Folded space-time-space switching network

Claim 2

A folded space-time-space switching network for a PCM switching exchange, comprising a space division switch including horizontals and verticals arranged to enable their interconnection through crosspoint switch means, means coupling each horizontal to X supermultiplexers, said supermultiplexers including means whereby each of a plurality of telephone lines can be coupled to an inlet terminal and to an outlet terminal of said space division switch to enable the exchange of PCM signals between the horizontals and selected telephone lines, and means coupling each vertical to X time division switches, said time division switches including means enabling the exchange of PCM signals between the verticals and the time division switches, the operating frequency of the space-division switch being selected to be at least X times that of the supermultiplexers and the time division switches, whereby the volume of the space division switch is minimal, as is the total volume of the combination of the space division switch and the time division switches.

Claim 3

The invention as claimed in claim 1, in which the means enabling the exchange of PCM signals between the verticals and the time division switches include means for providing time shifts to the PCM signals received from the verticals.

Claim 4

The invention as claimed in claim 2, in which the means for providing time shifts to the PCM signals include speech input memories for storing PCM signals received from the verticals, and speech memory output registers for transmitting PCM signals to the verticals following prescribed time periods.

Claim 5

A switching network for a time-division switching exchange for switching PCM signals, the said exchange comprising switching means for switching samples to and from K supermultiplexers, each supermultiplexer including a speech signal memory having at least P.R cells designed to store in each cell a time-division channel sample, said switching means connecting the K supermultiplexers to horizontals of a space-division switch, means connecting verticals of the space-division switch to time-division switches which provide a time shift for samples from the supermultiplexers with the purpose of exchanging them, the said time-division switches including at least P.R/2 cells, each cell being designed to store a time-division channel sample, said time division switches forming with the space-division switch a folded "space-time-space" switching network, and said space-division switch having an operating frequency which is a multiple X times as great as that of the supermultiplexers and of the time-division switches to enable minimization of the size of the space division switches and therefore the total size of the combination of the space division switch and the time division switches.

Claim 6

A switching network for a time-division switching exchange for switching PCM signals, the said exchange comprising switching means for switching samples to and from K supermultiplexers, each supermultiplexer including a speech signal memory having at least P.R cells designed to store in each cell a time-division channel sample, said switching means connecting the K supermultiplexers to horizontals of a space-division switch, means connecting verticals of the space-division switch to time-division switches which provide a time shift for samples from the supermultiplexers with the purpose of exchanging them, the said time-division switches including at least P.R/2 cells, each cell being designed to store a time-division channel sample, said time division switches forming with the space-division switch a folded "space-time-space" switching network, and said space-division switch having an operating frequency which is a multiple X times as great as that of the supermultiplexers and of the time-division switches to enable minimization of the size of the space division switches and therefore the total size of the combination of the space division switch and the time division switches.