RU device, DU device, and communication method

Abstract

The purpose of the present disclosure is to provide a radio unit (RU) device with which it is possible to suppress the growth of degradation of communication quality regarding the communication of an open-radio unit (O-RU). A radio unit (RU) device according to the present disclosure comprises a reception unit that receives a message that includes an extended antenna-carrier identifier (eAxC ID) when the RU device is operating in a first mode, and a transmission unit that transmits an alarm message indicating that abnormality has been detected, when the eAxC ID is an eAxC ID that is not used in the first mode and is used in a second mode.

Description

RU device, DU device, communication system, and communication method

[0001] The present disclosure relates to an RU device, a DU device, a communication system, and a communication method.

[0002] In recent years, radio access networks have been adopted that separate the baseband and radio sections of base stations and connect them via a fronthaul. The O-RAN (Open-Radio Access Network) fronthaul specifications established by the O-RAN Alliance define the fronthaul specifications between the O-RU (Radio Unit), which corresponds to the radio section, and the O-DU (Distributed Unit) and O-CU (Central Unit), which correspond to the baseband section. One of the goals of the O-RAN fronthaul specifications is to facilitate the connection of O-RUs from different vendors to O-DUs, thereby realizing multi-vendor radio access networks.

[0003] In the O-RAN fronthaul, specifications are defined for the C (Control)-Plane, U (User)-Plane, S (Synchronization)-Plane, and M-Plane. Non-Patent Document 1 mainly defines specifications for the M-Plane (Management-Plane) in the O-RAN fronthaul. Below, an overview of the functions related to the M-Plane disclosed in Non-Patent Document 1 will be described.

[0004] M-Plane provides management functions for O-RUs. Specifically, M-Plane defines O-DUs or NMSs (Network Management Systems) as network devices that manage O-RUs. M-Plane also defines NETCONF (Network Configuration Protocol), a protocol commonly used for managing network devices. In NETCONF, the network device that manages the O-RUs corresponds to the NETCONF client, and the O-RUs to be managed correspond to the NETCONF server.

[0005] Here, the M-Plane has a Configuration Management function. Specifically, a NETCONF client such as an O-DU obtains information from the O-RU, such as the device status and the NETCONF functions supported by the O-RU. Furthermore, the NETCONF client sets parameters in the O-RU. NETCONF defines edit-config, which sets parameters, and get-config, which obtains parameter values. By using edit-config, the NETCONF client can change the device (hardware) state of the O-RU that can be configured or changed. For example, the configurable hardware state is the power state. Changing the power state can achieve energy saving in the O-RU. Specifically, the NETCONF client transitions the O-RU to the awake or sleeping state.

[0006] The awake state is a state in which the O-RU operates normally (normal mode) rather than in energy saving mode. On the other hand, the sleeping state is a state in which the O-RU operates in energy saving mode. In the sleeping state, only functions related to the M-Plane are operated, and functions related to the C / U / S-Plane can be stopped to reduce power consumption (see, for example, Section 9.1.3 of Non-Patent Document 1). For example, in the energy saving mode, the operation of some of the multiple antennas that the O-RU has may be stopped.

[0007] Also, Non-Patent Document 1 discloses that a NETCONF client assigns an extended antenna-carrier identifier (eAxC_ID). The eAxC ID is used by a C-Plane or U-Plane application to manage eCPRI (enhanced Common Public Radio Interface) communication between an O-DU and an O-RU in the C-Plane or U-Plane. A different value may be set for the eAxC_ID for each antenna that the O-RU has.

[0008] O-RAN-WG4.MP.0-v09.00 O-RAN Working Group 4 (Open Fronthaul Interfaces WG) Management Plane Specification

[0009] When performing eCPRI communication with an O-RU, the O-DU transmits a message setting the eAxC ID to the O-RU. At this time, if the O-RU is operating in energy saving mode, the O-DU may transmit a message setting the eAxC ID associated with an antenna that is not in operation to the O-RU. In such a case, the message transmitted by the O-DU is discarded by the O-RU without being transmitted to a communication terminal or the like via the O-RU, which causes a problem of degradation in the communication quality of the O-RU's communication. Furthermore, if the O-DU continues to transmit a message setting the eAxC ID associated with an antenna that is not in operation to the O-RU, there is a problem of further degradation in the communication quality of the O-RU's communication.

[0010] In view of the above-mentioned problems, one of the objects of the present disclosure is to provide an RU device, a DU device, a communication system, and a communication method that can suppress the spread of deterioration in communication quality related to O-RU communications.

[0011] An RU device according to a first aspect of the present disclosure includes a receiving unit that receives a message including an eAxC ID (extended antenna-carrier identifier) ​​when the RU device is operating in a first mode, and a transmitting unit that transmits an alarm message indicating that an abnormality has been detected when the eAxC ID is an eAxC ID that is not used in the first mode and is used in a second mode.

[0012] A DU device according to a second aspect of the present disclosure includes a transmitting unit that transmits a message including an eAxC ID (extended antenna-carrier identifier) ​​to an RU device operating in a first mode, a receiving unit that receives an alarm message from the RU device caused by the eAxC ID being an eAxC ID that is not used in the first mode and is used in a second mode, and a determining unit that determines to execute a predetermined process based on the alarm message.

[0013] A communication system according to a third aspect of the present disclosure includes an RU device and a DU device. The RU device has a receiving unit that receives a message including an eAxC ID (extended antenna-carrier identifier) ​​when the RU device is operating in a first mode, and a transmitting unit that transmits an alarm message indicating that an abnormality has been detected when the eAxC ID is an eAxC ID that is not used in the first mode and is used in a second mode. The DU device has a transmitting unit that transmits a message including the eAxC ID (extended antenna-carrier identifier) ​​to the RU device operating in the first mode, a receiving unit that receives an alarm message from the RU device caused by the eAxC ID being an eAxC ID that is not used in the first mode and is used in the second mode, and a determining unit that determines to execute predetermined processing based on the alarm message.

[0014] A communication method executed in an RU device according to a fourth aspect of the present disclosure includes receiving a message including an eAxC ID (extended antenna-carrier identifier) ​​when the RU device is operating in a first mode, and transmitting an alarm message indicating that an abnormality has been detected if the eAxC ID is an eAxC ID that is not used in the first mode and is used in a second mode.

[0015] A communication method performed in a DU device according to a fifth aspect of the present disclosure includes transmitting a message including an eAxC ID (extended antenna-carrier identifier) ​​to an RU device operating in a first mode, receiving an alarm message from the RU device caused by the eAxC ID being an eAxC ID that is not used in the first mode and is used in a second mode, and determining to execute a predetermined process based on the alarm message.

[0016] The present disclosure makes it possible to provide an RU device, a DU device, a communication system, and a communication method that can suppress the spread of deterioration in communication quality related to O-RU communications.

[0017] FIG. 1 is a configuration diagram of an RU device according to the present disclosure. FIG. 2 is a configuration diagram of a DU device according to the present disclosure. FIG. 3 is a diagram illustrating a flow of communication processing executed in an RU device according to the present disclosure. FIG. 4 is a diagram illustrating a flow of communication processing executed in a DU device according to the present disclosure. FIG. 5 is a configuration diagram of a communication system according to the present disclosure. FIG. 6 is a diagram illustrating a processing flow related to get-config included in NETCONF operations according to the present disclosure. FIG. 7 is a diagram illustrating a data model generated by an O-DU according to the present disclosure. FIG. 8 is a diagram illustrating a data model generated by an O-DU according to the present disclosure. FIG. 9 is a diagram illustrating a data model generated by an O-DU according to the present disclosure. FIG. 10 is a diagram illustrating a processing flow related to get-edit included in NETCONF operations according to the present disclosure. FIG. 11 is a diagram illustrating a communication processing flow between an O-RU and an O-DU according to the present disclosure. FIG. 12 is a diagram illustrating a processing flow of an alarm message transmission process in an O-RU according to the present disclosure. FIG. 13 is a configuration diagram of a communication device according to the present disclosure.

[0018] (Embodiment 1) An example of the configuration of an RU device 10 will be described below with reference to Fig. 1. The RU device 10 may be software or a module in which processing is performed by a processor executing a program stored in a memory. The RU device 10 may be, for example, an O-RU node (hereinafter referred to as O-RU) defined by the O-RAN alliance. The node may correspond to an entity (device) or a function.

[0019] The RU device 10 has a receiving unit 11 and a transmitting unit 12. The receiving unit 11 and the transmitting unit 12 may be software or modules that are executed by a processor executing a program stored in a memory, or may be hardware such as a circuit or a chip.

[0020] The RU apparatus 10 operates according to several operating modes. For example, the RU apparatus 10 operates in a power saving mode or a normal mode. The RU apparatus 10 has multiple antenna elements. For example, in the normal mode, all antennas of the RU apparatus 10 may operate, and in the power saving mode, at least one of the multiple antennas of the RU apparatus 10 may be stopped. Alternatively, among all the antenna elements of the RU apparatus 10, some may operate in the normal mode and some may operate in the power saving mode. The multiple antenna elements may be arranged in an array. In other words, the multiple antenna elements may constitute at least one antenna array.

[0021] The RU device 10 has a wireless communication interface and, for example, combines Massive Multiple Input Multiple Output (MIMO) and digital beamforming technology to support wide bandwidths and enable more efficient communications. Massive MIMO, for example, arranges multiple antenna elements at equal intervals on a plane (antenna array) and electrically controls each antenna element to direct different beams to multiple users. As a result, multiple users can connect to the O-RU simultaneously.

[0022] An antenna array is configured with several antenna elements associated to form a desired radiation pattern at the RU unit 10. By configuring multiple antenna arrays at the RU unit 10, various radiation patterns can be realized for the beams emitted from the RU unit 10.

[0023] Furthermore, an eAxC ID is set for each antenna element. Alternatively, an eAxC ID may be set for each antenna element group including two or more antenna elements. Setting may also be rephrased as being assigned or associated.

[0024] The receiving unit 11 receives a message including an eAxC ID. A message including an eAxC ID is a message in which an eAxC ID is specified. The receiving unit 11 may receive a message including an eAxC ID from, for example, a DU device 15. Specifically, the DU device 15 may be an O-DU node (hereinafter referred to as O-DU). The message including an eAxC ID may be, for example, a message related to the C-Plane or U-Plane. A message related to the C-Plane or U-Plane may be rephrased as a message transmitted via the C-Plane or U-Plane.

[0025] Here, it is assumed that the RU device 10 is operating in a power saving mode or a normal mode. The power saving mode may be, for example, placing antenna elements in a sleeping state as defined by the O-RAN Alliance. Alternatively, the power saving mode may be stopping the supply of power to some of the antenna elements among multiple antenna elements and disabling all functions of some of the antenna elements. On the other hand, an operating mode in which normal operation is performed without disabling the functions of some of the antenna elements may be referred to as a normal mode. Alternatively, the normal mode may be operating more antenna elements than the number of antenna elements operating in the power saving mode.

[0026] For example, when operating in the power saving mode, the RU device 10 may receive a message including an eAxC ID set to an antenna element that does not operate in the power saving mode. Alternatively, when operating in the normal mode, the RU device 10 may receive a message including an eAxC ID set to an antenna element that does not operate in the normal mode or an eAxC ID that is not used in the normal mode.

[0027] In such a case, the RU device 10 transmits an alarm message indicating that an abnormality has been detected. The alarm message may be referred to as an error message. The RU device 10 may transmit the alarm message to the DU device that is the sender of the message containing the incorrect eAxC ID, or to another DU device. Alternatively, the RU device 10 may transmit the alarm message to a management device or control device that manages the RU device 10. The management device or control device that manages the RU device 10 may be referred to as an O-RU controller. The O-RU controller may be a Service Management and Orchestration (SMO) node (hereinafter referred to as SMO). Alternatively, the O-RU controller may be an O-DU. The O-RU and O-DU may simply be referred to as RU and DU.

[0028] However, the management device or control device that manages the RU device 10 is not limited to the O-DU or SMO. For example, such a management device or control device may be any node that can communicate with the O-RU and that functions as a NETCONF client.

[0029] Here, the alarm message may use, for example, common alarms in the O-RAN standard. In this case, however, it is preferable that a dedicated ID (more specifically, a Fault ID) is set for such an alarm. That is, a new Fault ID not described in Annex A of Non-Patent Document 1 may be set for such an alarm.

[0030] After transmitting the alarm message, the RU device 10 may perform the following operation. That is, if the alarm is not resolved for a predetermined period after transmitting the alarm message, the RU device 10 may attempt to recover by autonomously resetting itself. Details of this operation will be described in embodiment 2. Alternatively, the RU device 10 may increase the severity of the alarm and retransmit the alarm message.

[0031] Next, a configuration example of the DU device 15 will be described with reference to Fig. 2. The DU device 15 may be software or a module that executes processing by a processor executing a program stored in a memory. The DU device 15 may be, for example, an O-DU node (hereinafter referred to as O-DU) defined by the O-RAN Alliance.

[0032] The DU device 15 includes a transmitter 16, a receiver 17, and a decision unit 18. The transmitter 16, receiver 17, and decision unit 18 may be software or modules that are executed by a processor executing a program stored in a memory, or may be hardware such as a circuit or a chip.

[0033] The transmitter 16 transmits a message including the eAxC ID to the RU device 10 operating in the power saving mode or the normal mode. The receiver 17 receives an alarm message from the RU device 10 caused by the eAxC ID being an eAxC ID that is not used in the mode in which the RU device is currently operating but is used in the other mode.

[0034] The determination unit 18 determines a predetermined process based on the alarm message. The predetermined process will be described below.

[0035] When the receiving unit 17 receives an alarm message, the determining unit 18 may determine to retransmit a message including a correct eAxC ID to the RU device 10. The correct eAxC ID may be determined, for example, based on the eAxC ID set as the eAxC ID operating in the power saving mode or the eAxC ID operating in the normal mode in the data model transmitted by the DU device 15 to the RU device 10. For example, assume that the receiving unit 17 receives an alarm message when the eAxC ID included in the message transmitted by the transmitting unit 16 is the eAxC ID set for an antenna element operating in the normal mode. In this case, the determining unit 18 may determine that the RU device 10 is operating in the power saving mode and determine the eAxC ID set for the antenna element operating in the power saving mode as the correct eAxC ID. Alternatively, the alarm message received by the receiving unit 17 may include information indicating the current operation mode of the RU device 10 and may further include information indicating the antenna element currently operating in the RU device 10. In this case, the determination unit 18 may identify the current operation mode of the RU device 10 and determine that the eAxC ID set for the antenna element operating in the current operation mode is the correct eAxC ID.

[0036] Alternatively, when the receiving unit 17 receives an alarm message, it may determine to transmit the message transmitted to the RU device 10 to an RU device different from the RU device 10. Alternatively, when the receiving unit 17 receives an alarm message, the determining unit 18 may determine to stop the operation of the RU device 10. Alternatively, when the receiving unit 17 receives an alarm message, the determining unit 18 may determine to stop transmitting messages to the RU device 10. Alternatively, when a device different from the DU device 15 receives the alarm message, the device that received the alarm message may instruct the DU device 15 to transmit a message including a correct eAxC ID. In this case, the DU device 15 may determine to transmit a message including the correct eAxC ID. Alternatively, the device that received the alarm message may instruct a DU device different from the DU device 15 that transmitted the message including the incorrect eAxC ID to transmit a message including the correct eAxC ID.

[0037] Alternatively, when the receiving unit 17 receives an alarm message, the determining unit 18 may determine to deactivate the corresponding carrier (i.e., an existing carrier).

[0038] Next, the flow of communication processing in the RU device 10 will be described with reference to FIG. 3. First, the receiver 11 receives a message including an eAxC ID (S11). When operating in power saving mode, the receiver 11 receives a message including an eAxC ID set for an antenna element that does not operate in power saving mode. Alternatively, when operating in normal mode, the RU device 10 receives a message including an eAxC ID set for an antenna element that does not operate in normal mode. In this case, the transmitter 12 transmits an alarm message indicating that an abnormality has been detected (S12).

[0039] Next, the flow of communication processing in the DU device 15 will be described with reference to FIG. 4. First, the transmitter 16 transmits a message including an eAxC ID to the RU device 10 operating in power saving mode or normal mode (S15). Next, the receiver 17 receives an alarm message from the RU device 10 indicating that the eAxC ID is not used in the mode in which the RU device 10 is currently operating but is used in another mode (S16). Next, the determiner 18 determines a predetermined process based on the alarm message (S17).

[0040] As described above, the RU device 10 transmits an alarm message when it receives a message including an eAxC ID set to an antenna element that is not used in the current operating mode. The device that receives the alarm message operates to transmit a message including the correct eAxC ID to the RU device 10. Alternatively, the device that receives the alarm message operates to stop transmitting an incorrect eAxC ID to the RU device 10. As a result, the RU device 10 can receive a message including the correct eAxC ID or stop receiving a message including an incorrect eAxC ID, thereby suppressing the deterioration of communication quality caused by receiving a message including an incorrect eAxC ID.

[0041] (Embodiment 2) Next, an example of the configuration of a communication system will be described with reference to Fig. 5. The communication system of Fig. 3 illustrates the M-Plane architecture model defined by the O-RAN Alliance. The communication system of Fig. 5 includes an O-RU 20, an O-DU 30, and an SMO 40. The O-RU 20 corresponds to the RU device 10 of Fig. 1. The O-DU 30 corresponds to the DU device 15 of Fig. 2. In addition, the communication system may include an O-CU node and a Near-RT RIC (near real-time RAN intelligent controller) node, both of which are not shown. Furthermore, the SMO 40 may include a Non-RT RIC (non real-time RAN intelligent controller) node, both of which are not shown. The O-CU may simply be referred to as a CU.

[0042] Furthermore, the O-RU 20 and the O-DU 30 may perform communications related to the C-Plane and the U-Plane. A VLAN (Virtual Local Area Network) different from the VLAN assigned to the M-Plane may be assigned to the C-Plane and the U-Plane. Assigning a VLAN may mean assigning a VLAN ID. The C-Plane and the U-Plane may be assigned the same VLAN or different VLANs.

[0043] The O-RU 20 is a logical node that performs lower-level functions of the physical layer (PHY-Low) and RF (Radio Frequency) processing. Alternatively, the O-RU 20 may be a physical device that incorporates the O-RU, which is a logical node. The lower-level functions of the physical layer may be, for example, Fast Fourier Transform (FFT) / Inverse FFT (IFFT) processing, Bea Forming (BF) processing, etc.

[0044] The O-DU 30 is a logical node that performs functions in the Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Media Access Control (MAC) layer, as well as functions higher than the physical layer. Alternatively, the O-DU 30 may be a physical device that incorporates the O-DU, which is a logical node. The functions higher than the physical layer may be, for example, encoding and modulation processing, and decoding and demodulation processing. The functions in the PDCP layer may be performed in a logical node called a Central Unit (CU) (not shown).

[0045] The SMO 40 performs maintenance and orchestration (control) of the RAN (Radio Access Network) and the RIC (RAN Intelligent Controller), which is a platform that realizes optimization of radio resource management and automation of operations. While FIG. 5 illustrates a configuration in which the O-RU 20 and the O-DU 30 are connected and the O-DU 30 and the SMO 40 are connected, the O-RU 20 and the SMO 40 may be connected as indicated by dotted lines. Also, while FIG. 5 illustrates a one-to-one configuration in which the O-RU 20, the O-DU 30, and the SMO 40 are connected, the O-RU 20 may be managed by multiple O-DUs 30. Furthermore, the O-RU 20 may be managed by multiple SMOs 40. The SMO 40 may also be replaced with an NMS.

[0046] Next, the processing flow related to get-config, which is included in NETCONF operations executed in the Configuration Management function, will be described with reference to FIG. 6 . In FIG. 6 , the O-RU 20 operates as a NETCONF Server, and the O-DU 30 operates as a NETCONF Client. First, the O-DU 30 sends a request message to the O-RU 20 (S21). For example, an RPC (remote procedure call) get may be set in the request message. Next, the O-RU 20 sends a response message to the request message to the O-DU 30 (S22). For example, an RPC-reply may be set in the response message. The response message with an RPC-reply set contains, as data, parameters held by the O-RU 20 and the status of the O-RU 20. In other words, the O-DU 30 retrieves the parameters held by the O-RU 20, the status of the O-RU 20, and so on from the O-RU 20 by executing the get procedure.

[0047] The parameters held by the O-RU 20 may be represented, for example, in the form of a data model (YANG data model) described using YANG. Furthermore, a YANG data model indicating parameters or states of the O-RU 20 that can be changed by the O-DU 30 may be defined as a YANG module. Specifically, a YANG data model indicating parameters or states used in the M-Plane may be defined as a reusable YANG module.

[0048] For example, the O-DU 30 fetches, receives, or acquires a list of tx-arrays and rx-arrays in o-ran-uplane-conf.yang from the O-RU 20, and determines, identifies, or extracts the tx-array elements and rx-array elements. tx-arrays indicates the entire antenna array used for transmission, and rx-arrays indicates the entire antenna array used for reception. o-ran-uplane-conf.yang indicates a YANG module specified by the O-RAN Alliance. The tx-array elements and rx-array elements may be antenna arrays configured in the O-RU 20. The tx-array elements are antenna arrays related to transmission in the O-RU 20, and the rx-array elements are antenna arrays related to reception in the O-RU 20.

[0049] Furthermore, the O-DU 30 fetches, receives, or acquires a list of static-low-level-tx-endpoints and static-low-level-rx-endpoints in o-ran-uplane-conf.yang from the O-RU 20, and determines, identifies, or extracts static-low-level-tx-endpoint elements and static-low-level-rx-endpoint elements. The static-low-level-tx-endpoint elements are, for example, identification information of antenna elements related to transmission, and the static-low-level-rx-endpoint elements are, for example, identification information of antenna elements related to reception.

[0050] After determining the tx-array elements and static-low-level-tx-endpoint elements, O-DU 30 examines the relationship between the tx-array elements and the static-low-level-tx-endpoint elements. Furthermore, after determining the rx-array elements and static-low-level-rx-endpoint elements, O-DU 30 analyzes the relationship between the rx-array elements and the static-low-level-rx-endpoint elements.

[0051] As a result of the analysis, for example, O-DU 30 may identify a static-low-level-tx-endpoint element indicating the antenna elements that make up the tx-array element. Furthermore, O-DU 30 may identify a static-low-level-rx-endpoint element indicating the antenna elements that make up the rx-array element.

[0052] Furthermore, O-DU 30 creates or generates a low-level-tx-endpoint element for the static-low-level-tx-endpoint element and a low-level-rx-endpoint element for the static-low-level-rx-endpoint element. The low-level-tx-endpoint element and the low-level-rx-endpoint element may be used, for example, to set desired parameters or states for the static-low-level-tx-endpoint element and the static-low-level-rx-endpoint element.

