共查询到20条相似文献,搜索用时 62 毫秒
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应用于全光网络恢复优化的自适应性免疫算法 总被引:1,自引:0,他引:1
针对全光网的网络恢复问题, 提出了一种基于免疫进化算法的恢复路由优化算法。算法以全光网络的虚拓扑为主要研究对象, 通过对网络虚拓扑的全局优化, 完成网络受损业务恢复。算法在优化过程中引用自适应参数进行调节, 避免了传统进化算法中可能出现的早熟或局部收敛等现象。同时, 算法中还着重考虑了网络资源的利用率问题, 使网络资源利用率最大化, 尽量减少失效造成的业务阻塞。仿真计算结果表明, 该算法在MESH结构全光网络的业务恢复中体现良好的性能优越性。 相似文献
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在WDM全光网络上构建上层网络需要考虑上层网络的保护机制.上层网络按保护机制可分为最大故障链路数保护网和连通保护网.针对它们的不同特点给出了构建两类上层网络并使费用最低的启发式路由算法.与已有方法相比,具有算法简单,时间复杂性小,容易实用化的特点.大量的模拟计算也证明了算法的正确性. 相似文献
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Amit Wason 《Optik》2010,121(10):903-907
In this paper, we have developed a low complexity mathematical model which is used for the calculation of blocking probability of network and this model does not require any simulation statistics. The implementation of the model proposed has less complexity and the computation used in this model is quite efficient. This paper suggests an optimum path as a solution to routing problem and the appropriate number of wavelengths have also been suggested which should be free in a network to have the least blocking probability. This model can be implemented on different network topologies. Further, the model is also used to evaluate the blocking performance of NSFNet topology and hence used to improve its performance on the basis of blocking probability. 相似文献
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Fabrizio Forghieri Alberto Bononi Jian-Guo Zhang Paul R. Prucnal Giorgio Picchi Giancarlo Prati 《Fiber and Integrated Optics》2013,32(2):165-183
Abstract Some recent results on all-optical packet-switching and broadcasting networks are presented. The performance evaluation problem of packet-switching transparent optical networks with deflection routing is addressed. Transmission error arguments show how, for a given optical bit rate, the size of an all-optical nonregenerative multishop network is limited by the accumulation of noise and distortion in the optical fiber channel. Time-domain multiple access techniques are exploited in novel architectures based on recently proposed all-optical sampling gates to realize the matching of the ultrahigh optical speed allowed by the large bandwidth of the fiber with the lower speed of the electronic components needed at the user ends. These architectures allow great simplification of the node structure in the considered all-optical multihop and broadcast networks. 相似文献
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Fabrizio Forghieri Alberto Bononi Jian-Guo Zhang Paul R. Prucnal Giorgio Picchi Giancarlo Prati 《Fiber and Integrated Optics》1994,13(2):165-183
Some recent results on all-optical packet-switching and broadcasting networks are presented. The performance evaluation problem of packet-switching transparent optical networks with deflection routing is addressed. Transmission error arguments show how, for a given optical bit rate, the size of an all-optical nonregenerative multishop network is limited by the accumulation of noise and distortion in the optical fiber channel. Time-domain multiple access techniques are exploited in novel architectures based on recently proposed all-optical sampling gates to realize the matching of the ultrahigh optical speed allowed by the large bandwidth of the fiber with the lower speed of the electronic components needed at the user ends. These architectures allow great simplification of the node structure in the considered all-optical multihop and broadcast networks. 相似文献
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In this paper we have proposed a mathematical model to reduce the blocking probability of the WDM optical network. The mathematical model proposed has a closed-form expression and does not require simulated statistics, it has low implementation complexity and the computation is quite efficient. This model suggests us to choose the best path and appropriate number of free wavelengths in the network. We can go for the compromise between the path length and number of free wavelength. The model is also used to evaluate the blocking performance of NSFNet topology and hence used to improve its performance. 相似文献
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Amit Wason 《Optik》2010,121(16):1478-1486
In this paper, low-complexity mathematical model has been developed which is used for the calculation of the blocking probability of network and this model does not require any simulation statistics. The implementation of the model proposed has less complexity and the computation used in this model is quite efficient. The routing algorithm has also been proposed in this paper depending upon the proposed model, which is very efficient in calculation and minimization of the blocking probability. This algorithm suggests an optimum path as a solution to routing problem. The wavelength assignment technique has also been suggested in this paper to minimize the blocking probability. The proposed model and algorithms can be implemented on different network topologies. Furthermore, the model, routing algorithm and wavelength assignment technique is also used to evaluate the blocking performance of NSFNet and EUPAN Network topology and hence used to improve its performance on the basis of the blocking probability. 相似文献
