Past, Present and Future of Videoconferencing

at the University of Ghent

Geert De Soete and Michel RaesAcademic Computing Center, University of Ghent, Belgium

Past, Present and Future of Videoconferencing at the University of Ghent p.2

Overview

• Centrally provided videoconferencing facilities at Ghent University:

• The Multimedia Room• Technology• Costs• Types• Quality• Outlook

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.5

Examples of usage

• Local lecture with remote audience

Past, Present and Future of Videoconferencing at the University of Ghent p.6

Examples of usage

• Remote lecture with local audience

Past, Present and Future of Videoconferencing at the University of Ghent p.7

Examples of usage

• Group discussion for project management

Past, Present and Future of Videoconferencing at the University of Ghent p.8

Examples of usage

• PhD defense presentation from a remote site

Past, Present and Future of Videoconferencing at the University of Ghent p.9

Examples of usage

• PhD defense with local and remote jury members

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.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 !

Past, Present and Future of Videoconferencing at the University of Ghent p.14

Some notes on costs

– Cost overview:• 256 kbps is a good price-to-quality compromise

ISDN rates per hour in Euro 128 kbps 256 kbps 384 kbps

Local calls (e.g. within Ghent) 6 12 18 Interzonal calls (e.g. from Ghent to Brussels) 21 42 62 International calls to neighboring countries 54 107 161 International calls to some other European countries 119 238 357 Intercontinental calls to the USA and Canada 71 143 214 Intercontinental calls to Australia 143 286 428

Past, Present and Future of Videoconferencing at the University of Ghent p.15

Types of videoconferences

• Point-to-point videoconferences:– Simply connect two sites to each other

• Multipoint videoconferences:– Connect three or more sites

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.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• ...

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.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• ...

Past, Present and Future of Videoconferencing at the University of Ghent p.21

Quality

• Overall perceived quality is determined by technology related factors:– Audio quality– Video quality– Eliminating distance

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.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 !

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.27

Outlook to future trends

• T.120 data sharing• ATM-based videoconferencing• IP-based videoconferencing• Gateways

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.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...

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.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

Past, Present and Future of Videoconferencing at the University of Ghent p.32

Outlook: Gateways

– Connecting heterogeneous technologies for videoconferencing in a transparant way:

• H.320 ( ISDN )• H.321 ( ATM )• H.323 ( IP )

Past, Present and Future of Videoconferencing at the University of Ghent p.33

Outlook: Multimedia Room

– Extension plans for the videoconference room of Ghent University:

• H.323 codec for IP videoconferencing• H.320 - H.323 gateway

Past, Present and Future of Videoconferencing

at the University of Ghent

Geert De Soete and Michel RaesAcademic Computing Center, University of Ghent, Belgium