[0053] Furthermore, the O-DU 30 sets an eAxC (extended Antenna-Carrier) ID to the low-level-tx-endpoint element and the low-level-rx-endpoint. When the O-DU 30 generates multiple low-level-tx-endpoint elements, it sets a different eAxC ID value for each low-level-tx-endpoint element. Similarly, when the O-DU 30 generates multiple low-level-rx-endpoint elements, it sets a different eAxC ID value for each low-level-rx-endpoint element. The eAxC ID is a 16-bit value composed of a DU_Port_ID, an RU_Port_ID, a CC_ID, and a BandSector_ID. When the eAxC ID set in the low-level-tx-endpoint element is used for the C-Plane and the U-Plane, the eAxC ID used for the C-Plane may be different from or the same as the eAxC ID used for the U-Plane. When the eAxC ID set in the low-level-rx-endpoint is used in the C-Plane and the U-Plane, the eAxC ID when used in the C-Plane may be different from or the same as the eAxC ID when used in the U-Plane.

[0054] Furthermore, the O-DU 30 generates a tx-array-carrier and an rx-array-carrier. The tx-array-carrier and the rx-array-carrier have a parameter "active", and the parameter "active" is set to one of the values ​​"ACTIVE", "INACTIVE", or "SLEEP". The O-DU 30 generates a low-level-tx-links element and a low-level-rx-link element to associate the values ​​of the parameter "active" set in the tx-array-carrier and the rx-array-carrier with the low-level-tx-endpoint element and the low-level-rx-endpoint element. That is, the O-DU 30 associates the values ​​of the parameter "active" set in the tx-array-carrier and rx-array-carrier with the low-level-tx-endpoint element and low-level-rx-endpoint element via the low-level-tx-links element and low-level-rx-link element. "Associating" may be rephrased as "applying" or "setting," for example.

[0055] For example, when the parameter "active" is set to "ACTIVE", the antenna elements indicated by the static-low-level-tx-endpoint elements or the static-low-level-rx-endpoint elements may transition to an awake state. When the parameter "active" is set to "SLEEP", the antenna elements indicated by the static-low-level-tx-endpoint elements or the static-low-level-rx-endpoint elements may transition to a sleeping state. When the parameter "active" is set to "INACTIVE", all functions of the antenna elements indicated by the static-low-level-tx-endpoint elements or the static-low-level-rx-endpoint elements may be stopped.

[0056] O-DU 30 associates a tx-array-carrier whose parameter "active" is set to "SLEEP" with the low-level-tx-endpoint elements associated with the antenna element to be transitioned to the sleeping state. Also, O-DU 30 associates an rx-array-carrier whose parameter "active" is set to "SLEEP" with the low-level-rx-endpoint elements associated with the antenna element to be transitioned to the sleeping state.

[0057] Here, the data model generated by the O-DU 30 based on the parameters acquired from the O-RU 20 will be described with reference to FIGS.

[0058] FIG. 7 shows an example of a data model related to a transmitting antenna array in O-RU 20. The data model in FIG. 7 illustrates an example in which the transmitting antenna array in O-RU 20 is configured with two antenna arrays, tx-array #0 and tx-array #1. The data model in FIG. 7 indicates that static-low-level-tx-endpoint #0 through static-low-level-tx-endpoint #i (i is an integer equal to or greater than 1) configure tx-array #0. The data model in FIG. 7 also indicates that static-low-level-tx-endpoint #j through static-low-level-tx-endpoint #n (j and n are integers equal to or greater than 1, with n > j = i + 1) configure tx-array #1. The number of antenna elements configuring tx-array #0 may be the same as or different from the number of antenna elements configuring tx-array #1. For example, tx-array #0 and tx-array #1 may be antenna arrays with different polarization planes.

[0059] Furthermore, low-level-tx-endpoint #0, which indicates the setting of static-low-level-tx-endpoint #0, is associated with the value set to the parameter "active" in tx-array-carrier #0 via low-level-tx-link #0. Similarly, for other static-low-level-tx-endpoints, low-level-tx-endpoint #n, which indicates the setting of static-low-level-tx-endpoint #n, is associated with the value set to the parameter "active" in tx-array-carrier #n via low-level-tx-link #n.

[0060] 7 , when O-DU 30 operates some of the multiple antenna elements included in O-RU 20 in power saving mode, it transitions the state of all antenna elements that make up either tx-array #0 or tx-array #1 to sleeping. For example, when O-DU 30 transitions the state of all antenna elements that make up tx-array #0 to sleeping, it sets the value of the parameter "active" in tx-array-carriers #0 to #i to "SLEEP."

[0061] FIG. 8 shows another example of a data model related to a transmitting antenna array in the O-RU 20. The data model in FIG. 8 illustrates an example in which the transmitting antenna array in the O-RU 20 is configured with a single antenna array, tx-array #0. The data model in FIG. 8 indicates that static-low-level-tx-endpoint #0 to static-low-level-tx-endpoint #i (i is an integer equal to or greater than 1) configure tx-array #0. Here, tx-array #1 is defined as an antenna array configured with antenna elements operating in power-saving mode among the antenna elements corresponding to static-low-level-tx-endpoint #0 to static-low-level-tx-endpoint #i. In other words, a second data model corresponding to tx-array #1 may be additionally defined (i.e., separately prepared) for the first data model corresponding to tx-array #0. Furthermore, this second data model may be transmitted from the O-DU 30 to the O-RU 20 by a message. The message may be an RPC message as described above.

[0062] For example, tx-array #1 is composed of static-low-level-tx-endpoint #j to static-low-level-tx-endpoint #n. Here, static-low-level-tx-endpoint #j to static-low-level-tx-endpoint #n are each associated with one of static-low-level-tx-endpoint #0 to static-low-level-tx-endpoint #i. In "link to static-low-level-tx-endpoint #0'" shown in Fig. 8, #0' indicates that it is one of static-low-level-tx-endpoint #0 to static-low-level-tx-endpoint #i. Similarly, "link to static-low-level-tx-endpoint #i' indicates one of static-low-level-tx-endpoint #0 to static-low-level-tx-endpoint #i. static-low-level-tx-endpoint #j to static-low-level-tx-endpoint #n may be referred to as a subset indicating the static-low-level-tx-endpoints included in static-low-level-tx-endpoint #0 to static-low-level-tx-endpoint #i.

[0063] A capability indicating that a tx-array for power saving mode can be defined using static-low-level-tx-endpoint #j to #n associated as a subset of static-low-level-tx-endpoint #0 to #i may be notified from the O-RU 20 to the O-DU 30. For example, the capability may be exchanged between the O-RU 20 and the O-DU 30 using a hello message when a NETCONF session is established.

[0064] 8 also shows that one tx-array-carrier is associated with each antenna array (tx-array). Specifically, tx-array-carrier #0 is associated with low-level-tx-endpoint #0 to low-level-tx-endpoint #i via low-level-tx-link #0 to low-level-tx-link #i. tx-array-carrier #1 is associated with low-level-tx-endpoint #j to low-level-tx-endpoint #n via low-level-tx-link #j to low-level-tx-link #n. In this way, by associating tx-array-carriers with each antenna array (tx-array), the states of all antenna elements constituting one antenna array can be transitioned according to parameters set for one tx-array-carrier.

[0065] In the data model of Fig. 8, when transitioning the O-RU 20 to the power saving mode, the O-DU 30 may set the value of the parameter "active" in tx-array-carrier #0 to "ACTIVE" and set the value of "active" in tx-array-carrier #1 to "SLEEP". This allows the states of the antenna elements associated with static-low-level-tx-endpoint #j to static-low-level-tx-endpoint #n, among the antenna elements corresponding to static-low-level-tx-endpoint #0 to static-low-level-tx-endpoint #i, to transition to sleeping. Alternatively, the O-DU 30 may set the value of the parameter "active" in tx-array-carrier #0 to "SLEEP", and further set the value of the parameter "active" in tx-array-carrier #1 to "ACTIVE". This allows the state of antenna elements corresponding to static-low-level-tx-endpoint #0 to static-low-level-tx-endpoint #i that are not associated with static-low-level-tx-endpoint #j to static-low-level-tx-endpoint #n to transition to sleeping.

