Survivable Routing in Spectrally-Spatially Flexible Optical Networks with Back-to-Back Regeneration

In this article, we address the problem of survivable routing in spectrally-spatially flexible optical networks (SS-FONs) with dedicated path protection (DPP). The considered SS-FON supports spectral super-channel transmissions, in which flexible signal regeneration is realized with transceivers operating in back-to-back (B2B) configurations. We propose an Adaptive Survivable Routing with Back-to-Back Regeneration (ASRBR) algorithm to realize dynamic routing requests protected with the DPP method. The ASRBR algorithm is aware of limited spectrum and transceivers resources and makes use of the flexibility of the B2B regeneration. With the use of the ASRBR algorithm, we examine potential performance gains in terms of bandwidth blocking probability (BBP) in two regeneration scenarios: a reference one in which the use of regenerators is minimized and the modulation conversion is not allowed and intentional regeneration with possible modulation conversion. We analyze the efficiency of ASRBR for a set of various network scenarios using two representative topologies. Evaluation results show that the proposed method outperforms other reference algorithms. Moreover, the flexible B2B regeneration provides better utilization of both spectrum and transceiver resources, resulting in lower BBP than the minimal regeneration scenario. Finally, we study potential performance gains from applying a squeezed protection approach.