Processing device, network node, and control method for flexible operation of network slices

Abstract

To flexibly allocate network slices to communications of various terminal devices and applications.SOLUTION: A processing device functioning as an AF (Application Function) acquires identification information of a terminal device from the terminal device, transmits, to a network node in a core network of a cellular communication system, identification information of the terminal device, an identifier of a first network slice assigned to communication to be executed by the terminal device, and specification information specifying one or more second network slices that are requested to be assigned to the communication, and receives, from the network node, a response indicating whether or not it is permitted to change the network slice assigned to the communication from the first network slice to any of the one or more second network slices. In response to the permission of the change, the network slice assigned to the communication is changed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a technology that enables flexible operation of network slices. [Background technology]

[0002] Known methods of using network slices include a single slice in which one network slice is assigned to one terminal device, and a multi-slice in which multiple network slices are assigned to each application or communication category. In addition, in a multi-slice environment, a UE Route Selection Policy (URSP) is known as a mechanism for supporting the use of different network slices depending on the communication category associated with an application. The core network notifies the terminal device of a URSP rule, and the terminal device can select an appropriate network slice by matching an explicit request from the application with the URSP rule. Summary of the Invention [Problem to be solved by the invention]

[0003] When the URSP is used, a network slice is selected that corresponds to the network slice selection mechanism and is intended only for communication of an application that has explicitly requested the use of a network slice. In contrast, a default network slice may be assigned to a terminal device that does not correspond to the network slice selection mechanism or to communication of an application that does not explicitly request the use of a network slice. In other words, it may be assumed that an appropriate network slice cannot be assigned to a specific terminal device or application. [Means for solving the problem]

[0004] The present invention provides a technology that enables flexible allocation of network slices to communications of various terminal devices and applications.

[0005] A processing device according to one embodiment of the present invention is a processing device that functions as an AF (Application Function), and has an acquisition means for acquiring identification information of a terminal device from the terminal device, a transmission means for transmitting to a network node in a core network of a cellular communication system the identification information of the terminal device, an identifier of a first network slice assigned to communication performed by the terminal device, and identification information identifying one or more second network slices requesting allocation to the communication, and a receiving means for receiving from the network node a response indicating whether or not a change of the network slice assigned to the communication from the first network slice to any of the one or more second network slices is permitted, and the network slice assigned to the communication is changed in response to the change being permitted.

[0006] A network node according to one embodiment of the present invention is a network node in a core network of a cellular communication system, and has an acquisition means for acquiring from an Application Function (AF) identification information of the terminal device, an identifier of a first network slice assigned to the communication performed by the terminal device, and specific information identifying one or more second network slices requesting allocation to the communication, a determination means for determining whether to allow a change of the network slice assigned to the communication from the first network slice to any of the one or more second network slices, a transmission means for transmitting a response indicating the result of the determination to the AF, and an execution means for executing a process to change the network slice assigned to the communication in response to allowing the change. Effect of the Invention

