Process for transmission of messages in time multiplex communication system

Claim 1

In a process for transmission of PCM message signals in a time multiplex system having a plurality of exchange stations connected together over at least two transmission paths which respectively carry signals in arriving and departing transmission directions, in which the pulse signals are transmitted in time slots of a pulse frame composed of a plurality of time slots, with the pulses of one time channel being equally spaced from each other in adjacent pulse frames wherein the pulse frame of all lines departing from each exchange station are synchronized with each other, the pulse frames of all lines arriving at each exchange station are synchronized with each other through insertion of delay lines in said arriving lines; wherein, upon establishment of a connection through an exchange station in a signal channel, with the channel arriving at an exchange station in one time channel, there is assigned the next free time channel to the signal for the line departing from the station; and wherein the same time channel within a pulse frame is used for transmission of a message in both transmission directions; the improvement comprising: so selecting said delay lines that the pulse frames of the lines departing from the exchange stations are time-spaced from the pulse frames of the lines arriving at the same exchange stations by a delay time determined in accordance with a desired mean total time interval between the assigned time channels, using in one transmission path in both transmission directions for transmission of message signals through each exchange station, two time channels which are spaced apart by a whole number multiple of said delay time, and using in the other transmission path for transmission of message signals, through each exchange station, two channels which are in time coincidence within a pulse frame.