Algorithms for maximizing spectrum efficiency in elastic optical path networks that adopt distance adaptive modulation

Recent Advances in Elastic Optical Networking

“…Optical channels with a wide variety of spectrum widths are aligned using the minimum required guardbands between adjacent channels. Numerical evaluations of the traffic-accommodation efficiency have shown that elastic optical networks with adaptive spectrum allocation offer enhanced spectrum efficiency and better blocking probability Copyright c 2014 The Institute of Electronics, Information and Communication Engineers than fixed-grid fixed-modulation-format networks [3], [5], [6]. However, the increased complexity created by the parameters needed for realizing flexibility requires a truly sophisticated network design scheme.…”

“…A basic evaluation showed that distance-adaptive modulation can reduce spectrum resource requirements by more than 45 percent compared to ITU-T 100 GHz fixed grid [2]. Efficient RSA algorithms with distance-adaptive modulation are detailed in [6]. Similar solutions are referred to as routing, modulation level and spectrum assignment (RMLSA) algorithms [5].…”

Elastic Optical Path Network Architecture: Framework for Spectrally-Efficient and Scalable Future Optical Networks

“…Fortunately, stranded spectrum fragments can be reduced to a practically negligible level by employing sophisticated routing and spectrum assignment (RSA) algorithms that consider the spectrum-continuity constraint in the longitudinal direction as well as the spectrum adjacency constraint [11], [16], [17]. We compared provisional network Fig.…”

“…As shown in Fig. 6, if we employ RSA algorithms based on, for example, the first fit (FF) [11] algorithm or the maximize common large segment (MCLS) algorithm [16], which are intended to choose carefully the spectral segment assigned to each elastic optical path in order to retain as much as possible contiguous spectra for future utilization, we can minimize the influence of spectral fragmentation to within 4% to 7% based on the spectral adjacency constraint, while receiving the full benefits of spectral savings through the introduction of elastic and adaptive spectral resource allocation as descried in [9] and [11].…”

Spectrum Continuity and Contiguity based Dedicated Protection for Flexible Optical Networks

“…Takagi et al [15] proposed some algorithms to solve the RSA problem considering dedicated and shared path protection in EONs. The developed algorithms are based on an integer linear programming (ILP) model.…”