Network node, network node based method, and program

Abstract

The network node includes a control section and a communication section. The communication section is configured to receive a message requesting a switch of a network slice used by a terminal device from a first network slice to a second network slice, and the control section is configured to determine whether a predefined condition is satisfied and, when the condition is satisfied, switch the network slice from the first network slice to the second network slice.

Description

Cross-references of related applications

[0001] This application is based on and claims priority to Japanese Application No. 2024-041940, filed on March 18, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to a network node, a method and program based on a network node, and more particularly to a network node, a method and program based on a network node for reserving a network slice and switching to the reserved network slice. Background Technology

[0003] The Third Generation Partnership Project (3GPP) defines network slicing. Network slicing is a technology that uses virtual segmentation of the network to implement bandwidth limiting and priority control, thereby enabling fine-grained control of services for each application.

[0004] The network that is virtually segmented is called a network slice. Network slices are assigned an identifier called S-NSSAI (Single-Network Slice Selection Assistance Information). Existing technical documents Non-patent literature

[0005] Non-patent literature 1: 3GPP TS 28.531 V18.3.0 (2023-09) Summary of the Invention

[0006] Non-Patent Document 1 describes a network slice reservation procedure. In the network slice reservation procedure described in Non-Patent Document 1, during provisioning, the network slice subnet management service provider reserves resources.

[0007] Non-patent document 1 only describes reserving resources corresponding to the network slice subnet during configuration, but does not describe reserving the network slice that is currently in use and switching to the reserved network slice.

[0008] This disclosure provides a technique for reserving a network slice that is currently in use and switching to a reserved network slice.

[0009] To achieve the above objectives, the network node involved in the implementation includes a control unit and a communication unit. The communication unit is configured to receive a message requesting the switching of the network slice used by the terminal device from the first network slice to the second network slice. The control unit is configured to determine whether a predefined condition is met, and when the condition is met, to switch the network slice from the first network slice to the second network slice.

[0010] Furthermore, the method involved in the implementation is a method executed by a network node, the method comprising: receiving a message requesting to switch the network slice used by the terminal device from a first network slice to a second network slice; determining whether a predefined condition is met; and when the aforementioned condition is met, switching the aforementioned network slice from the aforementioned first network slice to the aforementioned second network slice.

[0011] Based on the above configuration, the use of the network slice being used can be ensured. Furthermore, the above configuration can be used to replace this effect or to achieve other effects in conjunction with it. Attached Figure Description

[0012] Figure 1 This is a diagram illustrating the configuration of the communication system according to the first embodiment. Figure 2 This is a block diagram illustrating the physical configuration of the network nodes according to the first embodiment. Figure 3 This is a block diagram illustrating the logical configuration of the network nodes involved in the first embodiment. Figure 4 This is a block diagram illustrating the physical configuration of the terminal device according to the first embodiment. Figure 5 This is a block diagram illustrating the logical configuration of the terminal device according to the first embodiment. Figure 6 This is a diagram illustrating an outline of the network slices involved in the first embodiment. Figure 7 This is a flowchart illustrating the registration process involved in the first embodiment. Figure 8 This is a flowchart illustrating the process of switching network slices according to the first embodiment. Figure 9 This is a flowchart illustrating the process of reserving network slices according to the first embodiment. Figure 10 This is a diagram illustrating the reserved data involved in the first embodiment. Figure 11 This is a flowchart illustrating the process of switching network slices according to the first embodiment. Figure 12 This is a flowchart illustrating the process of reserving network slices according to the second embodiment. Figure 13 This is a diagram illustrating the reserved data involved in the second embodiment. Figure 14 This is a flowchart illustrating the process of switching network slices according to the second embodiment. Figure 15 This is a flowchart illustrating the process of switching network slices according to the third embodiment. Detailed Implementation

[0013] Hereinafter, embodiments of this embodiment will be described in detail with reference to the accompanying drawings. Furthermore, in this specification and the accompanying drawings, elements that can be described in the same way are labeled with the same reference numerals, and repeated descriptions can be omitted.

[0014] The embodiments described below are merely examples of configurations that can implement this embodiment. The embodiments described below can be appropriately modified or changed depending on the configuration of the apparatus to which this embodiment is applied and various conditions. Not all combinations of elements included in the embodiments described below are necessary to implement this embodiment, and some elements can be appropriately omitted. Therefore, the scope of this embodiment is not limited to the configurations described in the embodiments described below. Configurations combining multiple configurations described in the embodiments described below can also be used, provided they do not contradict each other.

[0015] 1. First Implementation Method 1.1 Communication System Reference Figure 1 This describes the configuration of the communication system 1 involved in the implementation method. For example... Figure 1 As shown, the communication system 1 includes a network node 10, a terminal apparatus 20, and a RAN node (base station apparatus) 30. The network node 10 is connected to a data network (DN) 40. DN 40 includes networks such as the Internet. The communication system 1 is configured according to predetermined technical specifications (TS). For example, the communication system 1 may comply with the technical specifications defined by 3GPP (e.g., 5G, 5G evolution, and 6G).

[0016] In communication system 1, for example, communication is performed between the various network nodes 10 described later, according to the 5G NR specification. Additionally, communication is performed between terminal device 20, RAN node 30, and network node 10. The area between terminal device 20 and RAN node 30 is a radio band.

[0017] Network node 10 constitutes the core network. Network node 10 includes Access and Mobility Management Function (AMF) 10a, User Plane Function (UPF) 10b, Unified Data Management (UDM) / Unified Data Repository (UDR) 10c, Application Function (AF) 10d, Network Slice Selection Function (NSSF) 10e, Session Management Function (SMF) 10f, Policy Control Function (PCF) 10g, and Network Exposure Function (NEF).

[0018] Network node 10 is not limited to network nodes such as AMF10a mentioned above, and may include other network nodes specified or to be specified in the 3GPP technical specifications. Furthermore, a portion of network nodes 10, such as AF10d, may not necessarily constitute the 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 DN40.

[0019] In communication system 1, a user plane for sending and receiving user data and a control plane for sending and receiving control data are independently configured. That is, communication system 1 supports C / U separation. The user plane is called the U plane, and the control plane is called the C plane.

[0020] Terminal device 20 may be a device that wirelessly communicates with RAN node 30, for example, it may be a user equipment (UE) operating in accordance with the 3GPP 5G NR specification. Alternatively, terminal device 20 may be other devices specified in or to be specified in the 3GPP technical specifications.

[0021] 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 and a robot. Terminal device 20 may also be a vehicle (e.g., a car, a tram, etc.) or a device mounted thereon. Terminal device 20 may also be a transport vehicle other than a vehicle (e.g., a ship, an airplane, etc.) or a device mounted thereon. Terminal device 20 may also be a sensor or a device mounted thereon. Furthermore, terminal device 20 may also be referred to as a terminal, mobile station, mobile terminal, mobile device, mobile unit, subscriber station, subscriber terminal, subscriber device, subscriber unit, wireless station, wireless terminal, wireless device, wireless unit, remote station, remote terminal, remote device, remote unit, etc. Terminal device 20 may also 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).

[0022] 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, a cell belongs to a frequency (e.g., a carrier frequency) and consists of a component carrier. The term "cell" sometimes refers to a wireless communication resource and sometimes to the communication target of terminal device 20. RAN node 30 conducts wireless communication with terminal device 20 located in its cell in both the U-plane and C-plane. In other words, RAN node 30 terminates both the U-plane and C-plane protocols for terminal device 20.

[0023] RAN node 30 communicates with network node 10 in both the U-plane and the C-plane. More specifically, RAN node 30 is connected to AMF10a in the C-plane via an NG-C interface (not shown) and to UPF10b in the U-plane via an NG-U interface (not shown).

[0024] RAN node 30 may be, for example, a gNB that provides the terminal device 20 with the U-plane and C-plane according to the 3GPP 5G NR specification and connects to the 3GPP 5GC (5G Core Network). Alternatively, RAN node 30 may be other devices specified or to be specified in the 3GPP technical specifications.

[0025] Next, refer to Figure 2 This describes the physical configuration of network node 10. For example... Figure 2As shown, network node 10 includes a processor 101, a memory 102, and a transmitter / receiver 103 as hardware components. These elements in network node 10 are interconnected via an internal bus. Furthermore, network node 10 may include... Figure 2 Hardware elements other than those shown.

[0026] The processor 101 is a computing element that implements 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.

[0027] The memory 102 comprises at least one storage medium, such as read-only memory (ROM), random access memory (RAM), hard disk drive (HDD), and solid state drive (SSD). The memory 102 is an element that temporarily or permanently stores programs and data used to perform various processes in the network node 10. The programs include one or more instructions for the actions of the network node 10. The processor 101 implements the functions of the network node 10 by expanding the program stored in the memory 102 into the memory 102 and / or system memory (not shown) and executing it.

[0028] The transmitter receiver 103 transmits and receives signals between other network nodes 10 and RAN nodes 30.

[0029] Next, refer to Figure 3 This describes the logical configuration of network node 10. For example... Figure 3 As shown, network node 10 includes a control unit 110 and a communication unit 120 as functional blocks. The communication unit 120 includes at least one transmitting unit 111 and at least one receiving unit 122.

[0030] 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 implemented by the processor 101 and the memory 102. The control unit 110 performs 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 the transmission and reception of data / information / messages via the communication unit 120.

[0031] The communication unit 120 includes a transmitter / receiver 103. In other words, the communication unit 120 is implemented by the transmitter / receiver 103. The communication unit 120 communicates with other network nodes 10 and RAN nodes 30 by transmitting and receiving signals.

[0032] By operating the control unit 110, various processes of the network node 10 in this embodiment are executed.

[0033] Next, refer to Figure 4 This describes the physical configuration of terminal device 20. For example... Figure 4 As shown, the terminal device 20 includes a processor 201, a memory 202, an input / output interface 203, a transmitter / receiver 204, and an antenna 205 as hardware elements. These elements in the terminal device 20 are interconnected via an internal bus. Alternatively, the terminal device 20 may also include... Figure 4 Hardware elements other than those shown.

[0034] The processor 201 is a computing element that implements various functions of the terminal device 20. The processor 201 may be a CPU, or may also include other processors such as a GPU.

[0035] The memory 202 is composed of at least one storage medium such as RAM. The memory 202 is an element that temporarily or permanently stores programs and data for performing various processes in the terminal device 20. The program includes one or more instructions for the operation of the terminal device 20. The processor 201 implements the functions of the terminal device 20 by expanding the program stored in the memory 202 into the memory 202 and / or a system memory (not shown) and executing it.

[0036] The input / output interface 203 is an interface that receives operations from the terminal device 20 and provides them to the processor 201, and presents various information to the user. The input / output interface 203 is, for example, a touch panel.

[0037] Transmitter / receiver 204 is circuitry that performs various signal processing steps to enable wireless communication, including a baseband processor and RF circuitry. Transmitter / receiver 204 transmits and receives radio signals via antenna 205 to RAN node 30.

[0038] Next, refer to Figure 5 This describes the logical configuration of terminal device 20. For example... Figure 5 As shown, the terminal device 20 includes a control unit 210 and a communication unit 220 as functional blocks. The communication unit 220 includes at least one transmitting unit 121 and at least one receiving unit 122.

[0039] 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 implemented by the processor 201 and the memory 202. The control unit 210 performs 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 the transmission and reception of data / information / messages via the communication unit 220.

[0040] The communication unit 220 includes a transmitter / receiver 204 and an antenna 205. In other words, the communication unit 220 is implemented by the transmitter / receiver and the antenna 205. The communication unit 220 communicates wirelessly with the RAN node 30 by transmitting and receiving wireless signals.

[0041] By operating the control unit 210, various processes of the terminal device 20 in this embodiment are executed.

[0042] 1.2 Network Slicing Next, refer to Figure 6 This section provides an overview of network slicing. Each network slice is established by virtually segmenting the network to enable terminal device 20 to communicate with DN40 via RAN node 30 and network node (UPF) 10. Within a network slice, data is transmitted by establishing a Protocol Data Unit (PDU) session between terminal device 20 and network node 10.

