If you are presenting a videoconference, you need to have the best audio visual equipment available. You will have to decide what type of audio visual system you will purchase. There are several types to choose from: portable, rollabout, installed or PC-based. Depending on the group size, you will know what your choices are for using these systems. The PC-based ones are for one person only; the rollabouts are for three to four people, or possibly up to 15; the portables are for two to eight people; and the installed ones are for five to six people, possible up to 30.

Portable setups will be used in most videoconferences. The monitors for these setups will range from 20? ? 35? monitors. If the group is large, say 20 or more people, a system with an LCD projector would work better. The bandwidth is the size derived from the image and sound quality that is produced. With real time, video and audio signals are to press within each other so they can swiftly flow through telephone lines for teleconferences. Two 64K ISDN lines are what's used for the majority of videoconferences and the data is moved at 128K per second. In order for the videotape to go over smoothly, the bandwidth should be 384K or higher. This is especially imperative if the videoconferencing involves movement. Currently, people are using T1 or other digital lines for faster movement.

Another important component when looking to purchase audio visual equipment for videoconferencing is the audio quality. The audio for the equipment must be top notch if not the best available. People will not be pleased coming to a conference and the sound is distorted. Whatever system you decide to purchase, check out the sound to see if it is satisfactory. Also, make sure that whatever you get includes full-duplex audio and digital echo cancellation. The frequency response is a good judge of character when it comes to testing audio quality. However, you will still need to listen to it for yourself to make the final determination.

Some other features to consider include:

More than one monitor or projector ? you'll need to see two pictures during the entire time of the conference. One will be of the far-end participants and the other will be a preview of what they will see. Two monitors are better because the images will be larger and this helps if you have large groups in the conference.

More than one camera will give you an advantage in the event that you have a distance learning session and you as the presenter are not in proximity of the group that's being taught. If you're the presenter and you tend to move around a lot during the conference, you may want to consider a robotic camera that will follow you move around.

A telephone is good to have for those who can listen to the conference, but are not able to be there to see the presentation. A bridging service is used for multiple telephone connections. Speaking of connections, make sure the equipment you purchase is compatible with the systems that you're familiar with.

Get familiar with the controls. They should be nearby, where you don't have to stretch your arms to reach them. Check out the manufacturer and see how reliable their products are. If it's a well-known name brand, chances are that might be your best bet. Also, find out where you can get the equipment serviced if need be. The success of your videoconference will depend on the quality and reliability of the audio visual equipment.