Wireless Base Station and Wireless Communication Method

Abstract

A gNB (100) transmits and receives a prescribed message or response, acquires a propagation delay with respect to a UE (200) in accordance with reception of the message or the response, and executes propagation delay compensation. The propagation delay compensation is executed in a distributed unit (DU) (120) on the UE (200) side or a central unit (CU) (110) on a network side.

Description

Technical Field

[0001] The present disclosure relates to a radio base station capable of compensating for propagation delay with a terminal.

Background Art

[0002] The 3rd Generation Partnership Project (3GPP) has standardized the 5th generation mobile communication system (also called 5G, New Radio (NR), or Next Generation (NG)), and is also promoting the standardization of the next generation, called Beyond 5G, 5G Evolution, or 6G.

[0003] In 3GPP Release-17, with regard to the support for Industrial Internet of Things (IIoT) and Ultra-Reliable and Low Latency Communications (URLLC), it is targeted to achieve more accurate synchronization between a radio base station (gNB) and a terminal (User Equipment, UE) (Non-Patent Document 1).

[0004] For example, in a use case such as a smart grid, high synchronization accuracy in a wide service area is required (Non-Patent Document 2), so compensation for propagation delay in the radio section between the UE and the gNB is essential.

[0005] When such high synchronization accuracy in a wide service area is required, while applying a CU-DU split gNB deployment in which the CU (Central Unit) and DU (Distributed Unit) of the gNB are separated and arranged, it is conceivable to perform propagation delay compensation between the UE and the gNB (specifically, between the UE and the DU).

Prior Art Documents

Non-Patent Documents

[0006] [Non-Patent Document 1] "Enhanced Industrial Internet of Things (IoT) and ultra-reliable and low latency communication (URLLC) support for NR", RP-201310, 3GPP TSG RAN Meeting #88e, 3GPP, July 2020 [Non-Patent Document 2] 3GPP TS 22.104 V17.3.0, 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Service requirements for cyber-physical control applications in vertical domains; Stage 1 (Release 17), 3GPP, July 2020 [Summary of the Invention]

[0007] However, according to the current 3GPP specifications (Release-16), there is a problem that it is difficult for the CU and DU of the radio base station to properly cooperate to perform propagation delay compensation between the UE and the gNB.

[0008] Therefore, the following disclosure has been made in view of such a situation, and aims to provide a radio base station that can realize propagation delay compensation in the radio section with the terminal (UE) while meeting the requirement of high synchronization accuracy in a wide service area.

[0009] One aspect of the present disclosure is a radio base station (gNB100) including a transceiver (e.g., message transceiver 117) that transmits and receives a specified message or response, and a control unit (e.g., delay compensation control unit 115) that acquires a propagation delay with a terminal (UE200) in response to reception of the message or response and performs propagation delay compensation, wherein the propagation delay compensation is executed in a communication unit (DU120) on the terminal side or a communication unit (CU110) on the network side.

[0010] One aspect of the present disclosure is a radio base station (gNB100) including a transceiver (radio transmission unit 121 and radio reception unit 123) that transmits and receives a radio signal, and a control unit (delay compensation control unit 125) that acquires a propagation delay with a terminal (UE200) based on a time difference between reception and transmission of the radio signal and performs propagation delay compensation, wherein the propagation delay compensation is executed in a communication unit (DU120) on the terminal side.

[0011] One aspect of the present disclosure is a radio base station (gNB100) including a receiver (message transceiver 128) that receives a control message of time information including identification information of a terminal (UE200), and a transmitter (message transceiver 128) that transmits the time information adjusted based on a propagation delay with the terminal associated with the identification information.

[0012] One aspect of the present disclosure is a radio base station (gNB100) including a receiver (message transceiver 128) that receives a control message of time information including identification information of a terminal (UE200), and a transmitter (message transceiver 128) that transmits a response message including compensation information indicating whether propagation delay compensation with the terminal associated with the identification information has been performed.

[0013] One aspect of the present disclosure is a radio base station (gNB100) including a transmission unit (e.g., message transceiver 117) that transmits system information including time information used in a system or a message related to a downlink, and a control unit (e.g., delay compensation control unit 115) that includes in the system information or the message whether or not to instruct the terminal (UE200) for propagation delay compensation to the terminal.

Brief Description of the Drawings

[0014]

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DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments will be described with reference to the drawings. Note that the same or similar reference numerals are assigned to the same functions and configurations, and the description thereof will be omitted as appropriate.

[0016] (1) Overall schematic configuration of the wireless communication system FIG. 1 is an overall schematic configuration diagram of a wireless communication system 10 according to this embodiment. The wireless communication system 10 is a wireless communication system compliant with 5G New Radio (NR), and includes a Next Generation-Radio Access Network 20 (hereinafter, NG-RAN20) and a user terminal 200 (User Equipment 200, hereinafter, UE200).

[0017] Note that the wireless communication system 10 may also be a wireless communication system compliant with a system called Beyond 5G, 5G Evolution, or 6G.

[0018] NG-RAN 20 includes a radio base station 100 (hereinafter, gNB 100). Note that the specific configuration of the wireless communication system 10 including the number of gNBs and UEs is not limited to the example shown in FIG. 1.

[0019] NG-RAN 20 actually includes a plurality of NG-RAN nodes, specifically, gNBs (or ng-eNBs), and is connected to a 5G Core Network 5GC 30 that conforms to 5G. Note that NG-RAN 20 and 5GC 30 may be simply expressed as "network".

[0020] 5GC 30 may be provided with a User Plane Function 35 (hereinafter, UPF 35) that is included in the 5G system architecture and provides user plane functions. UPF 35 can be connected to a TSN Grandmaster 25 (hereinafter, TSC GM 25) that provides time information used in a Time Sensitive Network (TSN) via a specific interface. TSC GM 25 can provide high-precision time information (date and time) to an IoT device 40 connected to a UE 200 via NG-RAN 20 or the like. Note that the IoT device 40 may be called an end station or the like.

[0021] For example, TSN can be used as a network for Industrial Internet of Things (IIoT). TSN may be configured as a separate network from NG-RAN 20 and 5GC 30, that is, the NR (5G) system, and may be synchronized with the timing at which an independent clock is generated.

[0022] TSN may include networks related to services that require high synchronization accuracy in a wide service area, such as smart grids.

[0023] gNB100 is a radio base station compliant with NR and performs wireless communication with UE200 according to NR. gNB100 and UE200 can support Massive MIMO that generates a more directional beam by controlling radio signals transmitted from a plurality of antenna elements, carrier aggregation (CA) that bundles and uses a plurality of component carriers (CC), and dual connectivity (DC) that simultaneously communicates between the UE and each of a plurality of NG-RAN Nodes, etc.

[0024] The IoT device 40 may be a communication device (terminal) included in TSN, for example, IIoT, and may be synchronized with the timing (time information) within TSN.

[0025] Thus, in this embodiment, the NR (5G) system can connect the TSC GM25 and the IoT device 40, and a mechanism for compensating for the propagation delay between the UE200 and the gNB100 is provided.

[0026] FIG. 2 shows an example of support for TSN by the wireless communication system 10. As shown in FIG. 2, gNB100 may be composed of a Central Unit 110 (hereinafter, CU110) and a Distributed Unit 120 (hereinafter, DU120). A plurality of DU120s may be connected to CU110. A wired method (for example, Ethernet (registered trademark)) may be used for the connection between CU110 and DU120. Note that a wireless method may be used for the connection between CU110 and DU120.

[0027] The IoT device 40 connected to UE200 can operate in synchronization with the TSN time information provided by TSC GM25 (refer to the clock icon in the figure). On the other hand, within the NR (5G) system, the 5G Grand Master (5G GM) provides the time information used within the system. UPF35, CU110, DU120, and UE200 can operate in synchronization with the time information of 5G GM.

[0028] When a high synchronization accuracy is required in a wide service area such as a smart grid, the wireless communication system 10 applies a CU-DU split gNB deployment in which the CU 110 and a plurality of DUs 120 are geographically separated and arranged, thereby covering a wide service area (for example, up to 20 km 2 ).

[0029] Also, in order to achieve a high synchronization accuracy (for example, less than 1 μs), the propagation delay between the UE 200 and the gNB 100 can be compensated. Specifically, in the wireless communication system 10, the propagation delay in the radio section between the UE 200 and the DU 120 to which the UE 200 is connected can be compensated. Propagation delay compensation may be interpreted as adjusting the time information for TSN according to the amount of propagation delay in the radio section, and as a result, each of the IoT devices 40 can operate in synchronization with the time information for TSN. More simply, it may be interpreted as adjusting the time information obtained by subtracting the propagation delay between the UE 200 and the gNB 100 (DU 120) (radio section) from the time information for TSN.

[0030] Alternatively, propagation delay compensation may be interpreted as adjusting the time information obtained by subtracting the propagation delay between the UE 200 and the gNB 100 (DU 120) (radio section) from the time information of 5G GM. If accurate synchronization can be maintained within the 5G system, it may be interpreted that the 5G system plays the role of a TSN bridge and each of the TSN IoT devices can operate in synchronization with the time of TSN. (2) Functional block configuration of the wireless communication system Next, the functional block configuration of the wireless communication system 10 will be described. Specifically, the functional block configurations of the CU 110 and the DU 120 that constitute the gNB 100 will be described.

[0031] (2.1) CU 110 Figure 3 is a functional block configuration diagram of CU110. As shown in Figure 3, CU110 includes a network connection unit 111, a DU connection unit 113, a delay compensation control unit 115, a message transmission / reception unit 117, and a system information transmission unit 119.

[0032] The network connection unit 111 provides a communication interface with the network, specifically, other communication nodes constituting NG-RAN20, and a communication interface with communication nodes constituting 5GC30. For example, the communication interface may include N2, N3, etc.

[0033] The DU connection unit 113 provides a communication interface with DU120. For example, the communication interface may include F1, etc. Specifically, the DU connection unit 113 can provide a communication interface (such as Ethernet (registered trademark)) for wired-connecting a plurality of DU120.

[0034] The delay compensation control unit 115 executes control related to compensation for the propagation delay between UE200 and gNB100. In the present embodiment, the delay compensation control unit 115 may constitute a control unit.

[0035] Specifically, the delay compensation control unit 115 may acquire the propagation delay with UE200 based on a specified message transmitted or received by the message transmission / reception unit 117.

[0036] For example, the delay compensation control unit 115 can calculate the propagation delay between UE200 and gNB100 (specifically, DU120) based on the value of gNB Rx-Tx time difference transmitted from DU120. gNB Rx-Tx time difference may be interpreted as the difference (time difference) between the reception timing and the transmission timing of a specified subframe in gNB100 (DU120). gNB Rx-Tx time difference is defined in Section 5.2.3 of 3GPP TS38.215. gNB Rx-Tx time difference will be further described later.

[0037] In this way, in response to the reception of a message or response such as the gNB Rx-Tx time difference, the delay compensation control unit 115 can obtain the propagation delay with the UE 200 and perform propagation delay compensation. Note that, as will be described later, the propagation delay compensation may be performed in the DU 120, which is a communication unit on the UE 200 side, or in the CU 110, which is a communication unit on the network side.

[0038] Also, the delay compensation control unit 115 can include in the system information or a message related to the downlink whether or not to instruct the UE 200 of the propagation delay compensation for each UE 200. Specifically, it can be included in the DLInformationTransfer msg. The system information (SIB) can be transmitted (notified) to the UE 200 by the system information transmission unit 119 as will be described later. The UE 200 may perform propagation delay compensation based on such system information or a message related to the downlink.

[0039] The message transceiver unit 117 transmits and receives a specified message or response. In the present embodiment, the message transceiver unit 117 may constitute a transceiver unit.

[0040] Specifically, the message transceiver unit 117 can transmit a POSITIONING MEASUREMENT REQUEST to the DU 120 and receive a POSITIONING MEASUREMENT RESPONSE, which is a response to the POSITIONING MEASUREMENT REQUEST, from the DU 120. The POSITIONING MEASUREMENT RESPONSE may include the gNB Rx-Tx time difference. The POSITIONING MEASUREMENT REQUEST and the POSITIONING MEASUREMENT RESPONSE are defined in 3GPP TS38.473.

[0041] In addition, the message transceiver unit 117 can send REFERENCE TIME INFORMATION REPORTING CONTROL, which is a type of F1 message defined in 3GPP TS38.473, to the DU 120 and can receive a REFERENCE TIME INFORMATION REPORT, which is a response to REFERENCE TIME INFORMATION REPORTING CONTROL, from the DU 120. REFERENCE TIME INFORMATION REPORTING CONTROL may include a Propagation delay compensation request for instructing the DU 120 to perform propagation delay compensation.

[0042] Furthermore, the message transceiver unit 117 can send a message regarding the downlink that can include time information, specifically, a DLInformationTransfer msg., which is a unicast message, to the UE 200 via the DU 120. In this embodiment, the message transceiver unit 117 may constitute a transmitting unit.

[0043] Note that these messages are examples, and different messages may be used as long as they are messages transmitted and received between the CU 110 and the DU 120.

[0044] The system information transmitting unit 119 transmits system information to be notified, that is, broadcast, within the cell formed by the gNB 100. The system information may be referred to as a System Information Block (SIB). The SIB includes a plurality of types. In particular, in this embodiment, the system information transmitting unit 119 can notify the cell of an SIB9 including an information element (IE) called referenceTimeInfo-r16 via the DU 120. referenceTimeInfo-r16 indicates the Internal system clock (which may also be referred to as time or timing) of NR (5G).

[0045] That is, the system information transmitting unit 119 can transmit the system information transmitting unit 119 including the time information used in the wireless communication system 10. In the present embodiment, the system information transmitting unit 119 may constitute a transmitting unit.

