Deck 2: Wireless Data Transmission

Question 1

Hopping codes used in FHSS transmissions are configured on the base station by the network administrator.

Answer 1

False

Question 2

Which best describes an analog signal?

A) it starts and stops
B) intensity varies and is continuous
C) consists of discrete pulses
D) Morse code is an example

Answer 2

B

Question 3

The ASCII code uses 16 bits to represent 128 different characters.

Answer 3

False

Question 4

Which of the following best describes bandwidth in an analog system?

A) the range of frequencies that can be transmitted by a system
B) the number of bits transmitted per second
C) the number of bytes transmitted per minute
D) the maximum frequency supported by the medium

Question 5

Which of the following is a good application for an infrared wireless system?

A) stream movies from a server
B) wireless outdoor speakers
C) whole house wireless network
D) data transfer between laptop and camera

Question 6

Spread-spectrum signals are more susceptible to outside interference than narrow-band transmissions.

Question 7

Which type of radio signal is most susceptible from interference sources such as lightning?

A) AM
B) FM
C) PM
D) DM

Question 8

The distance between a point in one wave cycle and the same point in the next wave cycle is called which of the following?

A) amplitude
B) wavelength
C) carrier
D) frequency

Question 9

Which of the following is true about baud rate?

A) only one bit can be transferred per signal unit (baud)
B) multiple bits can be transferred with each signal unit
C) a baud rate of 2400 always means a bandwidth of 2400 bps
D) multiple signal units are needed to represent each bit

Question 10

Which of the following is NOT a type of modulation that can be applied to an analog signal?

A) phase
B) carrier
C) frequency
D) amplitude

Question 11

Which of the following is NOT a limitation of using infrared wireless systems?

A) they lack mobility
B) they use a line-of-sight principle
C) someone can eavesdrop from another room
D) diffused transmissions have a range of 50 feet

Question 12

Which of the following is true about wireless radio signal transmissions?

A) they travel at the speed of light
B) they require an atmosphere to move
C) they travel as discrete particles
D) they require visible light

Question 13

The frequency of a wave is best defined as which of the following?

A) encoding of bits onto an analog wave
B) the voltage difference between the peak and trough of the wave
C) a carrier wave that has been modulated
D) the number of times a cycle occurs within one second

Question 14

Which of the following is NOT true about infrared light?

A) it can be used in directed transmissions
B) it can be used in diffused transmissions
C) it is less susceptible to interference from visible light sources
D) all infrared signals are invisible

Question 15

The height of a radio wave is called the amplitude of the wave.

Question 16

What process must occur to transmit a digital signal over an analog medium?

A) modulation
B) decoupling
C) decoding
D) emitting

Question 17

What is the unit of measurement for radio frequency?

A) volt
B) rpm
C) Hz
D) amp

Question 18

What is the role of an antenna on a wireless device?

A) it receives data
B) it demodulates
C) it serves as a ground signal
D) it transmits and receives data

Question 19

Which of the following transmits a signal in an infrared device?

A) diffuser
B) emitter
C) detector
D) antenna

Question 20

Infrared light interferes with radio signals but is not affected by radio signals.

Question 21

MATCHING
a. ASCII
b. amplitude modulation
c. analog signal
d. baud rate
e. carrier signal
f. digital modulation
g. frequency modulation
h. hopping code
i. NRZ
j. PM
the sequence of changing frequencies used in FHSS

Question 22

Which binary signaling technique reduces the voltage to zero during the transmission of a 1 bit before the bit period ends.

A) NRZ-L
B) NRZ-I
C) RZ
D) NRZ

Question 23

MATCHING
a. ASCII
b. amplitude modulation
c. analog signal
d. baud rate
e. carrier signal
f. digital modulation
g. frequency modulation
h. hopping code
i. NRZ
j. PM
a technique that changes the height of a carrier wave in response to a change in the height of the input signal

Question 24

The _______________ non-return-to-zero encoding method represents a 1 bit by increasing voltage to a positive value and a 0 bit by decreasing the voltage to a negative value.

