Terminal, wireless communication method, base station and system

Abstract

A terminal according to an aspect of the present disclosure is characterized by having: a reception unit that receives downlink control information (DCI) including a field that indicates a transmission configuration indication (TCI) state and a field that indicates a serving cell switch, and also receives a configuration of cell-application timing; and a control unit that applies the TCI state after switching at a timing based on the configuration. According to an aspect of the present disclosure, cell-related configurations can be appropriately set.

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 a wireless communication system, it is being considered that one or more cells / transmission / reception points (Transmission / Reception Points (TRPs)) (Multi-TRPs (MTRPs)) perform downlink (DL) transmissions to a terminal (user terminal, User Equipment (UE)).

[0006] When multi-TRP is applied, a serving cell may be switched to a cell with a PCI different from that of the serving cell by signaling of at least one of layer 1 and layer 2 (layer 1 / layer 2 inter-cell mobility). However, when L1 / L2 inter-cell mobility is performed, problems such as a decrease in communication throughput may occur if the cell-related settings are not properly configured.

[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 cell-related settings.

[0008] A terminal according to one aspect of the present disclosure is characterized in that it has a receiving unit that receives downlink control information (DCI) including a field indicating a transmission configuration indication (TCI) state and a field indicating a serving cell switch, and receives a cell application timing setting, and a control unit that applies the TCI state after the switch at a timing based on the setting.

[0009] According to one aspect of the present disclosure, cell-related settings can be appropriately performed.

[0010] FIG. 1A shows an example of inter-cell mobility including a non-serving cell (e.g., inter-cell mobility with a single TRP). FIG. 1B shows an example of inter-cell mobility when using multiple TRPs. FIG. 2 shows an example of a MAC entity / HARQ entity. FIGS. 3A to 3C show examples of cell group configuration corresponding to FIG. 2. FIG. 4 shows an example of a MAC entity. FIG. 5 shows an example of application timing of an indicated TCI state. FIG. 6 shows an example of Option 1 of Embodiment 1-1. FIG. 7 shows an example of Option 2 of Embodiment 1-1. FIGS. 8A and 8B show an example of a serving cell switch in Supplement D. FIG. 9 shows another example of a serving cell switch in Supplement D. FIG. 10 shows an example of a serving cell switch in Variation 1. FIG. 11 shows an example of a serving cell switch in Variation 2. FIG. 12 shows an example of a serving cell switch in Variation 3. FIG. 13 shows an example of application timing of an indicated TCI state in Option 1 of the second embodiment. FIG. 14 is a diagram showing an example of a MAC CE according to embodiment 3-2. FIG. 15 is a diagram showing an example of a switching gap according to the fifth embodiment. FIG. 16 shows an example of a cell switch according to embodiment 6-1. FIG. 17 shows an example of a cell switch according to embodiment 6-2. FIG. 18 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 19 is a diagram showing an example of a configuration of a base station according to an embodiment. FIG. 20 is a diagram showing an example of a configuration of a user terminal according to an embodiment. FIG. 21 is a diagram showing an example of the hardware configuration of a base station and a user terminal according to an embodiment. FIG. 22 is a diagram showing an example of a vehicle according to an embodiment.

[0011] (Multi-TRP) It is being considered that one or more cells / transmission / reception points (TRPs) (Multi-TRPs (MTRPs)) perform DL transmission to a UE. It is also being considered that a UE performs UL transmission to one or more cells / TRPs. As a procedure in this case, the following Scenario 1 or Scenario 2 can be considered. Note that in the present disclosure, the serving cell may be interpreted as a TRP within the serving cell. Layer 1 / layer 2 (L1 / L2) signaling and Medium Access Control Control Element (MAC CE) / DCI may be interpreted as mutually interchangeable. 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." In Scenario 1, for example, the following procedure is performed.

[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 configuration necessary for using radio resources for data transmission and reception, including the SSB configuration for beam measurement of the TRP corresponding to a PCI different from that of the serving cell and the 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 UE-dedicated channels 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 or receives signals to or from a non-serving cell / TRP (a TRP corresponding to the PCI of the non-serving 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 the non-serving cell from the serving cell. Scenario 1 may be applied, for example, in Rel. 17.

[0015] <Scenario 2> In scenario 2, L1 / L2 inter-cell mobility is applied. With L1 / L2 inter-cell mobility, the serving cell can be changed using functions such as beam control without RRC reconfiguration. In other words, transmission and reception with a non-serving cell are possible without handover. Since handover requires RRC reconnection, which results in a period when data communication is unavailable, by applying L1 / L2 inter-cell mobility that does not require handover, data communication can be continued 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.

[0016] (1) The UE receives SSB configuration for a cell with a different PCI (non-serving cell) from the serving cell for beam measurement / serving cell change. (2) The UE performs beam measurement for a cell using a different PCI and reports the measurement results to the serving cell. (3) The UE may receive the configuration for a cell with a different PCI (serving 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 or separately from the configuration in (1). (4) Based on the above report, the TCI state of the cell with a different PCI may be activated via L1 / L2 signaling in accordance with 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 reception / transmission using the pre-configured UE-dedicated channel and TCI state.

[0017] That is, in scenario 2, the serving cell (the assumed serving cell in the UE) is updated by L1 / L2 signaling.

[0018] An example in which a UE receives channels / signals from multiple cells / TRPs during inter-cell mobility will be described with reference to Figures 1A and 1B.

[0019] 1A illustrates an example of inter-cell mobility (e.g., single-TRP inter-cell mobility) involving a non-serving cell. Single-TRP may refer to a case where only one TRP of multiple TRPs transmits to the UE (also referred to as single mode). Here, the UE receives channels / signals from the base station / TRP of cell #1 (PCI #1), which is the serving cell, and the base station / TRP of cell #3 (PCI #3), which is a non-serving cell.

[0020] For example, if the serving cell of a UE switches from cell #1 to cell #3, the DCI / MAC CE may update the TCI status and dynamically select a port (e.g., antenna port) / TRP / point. The UE can quickly change cells / beams by using the DCI / MAC CE.

[0021] Figure 1B shows an example of inter-cell mobility when using multiple TRPs. Here, a UE receives channels / signals from TRP #1 and TRP #2. Here, TRP #1 is located in cell #1 (PCI #1), and TRP #2 is located in cell #2 (PCI #2). Assume that the serving cell configurations of cell #1 (PCI #1) and cell #2 (PCI #2) are the same.

[0022] The multi-TRPs (TRPs #1 and #2) may be connected by an ideal / non-ideal backhaul to exchange information, data, etc. Each TRP of the multi-TRP may transmit a different code word (CW) and a different layer. Non-Coherent Joint Transmission (NCJT) may be used as a form of multi-TRP transmission. In FIG. 1B, NCJT may be performed between multiple cells (cells with different PCIs).

[0023] In the NCJT, for example, TRP#1 modulates and layer-maps a first codeword to transmit a first signal / channel (e.g., PDSCH) using a first number of layers (e.g., two layers) with a first precoding, and TRP#2 modulates and layer-maps a second codeword to transmit a second signal / channel (e.g., PDSCH) using a second number of layers (e.g., two layers) with a second precoding.

[0024] Multiple PDSCHs (multi-PDSCHs) that are non-coherent may be defined as partially or completely overlapping in time and / or frequency domain, i.e., a first PDSCH from TRP#1 and a second PDSCH from TRP#2 may overlap in time and / or frequency resources.

[0025] The first PDSCH and the second PDSCH may be assumed to be not quasi-co-located (QCL). Reception of multiple PDSCHs may be interpreted as simultaneous reception of PDSCHs that are not of a certain QCL type (e.g., QCL type D).

[0026] Multiple PDSCHs from multiple TRPs (which may be referred to as multiple PDSCHs) may be scheduled using one DCI (single DCI (S-DCI), single PDCCH) (single master mode). One DCI may be transmitted from one TRP of a multi-TRP. A configuration using one DCI in a multi-TRP may be referred to as single DCI-based multi-TRP (mTRP / MTRP).

[0027] A case may also be applied in which each of the multi-TRPs transmits a part of the control signal to the UE and the multi-TRP transmits the data signal (which may be called a master-slave mode).

[0028] Multiple PDSCHs from a multi-TRP may be scheduled using multiple DCIs (multiple DCI (M-DCI), multiple PDCCHs (multiple PDCCHs)), respectively (multiple master mode). Multiple DCIs may be transmitted from multiple TRPs, respectively. A configuration that utilizes multiple DCIs in a multi-TRP may be referred to as a multi-DCI-based multi-TRP (mTRP / MTRP).

[0029] It may be assumed that the UE transmits separate CSI reports (CSI reports) for different TRPs. Such CSI feedback may be referred to as separate feedback, separate CSI feedback, etc. In this disclosure, "separate" may be interchangeably read as "independent."

[0030] (L1 / L2 Inter-Cell Mobility) [Configuration of Candidate Serving Cells] An example of L1 / L2 inter-cell mobility will be described. When communicating with one TRP (when a single TRP is applied), the UE's L1 / L2 inter-cell mobility may be configured only for multiple cells having approximately the same serving cell configurations.

[0031] When communicating with one TRP (when a single TRP is applied), the UE may receive in advance configuration of multiple candidate serving cells that are non-serving cells corresponding to the frequency by higher layer signaling (RRC reconfiguration signaling). Then, when the UE receives an instruction indicating one of the multiple candidate serving cells by MAC CE / DCI, the UE may change the serving cell (handover) to the candidate serving cell indicated by the instruction.

[0032] The UE may receive (may be configured) a configuration of multiple candidate serving cells that are non-serving cells corresponding to a frequency by higher layer signaling (RRC reconfiguration signaling). Then, when the UE receives information (QCL / TCI) related to the QCL of the non-serving cell by MAC CE or DCI, the UE may change (handover) the serving cell to the candidate serving cell corresponding to (associated with) the non-serving cell and apply the QCL.

[0033] When multiple candidate serving cell configurations corresponding to a frequency are configured, the UE may simultaneously apply / maintain / support / hold at least two (or more) candidate serving cell configurations among the multiple candidate serving cell configurations, and may simultaneously communicate with multiple serving cells corresponding to the multiple candidate serving cell configurations.

[0034] <Example of MAC entity / HARQ entity> Figure 2 is a diagram showing an example of a MAC entity / HARQ entity. The cells in the box shown in A of Figure 2 are cells of a cell group (MCG / SCG) for CA / DC operation. Each cell corresponds to a different frequency. The cells in the box shown in B of Figure 2 are cells of a cell group for L1 / L2 inter-cell mobility operation, and are an example where the serving cell is an SpCell. Each cell in B corresponds to the same frequency. The cells in the box shown in C of Figure 2 are cells of a cell group for L1 / L2 inter-cell mobility operation, and are an example where the serving cell is an SCell. Each cell in C corresponds to the same frequency.

[0035] That is, in CA / DC, each cell corresponds to a different frequency (CC), but in L1 / L2 inter-cell mobility (multi-TRP), each cell (with a different PCI) corresponds to the same frequency (CC). Candidate cell #X in C may be different from candidate cell #1 in B (the PCI / frequency may be different). X may be a re-created index for a certain frequency, e.g., starting from 1. The re-created index may correspond to at least a part of the PCI and may be an index created for the candidate cell.

[0036] In another example, even in the case of L1 / L2 inter-cell mobility, each cell (SpCell / Scell, Candidate cell) may correspond to a different frequency, but may share the same HARQ entity corresponding to PDSCH scheduling.

[0037] Figures 3A to 3C are diagrams showing examples of cell group settings corresponding to Figure 2. Figures 3A to 3C correspond to the cells (cell groups) within boxes A, B, and C in Figure 2, respectively. "cellGroupId", "new indicator for cell group purpose", "spCellConfig", and "sCellToAddModList" correspond to the cells (cell groups) within boxes A, B, and C in Figure 2, respectively.

[0038] In this way, by reusing the CA / DC framework for L1 / L2 inter-cell mobility operation, cell group configuration for L1 / L2 inter-cell mobility can be performed without adding new RRC information elements.

[0039] <Serving Cell Change Indication> Implicit or explicit signaling for serving cell change indication will now be described.

[0040] [Implicit Signaling] Implicit signaling for a serving cell change indication will now be described, in which case, for example, the above-mentioned scenario 2 in multi-TRP may be applied.

[0041] [[Option 1]] When a specific control resource set (CORESET) (e.g., at least one of CORESET#0, CORESET of CH5 Type0-CSS, and CORESET of CH6 / CH7 / CH8 CSS) is indicated (activated) by a MAC CE together with one or more TCI states associated with cells of PCIs different from that of the serving cell (when one or more TCI states associated with cells of PCIs different from that of the serving cell are indicated / activated by a MAC CE for a specific CORESET), the UE may determine to change the serving cell to another cell (cell x, a cell with a different PCI). In other words, this activation may implicitly indicate that the serving cell will be changed to another cell.

[0042] Option 2: When the MAC CE activates / deactivates the TCI states of the PDSCH, if all such TCI states activated by the MAC CE are associated with the same cell x, which has a PCI different from that of the serving cell, the UE may determine to change the serving cell to another cell (cell x), i.e., this association may implicitly indicate that the serving cell will be changed to another cell.

[0043] [Explicit Signaling] Explicit signaling for a serving cell change indication will now be described, in which case, for example, the above-mentioned scenario 2 in multi-TRP may be applied.

[0044] [Option 3] An example of a serving cell change instruction will be described below. Note that activation / deactivation of a non-serving cell, change of a serving cell, and transmission / reception with another cell (non-serving cell) having a physical cell ID different from the physical cell ID of the serving cell may be interpreted as interchangeable.

[0045] The UE may receive a new MAC CE including at least one of the fields (information) indicating the following (1) to (3) corresponding to a non-serving cell, which is used for activating / deactivating the non-serving cell. When the UE receives the MAC CE, the UE may determine to change the serving cell to another cell (non-serving cell). Furthermore, the UE may control transmission and reception of DL signals / UL signals with the non-serving cell based on the information. Note that the non-serving cell may be one or multiple. In the example shown below, a MAC CE including multiple fields indicating multiple non-serving cell indexes is applied.

