Basic CS-Networks [TCS Placement]: Sample Questions 123 - 123 of 133

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Question 123

Networks
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Compare Error Detection and Error Correction:

Explanation

Compare Error Detection and Error Correction
Error DetectionError Correction
Checks only if any error has occurred. A single bit error is the same as a burst error.Finds exact number and location of corrupted bits. The number of the errors and size of message are important.
Depends on redundancy bits to detect errors and on ACKs and retransmissions to recover from the errors.Needs larger redundancy to detect and correct errors. Error correcting codes are often referred as forward error correction.
Verifies correctness of received information without any information on original message.Next step from error detection- the error is corrected by the error correcting codes.
Sender adds some redundant bits to the original message based on some property of message signal (i.e.. parity bits) and on the receiver side these bits are used to predict the error.In some cases it may ask the sender to resend the data.
Parity Checking,

Longitudinal Redundancy check (LRC) ,

Cyclic Redundancy Check (CRC) ,

Check Sum are commonly used error detection techniques

Hamming distance code is most common best error correction technique.

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