[0066] Furthermore, the eAxC ID set for low-level-tx-endpoint#j to low-level-tx-endpoint#n may be set to the same value as the eAxC ID of low-level-tx-endpoint#0 to #i associated by "link to static-low-level-tx-endpoint". For example, if static-low-level-tx-endpoint#j is associated with static-low-level-tx-endpoint#0, low-level-tx-endpoint#j may be set to the same eAxC ID as low-level-tx-endpoint#0. This makes it possible to reduce the number of eAxC IDs.

[0067] Alternatively, eAxC IDs with values ​​different from those of low-level-tx-endpoints #0 to #i may be set to low-level-tx-endpoints #j to #n. For example, if static-low-level-tx-endpoint #j is associated with static-low-level-tx-endpoint #0, different eAxC IDs are set to low-level-tx-endpoint #j and low-level-tx-endpoint #0. In this case, O-DU 30 may determine which static-low-level-tx-endpoint associated with which eAxC ID is to be used for data transmission in the C-plane and U-plane. For example, it is assumed that the static-low-level-tx-endpoint associated with the eAxC ID set to low-level-tx-endpoint #0 is determined to be used for data transmission in the C-plane and U-plane. In this case, even if the value of the parameter "active" in tx-array-carrier#0 and tx-array-carrier#1 is left as "ACTIVE" instead of being set to "SLEEP", static-low-level-tx-endpoint#j can be operated in power saving mode.

[0068] Fig. 9 shows another example of a data model related to a transmitting antenna array in O-RU 20. The data model in Fig. 9 shows an example in which the transmitting antenna array in O-RU 20 is configured by a single antenna array, tx-array #0. The data model in Fig. 9 shows that static-low-level-tx-endpoint #0 to static-low-level-tx-endpoint #i (i is an integer equal to or greater than 1) configure tx-array #0.

[0069] Furthermore, static-low-level-tx-endpoint #0 to static-low-level-tx-endpoint #i are associated with a parameter indicating whether they can transition to sleeping in power saving mode. For example, a static-low-level-tx-endpoint with the parameter "Saving mode: used" set can transition to sleeping in power saving mode. On the other hand, a static-low-level-tx-endpoint with the parameter "Saving mode: not used" set cannot transition to sleeping in power saving mode. The data model in FIG. 9 also shows that one tx-array-carrier #0 is associated with one antenna array, tx-array #0.

[0070] In the data model of FIG. 9 , when the O-DU 30 transitions the O-RU 20 to the power saving mode, it may set the value of the parameter "active" in tx-array-carrier #0 to "SLEEP." At this time, a static-low-level-tx-endpoint for which the parameter "Saving mode: not used" is set does not transition to sleeping even if the value of the parameter "active" in tx-array-carrier #0 is set to "SLEEP." In other words, when the value of the parameter "active" in tx-array-carrier #0 is set to "SLEEP," only a static-low-level-tx-endpoint for which the parameter "Saving mode: used" is set transitions to sleeping. In other words, the data model set in the O-RU 20 is a single data model used in both the normal mode and the power saving mode. Specifically, when O-RU 20 transitions to power saving mode, only the static-low-level-tx-endpoint in the data model for which the parameter "Saving mode: not used" is set is enabled even when O-RU 20 is in power saving mode.

[0071] A capability indicating that a parameter indicating whether or not the static-low-level-tx-endpoint can be associated with the static-low-level-tx-endpoint may be notified from the O-RU 20 to the O-DU 30. For example, the capability may be exchanged between the O-RU 20 and the O-DU 30 using a hello message when a NETCONF session is established.

[0072] Fig. 10 shows a data model relating to the antenna array on the receiving side in O-RU 20. The data model in Fig. 10 shows an example in which the antenna array on the transmitting side in O-RU 20 is configured with multiple antenna arrays rx-array #0 to rx-array #n. The data model in Fig. 10 shows that there is a one-to-one correspondence between static-low-level-rx-endpoint and rx-array.

[0073] The data model in FIG. 10 also shows that there is a one-to-one correspondence between rx-array-carrier and static-low-level-rx-endpoint.

[0074] 10, when the O-DU 30 transitions the O-RU 20 to the power saving mode, it sets the value of the parameter "active" in the rx-array-carrier to "SLEEP" or "ACTIVE" for each antenna array. This allows the O-DU 30 to transition to the power saving mode for each antenna array.

[0075] Next, the flow of processing related to edit-config included in NETCONF operations executed in the Configuration Management function will be described with reference to Fig. 11. As shown in Figs. 7 to 10, the O-DU 30 updates the configuration information acquired from the O-RU 20 to a data model indicating the antenna elements to be transitioned to power saving mode. The O-DU 30 transmits a request message in which rpc edit-config is set to the O-RU 20 (S31). The request message includes the data model updated in the O-DU 30.

[0076] Next, the O-RU 20 updates the state of each antenna element according to the received data model (S32). The O-RU 20 transitions the state of each antenna element to power-saving mode. For example, the O-RU 20 transitions the state of an antenna element associated with "SLEEP" in the received data model to sleeping.

[0077] Next, the O-RU 20 transmits a response message in which rpc-reply is set to the O-DU 30 (S33).

[0078] Next, the flow of communication processing between the O-RU 20 and the O-DU 30 will be explained using Figure 12. Communication related to the C-Plane and U-Plane (C / U Plane transport) between the O-RU 20 and the O-DU 30 may be performed on UDP / IP. Furthermore, communication related to the C-Plane and U-Plane (C / U Plane transport) between the O-RU 20 and the O-DU 30 may use IPv4 and IPv6, or either IPv4 or IPv6. Furthermore, the IP address used for communication related to the C-Plane and U-Plane may be different from the IP address used for communication related to the M-Plane. The IP address used for communication related to the C-Plane may be the same as or different from the IP address used for communication related to the U-Plane.

[0079] First, the O-DU 30 transmits a message related to the C-Plane or U-Plane to the O-RU 20 (S41). An eAxC ID is set in the message transmitted from the O-DU 30 to the O-RU 20. One eAxC ID or multiple eAxC IDs may be set in the message transmitted from the O-DU 30 to the O-RU 20. Although FIG. 12 shows an example in which one message is transmitted from the O-DU 30 to the O-RU 20, multiple messages may also be transmitted. When multiple messages are transmitted from the O-DU 30 to the O-RU 20, different eAxC IDs may be set in the respective messages, or the same eAxC ID may be set in some of the messages.

[0080] Next, if the O-RU 20 receives a message including an eAxC ID that is not used in the current operation mode, it transmits an alarm message to the O-DU 30 (S42). In step S41, if the O-RU 20 receives a message related to the C-Plane, it may transmit an alarm message related to the C-Plane to the O-DU 30. In step S41, if the O-RU 20 receives a message related to the U-Plane, it may transmit an alarm message related to the U-Plane to the O-DU 30. Alternatively, in step S41, if the O-RU 20 receives a message related to the C-Plane or U-Plane, it may transmit an alarm message related to the M-Plane to the O-DU 30. Upon receiving the alarm message, the O-DU 30 may transmit to the O-RU 20 a message that sets the eAxC ID that is used in the current operation mode of the O-RU 20. Alternatively, the O-DU 30 may transfer the alarm message to the SMO 40, or transmit a message notifying the SMO 40 of the occurrence of an alarm. Alternatively, when the O-DU 30 receives an alarm message, it may update the parameter “active” in the tx-array-carrier and rx-array-carrier to “INACTIVE” and transmit the updated data model to the O-RU 20.

[0081] Next, the flow of alarm message transmission processing in O-RU 20 will be explained using Figure 13. First, a control unit (not shown) configured by a processor etc. of O-RU 20 identifies the current operating mode (S51). Specifically, the control unit of O-RU 20 determines whether O-RU 20 is operating in normal mode or power-saving mode.

