Network node, method using network node, and program

Abstract

This network node includes a control unit. The control unit is configured to: store configuration data defining whether to allow switching of network slices; determine whether to switch the network slices on the basis of the configuration data; and switch the network slices from a first network slice to a second network slice in accordance with the determination.

Description

Network node, method and program using the network node CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on and claims the benefit of priority from Japanese Patent Application No. 2024-020766, filed February 15, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a network node, a method by the network node, and a program, and in particular to a network node, a method by the network node, and a program for controlling network slice switching.

[0003] The Third Generation Partnership Project (3GPP (registered trademark)) defines network slicing, a technology that virtually divides a network and controls traffic at a fine granularity for each application by implementing bandwidth restrictions and priority control.

[0004] A virtually divided network is called a network slice, and an identifier called S-NSSAI (Single-Network Slice Selection Assistance Information) is assigned to the network slice.

[0005] 3GPP TS 23.501 V18.4.0 (2023-12)

[0006] Non-Patent Document 1 describes network slice replacement. In network slice replacement, a specific network slice is switched to an alternative network slice. Network slice replacement is triggered by the S-NSSAI corresponding to the network slice before the switch becoming unavailable or congestion occurring in the network slice before the switch.

[0007] In network slice replacement, an alternative network slice is selected by the network. In other words, network slice replacement can be said to correspond to network controlled network slice selection.

[0008] Non-Patent Document 1 only describes that network slice replacement is performed in the above-mentioned cases, but does not describe controlling network slice selection by network control.

[0009] The present disclosure provides a technique for controlling network-controlled network slice selection based on pre-configured configuration data.

[0010] In order to achieve the above object, a network node according to an embodiment is a network node including a control unit, and the control unit is configured to store configuration data defining whether or not to allow switching of a network slice, determine whether or not to switch the network slice based on the configuration data, and switch the network slice from a first network slice to a second network slice in accordance with the determination.

[0011] Further, a method according to an embodiment is a method executed by a network node, and includes storing configuration data defining whether or not to allow switching of a network slice, determining whether or not to switch the network slice based on the configuration data, and switching the network slice from a first network slice to a second network slice in response to the determination.

[0012] According to the above configuration, it is possible to control the switching of network slices in accordance with configuration data that defines whether or not the switching of network slices is permitted. Note that the above configuration may achieve other effects instead of or in addition to the above effect.

[0013] 1 is a diagram illustrating the configuration of a communication system according to the first embodiment. 2 is a block diagram illustrating the physical configuration of a network node according to the first embodiment. 3 is a block diagram illustrating the logical configuration of a network node according to the first embodiment. 4 is a block diagram illustrating the physical configuration of a terminal device according to the first embodiment. 5 is a block diagram illustrating the logical configuration of a terminal device according to the first embodiment. 6 is a diagram illustrating an overview of a network slice according to the first embodiment. 7 is a flowchart illustrating a registration procedure according to the first embodiment. 8 is a flowchart illustrating a procedure for switching a network slice according to the first embodiment. 9 is a diagram illustrating network-controlled network slice selection-related subscription data according to the first embodiment. 10 is a flowchart illustrating a procedure for performing network slice selection according to the first embodiment. 11 is a flowchart illustrating a procedure for performing network slice selection according to the first embodiment. 12 is a diagram illustrating network-controlled network slice selection-related subscription data according to the second embodiment. 13 is a flowchart illustrating a procedure for performing network slice selection according to the second embodiment. 14 is a flowchart illustrating a procedure for performing network slice selection according to the third embodiment. 15 is a flowchart illustrating a procedure for performing network slice selection according to the fourth embodiment.

[0014] Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings. In this specification and drawings, elements that can be similarly described will be designated by the same reference numerals, and redundant description will be omitted.

[0015] Each embodiment described below is merely an example of a configuration that can realize this embodiment. Each embodiment described below can be modified or changed as appropriate depending on the configuration of the device to which this embodiment is applied and various conditions. Not all combinations of elements included in each embodiment described below are necessarily essential to realize this embodiment, and some elements can be omitted as appropriate. Therefore, the scope of this embodiment is not limited to the configurations described in each embodiment described below. As long as there are no mutual contradictions, a configuration that combines multiple configurations described in the embodiments described below can also be adopted.

[0016] 1. First Embodiment 1.1 Communication System The configuration of a communication system 1 according to an embodiment will be described with reference to FIG. 1 . As shown in FIG. 1 , the communication system 1 includes a network node 10, a terminal apparatus (Terminal Apparatus) 20, and a RAN node (Base Station Apparatus) 30. The network node 10 is connected to a data network (DN) 40. The DN 40 includes a network such as the Internet. The communication system 1 is configured in accordance with predetermined technical specifications (TS). For example, the communication system 1 may comply with technical specifications defined by 3GPP (e.g., 5G, 5G Advanced, 6G, etc.).

[0017] In the communication system 1, for example, communication is performed between each of the network nodes 10 described below in accordance with the 5G NR specification. Furthermore, communication is performed between the terminal device 20, the RAN node 30, and the network node 10. The section between the terminal device 20 and the RAN node 30 is a wireless section.

[0018] The network node 10 constitutes a core network. The network node 10 includes an Access and Mobility Management Function (AMF) 10a, a User Plane Function (UPF) 10b, a Unified Data Management (UDM) / Unified Data Repository (UDR) 10c, an Application Function (AF) 10d, a Network Slice Selection Function (NSSF) 10e, a Session Management Function (SMF) 10f, and a Policy Control Function (PCF) 10g.

[0019] The network nodes 10 are not limited to network nodes such as the AMF 10a described above, but may include other network nodes that are defined or will be defined in the 3GPP technical specifications. Furthermore, some of the network nodes 10, such as the AF 10d, do not necessarily constitute a core network. Such network nodes 10 are located outside the communication system 1 and communicate with network nodes 10 within the communication system 1 via the DN 40.

[0020] In the communication system 1, a user plane where user data is transmitted and received and a control plane where control data is transmitted and received are configured separately. That is, the communication system 1 supports C / U separation. The user plane is called the U-plane, and the control plane is called the C-plane.

[0021] The terminal device 20 may be a device that wirelessly communicates with the RAN node 30, and may be, for example, a user equipment (UE) that operates in accordance with the 3GPP 5G NR specifications, or may be any other device that is or will be defined in a 3GPP technical specification.

[0022] The terminal device 20 may be, for example, a mobile phone terminal such as a smartphone, a tablet terminal, a laptop PC, a communication module, a communication card, or an IoT device such as a surveillance camera or a robot. The terminal device 20 may be a vehicle (e.g., a car, a train, etc.) or a device provided therein. The terminal device 20 may be a transport vehicle other than a vehicle (e.g., a ship, an airplane, etc.) or a device provided therein. The terminal device 20 may be a sensor or a device provided therein. The terminal device 20 may also be referred to as a terminal, a mobile station, a mobile terminal, a mobile device, a mobile unit, a subscriber station, a subscriber terminal, a subscriber device, a subscriber unit, a wireless station, a wireless terminal, a wireless device, a wireless unit, a remote station, a remote terminal, a remote device, a remote unit, etc. The terminal device 20 may be a device adapted to one or more of enhanced Mobile Broadband (eMBB), Ultra-Reliable and Low Latency Communications (URLLC), and massive Machine Type Communications (mMTC).

[0023] The RAN node 30 forms a radio access network (RAN) and manages at least one cell. A cell constitutes the smallest unit of a communication area. For example, one cell belongs to one frequency (e.g., carrier frequency) and is composed of one component carrier. The term "cell" may represent wireless communication resources, or may represent a communication target of the terminal device 20. The RAN node 30 wirelessly communicates with the terminal device 20 located in its own cell in the U-plane and C-plane. In other words, the RAN node 30 terminates the U-plane protocol and the C-plane protocol for the terminal device 20.

[0024] The RAN node 30 communicates with the network node 10 in the U-plane and the C-plane. More specifically, the RAN node 30 connects to the AMF 10a via an NG-C interface (not shown) in the C-plane, and connects to the UPF 10b via an NG-U interface (not shown) in the U-plane.

[0025] The RAN node 30 may be, for example, a gNB that provides the terminal device 20 with a U-plane and a C-plane conforming to the 3GPP 5G NR specifications and connects to the 3GPP 5GC (5G Core Network). The RAN node 30 may also be any other device that is / will be defined in the 3GPP technical specifications.

[0026] Next, the physical configuration of the network node 10 will be described with reference to Fig. 2. As shown in Fig. 2, the network node 10 includes, as hardware elements, a processor 101, a memory 102, and a transceiver 103. The above-mentioned elements provided in the network node 10 are connected to each other by an internal bus. Note that the network node 10 may include hardware elements other than the elements shown in Fig. 2.

[0027] The processor 101 is a computing element that realizes various functions of the network node 10. The processor 101 may be a system-on-a-chip (SoC) that includes elements such as a central processing unit (CPU), a graphics processing unit (GPU), and a memory controller.

[0028] The memory 102 is configured by at least one storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), or a solid state drive (SSD). The memory 102 is an element that temporarily or permanently stores programs and data used to execute various processes in the network node 10. The programs include one or more instructions for operating the network node 10. The processor 101 implements the functions of the network node 10 by expanding and executing the programs stored in the memory 102 in the memory 102 and / or a system memory (not shown).

[0029] The transceiver 103 transmits and receives signals to and from other network nodes 10 and RAN nodes 30 .

[0030] Next, the logical configuration of the network node 10 will be described with reference to Fig. 3. As shown in Fig. 3, the network node 10 includes, as functional blocks, a control unit 110 and a communication unit 120. The communication unit 120 includes at least one transmission unit 111 and at least one reception unit 122.

[0031] The control unit 110 may include at least one processor 101 and at least one memory 102. In other words, the control unit 110 may be realized by the processor 101 and the memory 102. The control unit 110 executes various control processes in the network node 10. For example, the control unit 110 controls communication with other nodes (e.g., other network nodes 10 and RAN node 30) via the communication unit 120. That is, the control unit 110 controls transmission and reception of data / information / messages via the communication unit 120.

[0032] The communication unit 120 includes the transceiver 103. In other words, the communication unit 120 is realized by the transceiver 103. The communication unit 120 communicates with other network nodes 10 and RAN nodes 30 by transmitting and receiving signals to and from the other network nodes 10 and RAN nodes 30.

[0033] The control unit 110 operates to execute various processes of the network node 10 of this embodiment.

[0034] Next, the physical configuration of the terminal device 20 will be described with reference to Fig. 4. As shown in Fig. 4, the terminal device 20 includes, as hardware elements, a processor 201, a memory 202, an input / output interface 203, a transceiver 204, and an antenna 205. The above elements provided in the terminal device 20 are connected to each other by an internal bus. Note that the terminal device 20 may include hardware elements other than the elements shown in Fig. 4.

[0035] The processor 201 is a computing element that realizes various functions of the terminal device 20. The processor 201 may be a CPU, and may further include other processors such as a GPU.

[0036] The memory 202 is composed of at least one storage medium such as a RAM. The memory 202 is an element that temporarily or permanently stores programs and data used to execute various processes in the terminal device 20. The programs include one or more instructions for operating the terminal device 20. The processor 201 implements the functions of the terminal device 20 by expanding and executing the programs stored in the memory 202 in the memory 202 and / or a system memory (not shown).

[0037] The input / output interface 203 is an interface that receives operations on the terminal device 20 and supplies the operations to the processor 201, and presents various information to the user. The input / output interface 203 is, for example, a touch panel.

[0038] The transceiver 204 is a circuit that performs various signal processing to realize wireless communication, and includes a baseband processor and an RF circuit. The transceiver 204 transmits and receives wireless signals to and from the RAN node 30 via the antenna 205.

[0039] Next, the logical configuration of the terminal device 20 will be described with reference to Fig. 5. As shown in Fig. 5, the terminal device 20 includes, as functional blocks, a control unit 210 and a communication unit 220. The communication unit 220 includes at least one transmission unit 121 and at least one reception unit 122.

[0040] The control unit 210 may include at least one processor 201 and at least one memory 202. In other words, the control unit 210 may be realized by the processor 201 and the memory 202. The control unit 210 executes various control processes in the terminal device 20. For example, the control unit 210 controls wireless communication with the RAN node 30 via the communication unit 220. That is, the control unit 210 controls transmission and reception of data / information / messages via the communication unit 220.

[0041] The communication unit 220 includes the transceiver 204 and the antenna 205. In other words, the communication unit 220 is realized by the transceiver and the antenna 205. The communication unit 220 wirelessly communicates with the RAN node 30 by transmitting and receiving radio signals to and from the RAN node 30.

[0042] The control unit 210 operates to execute various processes of the terminal device 20 of this embodiment.

[0043] 1.2 Network Slices Next, an overview of network slices will be described with reference to Fig. 6. Each network slice is established by virtually dividing the network so that a terminal device 20 can communicate with a DN 40 via a RAN node 30 and a network node (UPF) 10. In a network slice, data is conveyed by establishing a protocol data unit (PDU) session between the terminal device 20 and the network node 10.

[0044] As shown in Figure 6, multiple network slices are established between the terminal device 20 and the network node 10. Each network slice is identified by an S-NSSAI.

[0045] The data format of the S-NSSAI includes a slice / service type (SST) and a slice differentiator (SD).

[0046] The SST defines the use of network slices and includes standard SSTs and individual SSTs. The standard SST defines eMBB, URLLC, Massive Internet of Things (MIoT), Vehicle to X (V2X), and High Performance Machine Type Communication (HMTC). The individual SST defines uses that can be freely set by operators. The SD is an identifier for separating multiple network slices in the same SST.

[0047] 1.3 Network Slice Registration The terminal device 20 holds an S-NSSAI applicable within a Public Land Mobile Network (PLMN). This S-NSSAI is called a Configured S-NSSAI. The terminal device 20 registers the S-NSSAI by executing a registration request to the AMF 10a. An overview of the registration procedure will be described with reference to FIG. 7.

[0048] The terminal device 20 transmits a registration request message to the RAN node 30 (step S701). The registration request message includes an S-NSSAI. This S-NSSAI is called a Requested S-NSSAI.

[0049] Next, the RAN node 30 selects an AMF 10a based on the Requested S-NSSAI and transmits a registration request message to the selected AMF 10a (step S702).

[0050] Next, the AMF 10a selects the UDM / UDR 10c and registers the S-NSSAI in the selected UDM / UDR 10c (step S703). This S-NSSAI is called a subscribed S-NSSAI. The subscribed S-NSSAI is stored in the UDM / UDR 10c as subscription data.

[0051] Next, the AMF 10a notifies the terminal device 20 of the registered S-NSSAI (step S704). This S-NSSAI is called an Allowed S-NSSAI.

[0052] In this way, the terminal device 20 can establish a PDU session corresponding to the network slice with the UPF 10b and communicate with the DN 40 through the established PDU session.

[0053] 1.4 Network-Controlled Network Slice Selection Non-Patent Document 1 describes network slice replacement. In network slice replacement, a specific network slice is switched to an alternative network slice. Network slice replacement is triggered by the S-NSSAI corresponding to the network slice before the switch becoming unavailable or congestion occurring in the network slice before the switch.

[0054] Switching a network slice refers to disconnecting the PDU session of the network slice currently being used by the terminal device 20, selecting an alternative network slice, and establishing a new PDU session for the alternative network slice. Hereinafter, the currently used network slice will be referred to as the "first network slice," and the alternative network slice will be referred to as the "second network slice."

[0055] For example, a case may be considered in which AF 10d requests to switch the network slice to meet the service requirements for an application managed by AF 10d. In such a case, for example, NSSF 10e selects a second network slice in response to a request from AF 10d. Then, SMF 10f disconnects the PDU session for the first network slice and establishes a PDU session for the second network slice. In this manner, the network slice is switched from the first network slice to the second network slice. An example of a procedure for switching the network slice will be described with reference to FIG. 8.

[0056] The AF 10d sends a network slice replacement request (Network Slice Switch Request) to the NSSF 10e / SMF 10f (step S801).

[0057] Next, the NSSF 10e selects a second network slice (step S802) by selecting one of the S-NSSAIs registered in the UDM / UDR 10c.

[0058] Next, the SMF 10f disconnects the PDU session established for the first network slice (step S803). Next, the SMF 10f establishes a PDU session for the second network slice selected in step S802 (step S804). In this way, the network slice is switched from the first network slice to the second network slice.

[0059] In both the case described with reference to FIG. 8 and the network slice replacement described in Non-Patent Document 1, a second network slice is selected by the network. Such network slice selection is referred to herein as network-controlled network slice selection. Note that possible triggers for performing network-controlled network slice selection include a request from AF 10d and the unavailability of S-NSSAI, but these are merely examples. Network-controlled network slice selection may also be performed in response to an event such as the occurrence of an emergency.

[0060] Since the network-controlled network slice selection disconnects the PDU session established for the first network slice, it will have some impact on the terminal device 20 using the first network slice. The technology described in Non-Patent Document 1 does not take into consideration the impact on the terminal device 20 of the network slice replacement.

[0061] For example, the number of users of a service that uses a specific network slice may suddenly increase, causing congestion in that network slice. In such a case, the application providing the service may request switching to another network slice, even if it tolerates a temporary network interruption due to disconnecting the PDU session. On the other hand, some terminal devices 20 may not tolerate a temporary network interruption. The technology described in Non-Patent Document 1 does not take such cases into consideration at all.

[0062] In this embodiment, network-controlled network slice selection is controlled based on preset configuration data. The configuration data is configured by adding a new data type to subscription data. In this embodiment, the terms "network slice selection," "network-controlled network slice selection," and "network slice switching" are used interchangeably.

[0063] A network node such as the NSSF 10e refers to the subscription data to determine whether to perform network-controlled network slice selection. Referring to Figure 9, data types added to the subscription data will be described.

[0064] A data type newly added to the subscription data is data for controlling network-controlled network slice selection. As shown in FIG. 9, the data type is, for example, network-controlled network slice selection related subscription data.

[0065] The network-controlled network slicing selection related subscription data includes three data fields: the first data field is a network-controlled network slicing selection allowed flag, the second data field is a service impact description, and the third data field is demanded service requirements.

[0066] The network-controlled network slice selection permission flag indicates whether it is permitted to perform network-controlled network slice selection. The network-controlled network slice selection permission flag may have values ​​such as "0: permitted" and "1: denied", for example.

[0067] The service impact description indicates the service impact that is tolerated (not tolerated) among the service impacts caused by switching the network slice. The service impact description may have values ​​such as "1: relaxed QoS parameters are not allowed" and "2: ssc mode 2 is allowed". "1: relaxed QoS parameters are not allowed" indicates that it is permitted to select only a second network slice that provides a Quality of Service (QoS) equivalent to that of the first network slice. "2: ssc mode 2 is allowed" indicates that it is permitted to perform network-controlled network slice selection only when the Session and Service Continuity (SSC) mode of the PDU session is 2.

[0068] The requested service requirement indicates a service requirement requested for the second network slice. The requested service requirement indicates, for example, a QoS value requested for each QoS parameter. The technical specifications defined by 3GPP define the QoS parameters shown in Table 1. The requested service requirement may have a combination of a value indicating a type of QoS parameter and a value indicating a corresponding QoS value, such as "1: packet delay budget" and "10 (ms)."

[0069] The data structure of the network-controlled network slice selection-related subscription data is merely an example, and data structures other than those described may be adopted. In particular, the service impact description described with reference to FIG. 9 is merely an example, and the service impact description may include specific numerical values ​​of the allowable service impact for the QoS parameters shown in Table 1.

