Question

Match the name of the technique with the algorithm. A. Even parity B. Odd parity C. Check digits D. Error-correcting codes E. Parity bit An extra bit is associated with each byte in the hardware that ensures that the number of 1 bits is odd or even across all bytes.

Short answer

The technique is 'E. Parity bit.'

Step-by-step solution

Understand the Problem

We need to match an algorithm to the description given: "An extra bit is associated with each byte in the hardware that ensures that the number of 1 bits is odd or even across all bytes." This is often used to detect errors in data transmission.

Identify Key Terms

The key terms in the description are "extra bit," "byte," and "number of 1 bits is odd or even." These terms hint at a parity system that uses an additional bit to ensure either odd or even counts of 1s.

Know the Definitions

1. **Even Parity**: Ensures the total number of 1s is even. 2. **Odd Parity**: Ensures the total number of 1s is odd. 3. **Check Digits**: Used in verifying the validity of numbers, such as account numbers. 4. **Error-Correcting Codes**: Techniques used to correct errors in data categories. 5. **Parity Bit**: An extra bit added to data to ensure even or odd parity.

Match the Description

Given the description, 'An extra bit is associated with each byte...' corresponds to the addition of a parity bit which makes the total count of 1s in the byte either odd or even. This is described as 'Parity Bit'.

Key concepts

Even Parity

The concept of even parity is often employed in digital communications to enhance the reliability of data transmission. At its core, even parity ensures that the total number of 1s in a set of data bits, typically a byte (8 bits), is even.
One additional bit, called the parity bit, is appended to the original data. If the count of 1s is odd, the parity bit is set to 1 so that the overall count becomes even. When the count of 1s is already even, the parity bit is set to 0.
This mechanism helps in detecting errors because if the data is received and the parity does not match the expected even count, it indicates that there might have been a transmission error. However, it is important to note that even parity only detects an odd number of errors; it cannot specify where the error occurred.

Odd Parity

Odd parity operates on a principle that is similar to even parity, but with a twist: it ensures that the total number of 1s in the group is odd.
Just like with even parity, an extra parity bit is added to the set of data. If the initial number of 1s is even, the parity bit is set to 1 to make the total number of 1s odd. If the count is already odd, the parity bit is set to 0.
The primary function of odd parity, as with even parity, is error detection. When data is transmitted and ends with an even total of 1s, it flags an error occurrence because it deviates from the expected odd count. Odder parity is simply another method in ensuring data integrity without actually correcting the detected errors.

Error Detection

Error detection is a critical aspect in data communication systems. It aims to identify when errors have occurred during the transmission of data.
Parity bits, both even and odd, are foundational error detection techniques. They provide a simple way to check whether data may have been altered during transmission by appending a single bit to the data.
While these methods are advantageous due to their simplicity and minimal additional data requirements, they have limitations in their abilities to detect only a single-bit error and not being able to precisely locate or correct the error. This is where more complex error detection and correction methods, such as error-correcting codes, come into play, though often at the expense of higher computational resources or additional data transmission overhead.
In more secure systems, combinations of different error detection and correction methods might be deployed to ensure higher reliability and accuracy of data transmission.