3G capable handsets support this and provide a menu option to make a video call to any number in the phone book. It uses the Circuit Switched Mode of operation, where a 64 kilobits/sec (Kbps) channel in each direction is reserved for the call for the entire duration of the call. With 3G, came the concept of a special call type for video, using a new protocol known as H324M. On the mobile network: Video Calling used to be a facility limited to PCs or Internet Protocol (IP) phones using an internet connection, until the availability of Third Generation (3G) technologies on the mobile. Detailed working will be discussed in module 2.8.3. The telecom operators charge for interconnection to their network, and so the users are charged for these calls. This situation arises when you try to call a mobile or landline number from a PC video calling application. These services are charged when the communication has to cross over from the internet to a telecom network, and has to pass through an interconnect gateway. The availability of the user, also known as presence, is indicated to other people with a status like offline, available, etc.

The user has to be logged into the application to receive the call. On the landline network: Video calling from PC to PC over internet is usually available as a free service, for example, from providers like Skype, Yahoo Messenger, and more recently Facebook. Video Calling is a service where two people can communicate using video, i.e., can see as well as hear each other on the phone or a personal computer (PC). Video CallingĬreative Commons Attribution-Share Alike 3.0 Unportedįigure 1: Different forms of video calling – on landline, mobile and internet (e.g., on Facebook) Some of the common forms of video communication are Video Calling, Video Conferencing, Telepresence and Video Sharing.

This, along with the availability of high speed IP networks facilitated video as a new means of communication. compression) techniques, it became possible to compress these large video files into much smaller files that could be transmitted without much loss or delay. Thanks to the digital technologies and availability of advanced digital encoding (i.e. As you can imagine, a video file in the raw (original) format would be huge. More pixels indicate more clarity, this is known as resolution. A video is a series of images captured at a rate faster than the eye can perceive.

Skype video conferencing bandwidth