Method performed by terminal or base station in wireless communication system, and device therefor

Abstract

A method performed by a terminal and a base station, and devices therefor are disclosed. The method performed by a terminal may comprise the steps of: receiving switching-related information of a plurality of carriers from a base station; and deactivating a first carrier and activating a second carrier, on the basis of the switching-related information, wherein a transmission / reception-related timer on the first carrier may be stopped during a first time interval in which the first carrier is deactivated.

Description

A method performed by a terminal or base station in a wireless communication system and an apparatus for the same.

[0001] The present disclosure relates to a wireless communication system, and more specifically, to a method and apparatus for transmitting or receiving uplink or downlink signals between a terminal or a base station in a wireless communication system.

[0002] Wireless communication systems are being widely deployed to provide various types of communication services, such as voice and data. Generally, a wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access) systems.

[0003] The technical problem to be solved by the present disclosure is to provide a method for efficiently performing a wireless signal transmission and reception process and an apparatus for doing so.

[0004] The technical tasks to be accomplished are not limited to this, and other technical tasks not mentioned can be inferred from the description below.

[0005] A method performed by a terminal according to one embodiment includes the step of receiving switching-related information of a plurality of carriers from a base station, and the step of deactivating a first carrier and activating a second carrier based on the switching-related information, and during a first time interval in which the first carrier is deactivated, a transmission-reception related timer on the first carrier may be stopped.

[0006] A transmission and reception related timer according to one embodiment may include a BWP inactive timer or a DRX (Discontinuous Reception) retransmission timer regarding an active BWP (Bandwidth Part) on a first carrier.

[0007] According to one embodiment, after a first time interval, the operation of a transmission / reception related timer on the first carrier can be resumed based on the activation of the first carrier.

[0008] According to one embodiment, stopping the transmission / reception related timer during the first time interval may include initializing the transmission / reception related timer.

[0009] A method according to one embodiment may further include the step of receiving a downlink signal scheduled on a second carrier during a first time interval.

[0010] Switching-related information according to one embodiment may include information regarding switching patterns between a plurality of carriers.

[0011] Switching-related information according to one embodiment can be received through upper layer signaling or DCI (Downlink Control Information).

[0012] At least one of the first carrier and the second carrier according to one embodiment may include a carrier group composed of a plurality of carriers located within a specific frequency band.

[0013] According to one embodiment, a first time interval in which the first carrier is deactivated and the second carrier is activated may include a time interval in which transmission and reception operations are impossible on the first carrier and at least one of transmission and reception operations is possible on the second carrier.

[0014] According to one embodiment, based on the first carrier and the second carrier being set as PCell (Primary Cell) and SCell (Secondary Cell), respectively, the expiry value of the BWP inactive timer associated with the active BWP (bandwidth part) on the first carrier may be determined differently depending on the active state of the second carrier.

[0015] According to one embodiment, a computer-readable non-transitory recording medium may be provided that records a program for performing the method described above.

[0016] An apparatus according to one embodiment comprises at least one processor and at least one memory configured to store instructions that cause at least one processor to perform operations by being executed by at least one processor, wherein the operations of the processor include receiving switching-related information of a plurality of carriers and, based on the switching-related information, deactivating a first carrier and activating a second carrier, and during a first time interval in which the first carrier is deactivated, a transmission-reception related timer on the first carrier may be stopped.

[0017] A device according to one embodiment may include a terminal including a transceiver or a processing device configured to control the terminal.

[0018] A method performed by a base station according to one embodiment includes the step of transmitting switching-related information of a plurality of carriers to a terminal, and the step of transmitting a downlink signal based on the switching-related information, wherein the downlink signal is transmitted on a second carrier during a first time interval in which a first carrier is deactivated and a second carrier is activated based on the switching-related information, and the transmission of the downlink signal can be performed by assuming that a transmission-reception-related timer on the first carrier is stopped during the first time interval.

[0019] A base station according to one embodiment includes at least one transceiver, at least one processor, and at least one memory configured to store instructions that cause at least one processor to perform operations by being executed by at least one processor, and the operations of the processor include transmitting switching-related information of a plurality of carriers to a terminal and transmitting a downlink signal to a terminal based on the switching-related information, and the downlink signal is transmitted on a second carrier during a first time interval in which a first carrier is deactivated and a second carrier is activated based on the switching-related information, and the transmission of the downlink signal can be performed by assuming that a transmit / receive related timer on the first carrier is stopped during the first time interval.

[0020] According to the present disclosure, wireless signal transmission and reception can be performed efficiently in a wireless communication system.

[0021] According to the present disclosure, in a situation where switching operations between a plurality of carriers are performed, a signal essential for the operation of a terminal can be reliably received.

[0022] According to the present disclosure, problems such as the terminal unintentionally switching to a default bandwidth part (BWP) or failing to receive retransmitted data due to carrier switching can be prevented.

[0023] According to the present disclosure, uncertainty in operation can be resolved when a timer related to transmission and reception on a specific carrier expires during a switching gap period required for switching operation between multiple carriers, or when a timer related to transmission and reception on a specific carrier expires during an active period of another carrier.

[0024] The technical effects of the present disclosure are not limited thereto, and other technical effects may be inferred from the description below.

[0025] FIG. 1 illustrates physical channels used in a 3GPP system, which is an example of a wireless communication system, and a general signal transmission method using them.

[0026] Figure 2 illustrates the structure of a radio frame.

[0027] Figure 3 illustrates a resource grid of slots.

[0028] Figure 4 illustrates an example where a physical channel is mapped within a slot.

[0029] Figure 5 illustrates the PDCCH / PDSCH reception and ACK / NACK transmission process.

[0030] Figure 6 illustrates the PUSCH (Physical Uplink Shared Channel) transmission process.

[0031] Figure 7 shows an example of carrier merging.

[0032] FIGS. 8 and 9 are drawings for explaining the operation of a terminal and a base station according to one embodiment.

[0033] FIG. 10 illustrates the flow of a method performed by a terminal according to one embodiment.

[0034] FIG. 11 illustrates the flow of a method performed by a base station according to one embodiment.

[0035] FIGS. 12 to 15 illustrate a communication system (1) and a wireless device applicable to the present disclosure.

[0036] The following technologies can be used in various wireless access systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented using radio technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented using radio technologies such as GSM (Global System for Mobile Communications), GPRS (General Packet Radio Service), and EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented using radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (Evolved UTRA). UTRA is part of the UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is part of E-UMTS (Evolved UMTS) using E-UTRA, and LTE-A (Advanced) is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A.

[0037] For clarity of explanation, the description is based primarily on 3GPP NR, but the technical concept of the present invention is not limited thereto.

[0038] In this specification, the expression "setting" may be replaced with the expression "configure / configuration," and the two may be used interchangeably. Additionally, conditional expressions (e.g., "if," "in a case," or "when") may be replaced with expressions such as "based on that" or "in a state / status." Furthermore, the operation of a terminal / base station or SW / HW configuration based on the fulfillment of the corresponding conditions may be inferred or understood. Moreover, regarding signal transmission and reception between wireless communication devices (e.g., base station, terminal), if the process of the receiving (or transmitting) side can be inferred or understood from the process of the transmitting (or receiving) side, such description may be omitted. For example, signal determination / generation / encoding / transmission on the transmitting side may be understood as signal monitoring reception / decoding / determination on the receiving side. Furthermore, the expression that the terminal performs (or does not perform) a specific operation can also be interpreted as the base station operating under the expectation / assumption (or expectation / assumption that the terminal does not perform) the specific operation. The expression that the base station performs (or does not perform) a specific operation can also be interpreted as the terminal operating under the expectation / assumption (or expectation / assumption that the base station does not perform) the specific operation. Additionally, the classification and indexing of each section, embodiment, example, option, method, or plan in the following description are for the convenience of explanation and should not be interpreted as implying that each necessarily constitutes an independent invention or that each must necessarily be implemented individually. Furthermore, when describing each section, embodiment, example, option, method, or plan, it can be inferred / interpreted that, unless there are explicitly conflicting or opposing technologies, at least some of them may be combined and implemented together, or that at least some may be omitted.

[0039] In a wireless communication system, a terminal receives information from a base station via a downlink (DL) and transmits information to the base station via an uplink (UL). The information transmitted and received by the base station and the terminal includes data and various control information, and various physical channels exist depending on the type and purpose of the information they transmit and receive.

[0040] FIG. 1 is a diagram illustrating physical channels used in 3GPP NR systems and a general signal transmission method using them.

[0041] When a terminal is turned on again after being turned off, or when it newly enters a cell, it performs an initial cell search operation, such as synchronizing with a base station in step S101. To do this, the terminal receives a Synchronization Signal Block (SSB) from the base station. The SSB includes a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). Based on the PSS / SSS, the terminal synchronizes with the base station and obtains information such as the cell identity. Additionally, the terminal can obtain in-cell broadcast information based on the PBCH. Meanwhile, during the initial cell search phase, the terminal can receive a Downlink Reference Signal (DL RS) to check the downlink channel status.

[0042] After completing the initial cell search, the terminal can obtain more specific system information by receiving the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH) based on the Physical Downlink Control Channel information in step S102.

[0043] Subsequently, the terminal may perform a Random Access Procedure such as steps S103 through S106 to complete connection to the base station. To this end, the terminal may transmit a preamble through a Physical Random Access Channel (PRACH) (S103) and receive a response message for the preamble through a Physical Downlink Control Channel and a corresponding Physical Downlink Shared Channel (S104). In the case of contention-based random access, a Contention Resolution Procedure may be performed, such as transmitting an additional Physical Random Access Channel (S105) and receiving a Physical Downlink Control Channel and a corresponding Physical Downlink Shared Channel (S106).

[0044] A terminal that has performed the procedure described above may subsequently perform the reception of a physical downlink control channel / physical downlink shared channel (S107) and the transmission of a physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) (S108) as a general uplink / downlink signal transmission procedure. The control information transmitted by the terminal to the base station is collectively referred to as Uplink Control Information (UCI). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CSI (Channel State Information), etc. CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), etc. UCI is generally transmitted via PUCCH, but if control information and traffic data need to be transmitted simultaneously, it may be transmitted via PUSCH. In addition, UCI can be transmitted non-periodically via PUSCH in response to network requests / instructions.

[0045] Meanwhile, the random access process (RACH process) is not limited to initial network access (e.g., S103 to S106) and can be used for various purposes. For example, the random access process may be used for at least one of the following: RRC Connection Re-establishment procedure, handover, UE-triggered UL data transmission, transition from RRC_INACTIVE, SCell time alignment, system information request and Beam failure recovery, and UL resource request, but is not limited thereto. The terminal may acquire UL synchronization and / or UL transmission resources through the random access process.

[0046] Figure 2 illustrates the structure of a radio frame. In NR, uplink and downlink transmissions consist of frames. Each radio frame has a length of 10 ms and is divided into two 5 ms half-frames (HF). Each half-frame is divided into five 1 ms subframes (SF). Subframes are divided into one or more slots, and the number of slots within a subframe depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 Orthogonal Frequency Division Multiplexing (OFDM) symbols depending on the cyclic prefix (CP). When a normal CP is used, each slot contains 14 OFDM symbols. When an extended CP is used, each slot contains 12 OFDM symbols.

[0047] Table 1 illustrates how the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS when a standard CP is used.

[0048] SCS (15*2^u)Nslot symb N frame,u slot N subframe,u slot 15KHz (u=0)1410130KHz (u=1)1420260KHz (u=2)14404120KHz (u=3)14808240KHz (u=4)1416016

[0049] * N slot symb : Number of symbols in the slot * N frame,u slot : Number of slots in the frame

[0050] * N subframe,u slot : Number of slots in the subframe

[0051] Table 2 illustrates how the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS when an extended CP is used.

[0052] SCS (15*2^u)N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0053] The structure of the frame is merely an example, and the number of subframes, slots, and symbols within the frame can be varied. In an NR system, the OFDM numerology (e.g., SCS) may be configured differently among multiple cells merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (collectively referred to as TU (Time Unit) for convenience) composed of the same number of symbols may be configured differently among the merged cells. Here, the symbols may include OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or Discrete Fourier Transform-spread-OFDM, DFT-s-OFDM symbols).

[0054] FIG. 3 illustrates a resource grid of slots. A slot contains multiple symbols in the time domain. For example, in the case of a standard CP, one slot contains 14 symbols, whereas in the case of an extended CP, one slot contains 12 symbols. A carrier contains multiple subcarriers in the frequency domain. A Resource Block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) is defined as multiple consecutive Physical Blocks (PRB) in the frequency domain and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can contain up to N (e.g., 5) BWPs. Data communication is performed through the active BWPs, and only one BWP can be active for a single terminal. Each element in the resource grid is referred to as a Resource Element (RE), and can be mapped to a single complex symbol.

[0055] FIG. 4 illustrates an example where physical channels are mapped within a slot. PDCCH can be transmitted in the DL control area, and PDSCH can be transmitted in the DL data area. PUCCH can be transmitted in the UL control area, and PUSCH can be transmitted in the UL data area. GP provides a time gap during the process of the base station and the terminal switching from transmit mode to receive mode or from receive mode to transmit mode. Some symbols at the time of transition from DL to UL within a subframe can be set as GP.

[0056] Below, each physical channel is explained in more detail.

[0057] The PDCCH carries Downlink Control Information (DCI). For example, the PCCCH (i.e., DCI) carries the transmission format and resource allocation for the DL-SCH (downlink shared channel), resource allocation information for the UL-SCH (uplink shared channel), paging information for the PCH (paging channel), system information on the DL-SCH, resource allocation information for higher-layer control messages such as random connection acknowledgments transmitted over the PDSCH, transmission power control commands, and the activation / deactivation of the CS (Configured Scheduling). The DCI includes a Cyclic Redundancy Check (CRC), which is masked or scrambled with various identifiers (e.g., Radio Network Temporary Identifier, RNTI) depending on the owner or use of the PDCCH. For example, if the PDCCH is for a specific terminal, the CRC is masked with the terminal identifier (e.g., Cell-RNTI, C-RNTI). If PDCCH is for paging, the CRC is masked by P-RNTI (Paging-RNTI). If PDCCH is for system information (e.g., System Information Block, SIB), the CRC is masked by SI-RNTI (System Information RNTI). If PDCCH is for a random access response, the CRC is masked by RA-RNTI (Random Access-RNTI).

[0058] A PDCCH consists of 1, 2, 4, 8, or 16 Control Channel Elements (CCEs) depending on the Aggregation Level (AL). A CCE is a logical allocation unit used to provide a PDCCH of a specified code rate according to the radio channel conditions. A CCE consists of 6 Resource Element Groups (REGs). A REG is defined by one OFDM symbol and one (P)RB. A PDCCH is transmitted via a Control Resource Set (CORESET). A CORESET is defined as a set of REGs with a given pneumonology (e.g., SCS, CP length, etc.). Multiple CORESETs for a single terminal may overlap in the time / frequency domain. A CORESET can be configured via system information (e.g., Master Information Block, MIB) or terminal-specific (UE-specific) upper-layer signaling (e.g., Radio Resource Control, RRC layer). Specifically, the number of RBs and the number of OFDM symbols (up to 3) constituting the CORESET can be set by the upper layer signaling.

[0059] To receive / detect a PDCCH, the terminal monitors PDCCH candidates. A PDCCH candidate represents the CCE(s) that the terminal must monitor for PDCCH detection. Each PDCCH candidate is defined by 1, 2, 4, 8, or 16 CCEs according to AL. Monitoring involves (blind) decoding the PDCCH candidates. The set of PDCCH candidates monitored by the terminal is defined as the PDCCH Search Space (SS). The Search Space includes a Common Search Space (CSS) or a Terminal-specific Search Space (UE-specific search space, USS). The terminal can acquire a DCI by monitoring PDCCH candidates in one or more Search Spaces configured by the MIB or upper-layer signaling. Each CORESET is associated with one or more Search Spaces, and each Search Space is associated with one CORESET. A Search Space can be defined based on the following parameters.

[0060] - controlResourceSetId: Indicates the CORESET associated with the search space.

[0061] - monitoringSlotPeriodicityAndOffset: Indicates the PDCCH monitoring period (in slots) and the PDCCH monitoring interval offset (in slots).

[0062] - monitoringSymbolsWithinSlot: Represents PDCCH monitoring symbols within the slot (e.g., represents the first symbol(s) of the CORESET)

[0063] - nrofCandidates: AL={1, 2, 4, 8, 16} represents the number of star PDCCH candidates (one of the values ​​0, 1, 2, 3, 4, 5, 6, or 8)

[0064] An opportunity (e.g., time / frequency resources) to monitor PDCCH candidates is defined as a PDCCH (monitoring) opportunity. One or more PDCCH (monitoring) opportunities may be configured within a slot.

[0065] Table 3 illustrates the characteristics of each search space type.

[0066] TypeSearch SpaceRNTIUse CaseType0-PDCCHCommonSI-RNTI on a primary cellSIB DecodingType0A-PDCCHCommonSI-RNTI on a primary cellSIB DecodingType1-PDCCHCommonRA-RNTI or TC-RNTI on a primary cellMsg2, Msg4 decoding in RACHType2-PDCCHCommonP-RNTI on a primary cellPaging DecodingType3-PDCCHCommonINT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, C-RNTI, MCS-C-RNTI, or CS-RNTI(s)UE SpecificUE SpecificC-RNTI, or MCS-C-RNTI, or CS-RNTI(s)User specific PDSCH decoding

[0067] Table 4 shows examples of DCI formats transmitted via PDCCH.

[0068] DCI formatUsage0_0Scheduling of PUSCH in one cell0_1Scheduling of one or multiple PUSCH in one cell, or indicating downlink feedback information for configured grant PUSCH (CG-DFI)0_2Scheduling of PUSCH in one cell1_0Scheduling of PDSCH in one cell1_1Scheduling of PDSCH in one cell, and / or triggering one shot HARQ-ACK codebook feedback1_2Scheduling of PDSCH in one cell2_0Notifying a group of UEs of the slot format, available RB sets, COT duration and search space set group switching2_1Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE2_2Transmission of TPC commands for PUCCH and PUSCH2_3Transmission of a group of TPC commands for SRS transmissions by one or more UEs

[0069] DCI format 0_0 is used to schedule TB-based (or TB-level) PUSCH, and DCI format 0_1 ​​can be used to schedule TB-based (or TB-level) PUSCH or CBG (Code Block Group)-based (or CBG-level) PUSCH. DCI format 1_0 is used to schedule TB-based (or TB-level) PDSCH, and DCI format 1_1 can be used to schedule TB-based (or TB-level) PDSCH or CBG-based (or CBG-level) PDSCH (DL grant DCI). DCI format 0_0 / 0_1 is referred to as UL grant DCI or UL scheduling information, and DCI format 1_0 / 1_1 can be referred to as DL grant DCI or DL ​​scheduling information. DCI format 2_0 is used to transmit dynamic slot format information (e.g., dynamic SFI) to terminals, and DCI format 2_1 is used to transmit downlink pre-Emption information to terminals. DCI format 2_0 and / or DCI format 2_1 may be transmitted to terminals within a group through a group common PDCCH, which is a PDCCH transmitted to terminals defined as a group.

[0070] DCI format 0_0 and DCI format 1_0 are referred to as fallback DCI formats, and DCI format 0_1 ​​and DCI format 1_1 may be referred to as non-fallback DCI formats. The DCI size / field configuration of the fallback DCI format remains the same regardless of terminal settings. On the other hand, the DCI size / field configuration of the non-fallback DCI format varies depending on the terminal settings.

[0071] PDSCH carries downlink data (e.g., DL-SCH transport block, DL-SCH TB), and modulation methods such as QPSK (Quadrature Phase Shift Keying), 16 QAM (Quadrature Amplitude Modulation), 64 QAM, and 256 QAM are applied. A codeword is generated by encoding the TB. PDSCH can carry up to two codewords. Scrambling and modulation mapping are performed for each codeword, and the modulation symbols generated from each codeword can be mapped to one or more layers. Each layer is mapped to a resource along with the DMRS (Demodulation Reference Signal) to generate an OFDM symbol signal, which is then transmitted through the corresponding antenna port.

[0072] PUCCH carries UCI (Uplink Control Information). UCI includes the following:

[0073] - SR(Scheduling Request): Information used to request UL-SCH resources.

[0074] - HARQ (Hybrid Automatic Repeat reQuest)-ACK (Acknowledgement): This is an acknowledgment for a downlink data packet (e.g., codeword) on the PDSCH. It indicates whether the downlink data packet was successfully received. A 1-bit HARQ-ACK is transmitted in response to a single codeword, and a 2-bit HARQ-ACK can be transmitted in response to two codewords. The HARQ-ACK response includes a positive ACK (simply ACK), a negative ACK (NACK), a DTX, or a NACK / DTX. Here, HARQ-ACK is used interchangeably with HARQ ACK / NACK and ACK / NACK.

[0075] - CSI (Channel State Information): This is feedback information regarding the downlink channel. MIMO (Multiple Input Multiple Output) related feedback information includes RI (Rank Indicator) and PMI (Precoding Matrix Indicator).

[0076] Table 5 provides examples of PUCCH formats. Depending on the PUCCH transmission length, they can be classified into Short PUCCH (formats 0, 2) and Long PUCCH (formats 1, 3, 4).

[0077] PUCCH formatLength in OFDM symbolsN PUCCH symb Number of bitsUsageEtc01 - 2≤2HARQ, SRSequence selection14 - 14≤2HARQ, [SR]Sequence modulation21 - 2>2HARQ, CSI, [SR]CP-OFDM34 - 14>2HARQ, CSI, [SR]DFT-s-OFDM(no UE multiplexing)44 - 14>2HARQ, CSI, [SR]DFT-s-OFDM(Pre DFT OCC)

[0078] PUCCH Format 0 carries a UCI of up to 2 bits in size and is transmitted by mapping based on the sequence. Specifically, the terminal transmits a specific UCI to the base station by transmitting one of multiple sequences via a PUCCH of PUCCH Format 0. The terminal transmits a PUCCH of PUCCH Format 0 within the PUCCH resource for the corresponding SR setting only when transmitting a positive SR. PUCCH Format 1 carries a UCI of up to 2 bits in size, and modulation symbols are spread by an Orthogonal Cover Code (OCC) in the time domain (configured differently depending on frequency hopping). DMRS is transmitted at symbols where modulation symbols are not transmitted (i.e., transmitted via Time Division Multiplexing (TDM)).

[0079] PUCCH Format 2 carries a UCI with a bit size greater than 2 bits, and modulated symbols are transmitted via DMRS and Frequency Division Multiplexing (FDM). DMRS is located at symbol indices #1, #4, #7, and #10 within a given resource block at a density of 1 / 3. A Pseudo Noise (PN) sequence is used for the DMRS sequence. Frequency hopping can be enabled for 2-symbol PUCCH Format 2.

[0080] PUCCH format 3 does not perform terminal multiplexing within the same physical resource blocks and carries a UCI with a bit size greater than 2 bits. In other words, PUCCH resources in PUCCH format 3 do not include orthogonal cover codes. Modulation symbols are transmitted via DMRS and TDM (Time Division Multiplexing).

[0081] PUCCH format 4 supports multiplexing of up to 4 terminals within the same physical resource blocks and carries a UCI with a bit size greater than 2 bits. In other words, the PUCCH resources of PUCCH format 3 contain an orthogonal cover code. Modulation symbols are transmitted via DMRS and TDM (Time Division Multiplexing).

[0082] PUSCH carries uplink data (e.g., UL-SCH transport block, UL-SCH TB) and / or uplink control information (UCI) and is transmitted based on a CP-OFDM (Cyclic Prefix - Orthogonal Frequency Division Multiplexing) waveform or a DFT-s-OFDM (Discrete Fourier Transform - spread - Orthogonal Frequency Division Multiplexing) waveform. When PUSCH is transmitted based on a DFT-s-OFDM waveform, the terminal transmits PUSCH by applying transform precoding. For example, if transform precoding is disabled, the terminal transmits PUSCH based on a CP-OFDM waveform, and if transform precoding is enabled, the terminal can transmit PUSCH based on a CP-OFDM waveform or a DFT-s-OFDM waveform. PUSCH transmissions can be dynamically scheduled by UL grants within DCI or semi-statically scheduled based on upper layer (e.g., RRC) signaling (and / or Layer 1 (L1) signaling (e.g., PDCCH)) configured grants. PUSCH transmissions can be performed in a codebook-based or non-codebook-based manner.

[0083] FIG. 5 illustrates the process of receiving PDCCH / PDSCH and transmitting ACK / NACK. Referring to FIG. 5, the terminal can detect PDCCH in slot #n. Here, PDCCH includes downlink scheduling information (e.g., DCI format 1_0, 1_1), and PDCCH represents the DL assignment-to-PDSCH offset (K0) and the PDSCH-HARQ-ACK reporting offset (K1). For example, DCI format 1_0, 1_1 may include the following information.

[0084] - Frequency domain resource assignment: Represents the set of RBs assigned to PDSCH

[0085] - Time domain resource assignment: Indicates K0 (e.g., slot offset), the starting position of the PDSCH within slot #n+K0 (e.g., OFDM symbol index), and the length of the PDSCH (e.g., number of OFDM symbols).

[0086] - PDSCH-to-HARQ_feedback timing indicator: Indicates K1

[0087] - HARQ process number (4 bits): Represents the HARQ process ID (Identity) for data (e.g., PDSCH, TB)

[0088] Subsequently, the terminal receives a PDSCH from slot #(n+K0) according to the scheduling information of slot #n, and when the reception of the PDSCH ends in slot #n1 (where, n+K0 ≤ n1), it can transmit a UCI via a PUCCH in slot #(n1+K1). Here, the UCI may include a HARQ-ACK response to the PDSCH. In FIG. 5, for convenience, it was assumed that the SCS for the PDSCH and the SCS for the PUCCH are identical and that slot #n1 = slot #n+K0, but the present invention is not limited thereto. If the SCSs are different, K1 may be indicated / interpreted based on the SCS of the PUCCH.

[0089] If the PDSCH is configured to transmit up to 1 TB, the HARQ-ACK response may consist of 1 bit. If the PDSCH is configured to transmit up to 2 TB, the HARQ-ACK response may consist of 2 bits if spatial bundling is not configured, and 1 bit if spatial bundling is configured. If the time for transmitting HARQ-ACKs for multiple PDSCHs is specified as slot #(n+K1), the UCI transmitted at slot #(n+K1) includes HARQ-ACK responses for multiple PDSCHs.

[0090] Table 6 is an excerpt from an existing NR standard document regarding the PDSCH-to-HARQ-ACK minimum processing time.

[0091]

[0092]

[0093]

[0094]

[0095]

[0096] Whether a terminal must perform spatial bundling for a HARQ-ACK response can be configured per cell group (e.g., RRC / upper layer signaling). For example, spatial bundling can be configured individually for each HARQ-ACK response transmitted via PUCCH and / or HARQ-ACK response transmitted via PUSCH.

[0097] Spatial bundling may be supported when the maximum number of TBs (or codewords) that can be received (or scheduled via 1 DCI) at one time in the corresponding serving cell is 2 (or more than 2) (e.g., when the upper layer parameter maxNrofCodeWordsScheduledByDCI corresponds to 2-TB). Meanwhile, more than 4 layers may be used for 2-TB transmission, and up to 4 layers may be used for 1-TB transmission. Consequently, if spatial bundling is configured in the corresponding cell group, spatial bundling may be performed on serving cells within the cell group where more than 4 layers are scheduleable. On the corresponding serving cell, a terminal that intends to transmit a HARQ-ACK response via spatial bundling may generate a HARQ-ACK response by performing a (bit-wise) logical AND operation on the A / N bits of multiple TBs.

[0098] For example, assuming that a terminal receives a DCI scheduling 2-TB and receives 2-TB via PDSCH based on the said DCI, the terminal performing spatial bundling can generate a single A / N bit by performing a logical AND operation on the first A / N bit for the first TB and the second A / N bit for the second TB. Consequently, if both the first TB and the second TB are ACK, the terminal reports the ACK bit value to the base station, and if either TB is NACK, the terminal reports the NACK bit value to the base station.

[0099] For example, if only 1-TB is actually scheduled on a serving cell configured to receive 2-TB, the terminal can generate a single A / N bit by performing a logical AND operation between the A / N bit for the 1-TB and the bit value 1. As a result, the terminal reports the A / N bit for the 1-TB to the base station as is.

[0100] Multiple parallel DL HARQ processes exist in the base station / terminal for DL ​​transmission. These multiple parallel HARQ processes enable DL transmission to be performed continuously while waiting for HARQ feedback regarding the successful or unsuccessful reception of the previous DL transmission. Each HARQ process is associated with a HARQ buffer of the MAC (Medium Access Control) layer. Each DL HARQ process manages state variables regarding the number of transmissions of MAC PDUs (Physical Data Blocks) in the buffer, HARQ feedback for MAC PDUs in the buffer, and the current redundancy version. Each HARQ process is distinguished by its HARQ process ID.

[0101] Meanwhile, HARQ-ACK codebooks are broadly defined into three types—Type-1, Type-2, and Type-3—depending on the method of configuring the HARQ-ACK bits (payload). For Type-1 codebooks, the HARQ-ACK payload is constructed based on a combination of a set of candidate HARQ-ACK timings (K1) and a set of candidate PDSCH occasions (SLIV) (configured for each cell) (e.g., a semi-static, fixed-size codebook based on RRC signaling). For Type-2 codebooks, the codebook size can change dynamically depending on the actual number of scheduled PDSCHs or the number of corresponding resource allocations (e.g., downlink assignment index, DAI). For Type-3 codebooks, the HARQ-ACK payload is constructed by mapping the HARQ-ACK bits corresponding to each HARQ process number (HPN) to match the maximum number of HARQ process(s) (e.g., one-shot A / N reporting). Recently, the Enhanced Type-3 Codebook was added to the NR standard as a form of Type-3 Codebook. To reduce signaling overhead, the Enhanced Type-3 Codebook is a method designed to report HARQ-ACK bits simultaneously for a specific subset of cells / HPNs designated to the base station, rather than for all cells / HPNs at once. Through upper-layer signaling, a subset of cells / HPNs associated with the Enhanced Type-3 Codebook is configured on the terminal. Subsequently, one of these configured subsets can be designated via a DCI that triggers the Enhanced Type-3 Codebook. The terminal can then report HARQ-ACKs for the cells / HPNs belonging to the designated subset.

[0102] Specifically, in the case of a Type-1 codebook, a set of multiple (e.g., N) candidate K1 values ​​is set (for each cell), and for each K1 value, all combinations of SLIVs that can be transmitted (or scheduled to be transmitted) within a DL slot K1 slots prior to the A / N transmission slot are calculated, and an A / N sub-payload corresponding to the DL slot is constructed (including determining the position / order of the A / N bits corresponding to each SLIV that can be transmitted within the slot) (this is defined as "SLIV Pruning"), and the entire A / N codebook is constructed by concatenating these A / N sub-payloads for the N K1 values, and at this time, a set of (N) DL slots corresponding to each K1 value can be defined as a bundling window corresponding to the A / N transmission slot.

[0103] In the case of the Type-2 HARQ-ACK codebook, the codebook for transmitting HARQ-ACK information on the same PUCCH / PUSCH is defined based on the counter DAI (downlink assignment indicator) (C-DAI) and total DAI (T-DAI) values ​​indicated by the actual transmitted PDCCH. In other words, the codebook is constructed based on the PDCCH information actually transmitted to the terminal. If the terminal fails to detect a specific PDCCH, it transmits a NACK to the bit corresponding to that PDCCH among the bits defined in the codebook. At this time, the terminal can recognize whether PDCCH detection has failed through the C-DAI and T-DAI values. C-DAI is the cumulative count of {serving cell index, PDCCH monitoring occasion}-pairs where PDSCH receptions are provided, counted up to the current serving cell and the current PDCCH monitoring occasion. First, for multiple PDSCH receptions for the same {serving cell index, PDCCH monitoring occasion}-pair, the PDSCH that is received first is counted first (assigned a lower C-DAI value). Next, among the different {serving cell index, PDCCH monitoring occasion}-pairs, if there are multiple pairs with the same PDCCH monitoring occasion index, the pair with the lower serving cell index is counted first. Next, among the different {serving cell index, PDCCH monitoring occasion}-pairs, if there are multiple pairs with the same serving cell index, the PDCCH monitoring occasion with the lower index is counted first.

[0104] Specifically, for Type-3 codebooks, one of two modes can be set from the BS to the UE: Mode 1, which feeds back the HARQ-ACK and the corresponding NDI together, and Mode 2, which feeds back only the HARQ-ACK without the NDI. When the UE is set to Mode 1, it operates to feed back the HARQ-ACK for the reception of the PDSCH of the corresponding HPN and the corresponding NDI (indicated via DCI) together for each HARQ Process Number (HPN). On the other hand, when set to Mode 2, the UE feeds back only the HARQ-ACK for the reception of the PDSCH of the corresponding HPN for each HPN.

[0105] FIG. 6 illustrates a PUSCH transmission process. Referring to FIG. 6, the terminal can detect PDCCH in slot #n. Here, PDCCH includes uplink scheduling information (e.g., DCI format 0_0, 0_1). DCI format 0_0, 0_1 may include the following information.

[0106] - Frequency domain resource assignment: Indicates the set of RBs assigned to PUSCH

[0107] - Time domain resource assignment: Indicates slot offset K2, the starting position (e.g., symbol index) and length (e.g., number of OFDM symbols) of PUSCH within the slot. The starting symbol and length may be indicated via SLIV (Start and Length Indicator Value) or indicated separately.

[0108] Subsequently, the terminal can transmit PUSCH at slot #(n+K2) according to the scheduling information of slot #n. Here, PUSCH includes UL-SCH TB.

[0109]

[0110] Carrier aggregation

[0111] NR can support wider uplink and downlink bandwidths by merging multiple uplink and downlink carriers (i.e., carrier merging). Through carrier merging, it is possible to transmit and receive signals on multiple carriers. When carrier merging is applied, each carrier (see Fig. A2) may be referred to as a component carrier (CC). CCs may be adjacent or non-adjacent to each other in the frequency domain. The bandwidth of each CC can be determined independently. Asymmetric carrier merging is also possible, where the number of UL CCs and DL CCs are different.

[0112] - PCell (Primary Cell): In the case of a terminal with carrier aggregation enabled, a cell operating on the primary frequency (e.g., Primary Component Carrier, PCC) where the terminal performs the initial connection establishment procedure or initiates the re-establishment procedure. In the case of DC (Dual Connectivity), an MCG (Master Cell Group) cell operating on the primary frequency where the terminal performs the initial connection establishment procedure or initiates the re-establishment procedure.

[0113] - SCell (Secondary Cell): For terminals with carrier aggregation enabled, a cell that provides additional wireless resources besides the special cell.

[0114] - PSCell (Primary SCG Cell): In the case of a DC, the SCG (Secondary Cell Group) cell where the terminal performs random access during the RRC reconfiguration and synchronization process.

[0115] - Special Cell (SpCell): In the case of DC, the special cell represents the PCell of the MCG or the PSCell of the SCG. Otherwise (i.e., non-DC), the special cell represents the PCell.

[0116] - Serving Cell (ServCell): Represents a cell configured for a terminal in the RRC_CONNECTED state. If CA / DA is not configured, only one serving cell (i.e., PCell) exists. If CA / DA is configured, the serving cell represents a set of cells including special cell(s) and all SCells.

[0117] Meanwhile, control information may be configured to be transmitted and received only through specific cells. For example, UCI may be transmitted through a special cell (e.g., PCell). If a SCell that allows PUCCH transmission (hereinafter referred to as PUCCH-SCell) is configured, UCI may also be transmitted through the PUCCH-SCell. As another example, the base station may allocate a scheduling cell (set) to reduce the complexity of PDCCH BD (blinding decoding) at the terminal side. For PDSCH reception / PUSCH transmission, the terminal may perform PDCCH detection / decoding only in the scheduling cell. Additionally, the base station may transmit PDCCH only through the scheduling cell (set). For example, a PDCCH for downlink allocation may be transmitted from cell #0 (i.e., the scheduling cell), and the corresponding PDSCH may be transmitted from cell #2 (i.e., the scheduled cell) (Cross-Carrier Scheduling, CCS). Scheduling cells (sets) can be configured in a terminal-specific, terminal-group-specific, or cell-specific manner. Scheduling cells include special cells (e.g., PCell).

[0118] For cross-carrier scheduling, the CIF (carrier indicator field) is used. The CIF is semi-static and can be disabled or enabled by terminal-specific (or terminal group-specific) upper-layer (e.g., Radio Resource Control, RRC) signaling. The CIF field is an x-bit field (e.g., x=3) within the PDCCH (i.e., DCI) and can be used to indicate the (serving) cell index of a scheduled cell.

[0119] - CIF Disabled: CIF is absent within the PDCCH. The PDCCH on the scheduling cell allocates PDSCH / PUSCH resources on the same cell. In other words, the scheduling cell is identical to the scheduled cell.

[0120] - CIF Enabled: A CIF exists within the PDCCH. The PDCCH in scheduling can use the CIF to allocate PDSCH / PUSCH resources on one of multiple cells. The scheduling cell may be the same as or different from the scheduled cell. PDSCH / PUSCH refers to PDSCH or PUSCH.

[0121] Figure 7 is a diagram illustrating carrier merging. In Figure 7, it is assumed that three cells are merged. When CIF is disabled, each cell can only transmit the PDCCH that schedules its own PDSCH / PUSCH (self-carrier scheduling, SCS). On the other hand, when CIF is enabled by terminal-specific (or terminal-group-specific or cell-specific) upper-layer signaling and Cell A is set as the scheduling cell, Cell A can transmit not only the PDCCH that schedules Cell A's PDSCH / PUSCH but also the PDCCH that schedules the PDSCH / PUSCH of other cells (i.e., scheduled cells) (cross-carrier scheduling, CCS). In this case, Cells B / C do not transmit the PDCCH that schedules their own cells.

[0122]

[0123] DL / UL operations based on switching between multiple carriers

[0124] Recently, in Release-19, low band carrier aggregation (CA) operation based on Rx / Tx switching between multiple carriers is being considered to address traffic congestion issues in the low frequency band spectrum while also taking into account the cost of antenna-related components and the complexity of the RF structure of the terminal. Table 7 below summarizes the points discussed regarding CA operation in the low frequency band spectrum.

[0125] [Justification]Operator interest for aggregating low band spectrum has always been high during the entire history of the carrier aggregation feature, spanning LTE and NR specifications. Considering the practicalities of handset RF front end architectures available in the market today, the operators have requested 3GPP to consider specifying a solution based on a switching scheme which can potentially accommodate the related limitations.A group of operators have submitted a contribution motivating this proposal previously in RP-241537 with the following problem statement:- We are rich in mid-band spectrum (~300 MHz) which is effective closer to sites, however we have limited low-band spectrum (15 MHz) which propagates farther- As our customers move between sites (urban and rural), they're spending more time in low-band coverage.- Low-band carries significant traffic volumes in urban and rural- Our customers spend 15% of their day on average in urban low-bands, and 50% in rural low-bands- Low-band capacity challenge has a huge impact on customer experience. Users will experience poor data speeds due to low-band congestion.- Low-Low band CA is one way of solving this problem, however OEM's have challenges to support low-low band CA and this ecosystem does not exist- B29 is widely deployed in our network and is underutilized- Bell and TELUS together has nationwide access to 10 MHz of MBS - DL only (n29) in 700MHz spectrum.- Band 29 reaches 83% of Canada's pop.An operator-suggested scenario involves the aggregation of n5 with n29. From the duplexer design perspective, the frequency separation between the bands does not pose a feasibility challenge in general. However, the large fractional bandwidth carries additional implementation challenges for smartphones from the antenna design perspective.If the OEM chooses to implement a single antenna to aggregate these bands, then some tuning solution might become necessary to optimize performance. Optimization for both bands simultaneously can be challenging due to their separation in frequency. A potential design choice to implement additional antenna elements to support these combinations may carry cost and RF architecture complexity impacts in terms of additional components and volume in the form factor. Although the band combination is already specified in TS38.101-1, this practical implementation challenge may pose a barrier for the combination's adoption in a wide range of devices.The motivation paper accompanying this new work item proposal provides further details on the frequency arrangements of the considered band combinations and the proposed switching scenarios.An enhancement of the 3GPP specification is needed to enable the following solution:- Device needs to support switching: when the SCell operation is triggered, UE needs to switch to the SCell, and during the operation period there is no simultaneous Tx / Rx between the PCell and the SCell- Device switches back to the PCell after the SCell operation is finishedRecognizing that this work item has impact on the RAN1 working group, the proposed objectives strive to minimize the impact on the physical layer procedures and are intended to implement the minimum useful functionality, from the operators' perspective. Additionally, the operators have prioritized the suggested effort on the proposed band combinations with one example band combination to be completed as part of the proposed work item and the remaining combinations to be handled via the band combination basket work item approach.[Objective]Introduce physical layer procedures and requirements to enable low band carrier aggregation via switching according to the following objectives:- Specify UE requirements, including at least switching gap (if needed), and corresponding physical layer procedures to allow switching between {case 1, case 2} [RAN4, RAN1]-Case 1: Tx / Rx on FDD carrier 1 and no Rx on SDL carrier 2- Case 2: Rx on SDL carrier 2 and no Tx / Rx on FDD carrier 1- RAN1 to specify only a semi-static switching pattern based on RRC configuration, liaising with RAN2 and RAN4 as necessary- Specify the switching delay and time mask for carrier switching [RAN4]- Specify necessary RRM requirements [RAN4]- Define the corresponding UE capabilities [RAN4, RAN2, RAN1]- Consider the following deployment constraints:- The carrier frequency for all cases is <1 GHz- Co-located and synchronized network deployment for both carriers- Both carriers are in a single TAG- SCS 15KHz on both carriers.

[0126] The present disclosure proposes a terminal operation method for carrier aggregation (CA) based on Rx / Tx switching between multiple carriers. For example, in a CA situation between FDD (DL and UL) carrier 1 and supplementary DL only carrier 2, i.e., SDL carrier 2, switching between two operation cases may be considered, and a semi-static switching pattern between the two cases may be set to the terminal through RRC signaling. For example, a pattern may be set in which the two cases are activated by switching over time intervals, such that Case 1 (or the first case) is activated from time T1 to time T2, Case 2 (or the second case) is activated from time T2 to time T3, and Case 1 is activated again from time T3 to time T4. In this case, carrier 1 and carrier 2 may be referred to as the first carrier and the second carrier, respectively.

[0127] The two cases mentioned above may include the following cases.

[0128] - Case 1: Transmission / reception possible on FDD carrier 1, reception impossible on SDL carrier 2

[0129] - Case 2: Reception possible on SDL carrier 2, transmission / reception impossible on FDD carrier 1

[0130] For example, in Case 1, the terminal can perform at least one of receiving a DL signal and transmitting a UL signal on carrier 1, but cannot perform receiving a DL signal on carrier 2. Also, in Case 2, the terminal can perform receiving a DL signal on carrier 2, but cannot perform receiving a DL signal and transmitting a UL signal on carrier 1.

[0131] The proposed embodiments are not limited to the switching or semi-static switching methods between Case 1 and Case 2 described above. For example, the proposed embodiments may be applied to switching between Case A and Case B in a form more generalized than Case 1 and Case 2 described above, and may also be applied to dynamic switching methods based on L1 signaling (e.g., DCI) rather than semi-static switching methods. Furthermore, in the proposed embodiments, the carrier may refer not to a single carrier but to a carrier group comprising multiple carriers located in a specific frequency band (e.g., the same frequency band). In this case, the multiple carriers may include multiple intra-band carriers, but are not limited thereto. Additionally, in the proposed embodiments, the carrier may refer to a serving cell where CA is performed or a (active) BWP set / instructed to the said cell.

[0132] For example, a generalized behavior case can be defined as follows.

[0133] (1) Case A: Tx and / or Rx on carrier 1, no Rx (and / or no Tx) on carrier 2

[0134] - Transmission and / or reception are possible on Carrier 1; reception (and / or transmission) is not possible on Carrier 2.

[0135] For example, in Case A, the terminal can perform at least one of transmission and reception on carrier 1, but cannot perform at least one of transmission and reception on carrier 2. For example, if carrier 2 is the aforementioned SDL carrier, reception on carrier 2 is impossible, and if carrier 2 is an FDD carrier capable of both transmission and reception, neither transmission nor reception on carrier 2 is possible. That is, in Case A, transmission and reception operations on carrier 2 cannot be performed.

[0136] (2) Case B: Rx (and / or Tx) on carrier 2 and no Tx and / or no Rx on carrier 1

[0137] - Reception (and / or transmission) is possible on Carrier 2; transmission and / or reception is not possible on Carrier 1.

[0138] For example, in Case B, the terminal can perform at least one of receiving and transmitting on carrier 2, and cannot perform at least one of transmitting and receiving on carrier 1.

[0139] Meanwhile, with carrier 1 and carrier 2 configured as the PCell and SCell of the terminal, respectively, the SCell may be switched to a deactivation state (or a dormant BWP state) during a specific time interval. In this case, the (semi-static) switching pattern is not applied during the corresponding time interval, and the terminal can perform DL reception and / or UL transmission through all slots on the PCell (similar to Case 1 or Case A). For example, if the SCell is switched to a dormant BWP state during a specific time interval, even if switching from carrier 1 to carrier 2 is scheduled during that time interval according to the (semi-static) switching pattern, the terminal can perform DL reception and / or UL transmission operations on the PCell without switching (or without applying the switching pattern).

[0140] In the future, in 6G systems, a multi-carrier serving cell structure (referred to as an “MC cell” for convenience) comprising multiple carriers to form a single (serving) cell may be considered for the purpose of reducing base station energy saving effects through the minimization of UE-common signal / channel transmissions that are periodically broadcast (for each cell), reducing DCI overhead required for data scheduling and processing, and reducing terminal capability. Multiple carriers belonging to the same MC cell may be composed of carriers that operate based on the same sync raster and / or have the same SIB information applied and / or have the same paging information applied.

[0141] In the present disclosure, a plurality of carriers may mean a plurality of carriers belonging to the same MC cell or a plurality of cells (each carrier) operating as an individual serving cell, or a plurality of sub-bands or a plurality of (sub-)BWPs configured within a cell or a carrier or a system BW or a channel BW, but are not limited to the examples described above.

[0142] [Proposed Method #1]

[0143] Based on the aforementioned (semi-static) switching pattern, there may be a time or period during which Case 2 is activated. Activation of Case 2 may mean that reception is performed or is possible on carrier 2. However, at the time or period during which Case 2 is activated, a specific (essential) DL signal or channel essential for the operation and / or resource management of the terminal may be set or indicated on carrier 1. For example, the essential DL signal / channel may refer to a signal / channel essential for the operation and / or resource management of the terminal, and specifically may include, but is not limited to, at least one of SSB transmission, PDCCH CSS for SIB (system information block) / paging / RAR (Random Access Response) scheduling, CSI-RS (Channel State Information-Reference Signal) transmission for RRM (Radio Resource Management) / RLM (Radio Link Monitoring) / BFR (Beam Failure Recovery), gap for measurement, or SMTC (SSB-based Measurement Timing Configuration). In this case, if the (semi-static) switching pattern is applied as is (i.e., Case 2 is enabled), the terminal will not be able to receive the corresponding essential DL signal or channel on carrier 1, and this may result in a degradation of at least one of the terminal's operation, resource management performance, and accuracy (based on procedures such as SIB acquisition, paging reception, RRM / RLM / BFR as described above).For example, if the SIB is not received, the terminal may not be able to obtain system information necessary for communication; if paging is not received, it may not recognize network calls; and if reference signals related to RRM / RLM / BFR are not received, the accuracy or performance of mobility, link maintenance, or BFR-related procedures may be degraded.

[0144] In the above situation, the terminal may exceptionally activate Case 1 instead of Case 2 (ignoring the switching pattern), and through the activation of Case 1, operate to receive the corresponding essential DL signal / channel on carrier 1. For example, in the interval where Case 2 is activated according to the (semi-static) switching pattern, the terminal activates Case 1 instead of Case 2, thereby being unable to perform a receiving operation on carrier 2, and can receive the essential DL signal / channel on carrier 1 (and / or transmit the UL signal or channel set / instructed on carrier 1). Or, (conversely to the above) in the time or interval where Case 1 is activated based on the switching pattern, if the transmission of the essential DL signal or channel on carrier 2 is set or instructed, the terminal may exceptionally activate Case 2 instead of Case 1 (ignoring the switching pattern) and operate to receive the essential DL signal or channel on carrier 2. Accordingly, according to the proposed embodiment, even if a carrier is deactivated at a specific time or interval based on a switching pattern, if the transmission of an essential DL signal / channel on the carrier is set / instructed, the terminal can exceptionally ignore the switching pattern and activate the carrier, and receive the essential DL signal / channel on the carrier. Accordingly, the transmission of the essential DL signal / channel can have a higher priority than the operation according to the (pre-set) switching pattern.

[0145] Additionally, according to one embodiment, for a specific (DL) signal / channel resource or a specific time interval, a terminal may be instructed via a specific L1 signaling (e.g., DCI) whether to apply the case set as active on the switching pattern as is, or to ignore the switching pattern and activate a different case (not the case set as active on the switching pattern). For example, the terminal may receive a DCI instructing to apply (or activate) a case other than the case based on the (semi-static) switching pattern in a specific slot or a specific symbol interval.

[0146] Meanwhile, in a section where Case X is set (to be activated) on the switching pattern, the operation of actually activating another Case Y (ignoring the switching pattern) may include (1) an operation of changing the entire corresponding Case X section into a Case Y section and activating it, or (2) an operation of activating Case Y only for the section related to the transmission of essential DL signals / channels or resources among the sections set as Case X. In this case, if Case Y is activated only for the section related to the transmission of essential DL signals / channels or resources, Case X may be activated in the remaining sections according to the originally set switching pattern. In the above, if X is 1, Y may be 2, and if X is 2, Y may be 1.

[0147] Additionally, during the period set as Case X (based on the switching pattern), the terminal may pause the transmit / receive related timer on Carrier Y. For example, the transmit / receive related timer on Carrier Y may include an inactivity timer for Carrier Y, and the inactivity timer may include, but is not limited to, a BWP inactivity timer for an active BWP on Carrier Y. For example, if the transmit / receive related timer on Carrier Y is a BWP inactivity timer for an active BWP on Carrier Y, the terminal may operate to pause the BWP inactivity timer for the active BWP on Carrier Y during the time period set as Case X, and then resume the timer at the start of the period set as Case Y immediately thereafter. Pausing the BWP inactivity timer may mean maintaining the timer's existing value and pausing the timer's counting for a specific time period (e.g., the time period set as Case X). Additionally, the terminal may resume the operation of the timer at the start of the time interval set as Case Y immediately after the time interval set as Case X ends. Resuming the operation of the timer may mean resuming the counting of the timer from the existing value of the timer. According to the proposed embodiment, even when the carrier Y is substantially unusable during the time interval set as Case X according to the switching pattern, the BWP inactive timer associated with the carrier Y operates, thereby preventing the inactive timer from expiring unreasonably. Alternatively, according to the embodiment, the terminal may operate to reset the BWP inactive timer on the carrier Y during the interval set as Case X, and then start (or restart) the corresponding timer again from the start of the interval set as Case Y immediately thereafter.In this case, if X is 1, Y can be 2, and if X is 2, Y can be 1. Alternatively, when carrier 1 and carrier 2 are configured as the PCell and SCell of the terminal, respectively, the (max) value of the BWP inactivity timer (for the active BWP on the PCell) to be applied during the time interval when the SCell operates in an active state (or non-dormant BWP) (or when the switching pattern is applied), and the (max) value of the BWP inactivity timer (for the active BWP on the PCell) to be applied during the time interval when the SCell is switched to an inactive state (or dormant BWP) (or when the switching pattern is not applied) can be set individually / independently. In the above, the time interval when the SCell operates in an active state or non-dormant BWP may refer to the time interval when the switching pattern is applied. For example, the time interval during which the SCell operates in an active or non-idle BWP state may include not only the time interval during which the SCell is actually activated and transmit / receive operations are performed according to the switching pattern, but also the entire time interval during which switching operations between the PCell and the SCell are performed with the switching pattern applied. Additionally, the time interval during which the SCell operates in an inactive or idle BWP state may refer to a time interval during which the switching pattern is not applied. For example, the time interval during which the SCell operates in an inactive or idle BWP state may refer to a time interval during which the switching pattern itself is not applied and transmit / receive operations are performed only on the PCell. The (max) value of the PCell's inactive timer applied during the time interval when the SCell is active may be set to be longer than the (max) value of the PCell's inactive timer applied during the time interval when the SCell is inactive. In this case, the maximum value of the inactive timer may refer to the maximum value that can be reached when the value of the inactive timer increases, and may refer to a reference value for determining whether the timer has expired.As described above, when the SCell (second carrier) is activated according to the switching pattern, a physical reception gap occurs in the PCell, and the PCell's inactivity timer expires, which may cause the PCell's active BWP to unintentionally switch to the default BWP. Accordingly, in the proposed embodiment, by setting the maximum value of the PCell's inactivity timer applied during the time interval when the SCell is active to be greater than the maximum value of the PCell's inactivity timer applied during the time interval when the SCell is inactive, the timing at which the PCell's active BWP switches to the default BWP can be efficiently controlled. Depending on the embodiment, the (maximum) value of the inactivity timer may be referred to as the expiration value of the inactivity timer, but is not limited to the aforementioned terms.

[0148] Meanwhile, when transitioning from Case X to Case Y based on a switching pattern, a specific time (e.g., a switching gap) required for the terminal to perform a switching operation from carrier X to carrier Y may be predefined or set. For example, the switching gap may be set considering the physical or procedural preparation time of the terminal related to RF chain reset, antenna tuning, or changes in the transmit / receive path. In this situation, the point at which the BWP inactivity timer for the active BWP on carrier X expires may fall within the Case Y period or the switching gap period. At this time, the terminal may switch or change the active BWP to a specific default BWP or initial BWP by applying a predefined or set BWP switching delay based on the expiration time of the timer. For example, the terminal may perform the BWP switch after applying a pre-set specific delay time based on the expiration time of the inactivity timer. Alternatively, according to an embodiment, the terminal may switch or change the active BWP to a default BWP or initial BWP by applying a predefined or set BWP switching delay based on the start time of the nearest Case X section after the Case Y section or switching gap section to which the timer expires. For example, if the time when the inactive timer expires falls within the inactive section of carrier X, the terminal may perform switching based on the start time of the next active section of carrier X. For example, if the inactive timer associated with carrier X expires during Case Y, which is the inactive section of carrier X, the terminal may not immediately switch the active BWP to a default BWP, but may switch to a default BWP by applying a preset BWP switching delay based on the start time of the next Case X.

[0149] Additionally, during the Case X period (based on the switching pattern), the terminal may stop the DRX retransmission timer for PDSCH or PUSCH transmission on carrier Y. Then, the timer may be resumed from the start of the immediately following Case Y period. The above operation is intended to prevent the retransmission timer from expiring improperly, as transmission and reception operations cannot be performed on carrier Y during the Case X period. Alternatively, during the above Case X period, the terminal may initialize the DRX retransmission timer on carrier Y and restart the DRX retransmission timer from the start of the immediately following Case Y period. In the above, if X is 1, Y may be 2, and if X is 2, Y may be 1. In another way, when carrier 1 and carrier 2 are set as PCell and SCell, respectively, the (max) value of the DRX retransmission timer (for PDSCH / PUSCH transmission on PCell) to be applied during the time interval when SCell is operating in an active state (or non-dormant BWP state) (or when a switching pattern is applied), and the (max) value of the DRX retransmission timer (for PDSCH / PUSCH transmission on PCell) to be applied during the time interval when SCell is switched to an inactive state (or dormant BWP state) (or when a switching pattern is not applied) can be set independently of each other.

[0150] FIG. 8 is a diagram showing the operation of a terminal and a base station according to a proposed embodiment.

[0151] Referring to FIG. 8, a terminal can receive switching-related information for a plurality of carriers from a base station (S800). The switching-related information may include information regarding the aforementioned switching pattern and may be transmitted via upper layer signaling (e.g., RRC (Radio Resource Control) signaling) or a specific L1 signaling (e.g., DCI). As described above, the switching pattern may refer to a pattern that activates one of the plurality of carriers during a specific time interval by performing switching between a plurality of carriers according to a time interval. The switching pattern may be semi-statically set via upper layer signaling, but may also be dynamically set via DCI according to an embodiment. Additionally, according to an embodiment, the switching-related information may include information instructing to ignore a preset switching pattern and activate another carrier for a specific time interval, and said information may be dynamically transmitted via a specific L1 signaling (e.g., DCI).

[0152] Referring to FIG. 8, the terminal can disable the first carrier and enable the second carrier based on switching-related information (S810). Disabling the first carrier and enabling the second carrier may mean a state in which transmission and reception on the first carrier are impossible, and at least one of transmission and reception on the second carrier is possible. The first carrier and the second carrier may correspond to the aforementioned carrier 1 and carrier 2, respectively, and disabling the first carrier and enabling the second carrier may correspond to the aforementioned Case 2.

[0153] However, even if the first carrier is deactivated during a time interval based on switching-related information, if a specific DL signal is scheduled on the first carrier, the terminal may exceptionally activate the first carrier and receive the specific DL signal on the first carrier. At this time, the specific DL signal may refer to a specific DL signal essential for the operation and / or resource management of the terminal, as described above. That is, in the case of an essential specific DL signal, even if the first carrier is deactivated during a time interval based on switching-related information, the terminal may exceptionally activate the first carrier and deactivate the second carrier, thereby allowing the terminal to receive the essential specific DL signal on the first carrier. Accordingly, according to the proposed embodiment, it is possible to prevent the terminal from failing to receive the essential DL signal due to the switching operation.

[0154] FIG. 9 is a diagram illustrating the operation between a terminal and a base station according to one embodiment.

[0155] Referring to FIG. 9, the base station may transmit switching-related information regarding a plurality of carriers to the terminal (S800). The switching-related information may include information regarding a switching pattern between the plurality of carriers. As described above, the switching pattern may refer to a pattern in which one of the plurality of carriers is activated during a specific time interval by performing switching between the plurality of carriers by dividing the time interval. The switching-related information may be transmitted via upper layer signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI).

[0156] Referring to FIG. 9, the terminal can disable the first carrier and enable the second carrier based on received switching-related information (S810). Disabling the first carrier and enabling the second carrier may mean that transmission and reception operations are impossible on the first carrier and transmission and reception operations are possible on the second carrier.

[0157] At this time, the terminal may stop a transmission and reception related timer on the first carrier during a first time interval in which the first carrier is deactivated (S820). For example, the transmission and reception related timer on the first carrier may include a BWP deactivation timer or a DRX (Discontinuous Reception) retransmission timer regarding an active BWP (bandwidth part) on the first carrier.

[0158]

[0159] [Proposed Method #2]

[0160] In the case of an existing Type-1 HARQ-ACK codebook, multiple candidate K1 values, for example, a set of N K1 values, may be established. For each cell / carrier, for each K1 value established for that cell / carrier, combinations of all possible PDSCH occasions (e.g., SLIV (Start and Length Indicator Value)) that can be transmitted within a DL slot located K1 slots prior to the HARQ-ACK transmission slot may be calculated. Through this, a HARQ-ACK sub-payload corresponding to the DL slot can be constructed, and this process may be defined as "SLIV pruning." The HARQ-ACK sub-payloads may be concatenated for the N K1 values ​​to form the entire HARQ-ACK codebook (see Section 9.1.2 of 3GPP TS 38.213 V16.2.0). At this time, the set of N DL slots corresponding to each K1 value can be defined as a bundling window corresponding to the HARQ-ACK transmission slot.

[0161] Meanwhile, when Case 1 and Case 2 are switched based on the aforementioned (semi-static) switching pattern, PDSCH scheduling / reception on carrier 2 is impossible during the Case 1 period, and PDSCH scheduling / reception on carrier 1 is impossible during the Case 2 period. Therefore, when determining a bundling window for configuring HARQ-ACK sub-payloads (corresponding to N K1 values) for each carrier, slots where PDSCH scheduling / reception is impossible on each carrier (or PDSCH opportunities where PDSCH scheduling / reception is possible) are considered / processed as invalid slots or invalid PDSCH occasions and excluded, and the bundling window can be configured using only the remaining slots (or PDSCH opportunities) (where PDSCH scheduling / reception is possible). For example, in the Case 2 interval, since PDSCH scheduling / reception on carrier 1 is impossible, among the DL slots located K1 slots prior to the HARQ-ACK transmission slot for carrier 1, the slots (or PDCCH opportunities) located in the Case 2 interval may be invalid slots (or PDCCH opportunities). In this case, the slots or PDCCH opportunities located in the Case 2 interval may each include one or more slots or one or more PDCCH opportunities. Therefore, for carrier 1, a bundling window can be configured using only the remaining valid slots or valid PDSCH opportunities, excluding the slots (or PDSCH opportunities) located in the Case 2 interval. And, based on the configured bundling window, a HARQ-ACK sub-payload corresponding to carrier 1 can be determined.Additionally, since PDSCH scheduling / reception on carrier 2 is not possible during the Case 1 interval, among the DL slots located K1 slots prior to the HARQ-ACK transmission slot for carrier 2, the slots (or PDCCH opportunities) located during the Case 1 interval may be invalid slots (or PDCCH opportunities). At this time, the slots or PDCCH opportunities located during the Case 1 interval may each include one or more slots or one or more PDCCH opportunities. Therefore, a bundling window can be constructed using only the remaining valid slots or valid PDSCH opportunities, excluding the invalid slots or invalid PDSCH opportunities included in the Case 1 interval. And, based on the constructed bundling window, a HARQ-ACK sub-payload corresponding to carrier 2 can be determined.

[0162] In another (equivalent) way, a set of valid slots (or PDSCH opportunities) on carrier 1 and valid slots (or PDSCH opportunities) on carrier 2 arranged in chronological order can be considered as a bundling window for a single virtual carrier. For example, even if two carriers exist physically, they can be interpreted as a single virtual carrier (or virtual single carrier) based on the fact that only one carrier is valid at a given time in terms of PDSCH scheduling possibility. In this case, a corresponding HARQ-ACK sub-payload can be constructed for each slot belonging to the bundling window for a single virtual carrier, and the constructed HARQ-ACK sub-payloads can be concatenated for (N) K1 values ​​to form an entire HARQ-ACK codebook. For example, HARQ-ACK sub-payloads corresponding to the slots associated with each K1 value can be concatenated to form an entire HARQ-ACK codebook. For example, if the K1 values ​​are set to N, there are N slots associated with each K1 value, and since a HARQ-ACK sub-payload corresponding to each of the N slots is configured, the N HARQ-ACK sub-payloads can be connected to form the entire HARQ-ACK codebook.

[0163] In addition, in the case of an existing Type-2 HARQ-ACK codebook (e.g., a dynamic codebook), when the terminal operates based on multiple cells or carriers through CA settings, both counter-DAI and total-DAI can be signaled / indicated via DCI (for PDSCH scheduling). On the other hand, when operating based only on a single cell or carrier without CA, since counter-DAI and total-DAI contain the same information, only counter-DAI can be signaled / indicated via DCI without total-DAI.

[0164] Meanwhile, when Case 1 and Case 2 are switched based on the aforementioned (semi-static) switching pattern, PDSCH scheduling / reception is possible only on one of carriers, carrier 1 or carrier 2, at the same time (e.g., the same slot or the same symbol). Therefore, although it is a CA situation between two carriers, from the perspective of PDSCH scheduling, it becomes substantially the same as operation based on a single carrier, so exceptionally, only counter-DAI can be signaled / indicated without total-DAI. Accordingly, according to the proposed embodiment, even if multiple carriers are physically set, DAI signaling can be simplified similar to operation based on a single carrier by considering a situation where only one carrier is subject to scheduling at a specific time depending on the switching pattern. For example, if scheduling is possible only on carrier 1 in slot #n and scheduling is possible only on carrier 2 in slot #(n+1), since scheduling for multiple carriers is not performed simultaneously at a specific time, signaling of total-DAI can be omitted and only counter-DAI can be signaled.

[0165] According to the aforementioned proposed embodiments, in an environment where switching between multiple carriers is performed, the terminal can efficiently perform switching operations between multiple carriers while stably receiving essential DL signals or channels. In addition, by managing the transmit / receive timers of each carrier based on the time interval during which the switching operation is disabled, it is possible to prevent transitioning to an irrational state (or default state) due to the switching operation.

[0166] In addition, when configuring the HARQ-ACK codebook, HARQ-ACK feedback suitable for a switching environment between multiple carriers can be performed by excluding invalid slots or invalid PDSCH opportunities, or by configuring a bundling window from the perspective of a virtual carrier.

[0167] In addition, the proposed embodiment can ensure the reception of essential DL signals and effectively manage the transmit / receive timers of each carrier and optimize HARQ-ACK operations while considering the complexity of terminal implementation and constraints of RF structure in a switching environment between multiple carriers to solve traffic congestion problems in the low frequency band spectrum.

[0168]

[0169] [Proposed Method #3]

[0170] If a specific (period) UL signal / channel is set / instructed on carrier 1 (e.g., UL carrier) during the time interval or point in time when Case 2 is activated (i.e., reception on carrier 2 is possible) based on a (semi-static) switching pattern, the terminal may operate under the assumption / consideration that the corresponding UL signal / channel resource (on carrier 1) is invalid, since transmission of the corresponding period UL signal / channel is impossible. For example, the specific period UL signal / channel may include, but is not limited to, at least one of a RACH occasion (RO), SR PUCCH, periodic / semi-persistent CSI PUCCH / PUSCH, HARQ-ACK PUCCH for SPS (Semi-Persistent Scheduling) PDSCH, SRS, CG (Configured Grant) PUSCH, and PUSCH / PUCCH repetition. Considering / assuming above that the relevant UL signal / channel resource is invalid may mean that the terminal operates so as not to perform UL signal / channel transmission through the resource.

[0171] For example, the terminal may consider an RO (on carrier 1) set within the Case 2 time interval (based on the switching pattern) as an invalid RO and not perform PRACH transmission through said RO. Meanwhile, if the RAR window interval or starting point corresponding to the RO (on carrier 1) within the Case 1 time interval (assuming that the RAR transmission corresponding to the RO transmission is performed on the same carrier 1) overlaps with the Case 2 time interval, the terminal may 1) operate to consider said RO as an invalid RO and not perform PRACH transmission through said RO, or 2) operate to attempt RAR reception (and PDCCH monitoring for RAR reception) only in the RAR window interval that does not overlap with the Case 2 time interval.

[0172] As another example, during the Case 2 time interval (based on the switching pattern), the terminal may pause the SR prohibit timer (for the SR PUCCH on Carrier 1) and resume the timer from the start of the immediately following Case 1 time interval. For example, pausing the timer may mean holding the last timer value of the immediately following Case 1 time interval. Additionally, resuming the timer may mean continuing to count from the last timer value of the immediately following Case 1 time interval. Alternatively, during the Case 2 time interval, the terminal may reset the SR prohibit timer (on Carrier 1) and start the timer again from the start of the immediately following Case 1 time interval. If the SR prohibit timer is reset, the last SR prohibit timer value of the immediately following Case 1 time interval is not held, and the SR prohibit timer begins counting from the beginning in the Case 1 time interval immediately following the reset. In another way, when carrier 1 and 2 are configured as the PCell and SCell of the terminal, respectively, the (max) value of the SR prohibit timer to be applied during the time interval when the SCell is operating in an active state (or non-idle BWP) and the (max) value of the SR prohibit timer to be applied during the time interval when the SCell is switched to an inactive state (or sleep BWP) can be set individually / independently. For example, the (max) value of the SR prohibit timer to be applied during the time interval when the SCell is operating in an active state or non-idle BWP and the (max) value of the SR prohibit timer to be applied during the time interval when the SCell is operating in an inactive state or sleep BWP can be set differently.For example, the (max) value of the SR prohibit timer applied during the time interval when the SCell operates in an active state (or non-idle BWP) may be set to a relatively large value. In this case, the (max) value of the SR prohibit timer may refer to the maximum value that can be reached when the value of the SR prohibit timer increases and counts. The (max) value of the SR prohibit timer may be referred to as the expiration value of the SR prohibit timer according to the embodiment, and is not limited to the aforementioned terms. The time interval during which the SCell operates in an active state or as a non-idle BWP may refer to the time interval during which the switching pattern is applied. For example, the time interval during which the SCell operates in an active state or as a non-idle BWP may include not only the time interval during which the SCell is actually activated and transmit / receive operations are performed according to the switching pattern, but also the entire time interval during which the switching operation between the PCell and the SCell is performed by applying the switching pattern. Additionally, the time interval during which the SCell operates in an inactive state or as a sleep BWP may refer to the time interval during which the switching pattern is not applied. For example, the time interval during which the SCell operates in an inactive state or as a sleep BWP may refer to a time interval during which the switching pattern itself is not applied and transmit / receive operations are performed only on the PCell.

[0173] As another example, during the Case 2 time interval (based on the switching pattern), the terminal may stop the CG retransmission timer (for the CG PUSCH on carrier 1) and resume the timer immediately from the start of the next Case 1 time interval. Alternatively, the terminal may initialize the CG retransmission timer (on carrier 1) during the Case 2 time interval and restart the timer immediately from the start of the next Case 1 interval. In another method, when carrier 1 and carrier 2 are configured as the PCell and SCell of the terminal, respectively, the (max) value of the CG retransmission timer to be applied during the time interval when the SCell is operating in an active state (or non-idle BWP) and the (max) value of the CG retransmission timer to be applied during the time interval when the SCell is switched to an inactive state (or sleep-independent BWP) may be set individually / independently. For example, the (max) value of the CG retransmission timer applied during the time interval when the SCell is active may be set longer than the (max) value of the CG retransmission timer applied during the time interval when the SCell is inactive. In the above, the time interval during which the SCell operates in an active state or as a non-idle BWP may refer to the time interval during which the switching pattern is applied. For example, the time interval during which the SCell operates in an active state or as a non-idle BWP may include not only the time interval during which the SCell is actually activated and transmit / receive operations are performed according to the switching pattern, but also the entire time interval during which switching operations between the PCell and the SCell are performed by applying the switching pattern. Additionally, the time interval during which the SCell operates in an inactive state or as a sleep BWP may refer to the time interval during which the switching pattern is not applied.As another example, (assuming that the HARQ-ACK transmission corresponding to the SPS PDSCH transmission is performed on the same carrier 1), if the HARQ-ACK transmission resource / time corresponding to the SPS PDSCH resource (on carrier 1) overlaps with the Case 2 time interval within the Case 1 time interval, the terminal may consider the said SPS PDSCH resource as invalid and omit receiving the SPS PDSCH through said resource. Additionally, even if the HARQ-ACK transmission resource / time corresponding to the SPS PDSCH resource (on carrier 1) within the Case 2 time interval is included in the Case 1 time interval, the terminal may operate while considering the said HARQ-ACK transmission resource as an invalid PUCCH resource.

[0174] As another example, if repeated transmission across multiple slots is set / instructed for a PUSCH / PUCCH transmission (on carrier 1), the terminal may not count the slots (on carrier 1) within the Case 2 time interval as available slots for the PUSCH / PUCCH repeated transmission.

[0175]

[0176] [Proposed Method #4]

[0177] Based on a (semi-static) switching pattern, the terminal may receive a PDSCH scheduled on carrier 2 during the Case 2 time interval and transmit HARQ-ACK feedback corresponding to the received PDSCH on carrier 1 (e.g., UL carrier) during the Case 1 time interval. In this case, considering the switching delay (or switching gap), the processing time required from receiving the PDSCH to transmitting the HARQ-ACK may be longer than usual (e.g., when no switching operation is performed). The switching delay or switching gap may refer to the delay / gap required for the terminal to switch from Case 2 to Case 1. Alternatively, the switching delay or switching gap may refer to the delay / gap required for the terminal to switch from carrier 2 to carrier 1, or it may refer to the delay / gap required to disable carrier 2 and enable carrier 1.

[0178] Therefore, as mentioned above, when operating in a multi-carrier switching-based CA method, the minimum (PDSCH-to-HARQ-ACK) processing time required by the terminal (e.g., T below) proc,1 The time corresponding to ) is, in the existing formula, the switching delay or switching gap (i.e., the delay or gap required to switch from Case 2 to Case 1, for example, T below). switch It can be defined as follows in the form of additionally adding the value corresponding to).

[0179]

[0180] In the above Equation 1, parameter T switch The value may be a value that the terminal reports to the base station as UE capability and / or a value that the base station sets for the terminal, and for each SCS T switchThe value can be defined. Meanwhile, if the SCS used by the carrier activated before switching and the carrier activated after switching are different, the above T is based on the switching delay / gap defined in the minimum SCS among those SCSs. switch The value can be determined.

[0181] FIG. 10 illustrates the flow of a method performed by a terminal according to one embodiment.

[0182] Referring to FIG. 10, a terminal according to one embodiment may receive switching-related information of a plurality of carriers from a base station (S1000). The switching-related information may include information regarding a switching pattern between a plurality of carriers. A switching pattern between a plurality of carriers may refer to a pattern in which one of the plurality of carriers is activated during a specific time interval while switching between the plurality of carriers according to a time interval. For example, the switching pattern may include a pattern in which a first carrier is activated from time T1 to time T2, a second carrier is activated from time T2 to time T3, and then the first carrier is activated again from time T3 to time T4, but is not limited to the above-mentioned example.

[0183] Switching-related information may be received via upper-layer signaling or L1 signaling. For example, a switching pattern may be set semi-statically via upper-layer signaling or dynamically via L1 signaling (e.g., DCI). According to an embodiment, the switching-related information may include information instructing to override a preset switching pattern for a specific period of time and activate a specific carrier, wherein the switching-related information may be dynamically instructed via L1 signaling.

[0184] Referring to FIG. 10, a terminal according to one embodiment can disable a first carrier and enable a second carrier based on switching-related information (S1010).

[0185] According to one embodiment, the first carrier may include a Frequency Division Duplexing (FDD) carrier, and the second carrier may include a Supplementary Downlink (SDL) carrier, but is not limited thereto. For example, when the first carrier and the second carrier are an FDD carrier and an SDL carrier, respectively, the activation of the first carrier may mean that at least one of transmission and reception operations is possible on the first carrier, the FDD carrier, and reception operations are impossible on the second carrier, the SDL carrier; and the activation of the second carrier may mean that transmission and reception operations are impossible on the first carrier, the FDD carrier, and reception operations are possible on the second carrier, the SDL carrier. Additionally, at least one of the first carrier and the second carrier may include a carrier group composed of a plurality of carriers located within a specific frequency band.

[0186] Additionally, during a first time interval in which the first carrier is deactivated, a timer related to transmission and reception on the first carrier may be stopped (or, the terminal may stop a timer related to transmission and reception on the first carrier during the first time interval). The timer related to transmission and reception on the first carrier may refer to a timer related to transmission and reception operations on the first carrier, and may include, for example, a BWP deactivation timer or a DRX retransmission timer related to an active BWP on the first carrier, but is not limited thereto. The terminal may stop the timer related to transmission and reception on the first carrier during the first time interval and, after the first time interval, resume the operation of the timer related to transmission and reception on the first carrier based on the activation of the first carrier. The activation of the first carrier after the first time interval may mean switching from the second carrier to the first carrier after the first time interval based on received switching information. Additionally, according to an embodiment, stopping the transmission-reception related timer during the first time interval may include initializing the transmission-reception related timer during the first time interval. If the transmission-reception related timer is initialized during the first time interval, the terminal may restart the transmission-reception related timer on the first carrier after the first time interval, based on the fact that the first carrier is activated.

[0187] Additionally, based on the first carrier and the second carrier being configured as PCell and SCell, respectively, the expiration value of the BWP inactivity timer associated with the active BWP on the first carrier may be determined differently depending on the active state of the second carrier. For example, based on switching between multiple carriers, if SCell is in an active state or a non-idle BWP state, a time interval may occur during which the PCell is unintentionally unable to perform transmit / receive operations. To prevent the PCell's active BWP from unnecessarily switching to a specific default (or initial) BWP due to the expiration of the PCell-related inactivity timer during that time interval, the expiration value of the PCell-related inactivity timer may be set to a relatively longer duration when SCell is in an active state or a non-idle BWP state. That is, the expiration value of the inactivity timer applied during the period when SCell is active may be set to a value greater than the expiration value of the inactivity timer applied during the period when SCell is inactive.

[0188] FIG. 11 illustrates the flow of a method performed by a base station according to one embodiment.

[0189] Referring to FIG. 11, a base station according to one embodiment may transmit switching-related information of a plurality of carriers to a terminal (S1100). As described above, the switching-related information may include information regarding switching patterns between a plurality of carriers. For example, the switching-related information may include at least one of information for setting a switching pattern and information for instructing to ignore a preset switching pattern during a specific time interval, but is not limited thereto. The switching-related information may be transmitted via upper layer signaling or L1 (layer 1) signaling (e.g., DCI). For example, the switching pattern between a plurality of carriers may be semi-statically set via upper layer signaling or dynamically set via L1 signaling.

[0190] A base station according to one embodiment may transmit a downlink signal to a terminal (S1110) based on switching-related information. For example, the downlink signal may be transmitted on the second carrier during a first time interval in which the first carrier is deactivated and the second carrier is activated based on switching-related information. Additionally, a base station according to one embodiment may perform transmission of the downlink signal by assuming that a transmit / receive related timer on the first carrier is stopped by the terminal during the first time interval in which the first carrier is deactivated and the second carrier is activated. For example, the transmit / receive related timer on the first carrier is a timer related to a transmit / receive operation performed on the first carrier, and may include, but is not limited to, a BWP deactivation timer or a DRX retransmission timer for an active BWP on the first carrier.

[0191] FIG. 12 illustrates a communication system (1).

[0192] Referring to FIG. 12, the communication system (1) includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Thing) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with wireless communication capabilities, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and can be implemented in the form of HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) equipped in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Portable devices may include smartphones, smartpads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops, etc.). Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, base stations and networks may be implemented as wireless devices, and a specific wireless device (200a) may operate as a base station / network node to other wireless devices.

[0193] Wireless devices (100a to 100f) can be connected to a network (300) through a base station (200). Artificial Intelligence (AI) technology may be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) through the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices (100a to 100f) may communicate with each other through the base station (200) / network (300), but they may also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0194] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base station (200) and base station (200) / base station (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR), such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and inter-base station communication (150c) (e.g., relay, IAB (Integrated Access Backhaul)). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various proposals of the present invention, at least some of the following may be performed: various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), resource allocation processes, etc.

[0195] FIG. 13 illustrates a wireless device that can be applied to the present invention.

[0196] Referring to FIG. 13, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} may correspond to {wireless device (100x), base station (200)} and / or {wireless device (100x), wireless device (100x)} of FIG. 12.

[0197] The first wireless device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memory (104) and / or transceivers (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or flowcharts of operation disclosed in this document. For example, the processor (102) may process information within the memory (104) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (106). Additionally, the processor (102) may receive a wireless signal containing a second information / signal through the transceiver (106) and then store information obtained from the signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may store software code containing instructions for performing some or all of the processes controlled by the processor (102) or for performing the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals through one or more antennas (108). The transceiver (106) may include a transmitter and / or receiver. The transceiver (106) may be combined with an RF (Radio Frequency) unit. In this specification, a wireless device may refer to a communication modem / circuit / chip.

[0198] The second wireless device (200) includes one or more processors (202) and one or more memories (204), and may additionally include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memory (204) and / or transceivers (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or operation sequences disclosed in this document. For example, the processor (202) may process information within the memory (204) to generate a third information / signal and then transmit a wireless signal containing the third information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and then store information obtained from the signal processing of the fourth information / signal in the memory (204). Memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, memory (204) may store software code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document. Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through one or more antennas (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeable with an RF unit. In this specification, a wireless device may mean a communication modem / circuit / chip.

[0199] Hereinafter, hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate a signal (e.g., baseband signal) containing a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this document and provide it to one or more transceivers (106, 206). One or more processors (102, 202) may receive a signal (e.g., baseband signal) from one or more transceivers (106, 206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document.

[0200] One or more processors (102, 202) may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be contained in one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0201] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memories (104, 204) may be composed of ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0202] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc., of this document to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc., disclosed in this document from one or more other devices. For example, one or more transceivers (106, 206) may be connected to one or more processors (102, 202) and may transmit and receive wireless signals. For example, one or more processors (102, 202) may control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be connected to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document through one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert the received wireless signal / channel, etc. from an RF band signal to a baseband signal in order to process the received user data, control information, wireless signal / channel, etc. using one or more processors (102, 202).One or more transceivers (106, 206) can convert user data, control information, wireless signals / channels, etc. processed using one or more processors (102, 202) from baseband signals to RF band signals. To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters.

[0203] FIG. 14 illustrates another example of a wireless device applicable to the present disclosure. The wireless device may be implemented in various forms depending on the use—example / service (see FIG. 12).

[0204] Referring to FIG. 14, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 13 and may be composed of various elements, components, units / parts, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 13. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 13. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and additional elements (140) and controls the general operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on a program / code / command / information stored in the memory unit (130). Additionally, the control unit (120) may transmit information stored in the memory unit (130) to an external (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external (e.g., another communication device) via a wireless / wired interface through the communication unit (110) in the memory unit (130).

[0205] The additional element (140) can be configured in various ways depending on the type of wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 12, 100a), a vehicle (Fig. 12, 100b-1, 100b-2), an XR device (Fig. 12, 100c), a portable device (Fig. 12, 100d), a home appliance (Fig. 12, 100e), an IoT device (Fig. 12, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or financial device), a security device, a climate / environment device, an AI server / device (Fig. 12, 400), a base station (Fig. 12, 200), a network node, etc. Wireless devices can be used in a movable or fixed location depending on the use—e.g., service.

[0206] In FIG. 14, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least partially connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be connected via a wire, and the control unit (120) and the first unit (e.g., 130, 140) may be connected wirelessly via the communication unit (110). Additionally, each element, component, unit / part, and / or module within the wireless device (100, 200) may include one or more additional elements. For example, the control unit (120) may be composed of one or more sets of processors. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an Electronic Control Unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory and / or a combination thereof.

[0207] FIG. 15 illustrates a vehicle or autonomous vehicle applicable to the present disclosure. The vehicle or autonomous vehicle may be implemented as a mobile robot, vehicle, train, manned or unmanned aerial vehicle (AV), ship, etc.

[0208] Referring to FIG. 15, a vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a driving unit (140a), a power supply unit (140b), a sensor unit (140c), and an autonomous driving unit (140d). The antenna unit (108) may be configured as part of the communication unit (110). Blocks 110 / 130 / 140a to 140d each correspond to blocks 110 / 130 / 140 of FIG. 14.

[0209] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, roadside base stations (Roadside units), etc.), and servers. The control unit (120) can perform various operations by controlling elements of the vehicle or autonomous vehicle (100). The control unit (120) may include an Electronic Control Unit (ECU). The driving unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The driving unit (140a) may include an engine, motor, power train, wheels, brakes, steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and may include wired / wireless charging circuits, batteries, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement technologies such as maintaining the driving lane, technologies for automatically adjusting speed such as adaptive cruise control, technologies for automatically driving along a predetermined path, and technologies for automatically setting a path and driving when a destination is set.

[0210] For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving path and a driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or the autonomous vehicle (100) moves along the autonomous driving path according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can acquire the latest traffic information data from an external server non-periodically and can acquire surrounding traffic information data from surrounding vehicles. Additionally, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving path and the driving plan based on the newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving path, driving plan, etc. to an external server. An external server can predict traffic information data in advance using AI technology, etc., based on information collected from vehicles or autonomous vehicles, and can provide the predicted traffic information data to vehicles or autonomous vehicles.

[0211] The embodiments described above are combinations of the components and features of the present invention in a specific form. Each component or feature should be considered optional unless otherwise explicitly stated. Each component or feature may be implemented in a form not combined with other components or features. Additionally, it is possible to construct embodiments of the present invention by combining some components and / or features. The order of operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment. It is obvious that embodiments may be constructed by combining claims that do not have an explicit citation relationship in the claims, or that new claims may be included by amendment after filing.

[0212] It is obvious to those skilled in the art that the present invention may be embodied in other specific forms without departing from the features of the invention. Accordingly, the foregoing detailed description should not be interpreted restrictively in all respects but should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention.

[0213] The present disclosure may be used in a terminal, base station, or other equipment of a wireless mobile communication system.

Claims

1. In a method performed by a terminal, A step of receiving switching-related information of multiple carriers from a base station; and Based on the above switching-related information, the method includes the step of deactivating the first carrier and activating the second carrier; A method in which a transmission / reception related timer on the first carrier is stopped during a first time interval in which the first carrier is deactivated.

2. In Paragraph 1, A method in which the above transmission and reception related timer includes a BWP inactive timer or a DRX (Discontinuous Reception) retransmission timer regarding an active BWP (Bandwidth Part) on the first carrier.

3. In Paragraph 1, A method in which, after the first time interval, the operation of the transmission / reception related timer on the first carrier is resumed based on the activation of the first carrier.

4. In Paragraph 1, A method in which the transmission / reception related timer is stopped during the first time interval, wherein the transmission / reception related timer is initialized.

5. In claim 1, the above method is, A method further comprising the step of receiving a downlink signal scheduled on the second carrier during the first time interval.

6. In Paragraph 1, A method in which the switching-related information includes information regarding the switching pattern between the plurality of carriers.

7. In Paragraph 1, The above switching-related information is received via upper layer signaling or DCI (Downlink Control Information).

8. In Paragraph 1, A method comprising at least one of the first carrier and the second carrier including a carrier group composed of a plurality of carriers located within a specific frequency band.

9. In Paragraph 1, A method comprising a first time interval in which the first carrier is deactivated and the second carrier is activated, wherein transmission and reception operations are impossible on the first carrier and at least one of the transmission and reception operations is possible on the second carrier.

10. In Paragraph 1, A method in which, based on the first carrier and the second carrier being set as PCell (Primary Cell) and SCell (Secondary Cell) respectively, the expiry value of a BWP inactive timer associated with an active BWP (bandwidth part) on the first carrier is determined differently depending on the active state of the second carrier.

11. A computer-readable non-transitory recording medium storing a program for performing the method described in claim 1.

12. In the device, At least one processor; and It includes at least one memory configured to store instructions that cause the at least one processor to perform operations by being executed by the at least one processor, and The operations of the above processor are, Receive switching-related information for multiple carriers, and Based on the above switching-related information, the operation includes deactivating the first carrier and activating the second carrier, and A device in which a transmission / reception related timer on the first carrier is stopped during a first time interval in which the first carrier is deactivated.

13. In Paragraph 12, The above device is a device comprising a terminal including a transceiver or a processing device configured to control the terminal.

14. In a method performed by a base station, A step of transmitting switching-related information of multiple carriers to a terminal; and Based on the above switching-related information, the method includes the step of transmitting a downlink signal to the terminal; The downlink signal is transmitted on the second carrier during a first time interval in which the first carrier is deactivated and the second carrier is activated based on the switching-related information, and A method in which the transmission of the above downlink signal is performed by assuming that the transmission / reception related timer on the first carrier is stopped during the first time interval.

15. Regarding base stations, At least one transceiver; At least one processor; and It includes at least one memory configured to store instructions that cause the at least one processor to perform operations by being executed by the at least one processor, and The operations of the above processor are, Transmit switching-related information of multiple carriers to the terminal, and Based on the above switching-related information, a downlink signal is transmitted to the terminal, and The downlink signal is transmitted on the second carrier during a first time interval in which the first carrier is deactivated and the second carrier is activated based on the switching-related information, and A method in which the transmission of the above downlink signal is performed by assuming that the transmission / reception related timer on the first carrier is stopped during the first time interval.

Images