[0046] (1) Serving cell ID, (2) BWP ID, and (3) Non-serving cell ID used for activation. The non-serving cell ID may be replaced with any information corresponding to the non-serving cell (that can identify the non-serving cell).

[0047] As an example of (3), any of (3-1) to (3-5) may be applied. (3-1) PCI (PCI used directly). For example, 10 bits are used. (3-2) Re-creation index (new ID) of non-serving cells. The new ID may be associated with a part of the PCI and configured only for serving and non-serving cells used (available) by the UE. The new ID can reduce the number of bits compared to the PCI. (3-3) CSI reporting configuration ID (CSI-ReportConfigId) (when CSI-ReportConfig corresponds to one or more non-serving cells). (3-4) CSI resource configuration ID (CSI-ResourceConfigId) (when CSI-ResourceConfigId corresponds to one or more non-serving cells). (3-5) Bitmap indicating activation / deactivation of each non-serving cell. The size (number of bits) of the bitmap may be the same as the number of non-serving cells configured on this CC. For example, when activating the second non-serving cell among three non-serving cells, "010" is set.

[0048] [Option 4] The UE may receive a MAC CE in which a new 1-bit field "C" is added to the existing MAC CE. The field indicates whether to change the serving cell. The UE may receive the MAC CE and determine whether to change the serving cell to another cell based on the field.

[0049] For example, at least one of a field indicating activation / deactivation of the TCI state of the PDSCH, a field indicating activation / deactivation of a cell with a different PCI, a field indicating an RS (e.g., SSB) for beam measurement / reporting of a cell with a different PCI, and a field indicating other purposes / functions may be added to the existing MAC CE. In this case, the number of cells associated / indicated with a different PCI in the MAC CE may be only one cell.

[0050] [Option 5] In addition to the MAC CE in Option 4, the MAC CE may further include fields indicating the serving cell index / PCI / other IDs (such as the new ID in Option 3 above), and fields indicating the TCI state / SSB / CSI-RS of the target cell (the serving cell after the change).

[0051] Options 3 to 5 may be combined, i.e. a MAC CE containing at least one of the fields shown in options 3 to 5 may be applied.

[0052] 4 is a diagram illustrating an example of a MAC entity. For example, in a serving cell SpCell#0 of an MCG / SCG, when an instruction to change the serving cell to a candidate cell #0-2 is given by L1 / L2 signaling, the candidate cell #0-2 becomes the new serving cell SpCell#0. Also, for example, in a serving cell SCell#2 of an MCG / SCG, when an instruction to change the serving cell to a candidate cell #2-1 is given by L1 / L2 signaling, the candidate cell #2-1 becomes the new serving cell SCell#2.

[0053] (DCI-Based TCI Status Indication for Unified TCI) This section describes DCI-based TCI status indication for the unified TCI of Rel. 17. The UE receives an indication in the TCI status field (maximum 3 bits) of DCI format 1_1 / 1_2 (with or without DL allocation) and applies (switches) the TCI status according to the indication. Note that one TCI code point in the DCI may be associated with one "joint TCI" or at least one of "DL TCI" and "UL TCI."

[0054] 5 is a diagram showing an example of the application timing of the indicated TCI state. The UE receives DCI and receives the PDSCH scheduled by the DCI. The UE then transmits an ACK for the PDSCH. The indicated TCI state is applied after the time indicated in the beam application timing / timer (BAT) from the transmission timing of the ACK. BeamAppTime_r17 may be configured in the UE by RRC signaling based on the UE capabilities.

[0055] (Analysis) As described above, when multi-TRP is applied, a serving cell may be switched to a cell with a PCI different from that of the serving cell by signaling of at least one of Layer 1 and Layer 2 (Layer 1 / Layer 2 inter-cell mobility). However, when L1 / L2 inter-cell mobility is performed, problems such as a decrease in communication throughput may occur if cell-related settings are not properly configured.

[0056] Therefore, the present inventors have conceived a terminal, a wireless communication method, and a base station that are capable of appropriately configuring settings related to a cell.

[0057] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Wireless communication methods according to the embodiments may be applied independently or in combination.

[0058] 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."

[0059] In the present disclosure, terms such as 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.

[0060] 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.

[0061] In the present disclosure, higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, etc., or a combination thereof.

[0062] 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.

[0063] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0064] In the present disclosure, the terms index, identifier (ID), indicator, resource ID, etc. may be interchangeable. In the present disclosure, the terms sequence, list, set, group, cluster, subset, etc. may be interchangeable.

[0065] In the present disclosure, the terms panel, UE panel, panel group, beam, beam group, precoder, Uplink (UL) transmitting entity, Transmission / Reception Point (TRP), base station, Spatial Relation Information (SRI), spatial relation, SRS Resource Indicator (SRI), Control Resource Set (CORESET), Physical Downlink Shared Channel (PDSCH), Codeword (CW), Transport Block (TB), Reference Signal (RS), antenna port (e.g., Demodulation Reference Signal (DMRS) port), antenna port group (e.g., DMRS port group), group (e.g., spatial relation group, Code Division Multiplexing (CDM) group, reference signal group, CORESET group, Physical Uplink Control Channel (PUCCH) group, PUCCH resource group), resource (e.g., reference signal resource, SRS resource), resource set (e.g., reference signal resource set), CORESET pool, downlink Transmission Configuration Indication state (TCI state) (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, Quasi-Co-Location (QCL), QCL assumption, etc. may be read as interchangeable.

[0066] Furthermore, the spatial relationship information identifier (ID) (TCI state ID) and the spatial relationship information (TCI state) may be interchangeable. The "spatial relationship information" may be interchangeable with "set of spatial relationship information," "one or more pieces of spatial relationship information," etc. The TCI state and the TCI may be interchangeable with each other.

[0067] In the present disclosure, the terms drop, abort, cancel, puncture, rate match, postpone, do not transmit, etc. may be read interchangeably.

[0068] In the present disclosure, applying the indicated TCI state may mean that at least one of the UE and the base station applies the indicated TCI state. Applying the indicated TCI state, switching the TCI state, and switching the cell (serving cell) may be interchangeable. In the present disclosure, switching the cell (cell switch) may mean switching the serving cell.

[0069] 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 MAC CE / DCI 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.

[0070] In the present disclosure, the terms cell, serving cell, source serving cell, CC, BWP, BWP within a CC, and band may be interchangeable. In the present disclosure, the terms other cell, non-serving cell, cell with a different PCI, 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. In the present disclosure, the terms switch, change, and update may be interchangeable.

[0071] (Wireless Communication Method) <First Embodiment> A UE may receive DCI including a field indicating a cell switch (switch / change / change / update of a serving cell), and may switch a cell for transmitting and receiving based on the DCI. In this embodiment, an instruction by DCI is described, but a cell switch may also be instructed by DCI / MAC CE (for example, applying the third embodiment described later).

[0072] [Embodiment 1-1] The field indicating a cell switch (a switch of a serving cell) in the DCI may be a one-bit (or multiple-bit) field for an explicit cell switch. In the case of multiple bits, the multiple bits may be used to notify both the cell switch instruction and the cell number of the cell switch destination (the ID of the source serving cell / target cell). Furthermore, without using a bit field for an explicit cell switch, the UE may determine that a cell switch has been indicated when the "existing DCI field" and the "RNTI for CRC scrambling the DCI" have predetermined values. In the present disclosure, the source serving cell is the serving cell before the cell switch, and the target cell is the serving cell after the cell switch.

[0073] <<Option 1>> The source serving cell is the cell that receives / detects the DCI (the cell corresponding to the BWP / CC that receives / detects the DCI). That is, the source serving cell is implicitly indicated by the reception of the DCI. The target cell to be switched to is the cell associated with the "TCI state indicated in the DCI" (the cell with the associated PCI). That is, the target cell is implicitly indicated by the TCI state. The target cell is associated with the source serving cell and is included in the configured candidate serving cells. Option 1 may be applied in the case of self-scheduling. By providing an implicit indication, the amount of DCI data can be reduced.

[0074] 6 is a diagram illustrating an example of Option 1 of Embodiment 1-1. The UE receives DCI indicating a field (e.g., 1 bit) indicating a serving cell switch in SCell#2 (source serving cell). Then, the serving cell is switched from SCell#2 to candidate cell#2-1 (target cell) associated with the TCI state indicated by this DCI. That is, candidate cell#2-1 becomes the new serving cell.

[0075] <<Option 2>> The source serving cell is the cell indicated by the carrier indicator field of the DCI. That is, the source serving cell is explicitly indicated by the DCI. The target cell to be switched to is the cell associated with the "TCI state indicated in the DCI" (the cell with the associated PCI). That is, the target cell is implicitly indicated by the TCI state. The target cell is associated with the source serving cell and is included in the configured candidate serving cells. Option 2 may be applied in the case of cross-carrier scheduling. By implicitly indicating the target cell, the amount of data in the DCI can be reduced.

[0076] 7 is a diagram illustrating an example of Option 2 of Embodiment 1-1. The UE receives DCI indicating a carrier indicator on SCell#2. Assume that the carrier indicator indicates SCell#1 (source serving cell). Then, the serving cell is switched from SCell#1 to candidate cell#1-1 (target cell) associated with the TCI state indicated by this DCI. That is, candidate cell#1-1 becomes the new serving cell.

[0077] [Embodiment 1-2] A UE may receive DCI including a new field indicating a source serving cell ID (or a cell group ID including the source serving cell) and a new field indicating a target cell ID, and may switch the serving cell from the source serving cell to the target serving cell based on the DCI. That is, the source serving cell and the target cell are explicitly indicated by the DCI.

[0078] Embodiment 1-1 and Embodiment 1-2 may be combined. For example, the DCI may include a new field indicating a source serving cell ID (explicit indication), and the target cell may be a candidate cell associated with the TCI state (implicit indication). For example, the source serving cell may be the cell that received the DCI or the cell indicated by the carrier indicator (implicit indication), and the DCI may include a new field indicating a target cell ID (explicit indication).

[0079] In the first and second embodiments, the DCI may or may not include one bit (or multiple bits) of information indicating a serving cell switch. For example, if the DCI does not include the one bit of information and includes a new field indicating a source serving cell ID and a new field indicating a target cell ID, the UE may decide to perform a serving cell switch.

[0080] [Supplementary A] When the new bit of DCI indicates a switch of serving cell, the following option 1 or 2 may be applied for the restriction between the indicated source serving cell and the indicated target cell for the switch.

[0081] <<Option 1>> The UE does not expect the indicated source serving cell and the indicated target cell of the switch to be the same.

[0082] <<Option 2>> There may be no restriction. That is, the source serving cell and the target cell may be the same. For example, if the indicated source serving cell and the indicated target cell for switching are the same, the UE may not perform a cell switch procedure (may ignore the switch instruction). Alternatively, if the indicated source serving cell and the indicated target cell for switching are the same, the UE may perform a specific cell switch procedure. In this case, there may be a specific UE operation to be performed for the cell switch (e.g., the fifth embodiment).

[0083] [Supplementary Note B] Regarding the restriction on the switch instruction of the SpCell in Option 2 of Embodiment 1-1, the following Option 1 or 2 may be applied.

[0084] <<Option 1>> The UE may be able to receive the DCI instructing the SpCell switch in any serving cell.

[0085] <<Option 2>> The UE may be able to receive the DCI instructing an SpCell switch only from the SpCell. That is, the DCI instructing a serving cell change on the Scell ​​can only instruct an Scell ​​change, but cannot instruct an SpCell change.

[0086] [Supplementary C] Regarding the DCI format for the new indication used for the serving cell switch, the following options 1 and 2 may be applied.

[0087] <<Option 1>> DCI format 1_1 / 1_2 (with or without data allocation) may be applied. For DCI format 1_1 / 1_2 without data allocation, the existing DCI format for the unified TCI status indication in Rel. 17 may be reused, and a new field for the serving cell switch indication may be added.

[0088] <<Option 2>> DCI formats 1_1 / 1_2 and 0_1 / 0_2 may be applied. The UL DCI format may also be used to indicate a serving cell switch.

[0089] [Supplementary Note D] It may be possible to simultaneously instruct a switch of multiple serving cells. For example, the UE may simultaneously receive a configuration / instruction of a serving cell switch for serving cells in one or more cell lists. For example, when a serving cell switch from a serving cell #x to a candidate cell #x_i associated with the serving cell #x is instructed, another serving cell (e.g., cell #y) in the same cell list may also be configured / instructed to be switched to a candidate cell #y_i associated with the serving cell #y. Note that there may be a constraint that the same number of candidate cells for cell switch are configured for all serving cells in the cell list.

[0090] For example, if the source / target cell is included in a CC list (an existing CC list (such as simultaneousTCI-UpdateList1-r17) or a new list), the serving cells (PCIs) of all BWPs / CCs in the CC list may be switched.

[0091] Figures 8A and 8B are diagrams showing examples of serving cell switching in Supplement D. In Figure 8A, if TCI state #4 is indicated by DCI in the TCI-state list in the PDSCH-config, the serving cell is switched to a candidate cell associated with TCI state #4. In this case, for all cells in the same cell list (CC list), the serving cell is switched to a candidate cell associated with TCI state #4. As shown in Figure 8B, even if the TCI-state list in the PDSCH-config is absent, the serving cell may also be switched to a candidate cell associated with TCI state #4.

[0092] FIG. 9 is a diagram showing another example of a serving cell switch in Supplementary D. FIG. 9 shows an example in which Supplementary D is combined with Option 1 of Embodiment 1-1. Assume that SpCell #0, SCell #1, SCell #2, and candidate cells #0-1, #1-1, and #2-1 are in the same cell list. The UE receives DCI indicating a field indicating a serving cell switch in SCell #2 (source serving cell). In this case, the serving cell is switched from SpCell #0, SCell #1, and SCell #2 to candidate cells #0-1, #1-1, and #2-1 (target cells) associated with the TCI state indicated by this DCI. Note that Supplementary D may also be combined with Option 2 of Embodiment 1-1 in a similar manner.

[0093] In the example of Supplement D, an explicit instruction by DCI / MAC CE indicating a serving cell switch may be applied. For example, embodiment 1-1 or 1-2 may be applied to the instruction of the switch.

[0094] According to Supplement D, since multiple serving cells can be switched simultaneously, cell switching processing can be performed efficiently.

[0095] According to the first embodiment, the settings / instructions for switching the serving cell are clear, so that the serving cell can be switched appropriately.

[0096] <Variation> After a switch of the serving cell of the Scell ​​(for example, cell #2-1) is instructed by L1 / L2 signaling, the cell (cell #2-1) that becomes the serving cell may become an SpCell, and the existing (before-switch) SpCell (or #0-1) may become a secondary cell (Scell). Note that SpCell refers to a special cell (including a primary cell (PCell) and a primary secondary cell (PSCell)).

[0097] [Variation 1] The RRC / MAC CE can set a global candidate cell ID (cell #0-1, #0-1, ..., 2-2) for each cell group, band, FR, and UE. The UE may be instructed to switch serving cells by the global candidate cell ID.

[0098] 10 is a diagram showing an example of a serving cell switch in Variation 1. The UE receives an instruction to change the serving cell (from cell #2-0 to cell #2-1) by MAC CE / DCI. Option 1 or 2 of Embodiment 1-1 may be applied to this instruction (applies only to switches in the same frequency band). Then, the indicated cell #2-1 becomes the SpCell of the new cell group. For cells other than the SpCell, the following Option 1 or 2 is applied.

[0099] <<Option 1>> Based on the order of the global candidate cell IDs, cell#0-0 becomes Scell#1, and cell#1-0 becomes Scell#2 (example of FIG. 10).

[0100] <<Option 2>> Cell #1-0 becomes Scell ​​#1 (no change), and cell #0-0 (previous SpCell) becomes Scell ​​#2. In other words, control is performed so that changes are minimized.

[0101] [Variation 2] The RRC / MAC CE can set a global candidate cell ID (cell #0-1, #0-1, ..., 2-2) for each cell group, band, FR, and UE. The UE may be instructed to switch serving cells by the global candidate cell ID.

[0102] 11 is a diagram showing an example of a serving cell switch in Variation 2. The UE receives an instruction to change the serving cell (from cell #0-0 to cell #2-1) by MAC CE / DCI. This instruction may be the instruction of option 1 or 2 in embodiment 1-1 (a switch in the same frequency band and a switch in a different frequency band are applied). Then, the indicated cell #2-1 becomes the SpCell of the new cell group. For cells other than the SpCell, cell #1-0 becomes SCell #1, and cell #2-0 becomes SCell #2.

[0103] [Variation 3] The RRC / MAC CE can set a candidate cell group ID (#0, #1, #2, #3) for each cell group, band, FR, and UE. The UE may be instructed to switch serving cells by the candidate cell group ID.

[0104] 12 is a diagram illustrating an example of a serving cell switch in Variation 3. The UE receives an instruction to change the serving cell (from cell group #0 to candidate cell group #1) by MAC CE / DCI. This instruction may be applied to the instruction in Option 1 or 2 of Embodiment 1-1 (and the sixth embodiment described later) (a switch in the same frequency band is applied).

[0105] Then, the indicated candidate cell group #1 becomes the new serving cell group. Cell #2-1 becomes Spcell #0. Cell #0-1 becomes Scell ​​#1. Cell #1-1 becomes Scell ​​#2.

[0106] According to the above variations, when the serving cell is switched, the special cell can be switched to a cell in a different frequency band.

[0107] <Second embodiment> A UE receives downlink control information (DCI) including a field indicating a TCI state and a field indicating a serving cell switch, receives a setting / instruction of cell application timing (CAT) by higher layer signaling or the like, and applies the TCI state / serving cell (target cell) after switching at a timing based on the setting / instruction. The DCI instruction and the serving cell switch may be subject to the processing of the first embodiment.

[0108] [Option 1] The UE transmits UE capability information related to cell application timing, receives a parameter (e.g., CellAppTime_r18) indicating the cell application timing corresponding to the UE capability via higher layer signaling (e.g., RRC), and determines the application timing of the cell / TCI state based on the parameter. This option describes application when a parameter (Beam application timing (BAT)) indicating the beam application timing is received via higher layer signaling (e.g., RRC).

[0109] <<Option 1-1>> If a parameter indicating the cell application timing is configured, the UE may ignore a parameter indicating the beam application timing (e.g., BeamAppTime_r17) (if configured). Note that CAT is usually equal to or greater than BAT. Therefore, the UE first performs a cell switch and applies the indicated TCI state to the target cell.

[0110] <<Option 1-2>> The UE determines the application timing of the TCI state based on the maximum value of the cell application timing and the beam application timing (e.g., max{CellAppTime_r18, BeamAppTime_r17}), and applies the maximum value to the cell switch and the beam switch. For example, when CAT<BAT, the UE needs to consider the maximum required times for both the cell switch and the beam switch.

[0111] 13 is a diagram illustrating an example of application timing of the indicated TCI state in Option 1 of the second embodiment. The UE receives the DCI and receives the PDSCH scheduled by the DCI. Then, the UE transmits an ACK for the PDSCH.

[0112] When Option 1-1 is applied, the UE applies the instructed TCI state after the time indicated by the parameter (BeamAppTime_r17) indicating the beam application timing from the transmission timing of the ACK. When Option 1-2 is applied, the UE applies the instructed TCI state after the time indicated by the maximum value of the cell application timing and the beam application timing (for example, max{CellAppTime_r18,BeamAppTime_r17}) from the transmission timing of the ACK.

[0113] [Option 2] The UE may receive a DCI including a field indicating the cell application timing, and determine the TCI status / serving cell application timing based on the indication. The cell application timing of the DCI may be included in a parameter (CellAppTime_r18) configured by higher layer signaling (e.g., RRC) and may be based on the UE's capabilities.

[0114] <<Option 2-1>> If the cell application timing is indicated by the DCI, the UE may ignore the parameter indicating the beam application timing (e.g., BeamAppTime_r17) (if set).

[0115] <<Option 2-2>> The UE applies the maximum value of the cell application timing and beam application timing indicated in the DCI (e.g., max{CAT, BeamAppTime_r17 indicated in the DCI) to the cell switch and beam switch.

[0116] <<Variations>> CATs may be configured separately for the SpCell and multiple SCells. Alternatively, different CATs may be applied simultaneously to a single-cell switch and a multi-cell switch. Note that SpCell switches may take longer than SCell switches. Multi-cell switches may take longer than single-cell switches.

[0117] After switching serving cells, the UE applies the indicated TCI. DL / UL channels / RSs that follow the indicated TCI may reuse the rules of Rel. 17. Other channels / RSs that do not follow the indicated TCI may apply pre-configuration by RRC from multiple candidate cells.

[0118] <Third embodiment> A UE may receive a Medium Access Control Element (MAC CE) including at least one of an ID of a serving cell after switching, a TCI state related to the cell, and an ID of a serving cell before switching, and may perform a cell switch based on the information included in the MAC CE.

[0119] The DCI instruction (e.g., the first or second embodiment) and the MAC CE instruction may be applied in combination. For example, when the UE receives the MAC CE (including the source serving cell ID, the target cell ID, the TCI status, etc.) according to the present embodiment and further receives a cell switch instruction by the DCI, the UE may perform a cell switch according to the information in the MAC CE.

