Terminal, wireless communication method, base station and system

Abstract

A terminal according to one embodiment of the present disclosure has: a reception unit that receives settings information relating to a plurality of serving cells and a candidate cell that is associated with each of the plurality of serving cells; and a control unit that, if setting of a timing advance group (TAG) ID is supported for the plurality of serving cells and the candidate cell, controls UL transmission on the basis of the TAG ID. One or a plurality of primary TAGs are set for the plurality of serving cells 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 UL transmission is performed to multiple transmission / reception points, how to control the UL transmission (for example, timing advance control) becomes an issue. If the UL transmission to each transmission / reception point is not appropriately controlled, the quality of communication using multiple transmission / reception points may deteriorate.

[0007] The present disclosure has been made in consideration of such 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 UL transmission even when communication is performed using multiple transmission points.

[0008] A terminal according to one aspect of the present disclosure has a receiving unit that receives configuration information regarding a plurality of serving cells and candidate cells that are respectively associated with the plurality of serving cells, and a control unit that controls UL transmission based on a timing advance group (TAG) ID if the setting of the timing advance group ID is supported for the plurality of serving cells and the candidate cells, and one primary TAG or a plurality of primary TAGs are set for the plurality of serving cells and the candidate cells.

[0009] According to one aspect of the present disclosure, UL transmission can be appropriately controlled even when communication is performed using multiple transmission points.

[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 examples 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 examples 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. FIG. 7 is a diagram illustrating an example of TAG configuration when TAG ID association with a candidate cell is supported. FIG. 8 is a diagram illustrating an example of configuration example 1 according to the first embodiment. FIG. 9 is a diagram illustrating an example of PTAG configuration according to the first embodiment. FIG. 10 is a diagram illustrating an example of TAG ID configuration during SpCell switching according to the first embodiment. FIG. 11 is a diagram illustrating another example of TAG ID setting when switching SpCells according to the first embodiment. FIGS. 12A and 12B are diagrams illustrating an example of TAG setting restrictions according to the first embodiment. FIG. 13 is a diagram illustrating an example of setting example 2 according to the second embodiment. FIG. 14 is a diagram illustrating an example of PTAG setting according to the second embodiment. FIG. 15 is a diagram illustrating an example of TAG ID setting when switching SpCells according to the second embodiment. FIG. 16 is a diagram illustrating an example of TAG setting restrictions according to the second embodiment. FIG. 17 is a diagram illustrating an example of setting example 3 according to the third embodiment. FIG. 18 is a diagram illustrating an example of PTAG setting according to the third embodiment. FIG. 19 is a diagram illustrating an example of TAG setting restrictions according to the third embodiment. FIG. 20 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 21 is a diagram illustrating an example of a configuration of a base station according to an embodiment. FIG. 22 is a diagram illustrating an example of a configuration of a user terminal according to an embodiment. FIG. 23 is a diagram illustrating an example of hardware configurations of a base station and a user terminal according to an embodiment. FIG. 24 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] (Candidate Cells) In inter-cell mobility, it is also assumed that one or more candidate cells are configured / managed for each serving cell.

[0041] 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).

[0042] 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.

[0043] In Alt. 1 / 2, activation / deactivation of candidate cells may be controlled by MAC CE / DCI.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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).

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] (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.

[0054] 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.

[0055] The UE may control the timing of UL transmission by applying timing advance (multiple timing advances) for each pre-configured timing advance group (TAG).

[0056] 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.

[0057] 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.

[0058] 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).

[0059] 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).

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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).

[0066] 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.

[0067] For example, when the time alignment timer expires, the following actions (e.g., predetermined PTAG action / predetermined STAG action) may be performed.

[0068] 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.

[0069] 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.

[0070] In future wireless communication systems, it is also assumed that in inter-cell mobility, UL transmission will be controlled based on timing advance for a serving cell (or a TRP of a serving cell) and a non-serving cell / additional cell (or a TRP of a non-serving cell / additional cell). Alternatively, in future wireless communication systems, it is also assumed that different TAGs (or TAG-IDs) will be set for one or more TRPs (e.g., multiple TRPs having different PCIs) corresponding to a certain cell (or CC). Alternatively, it is also assumed that different TRPs corresponding to a certain cell share a common TAG.

[0071] FIG. 7 is a diagram showing an example of TAG settings for multiple cells (or TRPs) with different PCIs.

[0072] It is also assumed that up to M PCIs (e.g., a serving cell plus candidate cells associated with the serving cell) can be configured for each CC, and that up to N TAGs (e.g., N≦M) can be configured for the M PCIs. In this case, one or more PCIs may be associated with one TAG.

[0073] Furthermore, one or more PCIs may be associated with one TAG for up to S serving cells in a cell group (or for up to S serving cells). In this case, up to T TAGs may be configured considering one PCI per CC (Case 1). That is, up to T×N TAGs may be configured for up to M×S cells. Alternatively, up to U TAGs may be configured for up to M×S cells (Case 2).

[0074] [Problem 1] When one PCI is assumed for each CC, a maximum of T tags (T=3 in FIG. 7) may be set in all carriers (Case 1), or a total of U tags (U=6 in FIG. 7) may be set (Case 2).

[0075] However, if each candidate cell shown in the serving cell / candidate cell configuration examples 1 to 3 can be associated with a TAG, the question arises as to how to define or configure a PTAG / STAG. Also, the question arises as to how to define or configure a TAG ID.

[0076] For example, existing systems (e.g., Rel. 17 and earlier) support the configuration of one PTAG and up to three STAGs for one cell group (e.g., MCG / SCG). In the case of a PTAG, TAG ID = 0. It is possible that the definitions of PTAG and TAG ID will change for L1 / L2 inter-cell mobility. In addition, after switching SpCells (e.g., SpCell switch) via L1 / L2 signaling, how to control the updating of PTAG and TAG ID (whether to update, or if so, how to update) becomes an issue.

[0077] Problem 2: When the time alignment timer of a TAG expires and the TAG contains only candidate cells (no serving cell), how to control the UE operation becomes an issue, such as whether to flush the HARQ buffer because the serving cell continues to function even if the candidate cell loses its time alignment.

[0078] [Problem 3] There is a problem of how to control the operation of cells that share the same TAG ID, for example, whether restrictions are set on cells that share the same TAG ID.

[0079] The inventors of the present invention have focused on the fact that at least one of the above-mentioned problems 1 to 3 occurs when one or more candidate cells are associated with / configured to a serving cell / MAC entity / cell group, and have studied timing advance control when candidate cells are supported, leading to the idea of ​​this embodiment. The timing advance control shown in this embodiment makes it possible to solve at least one of the problems 1 to 3.

[0080] 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.

[0081] 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."

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] The following description may be applied to inter-cell mobility (for example, L1 / L2 inter cell mobility), or may be applied to communication control other than inter-cell mobility.

[0092] (Wireless communication method) When a TAG ID is associated with a candidate cell configured in addition to a serving cell, the UE may control UL transmission in the serving cell / candidate cell based on the TAG ID. The UL transmission in the candidate cell may be UL transmission after switching between the serving cell (SpCell / SCell) and the candidate cell.

[0093] The UE may receive, via the RRC / MAC CE / DCI, configuration information regarding one or more serving cells and candidate cells associated with the one or more serving cells, respectively. The UE may also receive, via the RRC / MAC CE / DCI, information regarding at least one of a TAG corresponding to the serving cell and a TAG corresponding to the candidate cell.

[0094] Alternatively, the UE may receive configuration information regarding one or more serving cells belonging to a cell group and candidate cells associated with the cell group via the RRC / MAC CE / DCI. Also, the UE may receive information regarding at least one of TAGs corresponding to the serving cell and TAGs corresponding to the candidate cells via the RRC / MAC CE / DCI.

[0095] Alternatively, the UE may receive, via the RRC / MAC CE / DCI, configuration information regarding a plurality of serving cells belonging to a cell group, a candidate cell group, and a candidate cell included in the candidate cell group. Also, the UE may receive, via the RRC / MAC CE / DCI, information regarding at least one of a TAG corresponding to the serving cell, a TAG corresponding to the candidate cell group, and a TAG corresponding to the candidate cell.

[0096] When each cell group / candidate cell / candidate cell group is set, the UE may apply at least one of the following first to third embodiments to the setting of TAG (for example, PTAG / STAG), the setting of TAG ID, the UE operation after cell switching, etc. Note that the first to third embodiments may be applied in appropriate combination.

[0097] First Embodiment In a first embodiment, an example of timing advance control (for example, definition / setting of TAG ID / PTAG / STAG) in the case where candidate cell setting example 1 is applied will be described.

[0098] In the following description, a case where a serving cell and one or more candidate cells associated with the serving cell are configured in a cell group (for example, MCG or SCG) will be described (configuration example 1). Figure 8 shows a case where SpCell #0, SCell #1, and SCell #2 are configured as serving cells, and 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. Note that the number of serving cells configured, the number of candidate cells associated with each serving cell, etc. are examples and are not limited to these.

[0099] [Aspect 1-1] For L1 / L2 inter-cell mobility, when each candidate cell is associated with a TAG ID, the definition / configuration of PTAG and STAG may be controlled using at least one of the following options 1-1-1 to 1-1-2.

[0100] <<Option 1-1-1>> Only one PTAG may be defined / configured. For example, in a cell group, a TAG including an SpCell among the current serving cells may be defined / configured as the PTAG. The ID of the PTAG may be 0.

[0101] TAGs other than one PTAG may be defined / configured as STAGs. When a candidate cell group is configured, only one PTAG may be defined / configured for the candidate cell group.

[0102] <<Option 1-1-2>> Multiple PTAGs may be defined / configured. For example, in a cell group, at least one of a TAG including an SpCell among the current serving cells and a TAG including a candidate cell associated with the SpCell may be defined / configured as a PTAG. Note that a PTAG always includes a TAG including an SpCell that will become the serving cell, and one or more TAGs including candidate cells associated with the SpCell may additionally constitute a PTAG. TAGs other than the PTAG may be defined / configured as STAGs.

[0103] When multiple PTAGs are defined / configured, the IDs of the multiple PTAGs may include 0 and other values. For example, the ID of a TAG including an SpCell that is to be a serving cell may be 0, and the IDs of other PTAGs may be values ​​other than 0 (for example, 1). Alternatively, the ID of a PTAG including a specific candidate cell may be 0, and the IDs of other PTAGs may be values ​​other than 0 (for example, 1).

[0104] 9 shows an example in which multiple (here, two) PTAGs are configured. In FIG. 9, SpCell (PCI #0), SCell #1 (PCI #3), SCell #2 (PCI #7), SCell #3 (PCI #9), and SCell #4 (PCI #10) are configured as serving cells. SpCell (PCI #1) and SpCell (PCI #2) are associated with SpCell (PCI #0), which are candidate cells. SCell #1 (PCI #4) and SCell #1 (PCI #5) are associated with SCell #1 (PCI #3), which are candidate cells. SCell #2 (PCI #8) is associated with SCell #2 (PCI #7), which is a candidate cell. SCell #4 (PCI #11) is associated with SCell #4 (PCI #10), which is a candidate cell.

[0105] FIG. 9 also shows a case where SpCell (PCI #0), SCell #1 (PCI #3), and SCell #2 (PCI #7) are included in the same TAG (TAG ID = 0), SpCell (PCI #1) and SpCell (PCI #2) are included in the same TAG (TAG ID = 1), SCell #1 (PCI #4), SCell #1 (PCI #5), and SCell #2 (PCI #8) are included in the same TAG (TAG ID = 2), SCell #3 (PCI #9) and SCell #4 (PCI #10) are included in the same TAG (TAG ID = 3), and SCell #4 (PCI #11) is included in TAG ID-4.

[0106] 9, multiple TAGs (here, TAG ID=0 and TAG ID=1) may be defined / set as PTAGs, and other TAGs may be defined / set as STAGs. Also, a case is shown in which the ID of a PTAG including a serving cell SpCell (PCI#0) is set to 0, and the IDs of other PTAGs are set to 1.

[0107] The number of PTAGs configured in a cell group and at least one of the candidate cells included in the PTAG may be defined in a specification or may be configured / instructed to the UE by the base station via RRC / MAC CE / DCI.

[0108] [Aspect 1-2] When the SpCell is switched by L1 / L2 signaling, at least one of the following options 1-2-1 to 1-2-2 may be applied after the switch (or after the SpCell is switched).

[0109] <<Option 1-2-1>> When one PTAG is defined / configured (for example, option 1-1-1), the original TAG (or former TAG) containing the new (or switched) SpCell may be changed / updated to the PTAG, and the original TAG containing the old (or pre-switched) SpCell may be changed / updated to the STAG. In this case, the TAG ID may be determined based on at least one of the following options 1-2-1A to 1-2-1B.

[0110] [[Option 1-2-1A]] The TAG ID may not be changed. In this case, the TAG ID of the new PTAG may have a value (ID) other than 0 (Alt. 1A).

[0111] [[Option 1-2-1B]] The TAG ID may be updated. For example, the TAG ID of the new PTAG may be changed / updated to 0 (e.g., TAG ID = 0). In this case, the original PTAG (new STAG) may be changed / updated to a value (ID) other than 0. The TAG ID of the original PTAG (or new STAG) may be determined based on at least one of Alt. 1B-1 to Alt. 1B-3 below.

[0112] Alt. 1B-1: When the original PTAG (or the original PTAG) becomes a STAG, a new TAG ID may be configured by a higher layer parameter. When the original PTAG is switched to a STAG, the UE may apply the previously configured TAG ID to the switched STAG.

[0113] Alternatively, information about the TAG ID to be applied to each TAG after switching (e.g., a TAG switched to a STAG) may be indicated to the UE using L1 / L2 signaling instructing the SpCell switching. For example, multiple TAG ID candidates may be configured by higher layer parameters, and a specific TAG ID may be indicated by L1 / L2 signaling (e.g., DCI).

[0114] Alt. 1B-2 The original PTAG (or original PTAG) may have the original TAG ID of the new PTAG. That is, the new PTAG and the new STAG (or the TAGs performing the switch) may exchange TAG IDs.

[0115] Alt. 1B-3: Instead of autonomously updating / replacing the TAG ID, the UE may expect / assume that the base station will send an RRC / MAC CE / DCI to update the TAG ID.

[0116] FIG. 10 shows an example of the definition / setting of a TAG ID after the SpCell is switched in the case where one PTAG is defined / set.

[0117] In FIG. 10, SpCell (PCI #0), SCell #1 (PCI #3), SCell #2 (PCI #7), SCell #3 (PCI #9), and SCell #4 (PCI #10) are configured as serving cells. SpCell (PCI #1) and SpCell (PCI #2) are associated with SpCell (PCI #0), which are candidate cells. SCell #1 (PCI #4) and SCell #1 (PCI #5) are associated with SCell #1 (PCI #3), which are candidate cells. SCell #2 (PCI #8) is associated with SCell #2 (PCI #7), which is a candidate cell. SCell #4 (PCI #11) is associated with SCell #4 (PCI #10), which is a candidate cell.

[0118] FIG. 10 also shows a case where SpCell (PCI #0), SCell #1 (PCI #3), and SCell #2 (PCI #7) are included in the same TAG (TAG ID = 0), SpCell (PCI #1) and SpCell (PCI #2) are included in the same TAG (TAG ID = 1), SCell #1 (PCI #4), SCell #1 (PCI #5), and SCell #2 (PCI #8) are included in the same TAG (TAG ID = 2), SCell #3 (PCI #9) and SCell #4 (PCI #10) are included in the same TAG (TAG ID = 3), and SCell #4 (PCI #11) is included in TAG ID-4.

[0119] Here, a case is shown in which candidate cell PCI#1 becomes the serving cell SpCell (or SpCell (PCI#0) and SpCell (PCI#1) are switched) by L1 / L2 signaling.

[0120] In this case, the PTAG (original TAG ID=0) including the SpCell (PCI#0) is changed to a STAG, and the STAG (original TAG ID=1) including the SpCell (PCI#1) is changed to a PTAG.

[0121] When Option 1-2-1A (or Alt. 1A) is applied, the ID of the TAG (original TAG ID = 0) containing the SpCell (PCI #0) that is changed to STAG remains 0. Also, the ID of the TAG (original TAG ID = 1) containing the SpCell (PCI #1) that is changed to PTAG remains 1.

[0122] When Option 1-2-1B (or Alt. 1B-1) is applied, the ID of the TAG (original TAG ID = 0) including the SpCell (PCI #0) that is changed to a STAG is changed to a value (5 in this case) that is set in advance in an RRC parameter, etc. Also, the ID of the TAG (original TAG ID = 1) including the SpCell (PCI #1) that is changed to a PTAG is changed to 0.

[0123] When option 1-2-1B (or Alt. 1B-2) is applied, the original TAG ID (here, 0) of the TAG containing the SpCell (PCI #0) to be changed to STAG is exchanged with the original TAG ID (here, 1) of the TAG containing the SpCell (PCI #1) to be changed to PTAG.

[0124] <<Option 1-2-2>> When multiple PTAGs are defined / configured (e.g., Option 1-1-2), after an SpCell is switched, the TAGs (e.g., all TAGs) that include the SpCell or candidate cells associated with the SpCell may be updated / changed to PTAGs. That is, the TAGs that include the SpCell that will become a non-serving cell may maintain the PTAG. In this case, the TAG ID may be determined based on Option 1-2-2A to Option 1-2-2B.

[0125] [[Option 1-2-2A]] The TAG ID may not be changed. In this case, the ID of the TAG that will become a new PTAG (for example, a TAG having an SpCell that will become a serving cell after switching) may have a value (ID) other than 0 (Alt. 1A). On the other hand, the ID of the TAG having an SpCell that will become a non-serving cell after switching may remain 0. In this case, the PTAG concept and TAG ID may be applied without change in L1 / L2 mobility.

[0126] [[Option 1-2-2B]] The TAG ID may be updated. For example, the ID of a TAG that will become a new PTAG (e.g., a TAG having an SpCell that will be switched to a serving cell) may be changed / updated to 0 (e.g., TAG ID = 0). In this case, the TAG ID of the original PTAG (or a non-serving PTAG) may have a value (ID) other than 0. A non-serving PTAG may refer to a TAG that has an SpCell that will become a non-serving cell. The TAG ID of the original PTAG (or a non-serving PTAG) may be determined based on at least one of Alt. 2B-1 to Alt. 2B-3 below.

[0127] Alt. 2B-1: When the original PTAG (or the original PTAG) becomes a non-serving PTAG, a new TAG ID may be configured by a higher layer parameter. When the original PTAG switches to a non-serving PTAG, the UE may apply the previously configured TAG ID to the non-serving PTAG after the switch.

[0128] Alternatively, information about the TAG ID to be applied to each TAG after switching (e.g., a TAG switched to a STAG) may be indicated to the UE using L1 / L2 signaling instructing the SpCell switching. For example, multiple TAG ID candidates may be configured by higher layer parameters, and a specific TAG ID may be indicated by L1 / L2 signaling (e.g., DCI).

[0129] Alt. 2B-2 The original PTAG (or the non-serving PTAG after the switch) may have the TAG ID of the original ID of the new PTAG (or the serving PTAG after the switch). That is, the new PTAG and the original PTAG (or the TAGs performing the switch) may exchange TAG IDs.

[0130] Alt. 2B-3 Instead of autonomously updating / replacing the TAG ID, the UE may expect / assume that the base station will send an RRC / MAC CE / DCI to update the TAG ID.

[0131] FIG. 11 shows an example of the definition / setting of a TAG ID after the SpCell is switched in the case where one PTAG is defined / set.

[0132] In FIG. 11 , SpCell (PCI #0), SCell #1 (PCI #3), SCell #2 (PCI #7), SCell #3 (PCI #9), and SCell #4 (PCI #10) are configured as serving cells. SpCell (PCI #1) and SpCell (PCI #2) are associated with SpCell (PCI #0), which are candidate cells. SCell #1 (PCI #4) and SCell #1 (PCI #5) are associated with SCell #1 (PCI #3), which are candidate cells. SCell #2 (PCI #8) is associated with SCell #2 (PCI #7), which is a candidate cell. SCell #4 (PCI #11) is associated with SCell #4 (PCI #10), which is a candidate cell.

[0133] 11 also shows a case where SpCell (PCI #0), SCell #1 (PCI #3), and SCell #2 (PCI #7) are included in the same TAG (TAG ID = 0), SpCell (PCI #1) and SpCell (PCI #2) are included in the same TAG (TAG ID = 1), SCell #1 (PCI #4), SCell #1 (PCI #5), and SCell #2 (PCI #8) are included in the same TAG (TAG ID = 2), SCell #3 (PCI #9) and SCell #4 (PCI #10) are included in the same TAG (TAG ID = 3), and SCell #4 (PCI #11) is included in TAG ID = 4. Also shown is a case where TAG ID = 0 and TAG ID = 1 are set as PTAGs, and other TAGs are set as STAGs.

[0134] Here, a case is shown in which candidate cell PCI#1 becomes the serving cell SpCell (or SpCell (PCI#0) and SpCell (PCI#1) are switched) by L1 / L2 signaling.

[0135] In this case, the tag (original tag ID=0) including the SpCell (PCI#0) and the tag (original tag ID=1) including the SpCell (PCI#1) become PTAGs.

[0136] When Option 1-2-2A (or Alt. 2A) is applied, the ID of the TAG (original TAG ID = 0) containing the SpCell (PCI #0) that is changed to a non-serving PTAG remains 0. Also, the ID of the TAG (original TAG ID = 1) containing the SpCell (PCI #1) that is changed to a serving PTAG remains 1.

[0137] When Option 1-2-2B (or Alt. 2B-1) is applied, the ID of the TAG (original TAG ID = 0) including the SpCell (PCI #0) that is changed to a non-serving PTAG is changed to a value (5 in this case) that is set in advance in an RRC parameter, etc. Also, the ID of the TAG (original TAG ID = 1) including the SpCell (PCI #1) that is changed to a serving PTAG is changed to 0.

[0138] When Option 1-2-2B (or Alt. 2B-2) is applied, the original TAG ID (here, 0) of the TAG containing the SpCell (PCI #0) that is being changed to a non-serving PTAG is exchanged with the original TAG ID (here, 1) of the TAG containing the SpCell (PCI #1) that is being changed to a serving PTAG.

[0139] After an SCell switch via L1 / L2 signaling, the PTAG / STAG concept may not be changed. Furthermore, the ID of the SCell's TAG (or STAG) may not be changed. For example, after an SCell is switched via L1 / L2 signaling, the ID of the TAG containing the switched SCell may remain unchanged. If the TAG is a PTAG, the PTAG may be maintained after the switch. Furthermore, if the TAG is a STAG, the STAG may be maintained after the switch.

[0140] Aspect 1-2 may be applied to a switch by L1 / L2 signaling and a cell group switch via L1 / L2 signaling.

[0141] [Aspect 1-3] When the time alignment timer set for each TAG expires, the UE performs a predetermined operation (or a predetermined UE operation is defined / set). Depending on the number of PTAGs included in the cell group, the following option 1-3-1 or option 1-3-2 may be applied.

[0142] <<Option 1-3-1>> When one PTAG is defined / configured (e.g., Option 1-1-1 above), there is only one PTAG in the cell group, as in existing systems (e.g., Rel. 17 and earlier). In this case, when the time alignment timer of the PTAG expires, the UE operation for the PTAG may be the same as that of the existing system. On the other hand, multiple (e.g., two) different STAG types may be introduced for the STAG.

[0143] For example, when the time alignment timer expires, different UE behaviors may apply for STAG type 1 and STAG type 2. STAG type 1 (e.g., serving STAG) may refer to a STAG that includes at least a serving cell (or serving SCell).

[0144] STAG type 2 (e.g., non-serving STAG) may refer to a STAG that does not include a serving cell (or includes only non-serving / candidate cells), which may be associated with a serving SpCell or a serving SCell.

[0145] In STAG type 1, when the time alignment timer of a STAG (e.g., a serving STAG) expires, some / all of the same UE behaviors as in existing systems (e.g., before Rel. 17) may be applied.

[0146] In STAG Type 2, when the time alignment timer of a STAG (e.g., a non-serving STAG) expires, the corresponding non-serving / candidate cell may be deactivated / inactivated (e.g., deactivated / in-active) because the UL synchronization becomes asynchronous, making it difficult for the UE to schedule data transmission in the candidate cell (the associated serving cell remains functional), and a PRACH needs to be triggered to the candidate cell to obtain timing advance before the data transmission.

[0147] For example, when the time alignment timer expires, the following actions (e.g., predetermined PTAG action / predetermined STAG action) may be performed.

[0148] 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.

[0149] Actions for a given STAG If a time alignment timer is associated with a STAG containing the serving cell (e.g., STAG type 1), then for all serving cells belonging to that TAG: Flush all HARQ buffers; Notify RRC to release PUCCH, if configured; Notify 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 ＴＡThe above procedure is applied to candidate cells with which the corresponding serving cell is associated (and the corresponding candidate cells may be deactivated / inactivated). If the time alignment timer is associated with a STAG (e.g. STAG type 2) that does not include a serving cell (or that includes non-serving / candidate cells), then for all non-serving / candidate cells belonging to that STAG: The candidate cells are deactivated / inactivated.

[0150] <<Option 1-3-2>> When multiple PTAGs are defined / configured (e.g., Option 1-1-2 above), multiple (e.g., two) PTAGs exist in a cell group, unlike existing systems (e.g., Rel. 17 and earlier). In this case, multiple (e.g., two) different PTAG types may be introduced for the PTAG. Also, multiple (e.g., two) different STAG types may be introduced for the STAG.

