Power conservation and carbon footprint reduction has been embraced by ITU as a necessary goal. ITU-T has been exploring potential solutions to improve power conservation through reduced power consumption and other techniques within optical access networks. These solutions can have an impact on improving equipment performance and service longevity in battery-powered operation, as well as on power conservation and CO 2 emissions in general. While this Supplement focuses on GPON power savings, the results are expected to be applicable at least in part to GEPON as well as to NG-PON optical access.