Terminal, wireless communication method, and base station

Abstract

A terminal according to one aspect of the present disclosure is characterized by comprising: a transmission unit that transmits a medium access control control element (MAC CE) including information indicating a target cell that is a cell switching target; and a control unit that switches a serving cell to the target cell. This aspect of the present disclosure makes it possible to appropriately perform cell switching.

Description

Terminal, wireless communication method and base station

[0001] The present disclosure relates to a terminal, a wireless communication method, and a base station in a next-generation mobile communication system.

[0002] Long Term Evolution (LTE) has been specified for the Universal Mobile Telecommunications System (UMTS) network with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). Also, LTE-Advanced (3GPP Rel. 10-14) has been specified with the aim of achieving higher capacity and more advanced features than LTE (Third Generation Partnership Project (3GPP (registered trademark)) Release (Rel.) 8, 9).

[0003] Successor systems to LTE (e.g., 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 15 or later, etc.) are also being considered.

[0004] 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010

[0005] In future wireless communication systems, the use of L1L2-triggered mobility (LTM) defined in Rel. 18 when a terminal (user terminal, User Equipment (UE)) moves between cells is being considered. It is being considered that, at the time of a cell switch (switch of serving cell) in LTM, a cell switch command using MAC CE is transmitted from a base station (gNB) to a UE.

[0006] However, the base station may take time to determine whether a cell switch is necessary. Alternatively, if the TCI state of the target cell (candidate cell) used for the cell switch has not been activated in advance, the cell switch may take time. This may prevent the cell switch from being performed quickly, resulting in a decrease in communication throughput during the cell switch.

[0007] Therefore, one of the objects of the present disclosure is to provide a terminal, a wireless communication method, and a base station that can appropriately perform a cell switch.

[0008] A terminal according to one aspect of the present disclosure is characterized by having a transmitter that transmits a Medium Access Control Control Element (MAC CE) including information indicating a target cell to be subjected to cell switch, and a controller that switches a serving cell to the target cell.

[0009] According to one aspect of the present disclosure, a cell switch can be performed appropriately.

[0010] Figure 1 is a diagram showing an example of LTM considered in Rel. 18. Figure 2 is a diagram showing the process between a UE and a base station (gNB) in LTM in Rel. 18. Figure 3 is a diagram showing the process of fast DL synchronization between a UE and a base station (gNB) in LTM in Rel. 18. Figure 4 is a diagram showing the process of fast UL synchronization between a UE and a base station (gNB) in LTM in Rel. 18. Figure 5 is a diagram showing the features of CHO, DAPS, and LTM in Rel. 18 (R18 LTM). Figure 6A is a diagram showing an example of UE movement in an urban area. Figure 6B is a diagram showing the transition of L1-RSRP for PCI #1 and PCI #3 corresponding to Figure 6A. Figure 7A is a diagram showing an example of a UE passing through a tunnel. Figure 7B is a diagram showing the transition of L1-RSRP for PCI #1 and PCI #3 corresponding to Figure 7A. FIG. 8A is a diagram illustrating an example of a case where a UE moves between cells of a low earth orbit (LEO) satellite. FIG. 8B is a diagram illustrating the transition of L1-RSRP of PCI #1 and PCI #3 corresponding to FIG. 8A. FIG. 9 is a diagram illustrating the configuration of a MAC CE for unified TCI state activation / deactivation in Rel. 17. FIG. 10 is a diagram illustrating an example of a MAC CE for Type 1. FIG. 11 is a diagram illustrating an example of a MAC CE for Type 2 (Type 2-1 / 2-2). FIG. 12 is a diagram illustrating an example of a MAC CE for beam reporting. FIGS. 13A and 13B are diagrams illustrating differences between the current beam and measurement values. FIGS. 14A and 14B are diagrams illustrating MAC CEs for a UL cell switch command with a TCI state ID according to the first embodiment. FIGS. 15A and 15B are diagrams illustrating MAC CEs for a UL cell switch command with an RS ID according to the first embodiment. 16A and 16B are diagrams illustrating an example of a MAC CE for a UL cell switch command with a TCI state ID and an L1-RSRP in the first embodiment. FIG. 17A and 17B are diagrams illustrating an example of a MAC CE for a UL cell switch command with an RS ID and an L1-RSRP in the first embodiment. FIG. 18A and 18B are diagrams illustrating a first example of a MAC CE for a UL cell switch command in the second embodiment.19A and 19B are diagrams illustrating a second example of a MAC CE for a UL cell switch command in the second embodiment. FIGS. 20A and 20B are diagrams illustrating a third example of a MAC CE for a UL cell switch command in the second embodiment. FIGS. 21A and 21B are diagrams illustrating a fourth example of a MAC CE for a UL cell switch command in the second embodiment. FIG. 22A is a diagram illustrating a first example of a MAC CE according to aspect 4-1. FIG. 22B is a diagram illustrating a second example of a MAC CE according to aspect 4-1. FIG. 23A is a diagram illustrating an example of a MAC CE according to option 1 of aspect 4-2. FIG. 23B is a diagram illustrating an example of a MAC CE according to option 2 of aspect 4-2. FIG. 24 is a diagram illustrating an example of a MAC CE according to aspect 4-3. FIG. 25 is a diagram illustrating an example of a portion of a MAC CE according to option 1-1 of aspect 5-2. 26A and 26B are diagrams illustrating an example of a portion of a MAC CE of option 1-2 of aspect 5-2. FIGS. 27A and 27B are diagrams illustrating an example of a portion of a MAC CE of option 2 of aspect 5-2. FIG. 28 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 29 is a diagram illustrating an example of a configuration of a base station according to an embodiment. FIG. 30 is a diagram illustrating an example of a configuration of a user terminal according to an embodiment. FIG. 31 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. FIG. 32 is a diagram illustrating an example of a vehicle according to an embodiment.

[0011] (Reporting Configuration (ReportConfigNR)) The ReportConfigNR, an information element of RRC, specifies the trigger criteria for an NR measurement report event, CHO, Conditional PSCell Addition (CPA), Conditional PSCell Change (CPC) event, or Layer 2 UE-to-Network (L2U2N) relay measurement report event. For events labeled AN (N is 1 or 2) as shown below, the measurement report event and CHO, CPA, and CPC events are based on cell measurement results derived based on SS / PBCH blocks or CSI-RS. Note that serving, neighboring, and Primary Cell (PCell) / Primary Secondary Cell (PSCell) may be replaced with the measurement results (L1-RSRP / L1-SINR, etc.) of the serving cell, neighboring cell, and PCell / PSCell.

[0012] Event A1: Serving becomes better than an absolute threshold. Event A2: Serving becomes worse than an absolute threshold. Event A3: Neighbor has a better offset than the PCell / PSCell. Event A4: Neighbor becomes better than an absolute threshold. Event A5: PCell / PSCell becomes worse than absolute threshold 1 and neighbor / SCell becomes better than another absolute threshold 2. Event A6: Neighbor cell becomes a larger offset than the SCell.

[0013] Event D1: The distance between the UE and the reference location (referenceLocation1) becomes larger than a set threshold (distanceThreshFromReference1), and the distance between the UE and the reference location (referenceLocation2) becomes smaller than a set threshold (distanceThreshFromReference2). Conditional event A3: The conditional reconfiguration candidate has a better offset than the PCell / PSCell. Conditional event A4: The conditional reconfiguration candidate becomes better than an absolute threshold. Conditional event A5: The PCell / PSCell becomes worse than absolute threshold 1, and the conditional reconfiguration candidate becomes better than another absolute threshold 2. Conditional event D1: The distance between the UE and the reference location (referenceLocation1) becomes larger than a set threshold (distanceThreshFromReference1), and the distance between the UE and the reference location (referenceLocation2) of the conditional reconfiguration candidate becomes smaller than a set threshold (distanceThreshFromReference2).

[0014] Condition Event T1: The duration measured at the UE exceeds the configured threshold t1-Threshold but is less than t1-Threshold+duration. Event X1: The UE of the serving L2U2N relay becomes worse than absolute threshold 1 and the NR cell becomes better than another absolute threshold 2. Event X2: The UE of the serving L2U2N relay becomes worse than the absolute threshold. For Event I1, the measurement reporting event is based on Cross Link Interference (CLI) measurement results, which are derived based on SRS-RSRP or CLI-RSSI. Event I1: The interference becomes higher than the absolute threshold.

[0015] <Event A1> Event A1 indicates that the serving becomes better than a threshold. Specifically, the UE considers that the entry condition for this event is met when the following condition A1-1 is met, and that the departure condition for this event is met when A1-2 is met. Condition A1-1 Ms - Hys > Threshold Condition A1-2 Ms + Hys <Thresh

[0016] The variables in the above formulas of conditions A1-1 and A1-2 are defined as follows. - Ms is the measurement result of the serving cell, and the offset is not considered. - Hys is the hysteresis parameter of this event (i.e., the parameter (hysteresis) defined within the reporting configuration information (reportConfigNR) for this event). - Thresh is the threshold parameter of this event (i.e., the parameter (a1-Threshold) defined within the reporting configuration information (reportConfigNR) for this event). - The unit of Ms is dBm in the case of RSRP, and dB in the cases of RSRQ and RS-SINR. - Hys is expressed in dB. - The same unit as Ms is applied to Thresh.

[0017] <Event A2> Event A2 indicates that the serving (measurement result of the serving cell) becomes worse than the threshold. Specifically, the UE considers that the input condition of this event is satisfied when the following condition A2-1 is met, and considers that the departure condition of this event is satisfied when A2-2 is met. The meaning of the variables in each condition is the same as that of the variables in A1 above. - Condition A2-1 Ms + Hys < Thresh - Condition A2-2 Ms - Hys > Thresh

[0018] <Event A3> Event A3 indicates that, considering the offset, the neighbor (measurement result of the neighbor cell) becomes better than the SpCell. Specifically, the UE considers that the input condition of this event is satisfied when the following condition A3-1 is met, and considers that the departure condition of this event is satisfied when A3-2 is met.

[0019] - Condition A3-1 Mn + Ofn + Ocn - Hys > Mp + Ofp + Ocp + Off - Condition A3-2 Mn + Ofn + Ocn + Hys < Mp + Ofp + Ocp + Off

[0020] The variables in the formulas of the above conditions A3-1 and A3-2 are defined as follows: Mn is the measurement result of the neighboring cell, without taking into account the offset; Ofn is the measurement object-specific offset of the reference signal of the neighboring cell (i.e., the parameter (offsetMO) defined in the configuration information (measObjectNR) corresponding to the neighboring cell); Ocn is the cell-specific offset of the neighboring cell (i.e., the parameter (cellIndividualOffset) defined in the configuration information (measObjectNR) corresponding to the frequency of the neighboring cell), and is set to zero if not configured for the neighboring cell; Mp is the measurement result of the SpCell, without taking into account the offset; Ofp is the measurement object-specific offset of the SpCell (the parameter (offsetMO) defined in the configuration information (measObjectNR) corresponding to the SpCell); Ocp is the cell-specific offset of the SpCell (the parameter (cellIndividualOffset) defined in the configuration information (measObjectNR) corresponding to the SpCell), and is set to zero if not configured for the SpCell. - Hys is the hysteresis parameter of this event (i.e., the parameter (hysteresis) defined in the configuration information (reportConfigNR) for this event). - Off is the offset parameter of this event (i.e., the parameter (a3-Offset) defined in the configuration (reportConfigNR) for this event). - The units of Mn and Mp for RSRP are dBm, and the units of RSRQ and RS-SINR are dB. - The units of Ofn, Ocn, Ofp, Ocp, Hys, and Off are dB.

[0021] <Event A4> Event A4 indicates that the neighbor (measurement result of the neighbor cell) becomes better than a threshold. Specifically, the UE considers that the entry condition of this event is met when the following condition A4-1 is met, and that the departure condition of this event is met when A4-2 is met. The meanings of the variables in each condition are the same as those of the above-mentioned event A3.

[0022] - Condition A4-1: Mn + Ofn + Ocn - Hys > Thresh; - Condition A4-2: Mn + Ofn + Ocn + Hys < Thresh

[0023] <Event A5> Event A5 indicates that SpCell (measurement result of SpCell) becomes worse than Threshold 1 and the adjacent cell (measurement result of adjacent cell) becomes better than Threshold 2. Specifically, when both of the following specified conditions A5-1 and A5-2 are satisfied, the UE considers that the input condition of this event is satisfied, and when at least one of conditions A5-3 or A5-4 is satisfied, the UE considers that the departure condition of this event is satisfied. Thresh1 and Thresh2 are the thresholds of this event respectively. The unit of Thresh1 is the same as Mp, and the unit of Thresh2 is the same as Mn. The meanings of other variables are the same as those of the variables in Event A3 above.

