Integrating energy efficiency from end to end
However, energy savings may reduce or deteriorate either QoS or protection guarantees. These aspects should be taken into due account to ensure that energy saving techniques become a reality in operational networks. For example, the possible service disruption due to adaptation should be avoided and thus devices that implement the power saving modes and quick wake-up mechanisms need to be developed. Even though, service disruption may occur due to the standby mode, for example in ONUs. services should thus also support standby of equipment . This means that energy efficiency should be considered from end to end.