Terminal, base station, and communication method

Abstract

This terminal is provided with: a control unit for controlling uplink transmission using N bands selected from M bands (M being a natural number 3 or higher, and N being a natural number not greater than M); and a transmission unit for transmitting, to a network, capability information for reporting a switching period indicating a required duration for switching of uplink transmission between the M bands. If reporting an additional switching period distinct from the switching period, with regard to switching of uplink transmission between a pair of specific bands, the terminal reports a switching period that is identical to the switching period or is always longer than the switching period.

Description

Terminal, base station and communication method

[0001] The present disclosure relates to a terminal, a base station, and a communication method in a wireless communication system.

[0002] The 3rd Generation Partnership Project (3GPP: registered trademark) is developing specifications for the 5th generation mobile communication system (5G, also known as New Radio (NR) or Next Generation (NG)), and is also developing specifications for the next generation, known as Beyond 5G, 5G Evolution, or 6G.

[0003] Furthermore, in 3GPP Release 18, it is possible to set three or four bands (e.g., bands A, B, C, and D) as bands that can be used for uplink (UL) transmission, and a scheme that supports simultaneous transmission using up to two bands (UL Tx switching schemes across up to 3 or 4 bands with restriction of up to 2 Tx simultaneous transmission, hereinafter abbreviated as UL Tx switching schemes across up to 3 or 4 bands as appropriate) is being considered (Non-Patent Document 1).

[0004] Regarding such UL Tx switching, it has been agreed that a terminal (User Equipment, UE) should report a switching period (which may also be called a switching gap length) indicating the time required for switching UL transmission between bands (Non-Patent Document 2).

[0005] For example, when switching from band A, B to band C, D, the network (gNB) may assume the longest switching period between each band pair (A⇔C, B⇔D, A⇔D, B⇔C) reported by the UE (this may be called the Baseline UE assumption).

[0006] It has also been agreed that in addition to the Baseline UE assumption, a UE can separately report the switching period between specific band pairs (UplinkTxSwitchingAdditionalPeriodDualUL-r18) (Non-Patent Documents 3 to 5).

[0007] Furthermore, when switching from band A or B to band C or D, the possible switching combinations are (band A → band C) + (band B → band D) or (band A → band D) + (band B → band C), but it has also been agreed upon to specify any of the switching combinations (which may be called a band ordering based approach) (Non-Patent Document 6).

[0008] "New WID on Multi-carrier enhancements", RP-213577, 3GPP TSG RAN Meeting #94e, 3GPP, December 2021 "WF on UE Tx switching requirement for single TAG", R4-2220546, 3GPP TSG-RAN WG4 Meeting #105, 3GPP, November 2022 "LS on multi-carrier enhancement", R4-2310495, 3GPP TSG-RAN WG4 Meeting # 107, 3GPP, May 2023 "UE capabilities of Rel-18 UL Tx switching enhancements",R2-2306913, 3GPP TSG-RAN WG2 Meeting #122, 3GPP, May 2023 "UE capability reporting for Rel-18 UL Tx switching enhancements", R2-2306912, 3GPP TSG-RAN WG2 Meeting #122, 3GPP, May 2023 "WF on ambiguity issues for parallel switching of two Tx chain across 4 bands", R4-2310496, 3GPP TSG RAN WG4 Meeting #106-bis-e, 3GPP, April 2023

[0009] In the above-mentioned Baseline UE assumption, the longest switching period between each band pair may be assumed. Furthermore, in addition to the Baseline UE assumption, a switching period between a specific band pair (UplinkTxSwitchingAdditionalPeriodDualUL-r18) may be reported. However, according to the current agreement, a period shorter than the switching period based on the Baseline UE assumption may be reported as the UplinkTxSwitchingAdditionalPeriodDualUL-r18. In this case, there is a concern that the network may not be able to determine an appropriate switching period, and normal and stable operation may not be guaranteed.

[0010] Furthermore, when both the switching period between a specific band pair (UplinkTxSwitchingAdditionalPeriodDualUL-r18) and the band ordering based approach are applied, multiple options may arise regarding the switching period to be assumed, and there is a concern that the network will not be able to determine an appropriate switching period, and normal and stable operation may not be guaranteed.

[0011] The following disclosure has been made in light of this situation, and aims to provide a terminal, a base station, and a communication method that can eliminate ambiguity regarding the interpretation of the switching period and determine an appropriate switching period in UL Tx switching schemes across up to 3 or 4 bands.

[0012] One aspect of the present disclosure is a terminal comprising: a control unit (240) that controls uplink transmission using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a transmission unit (210) that transmits capability information to a network, reporting switching periods indicating the time required for switching the uplink transmission between each of the M bands, wherein when the transmission unit reports an additional switching period separate from the switching period for switching the uplink transmission between a specific pair of the bands, the transmission unit is a terminal that always reports a period that is the same as the switching period or longer than the switching period.

[0013] One aspect of the present disclosure is a terminal comprising: a control unit (240) that controls uplink transmission using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a transmission unit (210) that transmits capability information to a network, reporting switching periods indicating the time required for switching the uplink transmission between each of the M bands, wherein the transmission unit is a terminal that avoids reporting an additional switching period separate from the switching period when the time required for switching the uplink transmission between a specific pair of the bands is the same as or shorter than the switching period.

[0014] One aspect of the present disclosure is a terminal comprising: a control unit (240) that controls uplink transmission using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a transmission unit (210) that transmits capability information to a network, reporting switching periods indicating a time required for switching the uplink transmission between each of the M bands, wherein when M is 4 and N is 2, the transmission unit is a terminal that reports only either an additional switching period separate from the switching period of the uplink transmission between a specific pair of bands, or specific inter-band switching information indicating switching of the uplink transmission between the specific bands.

[0015] One aspect of the present disclosure is a base station comprising: a control unit (140) that controls uplink reception using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a receiving unit (120) that receives capability information from a terminal reporting switching periods indicating a required time for switching uplink transmission at the terminal between each of the M bands, wherein when M is 4 and N is 2, the receiving unit receives the capability information including both an additional switching period separate from the switching period of the uplink transmission between a specific pair of the bands and specific inter-band switching information indicating switching of the uplink transmission between the specific bands, and the control unit determines application of only either the additional switching period or the specific inter-band switching information.

[0016] 1 is a diagram for explaining a wireless communication system in an embodiment of the present invention. FIG. ... illustrating Case 1 and Case 2 in UL Tx switching. FIG. 2 is a diagram for illustrating an example configuration of antenna ports used for transmission in each case in UL Tx switching. FIG. 3 is a diagram for illustrating an example configuration of antenna ports used for transmission and reception in each case in UL Tx switching. FIG. 4 is a diagram for illustrating an example of UE capability. FIG. 5 is a diagram for illustrating an example RRC configuration. FIG. 6 is a diagram for illustrating an example switching period. FIG. 7 is a diagram for illustrating an example switching period. FIG. 8 is a diagram for illustrating an example length of Dl interruption. FIG. 9 is a diagram for illustrating Cases 1 to 3 in UL Tx switching. FIG. 10 is a diagram for illustrating an example configuration of antenna ports used for transmission in each case in UL Tx switching. FIG. 11 is a diagram for illustrating an example RRC configuration. FIG. 12 is a diagram for illustrating an example of UL Tx switching where one band includes multiple carriers. FIG. 13 is a diagram for illustrating an example configuration of antenna ports used for transmission in each case in UL Tx switching. FIG. 14 is a diagram for illustrating an example configuration when switching is performed across four bands. FIG. 15 is a diagram for illustrating an example configuration of antenna ports used for transmission when switching is performed across four bands. FIG. 16 is a diagram for illustrating an example of basic operation of an embodiment. Fig. 1 is a diagram illustrating an example of the capability of UplinkTxSwitchingAdditionalPeriodDualUL-r18. Fig. 2 is a diagram illustrating an example of the configuration of a base station 10. Fig. 3 is a diagram illustrating an example of the configuration of a terminal 20. Fig. 4 is a diagram illustrating an example of the hardware configuration of the base station 10 or the terminal 20 in an embodiment of the present invention. Fig. 5 is a diagram illustrating an example of the configuration of a vehicle.

[0017] Hereinafter, embodiments will be described with reference to the drawings. Note that identical functions and configurations are denoted by identical or similar reference numerals, and descriptions thereof will be omitted as appropriate. Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are examples, and embodiments to which the present invention is applicable are not limited to the following embodiments.

[0018] In operation of the wireless communication system according to the embodiment of the present invention, existing technology is used as appropriate, for example, existing LTE or existing NR, but is not limited to existing LTE or NR.

[0019] Furthermore, in the embodiments of the present invention described below, terms such as SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical random access channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), PUCCH (Physical Uplink Control Channel), and PUSCH (Physical Uplink Shared Channel) used in existing LTE or NR are used. This is for convenience of description, and similar signals, functions, etc. may be referred to by other names. Furthermore, the above-mentioned terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, etc. However, even signals used in NR are not necessarily referred to as "NR-".

[0020] Furthermore, in the embodiments of the present invention, the duplex method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or other methods (for example, Flexible Duplex, etc.).

[0021] Furthermore, in the embodiments of the present invention, "configuring" radio parameters etc. may mean that predetermined values ​​are pre-configured, or that radio parameters notified from the base station 10 or the terminal 20 are set.

[0022] Fig. 1 is a diagram showing a configuration example (1) of a wireless communication system according to an embodiment of the present invention. As shown in Fig. 1, the wireless communication system according to the embodiment of the present invention includes a base station 10 and a terminal 20. Although Fig. 1 shows one base station 10 and one terminal 20, this is an example, and there may be a plurality of each.

[0023] The base station 10 is a communication device that provides one or more cells and performs wireless communication with the terminal 20. Physical resources of a wireless signal are defined in the time domain and the frequency domain. The time domain may be defined by the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols, and the frequency domain may be defined by the number of subcarriers or resource blocks. The base station 10 transmits a synchronization signal and system information to the terminal 20. The synchronization signal may be, for example, NR-PSS or NR-SSS. The system information is transmitted, for example, via the NR-PBCH and is also referred to as broadcast information. The synchronization signal and system information may also be referred to as an SSB (SS / PBCH block). As shown in FIG. 1 , the base station 10 transmits control signals or data to the terminal 20 via the downlink (DL) and receives control signals or data from the terminal 20 via the uplink (UL). Both the base station 10 and the terminal 20 are capable of transmitting and receiving signals by beamforming. Furthermore, both the base station 10 and the terminal 20 are capable of applying MIMO (Multiple Input Multiple Output) communication to the DL or UL. In addition, both the base station 10 and the terminal 20 may communicate via a secondary cell (SCell: Secondary Cell) and a primary cell (PCell: Primary Cell) using CA (Carrier Aggregation). Furthermore, the terminal 20 may communicate via a primary cell of the base station 10 and a primary secondary cell group cell (PSCell: Primary SCG Cell) of another base station 10 using DC (Dual Connectivity).

