Impairment-aware routing, modulation, spectrum, and core allocation with bit loading in spectrally–spatially flexible optical networks

Abstract

This work proposes a physical layer impairment-aware routing, modulation, spectrum, and core allocation optimization framework in elastic optical networks with multi-core fibers. The inter- and intra-core impairments considered are crosstalk between adjacent cores, in-band crosstalk, non-linear interference, and amplified spontaneous emission noise. Further, bit loading is used in the proposed framework, independently modulating each demand’s frequency slots, depending on each frequency slot’s interference level. An optimization framework is initially developed for benchmarking purposes, followed by a heuristic algorithm and demand ordering technique for larger-sized networks. For both optimization and heuristic approaches, an end-to-end acceptable bit error rate is ensured for each provisioned demand. The benefits of the proposed approach are illustrated through simulations, demonstrating that they achieve lower fragmentation and less spectrum usage as compared to other state-of-the-art techniques.

A New Algorithm to Mitigate Fragmentation and Crosstalk in Multi-Core Elastic Optical Networks

“…In addition to classical spectrum allocation policies, many works in the literature have investigated more efficient ways to improve resource allocation in SDM-EON. Some of these works propose XT-aware strategies to deal with the problem of inter-core crosstalk [11][12][13][14][15][16][17][18][19][20][21][22]. On the other hand, the XT-avoid strategies appear as a low computational cost option [13,[23][24][25][26].…”

“…All related works deal with inter-core crosstalk either by the XT-avoid or XT-aware approaches. Related to the spectrum fragmentation issue, some works implement mechanisms to reduce fragmentation in the resource allocation process [12,[17][18][19][20][21]23,24]. Some of these works were performed through a static traffic matrix, while others generated arrivals and ends of new requests dynamically.…”

“…Therefore, the algorithms compared to the proposed algorithm on performance evaluation (Section 5) are also XT-avoid, and are designed for dynamic traffic. [24] yes yes XT-avoid dynamic 7 [11] yes no XT-aware dynamic 3, 7, and 12 [12] yes yes XT-aware dynamic 7 [25] yes no XT-avoid dynamic 7 [13] yes no XT-avoid dynamic 7 and 19 [14] yes no XT-aware static 3 and 7 [26] yes no XT-avoid dynamic 7 [15] yes no XT-aware static 3, 7, and 19 [16] yes no XT-aware static 6 and 7 [17] yes yes XT-aware dynamic 3 and 7 [18] yes yes XT-aware dynamic 7 [19] yes yes XT-aware static 7 [20] yes yes XT-aware dynamic 7 and 12 [21] yes yes XT-aware dynamic 7 [22] yes no XT-aware dynamic 7…”