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US3812294A
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Bilateral time division multiplex switching system
Assignee: AT&T Inc
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Filing: 1972-12-22
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Granted: 1974-05-21
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Expires: 1992-12-22
Abstract
Abstract A switching network comprising arrays of bilateral crosspoint stores is combined with a plurality of bilateral time slot interchangers connected in links between switching stages to form a complete switching system. The two connections required for a two-way communication are established through bilateral crosspoint stores and a bilateral time slot interchanger which are common to both connections, thereby eliminating hardware redundancy. The system is controlled by information stored in local control memories and associated auxiliary control memories. Call setup and release is implemented by means of pulse stuffing and pulse absorbing at registers in the crosspoint stores and time slot interchangers, and proceeds at all stages simultaneously instead of by propagating stage-by-stage through the network.
Inventors
- 👤 T Pedersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:23
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04; H04Q11/06
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
169 words
A time division multiplex switching system comprising A. at least one array of bilateral crosspoint switching elements, each of said arrays having a plurality of rows and a plurality of columns, B. a first plurality of bidirectional highways connected to respective rows of each of said switching arrays, and a second plurality of bidirectional highways connected to respective columns of each of said switching arrays, C. means interconnecting individual ones of said second plurality of highways for a given array to individual ones of said first plurality of highways for others of said arrays, and D. a plurality of bidirectional time slot interchangers for effecting first time slot interchanges for signals arriving in the input direction on each bidirectional highway connected to one of the rows or columns of at least one of said switching arrays, and second time slot interchanges, complementary to said first time slot interchanges, for signals in the associated output direction on each bidirectional highway connected to said row or column of said switching arrays.
Claim 2
Dependent Claim
169 words
A time division multiplex switching system comprising A. at least one array of bilateral crosspoint switching elements, each of said arrays having a plurality of rows and a plurality of columns, B. a first plurality of bidirectional highways connected to respective rows of each of said switching arrays, and a second plurality of bidirectional highways connected to respective columns of each of said switching arrays, C. means interconnecting individual ones of said second plurality of highways for a given array to individual ones of said first plurality of highways for others of said arrays, and D. a plurality of bidirectional time slot interchangers for effecting first time slot interchanges for signals arriving in the input direction on each bidirectional highway connected to one of the rows or columns of at least one of said switching arrays, and second time slot interchanges, complementary to said first time slot interchanges, for signals in the associated output direction on each bidirectional highway connected to said row or column of said switching arrays.
Claim 3
Dependent Claim
46 words
Apparatus according to claim 1 wherein each of said crosspoint switching elements comprises a first serial storage means for receiving and storing signals from a row highway during a given time frame and delivering said signals to a selected column highway in a subsequent time frame.
Claim 4
Dependent Claim
46 words
Apparatus according to claim 2 wherein said crosspoint switching elements each further comprises a second serial storage means for receiving and storing signals from a column highway during a given time frame and delivering said signals to a selected row highway in a subsequent time frame.
Claim 5
Dependent Claim
43 words
Apparatus according to claim 3 wherein saiD crosspoint switching elements each further comprises an extender circuit having input and output terminals for selectively delaying the delivery of signals from said first and second serial storage means to their respective column and row highways.
Claim 6
Dependent Claim
57 words
Apparatus according to claim 4 wherein said first and second serial storage means comprise respective first and second reversible shift registers, each having at least one input/output terminal and wherein each of said crosspoint switching elements further comprises means for alternately conditionally connecting said input/output terminals of said shift registers to said input terminal of said extender.
Claim 7
Dependent Claim
19 words
Apparatus according to claim 5 wherein said means for conditionally connecting comprises gate means responsive to applied control signals.
Claim 8
Dependent Claim
23 words
Apparatus according to claim 6 further comprising a source of control signals representative of the desired operational condition of said crosspoint switching elements.
Claim 9
Dependent Claim
74 words
Apparatus according to claim 7 wherein said source of control signals comprises first and second control memories adapted to store signals, and means for reading signals from said first memory when customer requests for service are in a static condition, and for reading signals from said second memory when it is desired to set up or release interconnections of said row highways to said column highways in response to changing demands for customer service.
Claim 10
Dependent Claim
50 words
Apparatus according to claim 1 wherein each of said time slot interchangers comprises a first serial storage means for receiving and storing signals from a row or column highway during a given time frame and delivering said signals to a selected row or column highway in a subsequent time frame.
Claim 11
Dependent Claim
50 words
Apparatus according to claim 9 wherein said time slot interchangers each further comprises a second serial storage means for receiving and storing signals from a row or column highway during a given time frame and delivering said signals to a selected row or column highway in a subsequent time frame.
Claim 12
Dependent Claim
47 words
Apparatus according to claim 10 wherein said time slot interchangers each further comprises first and second extender circuits, each xtender circuit having input and output terminals for selectively delaying the delivery of signals from said first and second serial storage means, respectively, to their respective output highways.
Claim 13
Dependent Claim
50 words
Apparatus according to claim 11 wherein said first and second serial storage means each have an output terminal and wherein said time slot interchangers each further comprises means for conditionally connecting said output terminals of said serial storage means to said input terminal of said first and second extenders respectively.
Claim 14
Dependent Claim
19 words
Apparatus according to claim 12 wherein said means for conditionally connecting comprises gate means responsive to applied control signals.
Claim 15
Dependent Claim
23 words
Apparatus according to claim 13 further comprising a source of control signals representative of the desired operational condition of said time slot interchangers.
Claim 16
Dependent Claim
74 words
Apparatus according to claim 14 wherein said source of control signals comprises first and second control memories adapted to store signals, and means for reading signals from said first memory when customer requests for service are in a static condition, and for reading signals from said second memory when it is desired to set up or release interconnections of said row highways to said column highways in response to changing demands for customer service.
Claim 17
Dependent Claim
53 words
Apparatus according to claim 4 wherein said time slot interchangers each further comprises first and second serial storage means for receiving and storing signals from respective row and column input highways during a given time frame and delivering said signals to selected respective column and row output highways in a subsequent time frame.
Claim 18
Dependent Claim
42 words
Apparatus according to claim 16 wherein said time slot interchangers each further comprise first and second extender circuits for selectively delaying the delivery of signaLs from said first and second serial storage means to said selected respective column and row output highways.
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) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |