What unique transmission characteristic does FEC rely on in SITOR communications?

FEC, or Forward Error Correction, is a technique used in SITOR (Simplex Telex over Radio) communications that enables the correction of errors in the received data without the need for retransmission. This characteristic is crucial in ensuring reliable communication over potentially error-prone channels, such as radio waves.

The reliance on parity checks as part of FEC is significant because it allows the system to identify and correct certain types of errors that may occur during transmission. Parity checks can help to determine whether a character has been received correctly, thereby enabling the system to make corrections when necessary. This capability enhances the overall reliability of communication in environments where retransmission may not be feasible or would introduce unacceptable delays.

In contrast, transmitting each character once does not provide any redundancy, making it impossible to detect or correct errors. Handshaking protocols are primarily aimed at establishing a connection and ensuring messages are delivered rather than correcting errors in the data itself. Although transmitting duplicate characters can provide a form of error resilience, it is not the specific mechanism employed by FEC in this context, which focuses on using parity for error identification and correction.