First near RT RIC, second near RT RIC, communication method, and program

Abstract

The purpose of the present disclosure is to provide a first Near RT RIC and a second Near RT RIC capable of achieving communication between Near RT RICs. A RIC according to the present disclosure comprises: a communication unit that receives list information of at least one E2 node from a second Near RT RIC connected to the at least one E2 node; and a selection unit that selects at least one first E2 node from the at least one E2 node included in the list information. The communication unit receives information held by the first E2 node from the at least one first E2 node via the second Near RT RIC.

Description

First Near RT RIC, Second Near RT RIC, Communication Method, and Program

[0001] The present disclosure relates to a first Near RT RIC, a second Near RT RIC, a communication method, and a program.

[0002] In recent years, a radio access network that separates the baseband unit and the radio unit of a base station and connects the baseband unit and the radio unit via a fronthaul has been used. The O-RAN (Open-Radio Access Network) fronthaul specification defined by the O-RAN Alliance defines the fronthaul specification between an O-RU (Radio Unit) corresponding to the radio unit and an O-DU (Distributed Unit) and an O-CU (Central Unit) corresponding to the baseband unit. One purpose of the O-RAN fronthaul specification is to facilitate the connection between an O-RU of a different vendor from the O-DU vendor and to achieve multi-vendorization of the radio access network. In addition, in order to achieve RAN intelligentization, the specification of the RIC (RAN Intelligent Controller) is also being studied.

[0003] In Non-Patent Document 1, for example, the function of a Near RT RIC (Near-Real Time RAN Intelligent Controller) is defined as a node for realizing RAN intelligentization that realizes autonomous RAN operation. Non-Patent Document 1 describes that the Near RT RIC acquires information specific to a UE (User Equipment) corresponding to a communication terminal from an E2 node including an O-CU and an O-DU using the REPORT Service.

[0004] Patent Document 1 describes that between Near RT RICs, each Near RT RIC notifies a list of cells supported by it.

[0005] Japanese Patent Translation of PCT International Publication No. 2024-535955

[0006] O-RAN.WG3.TS.E2GAP-R004-v07.00

[0007] In the future, an increase in E2 nodes is expected to lead to an increase in Near RT RICs connected to E2 nodes. With this increase in Near RT RICs, it is desirable to configure Near RT RICs in a multi-stage configuration to enable communication between them. However, a problem exists: Near RT RICs at higher levels of a multi-stage configuration cannot control the E2 nodes connected to Near RT RICs at lower levels.

[0008] One of the purposes of this disclosure is to provide a first Near RT RIC, a second Near RT RIC, a communication method, and a program configured to enable control of E2 nodes connected to Near RT RICs located at lower levels by a Near RT RIC located at a higher level in a multi-stage configuration.

[0009] The first Near RT RIC according to this disclosure includes a communication unit that receives list information of at least one E2 node from a second Near RT RIC connected to at least one E2 node, and a selection unit that selects at least one first E2 node from the at least one E2 node included in the list information, wherein the communication unit receives information held by the first E2 node from the at least one first E2 node via the second Near RT RIC.

[0010] The first Near RT RIC according to this disclosure includes a communication unit that receives a third request message from at least one second Near RT RIC, which includes control parameters relating to an E2 node controlled by each of the second Near RT RICs, and a determination unit that determines whether or not there is a conflict regarding the control parameters.

[0011] The second Near RT RIC according to this disclosure includes a communication unit that transmits a list of at least one connected E2 nodes to the first Near RT RIC, and the communication unit transmits to the first Near RT RIC information regarding a first E2 node selected by the first Near RT RIC from among the at least one E2 node.

[0012] The communication method according to this disclosure receives list information of at least one E2 node from a second Near RT RIC connected to at least one E2 node, selects at least one first E2 node from the at least one E2 node included in the list information, and receives information held by the first E2 node from the at least one first E2 node via the second Near RT RIC.

[0013] The communication method relating to this disclosure receives a third request message from at least one second Near RT RIC, which includes control parameters relating to an E2 node controlled by each of the second Near RT RICs, and determines whether there is a conflict regarding the control parameters.

[0014] The communication method relating to this disclosure transmits a list of at least one connected E2 node information to the first Near RT RIC, and transmits information to the first Near RT RIC regarding the first E2 node selected by the first Near RT RIC from among the at least one E2 node.

[0015] The program relating to this disclosure causes a computer to receive list information of at least one E2 node from a second Near RT RIC connected to at least one E2 node, select at least one first E2 node from the at least one E2 node included in the list information, and receive information held by the first E2 node from the at least one first E2 node via the second Near RT RIC.

[0016] This disclosure provides a first Near RT RIC, a second Near RT RIC, a communication method, and a program configured to enable control of E2 nodes connected to Near RT RICs located at lower levels by a Near RT RIC located at a higher level in a multi-stage configuration.

[0017] Figure 1 shows an example configuration of the first Near RT RIC. Figure 2 shows the flow of communication processing performed in the first Near RT RIC. Figure 3 shows an example configuration of the second Near RT RIC. Figure 4 shows the flow of communication processing performed in the second Near RT RIC. Figure 5 is a diagram showing an example configuration of the communication system. Figure 6 shows the flow of the process of transmitting list information via the E3 interface. Figure 7 shows the flow of the process of notifying an RIC Event Trigger via the E3 interface. Figure 8 shows the RIC Subscription procedure between the second Near RT RIC and the E2 node. Figure 9 shows the flow of communication processing between the first Near RT RIC and the second Near RT RIC. Figure 10 shows the flow of the process of controlling the E2 node by the first Near RT RIC. Figure 11 shows an example configuration of the first Near RT RIC. Figure 12 shows the flow of the parameter conflict check process in the first Near RT RIC. Figure 13 is a block diagram showing example configurations of the first Near RT RIC and the second Near RT RIC.

[0018] Embodiment 1 Figure 1 shows an example configuration of the first Near-RT RIC 10. The Near-RT RIC is a logical function that performs near-real-time control and optimization of RAN (Radio Access Network) elements and resources. Alternatively, the Near-RT RIC may be a physical device equipped with a logical function that performs near-real-time control and optimization of RAN elements and resources. Near-real-time control may be, for example, control performed with a period of about 10ms to 1s. Detailed data may be called near-real-time information. Near-real-time information may be, for example, information on a UE (User Equipment) basis, or information on a cell basis.

