Patent Description:
In <NUM> telecommunications networks, a network node that provides service is referred to as a producer network function (NF). A network node that consumes services is referred to as a consumer NF. A network function can be both a producer NF and a consumer NF depending on whether it is consuming or providing service.

A given producer NF may have many service endpoints, where a service endpoint is a combination of IP address and port number on a network node that hosts a producer NF. Producer NFs register with a network function repository function (NRF). The NRF maintains an NF profile of available NF instances and their supported services. Consumer NFs can subscribe to receive information about producer NF instances that have registered with the NRF.

One example of an NF that provides services to user equipment (UE) devices, such as Internet of Things (IoT) devices, is the access and mobility management function or AMF. The AMF provides registration management, connection management, reachability management, mobility management, and other services for UE devices. The AMF serves as the point of contact between the radio access network and the remaining nodes in the <NUM> core network. The AMF also serves as the point of access to network slice services.

Network slicing is a service provided in <NUM> networks where network resources are logically allocated in portions or slices for use by UE devices. Each network slice may provide particular capabilities or services to a UE. A network slice instance is defined as a set of network functions and the resources for the network functions which are arranged and configured to form and meet a specific set of network requirements or characteristics. For example, a network slice instance for access network services may be resources of a virtualized g-Node B and AMF to provide access network services for a UE. A network slice instance for a core network service may include resources of a virtualized NRF and network exposure function (NEF) configured to provide core network services for a UE, such as an Internet of things (IoT) device.

The third-generation partnership project (3GPP) defines service orchestration procedures for the creation and modification of network slices. However, these procedures do not include a feedback mechanism to optimize utilization of network slice components after their creation. For example, 3GPP TR <NUM> defines a network slice instance (NSI) lifecycle, including slice creation, modification, and decommissioning. However, slice modification post-creation is performed based on input from the service consumer, rather than performance feedback regarding slice utilization or capacity.

Accordingly, there exists a need for methods, systems, and computer readable media for network slice management using a feedback mechanism. "3rd Generation Partnership Project; <NUM>-<NUM> Technical Specification Group Services and System Aspects; Study of Enablers for Network Automation for <NUM> (Release <NUM>)" describes how to collect data and how to feedback data analytics to the network functions.

Embodiments not falling within the scope of the claims are exemplary and considered useful for understanding the invention.

<FIG> is a block diagram illustrating an exemplary <NUM> system network architecture. In <FIG>, the network includes NRF <NUM> and a service communications proxy (SCP) <NUM>. As described above, NRF <NUM> may maintain profiles of available producer NF service instances and their supported services and allow consumer NFs or SCPs to subscribe to and be notified of the registration of new/updated producer NF service instances. SCP <NUM> may also support service discovery and selection of producer NFs. In addition, SCP <NUM> may perform load balancing of connections between consumer and producer NFs.

NRF <NUM> is a repository for NF profiles. In order to communicate with a producer NF, a consumer NF or an SCP must obtain the NF profile from NRF <NUM>. The NF profile is a JavaScript object notation (JSON) data structure. The NF profile definition includes at least one of a fully qualified domain name (FQDN), an Internet protocol (IP) version <NUM> (IPv4) address or an IP version <NUM> (IPv6) address.

In <FIG>, any of the nodes (other than SCP <NUM> and NRF <NUM>) can be either consumer NFs or producer NFs, depending on whether they are consuming or providing services. In the illustrated example, the nodes include a policy control function (PCF) <NUM> that performs policy related operations in a network, a user data management (UDM) function <NUM> that manages user data, and an application function (AF) <NUM> that provides application services. The nodes illustrated in <FIG> further include a session management function (SMF) <NUM> that manages sessions between AMF <NUM> and PCF <NUM>. AMF <NUM> performs mobility and registration management operations similar to those performed by a mobility management entity (MME) in <NUM> networks. AMF <NUM> also serves as the access point for network slice services. AMF <NUM> may also perform AMF selection to select the serving AMF that will provide access to the network slice services requested by a UE during registration.

An authentication server function (AUSF) <NUM> performs authentication services for user equipment (UEs), such as UE <NUM>, seeking access to the network.

A network slice selection function (NSSF) <NUM> provides network slice subnet availability information (NSSAI) and NS selection services for devices seeking to access specific network capabilities. NSSF <NUM> may obtain AMF loading information from an NRF and NSSAI availability information from AMFs. NSSF <NUM> may store the AMF loading information and NSSAI availability information in an AMF selection database maintained by NSSF <NUM>. When NSSF <NUM> receives an NSSAI selection request from an AMF, NSSF <NUM> may utilize the stored AMF loading and NSSAI availability information to compute an AMF relevance score and a weight for each AMF capable of supporting the network slice services requested by a UE seeking access to network slice services. NSSF <NUM> may generate a prioritized list of AMFs capable of providing the requested services and the corresponding weights and communicate the list to the requesting AMF. The requesting AMF may then use the prioritized list of AMFs and the weights to select an AMF for providing access to the requested network slice services.

A network exposure function (NEF) <NUM> provides application programming interfaces (APIs) for application functions seeking to obtain information about Internet of things (IoT) devices and other UEs attached to the network. NEF <NUM> performs similar functions to the service capability exposure function (SCEF) in <NUM> networks.

A radio access network (RAN) <NUM> connects UE <NUM> to the network via a wireless link. Radio access network <NUM> may be accessed using a g-Node B (gNB) (not shown in <FIG>) or other wireless access point. A user plane function (UPF) <NUM> can support various proxy functionalities for user plane services. One example of such proxy functionality is multipath transmission control protocol (MPTCP) proxy functionality. UPF <NUM> may also support performance measurement functionality, which may be used by UE <NUM> to obtain network performance measurements. Also illustrated in <FIG> is a data network (DN) <NUM> through which UEs access data network services, such as Internet services.

Service edge protection proxy (SEPP) <NUM> filters incoming traffic from another PLMN and performs topology hiding for traffic exiting the home PLMN. SEPP <NUM> may communicate with an SEPP in a foreign PLMN which manages security for the foreign PLMN. Thus, traffic between NFs in different PLMNs may traverse a minimum of two SEPP functions, one for the home PLMN and the other for the foreign PLMN.

As indicated above, network slicing involves providing virtual network functions and allocating resources for the virtual network functions to meet a given requirement. For example, network slicing may involve virtualizing any of the network functions illustrated in <FIG> and providing access to services implemented by multiple different network functions as a network slice instance.

At the highest level, network slices are accessible via communication services provided by a communication service provider. Communication services can include business to consumer communication services, such as mobile web browsing, voice over LTE calling, and rich communication services. Communication services can also include business to business services, such as Internet access and local area network (LAN) interconnection.

Network slice as a service can be offered by communication services providers to their customers. Network slice services can be characterized by a number of parameters, including:.

<FIG> illustrates an example of the relationship between communication services, network slice instances (NSIs), network slice subnet instances (NSSIs), the core network (CN), and the access network (AN). Referring to <FIG>, communication services <NUM> provided by a communication service provider include service <NUM> <NUM>, service <NUM> <NUM>, and service <NUM> <NUM>. Each of service <NUM> <NUM>, service <NUM> <NUM>, and service <NUM> <NUM> is implemented using a network slice instance consisting of virtual NF resources in core network <NUM> and access network <NUM>. In the illustrated example, service <NUM> <NUM> is implemented using network slice instance A <NUM>. Network slice instance A <NUM> is implemented using core network NSSI <NUM> 212A and access network NSSI <NUM> 212B. Service2 <NUM> is implemented using network slice instance B <NUM>. Network slice instance B <NUM> is implemented using core network NSSI <NUM> 214A and access network NSSI <NUM> 214B. Service <NUM> <NUM> is implemented using network slice instance C <NUM>. Network slice instance C <NUM> is implemented using core network NSSI <NUM> 216A and access network NSSI <NUM> 214B. It should be noted that access network NSSI <NUM> 214B is shared by network slice instances <NUM> and <NUM>.

<FIG> is a network diagram illustrating exemplary relationships between network slice instances, network slice subnet instances, and network functions. In <FIG>, network slice instance X <NUM> and network slice instance Y <NUM> are illustrated. Network slice instance X <NUM> includes network slice subnet instance A <NUM> and network slice subnet instance C <NUM>. Network slice instance Y <NUM> includes network slice subnet instance B <NUM> and network slice subnet instance A <NUM>, which is shared with network slice instance Y <NUM>. Network slice subnet instance A <NUM> includes NFs NF1-NF4. Network slice subnet instance C <NUM> includes NFs NF5 and NF6. Network slice subnet instance C <NUM> includes NFs NF7-NF9. Thus, <FIG> further illustrates the concept of sharing network slice subnet instances and corresponding NF resources between network slice instances.

In order to manage communication services, network slice instances, and network slice subnet instances, 3GPP TR <NUM> defines three management functions, the communication service management function (CSMF), the network slice management function (NSMF), and the network slice subnet management function (NSSMF). These functions are illustrated in <FIG>. In <FIG>, CSMF <NUM> is the highest-level node in the management hierarchy and is responsible for translating communication-service-related requirements to network-slice-related requirements and for communicating with NSMF <NUM>. NSMF <NUM> is the next-level node in the hierarchy and is responsible for management and orchestration of network slice instances. NSMF <NUM> also derives network-slice-subnet-related requirements from network-slice-related requirements. NSMF <NUM> communicates with CSMF <NUM> and the NSSMF <NUM>. The lowest-level node in the management hierarchy is NSSMF <NUM>. NSSMF <NUM> is responsible for the management and orchestration of network slice subnet instances. NSSMF <NUM> communicates with NSMF <NUM> and with the NFs that implement network slice subnet instances.

3GPP TS <NUM> defines procedures for network slice service consumers to request creation, deletion, and check the feasibility of network slice instances and network slice subnet instances. The procedure defined for a network slice feasibility check by a network slice management service provider is illustrated in <FIG>. Referring to <FIG>, in line <NUM>, a Network Slice Subnet Management Service Provider (NSSMS_Provider) <NUM> receives a provisioning NSSI request (e.g., AllocateNssi request or ModifyNssi request) from Network Slice Subnet Management Service Consumer (NSSMS_Consumer) <NUM> with network-slice subnet-related requirements (e.g. area information, user number, traffic demand, QoS quality, whether the requested network slice instance can be shared). The request is evaluated and initial resources to be allocated are identified. NSSMS_Provider <NUM> may be NSMF <NUM> and NSSMS_Consumer <NUM> may be CSMF <NUM> described above with respect to <FIG>.

In line <NUM> of the message flow diagram in <FIG>, NSSMS_Provider <NUM> may optionally request information and updates from Other_MS_Provider <NUM> regarding the resources. Other_MS_Provider <NUM> may be an NSMF in another network.

In line <NUM> of the message flow diagram, NSSMS_Provider <NUM> sends reservation requests to Other_MS_Provider <NUM>, e.g., management and orchestration (MANO), TN manager. NSSMS_Provider <NUM> receives responses with information regarding reserved resources, e.g., their availability, identification information of reserved resources and so on.

In line <NUM> of the message flow diagram, NSSMS_Provider <NUM> evaluates the responses to determine if the network slice subnet requirements can be satisfied.

Lines 5a and 5b of the message flow diagram are executed by NSSMS_Provider <NUM> if the allocation of network resources is determined to be feasible. In line 5a, NSSMS_Provider <NUM> determines that it is ready for provisioning the required network slice resources. In line 5b of the message flow diagram, NSSMS_Provider <NUM> optionally sends a feasibility acknowledgement message to NSSMS_Consumer <NUM> indicating that the requested resources are available.

Lines 6a-6c of the message flow diagram are executed if NSSMS_Provider <NUM> determines that the requested allocation of resources is not feasible. In line 6a, NSSMS_Provider <NUM> cancels reservations and optionally may receive acknowledgements. In line 6b, NSSMS_Provider <NUM> determines that it is not ready for provisioning the requested network slice resources. In line 6c, NSSMS_Provider <NUM> optionally sends a negative acknowledgement regarding results of the reservation check to NSSMS_Consumer <NUM>.

Thus, <FIG> illustrates a network-slice-consumer-driven feasibility check of network slice resources. These steps are initiated by the network slice consumer and are executed prior to network slice resource allocation. What is needed is a network-slice-management-function- driven procedure, independent of monitoring requests form the network slice consumer for monitoring and modifying network slice and network slice subnet resources.

<FIG> is a diagram illustrating a procedure implemented by the NSMF for obtaining network slice load information from a network data analytics function (NWDAF), after creation of a network slice instance, dynamically during operation of the network slice instance, and independently of (i.e., without receiving a monitoring request from) a network slice services consumer. Referring to <FIG>, in line <NUM> of the message flow diagram, NSMF <NUM> sends an Eventsubscription_Subscribe/Unsubscribe message to NWDAF <NUM>. In this example, it is assumed that the message is an Eventsubsccription_Subscribe message. The Eventsubscription_Subscribe message is used by NSMF <NUM> to subscribe to receive information regarding the real-time, instantaneous load level of a network slice. Exemplary parameters that can be included in the event subscription message will be described in further detail below with respect to <FIG>. NWDAF <NUM> is an analytics function defined in 3GPP TS <NUM> that collects information regarding utilization of network functions and provides a subscription services for other nodes to be notified of the information it collects.

In line <NUM> of the message flow diagram, it is assumed that the network slice load information reporting condition(s) associated with the Eventsubscription_Subscribe message are met, and NWDAF <NUM> sends an Eventsubscription_Notify message to NSMF <NUM>. The Eventsubscription_Notify message includes network-slice-related parameters, such as load information parameters, concerning the status of the network slice.

In line <NUM> of the message flow diagram, NSMF <NUM> sends an NSSI modification request message to NSSMF <NUM> to modify a network slice subnet instance based on the load information received from NWDAF <NUM>. For example, if the Eventsubscription_Notify message indicated that the network slice is <NUM>% loaded, the NSSI modification request may request allocation of additional computing resources for the network slice subnet instances that make up the network slice. Thus, in <FIG>, network slice characteristics are dynamically monitored, and resource allocations are changed without requiring a message from the network slice service consumer. Because the resources associated with the network slice are dynamically updated transparently to the network slice service consumer, the consumer will not see any decrease in service quality and is not required to implement consumer-driven resource monitoring or updating to maintain service quality.

<FIG> illustrates the subscription and event notification process between the NSMF and NWDAF in more detail. Referring to <FIG>, in line <NUM> of the message flow diagram, NSMF <NUM> sends an Eventsubscription_Subscribe message to NWDAF <NUM>. The Eventsubscription_Subscribe message registers NSMF <NUM> to receive load information from NWDAF <NUM> for network slice instances identified in the Eventsubscription_Subscribe message. The network slice or network slices may be identified by individual network slice identifier(s), a group network slice identifier, or a parameter that identifies all slices monitored by NWDAF <NUM>. Other parameters that may be specified by the NSMF in the Eventsubscription_Subscribe message include data analytics parameters that are input to the analytics engine of NWDAF <NUM> to determine the trigger conditions that control dynamic network slice event reporting and the content of the reports to NSMF <NUM>. Examples of data analytics parameters that may be included in the Eventsubscription_Subscribe message include:
Event Type {location, time of day, day of week}
Data Selection Criteria {#sample, #interval, #both}
Sample {Integer: #samples - e.g. max number of
samples
to allow per month}
Interval {integer: value, e.g., hours, days, weeks}
Trigger Details
Type - periodic/threshold
Value - value of time interval/load threshold value
Notification URI - URI to which notification messages are to be
sent. Thus, the above-described parameters that may be included in the Eventsubscription_Subscribe message enable NSMF <NUM> to obtain load information regarding a network slice or group of network slices and to define conditions under which network slice load information reports are generated.

In line <NUM> of the message flow diagram, in response to the Eventsubscripton_Subscribe message and one or more report triggering conditions defined in the message being met, NWDAF <NUM> generates and sends an Eventsubscription_Notify message to NSMF <NUM>. The Eventsubscription_Notify message may include the following parameters:.

In the example above, the parameters included in the Eventsubscription_Notify message may include real time load information regarding a network slice. The real time load information may indicate a percentage of used (or unused) capacity of a network slice or network slice subnet along with a timestamp that indicates the time at which the network slice load information is recorded. The Eventsubscription_Notify message may also include one or more analytics data sets. In the example above, the analytics data sets include statistical load information per time period and/or location. For example, one analytics data set may include average, instantaneous, and maximum loading of a network slice instance or network slice subnet instance for a particular location during a day. The location may indicate the area served by the network slice instance or network slice subnet instance. Thus, the network slice and network slice subnet instance load information feedback received in <FIG> is generated independently of a request from a network slice service consumer and occurs dynamically after network slice creation when trigger conditions are met.

The NSMF with the NWDAF subscription interface described herein includes the following features:.

The network slice load information feedback illustrated in <FIG> may be used to change resource allocations among network slice instances and network slice subnet instances. For example, if an Eventsubscription_Notify message indicates that a network slice instance is <NUM>% loaded at the time a report is triggered, NSMF <NUM> may send a message to NSSMF <NUM> to allocate additional resources to the network slice subnet instances that make up the network slice instance. In another example, if the Eventsubscription_Notify message indicates that a network slice instance is only <NUM>% loaded during a given time period, NSMF <NUM> may send a message to NSSMF <NUM> to deallocate some of the resources assigned to network slice subnet instances corresponding to the underutilized network slice instance.

<FIG> is a block diagram illustrating an NSMF and an NWDAF suitable for implementing the network slice load information feedback mechanism described herein. Referring to <FIG>, NSMF <NUM> and NWDAF <NUM> each include at least one processor <NUM> and a memory <NUM>. NSMF <NUM> includes an NWDAF subscription interface <NUM> that subscribes directly with NWDAF <NUM> to receive network slice load information, obtains the load information, and stores the load information in a network slice load/resource allocation database <NUM>. NSMF further includes a network slice resource management function <NUM> that uses the load information in database <NUM> to issue network slice resource allocation and deallocation control commands via network slice resource management.

Providing an NSMF with a NWDAF subscription interface that subscribes directly with the NWDAF, defines criteria to trigger the sending of network slice load information, and uses the network slice load information to update network slice resource allocations dynamically is advantageous over static provisioning of network slices and even over implementations where the network slice load information is not tailored to criteria defined by the NSMF. For example, the NSMF described herein can define, as part of a network slice load information subscription, load information report triggering criteria that are based on a service level agreement with a communication service provider. If the NWDAF reports load information triggered by network conditions approaching criteria defined based on the SLA, the NSMF can maintain the service quality defined by the SLA independently and without the need for SLA monitoring by service consumers. In addition, a direct subscription interface between the NSMF and the NWDAF increases the likelihood that the load information reported to the NSMF will be current.

NWDAF <NUM> includes a network slice load information subscription manager <NUM>. Network slice load information subscription manager <NUM> receives subscription requests from NSMF <NUM> and other consumers that wish to receive load information concerning network slices. Network slice load information subscription manager <NUM>, after validating the subscribing entities, creates network slice load information subscriptions by storing records corresponding to the subscriptions in network slice analytics and subscriptions database <NUM>. The records may identify the subscribing entities (e.g., NSMF <NUM>), the network slice instances and network slice subnet instances to which each entity subscribes, and the trigger conditions that trigger reporting of network slice load information for each subscription.

A network slice load information analytics engine <NUM> receives load information from network functions (e.g., PCFs, SMFs, AMFs, etc.), performs analytics based on the load information, and stores results of the analytics and the load information in network slice analytics and subscription database <NUM>.

When network slice load information analytics engine <NUM> receives load information for a network slice, network slice load information analytics engine <NUM> updates any records in database <NUM> with the network slice load information.

Network slice load information analytics engine <NUM> may continually evaluate network slice reporting conditions associated with records in database <NUM> to determine whether a network slice load information event reporting condition is met. When network slice load information analytics engine <NUM> determines that a network slice load information event reporting condition associated a network slice instance load information subscription from NSMF <NUM> has been met, network slice load information analytics engine <NUM> generates and sends a report with the requested load information to NSMF <NUM>. NSMF <NUM> utilizes the load information to make network slice instance resource allocation and deallocation decisions.

It should be noted that while <FIG> illustrates network slice load information subscription manager <NUM> and network slice load information analytics engine <NUM> as separate functional blocks, their functionalities can be combined an implemented by a single logical or physical entity within NWDAF <NUM> without departing from the scope of the subject matter described herein.

<FIG> is a flow chart illustrating an exemplary process for providing and utilizing real time network slice load information feedback for network slice resource allocation. The steps illustrated in <FIG> may be implemented by NSMF <NUM>. Referring to <FIG>, in step <NUM>, the process includes subscribing directly with the NWDAF to receive network slice load information. For example, NSMF <NUM> may transmit an Eventsubscription_Subscribe message to NWDAF <NUM> identifying one or more network slice instances about which NSMF <NUM> desires to receive load information. The Eventsubscription_Subscribe message may also include event type, data selection, and trigger information parameters, as described above. The Eventsubscription_Subscribe message may be transmitted by or via NWDAF subscription interface <NUM> of NSMF <NUM> illustrated in <FIG>. The Eventsubscription_Subscribe message may include NSMF-defined criteria for triggering the reporting of real-time network slice load information by the NWDAF to the NSMF.

In step <NUM>, the process includes receiving network slice load information from the NWDAF. For example, NSMF <NUM> may receive an Eventsubscription_Notify message from NWDAF <NUM> containing load information for network slice instances and network slice subnet instances identified in the Eventsubscription_Subscribe message. The load information may identify the percentage loading (or availability) of each network slice instance or subnet instance. The Eventsubscription_Notify message may be received by or via NWDAF subscription interface <NUM> of NSMF <NUM> illustrated in <FIG>. The reporting may be triggered in response to the NSMF-defined criterion associated with the subscription being met,
In step <NUM>, the process includes determining whether a network slice resource allocation change is needed. In this step, NSMF <NUM> may compare the load information received in the Eventsubscription_Notify message with a threshold (such as an SLA-based threshold) and determine, based on a relationship between the load information and the threshold, whether a network slice resource allocation change is needed. For example, the network slice service provider may define a utilization threshold of <NUM>% for a given network slice before a resource allocation change is triggered. If the load information for the network slice indicates that the network slice is currently <NUM>% utilized, then NSMF <NUM> may determine that a network slice resource modification is needed. If the current loading of the network slice is less than the threshold, control returns to step <NUM> where the next load information concerning the network slice is received.

If NSMF <NUM> determines that a network slice resource modification is needed, control proceeds to step <NUM> where NSMF <NUM> dynamically modifies a network slice resource allocation. In one example, dynamically modifying a network slice resource allocation may include generating a sending a message to modify allocation of network slice resources. For example, if NSMF <NUM> determines that additional resources are needed for a given network slice instance, NSMF <NUM> may generate and send a message to NSSMF <NUM> to allocate additional resources to network slice subnets that make up a given network slice. Similarly, if NSMF <NUM> determines that resources assigned to a given network slice instance are underutilized, NSMF <NUM> may generate and send a message to NSSMF <NUM> to deallocate at least some of the resources assigned to network slice subnet instances that make up the network slice instance. In one example, the message sent to NSSMF <NUM> may be set by network slice resource management function <NUM> to NSSMF <NUM> via network slice resource management interface <NUM> of NSMF <NUM> illustrated in <FIG>.

<FIG> is a flow chart illustrating an exemplary process for providing network slice feedback information to a network slice management function. The steps illustrated in <FIG> are implemented by NWDAF <NUM>. Referring to <FIG>, in step <NUM>, the process includes receiving a message from an NSMF for creating a subscription to be notified of network slice load information. For example, NWDAF <NUM> may receive an Eventsubscription_Subscribe message from NSMF <NUM>. The Eventsubscription_Subscribe message may identify one or more network slice instances and/or subnet instances that NSMF <NUM> desires to monitor. The Eventsubscription_Subscribe message may also include event type, data selection, and trigger parameters, or other NSMF-defined network slice load information report triggering criteria, as described above. In one example, the Eventsubscription_Subscribe message may be received directly from NWDAF subscription interface <NUM> of NSMF <NUM> and by network slice load information subscription manager <NUM> of NWDAF <NUM> illustrated in <FIG>.

In step <NUM>, the process includes validating the NSMF. For example, NWDAF <NUM> may access an internal authentication database to determine whether NSMF <NUM> is authorized to receive load information concerning the network slices identified in the Eventsubscription_Subscribe message. In the example illustrated in <FIG>, it is assumed that the NSMF is successfully validated. In one example, the authentication may be performed by network slice load information subscription manager <NUM> using authentication data stored in network slice analytics and subscription database <NUM> of NWDAF <NUM> illustrated in <FIG>.

In step <NUM>, the NWDAF creates a subscription corresponding to the parameters received from the NSMF in the Eventsubscription_Subscribe message. For example, network slice load information subscription manager <NUM> of NWDAF <NUM> may create an entry in network slice analytics and subscription database <NUM> that identifies the subscribing NSMF as well as the type of network slice load information event notifications and parameters that the NSMF desires to receive.

In step <NUM>, the process includes checking NSMF-defined criteria associated with the subscriptions with respect to load information obtained from network functions received from NFs implementing network slice services. For example, network slice load information analytics engine <NUM> of NWDAF <NUM> may receive load information from NFs, such as an AMF, SMF, NRF, UDM, NEF, etc., and may determine whether the load information applies to any subscriptions in database <NUM>. If the received load information corresponds to a monitored network slice information subscription, control proceeds to step <NUM> where it is determined whether a network slice load information reporting criterion associated with one of the subscriptions has been met. If a network slice load information reporting criterion associated with one of the subscriptions has been met, control proceeds to step <NUM> where the network slice load information is communicated to the NSMF. For example, network slice load information analytics engine <NUM> of NWDAF <NUM> may generate an Eventsubscription_Notify message and send the message to NSMF <NUM>. The Eventsubscription_Notify message may contain load information for the requested network slice or network slice subnet and may also contain metadata about the network slice load information. The metadata may include the location and the time that the network slice load information was collected.

If in step <NUM> it is determined that a load information reporting criterion associated with one of the subscriptions has not been met, control returns to step <NUM> where the subscriptions are checked with respect to load information from NFs providing network slice services.

Claim 1:
A method for feedback-based network slice management, the method being performed by a network slice management function NSMF (<NUM>) including at least one processor, the method comprising:
subscribing (<NUM>), via a network data analytics function NWDAF (<NUM>) subscription interface of the NSMF, directly with the NWDAF to create a subscription to be notified of network slice load information and specifying, as part of the subscription, network slice load information report generation criteria defined by the NSMF;
receiving (<NUM>), directly from the NWDAF, via the NWDAF subscription interface of the NSMF and in response to the NSMF-defined network slice load information report triggering criteria being met, network slice load information;
determining (<NUM>), based on the network slice load information, that a network slice resource allocation change is needed; and
in response to determining that a network slice resource allocation change is needed, dynamically changing (<NUM>) the network slice resource allocation during operation of a network slice.