Terminal and wireless communication method

Abstract

This terminal transmits / receives beams to / from a first transmission / reception point and a second transmission / reception point, and controls beams to / from the first transmission / reception point and the second transmission / reception point. The terminal uses a counter and timer for the first transmission / reception point when a beam failure of the beams to / from the first transmission / reception point is detected in a state where the first transmission / reception point and the second transmission / reception point are set, and the terminal uses a counter and timer for the second transmit / receive point when a beam failure of the beams to / from the second transmission / reception point is detected in a state where the first transmission / reception point and the second transmission / reception point are set.

Description

[Technical Field]

[0001] The present disclosure relates to a terminal and a wireless communication method that support multiple transmission and reception points. [Background technology]

[0002] The 3rd Generation Partnership Project (3GPP) has developed specifications for the 5th generation mobile communication system (5G, also known as New Radio (NR) or Next Generation (NG)), and is also developing specifications for the next generation, known as Beyond 5G, 5G Evolution, or 6G.

[0003] In 3GPP Release 17, an extension of Multiple-Input Multiple-Output (MIMO) is being considered (Non-Patent Document 1). For example, it is being considered that a terminal (User Equipment, UE) will support operations related to multiple transmission / reception points (TRPs) between cells by signaling such as Layer 2.

[0004] In addition, methods for detecting (BFD) and restoring (BFR) beam failures (which may also be called antenna beams) in such a multiple TRP (mTRP) environment are also being studied (Non-Patent Document 2). For example, the introduction of a beam failure counter (BFI_COUNTER) and timer (beamFailureDetectionTimer) specific to each TRP using TRP / BFD-RS (Reference Signal) or BFR-RS is being considered. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] "Revised WID: Further enhancements on MIMO for NR", RP-202024, 3GPP TSG RAN Meeting #89e, 3GPP, September 2020 [Non-patent document 2] "Beam failure with mTRP", R2-2105870, 3GPP TSG-RAN WG2 Meeting #114 Electronic, 3GPP, May 2021 Summary of the Invention

[0006] As described above, in an mTRP environment, when settings such as counters and timers related to beam failure specific to each TRP are applied, the relationship with the beam failure counters and timers for the conventional serving cell is unclear, and the UE may not be able to operate properly.

[0007] Therefore, the following disclosure has been made in consideration of this situation, and aims to provide a terminal and a wireless communication method that can appropriately perform operations related to detecting and recovering from beam failure when supporting multiple TRPs (mTRPs).

[0008] One aspect of the present disclosure is a terminal (UE200) comprising a transceiver unit (wireless communication unit 210) that transmits and receives beams with a first transmission / reception point and a second transmission / reception point, and a control unit (control unit 240) that controls the beams with the first transmission / reception point and the second transmission / reception point, wherein when the first transmission / reception point and the second transmission / reception point are set and a beam failure of the beam with the first transmission / reception point is detected, the control unit uses a counter and timer for the first transmission / reception point, and when the first transmission / reception point and the second transmission / reception point are set and a beam failure of the beam with the second transmission / reception point is detected, the control unit uses a counter and timer for the second transmission / reception point.

[0009] One aspect of the present disclosure is a wireless communication method that includes steps of transmitting and receiving beams with a first transmission / reception point and a second transmission / reception point, and controlling the beams with the first transmission / reception point and the second transmission / reception point, wherein in the controlling step, when a beam failure of the beam with the first transmission / reception point is detected while the first transmission / reception point and the second transmission / reception point are set, a counter and a timer for the first transmission / reception point are used, and when a beam failure of the beam with the second transmission / reception point is detected while the first transmission / reception point and the second transmission / reception point are set, a counter and a timer for the second transmission / reception point are used. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing the overall schematic configuration of a wireless communication system 10. As shown in FIG. [Figure 2] Figure 2 is a functional block diagram of gNB100. [Figure 3] FIG. 3 is a functional block diagram of the UE 200. [Figure 4] FIG. 4 is a diagram showing an example of setting a beam BM in an mTRP environment. [Figure 5] FIG. 5 is a diagram illustrating an example of an operation flow related to BFD and BFR of the UE 200 according to the first operation example. [Figure 6] FIG. 6 is a diagram illustrating an example of an RRC communication sequence related to a beam failure according to the second and third operation examples. [Figure 7] FIG. 7 is a diagram illustrating an example of the configuration of an RLF report according to the second operation example. [Figure 8] FIG. 8 is a diagram illustrating an example of the configuration of MCGFailureInfo (FailureReportMCG) according to the second operation example. [Figure 9] FIG. 9 is a diagram illustrating an example of the configuration of SCGFailureInfo(FailureReportSCG) according to the second operation example. [Figure 10]FIG. 10 is a diagram illustrating a configuration example of beamFailureRecoverySCellConfig according to the third operation example. [Figure 11] FIG. 11 is a diagram showing an example of the hardware configuration of gNB100 and UE200. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described with reference to the drawings. Note that the same or similar reference numerals are used to designate the same functions or configurations, and descriptions thereof will be omitted as appropriate.

