Abstract: For the preparation of data such as digitized television channel signals or television channel bundles, useful data are periodically replaced by a frame marker (F) in at least one of N parallel partial data streams of different bit significance. For this replacement, a partial data stream of low bit significance is selected because there the degradation is lowest. Because of this measure, the bit rate does not have to be increased in order to include a frame marker and a simple structure is possible for the multiplexer and demultiplexer at the respective transmission interfaces.

Abstract: In a circuit arrangement for establishing and terminating a connection in a subscriber communication system, the arrangement including a data transmission device arranged to be connected to an associated subscriber line of the system and including a data terminal, a line connection device fed by the terminal, an automatic dialing device, a current supply fed through the subscriber line and a control device for performing and monitoring the sequence of individual operating states of the data transmitting device, a memory unit is connected for storing a representation of at least one operating state of the data transmission device.