QoT-aware elastic bandwidth allocation and spare capacity assignment in flexible island-based optical transport networks under shared risk link group constraints

This paper focuses on the problem of provisioning multi-granularity static lightpath connections with fault-tolerant requirements in survivable island-based translucent optical networks with traffic grooming capabilities. The problem is tackled for the first time, to the best of our knowledge, taking into account both Quality of Transmission (QoT) and Shared Risk Link Group (SRLG) constraints. A two phase heuristic algorithm is proposed relying on a novel generic purpose-built auxiliary graph model that may support various factors of network heterogeneity (i.e., network nodes with different wavelength-conversion, regeneration and traffic grooming capabilities), and represent numerous network constraints related mainly to QoT requirements and network-resources. The purpose of the proposed heuristic is to optimize the utilisation of the available network resources and hence the network throughput through the simultaneous use of traffic grooming and two resource sharing techniques namely the Generalized Backup-Backup multiplexing (GBBM) and the Generalized Adaptive Primary-Backup Multiplexing (GAPBM) which are combined for the first time, as far as we know, under a static traffic scenario, and performed in such a way that 100% QoT-aware SRLG-fault recoverability is still guaranteed for all serviced lightpath requests. The performances of the proposed solution are demonstrated through multiple simulation experiments conducted on different network topologies.