What is the primary function of FEC in communication systems?

The primary function of Forward Error Correction (FEC) in communication systems is to provide error correction in data transmission. FEC is a technique used to detect and correct errors that may occur during the transmission of data over a communication channel. By adding redundant information to the transmitted data, FEC allows the receiving system to identify errors and correct them without needing a retransmission. This is especially important in communication systems where retransmissions may be difficult or impossible, such as in satellite communication or real-time applications.

In contrast, enhancing voice clarity focuses on improving audio quality during communication, which is not the role of FEC. Increasing data transmission rates relates to bandwidth and modulation techniques, rather than error correction. Establishing a backup communication line involves strategies for redundancy but does not pertain to the specific function of FEC in improving the reliability of data transmission. Therefore, the correct answer highlights the critical role of FEC in maintaining data integrity and enhancing the reliability of communication systems.