[0043] like Figure 6 As shown, regarding network slicing, multiple network slices are established between terminal device 20 and network node 10. Each network slice is identified by S-NSSAI.

[0044] The S-NSSAI data format includes Slice / Service type (SST) and Slice Differentiator (SD).

[0045] SSTs define the purpose of network slices, including standard SSTs and specific SSTs. Standard SSTs specify eMBB, URLLC, Massive Internet of Things (MIoT), Vehicle-to-X (V2X), and High-performance Machine-Type Communication (HMTC). Specific SSTs specify purposes freely set by operators. SDs are identifiers used to separate multiple network slices within the same SST.

[0046] 1.3 Network Slice Registration Terminal device 20 maintains an S-NSSAI that can be used within a Public Land Mobile Network (PLMN). This S-NSSAI is referred to as a Configured S-NSSAI. Terminal device 20 registers the S-NSSAI by executing a registration request against AMF10a. (See reference...) Figure 7 This is an example illustrating the S-NSSAI registration process.

[0047] First, terminal device 20 sends a Registration Request message to RAN node 30 (step S701). The Registration Request message includes S-NSSAI. This S-NSSAI is referred to as Requested S-NSSAI.

[0048] Next, RAN node 30 selects AMF10a based on request S-NSSAI and sends a registration request message to the selected AMF10a (step S702).

[0049] Next, AMF10a selects UDM / UDR10c and registers the S-NSSAI into the selected UDM / UDR10c (step S703). This S-NSSAI is referred to as the Subscribed S-NSSAI. The Subscribed S-NSSAI is stored / registered in the UDM / UDR10c as Subscription Data.

[0050] Next, AMF10a notifies the terminal device 20 of the registered S-NSSAI (step S704). This S-NSSAI is referred to as the Allowed S-NSSAI.

[0051] In this way, the terminal device 20 can establish a PDU session with the UPF10b corresponding to the network slice, and communicate with the DN40 through the established PDU session.

[0052] 1.4 Network Slicing Reservation Non-patent document 1 describes the reservation process for network slices. During the reservation process, the network slice subnet management service provider reserves resources during configuration.

[0053] For example, consider the following scenario: AF10d requests a switch to a network slice to meet the service requirements of applications it manages. Network slice switching refers to terminal device 20 disconnecting the PDU session of the currently used network slice, selecting an alternative network slice, and establishing a new PDU session for the alternative network slice. Hereinafter, the currently used network slice is referred to as the "first network slice," and the alternative network slice is referred to as the "second network slice."

[0054] In the case of switching network slices, based on a request from AF10d, for example, NSSF10e selects a second network slice. Then, SMF10f terminates the PDU session for the first network slice and establishes a PDU session for the second network slice. Thus, the network slice is switched from the first network slice to the second network slice. (See reference...) Figure 8 This section provides an example illustrating the process of switching network slices.

[0055] AF10d sends a Network Slice Replacement Request (NSSF10e / SMF10f) to NSSF10e / SMF10f (step S801).

[0056] Next, NSSF10e selects a second network slice (step S802). This selection is made by choosing any one of the S-NSSAIs registered in UDM / UDR10c.

[0057] Next, SMF10f terminates the PDU session established for the first network slice (step S803). Next, SMF10f establishes a PDU session for the second network slice selected in step S802 (step S804). Thus, the network slice is switched from the first network slice to the second network slice.

[0058] By reference Figure 8 The process described allows switching network slices. By selecting the second network slice specified by AF10d, it is possible to meet the requirements of the services provided by AF10d, for example.

[0059] In the above scenario, the second network slice specified by AF10d is selected. However, when AF10d specifies a second network slice, such a network slice may not necessarily be available. For example, it may be considered that all network slices that meet the service requirements requested by AF10d are already in use.

[0060] In this embodiment, a network slice is reserved, and the system switches to the reserved network slice when specified conditions are met. By reserving a network slice and switching to it when conditions are met, the use of the specified network slice can be ensured. Furthermore, in this embodiment, "Network Slice Selection," "Network Slice Replacement," and "Network Slice Switch" are configured to be used interchangeably.

[0061] In this embodiment, AF10d reserves specific network slices. The reserved network slice is equivalent to a second network slice. For each reserved network slice, the corresponding S-NSSAI is registered in UDM / UDR10c. (Refer to...) Figure 9 This explains the network slice reservation process.

[0062] First, AF10d sends a ReservationRequest message to PCF10g via the API service through NEF10h (step S901). The ReservationRequest message includes data indicating the switching conditions. The switching conditions include the conditions that trigger a switch from the first network slice to the reserved second network slice.

[0063] Switching conditions may include, for example, reaching a specified date / time. When such conditions are included, the network slice is switched from the first network slice to the second network slice upon reaching the specified date / time. For example, the PCF10g measurement timer can be used to determine whether the specified date / time has been reached.

[0064] Switching conditions could include, for example, the amount / percentage of resources allocated to a reserved network slice being greater than / less than a specified amount / percentage of resources. When the switching conditions include the above, if the allocated network slice is greater than / less than the specified amount / percentage of resources (e.g., when the utilization rate is less than XX%), the network slice is switched from the first network slice to the second network slice. For example, resources can be monitored via OAM (Operation and Maintenance) to determine whether the allocated network slice is greater than / less than the specified amount / percentage of resources.

[0065] The handover conditions may include, for example, the condition that the terminal device 20 using a reserved network slice enters / leaves a specific area. When the handover conditions include the above condition, when the terminal device 20 enters / leaves a specific area, the network slice is switched from the first network slice to the second network slice. For example, the location of the terminal device 20 is monitored by AMF10a to determine whether the terminal device 20 has entered / left a specific area.

[0066] The switching conditions may include, for example, the number of terminal devices 20 using a reserved network slice being greater than or less than a specified number. When the switching conditions include the above condition, if the number of terminal devices 20 using a reserved network slice is greater than or less than the specified number, the network slice is switched from the first network slice to the second network slice. For example, the number of allowed S-NSSAIs registered in UDM / UDR10c is calculated by AMF10a to determine whether the number of terminal devices 20 using a reserved network slice is greater than or less than the specified number.

