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Basic foilset Master Set of Material on Tango and Collaboratoies

Given by Marek Podgorny at Dayton MAPINT 97 Workshop on 16-18 June 97. Foils prepared 27 June 97
Outside Index Summary of Material

This master foilset starts with an overview of types of Internet Collaboratories
Then it discusses Core Tango and Tango2 capabilities
WebWisdom and Video-on-Demand are covered in detail

Table of Contents for full HTML of Master Set of Material on Tango and Collaboratoies

 Denote Foils where Image Critical
Denote Foils where HTML is sufficient
1 Collaboratory systems: Taxonomy I
2 Collaboratory systems: Taxonomy II
3 Collaboratory systems: Taxonomy III
4 Collaboration Transparency
5 Event Broadcasting: con and pro
6 TANGO Collaboratory
7 TANGO: Highlights
8 TANGO: Highlights II
9 TANGO: Control Application
10 TANGO: application control
11 TANGO Applications
12 TANGO: Status
13 WebWisdom: Current Features Summary
14 WebWisdom: Current Capabilities
15 WebWisdom: Current Capabilities II
16 TANGO/Wisdom
17 Video on Demand: Features
18 Video on Demand: Capabilities
19 Video on Demand: Capabilities II
20 Video on Demand/TANGO Integration
21 Internet Video on Demand

Outside Index Summary of Material

HTML version of Basic Foils prepared 27 June 97

Foil 1 Collaboratory systems: Taxonomy I

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Basic architectures
  • Shared display: single instance of application, user input & display replicated via conference agent
    • Entire functionality of application is shared
    • Examples: Shared X (HP), NetMeeting (MS), ProShare (Intel), ShowMe (Sun), Timbuktu (Farallon)
    • Advantages: simple to implement
    • Disadvantages:
      • functional: simplistic, inflexible, awkward session control model, insecure (no data access control), no support for asynchronous collaboration, race condition problems
      • performance: generate heavy data traffic, unacceptable on WANs
      • incompatible with Web programming model assuming local intelligence
HTML version of Basic Foils prepared 27 June 97

Foil 2 Collaboratory systems: Taxonomy II

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Basic architectures
  • Event broadcasting: each workstation runs its own copy of application.
    • (A) Virtual instance: all events shared (collaboration transparency)
    • (B) Independent data views: some events shared
    • Examples: Habanero (NCSA - B), Java Collab. Toolset (Old Dominion - A ), ProMondia (Univ. of Nuremberg - B), UARC (Univ. of Michigan - B), TANGO (NPAC - B)
    • Disadvantages: new category of SW, difficult to implement
    • Advantages: infinitely flexible and adaptable, generates little network traffic, perfectly fit Web/Java paradigm, can implement security, can support asynchronous collaboration....
HTML version of Basic Foils prepared 27 June 97

Foil 3 Collaboratory systems: Taxonomy III

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Evolution of chat servers in a collaboratory
  • Chat servers multiply and offer 1D, 2D and even 3D interfaces:
    • Comic Chat (MS - 2D), Passport (BlackSun - 3D), Traveler (OnLive - 3D), The Palace (2D), MOO's .........
  • While technically similar, these products are geared towards creation of sophisticated and unproven rather than towards increasing functionality of a collaboratory
    • Collaboratory paradigm easily breaks when combined with orthodox cyberspace visualization paradigm
      • two avatars reading a Word document on a screen of the virtual computer rendered in VRML browser???
    • Conclusion: evolving chat servers are not key today to a collaboratory!
HTML version of Basic Foils prepared 27 June 97

Foil 4 Collaboration Transparency

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Concept: design a system that allows using an application designed for a single individual to be used by a group of people without changing anything in the application
  • Shared display applications implement collaboration transparency
Proposed extension of the paradigm to the event broadcasting architectures (Old Dominions' JCT, Virginia Tech's JAMM)
  • technical approach: modification of the Java AWT to distribute events
  • our evaluation: we support event distribution model, but consider collaboration transparency an unrealistic model.
  • Rather we modify applications to distribute events
HTML version of Basic Foils prepared 27 June 97

Foil 5 Event Broadcasting: con and pro

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Sharing possible only if applications deterministic
  • applications ARE deterministic or can be made so
Copies of applications must be present everywhere
  • but they are, being applets or downloaded via a push channel
Environments must be identical
  • Java VM takes care about this
Initial state of a newcomer impossible to define
  • not so for good OO design and object serialization mechanism
Cannot maintain consistency among copies
  • Difficult but not Impossible. Variety of sync mechanisms available
The pros win! Web model enables event broadcasting!
HTML version of Basic Foils prepared 27 June 97

Foil 6 TANGO Collaboratory

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
TANGO is a software framework supporting computer-based communication and collaboration
  • Initial design and implementation for Command and Control under a DoD contract
  • Runs in Web environment and uses standard Web technologies
  • Allows for implementation of arbitrary collaboratory applications (examples will follow)
  • Multiplatform run-time and multi-language API
    • UNIX/Windows; Java (applet or application), C, C++, JavaScript, VRML2
HTML version of Basic Foils prepared 27 June 97

Foil 7 TANGO: Highlights

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Technically, TANGO is a distributed system based on event broadcasting
  • TANGO does not implement collaborative transparency, although current design allows for it for certain applications
Core system is implemented in Java and as a browser plug-in
Base programming module is a Java applet
  • however, other shared entities supported as well, including Java, C/C++ applications, and JavaScript/VRML 2 modules
HTML version of Basic Foils prepared 27 June 97

Foil 8 TANGO: Highlights II

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Global architecture is a mesh of servers
  • migration via hand-off mechanism (work in progress)
Session metaphor is a meeting room with tools
  • a more flexible "application session" model has been shown indigestible for many early users
Asynchronous collaboration is (will be) enabled via session recording to database backend
TANGO modules can be downloaded from anywhere
  • can interact via a server at arbitrary location
HTML version of Basic Foils prepared 27 June 97

Foil 9 TANGO: Control Application

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Application select
buttons
Application
Domains
Open/close and
floor control
Session
information
User information
HTML version of Basic Foils prepared 27 June 97

Foil 10 TANGO: application control

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
TANGO session, sync, and
floor control buttons built
into the application control
panel.
HTML version of Basic Foils prepared 27 June 97

Foil 11 TANGO Applications

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Generic tools: chats (1D, 2D, 3D*), whiteboards (paint and draw)
Multimedia tools: audio/video conferencing, collaborative indexed streaming video
Shared browsers: slide shows, fully synchronized, shared JavaScript, customizable client-side apps
Virtual University: WebWisdom - interactive contents delivery system, a set of applets for physics curriculum
Domain specific applets: 2D and 3D (collaborative VRML) Visible Human, collaborative AutoCad (feasibility study only)
HTML version of Basic Foils prepared 27 June 97

Foil 12 TANGO: Status

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Core system implemented by a team of 3 programmers within ~6 months, available.
  • TANGO server for Unix and Windows NT
  • TANGO Plug-ins for Wndows95/NT, IRIX, Solaris
APIs for Java, C/C++, and JavaScript available
Two generations of GUI implemented
"Lessons learned" are being incorporated into TANGO II, scheduled for release end of October
  • new sessions paradigm, database support, multi-server support
HTML version of Basic Foils prepared 27 June 97

Foil 13 WebWisdom: Current Features Summary

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
WebWisdom is a knowledge dissemination system for Internet and intranets
  • Assumes a classic hierarchical model of Information which fits most Universities and other organizations
  • Supports original data in Persuasion, PowerPoint, HTML and screen dump form
  • Allows arbitrary mixing of this material via play list mechanism
  • Supports both synchronous and asynchronous learning modes
HTML version of Basic Foils prepared 27 June 97

Foil 14 WebWisdom: Current Capabilities

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Handles a wide variety of presentation formats (Persuasion, PowerPoint, Framemaker, Kodak PhotoSets, Screendumps and raw HTML) in general locations
Handles RealAudio for both recording (where it logs where presentation page changes) and playback
Handles general playlists where composite presentations are made up by selecting from base presentations.
HTML version of Basic Foils prepared 27 June 97

Foil 15 WebWisdom: Current Capabilities II

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Handles several different parameter sets (defining fonts, colors, applets etc used) which can be stored and read from server).
Has options to allow Applets for display of foil titles
Logging feature supports assessment and other such post-presentation review.
Attached Audio Editor supports processing of real audio files produced during delivery of lecture and allows one to cut audio files and associate them with particular foils
HTML version of Basic Foils prepared 27 June 97

Foil 16 TANGO/Wisdom

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Collaborative version of WebWisdom aimed at distance education
Uses the NPAC Collaborative System TANGO which has a well defined JavaScript API using LiveConnect for Java to JavaScript connectivity.
Supports asymmetric use with one multiframe WebWisdom ("master") controlling multiple clients running simpler single frame system.
With replicated course material, only control information is passed over the expensive network connection
HTML version of Basic Foils prepared 27 June 97

Foil 17 Video on Demand: Features

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
A complete, end-to-end system for
  • video delivery over local area networks
  • video contents marketing over Internet
Modular system supporting following functionality:
  • video digitization and compression to high (MPEG1) and low (H.263/GSM) rate formats
  • contents indexing and asset management via relational database backend
  • video server, codec independent and distributed
  • software and hardware supported intelligent multi-codec video clients
HTML version of Basic Foils prepared 27 June 97

Foil 18 Video on Demand: Capabilities

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Codec-independent streaming video server for Windows NT
  • supports any audio/video file format
Universal software video client
  • automatically recognizing and playing video formats
    • MPEG1, AVI (1.5 - 2 Mbps), QuickTime, H.263/GSM (28-128 Kpbs)
    • VCR-like capability (random stream access)
High-performance hardware supported video client
  • MPEG1 decoder from Optibase, full screen, 30 fps, VHS quality
  • Available for Windows 3, port to W95 requires some work
HTML version of Basic Foils prepared 27 June 97

Foil 19 Video on Demand: Capabilities II

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Video contents is indexed via the associated textual layer:
  • closed-captioning (automatic acquisition system)
  • manual annotations
  • random access from the web browser window
Video server asset management:
  • all system metadata stored in relational backend
  • web-based system administration interface
  • support for clustered distributed video server
HTML version of Basic Foils prepared 27 June 97

Foil 20 Video on Demand/TANGO Integration

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
Master-slave video client architecture
  • Master client for the teacher
    • has all capabilities of the stand-alone video client, including random access capability
    • uses unicast for server access
    • forwards video streams to a multicast address
  • Slave client for students/general audience
    • start/stop capability only
    • session control via TANGO session manager (more secure than standard MBONE)
No need for separate on-demand and broadcast video servers
HTML version of Basic Foils prepared 27 June 97

Foil 21 Internet Video on Demand

From Master Set of Material on Tango and Collaboratoies Dayton MAPINT 97 Workshop -- 16-18 June 97. *
Full HTML Index
MPEG1/AVI contents suitable for LANs
  • main application: corporate video archive, education
Internet delivery requires low bit rate
  • current commercial servers are codec dependent
    • multiple servers needed for LAN and Internet video
  • our system offers a conversion tool from MPEG1 to H.263/GSM encoding
    • bit rates: 33-12o Kbps (phone line - ISDN range)
    • both MPEG1 and H.263 representations stored on the server
Application: video contents marketing via Internet preview
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