Dynamic bandwidth allocation for efficient transport of real-time VBR video over ATM

The paper presents a novel approach to dynamic transmission bandwidth allocation for transport of real-time variable-bit-rate video in ATM networks. The authors describe video traffic in the frequency domain: the low frequency signal captures the slow time-variation of consecutive scene changes; the high frequency signal exhibits the feature of strong frame autocorrelation. The study indicates that the video transmission bandwidth in a finite-buffer system is essentially characterized by the low, frequency signal. Since the time scale of scene changes is usually in the range of a second or longer, the low frequency video signal is defined in a well-founded low frequency band. Hence, it is feasible to implement dynamic allocation of video transmission bandwidth using on-line observation and prediction of scene changes. Two prediction schemes are examined: the recursive least square method vs. the time delay neural network method. A time delay neural network with low-complexity high-order architecture, called a "pi-sigma network", is successfully used to predict scene changes. The proposed dynamic bandwidth allocation scheme is shown to be promising and practically feasible in obtaining efficient transmission of real-time video traffic with guaranteed quality of services.<
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