High speed digital mobile facsimile with effective error protection

A digital mobile facsimile, which can be operated under current analog FM channels, has been developed. Efficient FEC (forward error correction) and ARQ (automatic repeat request) is employed so that the developed facsimile can transmit image signal with good quality under fading. FEC can be switched among three schemes, no error correction, Reed Solomon code (7,5,3), and Reed Solomon code (7,3,5). In order to recover from uncorrectable long burst errors, selective repeat ARQ is also employed. Extensive field test under Japanese MCA system proved that more than 90 percent of service area can be covered by the developed facsimile.