Abstract: Digital transmission system providing multipoint connections in which a main data transceiver can communicate with a plurality of secondary data transceivers and the secondary data transceivers can each, in turn, communicate with the main data transceiver, transmission occurring via component digital words at certain low rates multiplexed into intermediate rate incoming digital channels which are themselves multiplexed into a high rate incoming highway. The words are given a first partial address in the low to intermediate rate multiplexing step and a second partial address in the intermediate to high rate multiplexing step. A digital switching network is provided for selectively switching the component words from the high rate incoming highway to word positions in a high rate outgoing highway according to their first and second partial addresses. A multipoint unit is connected to the switching network by intermediate rate incoming and outgoing digital channels and the high rate highway.

Abstract: A time division digital switching network comprises first multiplexing means 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 multiples of one another undergo a first multiplexing converting them into a second-order digital data channels having a second predetermined rate. Thereafter there are provided second multiplexing means in which the second-order digital channels undergo a second multiplexing converting them into third-order digital data channels having a third predetermined rate. In a digital switching unit having at least one buffer store, the first-order-channel words multiplexed into the third-order channels are grouped at an address whose first part depends upon the second-order channel they occupy in the third-order channel and whose second part depends upon the first-order channel they occupy in the second-order channel.