Interactive closed circuit TV allowing multiple use of lines - has branch network from central unit to subscriber unit having radial network.

: Schnee, R.; Kraus, F.; Kiel, F.

Abstract
DE 2807986 A UPAB: 19930901 The inter-communication t.v. system is layed out as a branch network from the central unit (1) down the local subscriber unit (3) and as as tar network from there to other subscribers (4). One cable (X) is common to all junctions (2) and the central unit (1) and transmits and receives narrow band data and audio channels and broad band t.v. channels in the i.f. range. Another cable (Y) is individual to each junction (2) and carries t.v. channels to the subscribers. Yet another cable (z) is connected to the multiplexer units in the junctions (2) and contains the subscriber frequencies for intercommunication.