Impact of ATM traffic control on MPEG-2 video quality
In this paper, a performance study of controlled MPEG-2 video traffic over an ATM network is presented. ATM networks are able to support variable bit rate (VBR) video sources. However, to implement QoS contract enforcement, traffic policers such as a Leaky Bucket (LB) need to be incorporated in order to change the VBR characteristics of a video stream. Our study investigates the video quality achievable by different traffic policing mechanisms. We use cell loss, frame corruption, and mean square error (MSE) to evaluate the influence of different traffic policers on the quality of the transmitted video stream. The performance evaluation is accomplished by simulating an ATM network using real MPEG-2 video streams. In our study, we also consider the layered video coding offered by the MPEG-2 standard. With traffic control, layered video achieves significant quality improvement for video transmission over ATM as compared to the one-layer case.