Terminal, wireless communication method, and base station

Abstract

A terminal according to one aspect of the present disclosure is characterized by comprising: a reception unit that receives the setting of an event for conditional L1L2-triggered mobility (CLTM); a transmission unit that, when the condition of a first event is satisfied, transmits a UL signal for notifying the possibility of a cell switch to a base station of a current serving cell; and a control unit that, when the condition of a second event is satisfied, executes a cell switch procedure. According to one aspect of the present disclosure, even when the CLTM is supported, the cell switch can be appropriately performed.

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 (e.g., NR), 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. If the LTM of Rel. 18 is applied, the interruption time of cell switching can be shortened.

[0006] It is expected that conditional LTM (CLTM) will be supported / introduced in Rel. 19 and later. However, sufficient consideration has not been given to how to control CLTM.

[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 even when CLTM is supported.

[0008] A terminal according to one aspect of the present disclosure is characterized by having a receiving unit that receives an event setting for conditional L1L2-triggered mobility (CLTM), a transmitting unit that transmits an UL signal to a base station of a current serving cell notifying the possibility of a cell switch when the conditions of a first event are met, and a control unit that executes a cell switch procedure when the conditions of a second event are met.

[0009] According to one aspect of the present disclosure, cell switching can be performed appropriately even when CLTM is supported.

[0010] Figure 1A is a diagram showing an example of UE mobility in Rel. 17. Figure 1B is a diagram showing an example of UE mobility in Rel. 18. Figure 2 is a diagram showing an example of a Rel. 18 LTM (R18 LTM) procedure. Figure 3 is a diagram showing a first example of conditional LTM operation. Figure 4 is a diagram showing a second example of conditional LTM operation. Figure 5 is a diagram showing an example of target cell operation in conditional LTM. Figure 6 is a diagram showing a third example of conditional LTM operation. Figure 7 is a diagram showing a fourth example of conditional LTM operation. Figure 8 shows an example of a MAC CE for Type 1. Figure 9 shows an example of a MAC CE for Type 2. Figure 10 is a diagram showing an example of a CLTM procedure in Variation 2 of the 0th embodiment. Figure 11 is a diagram showing examples of RS and TCI state IDs in the first embodiment. Figure 12 is a diagram showing an example of a CLTM procedure in Rel. 18. FIG. 13 is a diagram showing the correspondence between SSB, TRS, and DMRS in carrier aggregation in Rel. 17. FIG. 14 is a diagram showing an example of a cell switch processing procedure in CLTM according to the third embodiment. FIG. 15 is a diagram showing an example of a processing procedure for an event-triggered beam report according to the third embodiment. FIG. 16 is a diagram showing processing for option 1 in case 1 according to the fifth embodiment. FIG. 17 is a diagram showing processing for option 1 in case 2 according to the fifth embodiment. FIG. 18 is a diagram showing an example of option 1 according to the sixth embodiment. FIG. 19 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 20 is a diagram showing an example of a configuration of a base station according to an embodiment. FIG. 21 is a diagram showing an example of a configuration of a user terminal according to an embodiment. FIG. 22 is a diagram showing an example of the hardware configuration of a base station and a user terminal according to an embodiment. FIG. 23 is a diagram showing an example of a vehicle according to an embodiment.

[0011] (Inter-cell mobility) It is being considered that a UE performs UL transmission to one or more cells / TRPs. The following scenario 1 or scenario 2 can be considered as a procedure in this case. In the present disclosure, the term "serving cell" may be replaced with the TRP in the serving cell. Layer 1 / layer 2 (L1 / L2) and DCI / Medium Access Control Element (MAC CE) may be replaced with each other. In the present disclosure, a physical cell identity (PCI) different from the physical cell identity (PCI) of the current serving cell may be simply referred to as a "different PCI." A non-serving cell, a cell having a different PCI, and an additional cell may be replaced with each other.

[0012] <Scenario 1> Scenario 1 corresponds to, for example, multi-TRP inter-cell mobility, but may be a scenario that does not correspond to multi-TRP inter-cell mobility.

[0013] (1) The UE receives from the serving cell the SSB configuration for beam measurement of the TRP corresponding to a PCI different from that of the serving cell, and the configuration required to use radio resources for data transmission and reception (including resources of the different PCI). (2) The UE performs beam measurement of the TRP corresponding to the different PCI and reports the beam measurement results to the serving cell. (3) Based on the above report, the Transmission Configuration Indication (TCI) state associated with the TRP corresponding to the different PCI is activated by L1 / L2 signaling from the serving cell. (4) The UE transmits and receives using a UE-dedicated channel on the TRP corresponding to the different PCI. (5) The UE must always cover the serving cell, including in the case of multiple TRPs. As in conventional systems, the UE must use common channels from the serving cell, such as the Broadcast Control Channel (BCCH) and the Paging Channel (PCH).

[0014] In Scenario 1, when the UE transmits and receives signals to and from an additional cell / TRP (a TRP corresponding to the PCI of the additional cell), the serving cell (the serving cell assumption in the UE) is not changed. The UE is configured with higher layer parameters related to the PCI of non-serving cells from the serving cell. Scenario 1 may be applied, for example, in Rel. 17.

[0015] Figure 1A shows an example of UE movement in Rel. 17. Assume that the UE moves from a cell (serving cell) with PCI #1 to a cell (additional cell) with PCI #3 (which overlaps with the serving cell). In this case, Rel. 17 does not support switching of serving cells via L1 / L2.

[0016] The additional cell is a cell that has an additional PCI different from the PCI of the serving cell. The UE can receive / transmit a UE-dedicated channel (UE-dedicated CH) from the additional cell. On the other hand, the UE needs to be within the coverage of the serving cell to receive UE common channels (e.g., system information / paging / short messages). When the UE moves out of the coverage of the serving cell, a cell switch (e.g., a process such as RRC reconfiguration) is required due to handover (also called L3 mobility).

[0017] <Scenario 2> Scenario 2 applies L1 / L2 inter-cell mobility (e.g., L1L2-triggered mobility (LTM)). L1 / L2 inter-cell mobility enables the serving cell to be changed using functions such as beam control without RRC reconfiguration. In other words, transmission and reception with a candidate cell / additional cell is possible without handover. Since handover requires RRC reconnection and creates a period when data communication is unavailable, applying L1 / L2 inter-cell mobility that does not require handover makes it possible to continue data communication even when the serving cell is changed. Scenario 2 may be applied, for example, in Rel. 18. In scenario 2, for example, the following procedure is performed.

[0018] (1) The UE receives configuration information (e.g., SSB configuration, etc.) for a cell with a different PCI (additional cell / candidate cell / target serving cell) from the serving cell (current serving cell) for beam measurement / serving cell change. (2) The UE performs beam measurement of the cell using the different PCI and reports the measurement results to the serving cell. (3) The UE may receive the configuration of the cell with a different PCI (serving cell / candidate cell configuration) via higher layer signaling (e.g., RRC). That is, pre-configuration for the serving cell change may be performed. This configuration may be performed together with the configuration in (1) or separately. (4) Based on the above report, the TCI state of the cell with the different PCI may be activated via L1 / L2 signaling according to the serving cell change. The activation of the TCI state and the serving cell change may be performed separately. (5) The UE changes the serving cell (assumed serving cell) and starts receiving / transmitting using the pre-configured UE-specific channel and TCI state.

[0019] That is, in Scenario 2, the serving cell (the serving cell assumed by the UE) is updated by L1 / L2 signaling. Scenario 2 may be applied in Rel. 18.

[0020] Figure 1B shows an example of UE mobility in Rel. 18. In Rel. 18, the serving cell is switched by L1 / L2 (e.g., DCI / MAC CE). Here, the example shows a case where the serving cell is switched from PCI #1 corresponding to the current serving cell (e.g., current serving cell) to PCI #3 corresponding to the target serving cell (e.g., target serving cell) by L1 / L2 signaling.

[0021] The UE can receive / transmit common channels (e.g., system information / paging / short messages) / UE-dedicated channels to / from the new serving cell (target serving cell #3), which may cause the UE to move out of the coverage of the previous serving cell PCI #1.

[0022] (L1L2-triggered mobility (LTM) in Rel. 18) FIG. 2 is a diagram showing an example of LTM considered in Rel. 18. Here, the steps of LTM are shown, including LTM preparation (e.g., LTM preparation), early synchronization (e.g., early sync), LTM execution (e.g., LTM execution), and LTM completion (e.g., LTM completion), but the LTM steps are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps may be reversed with other operations included in other steps, or other steps (or other operations) may be added. Note that in the present disclosure, early synchronization may be read as synchronization.

[0023] <LTM preparation> 1: The UE sends a measurement report message to the gNB. The gNB determines the LTM configuration and starts preparation of one or more candidate cells.

[0024] 2: The gNB sends an RRC reconfiguration message to the UE including LTM candidate cell configurations for one or more candidate cells.

[0025] 3: The UE saves its LTM candidate cell configuration and sends an RRC reconfiguration complete message to the gNB.

[0026] <Early sync> 4a: The UE performs DL synchronization with one or more candidate cells before receiving a cell switch command. DL synchronization for candidate cells before a cell switch command may be supported, at least based on SSB.

[0027] 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.

[0028] <LTM execution> 5: The UE performs L1 measurements configured on the 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.

[0029] 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.

[0030] 7: If the UE does not have a valid TA for the target cell, it performs a random access procedure to the target cell.

[0031] <LTM completion> 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.

[0032] (Reporting Configuration (ReportConfigNR)) The RRC information element ReportConfigNR specifies the trigger criteria for an NR measurement reporting event, CHO, Conditional PSCell Addition (CPA), Conditional PSCell Change (CPC) event, or Layer 2 UE-to-Network (L2U2N) relay measurement reporting event. For events labeled AN (N is 1 or 2) as shown below, the measurement reporting 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 PCell / PSCell may be replaced with the measurement results (L1-RSRP / L1-SINR, etc.) of the serving cell, neighboring cell, and PCell / PSCell.

[0033] 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.

[0034] 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).

[0035] 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.

[0036] (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.

[0037] 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.

[0038] (Rel. 18 LTM and Rel. 16 CHO) While the above-mentioned LTM (e.g., Rel. 18 LTM) supports early sync / early L1 measurement report, CHO (e.g., Rel. 16 CHO) does not support early sync / early measurement report. In LTM, mobility decisions are made by the network (based on L1 beam reports), while in CHO, they are made by the UE (based on L3 measurements and CHO conditions).

[0039] In LTM, a MAC CE for cell switch command is sent from the base station to the UE. In CHO, the UE starts evaluating the CHO implementation conditions for the candidate cells after receiving the CHO configuration through RRC signaling. After deciding on mobility (or cell switch), RACH is required in CHO, but RACH may not be required in LTM.

[0040] (Conditional LTM) In the case where conditional LTM (eg, conditional LTM (CLTM)) is supported, an example of providing / signaling / evaluating execution conditions (eg, execution conditions) for candidate cells will be described.

[0041] Execution conditions may be set for each candidate cell by RRC signaling / MAC CE. The execution conditions (or may simply be called "conditions") may include at least one of an event, a reference signal type (RS type), a reference signal configuration (RS configuration), and a measurement quantity. The reference signal type (RS type) may indicate SSB / CSI-RS. The measurement quantity may indicate L1-RSRP / L3-RSRP / SINR / RSRQ.

[0042] The implementation conditions may be set separately for each candidate cell (e.g., the setting of different conditions may be supported). Alternatively, the implementation conditions may be set commonly for multiple candidate cells (e.g., a candidate cell group) or all candidate cells. Alternatively, some of the implementation conditions may be set commonly for each candidate cell, and the remaining implementation conditions may be set separately. Some of the implementation conditions may be events, and the remaining implementation conditions may be condition values, etc. Of course, this is not limited to this.

[0043] The number of candidate cells for which the enabling condition is provided may be predefined in a specification, may be configured in the UE by a network (e.g., a base station), or may be determined based on UE capabilities. For example, the number of cells for which the enabling condition is provided may be the same as the configured candidate cells, or may be less than all the configured candidate cells.

[0044] Settings for implementation conditions (e.g., detailed settings) may be the same as the condition settings of the existing system, which may be, for example, condition settings supported by CHO supported in Rel. 16 (e.g., condition settings based on L3 measurements).

[0045] Alternatively, the setting of the implementation conditions may be a new condition setting similar to that of an event-triggered L1 report (e.g., an event-triggered L1 report). Examples of conditions (or events) are as follows: Event A2: The measurement result of the serving cell is worse than a threshold. Event A3: The measurement result of the neighboring cell (the value obtained by adding an offset to the measurement result) is better than the measurement result of the SpCell (the value obtained by adding an offset to the measurement result). Event A4: The measurement result of the neighboring cell (the value obtained by adding an offset to the measurement result) is better than a threshold. Event A5: The measurement result of the SpCell is worse than a first threshold, and the measurement result of the neighboring cell (the value obtained by adding an offset to the measurement result) is better than a second threshold. Event A6: The measurement result of the neighboring cell (the value obtained by adding an offset to the measurement result) is better than the measurement result of the serving cell (Secondary Cell (SCell)) (the value obtained by adding an offset to the measurement result). Event I1: The interference measurement result is higher than a threshold. Event A4': The measurement result of one beam from a neighboring cell is better than a threshold. Event A4'': The statistic (e.g., average, sum, etc.) of the measurement results of multiple beams (e.g., the best X beams) is better than a threshold. X may be fixed or may be configurable by higher layer signaling, etc. Event A4''': The L1-RSRP measurement result of one beam from a neighboring cell is better than a threshold. Event A4'''': The L1-RSRP of each of the X beams from the neighboring cells is better than a threshold.

[0046] It should be noted that the applicable conditions / events are not limited to these, and a combination of the above events may be applied, or other events may be applied.

[0047] For each condition for each candidate cell (or for multiple / all candidate cells), the conditions (or events) to be set may be determined based on at least one of the following options 1 and 2.

[0048] [Option 1] One condition may be set for each candidate cell (or for multiple / all candidate cells), and the condition may correspond to only one event, i.e., one condition with only one event may be set for each candidate cell (or for multiple / all candidate cells).

[0049] When a condition (or an event corresponding to the condition) corresponding to each candidate cell is satisfied, the UE / base station may control to perform an LTM procedure / action for the candidate cell.

[0050] [Option 2] Multiple (e.g., up to X) conditions may be configured for each candidate cell (or for multiple / all candidate cells). X may be, for example, 2 or 3, or may be 4 or more. X may be defined in a specification, configured by the base station to the UE, or determined based on UE capabilities.

[0051] When at least one of a plurality of conditions (or events corresponding to each condition) corresponding to each candidate cell is satisfied, the UE / base station may be controlled to perform an LTM procedure / action for the candidate cell.

[0052] When multiple (e.g., X) conditions are supported for each candidate cell, restrictions may be set between the multiple conditions. The restrictions between the conditions may be, for example, RS configuration / RS type / event / measurement quantity. As an example, the same RS configuration / RS type may be set between the multiple conditions, and different event / measurement quantities may be set between the multiple conditions.

[0053] When different conditions correspond to different candidate cells, restrictions may be imposed between the conditions, or restrictions may not be imposed between the conditions.

[0054] The supported conditions (eg, RS configuration / RS type / event / measurement quantity), the number of conditions to be set may be according to the UE capability.

[0055] An example of the operation of the conditional LTM will be described below, but parts that are not particularly described may be the same as the procedure of the Rel. 18 LTM (R18 LTM) shown in FIG.

[0056] [Conditional LTM Operation Example 1] Fig. 3 is a diagram showing a first example of conditional LTM operation. Fig. 3 shows the steps of LTM preparation (e.g., LTM preparation), early synchronization (e.g., early sync), LTM execution (e.g., LTM execution), and LTM completion (e.g., LTM completion) as the conditional LTM operation, but the LTM steps are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps and other operations included in other steps may be reversed, or other steps (or other operations) may be added.

[0057] <<LTM Preparation>> In LTM preparation, a UE RRC-connected to a serving cell (e.g., a UE in RRC_CONNECTED) transmits a measurement report. The measurement report may be an L3 measurement report. The base station (or source base station / serving cell) performs LTM candidate preparation (e.g., LTM candidate preparation) based on the measurement report transmitted from the UE.

[0058] The base station performs an LTM candidate configuration (e.g., an LTM candidate configuration) and configuration of execution conditions (e.g., execution conditions) for a candidate cell by RRC (e.g., RRC reconfiguration). By the LTM candidate configuration, information about the candidate cell may be configured in the UE. By configuring the execution conditions for the candidate cell, the execution conditions may be configured in the UE for each candidate cell (or for multiple / all candidate cells).

[0059] Option 1 / Option 2 may be applied to the setting of implementation conditions for candidate cells.

[0060] Early sync: The UE performs early synchronization (e.g., early sync) with a candidate cell. DL / UL early synchronization with a candidate cell may be performed by the UE after RRC configuration (e.g., RRC reconfiguration) of the LTM candidate cell.

[0061] LTM execution: The UE performs measurements (e.g., L1 measurements) on configured candidate cells and sends measurement reports, which may be L1 measurement reports.

[0062] The base station (or source base station / serving cell) makes a conditional LTM (CLTM) decision based on the measurement report transmitted from the UE. For example, the base station determines the conditional LTM for one or more candidate target cells for which the enabling condition can be evaluated (or for which the UE needs to evaluate the enabling condition). The one or more candidate target cells for which the enabling condition can be evaluated may be determined based on the measurement report transmitted from the UE.

[0063] The base station may transmit a predetermined MAC CE to the UE, which may be used to indicate to the UE information about one or more candidate target cells for conditional LTM (or for which the implementation conditions are to be evaluated). The predetermined MAC CE may trigger the UE to evaluate the implementation conditions.

[0064] The UE may initiate an implementation evaluation for candidate target cells indicated by a predetermined MAC CE. If a target cell satisfies the implementation condition, the UE may implement LTM (or mobility) for the target cell. For example, if a candidate cell satisfies the implementation condition, the UE may detach (e.g., detach) from a source (e.g., source cell) and apply the configurations (e.g., target configurations) of the target cell to which the handover is to be performed.

[0065] For example, when a plurality of candidate cells (or candidate target cells) are indicated by a given MAC CE, the UE may determine a specific target cell to be subjected to mobility / cell switch by considering the implementation conditions corresponding to each candidate cell (or the implementation conditions common to the plurality of candidate cells).The given MAC CE may indicate the implementation conditions / events corresponding to each candidate cell (or the implementation conditions common to the plurality of candidate cells).

[0066] The UE may perform a random access procedure (RACH-based CLTM) to the selected (e.g., switched to) target cell.

[0067] For example, if the UE does not have a valid Timing Advance (TA) for the target cell / candidate cell (or a destination cell), it may perform a random access procedure to obtain a TA value for the target cell. On the other hand, if the UE has a valid Timing Advance for the target cell / candidate cell (or a destination cell), it may not perform the random access procedure (or may omit / skip the random access procedure). Note that the random access procedure may be performed when the UE has a valid TA for the target cell.

[0068] After receiving a predetermined MAC CE, the UE may determine whether to apply a random access procedure based on at least one of the predetermined MAC CE and an RRC parameter (e.g., an RRC parameter related to the setting of a TA acquisition method). For example, the UE may determine whether to apply a random access procedure based on a value of a predetermined field (e.g., a timing advance command field) included in the predetermined MAC CE. The UE may also determine whether to apply a random access procedure based on a TA acquisition method set by an RRC parameter (or the TA acquisition method and the value of a predetermined field in the predetermined MAC CE).

[0069] Note that, although Fig. 3 shows a case where a candidate target cell for conditional LTM (or a candidate target cell for evaluating an implementation condition) is indicated by a MAC CE, this is not limiting. For example, information on a candidate target cell for conditional LTM may be indicated to a UE by a DCI. Alternatively, the MAC CE may indicate a correspondence (or mapping) between information on multiple candidate target cells for conditional LTM (or multiple candidate target cells and implementation conditions for conditional LTM) and a codepoint in a predetermined field of the DCI, and a specific candidate target cell for conditional LTM may be indicated by the DCI.

[0070] <LTM Completion> The LTM cell switch procedure may be completed by the UE sending a predetermined message to the target cell / candidate cell.

[0071] In the case of RACH-based LTM, the UE may determine that the LTM implementation has been completed successfully if the random access procedure has been completed successfully.

[0072] In the case of RACH-less (e.g., RACH-less) LTM, the UE may determine that the LTM has been successfully performed if the UE determines that the network has successfully received the first UL data. For example, in the case of RACH-less LTM, the UE may transmit the first data to the target cell along with sending an RRC reconfiguration complete message. The UE may determine that the first UL data has been successfully received by receiving a PDCCH in the target cell that addresses the UE's C-RNTI. This PDCCH corresponds to the PDCCH that schedules a new transmission following the first UL data.

[0073] [Conditional LTM Operation Example 2] Figure 4 is a diagram showing a second example of conditional LTM operation. Figure 4 shows the steps of LTM preparation (e.g., LTM preparation), early sync and LTM execution (e.g., early sync and LTM execution), and LTM completion (e.g., LTM completion) as the conditional LTM operation, but the LTM steps are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps and other operations included in other steps may be reversed, or other steps (or other operations) may be added.

[0074] <LTM Preparation> This can be performed in the same manner as the LTM preparation in FIG.

[0075] <Early sync and LTM execution> The UE performs early synchronization (e.g., early sync) and LTM execution with the candidate cell.

