Acknowledgements This Technical Report was prepared by Giampiero Nanni (Symantec), in collaboration with Ziqin Sang (Fiberhome Technologies Group). The authors wish to acknowledge the guidance and support from all the members of the ITU‐T FG‐SSC Management Team, and especially Paolo Gemma (Huawei), Angelica V. Ospina (University of Manchester), Michael Mulquin (IS Communications Ltd), Sian John (Symantec), Wei Qin (Fiberhome Technologies Group) who have provided constructive comments towards the successful completion of this Technical Report. 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 at tsbsg5@itu.int.