Abstract: A multipoint communication digital transmission system in which the main data transceiver of each multipoint communication can communicate simultaneously with a plurality of secondary transceivers and they can each, in turn, communicate with the main data transceiver. First, second and third multiplexer means are provided, each at its own characteristic sampling rate. Selective switching is provided. Corresponding first, second and third multiplexing means are also provided.

Abstract: A digital switching unit is used in a multirate time-division multiplex digital switching network, in which first-order digital data channels transmitting words consisting of a given number of bits and having first rates which are different from, but multiple of, one another are given a first multiplexing converting them into the second-order digital data channels having a second predetermined rate. The switching unit comprises at least one buffer store in which the first-order channel words multiplexed into third-order channels are grouped at an address having first and second part, whose first part is the address of the second-order channel containing the first-order channel word in the third-order channel and whose second part is the address of the first-order channel in the second-order channel.