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Abstract. A dynamic quality of service (QoS) mapping control scheme, which includes feedforward and feedback QoS control, is proposed for the differentiated services (DiffServ) networks in this work. To achieve reliable and consistent end-to-end video streaming with relative service differentiation, the proposed solution consists of two parts: ( I ) relative priority-based indexing and categorization of streaming video content at the sending end-system and (2) dynamic and aggregate QoS mapping control with packet, session, and class-based gnnularity level for categorized packets at the edge of the DiffServ domain, called the video gateway (VG), based upon the load variation of the network. In particular, we focus on dynamic solutions to handle QoS demand variations of continuous media applications (e.g. varying priorities from aggregatedcategorizedpackets) and QoS supply variations of the DiffServ network (e.g. varying loss/delay due to fluctuating network loads). Thus, with the proposed dynamic QoS mapping control, video streaming with enhanced quality is demonstrated under a pricing model.

Several analytical models have been recently introduced to estimate the impact of the error propagation effect on the source video caused by lossy transmission channels. However, previous work focused either on the statistical aspects for the whole sequence or had a high computational complexity. In this work, we concentrate on estimating the distortion caused by the loss of a packet with a moderate computational complexity. The proposed model considers both the spatial filtering effect and the temporal dependency that affect the error propagation behavior. To verify this model, a real loss propagation effect is measured and compared with that of the expected distortion level derived by the model. Also, its applicability to the quality of service (QoS) of transmitted video is demonstrated through the packet video evaluation over the simulated differentiated service (DiffServ) forwarding mechanism.