[0019] The RAN element may be, for example, an E2 node 30. The E2 node 30 is a logical node that terminates the E2 interface. The E2 interface is an interface defined between the E2 node and the Near-RT RIC. Specifically, the E2 node 30 may be either an O-CU (Open-Central Unit) or an O-DU (Open-Distributed Unit). The E2 node 30 may be a physical device corresponding to either an O-CU or an O-DU, or it may be a physical device that integrates both an O-CU and an O-DU. If the E2 node 30 is a physical device that integrates both an O-CU and an O-DU, the E2 interface is an interface defined between the physical device that integrates both an O-CU and an O-DU and the Near-RT RIC.

[0020] An O-CU may be, for example, a logical node that hosts RRC (Radio Resource Control) and PDCP (Packet Data Convergence Protocol). Alternatively, an O-CU may be a physical device that houses an O-CU, which is a logical node. Hosting RRC and PDCP can be rephrased as terminating the RRC protocol and PDCP, or executing processing related to the RRC protocol and PDCP. Furthermore, when an O-CU hosts RRC and PDCP, it can be rephrased as the O-CU executing processing related to the RRC layer and the PDCP layer. In the following explanation, the term "host" may also be rephrased as described above.

[0021] An O-CU that performs processing related to the C-Plane (Control Plane) part of PDCP may be referred to as O-CU-CP (C-Plane). Furthermore, an O-CU that performs processing related to the U-Plane (User Plane) part of PDCP may be referred to as O-CU-UP (U-Plane).

[0022] The O-DU may be a logical node hosting RLC (Radio Link Control) and MAC (Medium Access Control). Furthermore, the O-DU may be a logical node hosting higher-level functions of the physical (PHY) layer. Alternatively, the O-DU may be a physical device housing the O-DU, which is a logical node. The O-DU may also perform PDCP-related processing in place of or together with the O-CU. Higher-level functions of the physical layer may include, for example, encoding and modulation processing, and further, decoding and demodulation processing, etc.

[0023] Here, the first Near RT RIC 10 and the second Near RT RIC 20 may be connected in a multi-stage configuration. In other words, the first Near RT RIC 10 may be arranged to aggregate multiple second Near RT RICs 20. The first Near RT RIC 10 may be referred to as a higher-level Near RT RIC, and the second Near RT RIC 20 as a lower-level Near RT RIC. Specifically, at least one second Near RT RIC 20 may be connected to one first Near RT RIC 10. The second Near RT RIC 20 is connected to at least one E2 node 30 via an E2 interface. The first Near RT RIC 10 may also be connected to at least one E2 node 30 via an E2 interface. Furthermore, the first Near RT RIC 10 may be connected to the second Near RT RIC 20, for example, via an E3 interface. The E3 interface is an exemplary name for an interface defined between the first Near RT RIC 10 and the second Near RT RIC 20, and the name of the interface may be changed. The E3 interface may also be used for connection between the second Near RT RIC 20. Furthermore, the first Near RT RIC 10 may be located on the cloud. In other words, the first Near RT RIC 10 may be a cloud system. The first Near RT RIC may also be referred to as a central Near RT RIC or a cloud Near RT RIC. Furthermore, the second Near RT RIC may also be referred to as a local Near RT RIC.

[0024] The first Near RT RIC 10 and the second Near RT RIC 20 may perform quasi-real-time control with different periods. For example, the period of the quasi-real-time control performed by the first Near RT RIC 10 may be longer than the period of the quasi-real-time control performed by the second Near RT RIC 20.

[0025] The second Near RT RIC 20 may be positioned closer to the E2 node 30 than the first Near RT RIC 10. In other words, the positions of the first Near RT RIC 10 and the second Near RT RIC 20 may be determined such that the distance between the second Near RT RIC 20 and the E2 node 30 is shorter than the distance between the first Near RT RIC 10 and the E2 node 30. By positioning the second Near RT RIC 20 closer to the E2 node 30 than the first Near RT RIC 10, near real-time control of the E2 node 30 can be performed at a shorter cycle than the first Near RT RIC 10.

[0026] The first Near RT RIC 10 and the second Near RT RIC 20 may be computer devices that operate by having a processor execute a program stored in memory.

[0027] The first Near RT RIC 10 has a communication unit 11 and a selection unit 12. The communication unit 11 and the selection unit 12 may be software or modules whose processing is performed by the processor executing a program stored in memory. Alternatively, the communication unit 11 and the selection unit 12 may be hardware such as a circuit or chip.

[0028] The communication unit 11 receives list information of at least one E2 node 30 from a second Near RT RIC 20 connected to at least one E2 node 30. The list information may include identification information that can uniquely identify each E2 node 30. The identification information may be, for example, address information assigned to each E2 node 30, or name information given in accordance with a naming policy determined by the network administrator or the like. The address information may be an IP (Internet Protocol) address or a MAC (Media Access Control) address. The identification information may be associated with, for example, the location where the E2 node 30 is installed, the services provided by the E2 node 30, and capability information related to the E2 node 30. The services provided by the E2 node 30 may be, for example, application services. The capability information may be, for example, information indicating the specifications of the E2 node 30, or it may be measurement information such as throughput and latency.

[0029] The selection unit 12 selects at least one first E2 node from at least one E2 node 30 included in the list information. For example, the selection unit 12 may select the first E2 node based on the location where the E2 node 30 is installed, the services provided by the E2 node 30, capability information regarding the E2 node 30, or other information. The selection unit 12 also selects a first E2 node to collect information from in order to collect information held by the E2 node 30. Collecting information can be rephrased as acquiring information, receiving information, etc.

[0030] The communication unit 11 receives information held by at least one first E2 node via the second Near RT RIC 20. The information held by the first E2 node may be, for example, information collected by the first E2 node from other devices, information generated by the first E2 node, etc. The information generated by the first E2 node may be, for example, information counting the data used by the first E2 node for communication with other devices, etc.

[0031] Figure 2 shows the flow of communication processing performed in the first Near RT RIC 10. First, the communication unit 11 receives list information of at least one E2 node 30 from the second Near RT RIC 20, which is connected to at least one E2 node 30 (S11). Next, the selection unit 12 selects at least one first E2 node from the at least one E2 node 30 included in the list information (S12). Next, the communication unit 11 receives information held by the first E2 node from at least one first E2 node via the second Near RT RIC 20 (S13).

[0032] Figure 3 shows an example configuration of the second Near RT RIC 20. The second Near RT RIC 20 has a communication unit 21. The communication unit 21 may be software or a module whose processing is performed by the processor executing a program stored in memory. Alternatively, the communication unit 21 may be hardware such as a circuit or chip.

[0033] The communication unit 21 transmits a list of at least one connected E2 node 30 to the first Near RT RIC 10. The communication unit 21 may also transmit the list information to the first Near RT RIC 10, which is the source of the request message, upon receiving a request message. Alternatively, if the communication unit 21 does not receive a request message, it may transmit the list information to the first Near RT RIC 10 at any time or periodically. Alternatively, the communication unit 21 may transmit the list information to the first Near RT RIC 10 when the number of connected E2 nodes 30 changes. The timing when the number of connected E2 nodes 30 changes may include, for example, when the connection between the first Near RT RIC 10 and an E2 node 30 is disconnected, or when a new E2 node 30 is connected to the first Near RT RIC 10.

[0034] Furthermore, the communication unit 21 transmits to the first Near RT RIC 10 information regarding the first E2 node selected by the first Near RT RIC 10 from among at least one E2 node 30. The communication unit 21 may also collect information regarding the first E2 node from the first E2 node. Alternatively, the information regarding the first E2 node may be generated based on data used for communication with the first E2 node. For example, the second Near RT RIC 20 may generate information regarding the first E2 node by counting the data used for communication with the first E2 node.

[0035] Figure 4 shows the flow of communication processing performed in the second Near RT RIC 20. First, the communication unit 21 transmits a list of at least one connected E2 node 30 to the first Near RT RIC 10 (S21). Next, the communication unit 21 transmits information about the first E2 node selected by the first Near RT RIC 10 from among the at least one E2 node 30 to the first Near RT RIC 10 (S22).

[0036] As described above, the first Near RT RIC 10 receives list information of at least one E2 node 30 connected to the second Near RT RIC 20 from the second Near RT RIC 20. This allows the first Near RT RIC 10 to recognize or identify E2 nodes 30 that are not connected to the first Near RT RIC 10. As a result, the first Near RT RIC 10 can receive information held by a desired E2 node 30 via the second Near RT RIC 20.

[0037] In this way, the first Near RT RIC 10 and the second Near RT RIC 20 are configured in a multi-stage configuration, and even if the first Near RT RIC 10 is not connected to the E2 node 30, the first Near RT RIC 10 can still collect information from the E2 node 30.

[0038] Embodiment 2 Next, Embodiment 2 will be described. Figure 5 is a diagram showing an example of the configuration of a communication system. The communication system in Figure 5 includes a first Near RT RIC 10, a second Near RT RIC 20, an E2 node 30, an O-RU 80, an SMO (Service Management and Orchestration) 90, and a UE 110. Furthermore, the E2 node 30 includes an O-CU 60 and an O-DU 70. The SMO 90 also includes a Non-RT (Non-Real-Time) RIC 100. Each device constituting the communication system may be a computer device that operates by having a processor execute a program stored in memory.

[0039] UE110 is used as a general term for communication terminals. For example, UE110 may be a mobile phone terminal, a smartphone terminal, or an IoT (Internet of Things) terminal. UE110 may support the wireless communication standard known as 5G in order to communicate wirelessly with O-RU80.

[0040] The E2 node 30 is a logical node that terminates the E2 interface. The E2 interface is an interface defined between the E2 node 30 and the first Near RT RIC 10 and the second Near RT RIC 20. In other words, the E2 interface is an interface defined between the O-CU 60 and the Near RT RIC, and further between the O-DU 70 and the Near RT RIC. The term Near RT RIC may be used to refer collectively to the first Near RT RIC 10 and the second Near RT RIC 20. The E2 node 30 may be a physical device corresponding to either the O-CU 60 or the O-DU 70, or it may be a physical device in which the O-CU 60 and the O-DU 70 are integrated. If the E2 node 30 is a physical device in which the O-CU 60 and the O-DU 70 are integrated, the E2 interface is an interface defined between the physical device in which the O-CU 60 and the O-DU 70 are integrated and the Near RT RIC.

[0041] O-RU 80 may be a logical node that hosts or executes the lower-layer functions of the physical layer and RF (Radio Frequency) processing. Alternatively, O-RU 80 may be a physical device that houses the O-RU which is a logical node. The lower-layer functions of the physical layer may be, for example, FFT (Fast Fourier Transform) / IFFT (Inverse FFT) processing, BF (Beam Forming) processing, and the like.

[0042] SMO 90 manages or supports the RAN domain. In other words, SMO 90 executes the control or optimization of the RAN domain. The RAN domain may be, for example, a network including O-CU 60, O-DU 70, and O-RU 80.

[0043] For example, SMO 90 may support FCAPS regarding the first Near RT RIC 10, the second Near RT RIC 20, O-CU 60, and O-DU 70 via the O1 interface. FCAPS indicates functions that execute fault management, configuration management, accounting management, performance management, and security management. Also, SMO 90 may support FCAPS regarding O-RU 80.

[0044] Further, the Non RT RIC 100 possessed by SMO 90 may execute processing regarding RAN optimization by communicating with the first Near RT RIC 10 and the second Near RT RIC 20 via, for example, the A1 interface. RAN optimization may be, for example, generating a control policy regarding the RAN and further notifying the control policy to the first Near RT RIC 10 and the second Near RT RIC 20.

[0045] The first Near RT RIC 10 and the second Near RT RIC 20 are logical functions that perform near real-time control and optimization of RAN elements and resources. Alternatively, the first Near RT RIC 10 and the second Near RT RIC 20 may be physical devices equipped with logical functions that perform near real-time control and optimization of RAN elements and resources. The RAN elements may be, for example, O-CU 60 and O-DU 70. Specifically, the second Near RT RIC 20 collects fine-grained data from O-CU 60 or O-DU 70 via the E2 interface. Near real-time control may be, for example, control performed with a period of about 10 ms to 1 s. The fine-grained data may be, for example, near real-time information. The near real-time information may be, for example, information per UE or information per cell. The first Near RT RIC 10 may acquire detailed data collected by the second Near RT RIC 20 from the second Near RT RIC 20. Alternatively, the first Near RT RIC 10 may acquire detailed data from the O-CU 60 or O-DU 70 via the E2 interface.

[0046] Figure 6 shows the flow of the process for transmitting list information via the E3 interface. First, the first Near RT RIC 10 sends an RIC Information Get Request message to the second Near RT RIC 20 (S31). The first Near RT RIC 10 needs to recognize at least one E2 node 30 connected to the second Near RT RIC 20 in order to collect information from at least one E2 node 30. Therefore, the first Near RT RIC 10 sends an RIC Information Get Request message to the second Near RT RIC 20 in order to collect list information from at least one E2 node 30. The RIC Information Get Request message may include information indicating a request for the transmission of list information from the E2 node 30. This information may be information elements, flags, or parameters.

[0047] Next, the second Near RT RIC 20 sends an RIC Information Get Response message to the first Near RT RIC 10 (S32). The second Near RT RIC 20 sends an RIC Information Get Response message containing the list information of E2 nodes 30 requested in the RIC Information Get Request message. The list information includes the identification information of at least one E2 node 30 connected to the second Near RT RIC 20. The E2 node 30 connected to the second Near RT RIC 20 may be an E2 node 30 that is in a state where it can communicate with the second Near RT RIC 20. For example, if a session is established between the second Near RT RIC 20 and the E2 node 30, then the second Near RT RIC 20 and the E2 node 30 are in a state where they can communicate.

[0048] Alternatively, the E2 node 30 connected to the second Near RT RIC 20 may be, for example, an E2 node 30 that has executed a RIC Subscription procedure with the second Near RT RIC 20. The RIC Subscription procedure may be, for example, a process in which the second Near RT RIC 20 requests to send a REPORT message, an INSERT message, and a POLICY message to the E2 node 30 when a predetermined condition is satisfied. The predetermined condition may be, for example, a RIC Subscription procedure Event Trigger or a RIC Event Trigger.

[0049] Figure 7 shows the flow of notification processing of a RIC Event Trigger via an E3 interface. First, the first Near RT RIC 10 transmits a RIC Event Request message to the second Near RT RIC 20 (S41). The RIC Event Request message may include, for example, information indicating a RIC Event Trigger and a process to be executed at the second Near RT RIC 20 when the RIC Event Trigger is detected. The process to be executed at the second Near RT RIC 20 when the RIC Event Trigger is detected may be, for example, to send a REPORT message, an INSERT message, and a POLICY message.

[0050] Specifically, the RIC Event Request message may include a RIC EVENT TRIGGER DEFINITION IE and a RIC ACTION DEFINITION IE as information elements. The RIC Event Request message may also include a RIC Request ID IE to identify the RIC Event Request message. Furthermore, the RIC Event Request message may include a Notification Type IE indicating whether the information detected or collected by the second Near RT RIC 20 should be notified as is, or edited, and if edited, how it should be edited.

[0051] The first Near RT RIC 10 may include information identifying the E2 node 30 selected from the E2 nodes 30 included in the list information in either the RIC EVENT TRIGGER DEFINITION IE or the RIC ACTION DEFINITION IE. The selected E2 node 30 may be indicated, for example, using an information element such as Event type. Alternatively, the selected E2 node 30 may be indicated as an E2nodeList IE.

[0052] The RIC EVENT TRIGER DEFINITION IE may be used, for example, to detect that the second Near RT RIC 20 has received a predetermined message, or that the second Near RT RIC 20 has sent a predetermined message. The predetermined message may be, for example, a message sent via an E2 interface defined between the second Near RT RIC 20 and the E2 node 30.

[0053] Alternatively, the RIC EVENT TRIGER DEFINITION IE may be used to detect that a call process has been detected at the E2 node 30 selected by the first Near RT RIC 10. For example, if the E2 node 30 detects a call process, it may notify the second Near RT RIC 20 that it has detected a call process.

[0054] Alternatively, the RIC EVENT TRIGER DEFINITION IE may be used to detect that the second Near RT RIC 20 has detected a change in information about the E2 node 30 selected by the first Near RT RIC 10. For example, the E2 node 30 may notify the second Near RT RIC 20 that a change has occurred in information about the E2 node 30.

[0055] A change in information regarding E2 node 30 may be interpreted as a change in the context information of the serving cell. Alternatively, a change in information regarding E2 node 30 may be interpreted as a change in information regarding the serving cell's adjacent cells. Alternatively, a change in information regarding E2 node 30 may be interpreted as a change in the slice information related to the serving cell. Alternatively, a change in information regarding E2 node 30 may be interpreted as a change in the MIB (Master Information Block) related to the serving cell. Alternatively, a change in information regarding E2 node 30 may be interpreted as a change in the common information (Serving Cell Config Common Information) in the serving cell. The serving cell may be, for example, one of the cells formed by the O-RU 80 connected to E2 node 30 that communicates with UE 110.

[0056] Alternatively, the RIC EVENT TRIGER DEFINITION IE may be used to detect that a change has occurred in the information regarding the UE 110 via the E2 node 30 selected in the first Near RT RIC 10. The information regarding the UE 110 may be referred to, for example, UE Context information. Changes in the UE Context information may be measured using values ​​such as RRC state, PDCP state variable, and RLC state variable.

[0057] The RIC ACTION DEFINITION IE may be used to instruct the second Near RT RIC 20 to notify the first Near RT RIC 10 of information regarding the E2 node 30 when the detection conditions shown in the RIC EVENT TRIGER DEFINITION IE are met. Notifying information may be rephrased as reporting information. The RIC ACTION DEFINITION IE may contain, for example, the identification information (UE ID) of the UE to be detected. Meeting the detection conditions may mean that the communication state of the UE to be detected reaches the value set as the detection condition.

[0058] Next, the second Near RT RIC 20 sends a RIC Event Response message to the first Near RT RIC 10 (S42).

[0059] Here, we will explain an example of the process by which the first Near RT RIC 10 selects a desired E2 node 30 from among the E2 nodes 30 included in the list information.

[0060] For example, the first Near RT RIC 10 may select a desired E2 node 30 based on the use case to be executed. The use case may be rephrased as an application or an application service. An application service may simply be called a service. Furthermore, the application executed in the first Near RT RIC 10 and the second Near RT RIC 20 may be called an xAPP.

[0061] Here, we will describe Quality of Service (QoS) control as a use case. For example, the second Near RT RIC 20 may perform QoS control aimed at optimizing resources for the E2 node 30 based on information collected from the E2 node 30. On the other hand, the first Near RT RIC 10 may perform QoS control aimed at optimizing resources on a network slice basis, rather than QoS for each individual E2 node 30. A network slice may, for example, contain multiple E2 nodes 30. Resource optimization may specifically involve resource allocation or resource configuration. Resource optimization may be performed, for example, to reduce latency between UEs, improve throughput, reduce packet loss, etc. Resource optimization may also involve controlling the resources allocated to an E2 node 30 that functions as virtualization software. Controlling resources may also involve controlling the number of E2 nodes 30 that function as virtualization software.

[0062] In such cases, the second Near RT RIC 20 performs QoS control based on information collected from the E2 node 30 connected to the second Near RT RIC 20. For example, if the information collected from the E2 node 30 indicates a decrease in throughput, an increase in latency, etc., in the UE 110, the second Near RT RIC 20 may increase the resources allocated to the E2 node 30.

[0063] On the other hand, the first Near RT RIC 10 performs QoS control based on information collected from a wide range of E2 nodes 30, such as E2 nodes 30 included in different network slices, E2 nodes 30 located in different regions, etc.

[0064] Therefore, for example, the first Near RT RIC 10 may select multiple E2 nodes 30 with different network slices from among multiple E2 nodes 30 included in the list information as E2 nodes 30 that collect information. Alternatively, the first Near RT RIC 10 may select multiple E2 nodes 30 with different locations. Furthermore, the first Near RT RIC 10 may select the E2 nodes 30 necessary to perform the use case based on information other than network slice or region.

[0065] Furthermore, as a use case different from QoS control, we will describe AI (Artificial Intelligence) / ML (Machine Learning). For example, the first Near RT RIC 10 or the second Near RT RIC 20 may use an AI / ML model to perform QoS control. The AI / ML model may be a model that takes information collected from the E2 node 30, for example, measurement information measured at the E2 node 30, as input and outputs the optimal value of the communication parameter. The value of the communication parameter may be, for example, a control parameter such as a timer value.

[0066] AI / ML models are generated by performing training using training data. Here, training an AI / ML model requires hardware such as a GPU (Graphics Processing Unit). Therefore, the cost of equipment or devices used for training an AI / ML model is higher than that of equipment not used for training an AI / ML model. To address this, the AI / ML model may be trained in the first Near RT RIC 10, which is fewer in number than the second Near RT RIC 20, and the AI / ML model generated in the first Near RT RIC 10 may then be used by the second Near RT RIC 20. By doing so, the number of pieces of equipment or devices used to train the AI / ML model can be reduced.

[0067] Therefore, the first Near RT RIC 10 selects an E2 node 30 to collect information for use in training an AI / ML model. The first Near RT RIC 10 may also select an E2 node 30 based on its specifications, location, the network slice to which it belongs, etc.

[0068] Figure 8 shows the RIC Subscription procedure between the second Near RT RIC 20 and the E2 node 30. In Figure 8, two E2 nodes 30 are shown: E2 node 30_1 and E2 node 30_2. Although Figure 8 shows processing using two E2 nodes 30, the number of E2 nodes 30 is not limited to two.

[0069] First, the second Near RT RIC 20 sends a RIC Subscription Request message to the E2 node 30_1 via the E2 interface (S51). The RIC Subscription Request message may include a RIC EVENT TRIGGER DEFINITION IE and a RIC ACTION DEFINITION IE as information elements. The RIC Subscription Request message may also include a RIC Request ID IE to identify the RIC Subscription procedure.

[0070] The RIC EVENT TRIGER DEFINITION IE may be used, for example, to detect that E2 node 30_1 has received a predetermined message or that E2 node 30_1 has sent a predetermined message. The predetermined message may be, for example, an RRC message.

[0071] Alternatively, the RIC EVENT TRIGER DEFINITION IE may be used to detect that the E2 node 30_1 has detected a call process.

[0072] Alternatively, the RIC EVENT TRIGER DEFINITION IE may be used to detect that a change has occurred in the information related to E2 node 30_1. A change in the information related to E2 node 30_1 may be a change in the context information of the serving cell. Alternatively, a change in the information related to E2 node 30_1 may be a change in the information related to the adjacent cells of the serving cell. Alternatively, a change in the information related to E2 node 30_1 may be a change in the slice information related to the serving cell. Alternatively, a change in the information related to E2 node 30_1 may be a change in the MIB (Master Information Block) related to the serving cell. Alternatively, a change in the information related to E2 node 30_1 may be a change in the Serving Cell Config Common Information in the serving cell.

[0073] Alternatively, the RIC EVENT TRIGER DEFINITION IE may be used to detect when the E2 node 30_1 has changed information about UE 110. Information about UE 110 may be referred to as, for example, UE Context information. Changes in UE Context information may be detected using values ​​such as RRC state, PDCP state variable, or RLC state variable.

[0074] The RIC ACTION DEFINITION IE may be used to instruct E2 node 30_1 to notify the second Near RT RIC 20 of information about E2 node 30_1 when the detection conditions shown in the RIC EVENT TRIGER DEFINITION IE are met. Notifying information may be rephrased as reporting information. The RIC ACTION DEFINITION IE may contain, for example, the identification information (UE ID) of the UE to be detected. Meeting the detection conditions may mean that the communication state of the UE to be detected reaches the value set as the detection condition.

[0075] Next, the E2 node 30_1 sends an RIC Subscription Response message to the second Near RT RIC 20 (S52). The second Near RT RIC 20, in steps S53 and S54, performs the same processing as in steps S51 and S52 with the E2 node 30_2.

[0076] Next, E2 node 30_1 and E2 node 30_2 each send an RIC Indication message to the second Near RT RIC 20 (S55, S56). E2 node 30_1 and E2 node 30_2 execute the processing defined in RIC ACTION DEFINITION IE when the conditions defined in RIC EVENT TRIGER DEFINITION IE are met. The processing defined in RIC ACTION DEFINITION IE may include sending a REPORT message, an INSERT message, or a POLICY message.

[0077] Figure 9 shows the communication processing flow between the first Near RT RIC 10 and the second Near RT RIC 20. In Figure 9, it is assumed that the second Near RT RIC 20 has collected information from at least one E2 node 30 using a REPORT message or the like. Furthermore, it is assumed that the second Near RT RIC 20 has detected an RIC Event Trigger notified in an RIC Event Request message.

[0078] The second Near RT RIC 20, after detecting a RIC Event Trigger, sends a RIC Event Notification message to the first Near RT RIC 10 (S61). For example, suppose the RIC ACTION DEFINITION IE of the RIC Event Request message specifies that a REPORT message should be sent. In this case, the second Near RT RIC 20 sends a RIC Event Request message containing the REPORT message to the first Near RT RIC 10. The second Near RT RIC 20 may include information collected from the E2 node 30 selected by the first Near RT RIC 10 in the REPORT message. The second Near RT RIC 20 may include some of the information collected from the E2 node 30 selected by the first Near RT RIC 10 in the REPORT message, or it may include all of the collected information in the REPORT message. Alternatively, the second Near RT RIC 20 may process the information collected from the E2 node 30 selected by the first Near RT RIC 10 and then include the processed information in the REPORT message. The processed information may be information showing the results of the information analysis, information that has been calculated, or information that has been converted to a different format.

[0079] The format or method of editing the information transmitted from the second Near RT RIC 20 to the first Near RT RIC 10 may be specified in the RIC Event Request message transmitted from the first Near RT RIC 10 to the second Near RT RIC 20. For example, the RIC Event Request message may include information specifying that a single message containing information about multiple E2 nodes 30 be sent to the first Near RT RIC 10. For example, information about multiple E2 nodes 30 may be set in NotificationInfo IE. Alternatively, the RIC Event Request message may include information specifying that information about each E2 node 30 be included in separate messages and sent to the first Near RT RIC 10.

[0080] Here, the second Near RT RIC 20 may execute the RIC Subscription procedure in Figure 8 independently of the RIC Event Request message in Figure 7, or it may execute it in conjunction with the RIC Event Request message.

[0081] For example, if the RIC Subscription procedure is linked to an RIC Event Request message, the second Near RT RIC 20 may initiate the RIC Subscription procedure upon receiving the RIC Event Request message. In this case, if the RIC Event Request message specifies an E2 node 30, the second Near RT RIC 20 may initiate the RIC Subscription procedure with the specified E2 node 30. Furthermore, if the RIC Event Request message specifies information to be collected, the second Near RT RIC 20 may notify the E2 node 30 in the RIC Subscription procedure that it will transmit the specified information. In this case, the second Near RT RIC 20 may transmit the information obtained from the E2 node 30 to the first Near RT RIC 10 in order to obtain the information specified by the second Near RT RIC 20.

[0082] If the RIC Subscription procedure is executed independently of the RIC Event Request message, the second Near RT RIC 20 may start the RIC Subscription procedure at any time. In this case, the second Near RT RIC 20 extracts or selects information about the E2 node 30 specified in the RIC Event Request message from the information collected from the multiple E2 nodes 30. The second Near RT RIC 20 may send the extracted or selected information to the first Near RT RIC 10.

[0083] Figure 10 shows the flow of control processing for the E2 node 30 by the first Near RT RIC 10. The first Near RT RIC 10 determines the values ​​of control parameters for the E2 node 30 based on the information about the E2 node 30 collected from the second Near RT RIC 20. The control parameters may be parameters used by the E2 node 30 to control communication with the UE 110.

[0084] First, the first Near RT RIC 10 sends a RIC Event Request message to the second Near RT RIC 20 (S71). The RIC Event Request message includes control parameters related to E2 nodes 30_1 and 30_2. Furthermore, the RIC Event Request message includes information indicating that the control parameters of E2 nodes 30_1 and 30_2 should be updated. This information indicating that the control parameters of E2 nodes 30_1 and 30_2 should be updated may, for example, be a RIC ACTION DEFINITION IE that specifies that a Control message should be sent.

[0085] Next, the second Near RT RIC 20 sends RIC Control Request messages to E2 nodes 30_1 and 30_2, which include control parameters related to E2 nodes 30_1 and 30_2 that are included in the RIC Event Request message (S72, S73).

[0086] The second Near RT RIC 20 decides to send RIC Control Request messages to E2 nodes 30_1 and 30_2 based on the RIC ACTION DEFINITION IE.

[0087] Upon receiving the RIC Control Request message, E2 nodes 30_1 and 30_2 update the control parameters to the values ​​included in the RIC Control Request message.

[0088] As explained above, the first Near RT RIC 10 can collect information about the E2 nodes 30 connected to the second Near RT RIC 20 via the second Near RT RIC 20. In other words, the first Near RT RIC 10 can collect information about E2 nodes 30 that are not directly connected to the first Near RT RIC 10 via the second Near RT RIC 20. As a result, the first Near RT RIC 10 does not need to connect to all E2 nodes 30 connected to the second Near RT RIC 20, thus preventing the network configuration from becoming complicated.

[0089] Furthermore, the first Near RT RIC 10 can provide control parameter instructions to the E2 node 30, which is not directly connected, via the second Near RT RIC 20.

[0090] Embodiment 3

[0091] Figure 11 shows an example configuration of the first Near RT RIC 15. The first Near RT RIC 15 has a configuration in which a determination unit 16 is added to the configuration of the first Near RT RIC 10. The determination unit 16 may be software or a module in which processing is performed by the processor executing a program stored in memory. Alternatively, the determination unit 16 may be hardware such as a circuit or chip.

[0092] The determination unit 16 performs a parameter conflict check. The parameter conflict check will be explained in detail using Figure 12.

[0093] Figure 12 shows the flow of the parameter conflict check process in the first Near RT RIC 10. The first Near RT RIC 10 and the second Near RT RIC 20 can each run applications independently. Running applications independently means, for example, that the first Near RT RIC 10 can run the application without considering the operating status of the application in the second Near RT RIC 20.

[0094] When the first Near RT RIC 10 and the second Near RT RIC 20 operate applications independently, the first Near RT RIC 10 and the second Near RT RIC 20 may each update control parameters related to the same E2 node 30. In this case, the value of the control parameter instructed by the first Near RT RIC 10 may differ from the value of the control parameter instructed by the second Near RT RIC 20. This state is described as a control parameter conflict between the first Near RT RIC 10 and the second Near RT RIC 20.

[0095] Furthermore, control parameter conflicts may occur between the second Near RT RICs 20. For example, if one E2 node 30 is connected to different second Near RT RICs 20, each second Near RT RIC 20 may apply different control parameter values ​​to the same E2 node 30.

[0096] The conflict check process shown in Figure 12 is performed to prevent conflicts in control parameters. First, the second Near RT RIC 20_1 sends a RIC Conflict Mitigation Request message to the first Near RT RIC 10 (S81). The RIC Conflict Mitigation Request message includes, for example, identification information that identifies each Request message and list information that shows a list of control parameters that the second Near RT RIC 20_1 may control. The list information may be included as a Control Parameter List IE. Identification information of the E2 node 30 may be associated with the control parameters.

[0097] Furthermore, the second Near RT RIC 20_2 also sends an RIC Conflict Mitigation Request message to the first Near RT RIC 10 (S82). The second Near RT RIC 20_1 and the second Near RT RIC 20_2 are different second Near RT RIC 20s.

[0098] Next, the determination unit 16 performs a conflict check using the list information contained in the RIC Conflict Mitigation Request messages received from the second Near RT RIC 20_1 and the second Near RT RIC 20_2 (S83).

[0099] For example, the determination unit 16 compares the control parameters managed as control targets in the first Near RT RIC 10 with the control parameters included in the list information and determines that the matching control parameters are the control parameters in which a conflict occurs. Alternatively, the determination unit 16 may compare the identification information of the E2 nodes 30 associated with the control parameters. For example, the determination unit 16 may determine that the control parameters are in which a conflict occurs if the identification information of the E2 nodes 30 associated with each control parameter matches.

[0100] The determination unit 16 determines that a conflict occurs between a control parameter managed by the first Near RT RIC 10 and at least one of the control parameters of the second Near RT RIC 20_1 and the second Near RT RIC 20_2. In this case, the first Near RT RIC 10 may choose not to control the conflicting control parameter. Alternatively, the first Near RT RIC 10 may send a response message to the second Near RT RIC 20_1 or the second Near RT RIC 20_2 to instruct them not to control the conflicting control parameter (S84 or S85). The response message may be an RIC Conflict Mitigation Response message.

[0101] Furthermore, suppose the determination unit 16 determines that a conflict in control parameters occurs between the second Near RT RIC 20_1 and the second Near RT RIC 20_2. In this case, the first Near RT RIC 10 may send a response message to instruct either the second Near RT RIC 20_1 or the second Near RT RIC 20_2 not to control the conflicting control parameters (S84 or S85). Alternatively, the first Near RT RIC 10 may send a response message to instruct both the second Near RT RIC 20_1 and the second Near RT RIC 20_2 not to control the conflicting control parameters (S84 and S85).

[0102] Furthermore, if the first Near RT RIC 10 determines that no control parameter conflict occurs, it may send a response message containing information indicating that no conflict has occurred to the second Near RT RIC 20_1 and the second Near RT RIC 20_2 (S84 and S85). The response message may be an RIC Conflict Mitigation Response.

[0103] As explained above, the first Near RT RIC 10 performs a conflict check between the control parameters controlled by each Near RT RIC. This prevents unintended updates of control parameters by each Near RT RIC.

[0104] Figure 13 is a block diagram showing an example configuration of the first Near RT RIC 10, the first Near RT RIC 15, and the second Near RT RIC 20 (hereinafter referred to as the first Near RT RIC 10, etc.). Referring to Figure 13, the first Near RT RIC 10, etc. includes a network interface 1201, a processor 1202, and memory 1203. The network interface 1201 may be used to communicate with a network node. The network interface 1201 may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series. IEEE stands for Institute of Electrical and Electronics Engineers.

[0105] The processor 1202 reads and executes software (computer programs) from the memory 1203 to perform processing on the information management device 10, etc., as described using a flowchart. The processor 1202 may be, for example, an MPU (Micro Processor Unit) or a CPU (Central Processing Unit). The processor 1202 may include multiple processors.

[0106] Memory 1203 is composed of a combination of volatile and non-volatile memory. Memory 1203 may include storage located away from the processor 1202. In this case, the processor 1202 may access memory 1203 via an I / O (Input / Output) interface, which is not shown.

[0107] In the example shown in Figure 13, memory 1203 is used to store a group of software modules. The processor 1202 can read these software modules from memory 1203 and execute them to perform the first Near RT RIC 10 and other processing.

[0108] As explained using Figure 13, each of the processors in the first Near RT RIC 10, etc., executes one or more programs that include a set of instructions for causing the computer to perform the algorithm described using the diagram.

[0109] In the examples described above, the program includes a set of instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more of the functions described in the embodiments. The program may be stored in a non-temporary computer-readable medium or a physical storage medium. Examples, but not limited to, include RAM (random-access memory), ROM (read-only memory), flash memory, SSD (solid-state drive), or other memory technologies, CD-ROM, DVD (digital versatile disc), Blu-ray® disc, or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage, or other magnetic storage devices. The program may be transmitted over a temporary computer-readable medium or a communication medium. Examples, but not limited to, include, a temporary computer-readable medium or a communication medium that includes an electrical, optical, acoustic, or other form of propagating signal.

[0110] Although the present disclosure has been described above with reference to embodiments, the present disclosure is not limited to the embodiments described above. Various modifications to the structure and details of the present disclosure can be made as can be understood by those skilled in the art within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0111] Each drawing is merely illustrative to illustrate one or more embodiments. Each drawing may be associated with one or more other embodiments, rather than being associated with only one specific embodiment. As those skilled in the art will understand, 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, for example, to create embodiments not explicitly shown or described. Not all features or steps shown in any one drawing to illustrate an exemplary embodiment are necessarily required, and some features or steps may be omitted. The order of steps described in any of the drawings may be changed as appropriate.

[0112] Some or all of the above embodiments may also be described as follows, but are not limited to the following: (Note 1) A first Near RT RIC comprising: a communication unit that receives list information of at least one E2 node from a second Near RT RIC connected to at least one E2 node; and a selection unit that selects at least one first E2 node from the at least one E2 node included in the list information, wherein the communication unit receives information held by the first E2 node from the at least one first E2 node via the second Near RT RIC. (Note 2) The first Near RT RIC according to Note 1, wherein the selection unit selects the at least one second E2 node based on an application executed in the first Near RT RIC. (Note 3) The first Near RT RIC according to Note 1 or 2, wherein the communication unit sends a first request message to the second Near RT RIC requesting the transmission of the list information, and receives a first response message to the first request message, which includes the list information. (Note 4) The first Near RT RIC according to any one of Notes 1 to 3, wherein the communication unit sends a second request message to the second Near RT RIC requesting the transmission of information held by the at least one first E2 node, and receives a notification message which includes the information held by the at least one first E2 node. (Note 5) The first Near RT RIC according to Note 4, wherein the second request message includes a parameter that specifies whether the information collected from two or more first E2 nodes is grouped together into one notification message, or whether each piece of information collected from two or more first E2 nodes is designated as a separate notification message. (Note 6) A first Near RT RIC comprising: a communication unit that receives a third request message from at least one second Near RT RIC, which includes control parameters relating to an E2 node controlled by each of the second Near RT RICs; and a determination unit that determines whether or not there is a conflict regarding the control parameters.(Note 7) The determination unit determines whether there is a conflict between a first control parameter controlled by a first second Near RT RIC and a second control parameter controlled by a second second Near RT RIC, as described in Note 6. (Note 8) The determination unit determines whether there is a conflict between a third control parameter controlled by a third second Near RT RIC and a fourth control parameter controlled by the first Near RT RIC, as described in Note 6. (Note 9) The second Near RT RIC includes a communication unit that transmits a list of at least one connected E2 nodes to the first Near RT RIC, the communication unit transmitting information about the first E2 node selected by the first Near RT RIC from among the at least one E2 node to the first Near RT RIC. (Note 10) The second Near RT RIC according to Note 9, wherein the communication unit receives a first request message from the first Near RT RIC requesting the transmission of the list information, and transmits a first response message to the first request message, including the list information, to the first Near RT RIC. (Note 11) The second Near RT RIC according to Note 9 or 10, wherein the communication unit receives a second request message from the first Near RT RIC requesting the transmission of information held by the first E2 node, and transmits a notification message to the first Near RT RIC including information about the first E2 node. (Note 12) The second Near RT RIC according to Note 11, wherein the second request message includes a parameter that specifies whether the information collected from two or more of the first E2 nodes is combined into one notification message, or whether a different notification message is created for each piece of information collected from two or more of the first E2 nodes.(Note 13) A communication method comprising: receiving list information of at least one E2 node from a second Near RT RIC connected to at least one E2 node; selecting at least one first E2 node from the at least one E2 node included in the list information; and receiving information held by the first E2 node from the at least one first E2 node via the second Near RT RIC. (Note 14) A communication method comprising: receiving a third request message from at least one second Near RT RIC, including control parameters relating to an E2 node controlled by each of the second Near RT RICs; and determining whether there is a conflict regarding the control parameters. (Note 15) A communication method comprising: transmitting list information of at least one connected E2 node to a first Near RT RIC; and transmitting information regarding the first E2 node selected by the first Near RT RIC from among the at least one E2 node to the first Near RT RIC. (Note 16) A program that causes a computer to receive list information of at least one E2 node from a second Near RT RIC connected to at least one E2 node, select at least one first E2 node from the at least one E2 node included in the list information, and receive information held by the first E2 node from the at least one first E2 node via the second Near RT RIC. (Note 17) A program that causes a computer to receive a third request message from at least one second Near RT RIC, which includes control parameters relating to an E2 node controlled by each of the second Near RT RICs, and determine whether there is a conflict regarding the control parameters. (Note 18) A program that causes a computer to transmit list information of at least one connected E2 node to the first Near RT RIC, and transmit information relating to the first E2 node selected by the first Near RT RIC from among the at least one E2 node to the first Near RT RIC.

[0113] Some or all of the elements (e.g., configuration and function) described in Appendices 2 to 5 that are dependent on Appendice 1 may also be dependent on Appendices 13 and 16 in the same way as those described in Appendices 2 to 5. Some or all of the elements (e.g., configuration and function) described in Appendices 7 to 8 that are dependent on Appendice 6 may also be dependent on Appendices 14 and 17 in the same way as those described in Appendices 7 to 8. Some or all of the elements (e.g., configuration and function) described in Appendices 10 to 12 that are dependent on Appendice 9 may also be dependent on Appendices 15 and 18 in the same way as those described in Appendices 10 to 12. Some or all of the elements described in any appendice may be applied to various hardware, software, recording means, systems, and methods for recording software.

[0114] Although the present invention has been described above with reference to embodiments, the present invention is not limited thereto. Various modifications to the structure and details of the present invention can be made that are understandable to those skilled in the art within the scope of the invention.

[0115] This application claims priority based on Japanese Patent Application No. 2025-010827, filed on 24 January 2025, and incorporates all of its disclosures herein.

[0116] 10 First Near RT RIC 11 Communication Unit 12 Selection Unit 15 First Near RT RIC 16 Determination Unit 20 Second Near RT RIC 21 Communication Unit 30 E2 Node 60 O-CU 70 O-DU 80 O-RU 90 SMO 100 Non RT RIC 110 UE

Claims

A communication means for receiving list information of at least one E2 node from a second Near RT RIC connected to at least one E2 node, The system includes a selection means for selecting at least one first E2 node from the at least one E2 node included in the list information, The aforementioned communication means is A first Near RT RIC that receives information held by the first E2 node from at least one first E2 node via the second Near RT RIC. 　 The aforementioned selection means is, The first Near RT RIC according to claim 1, wherein the at least one second E2 node is selected based on an application running in the first Near RT RIC. 　 The aforementioned communication means is A first Near RT RIC according to claim 1 or 2, which sends a first request message to a second Near RT RIC requesting the transmission of the list information, and receives a first response message to the first request message, which includes the list information. 　 The aforementioned communication means is The first Near RT RIC according to claim 1 or 2, which sends a second request message to the second Near RT RIC requesting the transmission of information held by the at least one first E2 node, and receives a notification message containing the information held by the at least one first E2 node. 　 The second request message is, The first Near RT RIC according to claim 4, comprising a parameter that specifies whether to combine the information collected from two or more of the first E2 nodes into a single notification message, or to create a different notification message for each piece of information collected from two or more of the first E2 nodes. 　 It includes a communication means for transmitting a list of at least one connected E2 node to a first Near RT RIC, The aforementioned communication means is A second Near RT RIC that transmits information about the first E2 node selected by the first Near RT RIC from among the at least one E2 node to the first Near RT RIC. 　 The aforementioned communication means is The second Near RT RIC according to claim 6, which receives a first request message from the first Near RT RIC requesting the transmission of the list information, and transmits a first response message to the first request message, which includes the list information, to the first Near RT RIC. 　 The aforementioned communication means is The second Near RT RIC according to claim 6 or 7, which receives a second request message from the first Near RT RIC requesting the transmission of information held by the first E2 node, and sends a notification message containing information about the first E2 node to the first Near RT RIC. 　 The second request message is, The second Near RT RIC according to claim 8, comprising a parameter that specifies whether to combine the information collected from two or more of the first E2 nodes into a single notification message, or to create a different notification message for each piece of information collected from two or more of the first E2 nodes. 　 The second Near RT RIC, which is connected to at least one E2 node, receives list information of the at least one E2 node, From the at least one E2 node included in the list information, select at least one first E2 node. A communication method for receiving information held by the first E2 node from at least one first E2 node via the second Near RT RIC. 　 Send a list of at least one connected E2 node to the first Near RT RIC. A communication method for transmitting information about the first E2 node selected by the first Near RT RIC from among the at least one E2 node to the first Near RT RIC. 　 The second Near RT RIC, which is connected to at least one E2 node, receives list information of the at least one E2 node, From the at least one E2 node included in the list information, select at least one first E2 node. A program that causes a computer to receive information held by the first E2 node from at least one first E2 node via the second Near RT RIC. 　 Send a list of at least one connected E2 node to the first Near RT RIC. A program that causes a computer to transmit to the first Near RT RIC information regarding the first E2 node selected by the first Near RT RIC from among the at least one E2 node.

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