Which of the following is included in packet radio transmission?

• A. A header containing the call sign
• B. A check sum for error detection
• C. Automatic repeat request in case of error
• D. All these choices are correct

Answer: (D)

Packet radio transmission incorporates several key components that ensure effective communication over radio frequencies. One of the primary elements included is a header that contains the call sign. This portion of the packet identifies the sender and helps in directing the data to the appropriate recipient.

Additionally, packet radio includes a checksum for error detection. This mathematical calculation is performed on the data being transmitted to verify its integrity upon receipt, ensuring that what was sent is exactly what is received without any corruption.

Moreover, packet radio systems utilize an automatic repeat request (ARQ) mechanism in the event of errors. If the checksum indicates that data has been corrupted during transmission, the system can automatically request the sender to retransmit the erroneous data, thus improving reliability.

Given that packet radio incorporates the header with the call sign, the checksum for error detection, and the ARQ protocol for error correction, it is entirely accurate to state that all these components are included in packet radio transmission.