[0012] (1) Overall configuration of the wireless communication system 1 is a schematic diagram of the overall configuration of a wireless communication system 10 according to this embodiment. The wireless communication system 10 is a wireless communication system conforming to 5G New Radio (NR), and includes a Next Generation-Radio Access Network 20 (hereinafter, NG-RAN 20) and a terminal 200 (User Equipment 200, hereinafter, UE 200).

[0013] The wireless communication system 10 may be a wireless communication system conforming to a system called Beyond 5G, 5G Evolution, or 6G.

[0014] The NG-RAN 20 includes a radio base station 100 (hereinafter, gNB 100). Note that the specific configuration of the radio communication system 10, including the number of gNBs and UEs, is not limited to the example shown in FIG.

[0015] The NG-RAN 20 actually includes multiple NG-RAN nodes, specifically, gNBs (or ng-eNBs), and is connected to a 5G-compliant core network (5GC, not shown). The NG-RAN 20 and the 5GC may also be simply referred to as a "network."

[0016] The gNB 100 is a radio base station conforming to NR, and performs radio communication conforming to NR with the UE 200. The gNB 100 and the UE 200 are capable of supporting Massive MIMO, which generates a more directional beam BM (see FIG. 4) by controlling radio signals transmitted from multiple antenna elements, specifically, multiple transmission / reception points, for example, transmission / reception point 101 and transmission / reception point 102 (not shown in FIG. 1, see FIG. 4), carrier aggregation (CA), which uses aggregating multiple component carriers (CCs), and dual connectivity (DC), which simultaneously communicates between the UE and multiple NG-RAN nodes.

[0017] The gNB 100 (radio base station) may transmit and receive radio signals via one or more transmission and reception points (TRPs). The gNB 100 may support single-user MIMO using one TRP, or may support distributed MIMO transmission of a predetermined channel (e.g., a physical downlink shared channel (PDSCH)) by coordinating two TRPs.

[0018] TRP may be interchangeably read as cell, radio base station, Node B, antenna port, antenna port group, antenna panel, panel, antenna element, transmission / reception point, etc.

[0019] In addition, in this embodiment, UE 200 may support operations related to multiple transmission / reception points (mTRPs) between cells by signaling such as Layer 1 and / or Layer 2. Specifically, UE 200 can support beam BM failure detection (BFD) and recovery (BFR) in an mTRP environment.

[0020] (2) Functional block configuration of wireless communication system Next, a description will be given of the functional block configuration of the wireless communication system 10. Specifically, the functional block configurations of the gNB 100 and the UE 200 will be described.

[0021] Fig. 2 is a functional block diagram of the gNB100. Fig. 3 is a functional block diagram of the UE200. Note that Figs. 2 and 3 only show main functional blocks relevant to the description of the embodiments, and that the gNB100 and UE200 have other functional blocks (e.g., a power supply unit, etc.). Figs. 2 and 3 show functional block configurations of the gNB100 and UE200, and for the hardware configuration, please refer to Fig. 11.

[0022] (2.1) gNB100 As shown in FIG. 2, the gNB 100 includes a radio communication unit 110, an RRC processing unit 120, a TRP setting unit 130, and a control unit 140.

[0023] The wireless communication unit 110 transmits downlink signals (DL signals) conforming to NR, and also receives uplink signals (UL signals) conforming to NR.

[0024] The RRC processing unit 120 executes various processes in the radio resource control layer (RRC). Specifically, the RRC processing unit 120 can transmit RRC Reconfiguration to the UE 200. The RRC processing unit 120 can also receive RRC Reconfiguration Complete, which is a response to the RRC Reconfiguration, from the UE 200. Note that the RRC processing unit 120 is not limited to these RRC layer messages, and may also execute processes related to other messages (for example, RRC Release and system information (SIB: System Information Block, etc.)).

[0025] The TRP setting unit 130 performs settings related to the TRP. As described above, the gNB 100 may include multiple TRPs. The TRP setting unit 130 can perform settings for the multiple TRPs (mTRPs). The TRP setting unit 130 may perform settings related to MIMO and beamforming. As described above, single-user MIMO may be supported, and multi-user MIMO may also be supported.

[0026] The TRP setting unit 130 can form multiple beams BM with different transmission directions using the TRP and set beam BM reception from the UE 200 using the TRP based on the control of the control unit 140. In addition, the TRP setting unit 130 can perform processing related to beam BM fault detection (BFD) and recovery (BFR).

[0027] The control unit 140 controls each functional block that constitutes the gNB 100. In particular, in this embodiment, the control unit 140 can execute control related to the beam BM in the mTRP environment.

[0028] Specifically, the control unit 140 can perform control related to beam measurement by the UE 200, beam reporting from the UE 200, and beam instructions from the gNB 100.

[0029] Beam fault recovery (BFR) may be interpreted as a procedure for quickly recovering a beam BM that has failed by sending a beam fault recovery request to gNB100 using a beam BM that is not experiencing a failure when a failure occurs in a beam BM that is communicating in a primary cell (PCell: Primary Cell) or PSCell (Primary SCell) due to factors such as a blocked propagation path.

[0030] The control unit 140 may perform beam control that takes into account interference between cells or TRPs based on a beam report reported from the UE 200, specifically, the received power (RSRP: Reference Signal Received Power) measured by the UE 200.

[0031] In addition, in this embodiment, the control unit 140 may introduce a beam failure counter (BFI_COUNTER) and a timer (beamFailureDetectionTimer) specific to each TRP using TRP / BFD-RS (Reference Signal) or BFR-RS for BFD and BFR in the mTRP environment. Note that TRP / BFD-RS and BFR-RS are tentative names, and are reference signals related to TRP and / or BFD / BFR, and may be interpreted as a type of DL-RS (Downlink Reference Signal).

[0032] (2.2)UE200 As shown in FIG. 3, the UE 200 includes a radio communication unit 210, an RRC processing unit 220, a beam setting unit 230, and a control unit 240.

[0033] The wireless communication unit 210 transmits an uplink signal (UL signal) conforming to NR. The wireless communication unit 210 also receives an uplink signal (DL signal) conforming to NR.

[0034] The wireless communication unit 210 receives multiple beams BM transmitted from the gNB 100. The wireless communication unit 210 also transmits a beam BM in a specific direction toward the gNB 100, that is, a beam BM having directionality. As described above, the beam BM may be transmitted and received between the UE 200 and the gNB 100 (radio base station), in other words, a transmission / reception point (TRP).

[0035] In addition, in this embodiment, the number of TRPs may be one or more. Therefore, the wireless communication unit 210 can transmit and receive beam BMs to and from multiple TRPs installed in different locations. The wireless communication unit 210 may constitute a transceiver that transmits and receives beam BMs to and from a first transceiver point (e.g., transceiver point 101 (see FIG. 4)) and a second transceiver point (e.g., transceiver point 102).

[0036] The RRC processing unit 220 executes various processes in the radio resource control layer (RRC). Specifically, the RRC processing unit 220 can send and receive messages in the radio resource control layer.

[0037] The RRC processing unit 220 can receive RRC Reconfiguration from the network, specifically, from the NG-RAN 20. The RRC processing unit 220 can also transmit RRC Reconfiguration Complete, which is a response to the RRC Reconfiguration, to the network.

[0038] Such RRC messages may include information about beam BM failure detection (BFD) and restoration (BFR), such as the setting values ​​of the beam failure counter (BFI_COUNTER) and timer (beamFailureDetectionTimer) specific to each TRP.

[0039] The message may also include a radio link failure (RLF) report and a cell group (master cell group (MCG) and secondary cell group (SCG)) failure report (MCGFailureInfo / SCGFailureInfo). The failure report may include information elements related to beam failure (e.g., beamFailureRecoveryFailure, beamFailureRecoveryFailureForMultiTRP).

[0040] Furthermore, the RRC processing unit 220 may receive system information, specifically, a Master Information Block (MIB) and a System Information Block (SIB), broadcast from the gNB 100. The system information includes a serving cell configuration (ServingCellConfig), and the configuration may include information elements (e.g., candidateBeamRS) related to the mTRP and the beam BM.

[0041] The beam setting unit 230 executes settings related to the beam BM transmitted and received by the wireless communication unit 210. Specifically, the beam setting unit 230 can execute settings related to transmission of a beam BM toward a specific TRP and reception of a beam BM from a specific TRP based on the control of the control unit 240. As described above, the number of TRPs to be the target of transmission and reception may be one, two, or more.

[0042] In addition, the beam setting unit 230 may transmit a report regarding the beam BM to the network. For example, the beam setting unit 230 can transmit a report (beamFailureRecoveryFailureForMultiTRP) indicating a failure in recovery of a beam failure targeting multiple TRPs to the network. In this embodiment, the beam setting unit 230 may configure a transceiver unit that transmits a report indicating a failure in recovery of a beam failure targeting multiple transmission / reception points.