[0024] - Condition A5-1: Mp + Hys < Thresh1; - Condition A5-2: Mn + Ofn + Ocn - Hys > Thresh2; - Condition A5-3: Mp - Hys > Thresh1; - Condition A5-4: Mn + Ofn + Ocn + Hys < Thresh2

[0025] <Event A6> Event A6 indicates that, considering the offset, the adjacent cell (measurement result of adjacent cell) becomes better than SCell (measurement result of SpCell). Specifically, when the following specified condition A6-1 is satisfied, the UE considers that the input condition of this event is satisfied, and when A6-2 is satisfied, the UE considers that the departure condition of this event is satisfied.

[0026] - Condition A6-1: Mn + Ocn - Hys > Ms + Ocs + Off; - Condition A6-2: Mn + Ocn + Hys < Ms + Ocs + Off

[0027] In this measurement, the secondary cell (SCell) corresponding to the configuration (measObjectNR) related to this event is considered as the serving cell. Furthermore, both the neighbor cell reference signal and the SCell reference signal are indicated in the related configuration (measObjectNR). The variables in the formulas of the above conditions A6-1 and A6-2 are defined as follows. The meanings of the other variables are the same as those of the variables in the above event A3. Ms is the measurement result of the serving cell, and the offset is not taken into account. Ocs is the cell-specific offset of the serving cell (i.e., cellIndividualOffset defined in the related configuration (measObjectNR)), and is set to zero if not configured in the serving cell.

[0028] <Event B1> Event B1 indicates that the inter-Radio Access Technology (RAT) neighbor cell (measurement result of the neighbor cell) becomes better than a threshold. For example, if the RAT of the serving cell is LTE (or NR / 5G), the inter-RAT neighbor cell may be an NR / 5G (or LTE) cell. Specifically, the UE considers that the entry condition of this event is met when the following condition B1-1 is met, and that the departure condition of this event is met when B1-2 is met.

[0029] ・Condition B1-1 Mn+Ofn+Ocn-Hys>Thresh ・Condition B1-2 Mn+Ofn+Ocn+Hys <Thresh

[0030] Mn is the measurement result of the inter-RAT neighbor cell without taking the offset into consideration. Ofn is the measurement target specific offset of the frequency of the inter-RAT neighbor cell (i.e., the parameter (utra-Q-OffsetRange) defined in the configuration information (measObjectEUTRA) corresponding to the frequency of the neighboring inter-RAT cell, and the parameter (utra-FDD-Q-OffsetRange) defined in the configuration information (measObjectUTRA-FDD) corresponding to the frequency of the neighboring inter-RAT cell). Ocn is the cell specific offset of the inter-RAT neighbor cell (i.e., the parameter (cellIndividualOffset) defined in the configuration information (measObjectEUTRA) corresponding to the neighboring inter-RAT cell), and is set to 0 if not configured for the neighbor cell. Hys is the hysteresis parameter of this event (i.e., the parameter (hysteresis) defined in the configuration information (reportConfigInterRAT) of this event). - Threshold indicates the threshold parameter of this event (i.e., the parameter (b1-ThresholdEUTRA) defined in the configuration information (reportConfigInterRAT) of this event or the parameter defined for UTRA-FDD (b1-ThresholdUTRA-FDD)). - The unit of Mn is dBm or dB depending on the measurement quantity of the inter-RAT neighboring cell. - The unit of Ofn, Ocn, and Hys is dB. - The same unit as Mn is used for Threshold.

[0031] <Event B2> Event B2 indicates that the PCell (measurement result of the PCell) becomes worse than threshold 1 and the inter-RAT neighboring cell (measurement result of the neighboring cell) becomes better than threshold 2. Specifically, the UE considers that the entry condition for this event is met when both conditions B2-1 and B2-2 specified below are met, and that the exit condition for this event is met when at least one of conditions B2-3 or B2-4 is met.

[0032] - Condition B2-1: Mp + Hys < Thresh1 - Condition B2-2: Mn + Ofn + Ocn - Hys > Thresh2 - Condition B2-3: Mp - Hys > Thresh1 - Condition B2-4: Mn + Ofn + Ocn + Hys < Thresh2

[0033] - Mp is the measurement result of PCell, and the offset is not considered. - Thresh1 and Thresh2 are the threshold values for this event, respectively. The unit of Thresh1 is the same as that of Mp, and the unit of Thresh2 is the same as that of Mn. The meanings of other variables are the same as those of the variables in Event B1 above.

[0034] <Event T1> Event T1 indicates that the measurement time of the UE is within a predetermined time from the threshold value. Specifically, when the UE satisfies the condition T1-1 defined below, it is considered that the input condition of this event is satisfied, and when the condition T1-2 is satisfied, it is considered that the departure condition of this event is satisfied.

[0035] - Condition T1-1: Mt > Thresh1 - Condition T1-2: Mt > Thresh1 + Duration

[0036] The variables in the formula are defined as follows: - Mt is the time measured by the UE. - Thresh1 is the threshold parameter of this event (that is, the parameter (t1-Threshold) defined in the configuration information (reportConfigNR) corresponding to this event). - Duration is the parameter indicating the period of this event (that is, the parameter (duration) defined in the configuration information (reportConfigNR) corresponding to this event). - The unit of Mt is ms. - The unit of Thresh1 is the same as that of Mt. - The unit of Duration is the same as that of Mt.

[0037] <Event I1> Event I1 indicates that the interference becomes higher than the threshold value. Specifically, when the UE satisfies the condition I1-1 defined below, it is considered that the input condition of this event is satisfied, and when the condition I1-2 is satisfied, it is considered that the departure condition of this event is satisfied.

[0038] ・Condition I1-1 Mi-Hys>Thresh ・Condition I1-2 Mi+Hys <Thresh

[0039] The variables in the equations for the above conditions I1-1 and I1-2 are defined as follows: Mi is the interference measurement result, and offset is not taken into account. Hys is the hysteresis parameter for this event (i.e., the parameter (hysteresis) defined in the configuration information (reportConfigNR) for this event). Threshold is the threshold parameter for this event (i.e., the parameter (i1-Threshold) defined in the configuration information (reportConfigNR) for this event). The units of Mi and Thresh are dBm. The unit of Hys is dB.

[0040] (L1L2-triggered mobility (LTM) in Rel. 18) Figure 1 shows an overview of LTM considered in Rel. 18. A UE establishes an RRC connection with its current serving cell (base station with PCI #1) and transmits an L3 measurement report. Based on the L3 measurement report, the serving cell decides to implement LTM and prepares for LTM with one or more candidate cells. The UE and the serving cell then perform RRC reconfiguration. Note that the one or more candidate cells may include a target cell (base station with PCI #3).

[0041] The UE, serving cell, target cell, and candidate cell perform DL synchronization. The UE performs and reports L1 (e.g., L1-RSRP / SINR) measurements of the serving / candidate / target cell. The UE, serving cell, target cell, and candidate cell perform UL synchronization.

[0042] The serving cell determines to switch the serving cell to the target cell (PCI #3) based on the L1 measurement report and sends a cell switch command to the UE. After receiving the cell switch command, the UE starts PDCCH monitoring for the target cell.

[0043] In the case of RACH-based LTM, the UE performs a RACH procedure to the target cell. In the case of RACH-less LTM, the UE sends an RRC reconfiguration complete message and transmits the first data to the target cell. This first data transmission is based on a dynamic grant or a configuration grant associated with the beam of the target cell. The target cell sends an ACK for this transmission to the UE.

[0044] Figure 2 is a diagram showing processing between a UE and a base station (gNB) in LTM in Rel. 18. The processing of each step in Figure 2 will be described in detail below.

[0045] 1: The UE sends a measurement report message to the gNB, which determines the LTM configuration and starts preparing one or more candidate cells.

[0046] 2: The gNB sends an RRC reconfiguration message to the UE including LTM candidate cell configurations for one or more candidate cells.

[0047] 3: The UE saves its LTM candidate cell configuration and sends an RRC reconfiguration complete message to the gNB.

[0048] 4a: The UE performs DL synchronization with one or more candidate cells before receiving a cell switch command. DL synchronization for candidate cells before the cell switch command may be supported based on at least SSB.

[0049] 4b: If requested by the network, the UE performs early TA acquisition with one or more candidate cells before receiving a cell switch command. This is triggered by a PDCCH order from the source cell via a CFRA. The UE then transmits a preamble to the indicated candidate cells. To minimize data interruption in the source cell due to Contention Free Random Access (CFRA) to the candidate cells, the UE does not receive a RAR intended for TA value acquisition. The TA value of the candidate cell is indicated in the cell switch command. The UE does not maintain a TA timer for the candidate cells and ensures the validity of the TA based on the network implementation.

[0050] 5: The UE performs L1 measurements on the configured candidate cells and sends an L1 measurement report to the gNB. L1 measurements are performed as long as the RRC reconfiguration in step 2 is applied.

[0051] 6: The gNB decides to perform a cell switch to the target cell and sends a MAC CE (Cell Switch Command) to trigger the cell switch. The MAC CE includes a candidate configuration for the index of the target cell. The UE switches to the target cell and applies the configuration indicated by the candidate configuration index.

[0052] 7: If the UE does not have a valid TA for the target cell, it performs a random access procedure to the target cell.

[0053] 8: The UE completes the LTM cell switch procedure by sending an RRC reconfiguration complete message. The UE performs the RA procedure in step 7, and considers the LTM execution to be completed successfully if the random access procedure is successfully completed. In RACH-less LTM, the UE considers the LTM execution to be completed successfully if the network determines that the first UL data has been successfully received. The UE determines the successful reception of the first UL data by receiving a PDCCH specifying the UE's C-RNTI in the target cell that schedules the next new transmission of the first UL data.

[0054] Note that the RRC reconfiguration complete message may always be sent in each LTM run, and steps 4-8 may be performed multiple times for subsequent LTMs using the candidate cell configuration provided in step 2.

[0055] Figure 3 shows the process for fast DL synchronization between a UE and a base station (gNB) in LTM in Rel. 18. When configured by the network, the UE's RRC connection (RRC_CONNECTED) is enabled to enable DL synchronization with a cell different from the current serving cell. This is possible by pre-activating the TCI state belonging to the cell requiring fast DL synchronization. The process for each step in Figure 3 is described in detail below. Figure 3 shows the network-triggered fast TCI state activation (fast DL synchronization) procedure.

[0056] 1: The gNB to which cell A belongs provides the UE with a list of TCI states for cell B in an RRC reconfiguration message. The gNB to which cell A belongs provides a list of TCI states for one or more cells. A fast TCI state activation procedure is performed by the UE for the one or more cells.

[0057] 2: The UE responds to the gNB with an RRC reconfiguration complete message.

[0058] 3: The gNB to which cell A belongs sends an Early TCI state activation MAC CE to initiate the early TCI state activation procedure for cell B. The early TCI state activation MAC CE may also indicate the TCI state of other cells during the TCI state activation procedure.

[0059] 4: The UE activates the TCI state of cell B indicated in the early TCI state activation MAC CE.

[0060] The UE assumes early DL synchronization of the gNB to which cell B belongs. The gNB to which cell A belongs may initiate a cell switch procedure to cell B by providing a cell switch command indicating to cell B that it is the target cell.

[0061] Figure 4 shows the process of fast UL synchronization between a UE and a base station (gNB) in LTM in Rel. 18. When configured by the network, the UE's RRC connection (RRC_CONNECTED) is possible to enable UL synchronization with a cell different from the current serving cell. The process of each step in Figure 4 is described in detail below. Figure 4 shows the fast TA acquisition (fast UL synchronization) procedure triggered by the network.

[0062] 1: The gNB to which cell A belongs provides the UE with a TA acquisition configuration in an RRC reconfiguration message. The TA acquisition configuration includes the RRC configuration information necessary to transmit a random access preamble to cell B. The gNB to which cell B belongs then calculates the TA value to be used by the UE. For example, an LTM cell switch procedure is performed for cell B. The TA acquisition configuration may include information about one or more cells for which the TA acquisition procedure is performed by the UE.

[0063] 2: The UE responds to the gNB with an RRC reconfiguration complete message.

[0064] 3: The gNB to which cell A belongs sends a PDCCH order message to initiate the TA acquisition procedure for cell B. The PDCCH order includes information necessary to transmit a random access preamble to cell B.

[0065] 4: The UE transmits a random access preamble to cell B so that the gNB to which cell B belongs can calculate the TA value to be used by the UE (e.g., when the LTM cell switch procedure is triggered by cell B). If the gNB to which cell A belongs fails to acquire the TA, it can instruct the retransmission of the preamble to acquire the TA.

[0066] 5: When an LTM cell switch procedure is triggered for cell B, the gNB to which cell A belongs provides the UE with the TA value calculated by the gNB to which cell B belongs during the TA acquisition procedure in the LTM cell switch command MAC CE to initiate the cell switch procedure to cell B.

[0067] (Conditional Handover (CHO)) This section describes conditional handover (CHO) in Rel. 16 and later. CHO is applied to, for example, non-terrestrial networks (NTN). In NTN, the following additional trigger conditions are supported for the UE to perform CHO to a candidate cell: Radio Resource Management (RRM) measurement-based event A4. Time-based trigger conditions. Location-based trigger conditions.

[0068] A time-based or location-based trigger condition is always configured together with one of the measurement-based trigger conditions (CHO events A3 / A4 / A5 described below). How the UE evaluates the time-based or location-based trigger conditions together with the RRM measurement-based events is up to the UE implementation.

[0069] (Cellular Systems for 6G) Cellular systems that integrate NTNs and Terrestrial Networks (NTNs) may be considered for 6G to provide network resiliency, sustainability, improved coverage, new services, and improved performance. In particular, in such systems, the Core Network (CN) may also be installed on satellites. In this case, depending on the service, communication quality, location, and time, the UE may switch between the TN and NTN, or may use both the TN and NTN simultaneously. Therefore, a common mobility system may be considered for a system that combines NTNs and TNs.

[0070] Figure 5 illustrates the features of CHO, Dual active protocol stack based handover (DAPS), and Rel. 18 LTM. In addition to legacy HO, the UE supports CHO, Conditional PSCell Addition (CPA), and Conditional PSCell Change (CPC). As shown in Figure 5, CHO and LTM are superior to DAPS in several aspects. CHO, in particular, is more robust. LTM has shorter interruption times. Future cellular systems may use higher frequencies and become more beam-centric (e.g., high-frequency → high-frequency, low-frequency → low-frequency). In this case, L1 measurement reports may be used in all operations. Therefore, mobility enhancement based on LTM is conceivable.

[0071] However, in the LTM of Rel. 18, there are cases where radio link failure (RLF) and handover failure (HOF) become difficult, especially in FR2.

[0072] (Mobility Scenarios) <Scenario 1> Fig. 6A is a diagram showing an example of UE movement in an urban area. Fig. 6B is a diagram showing the transition of L1-RSRP of PCI #1 and PCI #3 corresponding to Fig. 6A. In the case of FR2, dynamic channel changes are frequent, and therefore, in urban areas in particular, there is a possibility that L1-RSRP may suddenly decrease due to the influence of buildings, etc. As a result, Non-Line Of Site (NLOS) and other issues frequently occur.

[0073] In the example of FIG. 6A, the UE moves from the cell of PCI #1 (current serving cell) to the cell of PCI #3 (target cell). In this case, for example, in (1) of FIG. 6B, if the NW receives the measurement result of L1 and detects a drop in L1-RSRP, it decides to perform a cell switch. Then, in (2), the NW transmits a cell switch command to the UE. However, in (2), because the L1-RSRP of PCI #1 is low, there is a possibility that the UE will not be able to receive the cell switch command normally.

[0074] <Scenario 2> Figure 7A is a diagram showing an example in which a UE passes through a tunnel. Figure 7B is a diagram showing the transition of L1-RSRP of PCI #1 and PCI #3 corresponding to Figure 7A. When a UE passes through a tunnel or enters a room, the L1-RSRP may suddenly drop, which may cause a non-line of site (NLOS) or the like. In this case, as in scenario 1, the L1-RSRP of PCI #1 suddenly drops, which may cause the UE to be unable to properly receive a cell switch command.

[0075] <Scenario 3> FIG. 8A is a diagram showing an example in which a UE moves between cells of a low earth orbit (LEO) satellite. FIG. 8B is a diagram showing the transition of L1-RSRP of PCI #1 and PCI #3 corresponding to FIG. 8A. In LEO, the elevation angle is low, so there is a possibility that NLOS or the like may occur due to the influence of buildings, etc. The example of FIG. 8A assumes a case in which both non-terrestrial networks (NTNs) such as LEO and terrestrial networks (TNs) such as PCI #3 exist. In this case, as in Scenario 1, there is a possibility that the UE may not be able to properly receive a cell switch command due to a sudden drop in L1-RSRP of PCI #1. This is the same in both cases of mobility between TNs and NTNs (PCI #1-PCI #3) and mobility between NTNs and NTNs (PCI #1-PCI #4).

[0076] (Activate / Deactivate Unified TCI State MAC CE) The following describes the activate / deactivate unified TCI state MAC CE. The network may activate / deactivate the configured unified TCI state of a serving cell or a serving cell set configured in the simultaneous TCI update list (simultaneousU-TCI-UpdateList1, simultaneousU-TCI-UpdateList2, simultaneousU-TCI-UpdateList3, or simultaneousU-TCI-UpdateList4) by transmitting a activate / deactivate unified TCI state MAC CE. The configured unified TCI state is initially deactivated upon configuration / reconfiguration by higher layers and after reconfiguration by synchronization.

[0077] When the MAC entity receives a unified TCI state activation / deactivation MAC CE on the serving cell, it may indicate information about the unified TCI state activation / deactivation MAC CE to lower layers.

[0078] [Structure of Unified TCI State Activation / Deactivation MAC CE] Figure 9 shows the structure of a unified TCI state activation / deactivation MAC CE in Rel. 17. The unified TCI state activation / deactivation MAC CE is identified by a MAC subheader with an eLCID. This MAC CE has a variable size and consists of the following fields:

[0079] Serving Cell ID: This field indicates the ID of the serving cell to which the MAC CE applies. The length of this field is 5 bits. If the indicated serving cell is configured as part of a simultaneous TCI update list (simultaneousU-TCI-UpdateList1, simultaneousU-TCI-UpdateList2, simultaneousU-TCI-UpdateList3, or simultaneousU-TCI-UpdateList4), this MAC CE applies to all serving cells in the set of simultaneousU-TCI-UpdateList1, simultaneousU-TCI-UpdateList2, simultaneousU-TCI-UpdateList3, or simultaneousU-TCI-UpdateList4, respectively.

[0080] DL BWP ID: This field indicates the DL BWP to which the MAC CE applies as a codepoint in the DCI Bandwidth Part Indicator field. The length of the BWP ID field is 2 bits.

[0081] UL BWP ID: This field indicates the UL BWP to which the MAC CE applies as a codepoint in the DCI Bandwidth Part Indicator field. If the value of unifiedTCI-StateType of the serving cell indicated by the Serving Cell ID is Joint, this field is considered a reserved bit. The length of the BWP ID field is 2 bits.

[0082] Pi: This field indicates whether each TCI code point has multiple TCI states or a single TCI state. If the Pi field is set to 1, it indicates that the TCI code point includes both DL and UL TCI states. If the Pi field is set to 0, it indicates that the TCI code point includes only DL / joint TCI states or only UL TCI states. The code point to which a TCI state is mapped is determined by its ordinal position among all TCI State ID fields.

[0083] D / U: This field indicates whether the TCI state ID of the same octet is a joint / downlink TCI state or an uplink TCI state. If this field is set to 1, the TCI state ID of the same octet is for joint / downlink. If this field is set to 0, the TCI state ID of the same octet is for uplink.

[0084] TCI state ID: This field indicates the TCI state identified by the TCI state ID. If D / U is set to 1, a 7-bit long TCI state ID is used. If D / U is set to 0, the most significant bit of the TCI state ID is considered a reserved bit, and the remaining 6 bits indicate the UL TCI state ID. The maximum number of activated TCI states is 16.

[0085] R: Reserved bit, set to 0.

[0086] (Beam Report MAC CE) An example of a new beam report MAC CE will now be described.

[0087] [Option 1] MAC CE may be defined for each type of beam report (Type 1 indicating intra-cell beam report, and Type 2 indicating inter-cell beam report).

[0088] For example, Fig. 10 shows an example of a MAC CE for Type 1, and Fig. 11 shows an example of a MAC CE for Type 2 (Type 2-1 / 2-2). The MAC CE in Fig. 10 and the MAC CE in Fig. 11 may have different Logical Channel IDs (LCIDs).

[0089] As shown in FIG. 10, the MAC CE for Type 1 includes the second to fourth measurement results and a field indicating the presence of an RS ("C i " field (i = 2, 3, 4)), a field indicating the RS IDs corresponding to the top four beams ("RS ID i" field (i = 1, 2, 3, 4)), a field indicating the measurement results ("L1-RSRP i" field (i = 2, 3, 4)), and a reserved field ("R" field).

[0090] The field indicating the RS ID may consist of 6 bits in the case of SSBRI only, or 7 bits in the case of SSBRI / CRI.

[0091] In the diagram showing an example of MAC CE in the present disclosure, an example in which the measurement results are indicated by L1-RSRP is described, but this is merely an example, and the indicator of the measurement results is not limited to this.

[0092] In the MAC CE, the field corresponding to the measurement result of the best (first highest) beam may be defined by the first number of bits (e.g., 7 bits), in which case the field may indicate the absolute value of the measurement result.

[0093] In the MAC CE, a field corresponding to the measurement results of beams other than the best beam (e.g., the measurement results of the second to fourth beams) may be defined with a second number of bits (e.g., 4 bits), in which case the field may indicate a relative / differential value with respect to the measurement result of the best beam.

[0094] In the MAC CE, a field corresponding to the measurement results of beams other than the best beam (e.g., the measurement results of the second to fourth beams) may be defined by the first number of bits (e.g., 7 bits). In this case, the field may indicate the absolute value of the measurement results.

[0095] In the MAC CE, "C i The "C" field may be represented by 1 bit. i If the "C" field indicates a first value (e.g., 0), it may indicate that the corresponding beam is not reported. i If the " field indicates a second value (e.g., 1), it may indicate that reporting of the corresponding beam is performed.

[0096] For example, if the "C2", "C3", and "C4" fields each indicate 1, the measurement results and RS ID of the second beam, the measurement results and RS ID of the third beam, and the measurement results and RS ID of the fourth beam may be reported in the MAC CE. In other words, only when the "C2", "C3", and "C4" fields indicate 1, the fields (RSRP / PCI) corresponding to the second to fourth beams may be present.

[0097] In FIG. 10, the fields in octets 3 to 7 may be optional.

[0098] The MAC CE for Type 2 shown in FIG. 11 has 16 bits corresponding to octets 8 and 9 added to the MAC CE for Type 1 shown in FIG.

[0099] The additional fields may include a field indicating the PCI of the serving cell / additional cell / candidate cell ("PCI i" field (e.g., i = 1, 2, 3, 4)) and a reserved field ("R" field). The field indicating the PCI may be configured with, for example, 3 bits.

[0100] The additional fields (also utilizing the reserved fields) can indicate the PCI of up to seven additional cells in addition to the PCI of one serving cell. The size of each field can be changed as needed. The size of each field can be configured by the RRC, predefined by a specification, or determined by the UE capabilities.

[0101] For example, the size of a field indicating an RS ID (RS ID field) may be increased or decreased depending on whether a field indicating a PCI (PCI field) is included. For example, if a field indicating a PCI is not included (e.g., Type 2-1), the RS ID field may be increased / extended (e.g., 2 bits). That is, the size of the PCI field may be variable depending on the type of beam report.

[0102] [Current Beam Reporting] The following describes the reporting of the current beam. Fig. 12 is a diagram showing an example of a beam report MAC CE. Figs. 13A and 13B are diagrams showing the difference between the current beam and the measurement value.

[0103] In event-based beam reporting, the UE sends a beam report only when a specific event occurs, where the reported beam is assumed to be a better beam than the current beam.

[0104] Therefore, the beam to be reported can be reported as a difference value with respect to the current beam (based on the current beam). This can reduce the amount of information (number of bits) for reporting and save the overhead of MAC CE. Here, the difference value should always be a positive value with respect to the current beam.

[0105] In the MAC CE shown in FIG. 12, the second to fourth measurement results and a field indicating the presence of an RS ("C i " field (i = 2, 3, 4)), a field indicating the RS IDs corresponding to the top four beams ("RS ID i" field (i = 1, 2, 3, 4)), a field indicating the measurement results ("L1-RSRP i" field (i = 1, 2, 3, 4)), and a reserved field ("R" field).

[0106] In the MAC CE, the field corresponding to the measurement result of the beam may indicate a relative value / differential value with respect to the measurement result of the current beam. In this case, the measurement value (absolute value) of the current beam may not be included. By reporting only the differential value, the communication overhead of the MAC CE can be reduced.

[0107] Assuming that the reported beam is a better beam than the current beam, the difference values ​​of RS1 to RS4 relative to the current beam may be reported as positive values, as shown in FIG. 13A.

[0108] On the other hand, if a beam is not better than the current beam (e.g., RS4), as shown in Figure 13B, the difference value of RS4 may or may not be reported.

[0109] For example, when reporting using MAC CE, the field size is variable, so even if the UE is configured to report four beams, it does not need to report (do not include in the report) negative differential values ​​(RS4 differential values).

[0110] On the other hand, when reporting using UCI (UCI-based beam reporting), the payload is fixed, so the UE needs to report a negative differential value (RS4 differential value).

[0111] <Variations> Whether to add the absolute value of L1-RSRP for the current beam may be set / indicated by higher layer signaling / physical layer signaling, may be predefined by a specification, or may be determined by reporting of UE capabilities. For example, when reporting UE capabilities, the UE may add a new field to the MAC CE / UCI and report it.

[0112] <Further Variations> Whether to report the absolute value for the current beam may be determined based on a predetermined threshold. For example, the UE may report only if the absolute value for the current beam is smaller / larger than X dB. In this case, X may be set / indicated by higher layer signaling / physical layer signaling, may be predefined by a specification, or may be determined by reporting UE capabilities. Note that the gNB may want to know the absolute value of the current beam when the absolute value is very low (almost a failure).

[0113] (Analysis) As described above, the use of L1L2-triggered mobility (LTM) defined in Rel. 18 when a terminal (user terminal, User Equipment (UE)) moves between cells is being considered. It is being considered that, at the time of a cell switch (switch of serving cell) in LTM, a cell switch command using MAC CE is transmitted from a base station (gNB) to a UE.

[0114] However, the base station may take time to determine whether a cell switch is necessary. Alternatively, if the TCI state of the target cell (candidate cell) used for the cell switch has not been activated in advance, the cell switch may take time. This may prevent the cell switch from being performed quickly, resulting in a decrease in communication throughput during the cell switch.

[0115] Therefore, the present inventors came up with a method for appropriately performing a cell switch.

[0116] (Various Replacements, etc.) Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Wireless communication methods according to the embodiments may be applied independently or in combination.

[0117] In the present disclosure, "A / B" and "at least one of A and B" may be interpreted interchangeably. Also, in the present disclosure, "A / B / C" may mean "at least one of A, B, and C."

[0118] In the present disclosure, terms such as notify, activate, deactivate, indicate (or indicate), select, configure, update, and determine may be read interchangeably. In the present disclosure, terms such as support, control, controllable, operate, and operate may be read interchangeably.

[0119] In the present disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher layer parameters, fields, information elements (IEs), settings, etc. may be interchangeable. In the present disclosure, Medium Access Control (MAC) control elements (CEs), update commands, activation / deactivation commands, etc. may be interchangeable.

[0120] In the present disclosure, the higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, other messages (e.g., messages from the core network such as positioning protocol (e.g., NR Positioning Protocol A (NRPPa) / LTE Positioning Protocol (LPP)) messages), or a combination thereof.

[0121] In the present disclosure, MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. Broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0122] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0123] In the present disclosure, the terms index, identifier (ID), indicator, resource ID, etc. may be interchangeable. In the present disclosure, the terms sequence, list, set, group, cluster, subset, etc. may be interchangeable.

[0124] In the present disclosure, the terms panel, UE panel, panel group, beam, beam group, precoder, Uplink (UL) transmitting entity, Transmission / Reception Point (TRP), base station, Spatial Relation Information (SRI), spatial relation, SRS Resource Indicator (SRI), Control Resource Set (CORESET), Physical Downlink Shared Channel (PDSCH), Codeword (CW), Transport Block (TB), Reference Signal (RS), antenna port (e.g., Demodulation Reference Signal (DMRS) port), antenna port group (e.g., DMRS port group), group (e.g., spatial relation group, Code Division Multiplexing (CDM) group, reference signal group, CORESET group, Physical Uplink Control Channel (PUCCH) group, PUCCH resource group), resource (e.g., reference signal resource, SRS resource), resource set (e.g., reference signal resource set), CORESET pool, downlink Transmission Configuration Indication state (TCI state) (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, Quasi-Co-Location (QCL), QCL assumption, etc. may be read as interchangeable.

[0125] In the present disclosure, base station, gNB, and network (NW) may be read interchangeably.

[0126] In the present disclosure, L1-RSRP may be read as L1-SINR, RS and beam may be read as interchangeable, and activation and deactivation may be read as interchangeable.

[0127] In the present disclosure, the terms cell, PCI, serving cell, source serving cell, source cell, CC, BWP, BWP in CC, and band may be interchangeable. In the present disclosure, the terms cell, PCI, target configuration ID, target cell, cell with additional PCI, additional cell, other cell, non-serving cell, cell with a different PCI, candidate cell, candidate cell ID, candidate serving cell, cell with a PCI different from the PCI of the current serving cell, and another serving cell may be interchangeable. The target cell may be a cell selected from multiple candidate cells.

[0128] In the present disclosure, switch, change, and update may be interchangeable. A serving cell may be interchangeable with a serving cell before a switch or a serving cell after a switch. A cell switch may refer to a switch of a serving cell.

[0129] Unless otherwise specified, the function of each field of the MAC CE in each embodiment of the present disclosure may be the same as the function of each field shown in Figures 9 to 12. At least a part of the processing in Figures 1 to 4 may be combined with the processing in each embodiment. For example, the L1 measurement report transmitted by the UE and the cell switch command transmitted by the base station (gNB) may be replaced with the transmission of a MAC CE for the UL cell switch command transmitted by the UE in the first or second embodiment. If the base station first determines that a cell switch is necessary, the DL cell switch command (the cell switch command in Figures 1 and 2) may be applied, and if the UE first determines that a cell switch is necessary, the MAC CE for the UL cell switch command in the first or second embodiment may be applied.

[0130] (Wireless Communication Method) <Embodiment 0> Assuming that Rel. 18 LTM is the baseline, this section explains whether RACH implementation is necessary before transmitting a UL cell switch command and how to handle the situation if it is not implemented. Note that an initial cell switch may refer to the first cell switch with a new LTM setting. On the other hand, Rel. 18 LTM supports subsequent LTM. Subsequent LTM is a subsequent LTM cell switch procedure between multiple candidate cells, and the UE does not require reconfiguration by the network. In other words, the next cell switch can be configured with the same LTM setting as the previous cell switch. This cell switch using subsequent LTM corresponds to the second or subsequent cell switch case described below.

[0131] [Initial Cell Switch Case] ​​<RACH-based LTM Case (RACH is performed to the target cell after sending the cell switch command)> At least DL synchronization and L1 measurements are required. If the UE does not perform UL synchronization, it may use the same TA for the target cell as that of the source cell, or obtain the TA on RACH after the cell switch command. If TCI state activation is not performed, the UE may report the TCI state ID directly in the UL cell switch command, or specify the beam of the target cell on RACH after the cell switch command.

[0132] <RACH-less LTM Case (no RACH to the target cell after sending the cell switch command)> At least DL synchronization, L1 measurements and UL synchronization are required. The UE may report the TCI state ID directly in the UL cell switch command if no TCI state activation is performed.

[0133] [Case of Second or Later Start Switch] In the case of the second or later start switch, the same processing as in the case of the first start switch may be performed. Below, processing that can be performed in addition to the processing in the case of the first start switch will be described.

[0134] There may also be cases where DL synchronization to the target cell is not performed. If DL synchronization is not performed, the UE may maintain the previous DL synchronization to the target cell. If UL synchronization is not performed, the UE may already have and apply at least one of the target TA, PDCCH order RACH with RAR derived by UE-based TA measurements. If TCI state activation is not performed, the target TCI state may have been activated during the previous cell switch.

[0135] [UL Cell Switch Command] The UL cell switch command may include a target setting ID (e.g., 3 bits) for identifying a cell. The target setting ID indicates an index of the target cell / candidate cell setting applied to the cell switch in LTM. In addition, to obtain the advantages of LTM (no RACH after the cell switch command, short interruption time), the UL cell switch command may include an RS ID, a TCI state ID (e.g., 7 bits) / UL TCI state ID (e.g., 6 bits), or a Timing Advance Command (TAC) (e.g., 6 bits or 12 bits). This UL cell switch command will be described in detail in the first and second embodiments.

[0136] <First embodiment> When a condition is satisfied, the UE may transmit a MAC CE for a UL cell switch command including information indicating a target cell to be subjected to cell switch (target configuration ID) to a base station (gNB), perform a cell switch (switch of the serving cell) to the target cell, and start transmission and reception with the target cell / candidate cell. For example, when at least one of the conditions of the above-mentioned events is satisfied, the UE may transmit a MAC CE for the UL cell switch command to the base station.

[0137] The configuration of a MAC CE for a UL cell switch command will be described. Hereinafter, the MAC CE for a UL cell switch command may be simply referred to as a MAC CE. In order to reduce overhead, the MAC CE for a UL cell switch command may have information (E1, E2, E3) indicating whether beam-related information, TA-related information, and BWP-related information of the target cell are included.

[0138] E1 indicates whether the MAC CE includes beam-related information (e.g., at least one of D / U (information indicating whether the corresponding TCI state ID is a joint / downlink TCI state or an uplink TCI state), a TCI state ID, an RS ID, and an L1-RSRP). E2 indicates whether the MAC CE includes Timing Advance (TA)-related information (e.g., a Timing Advance Group (TAG) ID / timing advance command). E3 indicates whether the MAC CE includes a DL / UL BWP ID. Combinations of E1 to E3 and each piece of information may be other than those described above. The MAC CE may include at least one of E1 to E3. For example, E1 to E3 may be set to 0 if each piece of information does not exist, and set to 1 if each piece of information exists.

[0139] The target configuration ID, candidate cell ID, and Physical Cell Identity (PCI) may be associated with each other. This association may be pre-configured in the UE by RRC signaling. The target configuration ID may be associated with a part of the candidate cell ID / PCI. This may improve security and reduce the number of bits in the MAC CE compared to including the candidate cell ID / PCI in the MAC CE.

[0140] The MAC CE may include, instead of E1, at least one of information indicating whether or not a D / U is included, information indicating whether or not a TCI state ID is included, information indicating whether or not an RS ID is included, and information indicating whether or not an L1-RSRP is included.The MAC CE may include, instead of E2, at least one of information indicating whether or not a TAG ID is included, and information indicating whether or not a timing advance command is included.

[0141] Whether the MAC CE for the UL cell switch command includes each piece of information may be configured by the RRC, may be predefined in the specifications, or may be determined based on the UE capabilities.

[0142] 14A and 14B are diagrams illustrating MAC CEs for a UL cell switch command with a TCI state ID according to the first embodiment. The MAC CEs in Fig. 14A and 14B include a target configuration ID indicating a target cell for the cell switch, a DL BWP ID, a UL BWP ID, and a TCI state ID corresponding to the beam to be used. The MAC CE in Fig. 14A further includes a TAG ID and a timing advance command. The MAC CE in Fig. 14B further includes a timing advance command.

[0143] 15A and 15B are diagrams illustrating MAC CEs for a UL cell switch command with an RS ID in the first embodiment. The MAC CEs in Fig. 15A and 15B include a target configuration ID indicating a target cell to switch to, a DL BWP ID, a UL BWP ID, and an RS ID corresponding to a beam to be used. The MAC CE in Fig. 15A further includes a TAG ID and a timing advance command. The MAC CE in Fig. 15B further includes a timing advance command.

[0144] The RS ID may be, for example, an SS / PBCH Block Resource Indicator (SSBRI) / Channel State Information - Reference Signal (CSI-RS) Resource Indicator (CRI), and in that case, may be 7 bits.

[0145] The "Timing Advance Command" field of the MAC CE may be interpreted as "indication of whether the UE has acquired a valid TA", "whether to transmit RACH to the target cell", or "RACH resource to use for the target cell".

[0146] The UE can shorten the interruption time at the cell switch by transmitting the TCI state ID, RS ID, TAG ID, and timing advance command in advance before the cell switch.

[0147] 16A and 16B are diagrams illustrating examples of MAC CEs for a UL cell switch command having a TCI state ID and L1-RSRP in the first embodiment. The MAC CEs in Fig. 16A and 16B include a target configuration ID indicating a target cell to switch to, a DL BWP ID, a UL BWP ID, a TCI state ID corresponding to a beam to be used, and an L1-RSRP (absolute value). The MAC CE in Fig. 16A further includes a TAG ID and a timing advance command. The MAC CE in Fig. 16B further includes a timing advance command.

[0148] 17A and 17B are diagrams illustrating examples of MAC CEs for a UL cell switch command having an RS ID and an L1-RSRP in the first embodiment. The MAC CEs in FIGS. 17A and 17B include a target configuration ID indicating a target cell to switch to, a DL BWP ID, a UL BWP ID, an RS ID corresponding to a beam to be used, and an L1-RSRP (absolute value). The MAC CE in FIG. 17A further includes a TAG ID and a timing advance command. The MAC CE in FIG. 17B further includes a timing advance command.

[0149] The L1-RSRP (absolute value) in Figures 16A, 16B, 17A, and 17B may be the best L1-RSRP among the L1-RSRPs of the RSs received by the UE. If the received L1-RSRP is lower than a threshold, the base station (gNB) may send an instruction to the UE to suspend the cell switch.

[0150] According to the first embodiment, when a cell switch is performed, the UE notifies the base station in advance of beam-related information, TA-related information, and DL / UL BWP IDs, so that the cell switch can be performed quickly.

[0151] <Second embodiment> When a condition is satisfied, the UE may transmit a MAC CE for a UL cell switch command including an RS ID and an RS measurement result (L1-RSRP) to a base station (gNB), perform a cell switch (switch of the serving cell) to a target cell corresponding to the RS, and start transmission and reception with the target cell / candidate cell. The UE may transmit a MAC CE for a UL cell switch command to the base station when, for example, at least one of the conditions of the above-mentioned events is satisfied.

[0152] The MAC CE may include information (S1 to S4) indicating whether the corresponding RS ID is used in the target cell used for the cell switch. For example, if S1 is 1, it means that the RS with RS ID = 1 is used in the target cell used for the cell switch, and if S1 is 0, it means that the RS with RS ID = 1 is not used in the target cell used for the cell switch. Note that S1 to S4 do not need to be set for all RS IDs. For example, S1 to S4 may be set only for the RS ID with the highest L1-RSRP.

[0153] Any of S1 to S4 of the MAC CE being 1 may indicate that the MAC CE includes cell switch information (e.g., at least one of a Target configuration ID, TA-related information, and UL / DL BWP ID).

[0154] 18A and 18B are diagrams illustrating a first example of a MAC CE for a UL cell switch command in the second embodiment. The MAC CE in Fig. 18A and 18B is an example in which four of the Rs in the MAC CE in Fig. 12 and Fig. 10 are replaced with the above S1 to S4, and therefore, descriptions of the same parts as in Fig. 12 and Fig. 10 will be omitted.

[0155] If only one RS ID and L1-RSRP is included, it means that the RS ID and L1-RSRP are reports for a cell switch and the RS ID is used for the target cell. For example, if C2 to C3 = 0, only RS ID1 and L1-RSRP1 are included in the MAC CE.

[0156] 19A and 19B are diagrams illustrating a second example of a MAC CE for a UL cell switch command in the second embodiment. In Figures 19A and 19B, R, E1, E2, a target configuration ID indicating the target cell for cell switch, DL BWP ID, and UL BWP ID are added to the example of Figures 18A and 18B. E1 indicates whether the MAC CE includes DL / UL BWP information. E2 indicates whether the MAC CE includes a TAG ID / timing advance command.

[0157] 20A and 20B are diagrams illustrating a third example of a MAC CE for a UL cell switch command in the second embodiment. The MAC CE in Fig. 20A and 20B has two timing advance commands instead of the TAG ID and timing advance command in the example of Fig. 19A and 19B.

[0158] 19A and 19B and 20A and 20B, the target configuration ID may not be included. In that case, the target configuration ID may be determined based on the RS ID. In FIG. 19A and 19B, the DL / UL BWP ID may not be included. In that case (e.g., when Rel. 18 is the baseline), the DL / UL BWP ID may be pre-configured by RRC signaling.

[0159] 21A and 21B are diagrams showing a fourth example of a MAC CE for a UL cell switch command in the second embodiment. The MAC CE in Fig. 21A and Fig. 21B is an example in which S1 to S4 and PCI1 to PCI4 are added to the MAC CE in Fig. 12 and Fig. 10. Descriptions of the same parts as in Fig. 12 and Fig. 10 will be omitted.

[0160] In Figures 21A and 21B, S1 to S4 report which RS ID (PCI1) is used for the target cell used for the cell switch. That is, S1 to S4 indicate whether the corresponding RS ID or PCI is used for the target cell used for the cell switch. For example, if S1 is 1, this means that the RS with RS ID = 1 and PCI1 are used for the target cell used for the cell switch, and if S1 is 0, this means that the RS with RS ID = 1 and PCI1 are not used for the target cell used for the cell switch. The RS ID and PCI correspond to each other, and the correspondence may be preset by RRC signaling. Therefore, the MAC CE may include only one of the RS ID and PCI.

[0161] Any of S1 to S4 of the MAC CE being 1 may indicate that the MAC CE includes information for cell switching (target configuration ID, TA related information, UL / DL BWP ID).

[0162] The MAC CE in FIGS. 21A and 21B may further include the TAG ID / Timing Advance command shown in FIGS. 19A and 19B, and 20A and 20B.

[0163] The UE may transmit both the MAC CE of the first embodiment and the MAC CE of the second embodiment, or may transmit either one. When transmitting both MAC CEs, the UE may adjust the transmissions so that there are no overlapping items. For example, the UE may transmit the MAC CE of FIG. 14A or 14B after transmitting the MAC CE of FIG. 18A or 18B. For example, when the UE transmits the MAC CE of FIG. 19A, 19B, 20A, or 20B, it may not need to transmit the MAC CE of the first embodiment.

[0164] Since the MAC CE in the second embodiment includes the RS ID and the measurement result of the RS (L1-RSRP), at the time of cell switch, the NW can recognize the quality of the target cell used for the cell switch.

[0165] <Third embodiment> [Aspect 3-1] The UE may report the initiation of a cell switch (trigger a cell switch) to the NW (base station) using any of the following methods: Option 1: The UE reports using a UL cell switch command (e.g., MAC CE in the first embodiment). Option 2: The UE reports using an event-based beam report (e.g., MAC CE in the second embodiment, content independent). Option 2: The UE reports using an event-based beam report (e.g., MAC CE in the second embodiment, any of S1 to S4 is 1).

[0166] The UE may transmit a MAC CE for a UL cell switch command to the base station (gNB) based on DL measurement results (e.g., L1-RSRP / SINR, etc.) of the source cell. The UE may transmit the MAC CE for a UL cell switch command when the measurement results (e.g., L1-RSRP / SINR, etc. included in the CSI report) of the source cell are worse (lower) than a predetermined threshold. For example, the UE may transmit the MAC CE for a UL cell switch command when the measurement results are worse (lower) than a predetermined threshold in a predetermined period of time, or when the UE detects that the measurement results are worse (lower) than the predetermined threshold a predetermined number of times. The fact that the measurement results are worse than the threshold may be notified from the physical layer to the MAC layer, or may be counted by a counter in the MAC layer.

[0167] [Aspect 3-2] The operation of the UE after triggering a cell switch (transmitting a UL cell switch command MAC CE) will be described.

[0168] When the UL cell switch command MAC CE of the first embodiment is applied, the base station / UE may determine whether to perform RACH-less LTM or RACH-based LTM based on the contents of the MAC CE. RACH-less LTM may be performed when at least one of the following conditions is met: Option 1: E1 is 1 (e.g., beam-related information exists) and E2 is 1 (e.g., TA-related information exists). Option 2: The UE has acquired all information necessary for cell switch through a signal from the NW (e.g., the cell switch command MAC CE in the LTM in FIG. 2).

[0169] When the UL cell switch command MAC CE of the second embodiment is applied, the base station / UE may determine whether to perform RACH-less LTM or RACH-based LTM based on the contents of the MAC CE. RACH-less LTM may be performed when at least one of the following conditions is met: Option 3: E2 is 1 (e.g., TA-related information exists). Option 4: The UE has acquired all information necessary for cell switch through a signal from the NW (e.g., the cell switch command MAC CE in the LTM in FIG. 2).

[0170] If none of options 1 to 4 are satisfied, RACH-based LTM may be performed. If at least one of options 1 to 4 is not satisfied, RACH-based LTM may be performed.

[0171] When RACH-based LTM is implemented, the UE transmits PRACH to the target cell using the RACH source configured by RRC signaling and the RS (SSB) reported by the UL cell switch command (based on Rel. 18 LTM), and the UE stops communicating with the source cell.

[0172] When RACH-less LTM is implemented, the UE transmits the first UL data to the target cell on the occasion of the SSB-related configuration grant (configured by RRC) reported by the UL cell switch command (based on Rel. 18 LTM), or the UE monitors the target cell's PDCCH for dynamic scheduling (e.g., based on Rel. 18 LTM), and then the UE stops communicating with the source cell.

[0173] The UE operation of this aspect may be initiated when a specific time (e.g., X ms / symbol / slot) has elapsed after reporting the UL cell switch command. The specific time may be configured in the UE by, for example, RRC signaling, may be predefined in a specification, or may be configured based on the UE capabilities. If the UE receives a DL signal from the NW within the specific time, the cell switch may be canceled.

[0174] The cell switch completion condition may be the same as that of Rel. 18. For example, step 8 of FIG. 2 may be applied.

[0175] <Fourth embodiment> [Aspect 4-1] A UE may receive a MAC CE for TCI state activation / deactivation, in which the TCI state IDs of one or more candidate cells are included, and perform a cell switch (switch of serving cell) to a target cell corresponding to the candidate cells.

[0176] The UE may transmit the MAC CE in the first / second embodiment before the cell switch, or may receive the MAC CE for the cell switch command shown in Fig. 2 from the base station (gNB). The TCI state of the target cell indicated by the MAC CE in the first / second embodiment may be selected from the activated TCI states in the MAC CE in the fourth / fifth / sixth embodiment. This makes it possible to reduce the number of bits used for the TCI state ID of the MAC CE in the first / second embodiment.

[0177] Option 1: The MAC CE may include information indicating whether the TCI state IDs of one or more candidate cells are included in the MAC CE. Figure 22A is a diagram showing a first example of a MAC CE according to aspect 4-1. For example, if any one of R (e.g., R of Oct1) is 0, it may indicate that the MAC CE does not include the TCI state IDs of the candidate cells, and if that R is 1, it may indicate that the MAC CE includes the TCI state IDs of the candidate cells. The Serving Cell ID in Figure 22A may be replaced with a Candidate Cell ID.

[0178] The number of candidate cells corresponding to the TCI states that a single MAC CE can simultaneously activate may be configured in the UE by RRC signaling, may be indicated to the UE by the MAC CE, may be predetermined by a specification, may be determined based on the UE capabilities, or may be configured / indicated / determined in the UE by a combination thereof.

[0179] Option 2: The UE may assume / expect that the TCI state IDs of one or more candidate cells are always included in the MAC CE. Whether the TCI state IDs of candidate cells are always included in the MAC CE may be configured by RRC / predetermined by specifications / determined based on the UE's capabilities.

[0180] The number of candidate cells corresponding to the TCI states that a single MAC CE can simultaneously activate may be configured in the UE by RRC signaling, may be indicated to the UE by the MAC CE, may be predetermined by a specification, may be determined based on the UE capabilities, or may be configured / indicated / determined in the UE by a combination thereof.

[0181] Option 3: A candidate cell ID or a bitmap corresponding to the candidate cell may be included in the MAC CE to indicate whether the TCI state IDs of one or more candidate cells are included in the MAC CE. The MAC CE may include multiple candidate cell IDs. Each bit in the bitmap may correspond to the TCI state ID of one candidate cell. If the candidate cell ID or all bits in the bitmap are 0 (or 1), the TCI state IDs of the candidate cell may not be included in the MAC CE. If the candidate cell ID or all bits in the bitmap are other than 0, the TCI state IDs of the candidate cell may be included in the MAC CE.

[0182] In the MAC CE, the ID of the current serving cell that is configured as a candidate cell may be included in the serving cell ID field.

[0183] Variation: Figure 22B is a diagram showing a second example of a MAC CE of aspect 4-1. As shown in Figure 22B, the MAC CE may include one candidate cell ID. A set of octets in this figure constitutes one set of MAC CE. A one-bit "R" field in each set (e.g., the first set) may indicate whether a next set (e.g., the second set) exists.

[0184] By receiving the MAC CE of this aspect, the UE can know the TCI state IDs of the candidate cells to be activated / deactivated before the cell switch, and therefore can quickly perform the cell switch.

[0185] [Aspect 4-2] A method for indicating candidate cell IDs for TCI state activation will be described.

[0186] Option 1: The MAC CE may include one or more candidate cell IDs for TCI state activation. Fig. 23A is a diagram illustrating an example of a MAC CE according to Option 1 of Aspect 4-2. The MAC CE in Fig. 23A includes two 3-bit candidate cell IDs, but the number of candidate cell IDs included in the MAC CE does not have to be two.

[0187] The B bits for indicating candidate cell IDs are determined by the C candidate cells configured for LTM / TCI state activation (e.g., B=[log2C], where B is the number of bits and C is the number of candidate cells configured for LTM / TCI state activation). C may be configured in the UE by RRC signaling, indicated to the UE by MAC CE, predetermined by specifications, determined based on UE capabilities, or configured / indicated / determined in the UE by a combination thereof.

[0188] In the case of Option 3 of Aspect 4-1, for example, B may be [log2C+1]. A specific bit combination (for example, "000") may indicate a conventional MAC CE. When Option 1 of Aspect 4-1 is applied, a bit indicating whether the TCI status IDs of one or more candidate cells are included in the MAC CE may be included in the position of R in Oct 1 of Fig. 23A.

[0189] Option 2: The MAC CE may include a bit (bitmap) for each candidate cell indicating whether the TCI state IDs of one or more candidate cells are present in the MAC CE. Figure 23B is a diagram illustrating an example of a MAC CE for Option 2 of Aspect 4-2. In the example of Figure 23B, Cell #0 to #6 each correspond to the TCI state ID of one candidate cell. For example, if Cell #X is 0, this means that the MAC CE does not include the TCI state ID of the candidate cell corresponding to Cell #X. If Cell #X is 1, this means that the MAC CE includes the TCI state ID of the candidate cell corresponding to Cell #X.

[0190] The number of candidate cells corresponding to the TCI states that a single MAC CE can simultaneously activate may be configured in the UE by RRC signaling, may be indicated to the UE by the MAC CE, may be predetermined by a specification, may be determined based on the UE capabilities, or may be configured / indicated / determined in the UE by a combination thereof.

[0191] When option 1 of aspect 4-1 is applied, a bit indicating whether the TCI status IDs of one or more candidate cells are included in the MAC CE may be included in the position of Cell #0 in Oct 1 of FIG. 23B.

[0192] By receiving the MAC CE of this aspect, the UE can grasp the TCI state IDs of multiple candidate cells that will be activated / deactivated before the cell switch, so that the cell switch can be performed quickly even if there are multiple candidate cells that are candidates for the cell switch.

[0193] [Aspect 4-3] Fig. 24 is a diagram showing an example of a MAC CE according to aspect 4-3. As shown in Fig. 24, the MAC CE may include one or more TCI state IDs for each candidate cell ID. For example, TCI state IDs 1 to N indicate the TCI state of candidate cell ID 0, and TCI state IDs 1 to N (for Cell ID 1) indicate the TCI state of candidate cell ID 1. In the example of Fig. 24, the TCI state IDs are arranged in ascending order of candidate cell IDs, but they may also be arranged in descending order of candidate cell IDs.

[0194] The number (N) of TCI state IDs of each candidate cell included in the MAC CE may be determined as in Option 1 or 2 below: Option 1: N is the same as the number of TCI state IDs of the serving cell. Option 2: N may be configured to the UE by RRC signaling, indicated to the UE by the MAC CE, predetermined by specifications, determined based on UE capabilities, or configured / indicated / determined to the UE by a combination thereof.

[0195] The number (N) of TCI state IDs of each candidate cell included in the MAC CE may be set / indicated / determined for all candidate cells on a per-band / CC basis and per-candidate-cell basis.

[0196] By receiving the MAC CE of this aspect, the UE can quickly perform a cell switch even when there are multiple TCI states corresponding to candidate cells.

[0197] Fifth Embodiment The MAC CE in the fifth embodiment may be combined with at least a part of the MAC CE in the fourth embodiment. [Aspect 5-1] Option 1: The same eLCID-added MAC subheader as in the conventional MAC CE is applied, and a specific bit in the MAC CE (e.g., the first bit in Oct 1) may indicate whether the configuration of the cell in the subsequent MAC CE is for a serving cell or a candidate cell. In this case, the conventional MAC CE (e.g., FIG. 9) can be reused. For example, a 0 in the specific bit may indicate that the configuration of the subsequent cell is for a serving cell, and a 1 in the specific bit may indicate that the configuration of the subsequent cell is for a candidate cell.

[0198] Option 2: A new MAC CE (separate from the MAC CE for the serving cell) containing the TCI state ID of the candidate cell may be applied, in which case there is no need to allocate a bit indicating whether it is a serving cell or a candidate cell.

[0199] [Aspect 5-2] The new MAC CE includes information indicating one or more candidate cells for which the TCI state ID is used, and at least one of Pi, D / U, and the TCI state ID.

[0200] Pi may be set for each candidate cell, and if it is 1, it means that there are multiple TCI states, and if it is 0, it means that there is a single TCI state. D / U may be set for each TCI state ID, and if it is 1, it means that there is a joint / downlink TCI state, and if it is 0, it means that there is an uplink TCI state. The TCI state ID may be, for example, 6 bits or 7 bits.

[0201] As information indicating one or more candidate cells for which TCI state ID is used, one of the following options is applied: Option 1: Candidate cell ID for TCI state activation. Option 2: Bitmap (each bit corresponds to a candidate cell).

[0202] In the case of Option 1, the following options are further considered for setting / indicating the number (C) of candidate cells for which a single MAC CE can simultaneously activate the TCI state: Option 1-1: C may be configured in the UE by RRC signaling, may be predetermined by specifications, may be determined based on UE capabilities, or may be set / indicated / determined in the UE by a combination thereof. Option 1-2: C may be indicated by the single MAC CE.

[0203] 25 is a diagram showing an example of a part of MAC CE of option 1-1 of aspect 5-2. In this example, it is assumed that the number of candidate cells is set to 4. In this case, E1 to E3 in FIGS. 26A and 26B described below are unnecessary.

[0204] 26A and 26B are diagrams illustrating an example of a portion of a MAC CE according to Option 1-2 of Aspect 5-2. In this example, E1 to E3 indicate whether Cell IDs 1 to 3 exist, respectively (e.g., 0: not present, 1: present). Because at least one candidate cell (Cell ID 0 in this example) exists, E0 does not need to be included.

[0205] The total number of candidate cells configured for activation of the LTM / TCI state may be configured in the UE by RRC signaling, may be predetermined by specifications, may be determined based on UE capabilities, or may be configured / indicated / determined in the UE by a combination thereof.

[0206] 27A and 27B are diagrams illustrating an example of a portion of a MAC CE in Option 2 of Aspect 5-2. Cell#i (0 to 7 in FIG. 27A, 0 to 6 in FIG. 27B) in FIG. 27A and 27B respectively correspond to candidate cells, and the TCI status ID of the corresponding candidate cell indicates whether or not a MAC CE exists (e.g., 0: not present, 1: present).

[0207] Note that the MAC CE of this aspect may be combined with any MAC CE of the fourth embodiment. For example, Figures 25, 26A and 26B, and 27A and 27B may further include a serving cell ID, a DL / UL BWP ID, Pi, D / U, a TCI state ID, R, etc. Also, the MAC CE of this aspect may be combined with any MAC CE of the first or second embodiment.

[0208] The UE of this aspect is notified in the MAC CE of the number of candidate cells, whether or not a candidate cell exists, whether or not a TCI state ID of a candidate cell exists, and so on, and therefore, can improve the efficiency of processing without performing unnecessary reading.

[0209] Sixth Embodiment A UE may receive a MAC CE in the present disclosure in at least one of a PCell and an SCell.

[0210] If a MAC CE in the present disclosure includes one or more TCI state IDs configured for both the candidate cell and the serving cell, any of the following options may be applied: Option 1: The UE activates the TCI state configured for the serving cell only. Option 2: The UE activates the TCI state configured for the candidate cell only. Option 3: The UE activates the TCI state configured for both the candidate cell and the serving cell.

[0211] According to this embodiment, the TCI state IDs of the candidate cell and the serving cell are notified in one MAC CE, so that overhead can be reduced.

[0212] <Supplementary Information> [Notification of Information to UE] In the above-described embodiments, any information may be notified to the UE (from a network (NW) (e.g., a base station (BS))) (in other words, reception of any information from the BS by the UE) using physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal / channel (e.g., PDCCH, PDSCH, reference signal), or a combination thereof.

[0213] When the notification is performed by a MAC CE, the MAC CE may be identified by including a new Logical Channel ID (LCID) in the MAC subheader, which is not defined in existing standards.

[0214] When the notification is made by DCI, the notification may be made by a specific field of the DCI, a Radio Network Temporary Identifier (RNTI) used to scramble Cyclic Redundancy Check (CRC) bits assigned to the DCI, the format of the DCI, etc.

[0215] Furthermore, notification of any information to the UE in the above embodiments may be performed periodically, semi-persistently, or aperiodically.

[0216] [Notification of Information from UE] In the above-described embodiments, notification of any information from the UE (to the NW) (in other words, transmission / report of any information from the UE to the BS) may be performed using physical layer signaling (e.g., UCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal / channel (e.g., PUCCH, PUSCH, PRACH, reference signal), or a combination thereof.

[0217] When the notification is performed by a MAC CE, the MAC CE may be identified by including a new LCID, which is not defined in existing standards, in the MAC subheader.

[0218] If the notification is made by UCI, the notification may be transmitted using PUCCH or PUSCH.

[0219] Furthermore, any information in the above-described embodiments may be notified from the UE periodically, semi-persistently, or aperiodically.

[0220] [Application of Each Embodiment] At least one of the above-described embodiments may be applied when a specific condition is met. The specific condition may be defined in a standard or may be notified to a UE / BS using higher layer signaling / physical layer signaling.

[0221] At least one of the above-described embodiments may be applied only to UEs that have reported or support a specific UE capability. Note that "supporting" and "whether to support" may be interpreted as interchangeable.

[0222] The specific UE capability may indicate at least one of the following: - Supporting specific processing / operation / control / information for at least one of the above embodiments; - The maximum number of TCI state IDs, RS IDs, L1-RSRPs included in one MAC CE for UL Cell Switch Command; - Supporting MAC CE for UL Cell Switch Command; - Supporting activation of TCI state of candidate cell by MAC CE; - The maximum number of candidate cell IDs included in one MAC CE; - The maximum number of TCI state IDs corresponding to one candidate cell ID included in MAC CE.

[0223] Furthermore, the above-mentioned specific UE capability may be a capability that is applied across all frequencies (commonly regardless of frequency), or may be a capability for each frequency (e.g., one or a combination of a cell, a band, a band combination, a BWP, a component carrier, etc.), or may be a capability for each frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), or may be a capability for each subcarrier spacing (SubCarrier Spacing (SCS)), or may be a capability for each Feature Set (FS) or Feature Set Per Component-carrier (FSPC).

[0224] Furthermore, the specific UE capability may be a capability that is applied to all duplexing methods (commonly regardless of the duplexing method), or may be a capability for each duplexing method (e.g., Time Division Duplex (TDD) or Frequency Division Duplex (FDD)).

[0225] Furthermore, at least one of the above-described embodiments may be applied when the UE configures / activates / triggers specific information related to the above-described embodiment (or performs the operations of the above-described embodiment) through higher layer signaling / physical layer signaling. For example, the specific information may be any RRC parameter for a specific release (e.g., Rel. 18 / 19), etc.

