Abstract: In a transit exchange which transfers data signals from incoming to outgoing TDM-links carrying data channels having more than one time slot per TDM-frame in accordance with the channels data rate, there is disclosed a method and apparatus for minimizing the transfer time of data through the exchange by providing a buffer memory with addressed locations which receive incoming data signals via a switch memory from the incoming links and feeds such data signals from the buffer memory to the outgoing links. The data signals in time slots of data channels are read into addressed locations of the buffer memory which are calculated by sequential additions to insure that a minimum time elapses before the data signals are read from the buffer memory.

Abstract: A method of and an apparatus is disclosed for economically addressing memory positions in a switch memory of a transit exchange for the transfer of synchronous data signals between incoming and outgoing TDM links comprising data channels of several data rates, each constituting a multiple of a basic rate derived from the number of time slots in a TDM frame. The data signals are stored in a switch memory having a memory position for each of the data channels in the incoming links and are then transferred to a buffer memory having a memory position for each time slot of the data channels in the outgoing links before they are sent out on these links. The memory writing as well as the reading occurring at a repetition rate determined by the data rate of the respective data channel.

Abstract: The present invention relates to a transit exchange for the transmission of asynchronous data signals having a given character structure and data rate, with the aid of a control equipment, including a computer and a sampling device, which is common to a number of sending terminal equipments and works on the time division multiplex principle. The instantaneous values of the data signals received over each of a number of incoming lines are sampled at a frequency so selected in relation to the asynchronous data rate that at least one sampling pulse falls within a distortionless region of the respective character element. The transit exchange includes a detector working synchronously with the sampling device to establish, by means of the successive processing of the sampling pulses, the binary value of each character element.

Abstract: The present invention relates to a transit exchange for the transmission of asynchronous data signals having an unknown character structure and data rate with the aid of a control equipment including a processor and a sampling device which is common to a number of sending terminal equipments and which works on the time multiplex principle. The data signals received on each of a number of incoming lines are sampled at a frequency so selected in relation to the data rate, expressed in unit elements per second, that the number of sampling pulses per unit element of the data signals is not less than the reciprocal value of the permitted relative time distortion.