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自适应混合光交换的研究 总被引:1,自引:1,他引:1
针对已有混合光交换的不足之处,提出了自适应混合光交换.这种光交换方式能根据网络业务的状态,自适应调整光交换方式,从而提高了链路利用率,降低了网络丢包率.同时讨论了自适应混合光交换的边缘节点、核心节点的结构及其各部分功能. 相似文献
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主要研究光突发交换网络边缘节点组装算法,按其功能参数特性将组装算法分为固定参数组装算法、组装参数自适应调整算法和混合业务算法等三类,着重以伪代码的方式对其工作原理进行描述,以组装效率、组装时延、算法复杂度及业务整形能力为指标对各种算法进行性能分析。 相似文献
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光突发交换(Optcal Burst Switching.OBS)被认为是在下一代光网络中起到至关重要作用的一种交换技术。边缘节点处突发包的组装作为业务接入OBS网络的第一步,是OBS研究的关键课题之一。 该文重点阐述了几种常用的突发组装方案:基于突发长度组装方案、基于组装时间组装方案、混合组装方案及自适应组装方案,并分析了它们的性能和优缺点。最后指出综合考虑网络业务流量、边缘节点的处理速度和信道带宽等因素的更加有效的突发组装算法是重点研究的内容。 相似文献
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WDM技术的迅速发展使网络传输带宽大幅提升,由此出现了节点瓶颈问题.由于光器件技术的不成熟,出现了相对简单的过渡技术--光突发交换(OBS),成为当前最具应用前景和技术优势的交换方式.OBS中的突发汇聚技术是边缘节点的关键技术之一,文中在基本汇聚算法的基础上介绍了四种改进算法,分析说明合理的汇聚算法不仅可以减轻交换节点的处理负担,还可以实现流量整形及OoS区分功能,提高OBS网络的整体性能. 相似文献
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Kyriakos Vlachos Erik Van Breusegem Kostas Christodoulopoulos Didier Colle Kostas Ramantas Piet Demeester 《Photonic Network Communications》2007,13(3):227-240
In this article, we present a detailed performance evaluation of a hybrid optical switching (HOS) architecture called Overspill
Routing in Optical Networks (ORION). The ORION architecture combines (optical) wavelength and (electronic) packet switching,
so as to obtain the individual advantages of both switching paradigms. In particular, ORION exploits the possible idle periods
of established lightpaths to transmit packets destined to the next common node, or even directly to their common end-destination.
Depending on whether all lightpaths are allowed to simultaneously carry and terminate overspill traffic or overspill is restricted
to a sub-set of wavelengths, the architecture limits itself to constrained or un-constrained ORION. To evaluate both cases, we developed an extensive network simulator where the basic features of the ORION architecture
were modeled, including suitable edge/core node switches and load-varying sources to simulate overloading traffic conditions.
Further, we have assessed various aspects of the ORION architecture including two basic routing/forwarding policies and various
buffering schemes. The complete network study shows that ORION can absorb temporal traffic overloads, as intended, provided
sufficient buffering is present. We also demonstrate that the restriction of simultaneous packet insertions/extractions, to
reduce the necessary interfaces, do not deteriorate performance and thus the use of traffic concentrators assure ORION’s economic viability. 相似文献
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光突发交换中的突发包组装技术研究 总被引:3,自引:0,他引:3
光突发交换是近几年出现的一种很有前途的光交换技术,比电路交换灵活,带宽利用率高,又比光分组交换易于实现,突发包的组装是光突发交换的关键技术,在很大程度上影响到光突发交换网络的性能。文中介绍了光突发包的格式,描述了交换网络中突发包组装所需的层次结构和功能结构,并给出了一种典型的生成算法。最后,对选择突发包组装时间应考虑的各种因素进行了系统的分析。 相似文献
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阐述了可以弥补光电路交换和光突发交换二者缺点的混合交换技术,提出了一种采用混合交换技术的新型光交换网络,分析了该新型网络中的流量特性并提出了与该网络相应的传输机制.实验表明,采用该传输机制的新型光交换网络,在源负载低于0.75的情况下,其网络丢包率和吞吐量等性能均优于普通混合交换网络,能达到优化网络资源的目的. 相似文献
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支持OTDM的多粒度光交换结构研究 总被引:1,自引:1,他引:0
多粒度光交换能减小光交叉连接矩阵的规模,降低光节点的成本,然而现有多粒度光交换结构的最小交换粒度常为波长,该交换粒度太大,会导致核心节点的链路利用率低.文章在多层MG-OXC基础上,提出了一种新型多粒度交换结构,实现了波带交换和OTDM的结合.该新型MG-OXC结构端口较少,并且可以提高传输速率,同时也因此降低了同等信息量下波长的使用教量,为网络提供了更大的传输容量,能够很好地适应光网络发展的需要. 相似文献
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Delay-on-Demand: A Signaling Protocol to Reduce Blocking Probability in Optical Burst-Switching Networks 总被引:2,自引:0,他引:2
Optical burst switching (OBS) is emerging as one promising switching paradigm for the next generation optical networks. To support multiple services in burst-switching networks, the OBS paradigm should support some quality-of-service (QoS) provisioning. A major design issue in such networks is to reduce the blocking probability of the bursts arising due to resource contention at the intermediate core router. In this paper, we propose a signaling protocol which we call ‘Delay-on-Demand’ (OBS-DoD), to reduce blocking probability and support QoS in optical burst-switching networks. The proposed scheme guarantees that at least one of the bursts succeeds depending on its priority, propagation delay from the ingress router, and the burst-size when contention occurs at the core router. For this, we use a control packet to delay, in case of a contention, the transmission of bursts at the ingress router. We compare the performance of our proposal, by simulation, with an earlier proposed scheme, and show that the proposed OBS-DoD outperforms the earlier scheme in reducing the blocking probability. For simulation, we generated bursty traffic using an M/Pareto distribution. 相似文献
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Ingress nodes in optical burst switching (OBS) networks are responsible for assembling burst from incoming packets and forwarding these bursts into the OBS network core. Changes in the statistical characteristics of a traffic stream at an ingress switch can affect the capacity of the network to provide quality of service. Therefore, the statistical characteristics of the output flow of an ingress node must be known for appropriate network dimensioning. This paper evaluates the impact of burst assembly mechanisms on the scaling properties of multifractal traffic flows. Results show that the factor most relevant in determining the nature of the output traffic flow is the relationship between the cut-off time scale of the input traffic and the time scale of assembly threshold. Moreover, a procedure for the detection of the cut-off scale of incoming traffic is introduced. 相似文献
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说明通信网交换方式从电路交换至分组交换和Burst交换的演变以适应全光通信网的发展趋势。解释了通信网利用Burst交换所需的网络边缘设备和核心结点设备。 相似文献