School of Specs 38.300v19.3.0

3GPP 38.300 v19.3.0 — the document's own text

4.10.2.1 NR Femto node

Taught in 4. What NR actually is, in the shape its own document gives it (TSG RAN — the group that specifies the radio, overview).

An NR Femto node hosts the same functions as a gNB as described in clause 4.1, with the following additional specifics in case of connecting to the NR Femto GW:

  • Discovery of a suitable NR Femto GW;

NOTE 1: The NR Femto node may be configured with the identity and/or address of an appropriate NR Femto GW.

  • An NR Femto node shall only connect to a single NR Femto GW at one time:
    • The NR Femto node will not simultaneously connect to another NR Femto GW, or another AMF;

NOTE 2: NR Femto nodes may be deployed without network planning. An NR Femto node may be moved from one geographical area to another and therefore it may need to connect to a different NR Femto GW depending on its location.

    • The TAC(s) and PLMN ID(s) used by the NR Femto node shall also be supported by the NR Femto GW;
  • Selection of an AMF at UE attachment is performed by the NR Femto GW:
    • An NR Femto node shall provide any of the GUAMI, GUAMI Type or Requested NSSAI, if received from the UE, to the NR Femto GW in the INITIAL UE MESSAGE message.
  • At Xn handover:
    • Allowing the NR Femto GW to identify the serving AMF at path switch:
      • Including the GUAMI of the serving AMF in the PATH SWITCH REQUEST message;
    • Allowing the AMF to identify the termination of the source UE associated signalling connection:
      • Including the Source AMF UE NGAP ID IE in the PATH SWITCH REQUEST message to the NR Femto GW.
    • Sending the UE CONTEXT RELEASE REQUEST message including a GW Context Release Indication to the NR Femto GW after the successful Xn handover initiated by the NR Femto node, in order to indicate that the NR Femto GW may release the UE context.