Method and device for network-based slice selection in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a data transmission rate higher than that of a 4G communication system such as LTE. According to one embodiment of the present disclosure, a method performed by a first network entity in a wireless communication system may comprise the steps of: receiving, from a user equipment, through a base station, a session request message requesting a session for network-based slice selection (NBSS); transmitting, to a unified data management (UDM), a subscription information request message for requesting subscription information of the user equipment; receiving, from the UDM, a subscription information response message including subscription information of the user equipment; transmitting, to a network repository function (NRF), a network function (NF) discovery request message for requesting an address of a second network entity providing a network selection function; receiving, from the NRF, an NF discovery response message including the address of the second network entity; on the basis of the address of the second network entity, transmitting, to the second network entity, a slice selection request message for selecting a network slice to be provided to the UE; and receiving, from the second network entity, a slice selection response message including network slice information related to the selected network slice.

Description

Method and apparatus for network-based slice selection in a wireless communication system

[0001] The present disclosure relates to a method and apparatus for network-based slice selection in a wireless communication system.

[0002] Looking back at the evolution of wireless communication through successive generations, technologies have been developed primarily for human-oriented services, such as voice, multimedia, and data. Following the commercialization of 5G (5th Generation) communication systems, connected devices, which have been increasing explosively, are expected to be connected to communication networks. Examples of networked objects include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructures, construction machinery, and factory equipment. Mobile devices are expected to evolve into various form factors, such as augmented reality glasses, virtual reality headsets, and holographic devices. In the 6G (6th Generation) era, efforts are underway to develop improved 6G communication systems to connect hundreds of billions of devices and objects to provide diverse services. For this reason, 6G communication systems are being referred to as "beyond 5G" systems.

[0003] In the 6G communication system predicted to be realized around 2030, the maximum transmission speed is tera (i.e., 1,000 gigabit) bps (bit per second), and the wireless latency is 100 microseconds (μsec). In other words, compared to the 5G communication system, the transmission speed in the 6G communication system is 50 times faster, and the wireless latency is reduced to one-tenth.

[0004] To achieve such high data transmission speeds and ultra-low latency, 6G communication systems are being considered for implementation in the terahertz (THz) band (e.g., the 95 gigahertz (GHz) to 3 terahertz (3THz) band). Due to more severe path loss and atmospheric absorption phenomena compared to the millimeter wave (mmWave) band introduced in 5G, the importance of technologies capable of guaranteeing signal reach, or coverage, is expected to increase in the terahertz band. As key technologies to ensure coverage, new waveforms, beamforming, and multi-antenna transmission technologies such as massive Multiple-Input and Multiple-Output (MIMO), Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas, which are superior in terms of coverage compared to RF (Radio Frequency) devices, antennas, and OFDM (Orthogonal Frequency Division Multiplexing), must be developed. In addition, new technologies such as metamaterial-based lenses and antennas, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS) are being discussed to improve the coverage of terahertz band signals.

[0005] In addition, to improve frequency efficiency and system network, development is underway in 6G communication systems for full duplex technology, in which uplink and downlink simultaneously utilize the same frequency resources at the same time; network technology that integrates satellites and HAPS (High-Altitude Platform Stations); network structure innovation technology that supports mobile base stations and enables network operation optimization and automation; dynamic spectrum sharing technology through collision avoidance based on spectrum usage prediction; AI-based communication technology that utilizes AI (Artificial Intelligence) from the design stage and internalizes end-to-end AI support functions to realize system optimization; and next-generation distributed computing technology that realizes services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high performance communication and computing resources (Mobile Edge Computing (MEC), cloud, etc.). In addition, attempts are continuing to further strengthen connectivity between devices, further optimize networks, promote the softwareization of network entities, and increase the openness of wireless communication through the design of new protocols to be used in 6G communication systems, the implementation of hardware-based security environments, the development of mechanisms for the safe utilization of data, and the development of technologies regarding privacy maintenance methods.

[0006] Due to the research and development of such 6G communication systems, it is expected that a new dimension of hyper-connected experience will become possible through the hyper-connectivity of 6G communication systems, which encompasses not only connections between objects but also connections between people and objects. Specifically, it is projected that 6G communication systems will enable the provision of services such as truly immersive eXtended Reality (XR), high-fidelity mobile holograms, and digital replicas. Furthermore, services such as remote surgery, industrial automation, and emergency response, which are provided through 6G communication systems with enhanced security and reliability, will be applied in various fields including industry, healthcare, automotive, and home appliances.

[0007] The present disclosure aims to provide a method and apparatus capable of effectively providing services in a wireless communication system.

[0008] According to one embodiment of the present disclosure, a method performed by a first network entity in a wireless communication system comprises: receiving a session request message from a terminal (user equipment) requesting a session for network-based slice selection (NBSS) through a base station; transmitting a subscriber information request message to a unified data management (UDM) to request subscription information of the terminal; receiving a subscriber information response message from the UDM containing subscriber information of the terminal; transmitting a network function discovery request message to a network repository function (NRF) requesting the address of a second network entity providing a network selection function; receiving an NF discovery response message from the NRF containing the address of the second network entity; transmitting a slice selection request message to the second network entity for selecting a network slice to be provided to the terminal based on the address of the second network entity; and receiving from the second network entity information regarding a selected network slice It may include the step of receiving a slice selection response message containing network slice information.

[0009] According to one embodiment of the present disclosure, in a wireless communication system, a first network entity comprises at least one processor and at least one memory communicationly coupled to the at least one processor for storing instructions, wherein the instructions are executed individually or in any combination by the at least one processor, and the first network entity receives a session request message requesting a session for network-based slice selection (NBSS) through a base station from a terminal (user equipment), transmits a subscriber information request message to a unified data management (UDM) for requesting subscription information of the terminal, receives a subscriber information response message from the UDM containing subscriber information of the terminal, transmits a network function discovery request message to a network repository function (NRF) for requesting the address of a second network entity providing a network selection function, and receives from the NRF the address of the second network entity NF search response message is received, a slice selection request message for selecting a network slice to be provided to the terminal based on the address of the second network entity is transmitted to the second network entity, and a slice selection response message including network slice information regarding the selected network slice is received from the second network entity.

[0010] The present disclosure may provide an apparatus and a method capable of effectively providing services in a mobile communication system. The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure pertains from the description below.

[0011] FIG. 1 illustrates the structure of a network system according to various embodiments of the present disclosure.

[0012] FIG. 2 illustrates a flowchart of a terminal registration procedure according to one embodiment of the present disclosure.

[0013] FIG. 3 illustrates a flowchart of a session selection procedure through a non-access stratum (NAS) message according to one embodiment of the present disclosure.

[0014] FIG. 4 illustrates a flowchart of a session establishment procedure for slice selection based on a user plane according to one embodiment of the present disclosure.

[0015] FIG. 5 illustrates a flowchart of a user plane-based session slice selection procedure according to one embodiment of the present disclosure.

[0016] FIG. 6 illustrates the functional configuration of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0017] FIG. 7 illustrates the functional configuration of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0018] In wireless communication systems, network slicing technology may include technology capable of providing multiple custom networks that satisfy different requirements based on a single infrastructure.

[0019] A network slice may include virtual networks that satisfy specific transmission requirements (e.g., ultra-low latency, high bandwidth, a large number of devices, etc.). A method may be required to allocate an appropriate network slice based on the traffic generated.

[0020] In various embodiments of the present disclosure, a 5G mobile communication network may be composed of a 5G terminal (user equipment, UE), a 5G radio access network (RAN), and a 5G core network (CN).