[0151] For example, when the time alignment timer expires, different UE behaviors may apply for PTAG Type 1 and PTAG Type 2. PTAG Type 1 (e.g., serving PTAG) may refer to a PTAG that includes at least a serving cell (or serving SpCell).

[0152] PTAG Type 2 (e.g., non-serving PTAG) may refer to a PTAG that does not include an SpCell (or an SpCell that becomes a serving cell), i.e., a PTAG Type 2 TAG may include only non-serving / candidate cells associated with the serving SpCell.

[0153] In PTAG type 1, when the time alignment timer of a PTAG (e.g., a serving PTAG) expires, some / all of the same UE actions as those applied to PTAGs in existing systems (e.g., before Rel. 17) may be applied.

[0154] In PTAG Type 2, when the time alignment timer of a PTAG (e.g., a non-serving PTAG) expires, the corresponding non-serving / candidate cell may be deactivated / inactivated (e.g., deactivated / in-active) because the UL synchronization becomes asynchronous, making it difficult for the UE to schedule data transmission for the candidate cell, and a PRACH needs to be triggered to the candidate cell to obtain timing advance before the data transmission.

[0155] For STAG (e.g., STAG Type 1 / STAG Type 2), the UE behavior shown in Option 1-3-1 may apply.

[0156] When the time alignment timer expires, the following actions (e.g., predetermined PTAG action / predetermined STAG action) may be performed.

[0157] [Operations for a given PTAG] If a time alignment timer is associated with a PTAG containing the SpCell (PTAG type 1), then: Flush all HARQ buffers of 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 If the time alignment timer is associated with a PTAG that does not contain an SpCell (PTAG type 2): The corresponding candidate cell (e.g., the candidate cell included in the PTAG) is deactivated / inactivated.

[0158] Actions for a given STAG If a time alignment timer is associated with a STAG containing the serving cell (e.g., STAG type 1), then for all serving cells belonging to that TAG: Flush all HARQ buffers; Notify RRC to release PUCCH, if configured; Notify 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 The above procedure is applied to candidate cells with which the corresponding serving cell is associated (and the corresponding candidate cells may be deactivated / inactivated). If the time alignment timer is associated with a STAG (e.g. STAG type 2) that does not include a serving cell (or that includes non-serving / candidate cells), then for all non-serving / candidate cells belonging to that STAG: The candidate cells are deactivated / inactivated.

[0159] [Aspect 1-4] In aspect 1-4, an example of UE operation for a deactivated / inactivated candidate cell will be described.

[0160] The UE may perform the following UE actions when an SCell (e.g., serving SCell) is deactivated: - Do not transmit SRS in the SCell - Do not report CSI for the SCell - Do not transmit UL-SCH in the SCell - Do not transmit RACH in the SCell - Do not monitor PDCCH in the SCell - Do not monitor PDCCH for the SCell - Do not transmit PUCCH in the SCell.

[0161] On the other hand, if a candidate cell (e.g., a non-serving SCell) is deactivated, the UE may perform at least one of the following two options 1-4-1 to 1-4-2 for the deactivated candidate cell.

[0162] Note that Option 1-4-1 and Option 1-4-2 may imply different UE behavior compared to a deactivated SCell (e.g., serving SCell), and other UE behaviors (e.g., not transmitting SRS / UL-SCH / PUCCH, not monitoring PDCCH) may be applied to the candidate cell.

[0163] Option 1-4-1: The UE may perform CSI reporting for the deactivated candidate cell. The CSI reporting may be L1 measurement / reporting of reference signals (RS) from the deactivated candidate cell.

[0164] Option 1-4-2: The UE may transmit the PRACH on the deactivated candidate cell, thereby obtaining the effective timing advance of the candidate cell.

[0165] The activation / deactivation (eg, activation / deactivation) of the candidate cell may be controlled based on the RRC / MAC CE / DCI / timer.

[0166] For example, activation / deactivation may be instructed for a candidate cell that is pre-configured by an RRC parameter using a new MAC CE. In the configuration by the RRC parameter, the starting state (e.g., activation / deactivation) of each candidate cell may be configured.

[0167] Alternatively, a deactivation timer (e.g., deactivationTimer) may be configured for each candidate cell / candidate cell group. The deactivation timer may be configured similarly to a cell deactivation timer (e.g., CellDeactivationTimer) configured for each SCell in an existing system (e.g., Rel. 17 or earlier). When the deactivation timer expires, the corresponding candidate cell may be deactivated.

[0168] [Aspect 1-5] In aspect 1-5, a restriction on cells sharing the same TAG ID (or a restriction on setting a TAG ID) will be described.

[0169] In TAG setting, at least one of the following restrictions may be applied: Option 1-5-1 to Option 1-5-2.

[0170] <<Option 1-5-1>> Candidate cells of the same CC (or candidate cells associated with the same serving cell) may be configured not to have the same TAG ID. In other words, the same TAG ID may be set only for candidate cells associated with different CCs.

[0171] <<Option 1-5-2>> TAG IDs (0, 1,...) may be assigned first to a specific cell (e.g., a serving cell) and then to other cells (e.g., candidate cells). Aspect 1-5 may be applied to Aspect 1-1 to Aspect 1-4.

[0172] 12A and 12B, SpCell (PCI #0), SCell #1 (PCI #3), SCell #2 (PCI #7), SCell #3 (PCI #9), and SCell #4 (PCI #10) are configured as serving cells. SpCell (PCI #1) and SpCell (PCI #2) are associated with SpCell (PCI #0), which are candidate cells. SCell #1 (PCI #4) and SCell #1 (PCI #5) are associated with SCell #1 (PCI #3), which are candidate cells. SCell #2 (PCI #8) is associated with SCell #2 (PCI #7), which is a candidate cell. SCell #4 (PCI #11) is associated with SCell #4 (PCI #10), which is a candidate cell.

[0173] Figure 12A shows a case where SpCell (PCI #0), SCell #1 (PCI #3), and SCell #2 (PCI #7) are included in the same TAG (TAG ID = 0), SpCell (PCI #1) and SpCell (PCI #2) are included in the same TAG (TAG ID = 1), SCell #1 (PCI #4), SCell #1 (PCI #5), and SCell #2 (PCI #8) are included in the same TAG (TAG ID = 2), SCell #3 (PCI #9) and SCell #4 (PCI #10) are included in the same TAG (TAG ID = 3), and SCell #4 (PCI #11) is included in TAG ID -4.

[0174] When the restriction of Option 1-5-1 is applied, the same TAG ID cannot be configured for multiple candidate cells associated with the same serving cell. In this case, candidate cell SpCell (PCI#1) and candidate cell SpCell (PCI#2) cannot be included in the same TAG (here, TAG ID = 1). Similarly, candidate cell SCell (PCI#4) and candidate cell SCell (PCI#5) cannot be included in the same TAG (here, TAG ID = 2).

[0175] Figure 12B shows an example of TAG assignment when the restrictions of Option 1-5-1 and Option 1-5-2 are applied, where multiple candidate cells associated with the same serving cell belong to different TAGs, and TAG IDs are assigned to the serving cell first, followed by the candidate cells.

[0176] Second Embodiment In a second embodiment, an example of timing advance control (for example, definition / setting of TAG ID / PTAG / STAG) in the case where candidate cell setting example 2 is applied will be described.

[0177] In the following description, a case where one or more candidate cells are configured for a certain cell group (for example, MCG or SCG) / MAC entity (configuration example 2) will be described. Figure 13 shows a case where SpCell #0, SCell #1, and SCell #2 are configured as serving cells, and candidate cells #3-#8 are configured for the cell group. Note that the number of serving cells, the number of candidate cells, etc. configured are merely examples and are not limited to these.

[0178] A predetermined upper layer parameter (e.g., CellGroupConfig) may configure the UE with the ID of the cell group (here, 0), the SpCell configuration of the cell group (e.g., spCellConfig), a list of SCells (e.g., sCellToAddModList), and a list of candidate cells (or new cells / added cells) (e.g., newCellToAddModList).

[0179] [Aspect 2-1] For L1 / L2 inter-cell mobility, when each candidate cell is associated with a TAG ID, the definition / configuration of PTAG and STAG may be controlled using option 2-1-1 below.

[0180] <<Option 2-1-1>> Only one PTAG may be defined / configured for each cell group. For example, in a cell group, a TAG including an SpCell among the current serving cells may be defined / configured as a PTAG. The ID of the PTAG may be 0. TAGs other than the one PTAG may be defined / configured as STAGs.

