Content for TS 28.531 Word version: 18.1.0

4.1 Overview 4.2 Configuration information for the constituents of an NSI 4.3 General information for network slice instance 4.4 General information for network slice subnet instance
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4 General p. 8

4.1 Overview p. 8

A 5G system consists of a 5G Access Network (AN), and a 5G Core Network (5GC). Network slicing is one of the key 5G features.

The management aspects of a Network Slice Instance (NSI) are described by the four phases shown in Figure 4.3.1.1 of TS 28.530.

The provisioning of network slicing includes the four phases which are preparation, commissioning, operation and decommissioning:

In the preparation phase the NSI does not exist. The preparation phase includes network slice design, on-boarding, evaluation of the network slice requirements, preparing the network environment and other necessary preparations required to be done before the creation of an NSI.
During the NSI lifecycle stage which include commissioning phase, operation phase and decommissioning phase, the NSI provisioning operations include:
- Create an NSI;
- Activate an NSI;
- Deactivate an NSI;
- Modify an NSI;
- Terminate an NSI.

The operations of the provisioning of an NSI occurs during different phases of a NSI:

During the commissioning phase:
- Create an NSI.
During NSI creation all resources to the NSI have been created and configured to satisfy the network slice requirements. NSI creation may trigger NSSI(s) creation or using existing NSSI(s) and setting up the corresponding associations.
During the operation phase:
- Activate an NSI;
- Modify an NSI;
- Deactivate an NSI.
NSI activation includes any actions that make the NSI active to provide communication services. NSI activation may trigger NSSI activation.
NSI modification in operation phase could map to several workflows, e.g. changes of NSI capacity, changes of NSI topology, NSI reconfiguration. NSI modification can be triggered by receiving new network slice related requirements, new communication service requirements, or the result of NSI supervision automatically. NSI modification may trigger NSSI modification.
The NSI deactivation operation may be needed before NSI modification operation and the NSI activation operation may be needed after the NSI modification operation. NSI deactivation includes any actions that make the NSI inactive and not providing any communication services. NSI deactivation trigger NSSI deactivation to deactivate constituent NSSI(s) which is not used by other NSI(s). Operator may decide to keep the NSI without termination after deactivation and reactivate it when receives new communication service request.
During the decommissioning phase:
- Terminate an NSI.
NSI termination step includes any action that make the NSI does not exist anymore and release resources that are not used by other NSI(s). NSI termination may trigger NSSI termination to terminate constituent NSSI(s) which is not used by other NSI(s).

Similarly, provisioning for network slice subnet instance includes the following operations:

Create an NSSI;
Activate an NSSI and associate it with certain NSI to be used by the NSI;
Disassociate the NSSI with certain NSI and deactivate the NSSI if it's not associated with any NSI;
Modify an NSSI;
Terminate an NSSI.

4.2 Configuration information for the constituents of an NSI p. 10

To use network slice to support communication service or deliver a network slice as a service, the 3GPP defined constituents of the NSI should be configured by 3GPP management system according to the types and requirements of the network slice so that the NSI can be operated and maintained.

The configuration information of these components may include:

Information on the requirements to be applied to every NSI constituent to satisfy the requirements of multiple NSIs if the constituent is shared by multiple NSIs;
Network function selection information: Information on the selection of the NFs (e.g., AMF) according to the requirements of this NSI;
Connection information: The information of the logical links to carry the NSI's CP and UP data between the component and other NFs and NSSIs belonging to the NSI.

4.3 General information for network slice instance p. 10

The general information used to describe a network slice instance may include:

Resource model information, which describes the static parameters and functional components of network slice, includes service profile, network slice type (e.g. eMBB), additional system feature (e.g. multicast, Edge Computing), priority.
Management model information, which describes the information model that is used for network slice lifecycle management, includes configuration profile (e.g. application configuration parameters).
Capability model information, which describes the capability including supported communication service characteristic information (e.g. service type, UE mobility level, density of users, traffic density), QoS attributes (e.g. bandwidth, latency, throughput and so on) and capacity (e.g. maximum number of UEs), can be exposed to CSC .

4.4 General information for network slice subnet instance p. 10

The general information used to describe a network slice subnet instance may include:

Resource model information, which describes the static parameters and functional component of network slice subnet, includes slice profile, network slice subnet type (e.g. RAN eMBB, CN eMBB), additional system feature (e.g. multicast, Edge Computing), priority, QoS attributes (e.g. bandwidth, latency, number of subscribers and so on), NSD ID.
Management model information, which describes the information model that is used for network slice subnet lifecycle management, includes configuration profile (e.g. application configuration parameters).
Capability model information, which describes the capability including supported communication service characteristic information (e.g. service type, UE mobility level, density of users, traffic density), QoS attributes (e.g. bandwidth, latency, throughput and so on) and capacity (e.g. maximum number of UEs).