US3840709A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Busy outlet group control for switching system
Assignee: AT&T Inc
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Filing: 1973-06-25
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Granted: 1974-10-08
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Expires: 1993-06-25
Abstract
Abstract A common control crossbar telephone switching system is disclosed wherein originating markers attempt to effect connections toward switching destinations by searching for idle trunks among groups of trunks representing alternate switching routes toward those destinations. Provided in common to all markers is a trunk group busy circuit having four parts, each part having a separate timer and arranged to function with respect to one-fourth of the trunk groups being controlled by the group busy circuit. Any marker finding all trunks busy in a searched group causes an indication of that fact to be registered in the appropriate part of the trunk group busy circuit, such registration causing the associated timer to measure a prescribed interval of time (such as any desired interval from one to ten seconds). The busy trunk group registration is retained until the end of the measured time interval regardless of how long the actual all-trunks-busy condition exits; and, at the end of the measured time interval, the busy trunk group registration is released. Each marker is controlled by any busy trunk group registration for eliminating the indicated trunk group from its searching operation.
Inventors
- 👤 L Cerny
- 👤 H Rupprecht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:04
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0016
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
165 words
A switching system having a switching network; a plurality of groups of outlets terminating in the network, each group representing a switching route toward a switching destination; and, a plurality of control circuits, each control circuit effective, incident to registration therein of a signal designating a particular switching destination, to initiate a searching operation for an idle outlet in at least one group representing a switching route toward the particular switching destination; wherein the improvement comprises A. means controlled by any control circuit, upon the control circuit finding an all-outlets-busy condition in a searched group, for storing an indication of the busy condition of the searched group; B. means for erasing a stored group busy indication within a prescribed time interval independent of the time duration during which the actual group busy condition Exists; C. and, means in each control circuit controlled by any group busy indication stored in the storing means for eliminating the indicated group from the searching operation of the control circuit.
Claim 2
Dependent Claim
165 words
A switching system having a switching network; a plurality of groups of outlets terminating in the network, each group representing a switching route toward a switching destination; and, a plurality of control circuits, each control circuit effective, incident to registration therein of a signal designating a particular switching destination, to initiate a searching operation for an idle outlet in at least one group representing a switching route toward the particular switching destination; wherein the improvement comprises A. means controlled by any control circuit, upon the control circuit finding an all-outlets-busy condition in a searched group, for storing an indication of the busy condition of the searched group; B. means for erasing a stored group busy indication within a prescribed time interval independent of the time duration during which the actual group busy condition Exists; C. and, means in each control circuit controlled by any group busy indication stored in the storing means for eliminating the indicated group from the searching operation of the control circuit.
Claim 3
Dependent Claim
18 words
and means controlled by the ascertaining means for skipping the indicated group during the alternate route advance operation.
Claim 4
Dependent Claim
18 words
and means controlled by the ascertaining means for skipping the indicated group during the alternate route advance operation.
Claim 5
Dependent Claim
18 words
and means controlled by the ascertaining means for skipping the indicated group during the alternate route advance operation.
Claim 6
Dependent Claim
18 words
and means controlled by the ascertaining means for skipping the indicated group during the alternate route advance operation.
Claim 7
Dependent Claim
33 words
The invention defined in claim 1 wherein A. the storing means is common to all control circuits; B. the erasing means is included in the storing means; C. and, the eliminating means comprises
Claim 8
Dependent Claim
16 words
and means controlled by the ascertaining means for eliminating the indicated group from the searching operation.
Claim 9
Dependent Claim
16 words
and means controlled by the ascertaining means for eliminating the indicated group from the searching operation.
Claim 10
Dependent Claim
16 words
and means controlled by the ascertaining means for eliminating the indicated group from the searching operation.
Claim 11
Dependent Claim
16 words
and means controlled by the ascertaining means for eliminating the indicated group from the searching operation.
Claim 12
Dependent Claim
24 words
The invention defined in claim 2 wherein the ascertaining means is controlled by the storing means prior to the initiation of any searching operation.
Claim 13
Dependent Claim
63 words
The invention defined in claim 2 wherein A. the erasing means comprises a timer energizable to measure a prescribed time interval and to provide an erasing signal at the end of the said time interval; B. the timer is energized by the storing means upon the storing of a group busy indication; C. and, the erasing signal erases the stored group busy indication.