[0046] (2.2) DU120 FIG. 4 is a functional block configuration diagram of the DU 120. As shown in FIG. 4, the DU 120 includes a wireless transmitting unit 121, a wireless receiving unit 123, a CU connection unit 124, a delay compensation control unit 125, an RA processing unit 126, a time information processing unit 127, and a message transmitting / receiving unit 128.

[0047] The wireless transmitting unit 121 transmits a wireless signal according to NR toward the UE 200. The wireless receiving unit 123 receives a wireless signal transmitted from the UE 200 and conforming to NR. In the present embodiment, the wireless transmitting unit 121 and the wireless receiving unit 123 may constitute a transmitting / receiving unit for transmitting and receiving a wireless signal.

[0048] The CU connection unit 124 provides a communication interface with the CU 110. As described above, the communication interface may include F1 or the like, and the CU connection unit 124 can provide a communication interface for wired connection with the CU 110.

[0049] Similar to the delay compensation control unit 115 of the CU 110, the delay compensation control unit 125 executes control related to compensation for the propagation delay between the UE 200 and the gNB 100. In the present embodiment, the delay compensation control unit 125 may constitute a control unit.

[0050] Specifically, the delay compensation control unit 125 can obtain the propagation delay with the UE 200 based on the time difference between the reception and transmission of the wireless signal, and execute propagation delay compensation. The time difference between the reception and transmission of the wireless signal may be the above-described gNB Rx-Tx time difference. The wireless signal may be interpreted as a wireless frame, sub-frame, slot, symbol, or the like. Alternatively, the wireless signal may be reinterpreted as a message of a higher layer (e.g., a radio resource control layer (RRC)).

[0051] Note that the propagation delay compensation may be realized by the same operation as that of CU110. That is, the delay compensation control unit 125 can also acquire the propagation delay with UE200 in response to the reception of a message or a response, and execute the propagation delay compensation.

[0052] Specifically, the delay compensation control unit 125 may execute the propagation delay compensation in response to the reception of a random access preamble (msg. 1) from UE200 in a random access procedure (RA procedure). Note that executing in response to reception may mean executing simultaneously with reception, or executing within a certain time after reception.

[0053] More specifically, when the delay compensation control unit 125 receives a random access preamble (msg. 1), it may calculate a Timing advance (TA) command, calculate a propagation delay specific to each UE200 (UE specific propagation delay) at the same time, and execute the propagation delay compensation.

[0054] Also, the delay compensation control unit 125 may execute the propagation delay compensation in response to the reception of a REFERENCE TIME INFORMATION REPORTING CONTROL (control message) transmitted from CU110. The purpose of REFERENCE TIME INFORMATION REPORTING CONTROL is to instruct DU120 to transmit the required accurate time information (Time Reference Information) to CU110.

[0055] In this embodiment, REFERENCE TIME INFORMATION REPORTING CONTROL may include an information element (IE) for instructing DU120 to execute the propagation delay compensation. The IE may be called, for example, Propagation delay compensation request.

[0056] Thus, in this embodiment, the propagation delay compensation may be performed in the DU120, which is a communication unit on the UE200 side.

[0057] In addition, the delay compensation control unit 125 may include in the system information (SIB9) whether or not to instruct the UE200 of the propagation delay compensation for each UE200.

[0058] The RA processing unit 126 executes processing related to the RA procedure with the UE200. Specifically, the RA processing unit 126 may support the contention-based RA procedure (CBRA) and the contention-free RA procedure (CFRA). In addition, the RA processing unit 126 may support the 4-step and 2-step RA procedures.

[0059] The RA processing unit 126 can execute the RA procedure based on the random access preamble (msg. 1) received by the message transmission / reception unit 128 from the UE200. The RA procedure may include transmitting the random access response (msg. 2) to the UE200, receiving the scheduled transmission (msg. 3), and transmitting the contention resolution (msg. 4).

[0060] The time information processing unit 127 executes processing related to the time information (5G GM standard) used in the wireless communication system 10 and the time information for TSN (TSC GM25 standard).

[0061] Specifically, the time information processing unit 127 may adjust the time information for TSN based on the propagation delay with the UE200 associated with the identification information of the UE200 (which may be called the RAN UE ID) included in the REFERENCE TIME INFORMATION REPORTING CONTROL. Specifically, as described above, it may be interpreted as adjusting the time information obtained by subtracting the propagation delay from the time information for TSN.

[0062] The message transceiver unit 128 transmits and receives specified messages or responses. In this embodiment, the message transceiver unit 128 may constitute a transceiver unit.

[0063] Specifically, the message transceiver unit 128 can receive messages related to the RA procedure, specifically, a random access preamble (msg. 1), etc.

[0064] Also, the message transceiver unit 128 may transmit a POSITIONING MEASUREMENT RESPONSE including the value of the gNB Rx-Tx time difference obtained by the delay compensation control unit 125 to the CU 110.

[0065] The message transceiver unit 128 can also receive a control message of time information. In this embodiment, the message transceiver unit 128 may constitute a receiver unit. Specifically, the message transceiver unit 128 can receive REFERENCE TIME INFORMATION REPORTING CONTROL from the CU 110. The REFERENCE TIME INFORMATION REPORTING CONTROL may include a RAN UE ID as identification information that can uniquely identify each UE 200. Note that as long as it is identification information that can uniquely identify each UE 200, not limited to the RAN UE ID, other IDs may be used.

[0066] The message transceiver unit 128 can receive a control message of time information (REFERENCE TIME INFORMATION REPORTING CONTROL) including the identification information of the identification information (RAN UE ID) of the UE 200.

[0067] In addition, the message transmission / reception unit 128 can transmit the time information adjusted by the time information processing unit 127 to the CU 110. Specifically, the message transmission / reception unit 128 can transmit the time information adjusted based on the propagation delay with the UE 200 associated with a specific RAN UE ID. In the present embodiment, the message transmission / reception unit 128 may constitute a transmission unit. The time information may be included in a REFERENCE TIME INFORMATION REPORT which is a response message to REFERENCE TIME INFORMATION REPORTING CONTROL.

[0068] Furthermore, the message transmission / reception unit 128 can transmit a response message (REFERENCE TIME INFORMATION REPORT) including compensation information indicating whether propagation delay compensation with the UE 200 associated with a specific RAN UE ID has been executed.

[0069] Specifically, the message transmission / reception unit 128 can transmit a REFERENCE TIME INFORMATION REPORT including an information element (IE) of the compensation information. The IE may be called Propagation delay compensation needed or Propagation delay compensation completed, etc.

[0070] Furthermore, the message transmission / reception unit 128 can transmit (relay) the system information (SIB9) and DLInformationTransfer msg. transmitted from the CU 110 to the UE 200.

[0071] (3) Operation of the wireless communication system Next, the operation of the wireless communication system 10 will be described. Specifically, the operation related to propagation delay compensation in the CU-DU split gNB deployment will be described.

