Terminal, wireless communication system, and wireless communication method

Abstract

This terminal comprises: a control unit that sets, on the basis of whether or not switching between types of repetition opportunity for a random access signal is supported, a type of repetition opportunity; and a communication unit that transmits a signal at an opportunity of the type set by the control unit.

Description

Terminal, wireless communication system, and wireless communication method 【0001】 The present disclosure relates to a terminal, a wireless communication system, and a wireless communication method. 【0002】 3GPP (registered trademark) is standardizing the 5th generation mobile communication system (also called 5G, New Radio (NR), or Next Generation (NG)). Furthermore, standardization of the next-generation mobile communication system called Beyond 5G, 5G Evolution, or 6G is also underway. 【0003】 In Release 18, a multiplexing method that enables simultaneous use of the downlink (DL) and the uplink (UL) by using a plurality of sub-bands that constitute the time-division duplex (TDD) band has been discussed. Such a multiplexing method is called sub-band non-overlapping full duplex (SBFD). Note that the symbol to which SBFD is applied may also be called an SBFD symbol. Also, in the SBFD symbol, the sub-band used for DL may be called a DL sub-band, and the sub-band used for UL may be called a UL sub-band. 【0004】 Furthermore, for Release 19, extensions regarding UL transmission and DL reception over SBFD symbols and non-SBFD symbols in different slots are being considered (Non-Patent Document 1). 【0005】 “New WID: Evolution of NR duplex operation: sub-band full duplex (SBFD)”, RP-234035, 3GPP TSG RAN Meeting #102, 3GPP, December 11-15, 20233GPP TS 38.214 V18.3.0 (2024-06)3GPP TS 38.300 V18.2.0 (2024-06)3GPP TS 38.331 V18.1.0 (2024-03)3GPP TR 38.858 V18.1.0 (2024-03) 【0006】While multiple types of random access opportunities (e.g., RACH occasions) have been considered for random access to different types of symbols, such as SBFD symbols and non-SBFD symbols, there is room for further consideration regarding switching between these multiple types. 【0007】 One aspect of this disclosure contributes to providing a terminal, a wireless communication system, and a wireless communication method that can appropriately switch between multiple types of random access opportunities (e.g., RACH occasions). 【0008】 A terminal according to one aspect of the present disclosure includes a control unit that sets the type of repetition opportunity based on whether or not it supports switching the type of repetition opportunity for random access signals, and a communication unit that transmits the signal in the type of opportunity set by the control unit. 【0009】This is a schematic diagram of the overall configuration of a wireless communication system. This is a diagram showing the frequency range used in the wireless communication system. This is a diagram showing an example of the configuration of wireless frames, subframes, slots, and symbols used in the wireless communication system. This is a diagram showing an example of the TDD settings specified up to Rel-16. This is a diagram showing an example of the SBFD configuration. This is a diagram showing an example of SBFD operation. This is a diagram showing an example of an existing TDD setting. This is a diagram showing an example of a TDD including the SBFD setting. This is a diagram showing the pure time unit and the SBFD time unit. This is a diagram showing the pure time unit and the SBFD time unit. This is a diagram showing the pure time unit and the SBFD time unit. This is a diagram showing the pure time unit and the SBFD time unit. This is a diagram showing the pure time unit and the SBFD time unit. This is a sequence diagram showing an example of the CBRA procedure. This is a sequence diagram showing another example of the CBRA procedure. This is a sequence diagram showing an example of the CFRA procedure. This is a diagram showing an example of options for the RACH setting. This is a diagram showing an example of changing the number of RACH trials and repetitions. This is a diagram showing an example of switching between RACH trials and RACH opportunities. This is a diagram showing examples of each option of Proposal 2-3A. This figure shows examples of options B-1, B-2, and B-3 of Proposal 2-3B. This figure shows an example where option B-4 of Proposal 2-3B is applied. This is a block diagram showing an example of a base station configuration. This is a block diagram showing an example of a terminal configuration. This figure shows an example of the hardware configuration of a base station and a terminal. This figure shows an example of a vehicle configuration. 【0010】 The embodiments will be described below with reference to the drawings. Note that identical or similar reference numerals are used to denote the same functions and components, and their descriptions will be omitted as appropriate. 【0011】 <Configuration of the Wireless Communication System> The wireless communication system 10 shown in Figure 1 is a wireless communication system that conforms to a method called 5G. On the other hand, the wireless communication system 10 may also be a wireless communication system that conforms to a method called Beyond 5G, 5G Evolution, or 6G. 【0012】The wireless communication system 10 can support Massive Multiple-Input Multiple-Output (Massive MIMO), which generates a more directional beam by controlling the radio signals transmitted from multiple antenna elements; carrier aggregation (CA), which uses multiple component carriers (CCs) bundled together; and dual connectivity (DC), which enables simultaneous communication with two base stations. In this specification, "and / or" may be simply written as " / ". 【0013】 As shown in Figure 1, the wireless communication system 10 includes a base station 100 (hereinafter also referred to as gNodeB (gNB) 100) that constitutes the Next Generation-Radio Access Network (NG-RAN) 20, and a terminal 200 (hereinafter also referred to as user equipment (UE) 200) that communicates wirelessly with the gNB 100. The NG-RAN 20 is connected to a core network (CN) which is not shown. The CN is composed of multiple network functions (NFs). Examples of NFs include the Access and Mobility Management Function (AMF) and the Network Data Analytics Function (NWDAF). The AMF performs, for example, the registration of the UE 200. The NWDAF performs, for example, the optimization of the CN. Note that the specific configuration of the wireless communication system 10, such as the number of gNB 100s and UE 200s, is not limited to the example shown in Figure 1. Also, the NG-RAN 20 and CN may simply be referred to as the "network". 【0014】gNB100 may be a base station in a Centralized-Radio Access Network (C-RAN) configuration, having a Distributed Unit (DU) with the function of connecting to UE200 and a Central Unit (CU) with the function of connecting to the network. In this case, gNB100 may be interpreted as DU, as CU, or as DU and CU. When gNB100 is interpreted as DU, it may be called gNB-DU. When gNB100 is interpreted as CU, it may be called gNB-CU. When gNB100 is interpreted as DU and CU, the DU portion may be called gNB-DU and the CU portion may be called gNB-CU. 【0015】 Furthermore, the wireless communication system 10 may support multiple frequency ranges (FRs). That is, as shown in Figure 2, it may support the following FRs: • FR1: 410 MHz to 7.125 GHz • FR2-1: 24.25 GHz to 52.6 GHz • FR2-2: Over 52.6 GHz to 71 GHz 【0016】 In FR1, a subcarrier spacing (SCS) of 15, 30, or 60 kHz and a bandwidth (BW) of 5 to 100 MHz may be used. In FR2-1, an SCS of 60 or 120 kHz (or 240 kHz) and a BW of 50 to 400 MHz may be used. 【0017】 Note that SCS may also be interpreted as numerology. Numerology is defined in §5.1 of Non-Patent Document 3, etc., and corresponds to a single subcarrier interval in the frequency domain. 【0018】In FR2-2, to avoid an increase in phase noise, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) or Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) with a larger SCS may be applied. 【0019】 Figure 3 shows an example of the configuration of wireless frames (system frames), subframes, and slots used in the wireless communication system 10. As shown in Figure 3, one slot consists of 14 symbols, and the larger (wider) the SCS, the shorter the symbol period (and slot period). However, the SCS is not limited to the interval (frequency) shown in Figure 3. For example, 480 kHz, 960 kHz, etc. may be used as the SCS. 【0020】 Furthermore, the number of symbols constituting one slot does not necessarily have to be 14 (for example, it could be 28 or 56 symbols, etc.). In addition, the number of slots per subframe may differ depending on the SCS. 【0021】 The time direction (t) shown in Figure 3 may also be called the time domain, symbol period, or symbol time. The frequency direction may also be called the frequency domain, resource block, subcarrier, or bandwidth part (BWP). 【0022】 The wireless communication system 10 may support coverage enhancement (CE) to broaden the coverage of the cell (or physical channel) formed by the gNB100. Coverage enhancement may provide mechanisms to improve the reception success rate of various physical channels, such as repetition (repeated transmission) of PRACH (physical random access channel). 【0023】For example, the UE200 receives information related to random access procedures from the gNB100 as a downlink signal (DL: Downlink) (e.g., SIB1 (System Information Block Type 1)). 【0024】 Furthermore, for example, UE200 transmits PRACH to gNB100 using a RACH occasion, or RACH (transmit) opportunity (RO: RACH Occasion), which is a resource for transmitting a random access preamble as a UL signal. For example, UE200 replicates PRACH to gNB100 as a UL signal. 【0025】 The UL signal may include, for example, UL data signals and control information. For example, the UL signal may include information about the processing capabilities of the UE200 (e.g., UE capability). The UL signal may also include reference signals. 【0026】 The channels used to transmit UL signals include, for example, data channels and control channels. For example, the data channel may include a Physical Uplink Shared Channel (PUSCH), and the control channel may include a Physical Uplink Control Channel (PUCCH). For example, the UE200 transmits control information using PUCCH and transmits UL data signals using PUSCH. Note that PUSCH is an example of an uplink shared channel, and PUCCH is an example of an uplink control channel. Shared channels may also be called data channels. 【0027】The reference signals included in the UL signal may include, for example, at least one of the following: DMRS (Demodulation Reference Signal), PTRS (Phase Tracking Reference Signal), CSI-RS (Channel State Information - Reference Signal), SRS (Sounding Reference Signal), and PRS (Positioning Reference Signal) for position information. For example, reference signals such as DMRS and PTRS are used to demodulate the UL data signal and are transmitted using PUSCH. 【0028】 Meanwhile, the gNB100, in response to the operation of the UE200, transmits information related to the RACH procedure to the UE200 as a DL signal (e.g., SIB1, etc.). 【0029】 For example, gNB100 receives PRACH from UE200 as a UL signal. For example, gNB100 receives PRACH from UE200 as a repetition signal. 【0030】 The channels used to transmit DL signals include, for example, a data channel and a control channel. For example, the data channel may include a Physical Downlink Shared Channel (PDSCH), and the control channel may include a Physical Downlink Control Channel (PDCCH). For example, gNB100 transmits control information to UE200 using the PDCCH and transmits DL data signals using the PDSCH. Note that PDSCH is an example of a Downlink Shared Channel, and PDCCH is an example of a Downlink Control Channel. Note that PDCCH may be interpreted as Downlink Control Information (DCI), control information, etc., transmitted in the PDCCH. 【0031】The reference signals included in the DL signal may include, for example, at least one of DMRS, PTRS, CSI-RS, SRSRS, and PRS for location information. For example, reference signals such as DMRS and PTRS are used to demodulate the DL data signal and are transmitted using PDSCH. 【0032】 Next, we will explain SBFD, CG (Configured Grant), PUSCH / SPS (Semi-Persistent Scheduling), and PDSCH. 【0033】 <SBFD Operation> Considering the transmission / reception time ratio (e.g., DL:UL = 4:1) in Time Division Duplex (TDD) up to Rel-16, there may be cases where the opportunities to transmit UL signals / channels are fewer than the opportunities to receive DL signals / channels. In such cases, the UE200 may not be able to transmit UL signals / channels frequently, raising concerns about transmission delays for important UL signals / channels. Furthermore, because the opportunities to transmit UL signals are fewer than the opportunities to receive DL signals, signal / channel congestion during UL transmission is also a concern. In addition, in TDD, the time resources available for transmitting UL signals / channels are limited, which limits the application of UL coverage extension techniques such as repetition transmission. 【0034】 In future wireless communication systems (e.g., Rel-18 and beyond), the introduction of a time-frequency division duplex method combining TDD and frequency division duplex (FDD) for UL and DL is being considered. 【0035】 Examples of such time-frequency division duplexing methods include XDD (Cross Division Duplex) or Subband non-overlapping Full Duplex (SBFD). XDD or SBFD may also refer to a duplexing method that frequency-division multiplexes DL and UL within one component carrier (CC) of the TDD band (allowing simultaneous use of DL and UL). 【0036】 Figure 4A shows an example of a TDD configuration as defined up to Rel-16. In the example shown in Figure 4A, a TDD slot or symbol is set in the UE in a bandwidth such as one component carrier (CC) (which may also be called a cell or serving cell) or bandwidth portion (BWP). 【0037】 In the example shown in Figure 4A, the time ratio of DL slots to UL slots is 4:1. With such conventional TDD slot or symbol settings, sufficient UL time resources cannot be secured, which may lead to UL transmission delays and reduced coverage performance. 【0038】 Figure 4B shows an example of an SBFD configuration. In the example shown in Figure 4B, within a single component carrier (CC), the resources used for receiving DL and the resources used for transmitting UL overlap in time. With such a resource configuration, more UL resources can be secured, and the efficiency of resource utilization can be improved. 【0039】 For example, as shown in the example in Figure 4B, the ends of the frequency domain may be set as DL resources, and UL resources may be sandwiched between these DL resources. This can help avoid and mitigate cross-link interference (CLI) with neighboring carriers. In addition, a guard region may be set at the boundary between the DL resources and the UL resources. 【0040】 Considering the complexity of handling self-interference, it is conceivable that only the gNB100 would use DL and UL resources simultaneously. In other words, for wireless resources where DL and UL overlap in time, one UE200 may use the DL resource and another UE200 may use the UL resource. 【0041】 Figure 5 shows an example of SBFD operation. In the example shown in Figure 5, a portion of the DL resources in the TDD band are set as UL resources, and the DL and UL are configured to partially overlap in the time domain. 【0042】 In the example shown in FIG. 5, during the DL-only period, each of the plurality of UEs 200 (UE1 and UE2 in FIG. 5) receives DL channels / signals. 【0043】 Also, during the period when DL and UL overlap in time, one UE 200 (UE1 in the example of FIG. 5) receives DL channels / signals, and another UE 200 (UE2 in the example of FIG. 5) transmits UL channels / signals. During this period, gNB 100 performs simultaneous transmission and reception of DL and UL. 【0044】 Furthermore, during the UL-only period, each of the plurality of UEs 200 (UE1 and UE2 in FIG. 5) transmits UL channels / signals. 【0045】 In existing (e.g., defined up to Rel-15 / 16 / 17) NR, the DL frequency resources and UL frequency resources in the UE carrier are set as DL BWP and UL BWP, respectively. In order to switch the DL / UL frequency resources to another DL / UL frequency resource, a mechanism for setting a plurality of BWPs and adapting the BWPs is required. 【0046】 FIG. 6A is a diagram showing an example of an existing TDD setting. In FIG. 6A, the slot / symbol marked with "D" is a DL slot / symbol, the slot / symbol marked with "U" is a UL slot / symbol, and the slot / symbol marked with "F" is a flexible (hereinafter also referred to as FL) slot / symbol. Note that the same description may be used in the following figures. 【0047】 In existing NR, as shown in FIG. 6A, the time resources (time units such as symbols, slots, etc.) in the TDD carrier for UE 200 are set as at least one of DL, UL, and flexible (FL) in the TDD setting. 【0048】Figure 6B shows an example of an existing TDD setting. In Figure 6B, slots / symbols or subbands marked with "D" are DL slots / symbols or DL ​​subbands, and slots / symbols or subbands marked with "U" are UL slots / symbols or UL subbands. Similar notation may be used in the following figures. 【0049】 The SBFD symbol may be a symbol that is notified or set as UL (or DL) on one frequency resource (subband), or notified or set for UL transmission (or DL ​​reception), while on another frequency resource (subband), it may be a symbol that is notified or set as DL (or UL) or notified or set for DL ​​reception (or UL transmission), as shown in Figure 6B. Alternatively, the SBFD symbol may be a symbol that is notified or set as UL (or DL) on a portion of the frequency resource, or notified or set for UL transmission (or DL ​​reception). Alternatively, the SBFD symbol may be a symbol that is notified or set as DL (or UL) on a portion of the frequency resource, or notified or set for DL ​​reception (or UL transmission). 【0050】 Here, the time unit may be at the symbol level, the slot / subslot level, or a group of symbols / slots / subslots. That is, an SBFD time unit may be an SBFD symbol, a slot / subslot containing or overlapping an SBFD symbol, or a group of symbols / slots / subslots containing or overlapping an SBFD symbol. 【0051】A pure time unit may be a non-SBFD symbol (i.e., a symbol that is not an SBFD symbol, also called a non-SBFD symbol), a slot / subslot that does not contain or overlap SBFD symbols, or a group of symbols / slots / subslots that do not contain or overlap SBFD symbols, and may also be called a non-SBFD time unit. For example, a pure time unit may be referred to as a time unit consisting only of DLs on a frequency resource, as shown in Figure 7A, or as a time unit consisting only of ULs on a frequency resource, as shown in Figure 7B. 【0052】 Furthermore, with respect to the SBFD time unit, DL resources and UL resources may have various arrangement patterns in the frequency domain. For example, the SBFD time unit of frequency domain pattern #1 may have the arrangement pattern shown in Figure 7C. The SBFD time unit of frequency domain pattern #2 may have the arrangement pattern shown in Figure 7D. The SBFD time unit of frequency domain pattern #3 may have the arrangement pattern shown in Figure 7E. These arrangement patterns are merely examples, and other arrangement patterns may be used. The frequency domain pattern of the SBFD time unit may mean the resource recency pattern in the frequency domain for the SBFD time unit. 【0053】 As mentioned above, SBFD may be applied to each slot / symbol. In addition, each slot / symbol may be set to DL, UL, or Flexible (FL) which can be used as DL or UL, and then SBFD may be applied. 【0054】 SBFD is a type of (full-duplex) duplexing system based on time-division duplexing (TDD), enabling the simultaneous use of multiple subbands that make up the TDD band. SBFD can also be described as a duplexing system where multiple subbands are defined within the TDD band, or a duplexing system where UL and DL are allocated non-overlapping in the frequency direction within the TDD time unit, or as a full-duplexing system using subbands. 【0055】 Symbols to which SBFD applies are also called SBFD symbols. "SBFD applies" may be interpreted as SBFD being applied in at least part of the scheduling. That is, "symbols to which SBFD applies" may be interpreted as symbols to which SBFD applies in scheduling where SBFD is applied (SBFD symbols). Also, "time units to which SBFD does not apply" may be interpreted as symbols to which SBFD does not apply in scheduling where SBFD is applied (non-SBFD symbols). 【0056】 Furthermore, UEs that support SBFD operation (SBFD-aware UEs) are described as SBFD-aware UEs or SBFD-capable UEs, while UEs that do not support SBFD operation are described as Legacy UEs. For example, when SBFD is applied to a DL symbol, an SBFD-aware UE can recognize the UL subband (and DL subband) in this SBFD symbol, but a Legacy UE will recognize this SBFD symbol as a regular DL symbol. 【0057】 <Random Access Procedures> Random access procedures for NRs are performed for various purposes, such as initial access, beam fault recovery, and handover. Random access procedures include CBRA (Contention Based Random Access) procedures as collision-type random access procedures and CFRA (Contention Free Random Access) procedures as non-collision-type random access procedures. In CBRA procedures, since the UE200 starts spontaneously, collisions may occur if multiple UE200s start the random access procedure simultaneously. On the other hand, with CFRA, the gNB100 can instruct connected UE200s to execute the random access procedure in a way that avoids collisions between multiple UE200s. 【0058】In NR, a random access procedure may be performed by selecting the SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block, or by selecting CSI-RS. The SS / PBCH block may also be called the SSB or synchronization signal, and CSI-RS may be called the reference signal. 【0059】 Figure 8 is a sequence diagram showing an example of the CBRA procedure. 【0060】 gNB100 transmits an SSB for each beam, for example, and UE200 monitors the SSB for each beam. UE200 selects an SSB from among several SSBs whose received power (RSRP: Reference Signal Received Power) is greater than (or equal to) a threshold, and uses the RO associated with the selected SSB to transmit a random access preamble to gNB100 via PRACH (step S101). The random access preamble (sometimes abbreviated as RA preamble or RA Preamble) may be appropriately referred to as Preamble, PRACH preamble, Message1, Msg1, etc. 【0061】 gNB100 sends a response message to Msg1 as a second message to UE200 via PDSCH (step S102). This response message (second message) may be appropriately referred to as Random Access Response (RAR), RA Response, Message2, Msg2, etc. After sending Msg1, UE200 may monitor PDCCH, which is used for scheduling PDSCH including Msg2. Msg2 may include an uplink grant (UL Grant) (RAR uplink grant) used for scheduling PUSCH, which includes a third message transmitted by UE200. 【0062】UE200 transmits a PUSCH scheduled by the RAR uplink grant as a third message (step S103). For example, UE200 transmits a Radio Resource Control (RRC) connection request, an RRC connection re-establishment request, etc., to gNB100 via the PUSCH. The third message may be appropriately named Message3, Msg3, RRC Connection Request, etc. 【0063】 gNB100 transmits a contention resolution message as the fourth message via PDSCH (step S104). This contention resolution message (fourth message) may be appropriately referred to as message 4, Msg4, etc. After transmitting Msg3, UE200 may monitor the PDCCH used for scheduling the PDSCH containing Msg4. Msg4 may include a contention resolution ID (UE contention resolution ID). The contention resolution ID may be used to resolve a collision in which multiple UE200s transmit signals using the same radio resource. If the contention resolution ID contained in the Msg4 received by UE200 is the same value as the ID used to identify UE200, UE200 may determine that the contention resolution was successful and set the value of TC-RNTI (Temporary Cell - Radio Network Temporary Identifier) ​​in the C-RNTI (Cell - Radio Network Temporary Identifier) ​​field. When the value of TC-RNTI is set in the C-RNTI field, UE200 may consider the RRC connection to be complete. Msg4 may be referred to as RRC Connection Setup, etc. 【0064】Once the RRC connection is established, UE200 may send an Ack (Acknowledgement) via PUCCH (PUCCH resource) indicated by the PUCCH resource instruction field included in the PDCCH that scheduled Msg4 to gNB100 in order to notify gNB100 that the RRC connection has been established. After the RRC connection is established, UE200 may also send UE capability to gNB100. The random access procedure described above may also be referred to as the Type 1 RACH procedure, the 4-step RACH procedure, Type 1 RACH, the 4-step RACH, etc. 【0065】 Figure 9 is a sequence diagram showing another example of the CBRA procedure. 【0066】UE200 sends a message containing the RA preamble and data to gNB100 (step S201). For example, UE200 selects an RO (Robot Operator) and sends the RA preamble with that RO, and also sends the data with the PUSCH resource associated with that RO, similar to the RO selection in the 4-step RACH procedure. This message may be appropriately referred to as MessageA, MsgA, etc. The RA preamble and data here may correspond to Msg1 and Msg3 in the 4-step RACH procedure, respectively. MsgA contains one RA preamble (referred to as MsgA PRACH) and one data (referred to as MsgA PUSCH), and MsgA PRACH and MsgA PUSCH are transmitted using time-division multiplexing. More specifically, MsgA PRACH is a preamble with a preamble index within an MsgA RACH occasion (RO), and MsgA PUSCH is a PUSCH with a PUSCH resource unit (PRU) within an MsgA PUSCH occasion (PO) according to the MsgA PUSCH setting. Note that in this procedure, the resource for transmitting data is not limited to a PUSCH resource, but may be any channel resource for transmitting data (or control information). 【0067】 gNB100 sends a response message to UE200 as a second message (step S202). This response message (second message) may be appropriately referred to as MessageB, MsgB, etc. The contents of MessageB may correspond, for example, to Msg2 and Msg4 in the 4-step RACH procedure. MsgB includes one PDSCH (and one PDCCH that schedules the PDSCH). From the perspective of the physical layer, the contents of Msg2 and Msg4 are simply integrated into MsgB. 【0068】Once the RRC connection is established, UE200 may send an Ack via PUCCH (PUCCH resource) to notify gNB100 that the RRC connection is complete. Furthermore, after the RRC connection is established, UE200 may send UE capability to gNB100. The above-described random access procedure may also be referred to as the Type 2 RACH procedure, 2-step RACH procedure, Type 2 RACH, 2-step RACH, etc. 2-step RACH is supported to reduce RACH delay. 【0069】 Figure 10 is a sequence diagram showing an example of the CFRA procedure. 【0070】 UE200 is requested by gNB100 to send an RA preamble (Msg1). Here, gNB100 allocates the RA preamble (Msg1) via dedicated signaling (step S301). A PDCCH for such dedicated signaling may be called a PDCCH order. UE200 may monitor the PDCCH (PDCCH order) for performing the resource allocation of Msg1. 【0071】 UE200 transmits the above-mentioned Msg1 to gNB100 (step S302). 【0072】 gNB100 sends the above-described Msg2 to UE200 (step S303). Once the RRC connection is complete, UE200 may send an Ack via PUCCH (PUCCH resource) to notify gNB100 that the RRC connection is complete. After the RRC connection is established, UE200 may also send UE capability to gNB100. 【0073】 In this embodiment, in order to extend coverage in random access procedures, UE200 may repeatedly transmit Msg1 (and therefore PRACH) in, for example, the 4-step RACH procedure shown in Figure 8 and the CFRA procedure shown in Figure 10 described above. However, in this disclosure, Msg1 (and therefore PRACH) may also be repeatedly transmitted in the 2-step RACH procedure shown in Figure 9 described above. 【0074】 In the random access described above, the UE determines the random access opportunity to send a preamble to initiate random access, and from among the determined ROs, it determines which ROs are valid (and which are invalid). The random access opportunity may also be called a RACH Occasion. 【0075】 Next, we will explain the power control of PRACH and Msg3 transmitted by UE200 in the random access procedure shown in Figure 8, and MsgA transmitted by UE200 in the random access procedure shown in Figure 9. Note that Msg3 and MsgA are transmitted via PUSCH, and may therefore be written as Msg3 PUSCH and MsgA PUSCH, respectively. 【0076】 <Consideration of Duplex Extension for Rel-19> As mentioned above, for Rel-18, consideration has been given to enabling the simultaneous existence of downlink and uplink (full duplex, more specifically subband non-overlapping full duplex) on the gNB side within the conventional TDD band. Regarding SBFD, the impact on specifications, performance evaluation results, implementation feasibility, and impact on RF requirements are summarized in Non-Patent Document 5. 【0077】Non-patent document 1 focuses on the expansion of subband non-overlapping full duplex (SBFD) operation on the gNB side within a TDD carrier. The objectives of the study toward Rel-19 are as follows: (1) In RRC_CONNECTED mode, consider the specification for semi-static indication of the time position of the SBFD subband to the UE. The indication of the time position of the SBFD subband in SIB is not excluded. (2) In RRC_CONNECTED mode, consider the specification for semi-static indication of the frequency domain position of the SBFD subband to the UE. The indication of the frequency domain position of the SBFD subband in SIB is not excluded. (3) Consider the specification for SBFD operations to support random access of SBFD symbols by the UE in RRC CONNECTED mode. (4) Consider SBFD operations to support random access by the UE in RRC_IDLE / INACTIVE mode, and define the specification if appropriate. Confirm whether to proceed with standardization work in RAN#104. (5) Consider the specification for the operation and procedure of UE transmission / reception and measurement of SBFD symbols and / or non-SBFD symbols for SBFD-aware UEs. DL and / or flexible symbols as shown by TDD-UL-DL-ConfigCommon. Transmit / receive operation in the SBFD subband configured as (symbol) UL transmission only within the UL subband DL reception only within the DL subband (excluding CLI measurements by UE outside the DL subband) Note: When flexible symbols are used, it is not expected that the legacy uplink symbols will be converted to downlink / SBFD symbols. Enhanced frequency domain resource allocation in the following SBFD symbols Frequency domain resource allocation of PDSCH / CSI-RS spanning two DL subbands in the SBFD symbol SBFD subband and RBG (Resource Block)Handling of boundary inconsistencies between Group, CSI Report subband, CSI-RS resources, and PRG (Precoding Resource block Group) - Enhancements to physical channels / signals and procedures spanning SBFD and non-SBFD symbols in different slots, where each transmit / receive in a slot includes either all SBFD symbols or all non-SBFD symbols, including: Resource allocation in the frequency domain when different available frequency resources are used in different slots during SBFD and non-SBFD symbol transmit / receive - CSI reports of related CSI-RS instances occurring in both SBFD and non-SBFD symbols in different slots - SRS, PUCCH and PUSCH configuration in SBFD and non-SBFD symbols (resources, frequency hopping parameters, UL power control parameters and / or beam / spatial relationships, etc.) - Collision handling between DL receive in the DL subband and UL transmit in the UL subband in SBFD symbols (6) Based on TR 38.858 (Non-Patent Literature 5), the following is assumed: - SBFD on the gNB side - Half-duplex operation on the UE side Operation) ・FR1 and FR2-1 ・SBFD operation option 4 (for example, the time and frequency positions of the subband for SBFD operation are known to the SBFD-enabled UE) ・Coexistence of non-SBFD-enabled UEs (including legacy UEs) and SBFD-enabled UEs in a cell where SBFD is being operated on the gNB side ・SBFD scheme in a single configuration DL and UL BWP pair with aligned center frequencies ・One UL subband for SBFD operation in SBFD symbols (excluding legacy UL symbols / slots) within a TDD carrier ・The mechanism for SBFD operation must also consider the coexistence of adjacent channels between the two operators 【0078】 <Transmission / reception spanning SBFD and non-SBFD symbols> Section 6.1.2 of Non-Patent Document 5 examines whether or not to support transmission / reception spanning SBFD and non-SBFD symbols. 【0079】 For UL transmit / DL receive operations spanning SBFD and non-SBFD symbols in different slots (where each transmit / receive within a slot is either all SBFD or all non-SBFD symbols), the following options should be considered for SBFD-enabled UEs: Option 1: Transmit / receive is restricted to either SBFD symbols only or non-SBFD symbols only. Option 2: Transmit / receive can be performed using both SBFD and non-SBFD symbols. 【0080】 UL transmission / DL reception spanning SBFD and non-SBFD symbols includes the following information: • PDSCH / PUSCH / PUCCH repetition • SPS (Semi-Persistent Scheduling) PDSCH / CG PUSCH (Configured Grant PUSCH) • TBoMS (Transport Block processing over Multiple Slots) • Multiple PUSCH / PDSCH scheduled by a single DCI • Periodic / semi-persistent SRS / CSI-RS / PUCCH • PDCCH 【0081】Option 1 can be achieved by configuring or scheduling the gNB so that all transmit / receive occasions are limited to either SBFD symbols or non-SBFD symbols. Alternatively, Option 1 can be achieved by additional instructions or rules to determine whether a transmit / receive occasion is valid within one symbol type and invalid within another. Frequency resources, power control, and beam / spatial relationships for all transmit / receive occasions may be the same in Option 1, but may be different in Option 2. If they are different, additional specification work may be required. Option 1 may increase or not increase transmit / receive latency if transmit / receive is delayed in other symbol types, and may degrade performance if transmit / receive is dropped in other symbol types. Option 2 may or may not reduce transmit / receive latency and improve coverage. 【0082】 <Definition of Terms> The following explains the definitions of terms related to SBFD. 【0083】SBFD symbol: A symbol set in the SBFD subband. Non-SBFD symbol: A symbol not set in the SBFD subband. DL (or semistatic D) symbol: A symbol indicated as DL by tdd-UL-DL-ConfigurationCommon and / or tdd-UL-DL-ConfigDedicated. UL (or semistatic U) symbol: A symbol indicated as UL by tdd-UL-DL-ConfigurationCommon and / or TDD-UL-DL-ConfigDedicated. Flexible (or semistatic F, or flexible) symbol: A symbol indicated as flexible by tdd-UL-DL-ConfigurationCommon and / or tdd-UL-DL-ConfigDedicated. SBFD DL symbol: A symbol designated as Downlink (DL) by tdd-UL-DL-ConfigurationCommon and / or tdd-UL-DL-ConfigurationDedicated, in which the SBFD subband is set within the symbol. SBFD Flexible (FL) symbol: A symbol designated as Flexible by tdd-UL-DL-ConfigurationCommon and / or tdd-UL-DL-ConfigurationDedicated, in which the SBFD subband is set within the symbol. 【0084】The parameters for configuring the resources of the Sounding Reference Signal (SRS) may include an SRS Config. The SRS Config is a parameter that defines a list of SRS-ResourceSets and a list of SRS-Resources. The SRS-ResourceSets included in the list may include an identifier for the SRS-ResourceSet (srs-ResourceSetId), a list of identifiers for the SRS-Resource (srs-ResourceIdList), etc. The SRS-Resources included in the list include an identifier for the SRS-Resource (srs-ResourceId), the SRS resource in the frequency domain (e.g., resourceMapping), etc. resourceMapping includes the start position (startPosition), the number of symbols (nrofSymbols), the repetition factor, etc. The SRS Config may also be a parameter defined in §6.3.2 “Radio resource control information elements” of Non-Patent Literature 4. 【0085】 <Agreements in 3GPP> The following two options were considered for determining the valid RO in the SBFD symbol. Note that in the following, a valid RO may be referred to as a valid RO. Option 1: Single PRACH setting Option 2: Additional PRACH setting for SBFD Note that in Option 1, a single expandable RACH setting may be used. Furthermore, the RO in the UL subband of the SBFD symbol may be valid for SBFD-aware UEs. Option 2 may use two separate RACH settings, including a legacy RACH setting and an additional RACH setting. Furthermore, the RO in the UL subband of the SBFD symbol may be valid for SBFD-aware UEs. 【0086】The following points were agreed upon: For SBFD-aware UEs in the RRC_CONNECTED state, two options are supported: Option 1 of the RACH configuration with Alt 1-1 and Option 2 of the RACH configuration. Option 1 of the RACH configuration with Alt 1-1 uses a single RACH configuration and operates only based on the existing parameters of that single RACH configuration. Option 2 of the RACH configuration uses two distinct RACH configurations. These two distinct configurations include one legacy RACH configuration and one additional RACH configuration. It is not supported for both options to be available to a UE at the same time. 【0087】 Figure 11 shows examples of RACH setting options. Figure 11 shows examples of RACH settings for each of the two options. For each option in Figure 11, the horizontal axis represents the time axis, and the vertical axis represents the frequency axis. For each option in Figure 11, the RO set to SBFD symbols and non-SBFD symbols is shown. 【0088】 As shown in Option 1 of Figure 11, in Option 1, the ROs of both SBFD symbols and non-SBFD symbols are set by the legacy RACH configuration. As shown in Option 2 of Figure 11, in Option 2, the RO of SBFD symbols is set by an additional RACH configuration, and the RO of non-SBFD symbols is set by the legacy RACH configuration. 