Patent Description:
To meet the demand for wireless data traffic having increased since deployment of <NUM>th generation (<NUM>) communication systems, efforts have been made to develop an improved <NUM>th generation (<NUM>) or pre-<NUM> communication system. Therefore, the <NUM> or pre-<NUM> communication system is also called a 'Beyond <NUM> Network' or a 'Post long term evolution (LTE) System'.

In the <NUM> system, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

The Internet of everything (IoE), which is a combination of the loT technology and the Big Data processing technology through connection with a cloud server, has emerged. As technology elements, such as "sensing technology", "wired/wireless communication and network infrastructure", "service interface technology", and "Security technology" have been demanded for IoT implementation, a sensor network, a machine-to-machine (M2M) communication, machine type communication (MTC), and so forth have been recently researched. Such an loT environment may provide intelligent Internet technology services that create a new value to human life by collecting and analyzing data generated among connected things.

For example, technologies, such as a sensor network, machine type communication (MTC), and machine-to-machine (M2M) communication may be implemented by beamforming, MIMO, and array antennas. Application of a cloud radio access network (RAN) as the above-described Big Data processing technology may also be considered to be as an example of convergence between the <NUM> technology and the loT technology.

With the development of various information technology (IT) technologies, network equipment has evolved into a virtualized network function (NF, hereinafter, may be used interchangeably with a 'network element') by applying virtualization technology, and virtualized NFs may be implemented in a software form without physical limitations to be installed/operated in various types of clouds or data centers (DCs). In particular, the NF may be freely expanded, scaled, initiated, or terminated according to service requirements, a system capacity, or a network load. It should be noted that even if these NFs are implemented in a software form, the NFs do not exclude physical configurations, because the NFs should be basically driven on a physical configuration, for example, a fixed equipment. Further, NFs may be implemented only with a simple physical configuration, that is, hardware.

In order to support various services in these various network structures, network slicing technology has been introduced. Network slicing is a technology that logically configures a network as a set of network functions (NF) for supporting a specific service and that separates the network from other slices. One terminal may access two or more slices when receiving various services.

"<NPL>, discloses Stage <NUM> procedures and Network Function Services for the <NUM> system architecture.

Accordingly, an aspect of the disclosure is to provide a method and apparatus for effectively managing a network configured with network slices for supporting various services and preventing signaling loads and collisions.

According to disclosed embodiments of the disclosure, it is possible to efficiently use radio resources and efficiently provide various services to users by managing network slices in units of sets.

In addition, according to an embodiment of the disclosure, the user can efficiently access a desired network function entity by efficiently searching for a plurality of network function entities providing various services.

Terms used in the disclosure are used only to describe a specific embodiment of the disclosure, and may be not intended to limit the scope of other embodiments. Terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Among the terms used in the disclosure, those defined in commonly used dictionaries may be interpreted as having a meaning that is identical or similar to their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. In some cases, even terms defined in the disclosure should not be interpreted to exclude embodiments of the disclosure.

In various embodiments of the disclosure described below, a hardware approach is described as an example. However, as various embodiments of the disclosure include technologies using both hardware and software, various embodiments of the disclosure do not exclude a software-based approach.

Here, the same or similar reference symbols are used throughout the drawings to refer to the same or like parts. Descriptions of functions and structures well known in the art may be omitted to avoid obscuring the subject matter of the disclosure.

In the following description of embodiments of the disclosure, descriptions of technical details well known in the art and not directly related to the disclosure may be omitted. This is to more clearly convey the gist of the disclosure without obscurities by omitting unnecessary descriptions.

Likewise, in the drawings, some elements are exaggerated, omitted, or only outlined in brief. In addition, the size of each element does not necessarily reflect the actual size. The same reference symbols are used throughout the drawings to refer to the same or corresponding parts.

Advantages and features of the disclosure and methods for achieving them will be apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings. However, the disclosure is not limited to the embodiments disclosed below but may be implemented in various different ways, the embodiments are provided only to complete the disclosure and to fully inform the scope of the disclosure to those skilled in the art to which the disclosure pertains, and the disclosure is defined only by the scope of the claims. The same reference symbols are used throughout the specification to refer to the same parts.

Meanwhile, it will be appreciated that blocks of a flowchart and a combination of flowcharts may be executed by computer program instructions. These computer program instructions may be loaded on a processor of a general purpose computer, special purpose computer, or programmable data processing equipment, and the instructions executed by the processor of a computer or programmable data processing equipment create a means for carrying out functions described in blocks of the flowchart. To implement the functionality in a certain way, the computer program instructions may also be stored in a computer usable or readable memory that is applicable in a specialized computer or a programmable data processing equipment, and it is possible for the computer program instructions stored in a computer usable or readable memory to produce articles of manufacture that contain a means for carrying out functions described in blocks of the flowchart. As the computer program instructions may be loaded on a computer or a programmable data processing equipment, when the computer program instructions are executed as processes having a series of operations on a computer or a programmable data processing equipment, they may provide operations for executing functions described in blocks of the flowchart.

