Nonlinear Impairment-Aware Static Resource Allocation in Elastic Optical Networks

Magazine article, 2015

This paper studies the routing, modulation format, and spectrum allocation problem in elastic fiber-optical networks for static traffic. Elastic networks, based on Nyquist wavelength-division multiplexing or optical orthogonal frequency-division multiplexing, can efficiently utilize the optical fiber's bandwidth in an elastic manner by partitioning the bandwidth into hundreds or even thousands of subcarriers. Beside the amplified spontaneous emission noise, the nonlinear impairments of each connection is explicitly considered by utilizing an analytical model to calculate the nonlinear interference from other connections propagating in the same fibers. The objective of our work is to minimize the bandwidth, i.e., the number of used subcarriers across the network, while satisfying the demands on throughput and quality for all connections. A novel integer linear program formulation and low-complexity heuristics are proposed. Simulation results are presented to demonstrate the effectiveness of the proposed approaches. Compared with transmission reach-based benchmark methods, our methods can achieve up to 31% bandwidth reduction.