Patent US 4,048,447

A PCM-TASI signal transmission system utilizes assignment control means responsive to an output signal from means for detecting the presence of information on each of a plurality (m) of input trunks arranged in time-serial fashion. The assignment control means selectively assigns a PCM signal representing the input trunk signal, during the period when information is present thereon, to one of a second plurality (s) of transmission channels (s<m). The assignment control means includes means for generating and transmitting signals representing the selected assignments state of the input trunks. The assignment control means includes improvements comprising a first memory for storing the number of each input trunk to which a transmission channel must be newly assigned; a second memory for storing data identifying each transmission channel ready to accept a new assignment to an input trunk; a third memory for storing the designation of a newly assigned input trunk and its transmission channel; a fourth memory, in the assignment state signal generation means, partially renewing its memory content according to the contents of the third memory; means responsive to the contents of the first through fourth memories for deciding each assignment and for renewing the contents of the memories after each new assignment decision; means for varying the sequence of output signal transmission from the information detector means to the assignment control means for at least every superframe; and means for varying the sequence of reading the second memory for at least every superframe.