The Access Grid Collaboration Environment

The Access Grid, a series of "designed spaces" that support group-to-group collaboration for remote visualization or interactive applications, utilizes a high-bandwidth environment for virtual meetings and events.

Creating a working collaboration requires having a way to establish and maintain communication with one's collaborators. When your partners are in your own workplace, whether an academic or a corporate environment, communication is a relatively easy matter of holding meetings and engaging in casual social activities.

When your collaboration partners are not on-site, however, establishing and maintaining communication are more difficult. At the Futures Lab at Argonne National Laboratory (www.mcs.anl.gov/fl), we often work with groups outside our local community, and we have developed a theory about the stages of collaboration that proceeds along this continuum:

Awareness -> Interaction -> Cooperation -> Collaboration -> Virtual Organization

Awareness. Through journals, meetings, and word of mouth, we first become aware of others in our field who share common interests or ideas.

Interaction. We interact with some of those colleagues at conferences and meetings.

Cooperation and Collaboration. With a subset of those colleagues, we begin to cooperate on projects or papers, and soon we have groups of people from different organizations submitting joint proposals and finally entering into full collaborations.

Virtual Organization. As these groups grow and evolve, they eventually become a virtual organization of work partners.

To maintain and support this virtual organization and still remain cost-effective, we need a persistent virtual space where we can meet to share work and social activities. Persistence is the property that allows us to visit the space at any time, to hang out with others whenever we wish. The need for just such a virtual space led us to create the Access Grid group-to-group collaboration environment.

The Access Grid

The Futures Laboratory in the Mathematics and Computer Science Division at Argonne National Laboratory is a small group (8 to 12 people) working in the areas of advanced visualization, collaboration, and display technologies. Our research partners are almost exclusively from universities or other national laboratories. Based on the model of our own scientific collaborations, our space supports small groups in collaborative efforts. The target space for the Access Grid involves 3 to 10 people interacting on a regular basis with 3 to 5 similar groups. Desktop tools are wholly inadequate for creating a persistent space for this target audience; instead, a small or moderate-sized dedicated room that can be set up for audio, video, and computer-based interactions is ideal.


Researchers at Argonne National Laboratory using the Access Grid.


The goal of the Access Grid project is to enable high-quality group-to-group interactions by providing a user experience that is a substantial improvement over traditional desktop collaborative tools. We want to create a sense of presence with others and allow for natural interaction modalities. These goals are accomplished through multiple video streams emanating from a single space that provide varying perspectives and that support hands-free, full-duplex audio interactions.


Shared visualization on the Access Grid: The Visible Human.


The physical components that have evolved into standard specifications are a dedicated room with a large-scale three-projector display wall and four computers providing video capture, audio capture, display management, and control. Hands-free full-duplex audio communication among all participating sites is accomplished by strategic placement of high-quality microphones throughout the space and by the use of professional-quality echo cancellation equipment. Scalability of the environment comes from the use of IP multicast for all video and audio streams. Full specifications and software downloads are available at www.accessgrid.org.


The Access Grid space at Argonne National Laboratory.


We have also developed a standard suite of software to support this environment, control the four computers and echo-cancel gear, and maintain certain applications that are shared via the Access Grid. This software, called the Virtual Venue, implements a room-based spatial metaphor that provides persistence, controls the scope of interaction, and enhances navigation and discovery within the Access Grid.

Applications

While collaboration is largely about communication, we often think of it in terms only of the spoken and written word. In an electronic world there can be many other means of exploring ideas—computer-generated visualizations, computer-aided searching, shared software, image processing, virtual reality experiences, telepresence experiments, or remote instrument operation. Enabling these communications is an important part of the Access Grid research agenda. We have developed a small set of tools and are working on others. For high-fidelity presentations, we have created a distributed PowerPoint. In an Access Grid meeting, all remote sites receive a copy of the slides and run a local copy of PowerPoint. A master at the host site controls all remote PowerPoints, ensuring a high-fidelity version of the presentation with very low latency slide changes. For more general presentation needs, we use the Virtual Network Computer (VNC) software, which has a facsimile of a screen with optional control. This is a lower-fidelity facsimile with a higher transmission time, but it requires less advance setup and works for most applications and across various operating systems.

Bringing visualization applications with high-performance rendering requirements to the Access Grid presents more of a challenge. Most of our visualizations are driven by the Visualization Toolkit (VTK) software and are rendered on high-performance SGI computers or computational clusters. Access Grid computers do not possess high-performance rendering engines and are already heavily loaded. We have provided a solution by developing a VTK video renderer and a headless video encoder for placing visualization output on the Net as a video stream. We have patched the VIC video client used by the Access Grid to send mouse and keyboard events back to the VTK visualization application. This simple method of decoupling the control from the rendering via a video stream has allowed us to trivially create visualization applications that can be controlled by anyone. Distributed groups thus can jointly explore visualizations by using natural interactions and directly interacting with the images. This VTK/VIC software is available from the Futures Laboratory.

