Access Grid

The Access Grid (AG) consists of multimedia displays, presentation and interactive environments, interfaces to grid middleware, and interfaces to visualization environments, to support large-scale distributed meetings, collaborative work sessions, seminars, lectures, tutorials and training.


Access Grid

Penn State has deployed a number of facilities for Access Grid conferencing in the last few years. We find AG a cost effective alternative to other video conferencing solutions, and AG compliments our existing visualization facilities. The Access Grid Toolkit is an open source and extensible software set that provides multimedia conferencing capabilities on widely disparate and scalable systems.

What is Access Grid?

Access Grid (AG) facilitates group-to-group interaction across the grid, as opposed to person-to-person interaction you may be familiar with via desktop or video-phone conferencing. Done through multicast networking, AG functionality is theoretically almost infinitely scalable.

AG nodes are the facilities for this purpose and are "designed spaces", meaning that nodes inherently have large format displays, video cameras, mics, powered audio monitors and shared application environments.

Distributed data and visualization corridors allow for multiple sites to visualize and interact with data in real-time, allowing for command decisions to be made within shorter turn-around time. Visualization data can be shared through high-resolution streaming video, interactive 3D graphics, or shared desktops.

AG provides persistent electronic spaces that are always available in order to foster the growth of on-line communities. The persistent nature allows for multiple, physical locations to log on and "enter" the same virtual space to begin collaborating with a minimum of technical preparation.

AG, or what develops from it, has the possibility of becoming the next killer app. AG can revolutionize the way we collaborate, much like the World Wide Web did beginning in 1990.

Origins of Access Grid

AG grew out of the Computational Grid (Globus) to fill a need for human interaction and collaboration on the Grid.

Research is funded by the National Science Foundation's (NSF) Partnerships for Advanced Computational Infrastructure (PACI), and is an initiative of the National Computational Science Alliance (Alliance) multidisciplinary expeditions.

Two of the major player are Argonne National Laboratory: Future Laboratory (FL) and the National Center for Supercomputing Applications (NCSA).

An Enabling Technology

AG allows for a breakdown of time and space. Colleagues can collaborate over vast distances in real-time.

Reduced travel cost is a definite plus: time, money & stress. No more hopping a plane once a month to participate in a meeting. The researcher can now participate in more meetings, more often, without the down-time associated with travel and removal from the home environment.

The participating institutions within AG allow for access to high-quality, expert speakers and content. This access allows your local community exposure to content they may have not otherwise been able to experience. AG is a growing creative community with nodes located worldwide.

High-resolution audio/video/desktop sharing are central points that enable compelling interaction.

The Access Grid Toolkit (AGtk) is actively developed in an open community based off of Open Source Software, allowing for innovation and rapid development without licensing issues.

Required Resources

The first thing that is needed is adequate networking. Multicast networking must be enabled on your network and on all routers to the upstream provider. Multicast is key to the scalability of meetings and minimizing the load on your network. Multicast allows for the propagation of only one data stream for all clients from each source, as opposed to unicast that requires a data stream to every client from every source. It is a one-to-many model for group communication, instead of the unicast model of connections between every possible pairing. Muticast adresses are to

The interconnect between node hardware should be 100BaseT, and upstream connections should be at least T3 or DS3 to the Internet. A full T1/DS1 may be enough for limited functionality.

Physical space is not to be overlooked during planning and construction: adequate seating for your intended meeting sizes, good acoustics to minimize audio complications, good lighting for the camera, and accessibility for clientele.

Staffing a node properly requires a number of technical positions. Foremost is a competent systems administrator/programmer familiar with Windows, Linux, and audio/video systems. The administrator will work closely with senior networking technicians to support and debug multicast. A trained node operator familiar with the Access Grid Toolkit and A/V equipments needs to be on-hand during meetings. Non-technical staff is also required for scheduling and maintenance of room.

Equipment costs can vary widely depending on the size of your node. An average estimate would be about $25,000-$50,000+.

Node Setup

A short laundry list of on-going steps:

Penn State Node Equipment List

Computer Building 140B Node


This node is a small conference room configuration.

Thanks to Imprint Systems for helping spec and assemble A/V equipment.

video cameras

video projectors

display wall / projection screen display

computer workstations w/ required PCI multimedia cards

audio monitor speakers


level balancing device

telephone lines

power conditioning device

echo cancellation device

keyboard/video/mouse switch

presenter's laptop

tables, chairs, lighting, ports

insert psu room layout graphic

Immersive Environments Lab Node

This nodes will be a single workstation installation with limited functionality, as compared to our full installation located in 140B Computer Building.

Laptop Node

Personal Interface to the Grid

The most compact, portable and functionaly limited of the configurations.

A Compelling User Experience

Audio is the most crucial factor in creating a compelling user experience. Extra steps are taken to ensure the quality of the audio with specialized A/V equipment so people may merely talk to each other easily and fluidly.

Arranging equipment in a non-obtrusive and functional manner adds to the almost transparent nature of interaction during a well planned AG session. Placing mics in strategic spots to best capture sound, and placing video cameras near the projection screen to generate the sensation of eye contact are two easy steps.

The video is clear enough that natural communication takes place, even body language and normal face-to-face meeting etiquette. People will be more polite and less inclined to tap on their laptops and other such dis-courtesies if someone can see them clearly. Raising hands and taking turns talking becomes natural.

Distributed PowerPoint, shared VNC desktops, OpenGL and MPEG video offer rich content for the users.

Precipitation of Activity

After initial testing and debugging, our AG node was ready for general use. Once a node is listed as functional and some outreach/publicity is done, users most often find the node and ask to schedule of their own accord.

The nature of the content on AG is such that it precipitates interest and collaboration within your research community.

Select Past AG Sessions

Sessions of note:

Scheduled Events

Related/Similar Conferencing & Streaming Technologies


Further Reading

NCSA Access Grid Training Project Tutorials
includes everything from managerial overview to room construction to meeting organization
Access Grid Documentation Project
the main resource for all AG documentation


George Otto, Gavin Burris, Pupun Das and Vijay Agarwala

Contact Information & Help

Our node is open for free testing purposes to the Penn State community.

The Penn State Access Grid Node is located in 140B Computer Building, Penn State, University Park.

Please contact with all questions and scheduling queries.