Abstract: An apparatus transmits digital signals between a higher-ranking station and one or more subordinate stations through transmission devices. A signal transit time is automatically measured in the transmission devices, differences in transit time are automatically compensated for and useful signals in the various subordinate stations are automatically synchronized with one another.

Abstract: A transmission system includes a central station, a counterpart station and at least two base stations connected to the central station through at least one interface. The base stations wirelessly exchange signals with at least one mobile terminal station. At least one Uko standard interface is expanded by a device for transmitting and delaying synchronizing signals, in such a way that a transmission of the at least one Uko interface that is synchronized with the other interfaces is attained.

Abstract: A signal transmission apparatus includes a higher-level station, a lower-level station and a digital transmission device connected between the stations and having a signal transit time to be measured. Each of the stations has a transmitter for sending useful signals, each clocked by a respective clock signal, through the transmission device to other station. Each of the stations has a receiver for receiving the useful signals clocked by the other station and for separating out the clock signal superimposed on the applicable useful signal. The useful signal to be transmitted in the higher-level station is clocked by a given clock signal. The useful signal to be transmitted in the lower-level station is clocked by a clock signal derived from the clock signal separated out from the receiver of the lower-level station.

Abstract: A digital message switching system includes at least one digital message switching unit and a plurality of subordinate units each being coupled to the respective switching unit through a respective transmission link. In order to signal a request of a subordinate unit to transmit, that unit first sends at least one message of meaningless content to a higher-ranking unit and only then sends messages of meaningful content.