[0070] Network-controlled network slice selection-related subscription data is stored together with the Subscribed S-NSSAI as subscription data when it is stored in the UDM / UDR 10c. That is, data for controlling the network-controlled network slice selection shown in FIG. 9 is stored in the UDM / UDR 10c for each terminal device 20 or each group of terminal devices 20. The subscription data is registered and managed for each terminal device 20. Alternatively, the subscription data may be registered and managed for each network slice or for each combination of a terminal device 20 and a network slice.

[0071] Next, an example of a procedure for performing network-controlled network slice selection according to this embodiment will be described with reference to FIG. 10. In this embodiment, it is assumed that network-controlled network slice selection is performed in response to a request from AF 10d. In the process shown in FIG. 10, whether or not to perform network-controlled network slice selection is determined based only on the network-controlled network slice selection permission flag included in the subscription data. Hereinafter, in the figure, the network slice is referred to as "NW-S."

[0072] The AF 10d sends a network slice switching request to the PCF 10g (step S1001). The network slice switching request includes at least an S-NSSAI for the first network slice used by the AF 10d and an ID (UE-ID) of the terminal device 20. It may also include an S-NSSAI for the second network slice.

[0073] Next, the PCF 10g acquires the subscription data stored in the UDM / UDR 10c based on the UE-ID included in the network slice switching request. Then, the PCF 10g determines whether to perform network slice selection for the terminal device 20 that recorded the subscription data, based on the value of the network-controlled network slice selection permission flag included in the subscription data (step S1002). This determination is made based on whether the value of the network-controlled network slice selection permission flag is "0: permitted" or "1: rejected." The subscription data may be acquired based on the S-NSSAI for the first network slice instead of the UE-ID. The subscription data may also be acquired based on a combination of the UE-ID and the S-NSSAI for the first network slice.

[0074] If it is determined in step S1002 that the network slice selection is not to be performed, the PCF 10g transmits a message indicating that the network slice selection is not to be performed to the AF 10d (step S1003). In this case, the process illustrated in FIG. 10 ends.

[0075] If it is determined in step S1002 that network slice selection is to be performed, the PCF 10g instructs the NSSF 10e to select a second network slice (step S1004).

[0076] In step S1005, the NSSF 10e selects a second network slice by selecting an S-NSSAI from among the S-NSSAIs registered in the UDM / UDR 10c.

[0077] Next, the SMF 10f disconnects the PDU session established for the first network slice (step S1006). The PDU session established for the first network slice refers to the PDU session established for the terminal device 20 managed by the AF 10d that requested switching the network slice.

[0078] Next, the SMF 10f establishes a PDU session for the second network slice selected in step S1005 (step S1007). The PDU session is established for the terminal device 20 whose PDU session was disconnected in step S1006.

[0079] The above-described procedure for disconnecting and establishing a PDU session is performed by the NSSF 10e, the AMF 10a, and the SMF 10f in cooperation with each other according to the existing network slice replacement procedure. This also applies to other embodiments described later. In this manner, a network-controlled network slice selection is performed, and the network slice is switched from the first network slice to the second network slice.

[0080] Next, another example of a procedure for performing network-controlled network slice selection according to this embodiment will be described with reference to Fig. 11. In the process shown in Fig. 11, in addition to the process shown in Fig. 10, whether or not to perform network-controlled network slice selection is determined based on a service impact description and / or requested service requirements included in the subscription data. Hereinafter, in the figure, service impact is abbreviated as "SI."

[0081] The AF 10d sends a network slice switching request to the PCF 10g / NSSF 10e (step S1101). The network slice switching request includes at least an S-NSSAI for the first network slice used by the AF 10d and the UE-ID of the terminal device 20. It may also include an S-NSSAI for the second network slice.

[0082] Next, the PCF 10g / NSSF 10e acquires the subscription data stored in the UDM / UDR 10c based on the UE-ID included in the network slice switching request. Then, the PCF 10g determines whether to perform network slice selection for the terminal device 20 that recorded the subscription data based on the value of the network-controlled network slice selection permission flag included in the subscription data (step S1102). The subscription data may be acquired based on the S-NSSAI for the first network slice instead of the UE-ID. The subscription data may also be acquired based on a combination of the UE-ID and the S-NSSAI for the first network slice.

[0083] If it is determined in step S1102 that the network slice selection is not to be performed, the PCF 10g / NSSF 10e transmits a message indicating that the network slice selection is not to be performed to the AF 10d (step S1103). In this case, the process illustrated in FIG. 11 ends.

[0084] If it is determined in step S1102 that network slice selection is to be performed, the PCF 10g / NSSF 10e determines whether or not to allow a service impact according to the value of the service impact description included in the subscription data, and determines whether or not to perform network slice selection (step S1104). For example, if the service impact description indicates "2: ssc mode 2 is allowed," the PCF 10g / NSSF 10e determines to perform network slice selection only when the SSC mode of the PDU session is 2. Then, the PCF 10g / NSSF 10e selects a second network slice.

[0085] Furthermore, in the determination in step S1104, the PCF 10g / NSSF 10e may discover a second network slice that tolerates the service impact indicated by the value of the service impact description. For example, if the service impact description indicates "1: relaxed QoS parameters are not allowed," the PCF 10g / NSSF 10e discovers a second network slice that provides a QoS equivalent to the QoS of the first network slice. This discovery is performed by selecting an S-NSSAI from among the S-NSSAIs registered in the UDM / UDR 10c.

[0086] To find a second network slice that provides a QoS equivalent to that of the first network slice, QoS values ​​corresponding to the QoS provided by each network slice may be stored in the UDM / UDR 10c. The QoS values ​​may be stored as a QoS list in association with the S-NSSAI for each network slice for the QoS parameters shown in Table 1. Table 2 shows an example of a QoS list.

[0087] By storing the QoS list in the UDM / UDR 10c, a second network slice that provides a QoS equivalent to that of the first network slice can be appropriately discovered. Also, by storing the QoS list in the UDM / UDR 10c, the above discovery can be performed at a detailed QoS level.

[0088] By storing the QoS list, the service impact description can have a value indicating, for example, "3: packet delay budget within 10 ms is allowed" in addition to the above example. If the service impact description indicates "3: packet delay budget within 10 ms is allowed", a second network slice that provides a packet delay budget within 10 milliseconds is discovered.

[0089] Furthermore, by storing the QoS list, the service impact description can have a value indicating, for example, "4: packet delay budget within 10 ms after replacement is allowed" in addition to the above example. If the service impact description indicates "4: packet delay budget within 10 ms after replacement is allowed", a second network slice is discovered in which the difference between the packet delay budget provided by the first network slice and the packet delay budget provided by the second network slice is within 10 milliseconds.

[0090] In the determination in step S1104, in addition to or instead of the service impact description, the PCF 10g / NSSF 10e may find a second network slice that satisfies the values ​​of the requested service requirements included in the subscription data. For example, if the requested service requirements indicate "1: packet delay budget" and "10 (ms)," the PCF 10g / NSSF 10e finds a second network slice that satisfies the service requirements.

[0091] The service impact description indicates the numerical value and / or conditions of the acceptable impact of the service impact caused by switching to the second network slice. The requested service requirements indicate the numerical value and / or conditions of the requested service requirements. The PCF 10g / NSSF 10e finds the second network slice by referring to the QoS list based on any of the numerical value and / or conditions.

[0092] If it is determined in step S1104 that the network slice selection is not to be performed, the PCF 10g / NSSF 10e transmits a message indicating that the network slice selection is not to be performed to the AF 10d (step S1105). In this case, the process illustrated in FIG. 11 ends.

[0093] If it is determined in step S1104 that network slice selection is to be performed, the PCF 10g / NSSF 10e selects a second network slice (step S1106).

[0094] Next, the SMF 10f disconnects the PDU session established for the first network slice (step S1107). The PDU session established for the first network slice refers to the PDU session established for the terminal device 20 managed by the AF 10d that requested switching the network slice.

[0095] Next, the SMF 10f establishes a PDU session for the second network slice selected in step S1106 (step S1108). The PDU session is established for the terminal device 20 whose PDU session was disconnected in step S1107. In this way, network-controlled network slice selection is performed, and the network slice is switched from the first network slice to the second network slice.

[0096] In the present embodiment, an example in which a new data type is added to subscription data has been described. However, the new data type is not limited to subscription data and may be added to application data or other data. The application data is data stored in the UDM / UDR 10c by the AF 10d. In this case, whether to perform network-controlled network slice selection for each application is determined, and service impact and / or service requirements are determined.

[0097] That is, configuration data for controlling network slice selection may be stored in a data management system / repository used in the core network, such as a UDM / UDR 10c. The configuration data may be stored for each terminal device 20 or a group of terminal devices 20. In this case, the configuration data is stored as subscription data. The configuration data may also be stored for each application. In this case, the configuration data is stored as application data.

[0098] Furthermore, the configuration data may be stored per network slice, where it is determined whether to perform network-controlled network slice selection for each network slice, and service impact and / or service requirements are determined. Still further, the configuration data may be stored per DNN, where it is determined whether to perform network-controlled network slice selection for each DNN, and service impact and / or service requirements are determined.

[0099] As described above, the first embodiment has been described. In the first embodiment, whether or not to perform network-controlled network slice selection is controlled according to configuration data set by a terminal device, an application, a network slice, and / or a DNN that uses the network slice.

[0100] According to the first embodiment, whether to perform network-controlled network slice selection is determined taking into account the impact on terminal devices, applications, network slices, and / or DNNs.

[0101] In the first embodiment, the PCF 10g determines whether to perform network-controlled network slice selection, but the PCF 10g is merely an example. The procedure described in the first embodiment is executed by one or more of the network nodes 10.

[0102] 2. Second Embodiment Next, a second embodiment will be described. In the second embodiment, whether or not to perform network-controlled network slice selection is determined based on the procedure described in the first embodiment, and the use of the network slice is taken into consideration in the determination.

[0103] As described above, the data format of the S-NSSAI includes an SST and an SD. The SST specifies the use of a network slice. The SD is an identifier for separating multiple network slices in the same SST.

[0104] In the second embodiment, whether to perform network-controlled network slice selection is determined for each network slice application. With reference to Figure 12, the data types to be added to the subscription data are described.

[0105] 12 shows network-controlled network slice selection-related subscription data according to the second embodiment. The network-controlled network slice selection-related subscription data shown in FIG. 12 corresponds to the network-controlled network slice selection-related subscription data shown in FIG. 9.

[0106] As shown in Figure 12, the network-controlled network slice selection allowance flag, service impact description, and requested service requirements are defined for each network slice application. Note that the three data fields are the same as the data fields described with reference to Figure 9, so detailed description will be omitted.

[0107] Data fields such as the network-controlled network slice selection permission flag shown in Fig. 12 are defined corresponding to the SST in the S-NSSAI. The SST includes a standard SST and an individual SST.

[0108] Next, an example of a procedure for performing network-controlled network slice selection according to the second embodiment will be described with reference to Fig. 13. In the second embodiment, network-controlled network slice selection is also performed in response to a request from AF 10d. In the process shown in Fig. 13, whether or not to perform network-controlled network slice selection is determined based only on a network-controlled network slice selection permission flag included in the subscription data.

[0109] The AF 10d sends a network slice switching request to the PCF 10g (step S1301). The network slice switching request includes at least an S-NSSAI for the first network slice used by the AF 10d and the UE-ID of the terminal device 20. It may also include an S-NSSAI for the second network slice.

[0110] Next, the PCF 10g acquires the subscription data stored in the UDM / UDR 10c based on the UE-ID included in the network slice switching request. Then, the PCF 10g determines whether to perform network slice selection for the terminal device 20 that recorded the subscription data, based on the value of the network-controlled network slice selection permission flag corresponding to the SST in the S-NSSAI (step S1302). This determination is made based on whether the value of the network-controlled network slice selection permission flag is "0: permitted" or "1: rejected." The subscription data may be acquired based on the S-NSSAI for the first network slice instead of the UE-ID. The subscription data may also be acquired based on a combination of the UE-ID and the S-NSSAI for the first network slice.

[0111] If it is determined in step S1302 that the network slice selection is not to be performed, the PCF 10g transmits a message indicating that the network slice selection is not to be performed to the AF 10d (step S1303). In this case, the process illustrated in FIG. 10 ends.

[0112] If it is determined in step S1302 that network slice selection is to be performed, the PCF 10g instructs the NSSF 10e to select a second network slice (step S1304).

[0113] In step S1305, the NSSF 10e selects a second network slice by selecting an S-NSSAI from among the S-NSSAIs registered in the UDM / UDR 10c.

[0114] Next, the SMF 10f disconnects the PDU session established for the first network slice (step S1306). The PDU session established for the first network slice refers to the PDU session established for the terminal device 20 managed by the AF 10d that requested switching the network slice.

[0115] Next, the SMF 10f establishes a PDU session for the second network slice selected in step S1305 (step S1307). The PDU session is established for the terminal device 20 whose PDU session was disconnected in step S1306. In this way, network-controlled network slice selection is performed based on the definition of each network slice application, and the network slice is switched from the first network slice to the second network slice.

[0116] Next, another example of a procedure for performing network-controlled network slice selection according to the second embodiment will be described with reference to Fig. 14. In the process shown in Fig. 14, in addition to the process shown in Fig. 13, whether or not to perform network-controlled network slice selection is determined based on a service impact description and / or requested service requirements included in the subscription data.

[0117] The AF 10d sends a network slice switching request to the PCF 10g / NSSF 10e (step S1401). The network slice switching request includes at least an S-NSSAI for the first network slice used by the AF 10d and the UE-ID of the terminal device 20. It may also include an S-NSSAI for the second network slice.

[0118] Next, the PCF 10g / NSSF 10e acquires the subscription data stored in the UDM / UDR 10c based on the UE-ID included in the network slice switching request. Then, the PCF 10g determines whether to perform network slice selection for the terminal device 20 that recorded the subscription data based on the value of the network-controlled network slice selection permission flag corresponding to the SST in the S-NSSAI (step S1402). The subscription data may be acquired based on the S-NSSAI for the first network slice instead of the UE-ID. The subscription data may also be acquired based on a combination of the UE-ID and the S-NSSAI for the first network slice.

[0119] If it is determined in step S1402 that the network slice selection is not to be performed, the PCF 10g / NSSF 10e transmits a message indicating that the network slice selection is not to be performed to the AF 10d (step S1403). In this case, the process illustrated in FIG. 14 ends.

[0120] If it is determined in step S1402 that network slice selection is to be performed, the PCF 10g / NSSF 10e determines whether to tolerate a service impact according to the value of the service impact description corresponding to the SST in the S-NSSAI, and determines whether to perform network slice selection (step S1404). In addition, in the determination in step S1404, the PCF 10g / NSSF 10e may select a second network slice that tolerates the service impact indicated by the value of the service impact description.

[0121] In the determination in step S1404, in addition to or instead of the service impact description, the PCF 10g / NSSF 10e may select a second network slice that satisfies the value of the requested service requirement corresponding to the SST in the S-NSSAI.

[0122] If it is determined in step S1404 that the network slice selection is not to be performed, the PCF 10g / NSSF 10e transmits a message indicating that the network slice selection is not to be performed to the AF 10d (step S1405). In this case, the process illustrated in FIG. 14 ends.

[0123] If it is determined in step S1404 that network slice selection is to be performed, the PCF 10g / NSSF 10e selects a second network slice (step S1406).

[0124] Next, the SMF 10f disconnects the PDU session established for the first network slice (step S1407). The PDU session established for the first network slice refers to the PDU session established for the terminal device 20 managed by the AF 10d that requested switching the network slice.

[0125] Next, the SMF 10f establishes a PDU session for the second network slice selected in step S1406 (step S1408). The PDU session is established for the terminal device 20 whose PDU session was disconnected in step S1407. In this way, network-controlled network slice selection is performed based on the definition of each network slice application, and the network slice is switched from the first network slice to the second network slice.

[0126] As described above, the second embodiment has been described. In the second embodiment, whether or not to perform network-controlled network slice selection is controlled according to configuration data set for each application of the network slice.

[0127] According to the second embodiment, whether to perform network-controlled network slice selection is determined taking into account the impact on terminal devices, applications, network slices, and / or DNNs, depending on the application of the network slice.

[0128] 3. Third Embodiment Next, a third embodiment will be described. In the first and second embodiments, examples have been described in which a second network slice that tolerates the service impact indicated by the value of the service impact description and a second network slice that satisfies the value of the requested service requirement are selected. In the third embodiment, network slice selection is repeated until a second network slice that tolerates the service impact indicated by the value of the service impact description is found.

[0129] Another example of the procedure for performing network-controlled network slice selection according to the third embodiment will be described with reference to FIG. 15 . In the third embodiment, network-controlled network slice selection is also performed in response to a request from the AF 10d. In the process shown in FIG. 15 , a network slice is selected based on a service impact description and / or requested service requirements included in the subscription data. This selection is performed by selecting one of the S-NSSAIs registered in the UDM / UDR 10c.

[0130] The AF 10d sends a network slice switching request to the PCF 10g / NSSF 10e (step S1501). The network slice switching request includes at least an S-NSSAI for the first network slice used by the AF 10d and the UE-ID of the terminal device 20. It may also include an S-NSSAI for the second network slice.

[0131] Next, the PCF 10g / NSSF 10e acquires the subscription data stored in the UDM / UDR 10c based on the UE-ID included in the network slice switching request. Then, the PCF 10g determines whether to perform network slice selection for the terminal device 20 that recorded the subscription data based on the value of the network-controlled network slice selection permission flag included in the subscription data (step S1502). The subscription data may be acquired based on the S-NSSAI for the first network slice instead of the UE-ID. The subscription data may also be acquired based on a combination of the UE-ID and the S-NSSAI for the first network slice.

[0132] If it is determined in step S1502 that the network slice selection is not to be performed, the PCF 10g / NSSF 10e transmits a message indicating that the network slice selection is not to be performed to the AF 10d (step S1503). In this case, the process illustrated in FIG. 15 ends.

[0133] If it is determined in step S1502 that network slice selection is to be performed, the PCF 10g / NSSF 10e selects a network slice as the second network slice. Then, the PCF 10g / NSSF 10e determines whether the selected network slice is a network slice that tolerates the service impact indicated by the value of the service impact description included in the subscription data (step S1504).

[0134] As described above, the UDM / UDR 10c stores QoS values ​​for each network slice as a QoS list. The PCF 10g / NSSF 10e can refer to the QoS list based on the selected S-NSSAI and determine whether the network slice corresponding to the selected S-NSSAI is a network slice that allows service impact.

[0135] In the determination in step S1504, the PCF 10g / NSSF 10e may determine whether the selected network slice is a network slice that satisfies the values ​​of the requested service requirements included in the subscription data.

[0136] If the result of the determination in step S1504 is that the selected network slice is not a network slice that tolerates the service impact / satisfies the requested service requirements, the process of step S1504 is repeated until it is determined that the selected network slice is a network slice that tolerates the service impact / satisfies the requested service requirements.

[0137] The process of step S1504 may be repeated a preset number of times. The preset number of times may be stored in the UDM / UDR 10c, similar to the network control network slice selection permission flag.

[0138] If the result of the determination in step S1504 is that the selected network slice is a network slice that tolerates the service impact / satisfies the requested service requirements, the PCF 10g / NSSF 10e selects the determined network slice as the second network slice (step S1505).

[0139] Next, the SMF 10f disconnects the PDU session established for the first network slice (step S1506). The PDU session established for the first network slice refers to the PDU session established for the terminal device 20 managed by the AF 10d that requested switching the network slice.

[0140] Next, the SMF 10f establishes a PDU session for the second network slice selected in step S1505 (step S1507). The PDU session is established for the terminal device 20 whose PDU session was disconnected in step S1506. In this way, network-controlled network slice selection is performed, and the network slice is switched from the first network slice to the second network slice.

[0141] As described in the second embodiment, the network-controlled network slice selection permission flag in step S1503 may be defined for each use of the network slice. Similarly, the service impact description and the requested service requirements in step S1503 may also be defined for each use of the network slice.

[0142] As described above, the third embodiment has been described. In the third embodiment, network slice selection is repeated until a network slice that tolerates service impact / satisfies requested service requirements is found.

[0143] According to the third embodiment, the possibility of switching to a network slice that can tolerate service impact / meet the requested service requirements is increased.

[0144] 4. Fourth Embodiment Next, a fourth embodiment will be described. Whether to perform network control network slice selection is determined based on the procedures described in the first to third embodiments, and the determination takes into account the case where the second network slice is in use.

[0145] An example of a procedure for performing network-controlled network slice selection according to the fourth embodiment will be described with reference to Figure 16. In the fourth embodiment, network-controlled network slice selection is also performed in response to a request from AF 10d. In the process shown in Figure 14, whether or not to perform network-controlled network slice selection is determined based only on the network-controlled network slice selection permission flag included in the subscription data.

[0146] The AF 10d sends a network slice switching request to the PCF 10g (step S1601). The network slice switching request includes at least an S-NSSAI for the first network slice used by the AF 10d and the UE-ID of the terminal device 20. It may also include an S-NSSAI for the second network slice.

[0147] Next, the PCF 10g acquires the subscription data stored in the UDM / UDR 10c based on the UE-ID included in the network slice switching request. Then, the PCF 10g determines whether to perform network slice selection for the terminal device 20 that recorded the subscription data, based on the value of the network-controlled network slice selection permission flag included in the subscription data (step S1602). This determination is made based on whether the value of the network-controlled network slice selection permission flag is "0: permitted" or "1: rejected." The subscription data may be acquired based on the S-NSSAI for the first network slice instead of the UE-ID. The subscription data may also be acquired based on a combination of the UE-ID and the S-NSSAI for the first network slice.

[0148] If it is determined in step S1602 that the network slice selection is not to be performed, the PCF 10g transmits a message indicating that the network slice selection is not to be performed to the AF 10d (step S1603). In this case, the process illustrated in FIG. 16 ends.

[0149] If it is determined in step S1602 that network slice selection is to be performed, the PCF 10g instructs the NSSF 10e to select a second network slice (step S1604).

[0150] In step S1605, the NSSF 10e selects a second network slice by selecting an S-NSSAI from among the S-NSSAIs registered in the UDM / UDR 10c.

[0151] Next, the PCF 10g acquires the subscription data stored in the UDM / UDR 10c based on the UE-ID. Then, the PCF 10g determines whether to perform network slice selection for the terminal device 20 that recorded the subscription data, based on the value of the network-controlled network slice selection permission flag included in the subscription data (step S1606). This determination is made based on whether the value of the network-controlled network slice selection permission flag is "0: permitted" or "1: rejected." Note that, in step S1606, the subscription data may be acquired based on the S-NSSAI selected in step S1605, instead of the UE-ID. Alternatively, the subscription data may be acquired based on a combination of the UE-ID and the selected S-NSSAI.

[0152] If it is determined in step S1606 that the network slice selection is not to be performed, the PCF 10g transmits a message indicating that the network slice selection is not to be performed to the AF 10d (step S1607). In this case, the process illustrated in FIG. 16 ends.

[0153] If it is determined in step S1606 that network slice selection is to be performed, the SMF 10f disconnects the PDU session established for the first network slice (step S1608). The PDU session established for the first network slice refers to the PDU session established for the terminal device 20 managed by the AF 10d that requested switching the network slice.

[0154] Next, the SMF 10f establishes a PDU session for the second network slice selected in step S1605 (step S1609). The PDU session is established for the terminal device 20 whose PDU session was disconnected in step S1608. In this way, network-controlled network slice selection is performed based on the definition of each network slice application, and the network slice is switched from the first network slice to the second network slice.

[0155] The determination in step S1606 may be based on the service impact description and / or the requested service requirements included in the subscription data. The network-controlled network slice selection allowance flag in step S1606 may be defined for each use of the network slice. Similarly, the service impact description and the requested service requirements may also be defined for each use of the network slice.

[0156] The fourth embodiment has been described above. In the fourth embodiment, whether or not to perform network slice selection under network control is controlled according to configuration data set by a terminal device using a second network slice. The configuration data may be defined for each application, network slice, and / or DNN.

[0157] According to the fourth embodiment, when a terminal device or the like is using the second network slice to be switched to, the decision as to whether to perform network control network slice selection is made taking into consideration the impact on the terminal device or the like.

[0158] 5. Modifications Although the form for carrying out the present embodiment has been described above, the present embodiment is not limited to the above-described embodiment. It is naturally understood that the above-described embodiment is merely an example, and various modifications are possible.

[0159] The words, phrases, and other expressions used in the above embodiments are merely examples and may be replaced with substantially identical or similar expressions. In particular, since the technology according to the above embodiments relates to technical specifications, the expressions in the above embodiments may be replaced with substantially identical or similar expressions in technical specifications (e.g., technical specifications cited in this specification).

[0160] The information transmitted and received in the above embodiment may be contained in the same or a different message or element already described in the technical specifications, or may be contained in a newly defined message or element. The information transmitted and received in the above embodiment may be transmitted and received using a different layer and / or a different channel than those in the above embodiment.

[0161] The means and / or functions provided by the devices described in the above embodiments can be provided by software recorded in a tangible memory device and a computer that executes the software, software alone, hardware alone, or a combination thereof. For example, if any of the above devices is provided by an electronic circuit that is hardware, it can be provided by a digital circuit including a large number of logic circuits, or an analog circuit.

[0162] The device described in the above embodiment executes a program stored in a non-transitory tangible storage medium, and the execution of the program executes a method corresponding to the program.

[0163] 6. Supplementary Notes Some or all of the above embodiments and modified examples may also be described as, but are not limited to, the following supplementary notes. Below, a relationship is expressed in which a supplementary note that is dependent on multiple supplementary notes is dependent on another supplementary note that is dependent on multiple supplementary notes. All of the dependency relationships of the supplementary notes expressed below are included in the above embodiments.

[0164] (Supplementary Note 1) A network node including a control unit, wherein the control unit is configured to: store configuration data defining whether or not to allow switching of a network slice; determine whether or not to switch the network slice based on the configuration data; and switch the network slice from a first network slice to a second network slice in accordance with the determination.

[0165] (Supplementary Note 2) The network node according to Supplementary Note 1, wherein the configuration data includes data on acceptable / unacceptable service impacts caused by switching the network slice.

[0166] (Supplementary Note 3) The network node according to Supplementary Note 2, wherein the data on service impact includes data on acceptable service impact for QoS parameters.

[0167] (Supplementary Note 4) The network node according to Supplementary Note 2 or 3, wherein the control unit is further configured to select, as the second network slice, a network slice that tolerates the service impact based on the configuration data.

[0168] (Supplementary Note 5) The network node according to any one of Supplementary Notes 1 to 4, wherein the configuration data includes data on service requirements requested of the second network slice.

[0169] (Supplementary Note 6) The network node according to Supplementary Note 5, wherein the data on service requirements includes data on service requirements requested of the second network slice for QoS parameters.

[0170] (Supplementary Note 7) The network node according to Supplementary Note 5 or 6, wherein the control unit is further configured to select, based on the configuration data, a network slice that satisfies the service requirements as the second network slice.

[0171] (Supplementary Note 8) The network node according to any one of Supplementary Notes 1 to 7, wherein the configuration data is stored as subscription data together with an S-NSSAI corresponding to the first network slice.

[0172] (Supplementary Note 9) The network node according to any one of Supplementary Notes 1 to 7, wherein the configuration data is stored on a per-application basis.

[0173] (Supplementary Note 10) The network node according to any one of Supplementary Notes 1 to 7, wherein the configuration data is stored per network slice.

[0174] (Supplementary Note 11) The network node according to any one of Supplementary Notes 1 to 7, wherein the configuration data is stored per DNN.

[0175] (Supplementary Note 12) The network node according to any one of Supplementary Notes 1 to 11, wherein the configuration data is stored for each use of a network slice.

[0176] (Supplementary Note 13) The network node according to Supplementary Note 12, wherein the control unit is further configured to determine whether to switch the network slice based on the configuration data in accordance with an application of the first network slice.

[0177] (Supplementary Note 14) The network node according to Supplementary Note 13, wherein the control unit is further configured to determine the usage from an S-NSSAI corresponding to the first network slice.

[0178] (Supplementary Note 15) The network node according to Supplementary Note 4, wherein the control unit is further configured to select a network slice that tolerates the service impact as the second network slice by selecting one S-NSSAI from among registered S-NSSAIs.

[0179] (Supplementary Note 16) The network node according to Supplementary Note 15, wherein the control unit repeats selecting the S-NSSAI until a network slice that tolerates the service impact is found.

[0180] (Supplementary Note 17) The network node according to Supplementary Note 7, wherein the control unit is further configured to select a network slice that satisfies the service requirements as the second network slice by selecting one S-NSSAI from among registered S-NSSAIs.

[0181] (Supplementary Note 18) The network node according to Supplementary Note 17, wherein the control unit repeats selecting the S-NSSAI until it finds a network slice that satisfies the service requirements.

[0182] (Supplementary Note 19) The network node according to any one of Supplementary Notes 1 to 18, wherein the control unit is further configured to determine whether to switch the network slice based on configuration data for the first network slice, and to determine whether to switch the network slice based on configuration data for the second network slice.

[0183] (Supplementary Note 20) A method executed by a network node, comprising: storing configuration data defining whether or not to allow switching of a network slice; determining whether or not to switch the network slice based on the configuration data; and switching the network slice from a first network slice to a second network slice in response to the determination.

[0184] (Supplementary Note 21) A program that, when executed, causes a processor in a network node to: store configuration data defining whether or not to allow switching of a network slice; determine whether or not to switch the network slice based on the configuration data; and switch the network slice from a first network slice to a second network slice in accordance with the determination.

[0185] (Supplementary Note 22) A computer-readable non-transient tangible recording medium storing a program that, when executed, causes a processor in a network node to perform the following: store configuration data defining whether or not to allow switching of a network slice; determine whether or not to switch the network slice based on the configuration data; and switch the network slice from a first network slice to a second network slice in accordance with the determination.

[0186] (Supplementary Note 23) A terminal device including a control unit and a communication unit, wherein the control unit is configured to register configuration data in a network node defining whether or not to allow switching of a network slice, the configuration data being used by the network node to determine whether or not to switch the network slice, and the communication unit is configured to communicate with a data network using a second network slice switched from a first network slice in accordance with the determination.

[0187] The disclosures of the above prior art documents and references are incorporated herein by reference.

[0188] 10 Network node, 101 Processor, 102 Memory, 103 Transceiver, 110 Control unit, 120 Communication unit, 20 Terminal device, 201 Processor, 202 Memory, 203 Input / output interface, 204 Transceiver, 205 Antenna, 210 Control unit, 220 Communication unit, 30 RAN node, 40 DN

Claims

1. A network node including a control unit, wherein the control unit is configured to: store configuration data defining whether or not to allow switching of a network slice; determine whether or not to switch the network slice based on the configuration data; and switch the network slice from a first network slice to a second network slice in accordance with the determination.

2. The network node according to claim 1, wherein the configuration data includes data regarding acceptable / unacceptable service impacts caused by switching the network slice.

3. A network node according to claim 2, wherein the data on service impact includes data on acceptable service impact for QoS parameters.

4. The network node according to claim 2, wherein the control unit is further configured to select, based on the configuration data, a network slice that tolerates the service impact as the second network slice.

5. The network node of claim 1, wherein the configuration data includes data regarding service requirements requested from the second network slice.

6. The network node according to claim 5, wherein the data on service requirements includes data on service requirements requested of the second network slice for QoS parameters.

7. The network node according to claim 5, wherein the control unit is further configured to select, based on the configuration data, a network slice that satisfies the service requirements as the second network slice.

8. The network node of claim 1, wherein the configuration data is stored as subscription data together with an S-NSSAI corresponding to the first network slice.

9. The network node of claim 1, wherein the configuration data is stored on a per-application basis.

10. The network node of claim 1, wherein the configuration data is stored per network slice.

11. The network node of claim 1, wherein the configuration data is stored per DNN.

12. The network node of claim 1, wherein the configuration data is stored for each use of a network slice.

13. The network node of claim 12, wherein the control unit is further configured to determine whether to switch the network slice based on the configuration data in accordance with the intended use of the first network slice.

14. A method executed by a network node, comprising: storing configuration data defining whether or not to allow switching of a network slice; determining whether or not to switch the network slice based on the configuration data; and switching the network slice from a first network slice to a second network slice in response to the determination.

15. A program that, when executed, causes a processor in a network node to: store configuration data defining whether or not to allow switching of a network slice; determine whether or not to switch the network slice based on the configuration data; and switch the network slice from a first network slice to a second network slice in response to the determination.

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