Method and apparatus for simultaneous use of network slices

Abstract

A method and apparatus for efficiently provisioning and managing network slices is provided. [Solution] The present invention relates to a communication technique and system for converging a 5G communication system with IoT technology to support a higher data transmission rate than that of the 4G system. The present invention is applied to intelligent services (e.g., smart homes, smart buildings, smart cities, smart or connected cars, healthcare, digital education, smart retail, security, and safety-related services, etc.) based on 5G communication technology and IoT-related technology. The present invention discloses a method and apparatus for efficiently providing and managing network slices for terminal services.

Description

[Technical Field]

[0001] The present invention relates to wireless communication systems, and more particularly to an apparatus and method for providing network slicing in wireless or mobile communication systems. [Background technology]

[0002] To meet the increasing demand for wireless data traffic since the commercialization of the 4G communication system, efforts are underway to develop improved 5G or pre-5G communication systems. For this reason, 5G or pre-5G communication systems are called beyond-4G network (Beyond 4G Network) or post-LTE (Post-LTE) systems. The 5G communication system defined by 3GPP (registered trademark) is called the New Radio (NR) system.

[0003] To achieve high data transmission rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (e.g., the 60 GHz band). To mitigate propagation path loss in ultra-high frequency bands and increase transmission distances, technologies such as beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antennas are being discussed and applied to NR systems.

[0004] Furthermore, to improve the system's network, technological developments are being carried out in the 5G communication system, such as advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device communication, wireless backhaul, moving networks, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation.

[0005] Other advanced coding modulation (ACM) methods being developed for 5G systems include FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), as well as advanced connection technologies such as FBMC (Filter Bank Multi Carrier), NOMA (non-orthogonal multiple access), and SCMA (sparse code multiple access).

[0006] Meanwhile, the Internet is evolving from a human-centered network where humans generate and consume information to an IoT (Internet of Things) network where information is exchanged and processed among distributed components such as objects. The Internet of Everything (IoE) technology, which combines big data processing technology through connections to cloud servers and other devices, is also emerging. To realize the IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. In recent years, research has focused on sensor networks, M2M (Machine to Machine), and MTC (Machine Type Communication) for connecting things. In the IoT environment, intelligent IT (Internet Technology) services are provided that create new value in people's lives by collecting and analyzing data generated by connected objects. Through the convergence and integration of existing IT (information technology) technologies with various industries, the IoT is being applied to areas such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0007] As a result, various attempts are being made to apply 5G communication systems to IoT networks. For example, 5G communication technologies such as sensor networks, M2M (Machine to Machine), and MTC (Machine Type Communication) are being implemented using techniques such as beamforming, MIMO, and array antennas. The application of cloud radio access networks (cloud RAN) as the aforementioned big data processing technology is also seen as an example of the convergence of 5G and IoT technologies.

[0008] Meanwhile, with the recent development of communication systems, various studies have been conducted on methods for simultaneously providing different network slicing (or network slices). Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in consideration of the above-mentioned prior art, and an object of the present invention is to provide a method performed by an AMF (access and mobility function) entity in a wireless communication system, a method performed by a terminal, an AMF entity, and a terminal. [Means for solving the problem]

[0010] To achieve the above object, a method performed by an AMF (access and mobility function) entity in a wireless communication system according to one aspect of the present invention includes the steps of receiving a registration request message from a terminal, the registration request message including first information for a requested network slice; determining allowed network slices available in a second network based on the first information by the terminal; and transmitting a registration accept message to the terminal, the registration request message including second information indicating the allowed network slices, wherein the first information indicates at least one network slice according to a PDN (packet data network) connection established by the terminal in the first network.

[0011] To achieve the above object, a method performed by a terminal in a wireless communication system according to one aspect of the present invention includes the steps of sending a registration request message including first information for a requested network slice to an access and mobility function (AMF) entity, and receiving a registration accept message from the AMF including second information indicating allowed network slices available to the terminal in a second network determined based on the first information, wherein the first information indicates at least one network slice according to a packet data network (PDN) connection established by the terminal in the first network.

[0012] In order to achieve the above object, an AMF (access and mobility function) entity in a wireless communication system according to one aspect of the present invention comprises a transceiver unit configured to transmit and receive signals, and a control unit, wherein the control unit is configured to receive from a terminal a registration request message including first information for a requested network slice, determine allowed network slices available to the terminal in a second network based on the first information, and send to the terminal a registration accept message including second information indicating the allowed network slices, wherein the first information indicates at least one network slice according to a PDN (packet data network) connection established by the terminal in the first network.

[0013] A terminal in a wireless communication system according to one aspect of the present invention, which has been made to achieve the above object, comprises a transceiver unit configured to transmit and receive signals, and a control unit, wherein the control unit is configured to send a registration request message including first information for a requested network slice to an access and mobility function (AMF) entity, and receive a registration accept message from the AMF including second information indicating allowed network slices available to the terminal in a second network determined based on the first information, and the first information indicates at least one network slice according to a packet data network (PDN) connection established by the terminal in the first network. [Effects of the Invention]

[0014] According to the device and method of the present invention, by providing an interworking method between a 5G network system structure (e.g., 5GC (5G core)) and an EPS (evolved packet system) network system (e.g., EPC (evolved packet core)) that provides a network slice function, it is possible to effectively provide services in a mobile communication system.

[0015] The effects obtained by the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Brief explanation of the drawings]

[0016] [Figure 1] A diagram showing the configuration of a network slice IE according to one embodiment of the present invention. [Figure 2] FIG. 1 illustrates a structure of network slice interworking according to one embodiment of the present invention. [Figure 3]A diagram illustrating a network slice selection method according to one embodiment of the present invention. [Figure 4] A diagram illustrating a network slice selection method according to one embodiment of the present invention. [Figure 5] A diagram illustrating a method for managing a network slice according to one embodiment of the present invention. [Figure 6] FIG. 2 illustrates the structure of a terminal according to an embodiment of the present invention. [Figure 7] FIG. 2 illustrates the structure of a network function (NF) according to an embodiment of the present invention. [Figure 8] FIG. 2 is a diagram showing the structure of a base station according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, specific examples of embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the same components in the drawings are denoted by the same reference numerals whenever possible. Furthermore, detailed descriptions of known functions and configurations that may obscure the gist of the present invention will be omitted.

[0018] In describing the embodiments in this specification, technical details that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted in order to make the gist of the present invention clearer and more clearly communicated by omitting unnecessary details.

[0019] For the same reason, some components in the drawings are exaggerated, omitted, or illustrated schematically, and the sizes of the components do not necessarily reflect their actual sizes. The same or corresponding components in the drawings are denoted by the same reference numerals.

[0020] The advantages and features of the present invention, as well as methods for achieving them, will become clearer with reference to the following detailed embodiments in conjunction with the drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. The present embodiments are provided solely to complete the present invention and fully convey the scope of the invention to those skilled in the art. The present invention is defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

[0021] It will be understood that the combination of each block of the process flowchart with the flowchart figures is implemented by computer program instructions. These computer program instructions are loaded into a processor of a general-purpose computer, special-purpose computer, or other programmable data processing device, and the instructions, executed by the processor of the computer or other programmable data processing device, create means for performing the functions described in the flowchart blocks. These computer program instructions are stored in a computer-usable or computer-readable memory that directs the computer or other programmable data processing device to implement the functions in a particular manner, so that the instructions stored in the computer-usable or computer-readable memory can also produce an article of manufacture that embodies instruction means for performing the functions described in the flowchart blocks. The computer program instructions, when loaded onto a computer or other programmable data processing device, cause a series of operational steps to be performed on the computer or other programmable data processing device, and the instructions that create a computer-implemented process and cause the computer or other programmable data processing device to execute provide the steps for performing the functions described in the flowchart blocks.

[0022] Each block represents a module, segment, or portion of code that includes one or more executable instructions for performing a specified logical function. It should also be noted that in some alternative implementations, the functions described in the blocks may occur out of order. For example, two adjacent blocks may actually be performed substantially simultaneously, or the blocks may be performed in reverse order depending on the corresponding functions.

[0023] The term "module" used in this embodiment refers to software or hardware components such as FPGAs (field programmable gate arrays) or ASICs (application-specific integrated circuits), and the "module" performs either function. However, the term "module" is not limited to software or hardware. A "module" is configured to reside on an addressable storage medium and to execute one or more processors. Thus, by way of example, "module" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. Among the components and "modules," the provided functionality may be combined into fewer components and "modules" or further separated into additional components and "modules." Furthermore, the components and "modules" may be embodied to execute one or more CPUs within a device or security multimedia card.

[0024] Hereinafter, the present invention discloses an apparatus and method for providing interworking of network slices (or network slicing) in a wireless communication system. Specifically, the present invention describes a technique for interworking between a 5G network system structure that provides a network slice function in a wireless communication system and an EPS network system through the present invention.

[0025] In the following description, terms such as a signal, a channel, control information, a network entity or a network function (NF), and device components are provided as examples for the convenience of explanation. Therefore, the present invention is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

[0026] Furthermore, although the present invention will be described using terminology used in some communication standards (e.g., 3GPP (registered trademark): 3rd Generation Partnership Project), this is merely an example for the purpose of explanation. The various embodiments of the present invention can be easily modified and applied to other communication systems.

[0027] The 3GPP (registered trademark) standard standardizes the 5G network system architecture and procedures. Mobile carriers can provide various services through 5G networks. To provide each service, mobile carriers must satisfy different service requirements (e.g., latency, coverage, data rate, bandwidth, reliability, etc.) for each service. To this end, mobile carriers configure network slices and allocate network resources suitable for specific services for each network slice or for each set of network slices. Network resources refer to NFs, logical resources provided by NFs, or radio resource allocations of base stations.

[0028] For example, a mobile carrier configures network slice A to provide mobile broadband services, network slice B to provide vehicular communication services, and network slice C to provide IoT services. In other words, in a 5G network, each service can be efficiently provided to a terminal through a specialized network slice that corresponds to the characteristics of that service.

[0029] FIG. 1 is a diagram illustrating the configuration of a network slice IE according to one embodiment of the present invention.

[0030] The S-NSSAI (Single-Network Slice Selection Assistance Information) defined by 3GPP (registered trademark) is used by a partitioner to partition network slices. Figure 1 shows an example of the configuration of such an S-NSSAI IE (Information Element). One S-NSSAI includes at least one of an SST (Slice / Service Type) 116 used in a Home Public Land Mobile Network (HPLMN), an SD (Slice Differentiator) 118 used in the HPLMN, an SST 112 used in a serving PLMN, and an SD 114 used in the serving PLMN. The S-NSSAI IE also includes a field 110 indicating the length of the content included in the S-NSSAI IE.

[0031] In a non-roaming situation, the SST 112 used in the serving PLMN may be the same as the SST 116 used in the HPLMN, and the SD 114 used in the serving PLMN may be the same as the SD 118 used in the HPLMN.

[0032] In a roaming situation, the SST 112 used in the serving PLMN is the SST used in the VPLMN (Visited PLMN), and the SD 114 used in the serving PLMN is the SD used in the VPLMN.

[0033] Each SST and SD value that constitutes one S-NSSAI may or may not have a value depending on the situation.

[0034] An NSSAI (network slice selection assistance information) consists of one or more S-NSSAI. Examples of NSSAI include a Configured NSSAI stored in the terminal, a Requested NSSAI requested by the terminal, an Allowed NSSAI determined by a 5G core network NF (e.g., an access and mobility function (AMF), a session management function (SMF), a user plane function (UPF), a policy control function (PCF), a user data management (UDM), a user data repository (UDR), a network slice selection function (NSSF), etc.) and permitted for use by the terminal, and a Subscribed NSSAI to which the terminal subscribes. However, this is merely an example, and examples of NSSAI are not limited to those described above.

[0035] Mobile carriers operate both 5G networks and EPS (also called LTE-based networks or 4G networks) networks. A mobile terminal connects to the 5G network to use a service before moving to the EPS network. Alternatively, a mobile terminal connects to the EPS network to use a service before moving to the 5G network. This is called 5G (5G core)-EPC interworking, 5G (5G system)-EPS interworking, or 4G-5G interworking.

[0036] The present invention proposes an example of an interworking method between a 5G network system structure providing network slicing functionality and an EPS network system (i.e., 5GS-EPS interworking) or 5GC-EPC interworking method.

[0037] In addition, the present invention defines network operations and terminal operations that enable a terminal that establishes a session connection in EPS and uses a communication service to continuously use the service even when moving to 5GS.

[0038] FIG. 2 is a diagram illustrating the structure of network slice interworking according to one embodiment of the present invention.

[0039] Figure 2 shows the interworking structure between 5GS and EPS in a non-roaming situation. 5GS consists of a New Radio (NR) base station (NG-RAN (radio access node) or gNB (next generation node B)), AMF, SMF, UPF, PCF, NSSF, UDM, and UDR. EPS consists of an E-UTRA base station (E-UTRAN (Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network) or eNB (evolved node B)), a mobility management entity (MME), a serving gateway (SGW), a packet data network gateway (PGW, consisting of a PGW-U (user plane) and a PGW-C (control plane)), a policy and charging rule function (PCRF), and a home subscriber server (HSS).

[0040] According to one embodiment, the AMF and MME are Network Functions (NFs) that manage wireless network access and mobility for a terminal. The SMF, SGW, and PGW are NFs that manage sessions for a terminal, and the session information includes Quality of Service (QoS) information, charging information, and packet processing information. The UPF and PGW are NFs that process user traffic (e.g., user plane traffic) and are controlled by the SMF and SGW. The PCF and PCRF are NFs that manage operator policies (operator policy and / or PLMN policy) for providing services in a wireless communication system. Additionally, the PCF is divided into a PCF responsible for Access and Mobility (AM) policy and UE policy, and a PCF responsible for Session Management (SM) policy. The PCF responsible for AM / UE policy and the PCF responsible for SM policy are logically or physically separated NFs, or a single logical or physical NF. The UDM and HSS are NFs that store and manage UE subscription information. The UDR is an NF or database (DB) that stores and manages data. The UDR stores terminal subscription information and provides the terminal subscription information to the UDM. The UDR also stores operator policy information and provides operator policy information to the PCF. The NSSF is an NF that selects network slice instances to serve the terminal or performs the function of determining the NSSAI.

[0041] The 5GS UDM and EPS HSS are configured as one combo node (referred to as UDM+HSS). The 5GS SMF and EPS PGW-C are configured as one combo node (referred to as SMF+PGW-C). The UDM+HSS node stores terminal subscriber information. The 5GS UPF and EPS PGW-U are configured as one combo node (referred to as UPF+PGW-C). Terminals connect to the EPS MME via an E-UTRA base station to use EPS network services. Terminals also connect to the 5GS AMF via an NR base station to use 5GS network services.

[0042] In this way, one NF or network entity simultaneously supports different network systems. Such NFs, network nodes, or network entities are referred to as combo nodes, combo NFs, combined nodes, interworking nodes, or interworking NFs. For ease of illustration and description, NFs that simultaneously support different network systems are represented using the "+" or " / " symbols. For example, if an SMF and a PGW-C are configured in one combo node, it is represented as PGW-C / SMF, PGW-C+SMF, SMF / PGW-C, or SMF+PGW-C. When representing a combo node, the order in which the two names are concatenated does not affect the function or role of the combo node.

[0043] A network slice refers to a logical network that provides specific network capabilities and network characteristics. A mobile network operator (MNO) operates one or more network slices. For example, a mobile network operator supports S-NSSAI A, S-NSSAI B, and S-NSSAI C. A mobile network operator also defines the concept of simultaneous use of a network slice supported by the MNO based on at least one of operator policy, a service level agreement (SLA) with a third-party service provider, network slice characteristics, services supported by the network slice, network deployment, and UE subscription information. For example, a mobile network operator may define that S-NSSAI A and S-NSSAI C can be used simultaneously, but that S-NSSAI A and S-NSSAI B cannot be used simultaneously. Alternatively, a mobile network operator may define that S-NSSAI A cannot be used with any other network slice. Alternatively, for example, a mobile communication operator may define that S-NSSAI A is to be used with all network slices. Alternatively, for example, a mobile communication operator may define that S-NSSAIs with the same SST are to be used together. Alternatively, for example, a mobile communication operator may define that S-NSSAIs with the same SD are to be used together. For the purpose of describing the present invention, an operator policy defining the simultaneous use of the above-mentioned network slices is referred to as a SUNS (Simultaneous Use of the Network Slice) policy (policy or rule) or SUNS information. The SUNS information includes information on groups to which the S-NSSAI and the S-NSSAI are associated. One or more S-NSSAIs associated with the same group are used together simultaneously.For example, one or more S-NSSAIs associated with the same group are simultaneously included in the Allowed NSSAI. SUNS information is included in the terminal subscription information.

[0044] An NF according to an embodiment of the present invention supports at least one of the following functions to provide simultaneous use of network slices. One NF supports all of the following functions, or multiple NFs are distributed to support the following functions.

[0045] One or more specific NFs are configured with a SUNS policy, or an NF receives a SUNS policy from another NF.

[0046] Any NF stores and manages network slice information (e.g., S-NSSAI) associated with a session (protocol data unit (PDU) session or packet data network (PDN) connection) established by the UE.

[0047] Any NF determines a network slice (e.g., S-NSSAI) for a session (PDU session or PDN connection) requested by a UE. At this time, the NF determines the network slice (e.g., S-NSSAI) based on at least one of UE subscription information, UE request information (e.g., APN, etc.), network slice information (e.g., S-NSSAI) associated with other sessions established by the UE, and a SUNS policy.

[0048] Any NF transmits network slice information (e.g., S-NSSAI) determined by a specific NF, including itself, to other NFs (e.g., SMF + PGW-C, etc.).

[0049] In the following description, a proposed embodiment will be described on the assumption that some or all of the many functions described above are supported.

[0050] FIG. 3 is a diagram illustrating a method for selecting a network slice according to one embodiment of the present invention.

[0051] FIG. 3 illustrates a session connection procedure for an EPC according to an embodiment of the present invention.

[0052] Figure 3 describes NF operations according to one embodiment of the present invention to provide network slice concurrency during a session connection procedure.

[0053] Referring to FIG. 3, a terminal 300 connects to an EPS MME 302 via an E-UTRA base station (E-UTRAN or eNB) 301 to establish a PDN connection and use an EPS network service.

[0054] In step 310, the terminal 300 performs an attach process to receive 4G services after connecting to a 4G radio network (E-UTRAN 301), or a process to create a PDN connection if already registered. The terminal 300 performs an operation for establishing a PDN connection in the attach process. The terminal 300 includes desired access point name (APN) information in a non-access stratum (NAS) request message transmitted to the MME 302 to distinguish services to be subject to session generation. In addition, the terminal 300 includes capability indication, which indicates whether the terminal supports a network slice simultaneous use function, in the NAS request message transmitted to the MME 302.

[0055] In step 312, the MME 302 performs a process for creating a session based on information received from the UE 300. The MME 302 selects a GW (e.g., SGW, PGW) to process the session considering the APN and other parameters received from the UE, and then transmits a request message for session creation to the SMF+PGW-C (hereinafter referred to as SMF for convenience of explanation) 303 and transfers the request message for session creation to the SMF 303 via the SGW (not shown). The Create Session Request message transmitted by the MME 302 includes the APN and the subscriber ID (International Mobile Subscriber Identity (IMSI)) of the UE. If the MME 302 receives information (e.g., capability indication) indicating whether the UE 300 supports the simultaneous use of network slices, the Create Session Request message transmitted by the MME 302 includes information (e.g., capability indication) indicating whether the UE 300 supports the simultaneous use of network slices.

[0056] In step 314, the SMF 303 receives necessary information, such as a policy and subscription information, from a specific NF to process the PDN connectivity request message received from the UE 300 via the MME 302. For example, the SMF 303 receives a policy from the PCF+PCRF and subscription information from the UDM+HSS. The policy received by the SMF 303 from the PCF+PCRF or the subscription information received from the UDM+HSS includes various information related to network slices. For example, the policy or subscription information received by the SMF 303 includes information (capability indication) indicating whether the UE 300 supports the network slice simultaneous use function. Further, for example, the policy or subscription information received by the SMF 303 includes subscribed slices (subscribed S-NSSAIs) to which the UE 300 has subscribed. Further, for example, the policy or subscription information received by the SMF 303 includes S-NSSAI and / or APN (DNN (data network name)) information for which the network slice simultaneous use function is required. The S-NSSAI information for which the network slice simultaneous use function is required refers to the above-mentioned SUNS policy (information). Also, for example, the policy or subscription information received by SMF 303 includes network slice (e.g., S-NSSAI) information associated with other sessions established by terminal 100.

[0057] In step 314, the SMF 303 determines whether to apply the network slice simultaneous use function based on at least one of the information received from the terminal 300, the policy received from the PCF+PCRF, the subscription information received from the UDM+HSS, and the configuration information stored in the SMF 303. This is applied exclusively to a specific subscriber target, or exclusively to a specific S-NSSAI or APN.

[0058] According to one embodiment, if the information received from the terminal 300 and / or the subscription information received from the UDM+HSS includes information (capability indication) indicating that the terminal 300 supports the simultaneous use of network slices, the SMF 303 decides to apply the simultaneous use of network slices.

[0059] According to another embodiment, if the information received from the terminal 300 and / or the subscription information received from the UDM+HSS includes S-NSSAI and / or APN (DNN) information for which the network slice simultaneous use function is required, the SMF 303 decides to apply the network slice simultaneous use function.

[0060] If it is determined in step 314 that the network slice concurrent use function is to be applied, the procedures from step 316 onward are performed. The SMF 303 invokes a request service to select a network slice (S-NSSAI) for establishing a PDN connection from the NF for network slice interworking management (referred to as an Interworking NF in the present invention, but the name may be Network Slice Quota Management Function, etc., or the NSSF, PCF, UDM, UDR, etc. among NFs that already provide other functions) 304. For example, the SMF 303 transmits a slice selection request message to the Interworking NF 304. Alternatively, the SMF 303 supports the Interworking NF function described above in the present invention.

[0061] Here, the request message sent by the SMF 303 to the Interworking NF 304 includes at least one of one or more S-NSSAIs, a subscriber ID, and an APN.

[0062] The one or more S-NSSAIs included in the request message sent by the SMF 303 are one or more S-NSSAIs supported by the SMF 303. Alternatively, the one or more S-NSSAIs included in the request message sent by the SMF 303 are S-NSSAIs that the SMF 303 can support among the subscribed S-NSSAIs of the terminal.

[0063] As described above, if the policy received by SMF 303 from PCF+PCRF or the subscription information received from UDM+HSS includes a SUNS policy, the request message sent by SMF 303 to Interworking NF 304 includes the SUNS policy.

[0064] If the policy received by SMF303 from the PCF+PCRF or the subscription information received from UDM+HSS includes network slice (e.g., S-NSSAI) information associated with other sessions established by terminal 100, the request message sent by SMF303 to Interworking NF304 includes network slice (e.g., S-NSSAI) information associated with other sessions established by the terminal.

[0065] In step 318, the Interworking NF 304 processes the request message received from the SMF 303 in step 316. For example, the Interworking NF 304 determines whether the S-NSSAI requested by the SMF 303 can be supported, and selects one or more S-NSSAIs.

[0066] A SUNS policy for such a determination is preset in the Interworking NF 304 according to an embodiment of the present invention, or the Interworking NF 304 receives the SUNS policy from the SMF 303.

[0067] Furthermore, the Interworking NF 304 according to an embodiment of the present invention receives and / or manages S-NSSAI information associated with a session (PDU session or PDN connection) established by the UE. For example, the Interworking NF 304 stores and manages S-NSSAI information associated with a session (PDU session or PDN connection) established by the UE.

[0068] In another example, S-NSSAI information associated with a session (PDU session or PDN connection) established by the UE is stored in a separate NF or storage (e.g., UDM or UDR, 305). In this case, a procedure in which the Interworking NF 304 receives information from the separate NF or storage 305 is described in step 320 or 322.

[0069] According to yet another example, the Interworking NF 304 receives, from the SMF 303, S-NSSAI information associated with a session (PDU session or PDN connection) established by the terminal.

[0070] The Interworking NF 304 according to the embodiment of the present invention selects an S-NSSAI based on the SUNS policy and the S-NSSAI information of the session established by the terminal.

[0071] For example, if S-NSSAI A and S-NSSAI C can be used simultaneously (e.g., if S-NSSAI A and S-NSSAI C are associated with the same group), and S-NSSAI A and S-NSSAI B cannot be used simultaneously (e.g., if S-NSSAI A and S-NSSAI B are associated with different groups), and another session established by terminal 300 is associated with S-NSSAI A, and SMF303 can support S-NSSAI B and S-NSSAI C, Interworking NF304 selects S-NSSAI C that can be used simultaneously with S-NSSAI A.

[0072] If there is no S-NSSAI that can be selected based on the SUNS policy and the S-NSSAI information of the session established by the terminal, the Interworking NF304 does not select an S-NSSAI or selects a default S-NSSAI.

[0073] For example, if S-NSSAI A and S-NSSAI C can be used simultaneously (e.g., S-NSSAI A and S-NSSAI C are associated with the same group), but S-NSSAI A and S-NSSAI B cannot be used simultaneously (e.g., S-NSSAI A and S-NSSAI B are associated with different groups), and another session established by terminal 300 is associated with S-NSSAI A and SMF 303 can support S-NSSAI B, Interworking NF 304 either does not select any S-NSSAI or selects a default S-NSSAI because S-NSSAI B supported by SMF 303 cannot be used simultaneously with S-NSSAI A. In this case, the selected default S-NSSAI is the default S-NSSAI that belongs to the same group as S-NSSAI A associated with the other session established by the terminal.

[0074] In steps 320 and 322, if slice-related state information (S-NSSAI information associated with a session established by the terminal) is to be stored in a separate NF 305 or storage, the Interworking NF 304 transmits a request message for acquiring state information to the NF 305 providing the corresponding function, and this message includes the subscriber ID of the terminal. The NF 305 transmits slice information (S-NSSAI) associated with a session established by the terminal, referred to as the subscriber ID, to the Interworking NF 304.

[0075] According to one embodiment, when the NF 305 providing the storage function is a UDM, the Interworking NF 304 sends a request message to the UDM. If necessary, the UDM stores slice-related state information (S-NSSAI information associated with a session established by the terminal) in the UDR. According to another embodiment, when the NF 305 providing the storage function is a UDR, the Interworking NF 304 sends a request message to the UDR, and the request message is delivered to the UDR via the UDM.

[0076] In step 324, the Interworking NF 304 transmits the slice information (i.e., S-NSSAI) selected in step 318 to the SMF 303.

[0077] If there are multiple S-NSSAIs that can be selected based on the SUNS policy and the S-NSSAI information of the session established by the UE in step 318, the Interworking NF 304 includes the multiple S-NSSAIs in the response message, or includes one S-NSSAI selected according to an arbitrary criterion from the multiple S-NSSAIs in the response message.

[0078] If an S-NSSAI cannot be selected based on the SUNS policy and the S-NSSAI information of the session established by the terminal in step 318, the Interworking NF 304 does not include any S-NSSAI in the response message, and also includes an error message (reject message, error cause, etc.) indicating that the S-NSSAI selection failed in the response message.

[0079] In step 326, the SMF 303 finally determines the S-NSSAI to be transmitted to the terminal based on the information received from the Interworking NF 304 in step 324. If the message received in step 324 includes multiple S-NSSAIs, the SMF 303 selects one S-NSSAI from the multiple received S-NSSAIs according to arbitrary criteria. For example, the SMF 303 selects one S-NSSAI that the SMF 303 can support from the multiple received S-NSSAIs.

[0080] If no S-NSSAI is received in step 324, or if information indicating that S-NSSAI selection failed is received, or if there is no S-NSSAI that SMF 303 can support among the multiple S-NSSAIs received, SMF 303 determines that there is no S-NSSAI that can be selected. Accordingly, SMF 303 decides to reject the session request. In this case, the response message sent in step 328 or 330 is a reject message. Alternatively, SMF 303 selects an arbitrary S-NSSAI (e.g., a default S-NSSAI, an S-NSSAI that SMF can support, etc.). In step 328, SMF 303 transmits a Create Session Response message to MME 302. At this time, the selected S-NSSAI is included in the Protocol Configuration Options (PCO). This message is transmitted from SMF 303 to MME 302 via the SGW.

[0081] In step 330, the MME 302 transmits an accept message to the UE 300, notifying that the Attach or session creation is permitted. At this time, the MME 302 transmits the previously received PCO to the UE 300.

[0082] The terminal 300 eventually receives the S-NSSAI, and this information is used for the registration process and other session processing when the terminal 300 subsequently moves to 5G. After that, the terminal 300 moves to 5G and transmits a Requested NSSAI including an S-NSSAI associated with the session established in the EPC to the 5G AMF in order to continuously use the session established in the EPC in 5G. According to one embodiment of the present invention, since the S-NSSAI associated with the session established in the EPC is configured with a network slice that can be used simultaneously, the S-NSSAI included in the Requested NSSAI is configured with a network slice that can be used simultaneously.

[0083] According to yet another embodiment of the present invention, a mobile network operator does not apply a slice simultaneous usage policy (SUNS) when a terminal connects to an EPC according to a mobile network operator policy. A UDM according to an embodiment of the present invention determines whether to apply a slice simultaneous usage policy (i.e., a SUNS policy) depending on when a terminal subscription information request message is generated, received, or generated, or from which NF it is generated, received, or generated. For example, if a terminal subscription information request message is generated, received, or generated during a 5G registration procedure, the UDM determines to apply a simultaneous usage policy (i.e., a SUNS policy). Alternatively, if a terminal subscription information request message is generated, received, or generated during an EPC PDN connection establishment procedure, the UDM determines not to apply a simultaneous usage policy (i.e., a SUNS policy). This determination is made based on at least one of NF information (e.g., NF ID, NF type, etc.) transmitting the terminal subscription information request message, definitions of different types of request messages, and indicators included in the request message.

[0084] If it is determined that the concurrent use policy (i.e., SUNS policy) is not to be applied, the subscription information received by the SMF from the UDM in step 314 does not include SUNS information. In addition, the UDM determines the subscribed S-NSSAI according to the operator policy.

[0085] According to one embodiment, the subscribed S-NSSAIs sent by the UDM to the SMF include only S-NSSAIs belonging to the same group. For example, the UDM determines the S-NSSAIs associated with the group to which the default S-NSSAI belongs as subscribed S-NSSAIs and sends them to the SMF. In this case, all S-NSSAIs associated with all PDN connections established by the UE in the EPC belong to the same group.

[0086] According to yet another embodiment, the subscribed S-NSSAIs sent by the UDM to the SMF also include S-NSSAIs belonging to different groups, in which case the S-NSSAIs associated with the PDN connections established by the UE in the EPC belong to different groups.

[0087] FIG. 4 is a diagram illustrating a method for selecting a network slice according to one embodiment of the present invention.

[0088] FIG. 4 illustrates a session connection procedure for an EPC according to an embodiment of the present invention.

[0089] During the session connection procedure shown in Figure 4, the terminal operation according to one embodiment of the present invention to provide simultaneous use of network slices will be described.

[0090] Referring to FIG. 4, a terminal 300 connects to an EPS MME 302 via an E-UTRA base station 301 to establish a PDN connection and use EPS network services.

[0091] In step 410, a SUNS policy is preset in the terminal 300 according to an embodiment of the present invention. For example, the terminal 300 receives and stores a SUNS policy from an NF (AMF, PCF, UDM, etc.). The SUNS policy is information included in a terminal policy (UE policy, for example, a URSP (UE Route Selection Policy)) or in a Configured NSSAI. Alternatively, the SUNS policy is information independent of the URSP or the Configured NSSAI.

[0092] In addition, the terminal 300 according to an embodiment of the present invention manages S-NSSAI information associated with a session (PDU session, PDN connection) established by the terminal.

[0093] The terminal 300 according to an embodiment of the present invention selects an S-NSSAI for a newly established session based on the SUNS policy and the S-NSSAI information of a session established by the terminal.

[0094] For example, based on a terminal policy (e.g., a URSP), terminal 300 determines that a new session to be established is provided via S-NSSAI B or S-NSSAI C. Here, if the Configured NSSAI stored in terminal 300 includes S-NSSAI A, S-NSSAI B, and S-NSSAI C, and S-NSSAI A and S-NSSAI C can be used simultaneously, S-NSSAI A and S-NSSAI B cannot be used simultaneously, and another session established by terminal 300 is linked to S-NSSAI A, terminal 300 selects S-NSSAI C, which can be used simultaneously with S-NSSAI A.

[0095] If there is no S-NSSAI that can be selected based on the SUNS policy and the S-NSSAI information of the session established by the terminal, the terminal 300 does not select an S-NSSAI or selects a default S-NSSAI.

[0096] For example, based on a terminal policy (e.g., a URSP), terminal 300 determines that a new session to be established is provided via S-NSSAI B. Here, if the Configured NSSAIs stored in terminal 300 include S-NSSAI A and S-NSSAI B, and S-NSSAI A and S-NSSAI B cannot be used simultaneously, and another session established by terminal 300 is linked to S-NSSAI A, terminal 300 does not select any S-NSSAI or selects a default S-NSSAI because S-NSSAI B cannot be used simultaneously with S-NSSAI A.

[0097] In step 412, the terminal 300 performs a registration (Attach) process to receive 4G services after connecting to a 4G radio network (E-UTRAN or eNB, 301), or a process to create a PDN connection if already registered. The terminal 300 performs an operation for establishing a PDN connection in the Attach process. The terminal 300 includes a desired APN to distinguish services to be subject to session creation in an NAS request message sent to the MME 302, and includes the S-NSSAI selected by the terminal 300 in step 410 together with the APN. In addition, the terminal 300 includes information (capability indication) indicating whether the terminal supports a network slice simultaneous use function in the NAS request message sent to the MME 302.

[0098] In step 414, the MME 302 performs a process for creating a session based on the information received from the UE 300. The MME 302 selects a GW (e.g., SGW, PGW) to process the session considering the APN and other parameters, and transmits a request message for creating a session to the SMF+PGW-C (hereinafter referred to as SMF for convenience of explanation) 303. At this time, the session creation request message transmitted by the MME 302 is delivered to the SMF 304 via the SGW (not shown). The Create Session Request message transmitted by the MME 302 includes the APN and the subscriber ID (IMSI) of the UE. If the MME 302 receives information indicating whether the UE supports the S-NSSAI selected by the UE and / or the network slice simultaneous use function of the UE 300 (e.g., capability indication information) in step 412, the Create Session Request message transmitted by the MME 302 includes the S-NSSAI selected by the UE, information indicating whether the UE supports the network slice simultaneous use function of the UE 300 (e.g., capability indication information), etc.

[0099] In step 416, the SMF 303 receives necessary information, such as a policy and subscription information, from a specific NF to process the PDN connectivity request message received from the UE 300 via the MME 302. For example, the SMF 303 receives a policy from the PCF+PCRF and subscription information from the UDM+HSS. The policy received by the SMF 303 from the PCF+PCRF or the subscription information received from the UDM+HSS includes various information according to the network slice. For example, the policy or subscription information received by the SMF 303 includes information (capability indication) indicating whether the UE 300 supports the network slice simultaneous use function. Also, for example, the policy or subscription information received by the SMF 303 includes subscribed slices (subscribed S-NSSAIs) to which the UE 300 has subscribed. Also, for example, the policy or subscription information received by the SMF 303 includes S-NSSAI and / or APN (DNN) information for which the network slice simultaneous use function is required. S-NSSAI information for which the network slice simultaneous use function is required indicates a SUNS policy (or SUNS information).

[0100] In step 416, the SMF 303 determines whether to apply the network slice simultaneous use function based on at least one of the information received from the terminal 300, the policy received from the PCF+PCRF, the subscription information received from the UDM+HSS, and the configuration information stored in the SMF 303. This is applied exclusively to a specific subscriber or exclusively to a specific S-NSSAI or APN.

[0101] According to one embodiment, if the information received from the terminal 300 and / or the subscription information received from the UDM+HSS includes information (capability indication) indicating that the terminal 300 supports the simultaneous use of network slices, the SMF 303 decides to apply the simultaneous use of network slices.

[0102] According to yet another embodiment, if the information received from the terminal 300 and / or the subscription information received from the UDM+HSS includes S-NSSAI and / or APN (DNN) information for which the network slice simultaneous use function is required, the SMF 303 decides to apply the network slice simultaneous use function.

[0103] In step 418, the SMF 303 finally determines the S-NSSAI to be transmitted to the terminal based on the information received from the terminal 300, the subscription information received from the UDM, and the setting information stored in the SMF 303.

[0104] The SMF 303 checks whether the S-NSSAI received from the terminal 300 is included in the subscription information (subscribed S-NSSAIs) received from the UDM. The SMF 303 also checks whether the S-NSSAI received from the terminal 300 is an S-NSSAI that the SMF 303 can support.

[0105] If the S-NSSAI received from terminal 300 is included in the subscription information received from UDM and is an S-NSSAI that SMF 303 can support, SMF 303 decides to use the S-NSSAI received from terminal 300.

[0106] If the S-NSSAI received from the terminal 300 is not included in the subscription information received from the UDM or is not an S-NSSAI that the SMF 303 can support, the SMF 303 decides not to use the S-NSSAI received from the terminal 300. As a result, the SMF 303 decides to reject the session request. In this case, the response message sent in step 420 or 422 is a reject message. Alternatively, the SMF 303 selects an arbitrary S-NSSAI (e.g., a default S-NSSAI, an S-NSSAI that the SMF can support, etc.).

[0107] In step 420, the SMF 303 transmits a Create Session Response to the MME 302. At this time, the S-NSSAI selected by the SMF 303 is included in the PCO. This message sent by the SMF 303 is transmitted to the MME 302 via the SGW.

[0108] In step 422, the MME 302 transmits an accept message to the terminal, notifying that the Attach or session creation is permitted, including the previously received PCO.

[0109] The terminal 300 will eventually receive the S-NSSAI, and this information will be used for the registration process and other session processing when the terminal 300 moves to 5G in the future. In order to continue using the session established in the EPC in 5G, the terminal 300 that moves to 5G in the future will send a Requested NSSAI including an S-NSSAI associated with the session established in the EPC to the 5G AMF. According to one embodiment of the present invention, the S-NSSAI associated with the session established in the EPC is configured with a network slice that can be used simultaneously, and therefore, the S-NSSAI included in the Requested NSSAI is configured with a network slice that can be used simultaneously.

[0110] 5 is a diagram illustrating a method for managing a network slice according to an embodiment of the present invention. FIG. 5 illustrates a procedure for moving to 5GC in an EPC according to an embodiment of the present invention.

[0111] FIG. 5 describes NF operation according to an embodiment of the present invention to provide network slice concurrency during the registration procedure.

[0112] Referring to the embodiment of FIG. 5, the terminal 300 continuously uses the session established in the EPC after moving to the 5GC.

[0113] In step 510, the terminal 300 creates a PDN connection after connecting to 4G and uses a service. At this time, one session (i.e., PDN connection) is associated with one Slice ID (S-NSSAI), and the terminal 300 stores the Slice ID (S-NSSAI) associated with each session (i.e., PDN connection). For example, the first session established by the terminal in the EPC is associated with the first Slice ID, and the second session is associated with the second Slice ID.

[0114] In step 520, the terminal 300 that has moved to 5GC transmits a Registration Request message to the AMF 500 to connect to 5G. The Registration Request message includes a Requested NSSAI. Here, the Requested NSSAI included in the Registration Request message transmitted by the terminal includes a slice ID associated with the PDN connection established by the terminal 300 in the EPC. For example, the Requested NSSAI includes a first slice ID and a second slice ID.

[0115] According to an embodiment of the present invention, a SUNS policy is pre-configured in the terminal 300. For example, the terminal 300 receives and stores the SUNS policy from an NF (AMF, PCF, UDM, etc.). The SUNS policy is information included in a terminal policy (UE policy, for example, a UE Route Selection Policy (URSP)) or included in the Configured NSSAI. Alternatively, the SUNS policy is information independent of the URSP or the Configured NSSAI. When SUNS information is configured in the terminal 300, the terminal 300 constructs the Requested NSSAI based on the SUNS information. For example, when a first slice ID associated with a first session and a second slice ID associated with a second session established in the EPC belong to the same group, the terminal 300 includes the first slice ID and the second slice ID in the Requested NSSAI. Alternatively, if the first slice ID associated with the first session established in the EPC and the second slice ID associated with the second session belong to different groups, the terminal 300 includes only one of the first slice ID and the second slice ID in the Requested NSSAI.

[0116] According to an embodiment of the present invention, a SUNS policy may not be pre-configured in the terminal 300. For example, if the terminal 300 has never previously connected to (or registered with) a 5G network, a SUNS policy may not be pre-configured in the terminal 300. If SUNS information is not configured in the terminal 300, the terminal 300 configures the Requested NSSAI based on priority information for each slice. For example, the terminal 300 determines a slice priority between a first slice ID associated with a first session established in the EPC and a second slice ID associated with a second session. The terminal 300 includes the first slice ID, the second slice ID, and priority information for each slice ID in the Requested NSSAI. For example, the terminal 300 configures the order of slice IDs included in the Requested NSSAI according to the priority order.

[0117] In step 522, the AMF 500 determines an allowed slice (Allowed NSSAI) that the terminal 300 can use to connect to 5G, taking into account the concurrently available network slice policy. The AMF 500 also determines the Allowed NSSAI through the NSSF (not shown) in this process.

[0118] According to an embodiment of the present invention, the AMF 500 or the NSSF is configured with a SUNS policy. Alternatively, the AMF or the NSSF receives a SUNS policy from another NF (e.g., a PCF, a UDM, an AMF, etc.).

[0119] According to one embodiment of the present invention, the AMF 500 acquires PDN connection information (including S-NSSAI information associated with the PDN connection) established by the terminal in the EPC from another NF (e.g., MME, SMF, UDM, etc.).

[0120] In one embodiment of the present invention, the AMF 500 or NSSF determines the Allowed NSSAI based on at least one of the Requested NSSAI, the SUNS policy, the PDN connection information established by the terminal in the EPC, the terminal subscription information, the slice priority, and the S-NSSAI information that the SMF can support.

[0121] In one embodiment, the AMF 500 or NSSF determines, based on the SUNS policy, whether the first Slice ID and the second Slice ID included in the Requested NSSAI are simultaneously available network slices.

[0122] In the case of a network slice in which the first Slice ID and the second Slice ID can be used simultaneously, the AMF or NSSF includes the first Slice ID and the second Slice ID in the Allowed NSSAI.

[0123] If the first Slice ID and the second Slice ID are not network slices that can be used simultaneously, the AMF or NSSF includes only one of the first Slice ID and the second Slice ID in the Allowed NSSAI. When the AMF or NSSF determines the Allowed NSSAI, slice priority is taken into consideration. For example, the AMF or NSSF determines to include in the Allowed NSSAI a slice with a higher priority among network slices that cannot be used simultaneously. At this time, the slice priority is determined based on the network policy and / or information sent by the terminal (e.g., the procedure for the Slice ID included in the Requested NSSAI).

[0124] According to yet another embodiment, if the first slice ID and the second slice ID are not network slices that can be used simultaneously, the AMF or NSSF performs a slice change. For example, the AMF or NSSF decides to change the second slice ID to a third slice ID that can be used simultaneously with the first slice ID. Here, the third slice ID is a slice that can be used simultaneously with the first slice ID among the UE subscribed slices (subscribed S-NSSAIs). In addition, the third slice ID is a slice supported by the SMF serving the second session.

[0125] According to yet another embodiment, when the AMF or NSSF performs a slice change, slice priority is taken into consideration. For example, the AMF or NSSF determines to first change a slice with a lower priority among network slices that cannot be used simultaneously. In this case, the slice priority is determined based on a network policy and / or information sent by the terminal (e.g., the procedure for the Slice ID included in the Requested NSSAI). In this case, the AMF or NSSF includes the first Slice ID and the third Slice ID (the slice ID replaced with the second Slice ID) in the Allowed NSSAI.

[0126] In step 524, the AMF 500 transmits a Registration Accept message to the terminal 300. The Registration Accept message includes the Allowed NSSAI determined in step 522. If a slice change is performed in step 522, the AMF 500 includes information notifying that a slice change has occurred in the Registration Accept message.

[0127] Terminal 300 will eventually receive an S-NSSAI included in Allowed NSSAI, and if a slice ID change occurs, it updates the session information to reflect such a change.

[0128] Below, examples of the configuration of Requested NSSAI and Allowed NSSAI according to an embodiment of the present invention are shown. For the sake of explanation, it is assumed that the second slice ID associated with the second session is replaced with a third slice ID.

[0129] Requested NSSAI: {(1st Slice ID,-), (2nd Slice ID,-)}

[0130] The first slice ID and second slice ID included in the Requested NSSAI are the SST 112 and SD (optional) 114 of the serving PLMN shown in FIG.

[0131] Allowed NSSAI: {(1st Slice ID, -), (3rd Slice ID, 2nd Slice ID)}

[0132] The first Slice ID and the third Slice ID included in the Allowed NSSAI are the serving PLMN SST 112 and the serving PLMN SD (optional) 114 shown in Fig. 1. The second Slice ID is the mapped SST 116 and the mapped SD (optional) 118 shown in Fig. 2.

[0133] According to one embodiment of the present invention, the terminal 300 that sends the Requested NSSAI and receives the Allowed NSSAI confirms that the first Slice ID associated with the first session is included in the Allowed NSSAI without any changes in the serving PLMN's SST 112 and the serving PLMN's SD (114, optional), and determines that there are no changes to the S-NSSAI associated with the first session.

[0134] Furthermore, the terminal 300 confirms that the second Slice ID associated with the second session is included in the Allowed NSSAI in the mapped SST 116 and the mapped SD (optional) 118 and that the slice mapped to the second Slice ID is the third Slice ID, thereby determining that the S-NSSAI associated with the second session has been changed from the second Slice ID to the third Slice ID. In this case, the terminal 300 evaluates or reevaluates whether the service / application using the second session can use the third Slice ID based on the URSP stored in the terminal. If the second session can use the third Slice ID, the terminal 300 updates the S-NSSAI information associated with the second session to the third Slice ID. If the second session cannot use the third Slice ID, the terminal 300 requests a second session connection release.

[0135] If there is an S-NSSAI that is included in the Requested NSSAI requested by the terminal 300 but not included in the Allowed NSSAI received by the terminal 300, the terminal 300 knows that it cannot use the S-NSSAI any more, and accordingly, the terminal 300 releases or terminates the PDU session (or PDN connection) associated with the S-NSSAI.

[0136] Meanwhile, the above-described embodiments may be combined with each other. For example, a part or all of a specific embodiment may be combined with a part or all of another embodiment, and it is clear that such a combined form is also included in the scope of the present invention.

[0137] FIG. 6 is a diagram illustrating the structure of a terminal according to an embodiment of the present invention.

[0138] 6, the terminal includes a transceiver unit 610, a terminal control unit 620, and a memory unit 630. In the present invention, the terminal control unit 620 is defined as a circuit or an application-specific integrated circuit or at least one processor.

[0139] The transceiver 610 transmits and receives signals to and from base stations, other terminals, and network entities, such as receiving system information transmitted from a base station, or transmitting and receiving data based on synchronization signals, reference signals, and / or control information.

[0140] The terminal controller 620 controls the overall operation of the terminal according to the embodiment of the present invention. For example, the terminal controller 620 controls the signal flow between each block to perform the operations according to the above-mentioned drawings and flowcharts. Specifically, the terminal controller 620 operates according to control signals from the base station and exchanges messages or signals with the base station, other terminals, and / or network entities.

[0141] The storage unit 630 stores at least one of the information transmitted and received via the transmission / reception unit 610 and the information generated via the terminal control unit 620 .

[0142] 7 is a diagram illustrating the structure of a network function (NF) according to an embodiment of the present invention, in which the NF includes an NF instance.

[0143] The NF shown in Figure 7 refers to an entity that supports the various network functions described above, for example, at least one of a mobility management entity (MME), an access and mobility function (AMF), a session management function (SMF), an interworking NF, a user data management (UDM), a user data repository (UDR), and a policy control function (PCF), and is not limited to a specific NF. In addition, the NF is provided in the form of an instance, and when provided as an instance, the NF exists in the form of software code and means a state in which physical and / or logical resources are allocated from a computer system to perform the functions of the NF in a physical computer system, for example, a specific computer system existing on a core network, and is executable. Therefore, the structure of Figure 7 refers to both physical and logical divisions.

[0144] Referring to FIG. 7, the NF includes a transceiver unit 710, an NF control unit 720, and a storage unit 730.

[0145] The transceiver 710 transmits and receives signals to and from other network entities, such as other network entities (NFs) or base stations, exchanging signaling for transmitting and receiving control information and data.

[0146] The NF controller 720 controls the overall operation of the NF according to the embodiment of the present invention. For example, the NF controller 720 controls the signal flow between each block to perform the operations according to the above-mentioned figures and flowcharts. Specifically, the NF controller 720 operates according to signaling received from other network entities or base stations, and exchanges messages or signals with terminals, base stations, and / or other network entities.

[0147] The storage unit 730 stores at least one of information transmitted and received via the transmission / reception unit 710 and information generated via the NF control unit 720.

[0148] FIG. 8 is a diagram illustrating the structure of a base station according to an embodiment of the present invention.

[0149] 8, the base station includes a transceiver unit 810, a base station controller 820, and a memory unit 830. In the present invention, the base station controller 820 is defined as a circuit, an application-specific integrated circuit, or at least one processor.

[0150] The transceiver 810 transmits and receives signals to and from terminals and network entities, for example, by transmitting system information, synchronization or reference signals, or control information and data to terminals, and by exchanging messages and signaling to provide services to network entities and terminals.

[0151] The base station controller 820 controls the overall operation of the base station according to the embodiment of the present invention. For example, the base station controller controls the signal flow between each block to perform the operations according to the above-mentioned drawings and flowcharts. Specifically, the base station controller exchanges messages or signals with the terminal and / or network entity.

[0152] The storage unit 830 stores at least one of information transmitted and received via the transmission / reception unit 810 and information generated via the base station control unit 820 .

[0153] The embodiments disclosed in the above specification and drawings are presented in specific forms to easily explain the contents of the present invention and to facilitate understanding, and are not intended to limit the scope of the present invention. Therefore, the scope of the present invention should be interpreted as including all modifications and variations derived based on the present invention in addition to the embodiments disclosed in the specification. [Explanation of symbols]

[0154] 110 Field 112, 116 SST(Slice / Service Type) 114, 118 SD (Slice Differentiator) 300 devices 301 E-UTRA base station (E-UTRAN) 302 MME 303 SMF+PGW-C 304 Interworking NF 305 NF 500 AMF 610, 710, 810 Transmitter / Receiver 620 Terminal control unit 630, 730, 830 storage section 720 NF control section 820 Base Station Control Unit

Claims

1. 1. A method performed by an access and mobility function (AMF) entity in a wireless communication system, comprising: receiving a registration request message from a terminal, the registration request message including first information (Requested NSSAI) regarding a requested slice (NSSAI: network slice selection assistance information); acquiring information about a simultaneous use of the network slice (SUNS) policy and a slice ID associated with a packet data network (PDN) connection established by the terminal in an evolved packet core (EPC) from a unified data management (UDM) entity; Determining second information (Allowed NSSAI) regarding allowed slices available in 5G based on the first information, the SUNS, information about a PDN connection established by the terminal in an EPC, terminal subscription information, slice priority, and slices that a session management function (SMF) entity can support; sending a Registration Accept message to the terminal, the Registration Accept message including second information about the allowed slice; The first information includes a first slice identifier (ID) associated with a first PDN connection and a second slice identifier (ID) associated with a second PDN connection; When the first Slice ID and the second Slice ID are simultaneously available slices, the second information includes the first Slice ID and the second Slice ID; When the first slice ID and the second slice ID are not simultaneously available slices, the second information includes a slice ID having a higher priority among the first slice ID and the second slice ID; a priority order of the first slice ID and the second slice ID is determined based on a sequence of slice IDs included in the first information; A method, characterized in that, if the first slice ID and the second slice ID are the same SD (slice differentiator), it is determined that the first slice ID and the second slice ID can be used simultaneously.

2. When the first Slice ID and the second Slice ID are not slices that can be used simultaneously, the second information includes a third Slice ID that can be used simultaneously with the first Slice ID and the second Slice ID; The first slice ID has a higher priority than the second slice ID; The method of claim 1, wherein the third slice ID is a slice that can be used simultaneously with the first slice ID among a terminal subscribed slice (Subscribed S-NSSAI).

3. The method described in claim 2, characterized in that the registration approval message further includes information notifying that a slice change has occurred.

4. 1. A method performed by a terminal in a wireless communication system, comprising: sending a Registration Request message including first information (Requested NSSAI) on a requested slice (NSSAI), to an access and mobility function (AMF) entity; and receiving a Registration Accept message from the AMF entity, the Registration Accept message including second information (Allowed NSSAI) on allowed slices available in 5G; The first information includes a first Slice ID (identifier) ​​associated with a first PDN (packet data network) connection and a second Slice ID associated with a second PDN connection; Information regarding the simultaneous use of the network slice (SUNS) policy and the slice ID associated with the PDN connection established by the terminal in the evolved packet core (EPC) is transmitted from a unified data management (UDM) entity to the AMF entity, The second information is determined based on the first information, the SUNS, information about a PDN connection established by the terminal in an EPC, terminal subscription information, slice priority, and a slice that a session management function (SMF) entity can support; When the first Slice ID and the second Slice ID are simultaneously available slices, the second information includes the first Slice ID and the second Slice ID; When the first slice ID and the second slice ID are not simultaneously available slices, the second information includes a slice ID having a higher priority among the first slice ID and the second slice ID; a priority order of the first slice ID and the second slice ID is determined based on a sequence of slice IDs included in the first information; A method, characterized in that, if the first slice ID and the second slice ID are the same SD (slice differentiator), it is determined that the first slice ID and the second slice ID can be used simultaneously.

5. When the first Slice ID and the second Slice ID are not slices that can be used simultaneously, the second information includes a third Slice ID that can be used simultaneously with the first Slice ID and the second Slice ID; The first slice ID has a higher priority than the second slice ID; The method of claim 4, wherein the third slice ID is a slice that can be used simultaneously with the first slice ID among a terminal subscribed slice (Subscribed S-NSSAI).

6. The method described in claim 5, characterized in that the registration approval message further includes information notifying that a slice change has occurred.

7. An access and mobility function (AMF) entity in a wireless communication system, comprising: a transmitting / receiving unit for transmitting and receiving signals; a control unit coupled to the transceiver unit, The control unit receiving, from a terminal, a registration request message including first information (Requested NSSAI) regarding a requested slice (NSSAI: network slice selection assistance information); Acquires information about a simultaneous use of the network slice (SUNS) policy and a slice ID associated with a packet data network (PDN) connection established by the terminal in an evolved packet core (EPC) from a unified data management (UDM) entity; Determine second information (Allowed NSSAI) regarding allowed slices available in 5G based on the first information, the SUNS, information about a PDN connection established by the terminal in an EPC, terminal subscription information, slice priority, and slices that an SMF (Session Management Function) entity can support; configured to send a Registration Accept message to the terminal, the Registration Accept message including second information about the allowed slice; The first information includes a first slice identifier (ID) associated with a first PDN connection and a second slice identifier (ID) associated with a second PDN connection; When the first Slice ID and the second Slice ID are simultaneously available slices, the second information includes the first Slice ID and the second Slice ID; When the first slice ID and the second slice ID are not simultaneously available slices, the second information includes a slice ID having a higher priority among the first slice ID and the second slice ID; a priority order of the first slice ID and the second slice ID is determined based on a sequence of slice IDs included in the first information; If the first slice ID and the second slice ID are the same slice differentiator (SD), the first slice ID and the second slice ID are determined to be simultaneously usable. An AMF entity.

8. When the first Slice ID and the second Slice ID are not slices that can be used simultaneously, the second information includes a third Slice ID that can be used simultaneously with the first Slice ID and the second Slice ID; The first slice ID has a higher priority than the second slice ID; The AMF entity according to claim 7, wherein the third slice ID is a slice that can be used simultaneously with the first slice ID among the UE subscribed slices (Subscribed S-NSSAI).

9. The AMF entity described in Claim 8, characterized in that the registration approval message further includes information notifying that a slice change has occurred.

10. A terminal in a wireless communication system, a transmitting / receiving unit for transmitting and receiving signals; a control unit coupled to the transceiver unit, The control unit Send a Registration Request message to an access and mobility function (AMF) entity, the Registration Request message including first information (Requested NSSAI) about a requested slice (NSSAI); and configured to receive, from the AMF entity, a registration accept message including second information (Allowed NSSAI) on allowed slices available in 5G; The first information includes a first Slice ID (identifier) ​​associated with a first PDN (packet data network) connection and a second Slice ID associated with a second PDN connection; Information regarding the simultaneous use of the network slice (SUNS) policy and the slice ID associated with the PDN connection established by the terminal in the evolved packet core (EPC) is transmitted from a unified data management (UDM) entity to the AMF entity, The second information is determined based on the first information, the SUNS, information about a PDN connection established by the terminal in an EPC, terminal subscription information, slice priority, and a slice that a session management function (SMF) entity can support; When the first Slice ID and the second Slice ID are simultaneously available slices, the second information includes the first Slice ID and the second Slice ID; When the first slice ID and the second slice ID are not simultaneously available slices, the second information includes a slice ID having a higher priority among the first slice ID and the second slice ID; a priority order of the first slice ID and the second slice ID is determined based on a sequence of slice IDs included in the first information; A terminal characterized in that, when the first slice ID and the second slice ID are the same SD (slice differentiator), the terminal determines that the first slice ID and the second slice ID can be used simultaneously.

11. When the first Slice ID and the second Slice ID are not slices that can be used simultaneously, the second information includes a third Slice ID that can be used simultaneously with the first Slice ID and the second Slice ID; The first slice ID has a higher priority than the second slice ID; The terminal of claim 10, wherein the third slice ID is a slice that can be used simultaneously with the first slice ID among a terminal subscribed slice (Subscribed S-NSSAI).

12. The terminal described in Claim 11, characterized in that the registration approval message further includes information notifying that a slice change has occurred.

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