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United States Patent
5978835
Ludwig , ; et al.
November 2, 1999
Title
Multimedia mail, conference recording and documents in video conferencing
Abstract
A multimedia collaboration system that integrates separate real-time and asynchronous networks--the former for real-time audio and video, and the latter for control signals and textual, graphical and other data--in a manner that is interoperable across different computer and network operating system platforms and which closely approximates the experience of face-to-face collaboration, while liberating the participants from the limitations of time and distance. These capabilities are achieved by exploiting a variety of hardware, software and networking technologies in a manner that preserves the quality and integrity of audio/video/data and other multimedia information, even after wide area transmission, and at a significantly reduced networking cost as compared to what would be required by presently known approaches. The system architecture is readily scalable to the largest enterprise network environments. It accommodates differing levels of collaborative capabilities available to individual users and permits high-quality audio and video capabilities to be readily superimposed onto existing personal computers and workstations and their interconnecting LANs and WANs. In a particular preferred embodiment, a plurality of geographically dispersed multimedia LANs are interconnected by a WAN. The demands made on the WAN are significantly reduced by employing multi-hopping techniques, including dynamically avoiding the unnecessary decompression of data at intermediate hops, and exploiting video mosaicing, cut-and-paste and audio mixing technologies so that significantly fewer wide area transmission paths are required while maintaining the high quality of the transmitted audio/video.
Inventors:
Ludwig; Lester F.
(Foster City,
CA
)
, Lauwers; J. Chris
(Menlo Park,
CA
)
, Lantz; Keith A.
(Los Altos,
CA
)
, Burnett; Gerald J.
(Atherton,
CA
)
, Burns; Emmett R.
(Incline Village,
NV
)
Assignee:
Collaboration Properties, Inc.
(Incline Village,
NV
)
Appl. No.:
659949
Filed:
June 7, 1996
Current U.S. Class:
709/204
709/231
Field of Search:
395/324,330,806,807,773,331,200.04,200.34,200.35,200.36,200.37 379/201,202,204,205,206 370/260,261 707/515,530,901,902 709/204,205,206,207,231,248
U.S. Patent Documents
5315633
May 1994
Champa
5363507
November 1994
Nakayama et al.
5404435
April 1995
Rosenbaum
5408526
April 1995
McFarland et al.
5471318
November 1995
Ahuja et al.
Other References
Crawford et al., "Videomatic Switching: System and Services," Digital Communications, 1988 Int. (1988). .
Rangan et al. "Software Architecture for Integration of Video Services in the Etherphone System", IEEE Journal of Selected Area in Comm., V.9 n.9, Dec. 1991. .
Maneno et al. "Distributed Desktop Conferencing System (MERMAID) based on Group Communication Architecture", Communications--1991 IEEE Intl. Conf., 1991..~
Primary Examiner:
Dinh; Dung C.
Attorney, Agent or Firm:
Cooley Godward LLP Opperman, Esq.; Craig P.
Parent Case Text
STATEMENT OF RELATED CASES
This application is a division of application Ser. No. 08/131,523 filed Oct. 1, 1993 and issued as U.S. Pat. No. 5,689,641. This application is also related to other patents and applications claiming the priority of Ser. No. 08/131,523, in particular, application Ser. No. 08/661,530 now U.S. Pat. No. 5,915,091.
Claims
We claim:
1. A method for conducting a teleconference among a plurality of participants, comprising the steps of:
(a) capturing audio and video generated, during a videoconference, at the workstation of a preparing participant;
(b) preparing and storing, as a multimedia mail message, the captured video and audio; and
(c) managing a data conference during which data is shared among a plurality of the participants having workstations including monitors configured to reproduce the shared data;
(d) synchronizing both the video image and spoken audio of the participants during the videoconference and the data shared during the data conference;
(e) recording the synchronized video, audio and data as a multimedia message; and
(f) forwarding the multimedia mail message for receipt, by a receiving participant, at any one of the venues selected from the group consisting of
(i) in real time at a location removed from the preparing participant;
(ii) at a different time at the same location as the message was prepared; and
(iii) at a different time at a location removed from the preparing participant, in such a manner that subsequent playback of the recorded message will represent the relationship in which the audio, video and data were originally represented.
2. The method of claim 1, further comprising the steps of
(a) defining a marked portion of a multimedia mail message; and
(b) selectively displaying the marked portion when the multimedia mail message is reproduced.
3. The method of claim 2, further comprising the steps of:
(a) searching for a defined tag; and
(b) selectively displaying the portion of the message.
4. The method of claim 1, further comprising the steps of:
(a) capturing the data to be shared; and
(b) annotating the shared data during the data conference.
5. The method of claim 1, further comprising the step of storing a multimedia document such that the multimedia document can be retrieved by a participant.
6. A teleconferencing system comprising:
(a) at least one video signal source;
(b) at least one audio source;
(c) at least one video display device;
(d) at least one audio reproduction facility;
(e) at least one video communication path
(i) arranged for transport of audio and video signals,
(1) originating at one of the signal sources,
(2) to at least one of the display devices;
wherein the system is configured to
(ii) reproduce video images and audio,
(1) based on the transported video and audio signals,
(2) at one of the display devices,
(3) to define a video conference;
(f) at least one processor
(1) capable of providing data conferencing signals;
(g) at least one data communication path
(i) arranged for transmission of
(1) data conferencing visual information signals,
(ii) to one of the display devices;
wherein the system is further configured to
(iii) display visual information,
(1) based on the carried data conferencing signals,
(2) at one of the display devices
(3) to define a data conference;
(h) data annotation tools,
(i) that permit at least one associated participant
(1) to annotate the visual information displayed during the data conference; and
(f) at least one storage medium configured to
(i) store at least some of the data signals, annotations and related audio and/or video signals
(1) from the data and video conferences
(2) for subsequent retrieval, and
(3) synchronized play back
(4) in a manner representing the relationship in which they were created.
7. The teleconferencing system of claim 6, further comprising:
(a) a multimedia mail subsystem operable to receive and store multimedia mail messages under direction of at least one preparing participant.
8. The teleconferencing system of claim 7, wherein the multimedia mail is operable to process mail messages having at least one component selected from the group consisting of audio, video and data components.
9. The teleconferencing system of claim 6, wherein the AV capture tools, data capture tools and data annotation tools can be used to generate a multimedia document capable of being stored, in real time, on the storage medium.
10. The teleconferencing system of claim 9, further comprising:
(a) a multimedia mail system, in communication with the storage medium and configured to allow a sending participant to send the multimedia document to a receiving participant at a venue selected from the group consisting of:
(i) in real time at a location removed from the preparing participant;
(ii) at a different time at the same location as the document was prepared; and
(iii) at a different time at a location removed from the preparing participant.
11. The teleconferencing system of claim 10, wherein the multimedia mail system is in communication with a graphical animations originator device which can generate, save and replay animated graphical images that can be included in the multimedia mail document.
12. The teleconferencing system of claim 11, further comprising:
(a) a message marker that can be used to mark a portion of the multimedia document, wherein the marked portion can be selectively displayed by the receiving participant when the multimedia document is reproduced.
13. A teleconferencing system comprising:
(a) at least one video signal source;
(b) at least one audio source;
(c) at least one video display device;
(d) at least one audio reproduction facility;
(e) at least one video communication path
(i) arranged for transport of audio and video signals,
(1) originating at one of the signal sources,
(2) to at least one of the display devices;
wherein the system is configured to
(i) reproduce video images and audio,
(1) based on the transported video and audio signals,
(2) at one of the display devices,
(3) to define a video conference;
(f) at least one processor
(1) capable of providing data conferencing signals;
(g) at least one data communication path
(i) arranged for transmission of
(1) data conferencing visual information signals,
(ii) to one of the display devices;
wherein the system is further configured to
(i) display visual information,
(1) based on the carried data conferencing signals,
(2) at one of the display devices
(3) to define a data conference; and
(f) at least one storage medium configured to
(i) store at least some of the data signals plus related audio and/or video signals
(1) from the data and video conferences
(2) for subsequent retrieval, and
(3) synchronized play back
(4) in a manner representing the relationship in which they were created,
the system still further configured to
(i) prepare and store,
(1) as a multimedia mail message,
(2) the captured and annotated data, and
(ii) forward the multimedia mail message
(1) to a receiving participant,
(iii) such that the multimedia mail message can be received at a venue selected from the group consisting of:
(1) in real time at a location removed from the preparing participant;
(2) at a different time at the same location as the message was prepared; and
(3) at a different time at a location removed from the preparing participant.
14. The teleconferencing system of claim 13, further comprising
(a) a graphical animations originator device which can
(1) generate, save and replay animated graphical images
(2) to be included in the multimedia mail message.
15. The teleconferencing system of claim 13, further comprising:
(a) a message marker capable of defining a marked portion of the multimedia mail message, wherein the marked portion can be selectively displayed a the receiving participant when the multimedia mail message is reproduced.
16. The teleconferencing system of claim 15, further comprising a tag searcher configured to search for a defined tag, such that the portion of the message can be selectively displayed.
17. The teleconferencing system of claim 16, wherein the tag searcher can search a plurality of multimedia mail messages to locate the defined tag.
18. The teleconferencing system of claim 13, wherein the system is further configured to
(a) store audio and/or video signals
(i) which are either analog or digital signals.
19. A teleconferencing system comprising:
(a) at least one video signal source;
(b) at least one audio source;
(c) at least one video display device;
(d) at least one audio reproduction facility;
(e) at least one video communication path
(i) arranged for transport of audio and video signals,
(1) originating at one of the signal sources,
(2) to at least one of the display devices;
wherein the system is configured to
(i) reproduce video images and audio,
(1) based on the transported video and audio signals,
(2) at one of the display devices,
(3) to define a video conference;
(f) at least one processor
(1) capable of providing data conferencing signals;
(g) at least one data communication path
(i) arranged for transmission of
(1) data conferencing visual information signals,
(ii) to one of the display devices;
wherein the system is further configured to
(i) display visual information,
(1) based on the carried data conferencing signals,
(2) at one of the display devices
(3) to define a data conference;
(h) a multimedia conference recorder capable of
(i) synchronizing and recording
(1) both the video image and spoken audio of participants in the videoconference and
(2) the visual information displayed during the data conference; and
(f) at least one storage medium configured to
(i) store at least some of the data signals plus related audio and/or video signals
(1) from the data and video conferences
(2) for subsequent retrieval, and
(3) synchronized play back
(4) in a manner representing the relationship in which they were created.
20. The teleconferencing system of claim 19, wherein the recorded video images and audio includes video images and spoken audio directly associated with the participants and at least one other video image and spoken audio not directly associated with the preparing participants.
21. The teleconferencing system of claim 19, further comprising:
(a) annotation tools capable of annotating the shared data during a data conference, wherein the the system is further configured
(i) to synchronize the playback of the annotated data conference recordings with the videoconference recordings.
22. The teleconferencing system of claim 19, wherein the system is further configured to store and retrieve both the video image and spoken audio of the preparing participant and the recorded video image and spoken audio.
