US6026080A
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US
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Method for providing enhanced H.321-based multimedia conferencing services over the ATM wide area network
Assignee: AT&T Inc
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Filing: 1997-04-29
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Granted: 2000-02-15
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Expires: 2017-04-29
Abstract
Abstract An enhanced H.321-based multipoint, multimedia conferencing service is provided over the ATM WAN interconnecting geographically dispersed H.321 terminals with a centralized H.321 MCU located within the WAN. The performance of H.321 multimedia conferencing services over the ATM WAN is improved by providing a modified WAN-based H.321 MCU which de-jiterizes cell delay variation and detects cell losses. The MCU supplies the reference clock signal that will be used by all communicating entities for synchronization, smoothes ATM cell delay variation and creates dummy bits in the case of cell losses, to create a more accurate H.221 frame. The information about the dummy bits of the H.221 frame is sent to upper layer entities to facilitate compensation at the appropriate positions of the cell/bit losses for audio and/or video traffic. The higher layer audio and video entities compensate for audio and/or video cell/bit losses with the information provided by the lower entities. In addition, intramedia and intermedia synchronization are provided for both audio and video traffic. Finally, transport protocol suits are incorporated on the top of H.221 layer to recover data cell losses or errors. Customer premises-based H.321 terminals may also employ the modified H.321 services noted above in the H.321 MCU to compensate for audio and/or video cell losses or errors for improvement of performance.
Inventors
- 👤 Radhika R. Roy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:52
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/14; H04N7/141; H04N7/147; H04N7/15; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04L; H04L12/00; H04L12/54; H04L12/56; H04L12/5601; H04L2012/5614; H04L2012/5616; H04L2012/5638; H04L2012/5646; H04L2012/5647; H04L2012/5672; H04L2012/5674
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
105 words
A method for providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of terminals interconnected by an ATM wide area network (WAN), the WAN having a modified H.321 MCU, said method comprising the steps of: receiving cells at the AAL-1 layer of the modified H.321 MCU protocol, the modified H.321 MCU protocol utilizing a modified Recommendation H.321 protocol; storing the cells in a buffer; determining if any cells have been lost; creating a corresponding number of dummy cells if a determination is made in said determining step that cells have been lost; transferring cell loss information to upper layers; forming an H.221 frame.
Claim 2
Independent Claim
105 words
A method for providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of terminals interconnected by an ATM wide area network (WAN), the WAN having a modified H.321 MCU, said method comprising the steps of: receiving cells at the AAL-1 layer of the modified H.321 MCU protocol, the modified H.321 MCU protocol utilizing a modified Recommendation H.321 protocol; storing the cells in a buffer; determining if any cells have been lost; creating a corresponding number of dummy cells if a determination is made in said determining step that cells have been lost; transferring cell loss information to upper layers; forming an H.221 frame.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the modified H.321 MCU acts as a common central clock signal source to synchronize all participating terminals at the dispersed plurality of locations.
Claim 4
Dependent Claim
180 words
The method of claim 2, wherein the modified H.321 MCU compensates for lost audio and video cells using the cell loss information transferred in said transferring step to upper layers, comprising the additional steps of: receiving video bit streams from the H.221 frame; determining if any dummy video cells are included in the H.221 frame, wherein, if a determination is made that dummy bits are included, the dummy video bits are replaced with new video bit-streams, determining if all bits of the video frame have been received, wherein if all bits of the video frame have been received, the video frame is formed; receiving audio bit streams from the H.221 frame; determining if any dummy audio bits are included in the H.221 frame, wherein, if a determination is made that dummy bits are included, the dummy audio bits are replaced with new audio bit-streams; determining if all bits of the audio frame have been received, wherein if all bits of the audio frame have been received, the audio segment is formed; and synchronizing the video frame and the audio segment.
Claim 5
Dependent Claim
20 words
The method of claim 3, wherein the modified H.321 MCU provides synchronization between the audio segment and the video frame.
Claim 6
Dependent Claim
28 words
The method of claim 2 wherein the modified H.321 MCU provides TCP and IP protocol suits on the top of an H.221 layer of an H.320 protocol entity.
Claim 7
Dependent Claim
27 words
The method of claim 5 wherein the TCP and IP protocol suits provide means to recover from data cell/packet losses or errors transferred in said transferring step.
Claim 8
Dependent Claim
25 words
The method of claim 6 wherein the modified H.321 MCU provides address translation services between the ATM WAN and a TCP and IP socket layer.
Claim 9
Dependent Claim
37 words
The method of claim 1 wherein the modified H.321 MCU may participate in a point-to-point call between terminals at call setup to provide address translation services, directory services, and call control services using a signaling virtual circuit.
Claim 10
Dependent Claim
19 words
The method of claim 1, wherein an actual information transfer occurs via an optimal path within the ATM WAN.
Claim 11
Independent Claim
115 words
A method for providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of locations interconnected by an ATM wide area network (WAN), the WAN having a modified H.321 MCU, said method comprising the steps of: receiving audio bit streams into the modified H.321 MCU from an H.221 frame; determining if any dummy audio bits are included in the H.221 frame, wherein, if a determination is made in said determining step that dummy bits are included, the dummy audio bits are replaced with new audio bit-streams, and determining if all bits of the audio frame have been received, wherein if all bits of the audio frame have been received, the audio segment is formed.
Claim 12
Independent Claim
115 words
A method for providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of locations interconnected by an ATM wide area network (WAN), the WAN having a modified H.321 MCU, said method comprising the steps of: receiving audio bit streams into the modified H.321 MCU from an H.221 frame; determining if any dummy audio bits are included in the H.221 frame, wherein, if a determination is made in said determining step that dummy bits are included, the dummy audio bits are replaced with new audio bit-streams, and determining if all bits of the audio frame have been received, wherein if all bits of the audio frame have been received, the audio segment is formed.
Claim 13
Dependent Claim
29 words
The method of claim 10 wherein the modified H.321 MCU acts as a common central clock signal source to synchronize all participating terminals at the dispersed plurality of locations.
Claim 14
Independent Claim
114 words
A method for providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of locations interconnected by an ATM wide area network (WAN), the WAN having a modified H.321 MCU, said method comprising the steps of: receiving video bit streams into the modified H.321 from an H.221 frame; determining if any dummy video bits are included in the H.221 frame, wherein, if a determination is made in said determining step that dummy bits are included, the dummy video bits are replaced with new video bit-streams, and determining if all bits of the video frame have been received, wherein if all bits of the video frame have been received, the video frame is formed.
Claim 15
Independent Claim
114 words
A method for providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of locations interconnected by an ATM wide area network (WAN), the WAN having a modified H.321 MCU, said method comprising the steps of: receiving video bit streams into the modified H.321 from an H.221 frame; determining if any dummy video bits are included in the H.221 frame, wherein, if a determination is made in said determining step that dummy bits are included, the dummy video bits are replaced with new video bit-streams, and determining if all bits of the video frame have been received, wherein if all bits of the video frame have been received, the video frame is formed.
Claim 16
Dependent Claim
29 words
The method of claim 12 wherein the modified H.321 MCU acts as a common central clock signal source to synchronize all participating terminals at the dispersed plurality of locations.
Claim 17
Independent Claim
194 words
A method for providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of locations interconnected by an ATM wide area network (WAN), the WAN having an H.321 MCU, said method comprising the steps of: receiving video bit streams into the modified H.321 MCU from an H.221 frame; determining if any dummy video bits are included in the H.221 frame, wherein, if a determination is made in said determining step that dummy bits are included, the dummy video bits are replaced with new video bit-streams, determining if all bits of the video frame have been received, wherein if all bits of the video frame have been received, the video frame is formed; receiving audio bit streams from an H.221 frame; determining if any dummy audio bits are included in the H.221 frame, wherein, if a determination is made in said determining step that dummy bits are included, the dummy audio bits are replaced with new audio bit-streams; determining if all bits of the audio frame have been received, wherein if all bits of the audio frame have been received, the audio segment is formed; and synchronizing the video frame and the audio segment.
Claim 18
Independent Claim
194 words
A method for providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of locations interconnected by an ATM wide area network (WAN), the WAN having an H.321 MCU, said method comprising the steps of: receiving video bit streams into the modified H.321 MCU from an H.221 frame; determining if any dummy video bits are included in the H.221 frame, wherein, if a determination is made in said determining step that dummy bits are included, the dummy video bits are replaced with new video bit-streams, determining if all bits of the video frame have been received, wherein if all bits of the video frame have been received, the video frame is formed; receiving audio bit streams from an H.221 frame; determining if any dummy audio bits are included in the H.221 frame, wherein, if a determination is made in said determining step that dummy bits are included, the dummy audio bits are replaced with new audio bit-streams; determining if all bits of the audio frame have been received, wherein if all bits of the audio frame have been received, the audio segment is formed; and synchronizing the video frame and the audio segment.
Claim 19
Dependent Claim
29 words
The method of claim 14 wherein the modified H.321 MCU acts as a common central clock signal source to synchronize all participating terminals at the dispersed plurality of locations.
