Efficient and reliable video transmission over ATM networks
Jian Feng · UNSWorks (University of New South Wales, Sydney, Australia) · 2022
The development and standardization of digital video technologies and high-speed networking are undergoing remarkable progress in recent years. The MPEG standard is emerging as the universal coding format for various video applications while the ATM technology is evolving into the global communication network infrastructure. It is believed that digital video will play an important role in future media and telecommunications industries. The demand for transmission of various video services over public networks will increase dramatically. The performance of an ATM video transmission system depends not only on the coding process but also on network environments. It is clearly not possible to look at each area in isolation. Successful transmission of digital video over ATM networks therefore relies on the interworking between these two distinguished fields. This thesis presents the results of our works on bridging video coding and network environments for providing efficient and reliable video transmission over ATM networks. A number of contributions have been made in enhancement and analysis of the network performance for ATM video transmission. A simple but efficient adaptive block matching motion estimation algorithm is derived for MPEG encoding, and an error concealment method called modified boundary matching algorithm is developed to minimize the degradation of video quality due to cell loss. It is shown that with our proposed methods, the coding delay is greatly reduced and the image quality is preserved well at the decoder even when the cell loss rate is very high. In order to evaluate the network performance, a hierarchical traffic model is developed for MPEG video. The appropriateness of the model is demonstrated by its similarity to real MPEG data in terms of statistical characteristics as well as the accuracy in predicting the network performance for video transmission. As statistical multiplexing is the key characteristic of ATM networks, the impacts of different factors on the performance of an ATM multiplexer for MPEG video are investigated, and a source scheduling method is presented for improving the network performance of the multiplexer. Finally, a bandwidth allocation algorithm based on the scheduling method is formulated for connection admission of MPEG video in an ATM multiplexer. We have shown that our allocation method is effective. It not only achieves a higher link utilization than the peak bandwidth allocation method but also provides deterministic QOS guarantee for all input connections. With the outcome of our investigations, the whole transmission chain of MPEG video on ATM networks can be encompassed to deduce the optimum coding and transmission conditions.