US3566032A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct-current data set arranged for polar signaling and full duplex operation
Assignee: AT&T Inc
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Filing: 1968-12-23
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Granted: 1971-02-23
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Expires: 1988-12-23
Abstract
Abstract The direction and magnitude of the cumulative polar loop current on a full duplex two-wire line are monitored by a three-level detector which determines when the incoming and outgoing current signals are both marking, both spacing, or concurrent marking and spacing. An appropriate one of the detector outputs is selected depending on whether an outgoing marking or spacing signal is being transmitted enabling the identification of incoming signals. Detection of the direction of loop current is accomplished by a pair of emitter-coupled transistor signal slicers. A third transistor signal slicer, whose emitter is coupled via a diode to the common emitter circuit, detects for the high magnitude current produced when both data sets generate spacing currents.
Inventors
- 👤 John T Carbone
- 👤 George Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:31
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/14; H04L5/1423
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
103 words
In a full duplex data set including means for applying direct-current signals to a communication line and means jointly operated by the cumulative signaling current in said line and the means for applying direct-current signals to the line for recognizing incoming direct-current signals characterized in that said jointly operated means comprises at least two signal slicers, each having an input connected to the line, each of said signal slicers having a different slicing level and thereby operated for a different magnitude of line current, and means controlled by the signal applied to the line for disabling at least one of said signal slicers.
Claim 2
Dependent Claim
103 words
In a full duplex data set including means for applying direct-current signals to a communication line and means jointly operated by the cumulative signaling current in said line and the means for applying direct-current signals to the line for recognizing incoming direct-current signals characterized in that said jointly operated means comprises at least two signal slicers, each having an input connected to the line, each of said signal slicers having a different slicing level and thereby operated for a different magnitude of line current, and means controlled by the signal applied to the line for disabling at least one of said signal slicers.
Claim 3
Dependent Claim
125 words
A full duplex polar signaling data system having at least two stations, each station having means for impressing current on a signaling line so that the direction of the current impressed by each station corresponds to the data signal being transmitted and the magnitude and direction of the cumulative line current is determined by the currents impressed by both stations, and means for recovering incoming signals, said recovering means comprising: a three-level detector having a pair of output leads and having inputs connected to said line for detecting three different line current conditions with respect to magnitude and direction; and means responsive to said impressing means for selecting one or the other of said output leads in accordance with the direction of the impressed current.
Claim 4
Dependent Claim
125 words
A full duplex polar signaling data system having at least two stations, each station having means for impressing current on a signaling line so that the direction of the current impressed by each station corresponds to the data signal being transmitted and the magnitude and direction of the cumulative line current is determined by the currents impressed by both stations, and means for recovering incoming signals, said recovering means comprising: a three-level detector having a pair of output leads and having inputs connected to said line for detecting three different line current conditions with respect to magnitude and direction; and means responsive to said impressing means for selecting one or the other of said output leads in accordance with the direction of the impressed current.
Claim 5
Dependent Claim
51 words
A full duplex polar signaling data system in accordance with claim 2 wherein said three-level detector comprises a differentially coupled pair of signal slicers for determining the direction of the line current and a third signal slicer operated by a predetermined magnitude of line current for disabling the signal slicer pair.
Claim 6
Dependent Claim
38 words
A full duplex polar signaling data system in accordance with claim 3 wherein said differentially coupled pair of signal slicers comprise two emitter-coupled transistors, said output leads being connected to individual ones of the collectors of said transistors.
Claim 7
Dependent Claim
44 words
A full duplex polar signaling data system in accordance with claim 4 wherein said third signal slicer comprises a third transistor, the emitter of said third transistor being coupled to the common emitter circuit of said emitter-coupled transistors by way of an impedance device.
Claim 8
Dependent Claim
59 words
In a full duplex polar signaling data system, a three-level detector for detecting three different line current conditions with respect to magnitude and direction comprising a differentially coupled pair of signal slicers for determining the direction of the linE current and a third signal slicer operated by a predetermined magnitude of line current for disabling the signal slicer pair.
Claim 9
Dependent Claim
59 words
In a full duplex polar signaling data system, a three-level detector for detecting three different line current conditions with respect to magnitude and direction comprising a differentially coupled pair of signal slicers for determining the direction of the linE current and a third signal slicer operated by a predetermined magnitude of line current for disabling the signal slicer pair.
Claim 10
Dependent Claim
28 words
In a full duplex polar signaling data system in accordance with claim 6 wherein said differentially coupled pair of signal slicers comprises a pair of emitter coupled transistors.
Claim 11
Dependent Claim
47 words
In a full duplex polar signaling data system in accordance with claim 7 wherein said third signal slicer comprises a third transistor, the emitter of said third transistor being coupled to the common emitter circuit of said emitter coupled transistor pair by way of an impedance device.
Claim 12
Dependent Claim
20 words
In a full duplex polar signaling data system in accordance with claim 8 wherein said impedance device comprises a diode.
References Cited (Backward Citations)
US3267459A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |