In recent years, real-time systems are likely to be based on distributed architectures and utilize highly parallel algorithms. In such systems, cooperative tasks may be executed on different processors and communicate among each other via a high-speed network. With the growing demand on transmitting digital video in distributed multimedia applications, there is a need to study the on-time delivery of videos over a distributed system. Knowing the fact that unregulated transmission of MPEG video over a computer network may be hazardous to the network performance, in this paper, we exploit the characteristics of MPEG coded frame sequence and devise three transmission schemes for the MPEG video. The crux of the issue is to fully utilize the assigned bandwidth. In our schemes, the delayed frames mechanism can effectively utilize the assigned bandwidth and meet the objective of maximizing the number of video streams that can be supported in a timed token MAC network without sacrificing the video quality. Multiple classes of MPEG video are used in the study. These data are captured from real video programmes and we categorize these video clips according to their traffic burstiness and workload characteristics. The results reveal that by employing the Inter-stream Delayed Transmission Scheme, we could improve the performance by 66 to 166% depending on the availability of global information. When the technique is applied in an intra-stream level, we could improve the performance by 86%. When we combined these two schemes together, the performance improvement of the Total Delayed Transmission Scheme can be pushed to 178% which is a dramatic improvement over the original unregulated transmission scheme.
['Joseph Kee-Yin Ng', 'Victor C. S. Lee']
Delayed Frame Transmission Schemes for MPEG Videos in a Real-Time