Partners for Advanced Computational Services
Use New Technology

PACS representatives recently took part in the first Alliance administrative meeting held using Access Grid technologies. While the first designation could be disputed perhaps, none of those participating would dispute the effectiveness of the technology for a meeting debating resource allocation and deliverables. Held at Argonne National Laboratory (ANL) in late October, the quarterly meeting brought together PACS staff at five other locations: Boston University, University of Kentucky, University of New Mexico, ACCESS-DC, and NCSA.

PACS Chair Frank Gilfeather (left, shown on the Access Grid at the 1999 Boston Chautauqua), executive director of the High Performance Computing, Education and Research Center at the Albuquerque High Performance Computing Center, called the meeting to order from a ANL room with a clearly industrial feel, housing cameras, chases, and considerable equipment. The 15 or so people sitting around the table were joined remotely by more than 12 people at the other locations.

Access Grid Explained

The Access Grid distinguishes itself by offering group-to-group communication. Imagine a large - wall-size - screen with multiple windows displayed as tiles. Add to that some cameras, microphones, and several computers for managing the system. Such a set-up, in a classroom, conference room, or computer lab, is called a node. On one side of the screen is a long "list" of thumbnail-sized views as transmitted from participating sites. From this list, each site coordinator selects which video streams to offer on the local large screen. Some views remain a thumbnail, some are mid-sized, and one large image can usually be accommodated. Screens show people, whiteboards, presentation materials, or a view of a node screen.

The Access Grid gives participants a good sense of being there and participating in the larger meeting. At NCSA, for example, twelve views were easily visible throughout the PACS meeting, selected from 22 available windows. Although the sound faded in and out periodically, most conversations were clear, with the occasional asides often audible at distant locations. The images are what fascinate, though. Because the technology integration is still in development as are some of the component technologies, some interesting side effects are apparent. Due to the lack of adequate support for network multi-cast and lack of existence of network Quality of Service, time delays are apparent in the transfer of pixels. The on-screen representations of a person frequently leave a hand unattached to a body as the hand is moved from one position to another. Watching oneself on-screen is an interesting exercise. Cross your legs, wait a couple of seconds, and then watch it happen!

Remy Evard, manager of Advanced Computing and Networking at ANL and a PACS member, served as local host for the PACS meeting. Evard coordinated the logistics in the conference room with another ANL staff. He repositioned cameras and tweaked locations of microphones in response to the comments he received on the "back channel" - online conversations among the other technical staff making the Grid work.

Partner Development, Partner Use

The Access Grid was prototyped by ANL staff in collaboration with a number of Alliance partners in order to develop an environment to conduct remote meetings, site visits, training sessions, and educational events. As development continues, the Access Grid Nodes will also provide a research environment for the development of distributed data and visualization corridors and for studying issues relating to collaborative work in distributed environments.

The Access Grid was first demonstrated for a large audience at the 1999 Chautauqua held in Albuquerque in August. That event was quickly followed by two other Chautauquas in Lexington and Boston that made extensive use of Grid technologies. The Grid received positive reviews at each event for its ability to provide a collective feeling among participants at different locations. NCSA and Alliance Director Larry Smarr has called the Access Grid the most compelling thing he's seen since NCSA Mosaic.

"The PACS meeting was a terrific opportunity to experiment with the technology in a practical meeting setting as opposed to the lecture/seminar format of the Chautauquas," noted NCSA senior associate director and PACS liaison John Towns. "Attending a meeting remotely can save time and money, allow for more frequent meetings, and let people participate who might not be able to without the Grid technology."

In the Future

PACS is hoping to use Access Grid Nodes at various locations for training and other events over the next several months. The Grid will continue to be integral to the Alliance Chautauquas, to be held in 2000 in Ohio and Kansas with special participation at ACCESS-DC. ANL continues to work on advances to the Access Grid as part of their overall contributions to the Alliance, particularly as part of the Emerging Technologies (ET) team.

Currently the equipment required to construct an Access Grid Node consists of commonly available components including standard PCs and audio and video equipment. The significant advancement is how these elements are tied together with high performance networks and specialized software to support the system. To learn more about the technical details and implementations of Access Grid Nodes, visit the Access Grid website.