Question 1

The ratio of data bits to total bits is called the code rate .

Accepted Answer

This statement is true. The code rate is defined as the ratio of the number of information bits (data bits) to the total number of bits transmitted, including redundancy bits for error detection and correction.

Question 2

Redundant bits are not used by the receiver for error detection.

Accepted Answer

Redundant bits are specifically added by the sender to the data being transmitted so that the receiver can use them for error detection.

Question 3

A ________ error can occur in the presence of white noise when a slight random deterioration of the signal to noise ratio is sufficient to confuse the receiver's decision of a single bit.

Accepted Answer

This statement describes a single-bit error, which occurs when a noise-induced deterioration of the signal to noise ratio causes a misinterpretation of a single bit. Burst errors occur when multiple bits are corrupted in a row, while idle errors occur when there is no data transmission. Digital errors are a vague category that could refer to any type of error in digital communication.

Question 4

Error detection found in data link control protocols such as HDLC is not a useful technique.

Accepted Answer

Error detection is a necessary technique in data link control protocols such as HDLC. It allows for the detection of errors during data transmission and enables the retransmission of data that may have been corrupted.

Question 5

Modulo 2 arithmetic uses binary addition with no carries,which is just the exclusive-OR (XOR)operation.

Accepted Answer

Modulo 2 arithmetic, also known as binary arithmetic, uses XOR as the addition operation. XOR is often used in computer systems to perform binary addition without carries. Therefore, the statement is true.

Question 6

Error correction works by adding sufficient redundancy to the transmitted message.

Accepted Answer

Error correction techniques add additional data to the transmitted message to detect and correct errors that may occur during transmission. This added redundancy helps in improving the accuracy and reliability of the data transmission.

Question 7

The simplest error detecting scheme is to append a parity bit to the end of a block of data.

Accepted Answer

This is true, appending a parity bit (which is a single bit that is set to either 0 or 1 based on the number of 1's in the data) is a simple form of error detection. If an error occurs during transmission and the parity bit is different from what it should be, the receiver can detect that the block of data has been corrupted.

Question 8

The Internet checksum is considerably less effective than the CRC.

Accepted Answer

The CRC (Cyclic Redundancy Check) is a more effective error detection method compared to the Internet checksum. The CRC can detect more errors and has a lower probability of false positives.

Question 9

In ________ transmission each block of data is formatted as a frame that includes a starting and an ending flag.

Accepted Answer

In synchronous transmission, each block of data is formatted as a frame that includes a starting and an ending flag to indicate the beginning and end of the frame. Asynchronous transmission uses variable-length frames with start and stop bits to indicate the start and end of each byte. Parallel transmission sends multiple bits at a time over multiple wires. Analog transmission sends continuous signals that vary in amplitude or frequency.

Question 10

The characteristics that distinguish various data link configurations are topology and whether the link is half duplex or full duplex.

Accepted Answer

Topology and duplexing are two key factors that differentiate data link configurations. Topology refers to the physical arrangement of devices and cables in a network, such as bus, ring, or star. Duplexing describes whether a connection allows for simultaneous two-way communication, known as full duplex, or only one-way communication at a time, known as half duplex.

Question 11

________ is one of the most fundamental requirements in the transmission of a stream of bits from one device to another.

Accepted Answer

Synchronization is necessary in order to ensure that the receiving device can accurately interpret the transmitted bits. Without synchronization, the receiving device may misinterpret the timing and sequence of the bits, leading to errors in the transmission. Standardization, digitalization, and configuration are important factors in data transmission, but they do not directly address the issue of synchronization.

Question 12

In a(n)________ there is a cluster of bits in which a number of errors occur,although not necessarily all of the bits in the cluster suffer an error.

Accepted Answer

An error burst is characterized by a cluster of bit errors that occur in close proximity to each other, while not necessarily affecting all bits within the cluster. This can be caused by external factors such as electromagnetic interference or transmission channel issues. The other options are not relevant to describing this type of error.

Question 13

CRC-32 is not used in IEEE 802 LAN standards.

Accepted Answer

CRC-32 is used in several IEEE 802 LAN standards, such as Ethernet (802.3) and Wi-Fi (802.11).

Question 14

Error correction is best used with wireless applications.

Accepted Answer

The answer of Error correction is best used with wireless...

Question 15

Burst errors can be caused by impulse noise.

Accepted Answer

Burst errors are caused by sudden and temporary interference on a communication channel, which can be caused by impulse noise.

Question 16

An error detection code simply detects the presence of an error. .

Accepted Answer

An error detection code is designed to detect whether an error has occurred during data transmission or storage. It is not intended to correct the error, but only to indicate its presence.

Question 17

The use of Manchester encoding is a form of synchronization.

Accepted Answer

Manchester encoding is a form of encoding that involves changing the polarity of the signal to indicate a binary value. This change in polarity helps synchronize the receiver with the transmitter, making it a form of synchronization.

Question 18

Single bit errors are more common and more difficult to deal with.

Accepted Answer

Single bit errors are more common but are easier to deal with through error detection and correction techniques like parity bits and error-correcting codes (ECC).

Question 19

Regardless of the design of the transmission system,there will be errors,resulting in the change of one or more bits in a transmitted block of data.

Accepted Answer

Transmission errors can occur in any transmission system, causing changes in one or more bits in the transmitted data block.

Question 20

In __________ transmission systems,an error occurs when a binary 1 is transmitted and a binary 0 is received,or a binary 0 is transmitted and a binary 1 is received.

Accepted Answer

This is a characteristic of digital transmission systems, where bits are represented by 0s and 1s. In contrast, analog systems transmit continuous signals that can vary in amplitude and frequency, and errors are typically caused by interference, distortion, or attenuation of the signal. Parallel transmission refers to the simultaneous transmission of multiple bits or signals, but it is not inherently prone to this type of error. Therefore, option B is the correct answer.

Quiz 6: Error Detection and Correction