23. A method of making and storing a multimedia message, comprising the steps of:
(a) capturing
(i) images and/or audio
(ii) of a user
(iii) at an associated workstation;
(b) creating
(i) data signals,
(1) representing visual information
(2) other than the captured image
(ii) during the step of capturing;
(c) reproducing
(i) one or more of
(1) the visual information and
(2) captured image
(3) at the workstation; and
(d) storing
(i) the audio and/or video signals and
(ii) the associated visual information
(iii) in a synchronized manner
(iv) such that subsequent retrieval and playback
(1) of the associated visual information and the captured image and/or audio
(2) is in a manner representing the relationship in which they were created.
Description
BACKGROUND OF THE INVENTION
The present invention relates to computer-based systems for enhancing collaboration between and among individuals who are separated by distance and/or time (referred to herein as "distributed collaboration"). Principal among the invention's goals is to replicate in a desktop environment, to the maximum extent possible, the full range, level and intensity of interpersonal communication and information sharing which would occur if all the participants were together in the same room at the same time (referred to herein as "face-to-face collaboration").
It is well known to behavioral scientists that interpersonal communication involves a large number of subtle and complex visual cues, referred to by names like "eye contact" and "body language," which provide additional information over and above the spoken words and explicit gestures. These cues are, for the most part, processed subconsciously by the participants, and often control the course of a meeting.
In addition to spoken words, demonstrative gestures and behavioral cues, collaboration often involves the sharing of visual information--e.g., printed material such as articles, drawings, photographs, charts and graphs, as well as videotapes and computer-based animations, visualizations and other displays--in such a way that the participants can collectively and interactively examine, discuss, annotate and revise the information. This combination of spoken words, gestures, visual cues and interactive data sharing significantly enhances the effectiveness of collaboration in a variety of contexts, such as "brainstorming" sessions among professionals in a particular field, consultations between one or more experts and one or more clients, sensitive business or political negotiations, and the like. In distributed collaboration settings, then, where the participants cannot be in the same place at the same time, the beneficial effects of face-to-face collaboration will be realized only to the extent that each of the remotely located participants can be "recreated" at each site.
To illustrate the difficulties inherent in reproducing the beneficial effects of face-to-face collaboration in a distributed collaboration environment, consider the case of decision-making in the fast-moving commodities trading markets, where many thousands of dollars of profit (or loss) may depend on an expert trader making the right decision within hours, or even minutes, of receiving a request from a distant client. The expert requires immediate access to a wide range of potentially relevant information such as financial data, historical pricing information, current price quotes, newswire services, government policies and programs, economic forecasts, weather reports, etc. Much of this information can be processed by the expert in isolation. However, before making a decision to buy or sell, he or she will frequently need to discuss the information with other experts, who may be geographically dispersed, and with the client. One or more of these other experts may be in a meeting, on another call, or otherwise temporarily unavailable. In this event, the expert must communicate "asynchronously"--to bridge time as well as distance.
As discussed below, prior art desktop videoconferencing systems provide, at best, only a partial solution to the challenges of distributed collaboration in real time, primarily because of their lack of high-quality video (which is necessary for capturing the visual cues discussed above) and their limited data sharing capabilities. Similarly, telephone answering machines, voice mail, fax machines and conventional electronic mail systems provide incomplete solutions to the problems presented by deferred (asynchronous) collaboration because they are totally incapable of communicating visual cues, gestures, etc. and, like conventional videoconferencing systems, are generally limited in the richness of the data that can be exchanged.
It has been proposed to extend traditional videoconferencing capabilities from conference centers, where groups of participants must assemble in the same room, to the desktop, where individual participants may remain in their office or home. Such a system is disclosed in U.S. Pat. No. 4,710,917 to Tompkins et al. for Video Conferencing Network issued on Dec. 1, 1987. It has also been proposed to augment such video conferencing systems with limited "video mail" facilities. However, such dedicated videoconferencing systems (and extensions thereof) do not effectively leverage the investment in existing embedded information infrastructures--such as desktop personal computers and workstations, local area network (LAN) and wide area network (WAN) environments, building wiring, etc.--to facilitate interactive sharing of data in the form of text, images, charts, graphs, recorded video, screen displays and the like. That is, they attempt to add computing capabilities to a videoconferencing system, rather than adding multimedia and collaborative capabilities to the user's existing computer system. Thus, while such systems may be useful in limited contexts, they do not provide the capabilities required for maximally effective collaboration, and are not cost-effective.
Conversely, audio and video capture and processing capabilities have recently been integrated into desktop and portable personal computers and workstations (hereinafter generically referred to as "workstations"). These capabilities have been used primarily in desktop multimedia authoring systems for producing CD-ROM-based works. While such systems are capable of processing, combining, and recording audio, video and data locally (i.e., at the desktop), they do not adequately support networked collaborative environments, principally due to the substantial bandwidth requirements for real-time transmission of high-quality, digitized audio and full-motion video which preclude conventional LANs from supporting more than a few workstations. Thus, although currently available desktop multimedia computers frequently include videoconferencing and other multimedia or collaborative capabilities within their advertised feature set (see, e.g., A. Reinhardt, "Video Conquers the Desktop," BYTE, September 1993, pp. 64-90), such systems have not yet solved the many problems inherent in any practical implementation of a scalable collaboration system.
SUMMARY OF THE INVENTION
In accordance with the present invention, computer hardware, software and communications technologies are combined in novel ways to produce a multimedia collaboration system that greatly facilitates distributed collaboration, in part by replicating the benefits of face-to-face collaboration. The system tightly integrates a carefully selected set of multimedia and collaborative capabilities, principal among which are desktop teleconferencing and multimedia mail.
As used herein, desktop teleconferencing includes real-time audio and/or video teleconferencing, as well as data conferencing. Data conferencing, in turn, includes snapshot sharing (sharing of "snapshots" of selected regions of the user's screen), application sharing (shared control of running applications), shared whiteboard (equivalent to sharing a "blank" window), and associated telepointing and annotation capabilities. Teleconferences may be recorded and stored for later playback, including both audio/video and all data interactions.
While desktop teleconferencing supports real-time interactions, multimedia mail permits the asynchronous exchange of arbitrary multimedia documents, including previously recorded teleconferences. Indeed, it is to be understood that the multimedia capabilities underlying desktop teleconferencing and multimedia mail also greatly facilitate the creation, viewing, and manipulation of high-quality multimedia documents in general, including animations and visualizations that might be developed, for example, in the course of information analysis and modeling. Further, these animations and visualizations may be generated for individual rather than collaborative use, such that the present invention has utility beyond a collaboration context.
The preferred embodiment of the invention is a collaborative multimedia workstation (CMW) system wherein very high-quality audio and video capabilities can be readily superimposed onto an enterprise's existing computing and network infrastructure, including workstations, LANs, WANs, and building wiring.
In a preferred embodiment, the system architecture employs separate real-time and asynchronous networks--the former for real-time audio and video, and the latter for non-real-time audio and video, text, graphics and other data, as well as control signals. These networks are interoperable across different computers (e.g., Macintosh, Intel-based PCs, and Sun workstations), operating systems (e.g., Apple System 7, DOS/Windows, and UNIX) and network operating systems (e.g., Novell Netware and Sun ONC+). In many cases, both networks can actually share the same cabling and wall jack connector.
The system architecture also accommodates the situation in which the user's desktop computing and/or communications equipment provides varying levels of media-handling capability. For example, a collaboration session--whether real-time or asynchronous--may include participants whose equipment provides capabilities ranging from audio only (a telephone) or data only (a personal computer with a modem) to a full complement of real-time, high-fidelity audio and full-motion video, and high-speed data network facilities.
The CMW system architecture is readily scalable to very large enterprise-wide network environments accommodating thousands of users. Further, it is an open architecture that can accommodate appropriate standards. Finally, the CMW system incorporates an intuitive, yet powerful, user interface, making the system easy to learn and use.
The present invention thus provides a distributed multimedia collaboration environment that achieves the benefits of face-to-face collaboration as nearly as possible, leverages ("snaps on to") existing computing and network infrastructure to the maximum extent possible, scales to very large networks consisting of thousand of workstations, accommodates emerging standards, and is easy to learn and use. The specific nature of the invention, as well as its objects, features, advantages and uses, will become more readily apparent from the following detailed description and examples, and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enterprise view of a desktop collaboration system embodiment of the present invention.
FIGS. 2A and 2B are photographs which attempt to illustrate, to the extent possible in a still image, the high-quality of the full-motion video and related user interface displays that appear on typical CMW screens which may be generated during operation of a preferred embodiment of the invention.
FIG. 3 is a block and schematic diagram of a preferred embodiment of a "multimedia local area network" (MLAN) in accordance with a desktop collaboration system embodiment of the present invention.
FIG. 4 is a block and schematic diagram illustrating how a plurality of geographically dispersed MLANs of the type shown in FIG. 3 can be connected via a wide area network in accordance with the present invention.
FIG. 5 is a schematic diagram illustrating how collaboration sites at distant locations L1-L8 are conventionally interconnected over a wide area network by individually connecting each site to every other site.
FIG. 6 is a schematic diagram illustrating how collaboration sites at distant locations L1-L8 are interconnected over a wide area network in a preferred embodiment of the invention using a multi-hopping approach.
FIG. 7 is a block diagram illustrating a preferred embodiment of video mosaicing circuitry provided in the MLAN of FIG. 3.
FIGS. 8A, 8B and 8C illustrate the video window on a typical CMW screen which may be generated during operation of a preferred embodiment of the present invention, and which contains only the callee for two-party calls (8A) and a video mosaic of all participants, e.g., for four-party (8B) or eight-party (8C) conference calls.
FIG. 9 is a block diagram illustrating a preferred embodiment of audio mixing circuitry provided in the MLAN of FIG. 3.
FIG. 10 is a block diagram illustrating video cut-and-paste circuitry provided in the MLAN of FIG. 3.
FIG. 11 is a schematic diagram illustrating typical operation of the video cut-and-paste circuitry in FIG. 10.
FIGS. 12-17 (consisting of FIGS. 12A, 12B, 13A, 13B, 14A, 14B, 15A, 15B, 16, 17A and 17B) illustrate various examples of how a preferred embodiment of the present invention provides video mosaicing, video cut-and-pasting, and audio mixing at a plurality of distant sites for transmission over a wide area network in order to provide, at the CMW of each conference participant, video images and audio captured from the other conference participants.
FIGS. 18A and 18B illustrate various preferred embodiments of a CMW which may be employed in accordance with the present invention.
FIG. 19 is a schematic diagram of a preferred embodiment of a CMW add-on box containing integrated audio and video I/O circuitry in accordance with the present invention.
FIG. 20 illustrates CMW software in accordance with a preferred embodiment of the present invention, integrated with standard multitasking operating system and applications software.
FIG. 21 illustrates software modules which may be provided for running on the MLAN Server in the MLAN of FIG. 3 for controlling operation of the AV and Data Networks.
FIG. 22 illustrates an enlarged example of "speed-dial" face icons of certain collaboration participants in a Collaboration Initiator window on a typical CMW screen which may be generated during operation of a preferred embodiment of the present invention.
FIG. 23 is a diagrammatic representation of the basic operating events occurring in a preferred embodiment of the present invention during initiation of a two-party call.
FIG. 24 is a block and schematic diagram illustrating how physical connections are established in the MLAN of FIG. 3 for physically connecting first and second workstations for a two-party videoconference call.
FIG. 25 is a block and schematic diagram illustrating how physical connections are preferably established in MLANs such as illustrated in FIG. 3, for a two-party call between a first CMW located at one site and a second CMW located at a remote site.
FIGS. 26 and 27 are block and schematic diagrams illustrating how conference bridging is preferably provided in the MLAN of FIG. 3.
FIG. 28 diagrammatically illustrates how a snapshot with annotations may be stored in a plurality of bitmaps during data sharing.
FIG. 29 is a schematic and diagrammatic illustration of the interaction among multimedia mail (MMM), multimedia call/conference recording (MMCR) and multimedia document management (MMDM) facilities.
FIG. 30 is a schematic and diagrammatic illustration of the multimedia document architecture employed in a preferred embodiment of the invention.
FIG. 31A illustrates a centralized Audio/Video Storage Server.
FIG. 31B is a schematic and diagrammatic illustration of the interactions between the Audio/Video Storage Server and the remainder of the CMW System.
FIG. 31C illustrates an alternative embodiment of the interactions illustrated in FIG. 31B.
FIG. 31D is a schematic and diagrammatic illustration of the integration of MMM, MMCR and MMDM facilities in a preferred embodiment of the invention.
FIG. 32 illustrates a generalized hardware implementation of a scalable Audio/Video Storage Server.
FIG. 33 illustrates a higher throughput version of the server illustrated in FIG. 32, using SCSI-based crosspoint switching to increase the number of possible simultaneous file transfers.
FIG. 34 illustrates the resulting multimedia collaboration environment achieved by the integration of audio/video/data teleconferencing and MMCR, MMM and MMDM.
FIGS. 35-42 illustrate a series of CMW screens which may be generated during operation of a preferred embodiment of the present invention for a typical scenario involving a remote expert who takes advantage of many of the features provided by the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Overall System Architecture
Referring initially to FIG. 1, illustrated therein is an overall diagrammatic view of a multimedia collaboration system in accordance with the present invention. As shown, each of a plurality of "multimedia local area networks" (MLANs) 10
connects, via lines 13, a plurality of CMWs 12-1 to 12-10 and provides audio/video/data networking for supporting collaboration among CMW users. WAN 15 in turn connects multiple MLANs 10, and typically includes appropriate combinations of common carrier analog and digital transmission networks. Multiple MLANs 10 on the same physical premises may be connected via bridges/routes 11, as shown, to WANs and one another.
In accordance with the present invention, the system of FIG. 1 accommodates both "real time" delay- and jitter-sensitive signals (e.g., real-time audio and video teleconferencing) and classical asynchronous data (e.g., data control signals as well as shared textual, graphics and other media) communication among multiple CMWs 12 regardless of their location. Although only ten CMWs 12 are illustrated in FIG. 1, it will be understood that many more could be provided. As also indicated in FIG.
1, various other multimedia resources 16 (e.g., VCRs, laserdiscs, TV feeds, etc.) are connected to MLANs 10 and are thereby accessible by individual CMWs 12.
CMW 12 in FIG. 1 may use any of a variety of types of operating systems, such as Apple System 7, UNIX, DOS/Windows and OS/2. The CMWs can also have different types of window systems. Specific preferred embodiments of a CMW 12 are described hereinafter in connection with FIGS. 18A and 18B. Note that this invention allows for a mix of operating systems and window systems across individual CMWs.
In the preferred embodiment, CMW 12 in FIG. 1 provides real-time audio/video/data capabilities along with the usual data processing capabilities provided by its operating system. CMW 12 also provides for bidirectional communication, via lines
13, within MLAN 10, for audio/video signals as well as data signals. Audio/video signals transmitted from a CMW 12 typically comprise a high-quality live video image and audio of the CMW operator. These signals are obtained from a video camera and microphone provided at the CMW (via an add-on unit or partially or totally integrated into the CMW), processed, and then made available to low-cost network transmission subsystems.
Audio/video signals received by a CMW 12 from MLAN 10 may typically include: video images of one or more conference participants and associated audio, video and audio from multimedia mail, previously recorded audio/video from previous calls and conferences, and standard broadcast television (e.g., CNN). Received video signals are displayed on the CMW screen or on an adjacent monitor, and the accompanying audio is reproduced by a speaker provided in or near the CMW. In general, the required transducers and signal processing hardware could be integrated into the CMW, or be provided via a CMW add-on unit, as appropriate.
In the preferred embodiment, it has been found particularly advantageous to provide the above-described video at standard NTSC-quality TV performance (i.e., 30 frames per second at 640.times.480 pixels per frame and the equivalent of 24 bits of color per pixel) with accompanying high-fidelity audio (typically between 7 and 15 KHz). For example, FIG. 2A illustrates a CMW screen containing live, full-motion video of three conference participants, while FIG. 2B illustrates data shared and annotated by those conferees (lower left window).
MULTIMEDIA LOCAL AREA NETWORK
Referring next to FIG. 3, illustrated therein is a preferred embodiment of MLAN 10 having ten CMWs (12-1, 12-2, - - - 12-10), coupled therein via lines 13a and 13b. MLAN 10 typically extends over a distance from a few hundred feet to a few miles, and is usually located within a building or a group of proximate buildings.
Given the current state of networking technologies, it is useful (for the sake of maintaining quality and minimizing costs) to provide separate signal paths for real-time audio/video and classical asynchronous data communications (including digitized audio and video enclosures of multimedia mail messages that are free from real-time delivery constraints). At the moment, analog methods for carrying real-time audio/video are preferred. In the future, digital methods may be used. Eventually, digital audio and video signal paths may be multiplexed with the data signal path as a common digital stream. Another alternative is to multiplex real-time and asynchronous data paths together using analog multiplexing methods. For the purposes of the present application, however, we will treat these two signal paths as using physically separate wires. Further, as the current preferred embodiment uses analog networking for audio and video, it also physically separates the real-time and asynchronous switching vehicles and, in particular, assumes an analog audio/video switch. In the future, a common switching vehicle (e.g., ATM) could be used.
The MLAN 10 thus can be implemented in the preferred embodiment using conventional technology, such as typical Data LAN hubs 25 and A/V Switching Circuitry 30 (as used in television studios and other closed-circuit television networks), linked to the CMWs 12 via appropriate transceivers and unshielded twisted pair (UTP) wiring. Note in FIG. 1 that lines 13, which interconnect each CMW 12 within its respective MLAN 10, comprise two sets of lines 13a and 13b. Lines 13a provide bidirectional communication of audio/video within MLAN 10, while lines 13b provide for the bidirectional communication of data. This separation permits conventional LANs to be used for data communications and a supplemental network to be used for audio/video communications. Although this separation is advantageous in the preferred embodiment, it is again to be understood that audio/video/data networking can also be implemented using a single pair of lines for both audio/video and data communications via a very wide variety of analog and digital multiplexing schemes.
While lines 13a and 13b may be implemented in various ways, it is currently preferred to use commonly installed 4-pair UTP telephone wires, wherein one pair is used for incoming video with accompanying audio (mono or stereo) multiplexed in, wherein another pair is used for outgoing multiplexed audio/video, and wherein the remaining two pairs are used for carrying incoming and outgoing data in ways consistent with existing LANs. For example, 10BaseT Ethernet uses RJ-45 pins 1, 2, 4, and 6, leaving pins 3, 5, 7, and 8 available for the two A/V twisted pairs. The resulting system is compatible with standard (AT&T 258A, EIA/TIA 568, 8P8C, 10BaseT, ISDN, 6P6C, etc.) telephone wiring found commonly throughout telephone and LAN cable plants in most office buildings throughout the world. These UTP wires are used in a hierarchy or peer arrangements of star topologies to create MLAN 10, described below. Note that the distance range of the data wires often must match that of the video and audio. Various UTP-compatible data LAN networks may be used, such as Ethernet, token ring, FDDI, ATM, etc. For distances longer than the maximum distance specified by the data LAN protocol, data signals can be additionally processed for proper UTP operations.
As shown in FIG. 3, lines 13a from each CMW 12 are coupled to a conventional Data LAN hub 25, which facilitates the communication of data (including control signals) among such CMWs. Lines 13b in FIG. 3 are connected to A/V Switching Circuitry
30. One or more conference bridges 35 are coupled to A/V Switching Circuitry 30 and possibly (if needed) the Data LAN hub 25, via lines 35b and 35a, respectively, for providing multi-party Conferencing in a particularly advantageous manner, as will hereinafter be described in detail. A WAN gateway 40 provides for bidirectional communication between MLAN 10 and WAN 15 in FIG. 1. For this purpose, Data LAN hub 25 and A/V Switching Circuitry 30 are coupled to WAN gateway 40 via outputs 25a and 30a, respectively. Other devices connect to the A/V Switching Circuitry 30 and Data LAN hub 25 to add additional features (such as multimedia mail, conference recording, etc.) as discussed below.
Control of A/V Switching Circuitry 30, conference bridges 35 and WAN gateway 40 in FIG. 3 is provided by MLAN Server 60 via lines 60b, 60c, and 60d, respectively. In a preferred embodiment, MLAN Server 60 supports the TCP/IP network protocol suite. Accordingly, software processes on CMWs 12 communicate with one another and MLAN Server 60 via MLAN 10 using these protocols. Other network protocols could also be used, such as IPX. The manner in which software running on MLAN Server 60
controls the operation of MLAN 10 will be described in detail hereinafter.
Note in FIG. 3 that Data LAN hub 25, A/V Switching Circuitry 30 and MLAN Server 60 also provide respective lines 25b, 30b, and 60e for coupling to additional multimedia resources 16 (FIG. 1), such as multimedia document management, multimedia databases, radio/TV channels, etc. Data LAN hub 25 (via bridges/routers 11 in FIG. 1) and A/V Switching Circuitry 30 additionally provide lines 25c and 30c for coupling to one or more other MLANs 10 which may be in the same locality (i.e., not far enough away to require use of WAN technology). Where WANs are required, WAN gateways 40 are used to provide highest quality compression methods and standards in a shared resource fashion, thus minimizing costs at the workstation for a given WAN quality level, as discussed below.
The basic operation of the preferred embodiment of the resulting collaboration system shown in FIGS. 1 and 3 will next be considered. Important features of the present invention reside in providing not only multi-party real-time desktop audio/video/data teleconferencing among geographically distributed CMWs, but also in providing from the same desktop audio/video/data/text/graphics mail capabilities, as well as access to other resources, such as databases, audio and video files, overview cameras, standard TV channels, etc. FIG. 2B illustrates a CMW screen showing a multimedia EMAIL mailbox (top left window) containing references to a number of received messages along with a video enclosure (top right window) to the selected message.
A/V Switching Circuitry 30 (whether digital or analog as in the preferred embodiment) provides common audio/video switching for CMWs 12, conference bridges 35, WAN gateway 40 and multimedia resources 16, as determined by MLAN Server 60, which in turn controls conference bridges 35 and WAN gateway 40. Similarly, asynchronous data is communicated within MLAN 10 utilizing common data communications formats where possible (e.g., for snapshot sharing) so that the system can handle such data in a common manner, regardless of origin, thereby facilitating multimedia mail and data sharing as well as audio/video communications.
For example, to provide multi-party teleconferencing, an initiating CMW 12 signals MLAN Server 60 via Data LAN hub 25 identifying the desired conference participants. After determining which of these conferees will accept the call, MLAN Server
60 controls A/V Switching Circuitry 30 (and CMW software via the data network) to set up the required audio/video and data paths to conferees at the same location as the initiating CMW.
When one or more conferees are at distant locations, the respective MLAN Servers 60 of the involved MLANs 10, on a peer-to-peer basis, control their respective A/V Switching Circuitry 30, conference bridges 35, and WAN gateways 40 to set up appropriate communication paths (via WAN 15 in FIG. 1) as required for interconnecting the conferees. MLAN Servers 60 also communicate with one another via data paths so that each MLAN 10 contains updated information as to the capabilities of all of the system CMWs 12, and also the current locations of all parties available for teleconferencing.
The data conferencing component of the above-described system supports the sharing of visual information at one or more CMWs (as described in greater detail below). This encompasses both "snapshot sharing" (sharing "snapshots" of complete or partial screens, or of one or more selected windows) and "application sharing" (sharing both the control and display of running applications). When transferring images, lossless or slightly lossy image compression can be used to reduce network bandwidth requirements and user-perceived delay while maintaining high image quality.
In all cases, any participant can point at or annotate the shared data. These associated telepointers and annotations appear on every participant's CMW screen as they are drawn (i.e., effectively in real time). For example, note FIG. 2B which illustrates a typical CMW screen during a multi-party teleconferencing session, wherein the screen contains annotated shared data as well as video images of the conferees. As described in greater detail below, all or portions of the audio/video and data of the teleconference can be recorded at a CMW (or within MLAN 10), complete with all the data interactions.
In the above-described preferred embodiment, audio/video file services can be implemented either at the individual CMWs 12 or by employing a centralized audio/video storage server. This is one example of the many types of additional servers that can be added to the basic system of MLANs 10. A similar approach is used for incorporating other multimedia services, such as commercial TV channels, multimedia mail, multimedia document management, multimedia conference recording, visualization servers, etc. (as described in greater detail below). Certainly, applications that run self-contained on a CMW can be readily added, but the invention extends this capability greatly in the way that MLAN 10, storage and other functions are implemented and leveraged.
In particular, standard signal formats, network interfaces, user interface messages, and call models can allow virtually any multimedia resource to be smoothly integrated into the system. Factors facilitating such smooth integration include: (i) a common mechanism for user access across the network; (ii) a common metaphor (e.g., placing a call) for the user to initiate use of such resource; (iii) the ability for one function (e.g., a multimedia conference or multimedia database) to access and exchange information with another function (e.g., multimedia mail); and (iv) the ability to extend such access of one networked function by another networked function to relatively complex nestings of simpler functions (for example, record a multimedia conference in which a group of users has accessed multimedia mail messages and transferred them to a multimedia database, and then send part of the conference recording just created as a new multimedia mail message, utilizing a multimedia mail editor if necessary).
A simple example of the smooth integration of functions made possible by the above-described approach is that the GUI and software used for snapshot sharing (described below) can also be used as an input/output interface for multimedia mail and more general forms of multimedia documents. This can be accomplished by structuring the interprocess communication protocols to be uniform across all these applications. More complicated examples--specifically multimedia conference recording, multimedia mail and multimedia document management--will be presented in detail below.
WIDE AREA NETWORK
Next to be described in connection with FIG. 4 is the advantageous manner in which the present invention provides for real-time audio/video/data communication among geographically dispersed MLANs 10 via WAN 15 (FIG. 1), whereby communication delays, cost and degradation of video quality are significantly minimized from what would otherwise be expected.
Four MLANs 10 are illustrated at locations A, B, C and D. CMWs 12-1 to 12-10. A/V Switching Circuitry 30, Data LAN hub 25, and WAN gateway 40 at each location correspond to those shown in FIGS. 1 and 3. WAN gateway 40 in FIG. 4 will be seen to comprise a router/codec (R&C) bank 42 coupled to WAN 15 via WAN switching multiplexer 44. The router is used for data interconnection and the codec is used for audio/video interconnection (for multimedia mail and document transmission, as well as videoconferencing). Codecs from multiple vendors, or supporting various compression algorithms may be employed. In the preferred embodiment, the router and codec are combined with the switching multiplexer to form a single integrated unit.
Typically, WAN 15 is comprised of T1 or ISDN common-carrier-provided digital links (switched or dedicated), in which case WAN switching multiplexers 44 are of the appropriate type (T1, ISDN, fractional T1, T3, switched 56 Kbps, etc.). Note that the WAN switching multiplexer 44 typically creates subchannels whose bandwidth is a multiple of 64 Kbps (i.e., 256 Kbps, 384, 768, etc.) among the T1, T3 or ISDN carriers. Inverse multiplexers may be required when using 56 Kbps dedicated or switched services from these carriers.
In the MLAN 10 to WAN 15 direction, router/codec bank 42 in FIG. 4 provides conventional analog-to-digital conversion and compression of audio/video signals received from A/V Switching Circuitry 30 for transmission to WAN 15 via WAN switching multiplexer 44, along with transmission and routing of data signals received from Data LAN hub 25. In the WAN 15 to MLAN 10 direction, each router/codec bank 42 in FIG. 4 provides digital-to-analog conversion and decompression of audio/video digital signals received from WAN 15 via WAN switching multiplexer 44 for transmission to A/V Switching Circuitry 30, along with the transmission to Data LAN hub 25 of data signals received from WAN 15.
The system also provides optimal routes for audio/video signals through the WAN. For example, in FIG. 4, location A can take either a direct route to location D via path 47, or a two-hop route through location C via paths 48 and 49. If the direct path 47 linkcing location A and location D is unavailable, the multipath route via location C and paths 48 and 49 could be used.
In a more complex network, several multi-hop routes are typically available, in which case the routing system handles the decision making, which for example can be based on network loading considerations. Note the resulting two-level network hierarchy: a MLAN 10 to MLAN 10 (i.e., site-to-site) service connecting codecs with one another only at connection endpoints.
The cost savings made possible by providing the above-described multi-hop capability (with intermediate codec bypassing) are very significant as will become evident by noting the examples of FIGS. 5 and 6. FIG. 5 shows that using the conventional "fully connected mesh" location-to-location approach, thirty-six WAN links are required for interconnecting the nine locations L1 to L8. On the other hand, using the above multi-hop capabilities, only nine WAN links are required, as shown in FIG. 6. As the number of locations increase, the difference in cost becomes even greater, growing as the square of the number of sites. For example, for 100 locations, the conventional approach would require about 5,000 WAN links, while the multi-hop approach of the present invention would typically require 300 or fewer (possibly considerably fewer) WAN links. Although specific WAN links for the multi-hop approach of the invention would require higher bandwidth to carry the additional traffic, the cost involved is very much smaller as compared to the cost for the very much larger number of WAN links required by the conventional approach.
At the endpoints of a wide-area call, the WAN switching multiplexer routes audio/video signals directly from the WAN network interface through an available codec to MLAN 10 and vice versa. At intermediate hops in the network, however, video signals are routed from one network interface on the WAN switching multiplexer to another network interface. Although A/V Switching Circuitry 30 could be used for this purpose, the preferred embodiment provides switching functionality inside the WAN switching multiplexer. By doing so, it avoids having to route audio/video signals through codecs to the analog switching circuitry, thereby avoiding additional codec delays at the intermediate locations.
A product capable of performing the basic switching functions described above for WAN switching multiplexer 44 is available from Teleos Corporation, Eatontown, N.J. This product is not known to have been used for providing audio/video multi-hopping and dynamic switching among various WAN links as described above.
In addition to the above-described multiple-hop approach, the preferred embodiment of the present invention provides a particularly advantageous way of minimizing delay, cost and degradation of video quality in a multi-party video teleconference involving geographically dispersed sites, while still delivering full conference views of all participants. Normally, in order for the CMWs at all sites to be provided with live audio/video of every participant in a teleconference simultaneously, each site has to allocate (in router/codec bank 42 in FIG. 4) a separate codec for each participant, as well as a like number of WAN trunks (via WAN switching multiplexer 44 in FIG. 4).
As will next be described, however, the preferred embodiment of the invention advantageously permits each wide area audio/video teleconference to use only one codec at each site, and a minimum number of WAN digital trunks. Basically, the preferred embodiment achieves this most important result by employing "distributed" video mosaicing via a video "cut-and-paste" technology along with distributed audio mixing.
DISTRIBUTED VIDEO MOSAICING
FIG. 7 illustrates a preferred way of providing video mosaicing in the MLAN of FIG. 3--i.e., by combining the individual analog video pictures from the individuals participating in a teleconference into a single analog mosaic picture. As shown in FIG. 7, analog video signals 112-1 to 112-n from the participants of a teleconference are applied to video mosaicing circuitry 36, which in the preferred embodiment is provided as part of conference bridge 35 in FIG. 3. These analog video inputs
112-1 to 112-n are obtained from the A/V Switching Circuitry 30 (FIG. 3) and may include video signals from CMWs at one or more distant sites (received via WAN gateway 40) as well as from other CMWs at the local site.
In the preferred embodiment, video mosaicing circuitry 36 is capable of receiving N individual analog video picture signals (where N is a squared integer, i.e., 4, 9, 16, etc.). Circuitry 36 first reduces the size of the N input video signals by reducing the resolutions of each by a factor of M (where M is the square root of N (i.e., 2, 3, 4, etc.), and then arranging them in an M-by-M mosaic of N images. The resulting single analog mosaic 36a obtained from video mosaicing circuitry 36 is then transmitted to the individual CMWs for display on the screens thereof.
As will become evident hereinafter, it may be preferable to send a different mosaic to distant sites, in which case video mosaicing circuitry 36 would provide an additional mosaic 36b for this purpose. A typical displayed mosaic picture (N=4, M=2) showing three participants is illustrated in FIG. 2A. A mosaic containing four participants is shown in FIG. 8B. It will be appreciated that, since a mosaic (36a or 36b) can be transmitted as a single video picture to an other site, via WAN 15
(FIGS. 1 and 4), only one codec and digital trunk are required. Of course, if only a single individual video picture is required to be sent from a site, it may be sent directly without being included in a mosaic.
Note that for large conferences it is possible to employ multiple video mosaics, one for each video window supported by the CMWs (see, e.g., FIG. 8C). In very large conferences, it is also possible to display video only from a select focus group whose members are selected by a dynamic "floor control" mechanism. Also note that, with additional mosaic hardware, it is possible to give each CMW its own mosaic. This can be used in small conferences to raise the maximum number of participants (from M.sup.2 to M.sup.2 +1--i.e., 5, 10, 17, etc.) or to give everyone in a large conference their own "focus group" view.
Also note that the entire video mosaicing approach described thus far and continued below applies should digital video transmission be used in lieu of analog transmission, particularly since both mosaic and video window implementations use digital formats internally and in current products are transformed to and from analog for external interfacing. In particular, note that mosaicing can be done digitally without decompression with many existing compression schemes. Further, with an all-digital approach, mosaicing can be done as needed directly on the CMW.
FIG. 9 illustrates preferred audio mixing circuitry 38 for use in conjunction with the video mosaicing circuitry 36 in FIG. 7, both of which may be part of conference bridges 35 in FIG. 3. As shown in FIG. 9, audio signals 114-1 to 114-n are applied to audio summing circuitry 38 for combination. These input audio signals 114-1 to 114-n may include audio signals from local participants as well as audio sums from participants at distant sites. Audio mixing circuitry 38 provides a respective "minus-1" sum output 38-1, 38a-2, etc. for each participant. Thus, each participant hears every conference participant's audio except his/her own.
In the preferred embodiment, sums are decomposed and formed in a distributed fashion, creating partial sums at one site which are completed at other sites by appropriate signal insertion. Accordingly, audio mixing circuitry 38 is able to provide one or more additional sums, such as indicated by output 38, for sending to other sites having conference participants.
Next to be considered is the manner in which video cut-and-paste techniques are advantageously employed in the preferred embodiment. It will be understood that, since video mosaics and/or individual video pictures may be sent from one or more other sites, the problem arises as to how these situations are handled. In the preferred embodiment, video cut-and-paste circuitry 39, as illustrated in FIG. 10, is provided for this purpose, and may also be incorporated in the conference bridges 35 in FIG. 3.
Referring to FIG. 10, video cut-and-paste circuitry receives analog video inputs 116, which may be comprised of one or more mosaics or single video pictures received from one or more distant sites and a mosaic or single video picture produced by the local site. It is assumed that the local video mosaicing circuitry 36 (FIG. 7) and the video cut-and-paste circuitry 39 have the capability of handling all of the applied individual video pictures, or at least are able to choose which ones are to be displayed based on existing available signals.
The video cut-and-paste circuitry 39 digitizes the incoming analog video inputs 116, selectively rearranges the digital signals on a region-by-region basis to produce a single digital M-by-M mosaic, having individual pictures in selected regions, and then converts the resulting digital mosaic back to analog form to provide a single analog mosaic picture 39a for sending to local participants (and other sites where required) having the individual input video pictures in appropriate regions. This resulting cut-and-paste analog mosaic 39a will provide the same type of display as illustrated in FIG. 8B. As will become evident hereinafter, it is sometimes beneficial to send different cut-and-paste mosaics to different sites, in which case video cut-and-paste circuitry 39 will provide additional cut-and-paste mosaics 39b-1, 39b-2. etc. for this purpose.
FIG. 11 diagrammatically illustrates an example of how video cut-and-paste circuitry may operate to provide the cut-and-paste analog mosaic 39a. As shown in FIG. 11, four digitized individual signals 116a, 116b, 116c derived from the input video signals are "pasted" into selected regions of a digital frame buffer 17 to form a digital 2.times.2 mosaic, which is converted into an output analog video mosaic 39a or 39b in FIG. 10. The required audio partial sums may be provided by audio mixing circuitry 39 in FIG. 9 in the same manner, replacing each cut-and-paste video operation with a partial sum operation.
Having described in connection with FIGS. 7-11 how video mosaicing, audio mixing, video cut-and-pasting, and distributed audio mixing may be performed, the following description of FIGS. 12-17 will illustrate how these capabilities may advantageously be used in combination in the context of wide-area videoconferencing. For these examples, the teleconference is assumed to have four participants designated as A, B, C and D, in which case 2.times.2 (quad) mosaics are employed. It is to be understood that greater numbers of participants could be provided. Also, two or more simultaneously occurring teleconferences could also be handled, in which case additional mosaicing, cut-and-paste and audio mixing circuitry would be provided at the various sites along with additional WAN paths. For each example, the "A" figure illustrates the video mosaicing and cut-and-pasting provided, and the corresponding "B" figure (having the same figure number) illustrates the associated audio mixing provided. Note that these figures indicate typical delays that might be encountered for each example (with a single "UNIT" delay ranging from 0-450 milliseonds, depending upon available compression technology).
FIGS. 12A and 12B illustrate a 2-site example having two participants A and B at Site #1 and two participants C and D at Site #2. Note that this example requires mosaicing and cut-and-paste at both sites.
FIGS. 13A and 13B illustrate another 2-site example, but having three participants A, B and C at Site #1 and one participant D at Site #2. Note that this example requires mosaicing at both sites, but cut-and-paste only at Site #2.
FIGS. 14A and 14B illustrate a 3-site example having participants A and B at Site #1, participant C at Site #2, and participant D at Site #3. At Site #1, the three local videos A, B and C are put into a mosaic which is sent to both Site #2 and Site #3. At Site #2 and Site #3, cut-and paste is used to insert the single video (C or D) at that site into the empty region in the imported A, B, C mosaic, as shown. Accordingly, mosaicing is required at all three sites, and cut-and-paste is required for only Site #2 and Site #3.
FIGS. 15A and 15B illustrate another 3-site example having participant A at Site #1, participant B at Site #2, and participants C and D at Site #3. Note that mosaicing and cut-and-paste are required at all sites. Site #2 additionally has the capability to send different cut-and-paste mosaics to Sites #1 and Sites #3. Further note with respect to FIG. 15B that Site #2 creates mninus-1 audio mixes for Site #1 and Site #2, but only provides a partial audio mix (A&B) for Site #3. These partial mixes are completed at Site #3 by mixing in C's signal to complete D's mix (A+B+C) and D's signal to complete C's mix (A+B+D).
FIG. 16 illustrates a 4-site example employing a star topology, having one participant at each site; that is, participant A is at Site #1, participant B is at Site #2, participant C is at Site #3, and participant D is at Site #4. An audio implementation is not illustrated for this example, since standard minus-1 mixing can be performed at Site #1, and the appropriate sums transmitted to the other sites.
FIGS. 17A and 17B illustrate a 4-site example that also has only one participant at each site, but uses a line topology rather than a star topology as in the example of FIG. 16. Note that this example requires mosaicing and cut-and-paste at all sites. Also note that Site #2 and Site #3 are each required to transmit two different types of cut-and-paste mosaics.
The preferred embodiment also provides the capability of allowing a conference participant to select a close-up of a participant displayed on a mosaic. This capability is provided whenever a full individual video picture is available at that user's site. In such case, the A/V Switching Circuitry 30 (FIG. 3) switches the selected full video picture (whether obtained locally or from another site) to the CMW that requests the close-up.
Next to be described in connection with FIGS. 18A, 18B, 19 and 20 are various preferred embodiments of a CMW in accordance with the invention.
COLLABORATIVE MULTIMEDIA WORKSTATION HARDWARE
One embodiment of a CMW 12 of the present invention is illustrated in FIG. 18A. Currently available personal computers (e.g., an Apple Macintosh or an IBM-compatible PC, desktop or laptop) and workstations (e.g., a Sun SPARCstation) can be adapted to work with the present invention to provide such features as real-time videoconferencing, data conferencing, multimedia mail, etc. In business situations, it can be advantageous to set up a laptop to operate with reduced functionality via cellular telephone links and removable storage media (e.g., CD-ROM, video tape with timecode support, etc.), but take on full capability back in the office via a docking station connected to the MLAN 10. This requires a voice and data modem as yet another function server attached to the MLAN.
The currently available personal computers and workstations serve as a base workstation platform. The addition of certain audio and video I/O devices to the standard components of the base platform 100 (where standard components include the display monitor 200, keyboard 300 and mouse or tablet (or other pointing device) 400), all of which connect with the base platform box through standard peripheral ports 101, 102 and 103, enables the CMW to generate and receive real-time audio and video signals. These devices include a video camera 500 for capturing the user's image, gestures and surroundings (particularly the user's face and upper body), a microphone 600 for capturing the user's spoken words (and any other sounds generated at the CMW), a speaker 700 for presenting incoming audio signals (such as the spoken words of another participant to a videoconference or audio annotations to a document), a video input card 130 in the base platform 100 for capturing incoming video signals (e.g., the image of another participant to a videoconference, or videomail), and a video display card 120 for displaying video and graphical output on monitor 200 (where video is typically displayed in a separate window).
These peripheral audio and video I/O devices are readily available from a variety of vendors and are just beginning to become standard features in (and often physically integrated into the monitor and/or base platform of) certain personal computers and workstations. See, e.g., the aforementioned BYTE article ("Video Conquers the Desktop"), which describes current models of Apple's Macintosh AV series personal computers and Silicon Graphics' Indy workstations.
Add-on box 800 (shown in FIG. 18A and illustrated in greater detail in FIG. 19) integrates these audio and video I/O devices with additional functions (such as adaptive echo canceling and signal switching) and interfaces with AV Network 901. AV Network 901 is the part of the MLAN 10 which carries bidirectional audio and video signals among the CMWs and A/V Switching Circuitry 30--e.g., utilizing existing UTP wiring to carry audio and video signals (digital or analog, as in the present embodiment).
In the present embodiment, the AV network 901 is separate and distinct from the Data Network 902 portion of the MLAN 10, which carries bidirectional data signals among the CMWs and the Data LAN hub (e.g., an Ethernet network that also utilizes UTP wiring in the present embodiment with a network interface card 110 in each CMW). Note that each CMW will typically be a node on both the AV and the Data Networks.
There are several approaches to implementing Add-on box 800. In a typical videoconference, video camera 500 and microphone 600 capture and transmit outgoing video and audio signals into ports 801 and 802, respectively, of Add-on box 800. These signals are transmitted via Audio/Video I/O port 805 across AV Network 901. Incoming video and audio signals (from another videoconference participant) are received across AV network 901 through Audio/Video I/O port 805. The video signals are sent out of V-OUT port 803 of CMW add-on box 800 to video input card 130 of base platform 100, where they are displayed (typically in a separate video window) on monitor 200 utilizing the standard base platform video display card 120. The audio signals are sent out of A-OUT port 804 of CMW add-on box 800 and played through speaker 700 while the video signals are displayed on monitor 200. The same signal flow occurs for other non-teleconferencing applications of audio and video.
Add-on box 800 can be controlled by CMW software (illustrated in FIG. 20) executed by base platform 100. Control signals can be communicated between base platform port 104 and Add-on box Control port 806 (e.g., an RS-232, Centronics, SCSI or other standard communications port).
Many other embodiments of the CMW illustrated in FIG. 18A will work in accordance with the present invention. For example, Add-on box 800 itself can be implemented as an add-in card to the base platform 100. Connections to the audio and video I/O devices need not change, though the connection for base platform control can be implemented internally (e.g., via the system bus) rather than through an external RS-232 or SCSI peripheral port. Various additional levels of integration can also be achieved as will be evident to those skilled in the art. For example, microphones, speakers, video cameras and UTP transceivers can be integrated into the base platform 100 itself, and all media handling technology and communications can be integrated onto a single card.
A handset/headset jack enables the use of an integrated audio I/O device as an alternate to the separate microphone and speaker. A telephone interface could be integrated into add-on box 800 as a local implementation of computer-integrated telephony. A "hold" (i.e., audio and video mute) switch and/or a separate audio mute switch could be added to Add-on box 800 if such an implementation were deemed preferable to a software-based interface.
The internals of Add-on box 800 of FIG. 18A are illustrated in FIG. 19. Video signals generated at the CMW (e.g., captured by camera 500 of FIG. 18A) are sent to CMW add-on box 800 via V-IN port 801. They then typically pass unaffected through Loopback/AV Mute circuitry 830 via video ports 833 (input) and 834 (output) and into A/V Transceivers 840 (via Video In port 842) where they are transformed from standard video cable signals to UTP signals and sent out via port 845 and Audio/Video I/O port 805 onto AV Network 901.
The Loopback/AV Mute circuitry 830 can, however, be placed in various modes under software control via Control port 806 (implemented, for example, as a standard UART). If in loopback mode (e.g., for testing incoming and outgoing signals at the CMW), the video signals would be routed back out V-OUT port 803 via video port 831. If in a mute mode (e.g., muting audio, video or both), video signals might, for example, be disconnected and no video signal would be sent out video port 834. Loopback and muting switching functionality is also provided for audio in a similar way. Note that computer control of loopback is very useful for remote testing and diagnostics while manual override of computer control on mute is effective for assured privacy from use of the workstation for electronic spying.
Video input (e.g., captured by the video camera at the CMW of another videoconference participant) is handled in a similar fashion. It is received along AV Network 901 through Audio/Video I/O port 805 and port 845 of A/V Transceivers 840, where it is sent out Video Out port 841 to video port 832 of Loopback/AV Mute circuitry 830, which typically passes such signals out video port 831 to V-OUT port 803 (for receipt by a video input card or other display mechanism, such as LCD display 810 of CMW Side Mount unit 850 in FIG. 18B, to be discussed).
Audio input and output (e.g., for playback through speaker 700 and capture by microphone 600 of FIG. 18A) passes through A/V transceivers 840 (via Audio In port 844 and Audio Out port 843) and Loopback/AV Mute circuitry 830 (through audio ports
837/838 and 836/835) in a similar manner. The audio input and output ports of Add-on box 800 interface with standard amplifier and equalization circuitry, as well as an adaptive room echo canceler 814 to eliminate echo, minimize feedback and provide enhanced audio performance when using a separate microphone and speaker. In particular, use of adaptive room echo cancelers provides high-quality audio interactions in wide area conferences. Because adaptive room echo canceling requires training periods (typically involving an objectionable blast of high-amplitude white noise or tone sequences) for alignment with each acoustic environment, it is preferred that separate echo canceling be dedicated to each workstation rather than sharing a smaller group of echo cancelers across a larger group of workstations.
Audio inputs passing through audio port 835 of Loopback/AV Mute circuitry 830 provide audio signals to a speaker (via standard Echo Canceler circuitry 814 and A-OUT port 804) or to a handset or headset (via I/O ports 807 and 808, respectively, under volume control circuitry 815 controlled by software through Control port 806). In all cases, incoming audio signals pass through power amplifier circuitry 812 before being sent out of Add-on box 800 to the appropriate audio-emitting transducer.
Outgoing audio signals generated at the CMW (e.g., by microphone 600 of FIG. 18A or the mouthpiece of a handset or headset) enter Add-on box 800 via A-IN port 802 (for a microphone) or Handset or Headset I/O ports 807 and 808, respectively. In all cases, outgoing audio signals pass through standard preamplifier (811) and equalization (813) circuitry, whereupon the desired signal is selected by standard "Select" switching circuitry 816 (under software control through Control port 806) and passed to audio port 837 of Loopback/AV Mute circuitry 830.
It is to be understood that A/V Transceivers 840 may include muxing/demuxing facilities so as to enable the transmission of audio/video signals on a single pair of wires, e.g., by encoding audio signals digitally in the vertical retrace interval of the analog video signal. Implementation of other audio and video enhancements, such as stereo audio and external audio/video I/O ports (e.g., for recording signals generated at the CMW), are also well within the capabilities of one skilled in the art. If stereo audio is used in teleconferencing (i.e., to create useful spatial metaphors for users), a second echo canceler may be recommended.
Another embodiment of the CMW of this invention, illustrated in FIG. 18B, utilizes a separate (fully self-contained) "Side Mount" approach which includes its own dedicated video display. This embodiment is advantageous in a variety of situations, such as instances in which additional screen display area is desired (e.g., in a laptop computer or desktop system with a small monitor) or where it is impossible or undesirable to retrofit older, existing or specialized desktop computers for audio/video support. In this embodiment, video camera 500, microphone 600 and speaker 700 of FIG. 18A are integrated together with the functionality of Add-on box 800. Side Mount 850 eliminates the necessity of external connections to these integrated audio and video I/O devices, and includes an LCD display 810 for displaying the incoming video signal (which thus eliminates the need for a base platform video input card 130).
Given the proximity of Side Mount device 850 to the user, and the direct access to audio/video I/O within that device, various additional controls 820 can be provided at the user's touch (all well within the capabilities of those skilled in the art). Note that, with enough additions. Side Mount unit 850 can become virtually a standalone device that does not require a separate computer for services using only audio and video. This also provides a way of supplementing a network of full-feature workstations with a few low-cost additional "audio video intercoms" for certain sectors of an enterprise (such as clerical, reception, factory floor, etc.).
A portable laptop implementation can be made to deliver multimedia mail with video, audio and synchronized annotations via CD-ROM or an add-on videotape unit with separate video, audio and time code tracks (a stereo videotape player can use the second audio channel for time code signals). Videotapes or CD-ROMs can be created in main offices and express mailed, thus avoiding the need for high-bandwidth networking when on the road. Cellular phone links can be used to obtain both voice and data communications (via modems). Modem-based data communications are sufficient to support remote control of mail or presentation playback, annotation, file transfer and fax features. The laptop can then be brought into the office and attached to a docking station where the available MLAN 10 and additional functions adapted from Add-on box 800 can be supplied, providing full CMW capability.
COLLABORATIVE MULTIMEDIA WORKSTATION SOFTWARE
CMW software modules 160 are illustrated generally in FIG. 20 and discussed in greater detail below in conjunction with the software running on MLAN Server 60 of FIG. 3. Software 160 allows the user to initiate and manage (in conjunction with the server software) videoconferencing, data conferencing, multimedia mail and other collaborative sessions with other users across the network.
Also present on the CMW in this embodiment are standard multitasking operating system/GUI software 180 (e.g., Apple Macintosh System 7, Microsoft Windows 3.1, or UNIX with the "X Window System" and Motif or other GUI "window manager" software) as well as other applications 170, such as word processing and spreadsheet programs. Software modules 161-168 communicate with operating system/GUI software 180 and other applications 170 utilizing standard function calls and interapplication protocols.
The central component of the Collaborative Multimedia Workstation software is the Collaboration Initiator 161. All collaborative functions can be accessed through this module. When the Collaboration Initiator is started, it exchanges initial configuration information with the Audio Video Network Manager (AVNM) 60 (shown in FIG. 3) through Data Network 902. Information is also sent from the Collaboration Initiator to the AVNM indicating the location of the user, the types of services available on that workstation (e.g., videoconferencing, data conferencing, telephony, etc.) and other relevant initialization information.
The Collaboration Initiator presents a user interface that allows the user to initiate collaborative sessions (both real-time and asynchronous). In the preferred embodiment, session participants can be selected from a graphical rolodex 163 that contains a scrollable list of user names or from a list of quick-dial buttons 162. Quick-dial buttons show the face icons for the users they represent. In the preferred embodiment, the icon representing the user is retrieved by the Collaboration Initiator from the Directory Server 66 on MLAN Server 60 when it starts up. Users can dynamically add new quick-dial buttons by dragging the corresponding entries from the graphical rolodex onto the quick-dial panel.
Once the user elects to initiate a collaborative session, he or she selects one or more desired participants by, for example, clicking on that name to select the desired participant from the system rolodex or a personal rolodex, or by clicking on the quick-dial button for that participant (see, e.g., FIG. 2A). In either case, the user then selects the desired session type--e.g., by clicking on a CALL button to initiate a videoconference call, a SHARE button to initiate the sharing of a snapshot image or blank whiteboard, or a MAIL button to send mail. Alternatively, the user can double-click on the rolodex name or a face icon to initiate the default session type--e.g., an audio/video conference call.
The system also allows sessions to be invoked from the keyboard. It provides a graphical editor to bind combinations of participants and session types to certain hot keys. Pressing this hot key (possibly in conjunction with a modifier key, e.g., <Shift> or <Ctrl>) will cause the Collaboration Initiator to start a session of the specified type with the given participants.
Once the user selects the desired participant and session type, Collaboration Initiator module 161 retrieves necessary addressing information from Directory Service 66 (see FIG. 21). In the case of a videoconference call, the Collaboration Initiator then communicates with the AVNM (as described in greater detail below) to set up the necessary data structures and manage the various states of that call, and to control A/V Switching Circuitry 30, which selects the appropriate audio and video signals to be transmitted to/from each participant's CMW. In the case of a data conferencing session, the Collaboration Initiator locates, via the AVNM, the Collaboration Initiator modules at the CMWs of the chosen recipients, and sends a message causing the Collaboration Initiator modules to invoke the Snapshot Sharing modules 164 at each participant's CMW. Subsequent videoconferencing and data conferencing functionality is discussed in greater detail below in the context of particular usage scenarios.
As indicated previously, additional collaborative services--such as Mail 165, Application Sharing 166, Computer-Integrated Telephony 167 and Computer Integrated Fax 168--are also available from the CMW by utilizing Collaboration Initiator module
161 to initiate the session (i.e., to contact the participants) and to invoke the appropriate application necessary to manage the collaborative session. When initiating asynchronous collaboration (e.g., mail, fax, etc.), the Collaboration Initiator contacts Directory Service 66 for address information (e.g., EMAIL address, fax number, etc.) for the selected participants and invokes the appropriate collaboration tools with the obtained address information. For real-time sessions, the Collaboration Initiator queries the Service Server module 69 inside AVNM 63 for the current location of the specified participants. Using this location information, it communicates (via the AVNM) with the Collaboration Initiators of the other session participants to coordinate session setup. As a result, the various Collaboration Initiators will invoke modules 166, 167 or 168 (including activating any necessary devices such as the connection between the telephone and the CMW's audio I/O port). Further details on multimedia mail are provided below.
MLAN SERVER SOFTWARE
FIG. 21 diagrammatically illustrates software 62 comprised of various modules (as discussed above) provided for running on MLAN Server 60 (FIG. 3) in the preferred embodiment. It is to be understood that additional software modules could also be provided. It is also to be understood that, although the software illustrated in FIG. 21 offers various significant advantages, as will become evident hereinafter, different forms and arrangements of software may also be employed within the scope of the invention. The software can also be implemented in various sub-parts running as separate processes.
In the preferred embodiment, clients (e.g., software-controlling workstations, VCRs, laserdisks, multimedia resources, etc.) communicate with the MLAN Server Software Modules 62 using the TCP/IP network protocols. Generally, the AVNM 63
cooperates with the Service Server 69, Conference Bridge Manager (CBM 64 in FIG. 21) and the WAN Network Manager (WNM 65 in FIG. 21) to manage communications within and among both MLANs 10 and WANs 15 (FIGS. 1 and 3).
The AVNM additionally cooperates with Audio/Video Storage Server 67 and other multimedia services 68 in FIG. 21 to support various types of collaborative interactions as described herein. CBM 64 in FIG. 21 operates as a client of the AVNM 63 to manage conferencing by controlling the operation of conference bridges 35. This includes management of the video mosaicing circuitry 37, audio mixing circuitry 38 and cut-and-paste circuitry 39 preferably incorporated therein. WNM 65 manages the allocation of paths (codecs and trunks) provided by WAN gateway 40 for accomplishing the communications to other sites called for by the AVNM.
Audio Video Network Manager
The AVNM 63 manages A/V Switching Circuitry 30 in FIG. 3 for selectively routing audio/video signals to and from CMWs 12, and also to and from WAN gateway 40, as called for by clients. Audio/video devices (e.g., CMWs 12, conference bridges 35, multimedia resources 16 and WAN gateway 40 in FIG. 3) connected to A/V Switching Circuitry 30 in FIG. 3, have physical connections for audio in, audio out, video in and video out. For each device on the network, the AVNM combines these four connections into a port abstraction, wherein each port represents an addressable bidirectional audio/video channel. Each device connected to the network has at least one port. Different ports may share the same physical connections on the switch. For example, a conference bridge may typically have four ports (for 2.times.2 mosaicing) that share the same video-out connection. Not all devices need both video and audio connections at a port. For example, a TV tuner port needs only incoming audio/video connections.
In response to client program requests, the AVNM provides connectivity between audio/video devices by connecting their ports. Connecting ports is achieved by switching one port's physical input connections to the other port's physical output connections (for both audio and video) and vice-versa. Client programs can specify which of the 4 physical connections on its ports should be switched. This allows client programs to establish unidirectional calls (e.g., by specifying that only the port's input connections should be switched and not the port's output connections) and audio-only or video-only calls (by specifying audio connections only or video connections only).
Service Server
Before client programs can access audio/video resources through the AVNM, they must register the collaborative services they provide with the Service Server 69. Examples of these services indicate "video call", "snapshot sharing", "conference" and "video file sharing." These service records are entered into the Service Server's service database. The service database thus keeps track of the location of client programs and the types of collaborative sessions in which they can participate. This allows the Collaboration Initiator to find collaboration participants no matter where they are located. The service database is replicated by all Service Servers: Service Servers communicate with other Service Servers in other MLANs throughout the system to exchange their service records.
Clients may create a plurality of services, depending on the collaborative capabilities desired. When creating a service, a client can specify the network resources (e.g. ports) that will be used by this service. In particular, service information is used to associate a user with the audio/video ports physically connected to the particular CMW into which the user is logged in. Clients that want to receive requests do so by putting their services in listening mode. If clients want to accept incoming data shares, but want to block incoming video calls, they must create different services.
A client can create an exclusive service on a set of ports to prevent other clients from creating services on these ports. This is useful, for example, to prevent multiple conference bridges from managing the same set of conference bridge ports.
Next to be considered is the preferred manner in which the AVNM 63 (FIG. 21), in cooperation with the Service Server 69, CBM 64 and participating CMWs provide for managing A/V Switching Circuitry 30 and conference bridges 35 in FIG. 3 during audio/video/data teleconferencing. The participating CMWs may include workstations located at both local and remote sites.
BASIC TWO-PARTY VIDEOCONFERENCING
As previously described, a CMW includes a Collaboration Initiator software module 161, (see FIG. 20) which is used to establish person-to-person and multiparty calls. The corresponding collaboration initiator window advantageously provides quick-dial face icons of frequently dialed persons, as illustrated, for example, in FIG. 22, which is an enlarged view of typical face icons along with various initiating buttons (described in greater detail below in connection with FIGS. 35-42).
Videoconference calls can be initiated, for example, merely by double-clicking on these icons. When a call is initiated, the CMW typically provides a screen display that includes a live video picture of the remote conference participant, as illustrated for example in FIG. 8A. In the preferred embodiment, this display also includes control buttons/menu items that can be used to place the remote participant on hold, to resume a call on hold, to add one or more participants to the call, to initiate data sharing and to hang up the call.
The basic underlying software-controlled operations occurring for a two-party call are diagrammatically illustrated in FIG. 23. When a caller initiates a call (e.g., by selecting a user from the graphical rolodex and clicking the call button or by double-clicking the face icon of the callee on the quick-dial panel), the caller's Collaboration Initiator responds by identifying the selected user and requesting that user's address from Directory Service 66, as indicated by (2) in FIG. 23. Directory Service 66 looks up the callee's address in the directory database, as indicated by (3) in FIG. 23, and then returns it to the caller's Collaboration Initiator, as illustrated by (4) in FIG. 23.
The caller's Collaboration Initiator sends a request to the AVNM to place a video call to the caller with the specified address, as indicated by (5) in FIG. 23. The AVNM queries the Service Server to find the service instance of type "video call" whose name corresponds to the callee's address. This service record identifies the location of the callee's Collaboration Initiator as well as the network ports that the callee is connected to. If no service instance is found for the callee, the AVNM notifies the caller that the callee is not logged in. If the callee is local, the AVNM sends a call event to the callee's Collaboration Initiator, as indicated by (6) in FIG. 23. If the callee is at a remote site, the AVNM forwards the call request (5) through the WAN gateway 40 for transmission, via WAN 15 (FIG. 1) to the Collaboration Initiator of the callee's CMW at the remote site.
The callee's Collaboration Initiator can respond to the call event in a variety of ways. In the preferred embodiment, a user-selectable sound is generated to announce the incoming call. The Collaboration Initiator can then act in one of two modes. In "Telephone Mode," the Collaboration Initiator displays an invitation message on the CMW screen that contains the name of the caller and buttons to accept or refuse the call. The Collaboration Initiator will then accept or refuse the call, depending on which button is pressed by the callee. In "Intercom Mode," the Collaboration Initiator accepts all incoming calls automatically, unless there is already another call active on the callee's CMW, in which case behavior reverts to Telephone Mode.
The callee's Collaboration Initiator then notifies the AVNM as to whether the call will be accepted or refused. If the call is accepted, (7), the AVNM sets up the necessary communication paths between the caller and the callee required to establish the call. The AVNM then notifies the caller's Collaboration Initiator that the call has been established by sending it an accept event (8). If the caller and callee are at different sites, their AVNMs will coordinate in setting up the communication paths at both sites, as required by the call.
The AVNM may provide for managing connections among CMWs and other multimedia resources for audio/video/data communications in various ways. The manner employed in the preferred embodiment will next be described.
As has been described previously, the AVNM manages the switches in the A/V Switching Circuitry 30 in FIG. 3 to provide port-to-port connections in response to connection requests from clients. The primary data structure used by the AVNM for managing these connections will be referred to as a callhandle, which is comprised of a plurality of bits, including state bits.
Each port-to-port connection managed by the AVNM comprises two callhandles, one associated with each end of the connection. The callhandle at the client port of the connection permits the client to manage the client's end of the connection. The callhandle mode bits determine the current state of the callhandle and which of a port's four switch connections (video in, video out, audio in, audio out) are involved in a call.
AVNM clients send call requests to the AVNM whenever they want to initiate a call. As part of a call request, the client specifies the local service in which the call will be involved, the name of the specific port to use for the call, identifying information as to the callee, and the call mode. In response, the AVNM creates a callhandle on the caller's port.
All callhandles are created in the "idle" state. The AVNM then puts the caller's callhandle in the "active" state. The AVNM next creates a callhandle for the callee and sends it a call event, which places the callee's callhandle in the "ringing" state. When the callee accepts the call, its callhandle is placed in the "active" state, which results in a physical connection between the caller and the callee. Each port can have an arbitrary number of callhandles bound to it, but typically only one of these callhandles can be active at the same time.
After a call has been set up, AVNM clients can send requests to the AVNM to change the state of the call, which can advantageously be accomplished by controlling the callhandle states. For example, during a call, a call request from another party could arrive. This arrival could be signaled to the user by providing an alert indication in a dialog box on the user's CMW screen. The user could refuse the call by clicking on a refuse button in the dialog box, or by clicking on a "hold" button on the active call window to put the current call on hold and allow the incoming call to be accepted.
The placing of the currently active call on hold can advantageously be accomplished by changing the caller's callhandle from the active state to a "hold" state, which permits the caller to answer incoming calls or initiate new calls, without releasing the previous call. Since the connection set-up to the callee will be retained, a call on hold can conveniently be resumed by the caller clicking on a resume button on the active call window, which returns the corresponding callhandle back to the active state. Typically, multiple calls can be put on hold in this manner. As an aid in managing calls that are on hold, the CMW advantageously provides a hold list display, identifying these on-hold calls and (optionally) the length of time that each party is on hold. A corresponding face icon could be used to identify each on-hold call. In addition, buttons could be provided in this hold display which would allow the user to send a preprogrammed message to a party on hold. For example, this message could advise the callee when the call will be resumed, or could state that the call is being terminated and will be reinitiated at a later time.
Reference is now directed to FIG. 24 which diagrammatically illustrates how two-party calls are connected for CMWs WS-1 and WS-2, located at the same MLAN 10. As shown in FIG. 24, CMWs WS1 and WS-2 are coupled to the local A/V Switching Circuitry 30 via ports 81 and 82, respectively. As previously described, when CMW WS-1 calls CMW WS-2, a callhandle is created for each port. If CMW WS-2 accepts the call, these two callhandles become active and in response thereto, the AVNM causes the A/V Switching Circuitry 30 to set up the appropriate connections between ports 81 and 82, as indicated by the dashed line 83.
FIG. 25 diagrammatically illustrates how two-party calls are connected for CMWs WS-1 and WS-2 when located in different MLANs 10a and 10b. As illustrated in FIG. 25, CMW WS-1 of MLAN 10a is connected to a port 91a of A/V Switching Circuitry 30a of MLAN 10a, while CMW WS-2 is connected to a port 91b of the audio/video switching circuit 30b of MLAN 10b. It will be assumed that MLANs 10a and 10b can communicate with each other via ports 92a and 92b (through respective WAN gateways 40a and 40b and WAN 15). A call between CMWs WS-1 and WS-2 can then be established by AVNM of MLAN 10a in response to the creation of callhandles at ports 91a and 92a, setting up appropriate connections between these ports as indicated by dashed line 93a, and by AVNM of MLAN 10b, in response to callhandles created at ports 91b and 92b, setting up appropriate connections between these ports as indicated by dashed line 93b. Appropriate paths 94a and 94b in WAN gateways 40a and 40b, respectively are set up by the WAN network manager 65 (FIG. 21) in each network.
CONFERENCE CALLS
Next to be described is the specific manner in which the preferred embodiment provides for multi-party conference calls (involving more than two participants). When a multi-party conference call is initiated, the CMW provides a screen that is simnilar to the screen for two-party calls, which displays a live video picture of the callee's image in a video window. However, for multi-party calls, the screen includes a video mosaic containing a live video picture of each of the conference participants (including the CMW user's own picture), as shown, for example, in FIG. 8B. Of course, other embodiments could show only the remote conference participants (and not the local CMW user) in the conference mosaic (or show a mosaic containing both participants in a two-party call). In addition to the controls shown in FIG. 8B, the multi-party conference screen also includes buttons/menu items that can be used to place individual conference participants on hold, to remove individual participants form the conference, to adjourn the entire conference, or to provide a "close-up" image of a single individual (in place of the video mosaic).
Multi-party conferencing requires all the mechanisms employed for 2-party calls. In addition, it requires the conference bridge manager CBM 64 (FIG. 21) and the conference bridges 36 (FIG. 3). The CBM acts as a client of the AVNM in managing the operation of the conference bridges 36. The CBM also acts a server to other clients on the network. The CBM makes conferencing services available by creating service records of type "conference" in the AVNM service database and associating these services with the ports on A/V Switching Circuitry 30 for connection to conference bridges 36.
