Powerpoint Document - The Access Grid - What Is it and What ...
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The Access GridWhat Is it and What Can it do?
Alexander Terzian and Zachary WrightUniversity of Michigan
Michigan Center for Biological InformationVirtual Soldier Project
What is the Access Grid?• From the Access Grid website:
– The Access Grid™ is an ensemble of resources including multimedia large-format displays, presentation and interactive environments, and interfaces to Grid middleware and to visualization environments. These resources are used to support group-to-group interactions across the Grid. For example, the Access Grid (AG) is used for large-scale distributed meetings, collaborative work sessions, seminars, lectures, tutorials, and training. The Access Grid thus differs from desktop-to-desktop tools that focus on individual communication.
The promise: The Access Grid is next-generation collaborative technology.
The reality so far: The Access Grid is high-end videoconferencing
How does the Access Grid differ from traditional videoconferencing?– Multiple video/audio streams and unlimited number of participants (in theory)– Open source software – Centralized and (mostly) public meeting “locations” – Uses multicast-enabled networks
• inSORS– http://www.insors.com/
• ANL/NCSA Software– Access Grid Toolkit– http://www.accessgrid.org/
• VRVS– http://www.vrvs.org/
• These use variations of VIC (video) and RAT (audio) software
Three Ways to get on the Access Grid
VRVS• “VRVS is a web oriented system for videoconferencing and collaborative work over IP
networks. The Virtual Room Videoconferencing System (http://www.vrvs.org) provides a low cost, bandwidth-efficient, extensible means of videoconferencing and remote collaboration”
AccessGrid.org
• AG Software
• Virtual Rooms
• Community Support
“The AG technology was developed by the Futures Laboratory at Argonne National Laboratory and is deployed by the NCSA PACI Alliance”
inSors Grid (IG)
• Commercial all-in-one solution• “One Box”• Easy to use• Installation• Desktop Version• Tech Support
What is needed to get on the Access Grid?
Bare Minimum PreferredComputer Good Computer
Webcam or other computer camera Multiple cameras
Monitor Large screen, multiple displays
Microphone Multiple microphones with echo
cancellation hardware
Internet connection Multicast-enabled internet connection
Bandwidth: Megabit connection Bandwidth: Gigabit connection
Access Grid software (vic and rat) Software with support
Access Grid Software
• VIC (Video Conferencing Tool)– “Vic is a video conferencing application developed by the
Network Research Group at the Lawrence Berkeley National Laboratory in collaboration with the University of California, Berkeley.”
– Uses RTP– Designed for Multicast Backbone (MBone)– http://www-nrg.ee.lbl.gov/vic/
• RAT (Robust Audio Tool)– “The Robust Audio Tool (RAT) is a an open-source audio conferencing and
streaming application that allows users to participate in audio conferences over the internet. These can be between two participants directly, or between a group of participants on a common multicast group.”
– RTP – Multicast– Developed at University College London
inSors Grid Desktop
Unicast vs.Multicast (M-bone)
Multicast Virtual Rooms vs. Bridged•Multicast broadcasts to multicast video and audio addresses
•A bridged connection relies on an MCU “bridge” for protocol translation and unicast/multicast translation.
Our System
• Dell Precision 450 Xeon dual-processor 2.66 GHz, 512MB RAM, Windows XP Professional
• Xentera 4-output video card w/3 NEC Vt 660 Projectors• Gentner AP 400 echo-cancellation device• 4 Canon VC-C4 Cameras• 4 audio-technica table microphones• 2 projection screens• 4 ceiling-mounted speakers• Wireless keyboard and gyroscopic mouse• 4 track-mounted spotlights • inSORS Grid software• inSORS Grid Recorder server
Access Grid in Action
inSors Interface
Multiple Video Streams
Access Grid Conference Room
inSors IG Cube
What we’ve found
• There is no substitute for:– Good phone line and speakerphone
• Preferably connected to AG
– Shared-desktop system (e.g. VNC)
– Teleconference bridges• Many users, especially traveling users, do not
have access to a computer
Problems with Access Grid
• Other AG users– Access Grid software/hardware issues, problems – Non-echo canceling microphones– Restricted access to private rooms (e.g. inSORS rooms)– Poor multicast connection– Outdated CODECs (h.261)
• Non-AG users– H.323 to AG bridge problems– Low Bandwidth (especially home users)– Incompatible CODECs– Non-H.323 compatible cameras/software (e.g. iSight)
Keys to Future Success
• Improved CODECs• More multicast-enabled networks• Less expensive echo-canceling
microphones and hardware• Low-cost packages • Better documentation and support• More users on the Access Grid!
Art on the Grid
Complex Multisite Visual Collaboration
Distance Learning on the Grid