ABSTRACT
In this chapter the authors examine the subject of errors, the origins and the means used to detect and correct these errors. They define several methods from simple parity to sophisticated error correction schemes and several methods from simple parity to sophisticated error correction schemes. Even though encryption is not an error detection nor correction function, it does use some of the same types of techniques and can make errors obvious. Some error correction is automatic, but usually the errors are corrected by retransmission. In order to get the machines to do the error detection for us, the people need to add some extra bits to the transmitted signal. Forward-acting error correction implementations add sufficient information to our data stream to allow the machine not only to detect errors, but also to correct the errors. The machines that have been programmed to correct certain errors by themselves eliminate the need for retransmission.