The preferred embodiment provides two ways for initiating a conference call. The first way is to add one or more parties to an existing two-party call. For this purpose, an ADD button is provided by both the Collaboration Initiator and the Rolodex, as illustrated in FIGS. 2A and 22. To add a new party, a user selects the party to be added (by clicking on the user's rolodex name or face icon as described above) and clicks on the ADD button to invite that new party. Additional parties can be invited in a similar manner. The second way to initiate a conference call is to select the parties in a similar manner and then click on the CALL button (also provided in the Collaboration Initiator and Rolodex windows on the user's CMW screen).
Another alternative embodiment is to initiate a conference call from the beginning by clicking on a CONFERENCE/MOSAIC icon/button/menu item on the CMW screen. This could initiate a conference call with the call initiator as the sole participant (i.e., causing a conference bridge to be allocated such that the caller's image also appears on his/her own screen in a video mosaic, which will also include images of subsequently added participants). New participants could be invited, for example, by selecting each new party's face icon and then clicking on the ADD button.
Next to be considered with reference to FIGS. 26 and 27 is the manner in which conference calls are handled in the preferred embodiment For the purposes of this description it will be assumed that up to four parties may participate in a conference call. Each conference uses four bridge ports 136-1, 136-2, 136-3 and 136-4 provided on A/V Switching Circuitry 30a, which are respectively coupled to bidirectional audio/video lines 36-1, 36-2, 36-3 and 36-4 connected to conference bridge 36. However, from this description it will be apparent how a conference call may be provided for additional parties, as well as simultaneously occurring conference calls.
Once the Collaboration Initiator determines that a conference is to be initiated, it queries the AVNM for a conference service. If such a service is available, the Collaboration Initiator requests the associated CBM to allocate a conference bridge. The Collaboration Initiator then places an audio/video call to the CBM to initiate the conference. When the CBM accepts the call, the AVNM couples port 101 of CMW WS-1 to lines 36-1 of conference bridge 36 by a connection 137 produced in response to callhandles created for port 101 of WS-1 and bridge port 136-1.
When the user of WS-1 selects the appropriate face icon and clicks the ADD button to invite a new participant to the conference, which will be assumed to be CMW WS-3, the Collaboration Initiator on WS-1 sends an add request to the CBM. In response, the CBM calls WS-3 via WS-3 port 103. When CBM initiates the call, the AVNM creates callhandles for WS-3 port 103 and bridge port 136-2. When WS-3 accepts the call, its callhandle is made "active," resulting in connection 138 being provided to connect WS-3 and lines 136-2 of conference bridge 36. Assuming CMW WS-1 next adds CMW WS-5 and then CMW WS-8, callhandles for their respective ports and bridge ports 136-3 and 136-4 are created, in turn, as described above for WS-1 and WS-3, resulting in connections 139 and 140 being provided to connect WS-5 and WS-9 to conference bridge lines 36-3 and 36-4, respectively. The conferees WS-1, WS-3, WS-5 and WS-8 are thus coupled to conference bridge lines 136-1, 136-2, 136-3 and 136-4, respectively as shown in FIG. 26.
It will be understood that the video mosaicing circuitry 36 and audio mixing circuitry 38 incorporated in conference bridge 36 operate as previously described, to form a resulting four-picture mosaic (FIG. 8B) that is sent to all of the conference participants, which in this example are CMWs WS-1, WS-2, WS-5 and WS-8. Users may leave a conference by just hanging up, which causes the AVNM to delete the associated callhandles and to send a hangup notification to CBM. When CBM receives the notification, it notifies all other conference participants that the participant has exited. In the preferred embodiment, this results in a blackened portion of that participant's video mosaic image being displayed on the screen of all remaining participants.
The manner in which the CBM and the conference bridge 36 operate when conference participants are located at different sites will be evident from the previously described operation of the cut-and-paste circuitry 39 (FIG. 10) with the video mosaicing circuitry 36 (FIG. 7) and audio mixing circuitry 38 (FIG. 9). In such case, each incoming single video picture or mosaic from another site is connected to a respective one of the conference bridge lines 36-1 to 36-4 via WAN gateway 40.
The situation in which a two-party call is converted to a conference call will next be considered in connection with FIG. 27 and the previously considered 2-party call illustrated in FIG. 24. Converting this 2-party call to a conference requires that this two-party call (such as illustrated between WS-1 and WS-2 in FIG. 24) be rerouted dynamically so as to be coupled through conference bridge 36. When the user of WS-1 clicks on the ADD button to add a new party, (for example WS-5), the Collaboration Initiator of WS-1 sends a redirect request to the AVNM, which cooperates with the CBM to break the two-party connection 83 in FIG. 24, and then redirect the callhandles created for ports 81 and 83 to callhandles created for bridge ports
136-1 and 136-2, respectively.
As shown in FIG. 27, this results in producing a connection 86 between WS-1 and bridge port 136-1, and a connection 87 between WS-2 and bridge port 136-2, thereby creating a conference set-up between WS-1 and WS-2. Additional conference participants can then be added as described above for the situations described above in which the conference is initiated by the user of WS-1 either selecting multiple participants initially or merely selecting a "conference" and then adding subsequent participants.
Having described the preferred manner in which two-party calls and conference calls are set up in the preferred embodiment, the preferred manner in which data conferencing is provided between CMWs will next be described.
DATA CONFERENCING
Data conferencing is implemented in the preferred embodiment by certain Snapshot Sharing software provided at the CMW (see FIG. 20). This software permits a "snapshot" of a selected portion of a participant's CMW screen (such as a window) to be displayed on the CMW screens of other selected participants (whether or not those participants are also involved in a videoconference). Any number of snapshots may be shared simultaneously. Once displayed, any participant can then telepoint on or annotate the snapshot, which animated actions and results will appear (virtually simultaneously) on the screens of all other participants. The annotation capabilities provided include lines of several different widths and text of several different sizes. Also, to facilitate participant identification, these annotations may be provided in a different color for each participant Any annotation may also be erased by any participant. FIG. 2B (lower left window) illustrates a CMW screen having a shared graph on which participants have drawn and typed to call attention to or supplement specific portions of the shared image.
A participant may initiate data conferencing with selected participants (selected and added as described above for videoconference calls) by clicking on a SHARE button on the screen (available in the Rolodex or Collaboration Initiator windows, shown in FIG. 2A, as are CALL and ADD buttons), followed by selection of the window to be shared. When a participant clicks on his SHARE button, his Collaboration Initiator module 161 (FIG. 20) queries the AVNM to locate the Collaboration Initiators of the selected participants, resulting in invocation of their respective Snapshot Sharing modules 164. The Snapshot Sharing software modules at the CMWs of each of the selected participants query their local operating system 180 to determine available graphic formats, and then send this information to the initiating Snapshot Sharing module, which determines the format that will produce the most advantageous display quality and performance for each selected participant.
After the snapshot to be shared is displayed on all CMWs, each participant may telepoint on or annotate the snapshot, which actions and results are displayed on the CMW screens of all participants. This is preferably accomplished by monitoring the actions made at the CMW (e.g., by tracking mouse movements) and sending these "operating system commands" to the CMWs of the other participants, rather than continuously exchanging bitmaps, as would be the case with traditional "remote control" products.
As illustrated in FIG. 28, the original unchanged snapshot is stored in a first bitmap 210a. A second bitmap 210b stores the combination of the original snapshot and any annotations. Thus, when desired (e.g., by clicking on a CLEAR button located in each participant's Share window, as illustrated in FIG. 2B), the original unchanged snapshot can be restored (i.e., erasing all annotations) using bitmap 210a. Selective erasures can be accomplished by copying into (i.e., restoring) the desired erased area of bitmap 210b with the corresponding portion from bitmap 210a.
Rather than causing a new Share window to be created whenever a snapshot is shared, it is possible to replace the contents of an existing Share window with a new image. This can be achieved in either of two ways. First, the user can click on the GRAB button and then select a new window whose contents should replace the contents of the existing Share window. Second, the user can click on the REGRAB button to cause a (presumably modified) version of the original source window to replace the contents of the existing Share window. This is particularly useful when one participant desires to share a long document that cannot be displayed on the screen in its entirety. For example, the user might display the first page of a spreadsheet on his screen, use the SHARE button to share that page, discuss and perhaps alnotate it, then return to the spreadsheet application to position to the next page, use the REGRAB button to share the new page, and so on. This mechanism represents a simple, effective step toward application sharing.
Further, instead of sharing a snapshot of data on his current screen, a user may instead choose to share a snapshot that had previously been saved as a file. This is achieved via the LOAD button, which causes a dialog box to appear, prompting the user to select a file. Conversely, via the SAVE button, any snapshot may be saved, with all current annotations.
The capabilities described above were carefully selected to be particularly effective in environments where the principal goal is to share existing information, rather than to create new information. In particular, user interfaces are designed to make snapshot capture, telepointing and annotation extremely easy to use. Nevertheless, it is also to be understood that, instead of sharing snapshots, a blank "whiteboard" can also be shared (via the WHITEBOARD button provided by the Rolodex, Collaboration Initiator, and active call windows), and that more complex paintbox capabilities could easily be added for application areas that require such capabilities.
As pointed out previously herein, important features of the present invention reside in the manner in which the capabilities and advantages of multimedia mail (MMM), multimedia conference recording (MMCR), and multimedia document management (MMDM) are tightly integrated with audio/video/data teleconferencing to provide a multimedia collaboration system that facilitates an unusually higher level of comnunication and collaboration between geographically dispersed users than has heretofore been achievable by known prior art systems. FIG. 29 is a schematic and diagrammatic view illustrating how multimedia calls/conferences, MMCR, MMM and MMDM work together to provide the above-described features. In the preferred embodiment. MM Editing Utilities shown supplementing MMM and MMDM may be identical.
Having already described various preferred embodiments and examples of audio/video/data teleconferencing, next to be considered are various preferred ways of integrating MMCR, MMM and MMDM with audio/video/data teleconferencing in accordance with the invention. For this purpose, basic preferred approaches and features of each will be considered along with preferred associated hardware and software.
MULTIMEDIA DOCUMENTS
In the preferred embodiment, the creation, storage, retrieval and editing of multimedia documents serve as the basic element common to MMCR, MMM and MMDM. Accordingly, the preferred embodiment advantageously provides a universal format for multimedia documents. This format defines multimedia documents as a collection of individual components in multiple media combined with an overall structure and tiring component that captures the identities, detailed dependencies, references to, and relationships among the various other components. The information provided by this structuring component forms the basis for spatial layout, order of presentation, hyperlinks, temporal synchronization, etc., with respect to the composition of a multimedia document. FIG. 30 shows the structure of such documents as well as their relationship with editing and storage facilities.
Each of the components of a multimedia document uses its own editors for creating, editing, and viewing. In addition, each component may use dedicated storage facilities. In the preferred embodiment, multimedia documents are advantageously structured for authoring, storage, playback and editing by storing some data under conventional file systems and some data in special-purpose storage servers as will be discussed later. The Conventional File System 504 can be used to store all non-time-sensitive portions of a multimedia documen