Additionally, each block of a flowchart may correspond to a module, a segment or a code containing one or more executable instructions for executing one or more logical functions, or to a part thereof. It should also be noted that functions described by blocks may be executed in an order different from the listed order in some alternative cases. For example, two blocks listed in sequence may be executed substantially at the same time or executed in reverse order according to the corresponding functionality.

Here, the word "unit", "module", or the like used in the embodiments may refer to a software component or a hardware component, such as a field programmable gate array (FPGA) or application-specific integrated circuit (ASIC) capable of carrying out a function or an operation. However, "unit" or the like is not limited to hardware or software. A unit or the like may be configured so as to reside in an addressable storage medium or to drive one or more processors. For example, units or the like may refer to components, such as a software component, object-oriented software component, class component or task component, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, or variables. A function provided by a component and unit may be a combination of smaller components and units, and it may be combined with others to compose larger components and units. Components and units may be implemented to drive one or more processors in a device or a secure multimedia card.

Hereinafter, the disclosure relates to a method and apparatus for supporting various services in a wireless communication system. Specifically, the disclosure describes a technology for providing various services by supporting mobility of a terminal in a wireless communication system.

Those terms used in the following description for identifying an access node, indicating a network entity or network function (NF), indicating messages, indicating an interface between network entities, and indicating various identification information are taken as illustration for ease of description. Accordingly, the disclosure is not limited by the terms to be described later, and other terms referring to objects having an equivalent technical meaning may be used.

For convenience of description below, the disclosure may use terms and names defined in the <NUM>rd generation partnership project (3GPP) long term evolution (LTE) and <NUM>th generation (<NUM>) standards. However, the disclosure is not limited by the above terms and names, and may be equally applied to systems conforming to other standards.

In the disclosure, entities that exchange information for access control and state management will be collectively described as an NF. For example, the NF may be at least one entity among an access and mobility management function (AMF) entity, a session management function (SMF) entity, and a network slice selection function (NSSF) entity. However, embodiments of the disclosure may be equally applied even when an NF is actually implemented as an instance (e.g., AMF instance, SMF instance, or NSSF instance).

In the disclosure, an instance may indicate a state where a specific NF exists in the form of software code and can be executed on a physical computing system, for example, a specific computing system existing on the core network to perform the function of the NF by using physical or/and logical resources allocated from the computing system. Hence, this may mean that an instance of each NF, such as an AMF instance and an SMF instance may use physical or/and logical resources allocated from a specific computing system existing on the core network for the corresponding NF operation. Consequently, an NF instance, which uses physical or/and logical resources allocated from a specific computing system existing on the network for the NF operation, may perform the same operation as a case where an NF entity, such as a physical AMF or SMF exists.

<FIG> illustrates a wireless communication system according to an embodiment of the disclosure.

Referring to <FIG>, as a node using a radio channel in the wireless communication system, a base station (radio access node (RAN)) <NUM> and a terminal (user equipment (UE)) <NUM> are illustrated. Although only one base station <NUM> and one terminal <NUM> are shown in <FIG>, another base station identical or similar to the base station <NUM> may be further included. Additionally, in <FIG>, only a case where only one terminal <NUM> performs communication within one base station <NUM> is illustrated. However, it is evident that a plurality of terminals can actually communicate within one base station <NUM>.

The base station <NUM> is a network infrastructure that provides radio access to the terminal <NUM>. The base station <NUM> has a coverage defined as a certain geographic area based on the distance at which a signal can be transmitted (not shown in <FIG>). Besides radio access node (RAN), the base station <NUM> may be referred to as access point (AP), eNodeB (eNB), <NUM> node, wireless point, transmission/reception point (TRP), or as another term having an equivalent technical meaning.

The terminal <NUM> is a device used by a user and performs communication with the base station <NUM> through a radio channel. In some cases, the terminal <NUM> may be operated without user involvement. For example, the terminal <NUM> may be a device that performs machine type communication (MTC), and may be not carried by a user. The terminal <NUM> illustrated in <FIG> may include at least one user portable device, and may include at least one MTC device. The terminal <NUM> in <FIG> may be referred to as user equipment (UE), mobile station, subscriber station, remote terminal, wireless terminal, user entity, or as another term having an equivalent technical meaning.

The AMF entity <NUM> may be a network entity that manages wireless network access and mobility for the terminal <NUM>. The SMF entity <NUM> may be a network entity that manages a connection to a packet data network for providing packet data to the terminal <NUM>. The connection between the terminal <NUM> and the SMF <NUM> may be a PDU session.

The user plane function (UPF) entity <NUM> may be a gateway that delivers packets transmitted and to be received by the terminal <NUM> or a network entity serving as a gateway. The UPF <NUM> may be connected to the data network (DN) <NUM> connected to the Internet, and may provide a path for transmitting and receiving data between the terminal <NUM> and the DN <NUM>. Hence, the UPF <NUM> may route data to be delivered to the Internet among packets transmitted by the terminal <NUM> to an Internet data network.

The network slice selection function (NSSF) entity <NUM> may be a network entity that performs a network selection operation described in the disclosure, for example, an operation for selecting a network slice. The operation of the NSSF entity <NUM> will be described below with reference to the following drawings.

The authentication server function (AUSF) entity <NUM> may be an equipment (network entity) that provides a service for processing subscriber authentication.

The network exposure function (NEF) entity <NUM> may be a network entity that can access management information of the terminal <NUM> on a <NUM> network, subscribe a mobility management event for the terminal, subscribe a session management event for the terminal, make a request for session-related information, set charging information for the terminal, make a change request for the PDU session policy of the terminal, and transmit small data about the terminal.

The network repository function (NRF) entity <NUM> may be an NF (network entity) that can store state information of NFs and process a request for finding an NF to which other NFs can make access.

The policy and charging function (PCF) entity <NUM> may be a network entity that applies a service policy, a charging policy, and a PDU session policy of the mobile network operator to the terminal <NUM>.

The unified data management (UDM) entity <NUM> may be a network entity that stores information about the subscriber or/and the terminal <NUM>.

The application function (AF) entity <NUM> may be an NF (network entity) that provides services to users in cooperation with a mobile communication network.

The service communication proxy (SCP) entity <NUM> is an NF (network entity) that provides functions, such as NF discovery for communication between NFs and message transfer between NFs. The SCP <NUM> can operate in an integrated form with the NRF <NUM> according to the operator's selection. In this case, the SCP <NUM> may include the function of the NRF <NUM>, or, conversely, the NRF <NUM> may include the function of the SCP <NUM>.

Hereinafter, for ease of description, entities that exchange information for access control and state management will be collectively described as an NF. For example, the NF may be one of NF entities, such as the access and mobility management function (AMF) entity, the session management function (SMF) entity, and the network slice selection function (NSSF) entity. However, embodiments of the disclosure may be equally applied even when an NF is actually implemented as an instance (AMF instance, SMF instance, or NSSF instance).

<FIG> is a diagram illustrating a method that, when a new base station (RAN) is added in a mobile communication system or configuration information of a base station (e.g., tracking area (TA) supported by the base station, NW slice (logical network identified by single network slice selection assistance information (S-NSSAI)) is added or updated, can notify this to other NFs and enables a network slice suitable for the subscriber service to be selected accordingly according to an embodiment of the disclosure.

Referring to <FIG>, a base station may be newly added or may start to operate, or the configuration of the base station, that is, the tracking area (TA) or a NW slice (logical network identified by S-NSSAI) supported by the base station may be added or updated at operation <NUM>.

The base station may perform an NG setup procedure if a new relationship and connection for network configuration and management with the AMF is required, or may perform a RAN configuration update procedure if there is an existing connection at operation <NUM>. Here, the request message sent by the base station may include the name and identifier of the base station and a list of TAs supported by the base station, and the TA list may include, for each TA, one or more S-NSSAls supported in the TA.

The AMF may determine whether to consider addition or update of network slice and TA information in the slice selection process according to the information received from the base station. If the network configuration for slice selection is updated, the AMF may invoke the NSSF (which can be replaced with another NF like the NRF or SCP that manages and finds network state information) for a service of NSSAI availability update at operation <NUM>. The network slice selection assistance information (NSSAI) may be composed of one or more S-NSSAIs. Similarly, the service request message may include a list of TAls and NSSAls to be added or updated.

The NSSF may update or add information about a slice and an area (TA) where the slice is supported if necessary to update it according to the request from the AMF at operation <NUM>. Here, the data stored by the NSSF may be identified by using the identity (ID) of the AMF instance having made the request. The NSSF may determine the time of application for the updated NSSAI availability.

The NSSF transmits a response for the request from the AMF, in which case when the slice information (AuthorizedNssaiAvailability) allowed to be used by the AMF is updated or added, this may also be notified at operation <NUM>. Here, to match the application time of the updated availability with other AMFs, the NSSF may transmit the corresponding time information as a portion of the response to the AMF. Upon receiving the time information, the AMF operates with application of the updated information from the time point when the corresponding time condition is satisfied.

The AMF transmits a response for the request from the base station, in which case configuration information of the AMF may be included in the response at operation <NUM>. If the network configuration supported by the AMF (TA, supported NSSA, PLMN, or the like) is updated at operation <NUM>, the base station is notified through this process.

The disclosure proposes a method that can more effectively manage network slices and prevent signaling loads and collisions in a network configuration composed of NF sets.

In the embodiment of <FIG>, if two or more AMFs (including instances) are included in one AMF set and that set supports the same TAs and slices, addition or configuration update of a base station must be delivered to all NFs (e.g., AMF) belonging to the set and all NFs receiving this may have to transmit a request to other NSSFs (or NRFs) to notify the addition/update of their NSSAI availability. In this case, if the number of base stations is large or the number of AMFs in the set is large, a signaling overload may occur, or a mismatch or collision may occur in the network configuration information due to a time difference in transmission and processing of signaling.

<FIG> illustrates a method for more effectively managing NSSAI availability according to an embodiment of the disclosure.

In this embodiment of the disclosure, NSSAI availability management may be performed by the master AMF (or, default AMF) belonging to the AMF set.

One of the AMFs belonging to the AMF set may be selected as the master AMF. A designated AMF may be set to play the master role, or AMFs may be selected alternately in a round robin fashion to play the master role. Here, information may be exchanged between the AMFs to notify that only one AMF operates as the master in the AMF set at a specific time.

The base station may perform an NG setup procedure if a new relationship and connection for network configuration and management with the connected AMF and master AMF is required, or may perform a RAN configuration update procedure if there is an existing connection at operations <NUM>, <NUM>. Here, the request message sent by the base station may include the name and identifier of the base station and a list of TAs supported by the base station, and the TA list may include, for each TA, one or more S-NSSAls supported in the TA.

The master AMF may determine whether to consider addition or update of network slice and TA information in the slice selection process according to the information received from the base station. If the network configuration for slice selection is updated, the master AMF may invoke the NSSF (which can be replaced with another NF like the NRF or SCP that manages and finds network state information) for a service of NSSAI availability update at operation <NUM>. The network slice selection assistance information (NSSAI) may be composed of one or more S-NSSAls. Similarly, the service request message may include a list of TAls and NSSAls to be added or updated.

The NSSF may update or add information about a slice and an area (TA) where the slice is supported if necessary to update it according to the request from the master AMF at operation <NUM>. Here, the data stored by the NSSF may be identified by using the identity (ID) of the master AMF instance having made the request. The NSSF may determine the time of application for the updated NSSAI availability.

The NSSF transmits a response for the request from the master AMF, in which case when the slice information (e.g., AuthorizedNssaiAvailability) allowed to be used by the AMF is updated or added, this may also be notified to the master AMF at operation <NUM>. Here, to match the application time of the updated availability with other AMFs, the NSSF may transmit the corresponding time information as a portion of the response to the master AMF. Upon receiving the time information, the master AMF operates with application of the updated information from the time point when the corresponding time condition is satisfied.

The NSSF may also update the NSSAI available information of other AMF instances belonging to the AMF set requested from the master AMF at operation <NUM>. For example, the NSSF may find an AMF set related to the slice information received from the master AMF, find AMF instances belonging to the set, and update the NSSAI available information identified by the instance IDs of the AMF instances together.

If the NSSAI availability information is updated for other AMF instances belonging to the AMF set and AuthorizedNssaiAvailability is updated or added for each AMF instance, the NSSF may transmit a message notifying this to each AMF instance at operation <NUM>. This can be performed by using the NSSAI availability update notification service. Here, to match the application time of the updated availability with other AMF instances, the NSSF may transmit the corresponding time information as a portion of the message to the AMF. Upon receiving the time information, the AMF operates with application of the updated information from the time point when the corresponding time condition is satisfied.

The AMFs transmit a response for the request message from the base station, in which case configuration information of the AMF may be included in the response at operation <NUM>. If the network configuration supported by the AMF (TA, supported NSSA, PLMN, or the like) is updated in the NSSF, the AMF may notify this to the base station through the response message.

In addition, to address the above issue, the disclosure proposes a method that defines information shared commonly in a specific NF set separately as an NF set profile and uses this to improve signaling efficiency and match state information.

The NF set profile is stored or managed by using an identifier that can identify the corresponding NF set (NF set ID or ID of the NF instance that manages NF set information). The information shown in Table <NUM> may be included in the NF set profile, and any type of information shared by NF instances in the NF set (e.g., serving scope: supported area, or the like) may be added.

Likewise, information on available slices (NSSAI availability) can be shared and managed per set. In this case, the unit for storing/managing the slice information in the NF is not the ID of each AMF but the AMF set ID or the ID of the NF that manages information for each set. For example, the resource for which the NSSF stores corresponding information is managed per set, and may be identified by an AMF set ID or an ID of the NF that manages information for each set.

NSSAI availability information per set (NSSAI availability per set) may be composed of the following data shown in Table <NUM>.

supportedNssaiAvailabilityData may be configured as shown in Table <NUM> below.

