7 Provisioning procedures of networks and network slicing

28.5313GPPManagement and orchestrationProvisioningRelease 16TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

7.1 General

The procedures of provisioning of 5G networks are listed in this following subclauses.

7.2 Procedure of Network Slice Instance Allocation

The Figure 7.2-1 illustrates the procedure of creating a new NSI or using an existing NSI to satisfy the required network slice related requirements.

Figure 7.2-1: Network Slice Instance Allocation Request procedure

1) Network Slice Management Service Provider (NSMS_Provider) receives an AllocateNsi request (see AllocateNsi operation defined in clause 6.5.1) from Network Slice Management Service Consumer (NSMS_Consumer) with network slice related requirements (the network slice related requirements are defined as the attributes in the ServiceProfile see clause 6.3.3 in TS 28.541 [6]).

2) Based on the network slice related requiremen and the knowledge of the capabilities of existing deployed network slices, the NSMS_Provider compare/match the provided requirements against all the candidate NetworkSlice instances, and then decides whether to use an existing NSI or create a new NSI. If the network slice related requirements allow the requested NSI to be shared and if an existing suitable NSI can be reused, the NSMS_Provider may decide to use the existing NSI.

3a) If using an existing NSI and the existing NSI needs to be modified to satisfy the network slice related requirements, the NSMS_Provider invokes the procedure to modify the existing NSI as described in clause 7.6.

3b-1) If creating a new NSI, the NSMS_Provider derives the network slice subnet related requirements from the received network slice related requirements. Before NSMS_Provider derives the network slice subnet related requirements, NSMS_Provider may invoke corresponding network slice subnet capability information querying procedure as described in clause 7.8.

3b-2) The NSMS_Provider invokes the NSSI allocation procedure as described in clause 7.3.

3b-3) The NSMS_Provider creates the MOI for NSI and configures the MOI with the DN of MOI for the NSSI, other configuration information may be configured for the created MOI.

Note: The detailed configuration information is described in network slice NRM (see NetworkSlice IOC defined in clause 6.3.1 in TS 28.541 [6]).

4) The NSMS_Provider sends NSI allocation result (see AllocateNsi operation defined in clause 6.5.1) to the NSMS_Consumer. If an existing NSI is modified or a new NSI is created successfully to satisfy the network slice related requirements, the result includes the relevant network slice instance information (see NetworkSlice IOC defined in clause 6.3.1 in TS 28.541 [6]):

– DN of the MOI for NSI.

Otherwise the result may include the reason of failure, for example, the required latency or user number cannot be satisfied, or the physical resource is not enough.

7.3 Procedure of Network Slice Subnet Instance Allocation

The Figure 7.3-1 illustrates the procedure of creating a new network slice subnet instance or using an existing network slice subnet instance to satisfy the required network slice subnet related requirements.

Figure 7.3-1: Network Slice Subnet Instance Allocation Request procedure

1) Network Slice Subnet Management Service Provider (NSSMS_P) receives an AllocateNssi request (see AllocateNssi operation defined in clause 6.5.2) from Network Slice Subnet Management Service Consumer (NSSMS_C) with network slice subnet related requirements (network slice subnet related requirements defined in SliceProfile see clause 6.3.4 in TS 28.541 [6]).

2) NSSMS_P check the feasibility of network slice subnet related requirements. If the network slice subnet related requirements can be satisfied, the following step 3) are needed, else go to step 5).

3) Based on the network slice subnet related requirements and the existing NSSI capabilities, NSSMS_P decides whether to use an existing NSSI or create a new NSSI. If the network slice subnet related requirements allow the requested NSSI to be shared and if an existing suitable NSSI can be reused, the NSSMS_P decides to use the existing NSSI.

4.1a) If using an existing NSSI and the existing NSSI needs to be modified to satisfy the network slice subnet related requirements, the NSSMS_P invokes the procedure to modify the existing NSSI as described in clause 7.7.

4.1b.1) If creating a new NSSI, the NSSMS_P creates the MOI for the NSSI to be created. NSSMS_P derives the corresponding network slice subnet constituent (i.e. NF, constituent NSS) related requirements and transport network related requirements (e.g. 3GPP endpoint information, latency requirements, bandwidth requirements, isolation requirements) from the received network slice subnet related requirements. Before NSSMS_Provider derives the constituent network slice subnet related requirements, NSMS_Provider may invoke corresponding network slice subnet capability information querying procedure as described in clause 7.8.2.

4.1b.2) If the NSSI to be created contains virtualisation part (i.e. VNF or VL), NSSMS_P derives the NS instance instantiation information (the NS instance instantiation information is described in clause 7.3.2.2 and clause 7.3.3.2 [3]) based on network slice subnet related requirements. NSSMS_P determines VNF instance(s) that need to be deployed according to the necessary network function(s) and then derives the profile of virtual link(s) according to the connection requirements between the network functions. NSSMS_P chooses a proper NSD deployment flavour and creates data concerning the SAPs of the NS instance. NSSMS_P invokes the NS instantiation procedures to create a NS instance. NSSMS_P configures the NSS MOI with the NS instance identifier.

Note: NS instantiation procedure is described in TS 28.526 [7].

4.1b.3) For each required NSSI constituent, the following step 4.1b.3a) and 4.1b.3b) are needed:

4.1b.3a) If the required NSSI constituent is constituent NSSI, NSSMS_P invokes NSSI Allocation Procedure.

4.1b.3b) If the required NSSI constituent is NF instance, NSSMS_P invokes NF Creation Procedure as described in clause 7.10 or NF Modification Procedure as described in clause 7.11.

4.1b.4) NSSMS_P configures the MOI for NSSI with the DN of the MOI for NSSI constituent (i.e. NF, constituent NSSI).

4.1b.5) For each required transport network related requirements, NSSMS_P invokes corresponding procedure of coordination with relevant TN Manager to handle the TN part as described in clause 7.9.

5) The NSSMS_P sends the NSSI allocation result (see AllocateNssi operation defined in clause 6.5.2) to the NSSMS_C. If the NSSI is created successfully, the result includes the relevant constituent network slice subnet instance information (see NetworkSliceSubnet IOC defined in clause 6.3.2 in TS 28.541 [6]):

– DN of the MOI for NSSI.

– NS instance Info (e.g. NSinstanceId)

Otherwise the result may include the reason of failure, for example, the required latency or user Number cannot be satisfied, or the physical resource is not enough.

7.4 Procedure of Network Slice Instance Deallocation

Figure 7.4-1 depicts the procedure of deallocating a network slice instance by the network slice management service provider to satisfy the NSI deallocation request received from an authorized consumer.

Figure 7.4-1: Network slice instance deallocation procedure

1) The network slice management service provider (NSMS_P) receives a NSI deallocation request (see DeallocateNsi operation defined in clause 6.5.3) from network slice management service consumer (NSMS_C) indicating that the NSI is no longer needed for the consumer.

2) The NSMS_P sends the NSI deallocation response (see DeallocateNsi operation defined in clause 6.5.3) to NSMS_C.

3) The NSMS_P may decide to terminate the NSI, then it invokes the NSSI deallocation procedure as described in clause 7.5.

4) The NSMS_P may decide not to terminate the NSI but to modify the NSI, then it invokes the NSI modification procedure as described in clause 7.6.

7.5 Procedure of network slice subnet instance deallocation

Figure 7.5-1 depicts the procedure of deallocating a network slice subnet instance by the network slice subnet management service provider to satisfy the NSSI deallocation request received from an authorized consumer.

Figure 7.5-1: Network slice subnet instance deallocation procedure

1) The network slice subnet management service provider (NSSMS_P) receives NSSI deallocation request (see DeallocateNssi operation defined in clause 6.5.4) from network slice subnet management service consumer (NSSMS_C).

2) NSSMS_P sends response (see DeallocateNssi operation defined in clause 6.5.4) of NSSI deallocation service to NSSMS_C.

3-a) NSSMS_P may decide to terminate the NSSI, it invokes (constituent) NSSI deallocation procedure as described in clause 7.5 if the NSSI consists of constituent NSSI.

3-b) NSSMS_P invokes NF deletion procedure as described in clause 7.12 only if the NF is dedicated for this NSSI and not being used by any other NSSI in the network, otherwise, the NSSMS_P invokes NF modification procedure as described in clause 7.11.

3-c) NSSMS_P invokes TN related coordination procedure with responsible manager as described in clause 7.9 if the NSSI consists of TN part.

3-d) NSSMS_P invokes NS termination procedure if the NSSI contains virtualized part.

Note: NS termination procedure is described in TS 28.526 [7].

4) NSSMS_P may decide not to terminate the NSSI, it invokes NSSI modification procedure as described in clause 7.7.

7.6 Procedure of Network Slice Instance Modification

The Figure 7.6-1 illustrates the procedure of modifying an existing NSI.

Figure 7.6-1: Network Slice Instance Modification Request procedure

1) Network Slice Management Service Provider (NSMS_P) receives a ModifyNsi request (see modifyMOIAttributes operation defined in TS 28.532 [8]) from Network Slice Management Service Consumer (NSMS_C) with the management identifier of NSI and the new network slice related requirements (see ServiceProfile defined in clause 6.3.3 in TS 28.541[6]).

2) Based on the new network slice related requirements, NSMS_P invokes the feasibility check procedure. If the modification requirements can be satisfied, go to step 3), else go to step 5).

3) NSMS_P decomposes the NSI modification request into NSSI modification request(s), i.e., generating the new network slice subnet related requirements for each NSSI if needed.

4) NSMS_P, as the role of Network Slice Subnet Management Service Consumer (NSSMS_C), invokes the NSSI modification procedure.

5) NSMS_P sends NSI modification result (see modifyMOIAttributes operation defined in TS 28.532 [8]) to NSMS_C.

7.7 Procedure of Network Slice Subnet Instance Modification

The Figure 7.7-1 illustrates the procedure of modifying an existing NSSI.

Figure 7.7-1: Network Slice Subnet Instance Modification Request procedure

1) Network Slice Subnet Management Service Provider (NSSM_SP) receives a ModifyNssi request (see modifyMOIAttributes operation defined in TS 28.532 [8]) from Network Slice Subnet Management Service Consumer (NSSM_SC) with the management identifier of NSSI and the new network slice subnet related requirements (see SliceProfile defined in clause 6.3.3 in TS 28.541[6]).

2) Based on the new network slice subnet related requirements, NSSM_SP invokes the feasibility check procedure. If the modification requirements can be satisfied, go to step 3), else go to step 5).

3) NSSM_SP decomposes the NSSI modification request into modification requests for each NSSI constituent.

4a) If the requested NSSI constituent is constituent NSSI, NSSM_SP invokes NSSI modification procedure as described in clause 7.7.

4b) If the requested NSSI constituent is NF instance, NSSM_SP invokes NF creation procedure as described in clause 7.10 or NF modification procedure as described in clause 7.11.

4c) If the NSSI contains the virtualized part, NSSM_SP invokes the NS instance scaling and/or NS instance updating and/or NS instance instantiation procedure as described in TS 28.526 [7].

4d) If the NSSI contains the TN part, NSSM_SP invokes the TN related coordination procedure as described in clause 7.9.

5) NSSM_SP sends NSSI modification results (see modifyMOIAttributes operation defined in TS 28.532 [8]) to NSSM_SC.

7.8 Procedure of Obtaining Network Slice Subnet Capability

7.8.1 Introduction

The clause illustrates possible procedures of obtaining network slice subnet capability information (e.g. supported maximum latency, supported capacity (e.g. maximum user number)) of network slice subnet instance(s) which can be provided by network slice subnet management service provider.

7.8.2 Querying Network Slice Subnet Capability Information

Figure 7.8-2: Procedure of querying network slice subnet capability information

1) Network Slice Subnet Management Service Consumer (NSSMS_C) wants to query the NSS capability information of the NSSI(s) which can be provided by corresponding Network Slice Subnet Management Service Consumer (NSSMS_P), NSSMS_C sends NSS capability querying request (see getMOIAttributes operation defined in TS 28.532 [8]) to NSSMS_P to obtain the NSS capability information of the NSSI(s) which can be provided by corresponding NSSMS_P.

2) NSSMS_P processes the NSS capability information querying request.

3) NSSMS_P sends the NSS capability information (e.g. supported maximum latency, supported capacity (e.g. user number)) of NSSI(s) that can be provided by itself (see getMOIAttributes operation defined in TS 28.532 [8]) to NSSMS_C.

7.8.3 Void

7.9 Procedure of TN coordination supporting network slicing

7.9.1 Introduction

This clause describes procedures of coordination with TN Manager to handle TN part supporting network slicing.

NOTE: The present document: addresses interactions with NFVO as TN manager,. interactions with other types of TN Manager (e.g. Optical, IP bearer transport network, etc.) have not been addressed.

