Control device, gateway device, method, and program

Abstract

A control device according to the present invention includes: a first acquisition unit that acquires information indicating a feature of each CN node from at least one CN node that each manages access and mobility; a second acquisition unit that receives a first notification message indicating a congestion state of a first CN node from a first CN node among at least one CN node; and a selection unit that, in a case in which the second acquisition unit receives the first notification message indicating a congestion state of a first CN node from a first CN node among at least one CN node, selects a transfer destination node of a registration request message from at least one second CN node on the basis of information indicating respective features of at least one second CN node that is different from the first CN node, and information regarding an attribute of user equipment of a transmission source of the registration request message.

Description

Control device, gateway device, method, and program

[0001] The present disclosure relates to a control device, a gateway device, a method, and a program.

[0002] It is specified that when a RAN (Radio Access Network) node selects an AMF (Access and Mobility Management Function), the AMF may be selected using the weight factors of each of multiple candidate AMFs (e.g., Non-Patent Documents 1 and 2).

[0003] 3GPP TS 23.501 V18.5.0 Technical Specification, “3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; System architecture for the 5G System (5GS); Stage 2 (Release 18)”, March 20243GPP TS 23.502 V18.5.0 Technical Specification, “3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Procedures for the 5G System (5GS); Stage 2 (Release 18)”, March 2024

[0004] However, when an AMF is selected using the weight factors of multiple candidate AMFs as specified in Non-Patent Documents 1 and 2, it may not be possible to select an AMF that matches the user equipment (UE).

[0005] An object of the present disclosure is to provide a control device, a gateway device, a method, and a program that can select a core network node (CN) node that matches a user equipment. It should be noted that this object is only one of multiple objects that multiple embodiments disclosed in this specification aim to achieve. Other objects or problems and novel features will become apparent from the description of this specification or the accompanying drawings.

[0006] A control device according to the present disclosure includes a first acquisition unit that acquires information indicating characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; a second acquisition unit that receives a first notification message indicating a congestion state of the first CN node from a first CN node among the at least one CN node; and a selection unit that, when the second acquisition unit receives the first notification message indicating the congestion state of the first CN node from the first CN node among the at least one CN node, selects a destination node of the registration request message from the at least one second CN node based on information indicating characteristics of at least one second CN node different from the first CN node and information on attributes of a user equipment (UE) that is a sender of the registration request message.

[0007] A gateway device according to the present disclosure includes a first acquisition unit that acquires information indicating characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; a second acquisition unit that acquires a second notification message indicating a congestion state of a first CN node transmitted from a first CN node of the at least one CN node in association with transmission of a first notification message indicating a congestion state of the first CN node from the first CN node to an access network (AN) node; and a selection unit that, when the second acquisition unit receives the second notification message, selects a destination node of a registration request message of a user equipment (UE) forwarded from the AN node from the at least one second CN node based on information indicating characteristics of each second CN node different from the first CN node and information on attributes of the UE that is a sender of the registration request message.

[0008] The method according to the present disclosure is a method executed by a control device, and includes: obtaining information indicating characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; and, when receiving a first notification message from a first CN node of the at least one CN node indicating a congestion state of the first CN node, selecting a destination node for the registration request message from at least one second CN node different from the first CN node based on information indicating characteristics of each second CN node different from the first CN node and information on attributes of a user equipment (UE) that sent the registration request message.

[0009] The program of the present disclosure causes a control device to perform a process including: acquiring information indicating characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; and, when receiving a first notification message from a first CN node among the at least one CN node indicating a congestion state of the first CN node, selecting a destination node for the registration request message from the at least one second CN node based on information indicating characteristics of each of the second CN nodes that are different from the first CN node and information regarding attributes of a user equipment (UE) that sent the registration request message.

[0010] The present disclosure makes it possible to provide a control device, a gateway device, a method, and a program that can select a core network node (CN) node that matches a user equipment.

[0011] FIG. 1 is a block diagram showing an example of a control device of the present disclosure. FIG. 2 is a flowchart showing an example of a processing operation of a control device of the present disclosure. FIG. 3 is a diagram showing an example of a system of the present disclosure. FIG. 4 is a block diagram showing another example of a control device of the present disclosure. FIG. 5 is a sequence diagram showing an example of a processing operation of the system of the present disclosure. FIG. 6 is a flowchart showing another example of a processing operation of a control device of the present disclosure. FIG. 7 is a sequence diagram showing another example of a processing operation of the system of the present disclosure. FIG. 8 is a block diagram showing another example of a control device of the present disclosure. FIG. 9 is a sequence diagram showing an example of a processing operation of the system of the present disclosure. FIG. 10 is a sequence diagram showing another example of a processing operation of the system of the present disclosure. FIG. 11 is a diagram showing an example of a configuration of a control device. FIG. 12 is a diagram showing an example of a configuration of a RAN node. FIG. 13 is a diagram showing an example of a configuration of a network node.

[0012] Hereinafter, embodiments will be described with reference to the drawings. In this disclosure, the drawings may relate to one or more embodiments. Furthermore, each element in the drawings may apply to one or more embodiments. Furthermore, in the embodiments, identical or equivalent elements are given the same reference numerals, and redundant description will be omitted.

[0013] <First embodiment> <Configuration example of control device> Fig. 1 is a block diagram showing an example of a control device of the present disclosure. In Fig. 1, the control device 10 has an acquisition unit (first acquisition unit) 11, an acquisition unit (second acquisition unit) 12, and a selection unit 13. The control device 10 may be included in, for example, a RAN node (not shown) or a gateway device.

[0014] The acquisition unit 11 acquires information indicating the characteristics of each CN node from at least one CN (Core Network) node that manages access and mobility, respectively. This CN node is, for example, an Access and Mobility Management Function (AMF) of 5GC. The CN node characteristics may be, for example, performance parameters of the CN node. Examples of the performance parameters will be described later.

[0015] The acquisition unit 12 receives a notification message (hereinafter, sometimes referred to as a “first notification message”) from a CN node (hereinafter, sometimes referred to as a “first CN node”) among the at least one CN node, indicating a congestion state of the first CN node. The first notification message may indicate that the first CN node is expected to become congested, or may indicate that the first CN node is already in a congested state.

[0016] When the acquisition unit 12 receives the first notification message, the selection unit 13 selects a destination node for the registration request message from at least one CN node (hereinafter, sometimes referred to as a "second CN node") different from the first CN node. For example, the selection unit 13 may select the destination node based on information indicating the characteristics of each of the at least one second CN node and information on attributes of a user equipment (UE) that is a sender of the registration request message. The UE attributes may be, for example, one or both of carrier identification information of the UE and QoS (Quality of Service) information of the UE.

[0017] <Example of Operation of Control Device> FIG. 2 is a flowchart showing an example of processing operation of the control device of the present disclosure.

[0018] The acquisition unit 11 acquires information indicating the characteristics of each CN node from at least one CN node (step S11).

[0019] The selector 13 waits until the acquirer 12 receives the first notification message (step S12 NO). When the acquirer 12 receives the first notification message (step S12 YES), the selector 13 selects a destination node of the registration request message from at least one second CN node (step S13). The selector 13 selects the destination node based on information indicating the characteristics of each of the at least one second CN node and information on the attributes of the user equipment (UE) that is the sender of the registration request message.

[0020] As described above, according to the first embodiment, when the acquisition unit 12 receives the first notification message, the selection unit 13 in the control device 10 selects a destination node for the registration request message from at least one second CN node different from the first CN node. The selection unit 13 selects the destination node based on information indicating the characteristics of each of the at least one second CN node and information on the attributes of the user equipment (UE) that is the sender of the registration request message.

[0021] This configuration of the control device 10 allows the control device 10 to select a destination node from at least one second CN node based on information indicating the characteristics of each of the at least one second CN node and information on the attributes of the user equipment (UE) that has transmitted the registration request message, thereby allowing the control device 10 to select a CN node that matches the user equipment as the destination node.

[0022] <Second embodiment> <System configuration example> Figure 3 is a diagram showing an example of a system according to the present disclosure. In Figure 3, a system 1 includes a gateway device (GW) 20, a RAN node 30, AMFs 40-1, 40-2, and 40-3, and a UE 50. Hereinafter, when the AMFs 40-1, 40-2, and 40-3 are not to be distinguished from one another, each of the AMFs 40-1, 40-2, and 40-3, or the AMFs 40-1, 40-2, and 40-3, may be collectively referred to simply as AMF 40. Note that, although Figure 3 shows one RAN node 30 and three AMFs 40, the number of these is not limited to this.

[0023] The RAN node 30 corresponds to, for example, area 1. The RAN node 30 is connected to, for example, an AMF 40-1 corresponding to area 1. The RAN node 30 is also connected to a gateway device 20. The RAN node 30 is also wirelessly connected to a UE 50 present in area 1. The AMF 40-2 corresponds to, for example, area 2 different from area 1, and the AMF 40-3 corresponds to, for example, area 3 different from areas 1 and 2.

[0024] The gateway device 20 is connected to each of the AMFs 40-1, 40-2, and 40-3.

[0025] <Configuration example of control device> Fig. 4 is a block diagram showing another example of a control device of the present disclosure. In Fig. 4, the control device 60 has a communication control unit 61 and a selection unit 62. The communication control unit 61 has an acquisition unit 11, an acquisition unit 12, and a transfer control unit 61A. The control device 60 will be described as being included in the gateway device 20.

[0026] The acquisition unit 11 in the control device 60 acquires information indicating the characteristics of each AMF 40 from each AMF 40 .

[0027] For example, when the AMF 40-1 is in a congested state, the acquisition unit 12 in the control device 60 receives from the AMF 40-1 a first notification message indicating the congestion state of the AMF 40-1. Note that the notification message indicating the congestion state of the AMF 40-1 is also transmitted from the AMF 40-1 to the RAN node 30. That is, the first notification message is transmitted from the AMF 40-1 to the gateway device 20 in conjunction with the transmission of a notification message from the AMF 40-1 to the RAN node 30.

[0028] In the control device 60, the selection unit 62, similar to the selection unit 13, selects a destination node of the registration request message from at least one second CN node when the acquisition unit 12 receives the first notification message. For example, when the acquisition unit 12 receives the above-mentioned first notification message, the selection unit 62 selects a destination node from among the AMFs 40-2 and 40-3 based on information indicating the respective features of the AMFs 40-2 and 40-3 and information on the attributes of the UE 50 that is the transmission source of the registration request message. For example, the selection unit 62 may select a destination node using a correspondence relationship between a plurality of attribute candidates of the UE and the features of the AMF 40 corresponding to each attribute candidate. In this case, the selection unit 62 selects, as the destination node, an AMF 40 (AMF 40-2 or AMF 40-3) that has a feature corresponding to the attribute of the above-mentioned transmission source UE 50 in the correspondence relationship between a plurality of attribute candidates of the UE and the features of the AMF 40 corresponding to each attribute candidate.

[0029] In addition, when there are a plurality of forwarding destination candidates (AMFs 40) having characteristics corresponding to the attributes of the above-described source UE 50 in the correspondence relationship, the selection unit 62 may select, as the forwarding destination node, a forwarding destination candidate that is present within a predetermined distance from the location of the UE 50 among the plurality of forwarding destination candidates. For example, the selection unit 62 may select, as the forwarding destination node, a forwarding destination candidate that is present in a position closest to the location of the UE 50 among the plurality of forwarding destination candidates.

[0030] Here, when the RAN node 30 receives a notification message indicating the congestion state of the AMF 40-1, the RAN node 30 forwards the registration request message transmitted from the UE 50 to the gateway device 20, not to the AMF 40-1.

[0031] In the control device 60 , the transfer control unit 61 A transfers the registration request message from the RAN node 30 to the destination node selected by the selection unit 62 .

[0032] <Example of System Operation> Figures 5 and 6 are sequence diagrams showing an example of processing operations of the system of the present disclosure. Figure 6 is a sequence following the sequence of Figure 5.

[0033] The gateway device 20 including the control device 60 receives messages including information indicating the characteristics of each of the AMFs 40-1, 40-2, and 40-3 from each of the AMFs 40-1, 40-2, and 40-3 (steps S21-1, S21-2, and S21-3).

[0034] The RAN node 30 receives registration request messages from UE #1, #2, and #3, respectively (steps S22-1, S22-2, and S22-3). Then, the RAN node 30 transmits the registration request messages received from UE #1, #2, and #3, respectively, to the AMF 40-1 (steps S23-1, S23-2, and S23-3).

[0035] After communicating with the UDM, the AMF 40-1 transmits a registration response message corresponding to the registration request message from the UE #1 and a registration response message corresponding to the registration request message from the UE #2 to the UE #1 and UE #2 via the RAN node 30 (steps S24-1, S24-2, S25-1, S25-2).

[0036] Here, it is assumed that the AMF 40-1 is in a congested state. In this case, the AMF 40-1 transmits a notification message indicating the congestion state of the AMF 40-1 to the RNA node 30 (step S26). Then, along with transmitting the notification message to the RNA node 30, the AMF 40-1 also transmits a notification message indicating the congestion state of the AMF 40-1 to the gateway device 20 (step S27).

[0037] The RAN node 30 receives a registration request message from the UE #3 (step S28). For example, the UE #3 has not received a registration response message within a predetermined time since it last transmitted the registration request message (step S22-3), so it is transmitting the registration request message again.

[0038] Since the RAN node 30 has received the notification message indicating the congestion state of the AMF 40-1 in step S26, the RAN node 30 transfers the registration request message from the UE #3 to the gateway device 20 instead of the AMF 40-1 (step S29).

[0039] Having received the notification message indicating the congestion state of AMF 40-1 in step S27, the gateway device 20 (control device 60) selects a destination node of the registration request message from AMF 40-2, 40-3 (step S31). For example, the gateway device 20 (control device 60) selects a destination node from AMF 40-2, 40-3 based on information indicating the characteristics of each of AMF 40-2, 40-3 and information on the attributes of UE 50, which is the sender of the registration request message. Here, it is assumed that AMF 40-2 is selected as the destination node.

[0040] FIG. 7 is a flowchart showing another example of the processing operation of the control device of the present disclosure.

[0041] In the control device 60, the selection unit 62 determines whether the value of the 5G-S-TMSI (SAE-Temporary Mobile Subscriber Identity) (MCC (Mobile Country Code) / MNC (Mobile Network Code)) included in the UE context included in the registration request message corresponds to a predetermined carrier (for example, NTT Docomo, AU, or Rakuten) (step S51). In other words, the fact that the UE corresponds to a predetermined carrier is one attribute candidate.

[0042] If the value of 5G-S-TMSI does not correspond to a specified carrier (step S51 NO), the selection unit 62 selects a simple AMF as the destination node (step S53).

[0043] If the value of 5G-S-TMSI is a value corresponding to the predetermined carrier (step S51 YES), the selection unit 62 determines whether the IP Precedence value of the QoS information included in the UE context included in the registration request message is 5 (step S52). In other words, the selection unit 62 determines whether the traffic priority of the UE that sent the registration request message is high.

[0044] If the IP Precedence value is smaller than 5 (step S52 NO), the selection unit 62 selects the standard AMF as the destination node (step S54).

[0045] If the IP Precedence value is 5 (step S52 YES), the selection unit 62 selects the high-performance AMF as the destination node (step S55).

[0046] Here, the simple, standard, and high performance of AMF are examples of AMF characteristics. The simple, standard, and high performance of AMF may be expressed by performance parameters of the AMF. The performance parameters may be TPS (Transactions Per Second) values. The TPS value represents the number of transactions (operations or processes) that a system or process can process per second. A system with a higher TPS value can process a large number of transactions efficiently.

[0047] As described above, when there are multiple forwarding destination candidates, the selection unit 62 may select, as the forwarding destination node, the forwarding destination candidate (AMF 40) that is located closest to the location of UE #3 among the multiple forwarding destination candidates.

[0048] Returning to the description of FIG. 6, the gateway device 20 (control device 60) transfers the registration request message received in step S29 to the AMF 40-2 selected as the destination node (step S32).

[0049] After communicating with the UDM, the AMF 40-2 transmits a registration response message corresponding to the registration request message from the UE #3 to the UE #3 via the gateway device 20 and the RAN node 30 (steps S33, S34, S35).

[0050] <Modification of Second Embodiment> In the above description, the control device 60 is described as being included in the gateway device 20, but this is not limiting. The control device 60 may be included in the RAN node 30. In this case, the gateway device 20 does not need to be present in the system 1.

[0051] 8 and 9 are sequence diagrams showing another example of the processing operation of the system of the present disclosure, with Fig. 9 being a sequence following the sequence of Fig. 8.

[0052] The sequence in Fig. 8 corresponds to the sequence in Fig. 5. In the sequence in Fig. 8, the control device 60 is included in the RAN node 30. Therefore, the RAN node 30 including the control device 60 receives messages including information indicating the characteristics of each of the AMFs 40-1, 40-2, and 40-3 from each of the AMFs 40-1, 40-2, and 40-3.

[0053] The sequence in Fig. 9 corresponds to the sequence in Fig. 6. Having received the notification message indicating the congestion state of AMF 40-1 in step S26, the RAN node 30 (control device 60) selects a destination node of the registration request message from AMF 40-2, 40-3 (step S31). For example, the RAN node 30 (control device 60) selects a destination node from AMF 40-2, 40-3 based on information indicating the characteristics of each of AMF 40-2, 40-3 and information on the attributes of UE 50, which is the sender of the registration request message. Here, it is assumed that AMF 40-2 is selected as the destination node.

[0054] The RAN node 30 (control device 60) transfers the registration request message received in step S29 to the AMF 40-2 selected as the destination node (step S32).

[0055] After communicating with the UDM, the AMF 40-2 transmits a registration response message corresponding to the registration request message from the UE #3 to the UE #3 via the RAN node 30 (steps S33, S35).

[0056] Third Embodiment The configuration of a system according to a third embodiment is the same as that of the system 1 according to the second embodiment, so reference will be made to FIG.

[0057] <Configuration example of control device> Fig. 10 is a block diagram showing another example of a control device of the present disclosure. In Fig. 10, the control device 70 has a communication control unit 71 and a selection unit 72. The communication control unit 71 has an acquisition unit 11, an acquisition unit 12, an acquisition unit 71A, and a transfer control unit 61A. The control device 70 will be described as being included in the gateway device 20.

[0058] When the acquisition unit 12 receives from the AMF 40-1 a first notification message indicating the congestion state of the AMF 40-1, the acquisition unit 71A transmits to each of the AMFs 40-2 and 40-3 a report request message requesting a report of the current status of the AMF 40. Then, the acquisition unit 71A receives from each of the AMFs 40-2 and 40-3 a report message including information indicating the current status of the AMF 40 (for example, information regarding the load level of the AMF 40). This allows the acquisition unit 71A to acquire information regarding the load levels of each of the AMFs 40-2 and 40-3.

[0059] Similarly to the selection unit 62, when the acquisition unit 12 receives the first notification message, the selection unit 72 selects a destination node of the registration request message from at least one second CN node. For example, when the acquisition unit 12 receives the above-mentioned first notification message, the selection unit 72 selects a destination node from among the AMFs 40-2 and 40-3 based on information indicating the respective features of the AMFs 40-2 and 40-3 and information on the attributes of the UE 50 that is the transmission source of the registration request message. For example, the selection unit 72 may select a destination node using a correspondence relationship between a plurality of attribute candidates of the UE and the features of the AMF 40 corresponding to each attribute candidate. In this case, the selection unit 72 selects, as the destination node, an AMF 40 (AMF 40-2 or AMF 40-3) that has a feature corresponding to the attribute of the above-mentioned transmission source UE 50 in the correspondence relationship between a plurality of attribute candidates of the UE and the features of the AMF 40 corresponding to each attribute candidate.