Claim 20
Dependent Claim
28 words
The method of claim 14 wherein the modified H.321 MCU provides TCP and IP protocol suits on the top of an H.221 layer of an H.320 protocol entity.
Claim 21
Dependent Claim
27 words
The method of claim 16 wherein the TCP and IP protocol suits provide means to recover from data cell/packet losses or errors transferred in said transferring step.
Claim 22
Independent Claim
87 words
A method for providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of locations interconnected by an ATM wide area network (WAN), the WAN having a modified H.321 MCU, said method comprising the steps of: providing TCP and IP protocol suits on the top of an H.221 layer of an H.320 protocol entity for the modified H.321 MCU, the modified H.321 MCU utilizing a modified Recommendation H.321 protocol, wherein the TCP and IP protocol suits provide means to recover from data cell/packet losses or errors.
Claim 23
Independent Claim
87 words
A method for providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of locations interconnected by an ATM wide area network (WAN), the WAN having a modified H.321 MCU, said method comprising the steps of: providing TCP and IP protocol suits on the top of an H.221 layer of an H.320 protocol entity for the modified H.321 MCU, the modified H.321 MCU utilizing a modified Recommendation H.321 protocol, wherein the TCP and IP protocol suits provide means to recover from data cell/packet losses or errors.
Claim 24
Dependent Claim
29 words
The method of claim 18, wherein the modified H.321 MCU acts as a common central clock signal source to synchronize all participating terminals at the dispersed plurality of locations.
Claim 25
Independent Claim
120 words
A method of providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of terminals, interconnected by an ATM wide area network (WAN) having a modified H.321 MCU, wherein the plurality of terminals each include an H.321 terminal modified such that each terminal may perform a method comprising the steps of: receiving cells at an AAL-1 layer of the modified H.321 MCU protocol, the modified H.321 MCU protocol utilizing a modified Recommendation H.321 protocol; storing the cells in a buffer; determining if any cells have been lost; creating a corresponding number of dummy cells if a determination is made in said determining step that cells have been lost; transferring cell loss information to upper layers; forming an H.221 frame.
Claim 26
Independent Claim
120 words
A method of providing improved H.321-based multipoint multimedia conferencing services to a dispersed plurality of terminals, interconnected by an ATM wide area network (WAN) having a modified H.321 MCU, wherein the plurality of terminals each include an H.321 terminal modified such that each terminal may perform a method comprising the steps of: receiving cells at an AAL-1 layer of the modified H.321 MCU protocol, the modified H.321 MCU protocol utilizing a modified Recommendation H.321 protocol; storing the cells in a buffer; determining if any cells have been lost; creating a corresponding number of dummy cells if a determination is made in said determining step that cells have been lost; transferring cell loss information to upper layers; forming an H.221 frame.
Claim 27
Dependent Claim
29 words
The method of claim 20 wherein the modified H.321 MCU acts as a common central clock signal source to synchronize all participating terminals at the dispersed plurality of locations.
Claim 28
Dependent Claim
180 words
The method of claim 21, wherein each modified H.321 terminal compensates for lost audio and video cells using the cell loss information transferred in said transferring step to upper layers, comprising the additional steps of: receiving video bit streams from the H.221 frame; determining if any dummy video cells are included in the H.221 frame, wherein, if a determination is made that dummy bits are included, the dummy video bits are replaced with new video bit-streams, determining if all bits of the video frame have been received, wherein if all bits of the video frame have been received, the video frame is formed; receiving audio bit streams from the H.221 frame; determining if any dummy audio bits are included in the H.221 frame, wherein, if a determination is made that dummy bits are included, the dummy audio bits are replaced with new audio bit-streams; determining if all bits of the audio frame have been received, wherein if all bits of the audio frame have been received, the audio segment is formed; and synchronizing the video frame and the audio segment.
Claim 29
Dependent Claim
20 words
The method of claim 22, wherein each modified H.321 terminal provides synchronization between the audio segment and the video frame.
Claim 30
Dependent Claim
50 words
The method of claim 22 wherein each modified H.321 terminal provides TCP and IP protocol suits on the top of an H.221 layer of an H.320 protocol entity, wherein the TCP and IP protocol suits provide means to recover from data cell/packet losses or errors transferred in said transferring step.
Claim 31
Dependent Claim
30 words
The method of claim 7, wherein the address translation services between the ATM WAN and the TCP and IP socket layer allows registration or de-registration of TCP/IP socket layer addresses.
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) | 2003-02-14 | 2003-08-16 | 2004-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-02-14 | 2007-08-16 | 2008-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-02-14 | 2011-08-16 | 2012-02-15 | $7700.00 | Window Closed / Lapsed |