SRS-Proactive-Aware Resource Allocation Based on All-Optical Wavelength Converters in C+L Band Optical Networks

C+L band optical line systems are a promising scenario to meet future network capacity upgrades. While expanding the transmission capacity, this technology has also aggravated the influence of stimulated Raman scattering (SRS) which leads to reduced Signal-to-Noise Ratio (SNR). If the resource allocation is always pursuing the improvement of SNR, the possibility of generating spectrum fragments will increase, thereby reducing the spectrum efficiency. However, higher spectrum efficiency is very likely to be at the expense of SNR, because the spectrum occupation may be too close to decrease SRS. Therefore, there is a balanced relationship between the SNR and spectrum utilization. In this paper, we use C+L optical cross connect (C+L-OXC) based on all-optical wavelength converters to break spectrum contiguity constraints. In view of this, we establish a two-dimensional frequency-time slot model that considers the negative impact of newly arriving services on the SNR of the already carried services, ensuring optimal transmission time when the link load is minimized. Additionally, each service occupies the spectrum resources with the target of the least number of fragments, thereby enhancing spectrum efficiency. This approach effectively resolves the tradeoff between network average SNR and spectrum efficiency by decoupling them from each other. We have established an experimental platform for optical switching, and the experimental results show that the proposed algorithm improves the average SNR in the C+L band, and can effectively optimize the spectrum utilization to improve the spectrum efficiency.