Define a data frame in a telemetry packet and its typical fields.

• A. A data frame is a structured unit of transmission containing a header (packet ID, source/destination, timestamp), payload (sensor data), and error-checking trailer (CRC/checksum).
• B. A data frame is simply a raw stream of bits with no structure.
• C. A data frame includes video frames and audio channels for telemetry.
• D. A data frame is the physical frame in the satellite.

Answer: (C)

A data frame in a telemetry packet is a structured unit that organizes the transmission into three parts: a header, a payload, and a trailer. The header carries control information such as a packet ID, source and destination addresses, and a timestamp, which lets the receiver identify, route, and time-align the data. The payload holds the actual sensor or telemetry data being reported. The trailer includes error-checking information like a CRC or checksum to detect any corruption, and may also carry a length or sequence number to help reassemble and verify the data. This structure provides reliable data integrity, clear boundaries, and easy parsing at the receiving end. The other options miss the central idea: a raw bit stream has no defined structure, a physical frame refers to hardware packaging rather than the data layout, and video frames or audio channels are multimedia streams not the typical telemetry payload.