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A major obstacle in realizing fast packet switching in all-optical networks is the large tuning delays of tunable optical devices. This article proposes a multiaccess scheme for all-optical local area networks that employs both wavelength and code concurrency. In this scheme, several users share a wavelength channel through code multiplexing. The delay performance of hybrid wavelength/code division multiaccess is obtained under a simple, suboptimal access protocol based on cyclic search. Due to the reduction in the number of wavelength channels without an associated reduction in transmission concurrency, hybrid multiaccess is robust against tuning delays. At a given network throughput, the hybrid scheme achieves considerably lower delays than that of Wavelength Division Multiple Access even with a small amount of code concurrency. Conversely, the hybrid network can support a higher load when there is a maximum allowable value for the average packet delay. 相似文献
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All-optical shift registers are basic building modules for the development of ultra-high speed optical time division multiplexing networks. In this paper, we review the progress that has been made in this cutting-edge technology, focusing on implementations that exploit the attractive features of semiconductor optical amplifier (SOA)-based interferometric configurations. We present regenerative storage performed with an all-optical recirculating shift register with an inverter at 10 Gb/s using a SOA-assisted Sagnac switch and a second SOA to provide feedback. We demonstrate also an all-optical memory based on the SOA-assisted Ultrafast Nonlinear Interferometer capable of reading/writing 20 Gb/s packets of variable length without data inversion. These registers can find application in the development of two nontrivial complex all-optical circuits of enhanced functionality. The first is an all-optical pseudorandom binary sequence generator for which we describe an efficient design algorithm and propose ways for monitoring and verification. The second is an all-optical error counter for which we address the error detection and evaluation issues using a novel sampling technique. These circuits are key elements for the implementation of a high-speed, all-optical bit error rate tester (BERT), which has the potential to outperform its electronic equivalent and constitute a possible new product for the telecommunications industry. 相似文献
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E. N. Sawardecker C. A. Amundsen M. Sales-Pardo L. A.N. Amaral 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,72(4):671-677
Most real-world networks considered in the literature have
a modular structure. Analysis of these real-world networks often are
performed under the assumption that there is only one type of
node. However, social and biochemical systems are often bipartite
networks, meaning that there are two exclusive sets of nodes, and
that edges run exclusively between nodes belonging to different
sets. Here we address the issue of module detection in bipartite
networks by comparing the performance of two classes of group
identification methods – modularity maximization and clique
percolation – on an ensemble of modular random bipartite
networks. We find that the modularity maximization methods are able
to reliably detect the modular bipartite structure, and that, under
some conditions, the simulated annealing method outperforms the
spectral decomposition method. We also find that the clique
percolation methods are not capable of reliably detecting the
modular bipartite structure of the bipartite model networks
considered. 相似文献
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An all-optical packet filtering module for WDM broadcast-and-select star networks is introduced. At each time instant, only one packet per wavelength is allowed to pass to the star coupler. Therefore, collisions are avoided and the network performance is improved. The proposed module is based on the use of optical logic circuits for controlling the passing of the transmitted packets to the star coupler, without the need of optical to electronic translation or electronic processing of the network feedback information. In this way, the processing time is drastically reduced, while the need for slowly tunable optical filters is eliminated. Furthermore, due to the all-optical nature of the network hub, the reliability of the system is improved. 相似文献