3GPP 38.300 v19.3.0 — the document's own text
4.10.1 Architecture
Taught in 4. What NR actually is, in the shape its own document gives it (TSG RAN — the group that specifies the radio, overview).
Figure 4.10.1-1 shows a logical architecture for the NR Femto node to connect via the NG interface to the 5GC.
NOTE: The SeGW and NR Femto Mgmt System are out of RAN scope.
The NR Femto node may directly connect to the 5GC. The NG-RAN architecture may also deploy an NR Femto Gateway (NR Femto GW) to allow the concentration of the NG-C interface between NR Femto nodes and the 5GC. Based on implementation, the transport of NG-U between NR Femto nodes and the 5GC may be optionally concentrated in the NR Femto GW.
For the NR Femto node, the NG-C interface is defined as the interface:
- Between the NR Femto GW and the Core Network;
- Between the NR Femto node and the NR Femto GW;
- Between the NR Femto node and the Core Network.
The NR Femto GW appears to the AMF as a gNB. The NR Femto GW appears to the NR Femto node as an AMF. The NG interface between the NR Femto node and the 5GC is the same regardless whether the NR Femto node is connected to the 5GC via an NR Femto GW or not.
The functions supported by the NR Femto node shall be the same as those supported by a gNB (with possible exceptions e.g. NAS Node Selection Function when the NR Femto node connects via the NR Femto GW) and the procedures run between an NR Femto node, the NR Femto GW and the 5GC shall be the same as those between a gNB and the 5GC with specific handling as specified in clause 4.10.2.
Xn-connectivity is supported between NR Femto nodes and between NR Femto nodes and gNBs, independent of whether any of the involved NR Femto nodes is connected to an NR Femto GW. One NR Femto node serves one or more cells.