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 The number of 1 bits plus the parity bit is even.

Short answer

The technique is Even parity (A).

Step-by-step solution

Understand the Question

We need to identify which algorithm corresponds to the statement: "The number of 1 bits plus the parity bit is even." This means we are looking for an algorithm that ensures the total count of 1s (including the parity bit itself) results in an even number.

Match the Statement with the Technique

Read the given options: A. Even parity, B. Odd parity, C. Check digits, D. Error-correcting codes, E. Parity bit. The statement "The number of 1 bits plus the parity bit is even" directly describes the concept of ensuring evenness, which aligns with "A. Even parity." Even parity is a technique where the parity bit is set such that the total number of 1s, including the parity bit, is even.

Key concepts

Even Parity

Even parity is a method used in error detection to ensure that the total number of 1s in a binary sequence is even. It works by adding a parity bit at the end of a string of bits.

The role of this parity bit is to adjust the bit count to be even. For instance, if the number of 1s in the data is odd, the parity bit will be set to 1, making the total count even. Conversely, if the data already has an even number of 1s, the parity bit will remain 0.

• This method helps detect errors in data transmission.
• If data is received with an incorrect number of 1s, it indicates a transmission error.
• The receiver can then request a retransmission to correct the error.

Odd Parity

Odd parity is another error detection technique that is slightly different from even parity. As the name suggests, odd parity ensures that the total number of 1s in a string is odd, rather than even.

This parity scheme works similarly to even parity but with opposite goals. If a given set of data has an even number of 1s, the parity bit will be set to 1 to make the total odd. If the number of 1s is already odd, the parity bit remains at 0.

• Odd parity can also help detect errors during data transmission.
• If the received data string has an even number of 1s, an error is present.
• This allows us to detect, but not correct, errors just like with even parity.

Error-Correcting Codes

Error-correcting codes differ significantly from simple parity methods, as they not only detect but can also correct errors. These codes are based on more complex algorithms that include additional data redundancy beyond a single parity bit.

Error-correcting codes can identify where errors have occurred and often correct single-bit errors without needing a retransmission request.

• One common example is the Hamming code, which can detect up to two-bit errors and correct one-bit errors.
• These codes are vital in situations where data reliability is essential, like in hardware systems and digital communication.
• They involve sophisticated calculations to ensure that errors are identified and corrected efficiently.

Parity Bit

The parity bit is a simple error detection feature added to a data string to either maintain even or odd parity.

Its primary purpose is to catch transmission errors by checking whether the sum of 1s, including the parity bit, meets the intended parity condition.

• The parity bit can be set to either 0 or 1 based on the initial state of the data string.
• If the parity check fails at the receiving end, it indicates faulty transmission.
• This mechanism is straightforward and efficient for small data sets or systems where minor error protection is sufficient.