[0060] In addition, when there are multiple forwarding destination candidates (AMFs 40) having characteristics corresponding to the attributes of the source UE 50 in the correspondence relationship, the selection unit 72 may select a forwarding destination candidate having a load level below a predetermined level as a forwarding destination node from among the multiple forwarding destination candidates. Alternatively, when there are multiple forwarding destination candidates (AMFs 40) having characteristics corresponding to the attributes of the source UE 50 in the correspondence relationship, the selection unit 72 may select a forwarding destination candidate having the lowest load level from among the multiple forwarding destination candidates as a forwarding destination node. Alternatively, when there are multiple forwarding destination candidates (AMFs 40) having characteristics corresponding to the attributes of the source UE 50 in the correspondence relationship, the selection unit 72 may select a forwarding destination candidate having a load level below a predetermined level and the lowest load level from among the multiple forwarding destination candidates as a forwarding destination node. The load level may be a CPU usage rate.

[0061] Here, when the RAN node 30 receives a notification message indicating the congestion state of the AMF 40-1, the RAN node 30 forwards the registration request message transmitted from the UE 50 to the gateway device 20, not to the AMF 40-1.

[0062] In the control device 70 , the transfer control unit 61 A transfers the registration request message from the RAN node 30 to the destination node selected by the selection unit 72 .

[0063] <Example of System Operation> Fig. 11 is a sequence diagram showing an example of processing operation of the system of the present disclosure. Fig. 11 is a sequence following the sequence of Fig. 5 .

[0064] The gateway device 20 including the control device 70 transmits a report request message to each of the AMFs 40-2 and 40-3 requesting a report of the current status of the AMF 40 (steps S41-1 and S41-2).

[0065] The gateway device 20 receives a report message including information on the load level of the AMF 40 from each of the AMFs 40-2 and 40-3 (steps S42-1 and S42-2).

[0066] Having received the notification message indicating the congestion state of AMF 40-1 in step S27, the gateway device 20 (control device 70) selects a destination node of the registration request message from AMF 40-2, 40-3 (step S43). For example, similar to the control device 60, the gateway device 20 (control device 70) selects a destination node from AMF 40-2, 40-3 based on information indicating the characteristics of each of AMF 40-2, 40-3 and information on the attributes of UE 50, which is the sender of the registration request message. Here, it is assumed that AMF 40-2 is selected as the destination node.

[0067] As described above, when there are multiple destination candidates, the control device 70 may select, for example, the destination candidate (AMF 40) with the lowest load level among the multiple destination candidates as the destination node.

[0068] The gateway device 20 (control device 70) transfers the registration request message received in step S29 to the AMF 40-2 selected as the destination node (step S44).

[0069] After communicating with the UDM, the AMF 40-2 transmits a registration response message corresponding to the registration request message from the UE #3 to the UE #3 via the gateway device 20 and the RAN node 30 (steps S45, S46, S47).

[0070] <Modification of Third Embodiment> In the above description, the control device 70 is described as being included in the gateway device 20, but this is not limiting. The control device 70 may be included in the RAN node 30. In this case, the gateway device 20 does not need to be present in the system 1.

[0071] 12 is a sequence diagram showing another example of the processing operation of the system of the present disclosure, which is a continuation of the sequence of FIG.

[0072] The sequence in Fig. 12 corresponds to the sequence in Fig. 11. In the sequence in Fig. 12, the control device 70 is included in the RAN node 30. Therefore, the RAN node 30 including the control device 70 transmits a report request message to each of the AMFs 40-2 and 40-3, requesting a report of the current status of the AMF 40 (steps S41-1 and S41-2).

[0073] The RAN node 30 (control device 70) receives a report message including information on the load level of the AMF 40 from each of the AMFs 40-2 and 40-3 (steps S42-1 and S42-2).

[0074] Having received the notification message indicating the congestion state of the AMF 40-1 in step S26, the RAN node 30 (control device 70) selects a destination node of the registration request message from the AMFs 40-2 and 40-3 (step S43). For example, similar to the control device 60, the RAN node 30 (control device 70) selects a destination node from the AMFs 40-2 and 40-3 based on information indicating the characteristics of the AMFs 40-2 and 40-3 and information on the attributes of the UE 50 that is the sender of the registration request message. Here, it is assumed that the AMF 40-2 is selected as the destination node.

[0075] The RAN node 30 (control device 70) transfers the registration request message received in step S29 to the AMF 40-2 selected as the destination node (step S44).

[0076] After communicating with the UDM, the AMF 40-2 transmits a registration response message corresponding to the registration request message from the UE #3 to the UE #3 via the RAN node 30 (steps S45 and S47).

[0077] <Other Embodiments> <1> FIG. 13 is a diagram illustrating an example configuration of a control device. In FIG. 13, the control device 100 includes a processor 101 and a memory 102. The control devices 10, 60, and 70 may each have the configuration illustrated in FIG. 13. The processor 101 may be, for example, a microprocessor, a microprocessing unit (MPU), or a central processing unit (CPU). The processor 101 may include multiple processors. The memory 102 is configured by a combination of volatile memory and nonvolatile memory. The memory 102 may include multiple physically independent memory devices. The volatile memory may be, for example, static random access memory (SRAM), dynamic RAM (DRAM), or a combination thereof. The nonvolatile memory may be, for example, mask read only memory (MROM), electrically erasable programmable ROM (EEPROM), flash memory, or a hard disk drive, or any combination thereof. The memory 102 may include storage located remotely from the processor 101. In this case, the processor 101 may access the memory 102 via an I (Input) / O (Output) interface (not shown).

[0078] The memory 102 may store one or more software modules (computer programs) including instructions and data for performing processing by the control devices 10, 60, and 70 described in the above-described embodiments. In some implementations, the processor 101 may be configured to read and execute the software modules from the memory 102 to perform processing by the control devices 10, 60, and 70 described in the above-described embodiments.

[0079] <2> Figure 14 is a diagram showing an example configuration of a RAN node. In Figure 14, an apparatus 200 includes an antenna array 201, a radio frequency transceiver 202, a network interface 203, a processor 204, and a memory 205. The RAN node 30 may have the configuration shown in Figure 14. The RF transceiver 202 performs analog RF signal processing to communicate with UEs. The RF transceiver 202 may include multiple transceivers. The RF transceiver 202 is coupled to the antenna array 201 and the processor 204. The RF transceiver 202 receives modulation symbol data from the processor 204, generates a transmit RF signal, and provides the transmit RF signal to the antenna array 201. The RF transceiver 202 also generates a baseband receive signal based on the receive RF signal received by the antenna array 201 and provides the baseband receive signal to the processor 204. The RF transceiver 202 may include an analog beamformer circuit for beamforming. The analog beamformer circuitry includes, for example, multiple phase shifters and multiple power amplifiers.

[0080] The network interface 203 is used to communicate with a network node (e.g., a gateway device, an AMF), and may include, for example, a network interface card (NIC) that complies with the IEEE 802.3 series.

[0081] The processor 204 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. The processor 204 may include multiple processors. For example, the processor 204 may include a modem processor (e.g., a Digital Signal Processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., a Central Processing Unit (CPU) or a Micro Processing Unit (MPU)) that performs control plane processing.

[0082] The processor 204 may include a digital beamformer module for beamforming, which may include a Multiple Input Multiple Output (MIMO) encoder and precoder.

[0083] The memory 205 is configured by a combination of volatile memory and non-volatile memory. The volatile memory is, for example, Static Random Access Memory (SRAM), Dynamic RAM (DRAM), or a combination thereof. The non-volatile memory is, for example, Mask Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or a hard disk drive, or any combination thereof. The memory 205 may include storage located remotely from the processor 204. In this case, the processor 204 may access the memory 205 via the network interface 203 or an I / O interface (not shown).

[0084] The memory 205 may store one or more software modules (computer programs) including instructions and data for performing the processes of the RAN node 30 described in the above-described embodiments. In some implementations, the processor 204 may be configured to read and execute the software modules from the memory 205 to perform the processes of the RAN node 30 described in the above-described embodiments.

[0085] <3> Figure 15 is a diagram showing an example configuration of a network node. In the example of Figure 15, each or both of the gateway device 20 and the AMF 40 may be implemented as a computer system. The computer system 300 includes one or more processors 301, memory 302, and mass storage 303, which communicate with each other via a bus 307. The one or more processors 301 may include, for example, a central processing unit (CPU) or a graphics processing unit (GPU), or both. The computer system 300 may also include other devices such as one or more output devices 304, one or more input devices 305, and one or more peripherals 306. The one or more peripherals 306 may include a modem, a network adapter, or any combination thereof.

[0086] One or both of the memory 302 and the mass storage 303 may include a computer-readable medium having stored thereon one or more sets of instructions, which may be partially or completely located in memory within the one or more processors 301. These instructions, when executed in the one or more processors 301, cause the one or more processors 301 to provide the functionality of each or both of the gateway device 20 and the AMF 40 described in the above embodiments.

