Claims
- 1. A switching network for selectively connecting any one of N.sub.2 output ports to any one of N.sub.1 input ports, wherein N.sub.1 and N.sub.2 are positive integers, comprising
- a plurality of first-stage crossbars collectively having a total of said N.sub.1 input ports and each crossbar having multiple outputs;
- a plurality of second-stage crossbars each having multiple inputs and multiple outputs;
- means connecting each output of each first-stage crossbar to one input of two second-stage crossbars;
- a plurality of third-stage crossbars each having multiple inputs and collectively having a total of said N.sub.2 output ports; and
- means connecting each second-stage crossbar to each third-stage crossbar.
- 2. The switching network of claim 1, wherein each crossbar is a n.multidot.m generalized connector of depth one consisting of n crossbar inputs, m crossbar outputs and a crosspoint connected between each crossbar input and crossbar output.
- 3. The switching network of claim 1, wherein more than one output port may selectively connect to the same input port.
- 4. The switching network of claim 2, further comprising control means for selectively rearranging the crosspoint connections in each of said first, second and third-stage crossbars in accord with a routing algorithm to satisfy all requests to connect any one of said N.sub.2 output ports to any one of said N.sub.1 input ports.
- 5. The switching network of claim 4, wherein for a particular selection of input port by an output port said routing algorithm
- attempts to route a signal path for that selection by first determining all switching patterns possible in the crosspoints of the second and third-stage crossbars to satisfy all selections of input ports made by all output ports without switching any crosspoint in said first-stage crossbars and then
- implements the switching pattern which results in the minimum number of switched crosspoints in the second and third-stage crossbars.
- 6. The switching network of claim 4 further comprising a routing algorithm wherein
- failing to determine any switching pattern in the crosspoints of the second and third-stage crossbars which satisfies all of said selections,
- the algorithm then determines an exchange of first-stage outputs which does satisfy all of said selections and
- implements the exchange in said first-stage outputs which results in the minimum number of switched crosspoints in all of said second and third-stage crossbars.
- 7. A switching network for selectively connecting any one of N.sub.2 output ports to any one of N.sub.1 input ports, wherein N.sub.1 and N.sub.2 are positive integers, comprising:
- a plurality of first-stage crossbars each having multiple inputs and multiple outputs;
- a plurality of second-stage crossbars each having multiple inputs and collectively having a total of said N.sub.2 output ports;
- a set of said N.sub.1 input ports;
- means connecting each of said N.sub.1 input ports of the set to one input in each of two first-stage crossbars;
- means connecting each first-stage crossbar to each second-stage crossbar.
- 8. The switching network of claim 7, further comprising control means for selectively rearranging the crosspoint connections in each second-stage crossbar in accord with a routing algorithm to satisfy all requests to connect any one of said N.sub.2 output ports to any one of said N.sub.1 input ports.
- 9. The switching network of claim 8, wherein each crossbar is a n.multidot.m generalized connector of depth one consisting of n crossbar inputs, m crossbar outputs and a crosspoint connected between each crossbar input and crossbar output.
- 10. The switching network of claim 8, wherein more than one output port may selectively connect to the same input port.
Parent Case Info
This application is a continuation of application Ser. No. 07/657,447, filed Feb. 19, 1991, now abandoned.
US Referenced Citations (6)
Continuations (1)
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Number |
Date |
Country |
Parent |
657447 |
Feb 1991 |
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