Multipoint Video Conferencing

Multipoint video conferencing allows participants at more than two sites to engage in real-time communication by means of a Multipoint Control Unit (MCU) to which all the participants connect.

This is a bridge that interconnects calls from several sources (in a similar way to the audio conference call). All parties call the MCU unit, or the MCU unit can also call the parties which are going to participate, in sequence. There are MCU bridges for IP and ISDN-based videoconferencing. There are MCUs which are pure software, and others which are a combination of hardware and software. An MCU is characterised according to the number of simultaneous calls it can handle, its ability to conduct transposing of data rates and protocols, and features such as Continuous Presence, in which multiple parties can be seen onscreen at once

MCUs can be stand-alone hardware devices, or they can be embedded into dedicated VTC units

Some systems are capable of multipoint conferencing with no MCU, stand-alone, embedded or otherwise. These use a standards-based H.323 technique known as "decentralized multipoint", where each station in a multipoint call exchanges video and audio directly with the other stations with no central "manager" or other bottleneck.

The key difference in multipoint versus “normal” video conferencing is the fact that there are multiple participants at multiple locations rather than a single interaction between two webcams or two digital video cameras communicating directly through conferencing software.

Video conferencing is about making far-flung connections without the need to travel and conducting those interactions effectivel. With continued improvement in equipment, multipoint video conferencing will become an increasingly influential communication application.

There is an increasing demand for multipoint video teleconferencing for a number of reasons. Not only does it overcome the expense and delays caused by travel, but these meetings tend to be briefer and more focused than face-to-face encounters and thus more productive. Busy executives can budget their time more effectively when meeting with clients or employees and, compared to the cost of travel, establishing facilities for a multipoint video conference is much more cost effective.

Many systems now offer a built-in video conferencing bridge, which has made multipoint conferencing increasingly affordable. As multipoint video conferencing continues to grow in popularity, however, and systems with build-in bridges become more refined, prices will undoubtedly drop.

Planning a multipoint conference is similar to Planning for 2-Way Video. Multipoint vidconfonferences are more complex because you have to manage more sites and more people. Here are some suggestions for a successful multipoint videoconference:
Limit the number of sites to 3 or 4, especially if you're new to multipoint videoconferencing. Make sure that you have the voice number of each of the participants.

For important events, use your cell phone and stay connected throughout the event. That way you can monitor what is going on and make strategic changes to camera position, lighting, and so on without interrupting the flow of the event.
For large groups, it's helpful to have a "speaker's podium." With careful planning, you can switch views during the event from the whole group to the podium and back.

It's nice to have auxiliary microphones and cameras if possible. A wireless microphone can be passed around for audience participation. An auxiliary camera can be used for the podium and the regular camera and monitor can face the audience.