[0007] According to the present invention, network slices can be flexibly allocated to communications of various terminal devices and applications. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. [Diagram 2] A diagram showing an example of the processing flow when an AF requests a change in network slice. [Diagram 3] A diagram showing an example of the processing flow when an AF requests a change in network slice. [Figure 4] A figure showing an example of the flow of the process of determining whether a network slice can be moved. [Diagram 5] A diagram showing an example of the flow of the process of determining whether a network slice can be moved. [Figure 6] FIG. 13 is a diagram showing an example of presetting of combinations of source slices and post-movement slices. [Figure 7] A diagram showing an example of the processing flow when an AF requests a change in network slice. [Figure 8] A diagram showing an example of the processing flow when an AF requests a change in network slice. [Figure 9] A diagram showing an example of the processing flow when an AF requests a change in network slice. [Figure 10] FIG. 2 illustrates an example of a hardware configuration of a processing device and a network node. [Figure 11] FIG. 2 illustrates an example of a functional configuration of a processing device. [Figure 12] FIG. 2 is a diagram illustrating an example of a functional configuration of a network node. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features among the multiple features described in the embodiments may be arbitrarily combined. In addition, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0010] (System Configuration) FIG. 1 shows a configuration example of a wireless communication system according to this embodiment. The wireless communication system in FIG. 1 is, for example, a cellular wireless communication system conforming to the 5th generation (5G) standard of the 3rd Generation Partnership Project (3GPP (registered trademark)) or its successor standard. The wireless communication system is configured to provide wireless communication services to, for example, a terminal device (User Equipment). In this embodiment, this terminal device is called a UE 101. The UE 101 can communicate with an application server 105 via, for example, a RAN 102, a UPF 103, and a DN 104. Here, the RAN represents a Radio Access Network, the UPF represents a User Plane Function, and the DN represents a Data Network. The UPF 103 is a function of a core network of the cellular communication system, and the DN 104 is a network outside the core network. A gateway exists between the UPF 103 and the DN 104, but is not shown here. The core network further includes functions such as an AMF 106, an SMF 107, a PCF 108, and an NEF 109. Here, AMF stands for Access and Mobility Management Function, SMF stands for Session Management Function, PCF stands for Policy Control Function, and NEF stands for Network Exposure Function. The core network includes functions other than these, but for simplicity, they are not illustrated here. Each function in the core network may be implemented by a separate network node. However, this is not limited to this, and multiple functions may be aggregated and implemented in one network node. The application server 105 can access the core network via the NEF 109. The application provided by the application server 105 is also called an Application Function (AF).

[0011] UE101 may support, for example, URSP (UE Route Selection Policy) and explicitly request the use of a network slice in communication with AF. URSP, for example, associates applications installed in UE101 and communication contents executed by UE101 with network slices in advance, and UE101 requests the use of an explicit network slice according to the application to be executed and the content of communication when communicating. For example, a video distribution application is associated with a slice for video distribution, and a game application is associated with a slice for game in advance, respectively, and when communication of those applications is executed, the use of the corresponding slice is requested. Then, when the network side accepts this request, an appropriate network slice is set for the communication of those applications. In addition, a default network slice is set for communication different from the communication of those applications. Note that the setting of URSP is determined, for example, by a network operator, and the setting is notified to UE101, for example, at the time of initial registration of UE101.

[0012] In this way, the communication performed by UE 101 can use a network slice explicitly requested, for example, by using a URSP, depending on the application or content of the communication. On the other hand, currently, an appropriate network slice is not selected and assigned to the communication of UE 101 at the initiative of the application server 105. That is, for example, when UE 101 does not support a mechanism for slice selection by a URSP or when a network slice corresponding to an application to be executed is not defined in advance, a default network slice is assigned to the communication even if there is a more appropriate network slice. In addition, for example, a higher quality communication environment cannot be offered to the user while communication for a specific application is being executed.

[0013] In view of the above circumstances, this embodiment provides a procedure that enables the application server 105 to set a network slice to be allocated to communication of the UE 101 at its initiative. Hereinafter, the application server 105 is referred to as an AF.

[0014] (Processing flow) In this embodiment, for example, the AF requests a network node such as the PCF 108 or the AMF 106 to change the network slice to be assigned to the communication of the UE via the NEF 109. For example, the AF transmits a request to the network node including identification information of the UE, an identifier of a first network slice (source slice) before the change for the communication of the UE, and specification information for specifying one or more candidates of a second network slice (post-movement slice) after the change to be used by the UE. Then, in response to the network node permitting the change of the network slice, the network slice is switched by changing the session according to, for example, the procedure described in section 4.3.3.2 of 3GPP TS23.502 V18.3.0. This allows a network slice suitable for the communication of the UE 101 to be set in response to a request from the AF. That is, for example, even in the case of communication of an application not defined by the URSP policy or when the UE 101 does not support a slice selection mechanism, the AF side specifies a network slice suitable for the application in advance, so that a network slice suitable for the communication of the application can be set. It should be noted that the network node receiving the request does not necessarily have to accept the request and may reject it depending on the circumstances.

[0015] FIG. 2 shows an example of a process flow when the AF requests a change of the network slice according to the present embodiment. For example, the AF starts cooperation by the UE 101 executing a predetermined application, and acquires the identification information of the UE 101 (S201). Here, the identification information of the UE 101 is, for example, a combination of the IP (Internet Protocol) address, the DNN (Data Network Name), and the S-NSSAI (Single-Network Slice Selection Assistance Information) of the UE 101. That is, the AF may acquire, as the identification information of the UE 101, information on individual sessions established for the communication of the application of the UE 101. The identification information of the UE 101 may be a UE ID (User Equipment Identifier). In this case, the UE 101 is identified, but the session is not differentiated. The AF, for example, determines whether the network slice used in the communication with the UE 101 is a network slice (for example, a default network slice) that is not suitable for the application executed with the UE 101. In addition, in cases where an application that is not defined by the URSP policy is provided, a default network slice is assigned to all communications of that application, so the AF may always perform the following processing assuming that a change of the network slice is necessary.

[0016] When a change of the network slice is required, the AF transmits information indicating a request to change the network slice to the NEF 109 (S202). At present, since there is no interface for transmitting such information, the information is transmitted using a newly defined interface. This information includes, for example, the identification information of the UE 101 acquired in S201, an identifier of the network slice of the movement source, and an identifier of the network slice after the movement. As described above, the identification information of the UE 101 may be a combination of the IP address, DNN, and S-NSSAI of the UE 101, or may be a UE ID. The movement source network slice indicates a network slice allocated for the communication of the UE 101. The movement source network slice may not necessarily match the network slice that is actually allocated when the information of S202 is transmitted based on the recognition of the AF. The movement post network slice indicates a candidate of a network slice requested to be allocated to the communication of the UE 101. There may be more than one candidate of the movement post network slice. That is, the AF may transmit identifiers of multiple network slices to the NEF 109 as the identifier of the network slice after movement. The AF may also transmit identification information for identifying itself to the NEF 109. This is used, for example, when the NEF 109 notifies the AF of the result of the determination as to whether or not the network slice can be moved thereafter. However, if the AF is uniquely identified by some procedure, the explicit transmission of the AF's identifier may be omitted.

[0017] The NEF 109 transfers the received information to the PCF 108 (S203). When the NEF 109 receives an AF identifier, the NEF 109 may not transfer the identifier to the PCF 108. However, this is just an example, and the NEF 109 may also transfer the AF identifier to the PCF 108. Since an interface for transferring this information does not currently exist, the information is transmitted using a newly defined interface. When the PCF 108 receives this information, the PCF 108 determines whether or not to permit a change in the network slice assigned to the communication of the UE 101 (S204). Then, the PCF 108 notifies the AF of the result of the determination via the NEF 109 (S205, S206). When the determination indicates that the change in the network slice is permitted, the network slice is switched by changing the session according to, for example, the procedure described in Section 4.3.3.2 of TS23.502. For example, PCF108 changes the existing session to a session corresponding to the changed network slice by initiating processing according to step 1b shown in Figure 4.3.3.2-1 in section 4.3.3.2 of TS23.502.

[0018] In addition, in FIG. 2, an example is shown in which the PCF 108 judges whether or not the network slice can be changed, but this judgment may be executed by another function such as the AMF 106. FIG. 3 shows an example of a processing flow in the case where the AMF 106 makes this judgment. In the processing of FIG. 3, the PCF 108 transfers the received information to the AMF 106 (S301), and the AMF 106 judges whether or not the network slice can be changed based on the information (S302), and transmits the result to the AF, for example, via the PCF 108 (S303). In this way, the judgment of whether or not the network slice can be changed may be performed by the PCF 108 or the AMF 106. In addition, this judgment may be performed by another function, or a new function for making this judgment may be defined. In this case, when the change of the network slice is permitted, the network slice is changed by changing the session, for example, according to the procedure described in section 4.3.3.2 of TS23.502. For example, AMF106 changes the existing session to a session corresponding to the changed network slice by initiating processing according to step 1h shown in Figure 4.3.3.2-1 in section 4.3.3.2 of TS23.502.

[0019] Next, an example of a procedure for determining whether or not the above-mentioned network slice can be changed will be described with reference to Figures 4 and 5. These processes are executed by a network node that implements the PCF 108 or the AMF 106, for example.

