Room Evaluation

Careful consideration must be given when choosing the proper facility in which to install the Access Grid Node. You should consider the uses that your Access Grid Node must support, such as remote collaboration (both point to point and multipoint), instructor-led training, company-wide broadcasts, or other events. As an example, if you broadcast an instructor-led training course from your facility, you will need a room that is large enough to seat students, a way to capture of all of the students in the room on camera, and a way to project a clear, large image of the instructor. Compare this to a small distance-collaboration meeting from your conference room where all of your participants should be on camera because they will be talking to distant colleagues who are viewing the broadcast.

The size of the room will influence the number of projectors, cameras, and microphones and their placement, needed to cover the room. A minimum of three projectors is recommended to supply adequate real estate for Access Grid images. Please see the MuralGeom configuration tool at http://www.accessgrid.org/software/MuralGeom1b05.xls for assistance in calculating the proper size and spatial positioning of the displayed area. These projectors may be a front or rear mounted system depending on available space and budget. Rear projection systems provide for a better image and cleaner installation but typically cost more in dollar and real estate as compared to a front projection system. The image can be projected directly on an available wall that can be treated with flat white paint or WallTalker screen material. This is a wallpaper type product that can be written on and erased much like dry wipe boards.

The projection system should be installed so that a natural viewing angle is obtained for the participants in the room. A too high or too low placement causes the participants to look up or down which effects the overall experience by giving the remote participants the impression you are looking somewhere other than at them. This would cause them to wonder wether you are listening or focusing on their input. At the same time, large angles in the projection can cause "keystoning[1]", which distorts projected image and can impair the quality of the projected image. Even after the correction with the projector controls, aligning the multiple projectors can be problematic. The optimal location for placement of the projectors may not be possible and a compromise between placement and quality will need to be reached.

Cameras are placed so that there is full coverage of the participants in the room with primary and secondary views. The cameras should also cover demonstration material such as whiteboards, as well as the projected display wall. In most cases this will provide a complete image of the facility and requires 4 cameras - Presenter, Primary and Secondary Audience and a Projection Wall cameras.

Cameras may be mounted on tripods, shelves, or for a cleaner look, recessed into the wall. They should be placed so that a natural image of the participants is projected to the other users on the Grid. Placement too high or too low will give an unusual angle that may annoy users and will detract from the experience and thus should be avoided. If possible, placing the audience cameras just below the projected images creates the effect that the participants are looking at the people at the distant end. The overall impression that the Access Grid conveys is of actually being in the same room as the participants from the other nodes. As such, the placement of the camera and projected image should try to create this effect.

The microphone and speaker placement is critical for providing a compelling experience when using the Access Grid. Research has shown that the audio experience, even more so that the visual component is the most important aspect of the meeting and any degradation or impairment will reduce the experience. This can be to a point that the irritation of the poor sound quality will cause the users to abandon the use of the Access Grid. Sophisticated audio equipment, such as the Gentner AP400, is used to combat these issues, but the placement of the microphones and speakers in the room plays a major role. Microphones and speakers that are placed too close together will cause audio problems such as echo, feedback, and distortion. Some of these issues can be overcome through adjustment of the "gain controls" and the echo canceling abilities and of the Gentner AP400 & 800 (see the user manual for details).

Location and positioning of the microphones will be determined by room size, furniture layout, and intended usage. As a rule of thumb, microphones should be placed within 2 to 5 feet of any intended speaker. These include anyone participating in a group discussion. The tabletop Crown microphones may be placed on tables and other flat surfaces to pick up the normal conversations of the room. Directional microphones are best used for presenters or to help fill the gaps in the room coverage. Additionally special use systems like collar or lapel microphones, such as those used in TV broadcasts or wireless may also be employed.

The type of system that is being deployed as well as the Access Grid room will determine speaker placement. Genelec Monitor Bi-Amplified speakers are simply placed in an inconspicuous location near the projection wall. This placement will give the impression of the remote users voice is coming from the same location as their visual image, focusing the local users attention in that direction. This works well in a smaller room where the sound does not need to carry very far.

A surround sound system will deploy speakers throughout the room and provides a non-directional sound quality. This is best deployed in a large facility where front mounted speakers would not provide adequate coverage. While this normally provides superior sound quality, the speaker - microphone separation must be addressed during room configuration to eliminate audio feedback. This is readily accomplished in a large facility but can be problematic in a smaller space.