[0226] If the UE does not support at least one of the specific UE capabilities or is not configured with the specific information, the UE may apply, for example, the behavior of Rel. 15 / 16 / 17.

[0227] (Supplementary Notes) The following inventions are supplementary notes regarding one embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a transmitter that transmits a Medium Access Control Element (MAC CE) including information indicating a target cell to be subjected to cell switch; and a controller that switches a serving cell to the target cell. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the MAC CE includes at least one of a Transmission Configuration Indication (TCI) state ID, information indicating whether the corresponding TCI state ID is a joint or downlink TCI state, or an uplink TCI state, a Reference Signal (RS) ID, and a Layer 1-Reference Signal Received Power (L1-RSRP). [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the MAC CE includes at least one of a Timing Advance Group (TAG) ID and a timing advance command. [Supplementary Note 4] The terminal according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the control unit determines whether to perform Random Access Channel (RACH)-less L1L2-triggered mobility (LTM) or RACH-based LTM based on the contents of the MAC CE.

[0228] (Supplementary Notes) The following inventions are further supplemented with respect to one embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a transmitter that transmits a Medium Access Control Element (MAC CE) including a Reference Signal (RS) ID and a measurement result of the RS; and a controller that switches a serving cell to a target cell corresponding to the RS. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the MAC CE includes information indicating whether the RS ID is used in a target cell used for switching the serving cell. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the MAC CE includes a Physical Cell Identifier (PCI) corresponding to the RS ID. [Supplementary Note 4] The terminal according to any one of Supplementary Notes 1 to 3, wherein the controller determines whether to perform Random Access Channel (RACH)-less L1L2-triggered mobility (LTM) or RACH-based LTM based on the content of the MAC CE.

[0229] (Supplementary Notes) The following inventions are further supplemented with respect to one embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a receiver that receives a Medium Access Control Element (MAC CE) for activating or deactivating a Transmission Configuration Indication (TCI) state, the TCI state ID of one or more candidate cells is included; and a controller that switches a serving cell to a target cell corresponding to the candidate cell. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the MAC CE includes information indicating whether the TCI state IDs of the one or more candidate cells are included in the MAC CE. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the MAC CE includes IDs of the one or more candidate cells for TCI state activation, or a bit for each candidate cell indicating whether the TCI state IDs of the one or more candidate cells are present in the MAC CE. [Supplementary Note 4] The terminal according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the MAC CE includes information indicating whether a cell configuration in the MAC CE is for a serving cell or a candidate cell.

[0230] (Wireless Communication System) The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above embodiments of the present disclosure or a combination thereof.

[0231] 28 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 (which may be simply referred to as system 1) may be a system that realizes communication using Long Term Evolution (LTE) or 5th generation mobile communication system New Radio (5G NR) specified by the Third Generation Partnership Project (3GPP).

[0232] The wireless communication system 1 may also support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

[0233] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (Master Node (MN)), and the NR base station (gNB) is the secondary node (Secondary Node (SN)). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0234] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0235] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with a relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form small cells C2 that are smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The locations and numbers of the cells and user terminals 20 are not limited to the embodiment shown in the figure. Hereinafter, when there is no need to distinguish between the base stations 11 and 12, they will be collectively referred to as base station 10.

[0236] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CCs) and dual connectivity (DC).

[0237] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band higher than 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a higher frequency band than FR2.

[0238] Furthermore, the user terminal 20 may perform communication using at least one of time division duplex (TDD) and frequency division duplex (FDD) in each CC.

[0239] The multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with the Common Public Radio Interface (CPRI), an X2 interface, etc.) or wirelessly (e.g., NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0240] The base station 10 may be connected to the core network 30 directly or via another base station 10. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

[0241] The core network 30 may include network functions (Network Functions (NF)) such as a User Plane Function (UPF), an Access and Mobility management Function (AMF), a Session Management Function (SMF), a Unified Data Management (UDM), an Application Function (AF), a Data Network (DN), a Location Management Function (LMF), and Operation, Administration and Maintenance (Management) (OAM). A single network node may provide multiple functions. Communication with an external network (e.g., the Internet) may also be performed via the DN.

[0242] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0243] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the wireless communication system 1. For example, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0244] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (e.g., other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0245] In the wireless communication system 1, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), etc. may be used as the downlink channel.

[0246] Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), or the like may be used as an uplink channel.

[0247] The PDSCH transmits user data, higher layer control information, a System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit a Master Information Block (MIB).

[0248] Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, Downlink Control Information (DCI) including scheduling information for at least one of the PDSCH and the PUSCH.

[0249] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as a UL grant, a UL DCI, etc. Note that the PDSCH may be replaced with DL data, and the PUSCH may be replaced with UL data.

[0250] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources for searching for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor the CORESET associated with a certain search space based on the search space configuration.

[0251] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. Note that the terms "search space," "search space set," "search space configuration," "search space set configuration," "CORESET," "CORESET configuration," and the like in the present disclosure may be read interchangeably.

[0252] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery confirmation information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0253] In the present disclosure, downlink, uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning.

[0254] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, as the DL-RS, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted.

[0255] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including an SS (PSS, SSS) and a PBCH (and a DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as a reference signal.

[0256] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), or the like may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific reference signal).

[0257] 29 is a diagram showing an example of the configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that the base station may include one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

[0258] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0259] The control unit 110 performs overall control of the base station 10. The control unit 110 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0260] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0261] The transceiver unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transceiver unit 120 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0262] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be configured from a transmitting unit and a receiving unit. The transmitting unit may be configured from a transmission processing unit 1211 and an RF unit 122. The receiving unit may be configured from a reception processing unit 1212, the RF unit 122, and a measurement unit 123.

[0263] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0264] The transceiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

[0265] The transceiver 120 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0266] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0267] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0268] The transceiver unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 130.

[0269] On the other hand, the transceiver unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 130.

[0270] The transceiver 120 (reception processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, thereby acquiring user data, etc.

[0271] The transceiver 120 (measurement unit 123) may perform measurements on the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc. based on the received signal. The measurement unit 123 may measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

[0272] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30 (e.g., network nodes that provide NF), other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0273] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0274] The transceiver 120 may receive a Medium Access Control Element (MAC CE) including information indicating a target cell for cell switch.

[0275] The controller 110 may switch the serving cell to the target cell.

[0276] The transceiver 120 may receive a Medium Access Control Element (MAC CE) including a Reference Signal (RS) ID and a measurement result of the RS.

[0277] The controller 110 may switch the serving cell to the target cell corresponding to the RS.

[0278] The transceiver 120 may transmit a Medium Access Control Element (MAC CE) for activating or deactivating a Transmission Configuration Indication (TCI) state, which includes the TCI state IDs of one or more candidate cells.

[0279] The controller 110 may switch the serving cell to a target cell corresponding to the candidate cell.

[0280] (User terminal) Fig. 30 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0281] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0282] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, etc., which are described based on common understanding in the technical field to which the present disclosure relates.

[0283] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals and transfer them to the transceiver unit 220.

[0284] The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0285] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

[0286] The transmitting / receiving antenna 230 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0287] The transceiver 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, etc.

[0288] The transceiver unit 220 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0289] The transceiver unit 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0290] The transmitter / receiver unit 220 (transmission processing unit 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0291] Whether or not to apply DFT processing may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform, and if not, it may not be necessary to perform DFT processing as the transmission processing.

[0292] The transceiver unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 230.

[0293] On the other hand, the transceiver unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 230.

[0294] The transceiver unit 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, and acquire user data, etc.

[0295] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurements, CSI measurements, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0296] The measurement unit 223 may derive channel measurements for CSI calculation based on the channel measurement resources. The channel measurement resources may be, for example, non-zero power (NZP) CSI-RS resources. The measurement unit 223 may also derive interference measurements for CSI calculation based on the interference measurement resources. The interference measurement resources may be at least one of an NZP CSI-RS resource for interference measurement, a CSI-Interference Measurement (IM) resource, etc. Note that CSI-IM may be referred to as CSI-Interference Management (IM) or may be interchangeably read as Zero Power (ZP) CSI-RS. Note that in the present disclosure, CSI-RS, NZP CSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc. may be interchangeably read as interchangeable.

[0297] The transmitting unit and receiving unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving unit 220 and the transmitting / receiving antenna 230.

[0298] The transceiver 220 may transmit a Medium Access Control Element (MAC CE) including information indicating a target cell for cell switch.

[0299] The controller 210 may switch the serving cell to the target cell.

[0300] The MAC CE may include at least one of a Transmission Configuration Indication (TCI) state ID, information indicating whether the corresponding TCI state ID is a joint or downlink TCI state or an uplink TCI state, a Reference Signal (RS) ID, and a Layer 1-Reference Signal Received Power (L1-RSRP).

[0301] The MAC CE may include at least one of a Timing Advance Group (TAG) ID and a Timing Advance Command.

[0302] The transceiver 220 may transmit a Medium Access Control Element (MAC CE) including a Reference Signal (RS) ID and the measurement result of the RS.

[0303] The controller 210 may switch the serving cell to the target cell corresponding to the RS.

[0304] The MAC CE may include information indicating whether the RS ID is used in a target cell used for switching the serving cell.

[0305] The MAC CE may include a Physical Cell Identifier (PCI) corresponding to the RS ID.

[0306] The control unit 210 may determine whether to perform Random Access Channel (RACH)-less L1L2-triggered mobility (LTM) or RACH-based LTM based on the contents of the MAC CE.

[0307] The transceiver 220 may receive a Medium Access Control Element (MAC CE) for activating or deactivating a Transmission Configuration Indication (TCI) state, which includes the TCI state IDs of one or more candidate cells.

[0308] The controller 210 may switch the serving cell to a target cell corresponding to the candidate cell.

[0309] The MAC CE may include information indicating whether TCI state IDs of the one or more candidate cells are included in the MAC CE.

[0310] The MAC CE may include a bit per candidate cell indicating whether the IDs of the one or more candidate cells for TCI state activation or the TCI state IDs of the one or more candidate cells are present in the MAC CE.

[0311] The MAC CE may include information indicating whether the cell configuration in the MAC CE is for a serving cell or a candidate cell.

[0312] (Hardware Configuration) Note that the block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for 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 directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or the multiple devices.

[0313] Here, the 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, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As described above, the implementation method of each is not particularly limited.

[0314] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 31 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The above-described base station 10 and user terminal 20 may be physically 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.

[0315] In the present disclosure, the terms apparatus, circuit, device, section, unit, etc. may be used interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0316] For example, although only one processor 1001 is shown, there may be multiple processors. Furthermore, processing may be performed by one processor, or processing may be performed by two or more processors simultaneously, serially, or in other ways. Furthermore, processor 1001 may be implemented by one or more chips.

[0317] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading specified software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0318] The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transceiver unit 120 (220), etc. may be realized by the processor 1001.

[0319] 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-described embodiments. For example, the control unit 110 (210) may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be implemented in a similar manner.

[0320] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EEPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, cache, main memory, etc. The memory 1002 may store executable programs (program codes), software modules, etc. for implementing a wireless communication method according to an embodiment of the present disclosure.

[0321] Storage 1003 is a computer-readable recording medium and may be composed of at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, a key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as an auxiliary storage device.

[0322] 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 referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmission / reception unit 120 (220), transmission / reception antenna 130 (230), etc. may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be implemented as a transmission unit 120a (220a) and a reception unit 120b (220b) that are physically or logically separated.

[0323] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0324] Furthermore, 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 between each device.

[0325] Furthermore, the base station 10 and the user terminal 20 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 using this hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0326] (Modifications) Note that terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0327] A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may 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.

[0328] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and 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, radio frame structure, specific filtering performed by a transceiver in the frequency domain, and specific windowing performed by a transceiver in the time domain.

[0329] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may also be a time unit based on numerology.

[0330] A slot may include multiple minislots. Each minislot may consist of one or multiple 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 (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

[0331] A radio frame, a subframe, a slot, a minislot, and a symbol all represent time units for transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may be referred to by other names corresponding to the radio frame, the subframe, the slot, the minislot, and the symbol. Note that the time units such as a frame, a subframe, a slot, a minislot, and a symbol in the present disclosure may be interchangeable.

[0332] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as 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 (for example, 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.

[0333] 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. Note that the definition of TTI is not limited to this.

[0334] 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.

[0335] 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.

[0336] A TTI having a time length of 1 ms may be called a regular TTI (TTI in 3GPP 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.

[0337] 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 greater than or equal to 1 ms.

