Patent US3689699A successfully refreshed from Google Patents.
US3689699A
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US
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Synchronizing system
Assignee: General Electric Co
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Filing: 1971-04-12
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Granted: 1972-09-05
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Expires: 1991-04-12
Abstract
Abstract In a time-division multiplex, pulse-code modulation system, each sequence of four binary pulses representing information are converted to a group of three ternary pulses for transmission to a receiver. At the receiver, the same groups of three ternary pulses are converted back to four binary pulses for decoding and demultiplexing. Both conversions are made in accordance with a code in which three ternary zeros do not appear in any correct ternary grouping. If the receiver is out of frame, a condition which can be indicated by framing binary pulses, the receiver sends an alarm to the distant transmitter to cause the distant transmitter to send a special distinguishing code in place of the information. This distinguishing code produces a large number of three ternary zeros in sequence. If, at the receiver, three zeros appear in a ternary pulse group, the grouping is shifted until no group contains three ternary zeros. The distinguishing code also makes the framing binary pulses distinct so that binary framing is made rapidly and accurately. When the receiver is in frame, the alarm signal is removed so that the distant transmitter sends voice information again.
Inventors
- 👤 Theodore Brenig
- 👤 James S Smith Jr
- 👤 Paul E Woodie Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:23
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/38; H04L25/40; H04L25/49; H04L25/4917; H04L25/4923; H04L25/4925; H04J; H04J3/00; H04J3/02; H04J3/06; H04J3/0602; H04J3/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
273 words
In a multi-channel, time-division multiplex, pulse-code modulation carrier system having a near transmitter and receiver and a distant transmitter and receiver, wherein one of said channels contains alarm and framing signals, wherein each group of a first plurality of sequential binary pulses is converted in accordance with a selected code by a transmitter to a group of a second plurality of sequential ternary pulses for transmission, said code being selected so that a particular combination of ternary pulses is normally absent from each proper group of ternary pulses, and wherein the received ternary pulses are grouped and converted in accordance with said selected code by a receiver to binary pulses for decoding and demultiplexing, a synchronizing system comprising: a. means at said near receiver for sensing said framing signals, for detecting framing errors of binary pulses, and for producing an alarm signal in response to a detected framing error; b. means connected between said near receiver and transmitter for causing said near transmitter to transmit said alarm signal to said distant receiver; c. means at said near receiver for detecting a received alarm signal from said distant transmitter; d. means connected between said near receiver and transmitter for causing said near transmitter to transmit a distinguishing code in all but said one channel to said distant receiver in response to a detected distant alarm signal, said distinguishing code being such that it excludes said framing signals and being such that its corresponding ternary pulses have a plurality of said particular combinations; e. and means at said near receiver for grouping received ternary pulses and for framing said near receiver with said framing signals.
Claim 2
Dependent Claim
273 words
In a multi-channel, time-division multiplex, pulse-code modulation carrier system having a near transmitter and receiver and a distant transmitter and receiver, wherein one of said channels contains alarm and framing signals, wherein each group of a first plurality of sequential binary pulses is converted in accordance with a selected code by a transmitter to a group of a second plurality of sequential ternary pulses for transmission, said code being selected so that a particular combination of ternary pulses is normally absent from each proper group of ternary pulses, and wherein the received ternary pulses are grouped and converted in accordance with said selected code by a receiver to binary pulses for decoding and demultiplexing, a synchronizing system comprising: a. means at said near receiver for sensing said framing signals, for detecting framing errors of binary pulses, and for producing an alarm signal in response to a detected framing error; b. means connected between said near receiver and transmitter for causing said near transmitter to transmit said alarm signal to said distant receiver; c. means at said near receiver for detecting a received alarm signal from said distant transmitter; d. means connected between said near receiver and transmitter for causing said near transmitter to transmit a distinguishing code in all but said one channel to said distant receiver in response to a detected distant alarm signal, said distinguishing code being such that it excludes said framing signals and being such that its corresponding ternary pulses have a plurality of said particular combinations; e. and means at said near receiver for grouping received ternary pulses and for framing said near receiver with said framing signals.
Claim 3
Dependent Claim
23 words
The system of claim 1 wherein said alarm signal is produced only after an interval following a selected plurality of detected framing errors.
Claim 4
Dependent Claim
20 words
The system of claim 1 wherein said distinguishing code is transmitted during the time that information would normally be transmitted.
Claim 5
Dependent Claim
39 words
The system of claim 1 wherein said alarm signal is produced only after an interval following a selected plurality of detected framing errors, and wherein said distinguishing code is transmitted during the time that information would normally be transmitted.
Claim 6
Dependent Claim
47 words
The system of claim 1 and further comprising means connected between said near receiver and transmitter for causing said near transmitter to transmit said distinguishing code in all but said one channel to said distant receiver in response to an alarm signal produced by said near receiver.
Claim 7
Dependent Claim
23 words
The system of claim 5 wherein said alarm signal is produced only after an interval following a selected plurality of detected framing errors.
Claim 8
Dependent Claim
20 words
The system of claim 5 wherein said distinguishing code is transmitted during the time that information would normally be transmitted.
Claim 9
Dependent Claim
39 words
The system of claim 5 wherein said alarm signal is produced only after an interval following a selected plurality of detected framing errors, and wherein said distinguishing code is transmitted during the time that information would normally be transmitted.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |