VIDEOCONFERENCING
An
Overview
been evolving for over 40 years. The
breakthrough came with the evolution of microelectronics and efficient software
compression algorithms. This enabled the development of video codecs - in
essence, powerful, single purpose computers that code and decode massive
amounts of video picture data for transmission in near real-time over a small
amount of bandwidth. The modern video codec, more than any other piece of
equipment, has brought two-way interactive videoconferencing within reach of
most businesses as well as educational and other institutions. If your primary need is to transmit coursewear or produced television media from one location to many others then point-to-multipoint "business television" may be for you. If, however, your requirements are for fully interactive meetings among multiple sites, videoconferencing is what you need.
Videoconferencing is two-way interactive video with audio and graphics exchange. If you also need to share detailed documents or drawings, high resolution graphics transmission systems can be added. The recurring costs of videoconferencing depend on the type of
transmission and the bandwidth
you use. In videoconferencing, minimum bandwidth for acceptable quality is
generally 256Kbs, (four channels of a T1 or 2 ISDN BRI connections) going up
to, typically, 1.5+ megabits a second (a full T1). The majority of business and
educational users conference at 384Kbs. Very simply, the higher the bandwidth,
the higher the picture and audio quality. However, usage costs rise with higher
bandwidth. Transmission facilities range from private networks to common carriers. If the T1 line is structured point-to-point for a single customer, it is a private facility with a fixed monthly charge. Many large
companies and universities use private T1 lines in their data and
PBX networks. For videoconferencing, the entire T1 "data pipe" can be used for
high video quality. Or, the T1 can be segmented with part allocated to video
and the balance dedicated to voice, Internet and data transmission. Using
switched, public facilities allows companies the ability to "dial-up" locations
worldwide. Although there is a fixed monthly cost for the T1 to the phone
company, it is lower than a private T1 and usage costs are incurred only when
the T1 is being utilized . . . much like a long distance phone call.
Recently, a new transmission medium has evolved - the H.323 standard for conferencing over IP networks. Voice and data are coded into IP packets for transmission over local or wide area networks or even the public Internet. Although the quality can equal or surpass that of H.320 conferencing, care must be taken not to burden your existing network facilities. IP conferencing, unlike standard "burst mode" data transmission, requires a continuous data stream in order to maintain an acceptable quality of service. This continuous data stream can quickly bring a network with marginal bandwidth 'to its knees'. IP conferencing over the Internet? Well, only if you can tolerate the occasional delays, pauses, and disconnects that you have come to expect from surfing the web.
Videoconferencing equipment prices have come down as manufacturers have incorporated the latest technological developments. Compatibility between various codecs is governed by the CCITT H.320 and H.323 standards. (CCITT is the international agency that sets the standards for all types of telecommunications transmission for such applications as fax machines and modems.) In previous decades, because of proprietary transmission schemes, many manufacturer's codecs could not communicate with those of another. With standards in place, videoconferencing users can now be confident that the system purchased today is going to be compatible, and can communicate with other systems in the marketplace.
Conducting a videoconference no longer requires a technician. Typically, camera selection is performed using a remote device similar to the remote controls on
consumer
electronics. Communication links between videoconference sites can now be made
as easily as dialing your phone. And many rooms utilize touch screen type
controls with presets that simplify and automate meetings even more.
Videoconferencing is more cost justifiable than ever. It saves travel costs but
more importantly, it saves valuable productivity time by keeping you
home and close to your resources. Contact Media Cottage for expert help on creating the perfect environment for your videoconferencing system.
