3GPP 23.501 v20.2.0 — the document's own text
5.51.5 Subscription information aspects
Taught in 27. Overload, energy, deployment and the rest (The 5G system architecture, in depth).
The Subscription data for a UE may include an Energy Saving Indicator that the UE is subject to network energy saving operation. The values of the Energy Saving Indicator point to energy saving behaviour configured in the PCFs of the network. The possible energy saving behaviours for a network and the mapping of the Energy Saving Indicator values to the respective behaviour are operator-defined and outside the scope of this specification. The AMF receives the Energy Saving indicator in the UE Subscription data. The AMF forwards the Energy Saving indicator to the PCF.
The Energy Saving Indicator may be obtained by the PCF from the Policy Data in the UDR.