[0067] Switching conditions may include, for example, the traffic volume within the reserved network slice being greater than / less than a specified traffic volume. When the switching conditions include the above, if the traffic volume within the reserved network slice is greater than / less than the specified traffic volume (e.g., the traffic volume is greater than YY gigabytes), the network slice is switched from the first network slice to the second network slice. For example, in services monitoring user data via UPF10b and / or SMF10f, it is determined whether the traffic volume within the reserved network slice is greater than / less than the specified traffic volume.

[0068] The switching conditions described above are merely examples and may include other conditions associated with reserved network slices. Furthermore, switching conditions may include any combination of the above conditions and other conditions.

[0069] The reservation request message sent from AF10d in step S901 may include S-NSSAI. This S-NSSAI corresponds to the network slice reserved by AF10d. That is, when the reservation request message includes S-NSSAI, AF10d specifies the network slice it is reserving.

[0070] Additionally, the reservation request message sent from AF10d in step S901 may include the identifier (UE-ID) of the terminal device 20. The identifier is an identifier specific to the terminal device 20 managed by AF10d. As will be described later, when S-NSSAI is registered as subscription data corresponding to the reservation request message, it is registered in association with the identifier of the terminal device 20.

[0071] Furthermore, the reservation request message sent from AF10d in step S901 may include a transaction ID. The transaction ID is used, for example, to identify the transaction of the reservation request. For instance, the transaction ID is used when canceling a reservation request. The transaction ID may include a value assigned by NEF10h, etc.

[0072] Next, PCF10g selects UDM / UDR10c and registers the S-NSSAI corresponding to the reserved network slice in the selected UDM / UDR10c (step S902). This S-NSSAI corresponds to the S-NSSAI included in the reservation request message sent from AF10d in step S901.

[0073] S-NSSAI can be registered in UDM / UDR10c as subscription data. In this case, it is registered in association with the identifier (UE-ID) of the terminal device 20 included in the reservation request message sent from AF10d in step S901. Alternatively, S-NSSAI can be registered in UDM / UDR10c in any form other than subscription data.

[0074] Next, PCF10g notifies AF10d of the reserved S-NSSAI (step S903). This S-NSSAI is referred to as the reserved S-NSSAI. Furthermore, the reserved S-NSSAI can also be notified to the terminal device 20. In this case, it is notified to all terminal devices 20 managed by AF10d.

[0075] In this embodiment, the reserved S-NSSAI is registered as subscription data in association with the identifier (UE-ID) of the terminal device 20. A new data type defining the data associated with the reserved S-NSSAI is added to the subscription data.

[0076] The data type newly added to the subscription data is related to reserved network slices. For example... Figure 10 As shown, the data type is, for example, reserved data.

[0077] The reserved data includes three fields. The first field is S-NSSAI. The second field is the Condition for Switching Network Slice. The third field is the Transaction ID.

[0078] The S-NSSAI indicates the S-NSSAI corresponding to the reserved network slice, i.e., the reserved S-NSSAI. The S-NSSAI included in the reservation data is configured to be included in the reservation request message sent from AF10d in step S901.

[0079] The network slice switching condition indicates the conditions that trigger a switch from the first network slice to the reserved second network slice. The network slice switching conditions included in the reservation data are configured to indicate the switching conditions included in the reservation request message sent from AF10d in step S901.

[0080] The transaction ID indicates the identifier of the transaction for the reservation request. The transaction ID included in the reservation data is configured to be the transaction ID included in the reservation request message sent from AF10d in step S901.

[0081] The data structure for the reserved data is merely an example; other data structures besides those described can also be used. Specifically, refer to... Figure 10 The network slice switching conditions described are merely examples; network slice switching conditions can also have various values, such as numerical values ​​corresponding to the conditions.

[0082] When a reserved S-NSSAI is registered in UDM / UDR10c, the reserved data is stored along with the subscription data. That is, Figure 10 The reserved data shown is registered in UDM / UDR10c by terminal device 20 or group of terminal devices 20. In this embodiment, since the reserved data is registered according to the request from AF10d which manages the terminal device 20, the reserved data related to the multiple terminal devices 20 is registered at once when AF10d manages multiple terminal devices 20.

[0083] Subscription data is registered and managed by terminal device 20. Alternatively, subscription data may also be registered and managed by network slice, or by a combination of terminal device 20 and network slice.

[0084] In addition, Figure 9 In the process shown, reserved data is registered according to a request from AF10d, but is not limited to this form. For example, in step S901, terminal device 20 may send a reservation request message to PCF10g via AMF10a.

[0085] Next, refer to Figure 11 This embodiment describes the process of performing network slice switching. In this embodiment, when the network slice switching conditions are met, the network slice is switched from the first network slice to the second network slice. The second network slice is included in... Figure 10The network slice corresponding to S-NSSAI in the reserved data shown is hereinafter referred to as "NW-S" in the figure.

[0086] First, PCF10g determines whether the network slice switching conditions are met (step S1101). Step S1101 is repeated until the network slice switching conditions are met. This is in accordance with the procedures included... Figure 10 The data indicated by the network slice switching conditions in the reserved data shown is used to determine whether the network slice switching conditions are met.

[0087] The reserved data is obtained along with the subscription data based on the identifier (UE-ID) of the terminal device 20. Alternatively, instead of the identifier of the terminal device 20, the subscription data can be obtained based on the second S-NSSAI. Furthermore, the subscription data can also be obtained based on a combination of the UE-ID and the S-NSSAI for the first network slice. The identifier of the terminal device 20 and the S-NSSAI are referenced... Figure 9 The network slice reservation process is described in the reservation request message. Therefore, the identifier of the terminal device 20 and the S-NSSAI can be stored in PCF10g during the network slice reservation process.

[0088] The network slice handover conditions, as described above, include the condition of reaching a specified date / time and the condition of terminal device 20 entering / leaving a specific area. Regarding the condition of reaching the specified date / time, for example, PCF10g can determine whether the specified date / time has arrived at a certain time interval. Regarding the condition of terminal device 20 entering / leaving a specific area, PCF10g can request AMF10a to monitor terminal device 20 entering / leaving a specific area at a certain time interval. Alternatively, in response to AMF10a detecting that terminal device 20 has entered / leaved a specific area, PCF10g may receive a notification from AMF10a indicating this situation.

[0089] In step S1101, if the network slice switching conditions are determined to be met, PCF10g uses the API service via NEF10h to send a notification message instructing AF10d to perform a network slice switching (step S1102). Alternatively, it can wait for a response from AF10d and proceed to step S1103, which will be described later.

[0090] Next, PCF10g instructs NSSF10e to select a second network slice (step S1103). The second network slice is selected corresponding to S-NSSAI included in the reserved data.

[0091] In step S1104, NSSF10e selects a second network slice. This selection is made by choosing an S-NSSAI from those S-NSSAIs registered in UDM / UDR10c.

[0092] Next, SMF10f terminates the PDU session established for the first network slice (step S1105). The PDU session established for the first network slice refers to the PDU session established for the terminal device 20 managed by AF10d that reserves the second network slice.

[0093] Next, SMF10f establishes a PDU session for the second network slice selected in step S1104 (step S1106). A PDU session is established for the terminal device 20 whose PDU session was terminated in step S1105.

[0094] The aforementioned process of severing and establishing a PDU session is performed collaboratively by NSSF10e, AMF10a, and SMF10f. The other implementations described later follow the same procedure. Thus, network control network slice selection is performed, and the network slice is switched from the first network slice to the second network slice.

[0095] The first embodiment has been described above. In the first embodiment, a network slice is reserved, and in response to the satisfaction of specified conditions, the network slice is switched from a first network slice to a second network slice.

[0096] also, Figure 11 The order of steps shown is merely an example; you can also follow the steps in the following order. Figure 11 Execute in any order other than those shown. Alternatively, it can be omitted. Figure 11 The steps shown are part of a set; additional steps can be added.

[0097] According to the first embodiment, it is possible to ensure the use of a network slice when the specified network slice is not immediately available.

[0098] Furthermore, in the first embodiment, network slice reservation and network slice switching are performed by PCF10g, but the fact that PCF10g is the executing entity is merely an example. The process described in the first embodiment is performed by one or more of the network nodes 10.

[0099] 2. Second Implementation Method Next, the second implementation will be described. In the first implementation, an example of AF10d specifying a reserved network slice was described. In the second implementation, an example of NSSF10e selecting a network slice that meets the service requirements and / or purpose specified by AF10d is described.

[0100] Reference Figure 12This section explains the network slice reservation process involved in the second embodiment. The network slice reservation process involved in the second embodiment is similar to that described in the reference section. Figure 9 The network slice reservation process described is generally the same, but the data included in the reservation request message sent from AF10d is different.

[0101] First, AF10d sends a reservation request message to PCF10g via the API service through NEF10h (step S1201). The reservation request message is the same as that described in the first embodiment, including the identifier of the terminal device 20 (UE-ID), data indicating the network slice switching conditions, and the transaction ID.

[0102] Additionally, the reservation request message sent from AF10d may include data indicating the requested service requirements. The service request indicates the service requirements for a reserved second network slice. For example, the service request may indicate a QoS value requested according to QoS parameters. The QoS parameters shown in Table 1 are specified in the 3GPP technical specifications. The service request may include, for example, a combination of values ​​indicating the QoS parameter type and values ​​indicating the corresponding QoS value, such as "1: Packet Delay Budget" and "10 (ms)". [Table 1] Table 1: QoS Parameters

[0103] Furthermore, the reservation request message sent from AF10d may include data indicating the purpose of a network slice. The network slice purpose indicates the use of a network slice identified using a standard SST or a combination of a standard SST and a specific SST.

[0104] Next, PCF10g selects UDM / UDR10c and registers the reservation data related to the reserved network slice in the selected UDM / UDR10c (step S1202). Next, PCF10g sends a notification message to AF10d indicating that a network slice has been reserved (step S1203).

[0105] In the second embodiment, S-NSSAI is not included in the reservation request message sent from AF10d. Therefore, in step S1202, S-NSSAI may not be registered, and the reservation data may be registered in association with the request service requirement and / or network slicing purpose.

[0106] Alternatively, in step S1202, a network slice that meets the requested service requirements and / or the purpose of the network slicing can be selected. In this case, reserved data is registered in association with the S-NSSAI corresponding to the selected network slice. The method for selecting a network slice is as described below, referring to... Figure 14This is explained during the network switching process.

[0107] Reference Figure 13 This section explains the reserved data involved in the second embodiment. The reserved data involved in the second embodiment is referenced in... Figure 12 During the network slice reservation process, it is also registered as subscription data in UDM / UDR10c.

[0108] The reserved data includes three data fields. The first data field is the Demanded Service Requirements. The second data field is the Network Slice Application. The third data field is the Network Slice Switching Conditions. The fourth data field is the Transaction ID. The Network Slice Switching Conditions and Transaction ID are the same as those described in the first embodiment, therefore their detailed descriptions are omitted.

[0109] The service request indicates the service requirements for a reserved second network slice. The service request included in the reservation data is configured to indicate the data of the service request included in the reservation request message sent from AF10d in step S1201.

[0110] The network slice usage indication specifies the usage for the reserved second network slice. The network slice usage included in the reservation data is configured to indicate the data of the network slice usage included in the reservation request message sent from AF10d in step S1201.

[0111] In the second embodiment, reserved data including service request information is registered in UDM / UDR10c. In this state, network slice handover is performed. (See also...) Figure 14 This explains the process of performing network slice switching in the second embodiment.

[0112] First, PCF10g instructs NSSF10e to select a second network slice (step S1401).

[0113] In step S1402, NSSF10e selects a second network slice. The second network slice is selected from those that satisfy the condition of including... Figure 13 The requested service requirements shown in the reserved data and / or the network slices corresponding to the network slice uses included in the reserved data are selected.