[0076] The UE may perform DL early synchronization with the LTM candidate cell after RRC configuration (e.g., RRC reconfiguration) of the candidate cell. For example, the UE may perform DL synchronization with the configured candidate cell.

[0077] The UE performs measurements (e.g., L1 measurements) on the configured candidate cells and sends a measurement report, which may be an L1 measurement report.

[0078] The base station (or source base station / serving cell) makes a conditional LTM (CLTM) decision based on the measurement report transmitted from the UE. For example, the base station determines the conditional LTM for one or more candidate target cells for which the enabling condition can be evaluated (or for which the UE needs to evaluate the enabling condition). The one or more candidate target cells for which the enabling condition can be evaluated may be determined based on the measurement report transmitted from the UE.

[0079] The base station may transmit a predetermined MAC CE to the UE, which may be used to indicate to the UE information about one or more candidate target cells for conditional LTM (or for which the implementation conditions are to be evaluated). The predetermined MAC CE may trigger the UE to evaluate the implementation conditions.

[0080] The UE may perform DL synchronization with the LTM candidate cell after RRC configuration (e.g., RRC reconfiguration) of the candidate cell. In this case, the UE may perform UL synchronization with the candidate target cell for conditional LTM indicated by a predetermined MAC CE. In this way, by performing UL synchronization after receiving the predetermined MAC CE, it is possible to reduce the number of cells for which UL synchronization is performed.

[0081] The UE may also start an implementation evaluation for a candidate target cell indicated by a predetermined MAC CE. If there is a target cell that satisfies the implementation condition, the UE may perform LTM (or mobility) for the target cell. For example, if the implementation condition is satisfied, the UE may detach (e.g., detach) from a source (e.g., source cell) and apply the configuration (e.g., target configurations) of the target cell to which the handover is to be performed. Note that the UE may perform UL synchronization after the implementation evaluation.

[0082] For example, when a plurality of candidate cells (or candidate target cells) are indicated by a given MAC CE, the UE may determine a specific target cell to be subjected to mobility / cell switch by considering the implementation conditions corresponding to each candidate cell (or the implementation conditions common to the plurality of candidate cells).The given MAC CE may indicate the implementation conditions / events corresponding to each candidate cell (or the implementation conditions common to the plurality of candidate cells).

[0083] The UE may perform a random access procedure (RACH-based CLTM) to the selected (e.g., switched to) target cell.

[0084] For example, if the UE does not have a valid Timing Advance (TA) for the target cell / candidate cell (or a destination cell), it may perform a random access procedure to obtain a TA value for the target cell. On the other hand, if the UE has a valid Timing Advance for the target cell / candidate cell (or a destination cell), it may not perform the random access procedure (or may omit / skip the random access procedure). Note that the random access procedure may be performed when the UE has a valid TA for the target cell.

[0085] After receiving a predetermined MAC CE, the UE may determine whether to apply a random access procedure based on at least one of the predetermined MAC CE and an RRC parameter (e.g., an RRC parameter related to the setting of a TA acquisition method). For example, the UE may determine whether to apply a random access procedure based on a value of a predetermined field (e.g., a timing advance command field) included in the predetermined MAC CE. The UE may also determine whether to apply a random access procedure based on a TA acquisition method set by an RRC parameter (or the TA acquisition method and the value of a predetermined field in the predetermined MAC CE).

[0086] While Fig. 4 illustrates a case in which a candidate target cell for conditional LTM (or a candidate target cell for evaluating implementation conditions) is indicated by a MAC CE, this is not limiting. For example, information on a candidate target cell for conditional LTM may be indicated to a UE by a DCI. Alternatively, the MAC CE may indicate a correspondence (or mapping) between information on multiple candidate target cells for conditional LTM (or multiple candidate target cells and implementation conditions for conditional LTM) and a codepoint in a predetermined field of the DCI, and a specific candidate target cell for conditional LTM may be indicated by the DCI.

[0087] <LTM Completion> This can be done in the same way as the LTM completion in FIG.

[0088] [Example of Operation of Target Cell in Conditional LTM] Fig. 5 is a diagram showing an example of operation of a target cell in conditional LTM. Fig. 5 shows steps of LTM preparation (e.g., LTM preparation), early synchronization (e.g., early sync), LTM execution (e.g., LTM execution), and LTM completion (e.g., LTM completion) as the operation of conditional LTM (the example of Fig. 3 ), but the steps of LTM are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps and other operations included in other steps may be swapped (e.g., the example of Fig. 4 ), or other steps (or other operations) may be added.

[0089] <<LTM Preparation>> In LTM preparation, a UE that is RRC connected to a serving cell (e.g., a UE in RRC_CONNECTED) transmits a measurement report. The measurement report may be an L3 measurement report.

[0090] The base station (or source base station / serving cell) prepares an LTM candidate (e.g., LTM candidate preparation) based on the measurement report transmitted from the UE. In this case, information may be exchanged / shared among multiple candidate cells (which may include the serving cell). The information exchanged / shared among multiple candidate cells may be at least one of information about the measurement report reported from the UE, information about the configuration of the candidate cell to be configured, and information about the implementation conditions for each candidate cell.

[0091] The base station performs an LTM candidate configuration (e.g., an LTM candidate configuration) and configuration of execution conditions (e.g., execution conditions) for a candidate cell by RRC (e.g., RRC reconfiguration). By the LTM candidate configuration, information about the candidate cell may be configured in the UE. By configuring the execution conditions for the candidate cell, the execution conditions may be configured in the UE for each candidate cell (or for multiple / all candidate cells).

[0092] Option 2-1 / Option 2-2 may be applied to the setting of implementation conditions for candidate cells.

[0093] <Early Sync> The UE performs early synchronization (e.g., early sync) with a candidate cell. DL / UL early synchronization with a candidate cell may be performed by the UE after RRC configuration (e.g., RRC reconfiguration) of the LTM candidate cell. UL early synchronization may be performed after transmitting a measurement report (e.g., L1 measurement report) of the LTM implementation step or after receiving a predetermined MAC CE.

[0094] LTM execution: The UE performs measurements (e.g., L1 measurements) on configured candidate cells and sends measurement reports, which may be L1 measurement reports.

[0095] The base station (or source base station / serving cell) makes a conditional LTM (CLTM) decision based on the measurement report transmitted from the UE. For example, the base station determines the conditional LTM for one or more candidate target cells for which the enabling condition can be evaluated (or for which the UE needs to evaluate the enabling condition). The one or more candidate target cells for which the enabling condition can be evaluated may be determined based on the measurement report transmitted from the UE.

[0096] The base station may transmit a predetermined MAC CE to the UE, which may be used to indicate to the UE information about one or more candidate target cells for conditional LTM (or for which the implementation conditions are to be evaluated). The predetermined MAC CE may trigger the UE to evaluate the implementation conditions.

[0097] The base station may also notify the candidate cell of information related to the conditional LTM (CLTM) decision. For example, the base station may notify the candidate cell of information related to one or more candidate target cells for the conditional LTM (or for which the implementation conditions are to be evaluated). The candidate cells to which the information is notified may be limited to candidate cells selected as candidate cells for the conditional LTM (CLTM) or may not be limited to candidate cells (for example, the information may also be notified to candidate cells that are not selected as candidate cells for the conditional LTM (CLTM)).

[0098] The UE may initiate an implementation evaluation for candidate target cells indicated by a predetermined MAC CE. If a target cell satisfies an implementation condition, the UE may implement LTM (or mobility) for the target cell. For example, if the implementation condition is met, the UE may detach (e.g., detach) from a source (e.g., source cell) and apply the configurations (e.g., target configurations) of the target cell to which the handover is to be performed.

[0099] The UE may perform a random access procedure to the selected (e.g., target) cell. For example, if the UE does not have a valid timing advance for the target / candidate cell (or destination cell), the UE may perform the random access procedure to obtain a TA value for the target cell. On the other hand, if the UE has a valid timing advance (TA) for the target / candidate cell (or destination cell), the UE may not perform the random access procedure (or may omit / skip the random access procedure).

[0100] After receiving a predetermined MAC CE, the UE may determine whether to apply a random access procedure based on at least one of the predetermined MAC CE and an RRC parameter (e.g., an RRC parameter related to the setting of a TA acquisition method). For example, the UE may determine whether to apply a random access procedure based on a value of a predetermined field (e.g., a timing advance command field) included in the predetermined MAC CE. The UE may also determine whether to apply a random access procedure based on a TA acquisition method set by an RRC parameter (or the TA acquisition method and the value of a predetermined field in the predetermined MAC CE).

[0101] Note that, although the case where a candidate target cell for conditional LTM (or a candidate target cell for evaluating implementation conditions) is indicated by MAC CE has been shown here, this is not limiting. For example, information on a candidate target cell for conditional LTM may be indicated to a UE by DCI. Alternatively, the MAC CE may indicate a correspondence (or mapping) between information on multiple candidate target cells for conditional LTM (or multiple candidate target cells and implementation conditions for conditional LTM) and a code point in a predetermined field of the DCI, and a specific candidate target cell for conditional LTM may be indicated by the DCI.

[0102] <<LTM Completion>> The LTM cell switch procedure may be completed by the UE sending a predetermined message to the selected (e.g., switched to) target cell / candidate cell.

[0103] In the case of RACH-based LTM, the UE may determine that the LTM implementation has been completed successfully if the random access procedure has been completed successfully.

[0104] [Conditional LTM Operation Example 3] Fig. 6 is a diagram showing a third example of conditional LTM operation. Fig. 6 shows the steps of LTM preparation (e.g., LTM preparation), early synchronization (e.g., early sync), LTM execution (e.g., LTM execution), and LTM completion (e.g., LTM completion) as the conditional LTM operation, but the LTM steps are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps and other operations included in other steps may be reversed, or other steps (or other operations) may be added. Fig. 6 may also be suitably applied to RACH-less CLTM.

[0105] <<LTM Preparation>> In LTM preparation, a UE RRC-connected to a serving cell (e.g., a UE in RRC_CONNECTED) transmits a measurement report. The measurement report may be an L3 measurement report. The base station (or source base station / serving cell) performs LTM candidate preparation (e.g., LTM candidate preparation) based on the measurement report transmitted from the UE.

[0106] The base station performs an LTM candidate configuration (e.g., an LTM candidate configuration) and configuration of execution conditions (e.g., execution conditions) for a candidate cell by RRC (e.g., RRC reconfiguration). By the LTM candidate configuration, information about the candidate cell may be configured in the UE. By configuring the execution conditions for the candidate cell, the execution conditions may be configured in the UE for each candidate cell (or for multiple / all candidate cells).

[0107] Option 1 / Option 2 may be applied to the setting of implementation conditions for candidate cells.

[0108] <Early Sync> The UE performs early synchronization (e.g., early sync) with a candidate cell. DL / UL early synchronization with a candidate cell may be performed by the UE after RRC configuration (e.g., RRC reconfiguration) of the LTM candidate cell. UL early synchronization may be performed after transmitting a measurement report (e.g., L1 measurement report) of the LTM implementation step or after receiving a predetermined MAC CE.

[0109] LTM execution: The UE performs measurements (e.g., L1 measurements) on configured candidate cells and sends measurement reports, which may be L1 measurement reports.

[0110] The base station (or source base station / serving cell) makes a conditional LTM (CLTM) decision based on the measurement report transmitted from the UE. For example, the base station determines the conditional LTM for one or more candidate target cells for which the enabling condition can be evaluated (or for which the UE needs to evaluate the enabling condition). The one or more candidate target cells for which the enabling condition can be evaluated may be determined based on the measurement report transmitted from the UE.

[0111] The base station may transmit a predetermined MAC CE to the UE, which may be used to indicate to the UE information about one or more candidate target cells for conditional LTM (or for which the implementation conditions are to be evaluated). The predetermined MAC CE may trigger the UE to evaluate the implementation conditions.

[0112] The UE may initiate an implementation evaluation for candidate target cells indicated by a predetermined MAC CE. If a target cell satisfies an implementation condition, the UE may implement LTM (or mobility) for the target cell. For example, if the implementation condition is met, the UE may detach (e.g., detach) from a source (e.g., source cell) and apply the configurations (e.g., target configurations) of the target cell to which the handover is to be performed.

[0113] After the UE decides on mobility or cell switch (or selects a new target cell) based on the evaluation of the implementation conditions, the UE may send at least one of an RRC reconfiguration completion message (e.g., RRCReconfigurationComplete) and a MAC CE (e.g., new MAC CE) to the new target cell, which may indicate the UE's CLTM decision to the new target cell.

[0114] <LTM Completion> The LTM cell switch procedure may be completed by the UE sending a predetermined message / MAC CE to the target cell / candidate cell.

[0115] In the case of RACH-less (e.g., RACH-less) LTM, the UE may determine that the LTM has been successfully performed if the UE determines that the network has successfully received the first UL data. For example, in the case of RACH-less LTM, the UE may transmit the first data to the target cell along with an RRC reconfiguration complete message / MAC CE. The UE may determine that the first UL data has been successfully received by receiving a PDCCH in the target cell that addresses the UE's C-RNTI. This PDCCH corresponds to the PDCCH that schedules a new transmission following the first UL data.

[0116] [Conditional LTM Operation Example 4] Fig. 7 is a diagram showing a fourth example of conditional LTM operation. Fig. 7 shows the steps of LTM preparation (e.g., LTM preparation), early synchronization (e.g., early sync), LTM execution (e.g., LTM execution), and LTM completion (e.g., LTM completion) as the conditional LTM operation, but the LTM steps are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps and other operations included in other steps may be reversed, or other steps (or other operations) may be added. Fig. 7 may also be suitably applied to RACH-less CLTM.

[0117] <LTM Preparation> This can be performed in the same manner as the LTM preparation in FIG.

[0118] <Early Sync> This can be performed in the same manner as the early sync in FIG.

[0119] LTM execution: The UE performs measurements (e.g., L1 measurements) on configured candidate cells and sends measurement reports, which may be L1 measurement reports.

[0120] The base station (or source base station / serving cell) makes a conditional LTM (CLTM) decision based on the measurement report transmitted from the UE. For example, the base station determines the conditional LTM for one or more candidate target cells for which the enabling condition can be evaluated (or for which the UE needs to evaluate the enabling condition). The one or more candidate target cells for which the enabling condition can be evaluated may be determined based on the measurement report transmitted from the UE.

[0121] The base station may transmit a predetermined MAC CE to the UE, which may be used to indicate to the UE information about one or more candidate target cells for conditional LTM (or for which the implementation conditions are to be evaluated). The predetermined MAC CE may trigger the UE to evaluate the implementation conditions.

[0122] The UE may initiate an implementation evaluation for candidate target cells indicated by a predetermined MAC CE. If a target cell satisfies an implementation condition, the UE may implement LTM (or mobility) for the target cell. For example, if the implementation condition is met, the UE may detach (e.g., detach) from a source (e.g., source cell) and apply the configurations (e.g., target configurations) of the target cell to which the handover is to be performed.

[0123] After the UE makes a mobility or cell switch decision (or selects a new target cell) based on the evaluation of the implementation conditions, the UE may transmit a predetermined MAC CE to the current serving cell (e.g., the serving cell before the cell switch). The MAC CE may indicate the UE's CLTM decision to the current serving cell. The predetermined MAC CE may include at least one of information about the selected target cell and information about the latest L1 beam measurement, event-triggered L1 beam measurement, or L1 beam measurement report result.

[0124] After transmitting a predetermined MAC CE to the current serving cell, the UE may start a predetermined timer (or a new timer) and start monitoring the PDCCH transmitted from the reported / instructed new target cell. For example, the UE may start a predetermined timer after transmitting a predetermined MAC CE and control to monitor the PDCCH until the predetermined timer expires.

[0125] <<LTM Completion>> If the UE detects a DCI format (e.g., DCI format 1_0 / 0_0, etc.) to which the C-RNTI is applied from the target cell before a predetermined timer expires, the UE may determine that the CLTM is successful (or that the CLTM is completed). Otherwise, the UE may determine that the CLTM is unsuccessful.

[0126] (Beam Report MAC CE) An example of a new beam report MAC CE will now be described.

[0127] [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).

[0128] For example, Fig. 8 shows an example of a MAC CE for Type 1, and Fig. 9 shows an example of a MAC CE for Type 2. The MAC CE in Fig. 8 and the MAC CE in Fig. 9 may have different Logical Channel IDs (LCIDs).

[0129] As shown in FIG. 8, 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).

[0130] 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.

[0131] 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.

[0132] In the MAC CE, a 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] In FIG. 8, the fields in octets 3 to 7 may be optional.

[0138] The MAC CE for Type 2 shown in FIG. 9 has 16 bits corresponding to octets 8 and 9 added to the MAC CE for Type 1 shown in FIG.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] (Analysis) As mentioned above, it is assumed that a conditional cell switch for LTM (also called conditional LTM (CLTM)) will be supported in wireless communication systems of Rel. 19 and later. For example, it is conceivable that the LTM procedure will be triggered by the UE based on a condition set by the network.

[0143] However, if conditional LTM is supported, it is not clear how to control specific operations / procedures. For example, the following issues may arise:

[0144] <Problem 1> In LTM, the target cell / DU / CU needs to be notified of the TCI state ID to use before a cell switch. In Rel. 18 LTM, the network determines the TCI state ID, notifies the UE with a cell switch command MAC CE, and transmits it to the target DU over the L3 interface. On the other hand, in CLTM, the UE can determine the TCI state ID / QCL source RS to use for a cell switch. However, it is unclear how the network identifies the TCI state ID and RS to use in the target cell determined by the UE.

[0145] <Problem 2> The implementation of CLTM and event-triggered beam reporting in LTM is being considered. However, the settings for CLTM and event-triggered beam reporting are not clear. For example, it is preferable to clearly set which cell / beam (RS) is the target of event evaluation.

[0146] <Problem 3> It is being considered that an event-triggered beam report be used as an UL signal to request / notify the possibility of a cell switch to a candidate cell. However, even if an event-triggered report is transmitted, there are cases where a cell switch to a candidate cell is not requested / notified. Therefore, a method for identifying whether an event-triggered beam report includes a cell switch request is being considered.

[0147] <Problem 4> In Variation 2 of the 0th embodiment (e.g., FIG. 10 ), when multiple RSs / cells satisfy the first event, the UE evaluates another event (second event), but the specific processing in that case is not clear.

[0148] <Problem 5> When LTM (see, for example, FIG. 2) in Rel. 18 and CLTM (see, for example, FIGS. 3 to 7 and 10) are configured simultaneously, and a cell switch command (MAC CE) for LTM in Rel. 18 and an UL signal instructing a cell switch for CLTM are transmitted simultaneously, it is unclear how the UE will operate.

[0149] Therefore, the present inventors focused on the introduction / support of CLTM, studied the control of CLTM, and came up with an idea for one aspect of this embodiment.

[0150] Hereinafter, embodiments of 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.

[0151] (Various Reinterpretations) In the present disclosure, a word enclosed in "( )" in a sentence may indicate an explanation of the word immediately preceding it (for example, an explanation of spelling), a paraphrase, a specific example, a supplementary explanation, etc. Furthermore, in the present disclosure, a word enclosed in "[ ]" in a sentence may be interpreted including the word in the meaning of the entire sentence, or may be interpreted excluding (ignoring) the word in the meaning of the entire sentence. Note that "( )" and "[ ]" may also be used for purposes / meanings other than those mentioned above.

[0152] 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."

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0158] In the present disclosure, base station, gNB, network (NW), source gNB, and target gNB may be read interchangeably.

[0159] In the present disclosure, a cell group, a serving cell group, a master cell group (MCG), and a secondary cell group (SCG) may be interchangeable. L1 / L2, L1 / L2 signaling, and DCI / MAC CE may be interchangeable. A serving cell may be replaced with a cell that transmits a PDSCH. A candidate cell may refer to a cell that is a candidate to become a serving cell through L1 / L2 inter-cell mobility. L1L2-triggered mobility (LTM) and L1 / L2 inter-cell mobility may be interchangeable.

[0160] In the present disclosure, the terms cell, PCI, serving cell, source serving cell, source cell, CC, BWP, BWP within a CC, and band may be interchangeable. In the present disclosure, the terms cell, PCI, cell with an additional PCI, additional cell, other cell, non-serving cell, cell with a different PCI, candidate cell, candidate serving cell, cell with a PCI different from the PCI of the current serving cell, another serving cell, and target cell may be interchangeable. The target cell may be a cell selected from multiple candidate cells. In the present disclosure, the terms cell, base station (gNB) within a cell, base station (gNB) of a cell, and base station (gNB) may be interchangeable.

[0161] In the present disclosure, the terms "event," "event condition," and "implementation condition" may be interchangeable. The terms "event condition" and "implementation condition" may refer to conditions for a cell switch. The terms "candidate cell," "target cell," and "base station / gNB of the candidate cell / target cell" may be interchangeable. The term "cell switch" in the present disclosure may refer to a switch of the serving cell (a switch to the target cell).

[0162] The terms "event-triggered beam report," "event-triggered report," "beam report," and "CSI report" may be interchangeable. The event-triggered beam report may be an L1 / L3 beam report. The event-triggered beam report may be a report transmitted when the event condition set by the above-mentioned report configuration (ReportConfigNR) or the condition / event for the above-mentioned conditional LTM (CLTM) is satisfied. The base station may make a decision regarding LTM based on the event-triggered beam report. The terms "beam report / report" and "CSI report" may be interchangeable.

