Acknowledgements This Technical Report was researched and authored by Ziqin Sang (Fiberhome Technologies Group), Hongqing Ding (Fiberhome Technologies Group), Masayuki Higashi (Japan), Jiro Nakamura (NTT), Minako Hara (NTT), Takafumi Hashitani (Fujitsu), Junnosuke Sugiura (Fujitsu), Claudio Di Carlo (Italy), Paola Girdinio (Genoa University), Raffaele Bolla (Genoa University), Paolo Gemma (Huawei), Dewei Xu (Fiberhome Technologies Group), Jia Guo (Fiberhome Technologies Group), Pernilla Bergmark (Ericsson), Lelio Digeronimo (Avina) and Luis Castiella (San Andrés University) The authors wish to extend their gratitude to Ramy Ahmed Fathy (NTRA, Egypt), Michael Mulquin (IS Communications), Angelica V Ospina (University of Manchester), Mythili Menon (University of Geneva), Erica Campilongo (International Telecommunication Union) and Cristina Bueti (International Telecommunication Union) for their valuable inputs and support. The authors also acknowledges the guidance and support from all the members of the ITU‐T FG‐SSC Management Team. Additional information and materials relating to this Technical Report can be found at: www.itu.int/itu‐t/climatechange. If you would like to provide any additional information, please contact Cristina Bueti (ITU) at tsbsg5@itu.int.