[0338] A resource block (RB) is a resource allocation unit in the time domain and the 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 be determined based on numerology.

[0339] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI, each of which may be composed of one or more resource blocks.

[0340] In addition, 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.

[0341] 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.

[0342] A Bandwidth Part (BWP), which may also be referred to as a partial 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 BWP and numbered within the BWP.

[0343] The BWP may include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0344] 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."

[0345] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. 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, etc. may be changed in various ways.

[0346] 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 a predetermined index.

[0347] The names used for parameters and the like in this disclosure are not intended to be limiting in any way. Furthermore, the mathematical expressions and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (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.

[0348] 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.

[0349] Furthermore, information, signals, etc. may be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. may be input / output via multiple network nodes.

[0350] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0351] 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 in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0352] Note that the physical layer signaling may be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Furthermore, the RRC signaling may be referred to as an RRC message, such as an RRC Connection Setup message or an RRC Connection Reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0353] Furthermore, notification of specified information (e.g., notification that "it is X") is not limited to explicit notification, but may be made implicitly (e.g., by not notifying the specified information or by notifying other information).

[0354] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value represented by true or false, or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0355] 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.

[0356] 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), these wired and / or wireless technologies are included within the definition of transmission media.

[0357] As used in this disclosure, the terms "system" and "network" may be used interchangeably. A "network" may refer to devices included in the network (e.g., base stations).

[0358] In this 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," "layer," "number of layers," "rank," "resource," "resource set," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," "UE panel," "transmitting entity," "receiving entity," etc. may be used interchangeably.

[0359] In the present disclosure, the term "antenna port" may be interchangeably read as an antenna port for any signal / channel (e.g., a demodulation reference signal (DMRS) port). In the present disclosure, the term "resource" may be interchangeably read as a resource for any signal / channel (e.g., a reference signal resource, an SRS resource, etc.). The resource may include time / frequency / code / space / power resources. Furthermore, the spatial domain transmission filter may include at least one of a spatial domain transmission filter and a spatial domain reception filter.

[0360] The group may include, for example, at least one of a spatial relationship group, a Code Division Multiplexing (CDM) group, a Reference Signal (RS) group, a Control Resource Set (CORESET) group, a PUCCH group, an antenna port group (e.g., a DMRS port group), a layer group, a resource group, a beam group, an antenna group, a panel group, and the like.

[0361] In addition, in the present disclosure, beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, codeword (CW), transport block (TB), RS, etc. may be read as interchangeable terms.

[0362] In addition, in the present disclosure, the terms TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, joint TCI state, etc. may be read interchangeably.

[0363] Furthermore, in the present disclosure, terms such as "QCL," "QCL assumption," "QCL relationship," "QCL type information," "QCL property / properties," "specific QCL type (e.g., Type A, Type D) property," and "specific QCL type (e.g., Type A, Type D)" may be interchangeable.

[0364] In the present disclosure, terms such as index, identifier (ID), indicator, indication, and resource ID may be interchangeable. In the present disclosure, terms such as sequence, list, set, group, cluster, and subset may be interchangeable.

[0365] Furthermore, the spatial relationship information identifier (ID) (TCI state ID) and the spatial relationship information (TCI state) may be interchangeable. The "spatial relationship information (TCI state)" may be interchangeable with "set of spatial relationship information (TCI state)", "one or more pieces of spatial relationship information", etc. The TCI state and the TCI may be interchangeable. The spatial relationship information and the spatial relationship may be interchangeable.

[0366] In the present disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNB (eNodeB)," "gNB (gNodeB)," "access point," "transmission point (TP)," "reception point (RP)," "transmission / reception point (TRP)," "panel," "cell," "sector," "cell group," "carrier," "component carrier," etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0367] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be partitioned into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). 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 service within that coverage.

[0368] In the present disclosure, a base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control / operate based on the information.

[0369] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0370] A mobile station may also be referred to 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.

[0371] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. Note that at least one of the base station and the mobile station may be a device mounted on a moving object, the moving object itself, etc.

[0372] The mobile body is a movable object that can move at any speed and naturally includes cases where the mobile body is stationary. Examples of the mobile body include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon. The mobile body may also be a mobile body that moves autonomously based on an operation command.

[0373] 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). Note that 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.

[0374] 32 is a diagram showing an example of a vehicle according to an embodiment. The vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, an electronic control unit 49, various sensors (including a current sensor 50, an RPM sensor 51, an air pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

[0375] The drive unit 41 is configured with at least one of an engine, a motor, and a hybrid of an engine and a motor, for example. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by a user.

[0376] The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (for example, an input / output (IO) port) 63. Signals are input to the electronic control unit 49 from various sensors 50-58 provided in the vehicle. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

[0377] The signals from the various sensors 50-58 include a current signal from a current sensor 50 that senses the current of the motor, a rotation speed signal of the front wheels 46 / rear wheels 47 obtained by a rotation speed sensor 51, an air pressure signal of the front wheels 46 / rear wheels 47 obtained by an air pressure sensor 52, a vehicle speed signal obtained by a vehicle speed sensor 53, an acceleration signal obtained by an acceleration sensor 54, a depression amount signal of the accelerator pedal 43 obtained by an accelerator pedal sensor 55, a depression amount signal of the brake pedal 44 obtained by a brake pedal sensor 56, an operation signal of the shift lever 45 obtained by a shift lever sensor 57, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 58.

[0378] The information service unit 59 is composed of various devices, such as a car navigation system, an audio system, speakers, a display, a television, and a radio, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 59 uses information acquired from external devices via the communication module 60 or the like to provide various information / services (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0379] The information service unit 59 may include input devices (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) that accept input from the outside, and may also include output devices (e.g., displays, speakers, LED lamps, touch panels, etc.) that output to the outside.

[0380] The driving assistance system unit 64 includes various devices for providing functions to prevent accidents and reduce the driver's driving burden, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Units (IMUs), Inertial Navigation Systems (INSs)), artificial intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driving assistance functions or autonomous driving functions.

[0381] The communication module 60 can communicate with the microprocessor 61 and components of the vehicle 40 via the communication port 63. For example, the communication module 60 transmits and receives data (information) via the communication port 63 to and from the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and the various sensors 50-58, which are provided in the vehicle 40.

[0382] The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the base station 10 or the user terminal 20 described above. Furthermore, the communication module 60 may be, for example, at least one of the base station 10 and the user terminal 20 described above (or may function as at least one of the base station 10 and the user terminal 20).

[0383] The communication module 60 may transmit at least one of signals from the above-mentioned various sensors 50-58 input to the electronic control unit 49, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 59 to an external device via wireless communication. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include information based on the above-mentioned input.

[0384] The communication module 60 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from an external device and displays it on an information service unit 59 provided in the vehicle. The information service unit 59 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH received by the communication module 60 (or data / information decoded from the PDSCH)).

[0385] Furthermore, the communication module 60 stores various information received from external devices in a memory 62 that can be used by the microprocessor 61. Based on the information stored in the memory 62, the microprocessor 61 may control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, various sensors 50-58, and the like provided in the vehicle 40.

[0386] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, terms such as an uplink channel and a downlink channel may be read as a sidelink channel.

[0387] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station 10 may be configured to have the functions of the user terminal 20 described above.

[0388] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc.), or a combination thereof.

[0389] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. 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.

[0390] Each aspect / embodiment described in the present disclosure may be a technology other than Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or decimal number)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.17 (WiMAX (registered trademark)), IEEE 802.19 (WiMAX (registered trademark)), IEEE 802.20 (WiMAX (registered trademark)), IEEE 802.21 (Wi-Fi (registered trademark)), IEEE 802.22 (WiMAX (registered trademark)), IEEE 802.23 (WiMAX (registered trademark)), IEEE 802.24 (WiMAX (registered trademark)), IEEE 802.25 (WiMAX (registered trademark)), IEEE 802.26 (WiMAX (registered trademark)), IEEE 802.27 (WiMAX (registered trademark)), IEEE 802.28 (WiMAX (registered trademark)), IEEE 802.29 (WiMAX (registered trademark)), IEEE 802.30 (WiMAX (registered trademark)), IEEE 802.31 (Wi-Fi (registered trademark)), IEEE 802.32 (WiMAX (registered trademark)), IEEE 802.33 (WiMAX (registered trademark)), IEEE 802. The present invention may be applied to systems that use IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other suitable wireless communication methods, or to next-generation systems that are expanded, modified, created, or defined based on these. Furthermore, the present invention may be applied to a combination of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0391] 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."

[0392] 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 or that the first element must in some way precede the second element.

[0393] The term "determining" as used in this disclosure may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., looking up in a table, database, or another data structure), ascertaining, etc.

[0394] Additionally, "determining" may be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc.

[0395] Furthermore, "determination" may be considered to be "determining" resolving, selecting, choosing, establishing, comparing, etc. In other words, "determination" may be considered to be "determining" some kind of action. In the present disclosure, "determination" may be read interchangeably with the above-mentioned actions.

[0396] Furthermore, in this disclosure, "determine / determining" may be interchangeably read as "assume / assuming," "expect / expecting," "consider / considering," etc. Furthermore, in this disclosure, "does not expect to do..." may be interchangeably read as "assumes not to do...."

[0397] In the present disclosure, "expect" may be interchangeably read as "be expected." For example, "expect(s) ..." ("..." may be expressed, for example, as a that clause, a to-infinitive, etc.) may be interchangeably read as "be expected ...." "does not expect ..." may be interchangeably read as "be not expected ...." Furthermore, "An apparatus A is not expected ..." may be interchangeably read as "an apparatus B other than apparatus A does not expect ... from apparatus A" (e.g., if apparatus A is a UE, apparatus B may be a base station).

[0398] The "maximum transmit power" in this disclosure may mean the maximum value of transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0399] As used in this disclosure, 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."

[0400] In this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables, printed electrical connections, etc., as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, etc., as some non-limiting and non-exhaustive examples.

[0401] 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."

[0402] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0403] 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.

[0404] In the present disclosure, terms such as "less than or equal to," "less than," "greater than," "more than," "equal to," etc. may be interchangeable. Furthermore, in the present disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be interchangeable, not limited to the positive, comparative, and superlative. Furthermore, in the present disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be interchangeable, not limited to the positive, comparative, and superlative, as expressions with "i-th" (i is an arbitrary integer) attached (for example, "highest" may be interchangeable with "i-th highest").

[0405] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0406] In the present disclosure, terms such as "when A, B," "if A, (then) B," "B upon A," "B in response to A," "B based on A," "B during / while A," "B before A," "B at (the same time as) / on A," "B after A," "B since A," and "B until A" may be interchangeable. Note that A, B, and the like herein may be replaced with appropriate expressions such as nouns, gerunds, and regular sentences, depending on the context. Note that the time difference between A and B may be approximately zero (immediately after or immediately before). A time offset may also be applied to the time at which A occurs. For example, "A" may be interchangeable with "before / after a time offset at which A occurs." The time offset (eg, one or more symbols / slots) may be predefined or may be specified by the UE based on signaled information.

[0407] In the present disclosure, timing, time, duration, time instance, any time unit (e.g., slot, subslot, symbol, subframe), period, occasion, resource, etc. may be read interchangeably.

[0408] Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The description of the present disclosure is for illustrative purposes only and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. A terminal having: a transmitting unit that transmits a Medium Access Control Element (MAC CE) including information indicating a target cell to be subjected to cell switching; and a control unit that switches a serving cell to the target cell.

2. The terminal according to claim 1, wherein the MAC CE includes at least one of a Transmission Configuration Indication (TCI) state ID, information indicating whether the corresponding TCI state ID is a joint or downlink TCI state or an uplink TCI state, a Reference Signal (RS) ID, and a Layer 1-Reference Signal Received Power (L1-RSRP).

3. The terminal according to claim 1, wherein the MAC CE includes at least one of a Timing Advance Group (TAG) ID and a Timing Advance Command.

4. The terminal according to claim 1, wherein the control unit determines whether to perform Random Access Channel (RACH)-less L1L2-triggered mobility (LTM) or RACH-based LTM based on the contents of the MAC CE.

5. A wireless communication method for a terminal, comprising: a step of transmitting a Medium Access Control Element (MAC CE) including information indicating a target cell to be subjected to cell switch; and a step of switching a serving cell to the target cell.

6. A base station having: a receiving unit that receives a Medium Access Control Element (MAC CE) including information indicating a target cell to be subjected to cell switching; and a control unit that switches a serving cell to the target cell.

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