[0181] Figure 14 shows an example in which one PTAG is configured for a cell group (e.g., MCG or SCG). In Figure 14, SpCell #0, SCell #1, and SCell #2 are configured as serving cells. In addition, candidate cells #2-#10 are configured for the cell group (or MAC entity / MCG / SCG). The candidate cells may have the same frequency (or frequency band) as the current serving cell, or may have a different frequency (or frequency band).

[0182] 14 shows a case where SpCell #0 and SCell #1 are included in the same TAG (here, TAG ID = 0), and SCell #2 is included in another TAG (here, TAG ID = 1). Also, a case is shown where candidate cells #3-#6 are included in the same TAG (here, TAG ID = 2), and candidate cells #7-#10 are included in the same TAG (here, TAG ID = 3). The TAG to which each serving cell belongs, the TAG to which each candidate cell belongs, the number of TAGs to be set, and the number of serving cells / number of candidate cells included in each TAG are merely examples, and are not limited thereto.

[0183] In FIG. 14, the tag (here, tag ID=0) including SpCell#0 is the PTAG, and the other tags may be defined / set as STAGs.

[0184] Note that multiple PTAGs may be defined / configured for each cell group. In this case, the description shown in Option 1-1-2 above may be applied to candidate cells that become PTAGs.

[0185] [Aspect 2-2] When the SpCell is switched by L1 / L2 signaling, the following option 2-2-1 may be applied after the switch (or after the SpCell is switched).

[0186] <<Option 2-2-1>> When one PTAG is defined / configured (for example, option 2-1-1), the original TAG (or former TAG) containing the new (or switched) SpCell may be changed / updated to the PTAG, and the original TAG containing the old (or pre-switched) SpCell may be changed / updated to the STAG. In this case, the TAG ID may be determined based on at least one of the following options 2-2-1A to 2-2-1B.

[0187] [[Option 2-2-1A]] The TAG ID may not be changed. In this case, the TAG ID of the new PTAG may have a value (ID) other than 0 (Alt. 2A).

[0188] [Option 2-2-1B] The TAG ID may be updated. For example, the TAG ID of the new PTAG may be changed / updated to 0 (e.g., TAG ID = 0). In this case, the original PTAG (new STAG) may be changed / updated to a value (ID) other than 0. The TAG ID of the original PTAG (or new STAG) may be determined based on at least one of Alt. 2B-1 to Alt. 2B-3 below.

[0189] Alt. 2B-1: When the original PTAG (or the original PTAG) becomes a STAG, a new TAG ID may be configured by a higher layer parameter. When the original PTAG is switched to a STAG, the UE may apply the previously configured TAG ID to the switched STAG.

[0190] Alternatively, information about the TAG ID to be applied to each TAG after switching (e.g., a TAG switched to a STAG) may be indicated to the UE using L1 / L2 signaling instructing the SpCell switching. For example, multiple TAG ID candidates may be configured by higher layer parameters, and a specific TAG ID may be indicated by L1 / L2 signaling (e.g., DCI).

[0191] Alt. 2B-2 The original PTAG (or original PTAG) may have the original TAG ID of the new PTAG. That is, the new PTAG and the new STAG (or the TAGs performing the switch) may exchange TAG IDs.

[0192] Alt. 2B-3 Instead of autonomously updating / replacing the TAG ID, the UE may expect / assume that the base station will send an RRC / MAC CE / DCI to update the TAG ID.

[0193] On the other hand, if the SCell is switched via L1 / L2 signaling, the PTAG / STAG concept may not need to be changed, and in this case, changing the TAG ID, etc. may not be necessary.

[0194] FIG. 15 shows an example of the definition / setting of a TAG ID after the SpCell is switched in the case where one PTAG is defined / set.

[0195] FIG. 15 shows a case where SpCell #0, SCell #1, and SCell #2 are configured as serving cells, and candidate cells #2-#10 are configured for a cell group (or MAC entity / MCG / SCG).

[0196] 15 also shows a case where, before the SpCell switching, SpCell #0 and SCell #1 are included in the same TAG (here, TAG ID = 0), and SCell #2 is included in another TAG (here, TAG ID = 1). Also, candidate cells #3-#6 are included in the same TAG (here, TAG ID = 2), and candidate cells #7-#10 are included in the same TAG (here, TAG ID = 3).

[0197] Here, a case is shown in which candidate cell #4 becomes an SpCell (or serving SpCell) or SpCell #0 and candidate cell #4 are switched by L1 / L2 signaling.

[0198] In this case, the PTAG (original TAG ID=0) including SpCell#0 is changed to a STAG, and the STAG (original TAG ID=2) including candidate cell#3 is changed / updated to a PTAG.

[0199] When Option 2-2-1A (or Alt. 2A) is applied, the ID of the TAG (original TAG ID = 0) containing SpCell #0, which is changed to STAG, remains 0. Also, the ID of the TAG (original TAG ID = 2) containing candidate cell #3, which is changed to PTAG, remains 2.

[0200] When option 2-2-1B (or Alt. 2B-1) is applied, the ID of the TAG (original TAG ID = 0) including SpCell #0 to be changed to STAG is changed to a value (here, 5) previously set in an RRC parameter, etc. Also, the ID of the TAG (original TAG ID = 1) including candidate cell #3 to be changed to PTAG is changed to 0.

[0201] When option 2-2-1B (or Alt. 2B-2) is applied, the original TAG ID (here, 0) of the TAG containing SpCell #0 to be changed to STAG is exchanged with the original TAG ID (here, 2) of the TAG containing candidate cell #3 to be changed to PTAG.

[0202] [Aspect 2-3] When the time alignment timer set for each TAG expires, the UE performs a predetermined operation (or a predetermined UE operation is defined / set).

[0203] When one PTAG is defined / configured for a cell group (e.g., Option 2-1-1), there is only one PTAG in the cell group, as in existing systems (e.g., Rel. 17 and earlier). In this case, when the time alignment timer of the PTAG expires, the UE behavior for the PTAG may be the same as that of the existing system. On the other hand, multiple (e.g., two) different STAG types may be introduced for the STAG.

[0204] For example, when the time alignment timer expires, different UE behaviors may apply for STAG type 1 and STAG type 2. STAG type 1 (e.g., serving STAG) may refer to a STAG that includes at least a serving cell (or serving SCell).

[0205] STAG type 2 (e.g., non-serving STAG) may refer to a STAG that does not include a serving cell (or includes only non-serving / candidate cells).

[0206] In STAG type 1, when the time alignment timer of a STAG (e.g., a serving STAG) expires, some / all of the same UE behaviors as in existing systems (e.g., before Rel. 17) may be applied.

[0207] In STAG Type 2, when the time alignment timer of a STAG (e.g., a non-serving STAG) expires, the corresponding non-serving / candidate cell may be deactivated / inactivated (e.g., deactivated / in-active) because the UL synchronization becomes asynchronous, making it difficult for the UE to schedule data transmission in the candidate cell (the associated serving cell remains functional), and a PRACH needs to be triggered to the candidate cell to obtain timing advance before the data transmission.

[0208] For example, when the time alignment timer expires, the following actions (e.g., predetermined PTAG action / predetermined STAG action) may be performed.

[0209] 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.

[0210] Actions for a given STAG If a time alignment timer is associated with a STAG containing the serving cell (e.g., STAG type 1), then for all serving cells belonging to that TAG: Flush all HARQ buffers; Notify RRC to release PUCCH, if configured; Notify 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 ＴＡCandidate cells included in the STAG may be deactivated / inactivated. If the time alignment timer is associated with a STAG that does not contain a serving cell (e.g., STAG type 2), for all non-serving / candidate cells belonging to that STAG: Candidate cells are deactivated / inactivated.

[0211] The UE operation for the deactivated / inactivated candidate cell may be partially different from the UE operation for the serving cell, for example, aspects 1-4 of the first embodiment may be applied as the UE operation for the deactivated / inactivated candidate cell.

[0212] [Example 2-4] Example 2-4 describes a restriction on cells sharing the same TAG ID (or a restriction on the setting of a TAG ID).

[0213] In TAG setting, at least one of the following restrictions may be applied: Option 2-4-1 to Option 2-4-2.

[0214] <<Option 2-4-1>> A configuration may be adopted in which the same TAG ID is not set for multiple candidate cells having the same frequency band (e.g., the same center frequency). In other words, the same TAG ID may be set only for candidate cells having different frequencies (e.g., center frequencies).

[0215] <<Option 2-4-2>> TAG IDs (0, 1, . . .) may be assigned first to a specific cell (e.g., a serving cell) and then to other cells (e.g., candidate cells). Aspect 2-4 may be applied to Aspects 2-1 to 2-3.

[0216] FIG. 16 shows a case where SpCell #0, SCell #1, and SCell #2 are configured as serving cells, and candidate cells #2-#10 are configured for a cell group (or MAC entity / MCG / SCG).

