Color-Aware Packet Marking Based on H.264AVC Coder Extensions for Improved Video Quality

In recent years there is a noticeable trend to implement the video transmission systems based on shared IP networks. At the same time new generations of video codecs such as H.264 are used in industrial installations. This situation forces the need for consideration of methods for efficient video transmission in industrial networks such as surveillance, identification and control systems. The first part of the article discusses the features of modern video codecs, relevant to the streaming applications. Attention is focused on the extensions of the H.264 standard that increase the error-resilience, particularly Data Partitioning (DP) and Flexible Macroblock Ordering (FMO). Next, the principles of prioritization of the video traffic based on the DiffServ architecture is discussed. In this context, separated section presents in detail the rules for packets marking which enable appropriate forwarding the video data. This information is referenced to current recommendations and technical standards. Next the performance of several classical packet marking algorithms and their possible modifications using FMO- and DP-based errorresilience configurations of H.264 are verified in simulations.

QoS Control Strategy Simulation and Analysis Based on DiffServ

As the development and applying of real-time multimedia such as VoIP, video conferencing and so on, the Internet is required to provide a better QoS support. However, current IP network can only provide ‘Best Effort’ service and can not satisfy different network multimedia traffic quality requirements. Based on the analysis DiffServ architecture and studies its control mechanism, the OPNET simulation design different ToS value in IP header of VoIP traffic, and apply WFQ scheduling algorithm on the bottleneck link. The simulation results compare jitter, delay, delay variation of different ToS value of VoIP traffic, and analyze relationship of QoS and ToS value in the IP network.

A DiffServ Architecture for QoS-Aware Routing for Delay-Sensitive and Best-Effort Services in IEEE 802.16 Mesh Networks

In today's networks, the widespread use of real-time traffic such as video and audio applications demand special service guarantee in terms of throughput, delay, and jitter, thus making quality of service (QoS) a key problem. IEEE 802.16 mesh networks are likely to be the basis of next-generation last mile network connectivity. So, providing QoS is one of the major designing goals in IEEE 802.16 mesh network. While the standard defines five service classes for PMP mode, no standard defined service classes exist for mesh mode. In this paper, we describe a differentiated service (DiffServ) architecture for QoS support in IEEE 802.16 mesh network by considering a basic requirement for QoS guarantee—delay. A new cross-layer routing metric is proposed, namely, expected scheduler delay (ESD). An efficient distributed scheme is proposed to calculate ESD and route the packets using source routing mechanism. This scheme is capable of differentiating between delay sensitive and best-effort traffic and route packets accordingly. Finally, the results of the proposed scheme are compared with the standard schemes that take hop count as a routing metric.