MPEG-Video Sources in ATM-Systems — A new approach for the dimensioning of policing functions

Abstract

The ATM transport concept of B-ISDN allows for an efficient and flexible use of network resources for variable bit rate services with high transmission rates. One major traffic source which will make use of this capability will be video and multimedia applications. The changes in the cell rate of such sources are caused by the compression of the digitized video frames. The MPEG (ISO Moving Picture Expert Group) coding scheme is expected to be the major compression algorithm for the first ATM video applications. Thus there is a need to find source traffic descriptors of MPEG video sources which can be used efficiently for connection admission control and usage parameter control for these sources. Besides the peak cell rate, the sustainable cell rate might be used for these purposes. Both the ITU-T and the ATM Forum propose the Generic Cell Rate Algorithm (GCRA) for policing these two cell rates. In this paper we develop a novel model for the cell stream of an MPEG video coder output and present a cell loss analysis for a GCRA monitoring its sustainable cell rate. A variety of ATM link capacities and sustainable cell rate parameters are studied to show the accuracy of the analysis and to test the appropriateness of the sustainable cell rate as traffic descriptor of MPEG video sources.

Performance Analysis of Cell Rate Monitoring Mechanisms in ATM Systems

“…The next step is to focus on the extension of these results towards policing of video sources like MPEG sequences, which have a high degree of correlation. A first step in this direction can be found in [22]. Another study, where the employment of our algorithms or extensions of those looks promising, is the dimensioning of UPC functions in LAN-ATM network interfaces.…”