共查询到18条相似文献,搜索用时 62 毫秒
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在WDM网络中业务的带宽需求远低于一个波长所提供的带宽,业务量疏导可以聚集低速业务到大容量的光路中从而有效地利用波长带宽资源。目前大多数业务量疏导的研究限于环形网,考虑对WDM网状网中低速业务可靠疏导的文献更少.该文综合考虑WDM网状网生存性及业务量疏导,提出了基于波长分层图的共享保护业务量疏导算法(SPTG—LG,Slaared Protection Traffic Grooming algorithmbased on wavelength Layered—Graph),并对算法进行了仿真和分析. 相似文献
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波分复用(WDM)技术在主干传送网中巳广泛应用,WDM光网络的研究进展也非常迅速,光网络中的业务量疏导定义为复用、解复用和交换低速率业务流到大容量的光路中的行为。介绍了WDM光网络的业务量疏导的重要性,研究方法及其最新研究进展情况。 相似文献
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业务量疏导WDM网状网中的动态子通路保护算法 总被引:1,自引:0,他引:1
该文研究了业务量疏导WDM网状网中的生存性问题,提出一种自适应子通路保护(ASPP)算法.该算法根据网络当前状态以及到达业务连接请求的带宽要求动态调整链路权值;在此基础上选择一条最短路作为工作通路,然后将该通路分为互不重叠的n段子通路(每段经过的链路数为m),并分别找出各自的保护通路.仿真结果表明:ASPP既可以保证业务连接的可靠性要求,同时又允许网络管理者根据一定优化策略调整m值,从而可以在资源利用率和恢复时间之间进行折中. 相似文献
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Traffic grooming in optical networks has gained significant importance in recent years due to the prevailing sub-wavelength traffic requirement of end-users. In this paper, a methodology for dynamic routing of fractional-wavelength traffic in WDM grooming networks is developed. To evaluate the performance of routing algorithms, a new performance metric that reflects the network utilization is also proposed. The performances of shortest-widest path, widest-shortest path, and available shortest path routing algorithms are evaluated on a class of WDM grooming networks by considering traffic of different capacity requirements. The effect of dispersity routing, where higher capacity requests are broken into multiple unit capacity requests, is also investigated. The most interesting counter-intuitive result that is observed is that increasing the grooming capability in a network could result in degrading the performance of the widest-shortest path algorithm. 相似文献
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光网络中基于组播树的静态业务疏导算法 总被引:2,自引:1,他引:1
为了减少波分复用(WDM)网络中波长资源消耗,将组播路由算法的思想运用于静态业务疏导的计算,通过建立业务疏导树来实现静态业务疏导.为了减少疏导树的数量,从而减少网络中波长资源的消耗,将节点间的业务请求分组归并,利用装包算法使业务分组的数量最少,并通过构建最小生成树实现传输路径共享.仿真结果表明,本文的算法可以有效地减少... 相似文献
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针对具有多跳疏导能力的WDM光网络进行了研究,提出了一种基于固定备选路由的多跳业务量疏导算法(FO-HC-MH)。该算法对备选路由的跳数进行限制,因而可以节约使用网络的收发器资源。仿真实验表明,与FO-MH算法相比,在网络负载较低的情况下该算法节约效果明显。 相似文献
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In Wavelength Division Multiplexing (WDM) networks, the huge capacity of wavelength channels is generally much larger than the bandwidth requirement of individual traffic streams from network users. Traffic grooming techniques aggregate low-bandwidth traffic streams onto high-bandwidth wavelength channels. In this paper, we study the optimization problem of grooming the static traffic in mesh Synchronous Optical Network (SONET) over WDM networks. The problem is formulated as a constrained integer linear programming problem and an innovative optimization objective is developed as network profit optimization. The routing cost in the SONET and WDM layers as well as the revenue generated by accepting SONET traffic demands are modelled. Through the optimization process, SONET traffic demands will be selectively accepted based on the profit (i.e., the excess of revenue over network cost) they generate. Consiering the complexity of the network optimization problem, a decomposition approach using Lagrangian relaxation is proposed. The overall relaxed dual problem is decomposed into routing and wavelength assignment and SONET traffic routing sub-problems. The subgradient approach is used to optimize the derived dual function by updating the Lagrange multipliers. To generate a feasible network routing scheme, a heuristic algorithm is proposed based on the dual solution. A systematic approach to obtain theoretical performance bounds is presented for an arbitrary topology mesh network. This is the first time that such theoretical performance bounds are obtained for SONET traffic grooming in mesh topology networks. The optimization results of sample networks indicate that the roposed algorithm achieves good sub-optimal solutions. Finally, the influence of various network parameters is studied. 相似文献
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In this article, we consider traffic grooming and integrated routing in IP over WDM networks. The challenges of this problem
come from jointly considering traffic grooming, IP routing, and lightpath routing and wavelength assignment (RWA). Due to
the high bandwidth of optical fiber, there exists a mismatch between the capacity needed by an IP flow and that provided by
a single lightpath. Traffic grooming is therefore used to increase the network utilization by aggregating multiple IP flows
in a single lightpath. However, traffic grooming incurs additional delays that might violate Quality-of-Service (QoS) requirements
of IP users. In this work, the tradeoff between traffic grooming and IP QoS routing is well-formulated as a mixed integer
and linear optimization problem, in which the revenue from successfully provisioning IP paths is to be maximized. Problem
constraints include IP QoS, routing, optical RWA, and the WDM network capacity. We propose a novel Lagrangean relaxation (LGR)
algorithm to perform constraint relaxation and derive a set of subproblems. The Lagrangean multipliers are used in the proposed
algorithm to obtain a solution in consideration of grooming advantage and resource constraints simultaneously. Through numerical
experiments and comparisons between the proposed algorithm and a two-phase approach, LGR outperforms the two-phase approach
under all experimental cases. In particular, the improvement ratio becomes even more significant when the ratio of IP flow
to the wavelength capacity is smaller. 相似文献
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Hongyue Zhu Hui Zang Keyao Zhu Mukherjee B. 《Networking, IEEE/ACM Transactions on》2003,11(2):285-299
As the operation of our fiber-optic backbone networks migrates from interconnected SONET rings to arbitrary mesh topology, traffic grooming on wavelength-division multiplexing (WDM) mesh networks becomes an extremely important research problem. To address this problem, we propose a new generic graph model for traffic grooming in heterogeneous WDM mesh networks. The novelty of our model is that, by only manipulating the edges of the auxiliary graph created by our model and the weights of these edges, our model can achieve various objectives using different grooming policies, while taking into account various constraints such as transceivers, wavelengths, wavelength-conversion capabilities, and grooming capabilities. Based on the auxiliary graph, we develop an integrated traffic-grooming algorithm (IGABAG) and an integrated grooming procedure (INGPROC) which jointly solve several traffic-grooming subproblems by simply applying the shortest-path computation method. Different grooming policies can be represented by different weight-assignment functions, and the performance of these grooming policies are compared under both nonblocking scenario and blocking scenario. The IGABAG can be applied to both static and dynamic traffic grooming. In static grooming, the traffic-selection scheme is key to achieving good network performance. We propose several traffic-selection schemes based on this model and we evaluate their performance for different network topologies. 相似文献
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在WDM光网络中业务流量疏导能够有效地降低网络建设成本.为了疏导网络中的动态业务,提出动态业务流量的可重构疏导方案,并给出相应快速在线算法.此算法通过动态调整网络的虚拟拓扑结构,可使网络适应各种动态业务.计算机模拟结果表明,该算法能得到较优的疏导结果. 相似文献
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