Video conferencing systems are telecommunications devices consisting of cameras, microphones and codecs.
Cameras that transmit images of people and people in the videoconferencing room can be integrated or discrete into the system. Microphones perform the function of perceiving conversations in the room as sound. Multi-directional microphones are often used to block echo in Video conferencing systems. The Codec compresses analog audio and video information from the camera and microphone into a digital format, allowing it to be transmitted more easily from the communication infrastructure. Another task is to open compressed audio and video information from the other side, convert it to analog format and send it to the television or presentation device for display.
Usually ISDN or IP are used as communication infrastructures. IP systems are generally the systems that users use in their own network, so it is not possible for these systems to go outside directly. In ISDN-enabled Video conferencing systems, they can be dialed or dialed from anywhere in the world via the existing telephone number. The difference with regular telephone lines is that it allows for more reliable, fast and quality connections over a single line.
In today's technology, there is no other communication technology close to ISDN technology.
Video conference calls are made in two ways: Point to Point and Multipoint.
Point to point interview
In this type of Video conference calls, there are two parties, one caller and one called Location. On one screen, the image of the opposite side appears on the other.
Multipoint (Multipoint) Conversation
In this type of Video confefance talks, more than two locations meet simultaneously. This requires an external multipoint Control Unit ( MCU ) or an end system with MCU support. What is done in these interviews is to search for the MCU device and join one of the virtual rooms. Then it is to communicate with other systems in that virtual room. The image displayed according to the form of the meeting is that the person speaking comes to the screen and all the sounds are mixed and these sounds are transmitted to each location. Another form of meeting is the continuous presentation ( Continouos Presence ) screen divided by four or six to display everyone attending the meeting at the same time.