Friday, December 26, 2008


How Video Conference Call System works

  • Friday, December 26, 2008
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  • In this age of Technology, all the major organizations and businesses follow a simple formula: Time=Money. Especially in today’s radical world of dynamically changing economics, it is essential to cut costs and improve effectiveness in operations. For this purpose its imperious to save time. One of the major facilities availed for the simple purpose of cost cutting and improved productivity is Video conferencing Services . A videoconference is a set of interactive telecommunication technologies which allow two or more locations to interact via two-way video and audio transmissions calls simultaneously. It uses telecommunications of audio and video to bring people at different sites together for a meeting. This can be as simple as a conversation between two people in private offices (point-to-point) or involve several sites (multi-point) with more than one person in large rooms at different sites. Besides the audio and visual transmission of meeting activities, videoconferencing can be used to share documents, computer-displayed information, and whiteboards.

    The core technology used in a video teleconference (VTC) system is digital compression of audio and video streams in real time. This is performed through a CODEC, though which compression rates of up to 1:500 can be achieved. The resulting digital stream of 1s and 0s is subdivided into labeled packets, which are then transmitted through a Digital Network of some kind (usually ISDN or IP). The use of audio modems in the transmission line allow for the use of the Plain Old Telephone System. The video-conferencing facility uses several TELEPHONE CHANNELS simultaneously to carry a video signal and a high quality sound signal. The minimum number of channels that can be used is two (ISDN 2 at 128Kbps), and the maximum number is six (ISDN 6 at 768Kbps). The quality of picture and transmission depends on the equipment used for the purpose. The sophisticated encoding mechanism produces the highest quality sound and video output while using all 6 channels but can still work (with a diminished output) if only 2 channels are used.

    The ISDN 2 (2 channels) uses a lower frame rate between 10 – 20 frames per second, but nevertheless, are still perfectly usable, as long as the remote machine is capable of connecting using ISDN. However, for business standard calls, ISS recommended a call of ISDN 4 (256Kbps) or above is made.

    The equipment provided by Conference calling Services providers automatically utilizes as many channels as the remote unit is capable of using, unless we manually want to make some changes. For cheaper or older video systems only two channels are used with the picture quality not being the greatest. However, even though the other end’s picture will sometimes look rather blotchy, we can be pretty sure that the picture that they see of us will still look impressive, because the picture encoding done at our end will still be pretty good.

    I hope we have cleared some concepts here and understood the basic technology that makes sitting in our conference room and interacting with a client in some different part of the world possible.

    1 Responses to “How Video Conference Call System works”

    Mister Dee said...
    6:23 AM

    Very interesting stuff. Thank you.

    Do you know anything about patented video conferencing solutions? I have seen one that claims to have a legal multicast patent, but I'm not sure how they could claim that.

    Coincidentally, I have just written a short article about a handful of web video conferencing services & products (SpeedSight, iVisit, TokBox, Google Video Chat, Skype) without the technical insight that you provide.

    Let me know if you have any ideas about the patent issue.


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