[0043] In addition, the beam setting unit 230 may receive a setting (candidateBeamRS) indicating a candidate beam for each of a plurality of TRPs from the network. In this embodiment, the beam setting unit 230 may configure a transceiver unit that receives a setting indicating a candidate beam for each of a plurality of transceiver points.

[0044] Note that beam failure may be determined by measuring reception quality in a serving cell including the beam BM and non-serving cells. The reception quality may include RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSSI (Received Signal Strength Indicator), SINR (Signal-to-Interference plus Noise power Ratio), etc. The reception quality may also be CSI (Channel State Information).

[0045] The serving cell may be simply interpreted as the cell to which the UE 200 is connected, but more precisely, in the case of an RRC_CONNECTED UE in which carrier aggregation (CA) is not configured, there is only one serving cell that constitutes the primary cell. In the case of an RRC_CONNECTED UE configured using CA, the serving cell may be interpreted as indicating a set of one or more cells including the primary cell and all secondary cells.

[0046] The control unit 240 controls each functional block constituting the UE 200. In particular, in this embodiment, the control unit 240 can execute control related to the beam BM in the mTRP environment.

[0047] Specifically, the control unit 240 can control a beam BM with multiple TRPs, specifically, a first transmission / reception point (e.g., transmission / reception point 101 (see FIG. 4)) and a second transmission / reception point (e.g., transmission / reception point 102). The control of the beam BM may include the directivity, transmission power, transmission timing, BFD threshold setting, BFR execution, etc. of the beam BM.

[0048] In addition, when the control unit 240 detects a beam failure of the beam BM with the first transmission / reception point in a state where the first transmission / reception point and the second transmission / reception point are set, that is, in a state where multiple TRPs are set, the control unit 240 may use a counter and timer (BFI_COUNTER_TRP1, beamFailureDetectionTimer_TRP1) for the first transmission / reception point.

[0049] Specifically, when a beam failure with the first transmission / reception point occurs, the control unit 240 may increment (increase) BFI_COUNTER_TRP1 and start beamFailureDetectionTimer_TRP1.

[0050] Similarly, when multiple TRPs are set and the control unit 240 detects a beam failure of the beam BM with the second transmission / reception point, it may use a counter and timer (BFI_COUNTER_TRP2, beamFailureDetectionTimer_TRP2) for the second transmission / reception point.

[0051] Specifically, when a beam failure with the second transmission / reception point occurs, the control unit 240 may increment (increase) BFI_COUNTER_TRP2 and start beamFailureDetectionTimer_TRP2.

[0052] Furthermore, the control unit 240 may execute the initial access procedure when the value of either counter (BFI_COUNTER_TRP1 or BFI_COUNTER_TRP2) exceeds a threshold in a specific cell.

[0053] Specifically, if the threshold is exceeded, the control unit 240 may execute a random access (RA) procedure. Execution of the RA procedure may be interpreted as transmission of Message 1 (PRACH: Physical Random Access Channel) and / or Message 3.

[0054] Furthermore, the execution of the initial access procedure may be interpreted as the execution of beam failure recovery (BFR) including PRACH transmission. Note that the specific cell may refer to a special cell (SpCell), and the SpCell may refer to a PCell and a PSCell.

[0055] Furthermore, in the secondary cell (SCell), when the value of either counter (BFI_COUNTER_TRP1 or BFI_COUNTER_TRP2) exceeds a threshold, the control unit 240 may execute beam failure recovery (BFR) for the first transmission / reception point and the second transmission / reception point. Specifically, the control unit 240 may execute BFR including transmission of a BFR MAC-CE (Control Element).

[0056] (3) Operation of the wireless communication system Next, a description will be given of the operation of the wireless communication system 10. Specifically, a description will be given of the operation related to beam BM control in an mTRP environment, specifically, the operation related to beam failure detection (BFD) and restoration (BFR).

[0057] (3.1) Operation overview 4 shows an example of setting a beam BM in an mTRP environment. As shown in FIG. 4, UE 200 may transmit and receive beam BMs with multiple TRPs. Specifically, UE 200 can transmit and / or receive a beam BM with transmitting / receiving point 101, and simultaneously transmit and / or receive another beam BM (which may be interpreted as a beam with different directivity) with transmitting / receiving point 102.

[0058] The transmission / reception point 101 and the transmission / reception point 102 may be interpreted as different radio base stations (gNBs), or as positionally different transmission / reception points within the same radio base station.

[0059] Furthermore, the transmission / reception point 101 and the transmission / reception point 102 may each be interpreted as forming a cell.

