Source model for VBR coded video traffic in ATM networks

We present a new approach to modelling variable bit rate (VBR) coded video sources in asynchronous transfer mode (ATM) networks. Unlike the existing methods which model the number of cells generated by the coder for a sequence of video frames, the new approach improves the modelling accuracy by considering the characteristics of different cells generated by the coder, and modelling the number of cells in each type of macroblocks of a frame separately. The model is tested by comparing the autocorrelation function and mean queue size in the buffer by simulation of an ATM switch to the mean queue size produced when traces generated by the model are used as the source. Comparisons with the existing models are performed in the area of measuring the quality of their predictions for the network performance and the grade of service experienced by a user.