In this paper, we propose the correlated state transition (CST) scheme for the modelling of Moving Picture Experts Group (MPEG) video sources at slice level. Slices are the basic resynchronization units of video sources with the MPEG coding scheme; they provide a better understanding of the correlation property of a video source because their autocorrelation function separates the interframe (temporal) correlation from the intraframe (spatial) correlation. In the proposed CST scheme, each slice forms its state transition independently; nevertheless, the state transitions of all slices during traffic simulation are correlated by applying the same random number. The step size of the state transition is determined by taking the autocorrelation with one slice lag into consideration in order to maintain the histogram property. The experimental results show that the CST model performs well in capturing the characteristics of temporal autocorrelation, which is the most correlated part among slices, and preserving the behaviour of the histogram. Using the CST model, we also study the cell loss probability at slice level for a multiplexer connected with several video sources.
- Spatial correlation
- Temporal correlation