On the Benefits of Rate-Adaptive Transceivers: A Network Planning Study

TL;DR

This study evaluates how rate-adaptive transceivers with increased configuration granularity can optimize resource utilization in flexible-grid elastic optical networks, showing significant savings in network resources.

Contribution

It introduces an optimization algorithm for selecting efficient transceiver configurations and demonstrates the benefits of increased modulation rate adaptivity in network planning.

Findings

Up to 20% reduction in lightpaths with higher modulation rate adaptivity.

Minor resource savings from increased symbol rate granularity.

Network planning benefits from advanced transceiver configurations.

Abstract

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.