Video Conferencing for Today
Video conferencing hardware and software allows users to see and
hear the person they are communicating with.
A videoconference allows you to take part in live audio/video
presentations in your classroom, and to collaborate through
them. Calls can be made between 2 classrooms in the same town,
or between 2 classrooms in different parts of the globe. It is
also possible for multipoint conferences to take place, where
more than 2 schools take part in the same call.
Live video conferences have lots of advantages over other
multimedia resources, such as video recordings or television
presentations, but the main benefit is that they are
interactive, allowing you to talk face to face with someone else
in 'real time', but in a different location. This is great for
for gaining high levels of engagement from your students.
Multipoint videoconferencing
Simultaneous videoconferencing among three or more remote points
is possible by means of a Multipoint Control Unit (MCU). This is
a bridge that interconnects calls from several sources (in a
similar way to the well-known audio conference call). All
parties call the network ID number of 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 MCU which are pure software, and
others which are a combination of hardware and software. A MCU
is characterised according to the number of simultaneous calls
it can handle.
MCUs can be stand-alone hardware devices, or they can be
embedded into dedicated TVC units.
The technology of video conferencing
The core technology using in a videoteleconference (VTC) system
is in digital compression of audio and video streams in real
time.
There are basically two kinds of VTC systems:
Dedicated systems have all required components packaged into a
single equipment, usually a console with a high quality remote
controlled video camera on its top. These cameras can be
controlled at a distance to move in the horizontal and vertical
directions (pan and tilt, respectively) as well as to perform
image zooming, so they are called PTZ cameras. The console
contains all electrical interfaces, the control computer, modem,
and the software- or hardware-based codec. Omnidirectional
microphones are connected to the console, as well as a monitor
TV with loudspeakers and/or a video projector. There are several
types of dedicated VTC devices:
(a)Large group VTC are non-portable, large, more expensive
devices used for large rooms and auditoriums. Use of PTZ cameras
is practically mandatory.
(b)Small group VTC are non-portable or portable, smaller, less
expensive devices used for small meeeting rooms (e.g., up to 10
people) and PTZ cameras are usual
(c)Individual VTC are usually portable devices, meant for single
users, have fixed cameras, microphones and loudspeakers
integrated into the console.
Desktop systems are add-ons (hardware boards, usually) to normal
PC's, transforming them into VTC devices. A range of different
cameras and microphones can be used with the board, which
contains the necessary codec and transmission interfaces. Most
of the desktops systems work only with the H.323 standard. Video
conferences carried out via dispersed PCs are also known as
e-meetings.
About the author:
Bryan works for an LA company that provides video conferencing
services. He possesses great experience in video conferencing as
well as production.
For more about video conferencing, do visit http://www.for-the-touchdown.com/video_conferencing.htm>For
The Touchdown: Video Conferencing