Error Detection and Correction

Question 1

EXPLAIN PARITY CHECK

Answer 1

A specific bit in a byte is the parity bit
-The sum of the bits in a byte is odd if odd parity is being used and vice versa
-When a byte is received its parity is checked
-If parity of byte has changed an error has occured

Question 2

ECHO CHECKING

Answer 2

-When data is received
-A copy is transmitted back to sender
-Where its compared with the original
-If it differs the original data is transmitted
-Automatic process

Question 3

CHECKSUM

Answer 3

-An algorithm is applied
-To a block
-To create a checksum
-Checksum becomes part of block
-When block is received the checksum is recalculated
-Using same algorithm
-If it differs an error has occured

Question 4

CYCLIC REDUNDANCY CHECK

Answer 4

-Special checksum
-Applied to block of data
-An algorithm or polynomial
-Is applied to block
-The recipient applies the same algorithm to the block and compares the results
-If they don’t agree, the data has not been received successfully