Chapter 6

Question 1

………. which is also called thermal noise or Gaussian noise, is a relatively continuous type of noise and is much like the static you hear when a radio is being tuned between two stations.

Answer 1

White noise

Question 2

What is the interference that makes an analog or digital signal become fuzzy

Answer 2

White noise

Question 3

………… or noise spike, is a non-continuous noise and one of the most difficult errors to detect because it can occur randomly.

Answer 3

Impulse noise

Question 4

Typically, this noise is an analog burst of energy.

Answer 4

impulse noise

Question 5

……… is an unwanted coupling between two different signal paths.

Answer 5

Crosstalk

Question 6

……….. is the reflective feedback of a transmitted signal as the signal moves
through a medium.

Answer 6

Echo

Question 7

……….. is the result of small timing irregularities that become magnified during the transmission of digital signals as the signals are passed from one device to another.

Answer 7

Jitter

Question 8

……….. is the continuous loss of a signal’s strength as it travels through a
medium.

Answer 8

Attenuation

Question 9

attenuation can be eliminated with the use of …….. for analog systems or repeaters for digital systems.

Answer 9

amplifiers

Question 10

What is the easiest error-detection method to incorporate into a transmission system. It comes in two basic forms: even parity and odd parity?

Answer 10

Simple parity (aka redundancy check)

Question 11

The most basic error-detection techniques are ………., which are commonly used with asynchronous connections.

Answer 11

parity checks

Question 12

With ……. parity, the 0 or 1 added to the string produces an even number of binary 1s.

Answer 12

even

Question 13

With ……… parity, the 0 or 1 added to the string produces an odd number of binary 1s.

Answer 13

odd

Question 14

………….. tries to solve the main weakness of simple parity—that all even numbers of errors are not detected.

Answer 14

Longitudinal parity
(aka longitudinal redundancy check or
horizontal parity)

Question 15

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

Answer 15

cyclic redundancy checksum (CRC),
or cyclic checksum

Question 16

A ……….. is an industry-approved bit string used to create the cyclic checksum remainder.

Answer 16

generating polynomial

Question 17

The action that the receiver takes is called what?

Answer 17

error control

Question 18

What three actions could you take when doing error control?

Answer 18

• Toss the frame/packet.
• Return a message to the transmitter asking it to resend the data packet that
  was in error.

-Correct the error without retransmission.

Question 19

What is a technique usually associated with the stop-and-wait flow control protocol?

Answer 19

Stop-and-wait error control

Question 20

What protocol and its error-control technique are the oldest, simplest, and thus most restrictive?

Answer 20

Stop-and-wait error control

Question 21

a flow control scheme that allows a station to transmit a number of data packets at one time before receiving some form of acknowledgmen is called what.

Answer 21

Sliding window error control

Question 22

A ……….. is a specially designed code in which special check bits have
been added to data bits such that, if an error occurs during transmission, the receiver might be able to correct the error using the included check and data bits.

Answer 22

Hamming code