[0060] In the following operation example, we will explain the operation of more appropriately controlling the beam BM in such an mTRP environment using parameters for the beam BM that are specific to each TRP, specifically, parameters (which may be interpreted as information elements) associated with the beam failure counter (BFI_COUNTER) and the beam failure detection timer (beamFailureDetectionTimer).

[0061] (3.2) Example 1 In this operation example, UE200 may control multiple beams BM in an mTRP environment using a beam failure counter (BFI_COUNTER) and a beam failure detection timer (beamFailureDetectionTimer) specific to each TRP.

[0062] As described above, TRP / BFD-RS (tentative name) is premised on the introduction of BFI_COUNTER and beamFailureDetectionTimer for each TRP (per TRP). In this case, the relationship (separation) between BFI_COUNTER and beamFailureDetectionTimer for each serving cell (per Serving Cell) in 3GPP Release 16 is unclear, and UE 200 may not be able to operate properly with respect to BFD and BFR.

[0063] 5 shows an example of an operation flow related to BFD and BFR of UE 200 according to operation example 1. As shown in FIG. 5, UE 200 configures a TRP (S10). UE 200 may configure multiple TRPs (TRP1, TRP2 in this case). TRP1, TRP2 may be interpreted as corresponding to, for example, transmission / reception points 101, 102 shown in FIG. 4.

[0064] In this manner, in a state where TRP1 and TRP2 are set, UE200 determines whether or not beam fault detection (BFD) is performed in a lower layer (S20). Here, the lower layer may include layer 1 (PHY) and medium access control layer (MAC).

[0065] The UE 200 determines the number of configured TRPs (S25). Here, the UE 200 determines whether the number of configured TRPs is one or two.

[0066] If BFD is present, the UE 200 determines whether BFD has occurred in the TRP1 (S30). If BFD is present in the TRP1, the UE 200 starts a timer for the TRP1, specifically, a beamFailureDetectionTimer_TRP1, and increments (increases) a counter for the TRP1, specifically, a value of BFI_COUNTER_TRP1 (S40).

[0067] On the other hand, in the case of TRP2, the UE 200 starts a timer for TRP1, specifically, beamFailureDetectionTimer_TRP2, and increments (increases) the value of a counter for TRP1, specifically, BFI_COUNTER_TRP2 (S50). Note that if it is determined that two TRPs have been set, the processes of steps S40 and S50 may be executed, respectively.

[0068] The UE 200 determines whether or not the counter value satisfies a predetermined condition (S60, S65), and if the condition is satisfied, may execute BFR (S70).

[0069] The predetermined condition may be, for example, when BFI_COUNTER_TRP1>beamFailureInstanceMaxCount and / or BFI_COUNTER_TRP2>beamFailureInstanceMaxCount is satisfied in the SpCell.

[0070] Alternatively, if the sum of the values ​​of BFI_COUNTER_TRP1 and BFI_COUNTER_TRP2>beamFailureInstanceMaxCount is satisfied, the UE 200 may perform a random access (RA) procedure.

[0071] As described above, the random access procedure may be interpreted as a type of initial access procedure, or more broadly, as a cell-specific BFR including PRACH transmission in the PCell / PSCell defined in 3GPP Release 15 / 16.

[0072] As described above, BFR may be interpreted as a procedure for quickly recovering a beam BM that has experienced a failure by sending a beam failure recovery request to gNB100 using a beam BM that is not experiencing a failure when a failure occurs in a beam BM that is currently communicating due to factors such as the blocking of the propagation path.

[0073] Furthermore, if any of the above conditions is satisfied in the SCell, the UE 200 may perform BFR for both the cell corresponding to TRP1 (which may be a cell formed by TRP1, the same applies below) and the cell corresponding to TRP2.

[0074] Alternatively, if any of the above conditions is satisfied for the SCell, the UE 200 may perform per-cell BFR (particularly, BFR for the SCell and / or BFR including BFR MAC CE (Control Element) transmission) as defined in 3GPP Release 16.

[0075] Furthermore, when either beamFailureDetectionTimer_TRP1 or beamFailureDetectionTimer_TRP2 expires, the UE 200 may reset both BFI_COUNTER_TRP1 and BFI_COUNTER_TRP2, or may reset only one of the corresponding counters.

[0076] Furthermore, the UE 200 may also start an existing beamFailureDetectionTimer (that is, a timer for each cell that is not specific to a TRP) at the timing of starting the beamFailureDetectionTimer_TRP1 or the beamFailureDetectionTimer_TRP2.

[0077] Alternatively, the UE 200 may not start the existing beamFailureDetectionTimer at the timing when the beamFailureDetectionTimer_TRP1 or the beamFailureDetectionTimer_TRP2 is started.