[0163] (Wireless Communication Method) <Embodiment 0> A UE receives a setting of an event / implementation condition for conditional L1L2-triggered mobility (CLTM) via an RRC / MAC CE or the like, evaluates the event / implementation condition for CLTM (always / based on UE implementation), and if the event (event condition) / implementation condition is met, transmits a first UL signal indicating a cell switch request (e.g., an UL cell switch command via a MAC CE) to a current serving cell (a base station (gNB) of the serving cell). When the UE receives an ACK of the first UL signal (e.g., a MAC CE) from the gNB, the UE may perform a cell switch procedure (e.g., at least one of transmitting a PRACH to a target cell, monitoring a PDCCH in the target cell, transmitting a PUSCH to the target cell, and applying a target RRC reconfiguration / TCI state ID / TA / BWP ID).

[0164] <<Event Settings>> When CLTM and event-triggered beam reporting are configured at the same time, the events configured for CLTM and event-triggered beam reporting (e.g., the above-mentioned report configuration (ReportConfigNR), the event type, threshold, offset, hysteresis, Time To Trigger (TTT), etc. of conditional LTM) and the implementation conditions may be the same or different. The event-triggered beam reporting may be a beam reporting that is implemented based on the above-mentioned report configuration (ReportConfigNR).

[0165] <<Event Evaluation Timing>> The timing at which the UE evaluates a CLTM event may be defined as follows.

[0166] Option 1-A: When a specific DL (e.g., at least one of a PDCCH order, a TCI state activation / deactivation MAC CE, a semi-persistent (SP) CSI report activation / deactivation MAC CE, a cell switch command MAC CE, and a new MAC CE / DCI) is received, or when a certain time has elapsed after receiving the DL. The new MAC CE is, for example, the above-mentioned predetermined MAC CE (New MAC CE in FIGS. 3 to 7).

[0167] Option 1-B: When a specific UE operation (e.g., DL / UL synchronization, RRC reconfiguration, TCI state activation, etc.) is completed, or a certain period of time has elapsed since completion. If the event / implementation conditions set for the CLTM and the event-triggered beam report are different, after the event for the event-triggered beam report is met, or after the event-triggered beam report is transmitted. The event may be evaluated for the cell / RS that met the event for the event-triggered beam report.

[0168] The timing of the CLTM event evaluation may be within a certain time period after option 1-A / 1-B.

[0169] <<Example of UL signal indicating cell switch request transmitted after an event is satisfied>> Variation 1: The first UL signal may be an RRC message, UCI, or PRACH. If the events set for the CLTM and the event-triggered beam report are the same, the first UL signal may be used for the event-triggered beam report.

[0170] Variation 2: The UE may not transmit the first UL signal indicating a cell switch request. In this case, if an event (event condition) / execution condition is met, the UE may transmit a second UL signal (e.g., an event-triggered beam report) notifying the base station of the current serving cell of the possibility of a cell switch. In this case, the UE may perform the cell switch procedure before receiving an ACK for the second UL signal.

[0171] If Option 1-B is supported, the UE may evaluate the events for CLTM (e.g., the same event (event condition) as the event-triggered beam report is met for a specified time (e.g., timer / TTT), the counter reaches a specified value before the timer expires, an event type / parameter different from the event-triggered beam report is met once or continuously within a certain time, etc.) after the events for the event-triggered beam report are met, and perform a cell switch procedure if the events for CLTM are met.

[0172] If the event is not met, the UE may report to the NW via an UL signal that a cell switch will not be performed. If the gNB knows that the UE will not perform a cell switch before the timer expires, it can stop the resource reservation of the target cell early to improve efficiency. This UL signal may be, for example, a one-bit or more signal using MAC CE / UCI, and may report what kind of cell switch will not be performed. Alternatively, when evaluating an event on a cell or RS basis, if events for multiple cells or RSs are evaluated simultaneously, this UL signal may include a cell ID or RS ID to report only the cell or RS to be stopped.

[0173] If the UE receives any DL signal during CLTM event evaluation, the event evaluation may be stopped. If a Rel. 18 MAC CE for Cell Switch Command is received, the Rel. 18 MAC CE for Cell Switch Command or CLTM event evaluation takes priority.

[0174] Variation 3: The UE may send a first UL signal indicating a cell switch request, or a second UL signal in Variation 2, to the target cell.

[0175] Variation 4: The UE / gNB may perform a cell switch when an event occurs, when a new MAC CE is transmitted, when a timer expires, or after a certain time has elapsed from each timing. The specific operation / DL / time / value of the UE may be set by a higher-level parameter, may be predetermined in a specification, or may be determined based on the UE capabilities.

[0176] <<Example of CLTM Procedure>> Fig. 10 is a diagram showing an example of a CLTM procedure according to Variation 2 of the zeroth embodiment. Fig. 10 shows steps of LTM preparation (e.g., LTM preparation), early synchronization (e.g., early sync), LTM execution (e.g., LTM execution), and LTM completion (e.g., LTM completion) as CLTM operations, but the LTM steps are not limited to these. Some steps (or operations included in steps) may be omitted, the order of operations included in some steps and other operations included in other steps may be reversed, or other steps (or other operations) may be added. For example, at least some of the processes shown in Figs. 3 to 7 may be added.

[0177] <<LTM Preparation>> In LTM preparation, a UE connected to a serving cell via RRC (e.g., a UE in RRC_CONNECTED) transmits a measurement report. The measurement report may be an L3 measurement report. The base station (or source base station / serving cell) determines whether to perform LTM based on the measurement report transmitted from the UE.

[0178] The base station (Source gNB) sends an RRC reconfiguration message to the UE, including LTM candidate cell configurations for one or more candidate cells. The UE saves the LTM candidate cell configurations and sends an RRC reconfiguration complete message to the gNB. The base station (Source gNB) sends signaling including the LTM candidate cell configurations to the base station (Candidate gNB) of the candidate cell.

[0179] Early sync: The UE performs early synchronization (e.g., early sync) with a candidate cell. DL / UL early synchronization with a candidate cell may be performed by the UE after RRC configuration (e.g., RRC reconfiguration) of the LTM candidate cell.

[0180] LTM Execution: The UE evaluates whether the event is met, and if so, transmits a second UL signal (e.g., UL Cell Switch Command, Event Trigger Report) to the base station (Source gNB) indicating the possibility of a cell switch using the RS / TCI state of the candidate cell. The base station (Source gNB) then transmits signaling including the target cell ID and TCI state ID to the base station (Candidate gNB) of the candidate cell.

[0181] Since the UE can transmit an UL signal notifying the possibility of a cell switch before the cell switch decision, there is no need to transmit an UL signal when the LTM cell switch decision is made. In other words, it is possible to avoid the gNB being unable to receive the UL signal when the UE is at the cell edge. The base station (Source gNB) can forward the above signaling, including the target cell ID and TCI state ID, to the base station (Candidate gNB) (target gNB) before the cell switch decision is made, so that the target gNB can quickly secure resources for the UE. Note that in Rel8 LTM, this signaling is forwarded when the LTM cell switch decision is made.

[0182] The UE evaluates whether a second event is met, and if so, decides to perform an LTM cell switch. The second event may be the same as the first event or may be different. This is to avoid the ping-pong problem. For example, the UE may decide to perform an LTM cell switch and perform the cell switch procedure when the event is met for a predetermined time, or when all events are met within a predetermined time.

[0183] The UE applies the target cell configuration, and the UE, the base station (Source gNB), and the base station (Candidate gNB) (Target gNB) perform a cell switch procedure.

[0184] The event for transmitting the first UL signal and the event for transmitting the second UL signal may be the same or different, and the event for transmitting the first UL signal and the condition for performing the cell switch procedure after transmitting the second UL signal may be the same.

[0185] In the present disclosure, the UE determines whether to perform a cell switch and the target cell to switch to, so that the cell switch can be performed more quickly than when the base station makes the decision.

[0186] <First Embodiment> The contents included in the first UL signal indicating a cell switch request and the second UL signal notifying the possibility of a cell switch in the 0th embodiment will be described. That is, the UL signal in this embodiment may mean the first signal / second signal in the 0th embodiment. The UL signal may include at least one of a TCI state ID and an RS index corresponding to the target cell. The UL signal may include, for example, at least a portion of the contents of the beam report MAC CE (FIGS. 8 and 9).

[0187] If the UL signal contains a TCI state ID, the UE uses that TCI state ID.

[0188] When an RS index is included in an UL signal (e.g., an event-triggered beam report), at least one of the following may be applied: ・The UE uses a TCI state ID with a QCL source RS type D associated with the RS index. ・The NW may uniquely configure the QCL source RS type D for each TCI state ID. ・The QCL source RS may be any of types A, B, C, or D. ・When multiple RS indications are included in the UL signal, a rule may be defined to identify the TCI state ID to be used in the target cell based on the L1-RSRP / L1-SINR value, the RS indication, the RS type, etc. For example, the RS index with the largest L1-RSRP / L1-SINR may be selected. For example, the RS index with a usage indication (e.g., a 1-bit flag) may be selected.

[0189] After the UE decides to cell switch, if an RA procedure is performed to acquire the TA of the target cell, the UE may use the (root) QCL source RS associated with the RS index associated with the PRACH. In this case, the UE does not need to acquire the TA of the target cell before the cell switch.

[0190] If no RA procedure is performed after the UE decides to cell switch, the UE may use the (root) QCL source RS associated with the RS index to identify the configured grant PUSCH occasion, in which case the UE can obtain the TA of the target cell before the cell switch.

[0191] The UE operation of this embodiment may be valid within a certain time (e.g., X slots / symbols / ms) after the UL signal / event is satisfied, i.e., after the predetermined time, the UE may no longer be able to use the operation of this embodiment.

[0192] FIG. 11 is a diagram showing an example of RS and TCI state ID in the first embodiment. The UE measures L1-RSRP based on the RS and reports the measurement result. In the example of FIG. 11, since the L1-RSRP corresponding to RS #1 is the largest, the UE decides to use TCI state #2 corresponding to RS #1. Then, the UE transmits an UL signal including RS #1 and TCI state #2 to the gNB of the source cell / target cell. After the cell switch procedure, the UE uses TCI state #2 for the target cell. The NW may expect the UE to use TCI state #2 for the target cell and notify the target base station (Distributed Unit (DU)) / target cell.

[0193] Figure 12 is a diagram showing the correspondence between SSB, TRS, and DMRS for carrier aggregation in Rel. 15 and 16. In the example of Figure 12, there is one TRS that is a QCL source RS (type A, D) for each DMRS of the PDCCH / PDSCH. Also, there is one SSB that is a QCL source RS (type C, D) for each TRS. Therefore, if the UL signal includes a TRS (or a corresponding SSB index), the gNB can identify the DMRS or the corresponding CC.