[0020] In FIG. 4, the network node first determines whether UE 101 has a session of the source network slice (S401). That is, the network node determines whether the network slice notified as the source network slice is associated with a session for communication of UE 101. In addition, when the identification information of UE 101 is a combination of an IP address, a DNN, and an S-NSSAI, it can determine whether a session individually identified by the combination exists, and further determine whether the source network slice is assigned to the session. In addition, when the identification information of UE 101 is a combination of an IP address, a DNN, and an S-NSSAI, even if there are multiple sessions to which the same network slice is assigned, it can identify which of the sessions is the target of the network slice change request. When the network node determines that UE 101 has a session of the source network slice (YES in S401), it then determines whether the session allows the network slice to be changed (S402). That is, it is confirmed whether the session is set not to allow the network slice to be changed. For example, for a voice call session, a setting is made so that a change in the network slice is not permitted, and this determination may be made to prevent a change in the network slice of such a session. If the network node determines that the session held by UE 101 permits a change in the network slice (YES in S402), it determines whether UE 101 can use the network slice designated as the network slice after the movement (S403). If the network node determines that UE 101 can use the network slice designated as the network slice after the movement (YES in S403), it determines to permit a change in the network slice of the communication of UE 101 (S404).On the other hand, if the network node determines that UE101 does not have a session with the network slice from which the UE moves (NO in S401), if it determines that the session does not allow the network slice to be changed (NO in S402), or if the network slice specified as the network slice after the move is not available to UE101 (NO in S403), the network node determines not to allow the network slice for the UE101's communication to be changed (S405).

[0021] For example, when a PDU (Protocol Data Unit) session is established, a setting may be made to determine whether the session accepts a change in the network slice initiated by the network side (for example, an AF). A value (flag) indicating this setting may be held, for example, in the PCF 108. The above-mentioned determination of S402 may be made based on this setting. In this case, when the AMF 106 executes the determination process, the AMF 106 may inquire of the PCF 108 about the setting information held by the AMF 106. Even when the AMF 106 executes the determination process, the determination of S402 may be made by the PCF 108. In this case, when the PCF 108 determines that the session does not allow the change in the network slice, the PCF 108 may determine that the change is not permitted without notifying the AMF 106 of the information (S301), and may notify the AF of the determination result via the NEF 109. On the other hand, when the PCF 108 determines that the session allows the change in the network slice, the PCF 108 may perform the information notification of S301. In this case, AMF106 may omit the judgment of S402. This is because AMF106 can identify that the session allows the change of the network slice by the information notification of S301 being performed to AMF106, and therefore AMF106 does not need to perform the judgment. PCF108 may explicitly notify AMF106 of the result of the judgment, or may implicitly notify AMF106 depending on the presence or absence of information notification of S301. In addition, the judgment (S401) of whether UE101 has a session of the source network slice may also be performed by PCF108. Note that these are only examples, and for example, a value indicating a setting of whether the session accepts the change of the network slice may be held in a function different from PCF108. In addition, the division of the judgment process between AMF106 and PCF108 may be changed by another format.

[0022] Note that the determination in Fig. 4 is an example, and in addition to these determination criteria, a determination may be made based on additional conditions. That is, the network node may permit the change of the network slice only on the condition that UE 101 has a session with the source network slice, the session allows the change of the network slice, and UE 101 can use the network slice after the movement, or an additional condition may be required for the change of the network slice.

[0023] FIG. 5 shows an example of the flow of another determination process. The determination process of FIG. 5 may be used together with the determination process of FIG. 4. That is, in the determination process of FIG. 4, when it is determined that the UE 101 can use the network slice designated as the network slice after the movement (YES in S403), the process may not proceed to S404, and the determination process of FIG. 5 may be executed continuously. Also, only the determination process of FIG. 5 may be executed. In FIG. 5, a network node determines whether or not a combination of a source network slice and a destination network slice is a preset combination (S501). Then, the network node permits only a change in the preset combination (YES in S501) (S502), and does not permit any other combination (NO in S501) (S503). Here, an example of the preset combination is shown in FIG. 6(A). For example, in FIG. 6(A), when the source network slice is a default network slice, only "Gaming A", "Gaming B", and "Video A" are permitted as the destination network slice. Furthermore, when the source network slice is "Slice A", only "Gaming A" and "Gaming B" are permitted as the post-movement network slice. As an example, when the source network slice is "Slice A" and the post-movement network slice is specified as "Video A", the network node rejects the change of the network slice. On the other hand, when the source network slice is the default network slice and the post-movement network slice is specified as "Video A", the network node allows the change of the network slice. In addition to the judgment of FIG. 5, the network node may make a judgment based on additional conditions.

[0024] In the determination process of FIG. 4 and FIG. 5, for example, when there are multiple candidates for the network slice after the movement, if a change to any of the candidates is permitted, it may be determined that the network slice can be changed. For example, in the determination of S403, the network node determines whether or not UE101 can use any of the multiple candidates for the network slice after the movement. Then, the network node may decide to permit the slice change if UE101 can use any of the multiple candidates for the network slice after the movement. On the other hand, if UE101 cannot use any of the multiple candidates for the network slice after the movement, the network node may decide not to permit the slice change. In addition, in the determination of S501, the network node may determine whether each combination of the source network slice and the multiple candidates for the network slice after the movement is a preset combination. Then, the network node may decide to permit the slice change if any combination of the source network slice and the multiple candidates for the network slice after the movement is a preset combination. On the other hand, the network node may decide not to allow the slice change if all of the multiple candidate combinations of the source network slice and the target network slice are not pre-configured combinations.

[0025] In the above description, an example of a process flow in which the AF notifies the identifiers of one or more candidates for the network slice after the movement has been shown, but the AF may transmit to the NEF 109 a group of network slices after the movement corresponding to multiple candidates for the network slice after the movement. FIG. 7 shows an example of a process flow in this case. The AF transmits information indicating the group of the network slice after the movement to the NEF 109 instead of the identifier of the network slice after the movement (S701). When the NEF 109 receives the information indicating the group of the network slice, it performs mapping from the group to the identifier of the network slice (S702). That is, the NEF 109 holds information that associates the group with the identifier of the network slice, and identifies the identifier of the corresponding network slice from the information of the group. The NEF 109 may identify an identifier for one of the network slices included in the group, or may identify identifiers for all of the network slices included in the group. Then, the NEF 109 may convert the group information into an identifier of a network slice, and transfer the information from the AF to the PCF 108 (S702). Subsequent processing may be performed in a manner similar to that of, for example, FIG. 2 or FIG. 3.

[0026] In addition, the mapping from the group to the identifier of the network slice may be performed by a function other than the NEF 109. For example, as shown in FIG. 8, this mapping may be performed in the PCF 108 (S802). In this case, the group information received from the AF may be transferred as it is from the NEF 109 to the PCF 108 (S801). In addition, as shown in FIG. 9, this mapping may be performed in the AMF 106 (S902). In this case, the group information received from the AF may also be transferred as it is from the PCF 108 to the AMF 106 (S901). In addition, the group may include only one post-movement network slice candidate, or may include two or more post-movement network slice candidates. When multiple post-movement network slice candidates are included in the group, as described above, in the determination process of FIG. 4 and FIG. 5, it may be determined that the network slice can be changed if a change to any of the candidates is permitted. In addition, in the determination process of FIG. 5, it may be determined whether the source network slice and the post-movement network slice group are a preset combination. In this case, for example, in the pre-setting, the source network slice is associated with a group including one or more candidates for the destination network slice, as shown in Fig. 6(B). When this process is performed, the above-mentioned mapping may not be performed, and a process may be performed to select the destination network slice from within the group after determining that the change of the network slice is permitted.

[0027] As described above, the network slice can be changed at the initiative of the AF. This allows, for example, a network slice suitable for an application to be assigned to communication of a type of application not predefined in the URSP policy. In addition, for example, while the UE 101 is communicating in a predetermined network slice corresponding to a predetermined application, an offer to use a network slice corresponding to a higher quality environment can be made. In this case, for example, the AF can present to the user of the UE 101 that a higher quality network slice can be used in response to an additional fee, and when the user approves, the AF can request a change of the network slice.

[0028] (Device configuration) FIG. 10 shows an example of the hardware configuration of a processing device (functioning as, for example, an AF) that requests a change in the network slice, and a network node (functioning as, for example, a PCF 108 or an AMF 106) that responds to the request. In one example, the processing device and the network node are configured to include a processor 1001, a ROM 1002, a RAM 1003, a storage device 1004, and a communication circuit 1005. The processor 1001 is a computer configured to include one or more processing circuits such as a general-purpose CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit), and executes the overall processing of the device and each of the above-mentioned processes by reading and executing a program stored in the ROM 1002 or the storage device 1004. The ROM 1002 is a read-only memory that stores information such as programs and various parameters related to the processing executed by the processing device and the network node. The RAM 1003 functions as a workspace when the processor 1001 executes a program, and is a random access memory that stores temporary information. The storage device 1004 is, for example, configured by a removable external storage device. The communication circuit 1005 is configured by a circuit capable of communication in a core network in, for example, 5G core or a successor standard. Although one communication circuit 1005 is illustrated in FIG. 10, the processing device and the network node may have multiple communication circuits.

[0029] FIG. 11 is a diagram showing an example of the functional configuration of a processing device (functioning as an AF, for example). The processing device has, for example, a communication unit 1101, a slice change request unit 1102, and a response receiving unit 1103. Note that these functions can be implemented by, for example, the processor 1001 executing a program stored in the ROM 1002 or the storage device 1004. However, this is only an example, and the functions of FIG. 11 may be realized by other configurations. Also, the functions shown in FIG. 11 are only an example, and the above-mentioned various control processes may be realized by functional units other than these. Note that the detailed operations of each functional unit are as described above, so they will not be repeated here, and only a rough functional configuration will be described.

[0030] The communication unit 1101 communicates with the UE 101 via, for example, the RAN 102, the UPF 103, and the DN 104. The communication unit 1101 transmits and receives application data by communicating with the UE 101. The communication unit 1101 may also acquire, for example, identification information of the UE 101 (for example, a combination of an IP address, a DNN, and an S-NSSAI, or a UE ID) by communicating with the UE 101. The slice change request unit 1102 transmits information including the identification information of the UE 101, an identifier of the source network slice, and specific information for identifying one or more candidates for the network slice after the movement (for example, information indicating each identifier or group of the one or more candidates) to the NEF 109 to request a change of the network slice assigned to the communication of the UE 101. The response receiving unit 1103 receives, from the NEF 109, a response including a determination result as to whether the request by the slice change request unit 1102 is permitted or not.

[0031] FIG. 12 is a diagram showing an example of a functional configuration of a network node (functioning as, for example, PCF 108 or AMF 106). The network node includes, for example, a request receiving unit 1201, a change possibility determining unit 1202, a determination result notifying unit 1203, and a slice change processing unit 1204. These functions can be implemented, for example, by the processor 1001 executing a program stored in the ROM 1002 or the storage device 1004. However, this is only an example, and the functions of FIG. 12 may be realized by other configurations. Also, the functions shown in FIG. 12 are only an example, and the above-mentioned various control processes may be realized by other functional units. Note that the detailed operations of each functional unit are as described above, so they will not be repeated here, and only a rough functional configuration will be described.

[0032] The request receiving unit 1201 receives a request to change the network slice allocated to the communication of the UE 101 from the processing device (functioning as an AF) via the NEF 109. The change permission / non-permission determination unit 1202 determines whether or not to permit the change of the network slice allocated to the communication of the UE 101 based on information included in the change request. The determination result notifying unit 1203 notifies the processing device via the NEF 109 of the result of the determination by the change permission / non-permission determination unit 1202, for example, in the form of a response signal to the request signal. When the slice change processing unit 1204 permits the change of the network slice allocated to the communication of the UE 101, it executes processing for changing the network slice. The slice change processing unit 1204 can change the network slice, for example, according to a session modification procedure specified in section 4.3.3.2 of TS23.502.

[0033] As described above, according to this embodiment, the network slice can be changed at the initiative of the AF. This allows, for example, a network slice suitable for an application to be assigned to communication of a type of application not predefined in the URSP policy. This makes it possible to contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote sustainable industrialization and foster innovation."

[0034] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention.

Claims

1. A processing device that functions as an AF (Application Function), An acquisition means for acquiring identification information of a terminal device from the terminal device; a transmitting means for transmitting, to a network node in a core network of a cellular communication system, identification information of the terminal device, an identifier of a first network slice allocated to a communication performed by the terminal device, and specification information identifying one or more second network slices requested to be allocated to the communication; receiving means for receiving from the network node a response indicating whether a change of a network slice allocated to the communication from the first network slice to any of the one or more second network slices is permitted; having In response to the change being permitted, a network slice allocated to the communication is changed. A processing device comprising:

2. 2. The processing device according to claim 1, wherein the identification information of the terminal device is a combination of an IP (Internet Protocol) address, a DNN (Data Network Name), and an S-NSSAI (Single-Network Slice Selection Assistance Information) of the terminal device.

3. The processing device according to claim 1 , wherein the identification information of the terminal device is a UE ID (User Equipment Identifier).

4. The processing device according to claim 1 , characterized in that the specific information is information indicating a group of the one or more second network slices.

5. The processing device according to claim 1 , characterized in that the specific information is an identifier of each of the one or more second network slices.

6. A network node in a core network of a cellular communication system, comprising: An acquisition means for acquiring, from an AF (Application Function), identification information of a terminal device, an identifier of a first network slice allocated to a communication performed by the terminal device, and specific information for identifying one or more second network slices requesting allocation to the communication; a determination means for determining whether or not to allow a change of a network slice allocated to the communication from the first network slice to any one of the one or more second network slices; a transmitting means for transmitting a response indicating a result of the determination to the AF; an execution means for executing a process for changing a network slice to be allocated to the communication in response to the permission of the change; A network node comprising:

7. the network node is a Policy Control Function (PCF); The acquisition means acquires information from the AF via a Network Exposure Function (NEF); The transmitting means transmits the response to the AF via the NEF.

7. A network node according to claim 6.

8. The network node is an Access and Mobility Management Function (AMF), The acquiring unit acquires information from the AF via a Network Exposure Function (NEF) and a Policy Control Function (PCF); The sending means sends the response to the AF via the PCF and the NEF.

7. A network node according to claim 6.

9. The network node according to claim 6, characterized in that the identification information of the terminal device is a combination of an IP (Internet Protocol) address, a DNN (Data Network Name), and an S-NSSAI (Single-Network Slice Selection Assistance Information) of the terminal device.

10. 7. The network node according to claim 6, wherein the identification information of the terminal device is a UE ID (User Equipment Identifier).

11. The network node according to claim 6, characterized in that the determination means determines to allow the change on the condition that the terminal device has a session with the first network slice, the session allows the change of the network slice, and any one of the one or more second network slices is available.

12. The specific information is information indicating a group of the one or more second network slices, The network node according to claim 6, characterized in that the determination means determines not to allow the change when an identifier of the first network slice and the group of the one or more second network slices are not a predetermined combination.

13. The specific information is information indicating an identifier of each of the one or more second network slices, The network node according to claim 6, characterized in that the determination means determines not to allow the change when the identifier of the first network slice and any of the one or more second network slices are not a predetermined combination.

14. A control method executed by a processing device functioning as an AF (Application Function), comprising: acquiring identification information of a terminal device from the terminal device; transmitting to a network node in a core network of a cellular communication system an identification of the terminal device, an identifier of a first network slice allocated to a communication performed by the terminal device, and specification information identifying one or more second network slices to be allocated to the communication; receiving a response from the network node indicating whether a change of a network slice assigned to the communication from the first network slice to any of the one or more second network slices is permitted; Including, In response to the change being permitted, a network slice allocated to the communication is changed. A control method comprising:

15. 1. A control method performed by a network node in a core network of a cellular communication system, comprising: Obtaining, from an Application Function (AF), identification information of a terminal device, an identifier of a first network slice allocated to a communication performed by the terminal device, and specific information for identifying one or more second network slices to be allocated to the communication; determining whether to allow a change of a network slice allocated to the communication from the first network slice to any of the one or more second network slices; sending a response to the AF indicating the result of the determination; In response to allowing the change, executing a process for changing the network slice allocated to the communication; and A control method comprising the steps of:

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