[0078] Furthermore, when the existing beamFailureDetectionTimer expires, the UE 200 may expire beamFailureDetectionTimer_TRP1 and beamFailureDetectionTimer_TRP2, and reset both BFI_COUNTER_TRP1 and BFI_COUNTER_TRP2 to "0." Alternatively, when the beamFailureDetectionTimer_TRP1 or beamFailureDetectionTimer_TRP2 expires, the UE 200 may expire the existing beamFailureDetectionTimer, and reset the existing BFI_COUNTER for each cell to "0."

[0079] (3.3) Example 2 In this operation example, the UE 200 may report a BFR failure for each TRP. Fig. 6 shows an example of an RRC communication sequence related to a beam failure according to the second and third operation examples.

[0080] As shown in FIG. 6, the network (specifically, the NG-RAN 20) may transmit serving cell configuration information (ServingCellConfig) to the UE 200 (step 1).

[0081] Based on the received ServingCellConfig, the UE 200 performs configuration for the serving cell including the beam BM (step 2). Here, as described above, multiple TRPs and beam BMs may be transmitted and received.

[0082] The UE 200 detects beam failure based on the reception quality (RSRP, etc.) of the beam BM (step 3).

[0083] UE 200 may transmit a report about the beam failure to the network (step 4). The report about the beam failure may be included in at least one of an RLF report, an MCGFailureInfo, or an SCGFailureInfo.

[0084] The cause value beamFailureRecoveryFailure is defined in the rlf-cause / failure type of the RLF report, MCGFailureInfo, and SCGFailureInfo defined in 3GPP Release 16. However, in an mTRP environment, this cause value cannot express that beam failure recovery (BFR) has failed simultaneously in multiple TRPs, such as TRP1 and TRP2 (beamFailureRecoveryFailure).

[0085] In this operation example, beamFailureRecoveryFailureForMultiTRP (a tentative name may be used) is added as the rlf-cause / failure type of the RLF report, MCGFailureInfo, and SCGFailureInfo, and this may express that beam failure recovery (BFR) has failed simultaneously in multiple TRPs.

[0086] Fig. 7 shows an example of the configuration of an RLF report according to operation example 2. As shown in Fig. 7, beamFailureRecoveryFailureForMultiTRP for multiple TRPs may be added to beamFailureRecoveryFailure (underlined portion) of the RLF report defined in 3GPP TS38.331.

[0087] FIG. 8 shows an example of the configuration of MCGFailureInfo (FailureReportMCG) according to the second operation example, and FIG. 9 shows an example of the configuration of SCGFailureInfo (FailureReportSCG) according to the second operation example.

[0088] As shown in FIGS. 8 and 9, beamFailureRecoveryFailureForMultiTRP for multiple TRPs may be added to the beamFailureRecoveryFailure (underlined portion) of FailureReportMCG and FailureReportSCG defined in 3GPP TS38.331.

[0089] (3.4) Example 3 In this operation example, the UE 200 may control the beam BM according to the candidateBeamRS for each TRP. In 3GPP Release 16, the candidate beam included in the beamFailureRecoverySCellConfig is set for each cell, but in an mTRP environment, the candidate beam included in the beamFailureRecoverySCellConfig needs to be set for each TRP.

[0090] In this operation example, a candidateBeamRS for each TRP (which may be based on the TRP ID or RS set ID) may be set as information included in beamFailureRecoverySCellConfig.

[0091] Fig. 10 shows a configuration example of beamFailureRecoverySCellConfig according to operation example 3. As shown in Fig. 10, beamFailureRecoverySCellConfig defined in 3GPP TS38.331 may include a candidateBeamRS for each TRP, specifically, a CandidateBeamRSPerTRP (underlined portion).

[0092] Note that beamFailureRecoverySCellConfig may be included in ServingCellConfig, and candidate beam may be interpreted as a candidate beam BM that UE200 can use.

[0093] (4) Actions and Effects According to the above-described embodiment, the following advantageous effects can be obtained: Specifically, in an mTRP environment, the UE 200 can perform beam failure detection and / or recovery using a counter and a timer for each TRP.

[0094] In this way, by using parameters specific to each TRP, the relationship with the conventional counters and timers for each cell becomes clear, and UE200 can appropriately perform operations related to detecting and recovering from beam failure, i.e., beam management, in an mTRP environment.

[0095] In this embodiment, the UE 200 may perform an initial access such as an RA procedure including BFR when the value of either BFI_COUNTER_TRP1 or BFI_COUNTER_TRP2 exceeds a threshold in the SpCell. Also, the UE 200 may perform BFR including BFR MAC CE transmission when the value of either BFI_COUNTER_TRP1 or BFI_COUNTER_TRP2 exceeds a threshold in the SCell. This allows the UE 200 to respond to beam failure in an mTRP environment more quickly.

