TELECOMMUNICATION SYSTEM FOR PROTECTED TRANSLATION OF DIGITAL SIGNALS BY MEANS OF A PASSIVE OPTICAL BUS NETWORK

摘要

In a telecommunication system in which subscriber stations are connected via optical waveguide connection lines (LWLA), one or more optical branching devices (VZ) and optical waveguide subscriber connection lines (LWLTA) to an exchange (VSt), where one or more subscribers can be connected to an optical branching device (VZ), the digital signals destined for one subscriber are protected against unauthorised access by providing a scrambling circuit (CS) in each of the subscriber stations (TSt) which, when a connection is set up from the exchange (VSt), initiates a coding key which passes via directional branching elements (FMR) to the exchange (VSt), whereupon the digital signals to be transmitted from the exchange (VSt) are encrypted with the subscriber-specific coding key and transmitted via the optical waveguide connection line (LWLA), the (directional) branching elements (FOR) and the optical waveguide subscriber connection lines (LWLTA) to the subscriber stations (TStn).