What is a videoconference?

Videoconferencing is a technology which allows individuals at different locations to see and hear each other at the same time. Conferencing between only two sites is referred to as point-to-point. More sites in a conference is multipoint. Like a regular telephone call, one site dials up another as a video call. Then each location hears and sees the other in full motion and color. In addition to audio and video, data files may be transferred; and collaboration is possible through document and whiteboard sharing.

How does it work?

A videoconferencing system consists of audio-visual equipment such as video monitor, microphones, camera, speakers as well as a codec which transmits and receives signals in the H.320 protocol. For years satellite videoconferences provided TV quality pictures and sound but at a very high cost. Today, videoconferencing takes advantage of recent advancements in signal compression and uses telephone line and Internet connections for a fraction of the satellite costs.

Videoconferencing connections may be limited to a closed network (such as a LAN) or may use public networks (such as regular phone lines). Many connect via ISDN (Integrated Services Digital Network) because it is an economical (though still not cheap) solution for high-quality videoconferencing. ISDN works over regular copper telephone lines, transmits at a minimum of 128 Kbps per line, and provides dedicated bandwidth for smooth audio and video (15-30 frames per second). The preferred rate for events is at least 384 Kbps.

In contrast, an Internet-based connection using the H.323 protocol (IP) shares or competes for bandwidth with other Internet traffic. This may cause audio clipping or delays and results in jerky video on slow networks. The University of Florida and the Health Science Center are developing a high bandwidth network using Internet II and are experiencing very good results with IP videoconferencing. Many believe that the Internet will eventually replace ISDN as the medium of choice for videoconferencing.

Locally available service

The Health Science Center has available many videoconference sites for classes, meetings and other presentations in ISDN and IP. A room facilitator is also available to assure proper dial-up, line connection and A/V operation during conferences.

Using state-of-the-art conferencing technology, the Health Science Center maintains a complete network and routinely connects sites here in Gainesville, Jacksonville, and other Florida cities. Connections are also possible throughout the world where sites have comparable capabilities and standards-compliant systems.

In order to engage multiple sites in a conference, a dial-up initiates the call with participating sites. All of these must adhere to the same protocol, either H.320 or H.323. Each site must have at least a camera, monitors, speakers and a codec. Collaboration and data sharing are possible with multipoint conferencing.

Your own system

Recent advances in technology have made videoconferencing not only more reliable and but also more affordable. Some departments are considering buying their own videoconferencing facility. For departments who want to establish their own systems, valuable experience and advice are available for the asking from Teaching Laboratory Resources.

Do your homework

Videoconferencing systems do not operate in a vacuum. They are not like telephones or radios, which simply plug in and turn on. There is a wide variety of systems providing different features and requiring very specific operating conditions. Careful consideration before selecting a system can avoid very costly surprises and disappointments.

Deciding how you intend to use a videoconferencing unit is crucial. Try to anticipate your future needs as well as present ones both as presenter and as receiver of information. You may think right now that a “talking-head” conference is all you will ever need. Consider a few of the enhancements possible: multiple microphones, multiple cameras, document camera, CD/DVD VCR playback and record, streaming video/audio, RS232 data port, SXGA graphics, video projectors, slide projectors, and phone connection. All of these features are tools that can make an already good presentation even better, but they require careful planning and consideration.

Room design

The room in which the system will operate deserves serious consideration. Availability of space for equipment is only one consideration. Room participants need to be able to see the monitors. Lighting, acoustics, camera and microphone placement are critical. If more than one camera is to be used during conferences, an extra person may be required to facilitate camera changes, operate tape or CD players, and other A/V equipment.

Avoid Mix-and-match

Be aware that different brands may not be completely compatible and therefore may not share features. Particular applications within a system may not work well with similar applications in another brand. The brand conferencing unit which works most successfully in the Health Science Center and which is universally popular is Polycom.

Network

A codec makes up the heart of a system; but equally important is how that codec connects to networks. Conferences cannot happen without LAN and/or fiber connections. LAN ports necessary for connection are either 10 or 100mbs. These must be planned for and installed before conferencing equipment can even be configured for use. Poor planning here can delay getting a system started as well as compromise a clean conference connection. Health Net will see that ports are installed and that the connection is successful. http://www.healthnet.ufl.edu/

The Health Science Center provides a very sophisticated network and video bridge support services. The video bridge routs all H.320 videoconferences. Therefore, videoconferencing units need to be carefully configured for appropriate protocols in order to take advantage of bridge services.

Scheduling

To videoconference in the Health Science Center, consider first taking advantage of the existing facilities and staff of Teaching Laboratories Resources. The facilities are already established, successfully operating, and available for the asking. Call or contact Teaching Laboratory Resources (273-5064). http://schedules.tlr.ufl.edu/