[0096] In this embodiment, the UE 200 can transmit a report (beamFailureRecoveryFailureForMultiTRP) indicating a failure in recovery of a beam failure for multiple TRPs. Also, the UE 200 can receive a configuration (candidateBeamRS) indicating a candidate beam for each of the multiple TRPs. Therefore, precise beam control can be realized in an mTRP environment.

[0097] (5) Other embodiments Although the embodiments have been described above, it will be obvious to those skilled in the art that the present invention is not limited to the description of the embodiments and that various modifications and improvements are possible.

[0098] For example, in the above-described embodiment, it is assumed that multiple TRPs belong to different radio base stations, but multiple TRPs may belong to the same radio base station. Also, each TRP may form its own cell, or a radio base station including multiple TRPs may form a cell.

[0099] Also, in the above description, "configure," "activate," "update," "indicate," "enable," "specify," and "select" may be interchangeable. Similarly, "link," "associate," "correspond," and "map" may be interchangeable, and "allocate," "assign," "monitor," and "map" may also be interchangeable.

[0100] Furthermore, specific, dedicated, UE-specific, and UE-dedicated may be interchangeable. Similarly, common, shared, group-common, UE-common, and UE-shared may be interchangeable.

[0101] In the present disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "Quasi-Co-Location (QCL)," "Transmission Configuration Indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," etc. may be used interchangeably.

[0102] Furthermore, the block diagrams (FIGS. 2 and 3) used in the description of the above-described embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are connected directly or indirectly (for example, by wire, wirelessly, etc.) and these multiple devices. The functional block may also be realized by combining the single device or multiple devices with software.

[0103] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how each is implemented.

[0104] Furthermore, the above-described gNB100 and UE200 (the device) may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 11 is a diagram showing an example of the hardware configuration of the device. As shown in Fig. 11, the device 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, a bus 1007, etc.

[0105] In the following description, the term "apparatus" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the apparatus may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0106] Each functional block of the device (see Figure 2.3) is realized by any hardware element of the computer device or a combination of the hardware elements.

[0107] In addition, each function of the device is realized by loading specified software (programs) onto hardware such as processor 1001 and memory 1002, causing processor 1001 to perform calculations, control communication via communication device 1004, and control at least one of reading and writing data in memory 1002 and storage 1003.

[0108] The processor 1001 controls the entire computer by running, for example, an operating system, and may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control unit, an arithmetic unit, a register, and the like.

[0109] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-mentioned embodiments. Furthermore, the various processes described above may be executed by one processor 1001, or may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may be transmitted from a network via a telecommunications line.

[0110] The memory 1002 is a computer-readable recording medium and may be configured by, for example, at least one of a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a random access memory (RAM), etc. The memory 1002 may also be called a register, a cache, a main memory (primary storage device), etc. The memory 1002 can store a program (program code), a software module, etc., that can execute a method according to an embodiment of the present disclosure.

[0111] Storage 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray disc), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic strip, etc. Storage 1003 may also be referred to as an auxiliary storage device. The above-mentioned recording medium may be, for example, a database, a server, or other appropriate medium including at least one of memory 1002 and storage 1003.

[0112] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, or a communication module.

[0113] The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize, for example, at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD).

[0114] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0115] Furthermore, each device such as the processor 1001 and the memory 1002 is connected to a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0116] 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), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0117] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher 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. Furthermore, the 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, or the like.

[0118] 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, a 4th generation mobile communication system (4G), a 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), or other suitable system, and a next-generation system extended based on these. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G) may also be applied.

[0119] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless it is consistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0120] In the present disclosure, a specific operation described as being performed by a base station may also be performed by its upper node in some cases. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal may be performed by at least one of the base station and another network node other than the base station (for example, an MME or an S-GW, etc., but are not limited to these). Although the above example illustrates a case where there is one other network node other than the base station, a combination of multiple other network nodes (for example, an MME and an S-GW) may also be used.

[0121] Information, signals (information, etc.) may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0122] The input and output information may be stored in a specific location (for example, memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added to. The output information may be deleted. The input information may be sent to another device.

[0123] The determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0124] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, notification of predetermined information (e.g., notification that "X is true") is not limited to being done explicitly, but may be done implicitly (e.g., by not notifying the predetermined information).

[0125] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0126] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0127] The information, signals, etc. described in this 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 voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0128] Note that terms explained in this disclosure and terms necessary for understanding this disclosure 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). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0129] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0130] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by an index.