[0217] 16 also shows a case where SpCell#0 and SCell#1 are included in the same TAG (here, TAG ID = 0), and SCell#2 is included in another TAG (here, TAG ID = 1). Also, candidate cells #3-#5 are included in the same TAG (here, TAG ID = 2), and candidate cells #6-#8 are included in the same TAG (here, TAG ID = 3).

[0218] When the restriction of Option 2-4-1 is applied, the same TAG ID cannot be set for candidate cells with the same frequency (e.g., center frequency). In this case, candidate cell #6 and candidate cell #8 cannot be included in the same TAG (here, TAG ID = 3).

[0219] In this case, candidate cell #6 and candidate cell #8 may be included in different TAGs (here, candidate cell #6 may be included in TAG ID=3, and candidate cell #8 may be included in another TAG ID (for example, TAG ID=4).

[0220] If the restrictions of Option 2-4-2 apply, the TAG ID is assigned to the candidate cell after being assigned to the serving cell.

[0221] Third Embodiment In a third embodiment, an example of timing advance control (for example, definition / setting of TAG ID / PTAG / STAG) in the case where candidate cell setting example 3 is applied will be described.

[0222] In the following description, a case where one or more candidate cell groups (or cell group candidates) are configured for a certain cell group (e.g., MCG or SCG) / MAC entity (Configuration Example 3) will be described. Each candidate cell group may include one or more candidate cells (see FIG. 17).

[0223] 17 shows a case where SpCell #0, SCell #1, and SCell #2 are configured as serving cells, or a case where a serving cell group including SpCell #0, SCell #1, and SCell #2 is configured. Also, a case where candidate cell groups #1 and #2 having candidate cells #0-#2, and candidate cell group #3 having candidate cell #0 are configured separately from the serving cell group is shown. Note that the number of configured serving cells, the number of candidate cell groups, the number of candidate cells included in each candidate cell group, and the like are merely examples and are not limited thereto.

[0224] The UE may receive configuration information including at least one of information about configured candidate cell groups and information about candidate cells included in each candidate cell group. The configuration information may be received by RRC / MAC CE / DCI. The candidate cell groups may be configured separately for the MCG and the SCG, or may be configured commonly.

[0225] In the example shown in Figure 17, candidate cells #0-#2 included in candidate cell group #1 each have the same frequency as one of the serving cells. Some candidate cells (here, #0 and #1) included in candidate cell group #2 may have the same frequency as one of the serving cells, and another candidate cell (here, #2) may have a frequency different from that of the serving cell. The frequency may be a center frequency.

[0226] A predetermined upper layer parameter (e.g., CellGroupConfig) may configure the UE with the ID of the cell group (here, 1), a setting indicating the purpose / use of the cell group, an SpCell setting (e.g., spCellConfig), and a list of SCells (e.g., sCellToAddModList).

[0227] [Aspect 3-1] For L1 / L2 inter-cell mobility, where each candidate cell is associated with a TAG ID, one PTAG may be defined / configured for each candidate cell group.

[0228] In a candidate cell group, a candidate cell for which a PTAG is configured (or a candidate cell included in the PTAG) may be a predetermined candidate cell, which may be, for example, at least one of a candidate cell associated with an SpCell, a candidate cell having the same frequency (e.g., center frequency) as the SpCell, and a candidate cell having a predetermined ID (e.g., #0).

[0229] Alternatively, the candidate cells included in the PTAG in each candidate cell group may be configured / indicated to the UE by RRC / MAC CE / DCI.

[0230] When a PTAG is provided for each candidate cell group, the definition / setting of the TAG ID may be controlled using at least one of the following options 3-1-1 to 3-1-3.

[0231] <<Option 3-1-1>> For each candidate cell group, the TAG ID may start from 0. That is, the ID of the PTAG for each candidate cell group may be 0. In this case, PTAGs / STAGs with the same TAG ID may be supported at least between the serving cell group and the candidate cell group and between different candidate cell groups.

[0232] <<Option 3-1-2>> The TAG IDs of a serving cell group (e.g., MCG or SCG) and a candidate cell group for a cell group may have different values. For example, for a cell group switch, a global TAG ID may be configured for the serving cell group and the corresponding candidate cell group for each MAC entity / MCG / SCG.

[0233] That is, the TAG IDs for the MCG and the candidate cell groups of the MCG may start from 0. Also, the TAG IDs for the SCG and the candidate cell groups of the SCG may start from 0. In this case, the TAG IDs (0, 1, ...) may be assigned first to the serving cell group / serving cell, and then to each candidate cell group / candidate cell. Alternatively, the TAG IDs may be assigned first to the PTAG of the serving cell and the PTAG of each candidate cell group, and then to the STAG of the serving cell and the STAG of each candidate cell group.

[0234] <<Option 3-1-3>> The TAG ID may be set regardless of the candidate cell group. For example, the same TAG may be set for candidate cells in different candidate cell groups.

[0235] Figure 18 shows an example of a case where a PTAG is configured for each of one or more candidate cell groups configured for a certain cell group (e.g., MCG or SCG). In Figure 18, SpCell #0, SCell #1, and SCell #2 are configured as serving cells. Furthermore, candidate cell groups #1-#3 are configured for the cell group (or MAC entity / MCG / SCG). This shows a case where candidate cell group #1 includes candidate cells #0-#2, candidate cell group #2 includes candidate cells #0-#1, and candidate cell group #3 includes candidate cell #0.

[0236] 18 also shows a case where a TAG (here, TAG ID = 0) including SpCell #0 becomes a PTAG, and a TAG including candidate cell #0 included in each candidate cell group becomes a PTAG (or a PTAG is set based on candidate cell #0 included in each candidate cell group). Also, it shows a case where serving cells SCell #1 and SCell #2 are included in the same TAG (here, TAG ID = 1), and candidate cells #1 and #2 of candidate cell group #1 are included in the same TAG.

[0237] When option 3-1-1 is applied, the TAG ID of the PTAG included in each candidate cell group may be defined / set to 0. Also, the TAG ID of the TAG (or STAG) including candidate cells #1 and #2 of candidate cell group #1 may be set to 1.

[0238] When Option 3-1-2 is applied, the TAG IDs of the PTAGs included in each candidate cell group may be defined / configured separately (e.g., a value other than 0). For example, different TAG IDs may be configured for the PTAG of the serving cell, the STAG of the serving cell, the PTAG of the candidate cell group, and the STAG of the candidate cell group. This allows for flexible configuration of the timing advances of the serving cell and the candidate cell.

[0239] [Aspect 3-2] When cell groups are switched by L1 / L2 signaling, one of the candidate cell groups becomes the serving cell group. Meanwhile, the previous serving cell group may be changed / updated to a candidate cell group. When cell groups are switched, at least one of the following options 3-2-1 to 3-2-2 may be applied as the TAG ID setting.

[0240] <<Option 3-2-1>> When the TAG ID starts from 0 in each candidate cell group (for example, when Option 3-1-1 is applied), the TAG ID is set separately for each candidate cell group. In this case, it may not be necessary to change / update the TAG ID before and after switching the cell group.

[0241] In this case, the TAG may be jointly determined by the TAG ID and the candidate cell group ID for each MAC entity. In the MAC CE (e.g., MAC CE in the legacy system) with an indication of the TAG ID, a new field may be added to indicate the candidate cell group ID.

[0242] <<Option 3-2-2>> When different TAG IDs are assigned to the PTAG of the serving cell and the PTAG of the candidate cell group (for example, when Option 3-1-2 is applied), the TAG ID is configured for each MAC entity. In this case, the TAG ID may be determined based on at least one of the following Option 3-2-2A to Option 3-2-2B.

[0243] [[Option 3-2-2A]] When a cell group is switched, the TAG ID may not be changed / updated. In this case, the TAG ID of the new PTAG may have a value (ID) other than 0 (Alt. 3A).

[0244] [Option 3-2-2B] When a cell group is switched, the TAG ID may be changed / updated. For example, the TAG of the new cell group (new serving cell group) may start from 0. In this case, the ID of the PTAG of the new serving cell group is changed / updated to 0, and the ID of the STAG of the cell group (original serving cell group) changed to the candidate cell may start from 1.

[0245] The PTAG (new STAG) of the original serving cell group may be changed / updated to a value (ID) other than 0. In this case, the TAG ID of the PTAG of the original cell group may be determined based on at least one of Alt. 3B-1 to Alt. 3B-2 below.

[0246] Alt. 3B-1 One or more TAG IDs may be configured for the PTAG of the original cell group (or the original PTAG) by higher layer parameters. When the UE is changed / updated from the serving cell group to a candidate cell group due to cell group switching, the UE may apply the pre-configured TAG IDs to the new candidate cell group.

[0247] Alternatively, information about the TAG ID to be applied to each TAG after switching (e.g., a TAG switched to a STAG) may be indicated to the UE using L1 / L2 signaling instructing the SpCell switching. For example, multiple TAG ID candidates may be configured by higher layer parameters, and a specific TAG ID may be indicated by L1 / L2 signaling (e.g., DCI).

[0248] Alt. 3B-2: Instead of autonomously updating / replacing the TAG ID, the UE may expect / assume that the base station will send an RRC / MAC CE / DCI to update the TAG ID.

[0249] [Aspect 3-3] When the time alignment timer set for each TAG expires, the UE performs a predetermined operation (or a predetermined UE operation is defined / set).

[0250] For the current serving cell group, the PTAG and STAG may have the same meaning as the PTAG and STAG in the legacy system (e.g., Rel. 17 or earlier). In this case, when the time alignment timer expires, the UE operation for the PTAG / STAG may be the same as that in the legacy system.

[0251] On the other hand, for the candidate cell group, the PTAG and STAG are different from the PTAG and STAG of the existing system (e.g., Rel. 17 and earlier), so new PTAG types (or UE behavior for PTAG) and new STAG types (or UE behavior for STAG) may be supported for the candidate cell group.

[0252] For example, PTAG type 2 (e.g., a non-serving PTAG or a PTAG of a candidate cell group) may refer to a PTAG that does not include a serving cell (or includes only non-serving cells / candidate cells) or a PTAG of a candidate cell group.

[0253] For example, STAG type 2 (e.g., a non-serving STAG or a STAG of a candidate cell group) may refer to a STAG that does not include a serving cell (or includes only non-serving cells / candidate cells) or a STAG of a candidate cell group.

[0254] When the time alignment timer corresponding to the PTAG / STAG of a candidate cell group expires, the candidate cells included in the candidate cell group may be deactivated / inactivated (e.g., deactivated / in-active).

[0255] For example, when the time alignment timer expires, the following actions (e.g., predetermined PTAG action / predetermined STAG action) may be performed.

[0256] Actions for a given PTAG If a time alignment timer is associated with a PTAG of a serving cell group: Flush all HARQ buffers of 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 If the time alignment timer is associated with the PTAG of the candidate cell group (PTAG type 2): All candidate cells included in the candidate cell group are deactivated / inactivated.

[0257] Actions for a given STAG If a time alignment timer is associated with a STAG containing the serving cell (e.g., STAG type 1), then for all serving cells belonging to that TAG: Flush all HARQ buffers; Notify RRC to release PUCCH, if configured; Notify 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 If a time alignment timer is associated with a STAG of a candidate cell group (e.g., STAG type 2), for all non-serving / candidate cells belonging to that TAG: The candidate cell is deactivated / inactivated.

[0258] The PTAG Type 2 / STAG Type 2 may be one and the same new type (e.g., a candidate TAG type for a candidate cell group). The TAG may contain only candidate cells. When the time alignment timer of a candidate TAG expires, the candidate cells included in the candidate TAG may be deactivated / inactivated.

[0259] The UE operation for the deactivated / inactivated candidate cell may be partially different from the UE operation for the serving cell, for example, aspects 1-4 of the first embodiment may be applied as the UE operation for the deactivated / inactivated candidate cell.

[0260] [Example 3-4] Example 3-4 describes a restriction on cells sharing the same TAG ID (or a restriction on the setting of a TAG ID).

[0261] In TAG setting, at least one of the following restrictions may be applied: Option 3-4-1 to Option 3-4-2.

[0262] <<Option 3-4-1>> The same TAG ID may be set only to candidate cells within the same candidate cell group. In other words, the same TAG ID may be set only to candidate cells included in the same candidate cell group. On the other hand, the same TAG ID may not be set to candidate cells included in different candidate cell groups.

[0263] <<Option 3-4-2>> The same TAG ID may be set for candidate cells in different candidate cell groups.

[0264] 19 shows an example of a case where a serving cell group including serving cells SpCell #0, SCell #1, and SCell #2 and candidate cell groups #1-#3 are configured. Candidate cell group #1 includes candidate cells #0-#2, candidate cell group #2 includes candidate cells #0-#1, and candidate cell group #3 includes candidate cell #0.

[0265] 19 also shows a case where a TAG (here, TAG ID = 0) including SpCell #0 is a PTAG, and TAGs including candidate cell #0 included in each candidate cell group are PTAGs. Specifically, a TAG (here, TAG ID = 2) including candidate cell #0 of candidate cell group #1 is a PTAG, a TAG (here, TAG ID = 4) including candidate cell #0 of candidate cell group #2 is a PTAG, and a TAG (here, TAG ID = 6) including candidate cell #0 of candidate cell group #3 is a PTAG.

[0266] Also shown is a case where serving cells SCell#1 and SCell#2 are included in the same TAG (here, TAG ID = 1), candidate cells #1 and #2 of candidate cell group #1 are included in the same TAG (here, TAG ID = 3), and candidate cell #5 of candidate cell group #2 is included in a TAG (here, TAG ID = 5).

[0267] 19 shows an example of a case where the restriction of Option 3-4-1 is applied, in which candidate cells (candidate cells #1 and #2) in the same candidate cell group (candidate cell group #1) have the same TAG ID (=3).

[0268] <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.

[0269] The specific UE capability may indicate at least one of the following: - Supporting one or more PTAGs; - Supporting PTAG switching / changing (UE autonomously or via base station signaling); - Supporting TAG ID switching / changing (UE autonomously or via base station signaling); - Supporting two different STAG types (e.g., serving STAG, non-serving STAG); - Supporting two different PTAG types (e.g., serving PTAG, non-serving PTAG); - Supporting activation / deactivation of candidate cells in L1 / L2 inter-cell mobility (e.g., via RRC / MAC CE / DCI); - Supporting a deactivation timer per candidate cell / candidate cell group; - Supporting TAG configuration restrictions.

[0270] 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).

[0271] 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)).

[0272] 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.

[0273] 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.

[0274] (Supplementary Notes) The following inventions are supplemented with respect to one embodiment of the present disclosure. [Supplementary Note 1-1] A terminal comprising: a receiving unit that receives configuration information related to a plurality of serving cells and candidate cells associated with the plurality of serving cells, and a control unit that controls UL transmission based on timing advance group (TAG) IDs when configuration of the TAG IDs is supported for the plurality of serving cells and the candidate cells, wherein one primary TAG or a plurality of primary TAGs are configured for the plurality of serving cells and the candidate cells. [Supplementary Note 1-2] The terminal according to Supplementary Note 1-1, wherein, when the candidate cell is switched to a special cell, the control unit controls to change a TAG ID corresponding to the candidate cell switched to the special cell. [Supplementary Note 1-3] The terminal according to Supplementary Note 1-1 or Supplementary Note 1-2, wherein, when a time alignment timer corresponding to a TAG that does not include the serving cell or a TAG that includes the candidate cell expires, the candidate cell is deactivated. [Supplementary Note 1-4] The terminal according to any one of Supplementary Note 1-1 to Supplementary Note 1-3, wherein, when a plurality of candidate cells are associated with the same serving cell, different TAG IDs are set for the plurality of candidate cells.

[0275] [Supplementary Note 2-1] A terminal comprising: a receiving unit that receives configuration information related to a plurality of serving cells belonging to a cell group and a candidate cell associated with the cell group; and a control unit that controls UL transmission based on a timing advance group (TAG) ID when configuration of the TAG ID is supported for the plurality of serving cells and the candidate cell, wherein one primary TAG is configured for the cell group. [Supplementary Note 2-2] The terminal according to Supplementary Note 2-1, wherein, when the candidate cell is switched to a special cell, the control unit controls to change a TAG ID corresponding to the candidate cell switched to the special cell. [Supplementary Note 2-3] The terminal according to Supplementary Note 2-1 or Supplementary Note 2-2, wherein, when a time alignment timer corresponding to a secondary TAG that does not include the serving cell or a secondary TAG that includes the candidate cell expires, a candidate cell included in the secondary cell is deactivated. [Supplementary Note 2-4] The terminal according to any one of Supplementary Note 2-1 to Supplementary Note 2-3, wherein when a plurality of candidate cells having the same frequency as a frequency of a serving cell are set, different TAG IDs are set for the plurality of candidate cells.

[0276] [Supplementary Note 3-1] A terminal comprising: a receiving unit that receives configuration information regarding a plurality of serving cells belonging to a cell group, a candidate cell group, and a candidate cell included in the candidate cell group; and a control unit that controls UL transmission based on timing advance group (TAG) IDs when configuration of the timing advance group IDs is supported for the plurality of serving cells and the candidate cells, wherein a primary TAG is configured for each of the candidate cell groups. [Supplementary Note 3-2] The terminal according to Supplementary Note 3-1, in which IDs of primary TAGs included in different candidate cell groups are set to the same value. [Supplementary Note 3-3] The terminal according to Supplementary Note 3-1 or Supplementary Note 3-2, in which the control unit controls not to change TAG IDs when the candidate cell group is switched to a serving cell group. [Supplementary Note 3-4] The terminal according to any of Supplements 3-1 to 3-3, in which the candidate cell is deactivated when a time alignment timer corresponding to a TAG including the candidate cell expires.

[0277] (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.

[0278] 20 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).

[0279] 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.

[0280] 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.

[0281] 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))).

[0282] 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.

[0283] 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).

[0284] 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.

[0285] 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.

[0286] 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.

[0287] 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.

[0288] 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.

[0289] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0290] 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).

[0291] 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.

[0292] 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.

[0293] 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.

[0294] 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).

[0295] 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.

[0296] 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.

[0297] 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.

[0298] 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.

[0299] 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.

[0300] 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.

[0301] 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.

[0302] 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.

[0303] 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).

[0304] 21 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.

[0305] 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.

[0306] 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.

[0307] 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.

[0308] 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.

[0309] 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.

[0310] 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.

[0311] 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.

[0312] 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.

[0313] 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.

[0314] 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.

[0315] 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.

[0316] 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.

[0317] 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.

[0318] 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.

[0319] 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.

[0320] 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.

[0321] The transceiver 120 may transmit configuration information regarding a plurality of serving cells and candidate cells associated with the plurality of serving cells. The controller 110 may indicate timing advance group (TAG) IDs corresponding to the plurality of serving cells and candidate cells. One primary TAG or multiple primary TAGs may be configured for the plurality of serving cells and candidate cells.

[0322] The transceiver 120 may transmit configuration information regarding a plurality of serving cells belonging to a cell group and candidate cells associated with the cell group. The controller 110 may indicate timing advance group (TAG) IDs for the plurality of serving cells and the candidate cells. One primary TAG may be configured for the cell group.

[0323] The transceiver 120 may transmit configuration information regarding a plurality of serving cells belonging to a cell group, a candidate cell group, and candidate cells included in the candidate cell group. The controller 110 may instruct timing advance group (TAG) IDs for the plurality of serving cells and the candidate cells. A primary TAG may be set for each cell group.

[0324] (User terminal) Fig. 22 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.

[0325] 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.

[0326] 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.

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 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.

[0332] 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.

[0333] 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.

[0334] 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.

[0335] 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.

[0336] 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.

[0337] 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.

[0338] 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.

[0339] 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.

[0340] 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.

[0341] The transceiver 220 may receive configuration information regarding multiple serving cells and candidate cells associated with the multiple serving cells. The controller 210 may control UL transmission based on timing advance group (TAG) IDs if the configuration of TAG IDs is supported for the multiple serving cells and candidate cells. One primary TAG or multiple primary TAGs may be configured for the multiple serving cells and candidate cells.

[0342] When a candidate cell is switched to a special cell, the control unit 210 may control to change the TAG ID corresponding to the candidate cell switched to the special cell. When a time alignment timer corresponding to a TAG that does not include a serving cell or a TAG that includes a candidate cell expires, the control unit 210 may control to deactivate the candidate cell (or may control to assume that the candidate cell is deactivated). When multiple candidate cells are associated with the same serving cell, different TAG IDs may be set for the multiple candidate cells.

[0343] The transceiver 220 may receive configuration information regarding multiple serving cells belonging to a cell group and candidate cells associated with the cell group. The controller 210 may control UL transmission based on timing advance group (TAG) IDs if configuration of TAG IDs is supported for multiple serving cells and candidate cells. One primary TAG may be configured for the cell group.

[0344] When a candidate cell is switched to a special cell, the control unit 210 may control to change the TAG ID corresponding to the candidate cell switched to the special cell. When a time alignment timer corresponding to a secondary TAG that does not include a serving cell or a secondary TAG that includes a candidate cell expires, the control unit 210 may control to deactivate the candidate cell included in the secondary cell (or may control to deactivate the candidate cell). When multiple candidate cells having the same frequency as the frequency of the serving cell are configured, different TAG IDs may be configured for the multiple candidate cells.

[0345] The transceiver 220 may receive configuration information regarding a plurality of serving cells belonging to a cell group, a candidate cell group, and candidate cells included in the candidate cell group. If configuration of timing advance group (TAG) IDs is supported for a plurality of serving cells and candidate cells, the controller 210 may control UL transmission based on timing advance group IDs. A primary TAG may be configured for each candidate cell group.

[0346] The IDs of the primary TAGs included in different candidate cell groups may be set to the same value. When a candidate cell group is switched to a serving cell group, the control unit 210 may control not to change the TAG ID. When a time alignment timer corresponding to a TAG including a candidate cell expires, the control unit 210 may control the candidate cell to be deactivated (or may control the candidate cell assuming deactivation).

[0347] (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.

[0348] 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.

[0349] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 23 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.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] 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.

[0354] 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.

[0355] 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.

[0356] 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.

[0357] 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.

[0358] 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).

[0359] 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.

[0360] 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.

[0361] (Modifications) Note that terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0362] A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0363] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, Subcarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, Transmission Time Interval (TTI), number of symbols per TTI, radio frame structure, specific filtering performed by a transceiver in the frequency domain, and specific windowing performed by a transceiver in the time domain.

[0364] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may also be a time unit based on numerology.

[0365] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

[0366] A radio frame, a subframe, a slot, a minislot, and a symbol all represent time units for transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may be referred to by other names corresponding to the radio frame, the subframe, the slot, the minislot, and the symbol. Note that the time units such as a frame, a subframe, a slot, a minislot, and a symbol in the present disclosure may be interchangeable.

[0367] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc. instead of a subframe.

[0368] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. Note that the definition of TTI is not limited to this.

[0369] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0370] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0371] A TTI having a time length of 1 ms may be called a regular TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0372] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and greater than or equal to 1 ms.

[0373] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may be determined based on numerology.

[0374] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI, each of which may be composed of one or more resource blocks.

[0375] In addition, one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0376] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0377] A Bandwidth Part (BWP), which may also be referred to as a partial bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a Common Reference Point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0378] The BWP may include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0379] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0380] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0381] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

[0382] The names used for parameters and the like in this disclosure are not intended to be limiting in any way. Furthermore, the mathematical expressions and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0383] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0384] Furthermore, information, signals, etc. may be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. may be input / output via multiple network nodes.

[0385] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0386] 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.

[0387] 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).

[0388] 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).

[0389] 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).

[0390] 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.

[0391] 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.

[0392] 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).

[0393] 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.

[0394] 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.

[0395] 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.

[0396] 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.

[0397] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0398] 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.

[0399] 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.

[0400] 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.

[0401] 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.

[0402] 24 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.

[0403] 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.

[0404] 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).

[0405] 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.

[0406] 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.

[0407] 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.

[0408] 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.

[0409] 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.

[0410] 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).

[0411] 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.

[0412] 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)).

[0413] 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.

[0414] 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.

[0415] 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.

[0416] 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.

[0417] 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.

[0418] 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).

[0419] 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."

[0420] 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.

[0421] 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.

[0422] 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.

[0423] 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.

[0424] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0425] 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.

[0426] 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."

[0427] 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.

[0428] 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."

[0429] 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.

[0430] 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.

[0431] 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").

[0432] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0433] 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 receiving unit for receiving configuration information regarding a candidate cell associated with a plurality of serving cells; A terminal comprising: a control unit that controls to change a timing advance group (TAG) ID corresponding to the candidate cell when the candidate cell is switched to a special cell.

2. The terminal described in claim 1, wherein the control unit controls to change the value of a timing advance group (TAG) ID corresponding to the candidate cell to 0.

3. receiving configuration information regarding a candidate cell associated with a plurality of serving cells; When the candidate cell is switched to a special cell, a control step is performed to change a timing advance group (TAG) ID corresponding to the candidate cell.

4. a transmitter for transmitting configuration information regarding a candidate cell associated with a plurality of serving cells; A base station comprising: a control unit that determines that a timing advance group (TAG) ID corresponding to the candidate cell is changed when the candidate cell is switched to a special cell.

5. A system having a terminal and a base station, The terminal a receiving unit for receiving configuration information regarding a candidate cell associated with a plurality of serving cells; A control unit that controls to change a timing advance group (TAG) ID corresponding to the candidate cell when the candidate cell is switched to a special cell, The base station A system having a transmitting unit that transmits the setting information.