Flexible-grid Elastic Optical Networks (EONs) have been widely deployed in recent years to support the growing demand for bandwidth-intensive applications. To address this cost-efficiently, optimized utilization of EONs is required. Next-generation bandwidth-variable transceivers (BVTs) will offer increased adaptivity in symbol rate as well as modulation through probabilistic constellation shaping. In this work, we therefore investigate the impact of increased configuration granularity on various aspects of optical networks. We account for practical implementation considerations of BVT configurations for the estimation of the required signal-to-noise ratio. Additionally, an optimization algorithm is presented that selects the most efficient configuration for each considered data rate and bandwidth combination. Based on the advanced transceiver configurations, we conduct a network planning study using a physical-layer-aware algorithm for flexible-grid EONs, and present results for a national and a continental optical backbone network topology. Our research demonstrates that a rise in modulation rate adaptivity results in substantial savings in resources, decreasing the number of necessary lightpaths by as much as 20% in EONs. In contrast, increased symbol rate granularity only results in minor savings.

翻译：近年来，为支持日益增长的带宽密集型应用需求，灵活栅格弹性光网络（EONs）已广泛部署。为实现成本效益，需要优化EONs的利用率。下一代带宽可变收发器（BVTs）将通过概率星座整形在符号率和调制方式上提供更高的适应性。本研究因此探讨了配置粒度增加对光网络多方面的影响。在估计所需信噪比时，我们考虑了BVT配置的实际实现因素。此外，我们提出了一种优化算法，可为每个特定数据速率和带宽组合选择最有效的配置。基于先进的收发器配置，我们采用物理层感知算法对灵活栅格EONs进行网络规划研究，并展示了国家及洲际光骨干网络拓扑的结果。研究表明，调制速率自适应性的提升可带来显著的资源节约，将EONs中所需光路径数量减少多达20%。相比之下，符号率粒度的增加仅能带来微小节约。