Teleprinter subscriber communication system - uses digital link coupled to telephone sub-exchange system

摘要

A teletext communication facility linking teletypes by the transmission of coded digital data, employs the normal communication facilities of a telephone system. Teletext subscribers (A-N) are linked over sub-station links (NLA-NLN) to the substation (NA) over switching stages (TSA to TSN). The digital communication lines (DLI to DLN) are connected to standard subscriber circuits (TSA, TSN) in the substation. Transmission units (USI to USN) handle the coupling between the digital lines and the standard telephone system.