Navegando por Autor "Jaumard, Brigitte"
Agora exibindo 1 - 2 de 2
- Resultados por página
- Opções de Ordenação
Artigo Design of efficient node p-cycles in WDM mesh networks(Elsevier, 2016-04) Rocha, Caroline Thennecy de Medeiros; Jaumard, Brigitte; Li, Honghuip-cycles have been extensively studied under a single link failure scenario. Even though not as common, single node failures may occur as well, and the resulting consequences can be devastating. Failure-Independent Path-Protecting (FIPP) p-cycles provide end-to-end path protection, and thereby protection against node failures, assuming that precautions are taken. In this paper, we propose enhanced p-cycles, called node p-cycles, different from the FIPP p-cycle scheme, which can guarantee 100% protection against any single node failure. We design a scalable optimization model, which relies on a column generation formulation, in order to design the enhanced node p-cycles. Extensive comparative experiments have been conducted after designing a column generation framework for all compared protection schemes, in order to guarantee scalable models for each of them. Experiments include the (link) p-cycles, the node p-cycles of Onguetou and Grover (2009) [16], our enhanced node p-cycles and the FIPP p-cycles. We show that node p-cycles offering node and link protection only require slightly more spare capacity than link p-cycles, while requiring sometimes less, sometimes more spare capacity than FIPP p-cycles. For the comparison with the work of Grover and Onguetou (2009) [2], results show that our new node p-cycle scheme clearly outperforms their design in terms of capacity efficiencyArtigo A unified framework for shared protection schemes in optical mesh network(Sociedade Brasileira de Pesquisa Operacional, 2009-12) Rocha, Caroline Thennecy de Medeiros; Jaumard, BrigitteWhile the advantages of p-cycles and FIPP p-cycles are well established, there has been no systematic analysis of how much bandwidth they consume in comparison with the classical shared link and path protection schemes. It was recently observed that, even enumerating a huge number of cycles, is not necessarily a guarantee for obtaining good quality solutions with the ILP models if tools for large scale programming are not used. We propose to investigate the bandwidth protection costs of p-cycles and FIPP p-cycles in comparison with those of shared link and path protection by applying the column generation technique to solve relaxed LP models for the four protection schemes, and then solving the resulting ILP models. Provably near-optimal solutions allow us to perform accurate quantitative comparisons on real-world networks