HF data message and facsimile terminal system

The data terminal (HF-Maxi terminal) is an outcome of the research and development done by CRC. The first generation of the HF message terminal developed by CRC (HF-Mini terminal) used a simple selective ARQ protocol for data transmission reference. Alternate techniques were investigated to improve the ARQ protocol for the second generation of a HF packet radio system by utilizing the soft decision information received in a block with errors in subsequent receptions to improve throughput of the system. The HF-Maxi terminal system was designed built and extensively tested over sky wave paths to prove the viability of transmitting large data files at high speeds through HF radio channels. The system has facilities to input text, data and facsimile images for transmission