Switching of digital signals
AssigneeThe Post Office
InventorJohn H. M. Hardy
Life of this patent
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Abstract
A digital switching device of the stored program type operating under the control of a central control unit has a multiplexing stage for multiplexing signals from a plurality of ports, an input time switching stage which receives multiplexed signals from the multiplexing stage and outputs them in appropriate time slots, an interface unit connecting the input time switching stage to an output time switching stage and a demultiplexing stage which demultiplexes signals from the output time switching stage for transmission to said ports. The interface unit is an interchangeable unit which either provides a direct connection between the input and output time switching stages or comprises a space switching stage.
Claims6
A digital switching device for switching digital signals between plural input/output ports under the control of a central control unit, said switching device comprising:
- multiplexing means for multiplexing signals from a plurality of said ports,
- an input time switching stage means arranged to receive multiplexed signals from the multiplexing means and to output said signals in appropriate time slots under the control of the central control unit,
- an interface unit means for connecting the input time switching stage means to an output time switching stage, and
- demultiplexing means connected for demultiplexing signals passed through said interface unit means for transmission to said ports,
- said interface unit means being a unit which comprises a space switching stage,
- said input and output time switching stage means each including connection store means and said space switching stage means including comparing means arranged to compare the contents of said connection store means, the operation of the space switching stage being determined by said comparison.
Dependencies are inferred from the claim text.