Digital TDM switching exchange wherein switching is effected by the read/write sequences of data stores

摘要

A central exchange comprising at its input end a change-over arrangement having a change-over switch for each input line and at its output end a change-over arrangement of an identical structure having a change-over switch for each output line, which are controlled in parallel. Each change-over switch sequentially supplies at its output the channels of a multiplex frame on the different input lines. For each input line a data store and a control store are assigned to the change-over switch at the input end, in a predetermined sequence for each instant, each data store storing the words of all channels of always one input line, but always a different frame. Consequently, all the data stores together contain the words of all the input lines from a number of consecutive frames equal to the number of input lines. The control stores have the same number of addresses as the data store and address these addresses in a similar way, but always shifted through one frame length from data store to data store. This provides a switching matrix in which no blocking occurs and which behaves as a single-stage switching matrix, so that the switching path is controlled without path search.