[0021] According to one embodiment, a 5G core network may include, but is not limited to, an access and mobility management function (AMF) that provides mobility management functions for UEs, a session management function (SMF) that provides session management functions, a user plane function (UPF) that performs data delivery functions, a policy control function (PCF) that provides policy control functions, a unified data management function (UDM) that provides data management functions such as subscriber data and policy control data, and a unified data repository (UDR) that stores data for a plurality of network functions (NF) including the UDM.

[0022] In a 5G system, network slicing technology refers to a technology and structure that enables the implementation of multiple virtualized and independent logical networks within a single physical network. Network operators can provide services by configuring virtual end-to-end networks called network slices to satisfy the specialized requirements of services / applications. Network slices are distinguished by an identifier called S-NSSAI (single-network slice selection assistance information), and network operators can provide network slice(s) to terminals. Terminals can receive services based on the network slices provided by the network operator.

[0023] According to one embodiment of the present disclosure, for network registration of a terminal in a 5G system, the terminal may transmit identifier information (i.e., requested S-NSSAIs) for network slices to be requested from the network to the AMF. The AMF may provide the terminal with information (Allowed NSSAI) regarding network slices that the terminal can use, taking into account the requested S-NSSAIs and subscriber information. The Allowed NSSAI provided by the AMF to the terminal may include other information excluding the information corresponding to the requested S-NSSAIs requested by the terminal. For example, the Allowed NSSAI provided by the AMF to the terminal may include information (default configured NSSAI) regarding default slices and information (default subscribed S-NSSAIs) regarding slices configured by default among the subscribed slices included in the terminal subscriber information.

[0024] According to one embodiment of the present disclosure, if a network slice cannot be included in the Allowed NSSAI, the AMF may transmit a network registration rejection message to the terminal, including a cause code indicating that the registration is rejected due to the absence of available slices. For example, the AMF may transmit a network registration rejection message to the terminal if the Default Configured NSSAI and Default Subscribed S-NSSAIs do not exist, or if the Default Configured NSSAI and Default Subscribed S-NSSAIs are unavailable.

[0025] According to one embodiment of the present disclosure, in order to include any slice in the Allowed NSSAI, a Network Slice Admission Control (NSAC) procedure and a Network Slice-Specific Authentication and Authorization (NSSAA) procedure may be performed. In the NSAC procedure, whether to accept a slice may be determined based on the number of terminals currently registered in a specific slice and the maximum number of registered terminals allowed in that slice; that is, whether to include the slice in the Allowed NSSAI may be determined through the NSAC procedure.

[0026] According to one embodiment of the present disclosure, a Network Slice Admission Control Function (NSAF) monitors the number of registered terminals and the number of PDU sessions established per slice for network slices that are NSAC targets, and can perform control to ensure that the number of registered terminals and the number of PDU sessions established per slice are each kept below the maximum number of registered terminals and the maximum number of PDU sessions, respectively. An AMF may send an update request message to the NSACF to notify that a new terminal has been registered or an existing registered terminal has been deregistered in a slice that is an NSAC target when a new terminal is registered or an existing registered terminal is deregistered. An SMF may send an update request message to the NSACF to notify that a new PDU session has been created or an existing PDU session has been deregistered in a slice that is an NSAC target when a new PDU session is created or an existing PDU session is deregistered in a slice that is an NSAC target when a new PDU session is created or an existing PDU session is deregistered. When the NSAC receives a message notifying the registration of a new terminal or the creation of a new PDU session in a specific slice, it determines whether to allow it based on the maximum number of terminals and the maximum number of PDU sessions for that slice, and then includes the allowance status in each response message.

[0027] According to one embodiment of the present disclosure, for transmitting and receiving data to and from a specific data network (DN) through allowed slices (Allowed NSSAIs), a terminal may select one of the allowed slices, request the creation of a Packet Data Unit (PDU) session to a specific Data Network Name (DNN) in the slice, and transmit and receive data through the created PDU session. A PDU session may consist of multiple traffic flows. The traffic flows may consist of two types: a Guaranteed Bitrate Quality-of-Service Flow (GBR QoS Flow) and a non-GBR QoS Flow.

[0028] The present disclosure may provide methods and apparatus for performing network slicing in a wireless communication system. Additionally, the present disclosure describes various embodiments using terms defined in some communication standards (e.g., 3GPP (3rd generation partnership project)), but this is merely illustrative. Various embodiments of the present disclosure may be easily modified and applied to other communication systems. Furthermore, the present disclosure describes various embodiments based on a 5G network system or a 6G network system, but this is merely illustrative. It will be readily understood by those skilled in the art to which the present disclosure pertains that various embodiments of the present disclosure may be applied to other network systems.

[0029] FIG. 1 illustrates the structure of a network system according to various embodiments of the present disclosure.

[0030] Referring to FIG. 1, a 5G mobile communication network according to various embodiments of the present disclosure may be composed of a 5G UE (user equipment, terminal) (110), a 5G RAN (radio access network, base station, base station, gNB (5G nodeB), eNB (evolved nodeB, etc.) (120), and a 5G core network. The 5G core network may be composed of network functions such as an access and mobility management function (AMF) (150) providing mobility management functions for the UE, a session management function (SMF) (160) providing session management functions, a user plane function (UPF) (170) performing data delivery roles, a policy control function (PCF) (180) providing policy control functions, a unified data management function (UDM) (153) providing data management functions such as subscriber data and policy control data, and a unified data repository (UDR) storing data of various network functions such as the UDM.

[0031] In the present disclosure, a conceptual link connecting NFs within a 5G system may be referred to as a reference point. For example, with reference to FIG. 1, examples of reference points included in a 5G system architecture are as follows.

[0032] - N1: Reference point between UE and AMF

[0033] - N2: Reference point between (R)AN and AMF

[0034] - N3: Reference point between (R)AN and UPF

[0035] - N4: Reference point between SMF and UPF

[0036] - N5: Reference point between PCF and AF

[0037] - N6: Reference point between UPF and DN

[0038] - N7: Reference point between SMF and PCF

[0039] - N8: Reference point between UDM and AMF

[0040] - N9: Reference point between 2 core UPFs

[0041] - N10: Reference point between UDM and SMF

[0042] - N11: Reference point between AMF and SMF

[0043] - N12: Reference point between AMF and AUSF

[0044] - N13: Reference point between UDM and the authentication server function (AUSF)

[0045] - N14: Reference point between 2 AMFs

[0046] - N15: Reference point between PCF and AMF in non-roaming scenarios, reference point between PCF and AMF within the visited network in roaming scenarios

[0047] According to one embodiment of the present disclosure, as described above, network slicing in a 5G system may refer to a technology and structure that enables the implementation of multiple virtualized and independent logical networks within a single physical network. A network operator may provide services by configuring a virtual end-to-end network called a network slice to satisfy the specialized requirements of a service / application. A network slice may be distinguished by an identifier called S-NSSAI (single-network slice selection assistance information). The network may transmit to a terminal a set of slices allowed to the terminal (e.g., allowed NSSAI(s)) in a terminal registration procedure (e.g., UE registration procedure). The terminal may transmit and receive application data through a PDU (protocol data unit) session created through one of the S-NSSAIs (i.e., network slices) included in the set of slices allowed to the terminal transmitted from the network.

[0048] In the present disclosure, a mobile communication network in a 6G system may be defined as an evolved form of a 5G mobile communication network. In the present disclosure, a RAN in 6G may be referred to as a 6G RAN. Furthermore, in the present disclosure, 6G NFs included in a core network in 6G may be referred to as evolved AMF (eAMF), evolved SMF (eSMF), and evolved UPF (eUPF), respectively, as terms corresponding to 5G NFs (e.g., AMF, SMF, UPF, etc.). Of course, it will be obvious that entities included in a RAN in 6G and a core network in 6G may be referred to differently from those described above.

[0049] According to one embodiment, the 6G RAN and 6G core network can additionally support the following functions compared to the 5G RAN.

[0050] - 6G RAN: For example, in the case of 6G RAN, a WUS-based energy saving function can be supported as a basic function. An energy saving function may mean a function that switches to sleep mode (a low-power state that does not support some functions) and wakes up to normal operation (supports all functions) only when a Wake up signal (WUS) is received from a terminal.

[0051] - 6G RAN can utilize AI capabilities for various basic functions such as channel state prediction, downlink traffic scheduling, uplink packet scheduling, radio resource management, and handover. To this end, 6G RAN can provide AI model management functions tailored to each purpose, AI model application functions based on changed conditions, data collection and training functions for training AI models, and AI model-based inference functions.

[0052] - 6G RAN supports various Radio Access Technologies (RATs) and can support Multi-RAT Spectrum Sharing (MRSS), which allows for dynamic sharing of frequencies among various Radio Access Technologies (RATs). Additionally, 6G RAN supports various Radio Access Technologies (RATs) by default and can support Multi-RAT Spectrum Sharing (MRSS), which allows for dynamic sharing of frequencies among various Radio Access Technologies (RATs).

[0053] - While 5G RANs communicated with the 5G core network solely through AMFs, 6G RANs can provide interfaces for direct communication with various NFs of the 6G core network. For example, a 6G RAN can communicate directly with NFs that provide session management functions of the 6G core network (e.g., which may be located in eSMFs or 6G SMFs). Additionally, it can support SCTP-based protocols as well as, for example, HTTP protocols and / or QUIC-based Service-based Interfaces (SBIs), and can communicate with other NF(s) and RANs through SBIs.

[0054] According to one embodiment, a 6G core network can additionally support the following functions compared to a 5G core network including 5G NFs.

[0055] - The 6G Core Network provides interfaces for communication with the 6G RAN and 6G UE. At this time, it can provide interfaces with the 6G UE not only through the control plane but also through the user plane.

[0056] - 6G core networks can provide functions such as mobility management, connectivity management, authentication, policies, and service / data exposure. In addition, they can provide various new services such as Converged Computing Service, Integrated Sensing and Communication Service (ISAC), non-3GPP Sensing Service, and AI / ML.

[0057] According to one embodiment of the present disclosure, a mobile communication network in a 6G system may be composed of a 6G UE (user equipment, terminal), a 6G RAN (radio access network, base station, evolved gNB (egNB), etc.) and a 6G core network. The 6G core network may be composed of network functions such as an evolved UDR (eUDR) that stores data of various network functions, including an Evolved AMF (eAMF) that provides mobility management functions for the UE, an Evolved SMF (eSMF) that provides session management functions, an Evolved UPF (eUPF) that performs data delivery roles, an Evolved PCF (ePCF) that provides policy control functions, an Evolved UDM (eUDM) that provides data management functions such as subscriber data and policy control data.

[0058] Of course, the types of entities in the 6G system architecture are not limited to this. For example, an entity in the 6G system architecture (i.e., 6G entity) corresponding to an entity in the 5G system architecture of FIG. 1 (i.e., 5G entity) may include some or all of the functions of the 5G entity, and may also include other functions for 6G services. For example, an eAMF in the 6G system may provide mobility management, authentication management, and connection management functions for terminals provided by an AMF in the 5G system.

[0059] In the present disclosure, reference points between 6G entities may be expressed similarly to the names of reference points between 5G entities in FIG. 1. For example, in a 6G system, a reference point corresponding to N1 in a 5G system may be referred to as N1+.

[0060] In one embodiment of the present disclosure, a terminal may include application information in a message transmitted to a network. Alternatively, the terminal may receive application information from a message received from a network. In the present disclosure, other names may be used as terms corresponding to 'application information'. For example, terms such as traffic descriptor, application descriptor, or slice selection assistance information may be used as terms corresponding to application information.

[0061] According to one embodiment of the present disclosure, the application information may include information about a plurality of applications. For example, the application information may include information about a plurality of traffic flows.

[0062] According to one embodiment of the present disclosure, application information may include one or more of the following information. Alternatively, application information may include information that can be matched with the following information.

[0063] - App ID: Application identifier

[0064] - IP descriptor: Destination IP address, destination port number, protocol type used over IP (e.g., TCP, UDP, QUIC)

[0065] - non-IP descriptor: Information about the destination of non-IP traffic (e.g., MAC address, etc.)

[0066] - DNN(data network name)s: Application information may include at least one DNN.

[0067] - Connection Capabilities: Application information may include at least one Connection capability. A Connection capability may include a traffic category. The traffic category may represent information such as IMS (IP multimedia subsystem), MMS (multimedia messaging service), SUPL (secure user plane location), Internet, LCS UP (location services user plane) positioning, Operator Specific Connection Capabilities, or one of IoT (internet of things) Delay-tolerant, IoT-non-delay Tolerant, Downlink Streaming, Uplink Streaming, Vehicular communications, Real-time interactive, Unified Communications, Background, Mission Critical Communications, Time Critical Communications, Low latency loss tolerant communications in un-acknowledged mode.

[0068] - Domain descriptor(s): Information representing a domain, which may include FQDN (fully qualified domain name)(s) or regular expressions.

[0069] - PIN (Personal IoT Network) ID: May include a PIN identifier. A PIN can represent a group of devices or traffic belonging to a specific PIN network.

[0070] - Connectivity Group ID: The Connectivity Group ID may represent an identifier for a group of devices connected to the UE (e.g., Non-Authenticable Non-3GPP (NAUN3) devices or Authenticable Non-3GPP (AUN3) devices) or an identifier for traffic to said group of devices.

[0071] - Device ID: May include a Device ID to identify devices connected to the UE.

[0072] According to one embodiment of the present disclosure, application information may be transmitted in the form of parameters (i.e., a non-transparent container) or transmitted by being contained in a transparent container. When transmitted by being contained in a transparent container, the application information can be viewed only at the final destination receiving the application information.

[0073] FIG. 2 illustrates a flowchart of a terminal registration procedure according to one embodiment of the present disclosure.

[0074] According to one embodiment of the present disclosure, in step 210, the terminal (UE) may transmit an access network (AN) message (AN parameter, registration request) to the base station (RAN). The specific name of the registration request message is not limited to the example of step 210 of FIG. 2 and may be referred to by a name different from the registration request message. The registration request message is a message transmitted by the terminal to the core network and may include a message intended for initial access to initiate the terminal's mobile communication service, periodically reporting the terminal's location to the network, or reporting to the network when the terminal's location (e.g., Tracking Area) has changed.

[0075] According to one embodiment of the present disclosure, a terminal may transmit a registration request message to a network that includes an indicator (e.g., support of NBSS) corresponding to an AN parameter transmitted to a RAN when requesting (or supporting) Network-based Slice Selection (NBSS). The terminal may determine whether to request NBSS based on configuration information. For example, the terminal may determine whether to request NBSS based on configuration information that includes information on whether to allow NBSS requests per PLMN. Configuration information for determining whether to request NBSS may be pre-configured in the terminal or received from the network.

[0076] According to one embodiment of the present disclosure, the terminal may not include an NSSAI (i.e., a set containing S-NSSAIs that are slice identifiers). For example, if the terminal does not request network-based slice selection, it may not include an indicator (e.g., support of NBSS) corresponding to an AN parameter transmitted to the RAN, and may include an NSSAI (i.e., a set containing S-NSSAIs that are slice identifiers).

[0077] According to one embodiment of the present disclosure, a NAS message (e.g., a registration request message) transmitted by a terminal to an AMF may include at least one of a UE identifier (e.g., SUCI (subscription concealed identifier), 5G-GUTI (5G-globally unique temporary identity), or PEI (permanent equipment identifier), etc.), a Registration type, and information indicating core network-related support functions of the UE (e.g., 6G UE MM (mobility management) core network capability or 5G UE MM core network capability).

[0078] According to one embodiment of the present disclosure, when a terminal requests (or supports) network-based slice selection (or slice registration), a NAS message (e.g., a registration request message) transmitted by the terminal to an eAMF may not include network slice identifier information requested by the UE.

[0079] According to one embodiment of the present disclosure, when a terminal requests (or supports) network-based slice selection, the registration request message may include an indicator indicating that the terminal supports the requested function. The indicator may be included in information indicating core network-related support functions of the UE. The indicator indicating that the terminal supports the requested function may be expressed in various forms. For example, the indicator indicating that the terminal supports the requested function may be expressed as Support of 6G NAS, Support of 6G Network Slicing, Support of Network-based slice selection, or Support of reporting traffic descriptors. Of course, it is not limited thereto.

[0080] According to one embodiment of the present disclosure, when a terminal requests (or supports) network-based slice selection, the terminal may transmit to a network a registration request message including application information requesting network-based slice selection. The application information may include information about a plurality of applications. The application information may include information about a plurality of traffic flows.

[0081] According to one embodiment of the present disclosure, at step 220, the RAN may select an eAMF based on configuration information if the AN message received from the terminal contains a network-based slice selection indicator and / or does not contain an NSSAI. Alternatively, the RAN may select network slice(s) based on configuration information and then select an AMF that supports the corresponding slices.

[0082] According to one embodiment of the present disclosure, at step 220, the RAN may transmit an N2+ message (N2+ parameters, registration request) to the eAMF. The N2+ parameters may include a selected PLMN ID and location information of the terminal. For example, the location information of the terminal may include Location Information and a Cell ID associated with the cell where the UE is camping, a RAN node ID, etc., but is not limited thereto.

[0083] According to one embodiment of the present disclosure, at step 230, the eAMF may obtain subscriber information for a terminal from the eUDM. For example, the eAMF may send a subscription request message to the eUDM. The eAMF may receive a subscription response message from the eUDM. The subscriber information may include information indicating that NBSS is allowed. For example, the information indicating that NBSS is allowed within the subscriber information may include a list of allowed application information or a list of non-allowed application information.

[0084] According to one embodiment of the present disclosure, at step 240, the eAMF may determine whether to perform network-based slice selection for the terminal. For example, the eAMF may determine to perform network-based slice selection for the terminal if the subscriber information for the terminal obtained at step 230 includes information regarding network-based slice selection. For example, the eAMF may determine to perform network-based slice selection if a message received from the terminal (e.g., a registration request message) includes an indicator requesting network-based slice selection and / or does not include network slice identifier information requested by the UE. In another embodiment, the eAMF may determine to perform network-based slice selection based on information included in a message received from the RAN (N2+ message).

[0085] According to one embodiment of the present disclosure, if the eAMF determines a network-based slice selection for the terminal in step 240, the eAMF may transmit to the terminal a NAS message (e.g., registration accept or registration reject) containing an indicator for the network-based slice selection. For example, the eAMF may transmit to the terminal a NAS message containing an indicator for the network-based slice selection expressed as NBSS allowed. Additionally, if network-based slice selection is allowed for only some applications for the terminal, the eAMF may transmit to the terminal a NAS message containing a list of application information that allows network-based slice selection and / or a list of application information that does not allow network-based slice selection.

[0086] According to one embodiment of the present disclosure, if a message received from eAMF includes an indicator for network-based slice selection, the terminal determines that network-based slice selection is possible for an application and may transmit a message to the network containing application-specific application information. Additionally, the terminal may transmit a message to the network that does not include S-NSSAI(s) for the said application(s).

[0087] According to one embodiment of the present disclosure, if a message received from an eAMF includes an indicator for network-based slice selection and a list of application information for acceptable application(s), the terminal may store the received list and determine that network-based slice selection is possible for the applications included in the list.

[0088] According to one embodiment of the present disclosure, if a terminal receives a message from an eAMF that includes a list of application information for application(s) for which network-based slice selection is not allowed, the terminal may store the received list and determine that network-based slice selection is not possible for the applications included in the list. For applications for which network-based slice selection is not possible, the terminal may directly select an S-NSSAI based on configuration information. The terminal may transmit a message to the network that includes the directly selected S-NSSAI.

[0089] FIG. 3 illustrates a flowchart of a session selection procedure through a NAS message according to one embodiment of the present disclosure.

[0090] According to one embodiment of the present disclosure, in step 301, the terminal may send a session request message to the eAMF if session information for transmitting application traffic based on configuration information is required.

[0091] A session request message may be included in a NAS message and transmitted to eAMF. For example, a session request message may be included in a Session establishment request or a Session modification request and transmitted. The terminal may transmit a session request message to eAMF that includes at least one of the following information.

[0092] - Session ID: Can represent the session identifier.

[0093] - Session Type: May include information such as IP, Ethernet, or Non-IP.

[0094] - DNN (data network name): May contain information about the data network. The DNN can be expressed in the form of an FQDN and may represent, for example, IMS, the Internet, etc.

[0095] - NBSS indication: May be included if the UE requests network-based slice selection. The UE may also include the NBSS indication only if it receives the NBSS allowed indication during the registration process.

[0096] - Application information: The session request message may include application information. The application information may correspond to the application information described with reference to FIG. 1.

[0097] According to one embodiment of the present disclosure, in step 302, when the 6G RAN receives a message (e.g., a 6G NAS message) from a terminal in step 301, it may transmit a message including the message of step 301 to the eAMF.

[0098] According to one embodiment of the present disclosure, in step 303, if the message received from the terminal contains a DNN, the eAMF can identify whether the DNN included in the message of step 301 is valid based on the list of subscribed DNNs included in the terminal subscriber information. If the DNN included in the message is not included in the list of subscribed DNNs, the eAMF can send a rejection message for the request message of step 301 to the terminal.

[0099] eAMF may send a rejection message for the request message of step 301 to the terminal if the message received from the terminal contains support of NBSS or application information, and if NBSS is not allowed according to the terminal subscriber information.

[0100] According to one embodiment of the present disclosure, at step 303, if terminal subscriber information is not available, the eAMF may transmit a subscription request message to the eUDM and receive a subscription response message containing subscriber information from the eUDM. The subscriber information may include a list of subscribed DNNs and a list of subscribed S-NSSAIs.

[0101] According to one embodiment of the present disclosure, in step 304, if the message received from the terminal contains support of NBSS or application information, the eAMF may transmit an NF discovery request message to the eNRF to obtain the address of the NBSSF. The NF discovery request message may include terminal location (UE location) information and an NF type indicated by the NBSSF.

[0102] According to one embodiment of the present disclosure, in step 304, when the eNRF receives an NF search request message from the eAMF, it may send a response message to the eAMF containing an address for the NBSSF.

[0103] According to one embodiment of the present disclosure, at step 305, eAMF may send a request message to NBSSF for slice selection for a session. For example, at step 305, eAMF may send a slice selection request message to NBSSF. The request message for slice selection for a session may include the following information.

[0104] - UE location: The request message for slice selection for a session may include the cell ID, tracking area code, tracking area identifier, etc., as location information of the terminal.

[0105] - UE ID, Session ID: A request message for slice selection for a session may include a UE ID and / or a Session ID.

[0106] - PLMN ID: The request message for slice selection for a session may include a PLMN identifier composed of an MCC and an MNC, which is the PLMN connected to the terminal.

[0107] - Application information list: A request message for selecting a slice for a session may include an application information list. The application information may correspond to the application information described with reference to FIG. 1.

[0108] - DNN: A request message for slice selection for a session may include DNN information about the session.

[0109] - Subscribed S-NSSAIs: A request message for selecting a slice for a session may include the terminal's subscribed slice identifier information.

[0110] According to one embodiment of the present disclosure, in step 306, when the NBSSF receives a request message for slice selection for the session of step 305, it may select an S-NSSAI and / or DNN for application traffic corresponding to application information among the Subscribed S-NSSAIs based on configuration information.

[0111] According to one embodiment of the present disclosure, in step 306, the NBSSF may transmit to the eAMF a response message containing one or more application information and slice information selected for each application information (NW-selected S-NSSAI). Alternatively, the NBSSF may transmit to the eAMF a response message containing one or more application information and an identifier of the corresponding session (i.e., Session ID) for each application information, if there is a suitable session among the previously established sessions for one or more application information included in the message of step 305.

[0112] According to one embodiment of the present disclosure, at step 307, eAMF can determine whether to create a new session.

[0113] For example, at step 307, eAMF may decide not to create a new session if it determines that there is an existing session established for the UE for the S-NSSAI and DNN received at step 303 (or, if received at step 301, the DNN included in the message received at step 301), and decides to use that session for traffic corresponding to application information. If eAMF decides not to create a new session, eAMF may skip steps 308 through 310. If eAMF receives a Session ID at step 306, it may decide to use that session for application information (i.e., for traffic corresponding to TD) and perform steps 311 and 312.

[0114] For example, if eAMF decides to create a new session for the TD received in step 301, it may perform steps 308 through 310.

[0115] According to one embodiment of the present disclosure, step 308. eAMF may select an eSMF that supports the determined DNN and NW-selected S-NSSAI and send a session context create request message to the eSMF. The session context create request message may include a Session ID, NW-selected S-NSSAI, DNN, and application information.

[0116] According to one embodiment of the present disclosure, in step 309, the eSMF may transmit a session response message for step 308 to the eAMF. The session response message for step 308 may include information indicating the result of processing the request of step 308. For example, the session response message for step 308 may include information indicating success or failure regarding the session request message of step 308.

[0117] According to one embodiment of the present disclosure, at step 310, the rest of the session establishing procedure may be performed. The eSMF may transmit a Session ID, S-NSSAI, and DNN to the eUPF and the RAN to establish a tunnel between the RAN and the eUPF.

[0118] According to one embodiment of the present disclosure, the eSMF may transmit to the terminal information about an established session (e.g., UE IP address, Session ID, QoS Rule (e.g., information on which QFI should be used for application information), application information bound to the session ID, etc.) (step 315). The message may be transmitted by the eSMF to the UE via the RAN or by the eSMF to the UE via eAMF / RAN.

[0119] According to one embodiment of the present disclosure, when a session for application information is determined, the eSMF may transmit a message to the NBSSF containing binding information (i.e., information about which session or which S-NSSAI the traffic is associated with). The message may include a UE ID, a Session ID, an S-NSSAI, a DNN, and application information.

[0120] According to one embodiment of the present disclosure, at step 311, eAMF may obtain eSMF information for a determined existing session from eUDM. eAMF may send a request message to eUDM including S-NSSAI, DNN, and UE ID. Based on receiving the message from eAMF, eUDM may send a response message to eAMF including eSMF information registered for S-NSSAI, DNN, and UE ID.

[0121] According to one embodiment of the present disclosure, at step 312, eAMF may send a session context update request message to eSMF. The session context update request message may include a Session ID (or Session context ID), NW-selected S-NSSAI, DNN, and application information.

[0122] According to one embodiment of the present disclosure, at step 313, the eSMF may transmit a session context update response message to the eAMF for the session context update request message received at step 312. The session context update response message may include information regarding the processing result of the session context update request received at step 308. For example, the session context update response message may include information indicating success or failure of the session context update request received at step 308.

[0123] According to one embodiment of the present disclosure, at step 314, the rest of the session update procedure may be performed. If the existing S-NSSAI for the session is different from the S-NSSAI received at step 312, the eSMF may perform a procedure to change the S-NSSAI of the session to the S-NSSAI received at step 312. That is, the eSMF may transmit the S-NSSAI and Session ID received at step 312 to the eUPF and RAN. When the eUPF and RAN receive a message containing the S-NSSAI and Session ID received at step 312, they may each update the S-NSSAI for the session. The eSMF may transmit information about the changed session to the terminal. For example, the eSMF may transmit a message containing information about the changed session to the terminal via the RAN or eAMF. For example, a message containing information about a changed session may include the UE IP address, Session ID, QoS Rule, and application information bound to that Session ID. The QoS Rule may refer to information, for example, which QFI should be used for the application information. When a session for application information is determined, the eSMF may transmit the corresponding binding (binding information) to the NBSSF. The binding information may refer to information about which session or which S-NSSAI the traffic is associated with. The message transmitted by the eSMF to the NBSSF may include the UE ID, Session ID, S-NSSAI, DNN, and application information.

[0124] According to one embodiment of the present disclosure, in step 315, if the eAMF decides to establish a new session or use an existing session in step 307, the eAMF may transmit a message containing information about the session to the UE in step 310 or step 314. The message may be transmitted via eAMF / RAN or via RAN. Alternatively, the eAMF may transmit a Session ID to be used per application information to the terminal.

[0125] If the message of step 301 contains multiple application information and information regarding multiple sessions is determined for the multiple application information, the Session request response message may include 'session-specific application information list' information for the multiple sessions. For example, the session-specific application information list information for multiple sessions may include a session ID and information regarding the application information list corresponding to each session ID. For example, the session-specific application information list information<Session ID, 애플리케이션 정보 리스트> It can be represented as a pair. If a new session is established, the Session ID may contain information indicating that a new session has been established.

[0126] The message may be included in NAS messages (e.g., Session Establishment accept / reject, Session Modification accept / reject, etc.).

[0127] According to one embodiment of the present disclosure, in step 316, when the eAMF directly transmits session information regarding application information to the terminal (e.g., when the eAMF transmits to the UE in step 315), and when a session regarding application information is determined in step 315, the eAMF may transmit a slice selection result notify message to the NBSSF containing the binding information (i.e., information about which session or which S-NSSAI the traffic is associated with). The message may include a UE ID, a Session ID, an S-NSSAI, a DNN, and application information.

[0128] FIG. 4 illustrates a flowchart of a session establishment procedure for slice selection based on a user plane (UP) according to one embodiment of the present disclosure.

[0129] According to one embodiment of the present disclosure, in step 410, if the terminal needs Session information to transmit application traffic based on configuration information, it may send a session request message to eAMF.

[0130] Session request messages can be transmitted by being included in NAS messages. For example, session request messages can be transmitted by being included in NAS messages such as session establishment requests and session modification requests.

[0131] According to one embodiment of the present disclosure, a terminal may transmit a session request message to an eAMF that includes at least one of the following information.

[0132] - Session ID: Represents the session identifier.

[0133] - Session Type: May include information such as IP, Ethernet, or Non-IP.

[0134] - DNN (data network name): May contain information about the data network. The DNN can be expressed in the form of an FQDN and may represent, for example, IMS, the Internet, etc.

[0135] - NBSS indication: May be included if the UE requests network-based slice selection. The UE may also include the NBSS indication only if it receives the NBSS allowed indication during the registration process.

[0136] - Application information: The session request message may include application information. The application information may correspond to the application information described with reference to FIG. 1.

[0137] According to one embodiment of the present disclosure, in step 420, when the 6G RAN receives the message of step 1 (e.g., a 6G NAS message), it may transmit a message including the message of step 410 to the eAMF. For example, the 6G RAN may transmit a session establishment request message to the eAMF.

[0138] According to one embodiment of the present disclosure, at step 430, the eAMF may determine whether to establish a session for the NBSS based on information included in a message received from the terminal. For example, the eAMF may determine to establish a session for the NBSS in one or more of the following cases.

[0139] - If the message received from the UE contains a DNN, and it is a DNN for NBSS

[0140] - When the message received from the UE includes an NBSS indication

[0141] - When indicating to establish an NBSS session in the UE's subscriber information

[0142] According to one embodiment of the present disclosure, at step 430, if the eAMF decides to establish a session for NBSS, it may transmit a message containing information for obtaining the address of an eSMF that supports NBSS_UP (i.e., user plane-based network slice selection). For example, the eAMF may transmit an NF discovery request to the eNRF containing the following information.

[0143] - Support of NBSS: Can indicate a request for an eSMF that supports NBSS.

[0144] - UE location: May contain the UE's location information. May include one or more of Cell ID, TAC, and TAI.

[0145] - DNN or application information(s): If the message received from the UE contains DNN and / or application information, and the network supports NBSSF_UP or NBSSF for DNN / application information, such information may be included.

[0146] - NF type = information indicating eSMF may be included.

[0147] According to one embodiment of the present disclosure, in step 430, when the NRF receives an NF search request message from the eAMF, it may determine eSMF information (an identifier of the eSMF, an FQDN of the eSMF, an IP address, etc.) to be included in a response message sent to the eAMF by considering the information included in the NF search request message. If support of NBSS is included, the eNRF may include eSMF information that supports NBSS in the response message sent to the eAMF. Additionally, if the message received from the eAMF includes DNN or application information(s), the eNRF may include information about an eSMF that supports DNN or application information(s) in the response message sent to the eAMF.

[0148] According to one embodiment of the present disclosure, at step 440, the eAMF may select an eSMF for a session for NBSS based on the eSMF information included in the message received at step 430. The eAMF may send a session context create request message to the eSMF. The session context create request message may include a Session ID, NW-selected S-NSSAI, DNN, and NBSS_UP indication.

[0149] According to one embodiment of the present disclosure, at step 440, the eSMF may transmit a response message to the eAMF for a session context creation request message. The response message may include information indicating the result of processing the session context creation request. For example, the response message may include information indicating success or failure of the session context creation request.

[0150] According to one embodiment of the present disclosure, at step 450, the eSMF can determine whether NBSS_UP (i.e., user plane-based network-based slice selection) is allowed according to subscriber information if the message received at step 440 includes an NBSS_UP indication. If NBSS_UP is allowed, the eSMF can perform a procedure to select an eUPF that supports NBSS_UP.

[0151] According to one embodiment of the present disclosure, at step 450, the eSMF may transmit an NF discovery request message to the eNRF containing the following information.

[0152] - Support of NBSS_UP: Can indicate a request for eUPF that supports NBSS.

[0153] - DNN or application information(s): If the message received from eAMF contains DNN and / or application information, and the network supports NBSSF_UP for DNN / application information, such information may be included.

[0154] - Information indicating NF type = eUPF may be included.

[0155] According to one embodiment of the present disclosure, at step 450, when the NRF receives an NF search request message from the eSMF, it may determine eUPF information (eUPF identifier, FQDN, IP address, etc.) to be included in a response message transmitted to the eSMF based on the information included in the NF search request message. If support of NBSS_UP is included, the eNRF may include eUPF information that supports NBSS_UP. Additionally, if the received message includes DNN or application information(s), the eNRF may include information about an eUPF that supports DNN or application information(s).

[0156] According to one embodiment of the present disclosure, at step 460, eSMF may select eUPF based on eUPF information included in the message received at step 450 and send a session request message to eUPF including an NBSS_UP request indication.

[0157] According to one embodiment of the present disclosure, in step 460, if the session request message received from the eSMF contains an NBSS_UP request indication, the eUPF may send a response message containing NBSSF_UP information to the eSMF. The NBSSF_UP information may include the address of an NBSSF_UP accessible within the session (FQDN, IP address, port number, etc.). Additionally, the response message may include UE IP address and DNS (domain name system) server address information.

[0158] According to one embodiment of the present disclosure, in step 470, the eSMF may transmit to the terminal a session establishment response message (or session establishment acceptance message or rejection message) including the NBSSF_UP information received in step 460, UE IP address information, and DNS server information. The session establishment response message may be transmitted to the terminal via the eAMF and RAN, or transmitted to the terminal via RAN.

[0159] According to one embodiment of the present disclosure, at step 480, the rest of the PDU session establishment procedure may be performed. In FIG. 4, step 480 is depicted as being performed after step 470, but is not limited thereto. For example, step 480 may be performed before or after step 460. At step 480, eSMF may transmit a Session ID, DNN, and NBSSF_UP indication to eUPF and RAN to establish a tunnel between RAN and eUPF.

[0160] According to one embodiment of the present disclosure, at step 490, a user plane-based session slice selection procedure may be performed. For example, at step 490, the terminal may send a session information request message including an application information list to NBSSF_UP based on the NBSSF_UP information received at step 470.

[0161] FIG. 5 illustrates a flowchart of a user plane-based session slice selection procedure according to one embodiment of the present disclosure.

[0162] According to one embodiment of the present disclosure, in step 500a, the terminal can communicate with NBSSF_UP through a session that supports the established NBSSF_UP.

[0163] If the terminal intends to perform network-based slice selection for new application traffic or if the terminal receives a message from the network to establish a user plane session (or user plane connection) (e.g., a connection establishment command), the terminal may perform a procedure to establish a user plane session (or user plane connection) with NBSSF_UP.

[0164] A user plane session with NBSSF_UP may be implemented based on, for example, a Transport Layer Security (TLS) connection, a Quick UDP Internet Connections (QUIC) connection, or a separate protocol, depending on the support of the terminal and the network. For example, if the terminal uses a TLS connection, the terminal may perform a procedure to establish a TLS connection with NBSSF_UP. For example, if the UE uses a QUIC connection, the terminal may perform a procedure to establish a QUIC connection with NBSSF_UP.

[0165] If the terminal stores the IP address, etc., of NBSSF_UP received from the network, it may send a session request message to NBSSF_UP based on the stored information. Alternatively, the terminal may send a DNS query message to a DNS server to obtain the address of NBSSF_UP. In this case, the DNS query may include the FQDN, PLMN ID, UE ID, etc., of NBSSF_UP. Upon receiving the DNS query message, the DNS server may identify the IP address, port number, etc., of NBSSF_UP corresponding to the PLMN ID and send a DNS query response message containing the identified information.

[0166] According to one embodiment of the present disclosure, a terminal may transmit a session establishment request message (NBSS UP session establishment request) to NBSSF_UP via a user plane (UP). The session establishment request message may include a UE ID, a PLMN ID, UE location information, etc. The UE ID may include at least one of SUCI, GUTI, or other UE identifiers.

[0167] According to one embodiment of the present disclosure, in step 500b, if a temporary terminal identifier (e.g., GUTI) is included in a message received from a terminal, NBSSF_UP may send a request message containing the GUTI to eUDM. Upon receiving the message, eUDM may include the eAMF address responsible for the GUTI included in the message in a response message sent to NBSSF_UP. Based on the eAMF address received from eUDM, NBSSF_UP may send a request message containing the GUTI to eAMF to request and obtain a context for the terminal. NBSSF_UP may determine that authentication is successful if the GUTI is a valid GUTI and valid authentication information for the terminal regarding the GUTI exists.

[0168] According to one embodiment of the present disclosure, in step 500b, if the message received from the terminal includes a terminal identifier (e.g., SUCI), NBSSF_UP may send an authentication request (UE auth request) message for the terminal to AUSF. The authentication request message for the terminal may include SUCI, NBSSF_UP's PLMN ID, etc.

[0169] According to one embodiment of the present disclosure, in step 500c, when AUSF receives an authentication request message for a terminal from NBSSF_UP, it may include SUCI, which is included in the authentication request message for the terminal, in a terminal authentication request message transmitted to eUDM. If authentication of the terminal is successful, eUDM may include authentication information (e.g., Key information to be used by NBSSF_UP for the session) and SUPI, which is the result of decrypting SUCI, in a response message transmitted to AUSF. AUSF may transmit the information included in the response message received from eUDM to NBSSF_UP.

[0170] According to one embodiment of the present disclosure, in step 500d, NBSSF_UP may send a response message to the terminal based on whether the authentication of the UE ID in step 500b is successful.

[0171] For example, in step 500d, if authentication for the UE ID in step 500b is successful, NBSSF_UP may transmit to the terminal information indicating that authentication was successful and authentication information. The terminal may perform network authentication based on the authentication information. For example, if authentication for the UE ID fails, NBSSF_UP may transmit to the terminal a message containing information indicating that authentication failed.

[0172] According to one embodiment of the present disclosure, in step 501, if the terminal requires session information to transmit application traffic, it may transmit a session request message to NBSSF_UP based on configuration information.

[0173] The session request can be transmitted via a user flat session that supports NBSSF_UP.

[0174] The session request message may include one or more of the following information.

[0175] - Session ID: Represents the session identifier for the session to which the session request is sent.

[0176] - UE ID: Represents the UE identifier.

[0177] - Session Type: May include information such as IP, Ethernet, or Non-IP.

[0178] - DNN (data network name): May contain information about the data network. The DNN can be expressed in the form of an FQDN and may represent, for example, IMS, the Internet, etc.

[0179] - NBSS indication: May be included if the UE requests network-based slice selection. The UE may also include the NBSS indication only if it receives the NBSS allowed indication during the registration process.

[0180] - Application information: The request message may include application information. Here, application information may include information corresponding to the application information described above with reference to FIG. 1.

[0181] According to one embodiment of the present disclosure, steps 503 to 516 of FIG. 5 may correspond to the procedure in which eAMF is replaced by NBSSF_UP in the procedure from steps 303 to 315 of FIG. 3. For example, in steps 503 to 516 of FIG. 5, it may be understood that NBSSF_UP performs the role of eAMF in the procedure from steps 303 to 315 of FIG. 3. However, in the case of step 515 of FIG. 5, unlike in step 315 of FIG. 3 where the message transmitted to the terminal may be transmitted as a NAS message, the message transmitted to the terminal may be transmitted by being included in a PDU of the user plane. For example, the message transmitted to the terminal in step 515 of FIG. 5 may be transmitted by being included in an IP packet. More specifically, it may be transmitted via a TLS connection or a QUIC connection.

[0182] FIG. 6 illustrates the functional configuration of a terminal in a wireless communication system according to one embodiment of the present disclosure. The configuration exemplified in FIG. 6 can be understood as the configuration of a terminal (110). Terms such as '...part', '...unit', etc. used below refer to a unit that processes at least one function or operation, and this may be implemented in hardware or software, or a combination of hardware and software.

[0183] Referring to FIG. 6, the terminal includes a communication unit (610), a storage unit (620), and a control unit (630).

[0184] The communication unit (610) performs functions for transmitting and receiving signals through a wireless channel. For example, the communication unit (610) performs a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the system. For example, when transmitting data, the communication unit (610) generates complex symbols by encoding and modulating the transmitted bit sequence. Also, when receiving data, the communication unit (610) restores the received bit sequence by demodulating and decoding the baseband signal. Additionally, the communication unit (610) upconverts the baseband signal into an RF band signal and transmits it through an antenna, and downconverts the RF band signal received through the antenna into a baseband signal. For example, the communication unit (610) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

[0185] Additionally, the communication unit (610) may include a plurality of transmission and reception paths. Furthermore, the communication unit (610) may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit (610) may be composed of digital circuits and analog circuits (e.g., RFIC (radio frequency integrated circuit)). Here, the digital circuits and analog circuits may be implemented in a single package. Additionally, the communication unit (610) may include a plurality of RF chains. Furthermore, the communication unit (610) may perform beamforming.

[0186] The communication unit (610) transmits and receives signals as described above. Accordingly, all or part of the communication unit (610) may be referred to as a 'transmitter', a 'receiver', or a 'transmitter / receiver'. Additionally, in the following description, transmission and reception performed via a wireless channel are used to mean that processing as described above is performed by the communication unit (610).

[0187] The storage unit (620) stores data such as basic programs, application programs, and setting information for the operation of the terminal. The storage unit (620) may be composed of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Additionally, the storage unit (620) provides the stored data upon the request of the control unit (630).

[0188] The control unit (630) (e.g., controller) controls the overall operations of the terminal. For example, the control unit (630) transmits and receives signals through the communication unit (610). Additionally, the control unit (630) writes and reads data to and from the storage unit (620). Furthermore, the control unit (630) can perform the functions of the protocol stack required by the communication standard. To this end, the control unit (630) may include at least one processor or microprocessor, or be part of a processor. Additionally, part of the communication unit (610) and the control unit (630) may be referred to as a communication processor (CP).

[0189] According to various embodiments, the control unit (630) can control the terminal to perform operations according to various embodiments of the present disclosure.

[0190] FIG. 7 illustrates the functional configuration of a base station in a wireless communication system according to one embodiment of the present disclosure. The configuration exemplified in FIG. 7 can be understood as the configuration of a base station included in the RAN (120) of FIG. 1. Terms such as '... unit', '... unit' used below refer to a unit that processes at least one function or operation, and this may be implemented in hardware or software, or a combination of hardware and software.

[0191] Referring to FIG. 7, the base station may include a wireless communication unit (710), a backhaul communication unit (720), a storage unit (730), and a control unit (740).

[0192] The wireless communication unit (710) performs functions for transmitting and receiving signals through a wireless channel. For example, the wireless communication unit (710) performs a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the system. For example, when transmitting data, the wireless communication unit (710) generates complex symbols by encoding and modulating the transmitted bit sequence. Also, when receiving data, the wireless communication unit (710) restores the received bit sequence by demodulating and decoding the baseband signal.

[0193] Additionally, the wireless communication unit (710) upconverts a baseband signal into an RF (radio frequency) band signal and transmits it through an antenna, and downconverts the RF band signal received through the antenna into a baseband signal. To this end, the wireless communication unit (710) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC (digital to analog converter), an ADC (analog to digital converter), etc. Additionally, the wireless communication unit (710) may include a plurality of transmission and reception paths. Furthermore, the wireless communication unit (710) may include at least one antenna array composed of a plurality of antenna elements.

[0194] In terms of hardware, the wireless communication unit (710) may be composed of a digital unit and an analog unit, and the analog unit may be composed of a plurality of sub-units depending on operating power, operating frequency, etc. The digital unit may be implemented with at least one processor (e.g., a digital signal processor (DSP)).

[0195] The wireless communication unit (710) transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit (710) may be referred to as a 'transmitter', a 'receiver', or a 'transceiver'. Furthermore, in the following description, transmission and reception performed through a wireless channel are used to mean that processing as described above is performed by the wireless communication unit (710).

[0196] The backhaul communication unit (720) provides an interface for communicating with other nodes within the network. That is, the backhaul communication unit (720) converts a bit sequence transmitted from a base station to another node, e.g., another connection node, another base station, an upper node, a core network, etc., into a physical signal, and converts a physical signal received from another node into a bit sequence.

[0197] The storage unit (730) stores data such as basic programs, application programs, and configuration information for the operation of the base station. The storage unit (730) may be composed of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Additionally, the storage unit (730) provides the stored data upon the request of the control unit (740).

[0198] The control unit (740) (e.g., a controller) controls the overall operations of the base station. For example, the control unit (740) transmits and receives signals through the wireless communication unit (710) or through the backhaul communication unit (720). Additionally, the control unit (740) writes and reads data to and from the storage unit (730). Furthermore, the control unit (740) can perform the functions of a protocol stack required by the communication standard. According to other implementation examples, the protocol stack may be included in the wireless communication unit (710). To this end, the control unit (740) may include at least one processor.

[0199] According to various embodiments, the control unit (740) can control the base station to perform operations according to various embodiments of the present disclosure.

[0200] Methods according to the claims or embodiments described in the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0201] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs may include instructions that cause the electronic device to execute methods according to the claims or embodiments described in the specification of this disclosure.

[0202] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disc storage devices, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0203] Additionally, the program may be stored on an attachable storage device accessible via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

[0204] In the specific embodiments of the present disclosure described above, the components included in the invention are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0205] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples provided to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other variations based on the technical concept of the present disclosure are possible. Furthermore, each embodiment of the present disclosure may be combined and operated with one another as needed.

[0206] Meanwhile, the order of description in the drawings illustrating the method of the present invention does not necessarily correspond to the order of execution, and the order of execution may be changed or executed in parallel.

[0207] Alternatively, drawings describing the method of the present invention may omit some components and include only some components to the extent that the essence of the present invention is not compromised.

[0208] In addition, the method of the present invention may be implemented by combining some or all of the contents included in each embodiment within a scope that does not impair the essence of the invention.

Claims

1. In a wireless communication system, a method performed by a first network entity, said method comprises: A step of receiving a session request message from a terminal (user equipment) requesting a session for network-based slice selection (NBSS) through a base station; A step of transmitting a subscriber information request message to the UDM (unified data management) to request subscription information of the terminal; A step of receiving a subscriber information response message from the above UDM that includes subscriber information of the terminal; A step of transmitting an NF (network function) discovery request message to an NRF (network repository function) requesting the address of a second network entity that provides a network selection function; A step of receiving an NF search response message from the NRF that includes the address of the second network entity; A step of transmitting to the second network entity a slice selection request message for selecting a network slice to be provided to the terminal based on the address of the second network entity; and A method comprising the step of receiving a slice selection response message containing network slice information regarding a selected network slice from the second network entity.

2. In Paragraph 1, A method wherein the above session request message includes an indicator directing a request of the NBSS and application information of the terminal used for the NBSS.

3. In Paragraph 1, A method in which the subscriber information included in the above subscription request message includes a list of subscribed data network names (DNN) and a list of subscribed single network slice selection assistance information (S-NSSAI) of the terminal.

4. In Paragraph 1, A method in which the above NF search request message includes location information of the terminal and NF type information corresponding to the second network entity.

5. In Paragraph 1, A method wherein the slice selection request message comprises at least one of the following: location information of the terminal, PLMN (public land mobile network) ID (identifier), application information of the terminal, information about the DNN for the session to be created, and information about the terminal's subscribed S-NSSAI list.

6. In Paragraph 5, A method wherein the network slice information included in the slice selection response message comprises information regarding an S-NSSAI selected based on the application information of the terminal among at least one subscribed S-NSSAI in the subscribed S-NSSAI list of the terminal and information regarding the ID of the selected session.

7. In claim 1, the method is: A step of determining whether to create a new session for the selected network slice; If it is decided to create the new session, a step of selecting an SMF (session management function) that supports the selected slice; The step of sending a session context creation request message to the selected SMF; and A method further comprising the step of receiving a session context response message containing information about the result of creating the new session from the selected SMF.

8. In Paragraph 1, The first network entity above corresponds to an AMF or a user plane NF different from the AMF, and If the above first network entity corresponds to an AMF, the session request message is received via a NAS message, and A method in which, if the first network entity corresponds to the user plane NF, the session request message is received based on a user plane session established between the terminal and the first network entity.

9. In a wireless communication system, regarding the first network entity: At least one processor; and It includes at least one memory that is communicationally coupled to the above at least one processor and stores instructions, and The above instructions are executed individually or in any combination by the above at least one processor, so that the first network entity: Receive a session request message from a terminal (user equipment) requesting a session for network-based slice selection (NBSS) through a base station, and Send a subscriber information request message to the UDM (unified data management) to request the subscription information of the above terminal, and From the above UDM, receive a subscriber information response message including subscriber information of the terminal, and Sends an NF (network function) discovery request message to the NRF (network repository function) requesting the address of a second network entity that provides network selection functions, and Receive an NF search response message from the above NRF that includes the address of the second network entity, and To the second network entity, transmit a slice selection request message for selecting a network slice to be provided to the terminal based on the address of the second network entity, and A first network entity that receives a slice selection response message containing network slice information regarding a selected network slice from the second network entity.

10. In Paragraph 9, The above session request message is a first network entity comprising an indicator directing a request of the NBSS and application information of the terminal used for the NBSS.

11. In Paragraph 9, The subscriber information included in the above subscription request message is a first network entity comprising a list of subscribed data network names (DNN) and subscribed single network slice selection assistance information (S-NSSAI) of the terminal.

12. In Paragraph 9, The above NF search request message is a first network entity comprising location information of the terminal and NF type information corresponding to the second network entity.

13. In Paragraph 9, The above slice selection request message is a first network entity comprising at least one of location information of the terminal, a PLMN (public land mobile network) ID (identifier), application information of the terminal, information about a DNN for a session to be created, and information about a list of subscribed S-NSSAIs of the terminal.

14. In Paragraph 13, The network slice information included in the slice selection response message comprises a first network entity, wherein the network slice information includes information regarding an S-NSSAI selected based on the application information of the terminal among at least one subscribed S-NSSAI in the subscribed S-NSSAI list of the terminal and an ID of the selected session.

15. In claim 9, the above commands are that the first network entity: Determine whether to create a new session for the selected network slice above, and If it is decided to create the new session above, select an SMF (session management function) that supports the selected slice, and Send a session context creation request message to the selected SMF above, and A first network entity that receives a session context response message containing information about the result of creating the new session from the selected SMF.

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