[0082] Next, the receiving unit 11 of the O-RU 20 receives the message in which the eAxC ID is set (S52).

[0083] Next, the control unit of the O-RU 20 determines whether an eAxC ID that is not used in the current operating mode is set in the received message (S53). For example, a case will be described in which the O-RU 20 has the data model shown in FIG. 7 . In the data model shown in FIG. 7 , it is assumed that all antenna elements constituting tx-array #0 and tx-array #1 operate in normal mode, and that only the antenna element constituting tx-array #0 operates in power-saving mode. Under such assumptions, when the O-RU 20 operates in power-saving mode, the control unit determines whether an eAxC ID different from the eAxC ID set in the antenna element operating in power-saving mode is set in the message. The eAxC ID different from the eAxC ID set in the antenna element operating in power-saving mode is the eAxC ID set in the antenna element that operates only in normal mode.

[0084] 7, it is assumed that the antenna elements constituting tx-array #0 operate in normal mode, and the antenna elements constituting tx-array #1 operate in power-saving mode. In such a case, for example, the control unit of O-RU 20 operating in normal mode determines whether the eAxC IDs set in low-level-tx-endpoints #j to #n are set in the message. Also, the control unit of O-RU 20 operating in power-saving mode determines whether the eAxC IDs set in low-level-tx-endpoints #0 to #i are set in the message.

[0085] Next, a case will be described in which the O-RU 20 has the data model shown in Fig. 8. When the O-RU 20 is operating in the power saving mode, the control unit determines whether an eAxC ID different from the eAxC ID set for the antenna element operating in the power saving mode is set in the message.

[0086] Next, a case will be described in which the O-RU 20 has the data model shown in Fig. 8 and is operating in normal mode. For example, low-level-tx-endpoints #j to #n may be set with an eAxC ID with a value different from that of low-level-tx-endpoints #0 to #i. Low-level-tx-endpoints #j to #n are used, for example, when transitioning low-level-tx-endpoints #0 to #i associated with low-level-tx-endpoints #j to #n to power-saving mode. When the O-RU 20 is operating in normal mode, the control unit determines whether the eAxC ID set in low-level-tx-endpoints #j to #n is set in the message.

[0087] Next, a case will be described in which O-RU 20 has the data model shown in Fig. 9. When O-RU 20 having the data model shown in Fig. 9 is operating in power saving mode, the control unit determines whether an eAxC ID different from the eAxC ID set for the antenna element operating in power saving mode is set in the message.

[0088] Next, a case will be described in which the O-RU 20 has the data model shown in FIG. 10 . In the data model shown in FIG. 10 , it is assumed that all antenna elements constituting rx-array #0 to #n operate in normal mode, and that antenna elements constituting rx-array #0 to #i operate in power-saving mode. Under such assumptions, when the O-RU 20 operates in power-saving mode, the control unit determines whether an eAxC ID different from the eAxC ID set for the antenna element operating in power-saving mode is set in the message. The eAxC ID different from the eAxC ID set for the antenna element operating in power-saving mode is the eAxC ID set for the antenna element operating only in normal mode.

[0089] 10, it is assumed that the antenna elements constituting rx-array #0 to #i operate in normal mode, and the antenna elements constituting rx-array #j to #n operate in power-saving mode. In such a case, for example, the control unit of O-RU 20 operating in normal mode determines whether the eAxC IDs set in low-level-rx-endpoint #j to #n are set in the message. Also, the control unit of O-RU 20 operating in power-saving mode determines whether the eAxC IDs set in low-level-rx-endpoint #0 to #i are set in the message.

[0090] 13, if only eAxC IDs used in the current operating mode are set in the message, the control unit of O-RU 20 repeats the processing from step S52 onwards. If eAxC IDs not used in the current operating mode are set in the message, the control unit of O-RU 20 determines whether the alarm message transmission criteria are met (S54). Here, the alarm message transmission criteria will be explained.

[0091] The alarm message transmission criteria may be determined, for example, using the number of messages including eAxC IDs that are not used in the current operation mode within a predetermined period. Specifically, the control unit may determine that the alarm message transmission criteria are met when the number of messages including eAxC IDs that are not used in the current operation mode within a predetermined period exceeds a threshold, and that the alarm message transmission criteria are not met when the number does not exceed the threshold. Alternatively, the control unit may determine that the alarm message transmission criteria are met when the number of eAxC IDs that are not used in the current operation mode and that are set in the message exceeds a threshold, and that the alarm message transmission criteria are not met when the number does not exceed the threshold.

[0092] The predetermined period may be determined by, for example, one minute, ten minutes, etc. Alternatively, the predetermined period may be determined by the number of times a message transmitted from the O-DU 30 is received, such as five times, ten times, etc.

[0093] The value of the predetermined period may be set as a dedicated parameter (i.e., a new parameter not described in Non-Patent Document 1). Also, the value of the predetermined period may be a fixed value (1 minute, 10 minutes, etc.) as described above, or may be a value that varies depending on the implementation (i.e., an implementation-dependent value). The same applies to the threshold value.

[0094] If the control unit of O-RU 20 determines that the alarm transmission criteria are not met, it repeats the processing from step S52 onwards. If the control unit of O-RU 20 determines that the alarm transmission criteria are met, it transmits an alarm message (S55). From step S55 onwards, the processing from step S51 onwards may be repeated.

[0095] The control unit of O-RU 20 may include in the alarm message information indicating the current operating mode. Furthermore, the control unit of O-RU 20 may include in the alarm message information indicating the antenna elements operating in the current operating mode. Alternatively, the control unit of O-RU 20 may include in the alarm message information indicating the timing at which the current operating mode will be switched.

[0096] Furthermore, the control unit of the O-RU 20 may cancel the alarm state if, after transmitting the alarm message, a message received from the O-DU 30 within a predetermined period no longer satisfies the alarm message transmission criteria. For example, when canceling the alarm state, the control unit of the O-RU 20 may send an alarm cancellation message to the O-DU 30. The criteria used to cancel the alarm state may be the same as the alarm message transmission criteria, or may be different from the alarm message transmission criteria. The different criteria from the alarm message transmission criteria may be, for example, a value greater or smaller than the threshold used in the alarm message transmission criteria. If the state in which the alarm message transmission criteria is satisfied continues for a predetermined period, the control unit of the O-RU 20 may perform recovery processing, such as resetting or restarting the O-RU 20.

[0097] As described above, the O-DU 30 can generate a data model that transitions the state of antenna elements associated with the antenna array to sleeping. The O-DU 30 can transition the state of all antenna elements associated with the antenna array to sleeping collectively, or can transition the state to sleeping for each antenna element. In this way, the O-DU 30 can flexibly select the antenna elements in the O-RU 20 to transition to sleeping, thereby efficiently transitioning the O-RU 20 to the power saving mode.

[0098] Furthermore, when the O-RU 20 is operating in an operation mode specified by the O-DU 30 and receives a message with an eAxC ID that is not used in the current operation mode, it transmits an alarm message. This allows the device that received the alarm message to take action, such as retransmitting a message with the correct eAxC ID or changing the message transmission path. Furthermore, the O-RU 20 that transmitted the alarm message can perform recovery procedures such as resetting or restarting. As a result, it is possible to prevent further deterioration in communication quality in communications involving the O-RU 20.

[0099] FIG. 10 is a block diagram showing an example configuration of an RU device 10 and a DU device 15 (hereinafter referred to as the RU device 10, etc.). Referring to FIG. 10, the RU device 10, etc. includes a network interface 1201, a processor 1202, and a memory 1203. The network interface 1201 is used to communicate with network nodes (e.g., eNB, MME, P-GW, etc.). The network interface 1201 may include, for example, a network interface card (NIC) conforming to the IEEE 802.3 series. Here, eNB stands for evolved Node B, MME stands for Mobility Management Entity, and P-GW stands for Packet Data Network Gateway. IEEE stands for Institute of Electrical and Electronics Engineers.

