What is true of SITOR (NBDP) Mode B (FEC) regarding static crashes?

In SITOR (Selective Identified Transmission Over Radio) Mode B, also known as FEC (Forward Error Correction), the mechanism used enhances the reliability of data transmission, particularly in environments susceptible to static crashes and noise. This mode operates by encoding the data in such a way that each character is transmitted twice. By doing so, it allows the receiver to correct errors that may occur during transmission. If one of the transmitted characters is corrupted due to interference or other issues, the receiver can utilize the redundant second transmission to correct the error, thereby reducing the overall error rate.

This correction process is vital in maritime communications, where clear and accurate data transfer is critical for safety and operational efficiency. The technique is explicitly designed to cope with the intermittent and often unreliable nature of radio transmissions, which can lead to data loss. Therefore, the method of repeating each character effectively mitigates the impact of static crashes and makes the communication system more resilient.

The other options do not accurately reflect the fundamental characteristics of SITOR (NBDP) Mode B (FEC). The data flow rate does vary under different propagation conditions, but it is not a direct feature of the FEC mechanism itself. Idle character transmission and synchronization issues pertain to other operational aspects that are not