QoT Assessment of the Optical Spectrum as a Service in Disaggregated Network Scenarios

TL;DR

This paper evaluates the quality of optical spectrum as a service in disaggregated networks using live network data, focusing on GSNR-based QoT assessment and optimization techniques for improved capacity and margins.

Contribution

It introduces a method combining channel probing, spectral sweeping, and regime detection to assess and optimize OSaaS performance in live networks.

Findings

Achieved 0.05 dB GSNR estimation accuracy for wide-band services

Demonstrated spectral misalignment and ripple detection capabilities

Proposed continuous channel probing for network optimization

Abstract

The potential to operate third-party terminals over multi-domain transparent optical networks attracts operators and customers to implement Optical Spectrum as a Service (OSaaS). As infrastructure information cannot always be shared with OSaaS end customers, alternatives to off-line Quality of Transmission (QoT) estimation tools are required to assess the performance of the spectrum slot in order to estimate achievable throughput. In this paper, commercially available sliceable coherent transceivers are used to assess the Generalized Signal To Noise Ratio (GSNR) based QoT of the OSaaS in a live production network for both, narrow-band and wide-band OSaaS configurations. Extended channel probing based on symbol rate variability is combined with spectral sweeping and operation regime detection to characterize OSaaS implementations on 17 links with different underlying infrastructure configurations in order to maximize capacity and increase service margins in a low-margin operation regime. We achieve 0.05 dB estimation accuracy in GSNR for a wide-band spectrum services and 0.32 dB accuracy for narrow-band spectrum services. Based on the GSNR profile, spectral misalignment, spectral ripple, and operation regime are detected and service margin improvements are demonstrated. Finally, we discuss the network optimization perspective based on acquired data from channel probing and propose use-cases for continuous channel probing in transparent optical networks.