Transmission system and method for satellite relay short message data

A transmission system and method for satellite relay short message data belong to the technical field of satellite telemetering processing, the transmission system is composed of a comprehensive electronic unit and a relay measurement and control terminal, and the relay short message data can be downloaded through a telemetering channel without changing the existing telemetering frame framing method and transmission mode. The comprehensive electronic unit periodically performs acquisition, framing and transmission of telemetry data; when a short message data packet downloading demand exists, scheduling and management of a telemetering channel multiplexing time slot, collection and generation of a short message data packet, collection and framing of a channel multiplexing telemetering frame, processing of writing the short message data packet into the telemetering frame, safety protection processing of telemetering frame data, and transmission of the telemetering frame are carried out. And the relay measuremen