Principal components of the VKS system

Video conference codec

The codec – "brain" and "heart" of a system of video conference. This component codes audio and a video information and transfers her to a data transmission medium while on other end the codec obtains information, decodes it and provides on an output. The codec in many respects defines possibilities of a conference: support such functions as multipoint conferences, coding of audio and video in certain formats, connection of the additional hardware, etc.

Video conference camera

There is a set of types of cameras which are used for VKS: from the small cameras mounted on the monitor to the high-quality cameras supporting remote control of panning, an inclination and scaling. The group systems of video conference are often complemented with additional cameras, including the document camera.

Video conference microphone

The personal systems of a video conferencing are often completed with the simple microphone characteristic of personal computers. The group systems of a video conferencing are completed with the special microphone allowing to accept a sound from several participants. When using video conferences in big halls often there is a need for use of additional microphones for comfortable interaction of all participants.

Means of display for use with a video conference system

Means of display is selected according to the tasks which are carried out by the system of video conference. For personal video conferences of rather normal computer monitor if of course a system is not integrated into the monitor any more. Systems for carrying out group video conferences should have the big monitor or it is better a little. It is also possible to use LCD and DLP projectors, plasma display panels, LCD TVs and monitors, monitors and TVs on the basis of the CRT. Surely think over the choice of means of display as the convenience of holding of conferences will depend on it in many respects.

Network connection

Transfer of audio and video information in real time imposes rather high quality requirements of network connection. The majority of video conferences ensure normal functioning in the presence of network connection from 64 - 128 Kbps. And than quality requirements of the video image and a sound are higher, especially the broad band is required for holding a conference. The modern systems allow to use IP (H.323) or ISDN (H.320) of connection. When using ISDN use of one or several BRI or PRI lines is possible, but, as a rule, the additional hardware for this purpose is required. Advanced models work at the speed up to 2 Mbps (PRI) – 4 Mbps (IP). 
 If it is necessary to make connection between an IP and ISDN system, then the special gateway can be required. It is recommended that total bandwidth for all main types of traffic (a voice, video, data) did not exceed 75% of the general capacity of communication channels. It is necessary for acceptable quality of a video conferencing that the data transmission channel met the following requirements: loss of packets up to 1%, a delay - 850 ms, a variation of a delay (jitter) - 30 ms.

In general ensuring guaranteed quality of communication – the most important task for the VKS organization as these systems are very sensitive to delays and loss of packets and are exacting to performance management. Considering geographical remoteness of branches, quantity of trunk and network equipment, the problem with a delay of packets and their loss always comes to the forefront. In this case the great value is purchased by setup of the coordinated work of the equipment and the software of a trunk segment and 'the last mile'.

Additional hardware

When carrying out video conference there can be a need for information transfer directly with the PC, display of the paper document or creation of diagrams on a board. For implementation of these requirements the additional hardware is used: block of connection of the computer, document camera, digital 'white board'. When installing the system of a video conferencing special curbstones, racks, brackets which do use of a video conferencing by more comfortable can be necessary.

Possible options of use

For meeting rooms the VIDEOCONFERENCING group codec with information display system — as a rule will be an optimal solution, perhaps, these are two LCD panels for demonstration of the speaker and demonstration of the presentation.

Optimal solution for top heads — the VIDEOCONFERENCING group codec + a LCD panel; it is possible to bring the shown presentations to the additional monitor.

For line managers the optimal solution is a monitor with the VIDEOCONFERENCING built-in codec and the built-in camera. As a rule, the same monitor is also the PC monitor.

For the staff of different divisions (finance, the personnel, technical specialists) an optimal solution is the notebook + software of the VIDEOCONFERENCING.

Now there were VKS codecs capable to create a session of VKS with six — eight participants without use of the VIDEOCONFERENCING separate server (MCU). Therefore potential customers have an opportunity at the first stage to create VKS network without big initial capital costs. For example, to bring together participants of a multipoint session of a video conferencing on one of VKS terminals.