| Benefits of Video ConferencingVideo conferencing | | | | system is in digital compression of audio and video |
| hardware and software allows users to see and | | | | streams in real time.There are basically two kinds |
| hear the person they are communicating with.A | | | | of VTC systems:Dedicated systems have all |
| video conference allows you to take part in live | | | | required components packaged into a single |
| audio/video presentations in your classroom, and | | | | equipment, usually a console with a high quality |
| to collaborate through them. Calls can be made | | | | remote controlled video camera on its top. These |
| between 2 classrooms in the same town, or | | | | cameras can be controlled at a distance to move |
| between 2 classrooms in different parts of the | | | | in the horizontal and vertical directions (pan and |
| globe. It is also possible for multipoint conferences | | | | tilt, respectively) as well as to perform image |
| to take place, where more than 2 schools take | | | | zooming, so they are called PTZ cameras. The |
| part in the same call.Live video conferences have | | | | console contains all electrical interfaces, the control |
| lots of advantages over other multimedia | | | | computer, modem, and the software- or |
| resources, such as video recordings or television | | | | hardware-based codec. Omnidirectional |
| presentations, but the main benefit is that they | | | | microphones are connected to the console, as |
| are interactive, allowing you to talk face to face | | | | well as a monitor TV with loudspeakers and/or a |
| with someone else in 'real time', but in a different | | | | video projector. There are several types of |
| location. This is great for for gaining high levels of | | | | dedicated VTC devices:(a)Large group VTC are |
| engagement from your students.Multipoint | | | | non-portable, large, more expensive devices used |
| videoconferencingSimultaneous videoconferencing | | | | for large rooms and auditoriums. Use of PTZ |
| among three or more remote points is possible | | | | cameras is practically mandatory.(b)Small group |
| by means of a Multipoint Control Unit (MCU). This | | | | VTC are non-portable or portable, smaller, less |
| is a bridge that interconnects calls from several | | | | expensive devices used for small meeeting rooms |
| sources (in a similar way to the well-known audio | | | | (e.g., up to 10 people) and PTZ cameras are |
| conference call). All parties call the network ID | | | | usual(c)Individual VTC are usually portable devices, |
| number of the MCU unit or the MCU unit can also | | | | meant for single users, have fixed cameras, |
| call the parties which are going to participate, in | | | | microphones and loudspeakers integrated into the |
| sequence. There are MCU bridges for IP and | | | | console.Desktop systems are add-ons (hardware |
| ISDN-based videoconferencing. There are MCU | | | | boards, usually) to normal PC's, transforming them |
| which are pure software, and others which are a | | | | into VTC devices. A range of different cameras |
| combination of hardware and software. A MCU is | | | | and microphones can be used with the board, |
| characterised according to the number of | | | | which contains the necessary codec and |
| simultaneous calls it can handle.MCUs can be | | | | transmission interfaces. Most of the desktops |
| stand-alone hardware devices, or they can be | | | | systems work only with the H.323 standard. |
| embedded into dedicated TVC units.The | | | | Video conferences carried out via dispersed PCs |
| technology of video conferencingThe core | | | | are also known as e-meetings. |
| technology using in a videoteleconference (VTC) | | | | |