Switching network control arrangement

• US 4,229,624 A
• Filed: 12/21/1978
• Issued: 10/21/1980
• Est. Priority Date: 12/21/1978
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Inventors: Kepley, Garry D., Haben, Dale E., Vander Molen, Gordon L.
• Primary Examiner(s): Brown, Thomas W.
• Application Number:
  US05/972,073
• Time in Patent Office: 670 Days
• Field of Search: 179/6 C, 179/6 E, 179/27 FG, 179/27 FH, 179/18 E, 179/18 EA, 179/18 ES, 179/18 B, 179/18 BE
• US Class Current: 340/2.28
• CPC Class Codes: H04M 3/50 Centralised arrangements for answering calls; Centralised arrangements for recording messages for absent or busy subscribers H04M3/487 takes precedence; centralised dictation systems H04M11/10; Centralised arrangements for recording messages
• CPC Class Codes: H04Q 3/68 Grouping or interlacing selector groups or stages

Abstract

An arrangement tears down existing connection paths in a two stage switching network wherein switching paths are set up progressively by control circuits in both switching stages. A first-stage setup command is received by a first-stage control circuit and the second-stage control circuit of the previously established connection path. The first-stage control circuit responds to the first-stage setup command to set up a connection path through the first-stage switch and the second-stage control circuit responds to the first-stage setup command to tear down the previously established connection path.

Claims

1. A method of operating a multiple stage switching network wherein a first switching stage includes a control circuit which receives control signals from an input terminal and other switching stages include control circuits which receive control signals via switching connections established through preceding switching stages comprising:

(a) sending control signals to all control circuits associated with established switching connections;

CHARACTERIZED IN THAT

said method comprises the following additional steps;

(b) performing a first operation on said switching connections in said first switching stage in response to said control signals; and

(c) performing a second operation on said switching connections in at least one of said other switching stages in response to said control signals.

2. The method in accordance with claim 1 further characterized in that step (b) comprises setting up a connection path through the first switching stage, and step (c) comprises tearing down a connection path.

3. The method in accordance with claim 1 further characterized in that step (b) comprises setting up a connection path through the first switching stage and step (c) comprises tearing down connection paths through all remaining switching stages.

4. A switching network comprising an input terminal and a plurality of interconnecting switching stages wherein a first stage includes control means connected to said input terminal and each of the other stages includes control means connectible to said input terminal via switching connections previously established through a preceding switching stage;

CHARACTERIZED IN THAT

said control means of said first switching stage is responsive to defined control signals applied to said input terminal for performing a first operation on switching connections in said first switching stage and said control means of at least one of said other stages is responsive to said defined control signals applied to said input terminal for performing a second operation on switching connections in said one of said other switching stages.

5. The switching network in accordance with claim 4 characterized in that said control means of said first stage is responsive to said defined control signals to perform a connection path setup operation and said control means of said one of said other switching stages is responsive to said defined control signals to perform a connection path teardown operation.

6. The switching network in accordance with claim 4 further characterized in that said network comprises a second switching stage comprising a plurality of switching elements connected to said first stage, each of said switching elements having associated therewith a control unit for controlling said associated switching element wherein said associated control unit connected to said input terminal via said first stage is responsive to said defined control signals to tear down a connection in said associated switching element and wherein said control means of said first stage is responsive to said defined control signals to disconnect one of said switching elements from said input terminal and to connect another of said switching elements to said input terminal.

7. The switching network in accordance with claim 4 further characterized in that said plurality of interconnected switching stages comprises two switching stages, said first operation comprises the setting up of a connection path through the first switching stage of said network and said second operation comprises the tearing down of a connection path through the second stage of said network.