Network node and processing method

Abstract

Provided is a network node comprising; a control unit that, when a terminal is registered in a movement destination network, includes, in a message instructing to monitor a user plane, a mapped slice identifier included in a session establishment message; and a communication unit that transmits the message including the mapped slice identifier to a specific network node.

Description

Network node and processing method

[0001] The present invention relates to the control of slices in a network.

[0002] 3GPP (registered trademark) (3rd Generation Partnership Project) has introduced a wireless communication system called 5G or NR (New Radio) (hereinafter, the wireless communication system will be referred to as "5G" or "NR") in order to achieve a larger system capacity, a higher data transmission speed, and a lower latency in wireless sections. 5G introduces various wireless technologies to meet the requirement of achieving a throughput of 10 Gbps or more while reducing latency in wireless sections to 1 ms or less. Furthermore, 6G, a future communication system, is also being studied.

[0003] In addition, network slices (which may also be called slices) are being operated in 5GC to enable telecommunications carriers to provide services to users.

[0004] 3GPP TS 23.501 V18.3.0 (2023-09)3GPP TS 23.502 V18.3.0 (2023-09)3GPP TS 24.501 V18.3.0 (2023-06)3GPP TS 29.244 V18.2.1 (2023-06)

[0005] A technology has been proposed that enables the use of a slice to be stopped when a PDU session corresponding to the slice is established but there is no data transmission on the user plane for the slice (e.g., non-patent documents 1 to 4).

[0006] However, in the conventional technologies disclosed in Non-Patent Documents 1 to 4, etc., the operation of timers such as the PDU Session Inactivity Timer and the User Plane Inactivity Timer is unclear, and therefore it may not be possible to properly perform the monitoring required to stop slice usage.

[0007] The present invention has been made in view of the above points, and an object of the present invention is to provide a technique that enables appropriate monitoring required for stopping slice usage.

[0008] According to the disclosed technology, a network node is provided that includes: a control unit that includes a mapped slice identifier included in a session establishment message in a message instructing monitoring of the user plane when a terminal is registered in a destination network; and a transmission unit that transmits the message including the mapped slice identifier to a specific network node.

[0009] The disclosed technology provides a technology that enables appropriate monitoring required for stopping slice usage.

[0010] FIG. 1 is a diagram for explaining an example of a communication system. FIG. 1 is a diagram for explaining an example of a communication system in a roaming environment. FIG. 2 is a diagram for explaining an overview of Examples 1 to 4. FIG. 3 is a diagram for explaining an example when the S-NSSAI associated with a timer is S-NSSAI#1. FIG. 4 is a diagram showing association examples (A), (B), and (C). FIG. 5 is a diagram showing an image of deleting an S-NSSAI. FIG. 6 is a diagram for explaining an overview of Examples 5 to 7. FIG. 7 is a diagram showing an example of the functional configuration of network nodes 30, 40, and 50 in an embodiment of the present invention. FIG. 8 is a diagram showing an example of the functional configuration of terminal 20 in an embodiment of the present invention. FIG. 9 is a diagram showing an example of the hardware configuration of network nodes 30, 40, and 50 and terminal 20 in an embodiment of the present invention. FIG. 10 is a diagram showing an example of the configuration of vehicle 2001 in an embodiment of the present invention.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0012] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies are used as appropriate. However, the existing technologies include, but are not limited to, the existing LTE or the existing NR.

[0013] Below, we will first explain an example of a 5G network configuration as an example of a network, and then explain each example of the issues and operations for solving the issues.

[0014] Fig. 1 is a diagram illustrating an example of a communication system corresponding to a mobile network. As shown in Fig. 1, this communication system is composed of a UE 20 and multiple network nodes. Hereinafter, it is assumed that one network node corresponds to each function, but multiple functions may be realized by one network node, or multiple network nodes may realize one function. Furthermore, the "connection" described below may be a logical connection or a physical connection.

[0015] The RAN (Radio Access Network) 10 is a network node having a radio access function, which may include a base station, and is connected to the UE 20, the AMF (Access and Mobility Management Function) 30, and the UPF (User plane function) 50. The AMF 30 is a network node having functions such as terminating the RAN interface, terminating the NAS (Non-Access Stratum), registration management, connection management, reachability management, and mobility management. The UPF 50 is a network node having functions such as a PDU (Protocol Data Unit) session point to the outside that interconnects with the DN (Data Network), packet routing and forwarding, and user plane QoS (Quality of Service) handling. The UPF and the DN constitute a network slice.

[0016] The AMF 30 is connected to the UE 20, the RAN 10, a Session Management function (SMF) 40, a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Repository Function (NRF), a Unified Data Management (UDM), an Authentication Server Function (AUSF), a Policy Control Function (PCF), and an Application Function (AF). The AMF 30, the SMF 40, the NSSF, the NEF, the NRF, the UDM, the AUSF, the PCF, and the AF are network nodes connected to each other via interfaces, Namf, Nsmf, Nnssf, Nnef, Nnrf, Nudm, Nausf, Npcf, and Naf, based on their respective services.

[0017] The SMF 40 is a network node having functions such as session management, IP (Internet Protocol) address allocation and management for the UE 20, DHCP (Dynamic Host Configuration Protocol) function, ARP (Address Resolution Protocol) proxy, and roaming function. The NEF is a network node having a function of notifying other NFs (Network Functions) of capabilities and events. The NSSF is a network node having functions such as selecting a network slice to which the UE 20 connects, determining an allowed NSSAI (Network Slice Selection Assistance Information), determining an NSSAI to be set, and determining an AMF set to which the UE 20 connects. The PCF is a network node having a function of controlling network policies. The AF is a network node having a function of controlling application servers. The NRF is a network node having a function of discovering NF instances that provide services. The UDM is a network node that manages subscriber data and authentication data. The UDM is connected to a UDR (User Data Repository) that stores the data.

[0018] 2 is a diagram illustrating an example of a communication system in a roaming environment. As shown in FIG. 2, the network is made up of a UE 20 and a plurality of network nodes.

[0019] The SEPP is a non-transparent proxy that filters control plane messages between PLMNs (Public Land Mobile Networks). The vSEPP shown in Fig. 2 is a SEPP in a visited network, and the hSEPP is a SEPP in a home network. Note that the UE 20 may also be referred to as a terminal 20.

[0020] As shown in Fig. 2, UE 20 is in a roaming environment connected to a RAN and an AMF in a Visited PLMN (VPLMN). The VPLMN and a Home PLMN (HPLMN) are connected via a vSEPP and an hSEPP. UE 20 can communicate with a UDM in the HPLMN via the AMF in the VPLMN, for example.

[0021] The UE 20 and each network node in this embodiment can perform operations described in existing 3GPP (registered trademark) specifications (e.g., Non-Patent Documents 1 to 4). However, there are problems with only the operations described in the existing specifications. These problems are described below.

[0022] (Regarding the Issues) In the above-mentioned 5G network, slices are operated. S-NSSAI is used to identify slices.

[0023] In a general process related to slicing, the terminal 20 transmits a Requested NSSAI including one or more S-NSSAIs that the terminal 20 wishes to register to the AMF 30 through a registration procedure. The UE 20 receives from the AMF 30 an Allowed NSSAI including one or more S-NSSAIs that are allowed to be used in the serving PLMN, and a Configured NSSAI.

[0024] Furthermore, in the PDU session establishment procedure after the registration procedure, the UE 20 establishes a PDU session by transmitting a PDU session establishment request including an S-NSSAI indicating a desired slice to the AMF 30, and performs communication using the desired slice. Below, problem 1 and problem 2 will be described as specific problems.

[0025] <Issue 1> In relation to the above registration procedure, a Slice deregistration inactivity timer is defined as a timer for deregistration of an S-NSSAI that is registered but not used in a PDU session.

[0026] As described in Non-Patent Document 3, when the UE 20 and the NW support the network slice usage control function, the AMF 30 starts a slice deregistration inactivity timer for each allowed S-NSSAI that does not have an associated PDU session, and performs network slice usage monitoring.

[0027] For a certain S-NSSAI to be monitored, if the slice deregistration inactivity timer expires without a corresponding PDU session being established, the AMF 30 deletes the S-NSSAI from the Allowed NSSAI by sending a UE Configuration Update Command to the UE 20.

[0028] However, in the conventional techniques described in existing specifications, the detailed operations related to the slice deregistration inactivity timer or the detailed operations related to exceptions are unclear.

[0029] In this embodiment, examples 1 to 4 will be described as detailed operations related to deregistration of S-NSSAI to solve the above problem.

[0030] In the above example, the AMF 30 has a slice deregistration inactivity timer and performs the above operation, but the UE 20 may have a slice deregistration inactivity timer and perform the above operation.

[0031] Furthermore, controlling slice usage using a timer such as a slice deregistration inactivity timer may be referred to as "network slice usage control" or "network slice usage monitoring." "Network slice usage control" may also be referred to as "slice usage control." Furthermore, the S-NSSAI and various NSSAIs may be collectively referred to as slice identifiers. Furthermore, "Allowed" means permission for a terminal 20 that wishes to use a slice.

[0032] <Problem 2> In relation to the establishment of the PDU session described above, a PDU Session Inactivity Timer and a User Plane Inactivity Timer are defined as timers that enable stopping the use of a slice when a PDU session is established but no data is being transmitted in the user plane. In addition, a PDU session slice usage inactivity timer has been proposed as a timer with finer granularity.

[0033] As described in Non-Patent Document 1 and the like, the UPF 50 starts the PDU Session inactivity timer when data transmission / reception ceases. If the PDU Session inactivity timer expires without data transmission / reception, the UPF 50 notifies the SMF 40 that the PDU Session inactivity timer has expired, and causes the SMF 40 to release the PDU session. Furthermore, if a slice of the released PDU session is not being used by another PDU session, the AMF 30 executes a procedure to delete the slice from the Allowed NSSAI.

[0034] Furthermore, as described in Non-Patent Document 4 and the like, the UPF 50 notifies the SMF 40 when no traffic is detected for the time indicated by the User Plane Inactivity Timer.

[0035] However, in the conventional technology described in existing specifications, the detailed operation related to the timer is unclear.

[0036] In this embodiment, examples 5 to 7 will be described as detailed operations related to timers such as a PDU Session inactivity timer, a User Plane Inactivity Timer, and a PDU session slice usage inactivity timer.

[0037] In the following description, Allowed NSSAI is an example of the set of allowed S-NSSAIs, Rejected NSSAI is an example of the set of rejected S-NSSAIs, Pending NSSAI is an example of the set of pending (or on hold) S-NSSAIs, and Configured NSSAI is an example of the set of configured S-NSSAIs. Note that the number of elements in the set is 0 or more.

[0038] Any of the first to seventh embodiments described below can be combined and implemented.

[0039] (Outline of Examples 1 to 4) An outline of Examples 1 to 4 will be described with reference to Fig. 3. As shown in Fig. 3, Examples 1 to 4 are examples of operations related to a registration procedure between the UE 20 and the AMF 30. In the registration procedure performed in S100, basically, a Registration request is transmitted from the UE 20 to the AMF 30, and after processing in the AMF 30, a Registration accept or the like is transmitted from the AMF 30 to the UE 20.

[0040] The first embodiment is an embodiment relating to an exception to network slice usage control in an emergency call connection, etc. The first embodiment is also an embodiment relating to the UE capability "UE configuration of network-controlled Slice Usage Policy."

[0041] The second embodiment relates to the timer characteristics during roaming. The third embodiment relates to the operation according to the timer value. The fourth embodiment relates to the operation when the timer expires.

[0042] The timer in Examples 1 to 4 is assumed to be a Slice deregistration inactivity timer, but is not limited to this. A timer other than a Slice deregistration inactivity timer may be used as the timer in Examples 1 to 4.

[0043] (First Embodiment) When network slice usage control using a timer is performed and the registration of a desired S-NSSAI is cancelled, the UE 20 is unable to perform communication using the desired slice. Such control is not desirable for emergency call connections. Therefore, in the first embodiment, an exceptional operation of the network slice usage control will be described.

[0044] Hereinafter, Example 1 will be described by dividing it into Example 1-1, Example 1-2, Example 1-3, and Example 1-4.

[0045] <Example 1-1> Example 1-1 is an example of an operation of a UE 20 that notifies a NW of support for a network slice usage control function. Example 1-1 is assumed to be an example of an operation related to an emergency call connection, but is not limited to an emergency call connection.

[0046] Specifically, the UE 20 notifies the NW of support for the network slice usage control function. The NW is, for example, the AMF 30. More specifically, the operation is as follows.

[0047] If UE 20 supports network slice usage control, UE 20 sets the NSUC bit to "Network slice usage control supported" in the 5GMM capability IE of the REGISTRATION REQUEST message sent to the NW.

[0048] However, if the registration request is for an emergency call connection, the UE 20 does not notify the NW of "Network slice usage control supported". Here, the case where the registration request is for an emergency call connection may be the case where the 5GS registration type IE in the REGISTRATION REQUEST message is set to "emergency registration".

[0049] In other words, if UE 20 supports Network slice usage control and the 5GS registration type IE in the REGISTRATION REQUEST message is not set to "emergency registration", UE 20 sets the NSUC bit in the 5 GMM capability IE to "Network slice usage control supported".

[0050] <Example 1-2> In Example 1-2, the operation of the NW according to the support of the network slice usage control function will be described. Here, the NW is, for example, the AMF 30. Example 1-2 is assumed to be an operation example related to emergency call connection, but is not limited to emergency call connection. Specific operations of the NW are as follows.

[0051] When UE 20 and NW support network slice usage control, if the S-NSSAI becomes an allowed S-NSSAI (S-NSSAI permitted for UE 20) but there is no PDU session using the S-NSSAI, AMF 30 executes a slice deregistration inactivity timer for the S-NSSAI and access type and performs network slice usage monitoring.

[0052] If the registration request is for an emergency call connection, the NW does not monitor the network slice usage. Specific operations are as follows.

[0053] If the network supports network slice usage control and the 5GS registration type IE sent from the UE 20 is set to "emergency registration", the S-NSSAI becomes an allowed S-NSSAI, but even if there is no PDU session using the S-NSSAI, the AMF 30 does not perform network slice usage monitoring "by executing the slice deregistration inactivity timer for the S-NSSAI and access type."

[0054] In other words, if the network supports network slice usage control and the 5GS registration type IE is not set to "emergency registration", and the S-NSSAI becomes an allowed S-NSSAI but there is no PDU session using the S-NSSAI, AMF30 executes a slice deregistration inactivity timer for the S-NSSAI and access type and performs network slice usage monitoring.

[0055] The network slice usage monitoring by the AMF 30 may be performed when the UE 20 supports the network slice usage control function. That is, the implementation condition of the network slice usage monitoring by the AMF 30 may depend on whether the UE supports the network slice usage control function. Specific operations are as follows.

[0056] If UE 20 and NW support network slice usage control and the 5GS registration type IE sent from UE 20 is set to "emergency registration", the S-NSSAI becomes an allowed S-NSSAI, but even if there is no PDU session using the S-NSSAI, AMF 30 does not perform network slice usage monitoring "by executing the slice deregistration inactivity timer for the S-NSSAI and access type."

[0057] In other words, when UE 20 and NW support network slice usage control and the 5GS registration type IE is not set to "emergency registration", if the S-NSSAI becomes an allowed S-NSSAI but there is no PDU session using the S-NSSAI, AMF 30 executes a slice deregistration inactivity timer for the S-NSSAI and access type and performs network slice usage monitoring.

[0058] <Example 1-3> Next, Example 1-3 will be described. In Example 1-3, an operation in which the UE 20 notifies the NW of an exception to network slice usage control will be described. The specific operation is as follows. Note that the following operation is not limited to an operation related to an emergency call connection. The operation may be applied to any purpose as long as deletion of the S-NSSAI by the timer is not desired.

[0059] If UE 20 supports the network slice usage control function and requests prolonged slice registration, UE 20 indicates a request for prolonged S-NSSAI registration (a request for exception processing, i.e., a request for not applying network slice usage control) in the REGISTRATION REQUEST message. The indication may be an indication that an S-NSSAI usage request is pending.

[0060] For example, suppose UE 20 decides to send a registration request for emergency services (emergency call connection). If UE 20 initiates initial registration for emergency services or needs to extend S-NSSAI registration after completing the initial registration procedure, UE 20 sets an indication for requesting prolonged S-NSSAI registration in the REGISTRATION REQUEST message.

[0061] <Example 1-4> Next, Example 1-4 will be described. In Example 1-4, the operation of the NW with respect to the UE operation of Example 1-3 in the exception of network slice usage control will be described. Here, the NW is, for example, the AMF 30. The specific operation is as follows.

[0062] When UE 20 requests prolonged S-NSSAI registration by a REGISTRATION REQUEST message, AMF 30 does not immediately delete the S-NSSAI from the Allowed NSSAI when a timer (e.g., Slice deregistration inactivity timer) expires. "Do not immediately delete the S-NSSAI" may also mean "do not delete the S-NSSAI." Note that detailed operations when a timer expires will be described in Example 4.

[0063] The above example is a method in which the timer for network slice usage control starts and exceptional handling is performed in the control when the timer expires. In addition to this method, exceptional handling may also be achieved by not starting the timer for network slice usage control itself. The specific operation is as follows.

[0064] If the UE 20 requests prolonged S-NSSAI registration in the REGISTRATION REQUEST message, the AMF 30 does not start a timer (e.g., a Slice deregistration inactivity timer).

[0065] <Effects of First Embodiment> According to the first embodiment, even when the conditions for executing the network slice usage control are met, it is possible to exceptionally not apply the network slice usage control.

[0066] (Example 2) Next, Example 2 will be described. In the network slice usage control of the conventional technology, it is not clear which S-NSSAI a timer is associated with. Therefore, in the conventional technology, there is a possibility that network slice usage control for a desired S-NSSAI cannot be performed appropriately. Therefore, in Example 2, the operation of the NW regarding the association between the timer and the S-NSSAI will be described. Here, the NW is, for example, the AMF 30.

[0067] Specifically, the NW starts a timer by the following operation. Here, the timer is, for example, a slice deregistration inactivity timer. Furthermore, the AMF 30 can determine whether the UE 20 is registered in the HPLMN or the VPLMN for the UE 20 from information received from the UE 20 (for example, a registration request), information received from the SMF 40, or information received from a network node other than the SMF 40. The HPLMN may be called a home network, and the VPLMN may be called a visited network.

[0068] When the UE 20 and the NW support network slice usage control, if an S-NSSAI becomes an allowed S-NSSAI but there is no PDU session using the S-NSSAI, the AMF 30 executes a slice deregistration inactivity timer for the S-NSSAI and each access type, and performs network slice usage monitoring. The slice deregistration inactivity timer starts when the S-NSSAI is not used by any PDU session in the corresponding access type.

[0069] An example of the operation for the network to determine the S-NSSAI to which the timer is associated will be described below.

[0070] When UE 20 is registered (slice registered) with the HPLMN, the NW assumes that the S-NSSAI associated with the timer is the S-NSSAI included in the Allowed NSSAI (in the UE context). That is, the NW associates the timer used for slice usage control with the S-NSSAI included in the Allowed NSSAI in the HPLMN. Figure 4 shows an example where the S-NSSAI associated with the timer is S-NSSAI#1. Note that the Serving NSSAI is an NSSAI (a collection of S-NSSAIs) specific to the PLMN in which UE 20 resides.

[0071] Examples of operations when UE20 is registered (slice registered) in VPLMN include the following operations (A) to (C).

[0072] (A) When UE 20 is registered (slice registered) in the VPLMN, the NW sets the S-NSSAI to be associated with the timer to the mapped S-NSSAI included in the Allowed NSSAI (in the UE context). When UE 20 is registered in the VPLMN, the mapped S-NSSAI is the S-NSSAI of the HPLMN that is associated with (mapped to) the S-NSSAI in the VPLMN.

[0073] (B) When UE 20 is registered (slice registered) with the VPLMN, the NW sets the S-NSSAI to be associated with the timer as a combination of the S-NSSAI and the mapped S-NSSAI included in the Allowed NSSAI (in the UE context). The combination of the S-NSSAI and the mapped S-NSSAI may be expressed as [S-NSSAI, mapped S-NSSAI]. The S-NSSAI in [S-NSSAI, mapped S-NSSAI] is the S-NSSAI of the Serving NSSAI. In other words, the S-NSSAI is the S-NSSAI of the VPLMN, and the mapped S-NSSAI is the S-NSSAI of the HPLMN mapped to the S-NSSAI.

[0074] It is possible to map S-NSSAI#X of the HPLMN to multiple S-NSSAIs (e.g., S-NSSAI#1, S-NSSAI#2, S-NSSAI#3) in the VPLMN. Operation (B) allows you to specify which of the multiple mappings the timer should be applied to.

[0075] (C) When UE 20 is registered (slice registered) with VPLMN, the NW sets the S-NSSAI to be associated with the timer to the serving S-NSSAI included in the Allowed NSSAI (in the UE context).

[0076] FIG. 5 shows the above-mentioned (A), (B), and (C).

[0077] <Effects of Second Embodiment> According to the second embodiment, it is possible to clarify the S-NSSAI associated with the timer, and as a result, it is possible to appropriately perform network slice usage control.

[0078] (Third Embodiment) Next, a third embodiment will be described. In the network slice usage control of the conventional technology, the operation according to the timer value is not clear. Therefore, in the conventional technology, there is a possibility that the network slice usage control according to the timer value cannot be appropriately performed. Therefore, in the third embodiment, the operation according to the timer value set in the timer will be described.

[0079] Hereinafter, the operation of the NW will be described as Example 3-1, and the operation of the UE 20 will be described as Example 3-2. Here, the NW is, for example, the AMF 30.

[0080] <Example 3-1> In Example 3-1, the NW (AMF 30) performs network slice usage control according to a timer value as follows: Here, the timer is, for example, a slice deregistration inactivity timer.

[0081] The AMF 30 receives a new timer value from the UDM or PCF. Alternatively, in the AMF 30, the timer value is set and updated as an AMF local setting or an AMF local policy.

[0082] If the timer value is neither "0" nor "deactivated", the AMF 30 stops the timer if the timer count is running, and then starts the timer with a value configured locally in the AMF 30 or received from the UDM and / or PCF.

[0083] If the timer value is "0" or "deactivated", the AMF 30 stops the timer if the timer is running and immediately performs slice deregistration of the slice corresponding to the timer. The detailed process of slice deregistration will be described in Example 4.

[0084] Additionally, the following actions may be taken: If the timer value is "deactivated", the AMF 30 stops the timer if the timer count is running. The value "deactivated" means that the associated S-NSSAI is no longer monitored.

[0085] <Example 3-2> In Example 3-2, the UE 20 performs network slice usage control according to a timer value as follows: Here, the timer may be a slice deregistration inactivity timer.

[0086] The UE 20 receives a new timer value from the AMF 30. If the timer value is neither "0" nor "deactivated", the UE 20 stops the timer if the timer count is running, and then starts the timer with the value received from the AMF 30.

[0087] If the timer value is "0" or "deactivated", the UE 20 stops the timer if the timer is running and immediately performs slice deregistration for the slice corresponding to the timer. Detailed processing for slice deregistration will be described in Example 4.

[0088] Additionally, the following actions may be taken: If the timer value is "deactivated", the UE 20 stops the timer if the timer count is running. The value "deactivated" means that the associated S-NSSAI is no longer being monitored.

[0089] <Effects of Third Embodiment> According to the third embodiment, it is possible to clarify the operation according to the timer value, and as a result, it is possible to appropriately perform network slice usage control.

[0090] (Fourth Embodiment) Next, a fourth embodiment will be described. In the fourth embodiment, an operation related to slice deregistration that is performed when a timer expires will be described. In conventional techniques, only an operation of deleting an S-NSSAI whose timer has expired from Allowed NSSAI is specified as an operation related to slice deregistration. However, such conventional techniques make it difficult to perform flexible control. Therefore, in the fourth embodiment, various operations will be described that are not limited to an operation of deleting an S-NSSAI whose timer has expired from Allowed NSSAI.

[0091] Below, examples 4-1 to 4-13 will be described as specific operation examples.

[0092] <Example 4-1> Example 4-1 describes an example of an operation related to slice deregistration that is performed when a timer in a network expires. The timer is, for example, a slice deregistration inactivity timer. Also, S-NSSAI(s) indicates one or more S-NSSAIs. The network is, for example, an AMF 30.

[0093] When the timer expires, AMF 30 performs slice deregistration for S-NSSAI as follows: Cases 1 to 3 are described below.

[0094] [Case 1] The AMF 30 locally deletes S-NSSAI(s) whose associated timers have expired from the Allowed NSSAI(s). Furthermore, the AMF 30 includes allowed S-NSSAI(s) that have no timers associated with them or that have timers associated with them but have not yet expired in the Allowed NSSAI(s). The Allowed NSSAI(s) can be included in, for example, a REGISTRATION ACCEPT message or a CONFIGURATION UPDATE COMMAND message sent to the UE 20.

[0095] [Case 2] When the timers for all S-NSSAIs included in the Allowed NSSAI expire, the AMF 30 locally deletes the S-NSSAI(s) whose associated timers have expired from the Allowed NSSAI. Furthermore, the AMF 30 includes a "slice usage control" indication set to "slice usage is enabled" and / or an empty Allowed NSSAI in the REGISTRATION ACCEPT message or the CONFIGURATION UPDATE COMMAND message sent to the UE 20 to indicate that all S-NSSAIs included in the Allowed NSSAI are subject to deletion.

[0096] [Case 3] If AMF 30 detects that the removed S-NSSAI in the Allowed NSSAI is the last S-NSSAI in the Allowed NSSAI, AMF 30 notifies / instructs UE 20 of the situation using a REGISTRATION ACCEPT message or a CONFIGURATION UPDATE COMMAND message, and causes UE 20 to use the default configured S-NSSAI in the subsequent procedures.

[0097] The following operation may also be performed: The AMF 30 adds the default configured S-NSSAI to the Allowed NSSAI and transmits the default configured S-NSSAI to the UE 20 using a REGISTRATION ACCEPT message or a CONFIGURATION UPDATE COMMAND message.

[0098] <Example 4-2> In Example 4-2, the operation of UE 20 when a slice deregistration instruction is received from a NW performing the operation of Example 4-1 will be described. UE 20 performs the operation according to the slice deregistration instruction as shown below. The following cases 1 to 3 correspond to cases 1 to 3 in Example 4-2.

[0099] [Case 1] When a new Allowed NSSAI for a PLMN or SNPN is received, UE 20 performs an NSSAI storage update as specified in, for example, Non-Patent Document 3 (4.6.2.2). For example, UE 20 sets the S-NSSAI to be included in the Allowed NSSAI to the S-NSSAI of the received new Allowed NSSAI.

[0100] [Case 2] Upon receiving a "slice usage control" instruction and / or an empty Allowed NSSAI, UE 20 deletes all stored S-NSSAI(s) and mapped S-NSSAI(s) for the S-NSSAI(s) from its Allowed NSSAI(s). If, as a result of the deletion, UE 20 has neither an Allowed NSSAI for the current PLMN nor a configured NSSAI for the current PLMN, UE 20 uses the default configured NSSAI for subsequent registration procedures.

[0101] [Case 3] Upon receiving the instruction / information, UE 20 performs registration using the default configured S-NSSAI, where the instruction / information may be an instruction / information indicating that the removed S-NSSAI in the Allowed NSSAI is the last S-NSSAI in the Allowed NSSAI.

[0102] Example 4-3 Example 4-3 describes an example of an operation related to slice deregistration that is performed when a timer expires in a network. The network is, for example, the AMF 30. The timer is, for example, a slice deregistration inactivity timer. In Example 4-3, the S-NSSAI is deleted from the Allowed NSSAI, and the S-NSSAI is set to the Rejected NSSAI. Note that deletion from the Allowed NSSAI is performed in all examples described in Example 4.

[0103] When the timer expires, AMF 30 performs slice deregistration for S-NSSAI as follows: Cases 1 to 3 are described below.

[0104] [Case 1] The AMF 30 locally includes the S-NSSAI(s) whose associated timers have expired in the rejected NSSAI (or extended rejected NSSAI). Furthermore, the AMF 30 includes the S-NSSAI(s) whose associated timers have expired in the rejected NSSAI (or extended rejected NSSAI) in the REGISTRATION ACCEPT message or CONFIGURATION UPDATE COMMAND message sent to the UE 20.

[0105] Note that the meaning of "rejected NSSAI" may include "extended rejected NSSAI." Also, "including S-NSSAI(s) whose associated timers have expired in the rejected NSSAI (or extended rejected NSSAI) in a REGISTRATION ACCEPT message or a CONFIGURATION UPDATE COMMAND message" also means "including S-NSSAI(s) whose associated timers have expired that are included in the rejected NSSAI (or extended rejected NSSAI) in a REGISTRATION ACCEPT message or a CONFIGURATION UPDATE COMMAND message." The same applies to subsequent REGISTRATION ACCEPT messages or CONFIGURATION UPDATE COMMAND messages.

[0106] [Case 2] If the timers for all S-NSSAIs included in the Allowed NSSAI have expired, AMF 30 locally includes the S-NSSAI(s) whose associated timers have expired in the rejected NSSAI (or extended rejected NSSAI). Furthermore, AMF 30 includes those S-NSSAI(s) in the rejected NSSAI (or extended rejected NSSAI) in the REGISTRATION ACCEPT message or the CONFIGURATION UPDATE COMMAND message. Note that an S-NSSAI marked as a default configured NSSAI is not targeted for slice usage control. In other words, AMF 30 does not need to monitor the default configured NSSAI for slice usage control.

[0107] [Case 3] So far, the operation of AMF 30 for performing slice deregistration has been described. In Case 3, the operation of AMF 30 for enabling reuse of the S-NSSAI(s) for which slice deregistration has been performed after slice deregistration has been performed by the above-mentioned process will be described. Specifically, in order to enable reuse of the S-NSSAI(s) included in the rejected NSSAI (extended rejected NSSAI) by slice deregistration, AMF 30 performs the following operation.

[0108] In the REGISTRATION ACCEPT message or the CONFIGURATION UPDATE COMMAND message to be sent to the UE 20, the AMF 30 does not include the S-NSSAI(s) in the rejected NSSAI (extended rejected NSSAI), and includes "slice usage control" that is not set to "slice usage control is enabled" in the REGISTRATION ACCEPT message or the CONFIGURATION UPDATE COMMAND message.

[0109] The NW may perform the operation of Example 4-3 in combination with the operation of Example 4-1. For example, the AMF 30 performs the following operation.

[0110] The AMF 30 includes S-NSSAI(s) whose associated timers have expired in the rejected NSSAI (or extended rejected NSSAI), and further includes other S-NSSAI(s) that are allowed but have no timers associated with them, or have timers associated with them but have not yet expired, in the Allowed NSSAI. The AMF 30 may also perform the following operations.

[0111] If the timers for all S-NSSAIs included in the Allowed NSSAI have expired, AMF 30 includes "a slice usage control indication with slice usage set to enabled and / or an empty Allowed NSSAI" and "S-NSSAI(s) in the rejected NSSAI (extended rejected NSSAI) whose timers have expired that were included in the Allowed NSSAI" in the REGISTRATION ACCEPT message or CONFIGURATION UPDATE COMMAND message sent to UE 20 to indicate that all S-NSSAIs included in the Allowed NSSAI are to be deleted.

[0112] <Example 4-4> In Example 4-4, the operation of UE 20 when a slice deregistration instruction is received from a NW performing the operation of Example 4-3 will be described. UE 20 performs the operation according to the slice deregistration instruction as shown below. The following cases 1 to 3 correspond to cases 1 to 3 in Example 4-3.

[0113] [Case 1] When UE 20 receives an S-NSSAI(s) included in a rejected NSSAI (or an extended rejected NSSAI), UE 20 performs the NSSAI storage update specified in Non-Patent Document 3 (4.6.2.2). For example, UE 20 sets the S-NSSAI to be included in the rejected NSSAI to the S-NSSAI of the received rejected NSSAI.

[0114] [Case 2] When UE 20 receives an S-NSSAI(s) included in a rejected NSSAI (extended rejected NSSAI), UE 20 performs the NSSAI storage update specified in Non-Patent Document 3 (4.6.2.2). For example, UE 20 sets the S-NSSAI to be included in the rejected NSSAI to the S-NSSAI of the received rejected NSSAI. Furthermore, if UE 20 has neither an Allowed NSSAI for the current PLMN nor a configured NSSAI for the current PLMN, UE 20 uses the default configured NSSAI for the subsequent registration procedure.

[0115] [Case 3] If the S-NSSAI is not included in the rejected NSSAI (or extended rejected NSSAI) in the received REGISTRATION ACCEPT message or CONFIGURATION UPDATE COMMAND message and the "slice usage control" indication is not set to "slice usage control is enabled", UE 20 deletes all S-NSSAI(s) in the rejected NSSAI that have a corresponding cause value for the current PLMN. By deleting the S-NSSAI(s) from the rejected NSSAI, the S-NSSAI(s) can be reused.

[0116] Example 4-5 In Example 4-5, an example of an operation related to slice deregistration that is performed when a timer in a network expires will be described. The network is, for example, the AMF 30. The timer is, for example, a slice deregistration inactivity timer. In Example 4-5, the S-NSSAI is deleted from the Allowed NSSAI and the S-NSSAI is set to Pending NSSAI.

[0117] When the timer expires, AMF 30 performs slice deregistration for S-NSSAI as follows: Cases 1 to 3 are described below.

[0118] [Case 1] AMF 30 locally includes S-NSSAI(s) whose associated timers have expired in the pending NSSAI. Furthermore, AMF 30 includes S-NSSAI(s) whose associated timers have expired in the pending NSSAI in a REGISTRATION ACCEPT message or a CONFIGURATION UPDATE COMMAND message sent to UE 20.

[0119] [Case 2] If the timers for all S-NSSAIs included in the Allowed NSSAI expire, AMF 30 locally includes the S-NSSAI(s) whose associated timers have expired in the pending NSSAI. Furthermore, AMF 30 includes those S-NSSAI(s) in the pending NSSAI in the REGISTRATION ACCEPT message or the CONFIGURATION UPDATE COMMAND message.

[0120] [Case 3] So far, the operation of AMF 30 for performing slice deregistration has been described. In Case 3, the operation of AMF 30 for enabling the reuse of the S-NSSAI(s) for which slice deregistration has been performed after slice deregistration is performed will be described. Specifically, in order to make the S-NSSAI(s) included in the pending NSSAI by slice deregistration usable again, AMF 30 performs the following operation.

[0121] In the REGISTRATION ACCEPT message or the CONFIGURATION UPDATE COMMAND message to be sent to the UE 20, the AMF 30 does not include S-NSSAI(s) in the pending NSSA, and includes "slice usage control" that is not set to "slice usage control is enabled" in the REGISTRATION ACCEPT message or the CONFIGURATION UPDATE COMMAND message.

[0122] The following operations may be performed: In the REGISTRATION ACCEPT message or the CONFIGURATION UPDATE COMMAND message, the AMF 30 includes a timer associated with the S-NSSAI in the Pending NSSAI, which timer defines the duration until the S-NSSAI in the Pending NSSAI becomes available.

[0123] The NW may perform the operation of Example 4-5 in combination with the operation of Example 4-1. For example, the AMF 30 performs the following operation.

[0124] The AMF 30 includes the S-NSSAI(s) whose associated timers have expired in the pending NSSAI, and further includes other S-NSSAI(s) that are allowed and have no timers associated with them, or have timers associated with them but have not yet expired, in the allowed NSSAI. The AMF 30 may also perform the following operations.

[0125] If the timers for all S-NSSAIs included in the Allowed NSSAI have expired, AMF 30 includes "a slice usage control indication with slice usage set to enabled and / or an empty Allowed NSSAI" and "S-NSSAI(s) in the pending NSSAI whose timers have expired that were included in the Allowed NSSAI" in the REGISTRATION ACCEPT message or CONFIGURATION UPDATE COMMAND message sent to UE 20 to indicate that all S-NSSAIs included in the Allowed NSSAI are to be deleted.

[0126] <Example 4-6> In Example 4-6, the operation of UE 20 when a slice deregistration instruction is received from a NW performing the operation of Example 4-5 will be described. UE 20 performs the operation according to the slice deregistration instruction as follows. The following cases 1 to 3 correspond to cases 1 to 3 in Example 4-5.

[0127] [Cases 1 and 2] When UE 20 receives the S-NSSAI(s) included in the pending NSSAI, UE 20 performs the NSSAI storage update specified in Non-Patent Document 3 (4.6.2.2). For example, UE 20 sets the S-NSSAI to be included in the pending NSSAI to the S-NSSAI of the received pending NSSAI.

[0128] [Case 3] If the pending NSSAI does not include an S-NSSAI and the "slice usage control" indication is not set to "slice usage control is enabled" in the REGISTRATION ACCEPT message or the CONFIGURATION UPDATE COMMAND message, UE 20 deletes all (any) S-NSSAI(s) in the pending NSSAI for the current PLMN. UE 20 may also perform the following operations.

[0129] Upon receiving the timer, UE 20 starts a timer for each S-NSSAI in the Pending NSSAI. While the timer value is not "0" and the timer is running, UE 20 is not permitted to use those S-NSSAIs until the timer expires. If the timer value is not "0", UE 20 is permitted to use those S-NSSAIs when the timer expires. If the timer value is "0", UE 20 is permitted to use those S-NSSAIs.

[0130] Example 4-7 In Example 4-7, an example of an operation related to slice deregistration performed when a timer in a network expires will be described. The timer is, for example, a slice deregistration inactivity timer. The network is, for example, the AMF 30. In Example 4-7, when the timer for deleting the S-NSSAI from Allowed NSSAI and further deleting the S-NSSAI from Configured NSSAI expires, the AMF 30 executes slice deregistration for the S-NSSAI as follows.

[0131] The AMF 30 locally deletes the S-NSSAI(s) whose associated timers have expired from the configured NSSAI. Furthermore, the AMF 30 includes the S-NSSAI(s) excluding the S-NSSAI(s) whose associated timers have expired in the configured NSSAI. The configured NSSAI can be included in, for example, a REGISTRATION ACCEPT message or a CONFIGURATION UPDATE COMMAND message sent to the UE 20.

[0132] The NW may perform the operation of Example 4-7 in combination with the operation of Example 4-1. For example, the AMF 30 performs the following operation.

[0133] AMF 30 includes S-NSSAI(s) excluding S-NSSAI(s) whose associated timers have expired in the configured NSSAI, and further includes allowed S-NSSAI(s) that do not have a timer associated with them or that have a timer associated with them but have not yet expired in the Allowed NSSAI.

[0134] <Example 4-8> In Example 4-8, an operation of the UE 20 when a slice deregistration instruction is received from a NW that performs the operation of Example 4-7 will be described. The UE 20 performs the operation according to the slice deregistration instruction as follows.

[0135] When UE 20 is configured with a new configured NSSAI in a PLMN, if UE 20 receives the new configured NSSAI for this PLMN in the same CONFIGURATION UPDATE COMMAND message and a Configuration update indication IE with the Registration requested bit not set to "registration requested", UE 20 deletes the S-NSSAIs of the Allowed NSSAIs that are not included in the new configured NSSAI and / or deletes the stored mapped S-NSSAI(s) for the Allowed NSSAI (if any).

[0136] <Example 4-9> Example 4-9 describes the operation of the UE 20 when a timer that operates based on a timer value received from a NW that operates in the same manner as in Example 3 expires. Specifically, the UE 20 performs the following operation.

[0137] When the timer expires, the UE 20 may locally delete the S-NSSAI from the Allowed NSSAI (5.15.15.2 UE Configuration of network-controlled Slice Usage Policy in Non-Patent Document 1).

[0138] <Example 4-10> Example 4-10 describes the operation of the UE 20 when a timer that operates based on a timer value received from a NW that operates in the same manner as in Example 3 expires. Specifically, the UE 20 performs the following operation.

[0139] When the timer expires, the UE 20 performs slice deregistration for the S-NSSAI as follows: Case 1 and Case 2 are explained below.

[0140] [Case 1] UE 20 locally includes S-NSSAI(s) whose associated timers have expired in the rejected NSSAI (or extended rejected NSSAI).

[0141] [Case 2] If the timers for all S-NSSAIs included in the Allowed NSSAI expire, UE 20 locally includes the S-NSSAI(s) whose associated timers have expired in the rejected NSSAI (or extended rejected NSSAI). Furthermore, when UE 20 has neither an Allowed NSSAI for the current PLMN nor a configured NSSAI for the current PLMN, UE 20 uses the default configured NSSAI for subsequent registration procedures.

[0142] The UE 20 may perform the operation of Example 4-10 in combination with the operation of Example 4-9. For example, the UE 20 may perform the following operation.

[0143] UE 20 locally includes the S-NSSAI(s) whose associated timers have expired in the rejected NSSAI (or extended rejected NSSAI), and locally removes the S-NSSAI(s) whose associated timers have expired from the Allowed NSSAI.

[0144] <Example 4-11> Example 4-11 describes the operation of the UE 20 when a timer that operates based on a timer value received from a NW that operates in the same manner as in Example 3 expires. Specifically, the UE 20 performs the following operation.

[0145] When the timer expires, the UE 20 performs slice deregistration for the S-NSSAI as follows: Case 1 and Case 2 are explained below.

[0146] [Case 1] UE 20 locally includes, in the pending NSSAI, S-NSSAI(s) whose associated timers have expired.

[0147] [Case 2] If the timers for all S-NSSAIs included in the Allowed NSSAI expire, UE 20 locally includes the S-NSSAI(s) whose associated timers have expired in the Pending NSSAI. Furthermore, when UE 20 has neither an Allowed NSSAI for the current PLMN nor a configured NSSAI for the current PLMN, UE 20 uses the default configured NSSAI for subsequent registration procedures.

[0148] The UE 20 may perform the operation of Example 4-11 in combination with the operation of Example 4-9. For example, the UE 20 may perform the following operation.

[0149] UE 20 locally includes the S-NSSAI(s) whose associated timers have expired in the pending NSSAI, and locally deletes the S-NSSAI(s) whose associated timers have expired from the Allowed NSSAI.

[0150] <Example 4-12> Example 4-12 describes the operation of the UE 20 when a timer that operates based on a timer value received from a NW that operates in the same manner as in Example 3 expires. Specifically, the UE 20 performs the following operation.

[0151] When the timer expires, the UE 20 performs slice deregistration for the S-NSSAI as follows: Case 1 and Case 2 are explained below.

[0152] [Case 1] UE 20 locally deletes S-NSSAI(s) whose associated timers have expired from the configured NSSAI.

[0153] [Case 2] If the timers for all S-NSSAIs included in the Allowed NSSAI expire, UE 20 deletes the S-NSSAI(s) whose associated timers have expired from the locally configured NSSAI. Furthermore, when UE 20 has neither an Allowed NSSAI for the current PLMN nor a configured NSSAI for the current PLMN, UE 20 uses the default configured NSSAI for subsequent registration procedures.

[0154] The UE 20 may perform the operation of Example 4-12 in combination with the operation of Example 4-9. For example, the UE 20 may perform the following operation.

[0155] UE 20 locally deletes the S-NSSAI(s) whose associated timers have expired from the configured NSSAI, and locally deletes the S-NSSAI(s) whose associated timers have expired from the Allowed NSSAI.

[0156] Example 4-13 In Example 4-13, a description is given of the operation of the network related to slice usage control when the UE 20 does not request an S-NSSAI in the registration procedure or when there is no S-NSSAI that can be allowed for the UE 20. The specific operation is as follows. The network is, for example, the AMF 30.

[0157] If the UE 20 does not include an S-NSSAI in the requested NSSAI in the transmitted REGISTRATION REQUEST message, or if any of the S-NSSAIs in the requested NSSAI in the REGISTRATION REQUEST message is not allowed, the NW does not include S-NSSAI(s) that are subject to network slice usage control (or that are subject to execution of the deregistration inactivity timer) in the Allowed NSSAI. As a result, the NW does not monitor for network slice usage control.

[0158] Here, the AMF 30 can determine whether the S-NSSAI(s) are subject to network slice usage control based on the subscription data. Specifically, if a timer is associated with the S-NSSAI(s) in the subscription data, the AMF 30 determines that the S-NSSAI(s) are subject to network slice usage control. Here, the timer is, for example, a deregistration inactivity timer.

[0159] All of the embodiments of Example 4 have been described above. An image of deleting an S-NSSAI in Example 4 is shown in Figure 6. In Figure 6, option 1 indicates deleting the S-NSSAI from Allowed NSSAI. In addition to deleting the S-NSSAI from Allowed NSSAI, options 2 and 3 indicate including the S-NSSAI in Rejected NSSAI and Pending NSSAI, respectively. Option 4 indicates deleting the S-NSSAI from Allowed NSSAI and deleting the S-NSSAI from Configured NSSAI. As described above, when including the S-NSSAI in Rejected NSSAI, Pending NSSAI, etc., it is possible to restore the deleted S-NSSAI as described in Case 3.

[0160] <Effects of Fourth Embodiment> According to the fourth embodiment, various operations when a timer expires become clear, and as a result, network slice usage control can be appropriately executed.

[0161] (Outline of Examples 5 to 7) As described in the above-mentioned Problem 2, in the conventional technology described in existing specifications, the details of the operations related to timers such as the PDU Session Inactivity Timer, the User Plane Inactivity Timer, and the PDU session slice usage inactivity timer are unclear. In Examples 5 to 7, the operations of network nodes (specifically, the SMF 40 and the UPF 50) for solving Problem 2 are described. Note that the User Plane may be abbreviated as UP.

[0162] An overview of the fifth to seventh embodiments will be described with reference to Fig. 7. The timer used in the following description may be a User Plane Inactivity Timer, a PDU session slice usage inactivity timer, or any other timer.

[0163] In S200, a procedure is executed to establish a PDU session used by the UE 20. In S300, a procedure is executed to establish a Packet Forwarding Control Protocol (PFCP) session, which is a session between the SMF 40 and the UPF 50. At this time, the SMF 40 notifies the UPF 50 of a timer value (Non-Patent Document 4).

[0164] That is, the SMF 40 (which may also be called a CP function) notifies the UPF 50 (which may also be called an UP function) of the timer value, requesting that the UPF 50 report to the SMF 40 if it detects that no user plane data (packets) are being sent or received.

[0165] Furthermore, the UPF 50 that has received the timer value monitors user plane traffic, and if no traffic is received for the period of the timer value, reports this to the SMF 40. This enables the SMF 40 to stop using a slice for which a PDU session has been established but no data is being sent or received in the user plane.

[0166] A fifth embodiment is an embodiment of NSSAI information that the SMF 40 specifies when instructing the UPF 50 to monitor (specifically, UP inactivity monitoring). A sixth embodiment is an embodiment of S-NSSAI that associates a timer in the UPF 50. A seventh embodiment is an embodiment of an operation according to a timer value.

[0167] (Example 5) In the conventional technology, it is not clear which S-NSSAI is to be specified when UP inactivity monitoring is notified from the SMF 40 to the UPF 50. Therefore, in the conventional UP inactivity monitoring, there is a possibility that UP inactivity monitoring for a slice cannot be performed appropriately.

[0168] Therefore, in the fifth embodiment, an operation of the SMF 40 that notifies the UPF 50 of S-NSSAI information for performing UP inactivity monitoring will be described. The specific operation is as follows.