【0089】An additional RO is defined as follows: • For RACH configuration option 1, an additional RO includes ROs within SBFD symbols configured as DL by tdd-UL-DL-ConfigurationCommon, ROs spanning SBFD symbols configured as flexible by tdd-UL-DL-ConfigurationCommon, and ROs spanning SBFD symbols configured as DL. • For RACH configuration option 2, an additional RO is an RO configured by an additional RACH configuration. 【0090】 With regard to enabling RO for option 1 of a RACH configuration with Alt 1-1, an RO spanning SBFD symbols configured as flexible and SBFD symbols configured as DL by tdd-UL-DL-ConfigurationCommon is treated the same as an RO within an SBFD symbol configured as DL by tdd-UL-DL-ConfigurationCommon. Here, the RO includes at least one DL symbol configured by tdd-UL-DL-ConfigurationCommon. 【0091】 Option 2 of the RACH settings enables additional RO in any of the following cases: • The RO is within an SBFD symbol. • The network sets the RO to be enabled when the RO starts with an SBFD symbol and ends with a non-SBFD symbol within the same slot or across different slots. • The RO is after the last downlink non-SBFD symbol. ｇａｐ Starts at the symbol's position. The RO is N after the latest SSB. ｇａｐ Starts at the symbol's position; the RO does not overlap with the SSB in the time domain. 【0092】As described above, in Option 1 of the RACH configuration with Alt 1-1 (i.e., a single RACH configuration), legacy ROs and additional ROs correspond to the following ROs: • Legacy ROs are valid legacy ROs that include ULs or flexible symbols. • Additional ROs are ROs within SBFD DL symbols, or ROs that span SBFD DL symbols and SBFD flexible symbols. 【0093】 As described above, in RACH configuration option 2 (i.e., additional RACH configuration for SBFD), legacy RO and additional RO correspond to the following ROs: - Legacy RO is an active RO configured by the legacy RACH configuration. - Additional RO is an RO within an SBFD symbol, or an RO that is enabled when the network starts with an SBFD symbol and ends with a non-SBFD symbol in the same or different slots, as configured by the additional RACH configuration. 【0094】 "Legacy RO" refers to the enabled RO in UL symbols or flexible symbols, as set by the legacy RACH configuration based on legacy RO enabling rules. 【0095】 "Additional RO" represents the effective RO set by the legacy PRACH setting in the SBFD DL symbol when no additional PRACH setting for SBFD is configured. 【0096】 Alternatively, "Additional RO" represents the effective RO set by the legacy PRACH setting, spanning both SBFD DL symbols and SBFD flexible symbols, when no additional PRACH setting for SBFD is configured. 【0097】 Alternatively, "Additional RO" represents the valid RO in SBFD symbols that is set by the SBFD-specific PRACH setting when an additional PRACH setting for SBFD is configured. 【0098】 Alternatively, "Additional RO" refers to an RO configured by the SBFD-oriented PRACH configuration when an additional PRACH configuration for SBFD is configured, and the network configures the RO to be valid if it starts with an SBFD symbol and ends with a non-SBFD symbol, either within the same slot or across different slots. 【0099】<Number of Msg1 repetitions for initial attempt> Regarding the number of Msg1 repetitions exchanged in random access (RA), TS 38.321 (e.g., section 5.1.1b) specifies the following. Note that the number of Msg1 repetitions may also be written as Msg 1 repNum. If the BWP selected for the random access procedure is configured with a set of random access resources associated with an Msg1 repetition count of 8, and the RSRP referencing the downlink path loss is less than rsrp-ThresholdMsg1-RepetitionNum8, then Msg1 repetitions are applicable, and it is assumed that the number of Msg1 repetitions applicable to the current random access procedure includes 8. - If the BWP selected for the random access procedure is configured with a set of random access resources associated with 4 Msg1 repetition counts, and the RSRP referencing the downlink path loss is less than rsrp-ThresholdMsg1-RepetitionNum4, then Msg1 repetitions are applicable, and it is assumed that 4 Msg1 repetition counts are included in the number of Msg1 repetitions applicable to the current random access procedure. - If the BWP selected for the random access procedure is configured with a set of random access resources associated with 2 Msg1 repetition counts, and the RSRP referencing the downlink path loss is less than rsrp-ThresholdMsg1-RepetitionNum2, then Msg1 repetitions are applicable, and it is assumed that 2 Msg1 repetition counts are included in the number of Msg1 repetitions applicable to the current random access procedure. Assuming that the repetition of Msg1 is applicable to the current random access procedure, and that at least one of rsrp-ThresholdMsg1-RepetitionNumX is set, one of the following (a1) to (a4) is expected.- (a1) If rsrp-ThresholdMsg1-RepetitionNum8 is set and the RSRP referencing the downlink path loss is less than rsrp-ThresholdMsg1-RepetitionNum8, it is assumed that the number of repetitions of Msg1 applied to the current random access procedure will include 8. - (a2) If rsrp-ThresholdMsg1-RepetitionNum4 is set and the RSRP referencing the downlink path loss is less than rsrp-ThresholdMsg1-RepetitionNum4, it is assumed that the number of repetitions of Msg1 applied to the current random access procedure will include 4. - (a3) ​​If rsrp-ThresholdMsg1-RepetitionNum2 is set and the RSRP referencing the downlink path loss is less than rsrp-ThresholdMsg1-RepetitionNum2, it is assumed that the number of repetitions of Msg1 applied to the current random access procedure will include 2. - (a4) If the RSRP, which references the downlink path loss, is not smaller than any of the configured rsrp-ThresholdMsg1-RepetitionNumX, the number of Msg1 repetitions applicable to the current random access procedure is assumed to be the minimum number of Msg1 repetitions configured in this BWP. Here, X in NumX may be 2, 4, or 8. - If none of rsrp-ThresholdMsg1-RepetitionNumX are configured, the number of Msg1 repetitions applicable to the current random access procedure is assumed to be the number of Msg1 repetitions configured in this BWP. 【0100】 In other words, according to the provisions of TS 38.321 (for example, section 5.1.1b), the number of repetitions of Msg1 is determined based on a set RSRP threshold (for example, rsrp-ThresholdMsg1-RepetitionNumX (where X is, for example, an integer of 2 or more)). 【0101】Note that the repetition of Msg1 may be interpreted as the repetition of PRACH. For example, the number of repetitions of Msg1 may be interpreted as the number of PRACH repetitions. 【0102】 <Number of repetitions of Msg1 in retry (re-attempt)> The preamble for random access (e.g., Msg1) may be sent repeatedly. For example, if the random access procedure does not complete, the preamble for random access will be sent repeatedly. 【0103】 In cases where a preamble is transmitted during repetition, the number of preamble transmissions is counted, and when the counted number of transmissions reaches a threshold, the repetition number is changed. Here, the number of preamble transmissions corresponds to the number of RACH trials. The counter that counts the number of preamble transmissions is called PREAMBLE_TRANSMISSION_COUNTER. The threshold that is compared to the counted number of transmissions is set by a parameter called preambleTransMax-Msg1-Repetition. 【0104】 For example, if either of the following two conditions is met, the set of random access resources associated with the next highest Msg1 repetition count is selected. In other words, if either of the following two conditions is met, the next highest Msg1 repetition count is selected as the repetition count. Here, selection, change, update, setting, decision, etc., may be substituted for each other. Note that preambleTransMax-Msg1-Repetition is an integer value of 1 or more. • PREAMBLE_TRANSMISSION_COUNTER = [preambleTransMax-Msg1-Repetition] + 1 • PREAMBLE_TRANSMISSION_COUNTER = 2 × [preambleTransMax-Msg1-Repetition] + 1 【0105】 Figure 12 shows an example of changing the number of RACH trials and repetitions. Figure 12 shows the RACH opportunities and the number of repetitions in the RACH trials for each RACH opportunity. The value of PREAMBLE_TRANSMISSION_COUNTER represents the number of RACH trials, and the value of repK represents the number of repetitions. For example, the RACH trial corresponding to PREAMBLE_TRANSMISSION_COUNTER = i (where i is an integer greater than or equal to 1) is the i-th RACH trial. Also, the available number of repetitions in Figure 12 is 2, 4, and 8. 【0106】 In the example in Figure 12, the number of repetitions for each RACH trial corresponding to PREAMBLE_TRANSMISSION_COUNTER = preambleTransMax-Msg1-Repetition, starting from PREAMBLE_TRANSMISSION_COUNTER = 1, is 2. Then, the number of repetitions for a RACH trial where PREAMBLE_TRANSMISSION_COUNTER = [preambleTransMax-Msg1-Repetition] + 1 holds increases to "4", which is the second highest number of repetitions after "2" among the available repetitions. Also, the number of repetitions for a RACH trial where PREAMBLE_TRANSMISSION_COUNTER = 2 × [preambleTransMax-Msg1-Repetition] + 1 holds increases to "8", which is the second highest number of repetitions after "4" among the available repetitions. 【0107】 As described above, with respect to PRACH repetition, when the number of RACH trials reaches a certain value, the number of repetitions increases to the next highest number of available repetitions. In the example above, the specific value is [preambleTransMax-Msg1-Repetition] + 1, or 2 × [preambleTransMax-Msg1-Repetition] + 1. 【0108】If a random access attempt (or retry) of a RACH is successful (for example, if Msg2 is received from the base station and the subsequent steps are completed), then no further RACH retries are required. 【0109】 Furthermore, preambleTransMax-Msg1-Repetition, which is used to determine the number of repetitions in RACH retries, is included in BWP-UplinkCommon. BWP-UplinkCommon is used to set common parameters for the uplink's BWP. BWP-UplinkCommon is included, for example, in an information element (IE) called BWP-Uplink. 【0110】 <Retrying RACH for SBFD RA> In RAN2 #127bis, an agreement was reached regarding retrying RACH for SBFD RA. 【0111】 In a single RACH procedure, for the purpose of retrying a PRACH transmission, the UE may switch to a legacy RACH occasion after a certain number of RACH attempts in an SBFD RACH occasion. A legacy RACH occasion may be interpreted as a legacy RO (RACH occasion). SBFD RACH occasions, SBFD-ROs, and additional ROs may be interpreted as mutually exclusive. 【0112】 Figure 13 shows an example of switching between RACH trials and RACH opportunities. Figure 13 also shows the relationship between RACH trials and the types of symbols on which RACH trials are performed. 【0113】 As shown in Figure 13, in the SBFD symbol, N RACH trials are performed from the first RACH trial to the Nth RACH trial. Then, in the non-SBFD symbol, RACH trials from the (N+1)th trial onward are performed. Here, the RACH trials in the SBFD symbol correspond to RACH trials in the SBFD RACH opportunity, and the RACH trials in the non-SBFD symbol correspond to RACH trials in the legacy RACH opportunity. 【0114】In other words, in the example in Figure 13, when the number of RACH trials reaches a certain value, the PRACH in SBFD is switched to the PRACH in non-SBFD. In the example in Figure 13, after N RACH trials have been performed in the SBFD RACH opportunity, the UE switches to the legacy RACH opportunity. Here, the certain value can be considered as N or as N+1. Note that N is an integer greater than or equal to 1. 【0115】 <Switching from 2-Step RA to 4-Step RA> TS 38.321 (for example, section 5.1.3a) specifies the following regarding switching from 2-step RA to 4-step RA: - In cases where the random access procedure does not complete, if msgA-TransMax is applied and PREAMBLE_TRANSMISSION_COUNTER = msgA-TransMax + 1 is true, the type of RA is set to 4-step RA. 【0116】 The above-mentioned switching from a two-step RA to a four-step RA (for example, fallback) is similar to the RO type switching explained using Figure 13 as an example. 【0117】 <PRACH Repetition in SBFD> In RAN1, the following support for PRACH repetition has been agreed upon: - PRACH repetition using only additional ROs - PRACH repetition using only legacy ROs 【0118】 In other words, PRACH transmissions that perform preamble repetitions across additional ROs and legacy ROs are not supported. 【0119】 <Related Technology 1> As related technologies, we will describe the switching from PRACH in SBFD for RACH retries to PRACH in non-SBFD, and support for switching from PRACH in non-SBFD for RACH retries to PRACH in SBFD. SBFD may be read as SBFD symbol. non-SBFD may be read as non-SBFD symbol. 【0120】 <Related Technology 1-1> In Related Technology 1-1, the switching from PRACH in SBFD to PRACH in non-SBFD is determined based on a first condition. Switching may be interpreted as fallback. The first condition is that the number of RACH trials for PRACH in SBFD reaches a certain number. This certain number may be interpreted as a threshold. The following options are possible for Related Technology 1-1. 