Signal propagation time reducing PCM TDM telephone exchanges - has delay line which reduces interval necessary for PCM word retransmission

摘要

Coders and decoders are allocated to individual speech channels or subscriber lines, which convert analogue speech signals into PCM words. They reconvert incoming PCM words into analogue speech signals. A transmitter clock signal (T1) cyclically appearing and determining the beginning of transmission of a PCM word is applied through a delay circuit (VZ) to a switch taking over the analogue form into a PCM word, so that only a signal propagation time reduced by the delay time replaces the interval between the taking over of the speech signal by the switch and following sending out of the corresponding PCM word.