[0072] (3.1) Premise Table 1 shows the content of the Clock synchronisation service performance requirements defined in Section 5.6.2 of 3GPP TS22.104.

[0073]

Table 1

[0074] Therefore, in this embodiment, a CU-DU split gNB deployment in which CU110 and a plurality of DU120 are geographically separated and arranged is applied. As a result, a wide service area (up to 20 km) can be covered. 2 can be covered.

[0075] (3.2) Problems In order to satisfy high synchronization accuracy while applying CU-DU split gNB deployment, in particular, compensation for the propagation delay in the radio section between UE200 and DU120 is important. However, the problem is how CU110 and a plurality of DU120 cooperate to appropriately compensate for the propagation delay in the radio section with each of the plurality of UE200.

[0076] Specifically, the following problems are considered to exist.

[0077] ·(Problem 1): When the network (gNB100) side compensates for the radio propagation delay, it is not clear whether CU110 or DU120 will perform the compensation, and there is a possibility of double compensation or no compensation.

[0078] ·(Problem 2): Since both the REFERENCE TIME INFORMATION REPORTING CONTROL and the REFERENCE TIME INFORMATION REPORT, which are F1 messages defined in 3GPP TS38.473, are messages unrelated to the UE200 (non-UE associated msg.), when the network side performs propagation delay compensation, the DU120 cannot report to the CU110 the time information with the propagation delay of the radio interval subtracted for each UE200.

[0079] ·(Problem 3): In the F1 interface defined in 3GPP TS 38.473, there is signaling where the CU110 requests time information (Time Reference Information) from the DU120, and the DU120 reports Time Reference Information (which may also be called Reference Time Information) to the CU110. However, it is unclear whether the time information reported from the DU120 to the CU110 has been compensated for propagation delay, and there is a possibility of double compensation or no compensation.

[0080] ·(Problem 4): When instructing the UE200 to perform propagation delay compensation, it is not clear whether it is the CU110 or the DU120 that gives the instruction, and there is a possibility of double instruction or no instruction.

[0081] (3.3) Operation example The following describes an operation example that can solve the above-mentioned Problems 1 to 4.

[0082] (3.3.1) Operation example 1 This operation example corresponds to Problem 1. That is, it is not clear whether it is the CU110 or the DU120 that performs propagation delay compensation, and there is a possibility of double compensation or no compensation.

[0083] Specifically, any one of Operation Examples 1-1 to 1-4 can solve the said problem. In Operation Examples 1-1 to 1-4, either CU110 or DU120 surely executes propagation delay compensation.

[0084] (3.3.1.1) Operation Example 1-1 In this operation example, DU120 executes propagation delay compensation. FIG. 5 shows the sequence of propagation delay compensation according to Operation Example 1-1.

[0085] As shown in FIG. 5, in order to start a random access procedure (RA procedure) with gNB100 (DU120), UE200 transmits a random access preamble (msg.1) to DU120 (S10).

[0086] When DU120 receives the random access preamble, it calculates a Timing advance (TA) command and simultaneously calculates (it may also be referred to as acquisition and reading, the same hereinafter) a UE specific propagation delay specific to UE200 (S20). Note that the calculation of the UE specific propagation delay does not necessarily have to be simultaneous with the calculation of the TA command (TA value).

[0087] DU120 transmits a random access response including the TA command to UE200 (S30). Note that UE200 and DU120 may continue the RA procedure following the random access response.

[0088] DU120 executes propagation delay compensation based on the calculated UE specific propagation delay (S40). Specifically, DU120 may calculate time information obtained by subtracting the UE specific propagation delay and adjust the time information for TSN or the time information for the 5G system (5G GM).

[0089] (3.3.1.2) Operation Example 1-2 Even in this operation example, DU120 performs propagation delay compensation. FIG. 6 shows the sequence of propagation delay compensation according to Operation Example 1-2. Hereinafter, for the parts similar to Operation Example 1-1, the description will be omitted as appropriate.

[0090] As shown in FIG. 6, UE200 and DU120 may establish a connection (RRC connection) in the RRC layer and maintain the connection state in the RRC layer (S110). However, as long as the gNB Rx-Tx time difference can be measured, the connection in the RRC layer does not necessarily have to be established.

[0091] DU120 measures the gNB Rx-Tx time difference (S120). As described above, the gNB Rx-Tx time difference is defined in Section 5.2.3 of 3GPP TS38.215 and may be interpreted as the difference (time difference) between the reception timing and the transmission timing of the specified subframe in DU120.

[0092] Specifically, the gNB Rx-Tx time difference may be defined as (T gNB-RX -T gNB-TX ). Here, T gNB-RX is the reception timing of the positioning node (DU120) of the uplink subframe #i including the Sounding Reference Signal (SRS) associated with UE200, and may be defined by the path first detected within the time.

[0093] T gNB-TX is the transmission timing of the positioning node of the downlink subframe #j that is closest in time to the subframe #i received from DU120.

[0094] DU120 calculates the propagation delay (UE specific propagation delay) between UE200 and DU120 based on the calculated gNB Rx-Tx time difference (S130).

[0095] DU120 performs propagation delay compensation based on the calculated UE specific propagation delay (S140).

[0096] (3.3.1.3) Operation Example 1-3 Also in this operation example, DU120 performs propagation delay compensation. FIG. 7 shows the sequence of propagation delay compensation according to Operation Example 1-3.

[0097] As shown in FIG. 7, CU110 transmits REFERENCE TIME INFORMATION REPORTING CONTROL, which is a type of F1 message, to DU120 (S210). REFERENCE TIME INFORMATION REPORTING CONTROL includes a Propagation delay compensation request for instructing DU120 to perform propagation delay compensation.

[0098] FIG. 13 shows a configuration example of information elements included in the Reporting Request Type of REFERENCE TIME INFORMATION REPORTING CONTROL. As shown in FIG. 13, the Reporting Request Type may include a Propagation delay compensation request.

[0099] DU120 calculates the propagation delay (UE specific propagation delay) between UE200 and DU120 based on the Propagation delay compensation request included in REFERENCE TIME INFORMATION REPORTING CONTROL (S220).

[0100] DU120 performs propagation delay compensation based on the calculated UE specific propagation delay (S230).

[0101] (3.3.1.4) Operation Example 1-4 In this operation example, CU110 performs propagation delay compensation. FIG. 8 shows the sequence of propagation delay compensation according to Operation Example 1-4.

[0102] As shown in FIG. 8, CU110 transmits a POSITIONING MEASUREMENT REQUEST to DU120 (S310). The POSITIONING MEASUREMENT REQUEST may be defined in a positioning measurement procedure for exchanging positioning information of nodes.

[0103] In response to receiving the POSITIONING MEASUREMENT REQUEST, DU120 measures the gNB Rx-Tx time difference (S320).

[0104] DU120 returns a POSITIONING MEASUREMENT RESPONSE including the measured gNB Rx-Tx time difference to CU110 (S330).

[0105] Based on the gNB Rx-Tx time difference received from DU120, CU110 calculates the UE specific propagation delay between UE200 and DU120 (S340).

[0106] Based on the calculated UE specific propagation delay, CU110 performs propagation delay compensation (S350).

[0107] In addition, when DU120 sends a REFERENCE TIME INFORMATION REPORT to CU110, it may indicate that propagation delay compensation is needed in CU110. Alternatively, when DU120 receives a random access preamble (msg.1), it may calculate the TA command and simultaneously calculate the UE specific propagation delay of UE200, and then send the UE specific propagation delay to CU110.

[0108] (3.3.2) Operation Example 2 This operation example corresponds to Problem 2. That is, since REFERENCE TIME INFORMATION REPORTING CONTROL and REFERENCE TIME INFORMATION REPORT are non-UE associated messages, DU120 cannot report time information with the propagation delay of the radio interval subtracted for each UE200 to CU110.

[0109] In this operation example, in order to solve the above problem, REFERENCE TIME INFORMATION REPORTING CONTROL and / or REFERENCE TIME INFORMATION REPORT associated with the RAN UE ID are used.

[0110] Figure 9 shows the sequence of propagation delay compensation according to Operation Example 2. As shown in Figure 9, CU110 sends a REFERENCE TIME INFORMATION REPORTING CONTROL (S410). The REFERENCE TIME INFORMATION REPORTING CONTROL includes the RAN UE ID of UE200 that is the target of propagation delay compensation. As described above, the RAN UE ID is defined in 3GPP TS38.473 and the like.

[0111] Based on the RAN UE ID included in the REFERENCE TIME INFORMATION REPORTING CONTROL, DU120 identifies the target UE200 and calculates the time information (for example, the time information for TSN) used in the identified UE200 (S420). Specifically, DU120 calculates the time information after subtracting the propagation delay of the radio section with the UE200.

[0112] DU120 reports the calculated time information to CU110 by the REFERENCE TIME INFORMATION REPORT (S430). The REFERENCE TIME INFORMATION REPORT includes the RAN UE ID of the UE200.

[0113] Figure 14 shows a configuration example of the information elements included in the REFERENCE TIME INFORMATION REPORT. As shown in Figure 14, the REFERENCE TIME INFORMATION REPORT may include the RAN UE ID, time information (Time Reference Information Per UE), and Propagation delay compensation needed. Propagation delay compensation needed indicates that propagation delay compensation for the UE200 at CU110 is required. Note that the REFERENCE TIME INFORMATION REPORTING CONTROL may also include information elements such as the RAN UE ID.

[0114] CU110 performs propagation delay compensation based on the received time information (S440). Specifically, CU110 calculates the UE specific propagation delay of the UE200 to be compensated for propagation delay based on the received time information, and performs propagation delay compensation based on the calculated UE specific propagation delay.

[0115] (3.3.3) Operation Example 3 This operation example corresponds to Problem 3. That is, there is signaling to report Time Reference Information from DU120 to CU110, but it is unknown whether the time information reported from DU120 to CU110 is compensated for propagation delay, and there is a possibility of double compensation or no compensation.

[0116] In this operation example, in order to solve the problem, DU120 explicitly reports to CU110 that it has performed propagation delay compensation.

[0117] Figure 10 shows the sequence of propagation delay compensation according to Operation Example 3. As shown in Figure 10, CU110 transmits REFERENCE TIME INFORMATION REPORTING CONTROL (S510). Similar to Operation Example 2, the RAN UE ID of UE200 that is the target of propagation delay compensation may be included in the REFERENCE TIME INFORMATION REPORTING CONTROL.

[0118] Based on the RAN UE ID included in the REFERENCE TIME INFORMATION REPORTING CONTROL, DU120 identifies the target UE200 and calculates the time information (for example, the time information for TSN) used in the identified UE200 (S520). Specifically, similar to Operation Example 2, DU120 calculates the time information obtained by subtracting the propagation delay of the radio section with the UE200.

[0119] DU120 performs propagation delay compensation based on the calculated time information (S530). Specifically, DU120 calculates the UE specific propagation delay of UE200 that is the target of propagation delay compensation based on the calculated time information, and performs propagation delay compensation based on the calculated UE specific propagation delay.

[0120] DU120 reports the calculated time information to CU110 by using REFERENCE TIME INFORMATION REPORT (S540). The REFERENCE TIME INFORMATION REPORT may include the RAN UE ID of the UE200 and Propagation delay compensation completed.

[0121] FIG. 15 shows a configuration example of information elements included in Time Reference Information of REFERENCE TIME INFORMATION REPORT. As shown in FIG. 15, Time Reference Information may include Propagation delay compensation completed. Propagation delay compensation completed indicates that DU120 has already executed the propagation delay compensation for the UE200.

[0122] (3.3.4) Operation Example 4 This operation example corresponds to Problem 4. That is, when the network, specifically gNB100, instructs the UE200 to perform propagation delay compensation, it is not clear whether it is CU110 or DU120 that gives the instruction, and there is a possibility of double instruction or no instruction.

[0123] In this operation example, in order to solve the problem, a mechanism is introduced in which CU110 or DU120 can always instruct the UE200 to perform propagation delay compensation, specifically, to instruct Propagation delay compensation needed or Propagation delay compensation completed to the UE200.

[0124] Figure 11 shows the sequence (Part 1) of propagation delay compensation according to Operation Example 4. As shown in Figure 11, CU110 determines a method for compensating the propagation delay in the radio section between UE200 and gNB100 (DU120) (S610). Specifically, CU110 determines to execute propagation delay compensation in UE200.

[0125] Based on the determined method for propagation delay compensation, CU110 determines an instruction for propagation delay compensation for UE200 (S620).

[0126] CU110 transmits system information or a message including the instruction for propagation delay compensation for UE200 to UE200 via DU120 (S630). Specifically, CU110 transmits system information (SIB9) including referenceTimeInfo-r16 and Propagation delay compensation needed, or a DLInformationTransfer msg. including referenceTimeInfo-r16 and Propagation delay compensation needed to UE200.

[0127] Figure 12 shows the sequence (Part 2) of propagation delay compensation according to Operation Example 4. In Figure 11, CU110 determines the method for compensating the propagation delay, but in the sequence of Figure 12, DU120 determines the method for compensating the propagation delay.

[0128] As shown in Figure 12, CU110 transmits system information (SIB9) (S710). SIB9 includes referenceTimeInfo-r16 but does not include Propagation delay compensation needed.

[0129] DU120 determines a method for compensating the propagation delay in the radio section between UE200 and gNB100 (DU120) (S720). Specifically, DU120 determines to execute propagation delay compensation in UE200.

[0130] Based on the determined method for propagation delay compensation, DU120 determines an instruction for propagation delay compensation for UE200 (S730).

[0131] DU120 transmits system information (SIB9) including an instruction for propagation delay compensation for UE200 to UE200 (S740). The SIB9 or DLInformationTransfer msg. includes Propagation delay compensation needed.