[0120] [Embodiment 3-1] The following items may be applied as a new MAC CE for instructing a cell switch and possible fields in the MAC CE. The MAC CE of this embodiment may further include, for example, at least one field shown in the above-mentioned <Serving Cell Change Indication>. Target cell ID (ID of the serving cell after the switch). TCI status / SSB / CSI-RS related to the target cell. These are used for the UE to know both the DL beam and the DL / UL beam on the target cell. UL beam / TCI status / spatial relationship / SSB / CSI-RS / SRS of the target cell. These are used for the UE to recognize the UL beam on the target cell. Source serving cell ID (ID of the serving cell before the switch) or cell group ID including the source serving cell (ID of the cell group including the serving cell before the switch). CAT (for example, included in CellAppTime_r18 set by RRC).

[0121] [Embodiment 3-2] A UE may be instructed to switch multiple serving cells based on one MAC CE. For example, multiple sets of fields similar to those in embodiment 3-1 may exist in the MAC CE. A bitmap indicating which source serving cells require a cell switch (one bit is set for each serving cell or cell group ID corresponding to the source serving cell). At least one of fields indicating the target cell ID to be switched to, DL / joint TCI state / beam, UL TCI state / beam, and CAT for each source serving cell for which a cell switch is instructed.

[0122] 14 is a diagram illustrating an example of a MAC CE according to embodiment 3-2. C0 to C7 correspond to source serving cells. When C0 to C7 are "1," they indicate that the corresponding source serving cell is to be cell switched, and when they are "0," they indicate that the corresponding source serving cell is not to be cell switched.

[0123] The Target cell ID is set to the ID of the target cell corresponding to the source serving cell (cell with "1" in C0 to C7) where the cell switch is performed. The TCI state is set to the ID of the TCI state corresponding to the source serving cell (cell with "1" in C0 to C7) where the cell switch is performed. The size (number) of the Target cell ID field and the TCI state field is determined (variable) depending on the number of cells with "1" in C0 to C7.

[0124] The size of the target cell ID may be set to a fixed size according to specifications or RRC configuration. A target cell list (PCI list of target cells) may be configured by RRC. The 4-bit cell ID in the MAC CE may indicate one of the target cell lists (e.g., 16 cells) configured by RRC.

[0125] [Embodiment 3-3] A field for a cell switch instruction may be added to an existing MAC CE. The MAC CE of this embodiment may include, for example, at least one field shown in the above-mentioned <Serving Cell Change Instruction>.

[0126] Regarding the constraints on the indication of the SpCell switch, either option 1 or 2 below may be applied.

[0127] <<Option 1>> There may be no restriction on the instruction to switch the SpCell. For example, one MAC CE may be able to simultaneously instruct an SpCell change and an SCell change.

[0128] <<Option 2>> When one MAC CE can instruct multiple serving cell switches, it can instruct multiple Scell ​​switches at once, but it cannot instruct SpCell change and SCell change at the same time. In other words, SpCell change and Scell ​​change cannot be performed simultaneously.

[0129] For Cell Application Timing (CAT), either option 1 or 2 below may be applied.

[0130] <Option 1> The existing Cell Application Timing (CAT) in MAC CE may be followed.

[0131] <<Option 2>> After receiving a MAC CE or after ACK of the MAC CE, a cell switch (or a beam switch) is applied a certain time later. The cell application timing may be, for example, the example of the second embodiment. The MAC CE may be included in a new PDSCH with the same HARQ process number and with the NDI toggled.

[0132] When applying embodiment 3-1, it may be combined with supplement D of the first embodiment to switch between multiple serving cells with one serving cell switching instruction.

[0133] Fourth Embodiment A cell switch (a switch of a serving cell) may be triggered by a UE. For example, the UE may transmit information indicating a request for a cell switch in a specific UL transmission.

[0134] The UE may transmit a scheduling request (SR) / MAC CE to trigger a cell switch. For example, similar to beam failure recovery (BFR), the MAC CE may transmit information about the cell to be switched to, and the SR may indicate only the instruction / purpose of the cell switch. Alternatively, the MAC CE may indicate only the information about the cell to be switched to and the instruction for the cell switch. The UE may switch to a new cell after a predetermined period of time following the ACK of the MAC CE. As shown in the second and third embodiments, CellAppTime_r18, BeamAppTime_r17, etc. may be applied to the predetermined time. Alternatively, the UE may switch to a new cell at a predetermined timing based on an instruction from the NW (base station) using DCI / MAC in the first and third embodiments.

[0135] The MAC CE for cell switching transmitted by the UE may include fields similar to those of the MAC CE shown in the third embodiment (for example, FIG. 14).

[0136] The UE can trigger a cell switch (transmit information for triggering) when a specific event is met, for example, based on a comparison of the L1-RSRP, L3-RSRP / RSRQ of the serving cell and the L1-RSRP, L3-RSRP / RSRQ of the candidate cell. For example, the UE may trigger a cell switch when the L1-RSRP, L3-RSRP / RSRQ of the serving cell are lower than a predetermined threshold indicated by higher layer signaling / physical layer signaling, or when the L1-RSRP, L3-RSRP / RSRQ of the candidate cell are lower than a predetermined threshold indicated by higher layer signaling / physical layer signaling.

[0137] Fifth Embodiment A UE may receive a setting / instruction of a switching gap to be applied when switching a serving cell via higher layer signaling / physical layer signaling, and perform a cell switch procedure based on the setting / instruction. The UE may limit (e.g., suspend) DL reception / UL transmission during the switching gap because the UE may need time to switch the serving cell (e.g., due to DL / UL timing adjustment).

[0138] The switching gap may apply to both DL / UL, UL only, or DL ​​only. The switching gap may be determined by the specification, configured by higher layer signaling / physical layer signaling, or reported by UE capabilities. The switching gap may be per (Subcarrier Spacing (SCS)) or common to all SCSs.

[0139] During the switching gap, the UE does not perform (predict) reception / transmission of all / specific signals. If the UE is scheduled to receive / transmit DL / UL signals, the UE is not required to monitor / transmit DL signals.

[0140] The start timing of the switching gap may be defined. For example, in the case of a serving cell switch indicated by a TCI, the Beam Application Timing (BAT) of Rel. 17 may be applied. When a new mechanism is introduced, it is necessary to define a timing similar to the Beam Application Timing (BAT) to avoid misunderstandings between the UE and the gNB due to overlooking the DCI indication.

[0141] 15 is a diagram illustrating an example of a switching gap in the fifth embodiment. When a MAC CE instructs a serving cell switch, a switching gap starts a predetermined period after an ACK transmission from the MAC CE, and at the end of the switching gap, the instructed TCI state is applied and the serving cell is switched to the target cell. The predetermined period is, for example, 3 ms, and may be based on a parameter (BeamAppTime_r17) indicating the beam application timing of Rel. 17 or on other parameters.

[0142] If no serving cell switch is performed, the switching gap does not apply (or is set to 0). The PDSCH may or may not be scheduled (the DCI may or may not include DL assignments).

[0143] According to this embodiment, by applying a switching gap, UL / DL transmission can be stopped during the cell switch period, so that transmission and reception can be performed normally even when a cell switch is performed.