<FIG> and <FIG> are diagrams illustrating a method for managing slice information in units of sets according to various embodiments of the disclosure.

<FIG> is a diagram illustrating an overall process of managing slice information in units of sets according to the disclosure.

The master AMF may determine whether to consider addition or update of network slice and TA information for the AMF set in the slice selection process according to the information received from the base station. If the network configuration for slice selection is updated, the master AMF may invoke the NSSF (which can be replaced with another NF like the NRF or SCP that manages and finds network state information) for a service of NSSAI availability update in units of sets at operation <NUM>. The service request may include the NSSAI availability information per set described above.

The NSSF may update or add information about a slice to be applied to the set and an area (TA) where the slice is supported if necessary to update it according to the request from the master AMF at operation <NUM>. Here, the data stored by the NSSF may be identified by using the identity (ID) of the AMF set having made the request. The NSSF may determine the time of application for the updated NSSAI availability per set.

The NSSF transmits a response for the request from the master AMF, in which case when the slice information (e.g., AuthorizedNssaiAvailability) allowed to be used by the AMF set is updated or added, this may also be notified at operation <NUM>. Here, to match the application time of the availability updated at operation <NUM> with other AMFs, the NSSF may transmit the corresponding time information as a portion of the response to the master AMF. Upon receiving the time information, the master AMF operates with application of the updated information from the time point when the corresponding time condition is satisfied.

The NSSF may also update the NSSAI available information of other AMF instances belonging to the AMF set requested from the master AMF at operation <NUM>. For example, the NSSF may find an AMF set for the slice information received from the master AMF, find AMF instances belonging to the set, and update the NSSAI available information identified by the instance IDs of the AMF instances together.

The NSSF may notify the NSSAI availability information per set to other AMF instances belonging to the AMF set at operation <NUM>. For example, when AuthorizedNssaiAvailability per set is updated or added, the NSSF may transmit a message for notifying this to each AMF instance. This can be performed by using the NSSAI availability update notification service. Here, to match the application time of the updated availability with other AMF instances, the NSSF may transmit the corresponding time information as a portion of the message to the AMF. Upon receiving the time information, the AMF operates with application of the updated information from the time point when the corresponding time condition is satisfied.

Each AMF instance may separately update its own NSSAI available information by using the authorized slice information per set received from the NSSF at operation <NUM>.

The AMFs including the master AMF transmit a response for the request message from the base station, in which case configuration information of the AMF may be included in the response at operation <NUM>. If the network configuration supported by the AMF (TA, supported NSSA, PLMN, or the like) is updated in the NSSF, the AMF may notify this to the base station through the response message.

<FIG> is a diagram illustrating operations of the master AMF according to a time series flow in relation to the embodiment described in <FIG> according to an embodiment of the disclosure.

Referring to <FIG>, when a new relationship and connection is generated for the configuration and management of the AMF, the master AMF may receive a RAN configuration information update request message from the base station for requesting an NG setup procedure or RAN configuration update at operation <NUM>.

The master AMF may determine whether a network configuration update, such as adding or changing network slice and TA information, has occurred for the AMF set based on the RAN configuration update information message received from the base station at operation <NUM>.

If the network configuration for slice selection is updated, the master AMF may transmit the NSSF (which can be replaced with another NF like the NRF or SCP that manages and finds network state information) an update request message for NSSAI availability update in units of sets to receive a slice service under the network configuration updated by reflecting the above network configuration update at operation <NUM>.

Thereafter, the NSSF updates or adds network configuration update information by using the AMF set identifier included in the per-set update request message from the master AMF and transmits a response for the update request to the master AMF, and the master AMF may receive it at operation <NUM>.

The master AMF may transmit a response including AMF configuration information to the base station according to the slice information updated in units of sets at operation <NUM>. Update information of the network configuration (TA, supported NSSAI, PLMN, or the like) supported by the AMF may be transmitted to the base station through this.

<FIG> is a diagram illustrating a method for managing a profile in units of NF sets according to an embodiment of the disclosure.

In this embodiment of the disclosure, the management of the NF set profile may be performed by the master NF (or, default AMF) belonging to the NF set. One of the NFs belonging to the NF set may be selected as the master NF, where a designated NF instance may be set to play the master role, or NF instances may be selected alternately in a round robin fashion to play the master role. Here, information may be exchanged between the NF instances to notify that only one NF instance operates as the master in the NF set at a specific time.

Referring to <FIG>, an NF set may be newly created or added, or configuration information of an NF set may be updated at operation <NUM>. Here, the configuration information of an NF set may include a set of parameters or attributes that are shared by all NF instances belonging to the NF set and applied in common.

The master NF may perform a process for registering the profile of the NF set to which it belongs with the NRF (or SCP) at operation <NUM>. Here, an NF register or NF set register service can be invoked, and the service request may include the identifier (ID) of the NF set to be registered and NF set profile. The NF set profile may include identifiers of NF instances belonging to the NF set.

