On the effect of in-band crosstalk margins for optimized format selection in meshed optical networks

A framework for analyzing in-band crosstalk accumulation in ROADM-based optical networks

“…This interference is particularly harmful when both the signal and interference have the same nominal wavelength leading to the in-band crosstalk [4], which accumulates as the optical signal propagates along the lightpath in a network. The impact of this impairment on system performance for ROADM-based networks has been widely analyzed in the literature at the physical layer level for different modulations formats, considering the dependence of crosstalk accumulation on the number of cascaded April 22, 2020 ROADM nodes [3][4][5][6].…”

“…Another important aspect is to understand how in-band crosstalk accumulation influences network design. Numerous publications dealt with this issue, both in the context of dynamic networks [7][8][9][10] and in the context of static networks [11,12]. Reference [11] is a seminal work in the area, but the node structure considered is a quite simple one and the analysis is only applied to ring networks.…”

“…The work in [12] also tried to reduce its impact by assigning spectrum in such a way that the number of optical channels that interfere in each node is minimum. In [10] a channel provisioning policy that takes into account the in-band crosstalk levels in order to decide the best transmission channel format and spectrum assignment to be used is developed. However, most of the referred works failed to present a detailed analysis of the origin of the in-band crosstalk inside of multi-degree ROADMs, preventing an adequate understanding of the dependency of the number of crosstalk terms on node parameters and CDC properties.…”

“…However, most of the referred works failed to present a detailed analysis of the origin of the in-band crosstalk inside of multi-degree ROADMs, preventing an adequate understanding of the dependency of the number of crosstalk terms on node parameters and CDC properties. The only exception is [10], but the analysis presented is only focused on CD ROADM architectures and the study is based on a particular RWA algorithm.…”

“…With this information the number of crosstalk terms, at the receiver end, in a given lightpath can be computed. In addition, an empirical formula, which permits to quantify this number of accumulated crosstalk terms as a function of the network topology parameters is also derived, and the results April 22, 2020 are compared with the ones obtained with the proposed framework. Note that by knowing this number the performance degradation in terms of the bit error rate can be easily evaluated by relying on an appropriate model that takes into account the impact of crosstalk on system performance evaluation (see for example [4], [15]).…”