[0144] Sixth Embodiment In the sixth embodiment, cell switching in carrier aggregation (CA) is described. PCIs of different serving cells correspond to different TCI states / beams. To enable CA, all BWPs / CCs in CA may use the same TCI / beam (QCL type D).

[0145] [Embodiment 6-1] It is not permitted to use different numbers of candidate cells (cells that are candidates to become new serving cells) for all SpCells / Scells in a cell group. The UE assumes / expects that the same number of candidate cells correspond to each cell, including an SpCell / Scell. Furthermore, each cell group of candidate cells may include the same number of candidate cells. When one candidate cell is designated as a target cell (new serving cell), the group including the candidate cell is set as the serving cell group.

[0146] Fig. 16 shows an example of a cell switch in embodiment 6-1. The UE determines candidate cell #1 (cell group #1) as a new serving cell (serving cell group) through L1 / L2 signaling (DCI / MAC CE). The candidate cell may be configured in advance by RRC or may be activated by MAC CE. In the example of Fig. 16, the number of candidate cells for each SpCell / Scell ​​is three.

[0147] PCI#0-3 are new IDs for PCI indication in Rel. 17 and may differ from the actual PCI. In Rel. 17, up to seven additional PCIs may be configured by RRC. The 3-bit new ID (PCI#0-3) may indicate the serving cell PCI and one of the seven additional PCIs. PCI#0-3 may be the same index as the re-creation index described in (3-2) of the above <Serving Cell Change Indication>.

[0148] Multiple candidate cells corresponding to each serving cell may be configured as a new cell group for cell group switch via L1 / L2 signaling. For example, new cell group #1 includes cells #0-1, #1-1, and #2-1. MAC CE / DCI may indicate "cell group ID" as the cell group to be switched.

[0149] 16, when candidate cell #1 is designated as the target cell, cell #0-1 becomes Spcell, cell #1-1 becomes Scell ​​#1, and cell #2-1 becomes Scell ​​#2. When candidate cell #2 is designated as the target cell, cell #0-2 becomes Spcell, cell #1-2 becomes Scell ​​#1, and cell #2-2 becomes Scell ​​#2. When candidate cell #3 is designated as the target cell, cell #0-3 becomes Spcell, cell #1-3 becomes Scell ​​#1, and cell #2-3 becomes Scell ​​#2.

[0150] [Embodiment 6-2] For each cell including an SpCell / Scell ​​in a cell group, the use of a different number of candidate cells (cells that are candidates to become new serving cells) is permitted. Furthermore, each cell group of candidate cells may contain a different number of candidate cells. When one candidate cell is designated as a target cell (new serving cell), the group including the candidate cell is set as the serving cell group. However, only the SpCell / Scell ​​included in the designated group of candidate cells is activated, and other cells (cells not included in the designated group of candidate cells) are deactivated.

[0151] Fig. 17 shows an example of a cell switch in embodiment 6-2. Explanation of the same points as in Fig. 16 will be omitted. The UE determines that candidate cell #1 (cell group #1) is a new serving cell (serving cell group) through L1 / L2 signaling (DCI / MAC CE).

[0152] If candidate cell #1 is specified, cell #0-1 becomes an Spcell, cell #1-1 becomes an Scell ​​#1, and cell #2-1 becomes an Scell ​​#2. If candidate cell #2 is specified, cell #0-2 becomes an Spcell, cell #2-2 becomes an Scell ​​#2, and Scell ​​#1 (cell #1-2) becomes inactive. Alternatively, cell #2-2 may become an Scell ​​#1, and Scell ​​#2 (cell #1-2) may become inactive. If candidate cell #3 is specified, cell #0-3 becomes an Spcell, and all Scells become inactive.

[0153] If there is no SpCell corresponding to a candidate cell, the cell corresponding to the lowest (or highest) CC ID / PCI of the SCell may be the SpCell. Alternatively, the candidate cells may always include an SpCell.

[0154] <Supplementary Note> At least one of the above-described embodiments may be applied only to UEs that have reported or support a specific UE capability.

[0155] The specific UE capability may indicate at least one of the following: - Supporting specific processes / operations / control / information for at least one example in the above embodiments; - Supporting multiple serving cell switches simultaneously; - The maximum number of serving cells that can be switched at one time; - Whether multiple serving cells are limited to the Scell; - Supporting cell lists for simultaneous serving cell switches; - The maximum number of cell lists; - Cell application time; - Whether the CAT for the SpCell switch and the CAT for the Scell ​​switch are common or separate; - Whether the CAT for the single-cell switch and the CAT for simultaneous multi-cell switch are common or separate; - The maximum number of candidate cells configured / maintained for one serving cell, and whether the maximum number is common or separate for the SpCell and the Scell; - The maximum number of candidate serving cells configured for dynamic cell switch. The maximum number may be per cell group / MCG / SCG / UE / band. • Maximum number of candidate cells configured / maintained for all serving cells. • Support for UE triggered cell switch. • Supported events as triggers for cell switch.

[0156] 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).

[0157] 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)).

[0158] Furthermore, at least one of the above-described embodiments may be applied when the UE is configured with specific information related to the above-described embodiments by higher layer signaling, for example, the specific information may be any RRC parameter for a specific release (e.g., Rel. 17 / 18).

[0159] If the UE does not support at least one of the specific UE capabilities or is not configured with the specific information, the UE may apply, for example, Rel. 15 / 16 behavior.

[0160] (Supplementary Note A) The following inventions are added to one embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a receiver that receives downlink control information (DCI) including a field indicating a serving cell switch; and a controller that switches a cell for transmission and reception based on the DCI. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the serving cell before the switch is a cell that receives the DCI or a cell indicated by a carrier indicator of the DCI, and the serving cell after the switch is a cell associated with a Transmission Configuration Indication (TCI) state indicated in the DCI. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the DCI simultaneously instructs the switching of multiple serving cells. [Supplementary Note 4] The terminal according to any one of Supplements 1 to 3, wherein when the DCI instructs the switching of a serving cell to a secondary cell, the cell that becomes the serving cell becomes a special cell, and the special cell before the switch becomes a secondary cell.

[0161] (Supplementary Note B) The following inventions are added to one embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a receiver that receives downlink control information (DCI) including a field indicating a Transmission Configuration Indication (TCI) state and a field indicating a serving cell switch, and receives a cell application timing configuration; and a controller that applies the TCI state after the switch at a timing based on the configuration. [Supplementary Note 2] The terminal according to Supplementary Note 1, further having a transmitter that transmits capability information related to cell application timing, wherein the receiver receives a parameter indicating a cell application timing corresponding to the UE capability by higher layer signaling, and the controller determines the TCI state application timing based on the parameter. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the receiver receives a parameter indicating a beam application timing by higher layer signaling, and the controller determines the TCI state application timing based on the maximum value of the cell application timing and the beam application timing. [Supplementary Note 4] The terminal according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the receiving unit receives a Medium Access Control Element (MAC CE) including at least one of an ID of a serving cell after switching, a TCI state related to the cell, and an ID of a serving cell before switching, and the control unit executes a cell switch based on information included in the MAC CE.

[0162] (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.

[0163] 18 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).

[0164] 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.

[0165] 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.

[0166] 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))).

[0167] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with a relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form small cells C2 that are smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The locations and numbers of the cells and user terminals 20 are not limited to the embodiment shown in the figure. Hereinafter, when there is no need to distinguish between the base stations 11 and 12, they will be collectively referred to as base station 10.

[0168] 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).

[0169] 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.

[0170] 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.

[0171] The multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with the Common Public Radio Interface (CPRI), an X2 interface, etc.) or wirelessly (e.g., NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0172] 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.

[0173] 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.

[0174] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0175] 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).

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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).

[0180] 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.

[0181] 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.

[0182] 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.

[0183] 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.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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).

[0189] 19 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.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] On the other hand, the transceiver unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 130.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0206] The transceiver 120 may transmit downlink control information (DCI) including a field indicating a serving cell switch. The controller 110 may control transmission and reception with a terminal that has switched the cell for transmission and reception based on the DCI.

[0207] The transceiver 120 may transmit downlink control information (DCI) including a field indicating a transmission configuration indication (TCI) state and a field indicating a switch of the serving cell, and may transmit a setting of the cell application timing. The control unit 110 may apply the TCI state after the switch at a timing based on the setting.

[0208] The transceiver 120 may transmit a switching gap configuration to be applied when switching the serving cell, and the controller 110 may restrict at least one of downlink transmission and uplink reception during the switching gap.

[0209] (User Terminal) Fig. 20 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.

[0210] 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.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] 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.

[0224] 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.

[0225] The transmitting unit and receiving unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving unit 220 and the transmitting / receiving antenna 230.

[0226] The transceiver 220 may receive downlink control information (DCI) including a field indicating a serving cell switch. The controller 210 may switch the cell for transmission and reception based on the DCI.

[0227] The serving cell before the switch may be the cell that receives the DCI or the cell indicated by the carrier indicator of the DCI, and the serving cell after the switch may be the cell associated with the Transmission Configuration Indication (TCI) state indicated in the DCI.

[0228] The DCI may indicate the switching of multiple serving cells simultaneously.

[0229] When the DCI instructs a switch of the serving cell to a secondary cell, the cell that becomes the serving cell may become a special cell, and the special cell before the switch may become a secondary cell.

[0230] The transceiver 220 may receive downlink control information (DCI) including a field indicating a transmission configuration indication (TCI) state and a field indicating a switch of the serving cell, and may receive a setting of the cell application timing. The control unit 210 may apply the TCI state after the switch at a timing based on the setting.

[0231] The transceiver 220 may transmit capability information related to the cell application timing. The transceiver 220 may receive a parameter indicating the cell application timing corresponding to the UE capability through higher layer signaling. The control unit 210 may determine the application timing of the TCI state based on the parameter.

[0232] The transceiver 220 may receive a parameter indicating the beam application timing through higher layer signaling. The controller 210 may determine the application timing of the TCI state based on the maximum value of the cell application timing and the beam application timing.

[0233] The transceiver 220 may receive a Medium Access Control Element (MAC CE) including at least one of the ID of the serving cell after the switch, the TCI state associated with the cell, and the ID of the serving cell before the switch. The controller 210 may perform a cell switch based on the information included in the MAC CE.

[0234] The transceiver 220 may receive a setting for a switching gap to be applied when switching the serving cell, and the controller 210 may restrict at least one of downlink reception and uplink transmission during the switching gap.

[0235] The control unit 210 may assume that each cell corresponds to the same number of candidate cells that will become new serving cells. When one candidate cell is designated as the new serving cell, a group including the one candidate cell may be set as a serving cell group.

[0236] For each cell, a different number of candidate cells to become the new serving cell correspond, and when one candidate cell is designated as the new serving cell, a group including the candidate cell is set as a serving cell group, and cells not included in the group including the candidate cell may be deactivated.

[0237] (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.

[0238] 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.

[0239] 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. 21 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.

[0240] 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.

[0241] 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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] 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.

[0248] 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).

[0249] 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.

[0250] 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.

[0251] (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.

[0252] 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.

[0253] 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.

[0254] 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.

[0255] 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.

[0256] 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.

[0257] 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.

[0258] 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.

[0259] 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.

[0260] 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.

[0261] 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.

[0262] 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.

[0263] 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.

[0264] 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.

[0265] 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.

[0266] 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.

[0267] 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.

[0268] 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.

[0269] 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."

[0270] 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.

[0271] 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.

[0272] 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.

[0273] 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.

[0274] 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.

[0275] 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.

[0276] 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.

[0277] 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).

[0278] 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).

[0279] 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).

[0280] 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.

[0281] 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.

[0282] 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).

[0283] In the present disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "Quasi-Co-Location (QCL)," "Transmission Configuration Indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," etc. may be used interchangeably.

[0284] 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.

[0285] 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.

[0286] 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.

[0287] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0288] 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.

[0289] 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.

[0290] 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.

[0291] 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.

[0292] 22 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.

[0293] 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.

[0294] 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).

[0295] 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.

[0296] 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.

[0297] 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.

[0298] 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.

[0299] 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.

[0300] 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).

[0301] 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.

[0302] 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)).

[0303] 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.

[0304] 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.

[0305] 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.

[0306] 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.

[0307] 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.

[0308] 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).

[0309] 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."

[0310] 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.

[0311] 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.

[0312] 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.

[0313] Also, "determination" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "determination" may be considered to be "deciding" some action.

[0314] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0315] 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.

[0316] 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."

[0317] 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.

[0318] 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."

[0319] 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.

[0320] 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.

[0321] 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").

[0322] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0323] 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 invention according to the present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the invention as defined by the description of the claims. Therefore, the description of the present disclosure is intended to be illustrative and explanatory and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. A receiver that receives a Medium Access Control Element (MAC CE) for instructing cell switching, the MAC CE including a target cell ID and at least one of a Transmission Configuration Indication (TCI) state and an UL TCI state related to the target cell; a control unit that applies the TCI state or the UL TCI state included in the MAC CE after a specific time has passed since transmission of an ACKnowledgement (ACK) of the MAC CE; A terminal having:

2. Receiving a Medium Access Control Control Element (MAC CE) for instructing a cell switch, the MAC CE including a target cell ID and at least one of a Transmission Configuration Indication (TCI) state and an UL TCI state associated with the target cell; applying the TCI state or the UL TCI state included in the MAC CE after a specific time from transmission of an ACKnowledgement (ACK) of the MAC CE; A wireless communication method for a terminal having the above configuration.

3. A transmitter that transmits a Medium Access Control Control Element (MAC CE) for instructing cell switching, the MAC CE including a target cell ID and at least one of a Transmission Configuration Indication (TCI) state and an UL TCI state related to the target cell; a control unit that applies the TCI state or the UL TCI state included in the MAC CE after a specific time has elapsed since transmission of an ACKnowledgement (ACK) of the MAC CE in a terminal; A base station having

4. A system including a terminal and a base station, The base station a transmitter configured to transmit a Medium Access Control Element (MAC CE) for instructing a cell switch, the MAC CE including a target cell ID and at least one of a Transmission Configuration Indication (TCI) state and a UL TCI state related to the target cell; The terminal a receiving unit for receiving the MAC CE; and a control unit that applies the TCI state or the UL TCI state included in the MAC CE after a specific time has passed since transmission of an ACKnowledgement (ACK) of the MAC CE. system.