Traffic modeling and control based on the picture-type dependent statistics of MPEG videos in ATM networks

Abstract

The success or failure of ATM networks mainly depends on the development of an effective traffic management framework. In order to design and develop ATM network management functions, it is necessary to comprehend the characteristics and requirements of the traffic to be transmitted. It is the traffic model that provides a basis for the optimal design of the network control mechanisms. In this dissertation, we have studied the issues related to traffic modeling and control mechanisms for variable bit rate (VBR) MPEG video sources. In the viewpoint of traffic modeling, we make traffic models reflecting both the periodic pattern according to GOP (group of pictures) structure and the different statistical characteristics according to different coded picture types of VBR MPEG video traffic. In the viewpoint of traffic control, we develop traffic control mechanisms in order to solve the problems caused from periodic peak traffic due to I-pictures of VBR MPEG video traffic. Traffic controls considered in this dissertation are usage parameter control (UPC), scheduling and connection admission control (CAC). First, we investigate the problems related to UPC for VBR MPEG video source. We use a Leaky Bucket (LB) policer as an UPC device. We propose a slice-level composite traffic model for single VBR MPEG video source and analyze the performance of a LB policer with one threshold level control. The main result of the performance analysis is that ordinary LB policers are not sufficient for policing VBR MPEG video traffic. In the viewpoint of destination user``s visual quality of services, it had better keep I-picture cells from being dropped as much as possible. However, it is shown that the violation probabilities of I-pictures are always much higher than those of P-pictures whether threshold level control is adopted or not. For overcoming the shortages of ordinary LB policers, we propose a new LB policing mechanism called a picture-type dependent LB (PDLB) policer. Th...