Others have also developed applications for delivering visualization experiences to the Access Grid. The Electronic Visualization Laboratory at the University of Illinois at Chicago, inventors of the CAVE, have streamed second versions of CAVE applications with their CavernSoft middleware and are currently developing an Access Grid supplementary system, AGAVE, for delivering 3D content to the Access Grid. More information is available from the EVL Web pages (www.evl.uic.edu/).

At the University of New Mexico, the Flatland virtual reality environment has been adapted to run on the Access Grid. (See www.ahpcc.unm.edu/NewsPress/ flatland_ag.html for more information.)


Snapshot of time varying fractal deformation of spherical geometry in the VTK software. (Courtesy of Tony Lavoie.)


Partnerships

The Access Grid was first conceived to facilitate collaboration between the Futures Lab and university and D'E partners. We have had AG-enabled visualization and computing partnerships with the University of Chicago, the University of Utah, Lawrence Berkeley Laboratory, The University of Illinois at Chicago, the University of Illinois at Urbana, Los Alamos National Laboratory, and Princeton University. Existing collaborations with many universities have been strengthened by the use of Access Grid nodes. The University of Kansas Chemical Engineering Program is working with the University of Illinois; the Arctic Region Supercomputer Center works with universities in Bozeman and Missoula, Montana; and the University of New Mexico uses AG technology to collaborate with the Maui High Performance Computing Center, which the school administers. Access Grid collaborations are also being planned between the University of Chicago and Brown University medical schools. The Access Grid has grown to the point (more than 25 active nodes, over 40 in progress or planned) that many other collaborations of which we have little knowledge are being enabled across the country. We have been quite pleased with the system's ability to enable effective group-to-group collaborations.

Experiments

Experiments with the Access Grid technology outside the original target of small group-to-group collaborations have been proposed and conducted by university partners. The first Access Grid sites—the University of New Mexico Albuquerque High Performance Computing Center, the Maui High Performance Computing Center, Boston University, the University of Utah, the University of Kentucky, Argonne National Laboratory, and the NCSA Alliance sites at Access DC and at the University of Illinois at Urbana—worked together in 1999 hardening the systems and networking through a series of multiple-day, multi-site education and outreach meetings called Chautauquas, sponsored by the NCSA Alliance. Three Chautauquas were hosted by UNM, UKY, and BU. In 2000, Chautauquas were held at the Ohio Supercomputer Center and at the University of Kansas, with participants from the original six sites plus several others, including the Electronic Visualization Laboratory at the University of Illinois at Chicago. Experiments are under way to deploy this technology in support of remote education at tribal colleges in New Mexico. The Globus group at ANL has performed distance education experiments by conducting a two-day distributed tutorial among six Access Grid sites. A PETSc tutorial was conducted via the Access Grid by the Ohio Supercomputing Center. In each instance, the response from participants was good.


Shared visualization of a Raleigh-Taylor dataset.


Participation in the Access Grid

The Access Grid specification and software are open source and are freely available at the Access Grid Web site, where universities and their partners who wish to build an Access Grid node will find all the information they need. Users can join the Access Grid community by subscribing to the Ag-tech mailing list (ag-tech@mcs.anl.gov) where Access Grid technical issues are discussed.

In January 2001, Argonne National Laboratory hosted a four-day Access Grid retreat for academic and corporate institutions interested in joining the Access Grid community and furthering the development of the Access Grid. More than 130 persons from almost 60 institutions were represented, a full-day tutorial was held, and over 30 papers were presented. Proceedings are available at www.accessgrid.org. Future projects include a large-scale experiment to broaden the visibility of the annual SC convention by providing Access Grid-like capabilities in the technical venues and inviting similarly equipped international sites to participate in the conference from abroad. Many U.S. AG sites will also participate from their respective locations. More information is available at http://www.scglobal.org.

An Open-Source Project

The Access Grid group-to-group collaboration environment provides a comfortable, effective environment for face-to-face meetings of distributed collaborators. Developed by members of the Futures Laboratory at Argonne National Laboratory, Access Grid nodes have been deployed by the NCSA Alliance among our collaborators and receive almost daily use. Visualization applications that have been integrated into the AG framework allow concurrent multi-site collaborative visualization sessions.

Access Grid technology has attracted the attention of users who have experimented with distributed lectures, panels, tutorials, and multi-site, multi-day education and outreach conferences, and who are planning performance event experiments and distributed classrooms. Human factors studies are being proposed to learn how the technology can be improved for its present use or modified for some of the proposed new uses. The Access Grid is an open-source project, and new users and contributors are welcome and encouraged.

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