[0169] The CP function (SMF 40) provides the S-NSSAI IE to the UP function (UPF 50) for UP inactivity monitoring. The S-NSSAI IE is included in a PFCP Session Establishment Request message. The SMF 40 includes the following variations of the S-NSSAI IE in the message: Note that in the fifth and sixth embodiments, the PDU session establishment message (UL NAS transport message) shown below is an example of a message that notifies the S-NSSAI, and the corresponding S-NSSAI may be included in a message other than this message.

[0170] When UE 20 is registered (slice registered) with the HPLMN, SMF 40 assumes that the S-NSSAI to be included in the S-NSSAI IE is the S-NSSAI (S-NSSAI of HPLMN) included in the PDU session establishment message (UL NAS transport message). An example in which the S-NSSAI to be included in the S-NSSAI IE is S-NSSAI#1 is the same as that shown in Figure 4 above.

[0171] Examples of operations when UE20 is registered (slice registered) in VPLMN include the following operations (A) to (C).

[0172] (A) When UE 20 is registered (slice registered) in VPLMN, SMF 40 sets the S-NSSAI to be included in the S-NSSAI IE to the mapped S-NSSAI included in the PDU session establishment message (UL NAS transport message).

[0173] (B) When UE 20 is registered (slice registered) with VPLMN, SMF 40 sets the S-NSSAI to be included in the S-NSSAI IE as both (combination) of the serving S-NSSAI and the mapped S-NSSAI included in the PDU session establishment message (UL NAS transport message). This combination may be expressed as [S-NSSAI, mapped S-NSSAI].

[0174] (C) When UE 20 is registered (slice registered) in VPLMN, SMF 40 sets the S-NSSAI to be included in the S-NSSAI IE to the serving S-NSSAI included in the PDU session establishment message (UL NAS transport message).

[0175] The above-mentioned FIG. 5 shows the above-mentioned (A), (B), and (C).

[0176] <Effects of the Fifth Embodiment> According to the fifth embodiment, the SMF 40 can clearly notify the UPF 50 of the slice (S-NSSAI) to be monitored.

[0177] (Example 6) In the conventional technology, it is unclear for which slice (S-NSSAI) the UPF 50 performs UP inactivity monitoring using a timer. Therefore, in the conventional UP inactivity monitoring, there is a possibility that the UP inactivity monitoring cannot be performed appropriately.

[0178] Therefore, in the sixth embodiment, the operation of the NW that associates a timer with the S-NSSAI will be described. Here, the NW may be the UPF 50. Furthermore, the following operation may be the operation of the UFP 50 that receives an instruction from the operation of the SMF 40 in the fifth embodiment. Specifically, the NW performs the following operation. Here, the timer is, for example, a timer for user plane inactivity monitoring, such as a User Plane Inactivity Timer or a PDU session slice usage inactivity timer. However, the timer is not limited to these timers.

[0179] The NW determines the S-NSSAI to be associated with a timer for monitoring UP inactivity for a slice as follows: By monitoring the slice (S-NSSAI) associated as follows using the timer, the NW can determine whether there is no traffic in the slice for the period of the timer value.

[0180] When UE 20 is registered (slice registered) with the HPLMN, the NW assumes that the S-NSSAI to be associated with the timer is the S-NSSAI(HPLMN) included in the PDU session establishment message (UL NAS transport message). An example in which the S-NSSAI associated with the timer is S-NSSAI#1 is the same as that shown in Figure 4 above.

[0181] Examples of operations when UE20 is registered (slice registered) in VPLMN include the following operations (A) to (C).

[0182] (A) When UE 20 is registered (slice registered) in the VPLMN, the NW sets the S-NSSAI to be associated with the timer to the mapped S-NSSAI included in the PDU session establishment message (UL NAS transport message).

[0183] (B) When UE 20 is registered (slice registered) with the VPLMN, the NW associates the S-NSSAI with the timer as a combination of the serving S-NSSAI and the mapped S-NSSAI included in the PDU session establishment message (UL NAS transport message). This combination may be expressed as [S-NSSAI, mapped S-NSSAI].

[0184] (C) When UE 20 is registered (slice registered) with the VPLMN, the NW sets the S-NSSAI to be associated with the timer to the serving S-NSSAI included in the PDU session establishment message (UL NAS transport message).

[0185] The above-mentioned FIG. 5 shows the above-mentioned (A), (B), and (C).

[0186] <Effects of the Sixth Embodiment> According to the sixth embodiment, the S-NSSAI associated with the timer becomes clear, and as a result, it becomes possible to appropriately perform UP inactivity monitoring for the slice.

[0187] (Seventh Example) Next, a seventh example will be described. In UP inactivity monitoring in the conventional technology, the operation according to the timer value is not clear. Therefore, in the conventional technology, there is a possibility that UP inactivity monitoring according to the timer value for a slice cannot be performed appropriately. Therefore, in the seventh example, an operation according to the timer value set in the timer in the NW will be described. Here, the NW may be the UPF 50. The specific operation is as follows. Here, the timer is, for example, a timer for user plane inactivity monitoring, and more specifically, a User Plane Inactivity Timer, a PDU session slice usage inactivity timer, etc. However, the timer is not limited to these.

[0188] The UPF 50 receives a new timer value from the SMF 40. If the timer value is neither "0" nor "deactivated," the UPF 50 stops the timer if the timer count is running, and then starts the timer with the value received from the SMF 40.

[0189] If the timer value is "0" or "deactivated", the UPF 50 stops the timer if the timer count is running, and also stops user plane inactivity monitoring for the associated slice (the slice identified by the network slice instance ID and / or S-NSSAI).

[0190] Additionally, the following actions may be taken: If the timer value is "deactivated", the UPF 50 stops the timer if the timer count is running. The value "deactivated" means that the associated slice (the slice identified by the network slice instance ID and / or S-NSSAI) is no longer monitored (i.e., no UP inactivity report is required).

[0191] <Effects of the Seventh Embodiment> According to the seventh embodiment, the operation according to the timer value becomes clear, and as a result, it becomes possible to appropriately perform UP inactivity monitoring for the slice.

[0192] (Other examples (variations)) In all the examples described so far, the target of monitoring is a slice, and the S-NSSAI, which is the identifier of the slice, is associated with a timer and registered / deregistered, etc., but the target of the technology related to this embodiment is not limited to slices and S-NSSAI.

[0193] For example, the monitoring target may be a network path (path for each quality) instead of a slice, and the target for association with a timer and registration / deregistration, etc. may be an identifier for identifying a path for each quality instead of an S-NSSAI. That is, in all the embodiments described so far, the slice may be replaced with the above path, and the S-NSSAI may be replaced with the above identifier.

[0194] In another example, the monitoring target may be a slice instance instead of the slice identified by S-NSSAI, and the target for association with a timer and registration / deregistration, etc. may be a slice instance ID instead of S-NSSAI. In other words, in all the embodiments described so far, the slice identified by S-NSSAI may be replaced with the above slice instance, and S-NSSAI may be replaced with the above slice instance ID.

[0195] (Device Configuration) Here, the UE 20 is referred to as the terminal 20. An example of the functional configuration of the AMF 30, SMF 40, UPF 50, and terminal 30 that perform the processes and operations described above will be described. The AMF 30, SMF 40, and UPF 50 are all examples of network nodes, and have the same functional configuration. Therefore, hereinafter, the AMF 30, SMF 40, and UPF 50 will be collectively referred to as the network nodes 30, 40, and 50.

[0196] <Processing device 10> Fig. 8 is a diagram showing an example of the functional configuration of the network nodes 30, 40, and 50. As shown in Fig. 8, the network nodes 30, 40, and 50 have a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Fig. 8 is merely an example. The names of the functional divisions and functional units may be any as long as they can perform the operations related to the embodiment of the present invention.

[0197] The transmitting unit 110 has a function of generating a signal to be transmitted to another device and transmitting the signal via a wired or wireless connection. The receiving unit 120 has a function of receiving various signals transmitted from other devices and acquiring, for example, information of a higher layer from the received signal. A communication unit including the transmitting unit 110 and the receiving unit 120 may be configured. The transmitting unit 110 and the receiving unit 120 may be called a transmitter and a receiver, respectively.

[0198] The setting unit 130 stores preset setting information and various setting information to be transmitted to other devices in a storage device, and reads out the information from the storage device as needed.

[0199] The control unit 140 controls the network nodes 30, 40, and 50. The function unit in the control unit 140 related to signal transmission may be included in the transmitting unit 110, and the function unit in the control unit 140 related to signal reception may be included in the receiving unit 120.

[0200] <Terminal 20> Fig. 9 is a diagram showing an example of the functional configuration of the terminal 20. As shown in Fig. 9, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Fig. 9 is merely an example. The names of the functional divisions and functional units may be any as long as they can perform the operations related to the embodiment of the present invention.

[0201] The transmitting unit 210 has a function of generating a signal to be transmitted to another device and transmitting the signal wirelessly (or via a wired connection). The receiving unit 220 has a function of receiving various signals transmitted from another device (e.g., the base station 10) and acquiring, for example, information of a higher layer from the received signal. A communication unit including the transmitting unit 210 and the receiving unit 220 may be configured. The transmitting unit 210 and the receiving unit 220 may be called a transmitter and a receiver, respectively.

[0202] The setting unit 230 stores preset setting information and various setting information to be transmitted to other devices in a storage device, and reads out the information from the storage device as needed.

[0203] The control unit 240 controls the requesting device 20. The functional units in the control unit 240 related to signal transmission may be included in the transmitting unit 210, and the functional units in the control unit 240 related to signal reception may be included in the receiving unit 120.

[0204] (Hardware Configuration) The block diagrams (FIGS. 8 and 9) used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or the multiple devices.

[0205] Functions include, but are not limited to, judgment, determination, assessment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how these functions are implemented.

[0206] For example, the network nodes 30, 40, 50 and the terminal 20 according to an embodiment of the present disclosure may function as computers that perform processing of the communication method of the present disclosure. Fig. 10 is a diagram illustrating an example of the hardware configuration of the network nodes 30, 40, 50 and the terminal 20 according to an embodiment of the present disclosure. The network nodes 30, 40, 50 and the terminal 20 described above may be physically configured as computer devices including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0207] In the following description, the term "apparatus" can be read as a circuit, a device, a unit, etc. The hardware configurations of the network nodes 30, 40, 50 and the terminal 20 may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0208] Each function in the network nodes 30, 40, 50 and the terminal 20 is realized by loading specified software (programs) onto hardware such as the processor 1001, the memory device 1002, etc., so that the processor 1001 performs calculations, controls communication via the communication device 1004, and controls at least one of reading and writing data in the memory device 1002 and the auxiliary memory device 1003.

[0209] The processor 1001 controls the entire computer by running, for example, an operating system. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

[0210] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002 and executes various processes in accordance with the programs. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 140 of the network nodes 30, 40, and 50 shown in FIG. 8 may be implemented by a control program stored in the storage device 1002 and running on the processor 1001. For example, the control unit 240 of the terminal 20 shown in FIG. 9 may be implemented by a control program stored in the storage device 1002 and running on the processor 1001. While the above-described various processes have been described as being executed by one processor 1001, they may also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may also be transmitted from a network via a telecommunications line.

[0211] The storage device 1002 is a computer-readable recording medium and may be configured, for example, by at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), etc. The storage device 1002 may also be called a register, a cache, a main memory, etc. The storage device 1002 can store executable programs (program codes), software modules, etc. for implementing a communication method according to an embodiment of the present disclosure.

[0212] The secondary storage device 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, or other appropriate medium including at least one of the storage device 1002 and the secondary storage device 1003.

[0213] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, a transmission / reception antenna, an amplifier unit, a transmission / reception unit, a transmission path interface, etc. may be realized by the communication device 1004. The transmission / reception unit may be implemented as a transmission unit and a reception unit that are physically or logically separated.

[0214] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0215] Furthermore, each device such as the processor 1001 and the storage device 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0216] Furthermore, the network nodes 30, 40, 50 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0217] 11 shows a configuration example of a vehicle 2001 that can include network nodes 30, 40, and 50, and a terminal 20. As shown in FIG. 11 , the vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013. Each aspect / embodiment described in the present disclosure may be applied to a communication device mounted on the vehicle 2001, and may be applied to the communication module 2013, for example. For example, the network nodes 30, 40, and 50, or the terminal 20, may be included in the communication module 2013.

[0218] The drive unit 2002 is configured, for example, by an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel operated by the user.

[0219] The electronic control unit 2010 is composed of a microprocessor 2031, a memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals are input to the electronic control unit 2010 from various sensors 2021 to 2029 provided in the vehicle 2001. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0220] The signals from the various sensors 2021 to 2029 include a current signal from a current sensor 2021 that senses the current of the motor, a rotation speed signal of the front and rear wheels obtained by a rotation speed sensor 2022, an air pressure signal of the front and rear wheels obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, an accelerator pedal depression amount signal obtained by an accelerator pedal sensor 2029, a brake pedal depression amount signal obtained by a brake pedal sensor 2026, a shift lever operation signal obtained by a shift lever sensor 2027, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028.

[0221] The information service unit 2012 is composed of various devices, such as a car navigation system, an audio system, speakers, a television, and a radio, for providing (outputting) various types of information, such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 2012 uses information acquired from external devices via the communication module 2013 or the like to provide various types of multimedia information and multimedia services to the occupants of the vehicle 2001. The information service unit 2012 may include input devices (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, a touch panel, etc.) that accept input from the outside, and may also include output devices (e.g., a display, a speaker, an LED lamp, a touch panel, etc.) that output information to the outside.

[0222] The driving assistance system unit 2030 is composed of various devices that provide functions for preventing accidents and reducing the driving burden on the driver, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS, etc.), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps, etc.), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System), etc.), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. In addition, the driving assistance system unit 2030 transmits and receives various information via the communication module 2013 to realize the driving assistance function or the autonomous driving function.

[0223] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via the communication port. For example, the communication module 2013 transmits and receives data via the communication port 2033 to and from the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 29, which are provided in the vehicle 2001.

[0224] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, or the like.

[0225] The communication module 2013 may transmit, via wireless communication, to an external device at least one of signals from the various sensors 2021-2028 input to the electronic control unit 2010, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 2012. The electronic control unit 2010, the various sensors 2021-2028, the information service unit 2012, etc. may be referred to as input units that accept input.

[0226] The communication module 2013 receives various information (traffic information, traffic signal information, vehicle-to-vehicle information, etc.) transmitted from external devices and displays it on an information service unit 2012 provided in the vehicle 2001. The information service unit 2012 may be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 2013). The communication module 2013 also stores the various information received from external devices in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axles 2009, sensors 2021 to 2029, etc. provided in the vehicle 2001. When the communication module 2013 includes a network node 30, 40, 50 or a terminal 20, the communication module 2013 can perform the operations of the included network node 30, 40, 50 or terminal 20.

[0227] This specification discloses at least the configurations described in Supplementary Notes 1 to 6 below.

[0228] <Supplementary Note 1> (Supplementary Item 1) A network node comprising: a receiving unit that receives a registration request for a connection for a specific purpose from a terminal; and a control unit that has a function of deregistering a slice identifier that has no associated session for a certain period of time, and that, when the registration request is received, does not perform processing to deregister a slice identifier that has been authorized for the terminal. (Supplementary Item 2) The network node according to Supplementary Item 1, wherein the specific purpose is an emergency call connection. (Supplementary Item 3) A network node comprising: a receiving unit that receives a registration request from a terminal, including a request for registration of an extended slice identifier; and a control unit that has a function of deregistering a slice identifier that has no associated session for a certain period of time, and that, when the registration request is received, does not start a timer for the slice identifier that has been authorized for the terminal, or does not deregister the slice identifier even if the timer expires. (Supplementary Item 4) A terminal comprising: a control unit that decides to transmit a registration request for a specific purpose; and a transmitting unit that transmits the registration request, including a request for registration of an extended slice identifier, to a network node. (Supplementary Item 5) A processing method executed by a network node, comprising: a step of receiving a registration request for a connection for a specific purpose from a terminal; and a step executed by a control unit having a function of deregistering a slice identifier that does not have an associated session for a certain period of time, wherein when the registration request is received, the control unit does not perform processing to deregister a slice identifier that has been authorized for the terminal.

[0229] Any of Supplementary Items 1 to 5 provides a technique that enables appropriate deregistration of a slice identifier. Supplementary Item 2 makes it possible to realize exceptional operation in the case of an emergency call connection.

[0230] <Supplementary Note 2> (Supplementary Item 1) A network node comprising: a receiver that receives a registration request; and a control unit that, when a terminal is registered in a home network, associates a timer used for slice usage control with an authorized slice identifier in the home network. (Supplementary Item 2) A network node comprising: a receiver that receives a registration request; and a control unit that, when a terminal is registered in a visited network, associates a timer used for slice usage control with an authorized slice identifier that is a mapped slice identifier. (Supplementary Item 3) A network node comprising: a receiver that receives a registration request; and a control unit that, when a terminal is registered in a visited network, associates a timer used for slice usage control with an authorized slice identifier combination, that is a combination of a slice identifier of the visited network and a mapped slice identifier. (Supplementary Item 4) A network node comprising: a receiver that receives a registration request; and a control unit that, when a terminal is registered in a visited network, associates a timer used for slice usage control with an authorized slice identifier in the visited network. (Supplementary Item 5) A processing method executed by a network node, comprising: a step of receiving a registration request; and a step of associating a timer used for slice usage control with an allowed slice identifier in the home network when a terminal is registered in the home network.

[0231] Any of Supplementary Items 1 to 5 provides a technique that enables appropriate deregistration of a slice identifier.

[0232] <Supplementary Note 3> (Supplementary Item 1) A network node comprising: a receiving unit that receives a new timer value of a timer used for slice usage control from a specific network node; and a control unit that, when the timer value is neither 0 nor inactive, stops the timer if it is running and starts the timer with the new timer value or a locally set timer value. (Supplementary Item 2) The network node according to Supplementary Item 1, when the timer value is 0 or inactive, the control unit stops the timer and executes deregistration of the slice corresponding to the timer. (Supplementary Item 3) A terminal comprising: a receiving unit that receives a new timer value of a timer used for slice usage control from a specific network node; and a control unit that, when the timer value is neither 0 nor inactive, stops the timer if it is running and starts the timer with the new timer value. (Supplementary Item 4) The terminal according to Supplementary Item 3, when the timer value is 0 or inactive, the control unit stops the timer and executes deregistration of the slice corresponding to the timer. (Supplementary Item 5) A processing method executed by a network node, comprising the steps of: receiving a new timer value for a timer used for slice usage control from a specific network node; and, if the timer value is neither 0 nor inactive, stopping the timer if it is running, and starting the timer with the new timer value or a locally set timer value.

[0233] Any of Supplementary Items 1 to 5 provides a technique that enables appropriate deregistration of a slice identifier. Supplementary Items 2 and 4 enable deregistration of a slice according to a timer value.

[0234] <Supplementary Note 4> (Supplementary Note 1) A network node comprising: a control unit that, when a terminal is registered in a target network, includes a mapped slice identifier included in a session establishment message in a message instructing user plane monitoring, and a transmission unit that transmits the message including the mapped slice identifier to a specific network node. (Supplementary Note 2) A network node comprising: a control unit that, when a terminal is registered in a target network, includes a combination of a slice identifier of the target network and a mapped slice identifier included in a session establishment message in a message instructing user plane monitoring, and a transmission unit that transmits the message including the combination to a specific network node. (Supplementary Note 3) A network node comprising: a receiving unit that receives a PFCP session establishment request from a specific network node, and a control unit that, when a terminal is registered in a target network, associates a timer used for user plane monitoring with a mapped slice identifier included in a PDU session establishment message. (Supplementary Item 4) A network node comprising: a receiving unit that receives a PFCP session establishment request from a specific network node; and a control unit that, when a terminal is registered in a target network, associates a timer used for monitoring the user plane with a combination of a slice identifier of the target network and a mapped slice identifier contained in a PDU session establishment message. (Supplementary Item 5) A processing method executed by a network node, comprising: when a terminal is registered in a target network, including a mapped slice identifier contained in a session establishment message in a message instructing monitoring of the user plane; and transmitting the message including the mapped slice identifier to a specific network node.

[0235] Any of Supplementary Items 1 to 5 provides a technique that enables appropriate monitoring required for stopping slice usage.

[0236] <Supplementary Note 5> (Supplementary Note 1) A network node comprising: a receiving unit that receives a new timer value of a timer used to monitor a slice from a specific network node; and a control unit that, when the timer value is neither 0 nor inactive, stops the timer if it is running and starts the timer with the new timer value. (Supplementary Note 2) The network node according to Supplementary Note 1, when the timer value is 0 or inactive, the control unit stops the timer and stops monitoring of the slice corresponding to the timer. (Supplementary Note 3) A processing method executed by a network node, comprising: a step of receiving a new timer value of a timer used to monitor a slice from a specific network node; and a step of, when the timer value is neither 0 nor inactive, stopping the timer if it is running and starting the timer with the new timer value.

[0237] Any of Supplementary Items 1 to 5 provides a technique that enables appropriate monitoring required for stopping slice usage. According to Supplementary Item 2, it is possible to realize stopping of slice usage according to a timer value.

[0238] <Supplementary Note 6> (Supplementary Item 1) A network node comprising: a control unit that includes a slice identifier for which a timer used for slice usage control has expired in a set of rejected or pending slice identifiers; and a transmission unit that transmits a message including a slice identifier included in the set to a terminal. (Supplementary Item 2) The network node according to Supplementary Item 1, wherein the transmission unit transmits a message to the terminal that does not include a slice identifier in the set of rejected or pending slice identifiers. (Supplementary Item 3) A terminal comprising: a receiving unit that receives a message having a set of rejected or pending slice identifiers including a slice identifier for which a timer used for slice usage control has expired; and a control unit that updates slice identifiers stored in a storage device based on the set. (Supplementary Item 4) The terminal according to Supplementary Item 3, wherein, when the receiving unit receives a message that does not include a slice identifier in the set, the control unit deletes the slice identifier from the set of rejected or pending slice identifiers in the terminal. (Supplementary Item 5) A processing method executed by a network node, comprising the steps of: including a slice identifier for which a timer used for slice usage control has expired in a set of rejected or pending slice identifiers; and sending a message including the slice identifier included in the set to a terminal.

[0239] Any of Supplementary Items 1 to 5 provides a technique that enables proper deregistration of a slice identifier. Supplementary Items 2 and 4 enable revival of a rejected or pending slice identifier.

[0240] (Supplementary Notes on the Embodiments) Although the embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, and substitutions. While specific numerical examples have been used to facilitate understanding of the invention, unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention; matters described in two or more items may be used in combination as needed, and matters described in one item may apply to matters described in another item (unless inconsistent). Boundaries between functional units or processing units in functional block diagrams do not necessarily correspond to physical component boundaries. The operations of multiple functional units may be performed by a single physical component, or the operations of a single functional unit may be performed by multiple physical components. The order of processing steps described in the embodiments may be reversed as long as there is no contradiction. For convenience of processing description, the processing device 10 and requesting device 20 have been described using functional block diagrams. However, such devices may be implemented using hardware, software, or a combination thereof. The software operated by the processor of the base station 10 in accordance with an embodiment of the present invention and the software operated by the processor of the terminal 20 in accordance with an embodiment of the present invention may each be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server, or any other suitable storage medium.

[0241] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling), broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination thereof. Furthermore, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0242] Each aspect / embodiment described in the present disclosure may be implemented using any of the following standards: LTE (Long Term Evolution), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (x is, for example, an integer or a decimal number)), FRA (Future Radio Access), NR (new Radio), New radio access (NX), Future generation radio access (FX), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.17 (WiMAX (registered trademark)), IEEE 802.19 (WiMAX (registered trademark)), IEEE 802.20 (WiMAX (registered trademark)), IEEE 802.21 (Wi-Fi (registered trademark)), IEEE 802.22 (WiMAX (registered trademark)), IEEE 802.23 (WiMAX (registered trademark)), IEEE 802.24 (WiMAX (registered trademark)), IEEE 802.25 (WiMAX (registered trademark)), IEEE 802.26 (WiMAX (registered trademark)), IEEE 802.27 (WiMAX (registered trademark)), IEEE 802.28 (WiMAX (registered trademark)), IEEE 802.29 (WiMAX (registered trademark)), IEEE 802.30 (WiMAX (registered trademark)), IEEE 802.31 (Wi-Fi (registered trademark)), IEEE 802.32 (WiMAX (registered trademark)), IEEE 802.33 (WiMAX (registered trademark)), IEEE 802.34 ( The present invention may be applied to at least one of systems using 802.20, UWB (Ultra-Wide Band), Bluetooth (registered trademark), or other suitable systems, and next-generation systems that are extended, modified, created, or defined based on these systems. The present invention may also be applied to a combination of multiple systems (e.g., a combination of LTE and / or LTE-A with 5G).

[0243] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described herein may be rearranged unless it is consistent. For example, the methods described in this disclosure present elements of various steps using an example order and are not limited to the particular order presented.

[0244] The information, signals, etc. described in the present disclosure may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0245] Input and output information may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information may be overwritten, updated, or added to. Output information may be deleted. Input information may be transmitted to another device.

[0246] In the present disclosure, the determination may be made by a value represented by one bit (0 or 1), by a Boolean value (true or false), or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0247] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0248] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0249] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0250] Note that terms described in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0251] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0252] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, relative values ​​from a predetermined value, or other corresponding information. For example, a radio resource may be indicated by an index.

[0253] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0254] In the present disclosure, terms such as "base station (BS)," "radio base station," "base station device," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. A base station may also be referred to by terms such as a macrocell, a small cell, a femtocell, and a picocell.

[0255] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be partitioned into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication services within that coverage.

[0256] In the present disclosure, the network nodes 30, 40, 50 transmitting information to a terminal may be interpreted as the network nodes 30, 40, 50 instructing the terminal to control or operate based on the information.

[0257] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," and the like may be used interchangeably.

[0258] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0259] At least one of the network nodes 30, 40, 50 and the terminal 20 may be referred to as a transmitting device, a receiving device, a communication device, or the like. At least one of the network nodes 30, 40, 50 and the terminal 20 may be a device mounted on a mobile object, the mobile object itself, or the like. The mobile object refers to a movable object, and may move at any speed. Naturally, this also includes cases where the mobile object is stationary. Examples of the mobile object include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and objects mounted thereon. The mobile object may also be a mobile object that travels autonomously based on operational commands. The device may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Note that at least one of the processing device 10 and the requesting device 20 may be a device that does not necessarily move during communication operations. For example, at least one of the processing device 10 and the requesting device 20 may be an IoT (Internet of Things) device such as a sensor.

[0260] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0261] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using one or more wires, cables, and / or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0262] The reference signal may be abbreviated as RS (Reference Signal) or may be called a pilot depending on the applicable standard.

[0263] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0264] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0265] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0266] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0267] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0268] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0269] The aspects / embodiments described in this disclosure may be used alone, in combination, or switched depending on the implementation. Notification of predetermined information (e.g., notification that "X is true") is not limited to explicit notification, but may be implicit (e.g., not notifying the predetermined information).

[0270] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure.

[0271] 10 Base station 20 Terminal 30 AMF 40 SMF 50 UPF 110 Transmitter 120 Receiver 130 Setting unit 140 Controller 210 Transmitter 220 Receiver 230 Setting unit 240 Controller 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device

Claims

1. A network node comprising: a control unit that includes a mapped slice identifier contained in a session establishment message in a message instructing monitoring of a user plane when a terminal is registered in a destination network; and a transmission unit that transmits the message including the mapped slice identifier to a specific network node.

2. A network node comprising: a control unit that, when a terminal is registered in a target network, includes a combination of a slice identifier of the target network and a mapped slice identifier contained in a session establishment message in a message instructing monitoring of the user plane; and a transmission unit that transmits the message including the combination to a specific network node.

3. A network node comprising: a receiving unit for receiving a PFCP session establishment request from a specific network node; and a control unit for associating a timer used for monitoring a user plane with a mapped slice identifier included in a PDU session establishment message when the terminal is registered in a target network.

4. A network node comprising: a receiving unit that receives a PFCP session establishment request from a specific network node; and a control unit that, when a terminal is registered in a target network, associates a timer used to monitor the user plane with a combination of a slice identifier of the target network and a mapped slice identifier contained in a PDU session establishment message.

5. A processing method executed by a network node, comprising: a step of including a mapped slice identifier included in a session establishment message in a message instructing monitoring of a user plane when a terminal is registered in a target network; and a step of transmitting the message including the mapped slice identifier to a specific network node.