[0132] As shown in FIGS. 11 and 12, when including referenceTimeInfo-r16 in SIB9, either CU110 or DU120 may include (encode) an instruction for propagation delay compensation for UE200 (Propagation delay compensation needed) in SIB9. If CU110 does not encode the instruction for propagation delay compensation in SIB9, it may be interpreted that DU120 is implicitly instructed to encode the instruction for propagation delay compensation in SIB9.

[0133] Also, when including referenceTimeInfo-r16 in DLInformationTransfer msg., CU110 may include the instruction for propagation delay compensation in DLInformationTransfer msg.

[0134] Note that as in operation examples 1 to 3, when CU110 or DU120 performs propagation delay compensation, Propagation delay compensation completed may be included in SIB9 or DLInformationTransfer msg.

[0135] FIG. 16 shows a configuration example of the DL Information Transfer msg. As shown in FIG. 16, the DL Information Transfer msg. may include a field of Propagation delay compensation needed. Propagation delay compensation needed may indicate whether the network requests the UE 200 to perform propagation delay compensation. True may indicate that the network requests the UE to perform propagation delay compensation.

[0136] FIG. 17 shows a configuration example of SIB9. As shown in FIG. 17, SIB9 may also include a field of Propagation delay compensation needed.

[0137] (4) Operations and Effects According to the above-described embodiments, the following operations and effects can be obtained. Specifically, even when time information for TSN is handled in the radio communication system 10, the gNB 100 (CU 110 or DU 120) can surely perform compensation for the propagation delay in the radio section between the UE 200 and the gNB 100, or an instruction for propagation delay compensation.

[0138] Therefore, in a scenario of an application that requires high synchronization accuracy, such as IIoT (including a smart grid), even when the CU-DU split gNB deployment is applied, the roles and operations of the CU 110 and the DU 120 are clarified, and the CU 110 and the DU 120 can appropriately cooperate to perform propagation delay compensation between the UE 200 and the gNB 100.

[0139] More specifically, upon receiving a specified message or response (such as a random access preamble (msg. 1), POSITIONING MEASUREMENT RESPONSE, etc.), gNB 100 can obtain the propagation delay with UE 200 and perform propagation delay compensation, which can be executed in CU 110 or DU 120. Thus, the possibility of double compensation or no compensation can be reliably eliminated.

[0140] In this embodiment, gNB 100 (DU 120) can obtain the propagation delay with UE 200 based on the time difference between the reception and transmission of a radio signal (gNB Rx-Tx time difference) and perform propagation delay compensation. Thus, the possibility of double compensation or no compensation can be reliably eliminated.

[0141] In this embodiment, gNB 100 (DU 120) can transmit time information adjusted based on the propagation delay with UE 200 associated with the identification information of UE 200 (RAN UE ID). Thus, DU 120 can report to CU 110 the time information with the propagation delay in the radio section subtracted for each UE 200.

[0142] In this embodiment, gNB 100 (DU 120) can transmit a response message (REFERENCE TIME INFORMATION REPORT) including compensation information (Propagation delay compensation completed) indicating whether propagation delay compensation has been performed for UE 200 associated with the identification information of UE 200 (RAN UE ID). Thus, it can be clarified whether the time information reported from DU 120 to CU 110 has been compensated for propagation delay, and the possibility of double compensation or no compensation can be reliably eliminated.

[0143] In this embodiment, the gNB 100 (CU 110 or DU 120) can include whether or not to instruct the UE 200 on propagation delay compensation to the UE 200 in the system information (SIB9) or a downlink-related message (DL Information Transfer msg.). Therefore, even when instructing the UE 200 on propagation delay compensation, it is possible to clarify which of the CU 110 or DU 120 is making the instruction, and the possibility of double instruction or no instruction can be surely eliminated.

[0144] (5) Other embodiments As described above, the embodiments have been described, but it is obvious to those skilled in the art that the present invention is not limited to the description of the embodiments, and various modifications and improvements are possible.

[0145] For example, in the above-described embodiment, the application of CU-DU split gNB deployment was assumed, but CU-DU split gNB deployment is not necessarily required. That is, the CU 110 and the DU 120 may be arranged in a geographically relatively close location.

[0146] Furthermore, in the above-described embodiment, it was assumed that the radio communication system 10 is connected to the TSN, but it may not necessarily be a network or application scenario that requires high synchronization accuracy such as the TSN.

[0147] In addition, the block diagrams (Figs. 3 and 4) used in the description of the above-described embodiments show blocks of functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Also, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically combined device, or two or more physically or logically separated devices may be directly or indirectly connected (e.g., using wired, wireless, etc.), and realized using these multiple devices. The functional block may be realized by combining software with the above one device or the above multiple devices.

[0148] Functions include, but are not limited to, judgment, decision, determination, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, regarded as, notification (broadcasting), notification (notifying), communication (communicating), forwarding, configuration (configuring), reconfiguration (reconfiguring), allocation (allocating, mapping), assignment (assigning), etc. For example, a functional block (component) that functions as transmission is called a transmission unit or a transmitter. As described above, the realization method is not particularly limited.

[0149] Furthermore, the above-described gNB 100 (CU 110 and DU 120) may function as a computer that performs the processing of the wireless communication method of the present disclosure. Fig. 18 is a diagram showing an example of the hardware configuration of CU 110 and DU 120. As shown in Fig. 18, CU 110 and DU 120 may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, and a bus 1007, etc.

[0150] In the following description, the term "device" can be read as a circuit, device, unit, etc. The hardware configuration of the device may be configured to include one or more of each device shown in the figure, or may be configured without including some devices.

[0151] Each functional block of CU110 and DU120 (see FIGS. 3 and 4) is realized by any hardware element of the computer device or a combination of the hardware elements.

[0152] Also, each function in CU110 and DU120 is realized by causing a predetermined software (program) to be loaded onto hardware such as processor 1001 and memory 1002, so that processor 1001 performs operations, controls communication by communication device 1004, and controls at least one of reading and writing data in memory 1002 and storage 1003.

[0153] Processor 1001 controls the entire computer by operating, for example, an operating system. Processor 1001 may be constituted by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, a register, etc.

[0154] Also, processor 1001 reads a program (program code), software module, data, etc. from at least one of storage 1003 and communication device 1004 into memory 1002, and executes various processes according to these. As the program, a program for causing a computer to execute at least a part of the operations described in the above embodiments is used. Further, the above various processes may be executed by one processor 1001, or may be executed simultaneously or sequentially by two or more processors 1001. Processor 1001 may be mounted by one or more chips. Note that the program may be transmitted from a network via a telecommunication line.

[0155] The memory 1002 is a computer-readable recording medium and may be constituted by at least one of, for example, Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), Random Access Memory (RAM), etc. The memory 1002 may also be referred to as a register, a cache, a main memory (main storage device), etc. The memory 1002 can store a program (program code), a software module, etc. that can execute the method according to an embodiment of the present disclosure.

[0156] The storage 1003 is a computer-readable recording medium and may be constituted by at least one of, for example, an optical disc such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (for example, a compact disc, a digital versatile disc, a Blu-ray (registered trademark) disc), a smart card, a flash memory (for example, a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The storage 1003 may also be referred to as an auxiliary storage device. The above-described recording medium may be, for example, a database, a server, or other appropriate media including at least one of the memory 1002 and the storage 1003.

[0157] The communication device 1004 is hardware (a transmission / reception device) for performing communication between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, etc.

[0158] The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. in order to implement at least one of, for example, Frequency Division Duplex (FDD) and Time Division Duplex (TDD).

[0159] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives an external input. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that performs an external output. Note that the input device 1005 and the output device 1006 may have an integrated configuration (e.g., a touch panel).

[0160] Also, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus or may be configured using different buses for each device.

[0161] Furthermore, the device may be configured to include hardware such as a microprocessor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), etc., and some or all of each functional block may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0162] In addition, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and other methods may be used. For example, the notification of information may be implemented by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (e.g., RRC signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB))), other signals, or a combination thereof. Also, RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0163] Each aspect / embodiment described in the present disclosure may be applied to at least one of a system using Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), other suitable systems, and next-generation systems extended based thereon. Also, a plurality of systems may be combined (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) and applied.

[0164] The processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present disclosure may be rearranged as long as there is no contradiction. For example, for the methods described in the present disclosure, the elements of various steps are presented using an exemplary order and are not limited to the specific order presented.

[0165] Specific operations assumed to be performed by a base station in the present disclosure may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station, various operations performed for communication with a terminal can clearly be performed by at least one of the base station and other network nodes other than the base station (for example, but not limited to, an MME or an S-GW, etc.). Although the case where there is one other network node other than the base station is exemplified above, a combination of a plurality of other network nodes (for example, an MME and an S-GW) may also be possible.

[0166] Information, signals (such as information) can be output from an upper layer (or a lower layer) to a lower layer (or an upper layer). They may also be input and output via a plurality of network nodes.

[0167] The input and output information may be stored in a specific location (for example, a memory) or may be managed using a management table. The input and output information can be overwritten, updated, or appended. The output information may be deleted. The input information may be transmitted to other devices.

[0168] The determination may be made based on a value represented by 1 bit (0 or 1), or may be made based on a Boolean value (true or false), or may be made based on a numerical comparison (for example, comparison with a predetermined value).

[0169] Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched and used during execution. Further, the notification of predetermined information (for example, the notification of "being X") is not limited to being explicitly performed, and may be performed implicitly (for example, by not performing the notification of the predetermined information).

[0170] Software should be broadly construed to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc., whether called software, firmware, middleware, microcode, hardware description language, or by any other name.

[0171] Also, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, when software is transmitted from a website, server, or other remote source using at least one of wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and wireless technologies (such as infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of the transmission medium.

[0172] The information, signals, etc. described in the present disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0173] In addition, with regard to the terms described in this disclosure and the terms necessary for understanding this disclosure, they may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Also, a signal may be a message. Further, a component carrier (CC) may be referred to as a carrier frequency, a cell, a frequency carrier, or the like.

[0174] The terms "system" and "network" used in this disclosure are used interchangeably.

[0175] Also, the information, parameters, etc. described in this disclosure may be represented using absolute values, relative values from a predetermined value, or corresponding other information. For example, a radio resource may be indicated by an index.

[0176] The names used for the above-described parameters are not limiting names in any respect. Furthermore, mathematical formulas and the like using these parameters may be different from those explicitly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable names, the various names assigned to these various channels and information elements are not limiting names in any respect.

[0177] In the present disclosure, terms such as "Base Station (BS)", "radio base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", and "component carrier" may be used interchangeably. The base station may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0178] A base station can accommodate one or more (e.g., three) cells (also referred to as sectors). When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, and each of these smaller areas can also provide communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0179] The term "cell" or "sector" refers to a part or the whole of the coverage area of at least one of the base station and the base station subsystem that provides communication services within this coverage.

[0180] In the present disclosure, terms such as "Mobile Station (MS)", "user terminal", "User Equipment (UE)", and "terminal" may be used interchangeably.

[0181] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term.

[0182] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a communication device, etc. Note that at least one of the base station and the mobile station may be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), a moving body that moves unmanned (e.g., a drone, a self-driving vehicle, etc.), or a robot (humanoid or unmanned). Note that at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0183] Also, the base station in the present disclosure may be read as a mobile station (user terminal, the same hereinafter). For example, each aspect / embodiment of the present disclosure may be applied to a configuration in which communication between a base station and a mobile station is replaced with communication between a plurality of mobile stations (which may be referred to as, for example, Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). In this case, the functions of the base station may be configured as functions of the mobile station. Also, terms such as "uplink" and "downlink" may be read as terms corresponding to communication between terminals (e.g., "side"). For example, an uplink channel, a downlink channel, etc. may be read as a side channel.

[0184] Similarly, the mobile station in the present disclosure may be read as a base station. In this case, the functions of the mobile station may be configured as functions of the base station. A wireless frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that does not depend on numerology.

[0185] Numerology may be communication parameters applied to at least one of transmission and reception of a certain signal or channel. Numerology may indicate at least one of, for example, subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, wireless frame configuration, specific filtering processing performed by a transceiver in the frequency domain, specific windowing processing performed by a transceiver in the time domain, etc.

[0186] A slot may be composed of one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.) in the time domain. A slot may be a time unit based on numerology.

[0187] The slot may include a plurality of mini-slots. Each mini-slot may be composed of one or more symbols in the time domain. Also, the mini-slot may be called a sub-slot. The mini-slot may be composed of a smaller number of symbols than the slot. The PDSCH (or PUSCH) transmitted in a time unit larger than the mini-slot may be called PDSCH (or PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using the mini-slot may be called PDSCH (or PUSCH) mapping type B.

[0188] The radio frame, sub-frame, slot, mini-slot, and symbol all represent time units for transmitting signals. Different names corresponding to each of them may also be used.

[0189] For example, one sub-frame may be called a transmission time interval (TTI), or a plurality of consecutive sub-frames may be called a TTI, or one slot or one mini-slot may be called a TTI. That is, at least one of the sub-frame and the TTI may be the sub-frame (1 ms) in the existing LTE, or a period shorter than 1 ms (for example, 1 - 13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, a mini-slot, etc. instead of a sub-frame.

[0190] Here, the TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, the base station performs scheduling to allocate wireless resources (frequency bandwidth, transmission power, etc. that can be used in each user terminal) to each user terminal in TTI units. Note that the definition of the TTI is not limited to this.

[0191] The TTI may be a transmission time unit such as a channel-coded data packet (transport block), code block, codeword, etc., or may be a processing unit such as scheduling and link adaptation. When the TTI is given, the time interval (e.g., number of symbols) in which a transport block, code block, codeword, etc. are actually mapped may be shorter than the TTI.

