Method and apparatus for supporting service continuity in wireless communication systems, taking into account network slice areas.

Abstract

This disclosure relates to 5G or 6G communication systems for supporting higher data transmission rates. Specifically, this disclosure provides methods and apparatus for supporting service continuity with regard to network slice areas in wireless communication systems.

Description

Technical Field

[0001] The present disclosure relates to the field of communications and pertains to the operations of terminals and base stations. In particular, the present disclosure relates to a method and apparatus for supporting service continuity considering a network slice area in a wireless communication system.

Background Art

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services. Implementations are possible not only in frequency bands below 6 GHz (such as 3.5 gigahertz (3.5 GHz)) (referred to as "Sub 6GHz"), but also in ultra-high frequency bands (referred to as "Above 6GHz") such as 28 GHz and 39 GHz (referred to as millimeter waves (mmWave)). Further, in the case of 6G mobile communication technology, which is called a system beyond 5G communication (Beyond 5G), implementations in the terahertz (THz) band (for example, a band from 95 GHz to 3 terahertz (3THz)) are considered in order to achieve a transmission speed 50 times faster and an ultra-low (Ultra Low) latency time reduced to one-tenth compared to 5G mobile communication technology.

[0003] In the early stages of 5G mobile communication technology, the goal was to meet the service support and performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and Massive Machine-Type Communications (mMTC). This included beamforming and Massive MIMO to mitigate path loss and increase transmission distance in ultra-high frequency bands, various numerology support (such as operation of multiple subcarrier spacings) and dynamic operation of slot formats for efficient utilization of ultra-high frequency resources, initial access technologies to support multiple beam transmission and broadband, definition and operation of Band-Width Parts (BWP), new channel coding methods such as Low-Density Parity Check (LDPC) codes for high-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2 Standardization efforts were made for pre-processing and network slicing, which provides dedicated networks for specific services.

[0004] Currently, discussions are underway for initial improvements and enhancements to 5G mobile communication technology, taking into account the services that 5G mobile communication technology was intended to support. Physical layer standardization is progressing for technologies such as V2X (Vehicle-to-Everything), which assists autonomous vehicles in making driving decisions based on their own location and status information transmitted by the vehicle and increases user convenience; NR-U (New Radio Unlicensed), which aims for system operation that complies with various regulatory requirements on unlicensed spectrum; NR terminal power saving technology (UE Power Saving); Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to ensure coverage in areas where communication with terrestrial networks is impossible; and positioning.

[0005] Furthermore, standardization is underway in the field of wireless interface architecture / protocols for technologies such as Industrial Internet of Things (IIoT) to support new services through collaboration and convergence with other industries, Integrated Access and Backhaul (IAB) to provide nodes for network service area expansion by integrating support for wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step RACH for NR to simplify random access procedures. Standardization is also underway in the field of system architecture / services for 5G baseline architectures (e.g., Service-based Architecture, Service-based Interface) for the combination of Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) where services are provided based on the location of the terminal.

[0006] With the commercialization of such 5G mobile communication systems, it is expected that the explosively increasing number of connected devices will be connected to the communication network. Consequently, it is anticipated that enhancements to the functionality and performance of 5G mobile communication systems and the integrated operation of connected devices will be necessary. To this end, new research is planned on improving 5G performance and reducing complexity using Extended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR), as well as AI service support, metaverse service support, and drone communications.

[0007] Furthermore, the development of such 5G mobile communication systems could serve as the basis for the development of new technologies for 6G mobile communication, including new waveforms to guarantee terahertz band coverage, multiplex antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas, metamaterial-based lenses and antennas to improve terahertz band signal coverage, high-dimensional spatial multiplexing technologies using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS) technologies, as well as full duplex technologies to improve frequency efficiency and system network improvements for 6G mobile communication, satellites, AI (artificial intelligence) from the design stage, AI-based communication technologies that integrate end-to-end AI support functions to optimize the system, and next-generation distributed computing technologies that realize services of a complexity exceeding the limits of terminal computing power by utilizing ultra-high-performance communication and computing resources. [Overview of the project] [Problems that the invention aims to solve]

[0008] The disclosed embodiments aim to provide a method for supporting a network slice area in a wireless communication system, and a device and method for supporting service continuity when a terminal moves outside the network slice area in the said environment. [Means for solving the problem]

[0009] A method according to one embodiment of the present disclosure is characterized by including the steps of receiving a first control signal transmitted from a base station, processing the received first control signal, and transmitting a second control signal generated based on the processing to the base station. [Effects of the Invention]

[0010] This disclosure provides an apparatus and method for effectively providing services using a wireless communication system. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows a communication network including a core network entity in a wireless communication system according to one embodiment of the present disclosure. [Figure 2] This figure shows a wireless environment, including a core network, in a wireless communication system according to one embodiment of the present disclosure. [Figure 3] This figure shows how, in a handover procedure according to one embodiment of the present disclosure, the T-RAN (target radio access network) notifies the SMF (session management function) of a PDU (protocol data unit) session that it rejects based on the available slice area. [Figure 4]This figure shows how the AMF (access and mobility management function) processes PDU sessions while considering the NS AoS (network slice area of ​​service) in a registration procedure according to one embodiment of the present disclosure. [Figure 5] This figure shows how a base station processes a PDU session and notifies the AMF of slice availability information in a PDU session modification procedure according to one embodiment of the present disclosure. [Figure 6] This is a block diagram showing the structure of a terminal according to one embodiment of the present disclosure. [Figure 7] This is a block diagram showing the structure of a base station according to one embodiment of the present disclosure. [Figure 8] This block diagram shows the structure of a network entity according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0012] The operating principle of the present invention will be described in detail below with reference to the attached drawings. In describing this disclosure, if a specific description of a relevant known function or configuration is deemed to unnecessarily obscure the gist of this disclosure, such detailed description will be omitted. Furthermore, the terms described below are defined in consideration of the function of the present invention. Since these may differ depending on the intent or convention of the user or operator, their definitions should be based on the content throughout this specification.

[0013] For similar reasons, some components in the attached drawings are exaggerated, omitted, or shown schematically. Furthermore, the dimensions of each component do not fully reflect their actual size. The same or corresponding components are denoted by the same reference numeral in each drawing.

[0014] The advantages and features of the present invention, and the methods for achieving them, will become clearer by referring to the embodiments described in detail below with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and can be implemented in a variety of different forms, and these embodiments are merely provided to complete the disclosure of the present invention and to fully inform a person ordinary skill in the art to which the present invention pertains, and the present invention is defined solely by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components.

[0015] Here, it can be understood that each block of the processing flow diagram and the combination of the flow diagram can be performed by computer program instructions. Since these computer program instructions can be implemented in the processor of a general-purpose computer, a dedicated computer, or other programmable data processing equipment, the instructions performed by the processor of the computer or other programmable data processing equipment will generate means to perform the functions described in one or more blocks of the flow diagram. Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed to the computer or other programmable data processing equipment in order to implement the functions in a particular manner, the instructions stored in that computer-available or computer-readable memory can also produce manufactured items that contain instruction means to perform the functions described in one or more blocks of the flow diagram. Since computer program instructions can be installed on a computer or other programmable data processing equipment, instructions that operate a computer or other programmable data processing equipment by performing a series of operations on the computer or other programmable data processing equipment to generate a process executed on the computer can also provide steps for performing the functions described in one or more blocks of the flowchart.

[0016] Furthermore, each block may represent a module, segment, or portion of code containing one or more executable instructions for performing a specific logical function. It should also be noted that in some alternative embodiments, the functions mentioned in a block may occur in no particular order. For example, two blocks illustrated consecutively may actually occur substantially simultaneously, or the blocks may sometimes occur in reverse order by the functions in question.

[0017] In this embodiment, the term "~part" refers to software or hardware components such as FPGAs (Field Programmable Gate Arrays) or ASICs (Application Specific Integrated Circuits), and "~part" can perform any role. However, "~part" is not limited to software or hardware. "~part" may be configured to be stored in an addressable storage medium, or it may be configured to regenerate one or more processors. As an example, "~part" includes components such as software components, object-oriented software components, class components, or task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The components and functions provided within "~part" may be combined into fewer components and "~part," or further separated into additional components and "~part." Furthermore, components and "~part" may also be implemented to regenerate one or more CPUs within a device or security multimedia card. In an embodiment, "~part" may also include one or more processors.

[0018] In the following description of the present disclosure, when it is determined that a specific description of related known functions or configurations may unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be omitted. Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0019] Terms used in the present disclosure to refer to objects of network entities (network entity or network function) and edge computing (Edge Computing) systems, terms referring to messages, terms referring to identification information, etc. are exemplified for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

[0020] Hereinafter, for convenience, the present disclosure uses terms and names defined in the LTE and NR standards, which are the latest standards defined by the 3GPP (registered trademark) (The 3rd Generation Partnership Project) among existing communication standards. However, the present invention is not limited by the above terms and names, and can be similarly applied to systems based on other standards. In particular, the present invention can be applied to 3GPP NR (5th generation mobile communication standard). Also, embodiments of the present disclosure can be applied to other communication systems having similar technical backgrounds or channel forms. Further, embodiments of the present disclosure can be applied to other communication systems with some modifications within a range not significantly deviating from the scope of the present disclosure based on the judgment of those having skilled technical knowledge.

[0021] The 5G mobile communication network can be composed of a 5G UE (user equipment), a 5G RAN (radio access network), and a 5G core network. The 5G core network can be composed of NFs such as a UDR (unified data repository) that stores data of various network functions (network function, NF) such as an AMF (access and mobility management function) that provides the mobility management function of the UE, an SMF (session management function) that provides the session management function, a UPF (user plane function) that plays a role in data transmission, a PCF (policy control function) that provides the policy control function, and a UDM (unified data management) that provides data management functions such as subscriber data and policy control data.

[0022] Network slicing technology in 5G systems is a technology that allows a single physical network to provide a number of virtualized, independent logical networks. Network operators can configure virtual end-to-end networks called network slices to meet the specific requirements of services / applications and provide services. A third party providing a specific service (e.g., an application service provider) can enter into a contract with the network operator for one or more network slices and have traffic between terminals and servers for a specific application sent and / or received through the contracted one or more slices. Network slices can be distinguished by an identifier called S-NSSAI (single-network slice selection assistance information), and the network can support S-NSSAI in units of tracking area (TA). A TA represents a collection of cells, and all cells can be associated with a TA. The identifier of a TA (e.g., tracking area identity (TAI)) can consist of MCC (Mobile Country Code), MNC (Mobile Network Code), and TAC (tracking area code). For example, supporting S-NSSAI1 in TA1 means that all cells belonging to TA1 support S-NSSAI1, and that all cells belonging to TA1 are in a state where resources for S-NSSAI1 can be allocated. The 5G system can enforce that S-NSSAI cannot be used outside the area where it is supported.

[0023] The service area of ​​S-NSSAI (e.g., network slice area of ​​service (NS-AoS)) may be defined separately from the area where S-NSSAI is supported (e.g., supported area). In this case, NS-AoS is area information that may consist of one or more cell identifiers (or one or more TA identifiers) and can represent an area to which a UE can connect and receive services for a particular network slice.

[0024] On the other hand, network operators may want to provide slice services at a smaller unit than a TA, and for this purpose, a method may be needed to support cell-level slice service areas in the network. For example, if an NS-AoS for an S-NSSAI consists of some cells included in a TA, the network can allocate resources for the S-NSSAI only to the cells corresponding to the NS-AoS (e.g., some cells within the TA), and not allocate resources for the S-NSSAI to other cells (e.g., other cells within the TA), or allocate only minimal resources to them.

[0025] For example, in a scenario where TA1 includes cell1, cell2, cell3, and cell4, and TA1 supports S-NSSAI1, if the NS-AoS for S-NSSAI1 is set to cell1 and cell2, the 5G system needs to be able to allow the use of S-NSSAI1 only when connected via cell1 and cell2, and restrict its use when connected via a cell outside the NS-AoS for S-NSSAI1 (e.g., cell3 and cell4). Also, if a terminal that has established a session with S-NSSAI and is sending and / or receiving data moves to a cell that does not support that S-NSSAI (e.g., cell2 or cell3), a method to support session continuity may be required.

[0026] This invention proposes a method for supporting cell-level network slice service areas (e.g., NS-AoS) in a wireless communication system.

[0027] Specifically, we can propose a method for AMF to obtain network slice location availability information from base stations (for example, regional information corresponding to the Network Slice Area of ​​Service for each slice, which may consist of S-NSSAI and the corresponding TAC, TAI, or Cell ID set).

[0028] Furthermore, we propose a method for the Network Slice Selection Function (NSSF) to obtain network slice location availability information (e.g., S-NSSAI location availability information) from the AMF.

[0029] Furthermore, we can propose a method in which base stations and AMFs utilize S-NSSAI location availability information to control slice connections to terminals (for example, when a terminal moves outside the slice area, the session can be terminated or deactivated, and then the AMF can be notified).

[0030] Furthermore, if the S-NSSAI of the session being used becomes unavailable due to the device being moved, we propose a method to allow the device to connect to an alternative slice in order to ensure service continuity.

[0031] Figure 1 shows a communication network including a core network entity in a wireless communication system according to one embodiment of the present disclosure.

[0032] A 5G mobile communication network may consist of 5G UE (user equipment, terminal), 5G RAN (radio access network, base station, gNB (5G nodeB), eNB (evolved nodeB, etc.), and a 5G core network. The 5G core network may consist of network functions such as an AMF (access and mobility management function) 150 that provides mobility management functions for the UE, an SMF (session management function) 160 that provides session management functions, a UPF (user plane function) 170 that plays a role in data transmission, a PCF (policy control function) 180 that provides policy control functions, a UDM (unified data management) 153 that provides data management functions such as subscriber data and policy control data, or a UDR (unified data repository) that stores data for various network functions.

