RU DEVICE, DU DEVICE, AND COMMUNICATION METHOD

Abstract

The purpose of the present invention is to provide a Remote Unit (RU) device with which it is possible to effectively use statistical information of a packet generated in the RU device and a Distributed Unit (DU) device that perform functions in a separated base station. An RU device (10) according to the present invention comprises: a reception unit (11) that receives a packet from a DU device (20) that performs a process in a layer at a higher level than the layer on which the RU device (10) performs communication functions, among communication functions of a base station divided into a plurality of layers; and a transmission unit (12) that transmits an alarm signal to the DU device (20) or to a management device that manages a network, when the statistical information relating to the received packet satisfies a prescribed standard.

Description

[Technical field]

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

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

[0003] Non-Patent Document 1 specifies specifications related to the M (Management)-Plane that is defined for transmitting management data between the O-RU and the O-DU. Non-Patent Document 1 also discloses that the O-RU counts packets received from the O-DU and generates statistical information. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] O-RAN.WG4.MP.0-v03.00 Summary of the Invention [Problem to be solved by the invention]

[0005] However, Non-Patent Document 1 does not disclose a specific method for utilizing the statistical information generated by the O-DU or O-RU. This point is also true for the C-RAN (Centralized Radio Access Network) adopted in the LTE (Long Term Evolution) defined by the 3GPP (3rd Generation Partnership Project).

[0006] An object of the present disclosure is to provide an RU device, a DU device, a communication system, a communication method, and a program that are equipped with means for utilizing statistical information of packets generated in an RU device and a DU device that perform the functions of separated base stations. [Means for solving the problem]

[0007] A RU (Remote Unit) device according to a first aspect of the present disclosure includes a receiving unit that receives packets from a DU (Distributed Unit) device that performs processing of a layer higher than the layer performed by the RU (Remote Unit) device, among the communication functions of a base station divided into multiple layers, and a transmitting unit that transmits an alarm signal to the DU device or a management device that manages a network when statistical information regarding the received packets satisfies a predetermined criterion.

[0008] A DU device according to a second aspect of the present disclosure comprises a receiving unit that receives packets from an RU device that performs processing of a layer lower than the layer performed by the DU device among the communication functions of a base station divided into multiple layers, and a transmitting unit that transmits an alarm signal to a management device that manages the network when statistical information regarding the received packets satisfies a predetermined criterion.

[0009] A communications system according to a third aspect of the present disclosure is a communications system comprising: an RU device that performs some of the layer processing of the communication functions of a base station which are divided into multiple layers; a DU device that transmits and receives packets between the RU device and performs processing of a layer higher than the layer performed by the RU device; and a management device that manages a network including the RU device and the DU device, wherein at least one of the RU device and the DU device transmits an alarm signal to the management device when statistical information regarding the received packet satisfies a predetermined criterion, and the management device transmits the predetermined criterion to at least one of the RU device that transmits the alarm signal and the DU device that transmits the alarm signal.

[0010] A communication method according to a fourth aspect of the present disclosure receives a packet from a DU (Distributed Unit) device that performs processing at a higher layer than a layer performed by an RU (Remote Unit) device among the communication functions of a base station divided into multiple layers, and transmits an alarm signal to the DU device or a management device that manages the network when statistical information regarding the received packet satisfies a predetermined criterion.

[0011] A program according to a fifth aspect of the present disclosure causes a computer to receive a packet from a DU (Distributed Unit) device that performs processing at a higher layer than a layer performed by an RU (Remote Unit) device among the communication functions of a base station divided into multiple layers, and when statistical information regarding the received packet satisfies a predetermined criterion, transmit an alarm signal to the DU device or a management device that manages the network. Effect of the Invention

[0012] The present disclosure makes it possible to provide an RU device, a DU device, a communication system, a communication method, and a program that can effectively utilize statistical information of packets generated in an RU device and a DU device that perform the functions of a separated base station. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a configuration diagram of an RU device according to a first embodiment. [Diagram 2] FIG. 2 is a configuration diagram of a DU device according to a first embodiment. [Diagram 3] FIG. 11 is a configuration diagram of a communication system according to a second embodiment. [Figure 4] FIG. 11 is a diagram for explaining a delay management method according to the second embodiment. [Diagram 5] FIG. 11 is a diagram showing a flow of a management data setting process according to the second embodiment. [Figure 6] FIG. 11 is a diagram showing a flow of an alarm transmission process according to the second embodiment. [Figure 7] FIG. 13 is a configuration diagram of a communication system according to a fourth embodiment. [Figure 8] FIG. 13 is a configuration diagram of a communication system according to a fifth embodiment. [Figure 9] FIG. 13 is a configuration diagram of a communication system according to a sixth embodiment. [Figure 10] A diagram of an RU device etc. for each embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] (Embodiment 1) Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. A configuration example of an RU device 10 according to the first embodiment will be described with reference to Fig. 1. The RU device may be a computer device that operates by a processor executing a program stored in a memory.

[0015] The RU device 10 may execute a process of a lower layer among the communication functions of a base station divided into a plurality of layers. On the other hand, the DU device 20 may execute a process of a layer higher than the layer executed by the RU device 10. The RU device 10 performs wireless communication with a communication terminal present in a communication area formed by the RU device 10. The communication terminal may be, for example, a smartphone terminal, an IoT (Internet of Things) terminal, or the like. Alternatively, the communication terminal may be a device defined as UE (User Equipment) in 3GPP. The base station may be, for example, an eNB (evolved Node B) defined as a base station supporting LTE (Long Term Evolution) in 3GPP, or may be a base station supporting so-called 5G.

[0016] 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 a module that performs processing by a processor executing a program stored in a memory, or the receiving unit 11 and the transmitting unit 12 may be hardware such as a circuit or a chip.

[0017] The receiving unit 11 receives a packet from the DU device 20. The RU device 10 and the DU device 20 may be connected, for example, via a fixed communication network or via a wireless communication network. The packet received by the RU device 10 may be, for example, control data required for a communication terminal to use a mobile network provided by a communication carrier. Furthermore, the packet received by the RU device 10 may be user data addressed to the communication terminal. Furthermore, the packet received by the RU device 10 may be management data used to manage a communication network including the RU device 10 and the DU device 20.

[0018] When the statistical information regarding the received packets meets a predetermined standard, the transmitting unit 12 transmits an alarm signal to the DU device 20 or a management device that manages the network.

[0019] The statistical information on received packets may be, for example, information obtained by classifying received packets using the number of received packets. The number of received packets may be, for example, the number of normally received packets, the number of received packets containing an error, the number of packets received at a predetermined timing, the number of packets that could not be received at a predetermined timing, etc. The predetermined criterion may be, for example, that at least any of the ratios of the number of normally received packets, the number of received packets containing an error, the number of packets received at a predetermined timing, and the number of packets that could not be received at a predetermined timing to the total number of received packets exceeds or falls below a predetermined threshold. The predetermined criterion may also be, for example, the type of packet received. The RU device 10 may receive at least one of information indicating a predetermined criterion and information indicating a predetermined threshold from the DU device 20 or a management device that manages the network.

[0020] The management device that manages the network may be, for example, a device that manages a network including the DU device 20 and the RU device 10. Alternatively, the management device may be a device that manages a network including an access network including the DU device 20 and the RU device 10, and a core network that manages the access network.

[0021] The alarm signal may be a signal used to notify an abnormal state, a failure, a fault, or the like occurring in the RU device 10. Alternatively, the alarm signal may be a signal used to notify an abnormal state, a failure, a fault, or the like occurring on the transmission path between the RU device 10 and the DU device 20. Alternatively, the alarm signal may be a signal used to notify that at least one of the logical connections of the C-Plane and the U-Plane between the RU device 10 and the DU device 20 is unstable.

[0022] The transmitting unit 12 may transmit an alarm signal to the management device via the DU device 20, or may transmit an alarm signal to the management device without passing through the DU device 20. The transmitting unit 12 may transmit an alarm signal to the DU device 20 via the management device, or may transmit an alarm signal to the DU device 20 without passing through the management device. Furthermore, the transmitting unit 12 may stop transmitting an alarm signal to the DU device 20 or a management device that manages the network when statistical information regarding the received packets does not satisfy a predetermined standard.

[0023] Next, a configuration example of the DU device 20 according to the first embodiment will be described with reference to Fig. 2. The DU device 20 may be a computer device that operates when a processor executes a program stored in a memory.

[0024] The DU device 20 has a receiving unit 21 and a transmitting unit 22. The receiving unit 21 and the transmitting unit 22 may be software or a module that performs processing by a processor executing a program stored in a memory, or the receiving unit 21 and the transmitting unit 22 may be hardware such as a circuit or a chip.

[0025] The receiving unit 21 receives a packet from the RU device 10. The packet received by the DU device 20 may be, for example, control data required for a communication terminal to use a mobile network provided by a communication carrier. Furthermore, the packet received by the DU device 20 may be user data transmitted from a communication terminal via the RU device 10. Furthermore, the packet received by the DU device 20 may be management data used to manage a communication network including the RU device 10 and the DU device 20.

[0026] When the statistical information on the received packets meets a predetermined standard, the transmitter 22 transmits an alarm signal to a management device that manages the network. The statistical information on the received packets is the same as the statistical information in the RU device 10. The predetermined criteria may be the same as the predetermined criteria in the RU device 10. The DU device 20 may receive at least one of information indicating a predetermined criterion and information indicating a predetermined threshold value from a management device that manages the network.

[0027] As described above, the RU device 10 can transmit an alarm signal generated based on a received packet to devices other than the RU device 10. As a result, the administrator managing the DU device 20 or the administrator managing the management device can detect a fault or the like occurring in the RU device 10 or in the transmission path between the RU device 10 and the DU device 20 by receiving the alarm signal. In other words, the administrator managing the DU device 20 does not need to actively acquire statistical information managed in the RU device 10, and does not need to analyze statistical information to detect a fault or the like occurring in the RU device 10, etc. Therefore, by using the RU device 10, the management load of the administrator managing the network including the RU device 10 and the DU device 20 can be reduced.

[0028] Furthermore, like the RU device 10, the DU device 20 can also transmit an alarm signal to devices other than the DU device 20. As a result, the administrator who manages the management device can detect a fault or the like occurring in the DU device 20 or in the transmission path between the RU device 10 and the DU device 20 by receiving the alarm signal. The administrator who manages the management device does not need to actively obtain statistical information managed in the DU device 20, and does not need to analyze statistical information to detect a fault or the like occurring in the DU device 20, etc. Therefore, by using the DU device 20, the management load of the administrator who manages the network including the RU device 10 and the DU device 20 can be reduced.

[0029] (Embodiment 2)

[0030] Next, a configuration example of a communication system according to the second embodiment will be described with reference to FIG. 3. The communication system in FIG. 3 has an O-RU entity 30 and an O-DU entity 40 defined in the O-RAN alliance. Furthermore, an NMS (Network Management System) 50 is a system that manages the O-RU entity 30 and the O-DU entity 40. The NMS 50 corresponds to a management device. The NMS 50 may be replaced with an SMO (Service Management and Orchestration System). The O-RU entity 30 corresponds to an RU device 10. The O-DU entity 40 corresponds to a DU device 20. In the following description, it is assumed that the O-RU entity 30 has a receiving unit 11 and a transmitting unit 12 of the RU device 10, and the O-DU entity 40 has a receiving unit 21 and a transmitting unit 22 of the DU device 20.

[0031] The O-RU entity 30 performs, for example, radio frequency (RF) processing and processing related to the Low-PHY layer. The Low-PHY layer may be, for example, a layer that performs processing related to fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, and physical random access channel (PRACH) extraction. The PRACH extraction is, for example, processing in which the O-RU entity 30 extracts or detects the PRACH, which is the signal transmitted first from the UE, when the UE establishes a connection with the O-RU entity 30. The O-RU entity 30 may be a transmission reception point (TRP) or a radio remote head (RRH) defined by 3GPP.