【0121】 Related technology 1-1 sets a threshold for switching from SBFD symbols to non-SBFD symbols. 【0122】 For example, the threshold is preambleTransMax, which is included in an additional / individual RACH setting (RACH setting for SBFD). The threshold may also be used to decide whether or not to perform switching from SBFD symbols to non-SBFD symbols. 【0123】 For example, the threshold is a new parameter included in the legacy RACH configuration or the RACH configuration for SBFD (e.g., sbfd-TransMax). The threshold may be used to decide whether or not to perform switching from SBFD symbols to non-SBFD symbols. 【0124】 UE may assume that the threshold is less than or equal to preambleTransMax included in the legacy RACH configuration. 【0125】 <Related Technology 1-2> In Related Technology 1-2, the UE may perform the following actions regarding switching from an SBFD symbol to a non-SBFD symbol. Specifically, the case in which the first RACH attempt is the transmission of PRACH for an SBFD symbol is described. The case in which the first RACH attempt is the transmission of PRACH for an SBFD symbol is, for example, the case in which the PRACH transmission of the first RACH attempt is performed with a valid RO for an SBFD symbol, or the case in which the PRACH transmission of the first RACH attempt is performed with a valid RO set by an additional RACH setting for SBFD. 【0126】 For RACH retries, if the value of PREAMBLE_TRANSMISSION_COUNTER is less than or equal to a threshold (preambleTransMax or sbfd-TransMax), the UE decides to send a PRACH in the SBFD symbol for RACH retries. The PRACH in the SBFD symbol may be a PRACH in a valid RO in the SBFD symbol, or a PRACH in a valid RO set by the SBFD RACH setting. 【0127】 For RACH retries, if the value of PREAMBLE_TRANSMISSION_COUNTER is not greater than or less than a threshold (preambleTransMax or sbfd-TransMax), the UE decides to send a PRACH for non-SBFD symbols for RACH retries. A PRACH for non-SBFD symbols may be a PRACH for a valid RO in a non-SBFD symbol, or a PRACH for a valid RO set by the legacy RACH setting. 【0128】 <Points to Consider> In legacy PRACH repetitions, if the PRACH for multiple repetitions is determined in the first RACH trial, the UE may maintain or increase the number of repetitions based on the conditions. For example, in this case, the UE may maintain the number of repetitions in the second and subsequent RACH trials at the same number as the number of repetitions in the previous RACH trial, or increase it to the number of repetitions in the previous RACH trial, based on the conditions regarding the number of RACH trials. 【0129】 Furthermore, in legacy PRACH repetition, if a PRACH without repetition is determined in the first RACH attempt, the UE will send a PRACH without repetition in subsequent RACH retries. Subsequent RACH retries may, in other words, correspond to the second and subsequent RACH attempts. 【0130】According to the agreement in RAN2#127bis, if the number of RACH trials reaches a certain value, the UE can switch from additional RO to legacy RO. 【0131】 However, the agreement in RAN2#127bis did not consider the relationship between RO type switching and repetition, so there is room for further consideration regarding RO type switching. For example, there is room for consideration regarding the behavior of a UE's RO type switching when the UE sends a PRACH with repetition in an additional RO. 【0132】 For example, if a UE sends a PRACH with repetition in an additional RO, it is worth considering whether the UE can switch to a legacy RO for PRACH transmission. 【0133】 In cases where a UE transmits a PRACH with repetition in an additional RO, if it is uncertain whether the UE can switch to a legacy RO for PRACH transmission, a discrepancy may arise between the base station and the UE regarding the RO type switch, potentially preventing the RO type switch from being performed correctly and resulting in the inability to perform random access properly. Furthermore, in this case, a discrepancy may arise between the base station and the UE regarding the relationship between the RO type switch and the presence or absence of repetition, potentially preventing the repetition from being performed correctly after the RO type switch, and thus preventing the performance of random access properly. 【0134】 Furthermore, in cases where a UE transmits a PRACH with repetitions in an additional RO, and the UE is able to switch to a legacy RO for PRACH transmission, there is room for consideration regarding how to determine the number of repetitions in the legacy RO after the RO type switch. 【0135】If the UE can switch to a legacy RO for PRACH transmission, and the number of repetitions for the legacy RO after the RO type switch cannot be properly determined, then the repetitions before and after the RO type switch may not be performed properly, which could lead to problems with random access or an increase in the resources required for random access. 【0136】 Therefore, in this embodiment, when a PRACH with repetition is transmitted in an additional RO, the operation of the UE will be described depending on whether or not the UE supports switching to a legacy RO for PRACH transmission, and when the UE supports switching to a legacy RO for PRACH transmission, the timing of the RO type switch and the determination of the number of repetitions before and after the switch. 【0137】 <Summary of Proposals> Proposals 1 and 2, described below, are based on the premise that a preamble, as an example of a signal related to random access, is transmitted in multiple repetitions during the initial RACH trial. The following is a summary of the proposals. ・Proposal 1: RO type switching is not supported for RACH retries with PRACH repetitions. ・Proposal 2: RO type switching for PRACH repetitions is supported during RACH retries. The following points are explained in Proposal 2. - Proposal 2-1: Number of PRACH repetitions before switching RO types - Proposal 2-2: Switching RO types for PRACH repetitions - Proposal 2-3: Number of PRACH repetitions after switching RO types from SBFD-RO to legacy RO - Proposal 2-3A: Number of PRACH repetitions for the first RACH retry in legacy RO after switching RO types when UE switches from SBFD-RO to legacy RO - Proposal 2-3B: Maintaining or increasing the number of PRACH repetitions for subsequent RACH retries in legacy RO after switching RO types 【0138】<Proposal 1> In Proposal 1, the premise is that the preamble is sent in multiple repetitions during the initial RACH attempt. Furthermore, in Proposal 1, switching of RO types is not supported for RACH retries. Here, switching of RO types refers to, for example, switching to either an additional RO type or a legacy RO type. 【0139】 In cases where Proposal 1 applies, if the preamble is sent with multiple repetitions in the initial RACH attempt, RO type switching for RACH retries is not supported. In other words, in cases where Proposal 1 applies, RO type switching for RACH retries is supported only if the preamble is sent without repetitions in the initial RACH attempt. 【0140】 The number of PRACH repetitions may be increased or maintained based on legacy rules. For example, the UE may determine the number of PRACH repetitions based on legacy rules. Legacy rules may be, for example, the rules shown above in "Number of repetitions of Msg1 in retry (re-attempt)". 【0141】 <Variation of Proposal 1> The parameter preambleTransMax-Msg1-Repetition may be set separately for PRACH repetition in additional RO. That is, the parameter preambleTransMax-Msg1-Repetition for PRACH repetition in additional RO may be set separately from the parameter preambleTransMax-Msg1-Repetition for PRACH repetition in legacy RO. For example, a new parameter called preambleTransMax-Msg1-Repetition-sbfd-r19 may be set and used to determine whether to maintain or increase the number of PRACH repetitions. 【0142】If preambleTransMax-Msg1-Repetition for additional ROs is not set, the legacy parameter preambleTransMax-Msg1-Repetition may be used. PreambleTransMax-Msg1-Repetition for additional ROs may be referred to as, for example, the aforementioned preambleTransMax-Msg1-Repetition-sbfd-r19, or by other names. 【0143】 The UE will not switch to another RO type regardless of whether the set number of RACH attempts for RO type switching has been reached. Here, RO type switching based on whether the set number of RACH attempts for RO type switching has been reached corresponds to the switching exemplified in "RACH retries for SBFD RA" above. 【0144】 In Proposal 1, in the case where the UE transmits a PRACH with repetition in the additional RO, switching to the legacy RO for PRACH transmission is not supported. In other words, in this case, the UE does not switch to the legacy RO for PRACH transmission. According to Proposal 1, discrepancies between the base station and the UE regarding the switching of RO types can be avoided, so the switching of RO types can be performed appropriately, and random access can be performed appropriately. Furthermore, in this case, discrepancies between the base station and the UE regarding the relationship between the switching of RO types and the presence or absence of repetition can be avoided, so random access can be performed appropriately. 【0145】 <Proposal 2> In Proposal 2, as with Proposal 1, the premise is that the preamble is sent in multiple repetitions during the initial RACH attempt. In Proposal 2, switching of the RO type for the PRACH repetition is supported during the RACH retry. 【0146】In cases where Proposal 2 applies, if the preamble is sent with multiple repetitions in the initial RACH attempt, RO type switching is supported for RACH retries. In other words, in cases where Proposal 2 applies, RO type switching is supported for RACH retries whether the preamble is sent without repetitions in the initial RACH attempt or whether the preamble is sent with multiple repetitions in the initial RACH attempt. 【0147】 <Proposal 2-1> Proposal 2-1 explains how to determine the number of PRACH repetitions before switching to the RO type. 【0148】 In Proposal 2-1, the number of PRACH repetitions may be increased or maintained based on legacy rules. For example, the UE may determine the number of PRACH repetitions based on legacy rules. Legacy rules may be, for example, the rules shown above for "Number of repetitions of Msg1 in retry (re-attempt)". 【0149】<Variation of Proposal 2-1> The parameter preambleTransMax-Msg1-Repetition may be set separately for PRACH repetition in additional RO. That is, the parameter preambleTransMax-Msg1-Repetition for PRACH repetition in additional RO may be set separately from the parameter preambleTransMax-Msg1-Repetition for PRACH repetition in legacy RO. For example, a new parameter called preambleTransMax-Msg1-Repetition-sbfd-r19 may be set and used to determine whether to maintain or increase the number of PRACH repetitions. 【0150】 If preambleTransMax-Msg1-Repetition for additional ROs is not set, the legacy parameter preambleTransMax-Msg1-Repetition may be used. PreambleTransMax-Msg1-Repetition for additional ROs may be referred to as, for example, the aforementioned preambleTransMax-Msg1-Repetition-sbfd-r19, or by other names. 【0151】 When setting parameters used to determine the number of PRACH repetitions before switching RO types separately for PRACH repetitions in additional ROs and for PRACH repetitions in legacy ROs, it is possible to determine the appropriate number of repetitions for each. 【0152】 <Proposal 2-2> Proposal 2-2 explains the switching to RO type for PRACH repetition. 【0153】In Proposal 2-2, if the set number of RACH attempts for switching RO types is reached, the UE may switch to a different RO type. Alternatively, if the set number of RACH attempts for switching RO types is reached, the UE should switch to a different RO type. The set number of RACH attempts for switching RO types is, for example, the number set in the RAN2 agreement as shown in "RACH retries for SBFD RA" above. The set number of RACH attempts for switching RO types corresponds to a threshold that is compared with the number of RACH attempts to determine whether or not to switch RO types. The set number of RACH attempts for switching RO types is set, for example, by a parameter called preambleTransMax-sbfd. 【0154】 <Variation of Proposal 2-2> The number of RACH trials for switching RO types may be set separately for PRACH without repetition and for PRACH with repetition. 【0155】 The first parameter (e.g., preambleTransMax-sbfd) is set for the number of RACH trials without PRACH repetition in SBFD-RO (in other words, additional RO). The second parameter (e.g., preambleTransMax-sbfd-repetition) is set for the number of RACH trials with PRACH repetition in SBFD-RO. 【0156】 In this embodiment, the first parameter and the second parameter are referred to as preambleTransMax-sbfd and preambleTransMax-sbfd-repetition, respectively, but the first and second parameters are not limited to these names. For example, as shown in "Related Technology 1" above, names such as "preambleTransMax" or "sbfd-TransMax" may be used. 【0157】For example, if a UE sends a PRACH without repetition in an additional RO during its first RACH attempt, the UE uses a first parameter to decide whether to switch to (or fall back to) a legacy RO. For example, if the number of RACH attempts reaches a number set based on the first parameter, the UE switches the RO type to a legacy RO. Note that the decision to switch can also be considered as a decision on the timing of the switch. The number set based on the first parameter may be the number indicated by the first parameter. 【0158】 For example, if a UE sends a PRACH with repetition in an additional RO during the first RACH attempt, the UE uses a second parameter to determine whether to switch to a legacy RO (fallback). For example, if the number of RACH attempts reaches a number set based on the second parameter, the UE switches the RO type to a legacy RO. The number set based on the second parameter may be the number indicated by the second parameter. 【0159】 If the second parameter is not set, the UE will use the first parameter to determine the RO type switch (fallback). 【0160】 By setting the number of RACH trials for switching RO types individually for PRACH without repetition and for PRACH with repetition, it is possible to switch RO types at the appropriate timing for each. 【0161】<Proposal 2-3> Proposal 2-3 describes how to determine the number of PRACH repetitions after switching the RO type from SBFD-RO (in other words, Additional RO) to Legacy RO. Below, Proposal 2-3A shows the number of PRACH repetitions in the first RACH retry in the Legacy RO after the RO type switch, and Proposal 2-3B shows the number of PRACH repetitions in RACH retries after the first RACH retry in the Legacy RO after the RO type switch. 【0162】 <Proposal 2-3A> When a UE switches from SBFD-RO to legacy RO, at least one of the following options is applied to the first RACH retry in the legacy RO after the RO type switch. That is, at least one of the following options is applied to the number of PRACH repetitions in the first RACH retry in the legacy RO after the RO type switch. 【0163】 (Option A-1) The rule for determining the number of PRACH repetitions in the first RACH retry in the legacy RO after switching RO types (the rule for determining whether to maintain or increase the number) is the same as in legacy. In other words, switching RO types does not affect the maintenance / increment of the number of PRACH repetitions. Note that the legacy rule may be, for example, the rule shown above for "Number of repetitions of Msg1 in retry (re-attempt)". 【0164】 (Option A-2) The number of PRACH repetitions in the first RACH retry in legacy RO after RO type switching is the same as the number of PRACH repetitions in the last RACH trial in SBFD-RO. 【0165】(Option A-3) In the legacy RO after the RO type switch, the number of PRACH repetitions in the first RACH retry is reduced to the next lower repetition number (and a number greater than 1), if a next lower repetition number is available. The next lower repetition number is, for example, a repetition number lower than the number of PRACH repetitions in the RACH trial immediately preceding the first RACH retry in the legacy RO after the RO type switch. The RACH trial immediately preceding the first RACH retry in the legacy RO after the RO type switch may be the last RACH trial in the SBFD-RO. 【0166】 In addition, the following will be explained regarding the cases in which a lower number of repetitions is available under Option A-3. For example, if the available number of repetitions is 2, 4, and 8, and the number of PRACH repetitions in the RACH trial immediately preceding the first RACH retry in the legacy RO after the RO type switch is "4", then "2", which is the next lowest number of repetitions after "4", is included in the available number of repetitions. This is one of the cases in which a lower number of repetitions is available. 【0167】 In option A-3, if the available number of repetitions is 2, 4, or 8, and the number of PRACH repetitions in the RACH trial immediately preceding the first RACH retry in the legacy RO after the RO type switch is "2", then the next lowest number of repetitions after "2" is not included in the available number of repetitions. This is a case where the next lowest number of repetitions is unavailable. In option A-3, if the next lowest number of repetitions is unavailable, other options (for example, at least one of options A-1 to A-8 excluding option A-3) may be applied. 【0168】(Option A-4) In the legacy RO after the RO type switch, the number of PRACH repetitions in the first RACH retry is increased to the next higher number of repetitions if available. The next higher number of repetitions is, for example, a number of repetitions higher than the number of PRACH repetitions in the RACH trial immediately preceding the first RACH retry in the legacy RO after the RO type switch. The RACH trial immediately preceding the first RACH retry in the legacy RO after the RO type switch may be the last RACH trial in SBFD-RO. 【0169】 In addition, the following will be explained regarding the cases in which a higher number of repetitions is available under Option A-4. For example, if the available number of repetitions is 2, 4, and 8, and the number of PRACH repetitions in the RACH trial immediately preceding the first RACH retry in the legacy RO after the RO type switch is "4", then "8", which is the next highest number of repetitions after "4", is included in the available number of repetitions. This is one of the cases in which a higher number of repetitions is available. 【0170】 In option A-4, if the available repetition counts are 2, 4, and 8, and the PRACH repetition count in the RACH trial immediately preceding the first RACH retry in the legacy RO after the RO type switch is "8", then the next highest repetition count after "8" is not included in the available repetition counts. This is a case where the next higher repetition count is unavailable. In option A-4, if the next higher repetition count is unavailable, other options (for example, at least one of options A-1 to A-8 excluding option A-4) may be applied. 【0171】(Option A-5) The number of PRACH repetitions in the first RACH retry in the legacy RO after an RO type switch is reset to the lowest number of PRACH repetitions available for the legacy RO (and greater than 1). For example, if the available number of repetitions is 2, 4, or 8, the number of PRACH repetitions in the first RACH retry in the legacy RO after an RO type switch is reset to 2. 【0172】 (Option A-6) The number of PRACH repetitions in the first RACH retry in the legacy RO after an RO type switch is reset to the highest number of PRACH repetitions available in the legacy RO (and greater than 1). For example, if the available number of repetitions is 2, 4, or 8, the number of PRACH repetitions in the first RACH retry in the legacy RO after an RO type switch is reset to 8. 【0173】 (Option A-7) The UE re-selects the number of PRACH repetitions in the legacy RO based on the RSRP threshold. The RSRP threshold here is rsrp-ThresholdMsg1-RepetitionNum2 / 4 / 8. The re-selection method may be the same as the method described above for "Number of Msg1 repetitions for the initial attempt". 【0174】 (Option A-8) The PRACH repetition count is reset to 1. In other words, PRACH repetition will not be performed on the legacy RO after the RO type switch. 【0175】 Next, the number of repetitions for each of the above-mentioned options A-1 to A-8 will be explained using a diagram. 【0176】Figure 14 shows examples of each option in Proposal 2-3A. Figure 14 shows the RO type and the number of repetitions in the RACH trial for each RO. Figure 14 also shows an example where the number of RACH trials set for switching RO types is "4", the number of RACH trials set for increasing the number of PRACH repetitions is "2", and the set number of repetitions is selected from the set of "2, 4, and 8" for legacy ROs and additional ROs, respectively. The number of RACH trials set for switching RO types is represented, for example, as preambleTransMax-sbfd. The number of RACH trials set for increasing the number of PRACH repetitions is represented as preambleTransMax-Msg1-Repetition. 【0177】 Furthermore, as shown in the variation of Proposal 2-2, if the number of RACH trials for switching RO types is set separately for PRACH without repetition and for PRACH with repetition, and the parameter set for the number of RACH trials with PRACH repetition in the additional RO is called preambleTransMax-sbfd-repetition, then preambleTransMax-sbfd in Figure 14 may be replaced with preambleTransMax-sbfd-repetition. 【0178】 In Figure 14, the first and second RACH trials in the additional RO are performed with a repetition count of 2. Then, in the third RACH trial, "PREAMBLE_TRANSMISSION_COUNTER = preambleTransMax - Msg1 - Repetition + 1" is satisfied, so the repetition count increases to "4", which is the second highest repetition count after "2" among the {2, 4, 8}. 【0179】Furthermore, in the fifth RACH trial, "PREAMBLE_TRANSMISSION_COUNTER = preambleTransMax - sbfd + 1" is satisfied, so the RACH opportunity is switched from the additional RO to the legacy RO. In other words, the fifth RACH trial corresponds to the first RACH retry in the legacy RO after the RO type switch. The determination of the number of repetitions in the fifth RACH trial when each option is applied is shown below. 【0180】 In Option A-1, the rule for determining the number of PRACH repetitions is the same as in the legacy version. Therefore, when Option A-1 is applied, in the fifth RACH trial, "PREAMBLE_TRANSMISSION_COUNTER = 2*preambleTransMax-Msg1-Repetition+1" is satisfied, and the number of repetitions increases to "8", which is the second highest number of repetitions after "4" among the {2, 4, 8}. 【0181】 In Option A-2, the number of PRACH repetitions is the same as the number of PRACH repetitions in the last RACH trial in SBFD-RO. Therefore, when Option A-2 is applied, the number of repetitions in the fifth RACH trial is the same as the number of repetitions in the fourth RACH trial, which corresponds to the last RACH trial in SBFD-RO (i.e., additional RO). In other words, the number of repetitions in the fifth RACH trial is "4". 【0182】 In Option A-3, the number of PRACH repetitions is reduced to the next lower number of repetitions (and a number greater than 1), if a lower number of repetitions is available. Therefore, if Option A-3 is applied, the number of repetitions for the 5th RACH trial is reduced to "2", which is the next lower number of repetitions than the number of repetitions for the 4th RACH trial. 【0183】In Option A-4, the number of PRACH repetitions is increased to the next higher number of repetitions available, if any. Therefore, if Option A-4 is applied, the number of repetitions for the fifth RACH trial is increased to "8", which is the next higher number of repetitions than the number of repetitions for the fourth RACH trial. 【0184】 In Option A-5, the PRACH repetition count is reset to the lowest possible number of repetitions (and greater than 1) available for PRACH repetitions in the legacy RO. Therefore, if Option A-5 is applied, the repetition count for the fifth RACH trial is reset to "2," which corresponds to the lowest number of repetitions available for PRACH repetitions in the legacy RO (2, 4, and 8). 【0185】 Option A-6 resets the PRACH repetition count to the highest possible number of repetitions (and greater than 1) available for PRACH repetitions in the legacy RO. Therefore, if Option A-6 is applied, the repetition count for the fifth RACH trial will be reset to "8," which is the highest of the available repetition counts for PRACH repetitions in the legacy RO (2, 4, and 8). 【0186】 In Option A-7, the UE re-selects the number of PRACH repetitions in the legacy RO based on the RSRP threshold. Therefore, if Option A-7 is applied, the number of repetitions for the fifth RACH trial will be re-selected from the available repetition numbers for PRACH repetitions in the legacy RO: 2, 4, and 8. 【0187】 In Option A-8, the PRACH repeat count is reset to 1. Therefore, if Option A-8 is applied, the repeat count for the 5th RACH trial will be reset to "1". 【0188】<Variation of Proposal 2-3A> Different combinations of options may be possible based on the rules. 【0189】 For example, if the number of PRACH repeats in the last RACH trial in the Additional RO is greater than the highest number of repeats available in the Legacy RO, option A-6 applies. Otherwise, options A-1 / A-2 apply. 