US3601543A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Time division data transmission system
Assignee: Lignes Telegraphiques et Telephoniques LTT SA
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Filing: 1970-03-17
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Granted: 1971-08-24
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Expires: 1990-03-17
Abstract
Abstract A time division binary-coded data transmission system using two parallel and juxtaposed transmission lines, with a number of sending and receiving stations distributed along said lines and coupled to both of them. The first line transmits synchronization frames supplied by a central station, and the second one the information. The system is characterized in that at each sending station, the information signals transmitted by the second line are derived from the synchronization signals transmitted by the first, by means of a coupling circuit modulating the latter signals according to the coding conditions of the data to be transmitted, without altering the essential features of their waveshape. Thanks to this arrangement, the total lengths of line through which synchronization and coded data signals are transmitted are the same, and the thus preserved similarity of their waveshapes allows correct demodulation of the latter by simple comparison with the former.
Inventors
- 👤 Maurice M Maniere
- 👤 Henri L Tambutte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:57
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/40; H04L12/407; H04L12/417; H04J; H04J3/00; H04J3/02; H04J3/06; H04J3/0635; H04J3/0638; H04J3/0647; H04L12/42; H04L12/427; H04L12/43; H04L5/00; H04L5/22; H04L7/00; H04L7/04; H04L7/041; H04L2007/047; H04L7/0008; H04L7/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
244 words
A cyclic time-sharing multiplex data transmission system in which data are transmitted by coded bits which have a constant duration T and which have one or the other of two different binary values, said system using two juxtaposed transmission lines having substantially identical electrical characteristics, and a number of transmitting and receiving stations distributed along said lines and coupled with both of them, the first line being used for the transmission of sync frames delivered by a central generating station and repeated periodically in each operating cycle, and the second line being used for the transmission of data signals, any communication between any transmitting station and any receiving station being in a time slot selected in each operating cycle, each sync frame comprising a start signal of predetermined waveform and duration, followed by a number N of elementary sync signals each having the same individual time constant T and the same waveform as those of the data bits having one of the binary values; and in which the binary value of each bit received at the receiving station is identified by means for comparing such bit with the sync bits; the data bits having the first or second binary value are produced in each transmitting station from the sync bits by coupling means between said first and second lines; and said coupling means are controlled by the binary value of each of the data items delivered by a source of data to be transmitted.
Claim 2
Dependent Claim
244 words
A cyclic time-sharing multiplex data transmission system in which data are transmitted by coded bits which have a constant duration T and which have one or the other of two different binary values, said system using two juxtaposed transmission lines having substantially identical electrical characteristics, and a number of transmitting and receiving stations distributed along said lines and coupled with both of them, the first line being used for the transmission of sync frames delivered by a central generating station and repeated periodically in each operating cycle, and the second line being used for the transmission of data signals, any communication between any transmitting station and any receiving station being in a time slot selected in each operating cycle, each sync frame comprising a start signal of predetermined waveform and duration, followed by a number N of elementary sync signals each having the same individual time constant T and the same waveform as those of the data bits having one of the binary values; and in which the binary value of each bit received at the receiving station is identified by means for comparing such bit with the sync bits; the data bits having the first or second binary value are produced in each transmitting station from the sync bits by coupling means between said first and second lines; and said coupling means are controlled by the binary value of each of the data items delivered by a source of data to be transmitted.
Claim 3
Dependent Claim
35 words
A system according to claim 1, in which said two binary values are represented by bits which have the same value and waveform as one another but which are of opposite polarity to one another.
Claim 4
Dependent Claim
20 words
A system according to claim 1, in which one of the binary values is the value corresponding to zero signal.
Claim 5
Dependent Claim
124 words
A system according to claim 3, in which said line coupling means comprise a first circuit, comprising serially connected inductances in each line, and a second circuit inductively coupled with the first circuit and closed by a load resistance, the inductances and resistances and the mutual inductances between said first circuit and said second circuit being such that the series impedances introduced into the lines are substantially real and are at most equal to one-tenth of the characteristic impedance of the lines; and the second circuits respectively coupled with either line are at each transmitting station coupled together by amplifying one-way gating circuit whose conductive or nonconductive state depends upon the binary value of each of the data items delivered by said data source.
Claim 6
Dependent Claim
33 words
A system according to claim 4, in which said first circuit comprises at least one primary winding of a transformer and said second circuit comprises at least one secondary winding of a transformer.
Claim 7
Dependent Claim
47 words
A system according to claim 4, in which said gating circuit is also controlled by an auxiliary circuit delivering control signals derived from the sync frames received from said first line and which make said gating circuit conductive only during selected time slots in the operating cycle.
Claim 8
Dependent Claim
40 words
A system according to claim 6, in which said auxiliary circuit comprises a decoding matrix controlled by a binary counter whose input receives via a time differentiation circuit the sync bits in the sync frames received from said first line.
Claim 9
Dependent Claim
48 words
A system according to claim 1, in which said comparing means at each receiving station comprise a comparator circuit having two inputs and one output, at which a signal is output only when signals of substantially identical value and waveform are applied simultaneously to latter said two inputs.
Claim 10
Dependent Claim
61 words
A system according to claim 8, in which sampling and storage means are used in association with the output signal from the comparator circuit, and in which there is provided a circuit for gating the stored samples and controlled by sync pulses received from the first line, the latter circuit being operative only during selected time slots in the operating cycle.
Claim 11
Dependent Claim
45 words
A system according to claim 9, in which latter said gating circuit is controlled by a decoding matrix controlled by a binary counter which receives at its input via a time differentiation circuit the sync bits in the sync frames received from the first line.
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) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |