首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 62 毫秒
1.
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   

2.
WDM网状网中的基于平面构造的业务量疏导算法   总被引:3,自引:0,他引:3  
将多个低于一个波长带宽的低速业务流复用到一个波长上传输的业务量疏导已经得到越来越多 的研究.WDM/SDH环网中的业务量疏导已得到大量研究,WDM网状网中的业务流疏导问题研究相 对较少.该文研究静态环境下波长数目受限的业务量疏导问题,提出了一种基于平面构造的启发式业务量疏 导算法.仿真结果表明该算法比已知的算法具有更好的性能.  相似文献   

3.
该文综合考虑WDM网状网生存性及业务量疏导,采用部分光路共享保护机制为低速业务提供满足其可靠性和带宽需求的连接,提出了一种基于波长分层图的支持业务量疏导的区分共享保护算法—部分共享保护业务量疏导算法PSPTG(PartialShared-pathProtectionalgorithmsupportingTrafficGrooming)。仿真结果表明:该算法可以较好地利用资源。  相似文献   

4.
WDM网状网中基于共享风险链路组限制的业务量疏导算法   总被引:2,自引:0,他引:2  
该文研究了业务量疏导WDM网状网中如何建立可靠的业务连接问题,提出一种新的基于共 享风险链路组(SRLG)限制的共享通路保护算法。该算法既可以保证用户业务不同的可靠性要求,同时又 能够有效提高全网的资源利用率,从而大大降低全网的业务阻塞率.该文还对所提算法进行了仿真研究,并 给出了仿真结果。  相似文献   

5.
研究了WDM网状网在hose业务模型下基于Valiant负载平衡的鲁棒选路问题。借助业务量疏导的方法,以hose模型吞吐量最大化为优化目标,采用整数线性规划(ILP)加以解决,进而提出了2种快速的启发式算法——最短路径选路的最小跳数优先(SPR&MHF)算法和平衡选路的最小跳数优先(BR&MHF)算法。计算机仿真表明,SPR&MHF算法适用于链路数较少的小规模WPM网状网,而RR&MHF适用于链路数较多的大规模WDM网状网。  相似文献   

6.
WDM抗毁网状网络中的业务量疏导算法   总被引:3,自引:0,他引:3  
研究具有抗毁能力的WDM网状网中的业务量疏导设计问题,提出几种以网络吞吐量为优化目标的启发式算法,并通过计算机仿真分析,证实了基于最大化资源利用率的算法具有很好的性能。  相似文献   

7.
研究了WDM网状网中基于光连接(connection)的抗毁业务量疏导通道(path)保护问题,以最大化网络的吞吐量为目标,提出了新的基于共享风险链路组(Shared Risk Link Group,SRL G)的共享保护算法和专用保护算法.并以NSFNET为仿真网络,比较说明了这两种算法在网络拥塞率和波长利用率方面的性能优劣.  相似文献   

8.
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   

9.
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   

10.
WDM疏导网络中一种新的多播业务路由算法   总被引:2,自引:6,他引:2  
研究了波分复用(WDM)网状网中动态多播业务量疏导,提出一种新的辅助疏导模型,其可以描述当前网络资源状况和节点分光特点,并动态更新.进而提出一种有效的多播业务量疏导启发式算法(MGA),将业务的多播选路和波长分配同时完成.仿真表明,该算法在波长连续性限制、网络波长和节点收发器数目有限的情况下,具有较低网络阻塞率.  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
温海波  虞红芳  李乐民  王晟 《电子学报》2004,32(12):1992-1996
线性预编码是OFDM系统在频率选择性衰落信道中利用频率分集的有效方法.为了进一步提高性能,本文提出了一种线性预编码OFDM系统的迭代接收机,该迭代接收机采用基于线性最小均方误差准则(LMMSE)的turbo均衡算法及其简化方法,具有很低的计算复杂度.本文同时还提出通过使用长度不小于等效离散时间信道的时延扩展长度的线性预编码器和迭代接收机,可获得完全的频率分集增益.仿真表明本文提出的方法在多径干扰严重的信道条件下的误码率性能接近AWGN下界.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号