Abstract: An exchange having a digital switching network and peripheral units connected thereto, the peripheral units serving to interface with subscribers, other exchanges, or maintenance devices or to perform other functions, and the switching network serving to establish arbitrary traffic relations between the units, particularly to establish switched connections between attached subscribers or exchanges, characterized in that at the interface to the peripheral units, the digital switching network is overdimensioned more than twofold. The switching network may advantageously be an ATM switching network, and the interface between the switching network and the peripheral units may have narrow-band and broadband inputs and outputs.

Abstract: A space and time switching element comprises a plurality of input circuits for one input line each, on which a plurality of input signals are receivable in a time-division-multiplex mode, a plurality of output circuits for one output line each, on which a plurality of output signals can be output in a time-division-multiplex mode, and memories for temporarily storing signals, wherein a part of the input circuits and output circuits is provided for narrow-band input and output signals, respectively, and another part of the input circuits and output circuits for broadband input and output signals, respectively, and that via the memories, each narrow-band input circuit is connectable to every broadband output circuit, and each broadband input circuit to every narrow-band output circuit. The narrow-band input and output signals may be synchronous time-division-multiplex signals, while the broadband input and output signals may be asynchronous time-division-multiplex signals.