Download 02_Videoconferencing_Introduction

Introduction To
Videoconferencing
Larry Amiot
Northwestern University
[email protected]
Internet2 Commons Site Coordinator Training
September 27, 2004
Austin, Texas
Agenda
Videoconferencing in the Educational
Environment
Alternative Videoconferencing
Technologies
2
Videoconferencing
A conference call consisting of two or
more sites with the ability to
communicate between the sites via
video and audio and possibly data.
3
Digital Video In The Educational
Environment
• Classroom presentations- need for video clips
• Colloquiums- need to broadcast on the network
• Homework Assignments- Video-based reference
material
• Collaborative classes and seminars- need for
remote interaction between class participants
• Committee meetings- need for remote interaction
between participants
• Informal collaboration- need for remote interaction
between colleagues
• Conference presentations- need for remote
interaction between presenters and audience
4
Interactive Class- Parts of the
Puzzle
Web-based Virtual Classroom
• Blackboard at NU
Video Conferencing
Streamed Video
• Real-time video
• Archived Video
Collaborative Tools
5
Video Conferencing Alternatives
 ISDN-based
• H.320 (Legacy)
 Internet-based
• Access Grid
http://www-fp.mcs.anl.gov/fl/accessgrid/
• ConferenceXP
• Virtual Room Videoconferencing System (VRVS)
http://vrvs.cern.ch/
• MPEG2
• SIP-based Technologies
• DVTS
• H.323
6
Access Grid
7
What is the Access Grid?
 A videoconferencing system that supports:
•
•
•
•
•
•
large-scale distributed meetings,
collaborative work sessions,
seminars,
lectures,
tutorials and
training
 Focuses on group-to-group communication
 Designed spaces that explicitly contain the
high-end audio and visual technology
8
The Access Grid
 Provides high-quality audio and real-time
video that allow groups at multiple sites to
interact simultaneously and share data and
scientific instruments.
 Meeting participants appear in windows
projected onto a large screen.
 Data windows from participants' laptop
computers can be integrated into the
meeting
9
10
The Access Grid
Network Technology
• Multicasting WAN
• Multiple concurrent streams from many sites
The Access Grid was developed as part
of a National Computational Science
Alliance at Argonne National Laboratory
11
Conference XP
12
ConferenceXP
An initiative of Microsoft Research’s Learning
Sciences and Technology group
Interact and collaborate with others in a virtual
collaborative space, called a venue
Multiple virtual presence on your XP machine
Audio/video and chat plus ConferenceXP
Presentation for electronic whiteboard or
distributed Microsoft PowerPoint®
presentations
13
Virtual Room Videoconferencing
System (VRVS)
14
Virtual Room Videoconferencing
System
 VRVS is a web oriented system
for videoconferencing and
collaborative work
 Directed at the High Energy and
Nuclear Physics communities
 Recently extended to other
academic/research areas
 Provides collaboration tools:
MBone (vic/rat), H.323 (Polycom,
NetMeeting), QuickTime,
Desktop/Application sharing and
Chat on various platforms
15
16
17
18
MPEG2 Video
19
MPEG2
 High quality, broadcast quality video
 Compressed video (MPEG1 & MPEG2)
 Typically runs at between 4 Mbps and 12 Mbps
 Usually run point-to-point
 Multipoint using multicast possible
 Multipoint using multiple encoders/decoders
possible but expensive
 Several vendors (e.g. VBrick and Star Valley)
 Medical applications, Music Schools, VIP
presentations, etc.
 Expensive $2,200 to $6,000+ per end
20
DVTS
21
DVTS
 Internet2 investigating (Bob Riddle)- Big Video
Project
 Sends digital video over IP at 30Mbps
 Software provides encode/decode capability
 Fujitsu board provides encode/decode in
hardware
 Internet2, Research Channel, UMICH, New
World Symphony, and others trialing
22
Board
DV/Analog
Analog/DV
PC
Board
PC
PC
VGA
Internet
PC
Board
Board
PC
PC
DVTS
DVTS
Software- free
Board- $2,200
Analog/digital converter ~$300
24