Multimedia QoS through Content Aware Triage: An Integrated DiffServ Framework

Many architectures (Integrated Services, Differentiated Services, MPLS, Traffic Engineering, and our own Triage protocol etc.), have been proposed for providing end to end Quality of Service (QoS) to applications by identifying, handling and controlling traffic using various scheduling and resource reservation mechanisms, yet providing end to end QoS is still a key challenging for today´s tactical networks, particularly for supporting multimedia service due to its stringent requirements on time bounded parameters such as delay, jitter etc.. In this work, we present an integrated framework where the interaction between QoS aware video application, the content information of a packet and DiffServ network is taken into consideration. This interaction is performed through video application dynamically marking packet priorities for each video packets and the DiffServ forwarding mechanism such as per hop scheduling and queuing mechanism (Triage) to provide service differentiation based on the relative QoS requirements of each packet. This framework takes advantage of the nature of the unequal importance of video packets and provides a mechanism to try to preserve information that is most important to spatial/temporal quality when challenged with packet loss or long end-to-end delays. To validate the efficiency of the mechanism, we simulate end-to-end video transmission scenarios in OPNET. The results show that the proposed framework can maintain the same video quality (e.g. same Peak-Signal-Noise-Ratio (PSNR)) during network congestion, and at the same time freeing up resources to improve FTP download time, hence utilizing the network more efficiently.