[0024] The terminal 20 is a communication device equipped with a wireless communication function, such as a smartphone, a mobile phone, a tablet, a wearable terminal, or an M2M (Machine-to-Machine) communication module. As shown in Fig. 1, the terminal 20 receives control signals or data from the base station 10 via DL and transmits control signals or data to the base station 10 via UL, thereby utilizing various communication services provided by the wireless communication system. The terminal 20 also receives various reference signals transmitted from the base station 10 and measures the propagation path quality based on the reception results of the reference signals.

[0025] Terminal 20 is capable of performing carrier aggregation, which aggregates multiple cells (multiple CCs (Component Carriers)) to communicate with base station 10. In carrier aggregation, one PCell (Primary cell) and one or more SCells (Secondary cells) are used. Also, a PUCCH SCell having a PUCCH may be used.

[0026] FIG. 2 is a diagram illustrating an example (2) of a wireless communication system according to an embodiment of the present invention. FIG. 2 shows an example of the configuration of a wireless communication system in which DC (Dual Connectivity) is implemented. As shown in FIG. 2, a base station 10A serving as an MN (Master Node) and a base station 10B serving as an SN (Secondary Node) are provided. The base station 10A and the base station 10B are each connected to a core network. The terminal 20 can communicate with both the base station 10A and the base station 10B.

[0027] A cell group provided by base station 10A, which is an MN, is called an MCG (Master Cell Group), and a cell group provided by base station 10B, which is an SN, is called an SCG (Secondary Cell Group). In addition, in a DC, an MCG is composed of one PCell and one or more SCells, and an SCG is composed of one PSCell (Primary SCG Cell) and one or more SCells.

[0028] The processing operations in this embodiment may be executed in the system configuration shown in FIG. 1, in the system configuration shown in FIG. 2, or in any other system configuration.

[0029] 3GPP is currently studying ways to enhance multi-carrier operation. Specifically, it is considering the operation of a terminal that supports up to two simultaneous transmissions in FR1 (Frequency Range 1) to dynamically switch the band for UL transmission across three or four bands. In the following explanation, the terms "carrier," "CC," and "cell" may be used interchangeably.

[0030] (Regarding the Issues) In the prior art (Rel-16, Rel-17), a UL Tx switching function (uplink transmission switching function) that can switch UL transmission between two bands (two carriers) is supported in terminal 20. Even in terminal 20 that has only two transmission chains (Tx Chains), by using the UL Tx switching function, it is possible to perform operations such as transmitting using two antenna ports for one carrier, or using one antenna port for one carrier and another antenna port for another carrier by switching over time.

[0031] The transmission chain (which may also be called a Tx Chain or transmission system) is a physical function for transmission in the terminal 20, regardless of whether actual transmission is performed. One transmission chain can perform transmission using one carrier. By switching the carrier used by the transmission chain (the transmission function unit corresponding to the carrier), the carrier that can be transmitted by the transmission chain can be switched.

[0032] An antenna port is an antenna that can actually transmit using a transmit chain (Tx Chain). The terms transmit chain and antenna port are sometimes used synonymously. Also, an "antenna port" may be called a "port."

[0033] In the following description, unless otherwise specified, one band has one carrier. Therefore, in this specification and claims, "band" may be replaced with "carrier" and "carrier" may be replaced with "band." However, having one carrier in one band is an example, and one band may have multiple carriers. When one band has multiple carriers, the number and relationship of the carriers may be limited, for example, to two carriers that are contiguous in frequency. Multiple carriers in one band may be treated the same as one UL band (carrier) in the following description.

[0034] 3GPP is considering "UL Tx switching schemes across up to 3 or 4 bands with restriction of up to 2 Tx simultaneous transmission for FR1 UEs" (a function that enables UEs that support up to two simultaneous transmissions in FR1 to dynamically switch the UL transmission band across 3 or 4 bands). For convenience, this function may be called "Rel-18 UL Tx switching."

[0035] The above function allows a terminal that cannot perform UL CA (Carrier Aggregation) or can perform only up to two UL CAs to set three or four UL bands (carriers) and dynamically instruct the base station 10 to transmit on one or two of these UL bands (carriers).

[0036] This function allows the terminal 20 to be instructed to perform UL transmission using a UL band (carrier) suitable for use in each time resource, taking into consideration the traffic conditions and TDD configuration among multiple UL bands (carriers). This improves frequency utilization efficiency and UL throughput.

[0037] Rel-16 and Rel-17 specify UL Tx switching between two bands. However, in Rel-18 UL Tx switching, it is not clear how to set the UL band (carrier) that is a candidate for switching to the terminal 20.

[0038] Conventionally, in a terminal 20 supporting UL CA, multiple DL / UL carriers can be configured as serving cells with the number of CCs of the UL CA supported by the terminal 20, and the UL CC to be used for transmission can be dynamically specified among them. However, in Rel-18 UL Tx switching, it is necessary to configure a number of UL carriers greater than the number of CCs of the UL CA supported by the UL CA. However, conventional technology does not anticipate configuring a number of UL CCs greater than the supported number.

[0039] Another existing technology is supplemental uplink (SUL), which supports linking with and dynamic switching to normal uplink (NUL) in its framework, but is not intended to be extended.

[0040] In the following, we first explain UL Tx switching for Rel-16 and R-17. Then we explain the capabilities and configuration information proposed for Rel-18 UL Tx switching. However, the capabilities and configuration information specified for UL Tx switching for Rel-16 and R-17 may also be applied to Rel-18 UL Tx switching.

[0041] We will also explain the UL Tx switching for Rel-16 and R-17. Regarding power boosting, switching period, DL interruption, etc., the operation of these factors is basically the same in Rel-18 UL Tx switching as in Rel-16 and R-17.

[0042] (UL Tx switching in Rel-16) In Rel-16, the terminal 20 supports two carriers and has two transmission chains. One transmission chain is fixed to one carrier, while the other transmission chain can be associated with either of the two carriers using a switch. This allows, for example, simultaneous transmission using two antenna ports with one carrier. It is also possible for each antenna port to transmit using one carrier per antenna port. These methods can be dynamically switched. UL Tx switching in Rel-16 is called Rel-16 1Tx-2Tx switching.

[0043] As shown in FIG. 3, a configuration in which each transmission chain is associated with one carrier is called Case 1, and a configuration in which two transmission chains are associated with one carrier is called Case 2.

[0044] Figure 4 shows the configuration of the transmission chains used for transmission in the SUL for Case 1 and Case 2. For example, 1T+1T in Case 1 means that in the example of Figure 3, carrier 2 is connected to transmission chain 1, and carrier 1 is connected to transmission chain 2.

[0045] Also, 1P+0P in the 1T+1T state means that transmission is performed using carrier 1 on antenna port 2, but no transmission is performed on antenna port 1. In SUL, two carriers cannot be set simultaneously, so 1P+1P does not exist. Also, in SUL, transmission of only NUL (carrier 2) is not assumed in case 1, so 0P+1P does not exist.

[0046] Also, "0P+2P, 0P+1P" in case 2 means that transmission is performed using carrier 2 on antenna port 1 and antenna port 2, or that transmission is performed using carrier 2 on antenna port 1 only.

[0047] Rel-16 1Tx-2Tx switching in inter-band CA / EN-DC has two options: Option 1, which does not allow two carriers to be used simultaneously, and Option 2, which allows two carriers to be used simultaneously. The transmit chain configuration used for transmission in Option 1 is the same as that shown in Figure 4. The transmit chain configuration used for transmission in Option 2 is as shown in Figure 5.

[0048] Fig. 6 shows an example of UE capability that is defined in accordance with Rel-16 1Tx-2Tx switching and that is reported from terminal 20 to base station 10. Fig. 7 shows an example of CellGroupConfig and ServingCellConfig that are defined in accordance with Rel-16 1Tx-2Tx switching and that are set in terminal 20 by base station 10.

[0049] The uplinkTxSwitchingPeriodLocation-r16 in the ServingCellConfig indicates whether a UL Tx switching period is configured in the target cell (carrier). Examples of operation related to the UL Tx switching period are shown in Figures 8 and 9. Figure 8 shows an example in which a UL Tx switching period is configured to occur in carrier 1. In this case, a UL Tx switching period occurs in carrier 1 whether switching from carrier 1 to carrier 2 or from carrier 2 to carrier 1 is performed. For example, in the case of Figure 8, if an instruction to switch to carrier 2 is received while transmitting on carrier 1, transmission on carrier 2 will occur after the switching time (switching period) on carrier 1. Figure 9 shows an example in which a UL Tx switching period is configured to occur in carrier 2.

[0050] When dynamically switching between two carriers, the terminal 20 is allowed a DL interruption of a predetermined length in the DL carrier that overlaps with the UL switching period, the length of which (X OFDM symbols) is specified as shown in Figure 10.

[0051] The UL Tx switching in Rel-16 can be summarized as follows: Based on PUSCH scheduling (scheduling command, rank adaptation) from the base station 10, the terminal 20 can dynamically switch between "single-port transmission on carrier 1," "single-port transmission on carrier 2," "single-port transmission on carrier 1 + one-port transmission on carrier 2" (applicable only when option 2 is supported in inter-band CA), and "two-port transmission on carrier 2 (with or without 3 dB power boosting)."

[0052] A switching period occurs when the carrier connected to the transmit port is switched, and during this switching period, no UL transmission is performed on either carrier. In addition, a DL interruption may occur during the switching period.

[0053] <Rel-17> Next, Rel-17 will be described. In Rel-17, two transmission chains each can support two carriers, resulting in 2Tx-2Tx UL Tx switching. Since two-port transmission is also possible with carrier 1, compared to Rel-16, Case 3 is added to Cases 1 and 2 as a case of connection patterns between transmission chains and carriers, as shown in FIG. 11 . Therefore, it is necessary for the terminal 20 and the base station 10 to distinguish between Rel-17 (2Tx-2Tx UL Tx switching) and Rel-16 (1Tx-2Tx).

[0054] In Rel-17 (2Tx-2Tx UL Tx switching), the pattern of the number of transmit ports in each case is as shown in Figure 12. Figure 12 shows the pattern of the number of transmit ports for each case and each option (whether simultaneous transmission of two carriers is possible or not).

[0055] Here, for example, if 1P+0P is instructed in case 2 for terminal 20 performing UL CA option 2, or if 0P+1P is instructed in case 3, terminal 20 must decide which of the remaining two cases to switch to.

[0056] Fig. 13 shows an example of RRC settings in Rel-17. In Fig. 13, uplinkTxSwitching-2T-Mode-r17 indicates a setting to switch to 2Tx-2Tx UL Tx switching mode, and uplinkTxSwitching-DualUL-TxState-r17 is information for setting which case to switch to when there are multiple candidates for which case to switch to at the time of switching, as described above.

[0057] In addition, in the UL Tx switching of Rel-17, there are two bands, and one of the bands supports the use of two consecutive carriers, as shown in Figure 14. Examples of the configuration of the transmit port for each case in the example of Figure 14 are shown in Figures 15 and 16.

[0058] The functions, setting values, and specified values ​​of Rel-16 and R-17 described above may be applied to Rel-18 UL Tx switching.

[0059] (Rel-18 UL Tx switching) Possible cases for Rel-18 UL Tx switching and the configuration of ports that transmit in each case are shown in Figures 17 and 18. Here, as an example, four bands, A to B, are available for UL Tx switching.

[0060] As shown in Figure 17, there are two Tx Chains (two antenna ports), each of which can be switched to one of bands A to D. This is referred to as "2Tx-2Tx (-2Tx-2Tx) switching." Assuming one carrier is available for each band, the maximum number of cases is 10, as shown in Figure 18 (assuming CA option 2).

[0061] In addition to the above assumptions, a case of 1Tx-2Tx (-1Tx-1Tx) switching, in which the band (carrier) that one port can use is fixed, can also be considered.

[0062] Furthermore, as shown in FIG. 14, there may be cases where some bands have two consecutive carriers (a total of five or more carriers).

[0063] Regarding the Rel-18 UL Tx switching assumed as described above, there is no prior art regarding the capability report from the terminal 20 to the base station 10 and the contents of the settings / instructions from the base station 10 to the terminal 20. Therefore, with the prior art, it may not be possible to properly implement "UL Tx switching schemes across up to 3 or 4 bands with the restriction of up to 2 Tx simultaneous transmission."

[0064] Therefore, in this embodiment, a capability report and settings / instructions that enable appropriate implementation of "UL Tx switching schemes across up to 3 or 4 bands with the restriction of up to 2 Tx simultaneous transmission" will be described.

[0065] In this embodiment, "UL Tx switching schemes across up to 3 or 4 bands with the restriction of up to 2 Tx simultaneous transmission" is assumed, but this is just an example. The maximum number of bands within which transmission switching is performed may be greater than 4. Furthermore, the number of antenna ports used for transmission may be greater than 2. In other words, simultaneous transmission may occur on three or more antenna ports.

[0066] (Outline of the embodiment) The present embodiment includes first to third embodiments. An example of a basic operation common to the first to third embodiments will be described with reference to FIG.

[0067] In S101, the terminal 20 transmits capability information to the base station 10. An example of the capability information will be described in the first embodiment. In S102, the base station 10 transmits setting information (or instruction information) to the terminal 20. An example of the setting information / instruction information will be described in the second embodiment.

[0068] The base station 10 determines the setting / instruction contents for the terminal 20 within the range of the capabilities of the terminal 20 indicated in the capability information of the terminal 20 received in S101, creates the setting information / instruction information, and transmits it in S102. However, this assumption is just an example.

[0069] The terminal 20 that received the setting information / instruction information in S102 operates in accordance with that information. When the terminal 20 receives DCI from the base station 10 in S103, for example, in accordance with the setting information, the terminal 20 switches the band to which the port is connected based on the DCI, and performs transmission through the port after the switch in S104.

[0070] The transmission of the configuration information / instruction information at S102 may be performed by any of RRC signaling, MAC CE, and DCI. The first and second embodiments are each outlined below.

[0071] <Outline of First Embodiment> The terminal 20 reports at least one of the plurality of pieces of capability information listed below as capability information (capability) for functions supported by the terminal 20 for Rel-18 UL Tx switching to the base station 10. All of the examples listed below are examples of capability information related to bands.

[0072] ・Supported band combinations for UL Tx switching (e.g., up to 3 or 4 bands) ・Number of CCs that can be supported in each band ・Whether or not a DL carrier (downlink carrier) linked to each band is required ・For each combination of bands to be switched, {whether simultaneous transmission is supported, switching period, bands where DL interruption occurs, whether power boosting is supported} ・Number of ports that can switch bands ・Target bands for ports where the band is fixed ・Candidate bands for switching for each port

[0073] <Outline of Second Embodiment> The terminal 20 receives at least one of the multiple pieces of setting information / instruction information listed below from the base station 10 as setting information / instruction information for Rel-18 UL Tx switching. In other words, the base station 10 transmits at least one of the multiple pieces of setting information / instruction information listed below to the terminal 20. All of the examples listed below are examples of information related to band switching.

[0074] ・DL / UL serving cell and UL-only serving cell (or either DL / UL serving cell or UL-only serving cell) including UL used for Rel-18 UL Tx switching ・Other serving cells to which switching and / or simultaneous transmission can be instructed in each serving cell ・For each combination of each serving cell with other serving cells (whether or not a switching period is included, whether power boosting is allowed, whether simultaneous transmission is allowed, and case interpretation when switching from a specific port configuration to another specific port configuration is instructed) ・Number of ports subject to band switching ・Whether or not each serving cell is linked to a port subject to band switching (or not) The first and second embodiments will be described in detail below. Examples 1 to 9 of the first embodiment can be implemented in combination with any of Examples 1 to 9 of the second embodiment.

[0075] (First embodiment) In the first embodiment, the terminal 20 reports to the base station at least one of the capability information shown in the following examples 1 to 9. Also, the terminal 20 may report information that combines any or all of the capability information shown in examples 1 to 9.

[0076] <Example 1> The terminal 20 reports information on one or more band combinations (BCs) for UL Tx switching supported for Rel-18 UL Tx switching to the base station 10 separately from the BCs for UL CA.

[0077] The reported band combinations (BCs) for UL Tx switching may include BCs that are not compliant with UL CA. Each BC included in one or more band combinations (BCs) for UL Tx switching may be information indicating a combination of bands to be switched.

[0078] For example, when the terminal 20 reports BC1, BC2, and BC3 as BCs for UL CA, the terminal 20 may report BC4 and BC5 as band combinations (BCs) for UL Tx switching.

[0079] As a variation, there may be a restriction that each band combination (BC) included in one or more band combinations (BCs) for UL Tx switching to be reported must be a BC that supports UL CA.

[0080] As another variation, when reporting a BC for UL Tx switching in Rel-18, it may be necessary to report the capabilities specified in Rel-16 / 17 for each band combination within the BC. In this case, for example, when reporting a BC for Bands ABC in Rel-18, it is necessary to report the capabilities specified in Rel-16 / 17 for AB, AC, and BC.

[0081] As another variation, when reporting a BC for UL Tx switching in Rel-18, there may be a restriction that each "band combination" within the BC must be supported. In this case, for example, when reporting a BC for Band ABC in Rel-18, it is also necessary to support AB, AC, and BC.

[0082] <Example 2> The terminal 20 reports information about the number of CCs supported in each band of the BC for UL Tx switching described in Example 1 to the base station 10. The information about the number of CCs may be the number of CCs (number of cells) itself. Note that the band in Example 2 (the band for which the number of CCs is reported) may be a band other than the band within the BC reported in Example 1.

[0083] Furthermore, the specifications may specify the upper limit of the number of CCs or the total bandwidth that can be supported in each band in Rel-18 UL Tx switching. For example, for each band, the number of CCs that terminal 20 can support may be specified as "up to two consecutive CCs" or "consecutive CCs within a 100 MHz band." Furthermore, the upper limit of the number of CCs that can be supported or the total bandwidth may be specified for TDD and FDD separately, rather than for each band. For example, base station 10 sets CCs within the band for UL Tx switching for terminal 20 according to these specifications.

[0084] <Example 3> The terminal 20 reports to the base station 10 information on whether or not a DL carrier associated with each band of the BC for UL Tx switching described in Example 1 is required. For example, if a certain BC has bands A, B, and C, the terminal 20 reports information such as {band A: DL carrier required, band B: DL carrier not required, band C: DL carrier not required} for the BC. Note that the terminal 20 basically only needs to be able to perform DL reception with any of the carriers, and therefore may determine that a DL carrier is not required in a certain band.

[0085] In addition, the specifications may specify conditions for UL carriers / bands that do not require an associated DL carrier. Examples of such conditions include TDD (or FDD), a specific band, or only when a specific band is included in the BC.

[0086] Note that the band in Example 3 (the band for reporting whether or not the DL carrier is required) may be a band other than the band within the BC reported in Example 1.

[0087] <Example 4> The terminal 20 reports to the base station 10 information on whether simultaneous transmission is supported for each combination of bands switched in the BC for UL Tx switching described in Example 1.

[0088] For example, the terminal 20 reports to the base station 10 information such as that in BC of bands ABCD, bands AB are capable of simultaneous transmission (dual UL or both) and bands AC and AD are not capable of simultaneous transmission (switched UL).

[0089] In addition, the terminal 20 may report to the base station 10 information regarding whether simultaneous transmission is supported for each band, or for all combinations within a BC, or for all BCs for Rel-18 UL Tx switching supported by the terminal 20, rather than for each combination of bands to be switched.

[0090] The band in Example 4 (the band for which the presence or absence of simultaneous transmission support is reported) may be a band other than the band within the BC reported in Example 1.

[0091] <Example 5> The terminal 20 reports information about the switching period for each combination of bands to be switched in the BC for UL Tx switching described in Example 1. The information about the switching period may be the value of the switching period.

[0092] For example, the terminal 20 reports to the base station 10 information such as that in BC of bands ABCD, the switching period for band AB is n35 μs, and for AC and AD it is n140 μs.

[0093] Furthermore, the terminal 20 may report to the base station 10 information on the switching period not for each combination of bands to be switched, but for each band, or for all combinations within the above BCs, or for all BCs for Rel-18 UL Tx switching supported by the terminal.

[0094] Additionally, new candidate values ​​for the switching period may be defined for Rel-18 UL Tx switching, and some values ​​that could be reported for Rel-16 / 17 may not be reportable for Rel-18.

[0095] Note that the band in Example 5 (the band for reporting the switching period) may be a band other than the band within the BC reported in Example 1.

[0096] Example 6 The terminal 20 may report the bands in which DL interruptions occur for each combination of bands switched in the BC for UL Tx switching described in Example 1.

[0097] For example, the terminal 20 reports to the base station 10 that, for BC of band ABCD, 0100 is reported for band AB, and 1010 is reported for AC. This bitmap indicates bands ABCD, and means that a DL interruption occurs when switching in the band corresponding to a bit of 1.

[0098] Furthermore, the terminal 20 may report to the base station 10 information on the bands in which DL interruptions occur, not for each combination of bands to be switched, but for each band, or for all combinations within the above BCs, or for all BCs for Rel-18 UL Tx switching supported by the terminal.

[0099] Furthermore, the specifications may stipulate whether DL interruption is permitted for each band combination for Rel-18 UL Tx switching, or for each combination of two bands within a band combination.

[0100] Note that the band in Example 6 (the band for reporting DL interruption) may be a band other than the band within the BC reported in Example 1.

[0101] In Example 6, when the base station 10 receives information indicating that a DL interruption will occur in a certain band, the base station 10 may, for example, schedule DL reception in that band, taking into account the possibility of a DL interruption occurring.

[0102] <Example 7> The terminal 20 may report information on whether power boosting is supported for each combination of bands switched in the BC for UL Tx switching described in Example 1.

[0103] For example, the terminal 20 reports to the base station 10 information such as that, in band BC of bands ABCD, power boosting is possible in band AB but not possible in AC and AD. "Power boosting possible in bands AB" means, for example, that when the terminal 20 switches ports between bands AB and ends up transmitting from two ports in one band, the transmission power (output power) can be increased. Alternatively, "power boosting possible in bands AB" may mean that the transmission power (output power) can be increased when transmitting simultaneously on bands A and B.

[0104] Furthermore, the terminal 20 may report to the base station 10 information on whether power boosting is supported for each band, or for all combinations within a BC, or for all BCs for Rel-18 UL Tx switching supported by the terminal, rather than for each combination of bands to be switched.

[0105] The band in Example 7 (the band for which the availability of power boosting is reported) may be a band other than the band within the BC reported in Example 1.

[0106] When the base station 10 receives information indicating that power boosting is possible in a certain band, it may perform transmission power control on the terminal 20 using DCI or MAC CE so that power boosting is performed when scheduling simultaneous two-port transmission in that band.

[0107] <Example 8> The terminal 20 may report to the base station 10 information regarding the number of ports (e.g., 1 or 2) that can switch bands within the BC for UL Tx switching described in Example 1. Also, if there is a port for which the band is fixed, the terminal 20 may report the target band of the port for which the band is fixed. For example, the terminal 20 may report to the base station 10 information such as, "Port 1 is fixed to Band A in a BC of Bands ABCD."

[0108] In addition, if there is a port for which the band is fixed, a predetermined number of layers (e.g., 2) may be reported as the number of MIMO layers for that target band, and the predetermined number of layers (e.g., 2) may not be reported as the number of MIMO layers for other bands.

[0109] The band in Example 8 (the band for which the number of band-switchable ports is reported) may be a band other than the band within the BC reported in Example 1.

[0110] <Example 9> The terminal 20 may report information about switching candidate bands for each port in the BC for UL Tx switching described in Example 1. For example, the terminal 20 reports to the base station 10 information such as, in the BC of band ABCD, A and B are switching candidates for port 1, and A, B, C, and D are switching candidates for port 2.

[0111] Furthermore, the terminal 20 may report to the base station 10 the number of ports supported in each band within the BC (for example, A is 2, B is 2, C is 1, D is 1, etc.).

[0112] The band (candidate band for switching) in Example 9 may be a band other than the band within the BC reported in Example 1.

[0113] As described above, the technology according to the first embodiment explained using Examples 1 to 9 allows the base station 10 to know the UL Tx switching capabilities of the terminal 20, and therefore makes it possible to perform settings, instructions, or scheduling to appropriately perform UL Tx switching.

[0114] Second Embodiment In a second embodiment, the terminal 20 is configured or instructed by the base station 10 to use at least one of the following examples 1 to 9 by using any one or a combination of several of RRC signaling, MAC-CE, and DCI. Also, a combination of several or all of examples 1 to 9 may be configured or instructed by the base station 10 to the terminal 20.

[0115] <Example 1> A DL / UL serving cell (a cell having a UL carrier and a DL carrier) including a UL used for Rel-18 UL Tx switching, or a UL only serving cell (a cell with only a UL carrier) including a UL used for Rel-18 UL Tx switching, is configured to the terminal 20 by the base station 10. The terminal 20 may be configured with both a DL / UL serving cell including a UL used for Rel-18 UL Tx switching and a UL only serving cell including a UL used for Rel-18 UL Tx switching by the base station 10. Here, "certain information is configured" means that the terminal 20 receives the information from the base station 10.

[0116] The base station 10 can determine which cell to set for the terminal 20 based on the Capability received from the terminal 20 in the first embodiment. For example, the base station 10 can set the cell (carrier) included in the BC received in Example 1 of the first embodiment as the serving cell for the terminal 20.

[0117] Furthermore, for example, the base station 10 may set a cell in a band where the DL carrier is not required as a UL only serving cell to the terminal 20 based on the information received in Example 3 of the first embodiment.

[0118] The serving cell in the following Examples 2 to 9 is assumed to be the cell set in the terminal 20 in Example 1. However, this is not limited to this, and the serving cell in the following Examples 2 to 9 may be a cell other than the cell set in Example 1.

[0119] The settings / instructions in the following examples 2 to 9 may be made when the cell is set in example 1, or may be made at a timing after the cell is set in example 1.

[0120] <Example 2> When the terminal 20 receives a specific IE / parameter from the base station 10 by ServingCellConfig for a certain cell, the specific IE / parameter is set in the terminal 20.

[0121] The terminal 20 may recognize that the cell includes a UL used for Rel-18 UL Tx switching based on a specific IE / parameter received from the base station 10. Note that ServingCellConfig is an example, and other messages or signals may be used.

[0122] <Example 3> When a specific IE / parameter is set by the ServingCellConfig for a certain cell from the base station 10, the terminal 20 may recognize that the cell is a UL-only serving cell used for Rel-18 UL Tx switching.

[0123] Furthermore, the terminal 20 may recognize from the base station 10 that a particular IE / parameter is not set in the ServingCellConfig for a certain cell, and therefore the cell is a UL-only serving cell used for Rel-18 UL Tx switching.

[0124] Note that ServingCellConfig is an example, and other messages or signals may be used.

[0125] <Example 4> Information about other serving cells for which switching and / or simultaneous transmission can be instructed in each serving cell is configured in terminal 20 by base station 10. For example, assume that ServingCellConfig includes information about other serving cells for which switching / simultaneous transmission can be instructed.

[0126] For example, when terminal 20 receives an RRC message (e.g., ServingCellConfig) for cell A and detects in that RRC message that cell B is another serving cell for which switching / simultaneous transmission may be instructed, it assumes that switching / simultaneous transmission between cell A and cell B may be instructed.

[0127] <Example 5> Information regarding whether or not a switching period is included in each serving cell for each combination with another serving cell may be set to terminal 20 from base station 10. Alternatively, information regarding whether or not a switching period is included may be set for each serving cell or for each cell group, rather than for each combination with another serving cell.

[0128] For example, assume that a certain RRC message (e.g., ServingCellConfig, CellGroupConfig) includes information on whether or not a switching period is included. For example, assume that terminal 20 receives an RRC message for cell A and detects information in the RRC message that means that "when switching between cell A and cell B, a switching period exists in cell B." In this case, when terminal 20 receives UL scheduling information that causes switching between cell A and cell B, it performs switching in the switching period on the cell B side.

[0129] <Example 6> Information regarding whether power boosting is permitted for each serving cell for each combination with other serving cells is configured in terminal 20 by base station 10. Alternatively, information regarding whether power boosting is permitted may be configured on a serving cell basis or on a cell group basis, rather than for each combination with other serving cells.

[0130] For example, assume that a certain RRC message (e.g., ServingCellConfig, CellGroupConfig) contains information on whether power boosting is permitted. In this case, assume that terminal 20 receives the RRC message and detects information in the RRC message that means "power boosting is permitted when two-port simultaneous transmission is performed in cell A during switching between cell A and cell B." In this case, terminal 20 performs power boosting when it receives UL scheduling information indicating that two-port simultaneous transmission occurs in cell A due to switching from cell B to cell A.

[0131] <Example 7> Information regarding whether simultaneous transmission is permitted for each serving cell in combination with other serving cells is configured in terminal 20 from base station 10. Alternatively, information regarding whether simultaneous transmission is permitted may be configured on a serving cell basis or on a cell group basis, rather than on a serving cell basis. Regarding the configuration on a serving cell basis, for example, if "simultaneous transmission OK" is configured for cell A, this may mean that simultaneous transmission is OK with any cell in combination with cell A.

[0132] For example, assume that a certain RRC message (e.g., ServingCellConfig, CellGroupConfig) contains information regarding whether simultaneous transmission is permitted. In this case, assume that terminal 20 receives an RRC message for cell A and detects information within the RRC message indicating that "simultaneous transmission is permitted in cell A and cell B." In this case, it is assumed that terminal 20 receives UL scheduling information that causes simultaneous transmission in cell A and cell B. In this case, base station 10 can perform UL scheduling for terminal 20 that causes simultaneous transmission in cell A and cell B.

[0133] <Example 8> Information regarding case interpretation when a switching from a specific port configuration to another specific port configuration is instructed in each serving cell for each combination with another serving cell from the base station 10 may be set to the terminal 20. Alternatively, information regarding case interpretation when a switching from a specific port configuration to another specific port configuration is instructed on a serving cell basis or on a cell group basis, rather than for each combination with another serving cell, may be set.

[0134] For example, assume that information regarding case interpretation is included in a certain RRC message (e.g., ServingCellConfig, CellGroupConfig).

[0135] At this time, for example, when the terminal 20 receives the above-mentioned RRC message and detects that the RRC message contains "information for uniquely determining the case number of the destination when transitioning from a certain Tx chain state (certain case number) to another Tx chain state (another case number) after UL Tx switching and the case number of the destination cannot be uniquely determined," it determines the Tx chain (port configuration) to transition to after UL Tx switching according to the information.

[0136] The above "information for determination" may be an explicit "pair of case number before transition and case number to transition to," or it may be information indicating that "two ports are connected to one carrier," or information indicating that "one port is connected to one carrier."

[0137] Here, as an example, it is assumed that the case configurations and transmission port configurations of Figures 17 and 18 are used. Also, it is assumed that "option 2: simultaneous transmission across up to 2 carriers" is set. For ease of explanation, it is assumed that only Case 1, Case 2, and Case 3 of Figure 18 are used.

[0138] Assume that the above explicit information is set in terminal 20 as follows: "If terminal 20 is in case 2 before transition and there are cases 1 and 3 as candidate transition destinations, transition to case 3." In this case, terminal 20 switches to case 3 when, while in the case 2 state, scheduling equivalent to 1P+0P+0P+0P is performed by DCI.

[0139] It is assumed that the above information indicating that "one port is connected to one carrier" is set in the terminal 20. In this case, when the terminal 20 is in the state of case 2 and UL transmission of 1P+0P+0P+0P is scheduled by DCI, the terminal 20 switches to case 1.

[0140] The base station 10 can perform subsequent scheduling by assuming the above-mentioned transition destination.

[0141] <Example 9> Information regarding the number of ports subject to band switching on a cell group basis is configured in the terminal 20 by the base station 10. In addition to this, or instead of this, information regarding whether each serving cell is linked to a port subject to band switching may be configured in the terminal 20 by the base station 10. Furthermore, information regarding whether each serving cell is linked to a port not subject to band switching may be configured in the terminal 20 by the base station 10.

[0142] Information about whether a serving cell is associated with a port that is subject to band switching is an example of information about an antenna port that is subject to band switching. Information about whether a serving cell is associated with a port that is not subject to band switching is an example of information about an antenna port that is not subject to band switching.

[0143] For example, when terminal 20 receives information from base station 10 via an RRC message that corresponds to "cells A and B are subject to switching of port 1, and cell C uses port 2 fixedly," it is assumed that scheduling is performed corresponding to "transmission is performed in cell A or cell B using port 1, and in cell C using port 2." Furthermore, base station 10 can perform scheduling for terminal 20 that corresponds to "transmission is performed in cell A or cell B using port 1, and in cell C using port 2."

[0144] As described above, the technology according to the second embodiment using Examples 1 to 9 allows the base station 10 to set / instruct the terminal 20 according to its capabilities related to UL Tx switching, thereby enabling the terminal 20 to appropriately perform UL Tx switching.

[0145] (Third embodiment) <Prerequisites and problems> Regarding the above-mentioned UL Tx switching schemes across up to 3 or 4 bands with the restriction of up to 2 Tx simultaneous transmission (UL Tx switching schemes across up to 3 or 4 bands), a certain amount of time is required to switch UL transmission between the bands.

[0146] The time required for such switching may be called a switching period or a switching gap length. The switching period is used as a term when reporting a UE's capability, and the switching gap length may be used as the time actually required for switching.

[0147] For example, in the case of UL Tx switching between four bands, when switching from a 1T+1T configuration of band A and band B to a 1T+1T configuration of band C and band D (expressed as A+B→C+D), two switching patterns are possible. Specifically, two switching patterns are possible: a combination of switching from band A to band C and from band B to band D, or a combination of switching from band A to band D and from band B to band C.

[0148] The network (gNB) and UE may assume the longest switching period between each band pair (A⇔C, B⇔D, A⇔D, B⇔C) reported by the UE as the switching gap length (such an assumption may be referred to as the Baseline UE assumption).

[0149] Specifically, in the Baseline UE assumption, when switching from A+B to C+D, it is agreed that the network may assume the longest switching period reported by the UE as the worst-case length of the switching period among the switching periods A⇔C, B⇔D, A⇔D, and B⇔C without taking into account the ambiguity of whether the switching pattern is (A⇔C)+(B→D) or (A⇔D)+(B→C) (see Non-Patent Document 2).

[0150] For example, if the switching periods reported by the UE are A⇔C = 35 μs, B⇔D = 140 μs, A⇔D = 140 μs, and B⇔C = 210 μs (see Figure 17), the network may assume a switching gap length of 210 μs for UL Tx switching from A+B to C+D.

[0151] Furthermore, 3GPP has agreed that, as an option for UE capability, when switching from A+B to C+D, a different value can be reported instead of assuming the longest value among the switching periods A⇔C, B⇔D, A⇔D, and B⇔C (see Non-Patent Document 4).

[0152] For example, if A⇔C = 35 μs, B⇔D = 35 μs, A⇔D = 35 μs, and B⇔C = 35 μs, the UE can report a switching period of 140 μs for switching from A+B to C+D. The network may assume a switching period (switching gap length) of 140 μs instead of 35 μs for switching from A+B to C+D.

[0153] Furthermore, in the case of switching from A+B to C+D, the switching combination of (A→C)+(B→D) or the switching combination of (A→D)+(B→C) can be considered, but it has also been agreed upon to specify either of the switching combinations (band ordering based approach) (see Non-Patent Document 6).

[0154] (1) Issue 1 According to the current agreement on reporting and assumption of switching periods, the candidate values ​​of both switchingPeriodFor2T-r18 and switchingPeriodFor1T-r18 (switching periods for Baseline UE assumption, see Non-Patent Document 5) and UplinkTxSwitchingAdditionalPeriodDualUL-r18 (switching period for optional UE capability) are ENUMERATED {n35 us, n140 us, n210 us}, and there are no particular restrictions on the reporting values.

[0155] For example, in the case of switching from A+B to C+C, if UplinkTxSwitchingAdditionalPeriodDualUL-r18 is not reported by the UE, the network assumes the longer switching period of A → C or B → C. On the other hand, if UplinkTxSwitchingAdditionalPeriodDualUL-r18 is reported by the UE, the network may assume the value reported by UplinkTxSwitchingAdditionalPeriodDualUL-r18.

[0156] If the value of the switching period reported by UplinkTxSwitchingAdditionalPeriodDualUL-r18 is longer than the longer of the A→C and B→C switching periods, it is possible to reflect an implementation in which the time required to sequentially execute (A→C)+(B→C) switching on two Tx chains simultaneously is secured rather than the switching period required for A→C or B→C switching on one Tx chain (this makes it possible to avoid reporting an excessively long A→C or B→C switching period).

[0157] However, conversely, when the value of the switching period reported by UplinkTxSwitchingAdditionalPeriodDualUL-r18 is shorter than the longer switching period between A → C and B → C, the question arises as to what switching period the network should assume. First of all, there is also the question of whether implementation should be assumed to accommodate cases where the value of the switching period reported by UplinkTxSwitchingAdditionalPeriodDualUL-r18 is shorter than the switching period for the Baseline UE assumption.

[0158] (2) Issue 2 As described above, in the case where A⇔C = 35 μs, B⇔D = 140 μs, A⇔D = 140 μs, and B⇔C = 210 μs, the network assumes a switching period of 210 μs for switching from A+B to C+D under the Baseline UE assumption. However, if an Optional UE capability based on the band ordering approach is reported, the network can assume a switching period of (A→C)+(B→D) for switching from A+B→C+D, resulting in a max(35, 140)=140 μs switching period.

[0159] However, the specific methods and / or constraints regarding the UE capability and band ordering based approach to be applied in this case have not been clarified, and there is a concern that simply applying the UE capability and band ordering based approach will not allow the network to determine an appropriate switching period, and normal and stable operation will not be guaranteed.

[0160] An example of operation that can solve the above-mentioned problems 1 and 2 will be described below.

[0161] <Operation Example 1> This operation example addresses issue 1. In this operation example, restrictions on the reported value of the capability related to the switching period in switching (A+B⇔C+C) in two Tx chains involving a total of three bands may be defined by the 3GPP specifications. Note that similar restrictions may also be applied to switching in two Tx chains involving a total of three or more bands (specifically, four bands).

[0162] For example, when UplinkTxSwitchingAdditionalPeriodDualUL-r18 is reported to the network for switching between A and B and C, the value of the UplinkTxSwitchingAdditionalPeriodDualUL-r18 may be reported to be always longer than the switching period for A and C and the switching period for B and C. Note that the value of the UplinkTxSwitchingAdditionalPeriodDualUL-r18 may be set to be the same as at least one of the switching period for A and C and the switching period for B and C.

[0163] That is, the UE may control UL transmission using N bands (N is a natural number equal to or less than M) selected from M bands (M is a natural number equal to or greater than 3), and transmit capability information to the network reporting switching periods indicating the time required for switching UL transmission between each of the M bands. In this case, when the UE reports an additional switching period (UplinkTxSwitchingAdditionalPeriodDualUL-r18) separate from the switching period for switching UL transmission between a specific pair of bands as described above, the UE may report a period that is always the same as or always longer than the switching period.

[0164] Alternatively, if the value of UplinkTxSwitchingAdditionalPeriodDualUL-r18 is the same as or shorter than the switching period for A⇔C and the switching period for B⇔C, the network does not need to apply the value of UplinkTxSwitchingAdditionalPeriodDualUL-r18.

[0165] That is, the UE may control UL transmission using N bands (N is a natural number equal to or less than M) selected from M bands (M is a natural number equal to or greater than 3), and transmit capability information to the network reporting switching periods indicating the time required for switching UL transmission between each of the M bands. In this case, if the time required for switching UL transmission between a specific pair of bands is equal to or shorter than the switching period, the UE may avoid reporting an additional switching period (UplinkTxSwitchingAdditionalPeriodDualUL-r18) separate from the switching period.

[0166] Note that the above-mentioned "switching period for A⇔C and switching period for B⇔C" may be a switching period for 1T (switchingPeriodFor1T-r18) or a switching period for 2T (switchingPeriodFor2T-r18). In this case, the network (and / or UE) may compare only one of the switching period for 1T or 2T with UplinkTxSwitchingAdditionalPeriodDualUL-r18, or may compare both the switching period for 1T or 2T with UplinkTxSwitchingAdditionalPeriodDualUL-r18 and perform the above-mentioned operation.

[0167] 20 shows an example of the capability of UplinkTxSwitchingAdditionalPeriodDualUL-r18. As shown in FIG. 20, it may be specified that the value of UplinkTxSwitchingAdditionalPeriodDualUL-r18 must be greater than the value reported by switchingPeriodFor2T-r18 (or SwitchingPeriodFor1T-r18) for switching one of bands, bandPairIndex1-r18 and BandIndex-r18 (see the underlined part). Note that the value of UplinkTxSwitchingAdditionalPeriodDualUL-r18 may be expressed as "The value shall not be smaller than..." or as follows:

[0168] - If the capability is not reported or is reported with the value in UplinkTxSwitchingAdditionalPeriodDualUL-r18 which is smaller than the one reported in switchingPeriodFor2T-r18 [or switchingPeriodFor1T-r18] for switching between any band in bandPairIndex1-r18 and bandIndex-r18. This operation example eliminates the ambiguity regarding the interpretation of the switching period for UL Tx switching schemes across up to 3 or 4 bands reported from the UE to the network, allowing the UE and network to operate in accordance with appropriate constraints, thereby determining an appropriate switching period and ensuring normal and stable operation of the network as a whole.

[0169] <Operational Example 2> This operational example addresses issue 2. In this operational example, restrictions on reporting values ​​of capability related to switching periods in switching involving a total of four bands (A+B⇔C+D) may be defined by 3GPP specifications.

[0170] For example, it may be specified that the UplinkTxSwitchingAdditionalPeriodDualUL-r18 report and the Optional UE capability report based on the band ordering approach are not both reported simultaneously for switching between A+B and C+D. In other words, it may be specified that only one of the reports is applied for switching between a certain band pair, and reporting both may be excluded.

[0171] As in the first operational example, the UE may control UL transmission using N bands (N is a natural number equal to or less than M) selected from M bands (M is a natural number equal to or greater than 3), and transmit capability information to the network reporting switching periods indicating the time required for switching UL transmission between each of the M bands. In this case, when M is 4 and N is 2 (but N may be 2 or greater), the UE may report only either an additional switching period (UplinkTxSwitchingAdditionalPeriodDualUL-r18) separate from the UL transmission switching period between a specific pair of bands, or specific inter-band switching information (bands indicated by a band ordering based approach) indicating switching of UL transmission between specific bands (e.g., (A → C) + (B → D)). Note that a specific band, a band combination (switching combination), or identification information indicating these may also be reported by the band ordering based approach.

[0172] Alternatively, for switching between A+B and C+D, both the UplinkTxSwitchingAdditionalPeriodDualUL-r18 report and the Optional UE capability report based on the band ordering approach may be reported. In this case, the expected length of the switching period may be defined by the 3GPP specifications.

[0173] For example, the switching period may be estimated according to a rule predefined by the 3GPP specifications, or the UE may determine the reporting method based on a setting from the base station. That is, the base station (network) may control UL reception using N bands (N is a natural number equal to or less than M) selected from M bands (M is a natural number equal to or greater than 3), and may receive capability information from the UE reporting a switching period indicating the time required for the UE to switch UL transmission between each of the M bands. In this case, the base station may determine whether to apply only the additional switching period (UplinkTxSwitchingAdditionalPeriodDualUL-r18) or specific inter-band switching information (reporting Optional UE capability using a band ordering based approach).

[0174] Next, we will explain a specific example of constraints on the reported value of the capability related to the switching period in switching involving a total of four bands (A+B⇔C+D).

[0175] For example, for switching between A+B and C+D, both UplinkTxSwitchingAdditionalPeriodDualUL-r18 and support for the band ordering based approach may not be reported, but only one of them may be reported. In this case, reporting of only either UplinkTxSwitchingAdditionalPeriodDualUL-r18 or support for the band ordering based approach may be specified by at least one of the following:

[0176] - (Example 1): A statement such as "UE reporting UplinkTxSwitchingAdditionalPeriodDualUL-r18shall not report xxx..." will be included in the 3GPP specifications.

[0177] - (Example 2): In the UE capability signaling, a format is used in which only one of the two can be reported (for example, a selective format).

[0178] As described above, both the UplinkTxSwitchingAdditionalPeriodDualUL-r18 and support for the band ordering based approach may be reported, and in this case, at least one of the following methods may be applied.

[0179] ・(Example 1): If either one (the one specified by the 3GPP specifications or the long (or short) value) is reported, the other report will be ignored.

[0180] - (Example 2): If both are reported, the base station sets which one to apply.

[0181] Furthermore, in this operation example, the value of the switching period reported by UplinkTxSwitchingAdditionalPeriodDualUL-r18 may be restricted in the same way as in Operation Example 1. For example, the value of UplinkTxSwitchingAdditionalPeriodDualUL-r18 may be always the same as any one of the switching periods for A⇔C, B⇔D, A⇔D, and B⇔C, or a value longer than the switching period.

[0182] According to this operation example, with regard to support for UplinkTxSwitchingAdditionalPeriodDualUL-r18 and the band ordering based approach, the ambiguity regarding the interpretation of the switching period for UL Tx switching schemes across up to 3 or 4 bands is resolved, and the UE and the network can operate in accordance with the appropriate constraints, thereby determining an appropriate switching period and ensuring normal and stable operation of the network as a whole.

[0183] <Others> Either one of the above-described operation example 1 and operation example 2 may be applied, or both may be applied simultaneously. Furthermore, as described above, the switching period may be interpreted as a value reported as a capability of the UE, but it may also be interpreted as the time actually required for switching (switching gap length).

[0184] (Device Configuration) Next, an example of the functional configuration of the base station 10 and the terminal 20 that execute the processes and operations described above will be described.

[0185] <Base Station 10> Fig. 21 is a diagram showing an example of the functional configuration of the base station 10. As shown in Fig. 21, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Fig. 21 is merely an example. The names of the functional divisions and functional units may be any as long as they can execute the operations related to the embodiment of the present invention. Furthermore, the transmitting unit 110 and the receiving unit 120 may be collectively referred to as a communication unit.

[0186] The transmitter 110 has a function of generating a signal to be transmitted to the terminal 20 and transmitting the signal wirelessly. The receiver 120 has a function of receiving various signals transmitted from the terminal 20 and acquiring, for example, information of a higher layer from the received signals. The transmitter 110 also has a function of transmitting, to the terminal 20, NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DCI via PDCCH, data via PDSCH, etc.

[0187] The setting unit 130 stores preset setting information and various setting information to be transmitted to the terminal 20 in a storage device provided in the setting unit 130, and reads out the information from the storage device as needed.

[0188] The control unit 140 schedules DL reception or UL transmission of the terminal 20 via the transmission unit 110. The control unit 140 also includes a function for performing LBT. The functional unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and the functional unit related to signal reception in the control unit 140 may be included in the reception unit 120. The transmission unit 110 may also be called a transmitter, and the reception unit 120 may also be called a receiver.

[0189] <Terminal 20> Fig. 22 is a diagram showing an example of the functional configuration of the terminal 20. As shown in Fig. 22, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Fig. 22 is merely an example. As long as the operations related to the embodiment of the present invention can be performed, the names of the functional divisions and functional units may be any. The transmitting unit 210 and the receiving unit 220 may be collectively referred to as a communication unit.

[0190] The transmitter 210 creates a transmission signal from transmission data and transmits the transmission signal wirelessly. The receiver 220 wirelessly receives various signals and acquires a higher layer signal from the received physical layer signal. The receiver 220 also has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, DCI via PDCCH, data via PDSCH, and the like transmitted from the base station 10. For example, the transmitter 210 may transmit a PSCCH (Physical Sidelink Control Channel), a PSSCH (Physical Sidelink Shared Channel), a PSDCH (Physical Sidelink Discovery Channel), a PSBCH (Physical Sidelink Broadcast Channel), and the like to another terminal 20 as D2D communication, and the receiver 220 may receive the PSCCH, PSSCH, PSDCH, or PSBCH from the other terminal 20. The transmitter 210 also includes the antenna port described in this embodiment.

[0191] The setting unit 230 stores various pieces of setting information received from the base station 10 or other terminals by the receiving unit 220 in a storage device provided in the setting unit 230, and reads the information from the storage device as needed. The setting unit 230 also stores setting information that is set in advance.

[0192] The control unit 240 controls the terminal 20. The functional unit in the control unit 240 related to signal transmission may be included in the transmission unit 210, and the functional unit in the control unit 240 related to signal reception may be included in the reception unit 220. Furthermore, the transmission unit 210 may be called a transmitter, and the reception unit 220 may be called a receiver.

[0193] This embodiment provides at least the following terminal, base station, and communication method. The terminal, base station, and communication method are described below in six supplementary notes 1 to 6.

[0194] <Supplementary Note 1> (Supplementary Note 1) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, a terminal comprising: a transmitter that reports the number of antenna ports that can switch bands to a base station as capability information; and a receiver that receives from the base station information regarding antenna ports that are to be subject to band switching, or information regarding antenna ports that are not to be subject to band switching.

[0195] (Supplementary Item 2) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, a terminal comprising: a transmitter that reports, to a base station, information on bands used by antenna ports for which band switching is not performed as capability information; and a receiver that receives, from the base station, information on antenna ports for which band switching is to be performed, or information on antenna ports for which band switching is not to be performed.

[0196] (Supplementary Item 3) The terminal according to Supplementary Item 1 or 2, wherein, when there is an antenna port for which band switching is not performed, the transmitting unit reports the number of MIMO layers of the band used by the antenna port as 2.

[0197] (Supplementary Item 4) The terminal according to any one of Supplementary Items 1 to 3, wherein the transmitting unit reports information on candidate bands for switching at each antenna port.

[0198] (Supplementary Item 5) In a transmission switching method in which at least one of a plurality of antenna ports in a terminal is capable of switching bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, the base station comprises: a receiving unit that receives from the terminal the number of antenna ports that can switch bands as capability information; and a transmitting unit that transmits to the terminal information about antenna ports that are targets of band switching or information about antenna ports that are not targets of band switching.

[0199] (Supplementary Item 6) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, a communication method executed by a terminal that reports the number of antenna ports that can switch bands to a base station as capability information, and receives from the base station information about antenna ports that are subject to band switching, or information about antenna ports that are not subject to band switching.

[0200] Any of the above items 1 to 6 provides a technology that enables appropriate switching of the band used for uplink transmission in a wireless communication system. According to Supplementary Item 3, it becomes possible to appropriately set the number of MIMO layers. According to Supplementary Item 4, it becomes possible to clearly define simultaneous monitoring, making the operation clear. It becomes possible to receive single control information well in the scheduling source cell. According to Supplementary Item 3, it becomes possible to clarify candidate bands for switching.

[0201] <Supplementary Note 2> (Supplementary Note 1) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, a terminal comprising: a transmitter that reports information about the bands used in the transmission switching method to a base station as capability information; and a receiver that, when transitioning from a certain state related to the plurality of antenna ports to another state by band switching, receives information from the base station for determining one of the plurality of states to be the transition destination, when there are multiple states that are candidates for the transition destination.

[0202] (Supplementary Item 2) The terminal according to Supplementary Item 1, wherein the receiving unit receives, as information for determining the one state, the maximum number of antenna ports that can be used for transmission in one band, or a pair of a state before the transition and a state to which the transition is to be made.

[0203] (Supplementary Item 3) The terminal according to Supplementary Item 1 or 2, wherein the transmitter reports to the base station the number of carriers supported in the band used in the transmission switching method.

[0204] (Supplementary Item 4) The terminal according to any one of Supplementary Items 1 to 3, wherein the transmitter reports information on whether a downlink carrier is required in the band used in the transmission switching method.

[0205] (Supplementary Item 5) In a transmission switching method in which at least one of a plurality of antenna ports in a terminal can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, a base station comprising: a receiving unit that receives, from the terminal, information on the bands to be used in the transmission switching method as capability information; and a transmitting unit that, when transitioning from a certain state related to the plurality of antenna ports to another state by band switching, if there are multiple candidate states to transition to, transmits information to the terminal to determine one of the multiple states.

[0206] (Supplementary Item 6) In a transmission switching method in which at least one of a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, information about the bands used in the transmission switching method is reported to a base station as capability information, and when transitioning from a certain state related to the plurality of antenna ports to another state by band switching, if there are multiple candidate states to transition to, a communication method executed by a terminal that receives information from the base station to determine one of the multiple states.

[0207] Any of the above items 1 to 6 provides a technology that enables appropriate switching of the band used for uplink transmission in a wireless communication system. Supplementary item 2 eliminates ambiguity of the transition destination and enables appropriate operation. Supplementary item 3 clarifies the number of carriers in a band. Supplementary item 4 makes it possible to set up a cell that does not have a downlink carrier.

[0208] <Supplementary Note 3> (Supplementary Note 1) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, a terminal comprising: a transmitter that reports capability information indicating whether power boosting is possible when transmitting using the plurality of antenna ports to a base station; and a receiver that receives information from the base station regarding whether power boosting is possible when transmitting using the plurality of antenna ports.

[0209] (Supplementary Item 2) The terminal according to Supplementary Item 1, wherein the transmitting unit reports to the base station the capability information indicating whether power boosting is possible for each combination of bands that is switched within a band combination, for each band, for all combinations of bands within a band combination, or for all supported band combinations.

[0210] (Supplementary Item 3) The terminal according to Supplementary Item 1 or 2, wherein the receiving unit receives information on whether or not power boosting is permitted for each combination of serving cells, each serving cell, or each cell group.

[0211] (Additional Item 4) In a transmission switching method in which at least one of a plurality of antenna ports in a terminal can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, a base station comprising: a receiving unit that receives capability information from the terminal indicating whether power boosting is possible when transmitting using the plurality of antenna ports; and a transmitting unit that transmits information to the terminal indicating whether power boosting is possible when transmitting using the plurality of antenna ports.

[0212] (Supplementary Item 5) In a transmission switching method in which at least one of a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, a communication method executed by a terminal that reports capability information indicating whether power boosting is possible when transmitting using a plurality of antenna ports to a base station and receives information from the base station regarding whether power boosting is possible when transmitting using a plurality of antenna ports.

[0213] Any of the above items 1 to 5 provides a technology that enables a wireless communication system to appropriately switch the band used for uplink transmission. According to Supplementary Item 2, information about power boosting can be reported in various units. According to Supplementary Item 3, information about power boosting can be set in various units.

[0214] <Supplementary Note 4> (Supplementary Note 1) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, the terminal comprises a transmitter that reports capability information relating to a band in which downlink communication interruption occurs during switching to a base station, and a receiver that receives control information for scheduling uplink transmission from the base station.

[0215] (Supplementary Item 2) The terminal according to Supplementary Item 1, wherein the transmitting unit reports to the base station the capability information regarding bands in which downlink communication interruption occurs during switching for each combination of bands for which transmission switching is performed within a band combination, for each band, for all combinations of bands within a band combination, or for all supported band combinations.

[0216] (Supplementary Item 3) The terminal according to Supplementary Item 1 or 2, wherein the transmitting unit reports, as the capability information, a bitmap in which each bit indicates whether or not there is a downstream communication interruption in a band.

[0217] (Additional Item 4) In a transmission switching method in which at least one antenna port of a terminal can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the multiple antenna ports, the base station comprises: a receiving unit that receives capability information from the terminal regarding bands in which downlink communication interruptions occur during switching; and a transmitting unit that transmits control information for scheduling uplink transmissions to the terminal.

[0218] (Supplementary Item 5) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, a communication method executed by a terminal that reports capability information regarding bands in which downlink communication interruptions occur during switching to a base station and receives control information for scheduling uplink transmissions from the base station.

[0219] Any of the above items 1 to 5 provides a technology that enables a wireless communication system to appropriately switch the band used for uplink transmission. According to the supplementary item 2, information about a downlink communication interruption can be reported in various units. According to the supplementary item 3, information about a downlink communication interruption can be reported efficiently.

[0220] <Supplementary Note 5> (Supplementary Note 1) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, the terminal comprises: a transmitter that reports capability information indicating a switching time required for switching between bands to a base station; and a receiver that receives information from the base station regarding a cell in which the switching time occurs.

[0221] (Supplementary Item 2) The terminal according to Supplementary Item 1, wherein the transmitting unit reports the capability information indicating the switching time to the base station for each combination of bands to be switched within a band combination, for each band, for all combinations of bands within a band combination, or for all supported band combinations.

[0222] (Supplementary Item 3) The terminal according to Supplementary Item 1 or 2, wherein the receiving unit receives information about a cell in which the switching time occurs for each combination of serving cells, for each serving cell, or for each cell group.

[0223] (Additional Item 4) In a transmission switching method in which at least one of a plurality of antenna ports in a terminal can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, the base station comprises: a receiving unit that receives capability information indicating a switching time required for switching between bands from the terminal; and a transmitting unit that transmits information regarding a cell in which the switching time occurs to the terminal.

[0224] (Supplementary Item 5) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, this method is executed by a terminal that reports capability information indicating the switching time required for switching between bands to a base station and receives information from the base station regarding the cell in which the switching time occurs.

[0225] Any of the above items 1 to 5 provides a technology that enables a wireless communication system to appropriately switch the band used for uplink transmission. According to Supplementary Item 2, capability information indicating the switching time can be reported in various units. According to Supplementary Item 3, information related to the switching time can be set in various units.

[0226] <Supplementary Note 6> (Supplementary Note 1) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, the terminal comprises a transmitter that reports capability information indicating whether simultaneous transmission is possible between bands to a base station, and a receiver that receives information from the base station regarding cells in which simultaneous transmission is permitted.

[0227] (Supplementary Item 2) The terminal according to Supplementary Item 1, wherein the transmitting unit reports to the base station the capability information indicating whether simultaneous transmission is possible for each combination of bands that is switched within a band combination, for each band, for all combinations of bands within a band combination, or for all supported band combinations.

[0228] (Supplementary Item 3) The terminal according to Supplementary Item 1 or 2, wherein the receiving unit receives information about cells that may perform simultaneous transmission for each combination of serving cells, each serving cell, or each cell group.

[0229] (Additional Item 4) In a transmission switching method in which at least one antenna port of a terminal can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the multiple antenna ports, the base station comprises: a receiving unit that receives capability information indicating whether simultaneous transmission is possible between bands from the terminal; and a transmitting unit that transmits information to the terminal about cells in which simultaneous transmission is permitted.

[0230] (Supplementary Item 5) In a transmission switching method in which at least one antenna port among a plurality of antenna ports can switch bands across two or more bands, and the bands used for transmission are switched across a total of three or more bands for the plurality of antenna ports, a communication method executed by a terminal that reports capability information indicating whether simultaneous transmission between bands is possible to a base station and receives information from the base station regarding cells in which simultaneous transmission is permitted.

[0231] Any of the above items 1 to 5 provides a technology that enables appropriate switching of the band used for uplink transmission in a wireless communication system. According to Supplementary Item 2, capability information indicating whether simultaneous transmission is possible in various units can be reported. According to Supplementary Item 3, various pieces of information regarding simultaneous transmission can be set.

[0232] <Supplementary Note 7> (Supplementary Note 1) A terminal comprising: a control unit that controls uplink transmission using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to 3 or greater); and a transmission unit that transmits capability information to a network, reporting switching periods indicating the time required for switching the uplink transmission between each of the M bands, wherein when the transmission unit reports an additional switching period separate from the switching period for switching the uplink transmission between a specific pair of the bands, the transmission unit always reports a period that is the same as the switching period or longer than the switching period.

[0233] (Supplementary Item 2) A terminal comprising: a control unit that controls uplink transmission using N bands (N is a natural number equal to or less than M) that are selected from M bands (M is a natural number equal to or greater than 3); and a transmission unit that transmits capability information to a network that reports switching periods that indicate the time required for switching the uplink transmission between each of the M bands, wherein the transmission unit avoids reporting an additional switching period separate from the switching period when the time required for switching the uplink transmission between a specific pair of the bands is the same as or shorter than the switching period.

[0234] (Supplementary Item 3) A terminal comprising: a control unit that controls uplink transmission using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a transmission unit that transmits capability information to a network, reporting switching periods indicating the time required for switching the uplink transmission between each of the M bands, wherein when M is 4 and N is 2, the transmission unit reports only either an additional switching period separate from the switching period of the uplink transmission between a specific pair of the bands, or specific inter-band switching information indicating switching of the uplink transmission between the specific bands.

[0235] (Supplementary Item 4) A base station comprising: a control unit that controls uplink reception using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a receiving unit that receives from a terminal capability information reporting a switching period indicating a required time for switching uplink transmission at the terminal between each of the M bands, wherein when M is 4 and N is 2, the receiving unit receives the capability information including both an additional switching period separate from the switching period of the uplink transmission between a specific pair of the bands and specific inter-band switching information indicating switching of the uplink transmission between the specific bands, and the control unit determines whether to apply only either the additional switching period or the specific inter-band switching information.

[0236] (Supplementary Item 5) A communication method in a terminal, comprising: a step of controlling uplink transmission using N bands (N is a natural number equal to or less than M) that are selected from M bands (M is a natural number equal to 3 or greater); and a step of transmitting capability information to a network that reports switching periods that indicate the time required for switching the uplink transmission between each of the M bands, wherein in the transmitting step, when an additional switching period different from the switching period is reported for switching the uplink transmission between a specific pair of the bands, the terminal reports a period that is always the same as the switching period or always longer than the switching period.

[0237] (Supplementary Item 6) A communication method in a terminal, comprising: a step of controlling uplink transmission using N bands (N is a natural number equal to or less than M) selected from M bands (M is a natural number equal to or greater than 3); and a step of transmitting capability information to a network, reporting switching periods indicating a required time for switching the uplink transmission between each of the M bands, wherein in the transmitting step, when M is 4 and N is 2, the terminal reports only either an additional switching period separate from the switching period for the uplink transmission between a specific pair of bands, or a specific inter-band switching period indicating a required time for switching the uplink transmission between the specific bands.

[0238] (Supplementary Item 7) A communication method in a terminal, comprising: a step of controlling uplink transmission using N bands (N is a natural number equal to or less than M) selected from M bands (M is a natural number equal to or greater than 3); and a step of transmitting capability information to a network, reporting switching periods indicating a time required for switching the uplink transmission between each of the M bands, wherein in the transmitting step, when M is 4 and N is 2, only an additional switching period separate from the switching period of the uplink transmission between a specific pair of the bands, or specific inter-band switching information indicating switching of the uplink transmission between the specific bands is reported.

[0239] (Supplementary Item 8) A communication method in a base station, comprising: a step of controlling uplink reception using N bands (N is a natural number equal to or less than M) selected from M bands (M is a natural number equal to or greater than 3); and a step of receiving from the terminal capability information reporting a switching period indicating a time required for switching uplink transmission at the terminal between each of the M bands, wherein, when M is 4 and N is 2, the receiving step receives the capability information including both an additional switching period separate from the switching period of the uplink transmission between a specific pair of the bands and specific inter-band switching information indicating switching of the uplink transmission between the specific bands, and the controlling step determines application of only either the additional switching period or the specific inter-band switching information.

[0240] (Hardware Configuration) The block diagrams (FIGS. 21 and 22) used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of hardware and / or software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (e.g., wired, wireless, etc.) and these multiple devices. The functional block may also be realized by combining software with the single device or multiple devices.

[0241] Functions include, but are not limited to, judgment, determination, assessment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how these functions are implemented.

[0242] For example, the base station 10, the terminal 20, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 23 is a diagram illustrating an example of the hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. The base station 10 and the terminal 20 described above may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0243] In the following description, the term "apparatus" can be read as a circuit, a device, a unit, etc. The hardware configuration of the base station 10 and the terminal 20 may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0244] Each function in the base station 10 and the terminal 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001, the memory device 1002, etc., so that the processor 1001 performs calculations, controls communication by the communication device 1004, and controls at least one of reading and writing data in the memory device 1002 and the auxiliary memory device 1003.

[0245] The processor 1001 controls the entire computer by running, for example, an operating system. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

[0246] The processor 1001 also loads programs (program codes), software modules, data, etc. from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002 and executes various processes in accordance with the programs. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 140 of the base station 10 shown in FIG. 21 may be implemented by a control program stored in the storage device 1002 and running on the processor 1001. For example, the control unit 240 of the terminal 20 shown in FIG. 22 may be implemented by a control program stored in the storage device 1002 and running on the processor 1001. While the above-described various processes have been described as being executed by one processor 1001, they may also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may also be transmitted from a network via a telecommunications line.

[0247] The storage device 1002 is a computer-readable recording medium and may be configured, for example, by at least one of a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a random access memory (RAM), etc. The storage device 1002 may also be called a register, a cache, a main memory, etc. The storage device 1002 can store executable programs (program codes), software modules, etc. for implementing a communication method according to an embodiment of the present disclosure.

[0248] The secondary storage device 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray disc), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, or other suitable medium including at least one of the storage device 1002 and the secondary storage device 1003.

[0249] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, a transmission / reception antenna, an amplifier unit, a transmission / reception unit, a transmission path interface, etc. may be realized by the communication device 1004. The transmission / reception unit may be implemented as a transmission unit and a reception unit that are physically or logically separated.

[0250] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0251] Furthermore, each device such as the processor 1001 and the storage device 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0252] Furthermore, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0253] Furthermore, the terminal 20 or the base station 10 may be provided in a vehicle 2001. FIG. 24 shows a configuration example of a vehicle 2001. As shown in FIG. 24 , the vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013. Each aspect / embodiment described in the present disclosure may be applied to a communication device mounted on the vehicle 2001, and may be applied to the communication module 2013, for example. The functions of the terminal 20 may be mounted on the communication module 2013.

[0254] The drive unit 2002 is configured, for example, by an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel operated by the user.

[0255] The electronic control unit 2010 is composed of a microprocessor 2031, a memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals are input to the electronic control unit 2010 from various sensors 2021 to 2029 provided in the vehicle 2001. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0256] The signals from the various sensors 2021 to 2029 include a current signal from a current sensor 2021 that senses the current of the motor, a rotation speed signal of the front and rear wheels obtained by a rotation speed sensor 2022, an air pressure signal of the front and rear wheels obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, an accelerator pedal depression amount signal obtained by an accelerator pedal sensor 2029, a brake pedal depression amount signal obtained by a brake pedal sensor 2026, a shift lever operation signal obtained by a shift lever sensor 2027, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028.

[0257] The information service unit 2012 is composed of various devices, such as a car navigation system, an audio system, speakers, a television, and a radio, for providing various types of information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 2012 uses information obtained from external devices via the communication module 2013, etc., to provide various types of multimedia information and multimedia services to the occupants of the vehicle 2001.

[0258] The driving assistance system unit 2030 is composed of various devices that provide functions for preventing accidents and reducing the driver's driving burden, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS, etc.), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps, etc.), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System), etc.), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize driving assistance functions or autonomous driving functions.

[0259] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via the communication port. For example, the communication module 2013 transmits and receives data via the communication port 2033 to and from the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 29, which are provided in the vehicle 2001.

[0260] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, or the like.

[0261] The communication module 2013 transmits, via wireless communication to an external device, a current signal from the current sensor that is input to the electronic control unit 2010. The communication module 2013 also transmits, via wireless communication to an external device, the rotation speed signals of the front and rear wheels acquired by a rotation speed sensor 2022, the air pressure signals of the front and rear wheels acquired by an air pressure sensor 2023, the vehicle speed signal acquired by a vehicle speed sensor 2024, the acceleration signal acquired by an acceleration sensor 2025, the accelerator pedal depression amount signal acquired by an accelerator pedal sensor 2029, the brake pedal depression amount signal acquired by a brake pedal sensor 2026, the shift lever operation signal acquired by a shift lever sensor 2027, and the detection signals for detecting obstacles, vehicles, pedestrians, etc. acquired by an object detection sensor 2028, which are input to the electronic control unit 2010.

[0262] The communication module 2013 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from external devices and displays it on an information service unit 2012 provided in the vehicle 2001. The communication module 2013 also stores the various information received from the external devices in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axles 2009, sensors 2021 to 2029, etc. provided in the vehicle 2001.

[0263] (Supplementary Notes on the Embodiments) Although the embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, and substitutions. While specific numerical examples have been used to facilitate understanding of the invention, unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention; matters described in two or more items may be used in combination as needed, and matters described in one item may apply to matters described in another item (as long as they are not inconsistent). Boundaries between functional units or processing units in functional block diagrams do not necessarily correspond to boundaries between physical components. The operations of multiple functional units may be performed by a single physical component, or the operations of a single functional unit may be performed by multiple physical components. The order of processing steps described in the embodiments may be reversed as long as they are consistent. For convenience of processing description, the base station 10 and terminal 20 have been described using functional block diagrams. However, such devices may be implemented using hardware, software, or a combination thereof. The software operated by the processor of the base station 10 in accordance with an embodiment of the present invention and the software operated by the processor of the terminal 20 in accordance with an embodiment of the present invention may each be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

[0264] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling), broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination thereof. Furthermore, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0265] Each aspect / embodiment described in the present disclosure may be applied to at least one of systems using LTE (Long Term Evolution), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-Wideband), Bluetooth (registered trademark), or other suitable systems, and next-generation systems enhanced based on these. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A with 5G) may also be applied.

[0266] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described herein may be rearranged unless it is consistent. For example, the methods described in this disclosure present elements of various steps using an example order and are not limited to the particular order presented.

[0267] In this specification, a specific operation described as being performed by the base station 10 may also be performed by its upper node in some cases. In a network consisting of one or more network nodes including the base station 10, it is clear that various operations performed for communication with the terminal 20 may be performed by at least one of the base station 10 and another network node other than the base station 10 (such as, but not limited to, an MME or an S-GW). Although the above example illustrates a case where there is one other network node other than the base station 10, the other network node may be a combination of multiple other network nodes (such as an MME and an S-GW).

[0268] The information, signals, etc. described in the present disclosure may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0269] Input and output information may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information may be overwritten, updated, or added to. Output information may be deleted. Input information may be transmitted to another device.

[0270] In the present disclosure, the determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0271] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0272] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0273] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, code, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0274] Note that terms described in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0275] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0276] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by an index.

[0277] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0278] In this disclosure, terms such as "base station (BS)," "radio base station," "base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0279] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication service within that coverage area.

[0280] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0281] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0282] At least one of the base station and the mobile station may be referred to as a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile object, the mobile object itself, etc. The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0283] Furthermore, the base station in the present disclosure may be read as a terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a terminal is replaced with communication between a plurality of terminals 20 (which may be called, for example, D2D (Device-to-Device) or V2X (Vehicle-to-Everything)). In this case, the terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to communication between terminals (for example, "side"). For example, terms such as an uplink channel and a downlink channel may be read as a side channel.

[0284] Similarly, the term "terminal" in the present disclosure may be read as "base station." In this case, the base station may be configured to have the functions of the terminal described above.

[0285] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0286] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using one or more wires, cables, and / or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0287] The reference signal may also be abbreviated as RS (Reference Signal) and may be called a pilot depending on the applicable standard.

[0288] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0289] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0290] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0291] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0292] A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0293] Numerology may be communication parameters that apply to the transmission and / or reception of a signal or channel, such as subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering operations performed by the transceiver in the frequency domain, and specific windowing operations performed by the transceiver in the time domain.

[0294] A slot may consist of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol). A slot may be a time unit based on numerology.

[0295] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0296] The radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals, and may be referred to by other names corresponding to the radio frame, subframe, slot, minislot, and symbol.

[0297] For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, or the like instead of a subframe. Furthermore, one slot may be called a unit time. The unit time may differ for each cell depending on the numerology.

[0298] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate wireless resources (such as frequency bandwidth and transmission power that can be used by each terminal 20) to each terminal 20 in TTI units. Note that the definition of TTI is not limited to this.

[0299] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0300] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0301] A TTI having a time length of 1 ms may be called a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0302] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0303] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0304] The time domain of an RB may include one or more symbols and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0305] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0306] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0307] A Bandwidth Part (BWP) (which may also be referred to as a fractional bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within the BWP.

[0308] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0309] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0310] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be variously changed.

[0311] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0312] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0313] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. In addition, notification of predetermined information (e.g., notification that "X is true") is not limited to being done explicitly, but may be done implicitly (e.g., by not notifying the predetermined information).

[0314] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure.

[0315] 10 base station 110 transmitter 120 receiver 130 setting unit 140 controller 20 terminal 210 transmitter 220 receiver 230 setting unit 240 controller 1001 processor 1002 storage device 1003 auxiliary storage device 1004 communication device 1005 input device 1006 output device 2001 vehicle 2002 drive unit 2003 steering unit 2004 accelerator pedal 2005 brake pedal 2006 shift lever 2007 front wheel 2008 rear wheel 2009 axle 2010 electronic control unit 2012 information service unit 2013 communication module 2021 current sensor 2022 rotation speed sensor 2023 tire pressure sensor 2024 vehicle speed sensor 2025 Acceleration sensor 2026 Brake pedal sensor 2027 Shift lever sensor 2028 Object detection sensor 2029 Accelerator pedal sensor 2030 Driving assistance system section 2031 Microprocessor 2032 Memory (ROM, RAM) 2033 Communication port (IO port)

Claims

1. A terminal comprising: a control unit that controls uplink transmission using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a transmission unit that transmits capability information to a network, reporting a switching period indicating the time required for switching the uplink transmission between each of the M bands, wherein when the transmission unit reports an additional switching period separate from the switching period for switching of the uplink transmission between a specific pair of the bands, the transmission unit always reports a period that is the same as the switching period or is longer than the switching period.

2. A terminal comprising: a control unit that controls uplink transmission using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a transmission unit that transmits capability information to a network reporting a switching period indicating the time required for switching the uplink transmission between each of the M bands, wherein the transmission unit avoids reporting an additional switching period separate from the switching period when the time required for switching the uplink transmission between a specific pair of the bands is the same as or shorter than the switching period.

3. A terminal comprising: a control unit that controls uplink transmission using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a transmission unit that transmits capability information to a network reporting a switching period indicating the time required for switching the uplink transmission between each of the M bands, wherein when M is 4 and N is 2, the transmission unit reports only either an additional switching period separate from the switching period of the uplink transmission between a specific pair of the bands, or specific inter-band switching information indicating switching of the uplink transmission between the specific bands.

4. A base station comprising: a control unit that controls uplink reception using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a receiving unit that receives capability information from a terminal reporting a switching period indicating a time required for switching of uplink transmission at the terminal between each of the M bands, wherein when M is 4 and N is 2, the receiving unit receives the capability information including both an additional switching period separate from the switching period of the uplink transmission between a specific pair of the bands, and specific inter-band switching information indicating switching of the uplink transmission between the specific bands, and the control unit decides on application of only either the additional switching period or the specific inter-band switching information.

5. A communication method in a terminal comprising: a step of controlling uplink transmission using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a step of transmitting capability information to a network, the capability information reporting a switching period indicating the time required for switching the uplink transmission between each of the M bands, wherein in the transmitting step, when an additional switching period other than the switching period is reported for switching of the uplink transmission between a specific pair of the bands, the reporting period is always the same as the switching period or always longer than the switching period.

6. A communication method in a terminal comprising: a step of controlling uplink transmission using N bands (N is a natural number equal to or less than M), the N bands being selected from M bands (M is a natural number equal to or greater than 3); and a step of transmitting capability information to a network, the capability information reporting a switching period indicating the time required for switching the uplink transmission between each of the M bands, wherein in the transmitting step, when M is 4 and N is 2, the terminal reports only either an additional switching period separate from the switching period of the uplink transmission between a specific pair of the bands, or a specific inter-band switching period indicating the time required for switching the uplink transmission between the specific bands.

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