[0194] Figure 13 is a diagram showing the correspondence between SSB, TRS, and DMRS for carrier aggregation in Rel. 17. In the example of Figure 13, there is one TRS, which is the QCL source RS (Type A) for each DMRS of the PDCCH / PDSCH, for each DMRS. However, the RS, which is the QCL source RS (Type D) for each DMRS of the PDCCH / PDSCH, is one CSI-RS (repeated) corresponding to multiple DMRS (CC). Therefore, when using QCL source RS (Type D), even if the UL signal includes a TRS (or corresponding SSB index), the gNB cannot identify the DMRS or the corresponding CC.

[0195] In other words, it is possible that a CSI-RS using repetition is shared among multiple TCI states of different CCs. In this case, when a UE reports a source RS ID of QCL type D in an UL signal (e.g., an event-triggered beam report), the UE may include additional information in the UL signal to indicate the location of the target CC / BWP (the location of the TCI state ID).

[0196] The UE may transmit the CRI as an RS index in the UL signal. In this case, the association between the CRI and the CC index / BWP ID may be configured in advance by RRC signaling. The UE may transmit the CRI and the corresponding L1-RSRP / SINR in the UL signal.

[0197] According to this embodiment, since the TCI state ID / RS is included in the UL signal when performing a cell switch, the base station can easily identify the TCI state / beam for transmission and reception after the cell switch. According to this embodiment, the above-mentioned problem 1 can be solved.

[0198] Second Embodiment At least one of the functions and options of this embodiment may be applied to another embodiment. Also, different processing may be applied in the other embodiment depending on which function / option of this embodiment is applied.

[0199] [Feature A] There is an event configuration (event type A) for beam reporting by the UE in LTM. This event can trigger a UE beam report or a cell switch request by the UE. For this event configuration, one of the following options may be applied. Note that the LTM may be the Rel. 18 LTM shown in Figure 2. Option A-1: ​​One event configuration. Option A-2: Multiple event configuration.

[0200] [Feature B] For CLTM, an event setting (event type B) for CLTM evaluation / decision by the UE is considered. This event can trigger a cell switch request / decision of the UE. For this event setting, any of the following options may be applied. Note that the CLTM may be any of the CLTMs in Figures 3 to 7 and 10. Option B-1: One event setting. Option B-2: Multiple event setting.

[0201] Regarding the relationship between the above two functions and the corresponding event configurations (event configuration for beam reporting, event configuration for CLTM evaluation / decision), one of the following options may be applied: Option 1: The UE cannot apply both event configurations simultaneously. Option 2: The UE can apply both event configurations simultaneously.

[0202] <Third embodiment> Figure 14 is a diagram showing an example of a cell switch processing procedure in CLTM of the third embodiment. In LTM, the UE receives settings / instructions regarding at least the currently used beam (i.e., RS) / serving cell and candidate beam / candidate cell (S101), and may evaluate the event / implementation conditions for a cell switch in CLTM for each beam / cell (S102). If the event (event condition) / implementation condition for a cell switch is satisfied (YES in S103), the UE may transmit an UL signal indicating a cell switch request to the base station (gNB) (S104). This UL signal may be, for example, the first UL signal / second UL signal of the 0th embodiment.

[0203] 15 is a diagram showing an example of a processing procedure for an event-triggered beam report according to the third embodiment. In the LTM, the UE receives configuration / instructions regarding at least a currently used beam (i.e., RS) / serving cell and a candidate beam / candidate cell (S201), and may perform event evaluation for an event-triggered beam report for each beam / cell (S202). If the UE satisfies the event condition for the beam report (YES in S203), it may transmit a beam report (L1 / L3 beam report) to the base station (gNB) (S204). The base station (gNB) may determine the LTM based on the beam report.

[0204] The candidate beams / candidate cells may include the current beam / serving cell. The event may be, for example, each event configured in the above-mentioned reporting configuration (ReportConfigNR), conditional LTM, or other events.

[0205] <<Configuration of Current Beam / Serving Cell>> For the currently used beam / serving cell, the UE can evaluate the beams in the cell. For the configuration / instruction regarding the current beam / serving cell, for example, at least one of the following options 1 to 4 may be applied. The terms current beam / serving cell and currently used beam / serving cell may be read interchangeably.

[0206] Option 1: The current beam / serving cell may be set by the RRC IE of the current serving cell.

[0207] Option 2: The current beam / serving cell may be configured by an RRC IE other than the RRC IE of the current serving cell (e.g., ltm-CSI-SSB-ResourceSet). For example, the current beam / serving cell may be configured together with the candidate beam / candidate cell.

[0208] Option 3: The current beam / serving cell may correspond to a source RS with QCL type D configured in the indicated TCI state. The QCL type may be A, B, or C. The indicated TCI state may be a joint TCI state, a ULTCI state, or a DLTCI state.

[0209] If two or more TCI states are indicated, the UE may use both or any one of the indicated TCI states. For example, the UE may always use the first / second indicated TCI state. The TCI state to be used may be predefined in the specification or configured by higher layer signaling.

[0210] Option 4: The current beam / serving cell may correspond to a QCL type D source RS configured in the active TCI state for beam management of the current serving cell.

[0211] Option 5: The current beam / serving cell may correspond to a QCL type D source RS configured in an active TCI state for LTM (e.g., corresponding to an SpCell). In this case, the UE needs to identify the SpCell as in Rel. 18 LTM.

[0212] Option 5 describes a method for identifying the SpCell. If the UE is configured with the CSI reporting configuration for LTM (LTM-CSI-ReportConfig), the UE may perform the following process: If the RRC parameter (spCellInclusion) indicating the inclusion of the SpCell is configured, the UE performs reporting in a single reporting instance (nrOfReportedRS-PerCell) that is different from the SSBRI for the current SpCell and each of a predetermined number (nOfReportedCells-1) of candidate cells. Otherwise, the UE reports a different SSBRI for each of a predetermined number (nrOfReportedCells) of candidate cells in a single reporting instance (nrOfReportedRS-PerCell).

[0213] Here, SSBRI k (k≧0) corresponds to the configured (k+1)th entry of the associated list (ltm-CSI-SSB-ResourceList) in the corresponding LTM-CSI-SSB-ResourceSet.

[0214] If the RRC parameter (spCellInclusion) indicating the inclusion of an SpCell is set, the SSB resources in the ltm-CSI-SSB-ResourceList associated with the current SpCell correspond to multiple entries, where the PCI given by the parameter ltm-CandidatePCI and the frequency information given by ssbFrequency-r18 of the associated candidate cells (given by ldm-CandidateIdList) are equal to the PCI and the center frequency of the cell-defined SSB of the current SpCell.

[0215] <<Configuration of Candidate Beam / Candidate Cell>> For the candidate beam / candidate cell, the UE can evaluate the beams in the candidate cell. For the configuration / instruction regarding the candidate beam / candidate cell, for example, at least one of the following options 1 and 2 may be applied.

[0216] Option 1: Candidate beams / candidate cells may be configured by an RRC IE other than the current serving cell RRC IE. Option 2: Candidate beams / candidate cells may be indicated by a source RS of QCL type D configured in the active TCI state of LTM.

[0217] According to this embodiment, the UE can appropriately determine the beam / cell to be evaluated for evaluating the event / execution condition in the CLTM / event-triggered beam report, thereby solving the above-mentioned problem 2.

[0218] <Fourth Embodiment> The event-triggered beam report of this embodiment may be a beam report transmitted in the processing procedure (FIG. 14) of the event-triggered beam report described in the third embodiment. When CLTM is applied, the event-triggered beam report may request a cell switch (including a cell switch request), so it is necessary to be able to identify whether a cell switch is requested. Therefore, the UE may perform an event evaluation for the event-triggered beam report, and if the event conditions are met, transmit a beam report that can identify whether a cell switch is requested. At least one of the following options may be applied as a method of identifying whether a cell switch is requested.

[0219] <<Option 1>> An event-triggered beam report may include an indication (e.g., a one-bit indication) indicating whether a (potential) cell switch is required. For example, bit=0 may indicate a simple beam report (requiring a cell switch) and bit=1 may indicate a beam report that does not require a (potential) cell switch.

[0220] An indication of whether to include a cell switch request may be included in the UCI or MACCE. This indication may be included in the same report as the event-triggered beam report or in a separate report from the event-triggered beam report.

[0221] <<Option 2>> If supported, an event-triggered beam report may include an event ID that can identify whether a cell switch is requested. The NW (base station) can (implicitly) identify whether the report requests a cell switch by the event ID. The NW (base station) may configure the event (event ID) for the beam report / (potential) cell switch request in the UE in advance by RRC signaling, etc.

[0222] <<Option 3>> The number of contents (e.g., RS index, L1-RSRP / SINR) in the event-triggered beam report may implicitly indicate whether a cell switch is requested. The number of contents is variable and may be determined by the UE. For example, if only one content is included, it may indicate a (potential) cell switch request, otherwise (if there are two or more contents), it may indicate no cell switch request.

[0223] <<Option 4>> An event-triggered beam report may be determined to never require a cell switch, or may be determined to always require a (potential) cell switch.

[0224] <<Option 5>> In addition to the RS index and L1-RSRP / SINR, the contents included in the event-triggered beam report (e.g., cell ID, BWP ID, TA, TCI state ID, frequency ID) may indicate whether a cell switch is requested. For example, if the above contents are included, it may mean that a (potential) cell switch is requested, and if the above contents are not included, it may mean that a cell switch is not requested.

[0225] Option 6: A value in the event-triggered beam report (e.g., the value of L1-RSRP / SINR) may implicitly indicate whether a cell switch is required. For example, a value of L1-RSRP / SINR of the current beam lower than a predetermined value or a value of L1-RSRP / SINR of at least one candidate beam higher than a predetermined value may indicate a cell switch is required.

[0226] According to this embodiment, it is possible to appropriately notify the base station (gNB) whether the event trigger beam report requests a cell switch. This makes it possible to solve the above problem 3.

[0227] Fifth Embodiment This embodiment may be based on the processing of Variation 2 of the 0th embodiment (e.g., FIG. 10 ). The UE receives a configuration of an event (first event / second event) for CLTM, evaluates the event for the RS / cell, and, if the condition of the first event is met, transmits a second UL signal to the base station of the current serving cell, notifying the possibility of a cell switch. Then, if the RS / cell meets the condition of the second event, the UE may execute a cell switch procedure. The second event may be meeting the condition of the event (first event) for a predetermined period of time.

[0228] Regarding the case where the event condition is satisfied, the following two cases are considered: Case 1: Multiple RSs / cells satisfy the first event condition (at the same time); Case 2: A first RS / cell satisfies the first event condition, and then a second RS / cell satisfies the first event condition before the first RS / cell satisfies the second event condition.

[0229] <<Case 1>> In case 1, the UE evaluates the first event and then starts evaluating the second event. In this case, one of the following options may be applied:

[0230] Option 1: The UE performs evaluation of the second event for multiple RSs / cells (all / part of the first RSs / cells) that satisfy the condition of the first event. In this case, multiple RSs / cells may satisfy the condition of the second event, and the NW cannot know which RSs / cells will be used in the cell switch of the LTM.

