Patent US4488291A successfully refreshed from Google Patents.
US4488291A
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Circuit arrangement for setting up a conference call
Assignee: Alcatel Lucent NV
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Filing: 1982-11-30
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Granted: 1984-12-11
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Expires: 2002-11-30
Abstract
Abstract A conference circuit in a digital telephone switching system includes a first code converter (CCL), which converts nonlinearly coded speech samples into linearly coded speech samples, and adder (ADD), which sums the converted speech samples originating from the participants in the conference, and a second code converter (LCC), which reconverts the sum values into nonlinearly coded speech samples. To avoid distortion without increasing the insertion loss, the speech samples of the individual participants are integrated with respect to time and compared in an evaluation circuit (EVC). The speech samples of the loudest participant are fed to the adder unattenuated, while those of all other participants are attenuated by a predetermined value before being added.
Inventors
- 👤 Joachim Eschmann
- 👤 J/u/ rgen Zanzig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:14
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/42; H04M3/56; H04M3/561; H04Q; H04Q11/00; H04Q11/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
177 words
Circuit arrangement for setting up a conference call in a digital telephone switching system, comprising a first code converter converting the nonlinearly coded speech samples originating from the individual participants into linearly coded values, an adder summing the converted values, and a second code converter converting the sum values into nonlinearly coded speech samples, wherein the incoming speech samples are compared in an evaluation circuit and evaluated there over an integration time in such a way that the participant with the highest speech-signal intensity is determined, and that the speech samples of this participant are fed to the adder unattenuated, while the speech samples of the other participants are fed to the adder after being attenuated by a predetermined value; and wherein the evaluation circuit contains a first comparator comparing the speech samples, and a counter for each of the participants, and that on the basis of the result of the comparison, the counter assigned to the loudest participant is increased by one count, while the counters assigned to the remaining participants are decreased by one count.
Claim 2
Dependent Claim
177 words
Circuit arrangement for setting up a conference call in a digital telephone switching system, comprising a first code converter converting the nonlinearly coded speech samples originating from the individual participants into linearly coded values, an adder summing the converted values, and a second code converter converting the sum values into nonlinearly coded speech samples, wherein the incoming speech samples are compared in an evaluation circuit and evaluated there over an integration time in such a way that the participant with the highest speech-signal intensity is determined, and that the speech samples of this participant are fed to the adder unattenuated, while the speech samples of the other participants are fed to the adder after being attenuated by a predetermined value; and wherein the evaluation circuit contains a first comparator comparing the speech samples, and a counter for each of the participants, and that on the basis of the result of the comparison, the counter assigned to the loudest participant is increased by one count, while the counters assigned to the remaining participants are decreased by one count.
Claim 3
Dependent Claim
30 words
A circuit arrangement as claimed in claim 1, wherein the counters are followed by a second comparator which compares the counts and provides an output signal identifying the loudest participant.
Claim 4
Dependent Claim
26 words
A circuit arrangement as claimed in claim 1 wherein the counters are so designed that the loudest participant is identified after a maximum of 4 ms.
Claim 5
Dependent Claim
46 words
A circuit arrangement as claimed in claim 2 wherein the output signal of the second comparator is applied to a loss controller which provides to the first code converter a control signal which causes the respective speech sample converted therein to be attenuated or not attenuated.
Claim 6
Dependent Claim
20 words
A circuit arrangement as claimed in claim 2 wherein the second comparator compares the counts after every four time-division-multiplex frames.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-11 | 1988-06-11 | 1988-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-11 | 1992-06-11 | 1992-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-11 | 1996-06-11 | 1996-12-11 | $7700.00 | Window Closed / Lapsed |