【0190】 Any other combination of options A-1 to A-8 is possible. 【0191】 Which options apply may be defined by the specification, set by the RRC, or indicated by the SIB. 【0192】 In Proposal 2-3A, the UE determines the number of repetitions in the first RACH retry in the legacy RO after the RO type switch by at least one of the legacy rules, the number of RACH attempts, the number of PRACH repetitions in the last RACH attempt in SBFD-RO, one or more available repetitions, and the result of comparing RSRP with a threshold. The number of PRACH repetitions in the last RACH attempt in SBFD-RO is used in Options A-2 to A-4. One or more available repetitions are used in Options A-5 to A-6. The result of comparing RSRP with a threshold is used in Option A-7. Note that the last RACH attempt in SBFD-RO is an example of a RACH attempt in SBFD-RO before the RO type switch. 【0193】 <Proposal 2-3B> Proposal 2-3B describes subsequent RACH retries in legacy RO after an RO type switch. Here, subsequent RACH retries refer to RACH retries after the first RACH retry in legacy RO after an RO type switch. At least one of the following options applies to the number of PRACH repetitions in RACH retries after the first RACH retry in legacy RO after an RO type switch. 【0194】 (Option B-1) The same number of PRACH repetitions as the number of repetitions in the first RACH retry in the legacy RO after the RO type switch is applied to the number of PRACH repetitions in the RACH retries after the first RACH retry in the legacy RO after the RO type switch, without any further increment of the number of PRACH repetitions. 【0195】 (Option B-2) In the legacy RO after the RO type switch, the number of PRACH repetitions in the RACH retries after the first RACH retry is maintained or increased by the legacy rule, based on the number of RACH retries and the set number of RACH attempts for increasing the number of repetitions. Here, the set number of RACH attempts for increasing the number of repetitions is preambleTransMax-Msg1-Repetition. The legacy rule may be, for example, the rule shown in "Number of Msg1 repetitions in retries (re-attempt)" above. 【0196】 In option B-2, if either equation (B-2-1) or (B-2-2) below is true, and if a higher number of repetitions is available, the UE will select the next higher number of repetitions. If neither of the following two equations is true, the number of repetitions is maintained. • PREAMBLE_TRANSMISSION_COUNTER = [preambleTransMax-Msg1-Repetition] + 1 (B-2-1) • PREAMBLE_TRANSMISSION_COUNTER = 2 × [preambleTransMax-Msg1-Repetition] + 1 (B-2-2) 【0197】(Option B-3) The number of PRACH repetitions in the RACH retries after the first RACH retry in the legacy RO after the RO type switch is maintained or increased by the legacy rules based on the number of RACH retries in the legacy RO and the set number of RACH attempts for increasing the number of repetitions. Here, the set number of RACH attempts for increasing the number of repetitions is preambleTransMax-Msg1-Repetition. Note that the number of RACH retries in the legacy RO does not include the number of RACH retries in the additional RO. 【0198】 In option B-3, if either equation (B-3-1) or (B-3-2) below is true, and if a higher number of repetitions is available, the UE will select the next higher number of repetitions. If neither of the following two equations is true, the number of repetitions is maintained. • PREAMBLE_TRANSMISSION_COUNTER - preambleTransMax-sbfd = [preambleTransMax-Msg1-Repetition] + 1 (B-3-1) • PREAMBLE_TRANSMISSION_COUNTER - preambleTransMax-sbfd = 2 × [preambleTransMax-Msg1-Repetition] + 1 (B-3-2) 【0199】The parameter preambleTransMax-sbfd represents the set number of RACH trials for switching RO types. preambleTransMax-sbfd is a parameter that sets the threshold for switching, as shown in "Retrying RACH for SBFD RA" above. This parameter is shown in Proposal 2-2. This parameter is set separately from the value for PRACH repetition for RO type switching. Here, the value for PRACH repetition for RO type switching may be, for example, preambleTransMax-sbfd-repetition as shown in Proposal 2-2. 【0200】 Furthermore, if option B-3 is applied, the value of PREAMBLE_TRANSMISSION_COUNTER may be reset to 0 when the RO type is switched. In this case, PREAMBLE_TRANSMISSION_COUNTER will show 1 in the first RACH trial in legacy RO and 2 in the second RACH trial in legacy RO. If the value of PREAMBLE_TRANSMISSION_COUNTER is reset to 0 when the RO type is switched, for example, if either equation (B-2-1) or equation (B-2-2) is true, the UE will select the next higher number of repetitions if one is available. 【0201】If option B-3 is applied, a counter for counting RACH retries in legacy RO may be set separately from PREAMBLE_TRANSMISSION_COUNTER. The counter for counting RACH retries in legacy RO shows 1 for the first RACH attempt in legacy RO and 2 for the second RACH attempt in legacy RO. If the counter for counting RACH retries in legacy RO is set separately from PREAMBLE_TRANSMISSION_COUNTER, for example, PREAMBLE_TRANSMISSION_COUNTER on the left side of equations (B-2-1) and (B-2-2) is replaced with "the value of the counter for counting RACH retries in legacy RO". If either of these two replaced equations is true, and if a higher number of repetitions is available, the UE selects the next higher number of repetitions. 【0202】 (Option B-4) The number of PRACH repetitions is equal to 1. In other words, PRACH repetitions are not performed on the legacy RO after the RO type switchover. 【0203】 Option B-4 is likely to be applied in conjunction with Option A-8 of Proposal 2-3A, but may also be combined with other options of Proposal 2-3A. 【0204】Figure 15 shows examples of options B-1, B-2, and B-3 of Proposal 2-3B. Figure 15 shows the RO type and the number of repetitions in the RACH trial for each RO. Figure 15 also shows an example where the number of RACH trials set for switching RO types is "4", the number of RACH trials set for increasing the number of PRACH repetitions is "6", and the set number of repetitions is selected from the set of "2, 4, and 8" for legacy ROs and additional ROs, respectively. The number of RACH trials set for switching RO types is represented, for example, as preambleTransMax-sbfd. The number of RACH trials set for increasing the number of PRACH repetitions is represented as preambleTransMax-Msg1-Repetition. 【0205】 In Figure 15, the first four RACH trials in the additional RO are executed with a repetition count of 2. Then, in the fifth RACH trial, "PREAMBLE_TRANSMISSION_COUNTER = preambleTransMax - sbfd + 1" is satisfied, so the RACH opportunity is switched from the additional RO to the legacy RO. In other words, the fifth RACH trial corresponds to a RACH retry in the legacy RO after the RO type switch. 【0206】In the fifth RACH trial, either option A-1 or A-2 of proposal 2-3A described above is applied. In option A-1, the rule for determining the number of PRACH repetitions is the same as in legacy. Therefore, when option A-1 is applied, preambleTransMax-Msg1-Repetition=6, so the number of repetitions in the fifth RACH trial is "2". In option A-2, the number of PRACH repetitions is the same as the number of PRACH repetitions in the last RACH trial in SBFD-RO. Therefore, when option A-2 is applied, the number of repetitions in the fifth RACH trial is the same as the number of repetitions in the fourth RACH trial, which corresponds to the last RACH trial in SBFD-RO (i.e., additional RO). In other words, the number of repetitions in the fifth RACH trial is "2". 【0207】 Figure 15 shows the number of repetitions for the 6th and subsequent RACH trials when options B-1 to B-3 are applied, in the case where the number of repetitions for the 5th RACH trial is "2". 【0208】 In Option B-1, the same number of PRACH repetitions as the number of repetitions in the first RACH retry in the legacy RO after switching RO types are applied without any further increments of PRACH repetitions. Therefore, when Option B-1 is applied, the number of repetitions for the 6th and subsequent RACH trials will each be "2", which corresponds to the number of repetitions in the first RACH retry in the legacy RO. 【0209】In Option B-2, the PRACH repetition count is maintained or increased by legacy rules based on the number of RACH retries and the set number of RACH trials for increasing the repetition count. For example, when Option B-2 is applied, in the 7th RACH trial, the above equation (B-2-1) is true, so the repetition count for the 6th RACH trial is "2", and the repetition count for the 7th RACH trial is changed to "4", which is the next highest repetition count after 2. Also, the repetition count for the 8th to 12th RACH trials will be "4". Although not shown in the figure, in the 13th RACH trial, the above equation (B-2-2) is true, so the repetition count for the 13th RACH trial is changed to "8", which is the next highest repetition count after 4. 【0210】 In Option B-3, the number of PRACH repetitions is maintained or increased by legacy rules based on the number of RACH retries in legacy RO and the set number of RACH trials for increasing the number of repetitions. For example, when Option B-3 is applied, equation (B-3-1) is true in the 11th RACH trial, so the number of repetitions for the 7th to 10th RACH trials becomes "2", and the number of repetitions for the 11th RACH trial becomes "4". Also, the number of repetitions for the 12th to 16th RACH trials becomes "4". Although not shown in the figure, in the 17th RACH trial, equation (B-3-2) is true, so the number of repetitions for the 17th RACH trial is changed to "8", which is the next highest number of repetitions after 4. 【0211】Figure 16 shows an example where option B-4 of proposal 2-3B is applied. Figure 16 shows an example where option B-4 of proposal 2-3B is applied together with option A-8 of proposal 2-3A. Figure 16 shows the RO type and the number of repetitions in the RACH trial for each RO. Figure 16 also shows an example where the number of RACH trials set for switching RO types is "4", the number of RACH trials set for increasing the number of PRACH repetitions is "6", and the set number of repetitions is selected from the set of "2, 4, or 8" for legacy ROs and additional ROs, respectively. The number of RACH trials set for switching RO types is represented, for example, as preambleTransMax-sbfd. The number of RACH trials set for increasing the number of PRACH repetitions is represented as preambleTransMax-Msg1-Repetition. 【0212】 In Figure 16, the first four RACH trials in the additional RO are executed with a repetition count of 2. Then, in the fifth RACH trial, "PREAMBLE_TRANSMISSION_COUNTER = preambleTransMax - sbfd + 1" is satisfied, so the RACH opportunity is switched from the additional RO to the legacy RO. In other words, the fifth RACH trial corresponds to a RACH retry in the legacy RO after the RO type switch. 【0213】 In the fifth RACH trial, option A-8 of proposal 2-3A described above is applied. In option A-8, the number of PRACH repetitions is reset to 1. Therefore, when option A-8 is applied, the number of repetitions in the fifth RACH trial is reset to "1". 【0214】 Figure 16 shows the number of repetitions when option B-4 is applied to the 6th and subsequent RACH trials, in the case where the number of repetitions for the 5th RACH trial is "1". 【0215】In Option B-4, the number of PRACH repetitions is equal to 1. Therefore, as an example, when Option B-4 is applied, the number of repetitions for the 7th and subsequent RACH trials will each be "1". 【0216】 Note that while Figure 16 shows an example where both options A-8 and B-4 are applied, the combination of options is not limited to this. 【0217】 In summary, Proposal 2 supports switching to a legacy RO for PRACH transmission when the UE transmits a PRACH with repetition in an additional RO. In other words, in this case, the UE switches to a legacy RO for PRACH transmission. According to Proposal 2, discrepancies between the base station and the UE regarding RO type switching can be avoided, so RO type switching can be performed appropriately and random access can be performed appropriately. Furthermore, in this case, discrepancies between the base station and the UE regarding the relationship between RO type switching and the presence or absence of repetition can be avoided, so random access can be performed appropriately. 【0218】 Furthermore, according to Proposal 2-1, in cases where a PRACH with repetition is transmitted in an additional RO, the number of PRACH repetitions in the RACH trial before the RO type switch can be appropriately determined, thus enabling appropriate execution of random access with repetition. 【0219】 Furthermore, according to Proposal 2-2, the RO type can be switched for PRACH repeatation at an appropriate time, allowing for proper RO type switching and thus proper random access. 