The document discusses the past, present, and future of videoconferencing at the University of Ghent. It describes their central Multimedia Room facility, the technologies used including ISDN and H.320 standards, and types of videoconferences like point-to-point and multipoint. It also outlines costs, quality considerations, and the outlook for future technologies like T.120 data sharing, ATM and IP-based videoconferencing, and gateways to connect heterogeneous systems.

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. Overview Centrally provided videoconferencing facilities at Ghent University: The Multimedia Room Technology Costs Types Quality Outlook

3. Centrally provided videoconference facilities The Multimedia room History: 1995: Decision to build October 1996: First course ... 1999-2000: 4 or 5 videoconferences per week Concept Examples of usage

5. Examples of usage Local lecture with remote audience

6. Examples of usage Remote lecture with local audience

7. Examples of usage Group discussion for project management

8. Examples of usage PhD defense presentation from a remote site

9. Examples of usage PhD defense with local and remote jury members

10. Technology currently adopted Modular setup with heterogeneous equipment: more flexibility higher integration efforts H.320 compatible Codec using ISDN : flexible call set-up acceptable price-to-quality ratio

11. Technology currently adopted The ITU H.320 standard: Compatibility = interoperability Problems in the past… now resolved: small differences in implementation pre-standard implementations proprietary and non-standard protocols

12. Technology currently adopted ISDN: Digital, circuit switched, connection oriented, constant bitrate technology Widely available in developed countries But different implementations: eg. Euro-ISDN International connectivity was a problem Now interconnection is seamless and reliable Not available to some partners: Russia, Vietnam Some possiblities with partners in China, Ecuador

13. Some notes on costs Different bandwidths possible: Basic quality: 128 kbps ( 2B ) Medium quality: 256 kbps ( 4B ) High quality: 384 kbps ( 6B ) Proportional price-to-quality The party initiating the call has to pay Differences between countries and operators !

14. Some notes on costs Cost overview: 256 kbps is a good price-to-quality compromise

15. Types of videoconferences Point-to-point videoconferences: Simply connect two sites to each other Multipoint videoconferences: Connect three or more sites

16. Point-to-point videoconferences Require little preparation : exchange of essential information short test connection Easy technical set-up : By dialling the correct number Easy organisation: like a normal meeting

17. Point-to-point videoconferences Examples : Cryptography course with KUL Computer graphics course with Xerox Ghent University PhD defense with the candidate in the USA Ghent University PhD defense with a jury member in Australia ...

18. Multipoint videoconferences Connect three or more sites to each other Technically complex: Star topology with an MCU in the center MCU: image selection, audio multiplexing Complex to organize: Practical arrangements Extensive testing

19. Multipoint videoconferences Examples: Aquarius project management meetings with Ghent, Wageningen (NL) , Trondheim and Bergen (N) PhD defense in Ghent with jury members in Stirling (UK) and in Bordeaux (F) Continuing education courses on Information Technology with 12 participating sites ...

21. Quality Overall perceived quality is determined by technology related factors: Audio quality Video quality Eliminating distance

22. Audio quality Audio quality is a critical factor for room videoconferencing H.320 audio quality is in principle good: Telephone grade quality for low bandwidth Short delay, echo cancellation, voice-to-image synchronization No risk for audio drop-outs

23. Audio quality Overall audio quality also depends on: room acoustics amplifying circuitry type of microphones the way the person talking uses the microphone Precise tuning by the operator is a necessity

24. Video quality H.320 video quality is rather poor: at least compared to broadcast TV quality CIF resolution : 352 x 288 pixels Changing or moving images need time to stabilize More bandwidth only gives faster response in moving images, but no better resolution !

25. Video quality Is no problem for viewing a person talking Is a problem for visual materials: transparencies or printouts (via document camera) computer presentations (via scan converter) Solution: adapt to the restrictions… prepare visual materials according to specific guidelines for videoconference lecturing have a test session to show how the materials will be percieved on a remote site

26. Quality: Eliminating distance The goal: virtually eliminate physical distance between remote sites solving mobility problems reducing transport costs Limitations: the technological environment practical factors like time difference in interconentinental connections difficulty to maintain good interactivity for teaching

27. Outlook to future trends T.120 data sharing ATM-based videoconferencing IP-based videoconferencing Gateways

28. Outlook: T.120 data sharing T.120: transmitting visual materials as data resolution 800 x 600 ( instead of CIF ! ) application sharing, whiteboard Most systems rely on Microsoft NetMeeting System integration ? 2 viewing circuits are necessary in a room setup

29. Outlook: ATM-based VC ATM-based VC in the past: High cost Poor interoperability ATM-based VC in the future: more products for H.310 (native ATM) and H.321 (IP over ATM) But ATM deployment remains uncertain...

30. Outlook: IP-based VC IP-based VC in the past: Unpredictable performance over WAN Low quality: eg. audio drop-outs by packet loss No industry standard for interoperability Mbone tools for specialized academic users IP-based VC now: ITU H.323 standard good performance over high speed LANs

31. Outlook: IP-based VC IP-based VC in the future: Increase in bandwidth in IP networks: Gigabit / Terabit IP backbones using fiber optic Implementation of QoS mechanisms in IP networks: RSVP, DiffServ more H.323 compatible products

32. Outlook: Gateways Connecting heterogeneous technologies for videoconferencing in a transparant way: H.320 ( ISDN ) H.321 ( ATM ) H.323 ( IP )

33. Outlook: Multimedia Room Extension plans for the videoconference room of Ghent University: H.323 codec for IP videoconferencing H.320 - H.323 gateway

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