共查询到19条相似文献,搜索用时 171 毫秒
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光突发交换网络中路由的实现是网络生存性和健壮性的一个保证。文章提出了一种光突发交换网络路由技术的新方案,将免疫遗传算法这种仿生物体的智能算法,应用到光突发交换网络路由算法中,保证群体多样性,控制收敛方向。仿真结果表明,该方案可以降低OBS网络中的数据丢失率。 相似文献
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光突发交换网络中路由的实现是网络生存性和健壮性的一个保证。文章提出了一种光突发交换网络路由技术的新方案,将免疫遗传算法这种仿生物体的智能算法,应用到光突发交换网络路由算法中,保证群体多样性,控制收敛方向。仿真结果表明,该方案可以降低OBS网络中的数据丢失率。 相似文献
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OBS网络中多优先级业务冲突解决模型研究* 总被引:2,自引:0,他引:2
为了充分认识光突发交换(OBS)网络核心节点中的多业务冲突性能,以OBS网络核心节点为研究对象,采用基于优先级的信道抢占原则,给出了在配置光缓存情况下,多优先级业务的冲突解决模型。结果表明,所提出的模型保证了OBS网络的服务质量,有效解决了以往研究中出现的两个局限性问题,所得参数对OBS网络的实验化建设提供了理论依据。 相似文献
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针对当前无线网络路由算法存在丢包率高、节点拥塞严重的难题,提出一种基于改进蚁群优化算法的网络服务质量路由算法。首先根据无线网络的特点选择带宽、端到端的延迟、数据包丢失率以及链路花费作为QoS参数,并建立一个多约束网络服务质量路由优化问题的数学模型,然后采用具有正反馈机制和搜索能力强的蚁群优化算法对数学模型进行求解,并根据无线网络路由特点对标准蚁群优化算法进行改进,提高其搜索性能,最后采用具体仿真实验对路由算法的性能进行测试。实验结果表明,改进蚁群优化算法在满足网络质量要求的条件下,不仅降低了网络平均延时,而且减少了网络数据丢包率,性能优于其它算法。 相似文献
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GMPLS-based OBS光传输网络体系结构 总被引:1,自引:0,他引:1
提出一种采用GMPLS协议作为控制面的光突发交换(OBS)网络体系结构,给出了网络结构、节点功能模型、控制包格式和新增控制信令交换接口的建议。提出的网络结构是在OBS的突发控制包用通用标签代替地址,并使用GMPLS协议栈完成路由和信令功能,实现流量工程和生存性研究。 相似文献
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光突发交换竞争解决机制研究 总被引:2,自引:0,他引:2
作为下一代互联网的关键技术之一的光突发交换技术已受到业界的广泛关注。本文在介绍光突发交换基本概念、特点的基础上,重点探讨了解决光突发交换网中突发数据包之间争夺链路资源问题的竞争解决机制,主要包括光缓存、波长转换、偏转路由以及突发分片等技术,对这些技术的优缺点进行了分析比较,并给出了一种偏转路由和突发分片技术结合的竞争解决方法。 相似文献
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Abdeltouab Belbekkouche Abdelhakim Hafid Mariam Tagmouti Michel Gendreau 《Computer Networks》2010,54(18):3264-3279
Optical Burst Switching (OBS) is a promising switching technology for the next generation all-optical networks. An OBS network without wavelength converters and fiber delay lines can be implemented simply and cost-effectively using the existing technology. However, this kind of networks suffers from a relatively high burst loss probability at the OBS core nodes. To overcome this issue and consolidate OBS networks with QoS provisioning capabilities, we propose a wavelength partitioning approach, called Optimization-based Topology-aware Wavelength Partitioning approach (OTWP). OTWP formulates the wavelength partitioning problem, based on the topology of the network, as an Integer Linear Programming (ILP) model and uses a tabu search algorithm (TS) to resolve large instances efficiently. We use OTWP to develop an absolute QoS differentiation scheme, called Absolute Fair Quality of service Differentiation scheme (AFQD). AFQD is the first absolute QoS provisioning scheme that guarantees loss-free transmission for high priority traffic, inside the OBS network, regardless of its topology. Also, we use OTWP to develop a wavelength assignment scheme, called Best Effort Traffic Wavelength Assignment scheme (BETWA). BETWA aims to reduce loss probability for best effort traffic. To make AFQD adaptive to non-uniform traffic, we develop a wavelength borrowing protocol, called Wavelength Borrowing Protocol (WBP). Numerical results show the effectiveness of the proposed tabu search algorithm to resolve large instances of the partitioning problem. Also, simulation results, using ns-2, show that: (a) AFQD provides an excellent quality of service differentiation; (b) BETWA substantially decreases the loss probability of best effort traffic to a remarkably low level for the OBS network under study; and (c) WBP makes AFQD adaptive to non-uniform traffic by reducing efficiently blocking probability for high priority traffic. 相似文献
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《Performance Evaluation》2006,63(9-10):1016-1031
In this paper, we analyze the performance of a timer-based burst assembly for optical burst switching (OBS) networks. In our analytical model, an ingress edge node has multiple buffers where IP packets are stored depending on their egress edge nodes, and bursts are assembled at the buffers in round-robin manner. Moreover, bursts are transmitted in accordance with slotted scheduling where each burst transmission starts at the slot boundary. We construct a loss model with two independent arrival streams, and explicitly derive the burst loss probability, burst throughput, and data throughput. In numerical examples, we show the effectiveness of our analysis in comparison with the Erlang loss system. It is shown that our model is quite useful for an OBS network with a large number of input and output links. 相似文献
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《Computer Networks》2003,41(1):41-55
Wavelength division multiplexing (WDM) is a promising technology for realizing terabit networks. Optical burst switching (OBS) is a way to efficiently support bursty traffic on WDM-based optical Internet networks. In OBS networks, the control (header) and payload (data) components of a burst are sent separately with a time gap. The control packet first traverses the burst switching nodes and reserves suitable wavelengths on the links for the corresponding data burst by using a scheduling algorithm. Our work is motivated from the observation that the existing scheduling algorithms either have low computational complexity or high performance in terms of burst dropping probability, but not both simultaneously. Since the arrival of bursts is dynamic, it is highly desirable that the scheduling is done as quickly as possible. We develop scheduling algorithms which integrate the merits of both low computational complexity and high burst dropping performance. The key idea is to reschedule an existing burst by assigning a new wavelength to it keeping the burst arrival and leaving time unchanged in order to accommodate the new burst. We propose computationally simple rescheduling algorithms called on-demand burst rescheduling and aggressive burst rescheduling. The effectiveness of the proposed algorithms and the signaling overhead are studied through simulation experiments. 相似文献
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Optical burst switching (OBS) is a promising optical networking paradigm for efficient transport of bursty IP traffic over wavelength division multiplexing (WDM) optical Internet networks. In OBS, the header of a burst is sent in advance of the data burst to reserve a wavelength channel at each optical switching node along the path. The nodes use a scheduling algorithm to assign wavelengths to incoming bursts. Our work is motivated from the observation that existing scheduling algorithms assign a wavelength to a burst when its header arrives at the node. Thus, information about other bursts whose headers arrive later is not available when the scheduling decision is made. This leads to suboptimal scheduling decisions and unnecessary burst dropping. The key idea in our proposed algorithm, Ordered Scheduling, is to defer making the scheduling decision until just before the burst arrival in order to have full knowledge about other bursts. The effectiveness of the proposed algorithm is studied through simulation and the computational complexity and signalling overhead are analysed. 相似文献
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信道调度算法是光突发交换(OBS)网络的关键技术之一。在主动重调度算法的基础上,提出了一种新的多重主动重调度算法,通过搜索并重调度数据信道上所有能进行重调度的突发,使多个突发重调度后产生的间隔尽量小,从而降低突发丢失率。 相似文献
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《Computer Networks》2007,51(13):3919-3934
Optical burst switch (OBS) has been a hot topic in the area of optical networks. OBS can realize statistic multiplexing while having the advantage of simplicity in deployment. A key issue in OBS is how to reduce the rate of the burst dropping caused by the absence of optical buffers or by the limited number of Fiber Delay Line (FDL). Existing work addresses this issue in the wavelength, time, or space domains. This paper proposes an algorithm, which works from a new domain to address this problem. Specially, it works by using the idle bandwidth in upstream links to transmit redundant copies of bursts to provide more sending chances at the downstream node. Simulation results are given to demonstrate the high performance of our algorithm. 相似文献