[0231] Option 2: The UE performs evaluation of the second event for one RS / cell that satisfies the condition of the first event (e.g., the RS / cell with the best L1-RSRP / SINR). In this case, the NW may select one RS / cell based on L1-RSRP / SINR, etc.

[0232] <<Case 2>> In case 2, one of the following options may be applied:

[0233] Option 1: The UE also performs evaluation of a second event for a second RS / cell that satisfies the condition of the first event.

[0234] Option 2: The UE does not perform a second event evaluation for the second RS / cell that satisfies the first event (i.e., only one evaluation is always used). In this case, UL signaling can be sent as a beam report. This may be applied to the NW to instruct a cell switch when a cell switch command MAC CE from the base station takes precedence over a CLTM. For example, if the first RS / cell satisfies the event condition at time t0, the second RS / cell may not be evaluated for the second event until an event-triggered beam report is sent at time t1.

[0235] Option 3: The UE may perform evaluation of the second RS / cell that satisfies the first event (i.e., the latest RS / cell that satisfies the condition of the event) and stop evaluating the first RS / cell. That is, evaluation of only one RS / cell may be performed at a time. The NW may be notified of the evaluation status of each cell by UL signaling.

[0236] <<Example of Option 1 for Cases 1 and 2>> Figure 16 is a diagram showing the processing of Option 1 for Case 1 of the fifth embodiment. The UE transmits an UL signal indicating a plurality of first RSs / cells that satisfy the conditions of the first event to the gNB. Then, for all / some of the first RSs / cells, evaluation of a second event (Another event) begins. In this case, there is a problem that the NW cannot know which RSs / cells will be used when determining the cell switch of the LTM.

[0237] 17 is a diagram showing the processing of option 1 of case 2 of the fifth embodiment. The UE transmits to the gNB an UL signal indicating a first RS / cell that satisfies the conditions of the first event and an UL signal indicating a second RS / cell that satisfies the conditions of the first event. Then, for the first RS / cell and the second RS / cell, evaluation of the second event (Another event) begins. In this case, too, there is a problem in that the NW cannot know which RS / cell will be used when determining the cell switch of the LTM.

[0238] <<Variation of Option 1 in Case 1>> At least one of the following options may be applied to solve the above problem of Option 1 in Case 1. Option 1: The UE transmits an UL signal to the gNB to notify the gNB of RSs / cells for which evaluation has been stopped (or evaluation has not been stopped) among multiple RSs / cells that satisfy the conditions of the first event. Option 2: The UE may specify the priority of RSs / cells by DCI / MAC CE, by RRC signaling, or by pre-defined specifications based on L1-RSRP / SINR, RS type, etc. The UE may select one RS / cell among multiple RSs / cells that satisfy the conditions of the first / second event based on the priority, use it for cell switch, and notify the gNB.

[0239] For example, if two RSs are evaluated and the second-priority RS in option 2 is used for the cell switch, the UE may use option 1 to notify the gNB of the first-priority RS that it has stopped evaluating.

[0240] <<Variation of Option 1 in Case 2>> At least one of the following options may be applied to solve the above problem of Option 1 in Case 2. Option 1: The UE transmits an UL signal to the gNB to notify the RS / cell that has stopped evaluation (or has not stopped evaluation) among multiple RSs / cells that satisfy the condition of the first event. Option 2: The UE may select the RS / cell that first satisfied the second event among multiple RSs / cells that satisfy the condition of the second event, use that RS / cell for cell switch, and notify the gNB.

[0241] According to the fifth embodiment, the process when multiple RSs / cells satisfy the event condition becomes clear, thereby solving the above-mentioned problem 4.

[0242] Sixth Embodiment This section describes processing in the case where LTM in Rel. 18 (for example, the LTM procedure in which a base station transmits a cell switch command to a UE as shown in FIG. 2) and CLTM (for example, the LTM procedure in which a UE transmits an UL signal instructing a cell switch to a base station when an event condition is met as shown in FIGS. 3 to 7 and 10) are configured simultaneously (option 1 below), and a cell switch command (MAC CE) for LTM in Rel. 18 and an UL signal instructing a cell switch for CLTM are transmitted simultaneously. For example, the UE may preferentially apply either the cell switch command or the instruction in the UL signal of the CLTM to execute the cell switch procedure.

[0243] In this embodiment, the UL signal of the CLTM may be the first UL signal or the second UL signal in the 0th embodiment.

[0244] Option 1: The UE can be configured (supported) with Rel. 18 LTM and CLTM simultaneously. That is, the UE may receive configuration information indicating both Rel. 18 LTM and CLTM. Option 2: The UE cannot be configured (supported) with Rel. 18 LTM and CLTM simultaneously. That is, the UE may receive configuration information indicating either Rel. 18 LTM or CLTM.

[0245] 18 is a diagram illustrating an example of Option 1 of the sixth embodiment. When LTM and CLTM in Rel. 18 are configured simultaneously, the UE may transmit an UL signal requesting a cell switch to the source gNB when an event condition is met, and may further receive a cell switch command MAC CE from the source gNB.

[0246] If option 1 applies, at least one of the following options may also apply:

[0247] Option 1-1: The Rel. 18 cell switch command MAC CE always takes precedence over the UL signaling of the CLTM. For example, even if the cell switch procedure is performed by the CLTM, if the UE receives the Rel. 18 cell switch command MAC CE, it performs a cell switch according to the Rel. 18 cell switch command. For example, if the UE receives the Rel. 18 cell switch command MAC CE, it may stop evaluating the RS / cell. For example, if the base station sends the Rel. 18 cell switch command MAC CE, it may ignore the UL signaling of the CLTM.

[0248] Option 1-2: The UL signaling instruction of the CLTM procedure always takes precedence over the cell switch command MAC CE in Rel. 18.

[0249] Option 1-3: It is up to the UE implementation whether to prioritize the cell switch command MAC CE or the UL signal of CLTM in Rel. 18.

[0250] Option 1-4: Any one of multiple RSs / cells indicated in the UL signal of the CLTM procedure is indicated by the cell switch command MAC CE.

[0251] The cell switch command / LTM in Rel. 18 may be interpreted as RRC reconfiguration for L3 handover (i.e., handover (HO) in Rel. 15, dual active protocol stack handover (DAPSHO) in Rel. 16), or CHO, Conditional PSCell Addition or Change (CPAC).

[0252] During the CLTM cell switch procedure, it may or may not be possible to initiate any type of RACH procedure.

[0253] If the CLTM event conditions are met in both the MCG and the SCG, the UE may prioritize the Master Cell Group (MCG), i.e., the UE may deconfigure the Secondary Cell Group (SCG).

[0254] According to the sixth embodiment, even if the LTM and CLTM in Rel. 18 are set at the same time, the cell switch procedure can be executed appropriately, thereby solving the above-mentioned problem 5.

[0255] <Supplementary Information> <<Notification of Information to UE>> In the above-described embodiments, notification of any information 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) may be performed 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.

[0256] 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.

[0257] 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.

[0258] Furthermore, notification of any information to the UE in the above embodiments may be performed periodically, semi-persistently, or aperiodically.

[0259] <<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.

[0260] 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.

[0261] If the notification is made by UCI, the notification may be transmitted using PUCCH or PUSCH.

[0262] Furthermore, any information in the above-described embodiments may be notified from the UE periodically, semi-persistently, or aperiodically.

[0263] <<Regarding Application of Each Embodiment>> In a UE / BS, specific (one or more) processes / operations / controls / assumptions / information for at least one of the above-mentioned embodiments may be applied (used) when one or more of the following conditions are met: - a higher layer parameter indicating the specific processes / operations / controls / assumptions / information is configured; - the specific processes / operations / controls / assumptions / information is determined based on related higher layer parameters; - the specific processes / operations / controls / assumptions / information is specified / activated / triggered by a MAC CE / DCI / UCI / resource / channel / RS; - a specific UE capability indicating (or related to) the specific processes / operations / controls / assumptions / information is reported or supported; - the application of the specific processes / operations / controls / assumptions / information is determined based on specific conditions.

[0264] The specific UE capability may indicate at least one of the following: - Supporting the specific processing / operation / control / assumption / information - Supporting the application of CLTM - Supporting event-triggered beam reporting in LTM - Supporting setting of implementation conditions per candidate cell - Supporting RACH-less procedure in CLTM - The maximum number of TCI state IDs, RS IDs, and L1-RSRPs included in one MAC CE for the first / second UL signal - Supporting MAC CEs for the first / second UL signal - Supporting activation of the TCI state of a candidate cell by a 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 a MAC CE.

[0265] 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).

[0266] 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)).

[0267] If the above conditions are not met, the UE / BS may follow the behavior specified in existing 3GPP releases.

[0268] (Supplementary Notes) The following inventions are supplementary notes with respect to the 0th and 1st embodiments of the present disclosure. [Supplementary Note 1] A terminal having: a receiving unit that receives a setting of an event for conditional L1L2-triggered mobility (CLTM); and a control unit that evaluates the event and executes a cell switch procedure if the condition of the event is met. [Supplementary Note 2] The terminal according to Supplementary Note 1, further having: a transmitting unit that transmits a first UL signal indicating a cell switch request to a base station of a current serving cell if the condition of the event is met, and the control unit executes the cell switch procedure if it receives acknowledgement information (ACK) for the first UL signal. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, further having: a transmitting unit that transmits a second UL signal notifying the possibility of a cell switch to a base station of a current serving cell if the condition of the event is met, and the control unit executes the cell switch procedure if the condition of the event is met for a predetermined time. [Supplementary Note 4] The terminal according to any one of Supplementary Notes 1 to 3, further comprising a transmitter that transmits, when the event condition is satisfied, a first UL signal indicating a cell switch request or a second UL signal notifying a base station of a current serving cell, wherein the first UL signal or the second UL signal includes at least one of a Transmission Configuration Indication (TCI) state ID and a Reference Signal (RS) index corresponding to a target cell.

[0269] (Supplementary Note) The following inventions are further supplemented with respect to the third embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a control unit that performs an event evaluation for a cell switch in conditional L1L2-triggered mobility (CLTM) for each of a currently used beam or serving cell and a candidate beam or candidate cell; and a transmission unit that transmits a UL signal indicating a cell switch request when the event condition is met. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the control unit performs an event evaluation for an event-triggered beam report for each of a currently used beam or serving cell and a candidate beam or candidate cell, and the transmission unit transmits a beam report when the event condition is met. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the currently used beam corresponds to a Quasi-Co-Location (QCL) Type D source Reference Signal (RS) that is configured in an indicated Transmission Configuration Indication (TCI) state. [Supplementary Note 4] The terminal according to any one of Supplementary Notes 1 to 3, wherein the currently used beam corresponds to a Quasi-Co-Location (QCL) Type D source Reference Signal (RS) set in an active Transmission Configuration Indication (TCI) state for beam management or LTM of the current serving cell.

[0270] (Supplementary Notes) The following inventions are further supplemented with respect to the fourth embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a control unit that performs event evaluation for an event-triggered beam report when conditional L1L2-triggered mobility (CLTM) is applied; and a transmission unit that transmits a beam report that can identify whether a cell switch is requested when a condition of the event is met. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the beam report includes an event ID that can identify whether a cell switch is requested. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the number of contents in the beam report indicates whether a cell switch is requested. [Supplementary Note 4] The terminal according to any of Supplements 1 to 3, wherein the content included in the beam report indicates whether a cell switch is requested.

[0271] (Supplementary Notes) The following inventions are further supplemented with respect to the fifth embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a receiving unit that receives an event setting for conditional L1L2-triggered mobility (CLTM); a transmitting unit that transmits an UL signal notifying the base station of a current serving cell of the possibility of a cell switch when a condition of a first event is satisfied; and a control unit that executes a cell switch procedure when a condition of a second event is satisfied. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the transmitting unit transmits an UL signal for notifying an RS and a cell that have stopped evaluation among a plurality of RSs and cells that satisfy the condition of the first event. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the control unit selects one RS and one cell from a plurality of RSs and cells that satisfy the conditions of the first event and the second event based on a set priority, and uses the RS and one cell for a cell switch. [Supplementary Note 4] The terminal according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the control unit selects an RS and a cell that first satisfy the second event from among a plurality of RSs and cells that satisfy the conditions of the second event, and uses the RS and the cell for a cell switch.

[0272] (Supplementary Notes) The following inventions are further supplementary to the sixth embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a receiver that receives configuration information indicating an L1L2-triggered mobility (LTM) procedure in which a cell switch command is transmitted from a base station, and a conditional L1L2-triggered mobility (CLTM) procedure in which a conditional L1L2-triggered mobility (CLTM) procedure in which a UL signal instructing a cell switch is transmitted to a base station when an event condition is satisfied; and a controller that preferentially applies either the cell switch command or an instruction in the UL signal and executes the cell switch procedure. [Supplementary Note 2] The terminal according to Supplementary Note 1, in which the controller preferentially applies the cell switch command and executes the cell switch procedure. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, in which the controller preferentially applies the instruction in the UL signal and executes the cell switch procedure.

[0273] (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.

[0274] 19 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).

[0275] 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.

[0276] 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.

[0277] 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))).

[0278] 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 location, number, shape, size, etc. of each cell and user terminal 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 the base station 10.

[0279] The wireless communication system 1 may utilize multi-input multi-output (MIMO). For example, one cell may be formed by one antenna / base station 10, or may be formed by multiple antennas / base stations 10. One [virtual] cell (which may be called, for example, a supercell) may be composed of multiple [virtual] cells (which may be called, for example, subcells). A supercell may correspond to a cell with a fixed physical range, and a subcell may correspond to a cell with a quasi-static / dynamically variable physical range. In this case, the wireless communication system 1 may be called a cell-free system.

[0280] 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).

[0281] 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.

[0282] 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.

[0283] The multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with the Common Public Radio Interface (CPRI), an X2 / Xn 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.

[0284] 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.

[0285] 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.

[0286] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0287] 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).

[0288] 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.

[0289] 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.

[0290] 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.

[0291] 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).

[0292] 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.

[0293] 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.

[0294] 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.

[0295] 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.

[0296] 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.

[0297] 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.

[0298] 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.

[0299] 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.

[0300] 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).

[0301] (Base Station) Fig. 20 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.

[0302] 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.

[0303] 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.

[0304] 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.

[0305] 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.

[0306] 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.

[0307] 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.

[0308] 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.

[0309] 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.

[0310] 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.

[0311] 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.

[0312] 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.

[0313] On the other hand, the transmitting / receiving unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna 130.

[0314] 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.

[0315] 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.

[0316] 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.

[0317] The transmitter and receiver of the base station 10 in the present disclosure may be configured by at least one of the transmitter / receiver 120, the transmitter / receiver antenna 130, and the transmission path interface 140.

[0318] The base station 10 may be separated into three elements: a radio unit (RU), a distributed unit (DU), and a central unit (CU). For example, the RU may implement RF processing (digital beamforming, digital-to-analog conversion, analog beamforming, etc.) and lower-level functions of the physical layer (precoding, IFFT, FFT, etc.). The DU may implement higher-level functions of the physical layer (coding to resource element mapping, etc.), MAC layer functions, and RLC layer functions. The CU may implement the functions of the PDCP layer, Service Data Adaptation Protocol (SDAP) layer, and RRC layer.

[0319] In the present disclosure, the base station 10 may include a single device that realizes all of the functions of the RU, DU, and CU, or may include multiple devices that each realize some of the functions of the RU, DU, and CU and are connected to each other. In the present disclosure, the base station 10 may be interchangeably read as RU / DU / CU.

[0320] In the present disclosure, the base station 10 may be a source gNB, a target gNB (a gNB of a target cell), or a candidate gNB (a gNB of a candidate cell).

[0321] The transceiver 120 may transmit an event configuration for conditional L1L2-triggered mobility (CLTM). The controller 110 may evaluate the event and execute a cell switch procedure if the event conditions are met.

[0322] The transceiver 120 may transmit an event setting for a cell switch in conditional L1L2-triggered mobility (CLTM) for each of the currently used beam or serving cell and the candidate beam or candidate cell. The controller 110 may control reception of an UL signal indicating a cell switch request when the event conditions are met.

[0323] The transceiver 120 may transmit an event setting for an event-triggered beam report when conditional L1L2-triggered mobility (CLTM) is applied, and the controller 110 may control reception of a beam report that can identify whether a cell switch is requested when the event condition is met.

[0324] The transceiver 120 may transmit an event configuration for conditional L1L2-triggered mobility (CLTM). The transceiver 120 may receive an UL signal notifying the possibility of a cell switch if the conditions of a first event are met. The controller 110 may execute a cell switch procedure if the conditions of a second event are met.

[0325] The transceiver 120 may transmit configuration information indicating an L1L2-triggered mobility (LTM) procedure in which a cell switch command is transmitted from a base station, and a conditional L1L2-triggered mobility (CLTM) procedure in which an UL signal instructing a cell switch is transmitted to a base station when an event condition is satisfied. The controller 110 may execute the cell switch procedure by preferentially applying either the cell switch command or the UL signal instruction.

[0326] (User Terminal) Fig. 21 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.

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 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.

[0332] 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.

[0333] 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.

[0334] 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.

[0335] 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.

[0336] 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.

[0337] 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.

[0338] 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.

[0339] 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.

[0340] 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.

[0341] 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.

[0342] 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.

[0343] Note that the transmitting section and receiving section of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving section 220 and the transmitting / receiving antenna 230.

[0344] The transceiver unit 220 may perform at least one of the processes of the transmitter / receiver unit in any of the above appendices.

[0345] The control unit 210 may execute at least one of the processes of any of the control units described above.

[0346] (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.

[0347] 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.

[0348] 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. Fig. 22 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.

[0349] 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.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] 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.

[0354] 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.

[0355] 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.

[0356] 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.

[0357] 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).

[0358] 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.

[0359] 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.

[0360] In addition, the devices included in the core network 30 (for example, network nodes that provide NF) may also be realized by the above-mentioned functional block / hardware configuration.

[0361] (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.

[0362] 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.

[0363] 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.

[0364] 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.

[0365] 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.

[0366] 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.

[0367] 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.

[0368] 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.

[0369] 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.

[0370] 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.

[0371] 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.

[0372] 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.

[0373] 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.

[0374] 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.

[0375] 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.

[0376] 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.

[0377] 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.

[0378] 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.

[0379] 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."

[0380] 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.

[0381] 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.

[0382] 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.

[0383] 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.

[0384] 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.

[0385] 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.

[0386] With respect to any information (e.g., variables, constants, parameters) described in the present disclosure, even if not specifically stated in the above embodiments, any first device (e.g., UE / base station) may notify any second device (e.g., base station / UE) of information indicating / specifying (or relating to) the value of the any information.

[0387] 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.

[0388] 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).

[0389] 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).

[0390] 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).

[0391] 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.

[0392] 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.

[0393] 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).

[0394] 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.

[0395] 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.

[0396] 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.

[0397] 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.

[0398] 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.

[0399] 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.

[0400] 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.

[0401] 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.

[0402] 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.

[0403] 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.

[0404] 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.

[0405] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0406] 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.

[0407] 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.

[0408] 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.

[0409] 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.

[0410] 23 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.

[0411] 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.

[0412] 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).

[0413] 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.

[0414] 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.

[0415] 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.

[0416] 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.

[0417] 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.

[0418] 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).

[0419] 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.

[0420] 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)).

[0421] 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.

[0422] 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.

[0423] 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.

[0424] 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.

[0425] 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.

[0426] 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).

[0427] 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."

[0428] 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.

[0429] 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.

[0430] 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.

[0431] 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.

[0432] 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...."

[0433] 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 ..." or "do ... (if the above "..." is a to-infinitive, a verb with "to")," etc. "does not expect ..." may be interchangeably read as "be not expected ..." or "does not ... (if the above "..." is a to-infinitive, a verb with "to")," etc. 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" (for example, if apparatus A is a UE, apparatus B may be a base station).

[0434] 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.

[0435] 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."

[0436] 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.

[0437] 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."

[0438] 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.

[0439] 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.

[0440] 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").

[0441] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0442] 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.

[0443] 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.

[0444] 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 receiving unit that receives an event setting for conditional L1L2-triggered mobility (CLTM); a transmitting unit that transmits an UL signal to a base station of a current serving cell, notifying the possibility of a cell switch, when the conditions of a first event are met; and a control unit that executes a cell switch procedure when the conditions of a second event are met.

2. The terminal according to claim 1, wherein the transmitter transmits an UL signal for notifying the RS and cell for which evaluation has stopped among a plurality of RSs and cells that satisfy the condition of a first event.

3. The terminal according to claim 1, wherein the control unit selects one RS and cell from among a plurality of RSs and cells that satisfy the conditions of the first event and the second event based on a set priority, and uses the selected RS and cell for a cell switch.

4. The terminal according to claim 1, wherein the control unit selects the RS and cell that first satisfy the second event from among a plurality of RSs and cells that satisfy the conditions of the second event, and uses the selected RS and cell for cell switching.

5. A wireless communication method for a terminal, comprising: receiving an event configuration for conditional L1L2-triggered mobility (CLTM); transmitting an UL signal to a base station of a current serving cell notifying the possibility of a cell switch when the conditions of a first event are met; and executing a cell switch procedure when the conditions of a second event are met.

6. A base station having: a transmitter that transmits an event setting for conditional L1L2-triggered mobility (CLTM); a receiver that receives an UL signal that notifies the possibility of a cell switch when the conditions of a first event are met; and a controller that executes a cell switch procedure when the conditions of a second event are met.

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