[0032] The O-DU entity 40 performs processes related to, for example, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a High-PHY layer. The High-PHY layer is a layer that performs processes related to, for example, Forward Error Correction (FEC) encoding, FEC decoding, scrambling, modulation, and demodulation. The processes performed in the O-RU entity 30 and the O-DU entity 40 are not limited to the above and may be changed from the above.

[0033] The O-RU entity 30 communicates with the O-DU entity 40 via a transmission path 61 and a transmission path 62. The transmission path 61 transmits C-Plane data and U-Plane data. Furthermore, the transmission path 62 transmits M-Plane data. The C-Plane data, U-Plane data, and M-Plane data may be transmitted as packets. The transmission paths 61 and 62 may be referred to as fronthauls (FH) or fronthaul interfaces. Furthermore, the transmission paths 61 and 62 may require a predetermined frequency band.

[0034] The NMS 50 is connected to the O-DU entity 40 via a network. The NMS 50 may, for example, set management data in the O-DU entity 40, and further set the management data in the O-RU entity 30 via the O-DU entity 40. The management data may be transmitted to the O-RU entity 30 as M-Plane data via the transmission path 62. The management data may be set using the YANG DATA MODEL defined in the O-RAN Alliance. The management data may also be set in the O-RU entity 30 using, for example, the o-ran-supervision.yang Module or the o-ran-performance-management.yang Module. The management data may also be set in advance in at least one of the O-DU entity 40 or the O-RU entity 30.

[0035] C-Plane is a protocol for transferring control signals. U-Plane is a protocol for transferring user data. C-Plane and U-Plane support a protocol stack that transmits signals used in eCPRI (enhanced Common Public Radio Interface) or RoE (Radio over Ethernet) using Ethernet / IP / UDP (User Datagram Protocol). Alternatively, C-Plane and U-Plane may support a protocol stack that transmits signals used in eCPRI or RoE directly using Ethernet. M-Plane is a protocol for transferring monitoring signals used to monitor or maintain devices.

[0036] Next, statistical information generated by the O-RU entity 30 or the O-DU entity 40 will be described. The O-RU entity 30 or the O-DU entity 40 measures packets received as C-Plane data or U-Plane data using various counters. The various counters may be, for example, RX_ON_TIME, RX_ON_TIME_C, RX_EARLY, RX_EARLY_C, RX_LATE, RX_LATE_C, and RX_TOTAL. RX_ON_TIME, RX_ON_TIME_C, RX_EARLY, RX_EARLY_C, RX_LATE, RX_LATE_C, and RX_TOTAL are counter definitions specified as measurement-objects in Rx Window Statistics in the O-RAN Alliance.

[0037] Before describing the details of RX_ON_TIME, RX_ON_TIME_C, RX_EARLY, RX_EARLY_C, RX_LATE, RX_LATE_C, and RX_TOTAL, a delay management method executed in the O-RU entity 30 will be described with reference to Fig. 4. Fig. 4 shows transmission of a packet from the O-DU entity 40 to the O-RU entity 30. The delay management method executed in the O-DU entity 40 is similar to that of the O-RU entity 30, and therefore a detailed description thereof will be omitted.

[0038] 4 shows that the O-RU entity 30 and the O-DU entity 40 perform delay management using the same time axis. In other words, the O-RU entity 30 and the O-DU entity 40 perform time synchronization. T1 to T4 indicate times.

[0039] Time T4 is the timing when the O-RU entity 30 transmits radio data to the UE. In order for the O-RU entity 30 to transmit radio data at the predetermined time T4, delay management is performed in the O-RU entity 30 and the O-DU entity 40. The O-RU entity 30 needs to complete various processes such as iFFT, analog conversion, and beamforming in time for the transmission of radio data at time T4. The time from time T3' to time T4 is the time for the O-RU entity 30 to execute various processes such as iFFT, analog conversion, and beamforming. In FIG. 4, the time from time T3' to time T4 is defined as the O-RU processing delay.

[0040] In the O-RU entity 30, a receive window is set before time T4, which is the timing for transmitting wireless data, by the time of O-RU processing delay. The receive window is defined as a period during which the O-RU entity 30 can normally receive packets. In other words, if the O-RU entity 30 receives a packet in the receive window, it can transmit the received packet as wireless data at time T4, which is the timing for transmitting the wireless data. The receive window indicates a period before time T3'. The receive window may be a period from time T2 to time T3', which is the timing for transmitting a packet by the O-DU entity 40, or may be a period from any timing between time T2 and time T3' to time T3'.

[0041] The period from time T2 to time T3 is a transmission delay between the O-DU entity 40 and the O-RU entity 30, and may be referred to as a fronthaul delay. The fronthaul is a line between the O-DU entity 40 and the O-RU entity 30. For example, an optical fiber may be used for the fronthaul. Standards related to the fronthaul are defined by the O-RAN Alliance.

[0042] The period from time T1 to time T2 indicates an O-DU processing delay. The O-DU processing delay is a period during which the O-DU entity 40 performs processing to transmit a packet. A predetermined period from time T2 may be defined as a transmission window in the O-DU entity 40. The transmission window is a period during which a packet transmitted from the O-DU entity 40 can reach the O-RU entity 30 by the reception window in the O-RU entity 30.

[0043] 4 has been described as an example in which a receive window is set in the O-RU entity 30, but a receive window is also set in the O-DU entity 40. The O-DU entity 40 can normally transmit data to other devices by receiving packets transmitted from the O-RU entity 30 within the receive window.

[0044] Next, details of RX_ON_TIME, RX_ON_TIME_C, RX_EARLY, RX_EARLY_C, RX_LATE, RX_LATE_C, and RX_TOTAL will be described. RX_ON_TIME, RX_ON_TIME_C, RX_EARLY, RX_EARLY_C, RX_LATE, RX_LATE_C, and RX_TOTAL may be indicators for the O-RU entity 30 or the O-DU entity 40 to count the number of packets. The O-RU entity 30 or the O-DU entity 40 may count RX_ON_TIME, RX_ON_TIME_C, RX_EARLY, RX_EARLY_C, RX_LATE, RX_LATE_C, and RX_TOTAL for packets that arrive during a predetermined monitoring period. The monitoring period may be a C / U-plane monitoring period or a period measured by a C / U-plane Monitoring Timer. The monitoring period may be a configured-cu-monitoring-interval.

[0045] RX_ON_TIME counts the number of U-Plane data packets that arrive at the O-RU entity 30 or the O-DU entity 40 within the receive window. The number of U-Plane data packets that arrive within the receive window includes packets that have errors, such as packets with sequence number errors or packets with corruption.

[0046] RX_ON_TIME_C counts the number of C-Plane data packets that arrive at the O-RU entity 30 or the O-DU entity 40 within the receive window. The number of C-Plane data packets that arrive within the receive window includes packets that have errors, such as packets with sequence number errors or packets with corruption.

[0047] RX_EARLY counts the number of U-Plane data packets that arrive at the O-RU entity 30 or the O-DU entity 40 before the receive window starts. RX_EARLY_C counts the number of C-Plane data packets that arrive at the O-RU entity 30 or the O-DU entity 40 before the receive window starts.

[0048] RX_LATE counts the number of U-Plane data packets that arrive at the O-RU entity 30 or the O-DU entity 40 after the receive window ends. RX_LATE_C counts the number of C-Plane data packets that arrive at the O-RU entity 30 or the O-DU entity 40 after the receive window ends.

[0049] RX_TOTAL counts the number of all packets received in a given monitoring period including the receive window. All packets include C-Plane data and U-Plane data. In addition, all packets include all packets counted in RX_ON_TIME, RX_ON_TIME _C, RX_EARLY, RX_EARLY _C, RX_LATE, and RX_LATE_C. All packets may also include packets counted in other counters different from RX_ON_TIME, RX_ON_TIME _C, RX_EARLY, RX_EARLY_C, RX_LATE, and RX_LATE_C.

[0050] Next, the setting process of the management data in the O-DU entity 40 according to the second embodiment will be described with reference to FIG. 5. First, the receiver 21 of the O-DU entity 40 receives the management data from the NMS 50 (S10). The management data includes, for example, at least one of a packet type to be measured, an anomaly detection method, and a threshold value for notifying an alarm. The packet type to be measured is, for example, information indicating whether a packet that is C-Plane data, a packet that is U-Plane data, or both packets of C-Plane data and U-Plane data are to be measured. When measuring packets of both C-Plane data and U-Plane data, the C-Plane data and the U-Plane data may be measured with distinction, or the C-Plane data and the U-Plane data may be measured without distinction. The management data may be trigger information for the O-RU entity 30 or the O-DU entity 40 to transmit an alarm.

[0051] The abnormality detection method may be, for example, to transmit an alarm when the ratio of the number of RX_EARLY or RX_LATE to the total number of RX_ON_TIME, RX_EARLY, and RX_LATE exceeds a threshold. That is, the abnormality detection method may be, for example, to transmit an alarm when the ratio of packets received outside the reception window period exceeds a threshold. Or, it may be to transmit an alarm when the ratio of the number of RX_EARLY or RX_LATE to the number of RX_TOTAL exceeds a threshold. Or, it may be to transmit an alarm when the ratio of the number of RX_EARLY or RX_LATE to the number of RX_ON_TIME exceeds a threshold. The same applies to the number of packets counted using a counter related to C-Plane data.

[0052] Alternatively, the abnormality detection method may be to send an alarm when the ratio of the number of RX_ON_TIME to the total number of RX_ON_TIME, RX_EARLY, and RX_LATE is lower than a threshold value. Alternatively, the abnormality detection method may be to send an alarm when the ratio of the number of RX_ON_TIME to the number of RX_TOTAL is lower than a threshold value. Alternatively, the abnormality detection method may be to send an alarm when the ratio of the number of RX_ON_TIME to the number of RX_EARLY or RX_LATE is lower than a threshold value. The same applies to the number of packets counted using a counter related to C-Plane data.

[0053] Alternatively, the abnormality detection method may be to send an alarm when RX_ON_TIME exceeds a threshold. Alternatively, the abnormality detection method may be to send an alarm when at least one of RX_EARLY and RX_LATE exceeds a threshold. Alternatively, the abnormality detection method may be to send an alarm when at least one of RX_ON_TIME and RX_ON_TIME_C is lower than a threshold or is 0. The same applies to the number of packets counted using a counter related to C-Plane data.

[0054] Alternatively, the anomaly detection method may be to send an alarm when packets corresponding to RX_EARLY or RX_LATE are measured consecutively for a number of times determined as a threshold value. The same applies to the number of packets counted using a counter related to C-Plane data.

[0055] The threshold for sending an alarm may be a numerical value indicating a ratio, a number of packets, a count, etc. Sending an alarm may be rephrased as sending an alarm signal or an alarm message.

[0056] Next, the control unit of the O-DU entity 40 judges whether or not the management data includes the packet type to be measured (S11). The control unit may be, for example, a processor included in the O-DU entity 40. The processor included in the O-DU entity 40 may execute a program stored in a memory to perform the processing shown in Fig. 5.

[0057] When the control unit of the O-DU entity 40 determines that the management data includes a packet type to be measured, it sets the packet type specified in the management data as the packet to be measured (S12). When the control unit of the O-DU entity 40 determines that the management data does not include a packet type to be measured, it sets the packet type determined as a default value as the packet to be measured (S13). The default value may be stored in advance in a memory or the like in the O-DU entity 40.

[0058] After step S12 or S13, the control unit of the O-DU entity 40 judges whether or not the management data includes an anomaly detection method (S14). If the control unit of the O-DU entity 40 judges that the management data includes an anomaly detection method, it sets the anomaly detection method specified in the management data (S15). If the control unit of the O-DU entity 40 judges that the management data does not include an anomaly detection method, it sets the anomaly detection method that has been determined as a default value (S16). The default value may be stored in advance in a memory or the like in the O-DU entity 40.

[0059] After step S15 or S16, the control unit of the O-DU entity 40 judges whether or not the management data includes a threshold value for transmitting an alarm (S17). If the control unit of the O-DU entity 40 judges that the management data includes a threshold value for transmitting an alarm, it sets the threshold value specified in the management data (S18). If the control unit of the O-DU entity 40 judges that the management data does not include a threshold value for transmitting an alarm, it sets the threshold value that has been determined as a default value (S19). The default value may be stored in advance in a memory or the like in the O-DU entity 40.

[0060] 5 has been described as the flow of processing when the O-DU entity 40 receives management data from the NMS 50, but the same processing as in Fig. 5 is performed when the O-RU entity 30 receives management data from the NMS 50 via the O-DU entity 40. Therefore, a detailed description of the management data setting processing in the O-RU entity 30 will be omitted.

[0061] Next, the flow of the alarm transmission process in the O-RU entity 30 according to the second embodiment will be described with reference to FIG. 6. First, the receiver 11 of the O-RU entity 30 receives a packet of C-Plane data and a packet of U-Plane data from the O-DU entity 40 (S20). Next, the control unit of the O-RU entity 30 generates statistical information on the received packets (S21). Specifically, the control unit of the O-RU entity 30 measures packets using RX_ON_TIME, RX_ON_TIME_C, RX_EARLY, RX_EARLY_C, RX_LATE, RX_LATE_C, and RX_TOTAL. The number of measured packets may be used as the statistical information. For example, the control unit of the O-RU entity 30 may count packets using all counters, or may measure packets using only counters that count packets of a set packet type.

[0062] Next, the control unit of the O-RU entity 30 determines whether the statistical information exceeds a threshold in a preset anomaly detection method (S22). If the control unit of the O-RU entity 30 determines that the statistical information exceeds the threshold, the transmission unit 12 of the O-RU entity 30 transmits an alarm (S23). For example, the transmission unit 12 transmits the alarm to the O-DU entity 40. Alternatively, the transmission unit 12 may set the destination of the alarm to NMS 50 and transmit the alarm to NMS 50 via the O-DU entity 40.

[0063] If the control unit of the O-RU entity 30 determines that the statistical information does not exceed the threshold, it repeats the processes from step S20 onwards.

[0064] Although the flow of the alarm transmission process in the O-RU entity 30 has been described with reference to Fig. 6, the O-DU entity 40 also executes the same alarm transmission process as in Fig. 6. For example, in step S20 in Fig. 6, the O-DU entity 40 receives a C-Plane data packet and a U-Plane data packet from the O-RU entity 30. Also, in step S23, the O-DU entity 40 transmits an alarm to the NMS 50. Other processes in the alarm transmission process of the O-DU entity 40 are similar to those of the O-RU entity 30, and therefore detailed description thereof will be omitted.

[0065] As described above, the O-RU entity 30 and the O-DU entity 40 generate statistical information on received packets using RX_ON_TIME, RX_ON_TIME_C, RX_EARLY, RX_EARLY_C, RX_LATE, RX_LATE_C, and RX_TOTAL. Furthermore, the O-RU entity 30 and the O-DU entity 40 transmit an alarm when the statistical information exceeds a threshold in a preset anomaly detection method. The O-RU entity 30 and the O-DU entity 40 transmit an alarm to devices other than their own devices. Therefore, the administrator of the NMS 50 can receive statistical information from the O-RU entity 30 or the O-DU entity 40 without actively acquiring the statistical information generated in the O-RU entity 30 or the O-DU entity 40. As a result, the management load of the O-RU entity 30 and the O-DU entity 40 on the administrator of the NMS 50 can be reduced.

[0066] (Embodiment 3) Next, a description will be given of statistical information used in the third embodiment. In the third embodiment, the number of packets is measured using RX_CORRUPT, RX_DUPL, RX_SEQID_ERR, RX_SEQID_ERR_C, or RX_ERR_DROP as statistical information. RX_CORRUPT, RX_DUPL, RX_SEQID_ERR, RX_SEQID_ERR_C, or RX_ERR_DROP are counter definitions specified by the O-RAN Alliance.

[0067] RX_CORRUPT counts the number of corrupted packets among packets that arrive at the O-RU entity 30 or the O-DU entity 40 within the reception window. A corrupted packet may be, for example, a packet with an incorrect value set in its header, or a packet containing a protocol error. Among packets with an incorrect value set in their header, packets with an incorrect sequence ID may be counted using RX_SEQID_ERR, which will be described later. The number of corrupted packets may be measured by measuring packets of C-Plane data, or may be measured by measuring packets of U-Plane data, or may be measured without distinguishing between C-Plane data and U-Plane data.

[0068] RX_DUPL counts the number of duplicated packets among packets that arrive at the O-RU entity 30 or the O-DU entity 40 within the receive window.

[0069] RX_SEQID_ERR counts the number of packets with an error related to the sequence ID among the packets of U-Plane data that arrive at the O-RU entity 30 or the O-DU entity 40 within the receiving window. An error related to the sequence ID is when an incorrect sequence ID is set in a packet, for example, when the value set in the sequence ID field of the packet header is not consecutive from the sequence ID of the previously received packet.

[0070] RX_SEQID_ERR_C counts the number of packets containing an error related to the sequence ID among the C-Plane data packets that arrive at the O-RU entity 30 or the O-DU entity 40 within the receiving window.

[0071] RX_ERR_DROP counts the number of packets that are discarded by the O-RU entity 30 or the O-DU entity 40 among the packets of C-Plane data or U-Plane data that arrive at the O-RU entity 30 or the O-DU entity 40. The packets counted in RX_ERR_DROP may be packets that arrive within the receive window or packets that arrive outside the receive window.

[0072] An abnormality detection method will be described when RX_CORRUPT, RX_DUPL, RX_SEQID_ERR, RX_SEQID_ERR_C, or RX_ERR_DROP is used as the statistical information. In this case, the abnormality detection method may be, for example, transmitting an alarm when the ratio of the number of RX_CORRUPT, RX_DUPL, RX_SEQID_ERR, RX_SEQID_ERR_C, or RX_ERR_DROP to the number of RX_TOTAL exceeds a threshold.

[0073] Alternatively, the anomaly detection method may be to send an alarm if the ratio of the number of RX_CORRUPT, RX_DUPL, RX_SEQID_ERR, RX_SEQID_ERR_C, or RX_ERR_DROP to the number of RX_ON_TIME exceeds a threshold.

[0074] Alternatively, the abnormality detection method may be to send an alarm when at least one of RX_CORRUPT, RX_DUPL, RX_SEQID_ERR, RX_SEQID_ERR_C, or RX_ERR_DROP exceeds a threshold.

[0075] Alternatively, the abnormality detection method may be to send an alarm when packets corresponding to RX_CORRUPT, RX_DUPL, RX_SEQID_ERR, RX_SEQID_ERR_C, or RX_ERR_DROP are measured a number of times consecutively determined as a threshold.

[0076] As described above, in the third embodiment, the O-RU entity 30 or the O-DU entity 40 can transmit an alarm depending on the number of packets including an error. This reduces the management load of the O-RU entity 30 and the O-DU entity 40 on the administrator of the NMS 50, etc., as in the second embodiment.

[0077] (Embodiment 4) Next, a configuration example of a communication system according to the fourth embodiment will be described with reference to Fig. 7. Fig. 3 shows an example in which only one transmission path 61 exists as a transmission path for transmitting C-Plane data and U-Plane data, but Fig. 7 shows a configuration in which the C-Plane data and the U-Plane data are transmitted via a plurality of transmission paths.

[0078] As shown in FIG. 7, between the O-RU entity 30 and the O-DU entity 40, there are transmission paths 61_1 to 61_n (n is an integer of 2 or more) as transmission paths for transmitting C-Plane data and U-Plane data. Furthermore, there is a transmission path 62 as a transmission path for transmitting M-Plane data. In other words, between the O-RU entity 30 and the O-DU entity 40, there are a plurality of fronthauls for transmitting C-Plane data and U-Plane data, and a fronthaul for transmitting M-Plane data. Alternatively, the transmission path for transmitting M-Plane data may be shared with any of the transmission paths 61_1 to 61_n for transmitting C-Plane data and U-Plane data. In other words, any of the transmission paths 61_1 to 61_n for transmitting C-Plane data and U-Plane data may transmit M-Plane data.

[0079] The O-RU entity 30 or the O-DU entity 40 may generate statistical information for each transmission path, i.e., for each fronthaul, using at least one of RX_ON_TIME, RX_ON_TIME_C, RX_EARLY, RX_EARLY_C, RX_LATE, RX_LATE_C, and RX_TOTAL. Furthermore, the O-RU entity 30 or the O-DU entity 40 may generate statistical information for each transmission path using at least one of RX_CORRUPT, RX_DUPL, RX_SEQID_ERR, RX_SEQID_ERR_C, and RX_ERR_DROP.

[0080] Alternatively, the O-RU entity 30 or the O-DU entity 40 may collect packets transmitted on the transmission paths 61_1 to 61_n and generate statistical information using RX_ON_TIME or the like.

[0081] The O-RU entity 30 or the O-DU entity 40 may perform the anomaly detection method described in the second or third embodiment for each transmission path and determine whether the statistical information exceeds a threshold. If the statistical information exceeds the threshold, the O-RU entity 30 transmits an alarm to the O-DU entity 40, or transmits an alarm to the NMS 50 via the O-DU entity 40. If the statistical information exceeds the threshold, the O-DU entity 40 transmits an alarm to the NMS 50.

[0082] Alternatively, the O-RU entity 30 or the O-DU entity 40 may determine whether or not statistical information generated by collectively processing packets transmitted on the transmission paths 61_1 to 61_n exceeds a threshold value.

[0083] In FIG. 7, a description has been given of the use of multiple physically different transmission paths to transmit C-Plane data and U-Plane data between the O-RU entity 30 and the O-DU entity 40. Here, the multiple transmission paths used to transmit the C-Plane data and the U-Plane data may be multiple logical transmission paths set in one physical transmission path. For example, multiple logical transmission paths identified by using port identifiers may be set in one physical transmission path. For example, a logical transmission path may be identified by using a pair of port identifiers set in each of the O-RU entity 30 and the O-DU entity 40.

[0084] Furthermore, multiple logical transmission paths identified by using eaxc-id (extended antenna carrier-identification / identifier) ​​may be set in one physical transmission path. eaxc-id is composed of RU_Port_ID, DU_Port_ID, BandSector_ID, and CC_ID. RU_Port_ID is a port identifier of the O-RU entity 30, and DU_Port_ID is a port identifier of the O-DU entity 40. BandSector_ID is an identifier of a band sector, and CC_ID is an identifier of a component carrier. eaxc-id is defined in the O-RAN fronthaul specifications.

[0085] The O-RU entity 30 or the O-DU entity 40 may implement the anomaly detection method described in the second or third embodiment for each logical transmission path, and determine whether or not the statistical information exceeds a threshold value.

[0086] As described above, the O-RU entity 30 and the O-DU entity 40 can implement the anomaly detection method described in embodiment 2 or 3 for each of multiple physically different transmission paths or multiple logically different transmission paths. The O-RU entity 30 or the O-DU entity 40 autonomously transmits abnormal states related to multiple transmission paths to other devices, thereby reducing the management burden on the administrator, which increases as the number of transmission paths increases.

[0087] (Embodiment 5) Next, a configuration example of a communication system according to the fourth embodiment will be described with reference to Fig. 8. The communication system in Fig. 8 has a configuration in which a transmission path 62_2 for transmitting M-Plane data is added between the NMS 50 and the O-RU entity 30 in the communication system in Fig. 3. That is, the O-RU entity 30 transmits M-Plane data between the O-DU entity 40 via the transmission path 62_1, and transmits M-Plane data between the O-DU entity 40 and the NMS 50 via the transmission path 62_2.

[0088] 8, the O-RU entity 30 transmits an alarm to the NMS 50 without going through the O-DU entity 40. As a result, even if an abnormality occurs in the transmission path between the O-RU entity 30 and the O-DU entity 40, the NMS 50 can receive an alarm from the O-RU entity 30. As a result, the administrator can detect an abnormality between the O-RU entity 30 and the O-DU entity 40 at an early stage.

[0089] Also, in the communication system of FIG. 8, as described in embodiment 4, multiple transmission paths may be set up between the O-RU entity 30 and the O-DU entity 40 to transmit C-Plane data and U-Plane data.

[0090] (Embodiment 6) Next, a configuration example of a communication system according to the sixth embodiment will be described with reference to Fig. 9. The communication system in Fig. 9 has a configuration in which an FHM (Fronthaul Multiplexer) 80 is added to the communication system in Fig. 8. The FHM 80 copies the C-Plane data and U-Plane data received from the O-DU entity 40 and transmits them to multiple O-RU entities 30. Furthermore, the FHM 80 combines the C-Plane data and U-Plane data received from each O-RU entity 30 and transmits them to the O-DU entity 40.

[0091] The O-RU entity 30 transmits C-Plane data and U-Plane data between the O-RU entity 30 and the FHM 80 via a transmission path 71_1. Also, similar to Fig. 8, the O-RU entity 30 transmits management data to the O-DU entity 40 and the NMS 50 via a transmission path 62_1 and a transmission path 62_2.

[0092] The O-DU entity 40 transmits C-Plane data and U-Plane data between the O-DU entity 40 and the FHM 80 via a transmission path 71_2. Also, the O-DU entity 40 transmits management data between the O-DU entity 40 and the FHM 80 via a transmission path 72_1. In the transmission path 72_1, the management data may be transmitted as M-Plane data.

[0093] The NMS 50 transmits management data between the NMS 50 and the FHM 80 via the transmission path 72_2. Also, the NMS 50 may transmit management data between the NMS 50 and the O-DU entity 40 without the FHM 80, as in the case of FIG.

[0094] The FHM 80 generates statistical information and performs anomaly detection, similar to the O-RU entity 30 and the O-DU entity 40. When the FHM 80 detects an anomaly, it transmits an alarm to the NMS 50 or the O-DU entity 40.

[0095] 9, in a configuration including an FHM 80, the FHM 80 transmits an alarm to the O-DU entity 40 or the NMS 50. This allows the administrator to detect abnormalities that occur in the FHM 80 in addition to abnormalities that occur in the O-RU entity 30 and the O-DU entity 40.

[0096] Fig. 10 is a block diagram showing a configuration example of the RU device 10, the DU device 20, the O-RU entity 30, the O-DU entity 40, the NMS 50, and the FHM 80 (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 may be used to communicate with other network nodes. The network interface 1201 may include, for example, a network interface card (NIC) conforming to the IEEE 802.3 series.

[0097] The processor 1202 reads out and executes software (computer programs) from the memory 1203 to perform the processing of the RU device 10 and the like described using the flowcharts in the above-mentioned embodiments. The processor 1202 may be, for example, a microprocessor, an MPU, or a CPU. The processor 1202 may include multiple processors.

[0098] The memory 1203 is configured by a combination of volatile memory and non-volatile memory. The memory 1203 may include storage located away from the processor 1202. In this case, the processor 1202 may access the memory 1203 via an I / O (Input / Output) interface (not shown).

[0099] 10, the memory 1203 is used to store software modules. The processor 1202 reads out and executes the software modules from the memory 1203 to perform the processing of the RU device 10 and the like described in the above-mentioned embodiment.

[0100] As explained using FIG. 10, each of the processors of the RU device 10 etc. in the above-mentioned embodiments executes one or more programs including a set of instructions for causing a computer to perform the algorithms explained using the drawings.

[0101] In the above example, the program can be stored and provided to the computer using various types of non-transitory computer readable media. The non-transitory computer readable media includes various types of tangible storage media. Examples of the 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-ROM (Read Only Memory), CD-R, CD-R / W, and semiconductor memory (e.g., mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). The program may also be provided to the computer by various types of transitory computer readable media. Examples of the transitory computer readable media include electric signals, optical signals, and electromagnetic waves. The transitory computer readable media can provide the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

[0102] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present disclosure.

[0103] A part or all of the above-described embodiments can be described as, but is not limited to, the following supplementary notes. (Appendix 1) A receiving unit that receives packets from a DU (Distributed Unit) device that performs processing of a layer higher than a layer performed by an RU (Remote Unit) device among communication functions of a base station that are divided into a plurality of layers; An RU device comprising: a transmitter that transmits an alarm signal to the DU device or a management device that manages the network when statistical information regarding the received packet meets a predetermined standard. (Appendix 2) The statistical information regarding the packets is The RU device described in Appendix 1, which is information indicating that an abnormality has occurred in communication with the DU device. (Appendix 3) The statistical information regarding the packets is An RU device as described in Supplementary Note 2, which is information about a packet received during a period different from a receiving window, which is a period during which the packet transmitted from the DU device can be normally received. (Appendix 4) The transmission unit is The RU device of claim 3, further comprising: a receiving window configured to receive a packet from a receiving device that receives a packet from the receiving device; (Appendix 5) The transmission unit is The RU device of claim 3, further comprising: an RU device configured to transmit the alarm signal when a ratio of the number of packets received in a period other than the receiving window to all packets received in a period including the receiving window exceeds a predetermined threshold. (Appendix 6) The statistical information regarding the packets is 3. The RU device of claim 2, wherein the RU device is an erroneous packet. (Appendix 7) The transmission unit is 7. The RU apparatus of claim 6, further comprising: a RU device configured to transmit the alarm signal when the number of packets containing errors or a percentage of the number of packets containing errors exceeds a predetermined threshold. (Appendix 8) The receiving unit is A RU device described in any one of Supplementary Notes 1 to 7, which receives the specified criteria from the DU device or the management device. (Appendix 9) A receiving unit that receives packets from an RU device that executes processing of a layer lower than the layer executed by the DU device among the communication functions of the base station that are divided into multiple layers; A DU device comprising: a transmitter that transmits an alarm signal to a management device that manages the network when statistical information regarding the received packet meets a predetermined standard. (Appendix 10) The statistical information regarding the packets is The DU device described in Supplementary Note 9, which is information indicating that an abnormality has occurred in communication with the RU device. (Appendix 11) The statistical information regarding the packets is The DU device described in Supplementary Note 10, which is information about a packet received during a period different from a receiving window, which is a period during which the packet transmitted from the RU device can be normally received. (Appendix 12) The transmission unit is The DU device of claim 11, further comprising: a DU device configured to transmit the alarm signal when the number of packets received in a period different from the receiving window exceeds a predetermined threshold. (Appendix 13) The transmission unit is The DU device described in Appendix 11, which transmits the alarm signal when the ratio of the number of packets received in a period other than the receiving window to all packets received in a period including the receiving window exceeds a predetermined threshold. (Appendix 14) The statistical information regarding the packets is 11. The DU device of claim 10, wherein the information is about a packet including an error. (Appendix 15) The transmission unit is The DU device of claim 14, further comprising: a DU device configured to transmit the alarm signal when the number of packets containing the error or a percentage of the number of packets containing the error exceeds a predetermined threshold. (Appendix 16) The receiving unit is The DU device according to any one of Supplementary Notes 9 to 15, which receives the predetermined criteria from the management device. (Appendix 17) The transmission unit is 17. The DU device of claim 9, further comprising: a DU device configured to transmit the predetermined criteria to the RU device. (Appendix 18) A RU device that performs some layer processing among communication functions of a base station that are divided into multiple layers; A DU device that transmits and receives packets between the RU device and the DU device and executes processing in a layer higher than the layer executed by the RU device; A communication system comprising: a management device for managing a network including the RU device and the DU device, At least one of the RU device and the DU device, sending an alarm signal to the management device when statistical information regarding the received packets meets a predetermined criterion; The management device includes: A communication system that transmits the specified criterion to at least one of the RU device that transmits the alarm signal and the DU device that transmits the alarm signal. (Appendix 19) The statistical information regarding the packets is The communication system according to claim 18, wherein the information indicates that an abnormality has occurred in communication with the DU device. (Appendix 20) Among the communication functions of a base station divided into multiple layers, a packet is received from a DU (Distributed Unit) device that performs processing of a layer higher than the layer performed by an RU (Remote Unit) device, A communication method executed in an RU device, which transmits an alarm signal to the DU device or a management device that manages the network when statistical information on the received packets meets a predetermined criterion. (Appendix 21) Among the communication functions of the base station divided into multiple layers, a packet is received from an RU device that performs processing in a layer lower than the layer performed by the DU device, A communication method executed in a DU device, which transmits an alarm signal to a management device that manages the network when statistical information regarding the received packets meets a predetermined criterion. (Appendix 22) Among the communication functions of a base station divided into multiple layers, a packet is received from a DU (Distributed Unit) device that performs processing of a layer higher than the layer performed by an RU (Remote Unit) device, A program that causes a computer to transmit an alarm signal to the DU device or a management device that manages the network when statistical information regarding the received packets meets a predetermined standard. (Appendix 23) Among the communication functions of the base station divided into multiple layers, a packet is received from an RU device that performs processing in a layer lower than the layer performed by the DU device, A program that causes a computer to execute the following: when statistical information regarding the received packet satisfies a predetermined criterion, transmitting an alarm signal to a management device that manages the network.

[0104] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present disclosure. [Explanation of symbols]

[0105] 10 RU device 11 Receiving section 12 Transmitter 20 DU equipment 21 Receiving section 22 Transmitter 30 O-RU Entities 40 O-DU entities 50 NMS 61 Transmission Line 61_1 Transmission line 61_2 Transmission line 61_n Transmission line 62 Transmission Line 62_1 Transmission line 62_2 Transmission line 71_1 Transmission line 71_2 Transmission line 72_1 Transmission line 72_2 Transmission line 80 FHM

Claims

1. A receiving unit that receives packets from a DU (Distributed Unit) device that performs processing of a layer higher than the layer performed by an RU (Remote Unit) device among the communication functions of a base station that are divided into a plurality of layers; a transmission unit that transmits an alarm signal to the DU device or a management device that manages a network when statistical information about the received packet meets a predetermined criterion; The receiving unit is An RU device that receives from the DU device or the management device the specified criteria and a packet type to be measured indicating whether to measure packets that are C-Plane data, packets that are U-Plane data, or packets of both C-Plane data and U-Plane data.

2. The statistical information regarding the packets is The RU device according to claim 1 , wherein the information indicates that an abnormality has occurred in communication with the DU device.

3. The statistical information regarding the packets is The RU device according to claim 2, wherein the information is about a packet received during a period different from a receiving window, which is a period during which the packet transmitted from the DU device can be normally received.

4. The transmission unit is The RU device according to claim 3 , wherein the alarm signal is transmitted when the number of packets received in a period different from the receiving window exceeds a predetermined threshold.

5. The transmission unit is The RU device according to claim 3, wherein the alarm signal is transmitted when a ratio of the number of packets received in a period other than the receiving window to all packets received in a period including the receiving window exceeds a predetermined threshold.

6. The statistical information regarding the packets is The RU device of claim 2, wherein the information is about a packet including an error.

7. The transmission unit is The RU device of claim 6, further comprising: a RU device configured to transmit the alarm signal when the number of packets including the error or a percentage of the number of packets including the error exceeds a predetermined threshold.

8. A receiving unit that receives packets from an RU device that executes processing of a layer lower than the layer executed by the DU device among the communication functions of the base station that are divided into multiple layers; a transmitter that transmits an alarm signal to a management device that manages a network when statistical information related to the received packet satisfies a predetermined criterion; The receiving unit is The DU device receives from the management device the specified criteria and a packet type to be measured indicating whether to measure packets that are C-Plane data, packets that are U-Plane data, or packets of both C-Plane data and U-Plane data.

9. A method for measuring a communication function of a base station, the method comprising: receiving a predetermined criterion from a DU (Distributed Unit) device or a management device that performs processing of a layer higher than a layer performed by an RU (Remote Unit) device among communication functions of the base station divided into a plurality of layers; and receiving a packet type to be measured, the packet type indicating whether to measure a packet which is C-Plane data, a packet which is U-Plane data, or a packet which is both C-Plane data and U-Plane data; receiving a packet from the DU device; A communication method executed in an RU device, which transmits an alarm signal to the DU device or a management device that manages the network when statistical information on the received packets meets the specified criterion.

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