Link-Level Resource Allocation for Flexible-Grid Nonlinear Fiber-Optic Communication Systems

Resource allocation for transport optical networks has traditionally used a transmission reach constraint to estimate physical impairments. For flexible-grid networks, nonlinear impairments are not sufficiently well characterized by the transmission reach since various modulations and bandwidths can coexist on the same link. We propose a resource allocation algorithm for a single flexible-grid fiber link based on a nonlinear signal distortion model, as a first step toward whole-network design. An optimization problem is formulated to provide a close-to-optimal resource allocation that guarantees the quality of transmission for every channel. Compared with a simpler algorithm based on transmission reach, our proposed algorithm shows the potential of bandwidth savings. It is demonstrated to be insensitive to channel ordering.