US3769466A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone transmission system with echo suppressors
Assignee: Siemens AG
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Filing: 1971-10-12
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Granted: 1973-10-30
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Expires: 1991-10-12
Abstract
Abstract A telephone transmission system in which two transit time sections including speech circuits and respective echo suppressors are connected on a four-wire basis in an exchange which provides an echo suppressor for each of the connected circuits. The exchange is provided with apparatus for suprressing signals in the transmitting path including a switch off device having a control sound generator connected to a transmission path and a control sound receiver connected to the other transmission path for switching off an intermediate echo suppressor in response to control sound received over the associated transmission path.
Inventors
- 👤 Pfeil D Von
- 👤 J Sontheim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:16
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/20
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
521 words
A telecommunication transmission system comprising: first and second stations connected by a four-wire transmission circuit having two transmission paths, each of said stations including in said transmission paths a receiving speech circuit and a transmitting speech circuit connected to the transmitting speech circuit and the receiving speech circuit, respectively, of the other said station; first, second, third and fourth echo suppressors connected in each transmission path of said four-wire circuit, each of said echo suppressors including a control input, a transmission suppressor in one transmission path operated upon receipt of a control signal at said control input and a damping member connected in the other transmission path upon operation of the respective transmission suppressor, the first and third echo suppressors having their transmission suppressors connected in the transmission path which is connected to the transmitting speech circuit of said first station, the second and fourth echo suppressors having their transmission suppressors connected in the transmission path which is connected to the transmitting speech circuit of said second station, each of said echo suppressors including a control tone generator and a control tone receiver connected to the respective control input, first and second gates each having two inputs and an output, said control tone generator of said third echo suppressor connected to the transmission path including said transmitting circuit of said second station, said control tone receiver of said second echo suppressor connected to the last-mEntioned path and operated in response to receipt of the control tone of the control tone generator of said third echo suppressor, said control tone generator of said second echo suppressor and said control tone receiver of said second echo suppressor connected to respective inputs of said first gate, the output of said first gate connected to the transmitting path including said transmitting speech circuit of said first station, said control tone receiver of said third echo suppressor connected to the last-mentioned path and operated in response to receipt of the control tone from said control tone generator of said second echo suppressor, said control tone generator of said first echo suppressor connected to the transmission path including the transmitting speech circuit of said second station and at a point adjacent the hybrid circuit for said first station, said control tone receiver of said fourth echo suppressor connected to the last-mentioned path at a point adjacent the hybrid circuit for said second station and operated in response to receipt of the control tone of said control tone generator of said first echo suppressor, said control tone receiver and said control tone generator of said fourth echo suppressor connected to respective inputs of said second gate, the output of said second gate connected to the transmission path including the transmitting speech circuit of said first station at a point adjacent said hybrid circuit which is connected to said second station, said control tone receiver of said first echo suppressor connected to the last-mentioned transmission path at a point adjacent said hybrid which is connected to said first station and operated in response to receipt of the control tone of said control tone generator of said fourth echo suppressor.
Claim 2
Dependent Claim
521 words
A telecommunication transmission system comprising: first and second stations connected by a four-wire transmission circuit having two transmission paths, each of said stations including in said transmission paths a receiving speech circuit and a transmitting speech circuit connected to the transmitting speech circuit and the receiving speech circuit, respectively, of the other said station; first, second, third and fourth echo suppressors connected in each transmission path of said four-wire circuit, each of said echo suppressors including a control input, a transmission suppressor in one transmission path operated upon receipt of a control signal at said control input and a damping member connected in the other transmission path upon operation of the respective transmission suppressor, the first and third echo suppressors having their transmission suppressors connected in the transmission path which is connected to the transmitting speech circuit of said first station, the second and fourth echo suppressors having their transmission suppressors connected in the transmission path which is connected to the transmitting speech circuit of said second station, each of said echo suppressors including a control tone generator and a control tone receiver connected to the respective control input, first and second gates each having two inputs and an output, said control tone generator of said third echo suppressor connected to the transmission path including said transmitting circuit of said second station, said control tone receiver of said second echo suppressor connected to the last-mEntioned path and operated in response to receipt of the control tone of the control tone generator of said third echo suppressor, said control tone generator of said second echo suppressor and said control tone receiver of said second echo suppressor connected to respective inputs of said first gate, the output of said first gate connected to the transmitting path including said transmitting speech circuit of said first station, said control tone receiver of said third echo suppressor connected to the last-mentioned path and operated in response to receipt of the control tone from said control tone generator of said second echo suppressor, said control tone generator of said first echo suppressor connected to the transmission path including the transmitting speech circuit of said second station and at a point adjacent the hybrid circuit for said first station, said control tone receiver of said fourth echo suppressor connected to the last-mentioned path at a point adjacent the hybrid circuit for said second station and operated in response to receipt of the control tone of said control tone generator of said first echo suppressor, said control tone receiver and said control tone generator of said fourth echo suppressor connected to respective inputs of said second gate, the output of said second gate connected to the transmission path including the transmitting speech circuit of said first station at a point adjacent said hybrid circuit which is connected to said second station, said control tone receiver of said first echo suppressor connected to the last-mentioned transmission path at a point adjacent said hybrid which is connected to said first station and operated in response to receipt of the control tone of said control tone generator of said fourth echo suppressor.
Claim 3
Dependent Claim
88 words
The telecommunication transmission system set forth in claim 1, wherein two separate control tone frequencies are employed, said control tone generators of said first and third echo suppressors providing a tone signal of a first frequency, said control tone receivers of said second and fourth echo suppressors operated in response to said first frequency, said control tone generators of said second and fourth echo suppressors providing a second frequency, and said control tone receivers of said first and third echo suppressors operated in response to said second frequency.
Claim 4
Dependent Claim
40 words
The telecommunication transmission system set forth in claim 1, wherein the frequency of the control tone generators of said first and third echo suppressors are higher than that of the control tone generators of said second and fourth echo suppressors.
References Cited (Backward Citations)
US2990457A
Cited
US3647993A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |