Communication device, terminal device, and communication system

Abstract

[Problem] To provide a communication device, a terminal device, and a communication system that enhance availability of network slices. [Solution] A communication device according to the present disclosure comprises: at least one processor that: receives, from a terminal device, a first set of identification information of one or more first network slices for which registration is requested in a registration area in a home public mobile network; acquiring first information about whether registration of the first network slice identified by the identification information in the first set will be allowed in the registration area; and generating, based on the first information, second information about the guest public mobile network in which the first network slice may be provided at least in an area overlapping the registration area.

Description

Technical Field

[0001] The present disclosure relates to communication equipment, terminal equipment and communication system. Background Art

[0002] For the fifth generation mobile communication system (so-called 5G) having characteristics of high speed and large capacity (eMBB: enhanced mobile broadband), low latency and high reliability (URLLC: ultra-reliable low latency communication), and multiple simultaneous connections (mMTC: massive machine type communication), the first standard was established as Rel-15 in 2018, and services compatible with 5G were launched in Japan in March 2020. In addition, 5G is compatible with a concept called network slicing, which allows various traffic with different communication requirements to be efficiently handled according to their purposes.

[0003] Reference List

[0004] Patent Literature

[0005] Patent Document 1: JP 2021-166359A Summary of the invention

[0006] Technical issues

[0007] The availability of network slices of the 5G system is designed to be in units of areas called tracking areas (TAs), and the use registration of network slices is implemented in units of registration areas (RAs) including one or more tracking areas. Different network slices have different availability, and it is desirable to have a method for efficiently managing network slices with different availability in units of registration areas. In addition, it is assumed that network slices requiring high throughput are provided by supporting cells with higher carrier frequencies such as millimeter waves. Therefore, considering its narrower coverage and economic rationality, due to the limitation on the number of base stations to be installed, a management method with finer granularity than the tracking area is also desired. In addition, it is also considered to use roaming to improve the availability of network slices, and it is desirable to have an efficient roaming method in units of network slices.

[0008] In the case where the information about multiple tracking areas included in the information indicating the registration area includes tracking areas belonging to different PLMNs, Patent Document 1 discloses a method of storing information about allowed NSSAI (network slice selection assistance information) separately as allowed NSSAI for each PLMN (public land mobile network), wherein the allowed NSSAI is a set of network slices whose registration is allowed. However, Patent Document 1 does not mention providing necessary supplementary information by using a network slice that utilizes roaming in the tracking area of ​​a network slice whose registration is rejected, nor does it mention its procedures or a method for dealing with tracking areas that are independently set for each PLMN. In addition, Patent Document 1 does not mention a method for improving the availability of network slices by utilizing roaming in the tracking area using the first network slice under admission control.

[0009] The present disclosure provides communication equipment, terminal equipment and communication systems for improving the availability of network slicing.

[0010] Solutions to the Problem

[0011] A communication device according to the present disclosure includes at least one processor and a transceiver. The at least one processor receives from a terminal device a first set of identification information about at least one first network slice for which registration is requested in a registration area of ​​a home public land mobile network; obtains first information about whether registration of a first network slice is allowed in the registration area, the first network slice being indicated by the identification information in the first set; and generates, based on the first information, second information about a visitor public land mobile network that enables provision of the first network slice in an area overlapping at least the registration area. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a diagram showing the configuration of a network architecture of a 5G system.

[0013] Figure 2 is a diagram showing the configuration of a network architecture of a 5G system for roaming.

[0014] Figure 3 is a table showing normalized SST values.

[0015] Figure 4 is a diagram showing an example of a QoS architecture for 5GS.

[0016] Figure 5 is a diagram showing a deployment example of network slicing for 5GS.

[0017] Figure 6 is a diagram showing another deployment example of network slicing for 5GS.

[0018] Figure 7 is a diagram showing an example of network slice registration determination processing in the registration process.

[0019] Figure 8 is a diagram showing an example of a process of generating supplementary information on a rejected S-NSSAI in a registration process.

[0020] Fig. 9A is a diagram showing an example of registration processing for 5GS.

[0021] Fig. 9B is a diagram showing an example of registration processing for 5GS.

[0022] Fig.10 is a diagram showing an example of a procedure for checking the availability of a network slice.

[0023] Fig.11A is a diagram showing an example of the processing performed by the HPLMN side regarding candidate SNPN detection.

[0024] Fig. 11B is a diagram showing an example of processing performed by the SNPN side regarding candidate SNPN detection.

[0025] Fig.12 is a diagram showing an example of a process of updating registration information associated with admission control.

[0026] Fig.13 is a diagram showing an example of a process of updating registration information associated with network maintenance management.

[0027] Fig.14 is a block diagram showing an exemplary configuration of a terminal device according to the present disclosure.

[0028] Fig.15 is a block diagram showing an exemplary configuration of a communication device according to the present disclosure. DETAILED DESCRIPTION

[0029] Embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. Embodiments of the present invention relate to, for example, a communication device, a terminal device, and a communication system that perform processing to improve the availability of a network slice.

[0030] Figure 1 5G system is a diagram showing the configuration of the network architecture of the 5G system. In the following text, the 5G system is referred to as 5GS. Figure 1As shown in , 5GS includes user equipment (UE) 10, (R)AN 20 and 5G core (5GC) 30. It should be noted that 5GC 30 is also referred to as NG core (NGC) or core network. In addition, (R)AN represents a base station device including a radio access network (RAN) and an access network (AN). In addition, UE 10 is the terminal device described above. When 5GS is connected to an application server (AS) 40 that processes applications through the Internet, UE 10 can utilize the applications through 5G services.

[0031] In the case where the subject providing the application (such as a service provider) has an agreement such as a service layer agreement (SLA) with a public land mobile network (PLMN) operator providing 5G services, the application server 40 is arranged in the 5GC 30 as a DN 340. Alternatively, the application server 40 and the DN 340 can be connected to each other via a dedicated line or a virtual private network (VPN). It should be noted that the application server 40 is also called a cloud server and can be provided in the form of an edge server.

[0032] The control plane function group of 5GS includes access and mobility management function (AMF) 301, network exposure function (NEF) 302 and network repository function (NRF) 303. The control plane function group also includes network slice selection function (NSSF) 304, policy control function (PCF) 305, session management function (SMF) 306 and unified data management (UDM) 307. The control plane function group includes application function (AF) 308, authentication server function (AUSF) 309 and UE radio capability management function (UCMF) 310. The control plane function group includes location management function (LMF) 311 and network slice access control function (NSACF) 312. As described above, the control plane function group includes multiple network functions (NFs).

[0033] At least one or any combination of the functions of the control plane function group corresponds to the communication device described above. For example, AMF 301 corresponds to the communication device described above.

[0034] Here, the AF 308 may operate as an NF that processes a control plane of the application server 40. The AF 308 may be implemented as an entity that is logically different from the application server 40 but is physically the same device. In other words, the AF 308 may be implemented in the application server 40. In addition, the AF 308 may operate as an NF that processes a control plane of an application on a 5GS and may be arranged in the 5GC 30.

[0035] The service provider who manages and operates the application server 40 makes it possible to obtain information from each NF in the 5G system through the NEF 302 within the scope of the SLA with the PLMN operator. The NEF 302 makes it possible to securely ensure and expose the events and capabilities of each NF to the service provider.

[0036] UDM 307 includes a unified data repository (UDR) and a front end (FE). UDR maintains and manages subscriber information. FE processes subscriber information.

[0037] AMF 301 implements mobility management. The behavior details of AMF 301 according to this embodiment will be described later.

[0038] SMF 306 implements session management.

[0039] PCF 305 provides a unified policy framework for network management behavior and provides policy rules for each network function of the control plane. PCF 305 also accesses subscriber information in UDR to determine policies.

[0040] UCMF 310 maintains UE radio capability information corresponding to all UE radio capability IDs in the PLMN. UCMF 310 is responsible for assigning UE radio capability IDs assigned by each PLMN.

[0041] It should be noted that the NSSF 304, the LMF 311, and the NSACF 312 will be described later.

[0042] Namf is a service-based interface provided by AMF 301. Nsmf is a service-based interface provided by SMF 306. Nnef is a service-based interface provided by NEF 302.

[0043] Npcf is a service-based interface provided by PCF 305. Nudm is a service-based interface provided by UDM 307. Naf is a service-based interface provided by AF 308. Nnrf is a service-based interface provided by NRF 303.

[0044] Nnssf is a service-based interface provided by NSSF 304. Nausf is a service-based interface provided by AUSF 309. Nucmf is a service-based interface provided by UCMF 310. Nlmf is a service-based interface provided by LMF 311. Nnsacf is a service-based interface provided by NSACF 312.

[0045] By requesting or subscribing to a service, each NF makes it possible to receive a response or notification of a service provided by another network function. In other words, each NF exchanges information with other NFs via its service-based interface through request / response or subscription / notification.

[0046] The user plane function (UPF) 330 has a function of user plane processing. The data network (DN) 340 has a function of making it possible to connect to services unique to the mobile network operator (MNO), the Internet, and third-party services. The UPF 330 acts as a data forwarding processor for the user plane processed by the application server 40. The UPF 330 also acts as a gateway connected to the (R)AN 20.

[0047] Here, 5GS makes it possible to configure each NF of 5GC 30 through containerization, virtualization, etc., so as to implement it in a cloud server. In addition, 5GS makes it possible to set each NF in a dynamic and reconfigurable manner through software-defined networking (SDN).

[0048] (R)AN 20 has a function of enabling connection to RAN or AN other than RAN. (R)AN 20 includes a base station called gNB or ng-eNB. RAN may also be sometimes referred to as Next Generation RAN (NG-RAN).

[0049] In addition, the functions of the (R)AN 20 are divided into a central unit (CU) and a distributed unit (DU). The CU processes L2 / L3 functions at and above the packet data convergence protocol (PDCP) sublayer. The DU processes L2 / L1 functions at and below the radio link control (RLC) sublayer. The functions of the (R)AN 20 may be distributed decentralized through the corresponding F1 interface.

[0050] In addition, the functions of the DU are divided into the radio unit (RU) and the DU. The RU handles the low PHY sublayer and the radio unit (radio.) The DU handles the RLC sublayer, the medium access control (MAC) sublayer, and the high PHY sublayer. The functions of the RU are distributed decentralized through the fronthaul that complies with the evolved common public radio interface (eCPRI).

[0051] Here, 5GS makes it possible to configure the functions of CU and / or DU through containerization, virtualization, etc., so as to implement them in the cloud server. In addition, 5GS makes it possible to set the functions of CU and / or DU in a dynamic and reconfigurable manner through SDN.

[0052] UE10 and AMF 301 exchange information with each other via reference point N1. (R)AN20 and AMF 301 exchange information with each other via reference point N2. SMF306 and UPF 330 exchange information with each other via reference point N4.

[0053] Figure 2 1 is a diagram showing the configuration of a network architecture of a 5G system for roaming. A visitor PLMN (VPLMN) having an SLA with a home PLMN (HPLMN) makes it possible to provide 5G services to UE 10 through roaming. The 5GS of the HPLMN includes (R)AN 20-1 and 5GC 30-1. The 5GS of the VPLMN includes (R)AN 20-2 and 5GC 30-2.

[0054] The UE 10 makes it possible for the (R)AN 20-1 and the 5GC 30-1 to access the service provided by the application server 40 through the 5G service of the HPLMN.

[0055] In addition, by using roaming, the UE 10 makes it possible for the (R)AN 20-2 and the 5GC 30-2 to access the service provided by the application server 40 through the 5G service of the HVPLMN.

[0056] The control plane of 5GC 30-1 of HPLMN and the control plane of 5GC 30-2 of VPLMN are connected through a security edge protection proxy (SEPP). The home SEPP (hSEPP) of the control plane of 5GC 30-1 and the visitor SEPP (vSEPP) of the control plane of 5GC 30-2 are connected through a reference point N32.

[0057] By adding "-1" to Figure 1 The NFs of the control plane of 5GC 30-1 are represented by adding "-2" to the end of the reference numerals of the corresponding NFs in Figure 1 The NFs of the control plane of 5GC 30-2 are represented by the end of the reference numeral of the corresponding NF in the figure.

[0058] The NF of the control plane of the 5GC 30-1 makes it possible to request services provided by the NF of the control plane of the 5GC 30-2 through the NEF 302-2 of the 5GC 30-2 under the SLA with the VPLMN.

[0059] The NF of the control plane of the 5GC 30-2 makes it possible to request services provided by the NF of the control plane of the 5GC 30-1 through the NEF 301-2 of the 5GC 30-1 under the SLA with the HPLMN.

[0060] When roaming, the user plane of 5GC 30-2 is connected to the application server 40 through local distribution roaming or home routing roaming. In local distribution roaming, the UPF 330-2 of 5GC 30-2 is directly connected to the application server 40. In home routing roaming, the UPF 330-2 of 5GC 30-2 is connected to the UPF 330-1 of 5GC 30-1 through the reference point N9, and is connected to the application server 40 through the UPF 330-1 of 5GC 30-1.

[0061] [1. Network Slice Selection Assistance Information (NSSAI)]

[0062] A network slice is a service unit divided according to the characteristics of communication required for the corresponding communication service provided by 5G (e.g., data rate, latency, etc.).

[0063] A single network slice selection assistance information (S-NSSAI) is assigned to each network slice as information to assist in the selection of the network slice (network slice selection assistance information). The S-NSSAI includes a pair of a slice / service type (SST) and a slice distinguisher (SD). The SST is mandatory, consists of 8 bits, and identifies the slice type. The SD is optional, consists of 24 bits, and distinguishes different slices in the same SST.

[0064] S-NSSAI can use a standardized SST or its own SST that is not standardized. In the case of using a standardized S-NSSAI value, S-NSSAI only includes a standardized SST without SD. On the other hand, in the case of using a non-standardized S-NSSAI value, S-NSSAI includes a pair of a standardized SST and SD, a pair of a non-standardized SST and SD, or only a non-standardized SST. A non-standardized S-NSSAI value can only be used in a PLMN that uniquely uses the value, that is, it can only be used in a telecom operator.

[0065] Figure 3 is a table showing standardized SST values. The table is based on the table shown in "3GPP TS23.501". The "case of using standardized S-NSSAI" described above corresponds to the case of using S-NSSAI values ​​consisting only of such SST values ​​(eMBB: 1, URLLC: 2, MIoT: 3, V2X: 4, and HMTC: 5). In other words, non-standardized S-NSSAI values ​​are used for network slices other than this (e.g., network slices subdivided by SD).

[0066] The network slice configuration information includes one or more configured NSSAIs. The serving public land mobile network (serving PLMN) makes it possible for the UE 10 to set the configured NSSAI applied to each PLMN. Alternatively, the home PLMN (HPLMN) makes it possible to set a default configured NSSAI for the UE 10. Only when the configured NSSAI for the serving PLMN is not set for the UE 10, the UE 10 under the serving PLMN makes it possible to use the default configured NSSAI.

[0067] It should be noted that the default configured NSSAI may be pre-set for the UE 10. Furthermore, the UDM 307 of the HPLMN may provide or update the default configured NSSAI using UE parameter update through UDM control plane processing.

[0068] The configured NSSAI includes one or more S-NSSAIs.

[0069] The requested NSSAI is the NSSAI provided from the UE 10 to the serving PLMN during the registration process. The requested NSSAI should be one of the following:

[0070] -NSSAI is configured by default;

[0071] - NSSAI configured;

[0072] - is permitted to use the NSSAI or any part thereof; or

[0073] - NSSAI obtained by adding one or more S-NSSAI included in the configured NSSAI to the allowed NSSAI or a part thereof.

[0074] The allowed NSSAI is, for example, the NSSAI provided from the serving PLMN to the UE 10 during the registration process. The allowed NSSAI indicates the value of one or more S-NSSAIs that are available within the current registration area of ​​the current serving PLMN.

[0075] The rejected S-NSSAI indicates a value of an S-NSSAI that is unavailable in at least one tracking area in the current registration area of ​​the current serving PLMN among one or more S-NSSAIs included in the rejected S-NSSAI.

[0076] Here, the tracking area is an area to be used for mobility management and is identified by a tracking area identifier (TAI). In order to send a message or data to the UE 10 in the RRC_IDLE (RRC idle) state, the network (PLMN) manages the location of the UE 10 within the range of the tracking area set where the UE 10 resides. When registering the UE 10 on the network, the AMF 301 assigns the tracking area set included in the TAI list as the area (registration area) where the UE 10 will be registered. In other words, the network manages the registered UE 10 so that the registered UE 10 resides on any tracking area in the TAI list.

[0077] When the best cell is detected according to the criteria for cell reselection, UE 10 reselects and camps on the cell. At this time, the location registration process, that is, the process of updating the TAI list, is performed if the selected cell does not belong to any tracking area in the TAI list registered by UE 10.

[0078] The subscribed S-NSSAI is the S-NSSAI available to the UE 10 in the PLMN according to the agreement information.

[0079] NSSF 304 determines the allowed NSSAI and configured NSSAI, and determines the AMF set as a candidate list for AMF 301. For example, AMF 301 can be selected from the candidate list according to the network slice used by UE 10 and other criteria, and UE 10 is assigned to the selected AMF 301.

[0080] One or more S-NSSAIs included in the allowed NSSAI to be provided to the UE 10 may include a value that is not part of the current network slice configuration information about the UE 10 related to the serving PLMN. In this case, the network provides a mapping of each (multiple) S-NSSAI of the allowed NSSAI with the corresponding (multiple) S-NSSAI of the HPLMN according to the allowed NSSAI. Such information about the mapping allows the UE 10 to associate the application with the S-NSSAI of the HPLMN and the corresponding S-NSSAI of the allowed NSSAI according to each network slice selection policy (NSSP) under the UE routing selection policy (URSP) rule or according to each local configuration of the UE 10.

[0081] For example, if the HPLMN and / or VPLMN (visitor PLMN) use non-standardized S-NSSAI values, the UE 10 must provide information about mapping of the S-NSSAI value included in the requested NSSAI with the corresponding S-NSSAI value used in the HPLMN when roaming. Here, it is possible for the UE 10 to pre-acquire information about the mapping from the serving PLMN as a mapping of the S-NSSAI value included in the configured NSSAI with respect to the serving PLMN with the corresponding S-NSSAI value used in the HPLMN, or as a mapping of the S-NSSAI value included in the allowed NSSAI with respect to the access type and the serving PLMN with the corresponding S-NSSAI value used in the HPLMN.

[0082] [2. QoS control in 5G systems]

[0083] Figure 4 is a diagram showing an example of a QoS architecture for 5GS. Figure 4 It is based on the drawings shown in "3GPP TS38.300".

[0084] At the non-access stratum (NAS) layer, a QoS flow is the finest granularity of QoS differentiation within a protocol data unit (PDU) session. Within a PDU session, a QoS flow is identified by a QoS flow ID (QFI).

[0085] In addition, in XR or media services, the payload of a PDU set is delivered by a packet group. A PDU set includes one or more PDUs that deliver a payload in an information unit generated at the application level. Examples of the information unit include image frames, video slices of XR or media services, I, P, and B frames of video data in a GOP (Group of Pictures) format, etc.

[0086] In other words, the packets in a PDU set are treated as data units to be received and decoded within a specific period of time. By using PDU sets, it is possible to identify data with finer granularity in a QoS flow with the finest granularity in terms of QoS control. In addition to QoS control at the QoS flow level, 5GS makes it possible to apply QoS control at the PDU set level.

[0087] SMF 306 associates PCC rules with QoS flows based on QoS and service requests. SMF 306 assigns QFI to new QoS flows and obtains PCC rules and other information associated with QoS flows from PCF 305. SMF 306 obtains the QoS profile of the QoS flow, instructions about the corresponding UPF (e.g., N4 rules), and QoS rules from the PCC rules.

[0088] The base station (gNB) of the (R)AN 20 makes it possible to establish at least one data radio bearer (DRB) in addition to the PDU session with each UE 10. DRB is a logical path for delivering data. The 5G QoS model supports a guaranteed flow bit rate (GBR) in which bandwidth is guaranteed and a non-guaranteed flow bit rate (non-GBR) in which bandwidth is not guaranteed.

[0089] (R)AN 20 and 5GC 30 ensure the quality of service by mapping each packet to an appropriate QoS flow and DRB. That is, a two-step mapping is implemented. The two-step mapping includes mapping between IP flows and QoS flows in the non-access layer (NAS), and mapping between QoS flows and DRBs in the access layer (AS).

[0090] At the NAS level, QoS flows are characterized by QoS profiles provided from 5GC 30 to (R)AN 20 and QoS rules provided from 5GC 30 to UE 10.

[0091] The QoS profile is used by the (R)AN 20 to decide the processing method on the radio interface. The QoS rules are used to instruct the UE 10 on the mapping between user plane traffic in the uplink and QoS flows. Accordingly, the UE 10 is not provided with QoS rules or QoS parameters at the QoS flow level for a multicast / broadcast service (MBS) session's MBS QoS flow.

[0092] The QoS profile is provided from the SMF 306 to the (R)AN 20 through the AMF 401 and the reference point N2, or is pre-configured in the (R)AN 20.

[0093] Furthermore, the SMF 306 makes it possible to provide the UE 10 with one or more QoS rules and, if necessary, QoS flow-level QoS parameters related to the QoS rules, via the AMF 301 and the reference point N1.

[0094] In addition or in lieu thereof, reflective QoS control may also be applied to the UE 10. Reflective QoS control is QoS control that monitors the QFI of downlink packets and applies the same mapping to uplink packets.

[0095] Depending on the QoS profile, the QoS flow will be a GBR QoS flow or a non-GBR QoS flow. The QoS profile of a QoS flow includes, for example, QoS parameters such as a 5G QoS Identifier (5QI) and Allocation and Retention Priority (ARP).

[0096] ARP includes information about priority, preemption capability, and preemption vulnerability.

[0097] Priority defines the relative importance of a QoS flow, and the minimum value of priority (priority level) means the highest priority. Preemption capability is an indicator that defines whether a QoS flow can seize resources that have been assigned to another QoS flow with a lower priority.

[0098] Preemption vulnerability is an indicator that defines whether a QoS flow can yield its assigned resources to another QoS flow with a higher priority. Preemption capability and preemption vulnerability are set to an "enabled" state or a "disabled" state.

[0099] In a GBR QoS flow, the QoS profile includes the following:

[0100] - Uplink and downlink guaranteed flow bit rate (GFBR);

[0101] - Uplink and downlink Maximum Flow Bit Rate (MFBR);

[0102] - Uplink and downlink maximum packet loss rate;

[0103] - Delay critical resource types;

[0104] -Notification control; etc.

[0105] In non-GBR QoS flows, the QoS profile includes Reflective QoS Attributes (RQA), additional QoS flow information, and the like.

[0106] The Notification Control of the QoS parameter indicates whether to request notification from the (R)AN 20 if the QoS flow does not meet the GFBR. When the Notification Control is in the "enabled" state and it is determined that the GBR QoS flow does not meet the GFBR, the (R)AN 20 sends a notification about this to the SMF 306.

[0107] In this case, (R)AN 20 must maintain the QoS flow except for special cases where (R)AN 20 requests to release RAN resources for the GBR QoS flow. Examples of such special cases include radio link failure or RAN internal congestion.

[0108] Next, when a determination is made again and the determination indicates that the GFBR is satisfied with respect to the QoS flow, the (R)AN 20 sends a new notification indicating this to the SMF 306.

[0109] The aggregate maximum bit rate (AMBR) is related to the session-AMBR of each PDU session and the UE-AMBR of each UE 10. The session-AMBR limits the aggregate bit rate that is expected to be provided for all non-GBR QoS flows for a specific PDU session and is managed by the UPF 330. The UE-AMBR limits the aggregate bit rate that is expected to be provided for all non-GBR QoS flows for a specific UE 10 and is managed by the (R)AN 20.

[0110] In addition, each UE 10 can set a slice maximum bit rate (S-MBR) regarding a network slice (S-NSSAI). The S-MBR can be included in the subscriber information as a subscription UE-slice-MBR.

[0111] The UE-Slice-MBR limits the aggregate bit rate that is expected to be provided to all GBR and non-GBR QoS flows belonging to all PDU sessions established by the UE 10 for the same network slice (S-NSSAI).

[0112] (R)AN 20 receives the UE-slice-MBR corresponding to the network slice (S-NSSAI) from AMF301, and sets the session-AMBR and MFBR for UE 10 so that the sum of the MFBR and session-AMBR of the GBR QoS flows of all PDU sessions belonging to the network slice (S-NSSAI) is the UE-slice-MBR.

[0113] 5QI is related to QoS characteristics and provides guidelines (policies) for setting node-specific parameters for each QoS flow. Standardized or pre-configured 5G QoS characteristics are learned from 5QI rather than explicitly signaled. QoS characteristics that will be indicated by signaling can be included as part of the QoS profile.

[0114] The QoS characteristics include information about resource type, priority, packet delay budget, packet error rate, average window, maximum data burst, etc. The resource type is GBR QoS flow or non-GBR QoS flow. The packet delay budget may include the packet delay budget in 5GC 30.

[0115] At the AS level, DRB defines the packet processing method on the wireless interface (Uu interface). DRB provides the same packet forwarding processing for any packet.

[0116] (R)AN 20 maps the QoS flow to the DRB based on the QFI and the QoS profile set for the QFI. (R)AN 20 makes it possible to establish different DRBs for packets requiring different packet forwarding treatments (see Figure 4 ).

[0117] (R)AN20 also makes it possible to multiplex multiple QoS flows belonging to the same PDU session onto the same DRB (see Figure 4 ).

[0118] In the uplink, the mapping of QoS flows to DRBs is controlled by mapping rules that are signaled in two different ways.

[0119] One of the methods is called reflection mapping. In reflection mapping, the UE 10 monitors the QFI(s) of the downlink packets for each DRB and applies the same mapping to the uplink packets.

[0120] Another approach is called explicit configuration. In explicit configuration, the rules for mapping QoS flows to DRBs are signaled via Radio Resource Control (RRC).

[0121] In the downlink, QFI is signaled on the Uu interface for Reflective Quality of Service (RQoS) by the (R)AN 20. However, unless the (R)AN 20 and NAS use reflective mapping for the QoS flow carried in the DRB, neither the (R)AN 20 nor the NAS signals the QFI on the Uu interface for the DRB.

[0122] In the uplink, the (R)AN 20 makes it possible to configure the signaling of the QFI for the UE 10 on the Uu interface. The (R)AN 20 also makes it possible to configure a default DRB for each PDU session. In the case that an uplink packet does not fit either the explicit configuration or the reflective mapping, the UE 10 maps the packet to the default DRB for the PDU session.

[0123] Regarding non-GBR QoS flows, the 5GC 30 may send additional QoS flow information parameters associated with any QoS flow to the (R)AN 20. This is done to instruct to increase the frequency of a specific traffic compared to other non-GBR QoS flows in the same PDU session.

[0124] How to map multiple QoS flows in a PDU session to one DRB depends on the (R)AN 20. For example, the (R)AN 20 may map a GBR QoS flow and a non-GBR QoS flow to the same DRB, or may map them to different DRBs. In addition, the (R)AN 20 may map multiple GBR QoS flows to the same DRB, or may map them to different DRBs.

[0125] In 5G NR, a new Service Data Adaptation Protocol (SDAP) sublayer is introduced for QoS control through QoS flows. The SDAP sublayer maps the traffic of the QoS flow to the appropriate DRB. The SDAP sublayer can have multiple SDAP entities. The SDAP sublayer includes an SDAP entity for each PDU session on the Uu interface. The establishment or release of the SDAP entity is implemented through RRC.

[0126] The QoS flow is identified by the QFI in the PDU session container included in the GPRS Tunneling Protocol (GTP)-U header. The PDU session is identified by the GTP-U Tunnel Endpoint ID (TEID). The SDAP sublayer maps each QoS flow to a specific DRB.

[0127] When the PCF 305 receives the QoS monitoring request from the AF 308, the PCF 305 makes it possible to provide the SMF 306 with the authorized QoS monitoring policy by generating the QoS monitoring policy and including it into the PCC rules.

[0128] The SMF 306 makes it possible to activate end-to-end uplink (UL) / downlink (DL) packet delay measurements between the UE 10 and the PSA-UPF 330 with respect to a QoS flow during a PDU session establishment procedure or during a PDU session modification procedure.

[0129] SMF306 sends a QoS monitoring request to UPF 330 through reference point N4, and sends N2 signaling to request QoS monitoring between UPF330 and (R)AN 20.

[0130] The QoS monitoring request includes monitoring variables determined by the SMF 306 based on the QoS monitoring policy received from the PCF 305 or the authorized QoS monitoring policy pre-configured locally.

[0131] The (R)AN 20 measures the delay of the UL / DL packet in the (R)AN 20 part and provides the measured value to the UPF 330 through the reference point N3.

[0132] The UPF 330 calculates the UL / DL packet delay at the reference point N3 or N9. The UPF 330 sends the QoS monitoring result to the SMF 306 based on a predetermined condition. Here, the predetermined condition is, for example, a condition for implementing transmission only once, a condition for implementing transmission periodically, or a condition for transmitting by an event trigger (event trigger).

[0133] The UPF 330 also makes it possible to support the sending of QoS monitoring results to the AF 308 through the locally arranged NEF 302. Here, the QoS monitoring results are, for example, the measurement results of the bit rate (e.g., average bit rate, maximum bit rate) of each GBR QoS flow of the target PDU session, the measurement results of the aggregate bit rate of all non-GBR QoS flows of the target PDU session, the measurement results of the packet error rate of the target PDU session, the measurement results of the aggregate bit rate of all non-GBR QoS flows of the target UE 10, the measurement results of the packet error rate of the target UE 10, the measurement results of the UL / DL packet delay, or other results. The UL / DL packet delay is a delay including the UL / DL packet delay in the (R)AN 20 part obtained from the (R)AN 20 and the UL / DL packet delay at the reference point N3 or N9.

[0134] In addition, in the case where the PDU session is a session through a time-sensitive networking (TSN) bridge, the packet delay budget for the time-sensitive communication (TSC) QoS flow is the sum of the 5G access network (AN) packet delay budget (PDB) and the core network (CN) PDB. In order to measure the bit rate (e.g., average bit rate, maximum bit rate) between the UE 10 and the PSA-UPF 330 and to measure the end-to-end UL / DL packet delay, the QoS monitoring mechanism described above can also be applied to the TSC QoS flow.

[0135] [3. Network Slicing Deployment]

[0136] Figure 5 is a diagram showing an example of network slicing deployment for 5GS. The HPLMN with which UE 10 has a subscription configures a registration area (RA) with respect to the UE 10. The registration area includes, for example, four tracking areas (TAs), namely HPLMN_TA1, HPLMN_TA2, HPLMN_TA3, and HPLMN_TA4.

[0137] For example, HPLMN_TA1 supports three network slices, namely S-NSSAI-H1, S-NSSAI-H2 and S-NSSAI-H3. HPLMN_TA2 supports one network slice, namely S-NSSAI-H1. HPLMN_TA3 supports two network slices, namely S-NSSAI-H1 and S-NSSAI-H4. HPLMN_TA4 supports two network slices, namely S-NSSAI-H1 and S-NSSAI-H2.

[0138] With respect to the UE 10, the HPLMN sets the configured NSSAI including four NSSAIs, namely, S-NSSAI-H1, S-NSSAI-H2, S-NSSAI-H3 and S-NSSAI-H4.

[0139] UE 10 sends a registration request to the HPLMN as a serving network by using a registration request message, the registration request message including the requested NSSAI within the registration area. The requested NSSAI may include one or more S-NSSAIs included in the configured NSSAI. UE 10 sends the requested NSSAI to the HPLMN acting as a serving network, including four NSSAIs, such as S-NSSAI-H1, S-NSSAI-H2, S-NSSAI-H3, and S-NSSAI-H4.

[0140] The HPLMN confirms that S-NSSAI-H1, S-NSSAI-H2, S-NSSAI-H3, and S-NSSAI-H4 included in the requested NSSAI are included in the subscribed S-NSSAI based on the agreement information with the UE 10. In addition, based on the support status of the network slices in each tracking area in the registration area, the HPLMN generates an allowed NSSAI including S-NSSAI-H1 that is supported by all tracking areas in the registration area.

[0141] In addition, the HPLMN sets each S-NSSAI (i.e., S-NSSAI-H2, S-NSSAI-H3, and S-NSSAI-H4) included in the requested NSSAI but not included in the allowed NSSAI as a rejected S-NSSAI. Here, it is possible to generate a rejected NSSAI including a rejected S-NSSAI.

[0142] During the registration process, UE10 obtains information about the registration area, allowed NSSAI, and rejected S-NSSAI from the HPLMN. Here, the information about the registration area is, for example, a set of tracking areas constituting the registration area, namely, HPLMN_TA1, HPLMN_TA2, HPLMN_TA3, and HPLMN_TA4. Figure 5 In the example of network slice deployment shown in , UE 10 can only use S-NSSAI-H1 in the registration area. In addition, UE 10 is not allowed to request registration of the rejected S-NSSAI again in the registration area.

[0143] The HPLMN also makes it possible to provide information about tracking areas supporting rejected S-NSSAI to the UE 10. For example, the set of HPLMN_TA1 and HPLMN_TA4 is provided for S-NSSAI-H2, HPLMN_TA1 is provided for S-NSSAI-H3, and HPLMN_TA3 is provided for S-NSSAI-H4.

[0144] In the case where UE 10 acquires information on the tracking area supporting the rejected S-NSSAI, UE 10 makes it possible to request registration of the rejected S-NSSAI again in the tracking area supporting the rejected S-NSSAI even within the registration area.

[0145] Alternatively, the HPLMN may provide the UE 10 with information about tracking areas that do not support rejected S-NSSAI, such as providing a set of HPLMN_TA2 and HPLMN_TA3 for S-NSSAI-H2, providing a set of HPLMN_TA2, HPLMN_TA3, and HPLMN_TA4 for S-NSSAI-H3, and providing HPLMN_TA1, HPLMN_TA2, and HPLMN_TA4 for S-NSSAI-H4.

[0146] In the case where UE 10 obtains information about the tracking area that does not support the rejected S-NSSAI, even within the registration area, UE 10 makes it possible to request registration of the rejected S-NSSAI again in a tracking area other than the tracking area that does not support the rejected S-NSSAI, that is, a tracking area that supports the rejected S-NSSAI.

[0147] When UE 10 acquires information about the tracking area of ​​rejected S-NSSAI, UE 10 may receive information clearly indicating whether the information is about the tracking area supporting the rejected S-NSSAI or about the tracking area not supporting the rejected S-NSSAI.

[0148] The 5GC 30 may decide what information to send to the UE 10 according to the size of the information about the tracking area supporting the rejected S-NSSAI and the size of the information about the tracking area not supporting the rejected S-NSSAI. For example, in the case where the size of the information about the tracking area supporting the rejected S-NSSAI is smaller than the size of the information about the tracking area not supporting the rejected S-NSSAI, the 5GC 30 sends the information about the tracking area supporting the rejected S-NSSAI. In the case where the size of the information about the tracking area supporting the rejected S-NSSAI is larger than the size of the information about the tracking area not supporting the rejected S-NSSAI, the 5GC 30 sends the information about the tracking area not supporting the rejected S-NSSAI.

[0149] The HPLMN may also generate a second allowed NSSAI or a conditionally allowed NSSAI and provide it to the UE 10 during the registration process. The second allowed NSSAI or the conditionally allowed NSSAI includes information about one or more S-NSSAIs and tracking areas for which registration of the S-NSSAIs is allowed. For example, the second allowed NSSAI or the conditionally allowed NSSAI includes a set of S-NSSAI-H2, S-NSSAI-H3, and S-NSSAI-H4, a set of HPLMN_TA1 and HPLMN_TA4 as tracking areas for which registration of S-NSSAI-H2 is allowed, HPLMN_TA1 as a tracking area for which registration of S-NSSAI-H3 is allowed, and HPLMN_TA3 as a tracking area for which registration of S-NSSAI-H4 is allowed.

[0150] In the case where UE 10 acquires the second allowed NSSAI or the conditionally allowed NSSAI, in each tracking area that allows registration of the S-NSSAI included in the second allowed NSSAI or the conditionally allowed NSSAI, it is possible to send a PDU session establishment request message including the S-NSSAI to the HPLMN acting as a serving network.

[0151] The 5GC 30 may provide the UE 10 with a second allowed NSSAI or a conditionally allowed NSSAI in addition to the allowed NSSAI, or may provide the conditionally allowed NSSAI as the allowed NSSAI for the UE 10. Here, in the case where the conditionally allowed NSSAI is provided as the allowed NSSAI, information indicating that it is available in all tracking areas (such as "all") is added to the S-NSSAI available in all tracking areas of the registration area of ​​the conditionally allowed NSSAI as information about the tracking area.

[0152] Whether to provide the UE 10 with a second allowed NSSAI or a conditionally allowed NSSAI in addition to the allowed NSSAI, or to provide the UE 10 with the conditionally allowed NSSAI as the allowed NSSAI, can be set for each generation of public land mobile network systems (e.g., 5G, 5G-Advanced, or 6G) and even for each version of each generation.

[0153] Alternatively, the 5GC 30 may provide the UE 10 with information that explicitly indicates whether the UE 10 will be provided with a second allowed NSSAI or a conditionally allowed NSSAI in addition to the allowed NSSAI or with a conditionally allowed NSSAI as the allowed NSSAI.

[0154] In addition, in the case of setting a network slice available only in a tracking area supporting a specific frequency band, the AMF 301 makes it possible to decide a target NSSAI so that the UE 10 can be directed to a cell or tracking area operating on the frequency. The AMF 301 can cooperate with the NSSF 304 when deciding the target NSSAI. Here, the tracking area supporting a specific frequency can be set within the HPLMN_TA1, HPLMN_TA2, HPLMN_TA3, or HPLMN_TA4, can be set separately from the HPLMN_TA1, HPLMN_TA2, HPLMN_TA3, or HPLMN_TA4 to overlap with the HPLMN_TA1, HPLMN_TA2, HPLMN_TA3, or HPLMN_TA4, or can be set as a service area (AoS) (to be described later).

[0155] AMF 301 obtains the RAT / frequency selection priority index (RFSP index) suitable for the target NSSAI from PCF 305, and sends the information including the RFSP index to (R)AN 20 through reference point N2. In the case where PCF 305 is not installed, AMF 301 decides the RFSP index according to the rules set locally. In order to apply a separate radio resource management policy taking into account the available information, (R)AN 20 maps the RFSP index to the locally defined settings. That is, (R)AN 20 makes it possible to select the settings of the radio resource management policy for the corresponding target NSSAI suitable for the RFSP index.

[0156] The RFSP index is used to control the priority of UE-specific measurement frequencies for a cell reselection process in idle mode (e.g., RRC_IDLE), or to redirect a UE 10 in active mode (e.g., RRC_CONNECTED) to a cell, beam, or RAT operating on a different frequency.

[0157] HPLMN makes it possible to set the RFSP index in consideration of the subscription NSSAI. The AMF 301 acquires the subscription RFSP index from the UDM 307, for example, during the registration process.

[0158] AMF 301 uses:

[0159] - the same RFSP index as the subscribed RFSP index; and

[0160] - The RFSP index selected based on the subscribed RFSP indexes available in the AMF 301, locally defined operator policies, allowed NSSAI and context information related to the UE 10.

[0161] (R)AN 20 makes it possible to acquire the target NSSAI from AMF 301 and directs UE 10 to a cell supporting the network slice identified by the S-NSSAI included in the target NSSAI.

[0162] Among the requested NSSAIs, the target NSSAI may include at least one S-NSSAI that is not available in the current tracking area but is available in another tracking area in a different frequency band. The target NSSAI may also additionally include an S-NSSAI available in another tracking area as an S-NSSAI that is not available in the current tracking area.

[0163] In other words, the target NSSAI may include:

[0164] - when all S-NSSAIs of the requested NSSAI are not all available in the tracking area where the UE 10 currently resides, some (a plurality of) or all (a plurality of) rejected S-NSSAIs in the registration area;

[0165] - all (multiple) S-NSSAIs of allowed NSSAIs and all (multiple) denied S-NSSAIs or some (multiple) of them in the registration area;

[0166] - S-NSSAI(s) that are some of the allowed NSSAIs, and in case the operator policy selects the target NSSAI from the allowed NSSAIs, some of the S-NSSAI(s) or all of the denied S-NSSAI(s) in the registration area.

[0167] When the (R)AN 20 makes it possible to redirect the UE 10 to a new tracking area outside the registration area, the RFSP index associated with the target NSSAI is taken into account, otherwise the RFSP index of the allowed NSSAI is taken into account.

[0168] (R)AN 20 must control UE 10 so that it is possible to find a cell in a tracking area that can support all (multiple) S-NSSAIs of the target NSSAI. When such a cell is not found, (R)AN 20 makes it possible to control UE 10 so that it is possible to select a cell in a tracking area that most closely matches the target NSSAI. Here, the tracking area that most closely matches the target NSSAI is, for example, a tracking area that makes it possible to support more (multiple) S-NSSAIs of the target NSSAI. Alternatively, in the case of having information about the priority of (multiple) S-NSSAIs of the target NSSAI, the tracking area that most closely matches the target NSSAI is a tracking area that makes it possible to support more (multiple) S-NSSAIs with higher priority.

[0169] After successfully redirecting to a new tracking area outside the registration area, the UE 10 must perform a mobility registration update procedure. In order to allow redirection to a new tracking area outside the registration area, a mobility registration update procedure must be started, so that the UE 10 makes it possible to request registration of the S-NSSAI(s) whose registration has been rejected in the registration area. When providing the (R)AN 20 with a target NSSAI, the AMF 301 must set a registration area that does not include any tracking area in which the registration of the S-NSSAI(s) included in the target NSSAI has been rejected.

[0170] AMF 301 may also define a tracking area supporting network slices available only in a specific frequency band within the registration area as a tracking area available only for dual connectivity (DC) or carrier aggregation (CA) operations. Here, dual connectivity and carrier aggregation may be collectively referred to as multi-connectivity (MC).

[0171] (R)AN 20 makes it possible to control UE 10 so that, based on the RFSP index and the setting of the radio resource management policy corresponding to the RFSP index, a specific tracking area is taken into consideration only through cell selection / reselection of a dual-connected secondary cell group (SCG) or cell selection / reselection of a carrier-aggregated secondary cell (SCell).

[0172] In addition, the AMF 301 may make it possible to allow registration of network slices (S-NSSAI) that are only available for dual connectivity or carrier aggregation operation, and include the tracking area in which the network slice (S-NSSAI) is available into the registration area. Next, the AMF 301 may include the network slices (S-NSSAI) that are only available for dual connectivity or carrier aggregation operation into the allowed NSSAI.

[0173] Based on the UE radio capability information, the AMF 301 determines whether to register a network slice (S-NSSAI) that is available only for dual connectivity or carrier aggregation operation. For example, when the UE 10 supports dual connectivity or carrier aggregation, registration of the network slice (S-NSSAI) is allowed. When the UE 10 does not support dual connectivity or carrier aggregation, registration is rejected. In addition, when the UE 10 supports the operating frequency of the cell of the secondary cell group (SCG) for dual connectivity or the operating frequency of the secondary cell (SCell) for carrier aggregation, registration of the network slice (S-NSSAI) is allowed. When the UE 10 does not support the operating frequency of the cell of the SCG for dual connectivity or the operating frequency of the SCell for carrier aggregation, registration is rejected.

[0174] The AMF 301 may send information about the tracking areas within the registration area as supplementary information or auxiliary information about the allowed NSSAI to the (R)AN 20. Here, the information about the tracking areas within the registration area includes an indication of whether the cells of each tracking area included in the registration area are cells that are taken into consideration only by cell selection / reselection of a dual-connected SCG or cell selection / reselection of a carrier-aggregated SCell.

[0175] The allowed NSSAI and information about the tracking area within the registration area are transmitted to the UE 10 through the (R)AN 20 .

[0176] In addition, the AMF 301 may send network slice AS group (NSAG) information to the UE 10 as information about cell selection / reselection for each S-NSSAI included in the allowed NSSAI.

[0177] The NSAG information includes information indicating whether the network slice is available only in dual connectivity or carrier aggregation operation.

[0178] In addition, for network slices (S-NSSAI) that are only available in dual connectivity operations, it includes the priority of candidate frequencies of each cell in the dominant cell group (MCG), the priority of candidate frequencies of each cell in the SCG, and the like.

[0179] For network slices (S-NSSAI) that are available only in carrier aggregation operations, it includes the priority of candidate frequencies for the primary cell (PCell), the priority of candidate frequencies for the SCell, and the like.

[0180] The UE 10 establishes a PDU session through a cell of the MCG for the network slice based on the allowed NSSAI and information about the tracking area in the registration area and / or NSAG information to use the network slice that is only available in dual-connectivity operation. Here, the base station providing the cell of the MCG is referred to as the master node (MN).

[0181] Regarding UE 10, (R)AN 20 configures the measurement of the SCG cell supporting the network slice available only in the dual connection operation according to the RFSP index and the radio resource management policy corresponding to the RFSP index, and UE 10 sends the measurement result of the SCG cell to the MCG cell. The measurement of the SCG cell is configured through RRC. Here, the base station providing the SCG cell is called a secondary node. The MCG cell establishes a dual connection by sending an SN add request to the SCG cell based on the measurement result of the SCG cell obtained from UE 10.

[0182] With the establishment of dual connectivity, the MCG cell sends a PDU session modification indication to the AMF 301 during the PDU session path update procedure.

[0183] The UE 10 establishes a PDU session through the PCell for network slicing based on the allowed NSSAI and information about the tracking area in the registration area to use the network slice available only in the carrier aggregation operation.

[0184] Regarding UE 10, (R)AN 20 configures measurement of SCell supporting network slices available only in carrier aggregation operation according to the RFSP index and the radio resource management policy corresponding to the RFSP index, and UE 10 sends the measurement result of SCell to PCell. Measurement of SCell is configured through RRC.

[0185] The PCell adds the SCell for carrier aggregation through the RRC based on the measurement result of the SCell acquired from the UE 10 .

[0186] In addition, one of the requirements for network slicing is to ensure isolation between network slices. Specifically, in the case of supporting multiple network slices in limited radio resources, admission control is applied to prevent congestion in each network slice so that other network slices are not affected.

[0187] NSACF 312 monitors and controls the number of UEs 10 registered for each network slice, the number of PDU sessions established, and the number of UEs 10 with one or more PDU sessions established. NSACF 312 also supports notification and reporting of the status of the network slice to each NF in response to events.

[0188] [4. Admission control of network slices]

[0189] In order to control the number of UEs 10 registered for each network slice, the AMF 301 sets a validity period for a registered network slice according to the state of the network slice notified or reported by the NSACF 312. Examples of the state of the network slice include the number of UEs 10 registered for a target S-NSSAI, the number of PDU sessions established using the target S-NSSAI, the number of UEs 10 each having one or more PDU sessions established using the target S-NSSAI, a state in which the number of UEs 10 registered for the target S-NSSAI exceeds a preset threshold, a state in which the number of PDU sessions established using the target S-NSSAI exceeds a preset threshold, and a state in which the number of UEs 10 each having one or more PDU sessions established using the target S-NSSAI exceeds a preset threshold. The validity period for a registered network slice is set according to such a state of the network slice.

[0190] The AMF 301 sets a validity period for all or some of the S-NSSAIs included in the allowed NSSAI, and provides the allowed NSSAIs with the validity period set for all or some of the S-NSSAIs as a set of registered network slices for the UE 10. Here, the AMF 301 may provide the UE 10 with information about the validity period of all or some of the S-NSSAIs in the allowed NSSAI by including the information in the allowed NSSAI or as supplementary information (or auxiliary information) about the allowed NSSAI.

[0191] When the UE 10 obtains an allowed NSSAI for which a validity period is set for all or some of the S-NSSAIs, or obtains an allowed NSSAI and supplementary information about the allowed NSSAI, the timer starts based on the validity period set for the S-NSSAI. Next, when the validity period of the timer expires, the UE 10 deletes the S-NSSAI whose validity period has expired from the allowed NSSAI. Here, in the case where the UE 10 establishes a PDU session using the S-NSSAI for which a validity period is set, the timer stops when the PDU session is established. Next, when the PDU session is released, the timer is reset and started again. In other words, the timer works only when the network slice associated with the S-NSSAI for which a validity period is set is not used.

[0192] In addition, AMF 301 can set the validity period of all or part of the S-NSSAI included in its own allowed NSSAI according to the status of the network slice notified or reported by NSACF 312, and can update the allowed NSSAI or supplementary information about the allowed NSSAI.

[0193] When the allowed NSSAI or the supplementary information about the allowed NSSAI is updated, the AMF 301 provides the UE 10 with the updated allowed NSSAI or the updated supplementary information about the allowed NSSAI.

[0194] In addition, during the registration process, the NSSF 304, which has obtained information about the requested NSSAI from the AMF 301, can set the validity period for all or some of the S-NSSAIs included in the allowed NSSAI according to the status of the network slice notified or reported by the NSACF 312.

[0195] NSSF 304 may provide AMF 301 with information about the validity period of all or some of the S-NSSAIs in the allowed NSSAIs by including the information into the allowed NSSAIs or as supplementary information about the allowed NSSAIs.

[0196] In addition, when the target S-NSSAI is deleted from the allowed NSSAI due to expiration of the validity period, AMF 301 provides UE10 with information about the conditions for re-registration for the target S-NSSAI (deleted S-NSSAI). Here, the conditions are, for example, conditions for prohibiting requests for re-registration in the same registration area, in the same tracking area (mobile management area), or in the same service area (AoS), conditions for setting a back-off timer until re-registration in the same registration area, the same tracking area, or the same AoS, or other conditions. These conditions are determined, for example, by NSACF 312, NSSF 304, or AMF301. Here, AoS is an area defined at a finer granularity than a tracking area, such as a segment defined by a coordinate system such as latitude and longitude, a cell ID, a set of cell IDs, a base station ID, or a set of base station IDs.

[0197] In case the conditions prohibit a request for re-registration in the same registration area, the same tracking area or the same AoS, the UE 10 may be notified of an instruction to treat the target S-NSSAI (deleted S-NSSAI) as a rejected S-NSSAI or to add it to the rejected NSSAI.

[0198] In the case where the condition sets a backoff timer until re-registration in the same registration area, the same tracking area, or the same AoS, the UE 10 may be notified of an instruction to treat the target S-NSSAI (deleted S-NSSAI) as a pending S-NSSAI during the backoff period until re-registration, or an instruction to add it to the pending NSSAI.

[0199] The UE 10 may also include information on the priority of each S-NSSAI into the registration request message as supplementary information (or auxiliary information) of the requested NSSAI.

[0200] The NSSF 304 determines whether to allow registration of the S-NSSAI included in the requested NSSAI based on the information notified or reported by the NSACF 312, such as the number of registered UEs 10, the number of established PDU sessions, and / or the number of UEs 10 for which one or more PDU sessions have been established, and the registration priority of each S-NSSAI included in the supplementary information about the requested NSSAI. For example, registration of an S-NSSAI with a high registration priority is allowed, and registration of an S-NSSAI with a low registration priority is rejected. Here, the registration priority of each S-NSSAI may be a level depending on urgency. For example, registration of an S-NSSAI with a high registration urgency (i.e., a high registration priority) is allowed, and registration of an S-NSSAI with a low registration urgency (i.e., a low registration priority) is rejected.

[0201] In addition, the NSSF 304 and the AMF 301 may decide the validity period of each S-NSSAI whose registration will be allowed based on the following information: the number of registered UEs 10, the number of established PDU sessions and / or the number of UEs 10 that have established one or more PDU sessions, and the registration priority of each S-NSSAI included in the supplementary information about the requested NSSAI. For example, a long validity period is assigned to an S-NSSAI with a high registration priority, and a short validity period is assigned to an S-NSSAI with a low registration priority.

[0202] Based on the information about the validity period of each S-NSSAI for which registration will be allowed obtained from NSSF 304, or based on the validity period assigned by AMF 301 itself, AMF 301 sets the validity period of each S-NSSAI for which registration will be allowed.

[0203] [5. Location information management function]

[0204] In UE-based mode, the UE 10 makes it possible to obtain assistance data for positioning from the LMF 312 and performs measurements and position calculations with respect to a Global Navigation Satellite System (GNSS). The UE 10 makes it possible, for example, to use a well-known method called Assisted-GNSS.

[0205] It should be noted that, in the case where no signal is received from the GNSS or in other cases, the UE 10 may detect location information by means other than the GNSS. For example, the UE 10 makes it possible to detect information about its own location by using a method called sidelink positioning, WLAN positioning, Bluetooth (registered trademark) positioning, or Terrestrial Beacon System (TBS) positioning.

[0206] In sidelink positioning, the UE 10 measures the sidelink received signal strength indicator (SL RSSI) through sidelink communication with surrounding UEs 10 or roadside units (RSUs). The UE 10 calculates its position based on information about the positions of each UE 10 or roadside unit and the measured value of the SL RSSI. In addition, the UE 10 can measure the round trip time (RTT) between the UE 10 and the surrounding UEs 10 or roadside units and calculate its position.

[0207] In WLAN positioning, the UE 10 measures the received signal strength indicator (RSSI) associated with each WLAN access point. The UE 10 calculates its position based on the information about the known coordinates of each WLAN access point and its measured values. In addition, the UE 10 can measure the RTT between the UE 10 and the WLAN access point and calculate its position.

[0208] In Bluetooth positioning, the UE 10 may measure the RSSI for each Bluetooth beacon and calculate its position based on information about the known coordinates of the respective Bluetooth beacons and their measured values.

[0209] In case the UE 10 is equipped with a GNSS receiver, the UE 10 performs measurements on the GNSS in UE-assisted mode, such as measurements of code phase, Doppler, carrier phase, etc. The UE 10 sends such measurements to the LMF 312, and the LMF 312 calculates the position of the UE 10.

[0210] In addition, in the case where the UE 10 is equipped with a GNSS receiver but fails to receive a signal from the GNSS, or in the case where the UE 10 is not equipped with a GNSS, the LMF 312 may obtain information about the location of the UE 10 through the following positioning techniques:

[0211] -OTDOA (Observed Time Difference of Arrival);

[0212] -Multiple RTTs;

[0213] -DL AoD (Downlink Angle of Departure);

[0214] -DL TDOA (downlink time difference of arrival);

[0215] -UL TDOA (Uplink Time Difference of Arrival); or

[0216] -UL AoA (Angle of Arrival).

[0217] Alternatively, the LMF 312 may acquire information about the location of the UE 10 through a positioning technique using a cell ID (CID).

[0218] For example, in the case of OTDOA, the UE 10 receives downlink positioning reference signals (PRS) from multiple transmission points (TPs), and reports the physical cell ID, global cell ID, TP ID, and measurement values ​​related to the timing of the PRS to the LMF 312 through the LTE Positioning Protocol (LPP). Therefore, the LMF 312 calculates the position of the UE 10 based on the information about the known coordinates of each measured TP and the relative timing of the reported PRS.

[0219] In addition, for example, in the case of a positioning technology using CID, LMF 312 calculates the position of UE 10 based on information about the known coordinates of the ng-eNB or gNB and measurement results reported by UE 10 (to be described later).

[0220] The UE 10 reports, for example, an evolved cell global identifier (ECGI) or a physical cell ID and measurement results of reference signal received power (RSRP), reference signal received quality (RSRQ), and UE Rx-Tx time difference to the LMF 312. Here, the UE Rx-Tx time difference is defined as the time difference between the reception timing and the transmission timing of the UE 10.

[0221] [6. The first method to improve the availability of network slices]

[0222] exist Figure 5 In the example of network slice deployment shown in , UE 10 is not allowed to use S-NSSAI-H2 in HPLMN_TA2, for example. That is, by allowing UE 10 to use S-NSSAI-H2 in HPLMN_TA2, it is possible to improve the availability of network slices.

[0223] Figure 6 FIG. 1 is a diagram showing another example of network slicing deployment for 5GS. Here, the HPLMN has a roaming SLA with a VPLMN which is another PLMN.

[0224] By having an equivalent PLMN (EPLMN) list or an equivalent HPLMN (EHPLMN) list including PLMN IDs of respective VPLMNs, the UE 10 makes it possible to identify VPLMNs in which roaming is possible.

[0225] The VPLMN supports S-NSSAI-V2 in VPLMN_TA1. For example Figure 6 As shown in , VPLMN_TA1 overlaps with a portion of HPLMN_TA2 and a portion of HPLMN_TA3. It is assumed that a segment in which the VPLMN makes it possible to support S-NSSAI-V2 in HPLMN_TA2 is a service area (AoS) for S-NSSAI-V2 in HPLMN_TA2. Similarly, it is assumed that a segment in which the VPLMN makes it possible to support S-NSSAI-V2 in HPLMN_TA3 is an AoS for S-NSSAI-V2 in HPLMN_TA3.

[0226] In order to improve the availability of the HPLMN for the rejected S-NSSAI, the HPLMN provides the UE 10 with the PLMNID of the VPLMN, information about AoS, and information about mapping between the value of the rejected S-NSSAI in the HPLMN and the corresponding value of the S-NSSAI used in the VPLMN, as part of the information about the tracking area supporting the rejected S-NSSAI described above or as supplementary information. For example, the information about AoS is a set of HPLMN_TA2 and VPLMN_TA1, and the information about mapping is information indicating the correspondence between S-NSSAI-H2 and S-NSSAI-V2.

[0227] Based on the PLMN ID of the VPLMN, information on AoS and information on mapping, the UE 10 makes it possible to determine that the VPLMN serves as a serving PLMN and is in the AoS zone of S-NSSAI-H2 of the HPLMN when the UE 10 camps on HPLMN_TA2 and VPLMN_TA1.

[0228] [6.1. Determination of rejected S-NSSAI]

[0229] Figure 7 is a diagram showing an example of network slice registration determination processing in the registration process.

[0230] When the NSSF 304 receives the requested NSSAI from the UE 10 through the (R)AN 20 and the AMF 301 (step S501), the NSSF 304 performs a registration permission determination process for each S-NSSAI included in the requested NSSAI (step S502).

[0231] The NSSF 304, which has acquired the information about the requested NSSAI through the AMF 301, refers to the subscriber information maintained and managed by the UDR of the UDM 307 to check whether the target S-NSSAI is included in the subscription NSSAI (step S503). When the target S-NSSAI is not included, the NSSF 304 sets the target S-NSSAI to the rejected S-NSSAI due to lack of agreement (S504).

[0232] In step S503, when the determination target S-NSSAI is included in the subscription NSSAI, the NSSF 304 determines whether the registration area includes a tracking area that does not support the determination target S-NSSAI (step S505). When the registration area includes a tracking area that does not support the determination target S-NSSAI, the NSSF 304 sets the determination target S-NSSAI to a rejected S-NSSAI for the reason that the tracking area does not support it (step S506).

[0233] In step S505, when the registration area does not include a tracking area that does not support the determination of the target S-NSSAI, that is, when all tracking areas in the registration area support the determination of the target S-NSSAI, the NSSF 304 checks whether the determination of the target S-NSSAI is an S-NSSAI subject to the usage restriction of the NSACF 312 (step S507). When the determination of the target S-NSSAI is an S-NSSAI subject to the usage restriction of the NSACF 312, the NSSF 304 sets the determination of the target S-NSSAI to a rejected S-NSSAI for reasons of its admission control (step S508). Here, the NSSF 304 may determine whether the determination of the target S-NSSAI is an S-NSSAI subject to the usage restriction based on the state of the network slice notified or reported from the NSACF 312.

[0234] In step S507, when the determination target S-NSSAI is not the S-NSSAI subject to the usage restriction of the NSACF 312, the NSSF 304 adds the determination target S-NSSAI to the allowed NSSAI (step S509).

[0235] In addition, when determining that the target S-NSSAI requests a specific UE radio capability, NSSF 304 can determine whether to allow registration based on the UE radio capability information. Alternatively, based on the UE radio capability information, AMF 301 can also determine whether to allow registration with respect to (multiple) S-NSSAIs that NSSF 304 has determined to allow registration.

[0236] It should be noted that Figure 7Some or all of the processing shown in may be performed by AMF 301 instead of NSSF 304.

[0237] [6.2. Generation of Supplementary Information on Rejected S-NSSAI]

[0238] Figure 8 is a diagram showing an example of a process of generating supplementary information on a rejected S-NSSAI in a registration process.

[0239] Execution confirmed in Figure 7 The process of determining whether a rejected S-NSSAI is set in the registration determination process described above as shown in FIG6 (step S601). In the case where a rejected S-NSSAI is set, a target rejected S-NSSAI is specified from among the set rejected S-NSSAIs (step S602). As an example, all the set rejected S-NSSAIs are specified as target rejected S-NSSAIs.

[0240] Regarding the indicated rejected S-NSSAI, AMF 301 checks whether "Tracking Area Not Supported" is the reason for rejecting registration (step S603). When "Tracking Area Not Supported" is the reason, the tracking area in which the rejected S-NSSAI is not supported is indicated (step S604).

[0241] The AMF 301 checks whether the designated target tracking area includes a visitor PLMN (VPLMN) supporting the rejected S-NSSAI (step S605). When the target tracking area includes a VPLMN supporting the rejected S-NSSAI, the AMF 301 designates the VPLMN supporting the rejected S-NSSAI in the target tracking area (step S606), and adds the PLMN ID of the VPLMN in each target tracking area to the supplementary information (or auxiliary information) about the rejected S-NSSAI (step S607).

[0242] Next, the AMF 301 indicates the AoS of the VPLMN supporting the rejected S-NSSAI in the target tracking area (step S608), adds information indicating the AoS of the VPLMN in each target tracking area to the supplementary information about the rejected S-NSSAI (step S609), and ends the process. Here, the AoS of the VPLMN is, for example, a segment defined by the following items: a coordinate system such as latitude and longitude, a tracking area (mobile management area) set by the VPLMN, a cell ID, a set of cell IDs, a base station ID, a set of base station IDs, etc. In addition, the information about the AoS may include information about a frequency band or bandwidth part (BWP) supporting the rejected S-NSSAI in the AoS. In this case, the UE 10 determines that the rejected S-NSSAI is available only through the frequency band or BWP specified in the AoS. Here, the AoS is an example of a service segment according to the present embodiment.

[0243] Furthermore, in step S609, the supplementary information on the rejected S-NSSAI may include information explicitly indicating that sending a registration request for the rejected S-NSSAI to the VPLMN is allowed in the AoS of the VPLMN.

[0244] In addition, in the case where multiple VPLMNs are specified in step S606, priorities may be assigned to the VPLMNs based on the AoS of the VPLMNs specified in step S606. In step S609, information about the priorities of the VPLMNs may be added to the supplementary information about the rejected S-NSSAI. For example, a higher priority is assigned to a VPLMN with a wider AoS, and a lower priority is assigned to a VPLMN with a narrower AoS. Alternatively, a higher priority is assigned to a VPLMN with a wider frequency bandwidth covering the AoS, and a lower priority is assigned to a VPLMN with a narrower frequency bandwidth covering the AoS. Alternatively, in the case where a validity period is set for the AoS, a higher priority is assigned to a VPLMN whose AoS has a longer validity period, and a lower priority is assigned to a VPLMN whose AoS has a shorter validity period.

[0245] The UE 10 that has acquired the supplementary information on the rejected S-NSSAI makes it possible to select a VPLMN supporting the rejected S-NSSAI in the target tracking area based on such priority.

[0246] On the other hand, if "Tracking Area Not Supported" is not the reason in step S603, AMF 301 further checks whether "Restriction under admission control" is the reason for rejecting registration (step S610). When "Restriction under admission control" is the reason, the tracking area to be restricted is specified (step S611).

[0247] AMF 301 obtains the value of the back-off timer from NSACF 312 (step S612). This value indicates the period until the registration request of the rejected S-NSSAI is allowed for the specified tracking area. Subsequently, AMF 301 adds the value of the back-off timer of each target tracking area to the supplementary information about the rejected S-NSSAI (step S613), and ends the process.

[0248] In step S612, AMF 301 may set the value of the backoff timer according to the status of the network slice notified or reported by NSACF 312.

[0249] Here, in step S613, the supplementary information about the rejected S-NSSAI may include information that explicitly indicates that sending a re-registration request for the rejected S-NSSAI is allowed in the target tracking area of ​​the HPLMN after the set backoff timer expires.

[0250] Furthermore, in the case where the rejected S-NSSAI is an S-NSSAI having a high registration priority, the processing in step S605 and subsequent steps may be added after the processing in step S613.

[0251] In addition, in the case where "restriction under admission control" is not the reason in step S610, or in the case where the target tracking area does not include a VPLMN supporting the rejected S-NSSAI in step S605, the process ends.

[0252] In addition, in the case where multiple VPLMNs supporting the rejected S-NSSAI are indicated in step S606, the supplementary information about the rejected S-NSSAI may include a priority for PLMN selection. The supplementary information about the rejected S-NSSAI may also include an instruction to set a priority in the EPLMN list or the EHPLMN list.

[0253] Priority may also be set according to the size of the AoS of the VPLMN supporting the rejected S-NSSAI. For example, the priority of a VPLMN with a larger AoS may be set to high, and the priority of a VPLMN with a smaller AoS may be set to low.

[0254] In addition, the priority may be set according to the state of the network slice notified or reported by the NSACF 312-2 of the VPLMN. For example, the priority is set according to the number of UEs 10 registered in the network slice serving as the target of the VPLMN, the number of PDU sessions established by using the network slice serving as the target of the VPLMN, or the number of UEs 10 that have established one or more PDU sessions by using the network slice serving as the target of the VPLMN. A high priority is given to a VPLMN in which the number of registered UEs 10, the number of PDU sessions, or the number of UEs 10 that have established one or more PDU sessions is smaller. A low priority is given to a VPLMN in which the number of registered UEs 10, the number of PDU sessions, or the number of UEs 10 that have established one or more PDU sessions is larger.

[0255] Figure 8 An example is shown in which AMF 301 generates supplementary information about a rejected S-NSSAI. However, the function of performing such processing is not limited to AMF 301. It is also possible that supplementary information about a rejected S-NSSAI is generated by another NF in 5GC 30. For example, when an Nnssf_NSSelection_Get message is received from AMF 301 and an allowed NSSAI is generated, NSSF 304 may generate a rejected S-NSSAI and supplementary information. NSSF 304 responds to AMF 301 with an Nnssf_NSSelection_Get response message including an allowed NSSAI, a rejected S-NSSAI, and supplementary information about the rejected S-NSSAI.

[0256] [6.3, Registration Process]

[0257] In order to receive services through 5GC / NGC 30, UE 10 must register with the network (such as RAN, AN or core network) according to any of the following purposes: initial registration for 5GS; mobile registration update with a switch going to a new tracking area outside the registration area; periodic registration update; and emergency registration. UE 10, for example, selects a PLMN corresponding to 5GC 30 and performs a registration process.

[0258] Fig. 9A and 9B is a diagram showing an example of registration processing for 5GS. Fig. 9A and 9B is a diagram showing an example of a registration procedure. Fig. 9AAs shown in , UE 10 in RM-DEREGISTERED state (ie, UE 10 not registered with 5GC 30) sends a registration request message to (R) AN 20 to perform initial registration (step S701). At this time, UE 10 includes its UE identity in the registration request message and sends it.

[0259] In the case of a valid EPS Globally Unique Temporary Identifier (GUTI), the UE identity is a 5G-GUTI mapped from the EPS GUTI. Here, EPS (Evolved Packet System) means a 4G system corresponding to Long Term Evolution (LTE) and includes Evolved UMTS (Evolved Terrestrial Radio Access Network (EUTRAN)) and Evolved Packet Core (EPC). From a security perspective, the EPS GUTI is a temporary ID that will be used to identify the UE 10 in the EPS to replace an ID uniquely assigned to each UE such as an International Mobile Subscriber Identity (IMSI) or an International Mobile Equipment Identity (IMEI).

[0260] Alternatively, if available, the UE identity is the PLMN-specific 5G-GUTI assigned by the PLMN that the UE 10 is attempting to register with.

[0261] Alternatively, if available, the UE identity is a PLMN-specific 5G-GUTI assigned by a PLMN treated as an equivalent PLMN to the PLMN with which the UE 10 is attempting to register.

[0262] Alternatively, if available, the UE identity is a PLMN-specific 5G-GUTI assigned by any PLMN.

[0263] Otherwise, the UE 10 includes a Subscription Hidden Identifier (SUCI) into the Registration Request message. In this case, the SUCI is an ID obtained by encrypting a Subscription Permanent Identifier (SUPI) which is an ID uniquely assigned to each UE 10.

[0264] When the UE 10 registers for the 5GS of any PLMN, the requested NSSAI described above must be provided to the network if the UE 10 has a configured NSSAI or an allowed NSSAI for that PLMN. Therefore, the UE 10 includes the requested NSSAI in the registration request message, or includes a mapping of the various S-NSSAIs of the requested NSSAI to the S-NSSAI of the HPLMN in the registration request message. This can allow the network side to check whether the (multiple) S-NSSAIs included in the requested NSSAI are allowed based on the subscription S-NSSAI.

[0265] Furthermore, when using the default configured NSSAI, the UE 10 includes a default configured NSSAI indication into the Registration Request message.

[0266] The UE 10 also enables support for agreement-based restriction functionality regarding network slices that can be registered simultaneously. If the UE 10 supports this functionality, the UE 10 includes information indicating support for this functionality as part of the UE 5GMM core network capabilities in the registration request message at the time of initial registration and mobile registration update.

[0267] When providing a configured NSSAI to a UE 10 that has been notified that the UE 10 supports the agreement-based restriction functionality regarding network slices that can be simultaneously registered, the AMF 301 provides information about the relevant network slice simultaneous registration group (NSSRG) of the network slices ((multiple) S-NSSAIs) of the HPLMN.

[0268] A UE 10 receiving an NSSRG must include only the network slices (S-NSSAI) assigned to the common single NSSRG into the requested NSSAI.

[0269] In the case where the UE 10 acquires information about two or more NSSRGs, the UE 10 assigns relative priorities to two or more network slices (S-NSSAIs) included in the configured NSSAI, and selects information about the NSSRG including the S-NSSAI having the highest priority. The UE 10 generates the requested NSSAI including the two or more S-NSSAIs included in the selected information about the NSSRG.

[0270] Here, in a case where the number of information about the NSSRG including the S-NSSAI with the highest priority is two or more items, UE 10 selects information about the NSSRG including more S-NSSAIs with higher priorities, and generates the requested NSSAI including two or more S-NSSAIs included in the selected information about the NSSRG.

[0271] When receiving the registration request message from the UE 10, the (R)AN 20 performs AMF selection (step S702). In the case where the registration request message does not include the 5G-S Temporary Mobile Subscription Identifier (5G-S-TMSI) or the Globally Unique AMF Identifier (GUAMI), the (R)AN 20 selects the AMF 301 based on the radio access technology ((R)AT) and the requested NSSAI (if available). Alternatively, in the case where the 5G-S-TMSI or GUAMI included in the registration request message does not indicate a valid AMF 301, the (R)AN 20 selects the AMF 301 based on the radio access technology ((R)AT) and the requested NSSAI (if available).

[0272] In the case where (R)AN 20 is NG-RAN, the registration request is forwarded to AMF 301 (step S703). The registration request includes the selected PLMN ID (e.g., the PLMN corresponding to the 5GC 30 described above) or a pair of a network identifier (NID) and a PLMN ID to identify a standalone non-public network (SNPN).

[0273] In the case that UE 10 does not provide SUCI to AMF 301, AMF 301 starts identity request processing, sends an identity request message to UE 10, and requests SUCI (step S704).

[0274] In case that UE 10 receives the identity request message in step S704, UE 10 sends an identity response message including SUCI (step S705). In this case, UE 10 can obtain SUCI by using the public key of HPLMN.

[0275] The AMF 301 performs AUSF selection based on the SUPI or SUCI (step S706), and starts authentication of the UE 10.

[0276] When the AUSF 309 receives the authentication request from the AMF 301 , the AUSF 309 must perform authentication of the UE 10 .

[0277] In the authentication process, the AUSF 309 selects the UDM 307 and acquires authentication data from the UDM 307. When the UE 10 is authenticated, the AUSF 309 provides the AMF 301 with information on security.

[0278] When the authentication of UE 10 succeeds, AMF 301 starts NG Application Protocol (NGAP) processing and provides security context to (R)AN 20.

[0279] (R)AN 20 maintains the security context and sends a response to AMF 301. Subsequently, (R)AN 20 uses the security context to protect messages exchanged with UE 10.

[0280] The AMF 301 performs UDM selection based on the SUPI, and selects the UDM 307 (step S707).

[0281] The AMF 301 registers with the UDM 307 through the Nudm_UECM_Registration service (Nudm_UECM_Registration Request / Response) (steps S708 and S709).

[0282] In the case where AMF 301 does not have subscription data of UE 10, AMF 301 uses Nudm_SDM_Get service (Nudm_SDM_Get / Nudm_SDM_Get response) to obtain subscription data such as access and SMF selection subscription data from UDM 307 (steps S710 and S711). Here, the subscription data includes slice selection subscription data.

[0283] For example, in the case where slice selection becomes necessary because the AMF 301 has difficulty coping with all S-NSSAIs included in the requested NSSAI, the AMF 301 sends an Nnssf_NSSelection_Get message including the requested NSSAI, (multiple) subscribed S-NSSAIs, TAI, and PLMN ID of SUPI to the NSSF 304 (step S712). Subsequently, the NSSF 304 performs Figure 7 The network slice registration determination processing shown in (step S713).

[0284] NSSF 304 responds to AMF 301 with an Nnssf_NSSelection_Get response message including the allowed NSSAI, (multiple) rejected S-NSSAI, AMF address list or AMF set (step S714).

[0285] In the case where the AMF 301 acquires the information about the NSSRG in step S711, the AMF 301 sends an Nnssf_NSSelection_Get message including the information about the NSSRG to the NSSF 304 in step S712.

[0286] NSSRG is restriction information indicating the network slice groups that can be registered simultaneously based on subscription data. When S-NSSAI is related to NSSRG, the S-NSSAI must be included in at least one NSSRG.

[0287] The subscription data including information about the NSSRG must include at least one default S-NSSAI. When there are one or more default S-NSSAIs, these (multiple) default S-NSSAIs are associated with the same NSSRG. That is, the UE 10 is allowed to register all (multiple) default S-NSSAIs at the same time.

[0288] The NSSF 304 selects one or more S-NSSAIs to be included in the allowed NSSAIs based on the requested NSSAI, (multiple) subscription S-NSSAIs and information about the NSSRG. Here, in the case where the AMF 301 receives subscription data including information about the NSSRG, the allowed NSSAI can only include network slices (S-NSSAI) assigned to a common single NSSRG.

[0289] In the case where the AMF 301 has acquired information about the registration priority of each S-NSSAI as supplementary information (or auxiliary information) of the requested NSSAI, the AMF 301 sends an Nnssf_NSSelection_Get message including the information about the registration priority of each S-NSSAI to the NSSF 304 in step S712.

[0290] The NSSF 304 selects one or more S-NSSAIs to be included in the allowed NSSAIs based on the requested NSSAI, the subscribed S-NSSAI(s), information about the NSSRG, and information about the registration priority of each S-NSSAI.

[0291] For example, the NSSF 304 selects information about an NSSRG including an S-NSSAI I having the highest priority based on information about the registration priority of each S-NSSAI, and generates an allowed NSSAI including two or more S-NSSAIs included in the selected information about the NSSRG.

[0292] Here, in a case where the number of information about the NSSRG including the S-NSSAI with the highest priority is two or more items, the NSSF 304 selects information about the NSSRG including more S-NSSAIs with higher priorities, and generates an allowed NSSAI including two or more S-NSSAIs included in the selected information about the NSSRG.

[0293] The AMF 301 performs NSACF selection based on the example information about available NSACFs acquired from the NRF 303 or configured locally in the AMF 301, and selects the NSACF 312 (step S715).

[0294] AMF 301 sends a Nnsacf_SliceEventExposure_Subscribe request message to NSACF 312 using the Nnsacf_NSAC service (step S716). A registration process with the Nnsacf_SliceEventExposure service is then performed. When the registration is completed, AMF 301 receives a Nnsacf_SliceEventExposure_Subscribe response message from NSACF 312 as a response (step S717).

[0295] Here, the Nnsacf_SliceEventExposure_Subscribe service notifies the network function (such as AMF 301) that has registered the service of the number of current UEs 10 registered in the S-NSSAI (network slice) on an event basis, the number of current PDU sessions established by using the S-NSSAI, or the number of current UEs 10 that have established one or more PDU sessions by using the S-NSSAI.

[0296] The subscription request message for the service may include an event ID, an event filter, and event report information.

[0297] The event ID parameter defines whether to notify the number of UEs 10 registered to S-NSSAI, the number of PDU sessions established by using S-NSSAI, or the number of current UEs 10 that have established one or more PDU sessions by using S-NSSAI.

[0298] The event filter parameters are the S-NSSAI targeted as the number of currently registered UEs 10 to be notified of the network function registered for the service, the S-NSSAI targeted as the number of currently established PDU sessions, the S-NSSAI targeted as the number of current UEs 10 that have established one or more PDU sessions, or the S-NSSAI targeted as a collection thereof.

[0299] The event report information defines whether such notification is issued based on a threshold or periodically. In the case of issuing a notification based on a threshold, the event report is triggered when the number of current UEs 10 registered with the target S-NSSAI, the number of currently established PDU sessions, or the number of current UEs 10 with one or more PDU sessions established reaches a threshold. In the case of issuing a notification periodically, the notification is triggered when the validity period of the periodic timer expires. Here, a threshold can be set for each network slice. Optionally, it is also possible to configure settings for implementing immediate reporting.

[0300] AMF 301 generates supplementary information about S-NSSAI (step S718). Here, the supplementary information about S-NSSAI is, for example, information about Figure 8 The process shown in generates the supplementary information of the rejected S-NSSAI.

[0301] AMF 301 transmits a Registration Accept message including supplementary information (or auxiliary information) about S-NSSAI, allowed NSSAI, and rejected NSSAI to UE 10 (step S719), and receives a Registration Complete message as a response from UE 10 (step S720).

[0302] In addition, in the case where there is no S-NSSAI that can be included in the allowed NSSAI and the registration is rejected, the AMF 301 may set a RFSP index for guiding to the service area (AoS) of the tracking area (mobile management area) of the VPLMN supporting the rejected S-NSSAI and the target NSSAI including the rejected S-NSSAI, and may send the target NSSAI and the RFSP index for the target NSSAI to the (R)AN 20. At this time, the AMF 301 may request the (R)AN 20 to generate a radio resource management policy corresponding to the RFSP index. The radio resource management policy is, for example, to assign a higher priority to the VPLMN cell operating frequency than the HPLMN cell operating frequency in the cell selection / reselection process.

[0303] According to the radio resource management policy corresponding to the RFSP index, the (R)AN 20 sets the priority on the measurement frequency in the cell selection / reselection process with respect to the UE 10 .

[0304] The UE 10 makes it possible to perform a cell selection / reselection process according to the set priority of the measurement frequency, and detects a VPLMN cell. Next, the UE 10 makes it possible to request a registration including a rejected S-NSSAI as the NSSAI requested from the VPLMN cell. Here, the UE 10 makes it possible to obtain information about mapping of the rejected S-NSSAI of the HPLMN with the S-NSSAI of the VPLMN from the AMF 301, and includes the S-NSSAI of the VPLMN corresponding to the rejected S-NSSAI in the registration request as the requested NSSAI.

[0305] [6.4. Check on the Area of ​​Service (AoS) residing in the network slice]

[0306] Fig.108 is a diagram showing an example of a procedure for UE 10 to check the availability of a network slice. When UE 10 performs a registration process (step S801), UE 10 acquires information about a tracking area that supports a rejected S-NSSAI in addition to an allowed NSSAI during the registration process (step S802). Conventionally, a request for re-registering a rejected S-NSSAI in a registration area is not allowed. However, a registration request in a tracking area that supports a rejected S-NSSAI is allowed only if information about a tracking area that supports a rejected S-NSSAI has been acquired.

[0307] Here, information about the tracking area supporting the rejected S-NSSAI is provided by, for example, Figure 8 Supplementary information (or auxiliary information) about the rejected S-NSSAI generated by the process shown in .

[0308] When the process for utilizing the rejected S-NSSAI starts, UE 10 starts the process of registering the rejected S-NSSAI (step S803).

[0309] UE 10 performs a cell selection / reselection process on a cell belonging to the HPLMN, and specifies the tracking area of ​​the HPLMN to which the selected cell belongs (step S804). At this time, as a supplement or alternative to the cell selection / reselection process on the HPLMN, UE 10 may identify a synchronization signal block (SSB: synchronization signal / PBCH block) to specify a beam.

[0310] The synchronization signal block includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH), and the UE 10 receives the PSS and SSS of the synchronization signal block for cell search.

[0311] UE 10 receives the PBCH of the synchronization signal block and acquires the master information block (MIB) as system information. MIB includes parameters such as control resource set (CORESET) #0. These parameters are used to monitor the physical downlink control channel (PDCCH) that schedules the physical downlink shared channel (PDSCH), which delivers the system information block 1 (SIB1) that serves as system information.

[0312] The base station device transmits different synchronization signal blocks by using different antenna directions, and the UE 10 identifies the received synchronization signal blocks. This allows the UE 10 to specify one of the antenna directions transmitted from the base station device. Here, different antenna directions are controlled by the service and phase of the signals fed to the multiple antenna elements, and are also called beams.

[0313] Next, based on the information about the tracking area supporting the rejected S-NSSAI, it is checked whether the rejected S-NSSAI is supported in the designated tracking area of ​​the HPLMN (step S805). When the rejected S-NSSAI is supported in the tracking area of ​​the HPLMN, the UE 10 requests the HPLMN to register the rejected S-NSSAI (step S806), and the process ends.

[0314] When rejected S-NSSAI (e.g., NSSAI-H2) is not supported in the tracking area of ​​the HPLMN (e.g., HPLMN_TA2), the PLMN ID and AoS of the VPLMN that supports the rejected S-NSSAI in the tracking area of ​​the HPLMN are indicated based on the information about the tracking area that supports the rejected S-NSSAI (step S807). Here, the AoS is, for example, a section in which the HPLMN_TA2 and the VPLMN_TA1 overlap each other.

[0315] The UE 10 checks the EPLMN list or the EHPLMN list (step S808). It is checked whether the EPLMN list or the EHPLMN list includes the PLMN ID of the VPLMN specified in step S807 (step S809). When included, a cell selection / reselection process for a cell belonging to the VPLMN is started (step S810). Here, the cell selection / reselection process for a cell belonging to the VPLMN is set to be performed at a timing different from the timing of the cell selection / reselection process for a cell belonging to the HPLMN performed in step S804.

[0316] UE 10 performs a cell selection / reselection process on a cell belonging to the VPLMN and indicates the tracking area of ​​the VPLMN to which the selected cell belongs (step S811). At this time, as a supplement or alternative to the cell selection / reselection process on the VPLMN, UE 10 can identify a synchronization signal block to indicate a beam.

[0317] UE 10 checks whether it is camped on the tracking area of ​​the VPLMN set as the AoS specified in step S807 (step S812). When it is camped on the tracking area, it requests VPLMN registration to be rejected S-NSSAI (step S813), and the process ends.

[0318] In case that the AoS is set at the granularity of a tracking area, whether it camps on the AoS is checked by using information on a tracking area including a cell selected by a cell selection / reselection process on a cell belonging to the VPLMN.

[0319] In case of setting AoS with the granularity of a cell ID, whether it camps on AoS is checked by using information on the ID of a cell selected by the cell selection / reselection process on cells belonging to the VPLMN.

[0320] In the case where AoS is set as a zone using coordinates such as latitude and longitude, whether it resides on AoS is checked by using location information detected by UE 10. Location information on UE 10 is detected by the method described in [5. Location information management function], for example.

[0321] Here, the rejected S-NSSAI (eg, S-NSSAI-V2) about the VPLMN as the serving PLMN is designated as the S-NSSAI of the VPLMN corresponding to the S-NSSAI-H2 of the rejected S-NSSAI serving as the HPLMN based on the information about mapping.

[0322] Furthermore, in step S809, when the EPLMN list or the EHPLMN list does not include the PLMN ID of the VPLMN specified in step S807, the process ends.

[0323] Furthermore, when the UE 10 is not camping on the tracking area of ​​the VPLMN set as the AoS in step S812 , the cell selection / reselection process in step S810 is performed at set intervals with respect to cells belonging to the VPLMN.

[0324] As described above, with respect to the tracking area of ​​the HPLMN that does not support a specific network slice, information about the AoS and VPLMN that support network slicing within the tracking area, which are included in the EPLMN list or the EHPLMN list and serve as roaming candidates, is provided to the UE 10. This allows the UE 10 to use the network slice in the AoS of the VPLMN that is at least a part of the segment in the tracking area of ​​the HPLMN that could not use the network slice in the past. In other words, it is possible to improve the availability of the network slice for the UE 10.

[0325] In addition, with respect to the tracking area of ​​the HPLMN that restricts registration of a specific network slice under admission control, information about AoS and VPLMN that support network slicing within the tracking area among VPLMNs that serve as roaming candidates included in the EPLMN list or the EHPLMN list is provided to the UE 10. This allows the UE 10 to use the network slice in the AoS of the VPLMN that is at least a part of a segment in the tracking area of ​​the HPLMN that could not use the network slice in the past.

[0326] In addition, the segment unit that does not support a specific network slice and the segment unit that limits the registration of a specific network slice under admission control or based on subscription data is not limited to the tracking area (mobile management area). A registration area or a service area (AoS) may be used as such a segment unit. Here, the AoS is, for example, a segment defined by a coordinate system such as latitude and longitude, a cell ID, a set of cell IDs, a base station ID, or a set of base station IDs to define a segment that is finer-grained than a tracking area.

[0327] [7. Second method for improving the availability of network slices]

[0328] Figure 6 An example is shown where a VPLMN supporting a specific network slice is available in the tracking area of ​​a HPLMN that does not support the specific network slice. However, instead of the VPLMN, it is also possible to use a standalone non-public network (SNPN) such as local 5G. It should be noted that, unlike the VPLMN, it is assumed that the SNPN operator does not have an SLA for roaming with the HPLMN. Therefore, additional procedures are necessary to improve the availability of network slices by using SNPN instead of VPLMN. It should be noted that in the case where the SNPN operator has an SLA for roaming with the HPLMN, it can be used in a manner similar to the case of the VPLMN. Fig.10 The processing shown in .

[0329] (Candidate SNPN detection process)

[0330] Fig.11A is a diagram showing an example of a process implemented by the HPLMN side regarding candidate SNPN detection. When the candidate SNPN detection process starts, the 5GC 30 (e.g., AMF 301) of the HPLMN generates information about rejected S-NSSAI (e.g., S-NSSAI-H2) and tracking areas (e.g., HPLMN_TA2) that do not support the rejected S-NSSAI (step S901). Here, since the HPLMN does not have an SLA for roaming with the SNPN, the HPLMN does not have information about the mapping of each S-NSSAI supported by the SNPN to the corresponding S-NSSAI of the HPLMN.

[0331] The 5GC 30 of the HPLMN exposes a request including the rejected S-NSSAI and information about the tracking area that does not support the rejected S-NSSAI through the NEF 302 (step S902). The information about the rejected S-NSSAI is, for example, the number of QoS flows supported by the rejected S-NSSAI and the characteristics of each QoS flow. Here, the characteristics of the QoS flow can be, for example, a 5QI or a collection of information about resource type, priority, packet delay tolerance, packet error rate, average window, maximum data burst, etc.

[0332] In addition, the information related to the rejected S-NSSAI may include information indicating whether specific functions of the 5GC 30 are used, such as whether the rejected S-NSSAI uses an edge application server (EAS), whether an artificial intelligence (AI) / machine learning (ML) model is used, and whether a network data analysis function (NWDAF) is used.

[0333] The network data analysis function may include an analysis logic function (AnLF) that uses a trained AI / ML model to perform inference and generate analysis information, and a model training logic function (MTLF) that trains the AI / ML model.

[0334] The network data analysis function uses various sensing information obtained from the UE 10 and the AI / ML model obtained according to the application to implement, for example, image recognition, voice recognition, automatic translation, estimation of two-dimensional or three-dimensional position, estimation of synchronization time, calculation of auxiliary information to support autonomous driving or advanced driver assistance systems (ADAS), generation of quasi-static information layers, quasi-dynamic information layers and / or dynamic information layers that constitute dynamic maps, etc.

[0335] The NEF 302 of the 5GC 30 manages at least two access layers with respect to the SNPN. The two access layers include a first access layer that can only be accessed by the SNPN that has an SLA with the HPLMN, and a second access layer that can only be accessed by the SNPN that does not have an SLA with the HPLMN.

[0336] In step S902, the 5GC 30 of the HPLMN exposes information about the rejected S-NSSAI and the tracking area that does not support the rejected S-NSSAI at the second access layer. In other words, the SNPN that does not have an SLA with the HPLMN makes it possible to obtain information about the rejected S-NSSAI and the tracking area that does not support the rejected S-NSSAI through the NEF 302 of the 5GC30.

[0337] Through NEF 302, 5GC 30 of HPLMN obtains the following set (step S903):

[0338] - SNPN ID of the SNPN in the target tracking area;

[0339] - the mapping between the rejected S-NSSAI and the S-NSSAI of the SNPN; and

[0340] -AoS.

[0341] In case of requesting to utilize the SNPN service corresponding to the generated set, a message requesting the SLA for the generated set is sent to the SNPN (step S904).

[0342] Through the NEF 302, the 5GC 30 of the HPLMN obtains permission for the SLA of the generated set from the SNPN that received the request (step S905).

[0343] When obtaining permission for the SLA for the generated set from the SNPN, the HPLMN makes it possible to use the rejected S-NSSAI included in the set in a manner similar to the case of the VPLMN described above. Fig.10 The processing shown in .

[0344] The 5GC 30 of the HPLMN adds the set of SNPN IDs, the mapping of the rejected S-NSSAI with the S-NSSAI of the SNPN, and the AoS to the supplementary information (or auxiliary information) about the rejected S-NSSAI (step S906).

[0345] In addition, the 5GC 30 of the HPLMN may instruct that the SNPN ID be added to the EPLMN list or EHPLMN list of the UE 10 to allow the UE 10 to treat the SNPN corresponding to the SNPN ID as a roaming candidate.

[0346] Fig. 11B SNPN obtains information about the rejected S-NSSAI and the tracking area that does not support the rejected S-NSSAI through NEF 302 (step S907). It is possible for SNPN to obtain the information through NEF 302 at any timing or at a desired timing. For example, information for providing services can be obtained when there is a frequency band or radio resource that is not used by SNPN, and the unused frequency band or radio resource can be used (e.g., borrowed) by 5GC 30 of HPLMN.

[0347] The SNPN specifies the corresponding S-NSSAI (e.g., S-NSSAI-S2) of the SNPN based on the information about the rejected S-NSSAI obtained from the HPLMN (step S908). In the absence of a corresponding S-NSSAI, the SNPN may configure a corresponding rejected S-NSSAI based on the information about the rejected S-NSSAI (e.g., the number of supported QoS flows, the characteristics of each QoS flow).

[0348] Based on the information obtained from the HPLMN about the tracking area that does not support the rejected S-NSSAI, the SNPN checks the AoS of the corresponding S-NSSAI of the SNPN specified in step S908 within the target tracking area (step S909). Here, the AoS of the S-NSSAI of the SNPN is, for example, the SNPN ID corresponding to the network belonging to the SNPN, the tracking area of ​​the SNPN, or the cell ID of the base station belonging to the SNPN.

[0349] The SNPN ID used to identify the SNPN is an identifier obtained by combining the PLMN ID with a network identifier (NID). Here, unlike the PLMN ID which is a globally unique identifier (GUID) used in a public network integrated NPN (PNI-NPN), it is sufficient that the PLMN ID used for the SNPN ID is a local unique ID (e.g., an ID that is unique in the SNPN).

[0350] Next, it is checked whether the target tracking area includes the AoS of the corresponding S-NSSAI of the SNPN (step S910). If not included, the process ends.

[0351] Here, the information about the tracking area is, for example, information about a segment defined by latitude, longitude, and distance. For example, such a segment is a circular segment set based on the latitude and longitude of the coordinates indicating the distance of its center and its radius, or a polygonal segment set based on the latitude and longitude of the coordinates of each corner.

[0352] When the target tracking area includes the AoS of the corresponding S-NSSAI of the SNPN, the SNPN generates the following set (step S911):

[0353] -SNPN ID;

[0354] - the mapping between the rejected S-NSSAI and the S-NSSAI of the SNPN; and

[0355] -AoS.

[0356] Next, the SNPN provides the generated set to the NEF 302 (step S912).

[0357] The SNPN obtains an SLA request message regarding the generated set from the 5GC30 of the HPLMN through the NEF 302 (step S913).

[0358] When the SLA request on the generated set is allowed, the SNPN responds with an SLA Accept message on the generated set (step S914) and ends the process.

[0359] Furthermore, a validity period may be set for the SLA permission regarding the generated set in step S914. In other words, the UE 10 belonging to the HPLMN makes it possible to use the services corresponding to the set generated by the SNPN only within the validity period. Therefore, when the validity period expires, the information about the tracking area supporting the rejected S-NSSAI or the information added to the supplementary information (the SNPN ID of the SNPN, the information about the mapping of the value of the rejected S-NSSAI in the HPLMN and the corresponding value of the S-NSSAI used in the SNPN, and the information about the AoS) is deleted. In a similar manner, when the validity period expires, the SNPN ID added to the EPLMN list or the EHPLMN list of the UE10 is also deleted.

[0360] As described above, the 5GC 30 of the HPLMN exposes information about the rejected S-NSSAI and the tracking area that does not support the rejected S-NSSAI through the NEF 302, obtains information about the correspondence between the AoS that makes it possible to support the rejected S-NSSAI and the target network slice in the HPLMN and the target network slice in the SNPN from the SNPN, concludes a dynamic / on-demand SLA with the SNPN, and thereby makes it possible to treat the SNPN equally with the VPLMN described above. In other words, the availability of network slices can be further improved.

[0361] In addition, the segment unit that does not support a specific network slice is not limited to the tracking area (mobility management area). A registration area or a service area (AoS) may be used as such a segment unit. Here, the AoS is, for example, a segment defined by a coordinate system such as latitude and longitude, a cell ID, a set of cell IDs, a base station ID, or a set of base station IDs to define a segment that is finer-grained than a tracking area.

[0362] [8. The third method to improve the availability of network slices]

[0363] Fig.12 is a diagram showing an example of a process of updating registration information associated with admission control. Fig. 9A and Fig. 9B After the registration process shown in , UE 10 receives a registration accept message including supplementary information (or auxiliary information) about S-NSSAI, allowed NSSAI and rejected NSSAI from AMF 301 (step S719), and responds to AMF 301 with a registration complete message (step S720).

[0364] Through the Nnsacf_SliceEventExposure_Subscribe service registered in step S716, the AMF 301 receives the Nnsacf_SliceEventExposure_Subscribe notification message including the state of the network slice according to the event from the NSACF 312 (step S1001). Here, the state of the network slice includes, for example, at least one of the following items: the number of UEs 10 registered with the target network slice, the number of established PDU sessions, the number of UEs 10 with one or more PDU sessions established, a notification that the number of registered UEs 10 exceeds a threshold, a notification that the number of established PDU sessions exceeds a threshold, a notification that the number of UEs 10 with one or more PDU sessions established exceeds a threshold, etc.

[0365] AMF 301 updates the allowed NSSAI in response to the notification from NSACF 312 to implement admission control (step S1002). Here, the criteria for starting admission control can be set in AMF 301 for each network slice. The criteria may include the number of registered UEs 10, the number of connected PDU sessions, and the number of UEs 10 that have established one or more PDU sessions. Under admission control, AMF 301 makes it possible to decide whether to set a validity period for the S-NSSAI (network slice) registered as the allowed NSSAI or to delete the target S-NSSAI from the allowed NSSAI, and notifies UE 10 of such instructions as supplementary information (or auxiliary information) about S-NSSAI.

[0366] Here, it is possible to decide whether to set a validity period for the target S-NSSAI (network slice) included in the allowed NSSAI or to delete the target S-NSSAI from the allowed NSSAI based on the registration priority of each S-NSSAI included in the supplementary information (or auxiliary information) of the requested NSSAI.

[0367] It is also possible to decide whether to set a validity period for the target S-NSSAI included in the allowed NSSAI or to delete the target S-NSSAI from the allowed NSSAI based on the notification from the NSACF 312. For example, in a case where the number of currently established PDU sessions has not reached the maximum number but the number of currently registered UEs 10 has reached the maximum number, it is determined that the number of UEs 10 registered with the target S-NSSAI is large but the number of UEs 10 using the target S-NSSAI is small, and it is decided to set a validity period for registration of the target S-NSSAI.

[0368] In addition, as supplementary information about S-NSSAI, AMF 301 can decide the conditions for re-registration of S-NSSAI that has been registered as allowed NSSAI under admission control.

[0369] For example, in the case where the target S-NSSAI is deleted from the allowed NSSAI, the AMF 301 determines the conditions for re-registration of the target S-NSSAI as supplementary information about the S-NSSAI. Alternatively, in the case where the target S-NSSAI is deleted from the allowed NSSAI after the validity period set for the target S-NSSAI included in the allowed NSSAI expires, the AMF 301 determines the conditions for re-registration of the target S-NSSAI.

[0370] Here, the conditions for re-registration of the target S-NSSAI include, for example, a condition of prohibiting re-registration requests in the same registration area or the same tracking area, a condition of setting a backoff timer until re-registration in the same registration area or the same tracking area, or other conditions.

[0371] In the case where a re-registration request is prohibited in the same registration area, in the same tracking area, or in the same service area (AoS), the AMF 301 generates information about the AoS and VPLMN supporting the target S-NSSAI in the same registration area, the same tracking area, or the same AoS as supplementary information about the S-NSSAI. In addition, in the case where a re-registration request is prohibited in the same registration area, in the same tracking area (mobility management area), or in the same AoS, the AMF 301 may generate information about the AoS and VPLMN supporting the target S-NSSAI in the same registration area, the same tracking area (mobility management area), or the same AoS as supplementary information about the S-NSSAI.

[0372] As described above, the AMF 301 generates supplementary information about the S-NSSAI (step S1003). The supplementary information includes the setting of the validity period of the S-NSSAI registered as the allowed NSSAI, the instruction to delete the target S-NSSAI from the allowed NSSAI, the conditions for re-registration of the target S-NSSAI, the information about the AoS and VPLMN supporting the target S-NSSAI in the registration area, tracking area or AoS where the re-registration request is prohibited, the information about the SNPN and AoS, etc.

[0373] As a supplement or alternative to the updated allowed NSSAI, AMF 301 sends an instruction to update the allowed NSSAI including the supplementary information about S-NSSAI to UE 10 (step S1004). Here, the instruction to update the allowed NSSAI may be an instruction to replace the allowed NSSAI possessed by UE 10 with the updated allowed NSSAI, or an instruction to delete the target S-NSSAI from the allowed NSSAI.

[0374] When receiving the updated allowed NSSAI and / or supplementary information on S-NSSAI from the AMF 301, the UE 10 performs necessary processing (step S1005).

[0375] Upon receiving the updated allowed NSSAI, UE 10 updates the allowed NSSAI possessed by UE 10 with the newly received allowed NSSAI.

[0376] Upon receiving the supplementary information on the S-NSSAI, the UE 10 configures necessary settings according to the supplementary information.

[0377] For example, in a case where the supplementary information on the S-NSSAI includes an instruction to delete the target S-NSSAI from the allowed NSSAI, the UE 10 deletes the target S-NSSAI from the allowed NSSAI.

[0378] In case the supplementary information on the S-NSSAI includes an instruction to set a validity period for the S-NSSAI included in the allowed NSSAI, the UE 10 starts a timer for which the validity period is set.

[0379] In case the supplementary information on the S-NSSAI includes a condition for re-registration of the S-NSSAI registered as the allowed NSSAI, the UE 10 sets the condition for re-registration of the target S-NSSAI when deleting the target S-NSSAI in the allowed NSSAI.

[0380] For example, in case the condition for re-registration is a condition that a re-registration request is prohibited in the same registration area, the same tracking area, or the same AoS, the UE 10 sets the target S-NSSAI to a rejected S-NSSAI or adds it to a set of rejected NSSAIs.

[0381] In the case where the condition for re-registration is a condition to set a back-off timer until re-registration in the same registration area, the same tracking area, or the same AoS, the UE 10 starts a timer for a back-off period for which a target S-NSSAI is set.

[0382] The UE 10 sets the target S-NSSAI to the pending S-NSSAI or adds it to the set of pending NSSAIs during the backoff period.

[0383] This allows the UE 10 to request re-registration in the same registration area, the same tracking area or the same AoS when the timer of the location setting back-off period expires.

[0384] When the necessary settings are completed, UE 10 responds to AMF 301 with a response indicating that the update of the allowed NSSAI is completed (step S1006).

[0385] Next, in a case where the supplementary information about the S-NSSAI includes information about the AoS and VPLMN supporting the target S-NSSAI in the registration area, tracking area, or AoS in which the re-registration request is prohibited, the UE 10 confirms that the UE 10 resides on the registration area, tracking area, or AoS in which the re-registration request is prohibited and also resides on the AoS of the VPLMN supporting the target S-NSSAI, and then requests the VPLMN to register the S-NSSAI of the VPLMN corresponding to the target S-NSSAI.

[0386] In addition, in the case where the supplementary information about the S-NSSAI includes information about the AoS and SNPN supporting the target S-NSSAI in the registration area or tracking area where the re-registration request is prohibited, the UE 10 confirms that the UE 10 resides on the registration area, tracking area, or AoS where the re-registration request is prohibited and also resides on the AoS of the SNPN supporting the target S-NSSAI, and then requests the SNPN to register the S-NSSAI of the SNPN corresponding to the target S-NSSAI.

[0387] As described above, in the admission control based on the dynamic network slice state managed by the NSACF 312, there is a concern that the use of a specific network slice may be restricted in a specific registration area, a specific tracking area (mobility management area), or a specific AoS. However, by providing the UE 10 with information for supplementing it with a network slice provided by at least one of the VPLMN or SNPN through roaming within a restricted registration area, tracking area, or AoS, it is possible to improve the availability of the network slice.

[0388] It should be noted that the dynamic network slice status can be obtained not only through subscription / notification using the Nnsacf_SliceEventExposure_Subscribe service, but also through on-demand request / response using the Nnsacf_NSAC_NumOfUEsUpdate service, Nnsacf_NSAC_NumOfPDUsUpdate service or Nnsacf_NSAC_EACNotify service acting as a Nnsacf_NSAC service.

[0389] In response to a request including at least one or more S-NSSAIs (network slices) as check targets, the Nnsacf_NSAC_NumOfUEsUpdate service responds with a notification indicating whether the number of UEs 10 registered in each target S-NSSAI has reached a maximum number. In addition, in response to a request including at least one or more S-NSSAIs (network slices) as check targets, the Nnsacf_NSAC_NumOfUEsUpdate service may respond with a notification indicating whether the number of UEs 10 for which one or more PDU sessions have been established using each target S-NSSAI has reached a maximum number. Here, based on the instruction included in the request, it is determined whether to respond with a notification indicating whether the number of UEs 10 registered in each target S-NSSAI has reached a maximum number, to respond with a notification indicating whether the number of UEs 10 for which one or more PDU sessions have been established using each S-NSSAI has reached a maximum number, or to respond with both notifications. In other words, the information included in the request may indicate a question about whether the number of UEs 10 registered in each S-NSSAI has reached the maximum number, a question about whether the number of UEs 10 that have established one or more PDU sessions using each S-NSSAI has reached the maximum number, or both questions. In addition, in response to a request including one or more S-NSSAIs (network slices) as check targets, services other than the Nnsacf_NSAC_NumOfUEsUpdate service (such as Nnsacf_NSAC_NumOfUEsw / PDUsUpdate) may be defined as services that respond with a notification indicating whether the number of UEs 10 that have established one or more PDU sessions using each target S-NSSAI has reached the maximum number.

[0390] In response to a request including at least one S-NSSAI as a check target, the Nnsacf_NSAC_NumOfPDUsUpdate service responds with a notification indicating whether the number of PDU sessions established by using each S-NSSAI has reached the maximum number.

[0391] The Nnsacf_NSAC_EACNotify service makes it possible to activate or deactivate an Early Availability Check (EAC) mode with respect to the NSACF 312 according to a request including at least one or more target S-NSSAIs.

[0392] When the number of UEs 10 registered in the S-NSSAI serving as the inspection target exceeds a first threshold value set by the operator (PLMN) (e.g., a value corresponding to 75% of the maximum number of UEs 10 allowed to be registered), the EAC responds with a notification indicating that the EAC mode is activated. When the number of UEs 10 registered in the S-NSSAI serving as the inspection target falls below a second threshold value set by the operator, the EAC responds with a notification indicating that the EAC mode is deactivated. Here, the first threshold value may be the same value as the second threshold value, or may be a value different from the second threshold value.

[0393] It should be noted that when the number of UE10s that have established one or more PDU sessions using the S-NSSAI that serves as the inspection target exceeds a first threshold set by the operator (PLMN), the EAC may respond with a notification indicating that the EAC mode is activated. When the number of UEs 10 that have established one or more PDU sessions using the S-NSSAI that serves as the inspection target falls below a second threshold set by the operator, the EAC may respond with a notification indicating that the EAC mode is deactivated. When requesting or subscribing to the Nnsacf_NSAC_EACNotify service, the AMF 301 sets the number of UEs 10 registered in the S-NSSAI or the number of UEs 10 that have established one or more PDU sessions using the S-NSSAI as the inspection target. Alternatively, the AMF 301 may set both the number of UEs 10 registered in the S-NSSAI and the number of UEs 10 that have established one or more PDU sessions using the S-NSSAI as the inspection target. In this case, the NSACF 312 also responds with information indicating the standard used to activate / deactivate the EAC mode. The criteria include the number of UEs 10 registered in the S-NSSAI and the number of UEs 10 that have established one or more PDU sessions using the S-NSSAI.

[0394] As described above, by managing the number of UEs 10 registered in a network slice (S-NSSAI), the number of PDU sessions established using a network slice (S-NSSAI), and / or the number of UEs 10 that have established one or more PDU sessions using a network slice (S-NSSAI), and implementing admission control on the network slices provided by the HPLMN, it is possible for the HPLMN to ensure isolation between network slices and provide stable quality for services of each network slice. In addition, by implementing control so that the deviation between the number of UEs 10 registered in each network slice and the number of UEs 10 that actually use the network slice (that is, the number of UEs 10 that have established PDU sessions using the network slice) is reduced, it is also possible to improve network slice usage efficiency. In addition, by providing information about a VPLMN and / or a local network (SNPN) and an AoS that supports a target network slice in a registration area, a tracking area (mobility management area), or an AoS whose use is restricted under admission control, it is also possible to improve the availability of network slices while effectively utilizing HPLMN resources.

[0395] In addition, in step S1003, the AMF 301 may include information indicating the number of UEs 10 registered in the network slice (S-NSSAI), the number of PDU sessions established using the network slice (S-NSSAI), and / or the number of UEs 10 that have established one or more PDU sessions using the network slice (S-NSSAI), obtained from the NSACF 312, into the supplementary information about the S-NSSAI as information about admission control. In step S1004, the UE 10 makes it possible to obtain information about admission control, such as the number of UEs 10 registered for each network slice (S-NSSAI), the number of PDU sessions established, and / or the number of UEs 10 that have established one or more PDU sessions, through the AMF 301.

[0396] The UE 10 selects a network slice (S-NSSAI) from each allowed NSSAI based on the information obtained about the admission control to establish a PDU session. For example, the UE 10 selects a network slice (S-NSSAI) including a small number of registered UEs 10 from among multiple candidates supporting the application. Alternatively, the UE 10 selects a network slice (S-NSSAI) including a small number of established PDU sessions from among multiple candidates supporting the application. Alternatively, the UE 10 selects a network slice (S-NSSAI) including a small number of UEs 10 that have established one or more PDU sessions from among multiple candidates supporting the application.

[0397] The above-described processing implemented on the UE 10 achieves balancing with respect to the use of each network slice and makes it possible to reduce the risk of network slices being unavailable due to admission control. In other words, the availability of network slices can be improved.

[0398] [8. The fourth method to improve the availability of network slices]

[0399] Fig.13 1 is a diagram showing an example of a process of updating registration information associated with network maintenance management. In the update process, for example, the operation of a specific network slice is stopped to perform network maintenance management. Fig.13 In the implementation, similar to Fig.12 The processing steps are as follows Fig.12 The same reference numerals are used.

[0400] In execution Fig. 9A and Fig. 9B After the registration process shown in , UE 10 receives a Registration Accept message including supplementary information about S-NSSAI, allowed NSSAI and rejected NSSAI from AMF 301 (step S719), and responds to AMF 301 with a Registration Complete message (step S720).

[0401] For example, AMF 301 obtains a notification about network maintenance management from Operation, Administration and Maintenance (OAM) (not shown) (step S1101). The notification about network maintenance management is a notification about a specific network slice (S-NSSAI) (such as S-NSSAI-H2) stopping an operation in a specific registration area, a specific tracking area (mobile management area) or a specific AoS (service area) (such as HPLMN_TA4 (tracking area)).

[0402] AMF 301 updates the allowed NSSAI according to the notification about the maintenance management (step S1002). For example, AMF 301 deletes the network slice (e.g., S-NSSAI-H2) whose operation is to be stopped from the allowed NSSAI.

[0403] AMF 301 generates supplementary information about S-NSSAI (step S1003). The supplementary information includes an instruction to delete the target S-NSSAI (e.g., S-NSSAI-H2) from the allowed NSSAI, information about AoS and VPLMN supporting S-NSSAI-H2 in HPLMN_TA4 that does not support S-NSSAI-H2, information about SNPN and AoS, etc.

[0404] As a supplement or alternative to the updated allowed NSSAI, the AMF 301 sends an instruction to update the allowed NSSAI including supplementary information (auxiliary information) about the S-NSSAI to the UE 10 (step S1004). Here, the instruction to update the allowed NSSAI may be an instruction to replace the allowed NSSAI possessed by the UE 10 with the updated allowed NSSAI, or an instruction to delete a specific network slice (e.g., S-NSSAI-H2) from the allowed NSSAI.

[0405] When receiving the updated allowed NSSAI and / or supplementary information on S-NSSAI from the AMF 301, the UE 10 performs necessary processing (step S1005).

[0406] Upon receiving the updated allowed NSSAI, UE 10 updates the allowed NSSAI possessed by UE 10 with the newly received allowed NSSAI.

[0407] Upon receiving the supplementary information on the S-NSSAI, the UE 10 configures necessary settings according to the supplementary information.

[0408] For example, in a case where the supplementary information on the S-NSSAI includes an instruction to delete the target S-NSSAI from the allowed NSSAI, the UE 10 deletes the target S-NSSAI from the allowed NSSAI.

[0409] When the necessary settings are completed, UE 10 responds to AMF 301 with a response indicating that the update of the allowed NSSAI is completed (step S1006).

[0410] Next, in a case where the supplementary information about the S-NSSAI includes information about the AoS and VPLMN supporting the target S-NSSAI in a specific registration area, a specific tracking area, or a specific AoS that does not support a specific network slice, the UE 10 confirms that the UE 10 resides on the specific registration area, the specific tracking area, or the specific AoS and also resides on the AoS of the VPLMN supporting the target S-NSSAI, and then requests the VPLMN to register the S-NSSAI of the VPLMN corresponding to the target S-NSSAI.

[0411] Next, in a case where the supplementary information about the S-NSSAI includes information about the SNPN and the AoS of the SNPN supporting the target S-NSSAI in a specific registration area, a specific tracking area, or a specific AoS that does not support a specific network slice, the UE 10 confirms that the UE 10 resides on the specific registration area, the specific tracking area, or the specific AoS and also resides on the AoS of the SNPN supporting the target S-NSSAI, and then requests the SNPN to register the S-NSSAI of the SNPN corresponding to the target S-NSSAI.

[0412] In addition, the notification about network maintenance management obtained in step S1101 may include relevant information about the time when the network slice (S-NSSAI) whose operation is to be stopped will stop operating or the period until the operation is stopped.

[0413] When receiving the notification about the network maintenance management, UE 10 decides the validity period of the target S-NSSAI based on the time when the operation will be stopped or the period until the operation is stopped, and starts a timer for which the validity period is set.

[0414] In order to avoid momentary interruption of registration of the target network slice, UE 10 makes it possible to confirm that UE 10 resides on the AoS of the SNPN or VPLMN supporting the target S-NSSAI based on the supplementary information about the S-NSSAI during the validity period of the registration of the network slice of the HPLMN, and requests the SNPN or VPLMN to register the target S-NSSAI.

[0415] In addition, the notification about network maintenance management may include information about a temporarily provided network slice (temporary S-NSSAI) of the HPLMN as a replacement for the network slice (S-NSSAI) whose operation is to be stopped, and may also include information about the validity period of the temporary S-NSSAI. In addition, in the case where a notification about network maintenance management is provided to a UE 10 that has established a PDU session in RRC_CONNECTED mode by using the S-NSSAI whose operation is to be stopped, the notification about network maintenance management may include information that explicitly instructs the implementation of the handover from the S-NSSAI whose operation is to be stopped to the temporary S-NSSAI.

[0416] Here, even when the temporary S-NSSAI is not included in the subscribed NSSAI or configured NSSAI, the temporary S-NSSAI is still treated as a network slice available during the specified validity period as a substitute for the S-NSSAI whose operation will be stopped within the HPLMN.

[0417] When providing the UE 10 with a notification regarding network maintenance management including information regarding the temporary S-NSSAI, the AMF 301 may notify an instruction to add the temporary S-NSSAI to the allowed NSSAI.

[0418] As described above, in the case where the operation of a specific network slice (S-NSSAI) is stopped in a specific registration area, a specific tracking area (mobile management area), or a specific AoS due to network maintenance management, by providing information about the VPLMN and / or local network (SNPN) supporting the target network slice in the registration area, tracking area, or AoS whose operation is to be stopped, it is possible to implement maintenance and management for stable operation of the network while reducing the impact on users (subscribers).

[0419] It should be noted that each of the processes described above with respect to a network slice whose operation is to be stopped may be applied to a situation where registration of a target network slice with respect to a specific UE 10 is restricted due to admission control, or to a situation where use of the target network slice is stopped.

[0420] In addition, the various processes according to the embodiments described above are applicable to all RRC states (e.g., RRC_IDLE, RRC_INACTIVE, or RRC_CONNECTED) of the UE 10. For example, in the case where the UE 10 in the RRC_CONNECTED mode with respect to the target S-NSSAI of the HPLMN requests the VPLMN or SNPN to register the target S-NSSAI, a handover process to the VPLMN or SNPN is further implemented.

[0421] Here, the handover to the VPLMN or SNPN is valid only with respect to the registered target S-NSSAI, and a PDU session belonging to the target S-NSSAI of the VPLMN or SNPN is established.

[0422] In addition, as supplementary information about the rejected S-NSSAI, the AMF 301 may provide the UE 10 with relevant information about one or more corresponding S-NSSAIs of the VPLMN or SNPN that make it possible to implement the handover with respect to the target S-NSSAI of the HPLMN. In other words, before the handover or in conjunction with the handover, the UE 10 requests the VPLMN or SNPN to register based on the relevant information about one or more corresponding S-NSSAIs of the VPLMN or SNPN that make it possible to implement the handover, and the UE 10 implements the handover to one of the S-NSSAIs whose registration is allowed. Here, in the case where the one or more corresponding S-NSSAIs of the VPLMN or SNPN that make it possible to implement the handover include two or more S-NSSAIs, a priority may be further assigned. The UE 10 selects one S-NSSAI with a higher priority based on the priority.

[0423] Fig.14 1 is a block diagram showing an exemplary configuration of a UE 10 as a terminal device according to the present disclosure. The UE 10 includes a transceiver 101, at least one processor 102, a storage part 103, and a network communication part 104. The transceiver 101 includes a radio transmission circuit 101A and a radio reception circuit 101B. The transceiver 101 is provided with one or more antennas 105. For example, the transceiver 101 transmits and receives radio signals between at least one network component including a local 5GC, a 5GC 30, and an access point such as a base station device in the (R) AN 20 through the antenna 105. The storage part 103 stores instructions to be executed by the processor 102, data or information received from a network component, etc., data or information to be sent to a network component, etc., and data or information necessary for the processing to be performed by the processor 102. The processor 102 executes the instructions stored in the storage part 103, and performs various processing explained in the embodiments described above. The processor 102 forms a processing circuit. The network communication section 104 makes it possible to communicate information or data with network components or the like through the transceiver 101 .

[0424] The processor 102 may include any combination of hardware for manipulating data or information. The hardware may include, for example, at least one computer, at least one central processing unit (CPU), at least one graphics processing unit (GPU), at least one microprocessor, at least one application specific integrated circuit (ASIC), or at least one field programmable gate array (FPGA).

[0425] The storage portion 103 is a hardware storage device, for example, including at least one of a random access memory (RAM), a read-only memory (ROM), a hard disk, a compact disk (CD), or a digital video disk (DVD). The storage portion 103 may include any other volatile or non-volatile memory that stores information, data, and / or instructions that can be used by the processor 102 of the UE 10.

[0426] UE 10 may include Fig.14 UE 10 may include input devices (or input circuits) and output devices (or output circuits). Input devices include mechanisms for inputting data into UE 10. For example, input devices may include input mechanisms such as keyboards, mice, touch screens, microphones, etc. Output devices may include output mechanisms such as displays, speakers, etc.

[0427] Fig.15 312 is a block diagram showing an exemplary configuration of a communication device 300 according to the present disclosure. As an example, the communication device 300 may include any one or more of the components (nodes) 301-312, 330, and 340 in the 5GC 30. For example, the communication device 300 may be one or more NFs including the AMF 312. For example, the communication device 300 may be an AMF 312, a set of the AMF 312 and the NSSF 304, a set of the AMF 312 and the NSACF 312, a set of the AMF 312, the NSSF 304, and the NSACF 312, or any other combination of NFs.

[0428] The communication device 300 may include one or more of a transceiver 351, a processor 352, a storage part 353, and a network communication part 354. The communication device 300 does not necessarily include the transceiver 351. The transceiver 351 includes a radio transmission circuit 351A and a radio reception circuit 351B. The transceiver 351 is provided with one or more antennas 355. The transceiver 351 transmits and receives radio signals to / from the UE 10 and network components such as the base station device in the (R) AN 20, other NFs in the 5GC 30, and other 5GCs (visitor 5GC, local 5GC) through the antenna 355. The storage part 353 stores instructions to be executed by the processor 352, data or information received from the UE 10, network components, etc., data or information to be sent to the UE 10, network components, etc., and data or information necessary for the processing to be performed by the processor 352. The processor 352 executes the instructions stored in the storage part 353 and performs various processing explained in the embodiments described above. The processor 352 forms a processing circuit. The network communication section 354 makes it possible to communicate information or data with the UE 10 , network components, etc. through the transceiver 351 .

[0429] The processor 352 may include any combination of hardware for manipulating data or information. The hardware may include, for example, at least one computer, at least one central processing unit (CPU), at least one graphics processing unit (GPU), at least one microprocessor, at least one application specific integrated circuit (ASIC), or at least one field programmable gate array (FPGA).

[0430] The storage portion 353 is a hardware storage device, which may include, for example, at least one of a random access memory (RAM), a read-only memory (ROM), a hard disk, a compact disk (CD), or a digital video disk (DVD). The storage portion 353 may include any other volatile or non-volatile memory that stores information, data, and / or instructions that can be used by the processor 352 of the communication device 300.

[0431] The network communication unit 354 is communicatively coupled to the processor 352, receives input information or data to be processed by the processor 352, and sends information or data output from the processor 352. The network communication part 354 can implement processing such as protocol conversion for communicating with the UE 10 or the network components described above. The network communication part 354 may include appropriate hardware (e.g., a network interface card, etc.) and software.

[0432] Reference Fig.15 The communication device 300 described can also be used as a network component other than 5GC 30. For example, the communication device can be a 5GC communication device corresponding to a visitor-side public land mobile network including any one or more components (such as NF) in the visitor 5GC. Alternatively, the communication device can be a local-side communication device corresponding to any one or more components (such as NF) in the local 5GC. The visitor-side communication device and the local-side communication device do not have to include a transceiver. Such a communication device can be any one or more base station devices in the (R)AN 20.

[0433] According to the present embodiment, with respect to a mobile management area as a tracking area of ​​a home public land mobile network (HPLMN) that does not support a specific network slice among visitor public land mobile networks (VPLMN) included in the EPLMN list or the EHPLMN list serving as roaming candidates, information about visitor public land mobile networks that support network slicing in the tracking area and its service area (that is, service area AoS) is provided to the UE 10. This enables the UE 10 to use network slicing in the service area of ​​the visitor public land mobile network with respect to at least a partial section in the tracking area of ​​the home public land mobile network where network slicing could not be used in the past. In other words, it is possible to improve the availability of network slicing for the UE 10.

[0434] In addition, according to the present embodiment, with respect to the mobility management area of ​​the home public land mobile network for which registration of a specific network slice is restricted under admission control among the VPLMNs serving as roaming candidates in the EPLMN list or the EHPLMN list, information about the visitor public land mobile network supporting network slicing in the tracking area and its service area is provided to the UE 10. This enables the UE 10 to use the network slice in the service area of ​​the visitor public land mobile network with respect to at least a partial section in the tracking area of ​​the home public land mobile network for which the network slice could not be used in the past.

[0435] In addition, according to the present embodiment, the core network of the home public land mobile network exposes a request including information about an unsupported target network slice and an unsupported mobile management area through a network exposure function (NEF), obtains a response including information about a service area supporting the target network slice and information about the correspondence relationship of the target network slice between the home public land mobile network and the local network from the local network (SNPN), and concludes a dynamic / on-demand service layer agreement (SLA) with the SNPN. This makes it possible to treat the local network equally with the visitor public land mobile network described above. In other words, the availability of network slices can be further improved.

[0436] The present invention is not limited to the aforementioned embodiments as they are, and the present invention can be realized by modifying each component in the implementation process without departing from its spirit. In addition, various inventions can be formed by optionally combining multiple components disclosed in the previous embodiments. For example, some components can be omitted from all components shown in the embodiments. In addition, various components can be arbitrarily combined across different embodiments.

[0437] In addition, the procedures for the processing described in the present disclosure can be regarded as methods including such a series of procedures. Alternatively, the procedures can be regarded as programs for causing a computer to implement such a series of procedures. The procedures for the processing can be executed by causing the computer to load a recording medium storing the program. In addition, the processing described above is performed by a processing circuit or processor such as a CPU of a computer. In addition, since the type of the recording medium does not affect the embodiments of the present disclosure, its type is not particularly limited.

[0438] It should be noted that according to the present disclosure Figure 1Each component (NF) shown in the figure can be implemented by software or by hardware. For example, each component can be a software module implemented by software such as a microprogram, and each component can be implemented by a processor that executes the software module. Alternatively, each component can be implemented by a circuit block on a semiconductor chip (die), such as an integrated circuit such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). In addition, the number of components and the number of hardware that implements the components can be different. For example, a processor or circuit can implement multiple components. On the contrary, a component can be implemented by multiple processors or circuits.

[0439] It should be noted that the type of processor described in the present disclosure is not limited. For example, the processor may be a CPU, a microprocessing unit (MPU), a graphics processing unit (GPU), etc.

[0440] In addition, "Xth" of the Xth information (X represents any integer greater than or equal to 1) in the description of the present disclosure is used to distinguish various types of information, and the Xth information does not necessarily uniquely identify specific information. For example, information about whether registration of a network slice (first network slice) is allowed in a registration area of ​​a terminal device in a home public land mobile network may be described as the first information, or may be described as the Yth information (Y represents any integer greater than or equal to 2).

[0441] It should be noted that the present disclosure may also be configured as follows.

[0442] [Core network side communication equipment]

[0443] (1) A communication device that performs the following processing in a registration process of registering a terminal device or in an update process of updating the registration of a terminal device:

[0444] a process for receiving, from a terminal device, a first set of identification information about at least one network slice for which registration is requested in a registration area of ​​a home public land mobile network;

[0445] A process of acquiring first information on whether a first network slice indicated by identification information included in the first set is allowed to be registered in a registration area; and

[0446] Processing of generating second information about a visitor public land mobile network that enables provision of a first network slice in an area overlapping at least the registration area based on the first information.

[0447] (2) The communication device according to (1), wherein

[0448] The first set is the requested NSSAI.

[0449] (3) The communication device according to (1) or (2), wherein

[0450] In a case where the first information does not allow registration of the first network slice in the first mobility management area in the registration area of ​​the home public land mobile network, the communication device performs a process of generating second information, the second information including a first network identifier of the visitor public land mobile network and information for specifying a service segment that is part of the first mobility management area, the visitor public land mobile network enabling provision of the first network slice in the service segment.

[0451] (4) The communication device according to any one of (1) to (3), wherein

[0452] In a case where the first information indicates that registration of the first network slice in the first mobility management area is not allowed, the communication device performs processing to generate second information, the second information including a second network identifier of a local network and information for indicating a service segment that is part of the first mobility management area, the local network enabling the first network slice to be provided in the service segment.

[0453] (5) The communication device according to (4), wherein

[0454] The communication device performs the following processing:

[0455] exposing a request including geographic information corresponding to a first mobility management area and information about a first network slice;

[0456] a process of acquiring third information in response to the request, the third information comprising a second network identifier of a local network and information for indicating a service segment, the local network being capable of providing the first network slice; and

[0457] A process of generating second information based on third information, wherein the second information includes a second network identifier of a local network and information for indicating a service segment, and the local network is capable of providing a first network slice.

[0458] (6) The communication device according to (5), wherein

[0459] The information about the first network slice includes at least the number of QoS flows to be processed by the first network slice and the characteristics of each QoS flow.

[0460] (7) The communication device according to (6), wherein

[0461] The characteristics of the QoS flow include at least one of resource type, priority, packet delay budget, packet error rate, average window or maximum data burst size.

[0462] (8) The communication device according to (7), wherein

[0463] The resource type is either GBR QoS flow or non-GBR QoS flow.

[0464] (9) The communication device according to any one of (1) to (8), wherein

[0465] The second information includes information indicating that sending a registration request for the first network slice to the visitor public land mobile network is allowed in a service segment that is part of the first mobility management area.

[0466] (10) The communication device according to any one of (3) to (9), wherein

[0467] The second information includes information indicating that a registration request for the first network slice is allowed to be sent to the local network in a service segment that is part of the first mobility management area.

[0468] (11) The communication device according to any one of (1) to (10), wherein

[0469] The service segment is a second mobility management area belonging to a visitor public land mobile network.

[0470] (12) The communication device according to any one of (1) to (11), wherein

[0471] The service segment is a segment of a first cell belonging to a visitor public land mobile network.

[0472] (13) The communication device according to any one of (3) to (12), wherein

[0473] The service segment is a segment of a second cell belonging to the local network.

[0474] (14) The communication device according to any one of (3) to (13), wherein

[0475] The communication device performs the following processing:

[0476] a process of acquiring fourth information about a registration priority of a first network slice included in the first set; and

[0477] Based on the fourth information, determining whether to include a first network identifier of a visitor public land mobile network and information for indicating a service segment that is part of a first mobile management area into the processing of the second information, wherein the visitor public land mobile network enables provision of a first network slice in the service segment.

[0478] (15) The communication device according to any one of (3) to (14), wherein

[0479] The communication device performs the following processing:

[0480] a process of acquiring fourth information about registration priorities of network slices included in the first set; and

[0481] A process for determining whether to include a second network identifier of a local network and information indicating a service segment that is part of a first mobility management area into the second information based on fourth information, wherein the local network enables provision of a first network slice in the service segment.

[0482] (16) The communication device according to (1), wherein

[0483] In a case where the first information indicates that registration of the first network slice in the first mobility management area in the registration area of ​​the home public land mobile network is not allowed, the communication device performs a process of acquiring fifth information on a reason why registration is not allowed, and

[0484] In the case where the fifth information indicates a reason related to admission control,

[0485] The communication device performs the following processing:

[0486] A process of setting a backoff period, the backoff period being a period until re-registration of the first network slice in the registration area or in the first mobility management area is allowed; and

[0487] A process of generating second information including information about the backoff period.

[0488] (17) The communication device according to (1), wherein

[0489] In case the first information indicates that registration of the first network slice is allowed in the first mobility management area in the registration area of ​​the home public land mobile network,

[0490] The communication device performs the following processing:

[0491] receiving a sixth information processing related to admission control;

[0492] A process for setting a registration validity period of the first network slice based on the sixth information; and a process for adding information about the registration validity period of the first network slice to the second information.

[0493] (18) The communication device according to (17), wherein

[0494] The communication device performs the following processing:

[0495] A process for determining a condition for re-registration of the first network slice to be applied after expiration of a registration validity period of the first network slice; and

[0496] A process of adding seventh information about the decided condition for re-registration to the second information.

[0497] (19) The communication device according to (18), wherein

[0498] The condition for re-registration is that re-registration is prohibited in the registration area or in the first mobility management area.

[0499] (20) The communication device according to (18), wherein

[0500] The condition for re-registration is expiration of a backoff period until re-registration in the registration area or in the first mobility management area is permitted.

[0501] (21) The communication device according to any one of (17) to (20), wherein

[0502] After the registration validity period of the first network slice expires, the communication device performs a process of deleting the first network slice from the second set of network slices whose registration is allowed.

[0503] (22) The communication device according to any one of (18) to (21), wherein

[0504] In a case where the condition for re-registration is that re-registration is prohibited in the registration area or in the first mobility management area, the communication device performs a process of adding the first network slice to a third set of network slices whose registration is rejected.

[0505] (23) The communication device according to any one of (18) to (22), wherein

[0506] When adding the first network slice to the third set, the communication device performs a process of adding a first network identifier of a visitor public land mobile network and information for indicating a service segment that is part of a first mobility management area to the second information, wherein the visitor public land mobile network enables the first network slice to be provided in the service segment.

[0507] (24) The communication device according to any one of (18) to (23), wherein

[0508] When adding the first network slice to the third set, the communication device performs processing of adding a second network identifier of a local network and information for indicating a service segment that is part of a first mobility management area to the second information, wherein the local network enables the first network slice to be provided in the service segment.

[0509] (25) The communication device according to any one of (18) to (24), wherein

[0510] In a case where the condition for re-registration is expiration of a backoff period until re-registration in the registration area or in the first mobility management area is allowed, the communication device performs processing of adding the first network slice and information about the backoff period to a fourth set of network slices whose registration is pending.

[0511] (26) The communication device according to any one of (1) to (25), wherein

[0512] The communication device performs a process of providing second information to the terminal device.

[0513] (27) The communication device according to any one of (1) to (26), wherein

[0514] The first information comprises a second set of network slices for which registration is allowed, and

[0515] The communication device performs processing to generate a first set of mobility management areas that allow registration of each network slice included in the second set and a first set of mobility management areas that do not allow registration of each network slice included in the second set as second information.

[0516] (28) The communication device according to (27), wherein

[0517] The second information includes eighth information, and the eighth information indicates whether the information about the mobile management area included in the first set of mobile management areas is a mobile management area that allows registration of each network slice included in the second set or a mobile management area that does not allow registration of each network slice included in the second set.

[0518] (29) The communication device according to any one of (1) to (28), wherein

[0519] The first information comprises a second set of network slices for which registration is allowed, and

[0520] The communication device performs the following processing:

[0521] A process for obtaining ninth information about admission control;

[0522] Deciding, based on the ninth information, a process of a second condition for re-registering the first network slice included in the second set in the second mobility management area in the registration area of ​​the home public land mobile network; and

[0523] The second condition for registration of the first network slice is included in the processing of the second information.

[0524] (30) The communication device according to any one of (1) to (28), wherein

[0525] The first information comprises a second set of network slices for which registration is allowed, and

[0526] The communication device performs the following processing:

[0527] Processing of obtaining information about operation and maintenance of the network slice;

[0528] Deciding, based on the tenth information, processing of a second condition for registering the first network slice included in the second set in the second mobility management area in the registration area of ​​the home public land mobile network; and

[0529] The second condition for registration of the first network slice is included in the processing of the second information.

[0530] (31) The communication device according to (29) or (30), wherein

[0531] The second condition is to set a validity period for the registration of the first network slice.

[0532] (32) The communication device according to (29) or (30), wherein

[0533] The second condition is that the registration of the first network slice is cancelled.

[0534] (33) The communication device according to (31) or (32), wherein

[0535] The communication device performs the following processing:

[0536] a process of generating second information including a second condition; and

[0537] The process of sending the second information to the terminal device.

[0538] (34) A communication device according to any one of (1) to (33), wherein

[0539] The first information comprises a second set of network slices for which registration is allowed, and

[0540] The communication device performs the following processing:

[0541] a process of acquiring fourth information about registration priorities of network slices included in the first set;

[0542] A process of acquiring 11th information indicating two or more network slices that are simultaneously allowed to register; and

[0543] The processing of the network slice included in the second set is selected based on the first set, the fourth information and the 11th information.

[0544] (35) The communication device according to (34), wherein

[0545] The network slices included in the second set are selected so that more network slices having a higher priority of the fourth information are included compared to two or more network slices included in the 11th information.

[0546] (36) The communication device according to (3), wherein

[0547] In a case where the second information includes two or more first network identifiers of visitor public land mobile networks each capable of providing a first network slice, the communication device performs a process of assigning 12th information regarding a priority to each first network identifier.

[0548] (37) The communication device according to (36), wherein

[0549] The 12th information about the priority is determined based on a size of a service segment of the visitor public land mobile network corresponding to the first network identifier.

[0550] (38) The communication device according to (36), wherein

[0551] The 12th information about the priority is determined based on a size of a frequency bandwidth covering a service segment of the visitor public land mobile network corresponding to the first network identifier.

[0552] (39) The communication device according to (36), wherein

[0553] The 12th information about the priority is determined based on a validity period set for a service segment of the visitor public land mobile network corresponding to the first network identifier.

[0554] (40) A communication device according to any one of (29) to (33), wherein

[0555] The communication device performs a process of generating second information, wherein the second information includes identification information about a second network slice temporarily provided from a home public land mobile network and 13th information about allowing registration of the second network slice, wherein the 13th information is included as a substitute for registration for the first network slice.

[0556] [Terminal equipment]

[0557] (41) A terminal device performs the following processing:

[0558] a process for sending a first set of identification information about at least one network slice for which registration is requested in a registration area of ​​a home public land mobile network;

[0559] a process of receiving first information regarding whether registration of a first network slice indicated by identification information included in a first set is allowed in a registration area; and

[0560] Processing of receiving second information about a visitor public land mobile network that enables provision of a first network slice in an area overlapping with a registration area, the second information being generated based on the first information.

[0561] (42) A terminal device according to (41), wherein

[0562] The first set is the requested NSSAI.

[0563] (43) A terminal device according to (41) or (42), wherein

[0564] In a case where the first information indicates that registration of the first network slice in the first mobility management area within the registration area of ​​the home public land mobile network is not allowed, the terminal device performs a process of receiving second information, the second information including a first network identifier of the visitor public land mobile network and information indicating a service segment that is part of the first mobility management area, the visitor public land mobile network enabling provision of the first network slice in the service segment.

[0565] (44) A terminal device according to any one of (41) to (43), wherein

[0566] In a case where the first information indicates that registration of the first network slice in the first mobility management area is not allowed, the terminal device performs a process of receiving second information, wherein the second information includes a second network identifier of a local network and information for indicating a service segment that is part of the first mobility management area, the local network enabling the first network slice to be provided in the service segment.

[0567] (45) A terminal device according to any one of (41) to (44), wherein

[0568] The second information includes information indicating that sending a registration request for the first network slice to the visitor public land mobile network is allowed in a service segment that is part of the first mobility management area.

[0569] (46) A terminal device according to any one of (42) to (45), wherein

[0570] The second information includes information indicating that a registration request for the first network slice is allowed to be sent to the local network in a service segment that is part of the first mobility management area.

[0571] (47) A terminal device according to any one of (41) to (46), wherein

[0572] The service segment is a second mobility management area belonging to a visitor public land mobile network.

[0573] (48) A terminal device according to any one of (41) to (47), wherein

[0574] The service segment is a segment of a first cell belonging to a visitor public land mobile network.

[0575] (49) A terminal device according to any one of (44) to (48), wherein

[0576] The service segment is a segment of a second cell belonging to the local network.

[0577] (50) A terminal device according to any one of (43) to (49), wherein

[0578] The terminal device performs processing of sending third information about registration priorities of network slices included in the first set.

[0579] (51) A terminal device according to (41), wherein

[0580] The second information includes fourth information about a backoff period, the backoff period being a period until re-registration of the first network slice in the registration area or in the first mobility management area is allowed, and

[0581] The terminal device performs a process of setting a value of a first timer based on fourth information, the first timer controlling a period of transmission until re-registration of the first network slice.

[0582] (52) A terminal device according to (41) or (42), wherein

[0583] The second information includes fifth information about a registration validity period of the first network slice, and

[0584] The terminal device performs processing to set the value of the second timer based on the fifth information, and the second timer controls the registration validity period of the first network slice.

[0585] (53) A terminal device according to (52), wherein

[0586] The terminal device performs the following processing:

[0587] A process of establishing a session using a first network slice;

[0588] stopping processing of the second timer during a period in which the session is established; and

[0589] The process of resetting and restarting the second timer is performed when the session is released.

[0590] (54) A terminal device according to (52) or (53), wherein

[0591] The terminal device performs processing for obtaining sixth information about conditions for re-registration of the first network slice applied after the registration validity period of the first network slice expires.

[0592] (55) A terminal device according to (54), wherein

[0593] The condition for re-registration is that re-registration is prohibited in the registration area or in the first mobility management area.

[0594] (56) A terminal device according to (54), wherein

[0595] The condition for re-registration is expiration of a backoff period until re-registration in the registration area or in the first mobility management area is permitted.

[0596] (57) A terminal device according to (56), wherein

[0597] The terminal device performs a process of setting a value of a third timer based on sixth information, and the third timer controls a period of transmission until re-registration of the first network slice.

[0598] (58) A terminal device according to any one of (52) to (57), wherein

[0599] After the registration validity period of the first network slice expires, the terminal device performs a process of deleting the first network slice from the second set of network slices whose registration is allowed.

[0600] (59) A terminal device according to any one of (55) to (58), wherein

[0601] In a case where the condition for re-registration is that re-registration is prohibited in the registration area or in the first mobility management area, the terminal device performs a process of adding the first network slice to a third set of network slices whose registration is rejected.

[0602] (60) A terminal device according to (51), wherein

[0603] The terminal device performs processing to add the first network slice to a fourth set of network slices whose registration is pending.

[0604] (61) A terminal device according to any one of (43) to (60), wherein

[0605] the terminal device comprising a fifth set of network identifiers of public land mobile networks that are roaming candidates,

[0606] The terminal device performs a process of determining whether the fifth set includes the first network identifier included in the second information,

[0607] In case the fifth set includes the first network identifier,

[0608] The terminal device performs the following processing:

[0609] a first selection process or a first reselection process of a cell or a synchronization signal block provided by a first base station device belonging to a home public land mobile network; and

[0610] a second selection process or a second reselection process of a cell or a synchronization signal block provided by a second base station device belonging to the visitor public land mobile network, and

[0611] In the case where the first base station device associated with the cell or synchronization signal block selected by the first selection process or the first reselection process belongs to the first mobility management area and the second base station device associated with the cell or synchronization signal block selected by the second selection process or the second reselection process belongs to the service segment,

[0612] The terminal device sends a registration request for a first network slice to the visitor public land mobile network indicated by the first network identifier.

[0613] (62) A terminal device according to (61), wherein

[0614] the terminal device comprising a fifth set of network identifiers of public land mobile networks that are roaming candidates,

[0615] the terminal device performs a process of receiving an instruction to add the second network identifier to the fifth set,

[0616] The terminal device performs a process of determining whether the fifth set includes the second network identifier included in the second information,

[0617] In case the fifth set includes the second network identifier,

[0618] The terminal device performs a third selection process or a third reselection process of a cell or a synchronization signal block provided by a third base station device belonging to the local network indicated by the second network identifier, and

[0619] In the case where the first base station device associated with the cell or synchronization signal block selected by the first selection process or the first reselection process belongs to the first mobility management area and the third base station device associated with the cell or synchronization signal block selected by the third selection process or the third reselection process belongs to the service segment,

[0620] The terminal device sends a registration request for the first network slice to the local network indicated by the second network identifier.

[0621] (63) A terminal device according to (41), wherein

[0622] The first information comprises a second set of network slices for which registration is allowed, and

[0623] The second information includes a first set of mobility management areas that allow registration of each network slice included in the second set and a first set of mobility management areas that do not allow registration of each network slice included in the second set.

[0624] (64) A terminal device according to (63), wherein

[0625] The second information includes seventh information, and the seventh information indicates whether the information about the mobile management area included in the first set of mobile management areas is a mobile management area that allows registration of each network slice included in the second set or a mobile management area that does not allow registration of each network slice included in the second set.

[0626] (65) A terminal device according to (43), wherein

[0627] In a case where the second information includes two or more first network identifiers of visitor public land mobile networks, each of which is capable of providing a first network slice, and eighth information about priorities respectively assigned to the two or more first network identifiers, the terminal device performs processing of selecting a visitor public land mobile network corresponding to one of the two or more first network identifiers based on the eighth information.

[0628] (66) A terminal device according to (41), wherein

[0629] in a case where the second information includes identification information about a second network slice temporarily provided from a home public land mobile network and ninth information about allowing registration of the second network slice, the ninth information is included as a substitute for registration of the first network slice,

[0630] The terminal device performs processing to update a first session established through a first network slice to a second session established through a second network slice.

[0631] (67) A terminal device according to (66), wherein

[0632] In the handover process, the first session is updated to the second session.

[0633] (68) A terminal device according to (66) or (67), wherein

[0634] The identification information about the second network slice is identification information about a network slice that is not included in a fifth set, and the fifth set includes identification information about the subscribed network slice.

[0635] (69) A terminal device according to any one of (66) to (68), wherein

[0636] The second information includes tenth information about a registration validity period of the second network slice, and

[0637] The terminal device performs a process of starting a timer, the validity period of which is set based on the tenth information.

[0638] (70) A terminal device according to (69), wherein

[0639] The terminal device performs the following processing:

[0640] a process of adding identification information about a second network slice to a second set of network slices for which registration is allowed; and

[0641] The process of deleting identification information about the second network slice from the second set after the validity period of the timer expires.

[0642] [Communication System]

[0643] (71) A communication system comprising:

[0644] A terminal device sends a registration request for a first network slice, wherein the registration request includes a first set of identification information about at least one network slice for which registration is requested in a registration area of ​​a home public land mobile network; and

[0645] a communication device, acquiring first information about whether registration of a first network slice is allowed in a registration area based on the registration request, the first network slice being indicated by the identification information, and generating second information about a visitor public land mobile network that enables provision of the first network slice in an area overlapping the registration area based on the first information, wherein

[0646] In a case where the first information indicates that registration of the first network slice is permitted, the communication device includes information necessary for setting a registration period of the first network slice into the second information,

[0647] In the case where the first information indicates that the registration of the first network slice is rejected, the communication device includes information necessary for re-registering the first network slice into the second information, and

[0648] The terminal device receives the first information and the second information from the communication device.

[0649] [Local network side device]

[0650] (72) A communication device performs the following processing:

[0651] a process of acquiring geographical information corresponding to a first mobility management area and information about a first network slice from a home public land mobile network;

[0652] A process of checking whether a service section of a local network is included in an area indicated by the geographic information; and

[0653] The processing of setting the third network slice based on the information about the first network slice is performed when the service segment is included in the area indicated by the geographical information.

[0654] (73) The communication device according to (72), wherein

[0655] The information about the first network slice includes at least the number of QoS flows to be assigned to the first network slice and the characteristics of each QoS flow.

[0656] (74) The communication device according to (73), wherein

[0657] The characteristic of a QoS flow is the 5G QoS Identifier (5QI).

[0658] (75) The communication device according to (73), wherein

[0659] The characteristics of the QoS flow include at least one of resource type, priority, packet delay budget, packet error rate, average window or maximum data burst size.

[0660] (76) The communication device according to (75), wherein

[0661] The resource type is either GBR QoS flow or non-GBR QoS flow.

[0662] (77) A communication device according to any one of (73) to (75), wherein

[0663] The number of QoS flows assigned to the third network slice is set based on the number of QoS flows included in the information about the first network slice.

[0664] (78) A communication device according to any one of (73) to (77), wherein

[0665] Characteristics of the QoS flows assigned to the third network slice are set based on characteristics of the respective QoS flows included in the information about the first network slice.

[0666] (79) A communication device according to any one of (72) to (78), wherein

[0667] The communication device performs processing to generate second information about a mapping of a first network slice to a third network slice.

[0668] (80) A communication device according to any one of (72) to (79), wherein

[0669] The communication device performs the following processing:

[0670] a process of generating third information, the third information comprising a number of QoS flows to be assigned to a third network slice, characteristics of each QoS flow, and second information; and

[0671] The third information is provided to a process of the home public land mobile network.

[0672] [Terminal equipment with different forms]

[0673] (81) A terminal device performs the following processing:

[0674] a process for sending a first set of first identification information about at least one network slice for which registration is requested;

[0675] a process of acquiring first information related to admission control for each item of first identification information included in the first set; and

[0676] Processing of a second network slice to be used to establish a session is selected based on the first information.

[0677] (82) A terminal device according to (81), wherein

[0678] The terminal device performs the following processing:

[0679] a process of acquiring second information on whether registration of the network slice included in the first set is allowed; and

[0680] Processing of selecting a second network slice to be used to establish a session from third network slices whose registration is allowed, wherein the selection is performed based on first information and second information.

[0681] (83) A terminal device according to (81) or (82), wherein

[0682] The second information includes a set of second identification information about a third network slice, and

[0683] The terminal device performs the following processing:

[0684] A process of acquiring auxiliary information used to select identification information corresponding to a second network slice from a set of second identification information, wherein the acquiring is performed based on the first information; and

[0685] Based on the auxiliary information, processing of identification information corresponding to the second network slice is selected.

[0686] (84) A terminal device according to (83), wherein

[0687] For each item of second identification information, the first information includes the number of registered terminal devices, the number of established sessions, and / or the number of terminal devices each of which has established at least one session.

[0688] (85) A terminal device according to (83), wherein

[0689] For each item of second identification information, the first information includes the number of registered terminal devices, the number of terminal devices that have each established at least one session, and / or a notification indicating whether the number of established PDU sessions has reached a maximum value.

[0690] (86) A terminal device according to (83), wherein

[0691] For each item of second identification information, the first information includes the number of registered terminal devices, the number of terminal devices each of which has established at least one session, and / or a notification indicating that the number of established sessions exceeds a threshold.

[0692] (87) A terminal device according to (86), wherein

[0693] The threshold is set by the home public land mobile network.

[0694] (88) A terminal device according to (86), wherein

[0695] The threshold is set by the visitor public land mobile network.

[0696] [Registration area setting method]

[0697] (89) A method for setting a registration area including at least one mobility management area, the at least one mobility management area including a first mobility management area, the method comprising:

[0698] Setting a second mobility management area that is in the first mobility management area or overlaps with the first mobility management area; and

[0699] Control is implemented in such a way that selection or reselection of a cell or beam added through dual connectivity or selection or reselection of a cell or beam included in a component carrier added through carrier aggregation takes the second mobility management area into consideration.

[0700] (90) The method according to (89), further comprising:

[0701] Processing of registration of network slices available only in the second mobility management area is allowed.

[0702] [Base station equipment]

[0703] (91) A base station device performs the following processing in a registration area including at least one first mobility management area and at least one second mobility management area:

[0704] A process of selecting a setting of a priority regarding a measurement frequency band in a process of selecting or reselecting a cell or a beam;

[0705] Controlling the terminal device based on the setting of the priority of the measurement frequency band so that the measurement process for the process of selecting or reselecting the first cell or the first beam is performed on the first mobility management area; and

[0706] The terminal device is controlled based on the setting of the priority of the measurement frequency band so that measurement processing for selecting or reselecting the second cell or the second beam added by the dual connectivity is performed on the second mobility management area.

[0707] (92) The base station device according to (91), wherein

[0708] The second mobility management area includes a second base station device providing a second cell or a second beam operating in a specific frequency band.

[0709] (93) The base station device according to (91) or (92), wherein

[0710] The operating frequency bands are classified into two or more ranges, and

[0711] The specific frequency band is classified into a range of a higher frequency band among two or more ranges of the classified operating frequency bands.

[0712] Reference numerals list

[0713] 10——UE (User Equipment) or Terminal Equipment

[0714] 20——RAN / AN (Radio Access Network / Access Network)

[0715] 30 - Core Network

[0716] 301——AMF (Access and Mobility Management Function)

[0717] 302 - NEF (Network Exposure Function)

[0718] 303 – NRF (Network Repository Function)

[0719] 304 - NSSF (Network Slice Selection Function)

[0720] 305——PCF (Policy Control Function)

[0721] 306——SMF (Session Management Function)

[0722] 307——UDM (Unified Data Management)

[0723] 308——AF (application function)

[0724] 309——AUSF (Authentication Server Function)

[0725] 310——UCMF (UE Radio Capability Management Function)

[0726] 311——LMF (Location Management Function)

[0727] 312——NSACF (Network Slicing Access Control Function)

[0728] 40 - Application Server

[0729] 101 - Transceiver

[0730] 102 - Processor

[0731] 103——Storage section

[0732] 104——Network Communication Section

[0733] 101A——Radio Transmitter Circuit

[0734] 101B——Radio Receiving Circuit

[0735] 105——Antenna

[0736] 300——Communication equipment

[0737] 351——Transceiver

[0738] 352 - Processor

[0739] 353——Storage section

[0740] 354——Network Communication Section

[0741] 351A——Radio Transmitter Circuit

[0742] 351B——Radio Receiving Circuits

[0743] 355——Antenna

Claims

1. A communication device, comprising: at least one processor; as well as transceiver, wherein the at least one processor: receiving, from a terminal device, a first set of identification information about at least one first network slice for which registration is requested in a registration area of ​​a home public land mobile network; Obtaining first information about whether registration of a first network slice is allowed in a registration area, the first network slice being indicated by identification information in a first set; as well as Second information about a visitor public land mobile network that enables provision of the first network slice in an area overlapping with at least the registration area is generated based on the first information.

2. The communication device according to claim 1, wherein In a case where the first information indicates that registration of the first network slice in the first mobility management area in the registration area is not allowed, the at least one processor generates second information, the second information comprising a first network identifier of a visitor public land mobile network and information indicating a service segment that is part of the first mobility management area, the visitor public land mobile network enabling provision of the first network slice in the service segment.

3. The communication device according to claim 1, wherein In a case where the first information indicates that registration of the first network slice in the first mobility management area in the registration area is not allowed, the at least one processor generates second information, the second information including a second network identifier of a local network and information for indicating a service segment that is part of the first mobility management area, the local network enabling the first network slice to be provided in the service segment.

4. The communication device according to claim 3, wherein The at least one processor: exposing a request including geographic information corresponding to a first mobility management area and information about a first network slice; acquiring, in response to the exposed request, third information including a second network identifier of a local network and information for indicating a service segment, the local network being capable of providing the first network slice; and The second information is generated based on the third information, wherein the second information includes a second network identifier of a local network and information for indicating a service segment, and the local network is capable of providing a first network slice.

5. The communication device according to claim 4, wherein The information about the first network slice includes at least the number of QoS flows to be processed by the first network slice and the characteristics of each QoS flow.

6. The communication device according to claim 2, wherein The at least one processor: acquiring fourth information about a registration priority of the first network slice indicated by the identification information included in the first set; and Based on the fourth information, it is determined whether to include a first network identifier of a visitor public land mobile network and information indicating a service segment that is part of the first mobility management area into the second information, wherein the visitor public land mobile network enables provision of a first network slice in the service segment.

7. The communication device according to claim 1, wherein In a case where the first information indicates that registration of the first network slice in the first mobility management area in the registration area is not allowed, the at least one processor obtains fifth information about a reason why registration is not allowed, and In the case where the fifth information indicates a reason related to admission control, The at least one processor: setting a backoff period, the backoff period being a period until re-registration of the first network slice in the registration area or in the first mobility management area is allowed, and Second information including information about the backoff period is generated.

8. The communication device according to claim 1, wherein In a case where the first information indicates that registration of the first network slice is allowed in the first mobility management area in the registration area, The at least one processor: Obtaining sixth information about access control; Setting a registration validity period of the first network slice based on the sixth information; as well as Information about the registration validity period of the first network slice is included in the second information.

9. The communication device according to claim 8, wherein After the registration validity period of the first network slice expires, the at least one processor deletes the identification information about the first network slice from the second set of identification information about the network slices for which registration is allowed.

10. The communication device according to claim 9, wherein The at least one processor: determining a condition for re-registration of the first network slice to be applied after expiration of the registration validity period of the first network slice; and Information on the decided condition for re-registration is included in the second information.

11. A terminal device, comprising: at least one processor; as well as transceiver, where The processor: sending a first set of identification information about at least one first network slice for which registration is requested in a registration area of ​​a home public land mobile network; receiving first information about whether registration of a first network slice indicated by identification information included in the first set is allowed in a registration area of ​​a home public land mobile network; as well as Based on the first information, second information is received about a visitor public land mobile network that enables provision of the first network slice in an area overlapping with at least the registration area.

12. The terminal device according to claim 11, wherein In a case where the first information indicates that registration of the first network slice in the first mobility management area in the registration area is not allowed, the at least one processor receives second information, the second information comprising a first network identifier of a visitor public land mobile network and information indicating a service segment that is part of the first mobility management area, the visitor public land mobile network enabling provision of the first network slice in the service segment.

13. The terminal device according to claim 11, wherein In a case where the first information indicates that registration of the first network slice in the first mobility management area in the registration area is not allowed, the at least one processor receives second information, the second information including a second network identifier of a local network and information for indicating a service segment that is part of the first mobility management area, the local network enabling provision of the first network slice in the service segment.

14. The terminal device according to claim 11, wherein The second information includes third information about a backoff period, the backoff period being a period until re-registration of the first network slice in the registration area or in the first mobility management area in the registration area is allowed, and Based on the third information in the second information, the at least one processor sets a value of a first timer, and the first timer controls a period until a re-registration request for the first network slice is sent.

15. The terminal device according to claim 11, wherein The second information includes fourth information about a registration validity period of the first network slice, and Based on the fourth information in the second information, the at least one processor sets a value of a second timer, and the second timer controls the registration validity period of the first network slice.

16. The terminal device according to claim 15, wherein The at least one processor receives fifth information regarding a condition for re-registration of the first network slice that is applied after expiration of a registration validity period of the first network slice.

17. The terminal device according to claim 16, wherein The condition for re-registration is expiration of a backoff period, the backoff period being a period until re-registration is permitted in a registration area or in a first mobility management area in a registration area, and The at least one processor sets a value of a third timer that controls a backoff period based on fifth information.

18. The terminal device according to claim 15, wherein After the registration validity period of the first network slice expires, the at least one processor deletes the identification information about the first network slice from the second set of identification information about the first network slice whose registration is allowed.

19. The terminal device according to claim 11, wherein The second information includes a first network identifier of a visitor public land mobile network and information indicating a service segment that is part of a first mobility management area in a registration area, the visitor public land mobile network enabling provision of a first network slice in the service segment, the at least one processor determining whether a third set of network identifiers of public land mobile networks that are roaming candidates includes the first network identifier included in the second information, In case the third set includes the first network identifier, The at least one processor: making a first selection or a first reselection of a cell or a synchronization signal block provided by a first base station device belonging to a home public land mobile network; and making a second selection or a second reselection of a cell or synchronization signal block provided by a second base station device belonging to the visitor public land mobile network indicated by the first network identifier, and In the case where the first base station device associated with the cell or synchronization signal block selected by the first selection or the first reselection belongs to the first mobility management area and the second base station device associated with the cell or synchronization signal block selected by the second selection or the second reselection belongs to the service segment, The at least one processor sends a registration request for a first network slice to a visitor public land mobile network indicated by a first network identifier.

20. A communication system comprising: The terminal device sends a registration request for a first network slice, wherein the registration request includes a first set of identification information about at least one first network slice for which registration is requested in a registration area of ​​a home public land mobile network; as well as The communication device acquires first information about whether registration of a first network slice is allowed in a registration area of ​​a home public land mobile network based on the registration request, the first network slice being indicated by the identification information, and generates second information about a visitor public land mobile network that enables provision of the first network slice in an area overlapping with at least the registration area based on the first information, wherein In a case where the first information indicates that registration of the first network slice is permitted, the communication device includes information necessary for setting a registration period of the first network slice into the second information, In the case where the first information indicates that the registration of the first network slice is rejected, the communication device includes information necessary for re-registering the first network slice into the second information, and The terminal device receives the first information and the second information from the communication device.

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