Patent EP0472348A2 successfully refreshed from Google Patents.
EP0472348A2
Expired / Lapsed
EP
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Economical videoconference system
Assignee: AT&T Inc
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Filing: 1991-08-13
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Granted: —
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Expires: 2011-08-13
Abstract
Abstract A videoconferencing system includes a plurality of videoconferencing sites (A to D), and a centralized video conference bridge. Each site receives an audio signal (from 122) including a superimposed control signal (from 114 to 117). The control signal designates all sites as passive, except for one site, which is designated as dominant and whose video signal is thereby broadcast to all other sites. During the videoconference, while the dominant site may change frequently, only one site at a time is designated as dominant. Thus, only one video channel is required, rather than a high speed video channel from each site to the VCB, as was required in prior arrangements.
Inventors
- 👤 Jurgen W. Dannwolf
- 👤 Daniel Leed
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 18:48
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/42; H04M3/56; H04M3/567; H04N; H04N7/00; H04N7/14; H04N7/15; H04M2203/00; H04M2203/20; H04M2203/205
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
91 words
Apparatus for use at a site in a videoconference call system, said apparatus comprising means (216) for transmitting an audio signal, means (215) for receiving an audio signal, means (213) for receiving a control signal at various times in the videoconference, said control signal designating said site as either dominant or passive, and means (211,212,203,206) responsive to said control signal for transmitting a video signal when said control signal designates said site as dominant, and for inhibiting transmission of said video signal when said control signal designates said site as passive.
Claim 2
Dependent Claim
40 words
Apparatus as claimed in claim 1 wherein, in operation, the control signal is superimposed upon an incoming audio signal, and wherein the means for receiving the control signal comprises means for detecting the control signal in the incoming audio signal.
Claim 3
Dependent Claim
23 words
Apparatus as claimed in claim 1 or 2 wherein said means for transmitting comprises means for transmitting the video signal to a satellite.
Claim 4
Dependent Claim
87 words
A video conference bridge for implementing a videoconference among a plurality of sites, said bridge comprising means (122) for transmitting an audio signal from at least one site to at least one other site, means (113) for designating at least one of said sites as a dominant site, and for designating all remaining sites as passive sites, and means (114-117;105-108) for sending a control signal to one or more of the sites, said control signal being indicative of which of the sites has been designated as dominant.
Claim 5
Dependent Claim
32 words
A bridge as claimed in claim 4 wherein the means for sending comprises a plurality of couplers (105-108) for electromagnetically coupling control signal to each of a plurality of outgoing audio signals.
Claim 6
Dependent Claim
27 words
A bridge as claimed in claim 4 or 5 wherein the means for sending comprises a plurality of tone generators (114-117) for sending tones to the sites.
Claim 7
Dependent Claim
32 words
A bridge as claimed in claim 4,5 or 6 comprising a plurality of delay elements (118-121), each delay element being arranged to delay a separate audio signal being transmitted from the bridge.
Claim 8
Independent Claim
79 words
A method of implementing a videoconference among a plurality of sites, said method comprising the steps of receiving signals from a plurality of sites (A to D) at a video conference bridge, based upon said signals, designating at least one of said sites as dominant, and at least one of said sites as passive, and transmitting control signals to said sites, said control signals being indicative of whether each of said sites has been designated as dominant or passive.
Claim 9
Dependent Claim
27 words
A method as claimed in claim 8 wherein said step of transmitting comprises the step of superimposing said control signals upon audio signals at predetermined time intervals.
Claim 10
Dependent Claim
20 words
A method as claimed in claim 8 or 9 comprising the step of broadcasting the video signal from a satellite.
References Cited (Backward Citations)
No citation records indexed.
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