[0033] Referring to Figure 1, the user equipment (UE) 110 can communicate via a radio channel, i.e., an access network, formed with a base station (e.g., eNB, gNB). In some embodiments, the terminal 110 may be a device used by a user and configured to provide a user interface (UI). For example, the UE 110 may be an equipment terminal mounted on a vehicle for driving. In embodiments, the terminal 110 may be a device that performs machine-type communication (MTC) without user involvement, or an autonomous vehicle. In addition to being an electronic device, the UE may be referred to as "terminal," "vehicle terminal," "user equipment (UE)," "mobile station," "subscriber station," "remote terminal," "wireless terminal," or "user device," or other terms with equivalent technical meaning. In addition to UEs, customer-premises equipment (CPE) or dongle-type terminals can also be used as terminals. Customer-premises equipment is connected to NG-RAN nodes in the same way as UEs and can also provide network access to other communication equipment (e.g., laptops).

[0034] Referring to Figure 1, the AMF150 provides connectivity and mobility management functions on a per-terminal 110 basis, and essentially one AMF150 can be connected to each terminal 110. Specifically, the AMF150 can perform at least one of the following functions: core network node signaling for mobility between 3GPP access networks, inter-wireless access network (e.g., 5G RAN) interface (N2 interface), NAS signaling with terminal 110, SMF160 identification, and transmission of session management (SM) messages between terminal 110 and SMF160. Some or all of the functions of the AMF150 may be supported within a single instance of one AMF150.

[0035] Referring to Figure 1, the SMF160 provides session management functionality, and if terminal 110 has multiple sessions, each session may be managed by a different SMF160. Specifically, the SMF160 can perform at least one of the following functions: session management (e.g., session establishment, modification, and termination, including maintaining the tunnel between UPF170 and the access network node), selection and control of UP (user plane) functionality, traffic steering configuration for routing traffic to the appropriate destination on UPF170, termination of the SM portion of NAS messages, downlink data notification (DDN), and initiator of AN-specific SM information (e.g., transmission to the access network via the N2 interface through AMF150). Some or all of the functions of the SMF160 may be supported within a single instance of one SMF160.

[0036] In 3GPP systems, conceptual links connecting NFs within a 5G system are sometimes referred to as reference points. Reference points are also sometimes referred to as interfaces. The following are examples of reference points (hereinafter used interchangeably with interfaces) included in 5G system architectures as expressed across various embodiments of this disclosure. -N1: Reference point between UE110 and AMF150 -N2:(R)Reference point between AN120 and AMF150 -N3:(R)Reference point between AN120 and UPF170 -N4: Reference point between SMF160 and UPF170 -N5: Reference point between PCF180 and AF130 -N6: Reference point between UPF170 and DN140 -N7: Reference point between SMF160 and PCF180 -N8: Reference point between UDM153 and AMF150 -N9: Reference point between two core UPF170s -N10: Reference point between UDM153 and SMF160 -N11: Reference point between AMF150 and SMF160 -N12: Reference point between AMF150 and authentication server function (AUSF)151 -N13: Reference point between UDM153 and authentication server function 151 -N14: Reference point between two AMF150s -N15: Reference point between PCF180 and AMF150 in non-roaming scenarios, and between PCF180 and AMF150 within the visited network in roaming scenarios.

[0037] In 5G systems, network slicing refers to a technology and structure that enables a number of virtualized, independent logical networks within a single physical network. Network operators can provide services by configuring virtual end-to-end networks called network slices to meet the specialized requirements of services / applications. In this case, network slices can be distinguished by an identifier called S-NSSAI (single-network slice selection assistance information). The network transmits a set of slices (e.g., allowed NSSAI(s)) permitted to the terminal in a terminal registration procedure (e.g., UE registration procedure), and the terminal can send and receive application data via a PDU (protocol data unit) session generated through one of these S-NSSAI (e.g., network slices).

[0038] One embodiment of the present invention states that if the alternative network slice selected to replace an existing PDU session's network slice is determined to be a slice that has already reached its maximum number of sessions, the creation of PDU sessions to the alternative network slice to replace the existing PDU session slice will be rejected, and the continuity of application traffic will not be guaranteed. Therefore, a method to resolve this can be proposed.

[0039] Figure 2 shows a wireless environment, including a core network, in a wireless communication system according to various embodiments of the present disclosure.

[0040] Referring to Figure 2, the wireless communication system may include a radio access network (RAN) 120 and a core network (CN). The radio access network 120 may be a network directly connected to user equipment, such as a terminal 110, and may be an infrastructure that provides wireless connectivity to the terminal 110. The radio access network 120 includes a set of multiple base stations, including a base station 125, and the multiple base stations can communicate with each other via interfaces formed between them. At least some of the interfaces between the multiple base stations may be wired or wireless. The base station 125 may have a structure separated into a CU (central unit) and a DU (distributed unit). In this case, one CU can control multiple DUs. The base station 125 may also be referred to as an "access point (AP)", "gNB (next generation node B)", "5G node (5th generation node)", "wireless point", "transmission / reception point (TRP)", or other terms with equivalent technical meaning. Terminal 110 can connect to the wireless connection network 120 and communicate with the base station 125 via a wireless channel. Terminal 110 can also be referred to as "user equipment (UE)", "mobile station", "subscriber station", "remote terminal", "wireless terminal", or "user device", or other terms with equivalent technical meaning.

[0041] The core network is the network that manages the entire system, controlling the wireless connection network 120 and processing data and control signals for terminals 110 transmitted and received via the wireless connection network 120. The core network can perform various functions such as controlling the user plane and control plane, processing mobility, managing subscriber information, billing, and coordinating with other types of systems (e.g., LTE (Long Term Evolution) system). To perform the various functions described above, the core network can include a number of functionally separated entities, each with a different network function (NF). For example, the core network 200 can include an access and mobility management function (AMF) 150, a session management function (SMF) 160, a user plane function (UPF) 170, a policy and charging function (PCF) 180, a network repository function (NRF) 159, a unified data management function (UDM) 153, a network exposure function (NEF) 155, and a unified data repository (UDR) 157.

[0042] Terminal 110 can connect to the AMF150, which is connected to the wireless connection network 120 and performs the mobility management function of the core network. The AMF150 may be a function or device that is responsible for all aspects of the connection to the wireless connection network 120 and the mobility management of terminal 110. The SMF160 is a NF that manages sessions. The AMF150 can connect to the SMF160, and the AMF150 can route session-related messages to terminal 110 to the SMF160. The SMF160 can connect to the UPF170 to allocate user plane resources to be provided to terminal 110 and can establish a tunnel for transmitting data between base station 125 and UPF170. The PCF180 can control information related to the policy and charging for the sessions used by terminal 110.

[0043] The NRF159 can store information about NFs installed in the mobile carrier network and perform the function of notifying the stored information. The NRF159 can be connected to all NFs. When each NF starts operating in the carrier network, it can notify the NRF159 that the NF is operating in the network by registering with the NRF159. The UDM153 is an NF that plays a role similar to the HSS (home subscriber server) of a 4G network and can store subscription information of terminal 110 or the context used by terminal 110 in the network.

[0044] NEF155 can act as a link between a third-party server and the NF within the 5G mobile communication system. It can also provide, update, or retrieve data from UDR157. UDR157 can store subscription information for terminal 110, policy information, data to be exposed externally, and information required by third-party applications. UDR157 can also provide stored data to other NFs.

[0045] Figure 3 shows how T-RAN notifies SMF of PDU sessions that it rejects based on slice-available regions (which may be referred to as NS AoS or S-NSSAI location availability, etc.) in a handover procedure according to one embodiment of the present disclosure.

[0046] In step 1a, signaling for handover preparation may occur between the UE, S-RAN (source RAN), and T-RAN (target RAN). Handovers can occur in situations such as changes in the radio environment (radio condition), load balancing, or for supporting specific services. During the handover preparation process, S-RAN can transmit information about the UE (e.g., UE Radio Capability ID) to T-RAN.

[0047] In step 1b, T-RAN can transmit an N2 Path Switch Request message to the AMF to notify it that the UE has moved to the target cell. The N2 Path Switch Request message may contain at least one of the following pieces of information:

[0048] - A list consisting of PDU sessions that need to be switched and N2 SM information for each PDU session:

[0049] This may include information about one or more PDU sessions for which a switch has been decided.

[0050] Each PDU session may include at least one of the following: PDU Session ID (e.g., PDU session identifier), AN Tunnel Info (e.g., Tunnel address information that can receive data in T-RAN for the PDU session corresponding to the PDU session identifier), or List of QoS Flows to be activated. The PDU Session ID and AN Tunnel Info may be included in N2 SM Information (e.g., information transmitted to SMF via AMF).

[0051] - A list of PDU sessions that failed to be established and the failure cause provided in the N2 SM information element:

[0052] This may include information about one or more PDU sessions rejected by T-RAN and information indicating the reasons for rejection.

[0053] Each PDU session may include a Path Switch Request Setup Failed Transfer, which may contain the PDU Session ID and Cause IE.

[0054] If the Target NG-RAN stores the S-NSSAI information supported by the UE's current Tracking Area (TA) as configuration information, it can check if there are any PDU sessions to the UE that have an S-NSSAI that is not supported by the UE's current TA.

[0055] If there are PDU sessions for the UE that do not support S-NSSAI, T-RAN may include the corresponding PDU Session ID and Cause IE set to slice(s) not supported in the List of PDU Sessions that failed to be established with the failure cause given in the N2 SM information element.

[0056] For PDU sessions where Cause IE is set to slice(s) not supported, T-RAN may include other S-NSSAI information supported by the current TA (e.g., Backup S-NSSAI) in the message transmitted to AMF.

[0057] The Target NG-RAN may store at least one of the one or more cell identifiers (e.g., NG-RAN Cell Global Identifier (CGI)) or one or more TA identifiers (e.g., TAC) available for each S-NSSAI as a setting value. Based on information received from AMF or OAM, the NG-RAN can set at least one of the one or more cell identifiers (e.g., CGI) or one or more TA identifiers (e.g., TAC) available for each S-NSSAI.

[0058] If Target NG-RAN stores the available S-NSSAI information for the UE's current cell (e.g., the target cell) as configuration information, it can check if there are any PDU sessions for the UE that have S-NSSAI unavailable for the UE's current cell.

[0059] If there are PDU sessions for the UE for which S-NSSAI is unavailable, T-RAN may include the corresponding PDU Session ID and Cause IE for the PDU session in the List of PDU Sessions that failed to be established with the failure cause given in the N2 SM information element.

[0060] In this case, Cause IE may indicate at least one of the following: one or more slices are not available, or one or more slices are not within the service area of ​​service of slice(s).

[0061] For PDU sessions where Cause IE is set to slice(s) not available or not within area of ​​service of slice(s), T-RAN may include other S-NSSAI information available in the current cell (e.g., Backup S-NSSAI) in the message transmitted to AMF.

[0062] -UE Location Information: May indicate the location of the UE. UE location information may include a Cell ID or TA identifier.

[0063] In step 2, the AMF can include the information received from the T-RAN in a message transmitted to the SMF.

[0064] In step 2a, the SMF can decide to generate an UP path for the PDU sessions included in the List of PDU Sessions To Be Switched with N2 SM Information contained in the message received from the AMF. The SMF can also decide whether to continue using the existing UPF for the PDU sessions included in the List of PDU Sessions To Be Switched with N2 SM Information.

[0065] For PDU sessions included in the List of PDU Sessions that failed to be established with the failure cause given in the N2 SM information element, the SMF can identify that if the Cause IE indicates slice(s) not available or not within area of ​​slice(s), the S-NSSAI corresponding to the PDU session is supported in the current cell but is not set to an S-NSSAI available in the current cell (for example, not a cell included in NS AoS). The SMF can also decide whether to deactivate, rather than release, the PDU sessions included in the List of PDU Sessions that failed to be established with the failure cause given in the N2 SM information element.

[0066] SMF can transmit a message to the UE requesting that a PDU session be generated via another S-NSSAI (e.g., Backup S-NSSAI) for a PDU session where the IE indicates slice(s) not supported, slice(s) not available, or not within area of ​​slice(s).

[0067] In this case, if the information received from AMF includes an Alternative S-NSSAI for the PDU session included in the List of PDU Sessions that failed to be established with the failure cause given in the N2 SM information element, SMF may include the Alternative S-NSSAI in the message it transmits to the UE. If the information received from AMF does not include an Alternative S-NSSAI, SMF can decide which S-NSSAI to transmit to the UE based on the configuration information or by making its own judgment.

[0068] Specifically, the SMF may include in the N1 message (e.g., the message transmitted to the UE) which is a message transmitted to the UE, at least one of the following: PDU session ID, S-NSSAI, or information instructing the transmission of a PDU session establishment request to the same Data Network.

[0069] The SMF can transmit N1 messages (e.g., messages transmitted to the UE) and N2 messages (e.g., messages transmitted to the T-RAN) to the AMF. Based on the information received from the SMF, the AMF can transmit an N2 message containing an N1 message to the T-RAN. The T-RAN can transmit an N1 message contained within an N2 message received from the AMF to the UE.

[0070] Upon receiving an N1 message, the UE can transmit a PDU session establishment request message to the AMF via T-RAN. The PDU session establishment request message may contain at least one of the following: the same DNN for the PDU Session ID included in the N1 message, or the S-NSSAI included in the N1 message.

[0071] In step 3, the remaining handover procedure may be performed. At this time, the remaining handover procedure may include procedures that are the same as or similar to the handover procedure in an existing LTE or 5G communication system. However, the remaining handover procedure may also include new operations other than the existing handover procedure by organically combining the procedures of steps 1a to 2a described above.

[0072] In step 4, the registration procedure using T-RAN may be performed.

[0073] Figure 4 shows how the AMF processes a PDU session with NS AoS in mind in a registration procedure according to one embodiment of the present disclosure.

[0074] Referring to Figure 4, in step 1, the terminal (UE) can transmit an AN message (e.g., at least one of AN parameters or registration request) to the base station (RAN). At this time, the registration request message may include at least one of the following: UE identifier (e.g., at least one of SUCI (subscription concealed identifier), 5G-GUTI (5G-globally unique temporary identity), or PEI (permanent equipment identifier)), registration type, requested NSSAI, UE MM (mobility management) core network capability, or List of PDU Sessions to Be Activated.

[0075] If the UE provides the capability to perform slice connection control based on slice availability information and the UE's location (e.g., Cell ID), the UE MM core network capability in the registration request message may include information indicating that the UE supports the capability to perform slice connection control based on the slice availability information.

[0076] In step 2, the RAN can select the AMF based on the information in the AN message received from the UE.

[0077] In step 3, RAN can transmit an N2 message to AMF (e.g., at least one of N2 parameters or a registration request). The N2 parameters may include at least one of the following: selected PLMN ID, UE location information (e.g., Location Information and Cell ID associated with the cell where the UE is camping (e.g., NG-RAN CGI)), or UE context request. The N2 message may also include a RAN ID.

[0078] However, if no previous AMF exists for the UE (for example, if the registration request is an Initial Registration request), steps 4 and 5 may be omitted.

[0079] In step 4, if the AMF is changed, the changed AMF (hereinafter referred to as the New AMF) can identify the original AMF for the UE (hereinafter referred to as the Old AMF) based on the 5G-GUTI included in the information received in step 3. The New AMF can then transmit a Namf_Communication_UEContextTransfer Request message to the Old AMF. At this time, the Namf_Communication_UEContextTransfer Request message may include at least one of the following: the UE's Access Type, the UE's identifier (e.g., 5G-GUTI or SUPI), or supported features.

[0080] In step 5, when the Old AMF receives the Namf_Communication_UEContextTransfer Request message in step 4, it may include in the response message that it transmits to the New AMF at least one of the UE Context or SUPI for the UE identifier contained in the received message.

[0081] In one embodiment, the UE Context information transmitted from Old AMF to New AMF may include slice availability information for each S-NSSAI for the UE. The slice availability information for each S-NSSAI (e.g., at least one of NS-AoS or S-NSSAI location availability information) may include information on the area in which a particular S-NSSAI can be used. The UE Context information may also include a cell identifier (e.g., NG-RAN CGI) or a TA identifier (e.g., at least one of TAI or TAC).

[0082] In one embodiment, the UE Context information transmitted from Old AMF to New AMF may include whether or not the UE's slice availability area information is supported.

[0083] In step 6, the New AMF can request slice availability information (e.g., including at least one of NS-AoS or S-NSSAI location availability information) from the NSSF. In response to the request for slice availability information, the NSSF can receive slice availability information from the New AMF, including at least one of NS-AoS or S-NSSAI location availability information. Step 6 can be performed based on configuration information or by OAM if the information received from the Old AMF does not include slice availability information. In this case, the New AMF may include an indicator requesting S-NSSAI and slice availability information in the message it requests from the NSSF. If the message received from the New AMF includes an indicator requesting slice availability information, the NSSF may include S-NSSAI-specific slice availability information in the message it transmits to the New AMF for one or more S-NSSAIs included in the message received from the New AMF.

[0084] In step 7, the Authentication / Authorization procedure for the UE can be performed. Although not shown in Figure 4, the AMF can perform the Authentication / Authorization procedure for the UE via the AUSF.

[0085] In step 8, if New AMF received the UE Context from Old AMF in step 5, it can send a message to Old AMF to notify it of the registration status for the received UE Context. If there are one or more PDU session IDs in the UE Context that New AMF cannot support or that need to notify Old AMF (for example, if S-NSSAI network slice availability information is set and the current cell is not included in the network slice availability area), New AMF can send a Namf_Communication_RegistrationStatusUpdate message to Old AMF.

[0086] The Namf_Communication_RegistrationStatusUpdate message may contain at least one of the following pieces of information:

[0087] - One or more PDU session IDs to be released due to NS-AoS: If, among the PDU sessions in the UE Context, S-NSSAI slice availability information is set, and among the PDU sessions, the cell where the current UE is located is not included in the associated S-NSSAI availability area, and New AMF decides to release one or more PDU sessions where the cell where the current UE is located is not included in the associated S-NSSAI availability area, then the Namf_Communication_RegistrationStatusUpdate message may include one or more PDU session IDs of the one or more PDU sessions whose current cell is not included in the slice availability area. In this case, the Namf_Communication_RegistrationStatusUpdate message may include cause information indicating that the release is due to slice availability information (e.g., NS-AoS).

[0088] -One or more PDU session IDs to be deactivated due to NS-AoS: If there are PDU sessions in the UE Context that have S-NSSAI slice availability information set, and the current cell is not included in the slice availability area, and New AMF decides to deactivate one or more PDU sessions that are not included in the slice availability area, then the Namf_Communication_RegistrationStatusUpdate message may include one or more PDU session IDs of the one or more PDU sessions that are not included in the slice availability area. In this case, the Namf_Communication_RegistrationStatusUpdate message may include cause information indicating that the deactivation is due to slice availability information (e.g., NS-AoS).

[0089] In step 8a, if the Old AMF received a message from the New AMF in step 7 that contained PDU session ID(s) to be released due to NS-AoS, it can send an Nsmf_ReleaseSMContext request(PDU Session ID) to the SMF responsible for each PDU session to release one or more PDU sessions that are not included in the slice's available area. The SMF can then release the PDU sessions for the PDU Session IDs included in the received message.

[0090] If the Old AMF receives a message from the New AMF in step 7 that includes PDU session ID(s) to be released due to NS-AoS, it can send an Nsmf_UpdateSMContext request(PDU Session ID, Operation Type(deactivate)) to the SMF responsible for each PDU session to release one or more PDU sessions that are not included in the slice's available area. If the SMF receives a message with an Operation type indicating deactivate, it can perform a user plane(UP) deactivation on the included PDU session IDs.

[0091] In step 9, the New AMF can obtain subscriber information for the UE from the UDM. The New AMF can also register the Access Type with the UDM.

[0092] In step 10a, if the registration request received in step 3 includes a List of PDU Sessions to Be Activated, and if there are PDU session IDs in the List of PDU Sessions to Be Activated where the S-NSSAI's network slice availability information is set in New AMF and the current cell ID is not included in the slice availability area, New AMF can transmit a Release request to the SMF responsible for releasing the PDU session not included in the slice availability area. Alternatively, New AMF can transmit a deactivate request to the SMF responsible for deactivating the PDU session not included in the slice availability area. Alternatively, New AMF can transmit a message to the SMF responsible for requesting another S-NSSAI to perform a slice change (e.g., slice replacement) for the PDU session not included in the slice availability area. To provide continuity for the PDU session, AMF can transmit a slice replacement request message to use a PDU session with a different S-NSSAI for the PDU session in question.

[0093] A Release request message (e.g., an Nsmf_ReleaseSMContext request) may contain at least one of the following: PDU session ID(s) or SM Context ID(s).

[0094] A deactivate request message (e.g., an Nsmf_UpdateSMContext request) may contain at least one of the following: PDU session ID(s) or Operation Type (e.g., deactivate).

[0095] A slice replacement request message (e.g., an Nsmf_UpdateSMContext request) may include at least one PDU session ID or SM Context ID for a specific PDU session, along with the existing S-NSSAI (e.g., S-NSSAI for the PDU session) and the alternative S-NSSAI (e.g., Alternative S-NSSAI).

[0096] New AMF can determine, based on its configuration information, whether to send a release message, a deactivate message, or a slice replacement message for PDU sessions whose current cell ID is not included in the network slice available area, if the network slice available area information for a specific S-NSSAI is set in New AMF, among the one or more PDU session IDs included in List Of PDU Sessions To Be Activated.

[0097] In step 10b, if the SMF received the Nsmf_ReleaseSMContext message in step 10a, it can terminate the PDU session for the PDU Session ID included in the Nsmf_ReleaseSMContext message.

[0098] In step 10a, SMF receives the Nsmf_UpdateSmContext message, and if the Operation type in the Nsmf_UpdateSmContext message indicates deactivate, it can perform a user plane (UP) deactivation on the PDU Session ID included in the Nsmf_UpdateSmContext message.

[0099] In step 10a, the SMF receives the Nsmf_UpdateSmContext message, and if the Nsmf_UpdateSmContext message contains S-NSSAI and Alternative S-NSSAI, it can perform slice replacement of the PDU Session ID contained in the Nsmf_UpdateSmContext message with the Alternative S-NSSAI. Specifically, the SMF can include the Alternative S-NSSAI in the message it transmits to the UE. If the information received by the AMF contains the Alternative S-NSSAI, the SMF can include at least one of the following in the N1 message (e.g., the message transmitted to the UE): the PDU session ID, the Alternative S-NSSAI (e.g., the Alternative S-NSSAI contained in the message received from the AMF), or information instructing the transmission of a PDU session establishment request to the same Data Network. The SMF can then transmit the corresponding N1 message (e.g., the message transmitted to the UE) and N2 message (e.g., the message transmitted to the T-RAN) to the AMF. Based on the information received from the SMF, the AMF can transmit an N2 message containing an N1 message to the T-RAN. The T-RAN can transmit the N1 message contained within the N2 message received from the AMF to the UE. Upon receiving the N1 message from the T-RAN, the UE can transmit a PDU session establishment request message to the AMF via the T-RAN. The PDU session establishment request message may contain at least one of the following for the PDU Session ID contained in the N1 message: the same DNN or the Alternative S-NSSAI contained in the N1 message.

[0100] In step 11, the New AMF can transmit a Registration Accept message to the UE. The Registration Accept message can be transmitted to the UE via the RAN.

[0101] Figure 5 shows how a base station processes a PDU session and notifies the AMF of slice availability information in a PDU session modification procedure according to one embodiment of the present disclosure.

[0102] Referring to Figure 5, if the RAN stores slice availability information for each S-NSSAI (which can consist of, for example, a cell identifier or TA identifier, and can be referred to as NS AoS or S-NSSAI location availability information) as configuration information, it can identify the slice information that can be supported by a cell based on the slice availability information for each S-NSSAI (for example, if the slice availability information includes a cell identifier, the S-NSSAI is available in the cell indicated by the cell identifier).

[0103] In Step 1, if the RAN has any UEs under its responsibility that have a PDU session for an S-NSSAI that is unavailable in the serving cell (for example, the cell where the UE is currently located), the RAN can perform at least one of the following actions:

[0104] The RAN can transmit an N2 message to the AMF requesting the release of one or more PDU sessions for an S-NSSAI that is unavailable in the serving cell. The N2 message requesting the release can be transmitted after the RAN has released the session for the PDU session for the S-NSSAI that is unavailable in the serving cell. The N2 message may include at least one of the following: one or more PDU session IDs, a PDU session release indicator, or a cause indicating slice unavailability based on configuration information.

[0105] The RAN can transmit an N2 message to the AMF requesting resource deactivation for one or more PDU sessions to an S-NSSAI that are unavailable in the serving cell. The N2 message requesting resource deactivation can be transmitted after the RAN has deactivated the resources for the PDU sessions to the S-NSSAI that are unavailable in the serving cell. The N2 message may include at least one of the following: one or more PDU session IDs, a PDU session deactivation indicator, or a cause indicating slice unavailability based on configuration information.

[0106] The RAN can transmit an N2 message to notify the AMF of an unavailable S-NSSAI PDU session for one or more S-NSSAI PDU sessions in the serving cell. The N2 message may include at least one of one or more PDU session IDs or indicators indicating slice unavailability based on configuration information.

[0107] In step 2a, when the AMF receives the message from the RAN in step 1, it can transmit a message to the SMF containing at least one of the following pieces of information:

[0108] -PDU session ID(s) or SM Context ID(s): The message received in step 1 may contain at least one of the following: PDU session ID(s) or the corresponding SM Context ID(s).

[0109] -PDU session termination indicator: May be included if the message received in step 1 includes a PDU session deactivation indicator, or if the message received in step 1 includes an indicator indicating slice unavailable and AMF decides to terminate the PDU session.

[0110] - Operation type indicating PDU session deactivation: May be included if the message received in step 1 contains a PDU session release indicator, or if the message received in step 1 contains an indicator indicating slice unavailable and AMF decides to deactivate the PDU session.

[0111] -Alternative S-NSSAI: Based on the information received in step 1, AMF can determine that a PDU session is for an unavailable S-NSSAI (for example, if the message received in step 1 contains an indicator indicating slice unavailability or if the message received in step 1 contains a cause for slice unavailability), and decide to move the PDU session for the unavailable S-NSSAI to another S-NSSAI. This may include an Alternative S-NSSAI. AMF can use an Alternative S-NSSAI received from NSSF or PCF.

[0112] In step 2b, the SMF can transmit a response message to the AMF for step 2a.

[0113] In step 3, the message that the SMF transmits to the AMF based on the message it received from the AMF may contain at least one of the following pieces of information:

[0114] -If the message received by the AMF contains a PDU session release directive, the SMF can transmit at least one of the following to the AMF in the message: PDU session ID, N1 SM container (PDU Session Release Command), or N2 SM Container (N2 Resource Release request (PDU Session ID)). The SMF can also release the N4 resource corresponding to the PDU to the UPF.

[0115] -If the message received by the AMF contains a PDU session deactivation indicator, the SMF may transmit at least one of the following to the AMF in the message it sends back to the AMF: the PDU session ID or the N2 SM Container (N2 Resource Release Request (PDU Session ID)).

[0116] -If the message received by the AMF contains an Alternative S-NSSAI, the SMF may transmit at least one of the following to the AMF: a PDU session ID or an N1 SM container (PDU Session Release Command (Alternative S-NSSAI)). The Alternative S-NSSAI may be transmitted in a PDU Session Modification Command or other Command message.

[0117] In step 4, the SMF can transmit a response message to the AMF for step 3.

[0118] In step 5, when the AMF receives the message from the SMF in step 3, it can perform the following actions:

[0119] -If a message received from the SMF contains an N1 SM Container, the N1 message can contain an N2 message containing the PDU session ID and the N1 SM Container, which can then be transmitted to the UE via the RAN.

[0120] -If a message received from SMF contains an N2 SM Container, the N2 message containing the N2 SM Container can be transmitted to the RAN.

[0121] In step 6, if the RAN receives an N2 message from the AMF and that N2 message contains an N2 Resource Release request (PDU session ID), it can release the RAN resource for the PDU session ID. At this time, signaling with the UE for the release of the RAN resource may occur. If the N2 message received from the AMF contains an N1 message, the RAN can forward the N1 message to the UE.

[0122] In step 7, the remaining steps for PDU session termination or deactivation may be performed. These remaining steps may include procedures identical or similar to those used for PDU session termination or deactivation in existing LTE or 5G communication systems. However, the remaining steps for PDU session termination or deactivation may also include new operations other than existing PDU session termination or deactivation procedures by organically combining the procedures of steps 1 through 6 described above.

[0123] In step 8, if the message received from the RAN contains a PDU session ID and a PDU session release command (Alternative S-NSSAI) or a PDU session modification command (Alternative S-NSSAI), the UE can transmit a PDU session establishment request message to the RAN, which includes the Alternative S-NSSAI and the DNN for the PDU session ID. A new PDU session to the Alternative S-NSSAI can be created through the transmission of the PDU session establishment request message.

[0124] Figure 6 is a block diagram showing the structure of a terminal (UE) according to one embodiment of the present disclosure.

[0125] Referring to Figure 6, the terminal of this disclosure may include a processor 620, a transceiver 600, and a memory 610. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than those described above. Furthermore, the processor 620, the transceiver 600, and the memory 610 may be implemented in the form of a single chip.

[0126] According to one embodiment of the present disclosure, the processor 620 can control a series of processes that enable the base operation to be performed according to the embodiments of the present disclosure described above. For example, the processor 620 can control terminal components to carry out a method for supporting network slice changes according to the embodiments described above. The processor 620 can control terminal components so that the embodiments of the present disclosure described above are carried out by executing a program stored in memory 610. The processor 620 may also be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific integrated circuit, or at least one processor.

[0127] According to one embodiment of this disclosure, the transceiver 600 can transmit and receive signals with a network entity, another terminal, or a base station. The signals transmitted and received with the network entity, another terminal, or a base station may include control information and data. The transceiver 600 may consist of an RF transmitter that upconverts and amplifies the frequency of the transmitted signal, an RF receiver that low-noise amplifies the received signal and downconverts its frequency, and so on. However, this is only one example of the transceiver 600, and the components of the transceiver 600 are not limited to an RF transmitter and an RF receiver. Furthermore, the transceiver 600 can receive signals via a wireless channel and output them to a processor 620, and transmit signals output from the processor 620 via a wireless channel.

[0128] According to one embodiment of this disclosure, the memory 610 can store programs and data necessary for the operation of the terminal. The memory 610 can also store control information or data contained in signals transmitted and received by the terminal. The memory 610 may consist of a storage medium such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. There may also be multiple memory 610s. According to one embodiment, the memory 610 can also store a program for performing the method of supporting the network slice modification described above.

[0129] Figure 7 is a block diagram showing the structure of a base station according to one embodiment of the present disclosure.

[0130] Referring to Figure 7, the base station of this disclosure may include a processor 720, a transceiver 700, and a memory 710. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than those described above. Furthermore, the processor 720, the transceiver 700, and the memory 710 may be implemented in the form of a single chip.

[0131] According to one embodiment of the present disclosure, the processor 720 can control a series of processes that enable the base station to operate according to the embodiments of the present disclosure described above. For example, the processor 720 can control components of the base station to carry out a method for supporting network slice changes according to the embodiments described above. The processor 720 can control components of the base station so that the embodiments of the present disclosure described above are carried out by executing a program stored in the memory 710. The processor 720 may also be an AP (Application Processor), a CP (Communication Processor), a circuit, an application-specific integrated circuit, or at least one processor.

[0132] According to one embodiment of this disclosure, the transceiver 700 can transmit and receive signals with a network entity, another base station, or a terminal. The signals transmitted and received with the network entity, another base station, or a terminal may include control information and data. The transceiver 700 may consist of an RF transmitter that upconverts and amplifies the frequency of the transmitted signal, an RF receiver that low-noise amplifies the received signal and downconverts its frequency, and so on. However, this is only one embodiment of the transceiver 700, and the components of the transceiver 700 are not limited to an RF transmitter and an RF receiver. Furthermore, the transceiver 700 can receive signals via a wireless channel and output them to a processor 720, and transmit signals output from the processor 720 via the wireless channel.

[0133] According to one embodiment of this disclosure, the memory 710 can store programs and data necessary for the operation of the base station. The memory 710 can also store control information or data included in signals transmitted and received by the base station. The memory 710 may consist of a storage medium such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. There may also be multiple memories 710. According to one embodiment, the memory 710 can store a program for performing the method of supporting the network slice change described above.

[0134] Figure 8 is a block diagram showing the structure of a network entity according to one embodiment of the present disclosure.

[0135] Referring to Figure 8, the network entity of this disclosure may include a processor 820, a transceiver 800, and a memory 810. However, the components of the network entity are not limited to the examples described above. For example, the network entity may include more or fewer components than those described above. Furthermore, the processor 820, the transceiver 800, and the memory 810 may be implemented in the form of a single chip. Also, according to one embodiment of this disclosure, the network entity may mean a network function (NF), which may include RAN, AMF, PCF, UDM, AF, NEF, and UTM, etc.

[0136] According to one embodiment of the present disclosure, the processor 820 can control a series of processes by which the NF can operate according to the embodiments of the present disclosure described above. For example, the processor 820 can control components of a network entity to perform a method that supports network slice modification according to the embodiments described above. The processor 820 can control components of a network entity to perform the embodiments of the present disclosure described above by executing a program stored in memory 810. The processor 820 may also be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific integrated circuit, or at least one processor.

[0137] According to one embodiment of this disclosure, the transceiver 800 can transmit and receive signals with other network entities, base stations, or terminals. The signals transmitted and received with other network entities or terminals may include control information and data. The transceiver 800 may consist of an RF transmitter that upconverts and amplifies the frequency of the transmitted signal, an RF receiver that low-noise amplifies the received signal and downconverts its frequency, and so on. However, this is only one example of the transceiver 800, and the components of the transceiver 800 are not limited to an RF transmitter and an RF receiver. Furthermore, the transceiver 800 can receive signals via a wireless channel and output them to a processor 820, and transmit signals output from the processor 820 via the wireless channel.

[0138] According to one embodiment of this disclosure, the memory 810 can store programs and data necessary for the operation of a network entity. The memory 810 can also store control information or data contained in signals transmitted and received by the network entity. The memory 810 may consist of a storage medium such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. There may also be multiple memory 810s. According to one embodiment, the memory 810 can store a program for performing the method of supporting the network slice modification described above.

[0139] It should be noted that the configuration diagrams, control / data signal transmission / reception methods, and operating procedures illustrated in Figures 1 to 8 are not intended to limit the scope of rights for embodiments of this disclosure. In other words, not all components, entities, or operating steps described in Figures 1 to 8 should be interpreted as essential components for implementing the disclosure, and implementation may include only some components, as long as it does not impair the essence of the disclosure.

[0140] The operation of the above-described embodiment can be realized by providing a memory device storing the program code in any component within the device. That is, the control unit within the device can perform the above-described operation by reading the program code stored in the memory device using a processor or CPU (Central Processing Unit) and executing it.

[0141] The entities, or various components, modules, etc. of terminal devices described herein, may also be operated using hardware circuits such as complementary metal oxide semiconductor-based logic circuits, firmware, or software, and / or combinations of hardware and firmware and / or software embedded in a machine-readable medium. As an example, various electrical structures and methods may be implemented using electrical circuits such as transistors, logic gates, and application-specific integrated circuits.

[0142] The methods according to the embodiments described in the claims or specification of this disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0143] When implemented in software, a computer-readable storage medium may be provided to store one or more programs (software modules). The one or more programs stored on the computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to perform the methods according to the embodiments described in the claims or specification of this disclosure.

[0144] Such programs (software modules, software) can be stored in random access memory, non-volatile memory including flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disc storage devices, compact disc-ROMs (CD-ROMs), digital versatile discs (DVDs), or other forms of optical storage devices, magnetic cassettes, or in memory composed of some or all of these. Furthermore, each constituent memory may contain multiple instances.

[0145] Furthermore, the program may be stored in an attachable storage device that can be accessed via a communication network such as the Internet, intranet, LAN (local area network), WAN (wide area network), or SAN (storage area network), or a combination thereof. Such a storage device can access the device performing the embodiments of the disclosure via an external port. Alternatively, a separate storage device on the communication network can access the device performing the embodiments of the disclosure.

[0146] In the specific embodiments of the Disclosure described above, the components included in the Disclosure are expressed singly or plurally by the specific embodiments presented. However, the singly or plural expressions are selected to suit the context presented for the convenience of explanation, and the Disclosure is not limited to singly or plural components. Components expressed plural may consist of singular components, and components expressed singly may consist of plural components.

[0147] On the other hand, while specific embodiments have been described in the detailed description of this disclosure, it goes without saying that various modifications are possible within the limits that do not deviate from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the embodiments described, but should be defined not only by the claims described below, but also by equivalent claims.

Claims

1. A method performed by a base station in a wireless communication system, Steps include identifying a PDU (protocol data unit) session associated with a network slice based on first information regarding the availability of the network slice, The terminal moves from a first cell inside the NS-AoS (network slice area of ​​service) to a second cell outside the NS-AoS, and if at least one UP (user plane) resource is activated for the PDU session, the steps include deactivating the at least one UP resource for the PDU session, The steps include sending a second piece of information to an AMF (access and mobility management function) entity requesting the deactivation of at least one UP resource, Methods that include...

2. The first information is S-NSSAI (single network slice selection assistance information) location availability information, The S-NSSAI location availability information includes location information indicating cells of multiple TAs (tracking areas) associated with the available network slices. The method according to claim 1.

3. The N2 message for PDU session correction includes the second information: The method according to claim 1.

4. The N2 message further includes at least one of the ID of the PDU session or N2 SM (session management) information. The method according to claim 3.

5. A method performed by an AMF (access and mobility management function) entity in a wireless communication system, The process includes receiving first information from a base station requesting the deactivation of at least one UP (user plane) resource, A PDU (protocol data unit) session associated with a network slice is based on second information regarding the availability of the network slice, and When a terminal moves from a first cell inside the NS-AoS (network slice area of ​​service) to a second cell outside the NS-AoS, and at least one UP resource is activated for the PDU session, the at least one UP resource for the PDU session is deactivated. method.

6. The first information is S-NSSAI (single network slice selection assistance information) location availability information, and The S-NSSAI location availability information includes location information indicating cells of multiple TAs (tracking areas) associated with the available network slices. The method according to claim 5.

7. The N2 message for PDU session correction includes the second information: The method according to claim 5.

8. The N2 message further includes at least one of the ID of the PDU session or N2 SM (session management) information. The method according to claim 7.

9. A base station in a wireless communication system, Transceiver and, The transceiver is coupled to at least one processor, Includes, The aforementioned at least one processor is Based on first information regarding the availability of the network slice, identify the PDU (protocol data unit) session associated with the network slice, When a terminal moves from a first cell inside the NS-AoS (network slice area of ​​service) to a second cell outside the NS-AoS, and at least one UP (user plane) resource is activated for the PDU session, the at least one UP resource for the PDU session is deactivated, and The AMF (access and mobility management function) entity is configured to send second information requesting the deactivation of at least one UP resource. Base station.

10. The first information is S-NSSAI (single network slice selection assistance information) location availability information, The S-NSSAI location availability information includes location information indicating cells of multiple TAs (tracking areas) associated with the available network slices. The base station according to claim 9.

11. The N2 message for PDU session correction includes the second information: The base station according to claim 9.

12. The N2 message further includes at least one of the ID of the PDU session or N2 SM (session management) information. The base station according to claim 11.

13. An AMF (access and mobility management function) entity in a wireless communication system, Transceiver and, The transceiver is coupled to at least one processor, Includes, The aforementioned at least one processor is The base station is configured to receive first information requesting the deactivation of at least one UP (user plane) resource, A PDU (protocol data unit) session associated with a network slice is based on second information regarding the availability of the network slice, and When a terminal moves from a first cell inside the NS-AoS (network slice area of ​​service) to a second cell outside the NS-AoS, and at least one UP resource is activated for the PDU session, the at least one UP resource for the PDU session is deactivated. AMF entity.

14. The first information is S-NSSAI (single network slice selection assistance information) location availability information, and The S-NSSAI location availability information includes location information indicating cells of multiple TAs (tracking areas) associated with the available network slices. The AMF entity according to claim 13.

15. The N2 message for PDU session correction includes the second information: The AMF entity according to claim 13.

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