The result indicates that the performance of processing Real-time network data packet and scalable in QR-Linux is better than that in Linux. This certificates the performance of Real-time in QR-Linux, and can support the QoS of the Real-time multimedia task.

The research progress on the interleaver,decoding algorithm and the appliance of Turbo code is summarized. It is pointed that Turbo code can accurately decode and recover the signal under weak signal or strong noise. The Turbo code has become the criterion one of the channel codes in 3G with advantages such as large capacity,high data ratio and multimedia task.

A simple test has been done to certify that the system is stable,and it can guarantee the QoS of real-time multimedia task,especially the delay jitter.

A higher slope on drop rate is seen in the case of integrated multimedia task sets.

Continuous media service is a new kind of real time applications. It requires that hard and soft real time tasks should be supported in an integrated operating system framework. But the scheduling policies in traditional OS(e.g., UNIX or Windows NT)can't support this application to the best. This paper proposes a new QoS method, based on which a QoS based heuristic task scheduling algorithm supporting continuous media streams is described. The algorithm takes into account the success ratio and...

Continuous media service is a new kind of real time applications. It requires that hard and soft real time tasks should be supported in an integrated operating system framework. But the scheduling policies in traditional OS(e.g., UNIX or Windows NT)can't support this application to the best. This paper proposes a new QoS method, based on which a QoS based heuristic task scheduling algorithm supporting continuous media streams is described. The algorithm takes into account the success ratio and consecutive fail count of multimedia tasks in order to guarantee the quality of all media streams. Finally, simulation and comparison are performed to validate the effectiveness of this algorithm.

The algorithm of resource management and allocation is very important to guarantee the application's quality of service (QoS) in distributed multimedia systems. In resource management, the QoS negotiation and admission depend on scheduling algorithm. Thus it is the kernel of resource management. Early deadline first (EDF) and rate monotonic (RM) in real time systems have been used in distributed multimedia systems today. But they can result to schedule with much jitter. Recently, a new pinwheel...

The algorithm of resource management and allocation is very important to guarantee the application's quality of service (QoS) in distributed multimedia systems. In resource management, the QoS negotiation and admission depend on scheduling algorithm. Thus it is the kernel of resource management. Early deadline first (EDF) and rate monotonic (RM) in real time systems have been used in distributed multimedia systems today. But they can result to schedule with much jitter. Recently, a new pinwheel scheduling DSr that is little jitter scheduling is presented. But it is only suitable for uniprocessor systems. Although DSr is a distributed scheduling algorithm, its assumption is not very suitable for distributed systems so that it can not be adopted. This paper presents a jitterless integrated task scheduling algorithm DMSr that removes candidates step by step based on the pinwheel model of distance constraints. It discusses the time complexity and proves the schedulability condition. It can guarantee the QoS of multimedia tasks. Specially it can schedule with jitterless. Two examples illustrate scheduling algorithm procession and tight schedulability condition in this paper. Finally, the authors do experiments with client/server model in 100M switching Ethernet and make the compression about results in delay, jitter and CPU utilization among EDF, RM and DMSr.

A jitterless pinwheel scheduling algorithm for distributed multimedia tasks with distance constraints, DMSr, that removes candidates step by step to calculate periods in each node of distributed system is presented by Zhang Zhan Jun et al in 1999. This paper continues to study the issue of minimizing the total end to end delay. The concepts of delay and start phase are defined and the relation between delay, start phase and scheduling period is analyzed in this paper. It is proved that if the...

A jitterless pinwheel scheduling algorithm for distributed multimedia tasks with distance constraints, DMSr, that removes candidates step by step to calculate periods in each node of distributed system is presented by Zhang Zhan Jun et al in 1999. This paper continues to study the issue of minimizing the total end to end delay. The concepts of delay and start phase are defined and the relation between delay, start phase and scheduling period is analyzed in this paper. It is proved that if the total delay between nodes has a minimum value, it must be true that there is a delay with zero value, and transmission delay is a periodic function of the start phase with scheduling period. The delay is defined as a serrated line with a constant slope in this paper. To get the minimum delay, we can inspect all line segments in serrated line. But there are many drop points in the serrated line so that the complexity of searching algorithm is very high. In order to reduce the number of drop points searched, we define three operations, SUM, MAX and CUT for delay functions with period. The SUM is the sum of all delay function values. The MAX is the maximum of all delay function values. The CUT is domain size cut to partial size and keeps the minimum values and it not only cuts the domain size of serrated line, but also keeps their minimum values. An algorithm of calculating the start phase for minimizing the total end to end delay between two neighboring nodes, MinSum, is presented by above three operations and the time complexity is discussed in this paper. Next, we extend the MinSum to end to end delay by summing up any two consecutive nodes on router. Finally, we give our some simulation results of experiments near to the results from theory on a 100Mbps Ethernet switch.

作者于 1999年提出了一种分布式多媒体任务的风车调度算法 DMSr,它在分布式系统各节点上通过逐步消除候选项 ,计算出各任务的调度周期 ,使多媒体无抖动地传输 .在此基础上 ,作者继续研究了 DMSr风车调度延迟最小化问题 .文章定义了延迟时间和调度启动滞后时间概念 ,分析了调度启动滞后时间、调度周期和延迟时间之间的关系 ,证明了 DMSr调度传输延迟时间是启动滞后时间的周期性函数 ,延迟时间被描述为一组具有固定斜率的锯齿线段 ,并提出了一种启动滞后时间的计算算法 Min Sum ,它能使任务总延迟最小化 .