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In this paper, we investigate a scenario in which protected and unprotected services coexist in an elastic optical network under dynamic traffic. In the investigated scenario, unprotected services can reuse the reserved idle bandwidth to provide protection to the protected services. Under this scenario, we propose a new heuristic algorithm that enables such reuse as well as define and introduce a new assignment problem in elastic optical networks, named a Transmission Spectrum Assignment (T-SA) problem. In this paper, we consider a scenario in which services may be routed using the multipath routing approach. Additionally, protection using bandwidth squeezing is also considered. We assess our proposal through simulations on three different network topologies and compare our proposal against the classical protection approach, in which bandwidth reuse is not allowed. For the simulated range of network loads, the maximum (minimum) blocking probability reduction obtained by our proposal is approximately 48% (10%) in the European topology, 46% (7%) in the NSFNET topology, and 32% (6%) in the German topology. [ABSTRACT FROM AUTHOR]

We propose in this paper two heuristic strategies to solve the regenerator placement problem (RPP) in translucent networks under dynamic traffic. The heuristics are based on both the forecast of the offered load and estimates of blocking probabilities in the network nodes. The proposed heuristics are compared to other regenerator placement algorithms from the literature in two different topologies. The results show that one of the proposed algorithms outperforms, in the investigated scenarios, all other algorithms from the literature considered for comparison purposes in this paper, whereas the second proposed algorithm outperforms the algorithms from the literature only in some considered scenarios. [ABSTRACT FROM AUTHOR]

To overcome the inefficiency of the rigid spectrum allocation in traditional wavelength division multiplexing (WDM) networks, a flexible grid networking paradigm for spectrum allocation has been recently proposed. On these Flexible-Grid Optical Networks, the spectrum is not rigid, but flexible so that spectrum resources can be adaptively provided to client traffic demand. Spectrum allocation is performed by a process known in the literature as the Routing and Spectrum Assignment (RSA). The performance improvement imparted by RSA algorithms on currently proposed Flexible-Grid Optical Networks is a subject of current extensive investigation. In this paper, we propose a spectrum assignment algorithm based on First-Fit spectrum ordering, where slots are prioritized regarding to the number of forms how future variable-bandwidth path requests can be assigned. Case studies were carried out in order to analyze the benefits of the proposal. In the scenarios analyzed the proposed algorithm outperformed traditional First-Fit assignment. [ABSTRACT FROM AUTHOR]