Claim 14
Dependent Claim
64 words
The invention defined in claim 1 wherein A. the storing means comprises a plurality of storage means common to all control circuits, each storage means being individual to a different plurality of groups of outlets; B. the erasing means comprises a plurality of erasure means, each erasure means being individual to and included in a different storage means; C. and, the eliminating means comprises
Claim 15
Dependent Claim
24 words
The invention defined in claim 5 wherein the ascertaining means is controlled by the storage means prior to the initiation of any searching operation.
Claim 16
Dependent Claim
75 words
The invention defined in claim 5 wherein A. each erasure means comprises a timer energizable to measure a prescribed time interval and to provide an erasure signal at the end of the said time interval; B. each timer is energized by the corresponding storage means upon the storing in the said corresponding storage means of a group busy indication; C. and, each erasure signal erases the group busy indication stored in the corresponding storage means.
Claim 17
Dependent Claim
207 words
A switching system having a switching network; a plurality of outlets terminating in the network, each group representing a switching route toward a switching destination; and, a plurality of control circuits, each control circuit effective, incident to registration therein of a signal designating a particular switching destination for which a plurality of groups of outlets represent an alternate switching route searching pattern, to initiate a searching operation for an idle outlet among the groups of the alternate route pattern in a fixed order of groups and to advance the searching operation from one group to the next group in the said fixed order upon finding an all-outlets-busy condition in the one group; wherein the improvement comprises A. means controlled by any control circuit, upon the control circuit finding an all-outlets-busy condition in a searched group, for storing an indication of the busy condition of the searched group; B. means for erasing a stored group busy indication within a prescribed time interval independent of the time duration during which the actual group busy condition exists; C. and, means in each control circuit controlled by any group busy indication stored in the storing means for skipping the indicated group during the alternate route advance operation of the control circuit.
Claim 18
Dependent Claim
207 words
A switching system having a switching network; a plurality of outlets terminating in the network, each group representing a switching route toward a switching destination; and, a plurality of control circuits, each control circuit effective, incident to registration therein of a signal designating a particular switching destination for which a plurality of groups of outlets represent an alternate switching route searching pattern, to initiate a searching operation for an idle outlet among the groups of the alternate route pattern in a fixed order of groups and to advance the searching operation from one group to the next group in the said fixed order upon finding an all-outlets-busy condition in the one group; wherein the improvement comprises A. means controlled by any control circuit, upon the control circuit finding an all-outlets-busy condition in a searched group, for storing an indication of the busy condition of the searched group; B. means for erasing a stored group busy indication within a prescribed time interval independent of the time duration during which the actual group busy condition exists; C. and, means in each control circuit controlled by any group busy indication stored in the storing means for skipping the indicated group during the alternate route advance operation of the control circuit.
Claim 19
Dependent Claim
33 words
The invention defined in claim 8 wherein A. the storing means is common to all control circuits; B. the erasing means is included in the storing means; C. and, The skipping means comprises
Claim 20
Dependent Claim
23 words
The invention defined in claim 9 wherein the ascertaining means is controlled by the storing means prior to initiation of any searching operation.
Claim 21
Dependent Claim
63 words
The invention defined in claim 9 wherein A. the erasing means comprises a timer energizable to measure a prescribed time interval and to provide an erasing signal at the end of the said time interval; B. the timer is energized by the storing means upon the storing of a group busy indication; C. and, the erasing signal erases the stored group busy indication.
Claim 22
Dependent Claim
64 words
The invention defined in claim 8 wherein A. the storing means comprises a plurality of storage means common to all control circuits, each storage means being individual to a different plurality of groups of outlets; B. the erasing means comprises a plurality of erasure means, each erasure means being individual to and included in a different storage means; C. and, the skipping means comprises
Claim 23
Dependent Claim
23 words
The invention defined in claim 12 wherein the ascertaining means is controlled by the storage means prior to initiation of any searching operation.
Claim 24
Dependent Claim
75 words
The invention defined in claim 12 wherein A. each erasure means comprises a timer energizable to measure a prescribed time interval and to provide an erasure signal at the end of the said time interval; B. each timer is energized by the corresponding storage means upon the storing in the said corresponding storage means of a group busy indication; C. and, each erasure signal erases the group busy indication stored in the corresponding storage means.
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) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |