Terminal, wireless communication method, base station and system

Abstract

A terminal according to an aspect of the present disclosure includes: a reception unit that receives at least one of downlink control information including cell switching instruction information for switching from a serving cell to a candidate cell and a MAC control element (MAC CE); and a control unit that controls cell switching operations on the basis of the cell switching instruction information. At least one of an in-cell multiple transmission reception point and an inter-cell multiple transmission reception point is set to at least one of the serving cell and the candidate cell.

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) Release (Rel.) 8, 9).

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

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

[0005] In future wireless communication systems (e.g., wireless communication systems after Rel. 16 / 5G), it is expected that communications will be controlled based on inter-cell mobility including non-serving cells, or inter-cell mobility using multiple transmission / reception points (e.g., Multi-TRP (MTRP)).

[0006] However, when inter-cell mobility is applied, how to control UL transmission (for example, timing advance control, cell switching, etc.) becomes an issue. If inter-cell mobility cannot be performed appropriately, there is a risk that communication quality will deteriorate.

[0007] The present disclosure has been made in consideration of these points, and one of its objectives is to provide a terminal, a wireless communication method, and a base station that are capable of appropriately controlling communications even when inter-cell mobility is performed.

[0008] A terminal according to one aspect of the present disclosure includes a receiving unit that receives at least one of downlink control information and a MAC Control Element (MAC CE) including cell switching instruction information from a serving cell to a candidate cell, and a control unit that controls a cell switching operation based on the cell switching instruction information, wherein at least one of the serving cell and the candidate cell is configured with at least one of an intra-cell multiple transmission / reception point and an inter-cell multiple transmission / reception point.

[0009] According to one aspect of the present disclosure, communication can be appropriately controlled even when inter-cell mobility is performed.

[0010] 1A and 1B are diagrams illustrating an example of inter-cell mobility. FIG. 2 is a diagram illustrating an example of switching between a serving cell and an additional cell by L1 / L2 signaling. FIG. 3 is a diagram illustrating an example of configuration example 1-3 when a candidate cell is supported. FIGS. 4A to 4C are diagrams illustrating an example of switching between a candidate cell and a candidate cell group by L1 / L2 signaling in configuration example 1-3 when a candidate cell is supported. FIG. 5 is a diagram illustrating an example of a timing advance group (TAG) to which cells included in a cell group belong. FIG. 6 is a diagram illustrating an example of a MAC CE for a timing advance command. FIGS. 7A and 7B are diagrams illustrating an example of TAG IDs set for a serving cell and a candidate cell. FIG. 8 is a diagram illustrating an example of a successful L1 / L2 inter-cell mobility according to the first embodiment. FIG. 9 is a diagram illustrating another example of a successful L1 / L2 inter-cell mobility according to the first embodiment. FIG. 10 is a diagram illustrating an example of a failed L1 / L2 inter-cell mobility according to the first embodiment. FIG. 11 is a diagram illustrating another example of a case where L1 / L2 inter-cell mobility according to the first embodiment fails. FIGS. 12A and 12B are diagrams illustrating an example of application of L1 / L2 inter-cell mobility and L3 mobility according to the second embodiment. FIGS. 13A and 13B are diagrams illustrating another example of application of L1 / L2 inter-cell mobility and L3 mobility according to the second embodiment. FIG. 14 is a diagram illustrating an example of activation of TCI states for a serving cell and a candidate cell configured on the same frequency. FIG. 15 is a diagram illustrating an example of activation of TCI states for a serving cell and a candidate cell according to the third embodiment. FIG. 16 is a diagram illustrating an example of inter-frequency cell switching according to the third embodiment. FIG. 17 is a diagram illustrating another example of activation of TCI states for a serving cell and a candidate cell according to the third embodiment. FIG. 18 is a diagram illustrating another example of activation of TCI states for a serving cell and a candidate cell according to the third embodiment. FIG. 19 is a diagram illustrating another example of activation of TCI states for a serving cell and a candidate cell according to the third embodiment. FIG. 20 is a diagram for explaining a setting example #1 according to the third embodiment.Fig. 21 is a diagram for explaining a setting example #2 according to the third embodiment. Fig. 22 is a diagram illustrating an example of intra-cell multi-TRP setting and inter-cell multi-TRP setting for a serving cell / candidate cell according to the fourth embodiment. Fig. 23 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. Fig. 24 is a diagram illustrating an example of a configuration of a base station according to an embodiment. Fig. 25 is a diagram illustrating an example of a configuration of a user terminal according to an embodiment. Fig. 26 is a diagram illustrating an example of hardware configurations of a base station and a user terminal according to an embodiment. Fig. 27 is a diagram illustrating an example of a vehicle according to an embodiment.

[0011] (TCI, spatial relationship, QCL) In NR, it is considered to control the reception processing (e.g., at least one of reception, demapping, demodulation, and decoding) and transmission processing (e.g., at least one of transmission, mapping, precoding, modulation, and encoding) in a UE of at least one of a signal and a channel (referred to as a signal / channel) based on a transmission configuration indication state (TCI state).

[0012] The TCI state may represent that which is applied to a downlink signal / channel, and the equivalent of the TCI state that is applied to an uplink signal / channel may be expressed as a spatial relation.

[0013] The TCI state is information about the Quasi-Co-Location (QCL) of signals / channels, and may also be called spatial reception parameters, spatial relation information, etc. The TCI state may be configured in the UE for each channel or signal.

[0014] The QCL is an index indicating the statistical properties of signals / channels. For example, if a signal / channel has a QCL relationship with another signal / channel, it may mean that it can be assumed that at least one of a Doppler shift, a Doppler spread, an average delay, a delay spread, and a spatial parameter (e.g., a spatial Rx parameter) is the same between these different signals / channels (i.e., the signals / channels have a QCL with respect to at least one of these).

[0015] The spatial reception parameters may correspond to a reception beam (e.g., a reception analog beam) of the UE, and the beam may be identified based on a spatial QCL. The QCL (or at least one element of the QCL) in the present disclosure may be replaced with sQCL (spatial QCL).

[0016] A plurality of types (QCL types) of QCL may be defined. For example, four QCL types A to D may be provided, each having different parameters (or parameter sets) that can be assumed to be the same. The parameters (which may be referred to as QCL parameters) are as follows: QCL type A (QCL-A): Doppler shift, Doppler spread, mean delay, and delay spread QCL type B (QCL-B): Doppler shift and Doppler spread QCL type C (QCL-C): Doppler shift and mean delay QCL type D (QCL-D): Spatial reception parameters.

[0017] The UE's assumption that a Control Resource Set (CORESET), channel, or reference signal has a specific QCL (e.g., QCL type D) relationship with another CORESET, channel, or reference signal may be referred to as a QCL assumption.

[0018] The UE may determine at least one of a transmit beam (Tx beam) and a receive beam (Rx beam) for a signal / channel based on the TCI condition or QCL assumption of the signal / channel.

[0019] The TCI state may be, for example, information about the QCL between the channel of interest (in other words, the Reference Signal (RS) for that channel) and another signal (e.g., another RS). The TCI state may be set (indicated) by higher layer signaling, physical layer signaling, or a combination thereof.

[0020] 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.

[0021] The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. The 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.

[0022] The physical layer signaling may be, for example, Downlink Control Information (DCI).

[0023] The channel / signal to which the TCI state is applied may be called a target channel / reference signal (target channel / RS), or simply a target, and the other signal may be called a reference reference signal (reference RS), a source RS, or simply a reference.

[0024] The channel for which the TCI state or spatial relationship is set (specified) may be, for example, at least one of a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), and a physical uplink control channel (PUCCH).

[0025] Furthermore, the RS that has a QCL relationship with the channel may be at least one of, for example, a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), a tracking CSI-RS (also called a tracking reference signal (TRS)), a QCL detection reference signal (also called a QRS), a demodulation reference signal (DMRS), etc.

[0026] An SSB is a signal block including at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). An SSB may also be referred to as an SS / PBCH block.

[0027] An RS of QCL type X in a TCI state may refer to an RS that has a QCL type X relationship with a certain channel / signal (DMRS), and this RS may be called a QCL source of QCL type X in the TCI state.

[0028] (Inter-cell mobility) In NR, one or more transmission / reception points (Transmission / Reception Points (TRPs)) (multi-TRPs (MTRPs)) are considered to perform DL transmission to a UE. Also, it is considered that a UE performs UL transmission to one or more TRPs.

[0029] During inter-cell mobility (e.g., L1 / L2 inter cell mobility), a UE may receive channels / signals from multiple cells / TRPs (see Figures 1A and 1B).

[0030] FIG. 1A illustrates an example of inter-cell mobility (e.g., single-TRP inter-cell mobility) including a non-serving cell. A UE may be configured with one TRP (or a single TRP) in each cell. Here, the UE receives channels / signals from the base station / TRP of cell #1, which is the serving cell, and the base station / TRP of cell #3, which is not the serving cell (non-serving cell). For example, this corresponds to a case where the UE switches / switches from cell #1 to cell #3 (e.g., a fast cell switch).

[0031] In this case, the selection of the port (e.g., antenna port) / TRP may be performed dynamically or based on the TCI status indicated or updated by the DCI / MAC CE. Here, it is shown that different physical cell ID (e.g., PCI) configurations are supported for cell #1 and cell #3.

[0032] FIG. 1B illustrates an example of a multi-TRP scenario (e.g., multi-TRP inter-cell mobility). A UE may be configured with multiple (e.g., two) TRPs (or different CORESET pool indices) in each cell. Here, the UE receives channels / signals from TRP #1 and TRP #2. Also, here, TRP #1 corresponds to physical cell ID (PCI) #1, and TRP #2 corresponds to PCI #2.

[0033] The multi-TRPs (TRPs #1 and #2) may be connected via an ideal / non-ideal backhaul to exchange information, data, etc. The same or different code words (CWs) and the same or different layers may be transmitted from each TRP of the multi-TRP. As shown in FIG. 1B, non-coherent joint transmission (NCJT) may be used as one form of multi-TRP transmission. This example illustrates the case where NCJT is performed between TPRs corresponding to different PCIs. The same serving cell configuration may be applied / configured for TRPs #1 and #2.

[0034] Multiple PDSCHs (multi-PDSCHs) that are non-coherent may be defined as partially or completely overlapping in time and / or frequency domains. That is, the first PDSCH from TRP #1 and the second PDSCH from TRP #2 may overlap in time and / or frequency resources. The first PDSCH and the second PDSCH may be used for transmission of the same TB or for transmission of different TBs.

[0035] 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).

[0036] 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).

[0037] 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).

[0038] 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."

[0039] In Rel. 17 NR, it is assumed that the MAC CE / DCI supports beam direction to a TCI state associated with a different PCI, whereas in Rel. 18 NR and later, it is assumed that the L1 / L2 signaling (e.g., DCI / MAC CE) supports serving cell switching (e.g., serving cell change direction to a cell with a different PCI) (see Figure 2).

[0040] FIG. 2 shows a case where a UE switches cells from a serving cell to an additional cell (also called a candidate cell or a target cell) based on a cell switching instruction from a base station.

[0041] (Candidate Cells) In inter-cell mobility, it is also assumed that one or more candidate cells are configured / managed for each serving cell.

[0042] For example, one or more candidate cells with limited information (e.g., only some parameters are notified to the UE) may be configured in a predetermined higher layer parameter (e.g., ServingCellConfig) (Alt. 1). They may be configured in the same way as inter-cell beam management (inter-cell BM) in an existing system (e.g., Rel. 17).

[0043] Alternatively, a complete configuration (e.g., ServingCellConfig) of one or more candidate cells may be configured and associated with each serving cell (Alt. 2). For example, the carrier aggregation configuration framework (e.g., CA configuration framework) or the Conditional Handover (CHO) / Conditional PSCell Change (CPC) configuration framework may be reused.

[0044] In Alt. 1 / 2, activation / deactivation of candidate cells may be controlled by MAC CE / DCI.

[0045] At least one of the following configuration examples 1 to 3 may be applied as the configuration of the candidate cell (see FIG. 3). Here, SpCell #0, SCell #1, and SCell #2 are configured as serving cells, and an example of the configuration / association of the candidate cell (or additional cell) with the serving cell / cell group is shown. The following configuration examples 1 to 3 are merely examples, and the number of cells, the association of each cell, etc. are not limited to these and may be changed as appropriate. Alternatively, other configuration examples may be supported / applied in addition to / instead of configuration examples 1 to 3.

[0046] Configuration example 1 shows a case where one or more candidate cells are associated / configured with each serving cell (see FIG. 3). Specifically, it shows a case where candidate cells #0-1, #0-2, and #0-3 are associated with SpCell #0, candidate cell #1-1 is associated with SCell #1, and candidate cells #2-1 and #2-2 are associated with SCell #2. Information related to the association may be configured / instructed to the UE by the base station using RRC / MAC CE / DCI.

[0047] Configuration example 2 shows a case where candidate cells are associated / configured with a MAC entity / MCG / SCG (see FIG. 3 ). Specifically, it shows a case where candidate cells #3-#8 are associated with a MAC entity / MCG / SCG. In this case, candidate cells are not associated with each serving cell, but are configured with a MAC entity or a cell group (e.g., MCG / SCG). Information about the candidate cells configured for each cell may be configured / instructed to the UE by the base station via RRC / MAC CE / DCI.

[0048] In configuration example 3, one or more candidate cell groups may be configured (see FIG. 3 ). Specifically, a case is shown in which candidate cell group #1 having candidate cells #0-#2, candidate cell group #2 having candidate cells #0 and #1, and candidate cell group #3 having candidate cell #0 are configured. A candidate cell group has one or more candidate cells. A candidate cell included in a candidate cell group may be associated with at least one serving cell. Information about the candidate cell may be configured / instructed to the UE by the base station using RRC / MAC CE / DCI.

[0049] Existing systems (e.g., Rel. 17) support L1 beam indication (e.g., indication by the TCI status field of the DCI) to the TCI status associated with an additional PCI (or additional cell).

[0050] It is assumed that new L1 / L2 signals (e.g., DCI / MAC CE) that indicate a serving cell switch will be supported in Rel. 18 and later. At least one of implicit and explicit indications is expected to be supported. An implicit indication may mean, for example, that a CORESET is updated by a MAC CE to a TCI state associated with an additional PCI. An explicit indication may mean that a cell switch is directly indicated by a DCI / MAC CE.

[0051] For example, in candidate cell configuration example 1, a predetermined candidate cell may be designated as a serving cell (or switching to the serving cell may be instructed) via L1 / L2 signaling. Figure 4A shows a case where candidate cell #0-2 becomes an SpCell of the MCG / SCG through L1 / L2 signaling (SpCell #0 and candidate cell #0-2 are switched). Also, a case where candidate cell #2-1 becomes an SCell of the MCG / SCG through L1 / L2 signaling (SCell #2 and candidate cell #2-1 are switched) is shown.

[0052] Alternatively, in candidate cell configuration example 2, a predetermined candidate cell may be designated as a serving cell (or a switch to the serving cell may be instructed) via L1 / L2 signaling. Fig. 4B shows a case where candidate cell #4 becomes an SpCell of the MCG / SCG (SpCell #0 and candidate cell #4 are switched) via L1 / L2 signaling.

[0053] Alternatively, in candidate cell configuration example 3, a predetermined candidate cell group (or one or more candidate cells included in the predetermined candidate cell group) may be changed / updated to a serving cell group via L1 / L2 signaling. Fig. 4C shows a case where candidate cell group #1 (or candidate cells #0-#2 included in candidate cell group #1) becomes the serving cell group (the serving cell group and candidate cell group #1 are switched) via L1 / L2 signaling.

[0054] (Timing Advance Group) When multiple TRPs are used, the distances between the UE and each TRP may be different. The multiple TRPs may be included in the same cell (e.g., serving cell). Alternatively, one TRP may correspond to the serving cell and the other TRPs may correspond to non-serving cells. In this case, the distances between each TRP and the UE may be different.

[0055] In existing systems, the transmission timing of an uplink (UL) channel and / or an UL signal (UL channel / signal) is adjusted by a timing advance (TA). The reception timing of the UL channel / signal from different user terminals (UE) is adjusted by a radio base station (TRP: Transmission and Reception Point, also referred to as gNodeB: gNB) side.

[0056] The UE may control the timing of UL transmission by applying timing advance (multiple timing advances) for each pre-configured timing advance group (TAG).

[0057] When multiple timing advances are applied, Timing Advance Groups (TAGs) classified by transmission timing are supported. The UE may control the UL transmission timing for each TAG assuming that the same TA offset (or TA value) is applied to each TAG. In other words, the TA offset may be set independently for each TAG.

[0058] When multiple timing advance is applied, the UE independently adjusts the transmission timing of cells belonging to each TAG, so that even when multiple cells are used, the radio base station can synchronize the reception timing of uplink signals from the UE.

[0059] TAGs (e.g., serving cells belonging to the same TAG) may be configured by higher layer parameters. The same timing advance value may be applied to serving cells (e.g., serving cells for which UL is configured) belonging to the same TAG. A timing advance group including the SpCell of a MAC entity may be called a Primary Timing Advance Group (PTAG), and other TAGs may be called Secondary Timing Advance Groups (STAGs). In addition, the maximum number of TAGs may be X (e.g., X=4) per cell group (e.g., MCG / SCG).

[0060] In existing systems (e.g., Rel. 16 NR), the configuration of up to four TAGs per cell group (e.g., MCG / SCG) is supported (see Figure 5). Figure 5 shows a case where three TAGs are configured for a cell group including SpCell and SCell #1 to #4. Here, the SpCell and SCell #1 belong to the first TAG (PTAG or TAG #0), SCell #2 and SCell #3 belong to the second TAG (TAG #1), and SCell #4 belongs to the third TAG (TAG #2).

[0061] A timing advance command (TA command) may be notified to the UE using a MAC control element (e.g., MAC CE). The TA command indicates a transmission timing value of an uplink channel and is included in the MAC control element. The TA command is signaled from the radio base station to the UE at the MAC layer. The UE controls a predetermined timer (e.g., a TA timer) based on the reception of the TA command.

[0062] The MAC CE for a timing advance command may include a field for a timing advance group index (e.g., TAG ID) and a field for the timing advance command (see Figure 6). The TAG ID field is used to indicate the TAG ID of the addressed TAG. The Timing Advance Command field contains an index value TAG that is used to control the amount of timing adjustment that the MAC entity must apply. Ａ (0, 1, 2...63) may also be indicated.

[0063] Parameters corresponding to each TAG ID may be set by higher layer parameters. For example, a parameter such as a time alignment timer (e.g., timeAlignmentTimer) corresponding to each TAG ID may be set. Alternatively, the TAG ID for each serving cell may be set by higher layer parameters (e.g., tag-ID included in ServingCellConfig). Note that after being set by higher layer parameters, the TAG ID / parameter may be updated by MAC CE.

[0064] A time alignment timer may be maintained for UL time alignment. In Rel. 17, the time alignment timer may be configured / associated per TAG. When the UE receives a MAC CE for a timing advance command (e.g., TAC MAC CE), it starts or restarts the time alignment timer associated with the indicated timing advance group (e.g., TAG), respectively.

[0065] The MAC entity receives the TAC MAC CE and performs a predetermined value (N ＴＡ ) is maintained, apply a timing advance command for the indicated TAG or start or restart the time alignment timer associated with the indicated TAG. ＴＡ ) may be the timing advance between DL and UL.

[0066] The behavior when the time alignment timer expires may be defined separately for the PTAG and the STAG. Note that the timing advance group (TAG) including the SpCell of the MAC entity may be called the primary timing advance group (PTAG), and the other TAGs may be called secondary timing advance groups (STAGs).

[0067] For example, Rel. 17 supports that when a timing advance timer corresponding to a PTAG expires, a predetermined PTAG action is applied, and when a timing advance timer corresponding to a STAG expires, a predetermined STAG action is applied.

[0068] For example, when the time alignment timer expires, the following actions (e.g., predetermined PTAG action / predetermined STAG action) may be performed.

[0069] Actions for a given PTAG If a time alignment timer is associated with a PTAG: Flush all HARQ buffers for all serving cells. Inform RRC to release PUCCH for all serving cells, if configured. Inform RRC to release SRS, if configured. Clear all configured DL allocations and configured UL allocations. Clear PUSCH resources for semi-persistent CSI reporting. Allow all running time alignment timers to expire. Clear N for all TAGs. ＴＡ Maintain.

[0070] Actions for a given STAG: If a time alignment timer is associated with a STAG, then for all serving cells belonging to that TAG: Flush all HARQ buffers. Inform RRC to release PUCCH, if configured. Inform RRC to release SRS, if configured. Clear all configured DL and UL allocations. Clear PUSCH resources for semi-persistent CSI reporting. Clear N for that TAG. ＴＡ Maintain.

[0071] As described above, when candidate cells are set / defined, it is assumed that each candidate cell is associated with a TAG (see Figures 7A and 7B). Figure 7A shows an example of TAG (or TAG ID setting) for each cell group in an existing system (e.g., Rel. 17 or earlier), and Figure 7B shows an example of TAG ID setting for each candidate cell.

[0072] Also, if candidate cells are configured / applied / supported, it is assumed that different serving cells / different candidate cells are associated with the same TAG as shown in FIG. 7B.

[0073] If a TA for the candidate cell is obtained, RACH (or random access procedure) to the candidate cell may be supported.

[0074] In this way, when a candidate cell is configured / applied / supported, it is expected that inter-cell mobility (e.g., switching from a serving cell to a candidate cell (or additional cell / target cell)) will occur, but sufficient consideration has not been given to how to control such cases. If the switching between the serving cell and the candidate cell (e.g., inter-cell mobility) is not performed appropriately, there is a risk of communication quality degradation.

[0075] The inventors focused on inter-cell mobility (e.g., cell switching) when a candidate cell (or an additional cell, a target cell) is configured / supported, studied appropriate control methods for the inter-cell mobility, and came up with the present embodiment.

[0076] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that each of the following aspects (e.g., each case) may be used alone or in combination of at least two of them.

[0077] 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."

[0078] 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.

[0079] In the present disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher layer parameters, 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.

[0080] 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.

[0081] 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.

[0082] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] In the following embodiments, "multiple" and "two" may be interchangeable. Also, "TAG" and "TAG ID" may be interchangeable. Also, "cell", "CC", and "carrier" may be interchangeable.

[0087] The following description may be applied to inter-cell mobility (e.g., L1 / L2 inter cell mobility) or to communication control other than inter-cell mobility. L1 / L2 inter-cell mobility may be interpreted as at least one of cell switching, cell switch, and cell change.

[0088] (Wireless Communication Method) First Embodiment In the first embodiment, an example of UE operation / base station operation when (or after) receiving a cell switching instruction will be described.

[0089] The base station may configure the UE with information about the configurations of multiple candidate cells through higher layer signaling, which may be RRC reconfiguration signaling, higher layer parameters related to the cells, or other higher layer parameters.

[0090] The base station may also use the MAC CE / DCI to instruct the UE to change or switch the serving cell. The UE performs a cell switch procedure / switching operation based on the cell switch instruction indicated by the MAC CE / DCI. The cell switch instruction may also be called cell switch instruction signaling or L1 / L2 inter-cell mobility instruction.

[0091] At least one of information on a candidate cell to be switched to (e.g., a candidate cell index or a physical cell ID (PCI)), information on a serving cell to be switched to, and information on other candidate cells may be included in the MAC CE / DCI.

[0092] In the present disclosure, a change of a serving cell may be interpreted as a serving cell switch, a serving cell switching, or an L1 / L2 cell switch (e.g., an L1 / L2 cell switch). In the present disclosure, instructing a change of a serving cell may be interpreted as activating / enabling the change of a serving cell.

[0093] The UE may assume that L1 / L2 inter-cell mobility is enabled when a change of serving cell is indicated.

[0094] When the UE receives information instructing a change of serving cell (or a change to a candidate cell), the UE may change the serving cell configuration to the target cell (or a candidate cell) based on the cell configuration previously configured by higher layer parameters. The UE may receive DL transmissions from the target cell assuming a new beam / TCI state / spatial relationship. Information regarding the new beam / TCI state / spatial relationship may be previously configured / instructed by the base station to the UE using higher layer parameters (e.g., higher layer parameters related to the candidate cell).

[0095] If information regarding a new beam / TCI state / spatial relationship is not configured / indicated, the UE may assume a predetermined beam / TCI state / spatial relationship. The predetermined beam / TCI state / spatial relationship may be determined based on the PRACH transmission of the target cell (or candidate cell). For example, the UE may determine / assume the predetermined beam / TCI state / spatial relationship based on the latest PRACH transmission associated with the SSB of the target cell.

[0096] Furthermore, when the UE detects a MAC CE / DCI instructing a change of serving cell (or a change to a candidate cell), the UE may change the serving cell to the one configured in the RRC configuration of the cell to be updated (e.g., the RRC configuration of the candidate cell) after a predetermined period of time. In the present disclosure, the predetermined period of time may be read as a predetermined offset.

[0097] The predetermined period may be X ms or X symbols after the detected MAC CE / DCI. Alternatively, the predetermined period may be Y ms / Y symbols after the HARQ-ACK feedback for the detected MAC CE / DCI. X and Y may be determined based on the UE capability / UE type, may be defined in the specification, or may be configured to the UE by the base station.

[0098] In this way, when a cell switch (e.g., L1 / L2 inter-cell mobility) is successful, it is possible to control transmission and reception operations with the target cell as the serving cell. In this case, success / failure of the cell switch may be defined as follows: Option 1A-1 to Option 1A-3 show an example of a successful cell switch (e.g., L1 / L2 inter-cell mobility), and Option 1B-1 to Option 1B-2 show an example of a failed cell switch (e.g., L1 / L2 inter-cell mobility).

[0099] [Option 1A-1] If the UE transmits HARQ-ACK in response to a serving cell switching instruction, it means that the cell switching has been successful, and the UE operation / base station operation may be controlled. HARQ-ACK may mean ACK (ACKnowledgement) (see FIG. 8) or ACK / NACK.

[0100] 8 shows a case where a serving cell switch instruction (e.g., L1 / l2 cell switch indication signaling) is transmitted from a base station to a UE, and the UE transmits an ACK in response to the switch instruction, which indicates that the cell switch has been successful. In this case, a case where switching to a new serving cell is controlled after a predetermined period (e.g., Y) has elapsed since the cell switch was successful (e.g., after the ACK transmission).

[0101] If HARQ-ACK means ACK, then the UE sending a NACK (before sending the ACK) may not mean that the cell switch is successful, i.e., there may be a NACK feedback or a retransmission of L1 / L2 signaling before the ACK transmission.

[0102] For example, when a serving cell switching instruction is instructed in a MAC CE, it may be defined that the serving cell switching is successful if the HARQ-ACK feedback for the PDSCH carrying the MAC CE is ACK.

[0103] When a serving cell switching instruction is instructed by DCI, the definition of ACK may differ depending on whether the DCI includes DL assignment / UL assignment (e.g., DL assignment / UL assignment).

[0104] When a DCI including a DL allocation (e.g., a DL assignment) is used to instruct a serving cell switch, the serving cell switch may be defined as successful if the HARQ-ACK feedback for the PDSCH scheduled by the DCI is ACK.

[0105] When DCI that does not include a DL assignment / UL assignment (e.g., a DL assignment / UL assignment) is used to instruct a serving cell switch, the serving cell switch may be defined as successful if the HARQ-ACK feedback for the DCI (or the PDCCH that carries the DCI) is an ACK. In this case, the CRC added to the DCI may be scrambled by a predetermined RNTI (e.g., an RNTI other than the C-RNTI).

[0106] When a DCI including an UL assignment (e.g., an UL assignment) is used to indicate a serving cell switch, a PUSCH scheduled by the DCI may be regarded as HARQ-ACK feedback having an ACK. That is, a serving cell switch may be defined as successful based on the feedback of the PUSCH. Alternatively, a serving cell switch may be defined as successful when the base station reschedules a PUSCH with the same HPN (the same HPN with the NDI toggled).

[0107] [Option 1A-2] If the UE receives a DL from a new target cell (or a candidate cell to which the UE is to be changed) within a certain window / timer (e.g., a certain window / timer), this indicates that the cell change has been successful, and the UE operation / base station operation may be controlled (see FIG. 9). The DL received by the UE may be interpreted as at least one of a DL transmission, a DL signal, and a DL channel.

[0108] The specific window / timer may start, for example, after transmission of a HARQ-ACK (e.g., ACK) in response to a serving cell switch instruction, or after a predetermined period (e.g., Y) has elapsed since the transmission of the HARQ-ACK. Of course, the start time of the specific window / timer is not limited thereto. The specific window / timer (e.g., at least one of the start time (start slot, start symbol, etc.) and the length) may be defined in a specification, or may be configured / instructed to the UE by the base station using an RRC parameter / MAC CE / DCI.

[0109] The DL received by the UE may be at least one of the following options 1A-2-1 to 1A-2-3.

[0110] <<Option 1A-2-1>> The DL received by the UE may be a DL reference signal (e.g., DL-RS). For example, if the UE receives (or measures) a DL reference signal transmitted from the new target cell, it may indicate that the serving cell switch has been successful. The DL reference signal may be at least one of an SSB, a CSI-RS, and a source RS in the indicated TCI state transmitted from the new target cell.

[0111] <<Option 1A-2-2>> The DL received by the UE may be a DL channel (e.g., PDCCH / PDSCH) or downlink control information (e.g., DCI). For example, when the UE receives (or decodes / detects / monitors) a DL channel / DCI transmitted from a new target cell, it may mean that the serving cell switching has been successful. The DL channel (e.g., PDCCH / PDSCH) or DCI may be a PDCCH / PDSCH corresponding to a predetermined format / type.

[0112] For example, if the UE receives DCI in a common search space (e.g., CSS), it may mean that the serving cell switch was successful.

[0113] Alternatively, it may mean that the serving cell switch was successful if the UE receives a PDCCH / PDSCH with the same HARQ process ID as the previous L1 / L2 cell switch signaling (e.g., previous L1 / L2 cell switch signaling), which may have a toggled NDI (assuming no MAC reset).

[0114] Option 1A-2-3: The DL received by the UE may be an explicit indication to confirm (or activate, enable) the serving cell switch. The explicit indication may be, for example, an RRC parameter / MAC CE / DCI corresponding to the explicit indication.

[0115] In at least one of options 1A-2-1 to 1A-2-3, RACH transmission (or RACH procedure) to the new target cell may be completed before the cell switch, and a TA to the new target cell may be obtained before the cell switch.

[0116] [Option 1A-3] If the UE completes a random access procedure (or RACH procedure) to a new target cell (or a candidate cell to which the UE is to change) within a certain window / timer (e.g., a certain window / timer), this indicates that the cell switch is successful, and UE / base station operation may be controlled.

[0117] In Option 1A-3, it is possible that no RACH transmission (or RACH procedure) to the new target cell has been performed or no TA has been acquired before the cell switch, in which case the UE may perform a RACH procedure after switching to the new serving cell.

[0118] [Option 1B-1] Failure to receive a predefined DL before (or within) the end / expiry of a specific window / timer (after the UE sends a HARQ-ACK (e.g., ACK) in response to a serving cell switch instruction or after the UE applies a switch to a new target cell) may mean that the cell switch has failed (see Figures 10 and 11). The specific window / timer and predefined DL may be the window / timer and DL shown in Option 1A-2.

[0119] Figure 10 illustrates a case where the UE fails to receive a predetermined DL before (or within) the expiration / expiry of a specific window / timer after transmitting a HARQ-ACK (e.g., ACK) in response to a serving cell switch instruction, and Figure 11 illustrates a case where the UE fails to receive a predetermined DL before (or within) the expiration / expiry of a specific window / timer after applying a switch to a new target cell.

[0120] In this case, the UE may declare / indicate / report that the cell switch (e.g., L1 / L2 inter-cell mobility) has failed or that a cell switch (e.g., L1 / L2 inter-cell mobility) failure has occurred.

[0121] The period (e.g., start time / length, etc.) of a particular window / timer may be configured by the base station to the UE by an RRC parameter, or may be indicated by the base station to the UE by including it in a MAC CE / DCI instructing a cell switch. The start time may be a start slot or a start symbol.

[0122] [Option 1B-2] If the UE is unable to complete the random access procedure (or RACH procedure) to the new target cell before the end / expiry of a specific window / timer (or within a specific window / timer), this may mean that the cell switch has failed. In this case, the UE may declare / indicate / report that the cell switch (e.g., L1 / L2 inter-cell mobility) has failed or that a cell switch (e.g., L1 / L2 inter-cell mobility) failure has occurred.

[0123] If the cell switch fails (for example, option 1B-1 or option 1B-2), the UE may apply the UE actions shown in at least one of options 1-1 to 1-3 below.

[0124] <<Option 1-1>> The UE may return to the original serving cell (e.g., the serving cell from which it was switched) and monitor DL ​​transmissions (e.g., PDCCH) applying the last TCI state in that cell.

[0125] If the UE fails to receive DL within a certain window / timer (option 1B-1) or the RACH procedure is not completed (option 1B-2) after transmitting a HARQ-ACK (e.g., ACK) in response to the serving cell switch instruction, then at least the ACK transmission was successful, and the channel quality of the original serving cell is likely to be good enough for proper communication (e.g., DL reception).

[0126] <<Option 1-2>> The UE may transmit a RACH (or perform a random access procedure) to a specific cell (e.g., a certain cell). The specific cell may be at least one of the original serving cell (e.g., the serving cell from which the handover occurred) and the new target cell. For example, the random access procedure performed during a radio link failure (RLF) may be reused.

[0127] <<Option 1-3>> The UE may perform RACH transmission (or a random access procedure) to any cell (e.g., ayn cell). For example, the random access procedure performed by a UE in an idle state (UE in IDLE) may be reused.

[0128] UE capabilities may be introduced for different UE behavior after cell switching (e.g. L1 / L2 inter-cell mobility) failure.

[0129] Second Embodiment In a second embodiment, an example of UE operation / base station operation when different mobility procedures (or cell change procedures) are supported will be described.

[0130] In Rel. 18 and later, it is assumed that L1 / L2 inter-cell mobility (e.g., R18 L1 / L2 inter cell mobility) and L3 mobility (e.g., legacy L3 mobility) will be supported. L3 mobility may be, for example, handover, CHO (e.g., Conditional Handover), or CPC (Conditional PSCell Change). In such cases, it is necessary to appropriately control the interaction (or collision / action in the event of collision) of multiple (here, two) procedures.

[0131] When multiple mobility procedures are supported, at least one of the following options 2-1 to 2-4 may be applied. The mobility procedure may be interpreted as a cell change procedure, a cell switch procedure, a cell switching procedure, or a cell update procedure. In the following description, a first mobility (e.g., L1 / L2 inter-cell mobility) and a second mobility (e.g., L3 mobility) are given as examples of multiple mobility procedures, but the mobility type / type is not limited to this. The L3 mobility procedure may reuse a procedure (e.g., a handover procedure) of an existing system (e.g., Rel. 17 or earlier).

[0132] [Option 2-1] Assume that a first mobility procedure (e.g., a cell switch procedure between L1 / L2 cells) is in progress. The cell switch procedure between L1 / L2 cells is in progress (ongoing), for example, when the UE has already received signaling indicating an L1 / L2 cell switch instruction (and has not yet completed the cell switch).

[0133] In this case, the UE may not expect to receive the second mobility indication / perform the second mobility procedure before the completion (or success) of the L1 / L2 cell switch procedure (see Fig. 12A). Before the completion (or success) of the L1 / L2 cell switch procedure may mean before the success or failure of the cell switch described in the first embodiment.

[0134] This results in a configuration in which the second mobility is not performed while the first mobility (e.g., a cell switching procedure between L1 / L2 cells) is in progress, thereby avoiding cases in which two mobility procedures occur simultaneously.

[0135] [Option 2-2] Assume that a second mobility procedure (e.g., L3 mobility procedure) is in progress, and the UE does not receive a first mobility indication (e.g., L1 / L2 cell switch indication signaling) before the L3 mobility procedure (e.g., handover / CHO / CPC) is completed (see FIG. 12B).

[0136] This results in a configuration in which the first mobility (e.g., a cell switching procedure between L1 / L2 cells) is not performed while the second mobility (e.g., a handover procedure) is in progress, thereby avoiding cases in which two mobility procedures occur simultaneously.

[0137] [Option 2-3] If a first mobility procedure (e.g., a cell switch procedure between L1 / L2 cells) is in progress, reception of a second mobility indication / execution of a second mobility procedure may be permitted / supported before the completion (or success) of the L1 / L2 cell switch procedure, i.e., collision between the first mobility procedure and the second mobility procedure may be permitted / supported.

[0138] If an L3 handover command is received (or if the UE determines that the CHO / CPC conditions are met) before the L1 / L2 cell switching procedure is completed (or successful), at least one of the following options 2-3-1 to 2-3-3 may be applied.

[0139] <<Option 2-3-1>> A mobility procedure to be applied may be selected based on a priority corresponding to the mobility procedure. The priority corresponding to each mobility procedure may be defined in a specification or may be set by a base station to a UE using a higher layer parameter or the like.

[0140] For example, the UE may perform a first mobility procedure (e.g., a cell switching procedure between L1 / L2 cells). That is, the UE may perform the first mobility procedure with priority over the second mobility procedure. In this case, the second mobility procedure may be controlled not to be performed (or canceled).

[0141] Alternatively, the UE may perform a second mobility procedure (e.g., an L3 mobility procedure). That is, the UE may perform the second mobility procedure with priority over the first mobility procedure. In this case, the UE may control the first mobility procedure not to be performed (or canceled).

[0142] <<Option 2-3-2>> The mobility procedure to be applied may be selected based on the timing / order of instruction (or initiation) of the mobility procedure.

[0143] For example, a later-indicated (or initiated) mobility procedure may be given priority. If a second mobility indication is received / a second mobility procedure is performed while a first mobility procedure is in progress, the UE may cancel or stop the ongoing first mobility procedure and perform the later-indicated second mobility procedure (see FIG. 13A).

[0144] Alternatively, the first indicated (or initiated) mobility procedure may be given priority. If a second mobility indication is received / a second mobility procedure is performed while a first mobility procedure is in progress, the UE may be controlled to continue the first mobility procedure in progress and not to perform the second mobility procedure indicated later.

[0145] <<Option 2-3-3>> The UE may autonomously select the mobility procedure to be performed.

[0146] [Option 2-4] If a second mobility procedure (e.g., L3 mobility procedure) is in progress, reception of a first mobility indication (e.g., L1 / L2 cell switch indication signaling) / execution of the first mobility procedure may be allowed / supported before completion of the L3 mobility procedure (e.g., handover / CHO / CPC).

[0147] If a first mobility procedure (e.g., L1 / L2 cell switch indication signaling) is received before the second mobility procedure is completed (or successful), at least one of the following options 2-4-1 to 2-4-3 may be applied.

[0148] <<Option 2-4-1>> A mobility procedure to be applied may be selected based on a priority corresponding to the mobility procedure. The priority corresponding to each mobility procedure may be defined in a specification or may be set by a base station to a UE using a higher layer parameter or the like.

[0149] For example, the UE may perform a first mobility procedure (e.g., a cell switching procedure between L1 / L2 cells). That is, the UE may perform the first mobility procedure with priority over the second mobility procedure. In this case, the second mobility procedure may be controlled not to be performed (or canceled).

[0150] Alternatively, the UE may perform a second mobility procedure (e.g., an L3 mobility procedure). That is, the UE may perform the second mobility procedure with priority over the first mobility procedure. In this case, the UE may control the first mobility procedure not to be performed (or canceled).

[0151] <<Option 2-4-2>> The mobility procedure to be applied may be selected based on the timing / order of instruction (or initiation) of the mobility procedure.

[0152] For example, the mobility procedure indicated (or initiated) later may be given priority. If the first mobility indication is received while the second mobility procedure is in progress, the UE may cancel or stop the ongoing second mobility procedure and perform the first mobility procedure indicated later (see FIG. 13B).

[0153] Alternatively, the first indicated (or initiated) mobility procedure may be given priority. If the first mobility indication is received while a second mobility procedure is in progress, the UE may be controlled to continue the second mobility procedure in progress and not to execute the first mobility procedure indicated later.

[0154] <<Option 2-4-3>> The UE may autonomously select the mobility procedure to be performed.

[0155] In Option 2-1 to Option 2-4, the case where a handover procedure (e.g., L3 handover command procedure) and a CHO / CPC procedure (e.g., L3 CHO / CPC procedure) are included as L3 mobility has been shown, but this is not limited thereto. The handover procedure (e.g., L3 handover command procedure) and the CHO / CPC procedure (e.g., L3 CHO / CPC procedure) may be applied as separate procedures.

[0156] Regarding the interworking of the first mobility and the second mobility, different UE capabilities may be introduced / supported for each of the above options.

[0157] Third Embodiment In a third embodiment, an example of indicating / activating a TCI state associated with an additional PCI (will be described. In the present disclosure, the additional PCI may be read as an additional cell, a candidate cell, or a target cell.

[0158] Rel. 17 inter-cell beam management supports a MAC CE to activate up to eight TCI states, with some TCI states being associated with additional PCIs (e.g., additional PCIs), but only on the same frequency as the serving cell (see Figure 14).

[0159] Figure 14 shows a case where up to seven additional PCIs (or candidate cells, target cells, and additional cells) are configured in the same frequency as the serving cell in inter-cell beam management (ICBM) supported in Rel. 17. The MAC CE can instruct activation of the TCI state of the same frequency. The frequency may be read as a frequency domain or a frequency band.

[0160] In Rel. 18 and later, L1 / L2 inter-cell mobility is also expected to support the MAC CE activating a TCI state associated with an additional PCI in a frequency different from that of the serving cell, taking into account inter-frequency scenarios. To indicate / activate the TCI state in L1 / L2 inter-cell mobility, at least one of the following options 3-1 to 3-3 may be applied.

[0161] [Option 3-1] In L1 / L2 inter-cell mobility, the TCI state activated by the MAC CE for the serving cell may be associated with an additional PCI of the same frequency as the serving cell. The MAC CE may be a MAC CE for dynamic beam direction.

[0162] FIG. 15 shows an example where the TCI state that the MAC CE activates is associated with an additional PCI that corresponds to the same frequency as the serving cell.

[0163] Here, SpCell #0 is configured to a first frequency (e.g., f0), and for SpCell #0, the TCI state activated by the MAC CE is associated with SpCell #0, cell #0-1, cell #0-2, cell #0-3, and cell #0-4.

[0164] Also shown is a case where SCell#1 is configured on a second frequency (e.g., f1), and the TCI state that the MAC CE activates for SCell#1 is associated with SCell#1, cell#1-1, cell#1-2, and cell#1-3.

[0165] Since cells on different frequencies have different cell configurations and frequencies, UE operation may become complicated if dynamic beam pointing between these cells is supported. In this case, for each serving cell, the MAC CE may activate the same frequency TCI state.

[0166] Furthermore, the L1 / L2 cell switching may be performed intra-frequency or inter-frequency. Whether intra-frequency cell switching or inter-frequency cell switching is applied may be configured to the UE by the base station through higher layer signaling. Alternatively, whether intra-frequency cell switching or inter-frequency cell switching is applied may be determined based on UE capability information instead of (or in addition to) higher layer signaling.

[0167] Figure 16 shows an example of inter-frequency cell switch, where when cell switch is indicated by L1 / L2 cell switch signaling, a new target cell on a different frequency than the current serving cell may be indicated to the serving cell, and in this case, the TCI state corresponding to the target cell may be activated by a MAC CE on a different frequency.

[0168] For example, the UE may be instructed to switch from SpCell #0 to candidate cells #1-1 to #1-3 corresponding to a frequency different from that of the SpCell. In this case, the UE may assume that the TCI state corresponding to the cell after switching (e.g., candidate cell #1-1) is the TCI state activated in the MAC CE corresponding to SCell #1.

[0169] [Option 3-2] In L1 / L2 inter-cell mobility, the TCI state activated by the MAC CE for the serving cell may be associated with at least one of an additional PCI of the same frequency as the serving cell and an additional PCI of a different frequency. The MAC CE may be a MAC CE for dynamic beam direction.

[0170] Figure 17 shows an example where the MAC CE supports activating TCI states associated with additional PCIs corresponding to the same frequency as the serving cell and TCI states associated with additional PCIs corresponding to different frequencies.

[0171] 17 shows a case where candidate cells #0-1, #0-2, and #0-3 are set at the same frequency (f0) as SpCell #0, candidate cells #1-1 and #1-2 are set at a different frequency f1, and candidate cells #2-1 and #2-2 are set at a different frequency f2. Also shown is a case where SpCell #0 and candidate cells #0-1, #0-2, and #0-3 correspond to PCI #0, candidate cells #1-1 and #1-2 correspond to PCI #1, and candidate cells #2-1 and #2-2 correspond to PCI #2.

[0172] Here, for SpCell#0, the TCI state activated by the MAC CE is shown to be associated with SpCell#0, candidate cells#0-1, #0-2, #0-3, #1-1, #1-2, #2-1, and #2-2. More specifically, a case is shown in which a MAC CE (e.g., a MAC CE corresponding to SpCell #0) activates the TCI state of SpCell #0 (here, TCI #0), the TCI state of candidate cell #0-1 (here, TCI #1), the TCI state of candidate cell #0-2 (here, TCI #2), the TCI state of candidate cell #0-3 (here, TCI #3), the TCI state of candidate cell #1-1 (here, TCI #4), the TCI state of candidate cell #1-2 (here, TCI #5), the TCI state of candidate cell #2-1 (here, TCI #6), and the TCI state of candidate cell #2-2 (here, TCI #7).

[0173] In the case where multiple serving cells are configured (e.g., carrier aggregation), the multiple serving cells may share the activated TCI state of one or more MAC CEs (e.g., one or more MAC CEs corresponding to different frequencies / cells) (see Figure 18).

[0174] 18 shows a case where SpCell #0 and candidate cells #0-1, #0-2, and #0-3 are configured in the first frequency region (f0), SCell #1 and candidate cells #1-1 and #1-2 are configured in the second frequency region (f1), and SCell #2 and candidate cells #2-1 and #2-2 are configured in the third frequency region (f2). Also, the case where SpCell #0 and candidate cells #0-1, #0-2, and #0-3 correspond to PCI #0, SCell #1 and candidate cells #1-1 and #1-2 correspond to PCI #1, and SCell #2 and candidate cells #2-1 and #2-2 correspond to PCI #2 is shown.

[0175] Here, for SpCell#0, SCell#1, and SCell#2, the TCI state activated by MAC CE is shown to be associated with SpCell#0, candidate cells #0-1, #0-2, #0-3, #1-1, #1-2, #2-1, and #2-2.

[0176] A MAC CE may activate the TCI state of each cell on a different frequency. Alternatively, serving / candidate cells that share a MAC CE may be grouped. The group of cells whose TCI state is activated by a common MAC CE may be configured by higher layer signaling or defined in a specification.

[0177] [Option 3-3] The TCI state activated by the MAC CE for dynamic beam direction (or cell switching) is associated with an additional PCI of the same frequency, and the actual frequency (or PCI) to be applied may follow the frequency (or cell index, reference signal resource index (e.g., resource RS index)) of the source serving cell or target cell.

[0178] FIG. 19 shows an example where the TCI state that the MAC CE activates is associated with an additional PCI that corresponds to the same frequency as the serving cell.

[0179] Here, a case is shown in which SpCell #0 and candidate cells #0-1, #0-2, #0-3, and #0-4 are configured to a first frequency (for example, f0), and the TCI state activated by the MAC CE for SpCell #0 (or f0) is associated with SpCell #0, cell #0-1, cell #0-2, cell #0-3, and cell #0-4.

[0180] When applying an activated TCI state to a frequency corresponding to SCell#1, the same TCI state ID (or the same cell ID / resource RS index per frequency) may be applied to the frequency of SCell#1.

[0181] In this case, an association between cell indices of different frequencies may be set / defined, which may be implicit (e.g., implicit association) or explicit (e.g., explicit association).

[0182] As an implicit association, for example, cell index #x (e.g., cell(re-)index #x) of f0 may be associated with cell index #x (e.g., cell(re-)index #x) of f1. As an example, candidate cells #0-2 of f0 may be associated with candidate cells #1-2 of f1.

[0183] As an explicit association, multiple cells that apply the same TCI state in different frequencies (for example, cells of different frequencies) may be associated by higher layer signaling.

[0184] UE capabilities may be introduced regarding support for association between different frequency cells, and for additional PCI cell scenarios, UE capabilities may be introduced regarding whether to support application of the above-mentioned TCI conditions.

[0185] Configuration Example #1: Candidates for TCI states (also referred to as TCI state pools) that can be configured for a serving cell / candidate cell may be cell (or CC) specific. If the TCI state pool is CC specific, the TCI state ID for each CC / frequency may start from a predetermined value (e.g., 0). Furthermore, a resource RS (e.g., a QCL type A / D RS) may have a BWP / CC ID for each frequency.

[0186] For example, assume that for f0, TCI state #3 includes resources (e.g., SSB #2) from candidate cell #0-2, and for f1, TCI state #3 includes resources (SSB #3) from candidate cell #1-1 (see Figure 20).

[0187] 20 shows a case where SpCell #0, candidate cells #0-1, and #0-2 are set to f0, and SCell #1, candidate cells #1-1 and #1-2 are set to f1. Also shown is a case where TCI state ID #3 is set to candidate cell #0-2 (from which SSB #2 is transmitted) by higher layer parameters, and TCI state ID #3 is set to candidate cell #1-1 (from which SSB #3 is transmitted) by higher layer parameters.

[0188] In this case, if the MAC CE activates at least TCI state #3, it may mean that for each frequency (each TCI state pool of different CCs / frequencies), TCI state #3 is activated.

[0189] Furthermore, when the L1 / L2 cell switching signaling indicates candidate cell #1-1 as the target cell and indicates TCI state ID #3 as the TCI state, TCI state ID #3 of frequency f1 corresponding to the candidate cell #1-1 may be applied.

[0190] In the example shown in FIG. 20, it may be supported that the same TCI state ID of each CC has different resource RS and cell ID.

[0191] Configuration Example #2: The TCI state candidates (also referred to as TCI state pools) that can be configured for a serving cell / candidate cell may be cell (or CC) common. If the TCI state pool is CC common, the TCI state ID may be configured for a reference BWP / CC.

[0192] For example, for f0, consider the case where TCI state ID #3 includes resources (eg, SSB #2) from candidate cells #0-2 (see FIG. 21).

[0193] 21 shows a case where SpCell #0, candidate cells #0-1, and #0-2 are set to f0, and SCell #1, candidate cells #1-1 and #1-2 are set to f1. Also, a case where TCI state ID #3 is set to candidate cell #0-2 (to which SSB #2 is transmitted) by higher layer parameters is shown.

[0194] In this case, if the MAC CE activates at least TCI state #3 and the L1 / L2 cell switch signaling indicates candidate cell #1-1 as the target cell and indicates TCI state ID #3 as the TCI state, at least one of the following options B-1 to B-2 may be applied.

[0195] [Option B-1] The QCL resource RS ID may be SSB#2 from candidate cell #1-1, i.e., the same resource RS index from the target cell (or candidate cell) may correspond to the CL resource RS ID.

[0196] [Option B-2] The association between candidate cell #0-2 and candidate cell #1-2 may be configured implicitly / explicitly. In this case, only candidate cell #1-2 is available for TCI state ID #3 in f1. When L1 / L2 cell switching signaling indicates candidate cell #1-2 as the target cell and TCI state ID #3, the QCL resource RS ID is SSB #2 from candidate cell #1-2.

[0197] In the case where candidate cells of different frequencies are associated, if a TCI state ID is indicated for the target cell, the TCI state ID of the reference CC (or cell) may include resource RS from the cell having the cell ID associated as the target cell.

[0198] <Fourth embodiment> In the fourth embodiment, an example of setting synchronization (Sync) and asynchronous (Async) taking into account intra-cell multi-TRP / inter-cell multi-TRP in L1 / L2 intra-cell mobility (e.g., cell switching) will be described.

[0199] In Rel. 18 and later, it is assumed that per-TRP TA configuration will be supported for multi-DCI-based multi-TRP (e.g., mDCI MTRP). Both intra-cell and inter-cell multi-TRP may be supported. For example, for multi-DCI-based multi-TRP operation where multiple TAs (e.g., two) are supported, configuration of two Timing Advance Groups (TAGs) belonging to the serving cell is supported.

[0200] In L1 / L2 inter-cell mobility (e.g., L1 / L2 inter-cell mobility), different TAGs may be configured for the serving cell / candidate cell.

[0201] In L1 / L2 inter-cell mobility, at least one of intra-cell multi-TRP (e.g., the case where two TRPs share the same PCI) and inter-cell multi-TRP (e.g., the case where two TRPs have different PCIs (similar to the multi-DCI-based multi-TRP in Rel. 17 / 18)) may be supported.

[0202] Figure 22 shows an example of intra-cell multi-TRP and inter-cell multi-TRP. Here, multi-TRP (here, two TRPs) is configured in SpCell #0 and SCell #2, and multi-TRP (here, two TRPs) is configured in a candidate cell corresponding to the same frequency region as SCell #1. Information about the serving cell / candidate cell in which multi-TRP is configured may be configured / instructed to the UE by the base station using higher layer parameters / MAC CE / DCI, etc.

[0203] In the case of intra-cell multi-TRP, two TRPs corresponding to each cell may correspond to two TCI states associated with one PCI, respectively. In the case of inter-cell multi-TRP, two TRPs corresponding to different cells may correspond to two TCI states associated with two PCIs, respectively.

[0204] For L1 / L2 inter-cell mobility, at least one of the following options 4-1 to 4-10 may be applied to support / configure intra-cell multi-TRP and inter-cell multi-TRP, and to configure synchronization / asynchronous settings.

[0205] [Option 4-1] The serving cell (e.g., SpCell / SCell) may support intra-cell multi-TRP (e.g., intra-cell MTRP) configuration. Also, synchronous / asynchronous (e.g., sync / async) configuration for intra-cell multi-TRP may be supported.

[0206] When synchronous is set for multi-TRP in a cell, it may mean that multiple (e.g., two) TRPs in the cell are synchronous (e.g., belong to the same TAG). When asynchronous is set for multi-TRP in a cell, it may mean that multiple (e.g., two) TRPs in the cell are asynchronous (e.g., belong to different TAGs).

[0207] The setting of the intra-cell multi-TRP may be configured in the UE from the base station by a higher layer parameter, etc. Information regarding synchronization / asynchronous status between multiple TRPs in a cell (e.g., belonging to the same TAG / belonging to different TAGs) may be indicated by the random access response or by the RRC / MAC CE / DCI.

[0208] [Option 4-2] The serving cell (e.g., SpCell / SCell) may support the configuration of inter-cell multi-TRP (e.g., inter-cell MTRP). In addition, synchronous / asynchronous (e.g., sync / async) configuration may be supported for the inter-cell multi-TRP.

[0209] When inter-cell multi-TRP is set to synchronous, it may mean that multiple (e.g., two) TRPs between cells are synchronous (e.g., belong to the same TAG).When inter-cell multi-TRP is set to asynchronized, it may mean that multiple (e.g., two) TRPs between cells are asynchronous (e.g., belong to different TAGs).

[0210] The inter-cell multi-TRP configuration may be configured in the UE from the base station using higher layer parameters, etc. Information regarding synchronization / asynchronous status between multiple TRPs between cells (e.g., whether they belong to the same TAG / different TAGs) may be indicated by a random access response or by RRC / MAC CE / DCI.

[0211] Both Option 4-1 and Option 4-2 may be supported. For example, in the case of intra-cell multi-TRP, two TRPs belong to the same TAG, and in the case of inter-cell multi-TRP, two TRPs belong to different TAGs.

[0212] [Option 4-3] The serving cell (e.g., SpCell / SCell) may not support intra-cell multi-TRP (e.g., intra-cell MTRP) configuration. Also, synchronous / asynchronous (e.g., sync / async) configuration for intra-cell multi-TRP may not be supported.

[0213] [Option 4-4] The serving cell (e.g., SpCell / SCell) may not support the configuration of inter-cell multi-TRP (e.g., inter-cell MTRP). Also, the synchronous / asynchronous (e.g., sync / async) configuration for inter-cell multi-TRP may not be supported.

[0214] [Option 4-5] Option 4-1 to Option 4-4 may be applied in combination as appropriate. For example, a configuration (Option 4-1 + Option 4-2) may be used in which both the (sync / async) intra-cell multi-TRP setting and the (sync / async) inter-cell multi-TRP setting are supported. Alternatively, a configuration (Option 4-1 + Option 4-4) may be used in which the (sync / async) intra-cell multi-TRP setting is supported but the (sync / async) inter-cell multi-TRP setting is not supported. Alternatively, a configuration (Option 4-2 + Option 4-3) may be used in which the (sync / async) intra-cell multi-TRP setting is not supported but the (sync / async) inter-cell multi-TRP setting is supported.

[0215] [Option 4-6] The candidate cell may support the configuration of intra-cell multi-TRP (e.g., intra-cell MTRP). Also, the candidate cell may support the configuration of synchronous / asynchronous (e.g., sync / async) for intra-cell multi-TRP.

[0216] When synchronous is configured for intra-cell multi-TRP, it may mean that multiple (e.g., two) TRPs in the candidate cell are synchronous (e.g., belong to the same TAG). When asynchronous is configured for intra-cell multi-TRP, it may mean that multiple (e.g., two) TRPs in the candidate cell are asynchronous (e.g., belong to different TAGs).

[0217] The setting of intra-cell multi-TRP may be configured in the UE from the base station by a higher layer parameter, etc. Information regarding synchronization / asynchronous status (e.g., belonging to the same TAG / different TAG) between multiple TRPs in a candidate cell may be indicated by a random access response or by RRC / MAC CE / DCI.

[0218] [Option 4-7] The candidate cell may support the configuration of inter-cell multi-TRP (e.g., inter-cell MTRP). Also, the candidate cell may support the configuration of synchronous / asynchronous (e.g., sync / async) for the inter-cell multi-TRP.

[0219] When synchronization is set for inter-cell multi-TRP, it may mean that multiple (e.g., two) TRPs between candidate cells are synchronized (e.g., belong to the same TAG). When asynchronous setting for inter-cell multi-TRP, it may mean that multiple (e.g., two) TRPs between candidate cells are asynchronous (e.g., belong to different TAGs).

[0220] The inter-cell multi-TRP configuration may be configured in the UE from the base station using higher layer parameters, etc. Information regarding synchronization / asynchronous status (e.g., whether TRPs belong to the same TAG / different TAGs) between multiple TRPs in candidate cells may be indicated by the random access response or by the RRC / MAC CE / DCI.

[0221] Both options 4-6 and 4-7 may be supported. For example, in the case of intra-cell multi-TRP, two TRPs in a candidate cell belong to the same TAG, and in the case of inter-cell multi-TRP, two TRPs between candidate cells belong to different TAGs.

[0222] [Option 4-8] The candidate cell may not support intra-cell multi-TRP (e.g., intra-cell MTRP) configuration, and may not support synchronous / asynchronous (e.g., sync / async) configuration for intra-cell multi-TRP.

[0223] [Option 4-9] The candidate cell may not support the configuration of inter-cell multi-TRP (e.g., inter-cell MTRP), and may not support the configuration of synchronous / asynchronous (e.g., sync / async) for inter-cell multi-TRP.

[0224] [Option 4-10] Options 4-6 to 4-9 may be applied in combination as appropriate. For example, a configuration (Option 4-6 + Option 4-7) may be used in which both (sync / async) intra-cell multi-TRP configuration and (sync / async) inter-cell multi-TRP configuration are supported for candidate cell / cell group switching. Alternatively, a configuration (Option 4-6 + Option 4-9) may be used in which (sync / async) intra-cell multi-TRP configuration is supported for candidate cell / cell group switching, but (sync / async) inter-cell multi-TRP configuration is not supported for candidate cell / cell group switching. Alternatively, a configuration (Option 4-7 + Option 4-8) may be used in which (sync / async) intra-cell multi-TRP configuration is not supported for candidate cell / cell group switching, but (sync / async) inter-cell multi-TRP configuration is supported.

[0225] [Variations] In options 4-6 to 4-10, a candidate cell may be distinguished as a candidate cell for SpCell switching or a candidate cell for SCell switching. In this case, the presence or absence of intra-cell multi-TRP / inter-cell multi-TRP (or synchronous / asynchronous) configuration may be configured separately for a candidate cell corresponding to the SpCell and a candidate cell corresponding to the SCell (or each SCell).

[0226] Alternatively, the setting of intra-cell multi-TRP / inter-cell multi-TRP (or synchronous / asynchronous) may be configured in common for the candidate cell corresponding to the SpCell and the candidate cell corresponding to the SCell (or each SCell).

[0227] In Option 4-1 to Option 4-10, only one of synchronization and asynchronous (for example, synchronization) may be supported. For example, synchronization-related UE capabilities may be supported as basic UE capabilities, and asynchronous-related UE capabilities may be supported separately from synchronization-related UE capabilities (or in addition to synchronization-related UE capabilities).

[0228] <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.

[0229] The specific UE capability may indicate at least one of the following: - Support for specific UE behavior in case of cell switch failure; - Support for collision of L1 / L2 inter-cell mobility procedures / operations with L3 mobility procedures / operations; - Support for intra-frequency cell switch when the TCI states activated by the MAC CE are associated with serving / candidate cells corresponding to the same frequency region; - Support for inter-frequency cell switch when the TCI states activated by the MAC CE are associated with serving / candidate cells corresponding to the same frequency region; - TCI states activated by the MAC CE are associated with serving / candidate cells corresponding to different frequency regions, and in such cases the maximum number of frequency regions, the maximum number of candidate cells, and the maximum number of cells per frequency; - Support for configuration of intra-cell / inter-cell multi-TRP for the serving cell; - Support for configuration of intra-cell / inter-cell multi-TRP for the candidate cell.

[0230] 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).

[0231] 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)).

[0232] 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.

[0233] If the UE does not support at least one of the specific UE capabilities or is not configured with the specific information, the UE may apply, for example, the behavior of Rel. 15 / 16 / 17.

[0234] (Supplementary Notes) The following inventions are supplemented with respect to one embodiment of the present disclosure. [Supplementary Note 1-1] A terminal including: a receiving unit that receives at least one of downlink control information and a MAC Control Element (CE) including cell switch instruction information from a serving cell to a candidate cell; and a control unit that determines success or failure of switching from the serving cell to the candidate cell based on at least one of transmission of an ACK (acknowledgement) in response to the cell switch instruction information and reception of a DL transmission from the candidate cell within a specific window or timer period after receiving the cell switch instruction information. [Supplementary Note 1-2] The terminal according to Supplementary Note 1-1, wherein the specific window or timer starts after transmission of the ACK or a predetermined period after transmission of the ACK. [Supplementary Note 1-3] The terminal according to Supplementary Note 1-1 or Supplementary Note 1-2, wherein the control unit determines that switching from the serving cell to the candidate cell has failed if DL transmission from the candidate cell cannot be received or a random access procedure is not completed within the specific window or timer period. [Supplementary Note 1-4] The control unit controls to perform a random access procedure for at least one of the serving cell and the candidate cell when switching from the serving cell to the candidate cell fails. The terminal according to any one of Supplementary Note 1-1 to Supplementary Note 1-3.

[0235] [Supplementary Note 2-1] A terminal comprising: a receiving unit that receives at least one of first instruction information instructing an L1 / L2 inter-cell mobility procedure and second instruction information instructing an L3 mobility procedure; and a control unit that controls the L1 / L2 inter-cell mobility procedure based on the first instruction information and controls the L3 mobility procedure based on the second instruction information, wherein the control unit controls the L1 / L2 inter-cell mobility procedure and the L3 mobility procedure so that they are not performed simultaneously. [Supplementary Note 2-2] The terminal according to Supplementary Note 2-1, wherein the control unit assumes that the second instruction information will not be received if the L1 / L2 inter-cell mobility procedure is in progress, and assumes that the first instruction information will not be received if the L3 mobility procedure is in progress. [Supplementary Note 2-3] The terminal according to Supplementary Note 2-1 or Supplementary Note 2-2, wherein the control unit prioritizes a specific procedure when the L1 / L2 inter-cell mobility procedure and the L3 mobility procedure conflict. [Supplementary Note 2-4] The terminal according to any one of Supplementary Note 2-1 to Supplementary Note 2-3, wherein the control unit prioritizes a procedure that is instructed later when the L1 / L2 inter-cell mobility procedure and the L3 mobility procedure conflict.

[0236] [Supplementary Note 3-1] A terminal comprising: a receiver that receives a MAC Control Element (MAC CE) including information on active transmission configuration indicator (TCI) states associated with a serving cell and one or more candidate cells corresponding to the serving cell, respectively; and a controller that determines a TCI state corresponding to the serving cell and a TCI state corresponding to the candidate cells based on the MAC CE, wherein the TCI states activated by the MAC CE are associated with candidate cells corresponding to at least the same frequency region as the serving cell. [Supplementary Note 3-2] The terminal according to Supplementary Note 3-1, wherein the TCI states activated by the MAC CE are associated with candidate cells corresponding to the same frequency region as the serving cell and candidate cells corresponding to a frequency region different from that of the serving cell. [Supplementary Note 3-3] The terminal according to Supplementary Note 3-1 or Supplementary Note 3-2, wherein, when a plurality of serving cells are configured, at least one of active TCI states associated with the plurality of serving cells and active TCI states associated with one or more candidate cells respectively corresponding to the plurality of serving cells is indicated by one MAC CE. [Supplementary Note 3-4] The terminal according to any of Supplementary Note 3-1 to Supplementary Note 3-3, wherein the control unit determines a TCI state corresponding to at least one of a serving cell and a candidate cell corresponding to another frequency region, based on a TCI state ID indicated by the MAC CE for a serving cell corresponding to another frequency region.

[0237] [Supplementary Note 4-1] A terminal comprising: a receiving unit that receives at least one of downlink control information and a MAC Control Element (MAC CE) including cell switching instruction information from a serving cell to a candidate cell; and a control unit that controls a cell switching operation based on the cell switching instruction information, wherein at least one of an intra-cell multiple transmission / reception point and an inter-cell multiple transmission / reception point is set in at least one of the serving cell and the candidate cell. [Supplementary Note 4-2] The terminal according to Supplementary Note 4-1, wherein, when the intra-cell multiple transmission / reception point is set, a plurality of transmission / reception points included in at least one of the serving cell and the candidate cell are set synchronously or asynchronously. [Supplementary Note 4-3] The terminal according to Supplementary Note 4-1 or Supplementary Note 4-2, wherein, when the inter-cell multiple transmission / reception point is set, at least one of a plurality of transmission / reception points included in each of a plurality of serving cells and a plurality of transmission / reception points included in each of a plurality of candidate cells is set synchronously or asynchronously. [Supplementary Note 4-4] When the setting of both the intra-cell multi-transmission / reception point and the inter-cell multi-transmission / reception point is supported, the terminal according to any one of Supplementary Note 4-1 to Supplementary Note 4-3 supports that a plurality of transmission / reception points included in a certain cell are set to the same timing advance group, and a plurality of transmission / reception points included in different cells are set to different timing advance groups.

[0238] (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.

[0239] 23 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).

[0240] 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.

[0241] 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.

[0242] 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))).

[0243] 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.

[0244] 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).

[0245] 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.

[0246] 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.

[0247] 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.

[0248] 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.

[0249] 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.

[0250] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0251] 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).

[0252] 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.

[0253] 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.

[0254] 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.

[0255] 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).

[0256] 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.

[0257] 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.

[0258] 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.

[0259] 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.

[0260] 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.

[0261] 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.

[0262] 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.

[0263] 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.

[0264] 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).

[0265] 24 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.

[0266] 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.

[0267] 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.

[0268] 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.

[0269] 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.

[0270] 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.

[0271] 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.

[0272] 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.

[0273] 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.

[0274] 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.

[0275] 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.

[0276] 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.

[0277] 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.

[0278] 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.

[0279] 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.

[0280] 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.

[0281] 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.

[0282] The transceiver 120 may transmit at least one of downlink control information including cell switching instruction information from the serving cell to the candidate cell and a MAC Control Element (MAC CE) to the terminal. The control unit 110 may determine whether switching from the serving cell to the candidate cell has succeeded or failed based on an ACK (ACKnowledgement) in response to the cell switching instruction information transmitted from the terminal.

[0283] The transceiver 120 may transmit at least one of first instruction information instructing an L1 / L2 inter-cell mobility procedure and second instruction information instructing an L3 mobility procedure. The controller 110 may control the transmission of the first instruction information and the second instruction information so that the L1 / L2 inter-cell mobility procedure and the L3 mobility procedure do not collide.

[0284] The transceiver 120 may transmit a MAC Control Element (MAC CE) including information on active transmission configuration indicator (TCI) states associated with a serving cell and one or more candidate cells corresponding to the serving cell. The controller 110 may indicate the TCI state corresponding to the serving cell and the TCI state corresponding to the candidate cells based on the MAC CE. The TCI state activated by the MAC CE may be associated with candidate cells corresponding to at least the same frequency region as the serving cell.

[0285] The transceiver 120 may transmit at least one of downlink control information including cell switching instruction information from the serving cell to the candidate cell and a MAC Control Element (MAC CE). The control unit 110 may instruct a cell switching operation using the cell switching instruction information. At least one of the serving cell and the candidate cell may be configured with at least one of an intra-cell multiple transmission / reception point and an inter-cell multiple transmission / reception point.

[0286] (User terminal) Fig. 25 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.

[0287] 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.

[0288] 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.

[0289] 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.

[0290] 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.

[0291] 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.

[0292] 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.

[0293] 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.

[0294] 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.

[0295] 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.

[0296] 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.

[0297] 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.

[0298] 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.

[0299] 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.

[0300] 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.

[0301] 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.

[0302] 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.

[0303] The transceiver 220 may receive at least one of downlink control information including cell switch instruction information from the serving cell to the candidate cell and a MAC Control Element (CE). The control unit 210 may determine the success or failure of the switch from the serving cell to the candidate cell based on at least one of transmission of an ACK (acknowledgement) in response to the cell switch instruction information and reception of a DL transmission from the candidate cell within a specific window or timer period after receiving the cell switch instruction information. The specific window or timer may start after transmission of the ACK or a predetermined period after transmission of the ACK. The control unit 210 may determine that the switch from the serving cell to the candidate cell has failed if the DL transmission from the candidate cell cannot be received / the random access procedure is not completed within the specific window or timer period. If the switch from the serving cell to the candidate cell has failed, the control unit 210 may control to perform a random access procedure for at least one of the serving cell and the candidate cell.

[0304] The transceiver 220 may receive at least one of first instruction information instructing an L1 / L2 inter-cell mobility procedure and second instruction information instructing an L3 mobility procedure. The controller 210 may control the L1 / L2 inter-cell mobility procedure based on the first instruction information and control the L3 mobility procedure based on the second instruction information. The controller 210 may control (or assume) that the L1 / L2 inter-cell mobility procedure and the L3 mobility procedure are not performed simultaneously. The controller 210 may assume that the second instruction information will not be received if the L1 / L2 inter-cell mobility procedure is in progress. The controller 210 may assume that the first instruction information will not be received if the L3 mobility procedure is in progress. The controller 210 may prioritize a specific procedure if there is a conflict between the L1 / L2 inter-cell mobility procedure and the L3 mobility procedure. When an L1 / L2 inter-cell mobility procedure and an L3 mobility procedure conflict with each other, the control unit 210 may prioritize the procedure instructed later.

[0305] The transceiver 220 may receive a MAC Control Element (MAC CE) including information on active transmission configuration indicator (TCI) states associated with a serving cell and one or more candidate cells corresponding to the serving cell. The controller 210 may determine the TCI state associated with the serving cell and the TCI state associated with the candidate cells based on the MAC CE. The TCI state activated by the MAC CE may be associated with at least a candidate cell corresponding to the same frequency region as the serving cell. The TCI state activated by the MAC CE may be associated with a candidate cell corresponding to the same frequency region as the serving cell and a candidate cell corresponding to a different frequency region from the serving cell. When multiple serving cells are configured, one MAC CE may indicate at least one of active TCI states associated with multiple serving cells and active TCI states associated with one or more candidate cells corresponding to the multiple serving cells. The control unit 210 may determine the TCI state corresponding to at least one of the serving cell and the candidate cell corresponding to another frequency region based on the TCI state ID indicated for the serving cell corresponding to a certain frequency region by the MAC CE.

[0306] The transceiver unit 220 may receive at least one of downlink control information including cell switching instruction information from a serving cell to a candidate cell and a MAC Control Element (CE). The control unit 210 may control a cell switching operation based on the cell switching instruction information. At least one of an intra-cell multiple transmission / reception point and an inter-cell multiple transmission / reception point may be configured in at least one of the serving cell and the candidate cell. When an intra-cell multiple transmission / reception point is configured, multiple transmission / reception points included in at least one of the serving cell and the candidate cell may be configured synchronously or asynchronously. When an inter-cell multiple transmission / reception point is configured, at least one of multiple transmission / reception points included in each of the multiple serving cells and multiple transmission / reception points included in each of the multiple candidate cells may be configured synchronously or asynchronously. When configuration of both an intra-cell multiple transmission / reception point and an inter-cell multiple transmission / reception point is supported, it may be supported that multiple transmission / reception points included in a certain cell are configured to the same timing advance group, and multiple transmission / reception points included in different cells are configured to different timing advance groups.

[0307] (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.

[0308] 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.

[0309] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 26 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.

[0310] 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.

[0311] 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.

[0312] 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.

[0313] 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.

[0314] 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.

[0315] 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.

[0316] 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.

[0317] 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.

[0318] 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).

[0319] 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.

[0320] 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.

[0321] (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.

[0322] 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.

[0323] 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.

[0324] 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.

[0325] 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.

[0326] 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.

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 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.

[0332] 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.

[0333] 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.

[0334] 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.

[0335] 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.

[0336] 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.

[0337] 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.

[0338] 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.

[0339] 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."

[0340] 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.

[0341] 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.

[0342] 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.

[0343] 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.

[0344] 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.

[0345] 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.

[0346] 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.

[0347] 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).

[0348] 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).

[0349] 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).

[0350] 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.

[0351] 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.

[0352] 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).

[0353] 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.

[0354] 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.

[0355] 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.

[0356] 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.

[0357] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0358] 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.

[0359] 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.

[0360] 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.

[0361] 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.

[0362] 27 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.

[0363] 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.

[0364] 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).

[0365] 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.

[0366] 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.

[0367] 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.

[0368] 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.

[0369] 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.

[0370] 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).

[0371] 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.

[0372] 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)).

[0373] 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.

[0374] 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.

[0375] 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.

[0376] 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.

[0377] 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.

[0378] 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).

[0379] 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."

[0380] 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.

[0381] 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.

[0382] 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.

[0383] 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.

[0384] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0385] 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.

[0386] 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."

[0387] 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.

[0388] 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."

[0389] 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.

[0390] 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.

[0391] 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").

[0392] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0393] 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) that instructs cell switching from a serving cell to the candidate cell after a random access procedure in the candidate cell is completed and after a timing advance (TA) of the candidate cell is acquired; a control unit that controls the terminal to perform a random access procedure in an arbitrary cell when a physical downlink control channel (PDCCH) is not received from the candidate cell during a timer period after receiving the MAC CE.

2. After completion of a random access procedure in a candidate cell and after acquiring a timing advance (TA) of the candidate cell, receiving a Medium Access Control Element (MAC CE) instructing cell switching from a serving cell to the candidate cell; and when a physical downlink control channel (PDCCH) is not received from the candidate cell within a timer period after receiving the MAC CE, controlling to perform a random access procedure in an arbitrary cell.

3. A transmitter that transmits a Medium Access Control Element (MAC CE) to a terminal after a random access procedure in a candidate cell is completed and after a timing advance (TA) of the candidate cell is acquired, the MAC CE instructing a cell switch from a serving cell to the candidate cell; A control unit that determines that a random access procedure in an arbitrary cell is performed by the terminal when the terminal does not receive a physical downlink control channel (PDCCH) from the candidate cell within a timer period after receiving the MAC CE.

4. A system having a terminal and a base station, The terminal a receiving unit that receives a Medium Access Control Element (MAC CE) instructing cell switching from a serving cell to the candidate cell after a random access procedure in the candidate cell is completed and after a timing advance (TA) of the candidate cell is acquired; a control unit configured to perform control so as to perform a random access procedure in an arbitrary cell when a physical downlink control channel (PDCCH) is not received from the candidate cell during a timer period after receiving the MAC CE; The base station A system comprising a transmitter for transmitting the MAC CE.