共查询到17条相似文献,搜索用时 163 毫秒
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针对AFDX网络时延分析问题,研究应用确定性网络演算理论的端到端AFDX网络传输时延分析方法。建立AFDX网络数据传输元模型,确定数据帧网络传输的各个网络元件,分析数据帧传输路径上各网络元件的最大处理时延,累加计算获得整个网络的端到端最大时延。多路复用排队时延是主要的可变时延,也是AFDX网络时延分析的关键。针对典型的先进先出策略和静态优先级排队复用策略,基于网络演算理论,给出其最大时延计算方法。最后,对该方法进行实例分析,表明该方法能够有效计算AFDX网络最差情况下的端到端数据传输时延。 相似文献
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以往运用确定性网络演算理论已经得到EF(Expedited Forwarding)流端到端延时上界表达式,它对实际网络的QoS控制起到了重要参考作用,但是这个表达式不够精确,而且只能描述网络状况最坏情况下的延时上界.本文改进了用确定性网络演算得到的EF流端到端延时上界,推导出更精确的延时上界表达式.同时,引入生灭模型,得到EF流端到端延时上界的概率分布表达式,能够描述不同网络状况下的延时上界.相比以往的结果,本文推导出的延时上界概率分布能够更准确地描述延时上界,具有更好的参考价值. 相似文献
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为分析融合网络中聚合业务的端到端时延性能,提出一种基于聚合流的融合网络端到端统计时延界的新算法.该算法利用MGF(矩母函数)重新表征了网络端到端时延界的MGF形式的概率模型.数值分析结果表明了该算法的有效性和优越性,该算法很大程度上提高了独立统计复用,对融合网络性能评价具有参考意义. 相似文献
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基于网络演算的无线自组网QoS性能确定上界研究 总被引:7,自引:2,他引:5
为保证无线自组网的服务质量(QoS),需精确求解其性能确定上界.对进入无线自组网节点的数据流进行漏桶管制,节点为数据流提供基于速率-延迟(rate-latency)模型的服务保障,在已有无线自组网链路吞吐量模型的基础上利用网络演算理论推导了无线自组网节点的积压数据上界、端到端数据流的延迟上界以及端到端数据流的延迟抖动上界模型.对网格形式拓扑的无线自组网,不同数据流的仿真结果都在数值计算的上界范围之内,表明基于网络演算理论的无线自组网的QoS性能上界模型具有较好的性能. 相似文献
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提出了一类具有最大速率控制的速率保障(Maximum Rate Control-Guaranteed Rate,MRC-GR)算法,可对流同时提供速率保障和最大速率控制.当网络各节点执行MRC-GR算法时,提供了确定网络端到端时延上限和下限的方法,针对服从令牌桶模型和同步单元模型的业务源给出了网络时延上限和下限.针对MRC-GR算法实例——具有最大速率控制的最差情形公平加权公平排队(worst-case fair weighted fair queueing with maximum rate control)调度算法进行仿真实验,仿真结果验证了理论分析. 相似文献
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无线Mesh网中时延约束抖动优化的多路径流量分配算法 总被引:1,自引:0,他引:1
针对无线mesh网中多媒体应用的特点,研究多路径传输中路径时延满足约束且路径间抖动最小化的路径流量分配问题。首先,基于网络演算理论分析了数据分组在无线mesh网单路径传输中产生的队列时延,推导出单路径传输的时延上界以及多路径传输中的路径间时延抖动上界,并得到满足时延约束的路径最大容许流入速率;然后,基于时延及其抖动上界,提出满足时延约束抖动优化的路径流量分配算法DCJOTA,该算法根据路径最大容许流入速率按比例分配各路径流量,同时尽可能减小路径间的时延抖动;最后,分析了算法DCJOTA的可行性及其实现方法,并在NS2网络模拟器中验证了该算法的有效性。仿真实验表明,与AOMDV协议相比,集成了DCJOTA算法的多路径路由协议DCJO-AOMDV协议在时延及其抖动方面具有更好的表现:端到端平均时延降低3.9%,端到端平均时延抖动减小24.5%。另外,DCJOTA算法带来协议复杂性略微增加,DCJO-AOMDV协议下的网络吞吐量下降1.7%。 相似文献
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Ciucu F. Burchard A. Liebeherr J. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2006,52(6):2300-2312
The stochastic network calculus is an evolving new methodology for backlog and delay analysis of networks that can account for statistical multiplexing gain. This paper advances the stochastic network calculus by deriving a network service curve, which expresses the service given to a flow by the network as a whole in terms of a probabilistic bound. The presented network service curve permits the calculation of statistical end-to-end delay and backlog bounds for broad classes of arrival and service distributions. The benefits of the derived service curve are illustrated for the exponentially bounded burstiness (EBB) traffic model. It is shown that end-to-end performance measures computed with a network service curve are bounded by /spl Oscr/(H log H), where H is the number of nodes traversed by a flow. Using currently available techniques, which compute end-to-end bounds by adding single node results, the corresponding performance measures are bounded by /spl Oscr/(H/sup 3/). 相似文献
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复杂对抗下军事通信系统的随机延迟分析 总被引:1,自引:1,他引:0
随着信息化技术的发展,现代军事指挥越来越依靠综合化、集群化的军事通信系统。在战争局势复杂多变,尤其是敌方干扰严重、战场环境复杂等对抗性强的环境下,如何确保有效军事情报及时地准确地传递给指挥者显得尤为重要。针对战场有效数据产生的随机性和传输过程的不稳定性,提出了一种基于随机网络演算的端到端延迟分析方法。由此获得的端到端延迟上界,不仅为有效信息的传输提供了实时性能保证,而且能充分的利用系统资源。这对于军事通信系统的设计以及传输系统的性能改善有着非常重要的指导意义。 相似文献
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IntServ是目前常用的网络服务质量策略之一,其性能分析,特别是端到端的性能分析是一个没有很好解决的问题。深入研究网络演算技术在IntServ性能分析中的应用方法,推导出了IntServ确保服务下的最大端到端时延界、最大队列长度界和网络有效带宽等性能参数的计算公式,通过具体的应用实例,验证了计算结果的正确性和有效性。分析结果是网络接纳控制的基础。 相似文献
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We consider single channel wireless networks with interference constraint among the links that can be activated simultaneously. The traffic flows are assumed to be single hop. Delay performance of the well known throughput optimal maximum weight link scheduling algorithm has been studied recently. In this paper, we study the relation between network topology and delay of maximum weight link scheduling algorithm. First, we consider 1-hop interference model. Under this interference model, an upper bound for the average delay of packets is derived analytically in terms of edge chromatic number of the network graph. Then the results have been extended to the case of general interference model. Under this model of interference, an upper bound for delay as a function of chromatic number of conflict graph is derived. Since chromatic number and edge chromatic number are network topology parameters, the results show that how the upper bound of delay is affected by network topology. Simulation results confirm our analytical relations. 相似文献
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Mobile edge computing (MEC) networks can provide a variety of services for different applications. End-to-end
performance analysis of these services serves as a benchmark for the efficient planning of network resource allocation
and routing strategies. In this paper, a performance analysis framework is proposed for the end-to-end data-flows in
MEC networks based on stochastic network calculus (SNC). Due to the random nature of routing in MEC
networks, probability parameters are introduced in the proposed analysis model to characterize this randomness into
the derived expressions. Taking actual communication scenarios into consideration, the end-to-end performance of
three network data-flows is analyzed, namely, voice over Internet protocol (VoIP), video, and file transfer protocol
(FTP). These network data-flows adopt the preemptive priority scheduling scheme. Based on the arrival processes
of these three data-flows, the effect of interference on their performances and the service capacity of each node in
the MEC networks, closed-form expressions are derived for showing the relationship between delay, backlog upper
bounds, and violation probability of the data-flows. Analytical and simulation results show that delay and backlog
performances of the data-flows are influenced by the number of hops in the network and the random probability
parameters of interference-flow (IF). 相似文献