An overview of Video Conferencing solutions over IP
Why is a Video Conferencing application Exciting?
¤ In this global village, where places are becoming more and more accessible, Video Conferencing solutions are an important medium of connecting businesses across the world.
¤ In a corporate setting, with multiple offices across the world/country, Video Conferencing solutions help reduce cost by enabling people to meet face-to-face over the network at any point of time.
¤ The cost of travel and training are greatly reduced and the instant access to people and resources are available any time so that the decisions can be made now.
¤ Even in educational institutes, the Video Conferencing solutions enable experts from across the world address students real time and clarify their doubts immediately. It enables interactive learning.
¤ Tele-medicine applications via Video Conferencing systems have greatly reduced the need for doctors to travel long distances as Video Conferencing applications enable first level of medical procedures to be performed on-site with expert guidance from elsewhere. This saves a lot of time, money and resources.
¤ Interviews, corporate meetings, reviews, client meetings are just some of the processes that have been made faster and cheaper through the Video Conferencing solution.
Components of a Video Conferencing solution:
There are basically the following components for any professional grade Video Conferencing solution: The Codec (Heart of the VC system), A Display Unit and speakers, Microphones, Camera and a medium for transporting the real time data.
CODEC:
This is the heart of a professional Video Conferencing solution. The codec integrates the various other components of a VC solution – the display, speakers, microphones, IP Network and everything else. One other important job of a codec is to compress the video packets from the originating side and de-compress it at the receiving side. This part – compression is the most important aspect of a professional video conferencing solution at it gives a higher quality (Up to 30 frames per second) at a lower bandwidth. The codec also enables a dual stream of data – like a presentation or a document camera output to be shared along with the video conferencing itself. The codec enables Multi-Conferencing to be set up – The ability of more than two participants (Up to 6 for common VC Systems) to participate on the same Video call. The codec gives interfaces for the video packets to travel through IP or even a ISDN/PRI line as an option. There are advantages of taking the video call on an IP as you are using the existing bandwidth and there are no big costs involved in calling overseas but ISDN could also be looked as an alternative/backup if your IP Network is already used to its full extent and you have fewer no. of Video calls on a VC system throughout the year.
Display and Speakers:
Normally, a TV(LCD or CRT) or Plasma is used in a board room as the display unit for viewing the people on the remote end. It is not uncommon to use even LCD projectors as the display unit. The video output is via the RGB/S-Video interface. It is common to have dual display devices – one to see the participants in the remote end and the other to see the presentation/data that they want to show to everyone. During a multi-conference call, the TV screen splits into 4 or six sections to accommodate all the remote locations. A HD display is also supported in most of the video conferencing systems.
The speakers used in the VC system are the ones which come along with the display unit like a TV or separate set of speakers with a small amplifier is recommended. The VC systems support stereo, surround and wide band and most of the VC systems support G.722 codec for good clarity of speech.
Microphones:
The microphones are necessary to capture and send the audio (Speech) from the originating location to the remote location. Normally video conferencing vendors supply two microphones to be kept at either side of the board room for maximum coverage. Optionally, the microphones could also be kept at the ceiling to avoid cables on the table.
Camera:
The camera is required to capture the video signals form the originating source to the remote source and vice versa. The camera supplied with the Video Conferencing systems generally gives a wide angle coverage covering the participants up to 30 feet easily. The camera can be moved, tilted, zoomed to cover a particular section or a particular participant more closely. The movements of the camera are controlled by a remote control which comes along with the codec. In some VC systems, the camera is detached from the Codec and in most of them, they are attached with the codec. The camera can be voice activated but this is not very popular as the accuracy of such a camera is not good. A more viable alternative is to have pre-set positions for the camera set in the Codec and by press of a button on the remote control, the camera adjusts itself to pre-set positions which were stored earlier.
IP Network for Video Conferencing:
Inside a network, a video conferencing system runs on the LAN with a RJ-45 interface to the codec. But for transmitting the video packets to the remote location, the Video Conferencing system uses a leased line/Internet Leased Line/IPSec VPN or any shared bandwidth taken from a service provider. The minimum bandwidth required for a point to point call would be 128 Kbps. And for optimum performance and a higher frame rate, a higher bandwidth would be beneficial. It is suggested to limit the maximum bandwidth that a VC system operates on, in order for other applications on the LAN to utilize the bandwidth effectively. You could read a related article titled Bandwidth requirements and types of connectivity for video conferencing for further details.
excITingIP.com
That is an interesting post. It would be good to see the differences between a normal webcam and a professional grade video conferencing solution.
Destination Infinity
excellent, this is one of the site to usefull for students and proffessionals…..