Patent US3708625A successfully refreshed from Google Patents.
US3708625A
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US
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Circuit arrangement for utilizing idle channels of multiplex telecommunication system for data transmission
Assignee: Italtel SpA
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Filing: 1971-02-01
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Granted: 1973-01-02
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Expires: 1991-02-01
Abstract
Abstract A multiplex telephone system with n signal channels interconnecting two terminals has a data transmitter at one terminal and a data receiver at the other terminal, these two data-processing units being connectable to each other by way of any channel not engaged in voice communication. A line monitor at each terminal determines the number of idle incoming and outgoing lines, respectively, and controls an associated logical selector to allocate one or more disengaged channels to data transmission, according to the number of idle lines, with the aid of a switching circuit connecting such channel directly to the datatransmitter output and the data-receiver input. The n channels are divided into m groups, not more than one disengaged channel per group being allocable at any given time to the transmission of data; such allocation is promptly canceled by the selector whenever additional requests from calling subscriber lines reduce the number of available channels below a predetermined minimum.
Inventors
- 👤 E Angeleri
- 👤 M Bonatti
- 👤 G Costa
- 👤 I Poretti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:26
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/06; H04M11/064
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
241 words
In a telecommunication system including a first and a second station interconnected by n signal channels, a multiplicity of calling lines incoming at said first station, a multiplicity of called lines outgoing from said second station, and terminal equipment at said stations for temporarily engaging any of said channels to establish communication between a calling line and a called line, the combination therewith of: a source of stored information, transmittable over any of said channels, at said first station; a receiver for said stored information at said second station; monitoring means connected to said channels at said first station for ascertaining their state of engagement; first switching means at said first station for seizing a disengaged channel and connecting said source thereto under the control of said monitoring means; detector means connected to said channels at said second station for ascertaining the availability of any channel for seizure by said first switching means; and second switching means at said second station for extending a channel available for such seizure to said receiver under the control of said detector means, said monitoring means being responsive to requests for a seized channel from a calling line for releasing such channel and making same unavailable for transmission of said stored information; said monitoring means comprising a threshold circuit multipled across said channels for determining the number of disengaged channels and for actuating said first switching means upon said number exceedIng a predetermined critical value.
Claim 2
Dependent Claim
241 words
In a telecommunication system including a first and a second station interconnected by n signal channels, a multiplicity of calling lines incoming at said first station, a multiplicity of called lines outgoing from said second station, and terminal equipment at said stations for temporarily engaging any of said channels to establish communication between a calling line and a called line, the combination therewith of: a source of stored information, transmittable over any of said channels, at said first station; a receiver for said stored information at said second station; monitoring means connected to said channels at said first station for ascertaining their state of engagement; first switching means at said first station for seizing a disengaged channel and connecting said source thereto under the control of said monitoring means; detector means connected to said channels at said second station for ascertaining the availability of any channel for seizure by said first switching means; and second switching means at said second station for extending a channel available for such seizure to said receiver under the control of said detector means, said monitoring means being responsive to requests for a seized channel from a calling line for releasing such channel and making same unavailable for transmission of said stored information; said monitoring means comprising a threshold circuit multipled across said channels for determining the number of disengaged channels and for actuating said first switching means upon said number exceedIng a predetermined critical value.
Claim 3
Dependent Claim
85 words
The combination defined in claim 1, further comprising a first selector at said first station responsive to said threshold circuit for actuating said first switching means to seize one of several available channels in a predetermined preference pattern, said detector means including another threshold circuit analogous to that of said monitoring means and a second selector responsive to said other threshold circuit for actuating said second switching means at said second station in the preference pattern of said first switching means at said first station.
Claim 4
Dependent Claim
68 words
The combination defined in claim 2 wherein said n channels are divided into m groups, each threshold circuit including m sensors responsive to different numbers of disengaged channels exceeding respective critical values, each selector comprising logical circuitry establishing an individual order of precedence in each group for the seizure of not more than one channel thereof under the control of an individual sensor respectively assigned to each group.
Claim 5
Dependent Claim
30 words
The combination defined in claim 3 wherein said logical circuitry includes a set of AND gates and at least one OR gate connected to the outputs of said AND gates.
Claim 6
Dependent Claim
18 words
The combination defined in claim 3 wherein the lowest of said critical values is substantially equal to m.
Claim 7
Dependent Claim
52 words
The combination defined in claim 2 wherein each of said channels is provided with a local extension at said first station including a pair of talking conductors and a signaling wire receiving a busy signal upon connection thereof to a calling line, said monitoring means being connected to all said signaling wires.
Claim 8
Dependent Claim
56 words
The combination defined in claim 6 wherein said first switching means includes a set of m relays, one for each channel, with operating circuits connected to the signaling wires of the respective channels for preventing the seizure of a channel in the presence of a busy signal identifying such channel as engaged by a calling line.
Claim 9
Dependent Claim
54 words
The combination defined in claim 7 wherein each of said relays is provided with contacts for applying a simulated busy signal to the signaling wire of its channel while disconnecting such signaling wire from said monitoring means and from its own operating circuit to render the simulated busy signal ineffectual in controlling channel seizure.
Claim 10
Dependent Claim
54 words
The combination defined in claim 6 wherein each of said channels is provided with another local extension at said second station including a pair of talking conductors and a second signaling wire receiving a busy signal upon connection thereof to a called line, said detector means being connected to all said second signaling wires.
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) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |