Past, Present and Future of Videoconferencing at the University of Ghent Geert De Soete and Michel Raes Academic Computing...
Overview <ul><li>Centrally provided videoconferencing facilities at Ghent University: </li></ul><ul><ul><ul><li>The Multim...
Centrally provided videoconference facilities <ul><li>The Multimedia room </li></ul><ul><ul><li>History: </li></ul></ul><u...
 
Examples of usage <ul><ul><ul><li>Local lecture  with remote audience </li></ul></ul></ul>
Examples of usage <ul><ul><ul><li>Remote lecture  with local audience </li></ul></ul></ul>
Examples of usage <ul><ul><ul><li>Group discussion  for project management </li></ul></ul></ul>
Examples of usage <ul><ul><ul><li>PhD defense  presentation from a remote site </li></ul></ul></ul>
Examples of usage <ul><ul><ul><li>PhD defense  with local and remote jury members </li></ul></ul></ul>
Technology currently adopted <ul><li>Modular setup  with heterogeneous equipment: </li></ul><ul><ul><li>more flexibility <...
Technology currently adopted <ul><li>The ITU H.320 standard: </li></ul><ul><ul><li>Compatibility =  interoperability </li>...
Technology currently adopted <ul><li>ISDN: Digital, circuit switched, connection oriented, constant bitrate technology </l...
Some notes on costs <ul><ul><li>Different bandwidths possible: </li></ul></ul><ul><ul><ul><li>Basic quality:  128 kbps ( 2...
Some notes on costs <ul><ul><li>Cost overview: </li></ul></ul><ul><ul><ul><li>256 kbps is a good price-to-quality compromi...
Types of videoconferences <ul><li>Point-to-point  videoconferences: </li></ul><ul><ul><li>Simply connect two sites to each...
Point-to-point videoconferences <ul><ul><li>Require  little preparation : </li></ul></ul><ul><ul><ul><li>exchange of essen...
Point-to-point videoconferences <ul><ul><li>Examples : </li></ul></ul><ul><ul><ul><li>Cryptography course with KUL </li></...
Multipoint videoconferences <ul><ul><li>Connect  three or more sites  to each other </li></ul></ul><ul><ul><li>Technically...
Multipoint videoconferences <ul><ul><li>Examples: </li></ul></ul><ul><ul><ul><li>Aquarius project management meetings with...
 
Quality <ul><li>Overall perceived quality  is determined by technology related factors: </li></ul><ul><ul><li>Audio qualit...
Audio quality <ul><ul><li>Audio quality is  a critical factor  for room videoconferencing </li></ul></ul><ul><ul><li>H.320...
Audio quality <ul><ul><li>Overall audio quality also depends on: </li></ul></ul><ul><ul><ul><li>room acoustics </li></ul><...
Video quality <ul><ul><li>H.320 video quality is rather  poor: </li></ul></ul><ul><ul><ul><li>at least compared to broadca...
Video quality <ul><ul><li>Is no problem for viewing a person talking </li></ul></ul><ul><ul><li>Is a problem for  visual m...
Quality: Eliminating distance <ul><ul><li>The goal:  virtually eliminate physical distance  between remote sites </li></ul...
Outlook to future trends <ul><li>T.120 data sharing </li></ul><ul><li>ATM-based videoconferencing </li></ul><ul><li>IP-bas...
Outlook: T.120 data sharing <ul><ul><li>T.120: transmitting visual materials as data </li></ul></ul><ul><ul><ul><li>resolu...
Outlook: ATM-based VC <ul><ul><li>ATM-based VC in the past: </li></ul></ul><ul><ul><ul><li>High cost </li></ul></ul></ul><...
Outlook: IP-based VC <ul><ul><li>IP-based VC in the past: </li></ul></ul><ul><ul><ul><li>Unpredictable performance over WA...
Outlook: IP-based VC <ul><ul><li>IP-based VC in the future: </li></ul></ul><ul><ul><ul><li>Increase in bandwidth in IP net...
Outlook: Gateways <ul><ul><li>Connecting heterogeneous technologies  for videoconferencing in a transparant way: </li></ul...
Outlook: Multimedia Room <ul><ul><li>Extension plans  for the videoconference room of Ghent University: </li></ul></ul><ul...
 
 
 
Past, Present and Future of Videoconferencing at the University of Ghent Geert De Soete and Michel Raes Academic Computing...
Upcoming SlideShare
Loading in …5
×

( Powerpoint presentation )

492 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
492
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
7
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

( Powerpoint presentation )

  1. 1. Past, Present and Future of Videoconferencing at the University of Ghent Geert De Soete and Michel Raes Academic Computing Center, University of Ghent, Belgium
  2. 2. Overview <ul><li>Centrally provided videoconferencing facilities at Ghent University: </li></ul><ul><ul><ul><li>The Multimedia Room </li></ul></ul></ul><ul><ul><ul><li>Technology </li></ul></ul></ul><ul><ul><ul><li>Costs </li></ul></ul></ul><ul><ul><ul><li>Types </li></ul></ul></ul><ul><ul><ul><li>Quality </li></ul></ul></ul><ul><ul><ul><li>Outlook </li></ul></ul></ul>
  3. 3. Centrally provided videoconference facilities <ul><li>The Multimedia room </li></ul><ul><ul><li>History: </li></ul></ul><ul><ul><ul><li>1995: Decision to build </li></ul></ul></ul><ul><ul><ul><li>October 1996: First course </li></ul></ul></ul><ul><ul><ul><li>... </li></ul></ul></ul><ul><ul><ul><li>1999-2000: 4 or 5 videoconferences per week </li></ul></ul></ul><ul><ul><li>Concept </li></ul></ul><ul><ul><li>Examples of usage </li></ul></ul>
  4. 5. Examples of usage <ul><ul><ul><li>Local lecture with remote audience </li></ul></ul></ul>
  5. 6. Examples of usage <ul><ul><ul><li>Remote lecture with local audience </li></ul></ul></ul>
  6. 7. Examples of usage <ul><ul><ul><li>Group discussion for project management </li></ul></ul></ul>
  7. 8. Examples of usage <ul><ul><ul><li>PhD defense presentation from a remote site </li></ul></ul></ul>
  8. 9. Examples of usage <ul><ul><ul><li>PhD defense with local and remote jury members </li></ul></ul></ul>
  9. 10. Technology currently adopted <ul><li>Modular setup with heterogeneous equipment: </li></ul><ul><ul><li>more flexibility </li></ul></ul><ul><ul><li>higher integration efforts </li></ul></ul><ul><li>H.320 compatible Codec using ISDN : </li></ul><ul><ul><li>flexible call set-up </li></ul></ul><ul><ul><li>acceptable price-to-quality ratio </li></ul></ul>
  10. 11. Technology currently adopted <ul><li>The ITU H.320 standard: </li></ul><ul><ul><li>Compatibility = interoperability </li></ul></ul><ul><ul><li>Problems in the past… now resolved: </li></ul></ul><ul><ul><ul><li>small differences in implementation </li></ul></ul></ul><ul><ul><ul><li>pre-standard implementations </li></ul></ul></ul><ul><ul><ul><li>proprietary and non-standard protocols </li></ul></ul></ul>
  11. 12. Technology currently adopted <ul><li>ISDN: Digital, circuit switched, connection oriented, constant bitrate technology </li></ul><ul><ul><ul><li>Widely available in developed countries </li></ul></ul></ul><ul><ul><ul><li>But different implementations: eg. Euro-ISDN </li></ul></ul></ul><ul><ul><ul><li>International connectivity was a problem </li></ul></ul></ul><ul><ul><ul><li>Now interconnection is seamless and reliable </li></ul></ul></ul><ul><ul><ul><li>Not available to some partners: Russia, Vietnam </li></ul></ul></ul><ul><ul><ul><li>Some possiblities with partners in China, Ecuador </li></ul></ul></ul>
  12. 13. Some notes on costs <ul><ul><li>Different bandwidths possible: </li></ul></ul><ul><ul><ul><li>Basic quality: 128 kbps ( 2B ) </li></ul></ul></ul><ul><ul><ul><li>Medium quality: 256 kbps ( 4B ) </li></ul></ul></ul><ul><ul><ul><li>High quality: 384 kbps ( 6B ) </li></ul></ul></ul><ul><ul><li>Proportional price-to-quality </li></ul></ul><ul><ul><li>The party initiating the call has to pay </li></ul></ul><ul><ul><li>Differences between countries and operators ! </li></ul></ul>