Question 25

MATCHING
a. ASCII
b. amplitude modulation
c. analog signal
d. baud rate
e. carrier signal
f. digital modulation
g. frequency modulation
h. hopping code
i. NRZ
j. PM
a method of encoding a digital signal onto an analog carrier wave for transmission over media that does not support direct digital signal transmission

Question 26

Which radio transmission method uses a chipping code?

A) FM
B) FHSS
C) DSSS
D) AM

Question 27

In the presence of background interference, receivers can detect a ____________ change more reliably than a frequency or amplitude change.

Question 28

MATCHING
a. ASCII
b. amplitude modulation
c. analog signal
d. baud rate
e. carrier signal
f. digital modulation
g. frequency modulation
h. hopping code
i. NRZ
j. PM
the number of times that a carrier signal changes per second

Question 29

MATCHING
a. ASCII
b. amplitude modulation
c. analog signal
d. baud rate
e. carrier signal
f. digital modulation
g. frequency modulation
h. hopping code
i. NRZ
j. PM
a technique that changes the starting point of a wave cycle in response to a change in the amplitude of the input signal

Question 30

Which binary modulation technique employs NRZ coding such that the absence of a carrier signal represents a 0 bit?

A) ASK
B) BPSK
C) FSK
D) PSK

Question 31

When representing a wave with a garden hose, the distance between the peaks of the waves represents the ____________.

Question 32

MATCHING
a. ASCII
b. amplitude modulation
c. analog signal
d. baud rate
e. carrier signal
f. digital modulation
g. frequency modulation
h. hopping code
i. NRZ
j. PM
a technique that changes the number of wave cycles in response to a change in the amplitude of the input signal

Question 33

A signal that is broadcast as a continuous wave is called a(n) _______________ signal.

Question 34

MATCHING
a. ASCII
b. amplitude modulation
c. analog signal
d. baud rate
e. carrier signal
f. digital modulation
g. frequency modulation
h. hopping code
i. NRZ
j. PM
a signal in which the intensity (amplitude or voltage) varies continuously and smoothly over a period of time

Question 35

Data signals in a wireless communication system travel on _______________ waves.

Question 36

MATCHING
a. ASCII
b. amplitude modulation
c. analog signal
d. baud rate
e. carrier signal
f. digital modulation
g. frequency modulation
h. hopping code
i. NRZ
j. PM
a coding scheme that uses the numbers from 0 to 127 to represent alphanumeric characters and symbols

Question 37

MATCHING
a. ASCII
b. amplitude modulation
c. analog signal
d. baud rate
e. carrier signal
f. digital modulation
g. frequency modulation
h. hopping code
i. NRZ
j. PM
a signal of a particular frequency that is modulated to contain either analog or digital data

Question 38

MATCHING
a. ASCII
b. amplitude modulation
c. analog signal
d. baud rate
e. carrier signal
f. digital modulation
g. frequency modulation
h. hopping code
i. NRZ
j. PM
a binary signaling technique that increases the voltage to represent a 1 bit but provides no voltage for a 0 bit

Question 39

Which of the following is a spread spectrum technique that employs mathematical algorithms to recover lost data bits?

A) frequency hopping
B) direct sequence
C) narrow band
D) wide band

Question 40

Which of the following is NOT an advantage of digital modulation over analog modulation?

A) better use of bandwidth
B) requires less power
C) better performance during interference
D) modulation techniques are simpler

Question 41

What are the advantages and limitations of an infrared wireless system?

Question 42

Describe the NRZ technique of representing bit signals.

Question 43

Describe the components in an infrared wireless system.

Question 44

What are the three types of modulation that can be applied to an analog signal to enable it to carry information?

Question 45

How are bits transmitted using DSSS? Include the chipping code in your answer.

Question 46

Contrast analog signals with digital signals.

Question 47

How are radio waves transmitted using an antenna?

Question 48

What is phase shift keying? Describe how it works.

Question 49

Describe how radio transmitters use a carrier signal.

Question 50

Describe amplitude modulation.