[0131] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0132] In this 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. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0133] A base station can accommodate one or more (e.g., three) cells (also called sectors). When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0134] The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication services within that coverage area.

[0135] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0136] 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 terminology.

[0137] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile object, or the mobile object itself. The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. 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.

[0138] Furthermore, a base station in the present disclosure may be read as a mobile station (user terminal, the same applies hereinafter). For example, the aspects / embodiments 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 multiple mobile stations (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the mobile station may be configured to have the functions of a base station. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to communication between terminals (for example, "side"). For example, terms such as uplink channel and downlink channel may be read as side channel.

[0139] Similarly, a mobile station in the present disclosure may be interpreted as a base station, in which case the base station may have the functions of a mobile station. A radio 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 is independent of numerology.

[0140] Numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, such as subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering operations performed by a transceiver in the frequency domain, and specific windowing operations performed by a transceiver in the time domain.

[0141] A slot may consist of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) A slot may be a numerology-based time unit.

[0142] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0143] The radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals, and may be referred to by other names corresponding to the radio frame, subframe, slot, minislot, and symbol.

[0144] For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0145] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. However, the definition of TTI is not limited to this.

[0146] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0147] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0148] A TTI having a time length of 1 ms may be called a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0149] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0150] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0151] The time domain of an RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. Each TTI, subframe, etc. may be composed of one or more resource blocks.

[0152] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, or the like.

[0153] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0154] A Bandwidth Part (BWP) (which may also be referred to as a fractional bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0155] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0156] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0157] The above-described structures of the radio frame, subframe, slot, minislot, and symbol are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, and other configurations can be changed in various ways.

[0158] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using one or more wires, cables, and / or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0159] The reference signal may also be abbreviated as Reference Signal (RS), and may also be called a pilot depending on the applicable standard.

[0160] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0161] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0162] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some way.

[0163] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0164] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0165] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0166] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0167] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure. [Explanation of symbols]

[0168] 10. Wireless communication systems 20 NG-RAN 100 gNB 110 Radio Communication Department 120 RRC processing unit 130 TRP setting section 140 Control Unit 200 UE 210 Radio Communication Department 220 RRC processing unit 230 Beam setting unit 240 Control Unit 1001 processor 1002 memory 1003 Storage 1004 Communication equipment 1005 Input Device 1006 Output Device 1007 Bus

Claims

1. a transceiver unit that transmits and receives beams to and from a first transceiver point and a second transceiver point that are set in a specific cell; a control unit that controls the beams between the first transmitting / receiving point and the second transmitting / receiving point; Equipped with When the control unit detects a beam failure of the beam with the first transmitting / receiving point, the control unit starts a timer for the first transmitting / receiving point and increments a value of a counter for the first transmitting / receiving point; When the control unit detects a beam failure of the beam with the second transmitting / receiving point, the control unit starts a timer for the second transmitting / receiving point and increments a value of a counter for the second transmitting / receiving point; When the total value of the counter for the first transmission / reception point and the counter for the second transmission / reception point exceeds a threshold, the control unit executes a random access procedure in the specific cell.

2. a terminal and a radio base station that forms a specific cell, The terminal a transceiver unit that transmits and receives beams to and from a first transceiver point and a second transceiver point that are set in the specific cell; a control unit that controls the beams between the first transmitting / receiving point and the second transmitting / receiving point; Equipped with When the control unit detects a beam failure of the beam with the first transmitting / receiving point, the control unit starts a timer for the first transmitting / receiving point and increments a value of a counter for the first transmitting / receiving point; When the control unit detects a beam failure of the beam with the second transmitting / receiving point, the control unit starts a timer for the second transmitting / receiving point and increments a value of a counter for the second transmitting / receiving point; A wireless communication system, wherein when the total value of the counter for the first transmission / reception point and the counter for the second transmission / reception point exceeds a threshold, the control unit executes a random access procedure in the specific cell.

3. A step in which a terminal transmits and receives beams to and from a first transmitting / receiving point and a second transmitting / receiving point set in a specific cell; the terminal controlling the beams between the first transmitting / receiving point and the second transmitting / receiving point; Including, In the controlling step, When the terminal detects a beam failure of the beam with the first transmission / reception point, the terminal starts a timer for the first transmission / reception point and increments a value of a counter for the first transmission / reception point; When the terminal detects a beam failure of the beam with the second transmission / reception point, the terminal starts a timer for the second transmission / reception point and increments a value of a counter for the second transmission / reception point; a terminal performing a random access procedure in the specific cell when a total value of a counter for the first transmission / reception point and a counter for the second transmission / reception point exceeds a threshold.

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