  13. 14. Some notes on costs <ul><ul><li>Cost overview: </li></ul></ul><ul><ul><ul><li>256 kbps is a good price-to-quality compromise </li></ul></ul></ul>
  14. 15. Types of videoconferences <ul><li>Point-to-point videoconferences: </li></ul><ul><ul><li>Simply connect two sites to each other </li></ul></ul><ul><li>Multipoint videoconferences: </li></ul><ul><ul><li>Connect three or more sites </li></ul></ul>
  15. 16. Point-to-point videoconferences <ul><ul><li>Require little preparation : </li></ul></ul><ul><ul><ul><li>exchange of essential information </li></ul></ul></ul><ul><ul><ul><li>short test connection </li></ul></ul></ul><ul><ul><li>Easy technical set-up : </li></ul></ul><ul><ul><ul><li>By dialling the correct number </li></ul></ul></ul><ul><ul><li>Easy organisation: like a normal meeting </li></ul></ul>
  16. 17. Point-to-point videoconferences <ul><ul><li>Examples : </li></ul></ul><ul><ul><ul><li>Cryptography course with KUL </li></ul></ul></ul><ul><ul><ul><li>Computer graphics course with Xerox </li></ul></ul></ul><ul><ul><ul><li>Ghent University PhD defense with the candidate in the USA </li></ul></ul></ul><ul><ul><ul><li>Ghent University PhD defense with a jury member in Australia </li></ul></ul></ul><ul><ul><ul><li>... </li></ul></ul></ul>
  17. 18. Multipoint videoconferences <ul><ul><li>Connect three or more sites to each other </li></ul></ul><ul><ul><li>Technically complex: </li></ul></ul><ul><ul><ul><li>Star topology with an MCU in the center </li></ul></ul></ul><ul><ul><ul><li>MCU: image selection, audio multiplexing </li></ul></ul></ul><ul><ul><li>Complex to organize: </li></ul></ul><ul><ul><ul><li>Practical arrangements </li></ul></ul></ul><ul><ul><ul><li>Extensive testing </li></ul></ul></ul>
  18. 19. Multipoint videoconferences <ul><ul><li>Examples: </li></ul></ul><ul><ul><ul><li>Aquarius project management meetings with Ghent, Wageningen (NL) , Trondheim and Bergen (N) </li></ul></ul></ul><ul><ul><ul><li>PhD defense in Ghent with jury members in Stirling (UK) and in Bordeaux (F) </li></ul></ul></ul><ul><ul><ul><li>Continuing education courses on Information Technology with 12 participating sites </li></ul></ul></ul><ul><ul><ul><li>... </li></ul></ul></ul>
  19. 21. Quality <ul><li>Overall perceived quality is determined by technology related factors: </li></ul><ul><ul><li>Audio quality </li></ul></ul><ul><ul><li>Video quality </li></ul></ul><ul><ul><li>Eliminating distance </li></ul></ul>
  20. 22. Audio quality <ul><ul><li>Audio quality is a critical factor for room videoconferencing </li></ul></ul><ul><ul><li>H.320 audio quality is in principle good: </li></ul></ul><ul><ul><ul><li>Telephone grade quality for low bandwidth </li></ul></ul></ul><ul><ul><ul><li>Short delay, echo cancellation, voice-to-image synchronization </li></ul></ul></ul><ul><ul><ul><li>No risk for audio drop-outs </li></ul></ul></ul>
  21. 23. Audio quality <ul><ul><li>Overall audio quality also depends on: </li></ul></ul><ul><ul><ul><li>room acoustics </li></ul></ul></ul><ul><ul><ul><li>amplifying circuitry </li></ul></ul></ul><ul><ul><ul><li>type of microphones </li></ul></ul></ul><ul><ul><ul><li>the way the person talking uses the microphone </li></ul></ul></ul><ul><ul><li>Precise tuning by the operator is a necessity </li></ul></ul>
  22. 24. Video quality <ul><ul><li>H.320 video quality is rather poor: </li></ul></ul><ul><ul><ul><li>at least compared to broadcast TV quality </li></ul></ul></ul><ul><ul><ul><li>CIF resolution : 352 x 288 pixels </li></ul></ul></ul><ul><ul><ul><li>Changing or moving images need time to stabilize </li></ul></ul></ul><ul><ul><ul><li>More bandwidth only gives faster response in moving images, but no better resolution ! </li></ul></ul></ul>
