Carlos Simoes

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Ensuring network survivability is of the utmost importance in today's networks. A Shared Risk Link Group (SRLG) is the set of links in the network that share a common physical resource subject to fault(s). This concept allows an upper layer the ability to implement SRLG diverse routing. and the Iterative Modified Suurballe's Heuristic (IMSH), will be(More)
All-optical WDM networks are characterised by multiple metrics (hop-count, cost, delay, available band- width, loss probability, reliability), but generally routing algorithms only optimise one metric. Having in mind the inherent limitations of this type of approach, it seems potentially advantageous in the development of multicriteria models capable of(More)
—The operation of wavelength division multiplex-ing (WDM) networks involves not only the establishment of lightpaths, defining the sequence of optical fibres and the wavelength in each fibre for traffic flow, but also a fault management scheme in order to avoid the huge loss of data that can result from a single link failure. Dedicated path protection ,(More)
—Establishing end-to-end connections on wavelength division multiplexing (WDM) networks requires setting up lightpaths, defining the sequence of optical fibres and the wavelength in each fibre (the routing and wavelength assignment problem) for traffic flow. This paper reviews a bicriteria model for obtaining a topological path (unidirectional or symmetric(More)
Introduction Noninvasive ventilation is a safe and eff ective method to treat acute respiratory failure, minimizing the respiratory workload and oxygenation. Few studies compare the effi cacy of diff erent types of noninvasive ventilation interfaces and their adaptation. Objective To identify the most frequently noninvasive ventilation interfaces used and(More)
Network reliability can be implemented in several network layers. The concept of Shared Risk Link Group (SRLG) allows an upper layer to be capable of implementing SRLG diverse routing. If a given link is known to be protected, it can be omitted from the set of links to be avoided, when a SRLG disjoint protection path (or segment) for a given active path is(More)