7.9.2 Interaction with NFVO as TN Manager

This clause considers the procedure of interaction between the 3GPP management system and the NFVO, which behaves as TN Manager, to satisfy the TN related requirements for the virtual links used in NSSI. The procedure is applicable to creation and modification of the NSSI.

Figure 7.9.2-1: Interaction with NFVO as TN manager to support network slicing

1) Network Slice Subnet Management Service Provider (NSSMS_P) derives the TN related requirements (e.g. 3GPP endpoint information, latency requirements, bandwidth requirements, isolation requirements) for the TN part to be used in the NSSI.

2) To satisfy the TN related requirements NSSMS_P invokes the corresponding NS instance lifecycle management procedures as described in TS 28.526 [7].

3) After the NFVO executes the requested operation, it sends the corresponding notification to the NSSMS_P as described in TS 28.526 [7].

7.10 Procedure of NF instance creation

The Figure 7.10-1 illustrates the procedure of creating a new network function instance to satisfy the required network function related requirements.

Figure 7.10-1: Network Function Instance Creation procedure

1) Network Function Management Service Provider (NFMS_P) receives a CreateNf request (see createMOI operation defined in TS 28.532 [8]) from Network Function Management Service Consumer (NFMS_C) with network function related requirements.

Note: The network function related requirements see information model definition for NR NRM in clause 4 and information model definition for 5GC NRM in clause 5 in TS 28.541[6] .

2) If NF instance to be created contains virtualized part, NFMS_P derives the requirements for VNF instance based on the network function related requirements.

3) If corresponding VNF Package needs to be on-boarded or changed, the NFMS_P invoke corresponding VNF Package management procedure as described in clause 4.3 in TS 28.526 [7].

4) The NFMS_P invokes VNF lifecycle management with requirements for VNF instance as descried in clause 4.2.2.2 in TS 28.526 [7].

5) The NFMS_P creates the MOI for the NF instance to be created. If the NF instance contains virtualized part, the NFMS_P may send the request of creating the MOI to the NFMS_P in the NF.

6) The NFMS_P configures the new created MOI with corresponding configuration information (see information model definition for NR NRM in clause 4 and information model definition for 5GC NRM in clause 5 in TS 28.541[6]).

7) The NFMS_P sends the CreateNf response (see createMOI operation defined in TS 28.532 [8]) to NFMS_C with identifier of MOI and with identifier of NFMS_P which actually maintains the MOI for NF instance.

7.11 Procedure of NF instance modification

The Figure 7.11-1 illustrates the procedure of modify NF instance.

Figure 7.11-1: Network Function Instance Modify procedure

1) Network Function Management Service Provider (NFMS_P) receives a ModifyNf request (see modifyMOIAttributes operation defined in TS 28.532 [8])from Network Function Management Service Consumer (NFMS_C) with Identifier of MOI for NF instance and network function related requirements.

Note: The network funcation related requirements see information model definition for NR NRM in clause 4 and information model definition for 5GC NRM in clause 5 in TS 28.541[6].

2) If NF instance contains virtualized part, NFMS_P checks whether corresponding VNF instance needs to be scaled to satisfy the network function related requirements.

3) If corresponding VNF instance needs to be scaled, NFMS_P invokes corresponding VNF instance scaling procedure as described in clause 4.2.3 in TS 28.526 [7].

4) NFMS_P reconfigures corresponding MOI for the NF instance.

5) The NFMS_P sends the ModifyNf response (see modifyMOIAttributes operation defined in TS 28.532 [8]) to NFMS_C.

7.12 Procedure of NF instance deletion

The Figure 7.12-1 illustrates the procedure of deleting NF instance.

Figure 7.12-1: Network Function Instance Deletion procedure

1) Network Function Management Service Provider (NFMS_P) receives DeleteNf request (see deletetMOI operation defined in TS 28.532 [8]) from Network Function Management Service Consumer (NFMS_C) with Identifier of MOI for NF instance.

2) If the NF instance contains virtualized part, NFMS_P invokes VNF instance termination procedure as described in clause 4.2.4 in TS 28.526 [7].

3) NFMS_P deletes the MOI for the NF instance.

4) NFMS_P sends the DeleteNf response (see deleteMOI operation defined in TS 28.532 [8]) to NFMS_C.

7.13 Procedure of reservation and checking feasibility of NSI

Figure 7.13-1 Network slice feasibility check procedure

1) Network Slice Management Service Provider (NSMS_Provider) receives a provisioning NSI request (e.g., AllocateNsi request (see AllocateNsi operation defined in clause 6.5.1), ModifyNsi request (see modifyMOIAttributes operation defined in TS 28.532 [8])) from Network Slice Management Service Consumer (NSMS_Consumer) with network slice related requirements (e.g. Area information, User Number, traffic demand, QoS Quality, whether the requested network slice instance could be shared).

2) [Optional] NSMS_Provider may request information and updates from NSSMS_Provider and Other_MS_Provider regarding the resources.

3) NSMS_Provider sends reservation requests to Network Slice Subnet Management Service Provider (NSSMS_Provider) and (if needed) Other Management Service Providers (Other_MS_Provider), e.g., MANO, TN manager. NSMS_Provider receives responses with information regarding allocated resources, e.g., their availability, identification information of reserved resources and so on.

4) A reservation request to NSSMS_Provider can trigger NSSI feasibility checking.

5) NSMS_Provider evaluates the responses to determine if the network slice requirements can be satisfied.

6) If feasible,

6.a) NSMS_Provider is ready for provisioning.

6.b) [Optional] Acknowledgement regarding reservation check results can be sent to NSMS_Customer.

7) If not feasible,

7.a) NSMS_Provider cancels reservations, optionally may receive acknowledgement.

7.b) NSMS_Provider is not ready for provisioning.

7.c) NSMS_Provider may send negative acknowledgement regarding results of reservation check to NSMS_Customer.

7.14 Procedure of reservation and checking feasibility of network slice subnet

Figure 7.14-2 Network slice subnet feasibility check procedure

1) Network Slice Subnet Management Service Provider (NSSMS_Provider) receives a provisioning NSSI request (e.g., AllocateNssi request (see AllocateNssi operation defined in clause 6.5.2), ModifyNssi request (see modifyMOIAttributes operation defined in TS 28.532 [8])) from Network Slice Subnet Management Service Consumer (NSSMS_Consumer) with network slice subnet related requirements (e.g. Area information, User Number, traffic demand, QoS Quality, whether the requested network slice instance could be shared). The request is evaluated and initial resources to be allocated are identified.

2) [Optional] NSSMS_Provider may request information and updates from NSSMS_Provider and Other_MS_Provider regarding the resources.

3) NSSMS_Provider sends reservation requests to Other Management Service Providers (Other_MS_Provider), e.g., MANO, TN manager. NSSMS_Provider receives responses with information regarding reserved resources, e.g., their availability, identification information of reserved resources and so on.

4) NSSMS_Provider evaluates the responses to determine if the network slice subnet requirements can be satisfied.

5) If feasible:

5.a) NSSMS_Provider is ready for provisioning.

5.b) [Optional] Acknowledgement regarding reservation check results can be sent to NSSMS_Customer.

6) If not feasible,

6.a) NSSMS_Provider cancels reservations, optionally may receive acknowledgement.

6.b) NSSMS_Provider is not ready for provisioning.

6.c) NSSMS_Provider may send negative acknowledgement regarding results of reservation check to NSSMS_Customer.

7.15 Void

7.16 Procedure of allocating network with or without slicing for communication services

The Figure 7.16-1 illustrates the procedure of allocating network with or without slicing for communication services.

Figure 7.16-1 Allocating network with or without slicing for communication services

1) Network Service Provider (NS_Provider) receives AllocateNetwork request (see AllocateNetwork operation defined in clause 6.5.5) from Network Service Consumer (NS_Consumer). The received request includes network related service requirements (e.g. isolation, latency, coverage).

2) NS_Provider decides to use the network with or without slicing depending on these network related service requirements based on some internal admission control.

3) Based on the decision by NS_Provider:

3a) If NS_Provider decides to use a network with slicing, network slice instance allocation procedures in clause 7.2 follows. These procedures may result a new network slice to be created, or use an existing network slice with modification.

3b) If NS_Provider decides to use network without slicing, the network without slicing is utilized to satisfy the network related service requirements, there may be modification of the existing network or creation of a new network.

4) NS_Provider sends the AllocateNetwork response (see AllocateNetwork operation defined in clause 6.5.5) to NS_Consumer.