Which is the code used for SITOR-A and -B transmissions?

Which is the code used for SITOR-A and -B transmissions?

• A. Each character consists of 6 bits with 2 "zeros" and 4 "ones".
• B. Each character consists of 7 bits with 4 "zeros" and 3 "ones".
• C. Each character consists of 8 bits with 3 "zeros" and 5 "ones".
• D. Each character consists of 5 bits, all "ones".

Answer: (B)

The correct answer describes the character structure used for SITOR-A and SITOR-B transmissions, which are part of the SITOR (Simplex Telex Over Radio) system. In this system, each character is indeed encoded using 7 bits, with a binary composition of 4 zeros and 3 ones. This 7-bit encoding is consistent with a modified version of ASCII used in radio communications, allowing for efficient transmission of alphanumeric data in a compact format suitable for radio telex operations. The choice of 7 bits, particularly with a balance of zeros and ones, is critical for ensuring integrity in data transmission and minimizing the risk of errors. It allows enough combinations to represent the necessary characters while maintaining a level of redundancy that helps in error detection. The other options do not accurately reflect the bit structure of SITOR transmissions. For instance, 6 bits would limit the character set and make it impractical for the required transmissions, while 8 bits introduces unnecessary complexity for the SITOR system's needs. Lastly, having 5 bits with all "ones" would not fit the character encoding requirements, as it would not provide the necessary variability to represent different data effectively.

The correct answer describes the character structure used for SITOR-A and SITOR-B transmissions, which are part of the SITOR (Simplex Telex Over Radio) system. In this system, each character is indeed encoded using 7 bits, with a binary composition of 4 zeros and 3 ones. This 7-bit encoding is consistent with a modified version of ASCII used in radio communications, allowing for efficient transmission of alphanumeric data in a compact format suitable for radio telex operations.

The choice of 7 bits, particularly with a balance of zeros and ones, is critical for ensuring integrity in data transmission and minimizing the risk of errors. It allows enough combinations to represent the necessary characters while maintaining a level of redundancy that helps in error detection.

The other options do not accurately reflect the bit structure of SITOR transmissions. For instance, 6 bits would limit the character set and make it impractical for the required transmissions, while 8 bits introduces unnecessary complexity for the SITOR system's needs. Lastly, having 5 bits with all "ones" would not fit the character encoding requirements, as it would not provide the necessary variability to represent different data effectively.