Network transmission of digital video.

摘要

Transmission of digital video information has rapidly become an important application as modern global communications continues to expand. This thesis addresses aspects of the transmission of digital video for two networking paradigms that are expected to play an increasingly significant role in future systems: (i) Asynchronous Transfer Mode networks, and (ii) wireless communication.;The notion of quantized traffic shaping is introduced as a method to reduce the burstiness of variable bit-rate sources. The output of the quantized traffic shaper is a bit stream that transitions between a finite set of rates at fixed intervals, from which we determine the effective bandwidth. The quantized traffic shaper jointly smooths the original source and enables bandwidth parameterization. These methods for bandwidth determination are used for admission control and statistical multiplexing of N MPEG sources.;An undesirable trait of wireless mobile communications is the changing noise characteristics of the channel. In this thesis, new modulation schemes for unequal error protection are developed that combat this problem. These methods are applied to the transmission of MPEG video data. This approach is demonstrated to achieve graceful degradation of the picture SNR as the channel SNR decreases in the presence of additive Gaussian noise.;A challenging aspect in the transmission of compressed digital video is the bursty nature of its bit-rate traffic. This leads to difficulties in determining network bandwidth allocation for such sources. In this thesis, methods of burstiness parameterization of MPEG bit-streams are developed based on a probabilistic model. Network bandwidth requirements are estimated from these evaluated traffic parameters that are also used for traffic policing.