共查询到18条相似文献,搜索用时 109 毫秒
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由于WDM网络中的传输和交换是以波长为粒度进行的。因此波长分配算法就成为光网络的研究热点。有效的算法可大大提高波长的利用率,并可充分挖掘WDM的带宽资源。介绍了WDM全光网络中静态和动态波长分配算法,尤其是结合大型网孔网络详述了几种动态波长分配算法。针对波长变换器在全光网络中的应用。提出了一种可以解决任意类型光网络的分层图算法,它可以一次性解决路由选择和波长分配问题,大大提高了该算法的效率。是未来光网络中非常有前景的一种波长分配算法。 相似文献
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波长共享的WDM无源光网络 总被引:1,自引:1,他引:0
提出了波长共享的WDM无源光网络的系统结构及其媒质接入协议.这种方案结合了波长路由和功率分割,控制信道采用随机接入,并使用先到先服务的调度策略有效地分配上行带宽.分析了系统中的分组延时,数值计算表明系统具有良好的延时特性. 相似文献
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研制了一种新型的用于WDM全光网的全光型上/下载复用器,由一对相同的光纤环行器、串接其间的可调谐光纤Bragg光源、WDM复用器和解复用器构成。其中光纤Bragg光栅是用紫外光直写方式在普通单模光纤上制成。讨论了该利用器的工作原理、结构设计、性能和特点。利用磁极间磁场力使光纤光栅产生显著的波长偏移。用可编程磁 极调控光栅的波第偏移。其信道波长调谐速度快,装置无需外加能源即可保持信道波长的偏移。给出了其性能测试结果。信道波长间隔0.8nm,上/下载信道插入损耗1.5dB,通过信道插入损耗2.0dB,上/下端口隔离度30dB,串扰小于-30dB,可调谐信道波长范围6.0nm。其特点是结构简单,可靠。可实现信道波长再利用,从而提高网络的灵活性。 相似文献
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In this paper, we investigate the problem of enhancing multiple-fault restorability in the path protected wavelength-routed all-optical WDM networks. The system architecture considered is circuit-switched with dynamic arrival of session requests. We propose a mechanism, which is used to combat multiple link failures. A routing and wavelength assignment algorithm has been proposed with the name of fault-tolerant routing and wavelength assignment algorithm. The comparison of this algorithm has also been made with the best-fit and first-fit algorithms. This algorithm deals with the optical networks with multiple faults and is effective for the varying load applied to nodes. This algorithm works well for the load applied to the nodes varying from low to high. 相似文献
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We consider the routing and wavelength assignment problem on wavelength division multiplexing networks without wavelength conversion. When the physical network and required connections are given, routing and wavelength assignment (RWA) is the problem to select a suitable path and wavelength among the many possible choices for each connection such that no two paths using the same wavelength pass through the same link. In wavelength division multiplexing (WDM) optical networks, there is need to maximize the number of connections established and to minimize the blocking probability using limited resources. In this paper, we have proposed three dynamic link weight assignment strategies that change the link weight according to the traffic. The performance of the existing trend and the proposed strategies is shown in terms of blocking probability. The simulation results show that all the proposed strategies perform better than the existing trend. 相似文献
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In this paper dynamic routing and wavelength assignment strategies have been proposed for multiclass WDM optical networks. Multiclass optical networks provide multiple classes of services to the subscriber according to the requirement, which in turn increase operational profitability. Each class of service could be characterized by parameters like number of wavelengths, expected call holding time and average arrival rate of request. The proposed strategies have been analyzed and compared with existing strategies on the basis of blocking probabilities for multiclass traffic scenarios. Simulation results on different network topologies demonstrate that the performance of proposed strategies “Fixed shortest/alternate shortest path routing with wavelength reservation (FSASWR)” and “Fixed alternate shortest path routing with least priority wavelength assignment (FASPL)” are much better as compared to existing strategies. Proposed strategies minimize blocking probability of the multiclass network using limited number of wavelengths. 相似文献
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A routing and wavelength assignment algorithm is proposed to minimize the number of wavelengths and transceivers required simultaneously under static traffic in translucent optical networks design. 相似文献
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P. P. Monteiro H. L. Castro J. Castro R. Luí s D. Fonseca J. Pedro L. Pellegrino M. Hajduczenia S. Pato N. Garcia C. Santiago T. Silveira A. Ferreira 《Fiber and Integrated Optics》2005,24(3):395-410
This article summarizes the research activities carried out by the R&D Optical Networks Communications group (COM RD1), at Siemens S.A., in collaboration with both universities and other research institutes. These activities cover various aspects of advanced modulation formats, all optical wavelength conversion, optical quality of signal monitoring in transparent WDM networks, routing, and wavelength assignment in optical networks. 相似文献
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In this paper, two static and three dynamic routing algorithms have been proposed and compared to some of the existing algorithms on the basis of blocking probability. The two proposed static routing and wavelength assignment (RWA) algorithms reduce the blocking probability to maximize the utilization of network. For dynamic algorithms, first a model with no weights assignments is presented and then three algorithms are proposed and analysed with weight assignment resulting in reduction of blocking probability. All these algorithms are analysed and compared with four wavelength assignment schemes which are first-fit, random, most used and least used. It is shown that our proposed static algorithms give the best performance for first-fit wavelength assignment and most used wavelength assignment strategies with reduced complexity. For least used wavelength assignment and random wavelength assignment, 1 fixed and 2 alternate routing algorithm gives the lowest blocking probability. For dynamic routing, it has been shown that our proposed algorithm “less weight to maximum empty and nearest” gives the least blocking probability as compared to the other dynamic routing algorithms for random, most used and least used wavelength assignment strategies. 相似文献
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In this paper, we have investigated the problem of enhancing multiple-fault restorability in the path protected wavelength-routed all-optical WDM networks. The system architecture considered is circuit-switched with dynamic arrival of session requests. We have proposed a mechanism, which is used to combat multiple link failures. A survivable routing and wavelength assignment algorithm has been proposed which is very efficient for the networks having multiple failures. This algorithm deals with the optical networks with multiple faults and is effective for the varying load applied to nodes. This algorithm works well for the load applied to the nodes varying from low to high. 相似文献