公开(公告)号：US3581018A

公开(公告)日：1971-05-25

申请号：US3581018D

申请日：1969-06-12

Applicant: INT STANDARD ELECTRIC CORP

Inventor： HARLAND GEOFFREY ,  RONAYNE JOHN P

IPC: H04Q3/54 ,  H04Q3/00

CPC classification number: H04Q3/54

Abstract: A telecommunications exchange in which connections are set up through cascaded stages (designated A, B, C & D) of coordinate switching matrices. Certain of the stages are paired in two-stage networks, and a number of these networks (four are disclosed) are used. The intermediate stages (B and C) of a four stage exchange are paired, and certain of the B stage switches handle only calls to and from lines, and others handle only calls to and from junctions. The third or C stage mixes calls involved in traffic of either type. The switches of the final or D stage are used only between one side of the links and the switches of the C stage.