The present document is part of a TS-family covering the 3rd Generation Partnership Project Technical Specification Group Services and System Aspects Management and orchestration of networks, as identified below:
TS 28.540:
Management and orchestration of 5G networks; Network Resource Model (NRM); Stage 1.
TS 28.541:
Management and orchestration of 5G networks; Network Resource Model (NRM); Stage 2 and stage 3.
The present document specifies the requirements for the Network Resource Model (NRM) definition of NR, NG-RAN, 5G Core Network (5GC) and network slice, to support the management for:
variety of 5G radio access network functions and features, covering management for NR connectivity options defined in TS 37.340 and NG-RAN architectural options defined in TS 38.401.
variety of 5GC network functions and features defined in TS 23.501.
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
For the purposes of the present document, the terms and definitions given in TR 21.905 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.
5G Core Network:
For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.
5GC
According to NG-RAN architecture defined in TS 38.300, An NG-RAN node is either a gNB or an ng-eNB connected to 5GC.
A gNB may consist of a gNB-CU and one or more gNB-DU(s), and a gNB-CU may consist of a gNB-CU-CP and one or more gNB-CU-UP. From functional split point of view, there have following gNB deployment scenarios which are specified in TS 38.401:
gNB which does not consist split function.
gNB which consists of gNB-CU and gNB-DU(s).
gNB which consists of gNB-CU-CP, gNB-CU-UP(s) and gNB-DU(s).
Abovementioned deployment scenarios apply to en-gNB also.
Part of gNB (e.g. gNB-CU) can be deployed as virtualized network function.
Besides single connectivity operation, E-UTRAN, NR and NG-RAN support Multi-RAT Dual Connectivity (MR-DC) operation defined in TS 37.340, which can be further divided into following two categories based on connected core network types.
MR-DC with the EPC via EN-DC, the NR node in EN-DC is called en-gNB.
MR-DC with the 5GC via either NG-RAN E-UTRA-NR Dual Connectivity (NGEN-DC) or NR-E-UTRA Dual Connectivity (NE-DC).
There are different user plane connectivity options of the master node and secondary node involved in MR-DC (see detail in TS 37.340).
The 5G architecture is defined as service-based and the interaction between network functions is represented in the following two ways:
Service-based representation
Reference point representation
The network functions composed 5GC is specified in TS 23.501, network functions within the 5GC control plane shall only use service-based interfaces for their interactions.
5G system architecture allows UDM, PCF and NEF to store their data in the Unified Data Repository (UDR), and allows any NF to store and retrieve its unstructured data (e.g. UE context) into/from a UDSF.
When deploying AMF Region or AMF Set, AMF load balancing insides AMF Region/AMF Set is achieved by setting a weight factor for each AMF according to its relative capacity compared to other AMFs, see detail in clause 5.19.3 of TS 23.501.
Edge computing enables operator and 3rd party services to be hosted close to the UE's access point of attachment, so as to achieve an efficient service delivery through the reduced end-to-end latency and load on the transport network, see details in clause 5.13 of TS 23.501.
A remote interference scenario may involve a number of victim and aggressor cells, where the gNBs execute Remote Interference Management (RIM) coordination on behalf of their respective cells. Aggressor and victim gNBs or cells can be grouped into semi-static sets, where each cell is assigned a set ID, and is configured with a RIM Reference Signal (RIM-RS) and the radio resources associated with the set ID. As defined in TS 38.300.
Access control ensures that an MnS provided by an MnS producer can be consumed only by an authenticated entity with appropriate authorization as specified in TS 28.533.
The following specific requirements apply to management of 5GC NFs:
REQ-5GC_NRM-CON-001:
The NRM definitions shall support management of 5GC containing variety of network functions defined in TS 23.501.
REQ-5GC_NRM-CON-002:
The NRM definitions should support management of all the relationships between network functions and corresponding data storage functions where the network functions store/retrieve their data.
REQ-5GC_NRM-CON-003:
The NRM definitions shall support management of interworking between 5GC and EPC.
REQ-5GC_NRM-CON-004:
The NRM definitions shall support management of network slicing feature in 5GC.
REQ-5GC_NRM-CON-005:
The NRM definitions shall support management of 5GC network function services independently to align with requirements of TS 23.501.
REQ-5GC_NRM-CON-006:
The NRM definitions shall support NF service instance registration, deregistration, update, etc., with NRF during NF service instance lifecycle to align with requirements of TS 23.501 and TS 23.502.
REQ-5GC_NRM-CON-007:
The NRM definitions shall support configuration of NF profile for NF Service registration and discovery to align with requirements of TS 23.501 and TS 23.502.