[0100] The processor 1202 reads and executes software (computer programs) from the memory 1203 to perform the processing of the RU device 10 and the like described using flowcharts in the above-described embodiments. The processor 1202 may be, for example, a microprocessor, an MPU, or a CPU. The processor 1202 may include multiple processors.

[0101] The memory 1203 is configured by a combination of volatile memory and non-volatile memory. The memory 1203 may include storage located remotely from the processor 1202. In this case, the processor 1202 may access the memory 1203 via an I / O (Input / Output) interface (not shown).

[0102] 10, the memory 1203 is used to store software modules. The processor 1202 reads and executes these software modules from the memory 1203, thereby performing the processing of the RU device 10 and the like described in the above-described embodiment.

[0103] As explained using FIG. 10, each of the processors of the RU device 10, etc. executes one or more programs containing a group of instructions for causing a computer to perform the algorithm explained using the drawing.

[0104] The RU device 10 and the DU device 15 each have a similar network interface, processor, and memory. In addition, the RU device 15 has an antenna for wireless communication with a UE or another RU device. As described above, the antenna uses an antenna array (array antenna).

[0105] In the above example, the program can be stored and supplied to a computer using various types of non-transitory computer-readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-RWs, and semiconductor memories (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, and RAMs (Random Access Memory)). The program may also be supplied to a computer by various types of transitory computer-readable media. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. The transitory computer-readable media can be supplied to a computer via wired communication paths such as electric wires and optical fibers, or via wireless communication paths.

[0106] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the present disclosure.

[0107] Some or all of the above embodiments may be described as, but are not limited to, the following supplementary notes. (Supplementary Note 1) A radio unit (RU) device comprising: a receiver that receives a message including an extended antenna-carrier identifier (eAxC ID) when the RU device is operating in a first mode; and a transmitter that transmits an alarm message indicating that an abnormality has been detected if the eAxC ID is an eAxC ID that is not used in the first mode and is used in a second mode. (Supplementary Note 2) The RU device according to Supplementary Note 1, wherein the first mode is one of a power saving mode and a normal mode, and the second mode is one of the power saving mode and the normal mode that is different from the first mode. (Supplementary Note 3) The RU device according to Supplementary Note 1 or 2, wherein the eAxC ID is set for each of a plurality of antenna elements included in the RU device, and the transmitter transmits the alarm message when, when the RU device is operating in the first mode, it receives a message including an eAxC ID that is set for the antenna element that is not used in the first mode and is used in the second mode. (Supplementary Note 4) The RU device according to Supplementary Note 3, wherein the transmitter transmits the alarm message when, while the RU device is operating in a power saving mode, the transmitter receives a message including the eAxC ID set to an antenna element that does not operate in a power saving mode. (Supplementary Note 5) The RU device according to Supplementary Note 3 or 4, wherein, when the plurality of antenna elements constitute a plurality of antenna arrays and a first antenna array included in the plurality of antenna arrays is operating in a power saving mode, the transmitter transmits the alarm message when the eAxC ID is an eAxC ID set to an antenna element that constitutes a second antenna array included in the plurality of antenna arrays and that does not operate in the power saving mode but operates in a normal mode.(Supplementary Note 6) The RU apparatus according to Supplementary Note 3 or 4, wherein the plurality of antenna elements form one antenna array, a sub-antenna array is defined that includes at least one antenna element operating in a power saving mode among the plurality of antenna elements that form the one antenna array, and when the RU apparatus is operating in the power saving mode, the transmitter transmits the alarm message if the eAxC ID is an eAxC ID set for an antenna element among the plurality of antenna elements that is not included in the sub-antenna array. (Supplementary Note 7) The RU apparatus according to any one of Supplements 1 to 6, wherein the transmitter transmits the alarm message if the number of eAxC IDs that are not used in the first mode and are used in the second mode, or the number of messages including an eAxC ID that is not used in the first mode and is used in the second mode, exceeds a threshold within a predetermined period. (Supplementary Note 8) The RU apparatus according to any one of Supplementary Notes 1 to 7, wherein the receiver receives a message transmitted via a C-Plane or a U-Plane. (Supplementary Note 9) The RU device according to any one of Supplementary Notes 1 to 8, wherein the transmitter transmits the alarm message via an M-Plane. (Supplementary Note 10) A DU (Distributed Unit) device comprising: a transmitter that transmits a message including an eAxC ID (extended antenna-carrier identifier) ​​to an RU device operating in a first mode; a receiver that receives from the RU device an alarm message caused by the eAxC ID being an eAxC ID that is not used in the first mode and is used in a second mode; and a decision unit that decides to execute predetermined processing based on the alarm message. (Supplementary Note 11) The DU device according to Supplementary Note 10, wherein the decision unit decides to send to the RU device a message indicating that the RU device is to transition to an INACTIVE state. (Supplementary Note 12) The DU device according to Supplementary Note 10, wherein the decision unit decides to send to the RU device a retransmission message including an eAxC ID that is different from the eAxC ID included in the message.(Supplementary Note 13) A communication system including an RU device and a DU device, wherein the RU device has: a receiver that receives a message including an extended antenna-carrier identifier (eAxC ID) when the RU device is operating in a first mode, and a transmitter that transmits an alarm message indicating that an abnormality has been detected when the eAxC ID is an eAxC ID that is not used in the first mode and is used in a second mode, and the DU device has: a transmitter that transmits a message including the extended antenna-carrier identifier (eAxC ID) to the RU device operating in the first mode, a receiver that receives from the RU device an alarm message caused by the eAxC ID being an eAxC ID that is not used in the first mode and is used in the second mode, and a determiner that determines to execute predetermined processing based on the alarm message. (Supplementary Note 14) The communication system according to Supplementary Note 13, wherein the first mode is one of a power saving mode and a normal mode, and the second mode is one of the power saving mode and the normal mode that is different from the first mode. (Supplementary Note 15) A communication method executed in an RU (Radio Unit) device, comprising: receiving a message including an extended antenna-carrier identifier (eAxC ID) when the RU device is operating in a first mode; and transmitting an alarm message indicating that an abnormality has been detected if the eAxC ID is an eAxC ID that is not used in the first mode and is used in a second mode. (Supplementary Note 16) The communication method according to Supplementary Note 15, wherein the first mode is one of a power saving mode and a normal mode, and the second mode is one of the power saving mode and the normal mode that is different from the first mode.(Supplementary Note 17) The communication method according to Supplementary Note 15 or 16, wherein the eAxC ID is set to each of a plurality of antenna elements included in the RU device, and when transmitting the alarm message, the RU device transmits the alarm message when it receives a message including the eAxC ID set to the antenna element that is not used in the first mode and is used in the second mode while operating in the first mode. (Supplementary Note 18) The communication method according to Supplementary Note 17, wherein the alarm message is transmitted when it receives a message including the eAxC ID set to an antenna element that does not operate in the power saving mode while operating in the RU device. (Supplementary Note 19) The communication method according to Supplementary Note 17 or 18, wherein, when the plurality of antenna elements constitute a plurality of antenna arrays and a first antenna array included in the plurality of antenna arrays is operating in a power saving mode, the alarm message is transmitted if the eAxC ID is an eAxC ID set to an antenna element constituting a second antenna array included in the plurality of antenna arrays, the second antenna array not operating in a power saving mode but operating in a normal mode. (Supplementary Note 20) The communication method according to Supplementary Note 17 or 18, wherein, when the plurality of antenna elements constitute a single antenna array, a sub-antenna array is defined including at least one antenna element operating in a power saving mode among the plurality of antenna elements constituting the single antenna array, and the RU device is operating in a power saving mode, the alarm message is transmitted if the eAxC ID is an eAxC ID set to an antenna element not included in the sub-antenna array among the plurality of antenna elements.(Supplementary Note 21) The communication method according to any one of Supplementary Notes 15 to 20, wherein, when transmitting the alarm message, the alarm message is transmitted if the number of eAxC IDs not used in the first mode and used in the second mode or the number of messages including eAxC IDs not used in the first mode and used in the second mode exceeds a threshold within a predetermined period. (Supplementary Note 22) The communication method according to any one of Supplementary Notes 15 to 21, when receiving the message, a message transmitted via C-Plane or U-Plane is received. (Supplementary Note 23) The communication method according to any one of Supplementary Notes 15 to 22, when transmitting the alarm message, the alarm message is transmitted via M-Plane. (Supplementary Note 24) A communication method executed in a DU device, comprising: transmitting a message including an eAxC ID (extended antenna-carrier identifier) ​​to an RU device operating in a first mode; receiving an alarm message from the RU device caused by the eAxC ID being an eAxC ID that is not used in the first mode and is used in a second mode; and determining to execute predetermined processing based on the alarm message. (Supplementary Note 25) The communication method according to Supplementary Note 24, wherein, when executing the predetermined processing, it determines to send to the RU device a message indicating that the RU device is to transition to an INACTIVE state. (Supplementary Note 26) The communication method according to Supplementary Note 24, wherein, when executing the predetermined processing, it determines to send to the RU device a retransmission message including an eAxC ID that is different from the eAxC ID included in the message. (Supplementary Note 27) A program that causes a computer to execute the following steps: receive a message including an eAxC ID (extended antenna-carrier identifier) ​​when an RU device is operating in a first mode; and, if the eAxC ID is an eAxC ID that is not used in the first mode and is used in a second mode, transmit an alarm message indicating that an abnormality has been detected.(Supplementary Note 28) The program according to Supplementary Note 27, wherein the first mode is either a power saving mode or a normal mode, and the second mode is one of the power saving mode and the normal mode that is different from the first mode. (Supplementary Note 29) The program according to Supplementary Note 27 or 28, wherein the eAxC ID is set to each of a plurality of antenna elements of the RU device, and when transmitting the alarm message, the RU device transmits the alarm message if, while operating in the first mode, it receives a message including the eAxC ID set to the antenna element that is not used in the first mode and is used in the second mode. (Supplementary Note 30) The program according to Supplementary Note 29, wherein, when transmitting the alarm message, the RU device transmits the alarm message if, while operating in the power saving mode, it receives a message including the eAxC ID set to an antenna element that does not operate in the power saving mode. (Supplementary Note 31) The program according to Supplementary Note 29 or 30, wherein, when the plurality of antenna elements constitute a plurality of antenna arrays and a first antenna array included in the plurality of antenna arrays is operating in a power saving mode, the alarm message is transmitted if the eAxC ID is an eAxC ID set to an antenna element of a second antenna array included in the plurality of antenna arrays, the second antenna array not operating in a power saving mode but operating in a normal mode. (Supplementary Note 32) The program according to Supplementary Note 29 or 30, wherein, when the plurality of antenna elements constitute a single antenna array, a sub-antenna array is defined including at least one antenna element operating in a power saving mode among the plurality of antenna elements constituting the single antenna array, and the RU device is operating in a power saving mode, the alarm message is transmitted if the eAxC ID is an eAxC ID set to an antenna element of the plurality of antenna elements not included in the sub-antenna array.(Supplementary Note 33) The program according to any one of Supplements 27 to 32, which, when transmitting the alarm message, transmits the alarm message if the number of eAxC IDs not used in the first mode and used in the second mode or the number of messages including an eAxC ID not used in the first mode and used in the second mode exceeds a threshold within a predetermined period. (Supplementary Note 34) The program according to any one of Supplements 27 to 33, which, when receiving the message, receives a message transmitted via a C-Plane or a U-Plane. (Supplementary Note 35) The program according to any one of Supplements 27 to 34, which, when transmitting the alarm message, transmits the alarm message via an M-Plane. (Supplementary Note 36) A program that causes a computer to execute the following steps: transmit a message including an eAxC ID (extended antenna-carrier identifier) ​​to an RU device operating in a first mode; receive from the RU device an alarm message caused by the eAxC ID being an eAxC ID not used in the first mode and used in the second mode; and determine to execute predetermined processing based on the alarm message. (Supplementary Note 37) The program according to Supplementary Note 36, which, when executing the predetermined processing, determines to send to the RU device a message indicating that the RU device is to transition to an INACTIVE state. (Supplementary Note 38) The program according to Supplementary Note 36, which, when executing the predetermined processing, determines to send to the RU device a retransmission message including an eAxC ID different from the eAxC ID included in the message.

[0108] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0109] 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.

[0110] This application claims priority based on Japanese Patent Application No. 2022-151397, filed on September 22, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0111] REFERENCE SIGNS LIST 10 RU device 11 Receiving unit 12 Transmitting unit 15 DU device 16 Transmitting unit 17 Receiving unit 18 Determining unit 20 O-RU 30 O-DU 40 SMO

Claims

1. An RU (Radio Unit) device, comprising: Receiving means for receiving a message including an eAxC ID (extended antenna-carrier identifier) when the RU device is operating in a first mode; Transmitting means for transmitting an alarm message indicating that an abnormality has been detected when the eAxC ID is an eAxC ID that is not used in the first mode and is used in a second mode.

2. The first mode is either a power-saving mode or a normal mode, The second mode is a mode different from the first mode among the power-saving mode and the normal mode. The RU device according to claim 1.

3. The eAxC ID is set for each of a plurality of antenna elements of the RU device, The transmitting means: When the RU device is operating in the first mode and receives a message including an eAxC ID set for an antenna element that is not used in the first mode and is used in the second mode, the transmitting means transmits the alarm message. The RU device according to claim 1 or 2.

4. The transmitting means: When the RU device is operating in a power-saving mode and receives a message including the eAxC ID set for an antenna element that does not operate in the power-saving mode, the transmitting means transmits the alarm message. The RU device according to claim 3.

5. When the plurality of antenna elements constitute a plurality of antenna arrays and a first antenna array included in the plurality of antenna arrays is operating in a power-saving mode, The transmitting means: When the eAxC ID is an eAxC ID set for an antenna element that constitutes a second antenna array included in the plurality of antenna arrays, does not operate in the power-saving mode, and operates in the normal mode, the transmitting means transmits the alarm message. The RU device according to claim 3.

6. When the plurality of antenna elements constitute one antenna array, a sub-antenna array including at least one antenna element operating in a power-saving mode is defined among the plurality of antenna elements constituting the one antenna array, and the RU device is operating in a power-saving mode, The transmitting means: The RU device according to claim 3, wherein when the eAxC ID is set to an eAxC ID of an antenna element that is not included in the sub-antenna array among the plurality of antenna elements, the alarm message is transmitted.

7. The transmitting means The RU device according to claim 1 or 2, wherein when the number of eAxC IDs not used in the first mode and used in the second mode or the number of messages including the eAxC IDs not used in the first mode and used in the second mode exceeds a threshold within a predetermined period, the alarm message is transmitted.

8. The receiving means The RU device according to claim 1 or 2, which receives a message transmitted via a C-Plane or a U-Plane.

9. A DU (Distributed Unit) device comprising: a transmitting means for transmitting a message including an eAxC ID (extended antenna-carrier identifier) to an RU device operating in a first mode; a receiving means for receiving an alarm message from the RU device due to a factor that the eAxC ID is not used in the first mode and is used in the second mode; and a determining means for determining to execute a predetermined process based on the alarm message.

10. A communication method executed in an RU (Radio Unit) device, wherein when the RU device is operating in a first mode, a message including an eAxC ID (extended antenna-carrier identifier) is received, and when the eAxC ID is not used in the first mode and is used in the second mode, an alarm message indicating that an abnormality has been detected is transmitted.