Patent EP0583094A2 successfully refreshed from Google Patents.
EP0583094A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
ISDN-based system for making a video call
Assignee: AT&T Inc
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Filing: 1993-07-22
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Granted: —
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Expires: 2013-07-22
Abstract
Abstract A single medium (audio) voice grade call (on 201) initiated by an ISDN video phone and directed to another ISDN video phone is converted into a multimedia (audio and video) ISDN call by a) maintaining the connection for the voice grade call (on 201) while the ISDN audio and video connection is being established over a bearer channel (230) of the ISDN subscriber loop different from the bearer channel (201) being used by the voice grade connection, b) switching the audio signals (on 201) from the voice grade call to the ISDN audio and video connection (on 230), once the ISDN audio and video connection is established, and c) disconnecting the initial voice grade call (on 201).
Inventors
- 👤 Nuri Ruhi Dagdeviren
- 👤 Khashayer Mohammadi
- 👤 Andreas Constantine Papanicolaou
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 20:49
CPC Classifications
H; H04; H04L; H04L65/00; H04L65/1066; H04L65/1069; H04Q; H04Q11/00; H04Q11/04; H04L65/1083; H04L65/1089; H04Q11/0428; H04Q11/0435; H04Q11/0471; H04L65/40; H04L65/403; H04Q2213/00; H04Q2213/13034; H04Q2213/13096; H04Q2213/13176; H04Q2213/13201; H04Q2213/13204; H04Q2213/13208; H04Q2213/13209; H04Q2213/13292; H04Q2213/13332; H04Q2213/13337; H04Q2213/1336; H04Q2213/204; H04Q2213/337; H04Q2213/392
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
120 words
A method of completing an ISDN audio and video call using an ISDN video phone served by an ISDN subscriber loop having at least first and second logical bearer channels and a logical signaling channel, wherein said method comprises the steps of: establishing an initial audio connection to an ISDN video phone through said first logical bearer channel of said loop; establishing an ISDN audio and video connection using said second logical bearer channel of said loop while said initial audio connection is still maintained active; switching audio signals from said initial audio connection of said first logical bearer channel to said ISDN audio and video connection of said second logical bearer channel; and tearing down said initial audio connection.
Claim 2
Dependent Claim
64 words
The method of claim 1, wherein said establishing step of said ISDN audio and video connection further includes the step of: transmitting call setup messages by one ISDN video phone to the other ISDN video phone, wherein said call setup messages include information related to communication protocol, synchronization, and allocation of bandwidth for audio and video signals of said ISDN audio and video connection.
Claim 3
Dependent Claim
52 words
The method of claim 1, wherein said tearing down step of said initial connection is followed by the step of: reusing said first logical channel of said initial audio connection by assigning bandwidth previously used for said initial audio connection to audio and video signals of said ISDN audio and video connection.
Claim 4
Dependent Claim
170 words
In a communication switching system arranged to route POTS traffic and ISDN traffic, a method of converting a voice grade audio call between two parties having ISDN video phones, to an ISDN audio and video call connecting said ISDN video phones, each one served by an ISDN subscriber loop having a first logical bearer channel, a second logical bearer channel and a logical signaling channel, wherein said method comprises the steps of: setting up said ISDN audio and video call while maintaining said voice grade call occupying said first logical bearer channel; transmitting call setup messages via said signaling channel of said ISDN subscriber loop; exchanging synchronization signals between said video phones via said second logical bearer channel of said video phone; switching audio signals from said first logical bearer channel to said second logical bearer channel for said ISDN audio and video call, whereby a graceful transition from the voice grade audio call to the ISDN audio and video call is achieved; and tearing down said voice grade call.
Claim 5
Dependent Claim
27 words
The method of claim 4, wherein said synchronization signals include information to allocate bandwidth for the audio and video signals of said ISDN audio and video call.
Claim 6
Dependent Claim
62 words
The method of claim 4, wherein said setting up step of said ISDN audio and video call includes the step of activating in one of said video phones a mechanism that is linked to a processor included in said video phones having a memory arranged to store i) received telephone numbers of incoming calls, and ii) dialed telephone numbers of outgoing calls;
Claim 7
Dependent Claim
43 words
The invention of claim 6, wherein said activating step further includes the steps of: retrieving from said memory the last received telephone number stored in said memory when said voice grade call was received by said video phone; and dialing said retrieved number.
Claim 8
Dependent Claim
46 words
The method of claim 6, wherein said activating of said mechanism step further includes the steps of retrieving from said memory the last dialed telephone number stored in said memory when said voice grade call was initiated by said video phone; and dialing said retrieved number.
Claim 9
Independent Claim
122 words
A system of completing an ISDN audio and video call using an ISDN video phone served by an ISDN subscriber loop having at least first and second logical bearer channels and a logical signaling channel, comprising means for establishing an initial audio connection to an ISDN video phone through said first logical bearer channel of said loop; means for establishing an ISDN audio and video connection using said second logical bearer channel of said loop while said initial audio connection is still maintained active; means for switching audio signals from said initial audio connection of said first logical bearer channel to said ISDN audio and video connection of said second logical bearer channel; and means for tearing down said initial audio connection.
Claim 10
Dependent Claim
65 words
The system of claim 9, wherein said establishing means of said ISDN audio and video connection further includes: means for transmitting call setup messages by one ISDN video phone to the other ISDN video phone, wherein said call setup messages include information related to communication protocol signals, synchronization frames, and allocation of bandwidth for audio and video signals of said ISDN audio and video connection.
Claim 11
Dependent Claim
50 words
The system of claim 9, wherein said tearing down means of said initial connection further include: means for reusing said first logical channel of said initial audio connection by assigning bandwidth previously used for said initial audio connection to audio and video signals of said ISDN audio and video connection.
Claim 12
Dependent Claim
174 words
In a communication switching system arranged to route POTS traffic and ISDN traffic, a system of converting a voice grade audio call between two parties having ISDN video phones, to an ISDN audio and video call connecting said ISDN video phones, each one served by an ISDN subscriber loop having a first logical bearer channel, a second logical bearer channel and a logical signaling channel, comprising: means for setting up said ISDN audio and video call while maintaining said voice grade call occupying said first logical bearer channel; means for transmitting call setup messages via said signaling channel of said ISDN subscriber loop; means for exchanging synchronization signals between said video phones via said second logical bearer channel of said video phone; means for switching audio signals from said first logical bearer channel to said second logical bearer channel for said ISDN audio and video call, whereby a graceful transition from the voice grade audio call to the ISDN audio and video call is achieved; and means for tearing down said voice grade call.
Claim 13
Dependent Claim
27 words
The system of claim 12, wherein said synchronization signals include information to allocate bandwidth for the audio and video signals of said ISDN audio and video call.
Claim 14
Dependent Claim
62 words
The system of claim 12, wherein said setting up means of said ISDN audio and video call further includes means for activating in one of said video phones a mechanism that is linked to a processor included in said video phones having a memory arranged to store i) telephone numbers received for incoming calls, and ii) telephone numbers dialed for outgoing calls;
Claim 15
Dependent Claim
44 words
The invention of claim 14, wherein said activating means further includes: means for retrieving from said memory the last received telephone number stored in said memory when said voice grade call was received by said video phone; and means for dialing said retrieved number.
Claim 16
Dependent Claim
47 words
The system of claim 14, wherein said activating of said mechanism means further includes: means for retrieving from said memory the last dialed telephone number stored in said memory when said voice grade call was initiated by said video phone; and means for dialing said retrieved number.
Claim 17
Dependent Claim
168 words
Apparatus for use in an ISDN video phone for converting a voice grade audio call to an ISDN multimedia call, said video phone being connected to an ISDN subscriber loop comprised of two logical bearer channels and a signaling channel, comprising: a processor which generates, transmits and receives a) call set up messages to initiate said multimedia call, and b) handshake protocol and synchronization signals to establish a communication path over a logical bearer channel different from the logical channel being used by said voice grade call; means included in said processor for storing telephone numbers dialed for an outgoing calls and telephone numbers received for incoming calls; means for triggering said processor to initiate said multimedia call by generating said call setup messages including one of either the last stored dialed telephone number or the last stored received number; a matrix switch controlled by said processor which switches incoming and outgoing audio signals from said logical channel used for said voice grade call to said communication path.
References Cited (Backward Citations)
No citation records indexed.
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