Chapter 11 - Error Correction

Question 1

Briefly explain the difference between the two error control coding protocols - ARQ and FEC.

Answer 1

ARQ (Automatic Repeat reQuest): Detects errors and asks for retransmission if errors are found, needing two-way communication.

FEC (Forward Error Correction): Adds extra bits to correct errors on its own, suitable for one-way broadcasts where retransmission isn’t possible.

Question 2

briefly explain which technique overcomes burst errors in a broadcast system.

Answer 2

To overcome burst errors in a broadcast system, interleaving is used. I

nterleaving rearranges the data before transmission so that any burst errors are spread out over time when de-interleaved, making it easier for error correction codes to handle them effectively.

Question 3

Which error control code could be used on a broadcast system? Which code requires a duplex (two-way) link?

Answer 3

For a broadcast system, Forward Error Correction (FEC) codes are used.

For a duplex (two-way) link, Automatic Repeat reQuest (ARQ) codes are needed.