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A escolha de um método de compensação de dispersão adequado representa uma decisão muito importante em sistemas que operam em altas taxas e longas distâncias. Este trabalho investiga a aplicabilidade da fibra compensadora de dispersão em um sistema de longo alcance obedecendo aos critérios recomendados pelo ITU-T (G.692). Busca estabelecer parâmetros de projeto que permitam a operação numa ampla faixa de potências com baixa distorção e BER, utilizando o menor comprimento possível de fibra compensadora de dispersão.Analisando a Fig. 1, quando a propagação é linear os resultados se mostram praticamente independentes do

This paper discusses some novel strategies to tackle the difficulty problem of finding a good logical network topology with minimum traffic congestion. We apply our strategy on solving two typical topologies structures: the Mesh and the Self-Healing Rings. The typical strategies for solving the logical topology design for both structures are those based on the use of mixed-integer linear programming. However the literature shows that these approaches can be frustrating, time consuming and costly. As an alternative to these strategies, our approach combines the capability of meta-heuristics of finding good solutions in a very short computational time and provides the mixed-integer linear programming with good upperbounds in order to pruning great chunk of the searching space. In this work we show that our approach is promising as we are able to solve large problems in a reasonable amount of time for both type of topologies we studied.

Wavelength division multiplexing is the most effective way to take advantage of the huge transmission bandwidth provided by the optical media, but the possibility of increasing transmission speed by sharing the same physical link with many optical channels is not the only feature allowed by this technology. Wavelength division multiplexing can also be used to route traffic transparently through some network nodes, thus requiring less electronic data processing at intermediate nodes of a certain traffic route. In such a wavelength-routed network, the traffic is routed through a virtual topology, composed by concatenated ligthpaths embedded in the physical topology of fiber links. This work proposes a new approach to the virtual topology design problem in the core of the Mixed-Integer Linear Program formulation, suitable for a multiservice optical networks. This new formulation allows traffic partitioning in classes and differentiated delay constraining for each traffic class, providing an analysis of its influence on congestion.