexing (CDM)
 

 26. 

____ is a technology that allows a high-speed data signal to traverse a standard copper-based telephone line.
a.
DSL
c.
EIA-232F
b.
RS-232
d.
FireWire
 

 27. 

____ division multiplexing is a good choice for connecting a number of lower-speed devices that do not transmit data on a continuous basis to a remote computer system.
a.
Statistical time
c.
Discrete tone
b.
Time
d.
Frequency
 

 28. 

____ division multiplexing is a good technique for transmitting multiple concurrent signals over a fiber-optic line.
a.
Statistical time
c.
Frequency
b.
Synchronous time
d.
Wavelength
 

Completion
Complete each statement.
 

 1. 

____________________ twisted pair was designed to transmit 100 Mbps of data for distances up to 100 meters.
 

 

 2. 

____________________ 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.
 

 

 3. 

The two most common application areas of terrestrial microwave are ____________________ and business intercommunication.
 

 

 4. 

The ____________________ component of an interface deals with voltages, line capacitance, and other electrical issues.
 

 

 5. 

The ____________________ component of an interface describes the function of each pin that is used in a particular interface.
 

 

 6. 

____________________ is a digital interface that uses a standardized connector (plug) for all serial and parallel type devices.
 

 

 7. 

In a(n) ____________________ connection, a single character, or byte of data, is the unit of transfer between the sender and receiver.
 

 

 8. 

A(n) ____________________ bit performs an error check on only the data bits.
 

 

 9. 

____________________ is a noncontinuous noise and one of the most difficult errors to detect, because it can occur randomly.
 

 

 10. 

When a digital signal is being transmitted, the rises and falls of the signal can start to shift, or become blurry, and thus produce ____________________.
 

 

 11. 

____________________ is the continuous loss of a signal’s strength as it travels though a medium.
 

 

 12. 

Simple parity comes in two basic forms: even parity and ____________________ parity.
 

 

 13. 

The ____________________ method typically adds 8 to 32 check bits to potentially large data packets and yields an error detection capability approaching 100 percent.
 

 

 14. 

A(n) ____________________ connection is a single wire with the mainframe connected on one end and multiple terminals connected on the other end.
 

 

 15. 

____________________ is the process of taking data and somehow packing more of it into the same space.
 

 



 
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