GB1460698A - Time division switch - Google Patents

Abstract

1460698 Automatic exchange systems; multiplexing INTERNATIONAL STANDARD ELECTRIC CORP 18 March 1975 [22 March 1974] 11168/75 Headings H4K and H4M In a TDM system wherein information is switched between a pair of parallel super highways mpe, mps using a store MC for each time slot on the incoming super highway mpe, means M, DM are provided for multiplexing and demultiplexing a plurality of serial bit highways mse1-mse8, mss1-mss8 onto and off the superhighways and for simultaneously performing a serial to parallel or parallel to serial conversion. Fig. 2 shows the multiplexer/serial to paralle converter M for multiplexing eight, eight bit per channel 32 channel serial highways mse1-mse8 on to a single 256 channel, eight bit per channel parallel superhighway mpe. The arrangement comprises an 8 x 8 switching matrix MCE and a plurality of delay buffers cd each applying a delay of one bit length. By inserting a delay of x-1 bit lengths into the xth incoming highway msex, and a delay of 8-x bit lengths into the wire of the xth bit position of superhighway mpe, the eight input wires msed1-msed8 can be simultaneously switched to corresponding ones of the output wires mped1-mped8 during the length of each bit position, so as to provide the 256 channel parallel superhighway, thetotal delay for each bit through the multiplexer being one time slot of the incoming 32 slot highways. Figs. 3-6 (not shown) illustrate the above operation for the transfer of one time slot of an incoming highway. The demultiplexer DM uses the above arrangement in reverse. It is said that both the multiplexer and demultiplexer can be realised using a plurality of the shift switching matrices disclosed in Specification 1,415,919. The time switch MC for switching between super highways comprises a 256 position store into which the information on the incoming superhighway is written sequentially, the information being read out under the control of a connection store MTS in the appropriate time slots of the outgoing superhighway, to provide a non-blocking switch.