[0114] The reserved data is obtained along with the subscription data based on the identifier (UE-ID) of the terminal device 20. Alternatively, the subscription data can be obtained based on the second S-NSSAI instead of the identifier of the terminal device 20. Furthermore, the subscription data can also be obtained based on a combination of the UE-ID and the S-NSSAI for the first network slice.

[0115] To select a second network slice that meets the requested service requirements, QoS values ​​corresponding to the QoS offered by each network slice can be stored in UDM / UDR10c. These QoS values ​​can be stored as a QoS list for each network slice and associated with S-NSSAI, based on the QoS parameters shown in Table 1. Table 2 shows an example of a QoS list. [Table 2] Table 2: QoS List

[0116] Additionally, to select a second network slice corresponding to a specified network slice purpose, values ​​indicating the purpose of each network slice can be stored in the UDM / UDR10c. These purpose-indicating values ​​can be stored as a network slice purpose list, associated with S-NSSAI for each network slice. Table 3 shows an example of a network slice purpose list. [Table 3] Table 3: List of Network Slicing Applications

[0117] By storing the QoS list in UDM / UDR10c, a second network slice that meets the requested service requirements can be appropriately selected. Similarly, by storing the network slice usage list in UDM / UDR10c, a second network slice corresponding to the specified network slice usage can be appropriately selected.

[0118] Next, PCF10g determines whether the network slice switching conditions are met for the network slice selected in step S1402 (step S1403). The process of step S1403 is repeated until the network slice switching conditions are met. This is in accordance with the procedures included... Figure 13 The data indicated by the network slice switching conditions in the reserved data shown is used to determine whether the network slice switching conditions are met.

[0119] In step S1403, if the network slice switching conditions are determined to be met, PCF10g sends a notification message to AF10d via NEF10h using the API service. The notification message instructs the network slice switching to be performed (step S1404). Alternatively, a response from AF10d can be waited for before proceeding to step S1405, which will be described later.

[0120] Next, SMF10f terminates the PDU session established for the first network slice (step S1405). The PDU session established for the first network slice refers to the PDU session established for the terminal device 20 managed by AF10d that reserves the second network slice.

[0121] Next, SMF10f establishes a PDU session for the second network slice selected in step S1402 (step S1406). A PDU session is then established for the terminal device 20 whose PDU session was terminated in step S1405. Thus, network control network slice selection is performed, and the network slice is switched from the first network slice to the second network slice.

[0122] also, Figure 14 The order of steps shown is merely an example; you can also follow the steps in the following order. Figure 14 Execute in any order other than those shown. Alternatively, it can be omitted. Figure 14 The steps shown are part of a set; additional steps can be added.

[0123] The second embodiment has been described above. In the second embodiment, network slices are also reserved, and in response to the satisfaction of specified conditions, a network slice is switched from a first network slice to a second network slice. Furthermore, in the second embodiment, a network slice that meets the requested service requirements and / or corresponds to the specified network slice purpose is selected.

[0124] According to the second embodiment, in cases where the requested service requirements are met and / or the network slice corresponding to the specified network slice purpose is not immediately available, the use of such a network slice can be ensured. Furthermore, according to the second embodiment, even without specifying a specific network slice, the requested network slice is selected simply by specifying the requested service requirements and / or the network slice purpose.

[0125] 3. Third Implementation Method Next, the third implementation will be described. In the first and second implementations, examples of switching a network slice from a first network slice to a second network slice for a specific application were described. When a terminal device 20 is using the second network slice at the time of switching the network slice from the first network slice to the second network slice, it is necessary to terminate the PDU session established with the terminal device 20.

[0126] For a terminal device 20 that is using a second network slice, there is a situation where it is not preferable to terminate the PDU session in use without any notification. In the third embodiment, an example considering the case where a terminal device 20 is using a second network slice will be described.

[0127] Reference Figure 15This describes the network slice switching process involved in the third embodiment. The network slice switching process in the third embodiment, in addition to referring to... Figure 11 In addition to the network slice switching process described, there are also additional steps.

[0128] PCF10g determines whether the network slice switching conditions are met (step S1501). The process of step S1501 is repeated until the network slice switching conditions are met. Details regarding the determination of whether the network slice switching conditions are met are as described above.

[0129] In step S1501, if the network slice switching conditions are determined to be met, PCF10g sends a notification message instructing AF10d to perform a network slice switching via the API service of NEF10h (step S1502). Alternatively, it can wait for a response from AF10d and proceed to step S1503, which will be described later.

[0130] Next, PCF10g instructs NSSF10e to select a second network slice (step S1503). The second network slice is selected corresponding to S-NSSAI included in the reserved data.

[0131] In step S1504, NSSF10e selects a second network slice. This selection is made by choosing an S-NSSAI from those S-NSSAIs registered in UDM / UDR10c.

[0132] Next, PCF10g determines whether there is a terminal device 20 that is using the second network slice selected in step S1504 (step S1505). This determination is made by referring to subscription data. Specifically, it is done by determining whether a terminal device 20 is registered with or subscribed to S-NSSAI corresponding to the second network slice.

[0133] When a terminal device 20 is using the second network slice in step S1505, PCF10g sends a notification message to the terminal device 20 instructing it to perform a network slice switch or that the PDU session is terminated (step S1506).

[0134] Furthermore, after sending the notification message, PCF10g can transition to subsequent processing in response to receiving an acknowledgment (ACK) response from terminal device 20. In this case, for example, if a negative response (NACK) is received from terminal device 20, or if no acknowledgment response is received from terminal device 20, PCF10g can interrupt the process. Alternatively, PCF10g can return to step S1503, instructing NSSF10e to select another second network slice.

[0135] Additionally, PCF10g can transition to subsequent processing after a predefined time elapsed following receiving an acknowledgment response from terminal device 20. This predefined time may, for example, be registered in the subscription data for terminal device 20.

[0136] Next, SMF10f terminates the PDU session established for the second network slice (step S1507). The PDU session established for the second network slice refers to the PDU session established for the terminal device 20 that was determined to be using the second network slice in step S1505.

[0137] Next, SMF10f terminates the PDU session established for the first network slice (step S1508). The PDU session established for the first network slice refers to the PDU session established for the terminal device 20 managed by AF10d that reserves the second network slice.

[0138] Next, SMF10f establishes a PDU session for the second network slice selected in step S1104 (step S1509). A PDU session is then established for the terminal device 20 whose PDU session was terminated in step S1508. Thus, network control network slice selection is performed, and the network slice is switched from the first network slice to the second network slice.

[0139] also, Figure 15 The order of steps shown is merely an example; you can also follow the steps in the following order. Figure 11 Execute in any order other than those shown. Alternatively, it can be omitted. Figure 15 The steps shown are part of a set; additional steps can be added.

[0140] The third embodiment has been described above. In the third embodiment, a network slice is also reserved, and in response to the fulfillment of specified conditions, the network slice is switched from the first network slice to the second network slice. Furthermore, in the third embodiment, the terminal device 20 that is using the second network slice when switching network slices is notified to switch network slices.

[0141] According to the third embodiment, even when a designated network slice is not immediately available, its use can be ensured. Furthermore, according to the third embodiment, for a terminal device 20 that is using a second network slice when switching network slices, the sudden termination of the PDU session can be prevented.

[0142] The above describes the reference Figure 15 The network slice switching process described above, in addition to referring to... Figure 11 In addition to the network slice switching process described herein, additional steps are also included. Alternatively, the network slice switching process, in addition to referring to... Figure 14In addition to the network slice switching process described, additional steps may be included. That is, in the network slice switching process involved in the third embodiment, AF10d may specify the requested service requirements, and NSSF10e may select a network slice that meets the service requirements.

[0143] 4. Variation Example The above describes the methods for implementing this embodiment, but this embodiment is not limited to the above embodiments. It should be understood that the above embodiments are merely examples and various variations are possible.

[0144] The words, phrases, etc., used in the above embodiments are merely examples and can be replaced with substantially the same or identical expressions. In particular, since the technologies involved in the above embodiments are related to technical specifications, the expressions in the above embodiments can be replaced with substantially the same or identical expressions in the technical specifications (e.g., the technical specifications cited in this application specification).

[0145] In the above embodiments, the information sent and received may include the same or different messages or elements already described in the technical specifications, or it may include newly defined messages or elements. In the above embodiments, the information sent and received may use different layers and / or different channels than those described in the above embodiments.

[0146] The manner and / or function provided by the apparatus described in the above embodiments can be provided by software recorded in a physical memory device and a computer executing the software, by software alone, by hardware alone, or by a combination thereof. For example, in the case where any of the above-described apparatuses is provided by electronic circuitry as hardware, it can be provided by digital circuitry or analog circuitry including multiple logic circuits.

[0147] The apparatus described in the above embodiments executes a program stored in a non-transitory tangible storage medium. By executing this program, a method corresponding to the program is performed.

[0148] 5. Postscript The above-described embodiments and variations may be described in whole or in part as in the following notes, but are not limited to the content of the following notes. Hereinafter, the relationship of a note belonging to a note belonging to a note belonging to a note belonging to a note belonging to a note is expressed. All the subordinate relationships of notes expressed below are included in the above-described embodiments.

[0149] (Postscript 1) A network node includes a control unit and a communication unit. The aforementioned communication unit is configured to receive messages requesting a switch from a first network slice to a second network slice used by the terminal device. The aforementioned control unit is configured as follows: Determine whether the predefined conditions are met. When the aforementioned conditions are met, the aforementioned network slice is switched from the aforementioned first network slice to the aforementioned second network slice.

[0150] (Postscript 2) According to the network node described in Appendix 1, the aforementioned message indicates that the aforementioned second network slice is reserved.

[0151] (Note 3) According to the network node described in Appendix 1 or 2, the aforementioned conditions include arrival at the specified date / time.

[0152] (Note 4) For any of the network nodes described in any of Appendix 1 to 3, the aforementioned conditions include the resource quantity / proportion for the aforementioned second network slice being greater than / less than the specified resource quantity / proportion.

[0153] (Note 5) According to any one of Annexes 1 to 4, the aforementioned conditions include the terminal device using the aforementioned second network slice entering / leaving a specific area.

[0154] (Note 6) According to any one of Appendix 1 to 5, the aforementioned condition includes that the number of terminal devices using the aforementioned second network slice is greater than / less than a specified number.

[0155] (Note 7) For any of the network nodes described in any of Notes 1 to 6, the aforementioned conditions include the traffic volume within the aforementioned second network slice being greater than / less than the specified traffic volume.

[0156] (Postscript 8) According to any one of the network nodes in Notes 1 to 7, the aforementioned message includes S-NSSAI corresponding to the aforementioned second network slice. The aforementioned control unit is further configured to select the aforementioned second network slice based on the aforementioned S-NSSAI.

[0157] (Note 9) According to any one of the appendices 1 to 7, the aforementioned message includes data indicating the requested service request of the network node. The aforementioned control unit is further configured to select the aforementioned second network slice based on the aforementioned service requirements.

[0158] (Postscript 10) According to any one of Appendices 1 to 7 and 9, the aforementioned message includes data indicating the purpose of the network slice. The aforementioned control unit is further configured to select the aforementioned second network slice based on the aforementioned purpose.

[0159] (Postscript 11) According to any one of Appendices 1 to 10, the aforementioned communication unit is further configured to receive a message requesting a switch from a first network slice to a second network slice for network slices used by multiple terminal devices.

[0160] (Postscript 12) According to the network node described in Appendix 11, the aforementioned communication unit is further configured to receive the aforementioned message from the application function (AF), which manages the aforementioned plurality of terminal devices.

[0161] (Postscript 13) According to any one of Appendices 1 to 12, the aforementioned control unit is further configured to determine whether there is a terminal device using the aforementioned second network slice. The aforementioned communication unit is further configured to send a notification message to the aforementioned terminal device that is using the aforementioned second network slice, instructing it to switch the aforementioned network slice from the aforementioned first network slice to the aforementioned second network slice.

[0162] (Postscript 14) According to the network node described in Appendix 13, the aforementioned communication unit is further configured to receive an acknowledgment response from the aforementioned terminal device for the aforementioned notification message. The aforementioned control unit is further configured to, in response to receiving the aforementioned confirmation response, disconnect the PDU session established with the aforementioned terminal device that is using the aforementioned second network slice, thereby switching the aforementioned network slice from the aforementioned first network slice to the aforementioned second network slice.

[0163] (Postscript 15) According to the network node described in Appendix 13 or 14, the aforementioned control unit is further configured to interrupt the switching of the aforementioned network slice from the aforementioned first network slice to the aforementioned second network slice if the aforementioned communication unit does not receive an acknowledgment response for the aforementioned notification message from the aforementioned terminal device, or if it receives a negative response for the aforementioned notification message from the aforementioned terminal device.

[0164] (Postscript 16) According to the network node described in Appendix 13 or 14, the aforementioned control unit is further configured to, after a predetermined time, interrupt the switching of the aforementioned network slice from the aforementioned first network slice to the aforementioned second network slice if the aforementioned communication unit does not receive an acknowledgment response to the aforementioned notification message from the aforementioned terminal device, or if it receives a negative response to the aforementioned notification message from the aforementioned terminal device.

[0165] (Postscript 17) One method, executed by a network node, includes the following: Receive a message requesting a switch from the first network slice to the second network slice used by the terminal device; Determine whether the predefined conditions are met; and When the aforementioned conditions are met, the aforementioned network slice is switched from the aforementioned first network slice to the aforementioned second network slice.

[0166] (Postscript 18) A program that, when executed, causes the processor in a network node to perform the following: Receive a message requesting a switch from the first network slice to the second network slice used by the terminal device; Determine whether the predefined conditions are met; and When the aforementioned conditions are met, the aforementioned network slice is switched from the aforementioned first network slice to the aforementioned second network slice.

[0167] (Postscript 19) 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: Receive a message requesting a switch from the first network slice to the second network slice used by the terminal device; Determine whether the predefined conditions are met; and When the aforementioned conditions are met, the aforementioned network slice is switched from the aforementioned first network slice to the aforementioned second network slice.

[0168] (Postscript 20) A terminal device includes a control unit and a communication unit. The aforementioned control unit and communication unit are configured to send a message to the network node requesting a switch from the first network slice to the second network slice used by the aforementioned terminal device. When predefined conditions are met, the aforementioned network slice is switched from the aforementioned first network slice to the aforementioned second network slice through the aforementioned network node.

[0169] Furthermore, the disclosures in the aforementioned prior art documents and references are incorporated herein by reference. Figure Labels

[0170] 10 Network Nodes, 101 Processor, 102 Memory, 103 Transmitter / Receiver, 110 Control Unit, 120 Communication Unit, 20 Terminal Devices, 201 Processor, 202 Memory, 203 Input / Output Interface, 204 Transmitter / Receiver, 205 Antenna, 210 Control Unit, 220 Communication Unit, 30 RAN Nodes, 40 DN

Claims

1. A network node, comprising a control unit and a communication unit, The communication unit is configured to receive a message requesting a switch from a first network slice to a second network slice used by the terminal device, and the control unit is configured to... Determine whether the predefined conditions are met. When the condition is met, the network slice is switched from the first network slice to the second network slice.

2. The network node according to claim 1, wherein the message indicates that the second network slice is reserved.

3. The network node according to claim 1, wherein the condition includes arrival at the specified date / time.

4. The network node according to claim 1, wherein the condition includes the resource quantity / proportion for the second network slice being greater than / less than a specified resource quantity / proportion.

5. The network node according to claim 1, wherein the condition includes a terminal device using the second network slice entering / leaving a specific area.

6. The network node of claim 1, wherein the condition includes a number of terminal devices using the second network slice that is greater than or less than a specified number.

7. The network node according to claim 1, wherein the condition includes the communication volume within the second network slice being greater than / less than a specified communication volume.

8. The network node according to claim 1, wherein the message includes S-NSSAI corresponding to the second network slice. The control unit is further configured to select the second network slice based on the S-NSSAI.

9. The network node of claim 1, wherein the message includes data indicating the requested service request. The control unit is further configured to select the second network slice based on the service requirements.

10. The network node of claim 1, wherein the message includes data indicating the purpose of the network slice. The control unit is further configured to select the second network slice based on the intended use.

11. The network node according to claim 1, wherein the communication unit is further configured to receive a message requesting a switch of network slices used by a plurality of terminal devices from a first network slice to a second network slice.

12. The network node according to claim 11, wherein the communication unit is further configured to receive the message from an application function AF, the AF managing the plurality of terminal devices.

13. The network node according to claim 1, wherein the control unit is further configured to determine whether there is a terminal device currently using the second network slice. The communication unit is further configured to send a notification message to the terminal device that is using the second network slice, instructing it to switch the network slice from the first network slice to the second network slice.

14. The network node according to claim 13, wherein the communication unit is further configured to receive an acknowledgment response to the notification message from the terminal device. The control unit is further configured to, in response to receiving the confirmation response, disconnect the PDU session established with the terminal device that is using the second network slice, thereby switching the network slice from the first network slice to the second network slice.

15. The network node according to claim 13, wherein the control unit is further configured to interrupt the switching of the network slice from the first network slice to the second network slice if the communication unit does not receive an acknowledgment response for the notification message from the terminal device or receives a negative response for the notification message from the terminal device.

16. The network node according to claim 13, wherein the control unit is further configured to, if the communication unit does not receive an acknowledgment response to the notification message from the terminal device, or receives a negative response to the notification message from the terminal device, interrupt the switching of the network slice from the first network slice to the second network slice after a predetermined time has elapsed.

17. A method performed by a network node, the method comprising: Receive a message requesting a switch from the first network slice to the second network slice used by the terminal device; Determine whether the predefined conditions are met; as well as When the condition is met, the network slice is switched from the first network slice to the second network slice.

18. A program that, when executed, causes a processor in a network node to perform: Receive a message requesting a switch from the first network slice to the second network slice used by the terminal device; Determine whether the predefined conditions are met; as well as When the condition is met, the network slice is switched from the first network slice to the second network slice.

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