  23. 25. Video quality <ul><ul><li>Is no problem for viewing a person talking </li></ul></ul><ul><ul><li>Is a problem for visual materials: </li></ul></ul><ul><ul><ul><li>transparencies or printouts (via document camera) </li></ul></ul></ul><ul><ul><ul><li>computer presentations (via scan converter) </li></ul></ul></ul><ul><ul><li>Solution: adapt to the restrictions… </li></ul></ul><ul><ul><ul><li>prepare visual materials according to specific guidelines for videoconference lecturing </li></ul></ul></ul><ul><ul><ul><li>have a test session to show how the materials will be percieved on a remote site </li></ul></ul></ul>
  24. 26. Quality: Eliminating distance <ul><ul><li>The goal: virtually eliminate physical distance between remote sites </li></ul></ul><ul><ul><ul><li>solving mobility problems </li></ul></ul></ul><ul><ul><ul><li>reducing transport costs </li></ul></ul></ul><ul><ul><li>Limitations: </li></ul></ul><ul><ul><ul><li>the technological environment </li></ul></ul></ul><ul><ul><ul><li>practical factors like time difference in interconentinental connections </li></ul></ul></ul><ul><ul><ul><li>difficulty to maintain good interactivity for teaching </li></ul></ul></ul>
  25. 27. Outlook to future trends <ul><li>T.120 data sharing </li></ul><ul><li>ATM-based videoconferencing </li></ul><ul><li>IP-based videoconferencing </li></ul><ul><li>Gateways </li></ul>
  26. 28. Outlook: T.120 data sharing <ul><ul><li>T.120: transmitting visual materials as data </li></ul></ul><ul><ul><ul><li>resolution 800 x 600 ( instead of CIF ! ) </li></ul></ul></ul><ul><ul><ul><li>application sharing, whiteboard </li></ul></ul></ul><ul><ul><li>Most systems rely on Microsoft NetMeeting </li></ul></ul><ul><ul><li>System integration ? </li></ul></ul><ul><ul><ul><li>2 viewing circuits are necessary in a room setup </li></ul></ul></ul>
  27. 29. Outlook: ATM-based VC <ul><ul><li>ATM-based VC in the past: </li></ul></ul><ul><ul><ul><li>High cost </li></ul></ul></ul><ul><ul><ul><li>Poor interoperability </li></ul></ul></ul><ul><ul><li>ATM-based VC in the future: </li></ul></ul><ul><ul><ul><li>more products for H.310 (native ATM) and H.321 (IP over ATM) </li></ul></ul></ul><ul><ul><ul><li>But ATM deployment remains uncertain... </li></ul></ul></ul>
  28. 30. Outlook: IP-based VC <ul><ul><li>IP-based VC in the past: </li></ul></ul><ul><ul><ul><li>Unpredictable performance over WAN </li></ul></ul></ul><ul><ul><ul><li>Low quality: eg. audio drop-outs by packet loss </li></ul></ul></ul><ul><ul><ul><li>No industry standard for interoperability </li></ul></ul></ul><ul><ul><ul><li>Mbone tools for specialized academic users </li></ul></ul></ul><ul><ul><li>IP-based VC now: </li></ul></ul><ul><ul><ul><li>ITU H.323 standard </li></ul></ul></ul><ul><ul><ul><li>good performance over high speed LANs </li></ul></ul></ul>
  29. 31. Outlook: IP-based VC <ul><ul><li>IP-based VC in the future: </li></ul></ul><ul><ul><ul><li>Increase in bandwidth in IP networks: Gigabit / Terabit IP backbones using fiber optic </li></ul></ul></ul><ul><ul><ul><li>Implementation of QoS mechanisms in IP networks: RSVP, DiffServ </li></ul></ul></ul><ul><ul><ul><li>more H.323 compatible products </li></ul></ul></ul>
  30. 32. Outlook: Gateways <ul><ul><li>Connecting heterogeneous technologies for videoconferencing in a transparant way: </li></ul></ul><ul><ul><ul><li>H.320 ( ISDN ) </li></ul></ul></ul><ul><ul><ul><li>H.321 ( ATM ) </li></ul></ul></ul><ul><ul><ul><li>H.323 ( IP ) </li></ul></ul></ul>
  31. 33. Outlook: Multimedia Room <ul><ul><li>Extension plans for the videoconference room of Ghent University: </li></ul></ul><ul><ul><ul><li>H.323 codec for IP videoconferencing </li></ul></ul></ul><ul><ul><ul><li>H.320 - H.323 gateway </li></ul></ul></ul>
  32. 37. Past, Present and Future of Videoconferencing at the University of Ghent Geert De Soete and Michel Raes Academic Computing Center, University of Ghent, Belgium

×