US3613089A
Expired / Lapsed
US
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Associative memory control for a switching network
Assignee: AT&T Inc
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Filing: 1969-10-28
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Granted: 1971-10-12
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Expires: 1989-10-28
Abstract
Abstract A communication system is disclosed in which paths through a multistage switching network are located by reference to information stored in associative memory. Specific methods control the acquisition of the stored information for establishment and termination of the network paths.
Inventors
- 👤 Stephen S Karp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:12
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42; H04Q3/54; H04Q3/545
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
225 words
In a communication switching system having a multistage switching network and a central processor including an associative memory, said network including input and output subnetworks interconnected by junctors and switches interconnected by links, and said associative memory including first tables organized to indicate the condition of said junctors and certain of said links and second tables organized to indicate the condition of subnetwork terminals and other of said links, the method of establishing a path through said network comprising the steps of a. obtaining the identities of all possible junctors for the path between a particular input and a particular output subnetwork and storing a list of such identities; b. from a first associative memory table determining the busy/idle states of these junctors in one subnetwork; c. from the subnetwork terminal identification for one subnetwork determining the busy/idle state of links in said first table; d. from the junctor identities determining the busy/idle state of links in the second table for said one subnetwork; e. removing from the list of stored junctor identities those junctors for which links are busy; f. performing steps (a) through (e) for the other subnetwork; g. matching the two stOred lists of idle junctors to determine a possible path through the network; and h. based on one of these matches establishing the path through the identified idle links and junctor.
Claim 2
Dependent Claim
225 words
In a communication switching system having a multistage switching network and a central processor including an associative memory, said network including input and output subnetworks interconnected by junctors and switches interconnected by links, and said associative memory including first tables organized to indicate the condition of said junctors and certain of said links and second tables organized to indicate the condition of subnetwork terminals and other of said links, the method of establishing a path through said network comprising the steps of a. obtaining the identities of all possible junctors for the path between a particular input and a particular output subnetwork and storing a list of such identities; b. from a first associative memory table determining the busy/idle states of these junctors in one subnetwork; c. from the subnetwork terminal identification for one subnetwork determining the busy/idle state of links in said first table; d. from the junctor identities determining the busy/idle state of links in the second table for said one subnetwork; e. removing from the list of stored junctor identities those junctors for which links are busy; f. performing steps (a) through (e) for the other subnetwork; g. matching the two stOred lists of idle junctors to determine a possible path through the network; and h. based on one of these matches establishing the path through the identified idle links and junctor.
Claim 3
Dependent Claim
211 words
In a communication system comprising a multistage switching network having a plurality of terminals, a plurality of subnetworks each serving a distinct group of said terminals, a plurality of junctor links for interconnecting said subnetworks, each of said subnetworks comprising concentration, intermediate and distribution links for interconnecting said terminals and said junctor links and a network control comprising an associative memory having first tables organized to indicate the condition of said junctor links and second tables organized to indicate the condition of said terminals, the method of determining a path through said network from an input one of said terminals to an output one of said terminals comprising the steps of associatively searching a first table to locate all of the idle distribution links serving said input terminal and each of the idle junctor links, associatively searching a second table to locate the idle combined concentration and intermediate links serving said input terminal, associatively searching the first and second tables to locate idle links serving said output terminal, selecting an idle path from said located idle concentration, intermediate, distribution and junctor links between said input and output terminals, marking the links in the selected path as busy in the first and second tables, and completing the connection via said selected path.
Claim 4
Dependent Claim
211 words
In a communication system comprising a multistage switching network having a plurality of terminals, a plurality of subnetworks each serving a distinct group of said terminals, a plurality of junctor links for interconnecting said subnetworks, each of said subnetworks comprising concentration, intermediate and distribution links for interconnecting said terminals and said junctor links and a network control comprising an associative memory having first tables organized to indicate the condition of said junctor links and second tables organized to indicate the condition of said terminals, the method of determining a path through said network from an input one of said terminals to an output one of said terminals comprising the steps of associatively searching a first table to locate all of the idle distribution links serving said input terminal and each of the idle junctor links, associatively searching a second table to locate the idle combined concentration and intermediate links serving said input terminal, associatively searching the first and second tables to locate idle links serving said output terminal, selecting an idle path from said located idle concentration, intermediate, distribution and junctor links between said input and output terminals, marking the links in the selected path as busy in the first and second tables, and completing the connection via said selected path.
Claim 5
Dependent Claim
121 words
In a communication switching system having a multistage switching network including network terminals, links, and junctors, and control means including associative memory means having at least a first table identifying junctor busy/idle states and a second table identifying terminal busy/idle states, the method of establishing a path through the network comprising the steps of determining the junctors existing between a selected input and output subnetwork of the network, from the first table determining the busy/idle status of the junctors, from the second table determining the busy/idle status of the terminal, and associatively determining from each table by a search based on information from the other table the busy/idle status of various of the links available between the junctors and the terminal.
Claim 6
Dependent Claim
121 words
In a communication switching system having a multistage switching network including network terminals, links, and junctors, and control means including associative memory means having at least a first table identifying junctor busy/idle states and a second table identifying terminal busy/idle states, the method of establishing a path through the network comprising the steps of determining the junctors existing between a selected input and output subnetwork of the network, from the first table determining the busy/idle status of the junctors, from the second table determining the busy/idle status of the terminal, and associatively determining from each table by a search based on information from the other table the busy/idle status of various of the links available between the junctors and the terminal.
Claim 7
Dependent Claim
55 words
In a communication switching system, the method in accordance with claim 3 further comprising storing a list of the identity of the junctors determined to exist between a selected input and output terminal and reducing that list as various junctors are determined to be unusable because of the busy status of various of the links.
Claim 8
Dependent Claim
41 words
In a communication switching system, the method in accordance with claim 4 wherein the availability of junctors is determined independently for an input and an output subnetwork and further comprising the step of matching the input and output subnetwork junctor lists.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |