US3558827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone switching system with independent signalling channels employing time-division multiplex
Assignee: Baj Ltd
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Filing: 1968-05-08
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Granted: 1971-01-26
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Expires: 1988-05-08
Abstract
Abstract Branched telephone switching system including a principal exchange, intermediate subsidiary exchanges connected to the principal exchange through first information and signalling trunk channels and terminal subsidiary exchanges connected to said intermediate subsidiary exchanges through second information and signalling trunk channels and to the principal exchange through said first and second serially connected information and signalling channels. The information trunk channels and the signalling trunk channels are separate channels. The principal exchange comprises means for transmitting signalling code words to the subsidiary exchanges in successive first time slots respectively assigned thereto and means for receiving signalling code words from the subsidiary exchanges in successive second time slots respectively assigned thereto. Each intermediate and terminal subsidiary exchange comprises means for transmitting signalling code words to the principal exchange in the second time slots assigned to it and means for receiving signalling code words from the principal exchange in the first time slots assigned to it. The intermediate subsidiary exchanges comprise means for switching from the principal exchange towards a given terminal subsidiary exchange the signalling code words occurring in the first time slots assigned to this terminal subsidiary exchange and means for switching from a given terminal subsidiary exchange towards the principal exchange the signalling code words occurring in the second time slots assigned to the former.
Inventors
- 👤 Pierre M Lucas
- 👤 Jacques M Dondoux
- 👤 Jean F Duquesne
- 👤 Jean-Marie L Laprevote
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:40
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42; H04Q3/54
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
237 words
A branched telephone switching system including: a. a principal exchange; b. first and second message and signalling trunk channels, said message trunk channels and said signalling trunk channels being separate channels; c. intermediate subsidiary exchanges connected to said principal exchange through said first message and signalling trunk channels; d. terminal subsidiary exchanges connected to said intermediate subsidiary exchanges through said second message and signalling trunk channels; said principal exchange (a) comprising means for transmitting signalling code words to said subsidiary exchanges in recurrent first time slots respectively assigned to the subsidiary exchanges and means for receiving signalling code words from said intermediate and terminal subsidiary exchanges in recurrent second time slots respectively assigned to said subsidiary exchanges; said intermediate and terminal subsidiary exchanges (c) and (d) comprising means for transmitting signalling code words to said principal exchange in the second time slots and means for receiving signalling code words from said principal exchange in the first time slots; and said intermediate subsidiary exchanges (c) further comprising means for switching from the principal exchange towards a given terminal subsidiary exchange the signalling code words occurring on the first signalling trunk channels in the first time slots assigned to said terminal subsidiary exchange and means for switching from a given terminal subsidiary exchange towards the principal exchange the signalling code words occurring on the second signalling trunk channels in the second time slots assigned to said terminal subsidiary exchange.
Claim 2
Dependent Claim
237 words
A branched telephone switching system including: a. a principal exchange; b. first and second message and signalling trunk channels, said message trunk channels and said signalling trunk channels being separate channels; c. intermediate subsidiary exchanges connected to said principal exchange through said first message and signalling trunk channels; d. terminal subsidiary exchanges connected to said intermediate subsidiary exchanges through said second message and signalling trunk channels; said principal exchange (a) comprising means for transmitting signalling code words to said subsidiary exchanges in recurrent first time slots respectively assigned to the subsidiary exchanges and means for receiving signalling code words from said intermediate and terminal subsidiary exchanges in recurrent second time slots respectively assigned to said subsidiary exchanges; said intermediate and terminal subsidiary exchanges (c) and (d) comprising means for transmitting signalling code words to said principal exchange in the second time slots and means for receiving signalling code words from said principal exchange in the first time slots; and said intermediate subsidiary exchanges (c) further comprising means for switching from the principal exchange towards a given terminal subsidiary exchange the signalling code words occurring on the first signalling trunk channels in the first time slots assigned to said terminal subsidiary exchange and means for switching from a given terminal subsidiary exchange towards the principal exchange the signalling code words occurring on the second signalling trunk channels in the second time slots assigned to said terminal subsidiary exchange.
Claim 3
Dependent Claim
353 words
A branched telephone switching system including: a. a principal exchange; b. first and second message and signalling trunk channels, said message trunk channels and said signalling trunk channels being separate channels; c. intermediate subsidiary exchanges connected to said principal exchange through said first message and signalling trunk channels; and d. terminal subsidiary exchanges connected to said intermediate subsidiary exchanges through said second message and signalling trunk channels; said principal exchange (a) comprising means for transmitting signalling code words to said subsidiary exchanges in recurrent first time slots respectively assigned to the subsidiary exchanges, means for receiving signalling code words including acknowledgment appendix signals from said intermediate and terminal subsidiary exchanges in recurrent second time slots respectively assigned to said subsidiary exchaNges, means for checking the received signalling code words, and means for adding to the next signalling code word to be transmitted an acknowledgment appendix signal in response to said checking means; said intermediate and terminal subsidiary exchanges (c) and (d) comprising means for transmitting signalling code words to said principal exchange in the second time slots assigned to said transmitting subsidiary exchange, means for receiving signalling code words from said principal exchange in the first time slots assigned to said receiving subsidiary exchange and acknowledgment appendix signals from said principal exchange in first time slots nonassigned to said receiving subsidiary exchange, means for checking the received signalling code words, and means for adding to the next signalling code word to be transmitted an acknowledgment appendix signal in response to said latter checking means; said intermediate subsidiary exchanges (c) further comprising means for switching from the principal exchange towards a given terminal subsidiary exchange the signalling code words occurring on the first signalling trunk channels in the first time slots assigned to said terminal subsidiary exchange and the acknowledgment appendix signals occurring in the first time slots nonassigned to said terminal subsidiary exchange, and means for switching from a given terminal subsidiary exchange towards the principal exchange the signalling code words and acknowledgment appendix signals occurring on the second signalling trunk channels in the second time slots assigned to said terminal subsidiary exchange.
Claim 4
Dependent Claim
353 words
A branched telephone switching system including: a. a principal exchange; b. first and second message and signalling trunk channels, said message trunk channels and said signalling trunk channels being separate channels; c. intermediate subsidiary exchanges connected to said principal exchange through said first message and signalling trunk channels; and d. terminal subsidiary exchanges connected to said intermediate subsidiary exchanges through said second message and signalling trunk channels; said principal exchange (a) comprising means for transmitting signalling code words to said subsidiary exchanges in recurrent first time slots respectively assigned to the subsidiary exchanges, means for receiving signalling code words including acknowledgment appendix signals from said intermediate and terminal subsidiary exchanges in recurrent second time slots respectively assigned to said subsidiary exchaNges, means for checking the received signalling code words, and means for adding to the next signalling code word to be transmitted an acknowledgment appendix signal in response to said checking means; said intermediate and terminal subsidiary exchanges (c) and (d) comprising means for transmitting signalling code words to said principal exchange in the second time slots assigned to said transmitting subsidiary exchange, means for receiving signalling code words from said principal exchange in the first time slots assigned to said receiving subsidiary exchange and acknowledgment appendix signals from said principal exchange in first time slots nonassigned to said receiving subsidiary exchange, means for checking the received signalling code words, and means for adding to the next signalling code word to be transmitted an acknowledgment appendix signal in response to said latter checking means; said intermediate subsidiary exchanges (c) further comprising means for switching from the principal exchange towards a given terminal subsidiary exchange the signalling code words occurring on the first signalling trunk channels in the first time slots assigned to said terminal subsidiary exchange and the acknowledgment appendix signals occurring in the first time slots nonassigned to said terminal subsidiary exchange, and means for switching from a given terminal subsidiary exchange towards the principal exchange the signalling code words and acknowledgment appendix signals occurring on the second signalling trunk channels in the second time slots assigned to said terminal subsidiary exchange.
Claim 5
Dependent Claim
405 words
A branched telephone switching system including: a. a principal exchange; b. first and second message and signalling trunk channels, said message trunk channels and said signalling trunk channels being separate channels; c. intermediate subsidiary exchanges connected to said principal exchange through said first message and signalling trunk channels; and terminal subsidiary exchanges connected to said intermediate subsidiary exchanges through said second message and signalling trunk channels; said principal exchange (a) comprising means for transmitting signalling code words to said subsidiary exchanges in recurrent first time slots respectively assigned to the subsidiary exchanges, means for receiving signalling code words including acknowledgment appendix signals from said intermediate and terminal subsidiary exchanges in recurrent second time slots respectively assigned to said subsidiary exchanges, means for checking the received signalling code words, means for adding to the next signalling code word to be transmitted an acknowledgment appendix signal in response to said signalling code word checking means, means for checking the acknowledgment appendix signal, and means for selectively repeating the signalling code words in response to said acknowledgement appendix signal checking means; said intermediate and terminal subsidiary exchanges (c) and (d) comprising means for transmitting signalling code words to said principal exchange in the second time slots assigned to said transmitting subsidiary exchange, means for receiving signalling code words from said principal exchange in the first time slots assigned to said receiving subsidiary exchange and acknowledgment appendix signals from said principal exchange in first time slots nonassigned to said receiving subsidiary exchange, means for checking the received signalling code words, means for adding to the next signalling code word to be transmitted an acknowledgment appendix signal in response to said signalling code word checking means, means for checking the acknowledgment appendix signal, and means for selectively repeating the signalling code words in response to said acknowledgment appendix signal checking means; and said intermediate subsidiary exchanges further comprising means for switching from the principal exchange towards a given terminal subsidiary exchange the signalling cOde words occurring on the first signalling trunk channels in the first time slots assigned to said terminal subsidiary exchange and the acknowledgment appendix signals occurring in the first time slots nonassigned to said terminal subsidiary exchange, and means for switching from a given terminal subsidiary exchange towards the principal exchange the signalling code words and acknowledgment appendix signals occurring on the second signalling trunk channels in the second time slots assigned to said terminal subsidiary exchange.
Claim 6
Dependent Claim
405 words
A branched telephone switching system including: a. a principal exchange; b. first and second message and signalling trunk channels, said message trunk channels and said signalling trunk channels being separate channels; c. intermediate subsidiary exchanges connected to said principal exchange through said first message and signalling trunk channels; and terminal subsidiary exchanges connected to said intermediate subsidiary exchanges through said second message and signalling trunk channels; said principal exchange (a) comprising means for transmitting signalling code words to said subsidiary exchanges in recurrent first time slots respectively assigned to the subsidiary exchanges, means for receiving signalling code words including acknowledgment appendix signals from said intermediate and terminal subsidiary exchanges in recurrent second time slots respectively assigned to said subsidiary exchanges, means for checking the received signalling code words, means for adding to the next signalling code word to be transmitted an acknowledgment appendix signal in response to said signalling code word checking means, means for checking the acknowledgment appendix signal, and means for selectively repeating the signalling code words in response to said acknowledgement appendix signal checking means; said intermediate and terminal subsidiary exchanges (c) and (d) comprising means for transmitting signalling code words to said principal exchange in the second time slots assigned to said transmitting subsidiary exchange, means for receiving signalling code words from said principal exchange in the first time slots assigned to said receiving subsidiary exchange and acknowledgment appendix signals from said principal exchange in first time slots nonassigned to said receiving subsidiary exchange, means for checking the received signalling code words, means for adding to the next signalling code word to be transmitted an acknowledgment appendix signal in response to said signalling code word checking means, means for checking the acknowledgment appendix signal, and means for selectively repeating the signalling code words in response to said acknowledgment appendix signal checking means; and said intermediate subsidiary exchanges further comprising means for switching from the principal exchange towards a given terminal subsidiary exchange the signalling cOde words occurring on the first signalling trunk channels in the first time slots assigned to said terminal subsidiary exchange and the acknowledgment appendix signals occurring in the first time slots nonassigned to said terminal subsidiary exchange, and means for switching from a given terminal subsidiary exchange towards the principal exchange the signalling code words and acknowledgment appendix signals occurring on the second signalling trunk channels in the second time slots assigned to said terminal subsidiary exchange.
References Cited (Backward Citations)
US3377431A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |