Wireless devices, intermediate devices, methods, programs

Abstract

To transmit signals appropriately based on the presence or absence of user equipment.SOLUTION: A wireless device of the present disclosure communicates with an intermediate device that duplicates or combines signals and transmits the signals between a radio access network node communicating with user equipment via the wireless device and a plurality of wireless devices, detects a PRACH signal transmitted from the user equipment, and transmits a U-Plane signal to the radio access network node via the intermediate device based on a detection result of the PRACH signal by a detection unit.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a wireless device, an intermediate device, a method, and a program.

Background Art

[0002] When a radio access network node communicates with a user equipment (UE) via a plurality of radio devices, a configuration in which a front haul multiplexer (FHM) is arranged between the radio access network node and the radio device is known. The FHM copies a signal from the radio access network node and transmits it to a plurality of slave stations for a signal on the front haul in the downlink. On the other hand, in the uplink, the FHM synthesizes signals from a plurality of slave stations and transmits them to the radio access network node. Non-Patent Document 1 describes that by arranging the FHM between the radio access network node and a plurality of radio devices, a plurality of radio devices can be accommodated as one cell.

[0003] Also, as described in Non-Patent Document 2, in the Open Radio Access Network (O-RAN) Alliance, an O-RAN front haul specification is defined as an interface between a radio access network node (O-DU: O-RAN Distributed Unit) and a radio device (O-RU; O-RAN Radio Unit). Further, in the O-RAN front haul specification, a function split of the front haul for the O-RAN U-Plane (User data plane) and the O-RAN C-Plane (Control plane) is defined.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

[0005] In the O-RAN fronthaul specification described above, when an O-DU communicates with an UE via multiple O-RUs, it is possible to place an FHM between the O-DU and the multiple O-RUs. In this case, the uplink signals transmitted from the multiple O-RUs are combined by the FHM and demodulated by the O-DU. However, if there are cells without UEs within the area covered by the multiple O-RUs, interference from other cells and equipment noise will be combined by the FHM. As a result, there was a problem in that the demodulation performance of the O-DU deteriorated compared to when only signals from cells with UEs are demodulated.

[0006] The reason for this is that uplink signals are sent from multiple O-RUs to the O-DU regardless of whether an UE is present or not.

[0007] In view of the above-mentioned problems, the purpose of this disclosure is to provide a wireless device, a method for a wireless device, and a program that enable the transmission of signals appropriately based on the presence or absence of a user device. [Means for solving the problem]

[0008] A wireless device in one aspect of the present invention includes a wireless access network node that communicates with a user device via a wireless device, a communication unit that communicates with an intermediate device that duplicates or combines signals between a plurality of wireless devices and transmits them, and a detection unit that detects a PRACH signal transmitted from a user device. Based on the detection result of the PRACH signal by the detection unit, the communication unit transmits a U-Plane signal to the wireless access network node via the intermediate device.

[0009] An intermediate device in one aspect of the present invention is an intermediate device that duplicates or combines and transmits signals between a plurality of wireless devices communicating with a user device and a wireless access network node communicating with the user device via the wireless devices, and has a communication unit that communicates with the wireless devices and the wireless access network node, the communication unit receives the detection result of a PRACH signal transmitted from the user device from the wireless device, and the communication unit transmits the U-Plane signal received from the wireless device to the wireless access network node based on the detection result.

[0010] A method in one aspect of the present invention involves a wireless access network node communicating with a user device via a wireless device, and an intermediate device that duplicates or combines signals and transmits them between a plurality of wireless devices. The intermediate device detects a PRACH signal transmitted from the user device and, based on the PRACH signal detection result, transmits a U-Plane signal to the wireless access network node via the intermediate device.

[0011] A program in one aspect of the present invention communicates with an intermediate device that duplicates or combines signals and transmits them between a wireless access network node that communicates with a user device via a wireless device and a plurality of wireless devices, detects a PRACH signal transmitted from the user device, and transmits a U-Plane signal to the wireless access network node via the intermediate device based on the PRACH signal detection result. [Effects of the Invention]

[0012] According to the present disclosure, a wireless device, an intermediate device, a method, and a program that enable appropriate signal transmission based on the presence or absence of a user device can be provided.

Brief Description of the Drawings

[0013] [Figure 1] It is a block diagram showing the configuration of the wireless device in the first embodiment. [Figure 2] It is a block diagram showing the configuration of the wireless communication system 100 in the first embodiment. [Figure 3] It is a flowchart showing the operation of the wireless device in the first embodiment. [Figure 4] It is a block diagram showing a configuration example of the wireless device in the second embodiment. [Figure 5] It is a block diagram showing the configuration of the wireless device in the third embodiment. [Figure 6] It is a block diagram showing the configuration of the wireless communication system in the third embodiment. [Figure 7] It is a flowchart showing the operation of the wireless device in the third embodiment. [Figure 8] It is a block diagram showing the configuration of the wireless device in the fourth embodiment. [Figure 9] It is a block diagram showing the configuration of the wireless communication system in the fourth embodiment. [Figure 10] It is a block diagram showing a configuration example of the wireless device in the fourth embodiment. [Figure 11] It is a flowchart showing the operation of the wireless device in the fourth embodiment. [Figure 12] It is a block diagram showing the configuration of the intermediate device in the fifth embodiment. [Figure 13] It is a block diagram showing the configuration of the wireless communication system in the fifth embodiment. [Figure 14] It is a flowchart showing the operation of the intermediate device in the fifth embodiment. [Figure 15] It is a block diagram showing an example of the intermediate device in the fifth embodiment. [Figure 16] It is a block diagram showing an example of an intermediate device in the fifth embodiment. [Figure 17] It is a block diagram showing an example of an intermediate device in the fifth embodiment. [Figure 18] It is a block diagram showing the configuration of an intermediate device in the sixth embodiment. [Figure 19] It is a block diagram showing the configuration of a wireless communication system in the sixth embodiment. [Figure 20] It is a flowchart showing the operation of an intermediate device in the sixth embodiment. [Figure 21] It is a block diagram showing the configuration of an intermediate device in the seventh embodiment. [Figure 22] It is a block diagram showing the configuration of a wireless communication system in the seventh embodiment. [Figure 23] It is a flowchart showing the operation of an intermediate device in the seventh embodiment. [Figure 24] It is a block diagram showing the configuration of an intermediate device in the eighth embodiment. [Figure 25] It is a block diagram showing the configuration of a wireless communication system in the eighth embodiment. [Figure 26] It is a flowchart showing the operation of an intermediate device in the eighth embodiment. [Figure 27] It is a block diagram showing the configuration of an intermediate device in the ninth embodiment. [Figure 28] It is a block diagram showing the configuration of a wireless communication system in the ninth embodiment. [Figure 29] It is a flowchart showing the operation of an intermediate device in the ninth embodiment.

Embodiments for Carrying Out the Invention

[0014] Next, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In each of the drawings and embodiments described in the specification, components having the same functions are given the same reference numerals. [First Embodiment] Figure 1 is a block diagram showing the configuration of the wireless device 1 in the first embodiment of this disclosure.

[0015] Referring to Figure 1, the wireless device 1 in the first embodiment of this disclosure comprises a communication unit 11 and a detection unit 12.

[0016] Figure 2 is a block diagram showing the configuration of the wireless communication system 100 in the first embodiment of this disclosure.

[0017] Referring to Figure 2, the wireless communication system 100 in the first embodiment of this disclosure comprises a plurality of wireless devices 1, a user device 10, an intermediate device 30, and a wireless access network node 40.

[0018] Wireless device 1 is a device that communicates with user device 10 and processes radio frequencies.

[0019] The communication unit 11 of the wireless device 1 transmits and receives data with other devices. The communication unit 11 transmits data sent from the user device 10 to the wireless access network node 40 via the intermediate device 30.

[0020] The detection unit 12 of the wireless device 1 detects the PRACH (Physical Random Access Channel) signal transmitted from the user device 10. The PRACH signal is used when the user device 10 establishes a connection with a cell due to initial access or handover, or when it performs resynchronization.

[0021] Furthermore, the communication unit 11 transmits a U-Plane signal to the wireless access network node 40 based on the detection result of the PRACH signal by the detection unit 12.

[0022] The user device 10 communicates with the wireless access network node 40 via the wireless device 1 and the intermediate device 30.

[0023] The intermediate device 30 is positioned between the multiple wireless devices 1 and the wireless access network node 40. The intermediate device 30 duplicates or combines signals from the wireless devices 1 and the wireless access network node 40 and transmits them. For example, the intermediate device 30 combines the uplink signals from the multiple wireless devices 1 (signals from the wireless devices 1 to the wireless access network node 40) and transmits them to the wireless access network node 40. Alternatively, for example, the intermediate device 30 duplicates the downlink signals from the wireless access network node 40 (signals from the wireless access network node 40 to the wireless devices 1) and transmits them to the multiple wireless devices 1.

[0024] The wireless access network node 40 communicates with the user device 10 via the wireless device 1 and the intermediate device 30.

[0025] Figure 3 is a flowchart showing the operation of the wireless device 1 in the first embodiment of this disclosure.

[0026] In step S1001, the detection unit 12 of the wireless device 1 detects the PRACH signal transmitted from the user device 10.

[0027] In step S1002, the communication unit 11 of the wireless device 1 transmits a U-Plane signal based on the detection result of the PRACH signal by the detection unit 12. Specifically, the communication unit 11 transmits the U-Plane signal to the wireless access network node 40 via the intermediate device 30.

[0028] In the first embodiment, the wireless device 1 transmits a U-Plane signal to the wireless access network node 40 via the intermediate device 30 based on the detection result of the PRACH signal transmitted from the user device 10.

[0029] Therefore, the wireless device 1 in the first embodiment can transmit a U-Plane signal based on the detection result of the PRACH signal. As a result, the wireless device 1 can transmit signals appropriately based on the presence or absence of user equipment. For example, if there is no user equipment connected to the wireless device 1, the wireless device 1 can choose not to transmit a U-Plane signal. This prevents the problem of interference from other cells and equipment noise being combined in the intermediate device in cells where no user equipment exists, which would degrade the demodulation performance at the wireless access network node (e.g., O-DU). [Second Embodiment] The wireless device 1 and wireless communication system 100 in a second embodiment of this disclosure will be described below.

[0030] The wireless device 1 in this embodiment has the same configuration as the wireless device 1 in the first embodiment. The wireless communication system 100 in this embodiment has the same configuration as the wireless communication system 100 in the first embodiment.

[0031] The wireless communication system 100 in the second embodiment of this disclosure comprises a plurality of wireless devices 1, a user device 10, an intermediate device 30, and a wireless access network node 40.

[0032] Wireless device 1 is a device that communicates with user device 10 and processes radio frequencies. In Figure 2, one user device is connected to one wireless device, but multiple user devices may be connected to one wireless device. Wireless device 1 also communicates with intermediate device 30. Wireless device 1 communicates with wireless access network node 40 via intermediate device 30.

[0033] Furthermore, the wireless device 1 may be the O-RU described above, but is not limited thereto. If the wireless device 1 is an O-RU, it may have a configuration such as that shown in Figure 4. Referring to Figure 4, the wireless device 1 includes Analog Beamforming 201, Analog to Digital 203, Filtering 204, Digital Beam forming 206, Re Demapping 208, and Detection 212 as PRACH functions. The wireless device 1 also includes Analog Beamforming 202, Analog to Digital 203, FFT and CP removal 205, Digital Beam forming 207, and IQ Compression 211 as PUxCH functions. Note that Figure 4 is a modified version of the O-RAN fronthaul specification described in Non-Patent Document 2. The change is that the wireless device 1 (O-RU) possesses the detection function that the wireless access network node (O-DU) has in the O-RAN fronthaul specification described in Non-Patent Document 2.

[0034] The communication unit 11 of the wireless device 1 receives and transmits data from other devices. The communication unit 11 transmits data sent from the user device 10 to the wireless access network node 40 via the intermediate device 30. For example, based on an O-RAN C-Plane signal sent from the wireless access network node 40, an O-RAN U-Plane signal is transmitted from the user device 10. In this case, the communication unit 11 transmits the U-Plane signal to the wireless access network node 40 via the intermediate device 30. For example, the communication unit 11 corresponds to the IQ Compression 211 in Figure 4. Note that a C-Plane signal is a signal containing C-Plane packets. A U-Plane signal is a signal containing U-Plane packets.

[0035] The detection unit 12 of the wireless device 1 detects that the user device 10 has transmitted a PRACH signal. For example, the detection unit 12 corresponds to Detection 212 in Figure 4.

[0036] Furthermore, the communication unit 11 transmits a U-Plane signal to the wireless access network node 40 based on the detection result of the PRACH signal by the detection unit 12. For example, if the detection unit 12 detects a PRACH signal, the communication unit 11 may transmit a U-Plane signal to the wireless access network node 40. In this case, if the detection unit 12 does not detect a PRACH signal, the communication unit 11 does not transmit a U-Plane signal to the wireless access network node 40.

[0037] Furthermore, the data transmitted from the user device 10 to the wireless access network node 40 via the communication unit 11 is not limited to U-Plane signals.

[0038] The user device 10 communicates with the wireless access network node 40 via the wireless device 1 and the intermediate device 30. The user device 10 may be the UE described above, but is not limited thereto.

[0039] The intermediate device 30 is positioned between the multiple wireless devices 1 and the wireless access network node 40. The intermediate device 30 duplicates or combines signals from the wireless devices 1 and the wireless access network node 40 and transmits them. For example, the intermediate device 30 duplicates downlink signals (signals from the wireless access network node 40 to the wireless devices 1) and transmits them to the multiple wireless devices 1. The intermediate device 30 also combines uplink signals (signals from the wireless devices 1 to the wireless access network node 40) from the multiple wireless devices 1 and transmits them to the wireless access network node 40. Furthermore, the combination of uplink signals is not limited to simple combination (e.g., calculation of sum or average), but may also be selective combination (e.g., simple combination of selected uplink signals, or simple combination of multiple uplink signals with weighting). The intermediate device 30 may be, but is not limited to, the fronthaul multiplexer (FHM) described above.

[0040] The wireless access network node 40 communicates with the user device 10 via the wireless device 1 and the intermediate device 30. The wireless access network node 40 may be, but is not limited to, the O-DU described above.

[0041] The operation of the wireless device 1 in this embodiment is the same as that of the wireless device 1 in the first embodiment.

[0042] In step S1001 of Figure 3, the detection unit 12 of the wireless device 1 detects the PRACH signal transmitted from the user device 10. The detection unit 12 may transmit the PRACH signal detection result to the communication unit 11. The PRACH signal detection result may include, but is not limited to, the presence or absence of the PRACH signal and the time it was detected. For example, if the detection unit 12 detects a PRACH signal, it may output a signal to the communication unit 11 indicating that a PRACH signal has been detected.

[0043] In step S1002, the communication unit 11 of the wireless device 1 transmits a U-Plane signal based on the detection result of the PRACH signal. Specifically, the communication unit 11 transmits the U-Plane signal to the wireless access network node 40 via the intermediate device 30. The communication unit 11 may acquire the detection result of the PRACH signal from the detection unit 12 as a signal or the like, but the method of acquisition is not limited to this. Also, the signal output by the detection unit 12 may be a signal that controls the transmission of the U-Plane signal by the communication unit 11, instead of a signal indicating the detection result of the PRACH signal.

[0044] The timing at which the communication unit 11 transmits the U-Plane signal follows, for example, the transmission timing information for the U-Plane signal. This transmission timing information is included, for example, in the C-Plane signal transmitted from the wireless access network node 40 via the intermediate device 30.

[0045] In the second embodiment, the wireless device 1 transmits a U-Plane signal to the wireless access network node 40 via the intermediate device 30 based on the detection result of the PRACH signal transmitted from the user device 10.

[0046] As a result, this embodiment also achieves the same effects as the first embodiment. [Third Embodiment] Next, a third embodiment of this disclosure will be described with reference to the drawings. The wireless device 2 of the third embodiment differs from the wireless device 1 of the second embodiment in that the wireless device 1 of the second embodiment further includes a recording unit 13.

[0047] The following will provide a detailed explanation with reference to the drawings. In the following, components similar to those in the second embodiment will be denoted by the same reference numerals, and their descriptions will be omitted.

[0048] Figure 5 is a block diagram showing the configuration of the wireless device 2 in the third embodiment of this disclosure.

[0049] Referring to Figure 5, the wireless device 2 in the third embodiment of this disclosure comprises a communication unit 11, a detection unit 12, and a recording unit 13.

[0050] Figure 6 is a block diagram showing the configuration of the wireless communication system 101 in the third embodiment of this disclosure.

[0051] Referring to Figure 6, the wireless communication system 101 in the third embodiment of this disclosure comprises a plurality of wireless devices 2, a user device 10, an intermediate device 30, and a wireless access network node 40.

[0052] The detection unit 12 of the wireless device 2 detects the PRACH signal transmitted from the user device 10. The detection unit 12 notifies the recording unit 13 of the PRACH signal detection result. Here, the detection unit 12 may notify the detection result only when it detects a PRACH signal.

[0053] The recording unit 13 of the wireless device 2 receives notification indicating the detection result of the PRACH signal by the detection unit 12. The recording unit 13 then acquires the detection result of the PRACH signal by the detection unit 12. Furthermore, the recording unit 13 records the detection result of the PRACH signal by the detection unit 12. For example, the recording unit 13 may, but is not limited to, recording the detection result of the PRACH signal by the detection unit 12 in memory. For example, the recording unit 13 may record the detection result only when the detection unit 12 has detected a PRACH signal. The recording unit 13 also outputs a signal based on the detection result of the PRACH signal by the detection unit 12. For example, the recording unit 13 may transmit a signal to the communication unit 11 indicating that the detection unit 12 has detected a PRACH signal. Alternatively, the recording unit 13 does not need to output a signal if it receives a detection result indicating that the detection unit 12 did not detect a PRACH signal. Or, if the recording unit 13 does not receive a detection result indicating that the detection unit 12 detected a PRACH signal, it does not need to output a signal. Furthermore, the recording unit 13 may output a signal based on the detection results of past PRACH signals by the detection unit 12.

[0054] Next, the communication unit 11 transmits a U-Plane signal to the wireless access network node 40 based on the signal output from the recording unit 13. For example, the communication unit 11 may transmit a U-Plane signal to the wireless access network node 40 when it obtains a signal from the recording unit 13 indicating that the detection unit 12 has detected a PRACH signal. Alternatively, the communication unit 11 may not transmit a U-Plane signal to the wireless access network node 40 if it does not obtain such a signal from the recording unit 13. Or, the communication unit 11 may not transmit a U-Plane signal to the wireless access network node 40 when it obtains a signal from the recording unit 13 indicating that the detection unit 12 has not detected a PRACH signal.

[0055] Figure 7 is a flowchart showing the operation of the wireless device 2 in the third embodiment of this disclosure.

[0056] In step S2001, the detection unit 12 of the wireless device 2 detects the PRACH signal transmitted from the user device 10. The detection unit 12 notifies the recording unit 13 of the PRACH signal detection result. The PRACH signal detection result may include, but is not limited to, the presence or absence of the PRACH signal and the time it was detected. For example, if the detection unit 12 detects a PRACH signal, it may output a signal to the recording unit 13 indicating that a PRACH signal has been detected. The detection unit 12 may also notify the communication unit 11 of the PRACH signal detection result.

[0057] In step S2002, the recording unit 13 of the wireless device 2 records the detection result of the PRACH signal by the detection unit 12.

[0058] In step S2003, the recording unit 13 of the wireless device 2 outputs a signal based on the detection result of the PRACH signal by the detection unit 12. The signal output by the recording unit 13 may include information indicating the detection result of the PRACH signal by the detection unit 12. The signal output by the recording unit 13 may also be a signal that controls the transmission of the U-Plane signal by the communication unit 11. Specifically, if the detection unit 12 detects a PRACH signal, the recording unit 13 may output a control signal to the communication unit 11 to control the transmission of the U-Plane signal. If the detection unit 12 does not detect a PRACH signal, the recording unit 13 does not need to output a control signal to the communication unit 11 to control the transmission of the U-Plane signal. Alternatively, if the detection unit 12 does not detect a PRACH signal, the recording unit 13 may output a control signal to the communication unit 11 to control the transmission of the U-Plane signal.

[0059] In step S2004, the communication unit 11 of the wireless device 2 transmits a U-Plane signal based on the detection result of the PRACH signal. Specifically, the communication unit 11 transmits the U-Plane signal to the wireless access network node 40 via the intermediate device 30. The communication unit 11 obtains the detection result of the PRACH signal by receiving a signal output from the recording unit 13. The communication unit 11 may also obtain whether or not the U-Plane signal can be transmitted by receiving a signal output from the recording unit 13. Alternatively, the communication unit 11 may obtain the detection result of the PRACH signal by receiving a signal output by the detection unit 12.

[0060] The timing at which the communication unit 11 transmits the U-Plane signal follows, for example, the transmission timing information for the U-Plane signal. This transmission timing information is included, for example, in the C-Plane signal transmitted from the wireless access network node 40 via the intermediate device 30. Therefore, the recording unit 13 may record the detection result of the PRACH signal by the detection unit 12 and the transmission timing information, and when the transmission timing indicated by the transmission timing information approaches, it may output a signal to the communication unit 11 indicating the detection result of the PRACH signal. In this case, the recording unit 13 may output a signal to the communication unit 11 that controls the transmission of the U-Plane signal instead of the signal indicating the detection result of the PRACH signal.

[0061] In the third embodiment, the wireless device 2 records the detection result of the PRACH signal transmitted from the user device 10, and based on the signal output based on the detection result, transmits a U-Plane signal to the wireless access network node 40 via the intermediate device 30.

[0062] Therefore, the wireless device 2 in the third embodiment can record the detection result of the PRACH signal and transmit a U-Plane signal based on the signal output based on the detection result.

[0063] As a result, this embodiment also achieves the same effects as the first embodiment. [Fourth Embodiment] Next, a fourth embodiment of this disclosure will be described with reference to the drawings. The wireless device 3 of the fourth embodiment differs from the wireless device 2 of the third embodiment in that the wireless device 2 of the third embodiment further includes a transmission control unit 14.

[0064] The following will provide a detailed explanation with reference to the drawings. In the following, components similar to those in the third embodiment will be denoted by the same reference numerals, and their descriptions will be omitted.

[0065] Figure 8 is a block diagram showing the configuration of the wireless device 3 in the fourth embodiment of this disclosure.

[0066] Referring to Figure 8, the wireless device 3 in the fourth embodiment of this disclosure comprises a communication unit 11, a detection unit 12, a recording unit 13, and a transmission control unit 14.

[0067] Figure 9 is a block diagram showing the configuration of the wireless communication system 102 in the fourth embodiment of this disclosure.

[0068] Referring to Figure 9, the wireless communication system 102 in the fourth embodiment of this disclosure comprises a wireless device 3, a user device 10, an intermediate device 30, and a wireless access network node 40. For example, the wireless communication system 102 may have the configuration shown in Figure 10, but is not limited thereto. Referring to Figure 10, the wireless device 3 comprises an Analog Beamforming 201, an Analog Beamforming 202, an Analog to Digital 203, a Filtering 204, an FFT and CP removal 205, a Digital Beam forming 206, a Digital Beam forming 207, a Re Demapping 208, an IQ Compression 211, a Detection 212, a recording unit 213, a transmission control unit 214, and an O-RAN C-Plane analysis unit 215. Referring to Figure 10, the user device 10 comprises a PRACH transmission unit 110 and a PUSCH transmission unit 120. Referring to Figure 10, the intermediate device 30 comprises an O-RAN C-Plane packet copying unit 301, a packet determination unit 302, and an O-RAN U-Plane synthesis unit 303. Referring to Figure 10, the wireless access network node 40 comprises a PRACH O-RAN C-Plane packet creation unit 401, a PUSCH O-RAN C-Plane packet creation unit 402, an O-RAN C-Plane packet transmission unit 403, a Detection result receiving unit 404, and an O-RAN U-Plane packet receiving unit 405. The wireless device 4 has the same configuration as the wireless device 3.

[0069] The recording unit 13 of the wireless device 3 receives notification indicating the detection result of the PRACH signal by the detection unit 12. The recording unit 13 records the detection result of the PRACH signal by the detection unit 12. The recording unit 13 also outputs a signal to the transmission control unit 14 based on the detection result of the PRACH signal by the detection unit 12. For example, this signal may include a flag indicating whether or not the communication unit 11 will transmit a U-Plane signal. The signal may also include information indicating the detection result of the PRACH signal by the detection unit 12. The recording unit 13 may not output a signal if the detection unit 12 does not detect a PRACH signal.

[0070] The transmission control unit 14 of the wireless device 3 controls the transmission of the U-Plane signal by the communication unit 11 based on the signal received from the recording unit 13. For example, if the received signal indicates that a flag indicating that the communication unit 11 should transmit the U-Plane signal is turned on, the transmission control unit 14 permits the communication unit 11 to transmit the U-Plane signal. On the other hand, if the flag is turned off, the transmission control unit 14 does not permit the communication unit 11 to transmit the U-Plane signal.

[0071] Furthermore, the communication unit 11 transmits a U-Plane signal to the wireless access network node 40 based on the control by the transmission control unit 14.

[0072] Furthermore, the transmission control unit 14 may also check whether a U-Plane signal has been transmitted from the communication unit 11 to the intermediate device 30. If no U-Plane signal is transmitted from the communication unit 11 to the intermediate device 30 for a certain period of time, the transmission control unit 14 may control the communication unit 11 not to transmit the U-Plane signal. In this case, the transmission control unit 14 may also prohibit the communication unit 11 from transmitting the U-Plane signal until it receives a signal again from the recording unit 13. In other words, the transmission control unit 14 may only allow the communication unit 11 to transmit the U-Plane signal after it has received a signal again from the recording unit 13.

[0073] Figure 11 is a flowchart showing the operation of the wireless device 3 in the fourth embodiment of this disclosure.

[0074] In step S3001, the detection unit 12 of the wireless device 3 detects the PRACH signal transmitted from the user device 10. The detection unit 12 corresponds to Detection 212 in Figure 10. For example, referring to Figure 10, the PRACH signal transmitted from the PRACH transmission unit 110 of the user device 10 is received by the wireless device 3. The PRACH signal received by the wireless device 3 is then analyzed in the following order: Analog Beamforming 201, Analog to Digital 203, Filtering 204, Digital Beam forming 206, and Re Demapping 208, and is detected in Detection 212.

[0075] In step S3002, the recording unit 13 of the wireless device 3 records the detection result of the PRACH signal by the detection unit 12. The recording unit 13 corresponds to the recording unit 213 in Figure 10. For example, referring to Figure 10, the detection result of the PRACH signal by Detection 212 is notified to the recording unit 213. The recording unit 213 then records the detection result.

[0076] In step S3003, the recording unit 13 of the wireless device 3 outputs a signal to the transmission control unit 14 based on the detection result of the PRACH signal by the detection unit 12. For example, this signal includes a flag indicating whether or not the communication unit 11 will transmit a U-Plane signal based on the detection result of the PRACH signal by the detection unit 12. Referring to Figure 10, for example, the recording unit 213 outputs a signal including this flag to the transmission control unit 214.

[0077] In step S3004, the transmission control unit 14 of the wireless device 3 controls the transmission of the U-Plane signal in the communication unit 11 based on the signal received from the recording unit 13. The transmission control unit 14 corresponds to the transmission control unit 214 in Figure 10. Referring to Figure 10, for example, the transmission control unit 214 controls the transmission of the U-Plane signal by the IQ Compression 211.

[0078] In step S3005, the communication unit 11 of the wireless device 3 transmits a U-Plane signal based on the control of the transmission control unit 14. Specifically, the communication unit 11 transmits the U-Plane signal to the wireless access network node 40 via the intermediate device 30. For example, the communication unit 11 corresponds to the IQ Compression 211 in Figure 10. Referring to Figure 10, for example, the IQ Compression 211 transmits the U-Plane signal to the intermediate device 30. The U-Plane signal received by the intermediate device 30 is transmitted to the O-RAN U-Plane synthesis unit 303 via the packet determination unit 302 of the intermediate device 30. The O-RAN U-Plane synthesis unit 303 then synthesizes the received U-Plane signal with the U-Plane signal transmitted from other wireless devices 4 connected to the intermediate device 30.

[0079] Furthermore, the communication unit 11 may transmit the detection result of the PRACH signal to the intermediate device 30. In this case, specifically, the packet determination unit 302 of the intermediate device 30 routes the U-Plane packet and the detection result packet. At this time, the packet determination unit 302 may determine that the received packet is a C-Plane packet when eCPRI message=2, as described in Non-Patent Literature 2. Alternatively, the packet determination unit 302 may determine that the received packet is a U-Plane packet when eCPRI message=0. The detection result packet may be defined as O-RAN C-Plane Section Type 8 in the O-RAN Alliance. If the packet determination unit 302 determines that the received packet is a U-Plane packet, it forwards the received packet to the O-RAN U-Plane synthesis unit 303. The O-RAN U-Plane synthesis unit 303 buffers the U-Plane packets of the same slot in the wireless device 3 and the wireless device 4. Then, the O-RAN U-Plane synthesis unit 303 adds up the IQ data in these U-Plane packets and synthesizes them. If the packet determination unit 302 determines that the received packet is a detection result, it forwards it to the Detection result receiving unit 404 of the wireless access network node 40.

[0080] Subsequently, the O-RAN U-Plane packet receiving unit 405 of the wireless access network node 40 receives the U-Plane signal synthesized in the intermediate device 30.

[0081] In the fourth embodiment, the wireless device 3 controls the transmission of the U-Plane signal based on a signal output based on the detection result of the PRACH signal transmitted from the user device 10.

[0082] Therefore, in the fourth embodiment, the wireless device 3 can control the transmission of the U-Plane signal based on the detection result of the PRACH signal. As a result, it can appropriately transmit signals based on the presence or absence of user devices, similar to the first to third embodiments. Furthermore, in this embodiment, if the wireless device 3 does not transmit a U-Plane signal for a certain period of time, it can be controlled so that the wireless device 3 does not transmit a U-Plane signal to the wireless access network node 40. As a result, power saving of the wireless device is also possible. [Fifth Embodiment] Next, a fifth embodiment of the present disclosure will be described with reference to the drawings. The wireless device 1 in this embodiment has the same configuration as the wireless device 1 in the first embodiment. This embodiment differs from the first embodiment in that the intermediate device controls the transmission of the U-Plane signal.

[0083] Figure 12 is a block diagram showing the configuration of the intermediate device 31 in the fifth embodiment of this disclosure.

[0084] Referring to Figure 12, the intermediate device 31 in the fifth embodiment of this disclosure includes a communication unit 311.

[0085] Figure 13 is a block diagram showing the configuration of the wireless communication system 103 in the fifth embodiment of this disclosure.

[0086] Referring to Figure 13, the wireless communication system 103 in the fifth embodiment of this disclosure comprises a plurality of wireless devices 1, a user device 10, an intermediate device 31, and a wireless access network node 40.

[0087] The communication unit 11 of the wireless device 1 receives and transmits data from other devices. The communication unit 11 receives the PRACH signal transmitted from the user device 10.

[0088] The detection unit 12 of the wireless device 1 detects that the user device 10 has transmitted a PRACH signal. The detection unit 12 notifies the communication unit 11 of the wireless device 1 of the PRACH signal detection result.

[0089] Furthermore, the communication unit 11 of the wireless device 1 acquires the detection result of the PRACH signal from the detection unit 12. The communication unit 11 transmits the detection result of the PRACH signal to the communication unit 311 of the intermediate device 31.

[0090] The communication unit 311 of the intermediate device 31 communicates with the wireless device 1 and the wireless access network node 40. The communication unit 311 receives the detection result of the PRACH signal transmitted from the user device 10 from the wireless device 1. Here, the detection result of the PRACH signal may be information indicating whether or not the detection unit 12 of the wireless device 1 detected it, or it may be the PRACH signal itself.

[0091] Furthermore, the communication unit 311 of the intermediate device 31 transmits the U-Plane signal sent from the user device 10 to the wireless access network node 40 based on the detection result of the PRACH signal. For example, if the detection unit 12 of the wireless device 1 detects the PRACH signal, the communication unit 311 may transmit the U-Plane signal to the wireless access network node 40. If the detection unit 12 of the wireless device 1 does not detect the PRACH signal, the communication unit 311 may not transmit the U-Plane signal to the wireless access network node 40.

[0092] Figure 14 is a flowchart showing the operation of the wireless device 1 and the intermediate device 31 in the fifth embodiment of this disclosure.

[0093] In step S4001, the detection unit 12 of the wireless device 1 detects the PRACH signal transmitted from the user device 10. The detection unit 12 notifies the communication unit 11 of the PRACH signal detection result. The PRACH signal detection result may include, but is not limited to, the presence or absence of the PRACH signal and the time it was detected. For example, if the detection unit 12 detects a PRACH signal, it may output a signal to the communication unit 11 indicating that a PRACH signal has been detected. Alternatively, the detection unit 12 may output the detected PRACH signal itself to the communication unit 11 as the PRACH signal detection result.

[0094] In step S4002, the communication unit 11 of the wireless device 1 transmits the detection result of the PRACH signal to the communication unit 311 of the intermediate device 31. Here, the communication unit 11 of the wireless device 1 obtains the detection result of the PRACH signal from the detection unit 12.

[0095] In step S4003, the communication unit 311 of the intermediate device 31 receives the detection result of the PRACH signal transmitted from the user device 10 from the wireless device 1.

[0096] In step S4004, the communication unit 311 of the intermediate device 31 transmits a U-Plane signal based on the detection result of the PRACH signal. Specifically, the communication unit 311 transmits the U-Plane signal to the wireless access network node 40.

[0097] Next, a more specific example of this embodiment will be described.

[0098] The first embodiment of this model will be described using Figure 15. The intermediate device 31 in this embodiment may include a recording unit 313, as shown in Figure 15. The operation of this embodiment will be described below.

[0099] The communication unit 311 of the intermediate device 31 further notifies the recording unit 313 of the detection result of the PRACH signal transmitted from the user device 10.

[0100] The recording unit 313 of the intermediate device 32 receives notification from the communication unit 311 regarding the detection result of the PRACH signal by the detection unit 12 of the wireless device 1. The recording unit 313 records the detection result of the PRACH signal. For example, the recording unit 313 may, but is not limited to, record the detection result of the PRACH signal in memory. For example, the recording unit 313 may record the detection result only when the detection unit 12 of the wireless device 1 has detected the PRACH signal. The recording unit 313 also outputs a signal based on the detection result of the PRACH signal. For example, the recording unit 313 may transmit a signal to the communication unit 311 indicating that the detection unit 12 of the wireless device 1 has detected the PRACH signal. The recording unit 313 does not have to output a signal if the detection unit 12 of the wireless device 1 has not detected the PRACH signal. In addition, the recording unit 313 may output a signal based on past PRACH signal detection results by the detection unit 12 of the wireless device 1.

[0101] Furthermore, the communication unit 311 of the intermediate device 31 transmits a U-Plane signal to the wireless access network node 40 based on the signal output from the recording unit 313. For example, if the detection unit 12 of the wireless device 1 obtains a signal from the recording unit 313 indicating that it has detected a PRACH signal, the communication unit 311 may transmit a U-Plane signal to the wireless access network node 40. If no signal is obtained from the recording unit 313, the communication unit 311 may not transmit a U-Plane signal to the wireless access network node 40. Also, if the detection unit 12 of the wireless device 1 obtains a signal from the recording unit 313 indicating that it has not detected a PRACH signal, the communication unit 311 may not transmit a U-Plane signal to the wireless access network node 40.

[0102] Next, a second embodiment of this model will be described using Figure 16. In this embodiment, the intermediate device 31 may include a transmission control unit 314, as shown in Figure 16. The operation of this embodiment will be described below.

[0103] The recording unit 313 of the intermediate device 31 further outputs a signal to the transmission control unit 314 based on the detection result of the PRACH signal by the detection unit 12 of the wireless device 1. For example, this signal includes a flag indicating whether or not the communication unit 311 will transmit a U-Plane signal based on the detection result of the PRACH signal by the detection unit 12. The signal may also include the detection result of the PRACH signal by the detection unit 12. The recording unit 313 does not need to output a signal if the detection unit 12 does not detect a PRACH signal.

[0104] The transmission control unit 314 of the intermediate device 31 controls the transmission of the U-Plane signal by the communication unit 311 based on the signal received from the recording unit 313. For example, if the received signal indicates that a flag indicating that the communication unit 311 should transmit the U-Plane signal is turned on, the transmission control unit 314 permits the communication unit 311 to transmit the U-Plane signal. On the other hand, if the flag is turned off, the transmission control unit 314 does not permit the communication unit 311 to transmit the U-Plane signal.

[0105] Furthermore, the communication unit 311 transmits a U-Plane signal to the wireless access network node 40 based on the control of the transmission control unit 314.

[0106] Next, a third embodiment of this model will be described using Figure 17. The intermediate device 31 in this embodiment may include a combining section 315, as shown in Figure 17. The operation of this embodiment will be described below. The combining unit 315 of the intermediate device 31 combines the U-Plane signals received by the communication unit 311 based on the detection result of the PRACH signal by the detection unit 12 of the wireless device 1. The combining unit 315 may also combine the U-Plane signals based on the detection result of the PRACH signal acquired from the recording unit 313. For example, the combining unit 315 may combine the U-Plane signals received from the wireless device that transmitted the PRACH signal detected by the detection unit 12. In this case, U-Plane signals transmitted from wireless devices that did not transmit the PRACH signal detected by the detection unit 12 may not be combined. The combining unit 315 may also acquire the detection result of the PRACH signal from the communication unit 311.

[0107] Furthermore, the communication unit 311 transmits the U-Plane signal synthesized by the synthesis unit 315 to the wireless access network node 40. Note that the data transmitted from the user device 10 to the wireless access network node 40 via the wireless device 20 is not limited to the U-Plane signal.

[0108] As described above, in the fifth embodiment, the intermediate device 31 transmits a U-Plane signal based on the detection result of the PRACH signal transmitted from the user device 10.

[0109] In this embodiment, the function of the communication unit of the intermediate device, namely the function of transmitting a U-Plane signal based on the PRACH detection result, is a function not defined in the current O-RAN Alliance (specifications described in Non-Patent Document 2). In this embodiment, by assigning this function to the intermediate device instead of the wireless device, in addition to the same effects as in the first embodiment, the wireless device can be configured without making significant changes to the functions defined in the current O-RAN Alliance (specifications described in Non-Patent Document 2). [Sixth Embodiment] Next, a sixth embodiment of the present disclosure will be described with reference to the drawings. This embodiment differs from the first to fifth embodiments in that the detection unit, which was provided in the wireless device in the first to fifth embodiments, is provided in the intermediate device.

[0110] Figure 18 is a block diagram showing the configuration of the intermediate device 32 in the sixth embodiment of this disclosure.

[0111] Referring to Figure 18, the intermediate device 32 in the sixth embodiment of this disclosure comprises a communication unit 311 and a detection unit 312.

[0112] Figure 19 is a block diagram showing the configuration of the wireless communication system 104 in the sixth embodiment of this disclosure.

[0113] Referring to Figure 19, the wireless communication system 104 in the sixth embodiment of this disclosure comprises a plurality of wireless devices 20, a user device 10, an intermediate device 32, and a wireless access network node 40.

[0114] The wireless device 20 is a device that communicates with the user device 10 and processes radio frequencies. In Figure 19, one user device is connected to one wireless device 20, but multiple user devices may be connected to one wireless device 20. The wireless device 20 may be the O-RU described above, but is not limited to this.

[0115] The user device 10 communicates with the wireless access network node 40 via the wireless device 20 and the intermediate device 32. The user device 10 may be the UE described above, but is not limited thereto.

[0116] The intermediate device 32 is positioned between the multiple wireless devices 20 and the wireless access network node 40. The intermediate device 32 duplicates or combines signals from the wireless devices 20 and the wireless access network node 40 and transmits them. For example, the intermediate device 32 combines uplink signals (signals from the wireless devices 20 to the wireless access network node 40) from the multiple wireless devices 20 and transmits them to the wireless access network node 40. The combination of uplink signals by the intermediate device 32 is not limited to simple combination (e.g., calculation of sum or average), but may also be selective combination (e.g., simple combination of selected uplink signals, or simple combination of multiple uplink signals with weighting). Also, for example, the intermediate device 32 duplicates downlink signals (signals from the wireless access network node 40 to the wireless devices 20) from the wireless access network node 40 and transmits them to the multiple wireless devices 20. The intermediate device 32 may be, but is not limited to, the FHM described above.

[0117] The communication unit 311 of the intermediate device 32 receives and transmits data from other devices. The communication unit 311 receives data transmitted from multiple wireless devices 20. The data that the communication unit 311 receives from multiple wireless devices 20 includes, for example, PRACH signals and U-Plane signals. The communication unit 311 transmits data transmitted from the user device 10 via the wireless device 20 to the wireless access network node 40. For example, if an O-RAN U-Plane signal is transmitted from the user device 10 via the wireless device 20 based on an O-RAN C-Plane signal sent from the wireless access network node 40, the communication unit 311 transmits the U-Plane signal to the wireless access network node 40.

[0118] The detection unit 312 of the intermediate device 32 detects the PRACH signal transmitted from the user device 10 via the wireless device 20.

[0119] Furthermore, the communication unit 311 transmits a U-Plane signal to the wireless access network node 40 based on the detection result of the PRACH signal by the detection unit 312. Note that the data transmitted from the user device 10 to the wireless access network node 40 via the wireless device 20 is not limited to the U-Plane signal. The wireless access network node 40 communicates with the user device 10 via the wireless device 20 and the intermediate device 32. The wireless access network node 40 may be, but is not limited to, the O-DU described above.

[0120] Figure 20 is a flowchart showing the operation of the intermediate device 31 in the sixth embodiment of this disclosure.

[0121] In step S5001, the detection unit 312 of the intermediate device 32 detects the PRACH signal transmitted from the user device 10 via the wireless device 20. The detection unit 312 may transmit the detection result of the PRACH signal to the communication unit 311. The detection result of the PRACH signal may include, but is not limited to, the presence or absence of the PRACH signal and the time it was detected. For example, if the detection unit 312 detects a PRACH signal, it may output a signal to the communication unit 311 that includes information indicating that a PRACH signal has been detected.

[0122] In step S5002, the communication unit 311 of the intermediate device 32 transmits a U-Plane signal based on the detection result of the PRACH signal. Specifically, the communication unit 311 receives the U-Plane signal transmitted from the wireless device 20 and transmits it to the wireless access network node 40. The timing at which the communication unit 311 transmits the U-Plane signal follows, for example, the transmission timing information of the U-Plane signal. This transmission timing information is included, for example, in the C-Plane signal transmitted from the wireless access network node 40 via the intermediate device 32.

[0123] As described above, in the sixth embodiment, the intermediate device 32 transmits a U-Plane signal to the wireless access network node 40 based on the detection result of the PRACH signal transmitted from the user device 10.

[0124] Therefore, in the sixth embodiment, the intermediate device 32 can transmit a U-Plane signal to the wireless access network node 40 based on the detection result of the PRACH signal. As a result, the intermediate device 32 can transmit signals appropriately based on the presence or absence of user devices. For example, if there are no user devices connected to the wireless device 20 connected to the intermediate device 32, the intermediate device 32 can choose not to transmit the U-Plane signal received from the wireless device 20. This prevents the problem of interference from other cells and device noise being combined in the intermediate device in cells where no user devices exist, which would degrade the demodulation performance at the wireless access network node (e.g., O-DU). [Seventh Embodiment] Next, a seventh embodiment of this disclosure will be described with reference to the drawings. The intermediate device 33 of the seventh embodiment differs from the intermediate device 32 of the sixth embodiment in that it includes a recording unit 313 in addition to the intermediate device 32 of the sixth embodiment.

[0125] The following will provide a detailed explanation with reference to the drawings. In the following, components similar to those in the sixth embodiment will be denoted by the same reference numerals, and their descriptions will be omitted.

[0126] Figure 21 is a block diagram showing the configuration of the intermediate device 33 in the seventh embodiment of this disclosure.

[0127] Referring to Figure 21, the intermediate device 33 in the seventh embodiment of this disclosure comprises a communication unit 311, a detection unit 312, and a recording unit 313.

[0128] Figure 22 is a block diagram showing the configuration of the wireless communication system 105 in the seventh embodiment of this disclosure.

[0129] The wireless communication system 105 in the seventh embodiment of this disclosure comprises a plurality of wireless devices 20, a user device 10, an intermediate device 33, and a wireless access network node 40.

[0130] The detection unit 312 of the intermediate device 33 detects that it has received a PRACH signal from the user device 10 via the wireless device 20. The detection unit 312 notifies the recording unit 313 that it has detected a PRACH signal.

[0131] The recording unit 313 of the intermediate device 33 receives notification of the detection result of the PRACH signal by the detection unit 312. The recording unit 313 records the detection result of the PRACH signal by the detection unit 312. For example, the recording unit 313 may, but is not limited to, record the detection result of the PRACH signal by the detection unit 312 in memory. For example, the recording unit 313 may record the detection result only when the detection unit 312 has detected a PRACH signal. The recording unit 313 also outputs a signal based on the detection result of the PRACH signal by the detection unit 312. For example, the recording unit 313 may transmit a signal to the communication unit 311 that includes information that the detection unit 312 has detected a PRACH signal. The recording unit 313 does not have to output a signal if the detection unit 312 has not detected a PRACH signal. In addition, the recording unit 313 may output a signal based on past PRACH signal detection results by the detection unit 12.

[0132] Furthermore, the communication unit 311 transmits a U-Plane signal to the wireless access network node 40 based on the signal output from the recording unit 313. For example, if the detection unit 312 obtains a signal from the recording unit 313 indicating that it has detected a PRACH signal, the communication unit 311 may transmit a U-Plane signal to the wireless access network node 40. If no signal is obtained from the recording unit 313, the communication unit 311 may not transmit a U-Plane signal to the wireless access network node 40. Also, if the detection unit 312 obtains a signal from the recording unit 313 indicating that it has not detected a PRACH signal, the communication unit 311 may not transmit a U-Plane signal to the wireless access network node 40.

[0133] Figure 23 is a flowchart showing the operation of the intermediate device 33 in the seventh embodiment of this disclosure.

[0134] In step S6001, the detection unit 312 of the intermediate device 33 detects the PRACH signal transmitted from the user device 10 via the wireless device 20. The detection unit 312 notifies the recording unit 313 of the PRACH signal detection result. The PRACH signal detection result may include, but is not limited to, the presence or absence of the PRACH signal and the time it was detected. For example, if the detection unit 312 detects the PRACH signal, it may output a signal to the recording unit 313 indicating that the PRACH signal has been detected. The detection unit 312 may also notify the communication unit 311 of the PRACH signal detection result.

[0135] In step S6002, the recording unit 313 of the intermediate device 33 records the detection result of the PRACH signal by the detection unit 312.

[0136] In step S6003, the recording unit 313 of the intermediate device 33 outputs a signal based on the detection result of the PRACH signal by the detection unit 312. The signal output by the recording unit 313 may include the detection result of the PRACH signal by the detection unit 312. Alternatively, the signal output by the recording unit 313 may be a signal that controls the transmission of the U-Plane signal by the communication unit 311. In this case, if the PRACH signal is detected by the detection unit 312, the recording unit 313 outputs a control signal to cause the communication unit 311 to transmit the U-Plane signal. If the PRACH signal is not detected by the detection unit 312, the recording unit 313 does not need to output a control signal to cause the communication unit 311 to transmit the U-Plane signal. Alternatively, the recording unit 313 may output a control signal that controls the communication unit 311 not to transmit the U-Plane signal.

[0137] In step S6004, the communication unit 311 of the intermediate device 33 transmits a U-Plane signal based on the detection result of the PRACH signal. Specifically, the communication unit 311 transmits the U-Plane signal to the wireless access network node 40. The communication unit 311 obtains the detection result of the PRACH signal by receiving a signal output from the recording unit 313. The communication unit 311 may also obtain whether or not the U-Plane signal can be transmitted by receiving a signal output from the recording unit 313. Alternatively, the communication unit 311 may obtain the detection result of the PRACH signal by receiving a signal output by the detection unit 312.

[0138] The timing at which the communication unit 311 transmits the U-Plane signal follows the transmission timing information for the U-Plane signal. This transmission timing information is included, for example, in the C-Plane signal transmitted from the wireless access network node 40 via the intermediate device 33. Therefore, after the detection unit 312 detects the PRACH signal, the recording unit 313 may record the detection result and the transmission timing information. The recording unit 313 may then output a signal to the communication unit 311 that includes the detection result of the PRACH signal when the transmission timing approaches. Alternatively, the recording unit 313 may output a signal to the communication unit 311 that controls the transmission of the U-Plane signal when the transmission timing approaches.

[0139] In the seventh embodiment, the intermediate device 33 records the detection result of the PRACH signal transmitted from the user device 10 via the wireless device 20, and transmits a U-Plane signal to the wireless access network node 40 based on the signal output based on the detection result.

[0140] Therefore, the intermediate device 33 in the seventh embodiment can record the detection result of the PRACH signal and transmit a U-Plane signal based on the signal output based on the detection result. As a result, this embodiment also achieves the same effects as the sixth embodiment. [Eighth Embodiment] Next, an eighth embodiment of the present disclosure will be described with reference to the drawings. The intermediate device 34 of the eighth embodiment differs from the intermediate device 33 of the seventh embodiment in that the intermediate device 33 of the seventh embodiment further includes a transmission control unit 314.

[0141] The following will provide a detailed explanation with reference to the drawings. In the following, components similar to those in the seventh embodiment will be denoted by the same reference numerals, and their descriptions will be omitted.

[0142] Figure 24 is a block diagram showing the configuration of the intermediate device 34 in the eighth embodiment of this disclosure.

[0143] Referring to Figure 24, the intermediate device 34 in the eighth embodiment of this disclosure comprises a communication unit 311, a detection unit 312, a recording unit 313, and a transmission control unit 314.

[0144] Figure 25 is a block diagram showing the configuration of the wireless communication system 106 in the eighth embodiment of this disclosure.

[0145] Referring to Figure 25, the wireless communication system 106 in the eighth embodiment of this disclosure comprises a wireless device 20, a user device 10, an intermediate device 34, and a wireless access network node 40.

[0146] The recording unit 313 of the intermediate device 34 receives notification of the detection result of the PRACH signal by the detection unit 312. The recording unit 313 records the detection result of the PRACH signal by the detection unit 312. The recording unit 313 also outputs a signal to the transmission control unit 314 based on the detection result of the PRACH signal by the detection unit 312. For example, this signal includes a flag indicating whether or not the communication unit 311 will transmit a U-Plane signal based on the detection result of the PRACH signal by the detection unit 312. The signal may also include the detection result of the PRACH signal by the detection unit 312. The recording unit 313 does not need to output a signal if the detection unit 312 did not detect a PRACH signal.

[0147] The transmission control unit 314 of the intermediate device 34 controls the transmission of the U-Plane signal by the communication unit 311 based on the signal received from the recording unit 313. For example, if the received signal contains a flag indicating that the communication unit 311 should transmit a U-Plane signal, based on the detection result of the PRACH signal detected by the detection unit 312, the transmission control unit 314 allows the communication unit 311 to transmit the U-Plane signal. In this case, if the flag is off, the transmission control unit 311 is not allowed to transmit the U-Plane signal.

[0148] Furthermore, the communication unit 311 transmits a U-Plane signal to the wireless access network node 40 based on the control of the transmission control unit 314.

[0149] Furthermore, the transmission control unit 314 may also check whether a U-Plane signal has been transmitted from the communication unit 311 to the wireless access network node 40. If no U-Plane signal is transmitted for a certain period of time, the transmission control unit 314 may prohibit the communication unit 311 from transmitting a U-Plane signal. In this case, the transmission control unit 314 may prohibit the communication unit 311 from transmitting a U-Plane signal until it receives a signal again from the recording unit 313. In other words, the transmission control unit 314 may only permit the communication unit 311 to transmit a U-Plane signal if it receives a signal again from the recording unit 313.

[0150] Figure 26 is a flowchart showing the operation of the intermediate device 34 in the eighth embodiment of this disclosure.

[0151] In step S7001, the detection unit 312 of the intermediate device 34 detects the PRACH signal transmitted from the user device 10 via the wireless device 20.

[0152] In step S7002, the recording unit 313 of the intermediate device 34 records the detection result of the PRACH signal by the detection unit 312.

[0153] In step S7003, the recording unit 313 of the intermediate device 34 outputs a signal to the transmission control unit 314 based on the detection result of the PRACH signal by the detection unit 312. For example, this signal includes a flag indicating whether or not the communication unit 311 will transmit a U-Plane signal based on the detection result of the PRACH signal by the detection unit 312.

[0154] In step S7004, the transmission control unit 314 of the intermediate device 34 controls the transmission of the U-Plane signal in the communication unit 311 based on the signal received from the recording unit 313.

[0155] In step S7005, the communication unit 311 of the intermediate device 34 transmits a U-Plane signal based on the control of the transmission control unit 314. Specifically, the communication unit 311 transmits the U-Plane signal to the wireless access network node 40.

[0156] In the eighth embodiment, the intermediate device 34 controls the transmission of the U-Plane signal based on a signal output based on the detection result of the PRACH signal transmitted from the user device 10 via the wireless device 20.

[0157] Therefore, the intermediate device 34 in the eighth embodiment can control the transmission of the U-Plane signal based on the detection result of the PRACH signal. As a result, it can transmit signals appropriately based on the presence or absence of user equipment. Furthermore, if the U-Plane signal is not transmitted for a certain period of time, the transmission of the U-Plane signal can also be controlled. As a result, power saving of the intermediate device is also possible.

[0158] [Ninth Embodiment] Next, a ninth embodiment of the present disclosure will be described with reference to the drawings. This embodiment differs from the fifth embodiment in that the intermediate device 35 has a composite section.

[0159] Figure 27 is a block diagram showing the configuration of the intermediate device 35 in the ninth embodiment of this disclosure.

[0160] Referring to Figure 27, the intermediate device 35 in the ninth embodiment of this disclosure comprises a communication unit 311, a detection unit 312, and a synthesis unit 315.

[0161] Figure 28 shows the configuration of the wireless communication system 107 in the ninth embodiment of this disclosure. Referring to Figure 28, the configuration of the wireless communication system 107 in the ninth embodiment of this disclosure is such that a combining unit 315 is added to the intermediate device 32 in Figure 18.

[0162] The wireless device 20 is a device that communicates with the user device 10 and processes radio frequencies. In Figure 28, one user device is connected to one wireless device 20, but multiple user devices may be connected to one wireless device 20. The wireless device 20 may be the O-RU described above, but is not limited to this.

[0163] The user device 10 communicates with the wireless access network node 40 via the wireless device 20 and the intermediate device 35. The user device 10 may be the UE described above, but is not limited thereto.

[0164] The intermediate device 35 is positioned between the multiple wireless devices 20 and the wireless access network node 40. The intermediate device 35 duplicates or combines signals from the wireless devices 20 and the wireless access network node 40 and transmits them. For example, the intermediate device 35 combines uplink signals (signals from the wireless devices 20 to the wireless access network node 40) from the multiple wireless devices 20 and transmits them to the wireless access network node 40. The combination of uplink signals by the intermediate device 31 is not limited to simple combination (e.g., calculation of sum or average), but may also be selective combination (e.g., simple combination of selected uplink signals, or simple combination of multiple uplink signals with weighting). Also, for example, the intermediate device 35 duplicates downlink signals (signals from the wireless access network node 40 to the wireless devices 20) from the wireless access network node 40 and transmits them to the multiple wireless devices 20. The intermediate device 35 may be, but is not limited to, the FHM described above.

[0165] The communication unit 311 of the intermediate device 35 receives and transmits data from other devices. The communication unit 311 receives data transmitted from multiple wireless devices 20. The data that the communication unit 311 receives from multiple wireless devices 20 includes, for example, PRACH signals and U-Plane signals. The communication unit 311 transmits data transmitted from the user device 10 via the wireless device 20 to the wireless access network node 40. For example, if a U-Plane signal is transmitted from the user device 10 via the wireless device 20 based on a C-Plane signal sent from the wireless access network node 40, the communication unit 311 transmits the U-Plane signal to the wireless access network node 40.

[0166] The detection unit 312 of the intermediate device 35 detects the PRACH signal transmitted from the user device 10 via the wireless device 20.

[0167] The combining unit 315 of the intermediate device 35 combines the U-Plane signals received by the communication unit 311 based on the detection result of the PRACH signal by the detection unit 312. For example, the combining unit 315 may combine U-Plane signals received from wireless devices that transmitted the PRACH signal detected by the detection unit 312. In this case, U-Plane signals received from wireless devices that did not transmit the PRACH signal detected by the detection unit 312 may not be combined.

[0168] Furthermore, the communication unit 311 transmits the U-Plane signal synthesized by the synthesis unit 315 to the wireless access network node 40. Note that the data transmitted from the user device 10 to the wireless access network node 40 via the wireless device 20 is not limited to the U-Plane signal.

[0169] The wireless access network node 40 communicates with the user device 10 via the wireless device 20 and the intermediate device 35. The wireless access network node 40 may be, but is not limited to, the O-DU described above.

[0170] Figure 29 is a flowchart showing the operation of the intermediate device 35 in the ninth embodiment of this disclosure.

[0171] In step S8001, the detection unit 312 of the intermediate device 35 detects the PRACH signal transmitted from the user device 10 via the wireless device 20. The detection unit 312 may transmit the detection result of the PRACH signal to the synthesis unit 315. The detection result of the PRACH signal may include, but is not limited to, the presence or absence of the PRACH signal and the time it was detected. For example, if the detection unit 312 detects a PRACH signal, it may output a signal to the synthesis unit 315 indicating that a PRACH signal has been detected. Alternatively, the detection result of the PRACH signal transmitted by the detection unit 312 may be the PRACH signal itself that the detection unit 312 detected.

[0172] In step S8002, the communication unit 311 of the intermediate device 35 receives U-Plane signals transmitted from multiple wireless devices 20.

[0173] In step S8003, the combining unit 315 of the intermediate device 35 combines the U-Plane signals received by the communication unit 311 based on the detection result of the PRACH signal by the detection unit 312. Specifically, the combining unit 315 combines the U-Plane signals received from the wireless device 20 that transmitted the PRACH signal detected by the detection unit 312. At this time, the combining unit 315 does not combine U-Plane signals received from wireless devices 20 that did not transmit the PRACH signal detected by the detection unit 312. The combining unit 315 may acquire the detection result of the PRACH signal from the detection unit 312 as a signal or the like, but the method of acquisition is not limited to this. The signal from the detection unit 312 may be a signal indicating the detection result, or it may be a signal that controls the combining of U-Plane signals by the combining unit 315.

[0174] In step S8004, the communication unit 311 transmits the U-Plane signal synthesized by the synthesis unit 315 to the radio access network node 40. The timing of the communication unit 311's transmission of the U-Plane signal follows, for example, the transmission timing information for the U-Plane signal. This transmission timing information is included, for example, in the C-Plane signal transmitted from the radio access network node 40 via the intermediate device 35.

[0175] As described above, the intermediate device 35 in the ninth embodiment synthesizes a U-Plane signal based on the detection result of the PRACH signal transmitted from the user device 10.

[0176] Therefore, the intermediate device 35 in the ninth embodiment can transmit the U-Plane signal synthesized based on the detection result of the PRACH signal to the wireless access network node 40. As a result, the intermediate device 35 can appropriately transmit signals based on the presence or absence of user devices. For example, if there are no user devices connected to the wireless device 20, the intermediate device 35 can choose not to synthesize the U-Plane signal received from the wireless device 20. This prevents the problem of interference from other cells or device noise being synthesized by the intermediate device in cells where no user devices exist, which would degrade the demodulation performance at the wireless access network node (e.g., O-DU).

[0177] In this embodiment, the intermediate device 35 may be configured to have the recording unit 313 as in the seventh embodiment.

[0178] Although the present disclosure has been described above with reference to various embodiments and specific examples, the present disclosure is not limited to the embodiments described above. Various modifications to the structure and details of the present disclosure can be understood by those skilled in the art within the scope of the present disclosure.

[0179] For example, the steps in the process described herein do not necessarily have to be executed chronologically in the order shown in the flowchart. For instance, the steps in the process may be executed in a different order than that shown in the diagram, or they may be executed in parallel. Furthermore, some steps in the process may be deleted, or additional steps may be added to the process.

[0180] Furthermore, methods including processing of components of the information device described in this disclosure (for example, at least one of a communication unit, a detection unit, a recording unit, and a transmission control unit) may be provided, and programs for causing a processor to perform processing of the above components may be provided. A non-transitory computer-readable medium on which such a program is recorded may also be provided. Naturally, such devices, modules, methods, programs, and computer-readable non-transitory media are also included in this disclosure.

[0181] Some or all of the above embodiments may also be described as follows, but are not limited to these. (Note 1) A wireless device that communicates with a user device and processes radio frequencies, A wireless access network node that communicates with the user device via the wireless device, and a communication unit that communicates with an intermediate device that duplicates or combines signals and transmits them between a plurality of the wireless devices, It has a detection unit that detects the PRACH signal transmitted from the user device, The communication unit is a wireless device that transmits a U-Plane signal to the wireless access network node via the intermediate device based on the detection result of the PRACH signal by the detection unit. (Note 2) The wireless device according to Appendix 1, further comprising a recording unit for recording the aforementioned detection results. (Note 3) The wireless device according to Appendix 2, further comprising a transmission control unit that controls the transmission of the U-Plane signal by the communication unit based on the detection result. (Note 4) The recording unit further outputs a signal based on the detection result, The wireless device as described in Appendix 3, wherein the transmission control unit controls the transmission of the U-Plane signal by the communication unit based on the signal. (Note 5) The transmission control unit further confirms whether or not the communication unit has transmitted the U-Plane signal, as described in Appendix 4. (Note 6) The wireless device as described in Appendix 5, wherein the transmission control unit controls the communication unit not to transmit the U-Plane signal if the communication unit does not transmit the U-Plane signal for a certain period of time. (Note 7) The wireless device is an O-RAN Radio Unit (O-RU), as described in Appendix 1 or 2. (Note 8) The wireless device as described in Appendix 1, wherein the communication unit further transmits the information of the PRACH signal detected by the detection unit to the wireless access network node. (Note 9) The recording unit is a wireless device as described in Appendix 2, which acquires the detection result from the detection unit. (Note 10) The wireless device as described in Appendix 4, wherein the recording unit outputs a control signal to the communication unit that permits the transmission of the U-Plane signal when the detection unit detects the PRACH signal. (Note 11) The aforementioned wireless access network node is an O-RAN Distributed Unit (O-DU), as described in Appendix 1. (Note 12) An intermediate device that duplicates or combines signals and transmits them between a plurality of wireless devices communicating with a user device and a wireless access network node communicating with the user device via the wireless devices, It has a communication unit that communicates with the wireless device and the wireless access network node, The communication unit receives the detection result of the PRACH signal transmitted from the user device from the wireless device. The communication unit is an intermediate device that transmits the U-Plane signal received from the wireless device to the wireless access network node based on the detection result. (Note 13) The intermediate device is a front haul multiplexer (FHM), as described in Appendix 12. (Note 14) A recording unit records the aforementioned detection results, The intermediate device according to Appendix 12, further comprising: a transmission control unit that controls the transmission of a U-Plane signal by the communication unit based on the detection result. (Note 15) The intermediate device according to Appendix 12, further comprising a synthesis unit that synthesizes U-Plane signals received from the wireless device based on the detection results. (Note 16) A method performed in a wireless device that communicates with a user device and processes radio frequencies, A wireless access network node that communicates with the user device via the wireless device communicates with an intermediate device that duplicates or combines signals and transmits them between a plurality of the wireless devices, The PRACH signal transmitted from the user device is detected, A method for transmitting a U-Plane signal to the wireless access network node via the intermediate device based on the detection result of the PRACH signal. (Note 17) A program that causes one or more processors of a wireless device to perform a method for communicating with a user device and processing radio frequencies, The aforementioned method, A wireless access network node that communicates with the user device via the wireless device communicates with an intermediate device that duplicates or combines signals and transmits them between a plurality of the wireless devices. To detect the PRACH signal transmitted from the user device, Based on the detection result of the PRACH signal, the U-Plane signal is transmitted to the wireless access network node via the intermediate device. A program that includes the following features. (Note 18) A wireless communication system comprising: a plurality of wireless devices; a wireless access network node that communicates with a user device via the plurality of wireless devices; and an intermediate device that duplicates or combines signals between the plurality of wireless devices and the wireless access network node for transmission, A detection unit for detecting the PRACH signal transmitted from the user device, A communication unit transmits a U-Plane signal to the wireless access network node based on the detection result of the PRACH signal by the detection unit, A wireless communication system equipped with [the following features]. (Note 19) A method performed in an intermediate device that duplicates or combines signals and transmits them between a wireless device that communicates with a user device and a wireless access network node that communicates with the user device via the wireless device, The wireless device and the wireless access network node communicate with each other. The detection result of the PRACH signal transmitted from the user device is received from the wireless device. Based on the detection results, the U-Plane signal received from the wireless device is transmitted to the wireless access network node. method. (Note 20) A program for causing one or more processors of an intermediate device that duplicates or combines and transmits signals between a wireless device that communicates with a user device and a wireless access network node that communicates with the user device via the wireless device to perform a method, The aforementioned method, To communicate with the aforementioned wireless device and the aforementioned wireless access network node, The detection result of the PRACH signal transmitted from the user device is received from the wireless device. Based on the detection results, the U-Plane signal received from the wireless device is transmitted to the wireless access network node. A program that includes the following features. (Note 21) A method performed in a wireless communication system including a plurality of wireless devices, a wireless access network node that communicates with a user device via the plurality of wireless devices, and an intermediate device that duplicates or combines signals between the plurality of wireless devices and the wireless access network node for transmission, The PRACH signal transmitted from the user device is detected, A method for transmitting a U-Plane signal to a wireless access network node based on the detection result of the PRACH signal detected. (Note 22) A program for causing one or more processors of a wireless communication system, which includes a plurality of wireless devices, a wireless access network node that communicates with a user device via the plurality of wireless devices, and an intermediate device that duplicates or combines signals between the plurality of wireless devices and the wireless access network node and transmits them, to perform a method, The aforementioned method, To detect the PRACH signal transmitted from the user device, Based on the detection result of the PRACH signal detected, the U-Plane signal is transmitted to the wireless access network node. A program that includes the following features. [Explanation of Symbols]

[0182] 1, 2, 3, 4, 20 Radio equipment 10 User devices 11, 311 Communications Department 12, 312 detection unit 13, 213, 313 Records Section 14, 214, 314 Transmitting Control Unit 315 Synthesis part 30, 31, 32, 33, 34, 35 Intermediate device 100, 101, 102, 103, 104, 105, 106, 107 Wireless communication systems 110 PRACH Transmitter 120 PUSCH Transmitter 201, 202 Analog Beamforming 203 Analog to Digital 204 Filtering 205 FFT and CP removal 206, 207 Digital beam forming 208 Re Demapping 211 IQ Compression 212 signals 215 O-RAN C-Plane Analysis Department 301 O-RAN C-Plane Packet Copy Unit 302 Packet determination unit 303 O-RAN U-Plane synthesis section 401 PRACH O-RAN C-Plane Packet Creation Unit 402 PUSCH O-RAN C-Plane packet creation unit 403 O-RAN C-Plane Packet Transmission Unit 404 Detection Result Receiving Unit 405 O-RAN U-Plane Packet Receiving Unit

Claims

1. A wireless device that communicates with a user device and processes radio frequencies, A wireless access network node that communicates with the user device via the wireless device, and a communication unit that communicates with an intermediate device that duplicates or combines signals and transmits them between a plurality of the wireless devices, It has a detection unit that detects the PRACH signal transmitted from the user device, The communication unit is a wireless device that transmits a U-Plane signal to the wireless access network node via the intermediate device based on the detection result of the PRACH signal by the detection unit.

2. The system further includes a recording unit for recording the aforementioned detection results. The wireless device according to claim 1.

3. The system further includes a transmission control unit that controls the transmission of the U-Plane signal by the communication unit based on the detection results. The wireless device according to claim 2.

4. The recording unit further outputs a signal based on the detection result, The transmission control unit controls the transmission of the U-Plane signal by the communication unit based on the signal. The wireless device according to claim 3.

5. The transmission control unit controls the communication unit not to transmit the U-Plane signal if the communication unit does not transmit the U-Plane signal for a certain period of time. The wireless device according to claim 4.

6. The aforementioned wireless device is an O-RAN Radio Unit (O-RU). The wireless device according to claim 1 or 2.

7. An intermediate device that duplicates or combines signals and transmits them between a plurality of wireless devices communicating with a user device and a wireless access network node communicating with the user device via the wireless devices, It has a communication unit that communicates with the wireless device and the wireless access network node, The communication unit receives the detection result of the PRACH signal transmitted from the user device from the wireless device. The communication unit is an intermediate device that transmits the U-Plane signal received from the wireless device to the wireless access network node based on the detection result.

8. The aforementioned intermediate device is a front-haul multiplexer (FHM). The intermediate device according to claim 7.

9. A method performed in a wireless device that communicates with a user device and processes radio frequencies, A wireless access network node that communicates with the user device via the wireless device communicates with an intermediate device that duplicates or combines signals and transmits them between a plurality of the wireless devices, The PRACH signal transmitted from the user device is detected, A method for transmitting a U-Plane signal to the wireless access network node via the intermediate device based on the detection result of the PRACH signal.

10. A program that causes one or more processors of a wireless device to perform a method for communicating with a user device and processing radio frequencies, The aforementioned method, A wireless access network node that communicates with the user device via the wireless device communicates with an intermediate device that duplicates or combines signals and transmits them between a plurality of the wireless devices. To detect the PRACH signal transmitted from the user device, Based on the detection result of the PRACH signal, the U-Plane signal is transmitted to the wireless access network node via the intermediate device. A program that includes the following features.

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