[0192] When one slot or one mini-slot is called a TTI, one or more TTIs (i.e., one or more slots or one or more mini-slots) may be the minimum time unit for scheduling. Also, the number of slots (mini-slots) constituting the minimum time unit for the scheduling may be controlled.

[0193] A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel.8 - 12), normal TTI, long TTI, normal subframe, normal subframe, long subframe, slot, etc. A TTI shorter than the normal TTI may be called a shortened TTI, short TTI, partial TTI (partial or fractional TTI), shortened subframe, short subframe, mini-slot, sub-slot, slot, etc.

[0194] Note that the long TTI (e.g., normal TTI, subframe, etc.) may be read as a TTI having a time length exceeding 1 ms, or the short TTI (e.g., shortened TTI, etc.) may be read as a TTI having a TTI length less than that of the long TTI and not less than 1 ms.

[0195] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and in the frequency domain, it may include one or a plurality of consecutive subcarriers. The number of subcarriers included in the RB may be the same regardless of the numerology, for example, it may be 12. The number of subcarriers included in the RB may be determined based on the numerology.

[0196] Also, the time domain of the RB may include one or more symbols and may have the length of one slot, one mini-slot, one sub-frame, or one TTI. One TTI, one sub-frame, etc. may each be composed of one or more resource blocks.

[0197] Note that one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0198] Also, the resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource area of one sub-carrier and one symbol.

[0199] The bandwidth part (BWP) (which may also be referred to as a partial bandwidth, etc.) may represent a subset of consecutive common resource blocks (common RBs) for a certain numerology in a certain carrier. Here, the common RB may be specified by the index of the RB based on the common reference point of the carrier. The PRB is defined in a certain BWP and may be numbered within the BWP.

[0200] The BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs may be set within one carrier for the UE.

[0201] At least one of the set BWPs may be active, and the UE may not be assumed to transmit and receive a predetermined signal / channel outside the active BWP. Note that "cell", "carrier", etc. in the present disclosure may be read as "BWP".

[0202] The structures such as the above-mentioned radio frames, sub-frames, slots, mini-slots, and symbols are merely examples. For example, the number of sub-frames included in a radio frame, the number of slots per sub-frame or radio frame, the number of mini-slots included in a slot, the number of symbols and RBs included in a slot or mini-slot, the number of sub-carriers included in an RB, and the number of symbols, symbol length, Cyclic Prefix (CP) length, etc. within a TTI can be variously changed.

[0203] The terms "connected" and "coupled", or any variations thereof, mean any direct or indirect connection or coupling between two or more elements, and can include the presence of one or more intermediate elements between two elements "connected" or "coupled" to each other. The coupling or connection between elements can be physical, logical, or a combination thereof. For example, "connected" may be read as "accessed". As used in this disclosure, two elements can be considered to be "connected" or "coupled" to each other using at least one of one or more electric wires, cables, and printed electrical connections, and also, by way of some non-limiting and non-exhaustive examples, electromagnetic energy having wavelengths in the radio frequency region, microwave region, and optical (both visible and invisible) region.

[0204] The reference signal can also be abbreviated as Reference Signal (RS) and may be called a Pilot depending on the applicable standard.

[0205] The description "based on" used in this disclosure does not mean "only based on" unless otherwise specified. In other words, the description "based on" means both "only based on" and "at least based on".

[0206] In the configurations of each of the above devices, the "means" may be replaced with a "section", "circuit", "device", or the like.

[0207] Any reference to an element using designations such as "first", "second", etc. used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not mean that only two elements may be employed there, or that the first element must precede the second element in any way.

[0208] In this disclosure, when terms such as "include", "including" and their variants are used, these terms are intended to be inclusive, similar to the term "comprising". Further, the term "or" used in this disclosure is not intended to be an exclusive disjunction.

[0209] In this disclosure, for example, when articles are added by translation, such as a, an and the in English, this disclosure may include that the nouns following these articles are in the plural form.

[0210] As used herein, the terms "determining" and "deciding" may encompass a wide variety of operations. "Determining" and "deciding" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up (e.g., searching a table, database, or other data structure), ascertaining, and considering something as having been "determined" or "decided". "Determining" and "deciding" may also include receiving (e.g., receiving information), transmitting (e.g., transmitting information), inputting, outputting, accessing (e.g., accessing data in memory), and considering something as having been "determined" or "decided". "Determining" and "deciding" may further include resolving, selecting, choosing, establishing, comparing, etc., and considering something as having been "determined" or "decided". That is, "determining" and "deciding" may include considering that some operation has been "determined" or "decided". Also, "determining (deciding)" may be read as "assuming", "expecting", "considering", etc.

[0211] As used herein, the term "A and B are different" may mean that "A and B are different from each other". Note that the term may also mean that "A and B are each different from C". Terms such as "separated", "coupled", etc. may also be interpreted in the same way as "different".

[0212] As described above in detail, it is obvious to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented as modifications and variations without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is for illustrative purposes only and has no restrictive meaning for the present disclosure.

Description of Reference Numerals

[0213] 10 Wireless communication system 20 NG-RAN 25 TSC GM 30 5GC 35 UPF 40 IoT device 100 gNB 110 CU 111 Network connection part 113 DU connection part 115 Delay compensation control part 117 Message transmission / reception part 119 System information transmission part 120 DU 121 Wireless transmission part 123 Wireless reception part 124 CU connection part 125 Delay compensation control part 126 RA processing part 127 Time information processing part 128 Message transmission / reception part 200 UE 1001 Processor 1002 Memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus

Claims

A radio base station comprising a first communication node which is a Central Unit and at least one or more second communication nodes which are Distributed Units, The first communication node transmits a request including identification information of a terminal to the second communication node, The second communication node returns a response including a time difference between reception and transmission of a radio signal to the first communication node in response to the request, The first communication node is a radio base station that performs propagation delay compensation based on the response. A radio base station comprising a first communication node which is a Central Unit and at least one or more second communication nodes which are Distributed Units, The first communication node transmits a request including identification information of a terminal to the second communication node, The second communication node returns a response including a time difference between reception and transmission of a radio signal to the first communication node in response to the request, The first communication node is a radio base station that transmits a message including an instruction for propagation delay compensation to the terminal. A radio base station comprising a first communication node which is a Central Unit and at least one or more second communication nodes which are Distributed Units, The first communication node transmits a request including identification information of a terminal to the second communication node, The second communication node returns a response including a time difference between reception and transmission of a radio signal to the first communication node in response to the request, The first communication node is a radio base station that transmits a message including time information regarding propagation delay to the terminal. A wireless communication method by a radio base station comprising a first communication node which is a Central Unit and at least one or more second communication nodes which are Distributed Units, The first communication node transmits a request including identification information of a terminal to the second communication node, In response to the request, the second communication node returns a response including a time difference between reception and transmission of a wireless signal to the first communication node, The first communication node is a wireless communication method that performs propagation delay compensation based on the response.

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