Important editorial note: The general principles in this document are relevant, but the specific hardware references are outdated.
An Access Grid node is defined as a specific ensemble of hardware and software. This definition enables the software to make certain assumptions about the environment in which it is executing. It also provides the community with a common experience, and resulting common body of knowledge.
The hardware components of an AG node fall into three broad categories. Computing equipment includes the four computers that drive the node and the associated adapter cards, network hardware, monitors, keyboards, and so on. Media equipment includes the audio processing hardware, microphones, speakers, video cameras, etc. Projection equipment includes the projectors for the display, mounting hardware, screen materials, and so on.
While we strive to define a node configuration that can be replicated identically from site to site, there are some parts of this specification that can vary from site to site. Specific brands of computers or microphones do not necessarily make an impact on the performance of the node (however, we have heard of particular brands that do not work well, and we have experience with brands that work very well). We will flag both those components that can be substituted and those that cannot. When in doubt, call or email us with your questions and we can let you know of our experience or lack of it with a given piece of equipment.
One may wish to reduce the quantity of projectors, cameras, or microphones to reduce the cost of the node. We require that for an installation to comply with the definition of an Access Grid node, it must have at least three projectors, four cameras, and enough microphones to ensure that all users of the node can be heard remotely without any special effort on their part. We find that it typically takes at least four microphones to accomplish this for any usable workspace. For the purpose of price estimates and equipment choice, we lay out a "small node" and "large node" configuration for the audio hardware.
The prices in the tables in this document are for estimation purposes only.