[0087] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0088] Each drawing is merely an example for describing one or more embodiments. Each drawing may not relate to only one particular embodiment, but may also relate to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0089] Some or all of the above embodiments may be described as, but are not limited to, the following supplementary notes: (Supplementary Note 1) A control device comprising: a first acquisition unit that acquires information indicating a feature of each CN node from at least one core network (CN) node that manages access and mobility, respectively; a second acquisition unit that receives a first notification message from a first CN node of the at least one CN node, the first notification message indicating a congestion state of the first CN node; and a selection unit that, when the second acquisition unit receives the first notification message from the first CN node of the at least one CN node, selects a destination node of a registration request message from the at least one second CN node, based on information indicating a feature of at least one second CN node different from the first CN node and information on an attribute of a user equipment (UE) that is a source of the registration request message. (Supplementary Note 2) The control device according to Supplementary Note 1, wherein the selection unit selects, from the at least one second CN node, a second CN node having a characteristic that corresponds to the attribute of the source UE in a correspondence relationship between a plurality of UE attribute candidates and characteristics of CN nodes corresponding to each attribute candidate. (Supplementary Note 3) The control device according to Supplementary Note 1 or 2, wherein, when there are a plurality of forwarding destination candidates in the at least one second CN having the characteristic that matches the attribute of the UE, the selection unit selects, as the forwarding destination node, a second CN node that is located within a predetermined distance from a position of the UE from among the plurality of forwarding destination candidates. (Supplementary Note 4) The control device according to Supplementary Note 1 or 2, further comprising: a third acquisition unit that acquires information regarding the load level of each second CN node from each of the at least one second CN node when a first notification message indicating a congestion state of the first CN node is received from the first CN node; and the selection unit, when there are multiple candidate forwarding destinations in the at least one second CN node that have the characteristics that match the attributes of the UE, selects the second CN node with the lowest load level from the multiple candidate forwarding destinations as the destination node.(Supplementary Note 5) The control device according to Supplementary Note 1 or 2, further comprising: a third acquisition unit configured to acquire, when receiving a first notification message indicating a congestion state of the first CN node from the first CN node, information on a load level of each second CN node from each of the at least one second CN node, wherein, when there are multiple forwarding destination candidates in the at least one second CN having the characteristic matching the attribute of the UE, the selector selects, as the forwarding destination node, a second CN node whose load level is equal to or lower than a predetermined level from among the multiple forwarding destination candidates. (Supplementary Note 6) The control device according to Supplementary Note 1, wherein the characteristic is a performance parameter of a CN node. (Supplementary Note 7) The control device according to Supplementary Note 1, wherein the information on the attribute is one or both of carrier identification information of the UE and Quality of Service (QoS) information of the UE. (Supplementary Note 8) A RAN node including the control device according to any one of Supplements 1 to 7. (Supplementary Note 9) A gateway device including the control device according to any one of Supplements 1 to 7. (Supplementary Note 10) A gateway device comprising: a first acquisition unit that acquires information indicating characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; a second acquisition unit that acquires a second notification message that indicates a congestion state of a first CN node, the second notification message being transmitted from a first CN node of the at least one CN node in association with transmission of a first notification message that indicates a congestion state of the first CN node from the first CN node to an access network (AN) node; and a selection unit that, when the second acquisition unit receives the second notification message, selects a destination node of a registration request message of a user equipment (UE) forwarded from the AN node from the at least one second CN node, based on information indicating characteristics of at least one second CN node different from the first CN node and information on attributes of a UE that is a sender of the registration request message.(Supplementary Note 11) A method executed by a control device, comprising: acquiring information indicating characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; and, when receiving a first notification message from a first CN node of the at least one CN node indicating a congestion state of the first CN node, selecting, from the at least one second CN node, a destination node for the registration request message based on information indicating characteristics of at least one second CN node different from the first CN node and information on attributes of a user equipment (UE) that has transmitted the registration request message. (Supplementary Note 12) The method according to Supplementary Note 11, wherein the selecting includes selecting, as the destination node, a second CN node from the at least one second CN node that has characteristics corresponding to the attributes of the source UE in a correspondence relationship between a plurality of UE attribute candidates and CN node characteristics corresponding to each attribute candidate. (Supplementary Note 13) The method of Supplementary Note 11 or 12, wherein the selecting includes, when there are multiple candidate destinations in the at least one second CN having the characteristics matching the attributes of the UE, selecting a second CN node that is located within a predetermined distance from a location of the UE as the destination node from among the multiple candidate destinations. (Supplementary Note 14) The method of Supplementary Note 11 or 12, wherein, when a first notification message indicating a congestion state of the first CN node is received from the first CN node, obtaining information on a load level of each second CN node from each of the at least one second CN node, and wherein the selecting includes, when there are multiple candidate destinations in the at least one second CN having the characteristics matching the attributes of the UE, selecting a second CN node that has the lowest load level from among the multiple candidate destinations as the destination node.(Supplementary Note 15) The method of Supplementary Note 11 or 12, comprising, when receiving a first notification message from the first CN node indicating a congestion state of the first CN node, obtaining information on a load level of each second CN node from each of the at least one second CN node, and when there are multiple candidate forwarding destinations in the at least one second CN having the characteristics matching the attributes of the UE, selecting a second CN node from the multiple candidate forwarding destinations whose load level is equal to or lower than a predetermined level as the destination node. (Supplementary Note 16) The method of Supplementary Note 11, wherein the characteristics are performance parameters of CN nodes. (Supplementary Note 17) The method of Supplementary Note 11, wherein the information on the attributes is one or both of carrier identification information of the UE and QoS information of the UE. (Supplementary Note 18) A program causing a control device to execute a process including: acquiring information indicating characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; and, when receiving a first notification message from a first CN node of the at least one CN node indicating a congestion state of the first CN node, selecting, from the at least one second CN node, a destination node for the registration request message, based on information indicating characteristics of at least one second CN node different from the first CN node and information on attributes of a user equipment (UE) that has transmitted the registration request message. (Supplementary Note 19) The program according to Supplementary Note 18, wherein the selecting includes selecting, as the destination node, a second CN node from the at least one second CN node that has characteristics corresponding to the attributes of the source UE in a correspondence relationship between a plurality of attribute candidates of UE and characteristics of CN nodes corresponding to each attribute candidate. (Supplementary Note 20) The program described in Supplementary Note 18 or 19, wherein the selecting includes, when there are multiple candidate forwarding destinations in the at least one second CN that have the characteristics that match the attributes of the UE, selecting a second CN node from the multiple candidate forwarding destinations that is located within a predetermined distance from the location of the UE as the destination node.(Supplementary Note 21) The program according to Supplementary Note 18 or 19, wherein the processing includes, when receiving a first notification message from the first CN node indicating a congestion state of the first CN node, obtaining information regarding the load level of each second CN node from each of the at least one second CN node, and the selecting includes, when there are multiple candidate forwarding destinations in the at least one second CN having the characteristics matching the attributes of the UE, selecting the second CN node with the lowest load level as the destination node. (Supplementary Note 22) The program according to Supplementary Note 18 or 19, wherein the processing includes, when receiving a first notification message from the first CN node indicating a congestion state of the first CN node, acquiring information on a load level of each second CN node from each of the at least one second CN node, and wherein the selecting includes, when there are multiple candidate forwarding destinations in the at least one second CN having the characteristics matching the attributes of the UE, selecting a second CN node whose load level is equal to or lower than a predetermined level as the destination node. (Supplementary Note 23) The program according to Supplementary Note 18, wherein the characteristics are performance parameters of CN nodes. (Supplementary Note 24) The program according to Supplementary Note 18, wherein the information on the attributes is one or both of carrier identification information of the UE and QoS information of the UE.

[0090] This application claims priority based on Japanese Patent Application No. 2024-091946, filed on June 6, 2024, the disclosure of which is incorporated herein in its entirety by reference.

[0091] REFERENCE SIGNS LIST 1 System 10 Control device 11 Acquisition unit (first acquisition unit) 12 Acquisition unit (second acquisition unit) 13 Selection unit 20 Gateway device (GW) 30 RAN node 60 Control device 61 Communication control unit 61A Transfer control unit 62 Selection unit 70 Control device 71 Communication control unit 71A Acquisition unit 72 Selection unit

Claims

1. A control device comprising: a first acquisition unit that acquires information indicating characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; a second acquisition unit that receives a first notification message indicating a congestion state of the first CN node from a first CN node of the at least one CN node; and a selection unit that, when the second acquisition unit receives the first notification message indicating the congestion state of the first CN node from the first CN node of the at least one CN node, selects a destination node of the registration request message from the at least one second CN node based on information indicating characteristics of at least one second CN node different from the first CN node and information regarding attributes of a user equipment (UE) that is a sender of the registration request message.

2. The control device according to claim 1, wherein the selection unit selects, as the destination node, from the at least one second CN node, a second CN node having a characteristic corresponding to the attribute of the source UE in a correspondence relationship between a plurality of attribute candidates of the UE and characteristics of the CN node corresponding to each attribute candidate.

3. The control device according to claim 1 or 2, wherein, when there are multiple candidate forwarding destinations in the at least one second CN that have the characteristics that match the attributes of the UE, the selection unit selects a second CN node from the multiple candidate forwarding destinations that is located within a predetermined distance from the location of the UE as the destination node.

4. The control device according to claim 1 or 2, further comprising a third acquisition unit that acquires information regarding the load level of each second CN node from each of the at least one second CN node when a first notification message indicating the congestion state of the first CN node is received from the first CN node, and the selection unit selects, if there are multiple candidate forwarding destinations in the at least one second CN node that have the characteristics matching the attributes of the UE, the second CN node with the lowest load level from among the multiple candidate forwarding destinations as the destination node.

5. The control device according to claim 1 or 2, further comprising a third acquisition unit that acquires information regarding the load level of each second CN node from each of the at least one second CN node when a first notification message indicating the congestion state of the first CN node is received from the first CN node, and the selection unit, when there are multiple candidate forwarding destinations in the at least one second CN node that have the characteristics that match the attributes of the UE, selects a second CN node from the multiple candidate forwarding destinations whose load level is below a predetermined level as the destination node.

6. The control device of claim 1, wherein the characteristics are performance parameters of the CN nodes.

7. The control device according to claim 1, wherein the information relating to the attributes is one or both of carrier identification information of the UE and QoS (Quality of Service) information of the UE.

8. A gateway device comprising: a first acquisition unit that acquires information indicating characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; a second acquisition unit that acquires a second notification message indicating a congestion state of a first CN node transmitted from a first CN node of the at least one CN node in conjunction with transmission of a first notification message indicating the congestion state of the first CN node from the first CN node to an access network (AN) node; and a selection unit that, when the second acquisition unit receives the second notification message, selects a destination node for a registration request message of a user equipment (UE) transmitted from the AN node from the at least one second CN node based on information indicating characteristics of each second CN node different from the first CN node and information regarding attributes of the UE that sent the registration request message.

9. A method executed by a control device, comprising: acquiring information indicating characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; and, when receiving a first notification message from a first CN node of the at least one CN node indicating a congestion state of the first CN node, selecting a destination node for the registration request message from the at least one second CN node based on information indicating characteristics of each of at least one second CN node different from the first CN node and information regarding attributes of a user equipment (UE) that sent the registration request message.

10. A program that causes a control device to execute a process including: acquiring information indicating the characteristics of each CN node from at least one core network (CN) node that manages access and mobility, respectively; and, when receiving a first notification message from a first CN node of the at least one CN node indicating the congestion state of the first CN node, selecting a destination node for the registration request message from the at least one second CN node based on information indicating the characteristics of each of at least one second CN node different from the first CN node and information regarding the attributes of the user equipment (UE) that sent the registration request message.

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