Real-time multimedia services over Internet

This paper is concerned with the study of communication protocols and coding techniques required in the conception of tools supporting real-time multimedia transport on the Internet. To run multimedia over the Internet, several issues must be addressed. First, most multimedia applications require real-time traffic. Audio and video data must be played back continuously at the same rate as when generated. Second, multimedia traffic is extremely dense and heavy. To overcome these problems, we use the RTP protocol to support transmission of real-time data over IP and we choose MPEG-4 video coding. This coding technique provides a very low bit rate for multimedia applications. We show that by using RTP and MPEG-4, we obtain a high video quality that remains acceptable when the bandwidth decreases to 56 kbps. A multimedia transmission tool developed in our laboratory and allowing real-time video-on-demand transmission and TV in live multicast on the Internet are presented. Another advantage of the multimedia application is the ability to support multicast.