Collaborative Web Browsing Tool Supporting Audio/Video Interactive Presentations

Transcription

1 14th IEEE International Workshops on Enabling Technologies: Infrastructures for Collaborative Enterprises Linköping University, June 13 th 15 th, 2005, Linköping, Sweden Collaborative Web Browsing Tool Supporting Audio/Video Interactive Presentations Guillermo de Jesús HOYOS-RIVERA Roberta LIMA-GOMES & Jean-Pierre COURTIAT LAAS-CNRS Toulouse, France {ghoyos, rgomes, Roberto WILLRICH Department of Computer Science (INE) Santa Catarina Federal University (UFSC) Florianópolis, Brazil LAAS - CNRS Toulouse - France

2 Presentation Outline Collaborative Web Browsing Synchronization Model Functional Architecture Operational behavior of CoLab Conclusions and Future Work 2/30

3 Collaborative Web Browsing Users are isolated when they browse the Web Web Server A Web Server B Web Server C User 1 User 2 We propose to provide Web users with a group awareness 3/30

4 Collaborative Web Browsing The number of Web pages containing embedded continuous media increases quickly New challenge for Collaborative Web Browsing Particularly useful in e-learning 4/30

5 Collaborative Web Browsing Synchronization of HTTP Server Web Browsing HTTP GET HTTP GET Continuous media presentations User 1 User 2 User 3 RSTP Server RSTP RSTP User 1 User 2 User 3 PAUSE! STOP! PLAY! PAUSE! STOP! PLAY! PAUSE! STOP! PLAY! 5/30

6 Collaborative Web Browsing Web browsing synchronization solutions Communication tools Windows Messenger ICQ Browsing indexing CoBrow Let s Browse PROOF 6/30

7 Collaborative Web Browsing Web browsing synchronization solutions Browsing synchronization Application sharing (VNC) E-coBrowse WABX PROOF Integrated collaboration environments (NetDive, PlaceWare, WebEx, ) Possibility of flexibly creating/releasing browsing synchronization relations 7/30

8 Collaborative Web Browsing It seems that there is no currently existing solution allowing users to synchronize embedded continuous media presentations in Web pages Some problems arise, due to Response times when clicking the Play button Connection delays Transmission delays of the RSTP packets Transmission delays of the stream Initial buffering times 8/30

9 Presentation Outline Collaborative Web Browsing Synchronization Model Functional Architecture Operational behavior of CoLab Conclusions and Future Work 9/30

10 Synchronization Model The synchronization state of a collaborative Web browsing session is represented in a tree structure called SDT (Synchronization Dependency Tree) 1 Asynchronous User Browsing Activities Propagation Direction Synchronous Users 10/30

11 Synchronization Model Browsing synchronization in SDTs URL1 1 Browse(URL1) 1 Browse(URL1) URL1 2 Browse(URL1) 2 Browse(URL1) URL2 3 Browse(URL2) URL2 URL1 Browse(URL1) 3 Browse(URL2) 4 5 Browse(URL2) Browse(URL1) 4 5 Browse(URL1) 11/30

12 Synchronization Model Synchronization Relations are dynamically created and released by using Synchronization Requests, which are subject to an authorization protocol: I_Follow_You You_Follow_Me I_Leave_You 12/30

13 Synchronization Model The I_Follow_You request: A Can I see what you are reading? Of course! B SDT B A I_Follow_You I_Accept 13/30

14 Synchronization Model The I_Leave_You request: A I quit you, See you! B SDT B A I_Leave_You 14/30

15 Synchronization Model The You_Follow_Me request: A OK, I m coming! Do you want to see this information? B SDT B A You_Follow_Me I_Accept 15/30

16 Synchronization Model Continuous media presentations synchronization is made according to the synchronization relations among users: the user at the root of a SDT has the control 16/30

17 Presentation Outline Collaborative Web Browsing Synchronization Model Functional Architecture Operational behavior of CoLab Conclusions and Future Work 17/30

18 Functional Architecture External Tools Integration API Capture Integration Session Browsing Managing Resource PrepareToPlay state changes with request the server and execute Play, and treating integration retrieval Stop synchronization Playback & Pause Control requests messages treating Client Session Information Exchange Broker Browsing Requests Resource Retrieval Session Manager Browsing Manager Session Information Exchange MediaSync Manager Users Role Login/out & Synchronization Actions Browsing Actions Playback control & State Changes Internet/Intranet Browsing Controller Browser Media Streaming Plug-in Media Controller Playback Control & State Changes 18/30

19 Presentation Outline Collaborative Browsing Synchronization Model Functional Architecture Operational behavior of CoLab Conclusions and Future Work 19/30

20 Current Implementation MediaSync Manager Cache Get cached 17 Session Manager Browsing Manager 9 Synchronization Playback Control State Change 22 Module 13 Slave URL Caching Cache Module 2 Can access? 8 4 Cached? Get cached 18 Synchronize? 12 Playback Control State Change HTTP req. Trans. resp. 16 resp. Trans. Internet/Intranet Translator req.7 Trans. resp. 8 Retriever Broker HTTP Synchronous User HTTP req. HTTP resp. HTTP resp. 11 HTTP req Asynchronous User 1 5 HTTP request HTTP response Control Data 6 20/30

21 Current Implementation Media synchronization mechanism The PrepareToPlay command allows us to control the synchronization of the state of the whole presentation in spite of the non deterministic connection and buffering times MediaSync Manager Client A Client B Client C Connecting PrepareToPlay ReadyToPlay ReadyToPlay ReadyToPlay Play 21/30

22 Current Implementation 22/30

23 Current Implementation Browsing Frame GUI 23/30

24 Current Implementation User s Identity and Session Name Awareness & Synchronization State Browsing Controls Synchronization Controls (for Users and Roles) 24/30

25 Current Implementation 25/30

26 Current Implementation Average Retrieval Time 1 N T i m e ( m s ) Number of Users 26/30

27 Presentation Outline Collaborative Browsing Synchronization Model Functional Architecture Operational behavior of CoLab Conclusions and Future Work 27/30

28 Conclusions Allowing flexible synchronization relations creation/release is a good issue Usable on any standard browser following the W3C standard specification and supporting the automatic proxy configuration and on any HTML resource Continuous media presentations synchronization: a new issue particularly useful in e-learning Flexible extensible architecture Good performance 28/30

29 Future Work Implementation of a distributed version API s development for integrating our platform with other collaborative tools Implementing enhanced synchronization mode using roles privileges: I_Spy_You & You_Join_Me 29/30

30 Thanks 30/30