Networking Chapter 10

Question 1

Which of the following best describes a single-bit error?

A) A single bit is inverted
B) A single bit per transmission is inverted
C) A single bit per data unit is inverted
D) All of the choices are correct

Answer 1

C) A single bit per data unit is inverted

Question 2

Which error detection method uses one’s complement arithmetic?

A) Simple parity check
B) Checksum
C) Two-dimensional parity check
D) CRC

Answer 2

B) Checksum

Question 3

Which error detection method consists of just one redundant bit per data unit?

A) Two-dimensional parity check
B) CRC
C) Simple parity check
D) Checksum

Answer 3

C) Simple parity check

Question 4

Which error detection method involves polynomials?

A) CRC
B) Simple parity check
C) Two-dimensional parity check
D) Checksum

Answer 4

A) CRC

Question 5

In cyclic redundancy checking, what forms the check bits?
A) The remainder
B) The divisor
C) The quotient
D) The dividend

Answer 5

A) The remainder

Question 6

In CRC, if the dataword is 111111, the divisor 1010, and the remainder 110, what is the codeword at the receiver?
A) 111111011
B) 1010110
C) 111111110
D) 110111111

Answer 6

C) 111111110

Question 7

At the CRC generator, _______ is (are) added to the dataword after the division process to create the codeword.
A) 0’s
B) 1’s
C) the remainder
D) the divisor

Answer 7

C) the remainder

Question 8

The sum of the checksum and data at the receiver is _______ if no error is detected.
A) − 0
B) + 0
C) the complement of the checksum
D) the complement of the dataword

Answer 8

A) − 0

Question 9

In CRC, the quotient at the sender _______.
A) becomes the dividend at the receiver
B) becomes the divisor at the receiver
C) is the remainder
D) is discarded

Answer 9

D) is discarded

Question 10

At the CRC checker, _______ means that the dataword is damaged.
A) a string of alternating 1s and 0s
B) a nonzero remainder
C) a string of 0s
D) None of the choices are correct

Answer 10

B) a nonzero remainder

Question 11

A codeword of 10 bits has only four 0s, how many terms are in the polynomial representation of this code?
A) 4
B) 6
C) 8
D) None of the choices are correct

Answer 11

B) 6

Question 12

In CRC, if the remainder is only three bits, the divisor should be __________ bits.
A) 3
B) 2
C) 4
D) None of the choices are correct

Answer 12

C) 4

Question 13

How many bits are in the divisor if we use CRC-8?
A) 9
B) 8
C) 10
D) None of the choices are correct

Answer 13

A) 9

Question 14

Checksum uses ____________ addition.
A) one’s complement
B) two’s complement
C) three’s complement
D) None of the choices are correct

Answer 14

A) one’s complement

Question 15

To detect five errors, the Hamming distance between each pair of codewords should be at least_________.
A) 5
B) 6
C) 11
D) None of the choices are correct

Answer 15

B) 6

Question 16

To correct five errors, the Hamming distance between each pair of codewords should be at least_________.
A) 5
B) 6
C) 11
D) None of the choices are correct

Answer 16

C) 11

Question 17

A checksum can _________ errors.
A) only detect
B) only correct
C) both detect and correct
D) None of the choices are correct

Answer 17

C) both detect and correct