Hantering av QoS i Distribuerade MPEG-videosystem

• Main Author: Dulgheru, Natalia
• Format: Others
• Language: Swedish
• Published: Linköpings universitet, Institutionen för datavetenskap 2004
• Subjects: Datalogi; Quality of Service; Distributed Video Systems; Imprecise Computation; Feedback Quality of Service; Feedback Control Scheduling; Congestion; MPEG Compression Standard.; Computer Sciences; Datavetenskap (datalogi)
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2247

With the advance in computer and network technologies, multimedia systems and Internet applications are becoming more popular. As broadband network is prevailing, more clients are able to watch streaming videos or to play multimedia data over the Internet in real-time. Consequently, there is an increasing demand in the Internet for streaming video systems. As the run-time environment of such applications tends to be dynamic, it is imperative to handle transient overloads effectively. The goal of this work is to develop an algorithm that would provide a robust and controlled behavior of the video system so that important data is delivered on time to the video clients. In order to address this problem, we propose a QoS-sensitive approach that is using the technique of imprecise computation and is based on the principle of tuning. Our algorithm is aimed to provide the best possible QoS to the clients in the current available network capacity. As an environment to work with we have used a video system called QMPEGv2. A set of experiments were carried out to evaluate the performance of the algorithm. Through experiments, we show that the system can adapt to dynamic changes in network conditions and provide almost always the best possible QoS to its clients. Guaranteeing a certain minimal QoS level to all clients is only possible when, in run time, an admission controller adjusts the number of clients admitted tothe system according to the capacity of the network and video servers.