An information transmission system and more precisely a telephone system

摘要

The present invention relates to a system for transmitting information from a central station such as an automatic exchange (1) to a peripheral station such as a subscriber's terminal (4). The central station (1) is connected to a bi-directional analog-digital converter (7) on the exchange side through a central bi-directional analog-digital converter (5) and an analog transmission line (11). The bi-directional analog-digital converter (7) on the exchange side has its corresponding output or input connected to a bi-directional analog-digital converter (8) on the peripheral side via a digital transmission line and interfaces associated to the line terminals. The bi-directional analog-digital converter (8) is connected on the output or input side to the peripheral station via another analog transmission line (30). The characteristic curve of the bi-directional analog-digital converter (7) on the exchange side and that of the bi-directional analog-digital converter (8) on the peripheral side are linear. The transmission line consists in a high-speed transmission line (12, 21, 31).