Predictive shaping for VBR MPEG video traffic transmission over ATM networks
Luís A. da Silva Cruz, Juan J. Alins, J. Mata · 1998
The use of smoothing techniques to remove the periodic fluctuations of the bit rate generated by the codification modes of the MPEG algorithm is very suitable in video transmission. In this way, the multiplexing gain is maximized and the resource allocation is reduced in ATM Networks. The traffic smoothing can be achieved storing the cells in a buffer. This buffer is allocated between the coder and the user-interface. To reduce the delay introduced in the storage process a new technique to forecast the VBR MPEG traffic is presented. This technique is based on the characterization of bits per frame generated by the MPEG coder as an ARIMA process. In this study the invariance of the ARIMA coefficients is verified for all coded sequences used. In addition, these coefficients are invariant also in front of the changes of the selected image quality in the coder. This characterization allows to propose a new traffic shaper scheme when forecast techniques are applied. Moreover, numerical results allows to compare the smoothing effects introduced, as well as the delays for the classic shaper and the predictive shaper.