The NRF may use the received information to store the profile of the NF set and generate resources for this at operation <NUM>. Thereafter, the resource for the NF set profile can be identified by the NF set ID.

The NRF transmits a response for the request to the master NF at operation <NUM>.

The NRF may deliver the NF set profile to other NF instances belonging to the NF set to notify the created/updated set profile at operation <NUM>. Here, the NRF may use an NF status notify or NF set status notify service.

Those NF instances having received a notification from the NRF may transmit an acknowledgment for the notification to the NRF at operation <NUM>.

<FIG> is a diagram illustrating a method for creating or adding an NF set, or updating configuration information of the NF set according to an embodiment of the disclosure.

The master NF may perform a process for registering the profile of the NF set to which it belongs with the NRF (or, SCP) at operation <NUM>. Here, an NF register or NF set register service can be invoked, and the service request may include the identifier (ID) of the NF set to be registered and NF set profile. The NF set profile may include identifiers of NF instances belonging to the NF set.

If the registration of the NF set profile is successful, the master NF may transmit the NF set profile to other NF instances to notify the created/updated set profile at operation <NUM>. Here, the master NF may use an NF status notify or NF set status notify service or a heartbeat service.

Those NF instances having received a notification from the master NF transmit an acknowledgment for the notification to the master NF at operation <NUM>.

<FIG> is a diagram illustrating an AMF selection process using a master AMF. The role and selection scheme of the master AMF are the same as those disclosed in <FIG> and <FIG> according to an embodiment of the disclosure.

Referring to <FIG>, the terminal may transmit an RRC message containing a NAS message for registration to the base station at operation <NUM>. Here, the terminal may include slice information (NSSAI) to be accessed by it as an AS layer parameter.

The base station may determine whether it is possible to perform AMF selection by using the identifier (ID) used by the terminal, slice information, and configured information. If the base station cannot perform AMF selection using the slice information or AS layer slice information is not included in the message received from the terminal at operation <NUM>, the base station selects the master (or default) AMF and forwards the initial UE message received from the terminal to the master AMF at operation <NUM>.

The master AMF may receive subscription information from the UDM if necessary, in which case slice information and subscribed S-NSSAls applicable to the subscriber may be received at operation <NUM>. If the terminal includes selected slice information (requested NSSAI) in the NAS layer, the master AMF may take this into account and selects an AMF based on the subscription information received from the UDM at operation <NUM>. If the master AMF can provide a service to the terminal, it performs the remaining portion of the registration process. If another AMF is selected, the master AMF transmits the base station a reroute NAS message including information for identifying the selected AMF (AMF information, AMF set information, or other master AMF information) and an initial UE message (registration request) received from the terminal at operation <NUM>.

The base station may select again an AMF to which the request of the terminal is to be transmitted by using the information received from the master AMF at operation <NUM>. If an AMF is designated and interworking with the designated AMF is possible, the base station may select the designated AMF. If AMF set information is received, one AMF can be selected from the corresponding AMF set. If another master AMF information is received, the base station may select the corresponding master AMF and transmit a message thereto.

<FIG> is a diagram illustrating an NF registration process according to an embodiment of the disclosure.

Referring to <FIG>, an NF of the network may transmit an NF registration request message to the NRF to perform an NF register process for registering its information at operation <NUM>. Here, the request message transmitted by the NF may include the profile of the NF, and may also include information about supported features indicating functions supported by the NF. In particular, indications of whether indirect communication, delegated discovery, SM context transfer, binding indication, and NF set are supported as enhancements to the SBA, among the functions supported by the NF, may be included. Information about the supported features may be included as a portion of the NF profile, or may be separated from the NF profile and included in the request message as separate data.

The NRF transmits a response message for the request of the NF at operation <NUM>, in which case the response message may include supported features available in the network where the NF is currently registered. The contents and message composition that may be included in the supported features may be the same as those of the supported features included in the request message. In addition, the response of the NRF may additionally include information to be applied when the NF uses the SCP in the network. The SCP information may include the address of the SCP, the operation mode of the SCP (one of modes A, B, C and D), whether indirect communication is used, and whether delegated discovery is used.

The NF stores the information received from the NRF, and performs subsequent operations by using the received information (whether the SCP, indirect communication, or delegated discovery is used) at operation <NUM>.

With reference to <FIG>, an NF of the network may transmit an NF registration request message to the NRF to perform an NF register process for registering its information at operation <NUM>. Here, the request message transmitted by the NF may include the profile of the NF, and may also include information about supported features indicating functions supported by the NF. In particular, indications of whether indirect communication, delegated discovery, SM context transfer, binding indication, and NF set are supported as enhancements to the SBA, among the functions supported by the NF, may be included. Information about the supported features may be included as a portion of the NF profile, or may be separated from the NF profile and included in the request message as separate data. In this case, the SCP can play a role of receiving and forwarding messages between the NF and the NRF. For example, the SCP may receive a registration request message from the NF and forward it to the NRF.

The NRF transmits a response for the request of the NF at operation <NUM>, in which case the response message may include supported features available in the network where the NF is currently registered. The contents and message composition that may be included in the supported features may be the same as those of the supported features included in the request message.

The response message transmitted by the NRF is first received by the SCP, and the SCP may include SCP operation information in the response message before forwarding at operation <NUM>. The SCP information may include the address of the SCP, the operation mode of the SCP (one of modes A, B, C and D), whether indirect communication is used, and whether delegated discovery is used. The SCP may transmit the NF a response message including the above information in addition to the information received from the NRF.

The NF stores the information received from the NRF (and the SCP), and may perform subsequent operations by using the received information (whether the SCP, indirect communication, or delegated discovery is used) at operation <NUM>.

Referring to <FIG>, one NF of the network may transmit a discovery request message to the NRF to find or select another NF or receive information thereof at operation <NUM>. Here, the request message transmitted by the NF may include information related to the target to be found. To discover a desired NF, the NF may include indications of whether indirect communication, delegated discovery, SM context transfer, binding indication, and NF set are supported as enhancements to the SBA in the request message as query parameters.

The NRF searches for a candidate NF that satisfies the condition for the request of the NF and transmits a response at operation <NUM>. The response message may include information about candidate NFs that the requesting NF can select and supported features of the candidate NFs. The response of the NRF may additionally include information to be applied when the requesting NF uses the SCP in the network to communicate with the candidate NFs. The SCP information may include the address of the SCP, the operation mode of the SCP (one of modes A, B, C and D), whether indirect communication is used, and whether delegated discovery is used.

The NF stores the information received from the NRF, and may perform subsequent operations by using the received information (information about candidate NFs, whether the SCP, indirect communication, or delegated discovery is used) at operation <NUM>.

Referring to <FIG>, one NF of the network (operating as a consumer NF) may transmit a request message for a specific service to another NF (operating as a producer NF) at operation <NUM>. Here, the request message transmitted by the consumer NF may include parameters for performing the corresponding service and information on the supported features of the consumer NF. The information on the supported features may include indications of whether indirect communication, delegated discovery, SM context transfer, binding indication, and NF set are supported particularly as enhancements to the SBA, among the functions supported by the consumer NF. The supported features may be included as one of service request parameters, or may be separated and included in the request message as separate data.

The producer NF may process the service request from the consumer NF and transmit a response message corresponding thereto at operation <NUM>. Here, the response message transmitted by the producer NF may include parameters for the result of performing the corresponding service and information on the supported features of the producer NF. The information on the supported features may include indications of whether indirect communication, delegated discovery, SM context transfer, binding indication, and NF set are supported particularly as enhancements to the SBA, among the functions supported by the producer NF. The supported features may be included as one of service result parameters, or may be separated and included in the response message as separate data.

The consumer NF and the producer NF may store the information exchanged therebetween, and may perform subsequent operations by using the received information (information on peer NFs, whether the SCP, indirect communication, or delegated discovery is used) at operation <NUM>.

<FIG> is a diagram illustrating a method for an NF to receive SCP information through an NRF according to a claimed embodiment of the disclosure.

Referring to <FIG>, one NF of the network (which can operate as a consumer NF or a producer NF) may transmit a discovery request message to the NRF to receive information for using the SCP in the configuration of the network at operation <NUM>. Here, the request message transmitted by the NF may include a parameter indicating that the target of discovery is an SCP and information on supported features of the NF. The information on the supported features may include indications of whether indirect communication, delegated discovery, SM context transfer, binding indication, and NF set are supported, particularly as enhancements to the SBA, among the functions supported by the NF. The supported features may be included as one of service request parameters, or may be separated and included in the request message as separate data. In addition, when the requesting NF needs to receive SCP information for a specific NW slice, it may include the identifier of the target slice in the request message. The above request may be a regular NF discovery request, a SCP discovery request for the SCP only, or a request for receiving message delivery/routing information.

The NRF may search for a SCP that satisfies the condition for the request of the NF and transmit a response message at operation <NUM>. The response message may include information about the SCP that the requesting NF can use (SCP address, NF ID, identifiers of slices supported by the SCP, connection relationship between the SCP and other SCPs, or the like) and supported features of the SCP. The response of the NRF may additionally include information to be applied when the requesting NF uses the SCP in the network to communicate with other NFs. This may include the operation mode of the SCP (one of modes A, B, C and D), whether indirect communication is used, and whether delegated discovery is used. If there is no SCP that satisfies the request of the NF, the NRF may explicitly notify this to the NF through the response message. The above response is a response for the request message from the NF, that is, a response corresponding to a regular NF discovery request, a SCP discovery request for the SCP only, or a request for receiving message delivery/routing information. If the connection between the NF and the SCP is composed of multiple hops in the network configuration, the discovery response may include information about the next-hop NF (or SCP) only from the viewpoint of the discovery requesting NF (or SCP), or may include information about all NFs (or SCPs) along the hop sequence on the transmission path.

The NF may store the information received from the NRF, and may perform subsequent operations by using the received information (whether the SCP is used, SCP address, NF ID, whether indirect communication or delegated discovery is used, or the like) at operation <NUM>. If the received response message contains information that there is no SCP or does not contain SCP information, the NF may assume that there is no SCP for subsequent operations.

<FIG> is a block diagram of a terminal according to an embodiment of the disclosure.

Referring to <FIG>, the terminal may include a transceiver <NUM>, a terminal controller <NUM>, and a storage <NUM>. In the disclosure, the terminal controller <NUM> may be defined as a circuit, an application-specific integrated circuit, or at least one processor.

The transceiver <NUM> may transmit and receive signals to and from another network entity. The transceiver may receive system information, a synchronization signal, or a reference signal from, for example, a base station.

The terminal controller <NUM> may control the overall operation of the terminal according to an embodiment proposed in the disclosure. For example, the terminal controller may control signal flows between blocks to perform operations according to the above-described drawings and flowcharts. Specifically, the terminal controller may operate according to a control signal from the base station and may exchange messages or signals with another terminal and/or network entity.

The storage <NUM> may store at least one of information transmitted and received through the transceiver <NUM> or information generated through the terminal controller.

<FIG> is a block diagram of a base station according to an embodiment of the disclosure.

Referring to <FIG>, the base station may include a transceiver <NUM>, a base station controller <NUM>, and a storage <NUM>. In the disclosure, the base station controller <NUM> may be defined as a circuit, an application-specific integrated circuit, or at least one processor.

The transceiver <NUM> may transmit and receive signals to and from another network entity. The transceiver may transmit system information, a synchronization signal, or a reference signal to, for example, a terminal, and may receive information from an NF to provide a service to the terminal.

The base station controller <NUM> may control the overall operation of the base station according to an embodiment proposed in the disclosure. For example, the base station controller may control signal flows between individual blocks to perform operations according to the above-described drawings and flowcharts. Specifically, the base station controller may exchange messages or signals with a terminal, another base station and/or network entity.

The storage <NUM> may store at least one of information transmitted and received through the transceiver or information generated through the base station controller.

<FIG> is a block diagram of an NF (including an NF instance) according to an embodiment of the disclosure.

The NF shown in <FIG> may include at least one of the AMF, master AMF, NSSF, SCP, or NRF described above, and is not limited to a specific NF.

Referring to <FIG>, the NF may include a transceiver <NUM>, an NF controller <NUM>, and a storage <NUM>.

The transceiver <NUM> may transmit and receive signals to and from another network entity. The transceiver may transmit data and control information for providing a service to a base station (RAN), and may transmit information according to the disclosure to another NF.

The NF controller <NUM> may control the overall operation of the NF according to an embodiment proposed in the disclosure.

The storage <NUM> may store at least one of information transmitted and received through the transceiver or information generated through the NF controller.

The methods according to the embodiments described in the claims or specification of the disclosure may be implemented in the form of hardware, software, or a combination thereof.

When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured to be executable by one or more processors of an electronic device. The one or more programs include instructions that cause the electronic device to execute the methods according to the embodiments described in the claims or specification of the disclosure.

Such a program (software module, software) may be stored in a random access memory, a nonvolatile memory, such as a flash memory, a read only memory (ROM), an electrically erasable programmable read only memory (EEPROM), a magnetic disc storage device, a compact disc ROM (CD-ROM), a digital versatile disc (DVD), other types of optical storage devices, or a magnetic cassette. Or, such a program may be stored in a memory composed of a combination of some or all of them. In addition, a plurality of component memories may be included.

In addition, such a program may be stored in an attachable storage device that can be accessed through a communication network, such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a communication network composed of a combination of these. Such a storage device may access the device that carries out an embodiment of the disclosure through an external port. In addition, a separate storage device on a communication network may access the device that carries out an embodiment of the disclosure.

Claim 1:
A method performed by a service communication proxy, SCP, entity (<NUM>) in a wireless communication system, the method comprising:
transmitting, to a network repository function, NRF, entity (<NUM>), a discovery request message indicating a type of a target network function, NF, is an SCP; and
as a response to the discovery request message, receiving, from the NRF entity (<NUM>), a first message comprising information associated with the target NF,
wherein the information associated with the target NF comprises at least one of the type of the target NF indicating the SCP, an NF identifier of the target NF, or an address of the target NF.