Optical Spectrum as a Service (OSaaS) spanning over multiple transparent optical network domains, can significantly reduce the investment and operational costs of the end-to-end service. Based on the black-link approach, these services are empowered by reconfigurable transceivers and the emerging disaggregation trend in optical transport networks. This work investigates the accuracy aspects of the channel probing method used in Generalized Signal to Noise Ratio (GSNR)-based OSaaS characterization in terrestrial brownfield systems. OSaaS service margins to accommodate impacts from enabling neighboring channels and end-of-life channel loads are experimentally derived in a systematic lab study carried out in the Open Ireland testbed. The applicability of the lab-derived margins is then verified in the HEAnet production network using a 400 GHz wide OSaaS. Finally, the probing accuracy is tested by depleting the GSNR margin through power adjustments utilizing the same 400 GHz OSaaS in the HEAnet live network. A minimum of 0.92 dB and 1.46 dB of service margin allocation is recommended to accommodate the impacts of enabling neighboring channels and end-of-life channel loads. Further 0.6 dB of GSNR margin should be allocated to compensate for probing inaccuracies.

翻译：摘要：跨越多域透明光网络的光谱即服务(OSaaS)可显著降低端到端服务的投资与运营成本。基于黑链路方法，这类服务依托可重构收发器及光传输网络新兴的去聚合趋势得以实现。本研究聚焦于棕色地带陆地系统中基于广义信噪比(GSNR)的OSaaS表征所采用的信道探测方法的精度问题。通过在Open Ireland测试平台开展的系统性实验室研究，实验推导了OSaaS服务余量，以应对启用相邻信道及生命周期信道负载带来的影响。随后，利用400 GHz宽频OSaaS在HEAnet生产网络中验证了实验室推导余量的适用性。最后，通过在HEAnet现网中利用同一400 GHz OSaaS进行功率调整耗尽GSNR余量，测试了探测精度。建议分配至少0.92 dB和1.46 dB的服务余量，以分别应对启用相邻信道及生命周期信道负载的影响。此外，应额外分配0.6 dB的GSNR余量用于补偿探测误差。