Algoritmos RWA para redes ópticas transparentes considerando limitações da camada física / RWA algorithms for optical transparent networks considering physical impairments

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

With the proliferation of new multimedia services such as VoIP and IP-TV, an increasing demand for high rates of data transfer is being seen. Thus, the demand on the core of the network is continuously growing, so its capacity must increase in the same ratio to provide a reliable service to end users. The Transparent Optical Networks with WDM appears as a solution to this problem. In this new technology, the channel of transmission of data is called the optical path, which consists of an end-to-end optical circuit established through the assignment of a wavelength on every link of fiber optic route of origin-destination. The optical signal can travel by the nodes of a totally transparent network without suffering conversion opto-electro-optical (OEO), minimizing the cost of the network, whose most expensive elements are the devices that perform OEO switching. However, despite the advantage to reduce the cost, it is observed that these networks are more susceptible to the restrictions of the physical layer, because the signal is not regenerated at each node. Amplified Spontaneous Emission (ASE), Polarization Mode Dispersion (PMD), among others, degrade the optical signal to noise ratio (OSNR) in reception, which could lead to a high bit error rate (BER). Besides the degrading effects of the signal, another relevant issue in optical networks is protection. When the dependence on network resources is considerable, it is necessary to develop mechanisms to increase the reliability on services provided by the network. Thus, when a fiber optic is cut, the calls that did use this fiber need to be rerouted, so that the interruption of the signal has the smallest impact possible. This thesis presents a study of the limitations of the physical layer protection in the context of transparent optical networks. For the first time, theses effects were studied over protected networks with shared path protection, and a more efficient novel algorithm has been developed. Differentiated reliability has also been analyzed

ASSUNTO(S)

confiabilidade (engenharia) computer networks optical comunications reability (engineering) redes de computadores comunicações óticas

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