Telecommunication switching network having a multistage reversed trunking scheme

摘要

The switching network having a reversed trunking scheme of a PCM-(pulse code modulated -) exchange is formed by a first (time division) switching stage (A) consisting of individual switching groups (G l to G m) combined into one major switching group (GG), a second (space division) switching Stage (B1) formed by a number of PCM-lines equal to the number of switching groups (G l to G m) within one major switching group (GG), whereby each switching group is connected with a PCM-line in the outgoing direction, whereas a switching group individual multiplexer (M) performing the access of all PCM-lines to each switching group (G) and a third (space division) switching stage (B2) formed by a number of PCM-lines equal to the number of major switching groups (GG), the bitrate on said PCM-lines being a multiple number of the bitrate of the PCM-lines of the second (space division) switching stage. In the third switching stage (B2) all major switching groups have access to all PCM-lines of the second switching stage (B1) in the incoming direction, whereas in the outgoing direction acess is provided to the individual switching groups of the first switching stage (A). For adaptation of the faster third switching stage (B2) to the slower stages (A and B1) each major switching group (GG) is equipped with the necessary bitrate converters.