How Does Video Conferencing Work


Overview: Video conferencing has emerged over the years as one of the powerful and efficient tool in the communication industry. With the high speed internet connectivity being available in more and more locations, the efficiency and therefore the popularity of video conferencing has increased many folds in the last decade. It has grown from being a communication medium by which two people could talk to each other at a lower cost, to one of the leader in the industry having significant applications in the field of medicine education, management, entertainment industry etc. as mentioned earlier, the advent of higher bandwidth internet has facilitated not only the exchanging of ideas and thoughts, but also transfer of files electronically which saves precious time and money.

The working technology behind video conferencing:
The basic technology behind video conferencing is the compressing of the audio/video signals that is input to the system using tools known as codecs. Modern codecs achieve a compression rate of up to 1/500. The stream that results is transferred into an internet network using modems after dividing them further into small packets of data.
To realize a video conference involving three stations or more, a multipoint control unit is made use of. This connects calls from the different stations involved in the conference to one another. A multipoint control unit (MCU in short) can either be software or a combination of hardware and software. The MCU s is categorized based on the amount of calls that it is capable of handling at a given point of time. Separate MCU units are available for internet based conferencing as well as for the ISDN based ones

A basic video conferencing kit contains the following:
Input devices for audio (e.g. mike) and video (web camera or other video camera suitable for internet use) signals.
Audio output device like speakers and video output device such as TV screen or computer monitor.
Local area network / internet connection to enable data transfer between the stations that are involved in the video conferencing.
Echo cancellation software: this is imperative to have in your video conferencing system as it allows the parties involved in the conferencing to hear the voice of the speaker clearly without any interruptions or disturbances. An absence of such software may lead to problems like hearing one's own voice and confusions due to the time delay for the sound to reach others from the person who is speaking.

A video conferencing session over is realized as follows. The audio and video inputs are digitally compressed real time by means of a codec where in the size could be reduced to nearly 0.2% of the initial size. The compressed data are transmitted through the internet network using modem, which is received by the receiver and viewed and heard through the monitor and speakers. This process takes place simultaneously at all the points of the users who participate in the video conference, thereby realizing the communication between them like they would have been doing in a real conference.