A novel adaptive restoration algorithm for cost minimization of translucent optical networks

The cost of translucent optical networks is mainly associated to the deployed optoelectronic devices, some of them used for traffic insertion, others (3R devices) for coping with optical layer transmission constraints (regeneration and wavelength conversion). When designing a network with a required traffic resiliency, operators want to reduce the overall number (hence the cost) associated to optoelectronic devices at the optical layer without incurring in traffic blocking. In generalized multiprotocol label switching (GMPLS)-based optical networks the computation and set-up of alternative paths after fiber failures (restoration) ensure traffic survivability. In such networks 3Rs can be either associated to a specific nominal path (nominal-3Rs) or shared among several restoration paths (restoration-3Rs). An effective computation of restoration paths allows to maximize restoration-3Rs sharing, hence to minimize the network cost. In this work, we focused on the path computation of restoration paths to improve restoration3Rs sharing. To this aim, we propose an adaptive alternative routing algorithm which is aware of the already deployed restoration-3Rs and favors the computation of alternative restoration paths able to reuse already installed 3Rs. The advantages of the proposed method are estimated by comparing the number of restoration-3Rs with respect to another method available in the literature.