Overhead

Approach type

Error method

One or more bits add to the character

ARQ

Parity bit

One bit per character plus LRC character

ARQ/FEC

LRC

Checksum character at end of message

ARQ

Checksum

CRC bytes at end of message

ARQ

CRC

Hamming bits inserted into data stream

ARQ/FEC

Hamming code

One bit per character plus signature character

ARQ/FEC

Signature