【0220】 Furthermore, according to Proposal 2-3, in the case where a PRACH with repetition is sent in an additional RO, the number of PRACH repetitions in the first RACH retry after the RO type switch and in the RACH retries after the first RACH retry can be appropriately determined, thus enabling appropriate execution of random access with repetition. 【0221】 <Variations of this embodiment> The UE may anticipate that the same number of PRACH repetitions will be set for the legacy RO and the additional RO. For example, if the number of repetitions set for PRACH repetitions in the legacy RO is the set {2, 4, 8}, the UE may anticipate that the number of repetitions set for PRACH repetitions in the additional RO will also be the set {2, 4, 8}. 【0222】 UE may anticipate that different PRACH repetition counts will be set for legacy RO and additional RO. For example, if the set of repetition counts for PRACH repetitions in legacy RO is the set {2, 4, 8}, UE may anticipate that the set of repetition counts for PRACH repetitions in additional RO will be the set {2, 4, 8, 16}. 【0223】 UE may anticipate that the highest number of repeats in Additional RO will not be less than the highest number of repeats in Legacy RO. Alternatively, UE may anticipate that the highest number of repeats in Additional RO will not be greater than the highest number of repeats in Legacy RO. 【0224】 Any combination of any two or more of the above-mentioned proposals, or any combination of any two or more of the options within each proposal, may be applied. Furthermore, any two or more of the above-mentioned proposals, or any two or more of the options within each proposal, may be switched dynamically or semi-persistently. 【0225】 Each of the above suggestions may be applied to a UE in connected mode or to a UE in RRC idle mode. 【0226】 Each of the above proposals may be applied to CBRA or to CFRA. 【0227】Each of the options in the above proposals may be applied to a UE in connected mode or to a UE in RRC idle mode. 【0228】 Different proposals may be applied to RACH setting option 1 and RACH setting option 2, or different options of a given proposal may be applied. Here, RACH setting option 1 is a setting option without additional RACH repetition for SBFD, and RACH setting option 2 is a setting option with additional RACH for SBFD. 【0229】 Any combination of the options in Proposal 1, Proposal 2-1, Proposal 2-2, and Proposal 2-3 may be possible. 【0230】 (Combinations with Options) In each proposal of this disclosure, which proposal applies, or which option or alternative is used, may be determined by: - ​​Setting by higher-level parameters - Determining by relevant higher-level parameters - Indicated in MAC CE or DCI - Determining based on UE capabilities - Stated in the specification - Determining based on conditions stated in the specification - Determining by the higher-level parameters / MAC CE / DCI configuration and reported UE capabilities (combinations of the above determinations) 【0231】 In each proposal of this disclosure, multiple options and alternatives may be combined into a single option / alternative. Throughout the proposals, the measured RS (reference signal) will be the QCL source RS in the active TCI state / indicated TCI state. 【0232】(Signals from NW to UE) In this disclosure, the UE may receive the following types of information from the network (NW). Throughout the proposal, the network (NW) may also be referred to as a gNB. • Information via upper-layer signaling (e.g., RRC messages / LPP (LTE propositioning protocol) messages) • MAC CE subheader with a new LCID extending the existing MAC CE (e.g., introducing a new octet) • DCI DCI field: Existing DCI field or newly introduced DCI field RNTI: Existing RNTI or DCI with a scrambled CRC by the newly introduced RNTI DCI format: Existing DCI format or newly introduced DCI format • Combinations of the above information 【0233】 In this disclosure, the UE may receive information from the network (NW) in the following periodic forms: Option 1: Receive information periodically; Option 2: Receive information semi-persistently (triggered by instructions from the UE or gNB); Option 3: Receive information aperiodically (triggered by instructions from the UE or gNB). 【0234】 In this disclosure, the UE may receive information from the network (NW) as the following QCL rules: • QCL Type A • QCL Type B • QCL Type C • QCL Type D 【0235】 In this disclosure, the QCL resource RS for each QCL type may be configured as follows: • SSB (SS / PBCH Block) • CSI-RS with / without repetition • TRS (tracking reference signal) • PDCCH / PDSCH DMRS 【0236】 In this disclosure, information from the network (NW) is set / presented as follows: • Common to UE / Dedicated to UE • Cell-specific / Common to cell • Per UE / CC / BWP / Bandwidth / Cell / CG 【0237】(Signals from UE to NW) In this disclosure, the UE may report the following types of information to the network (NW). Throughout the proposal, the network (NW) may also be referred to as gNB. - Information via upper layer signaling (e.g., RRC messages / LPP messages) - MAC CE subheader with a new LCID, extending an existing MAC CE (e.g., introduction of a new octet) - UCI on PUCCH or PUSCH - Combinations of the above information 【0238】 In this disclosure, the UE may report information to the network (NW) in the following periodic forms: Option 1: Send information periodically Option 2: Send information semi-persistently (triggered by instructions from the UE or gNB) Option 3: Send information aperiodically (triggered by instructions from the UE or gNB) 【0239】 <UE capability> The UE capability, which indicates the capabilities of a terminal, may include the following information indicating the capabilities of the terminal. For example, the following new UE capability and report signaling (and RRC settings) may be defined. Note that the information indicating the capabilities of a terminal may correspond to the information defining the capabilities of the terminal. The UE may report the following information indicating the capabilities of the terminal to the gNB: - The capabilities of the terminal for each proposal - The capabilities of each option in each proposal, or each combination of options - The capabilities of each alternative in each proposal, or each combination of alternatives The UE may report the above information indicating the capabilities of the terminal for each frequency to the gNB: - Capabilities for each UE / FR1 / FR2 / FR2-1 / FR2-2 / FR3 / SCS / band / BC / FC / FSPC, etc. The UE may report the above information indicating the capabilities of the terminal for each cell to the gNB: - Capabilities for each UE / cell / TDD / FDD, etc. 【0240】The capabilities of the UE described above and the configuration of this proposal are closely related, and if the functionality of each option in each proposal depends on the capabilities of the UE, the gNB may select or permit the functionality of each option based on the capabilities reported by the UE. 【0241】 Next, the configurations of gNB100 and UE200 will be described. Note that the configurations of gNB100 and UE200 described below are examples of functions related to this embodiment. gNB100 and UE200 may have functions not shown. Furthermore, the function classification and / or the name of the function unit are not limited, as long as the function performs the operations related to this embodiment. 【0242】 <Base Station Configuration> Figure 17 is a block diagram showing an example of the configuration of a base station 100 (gNodeB (gNB) 100) according to this embodiment. The gNB 100 includes, for example, a transmitting unit 101, a receiving unit 102, and a control unit 103. The gNB 100 communicates wirelessly with the UE 200 (see Figure 18). 【0243】 The transmitter 101 transmits downlink (DL) signals to the UE200. For example, the transmitter 101 transmits DL signals (e.g., RRC, SIB, MAC CE, DCI, notification, acknowledgment, etc., as described above) under the control of the control unit 103. 【0244】 The DL signal may include, for example, downlink data signals and control information (e.g., Downlink Control Information (DCI)). The DL signal may also include information indicating the scheduling of signal transmission for the UE200 (e.g., UL grants). Furthermore, the DL signal may include control information from higher layers (e.g., Radio Resource Control (RRC) control information). Finally, the DL signal may include reference signals. 【0245】The channels used to transmit DL signals include, for example, a downlink data channel and a downlink control channel. For example, the downlink data channel may include a PDSCH (Physical Downlink Shared Channel), and the downlink control channel may include a PDCCH (Physical Downlink Control Channel). For example, gNB100 transmits downlink control information to UE200 using the PDCCH and transmits downlink data signals using the PDSCH. 【0246】 The reference signals included in the DL signal may include, for example, at least one of the following: Demodulation Reference Signal (DMRS), Phase Tracking Reference Signal (PTRS), Channel State Information-Reference Signal (CSI-RS), Sounding Reference Signal (SRS), and Positioning Reference Signal (PRS). For example, reference signals such as DMRS and PTRS are used for demodulating the downlink data signal and are transmitted using PDSCH. 【0247】 The receiving unit 102 receives uplink (UL) signals transmitted from the UE200. For example, the receiving unit 102 receives UL signals (e.g., the requests and notifications mentioned above) under the control of the control unit 103. 【0248】 The transmitting unit 101 and the receiving unit 102 may together be referred to as the communication unit. 【0249】 The control unit 103 controls the communication operation of the gNB100, including the transmission process of the transmission unit 101 and the reception process of the reception unit 102. For example, the control unit 103 performs operations other than the transmission and reception described in the above embodiment (these operations may be performed by the reception unit 102 and / or the transmission unit 101). 【0250】For example, the control unit 103 acquires information such as data and control information from the upper layer and outputs it to the transmission unit 101. The control unit 103 also outputs the data and control information received from the reception unit 102 to the upper layer. 【0251】 For example, the control unit 103 allocates resources (or channels) used for transmitting and receiving DL signals and / or resources used for transmitting and receiving UL signals based on signals received from the UE200 (e.g., data and control information, etc.) and / or data and control information, etc. acquired from higher layers. Information regarding the allocated resources may be included in the control information transmitted to the UE200. 【0252】 <Terminal Configuration> Figure 18 is a block diagram showing an example of the configuration of the UE200 according to this embodiment. The UE200 includes, for example, a receiving unit 201, a transmitting unit 202, and a control unit 203. The UE200 communicates with, for example, the gNB100 wirelessly. 【0253】 The transmitter 202 transmits the UL signal to the gNB100. For example, the transmitter 202 transmits the UL signal under the control of the control unit 203. For example, the transmitter 202 may transmit MsgA PRACH in a valid MsgA RO determined by the control unit 203, or MsgA PUSCH in a valid MsgA PO determined by the control unit 203. 【0254】 The UL signal may include, for example, data signals for the uplink and control information (e.g., UCI). It may also include, for example, information regarding the processing capability of the UE200 (e.g., UE capability). Furthermore, the UL signal may include reference signals. 【0255】The channels used to transmit UL signals include, for example, an uplink data channel and an uplink control channel. For example, the uplink data channel includes PUSCH (Physical Uplink Shared Channel), and the uplink control channel includes PUCCH (Physical Uplink Control Channel). For example, UE200 transmits uplink control information to gNB100 using PUCCH and transmits uplink data signals using PUSCH. 【0256】 The reference signals included in the UL signal may include, for example, at least one of DMRS, PTRS, CSI-RS, SRS, and PRS. For example, reference signals such as DMRS and PTRS are used for demodulating the uplink data signal and are transmitted using an uplink channel (e.g., PUSCH). 【0257】 The receiving unit 201 and the transmitting unit 202 may together be referred to as the communication unit. 【0258】 The control unit 203 controls the communication operation of the UE200, including the receiving process in the receiving unit 201 and the transmitting process in the transmitting unit 202. For example, the control unit 203 performs operations other than the transmission and reception described in the above embodiment (these operations may be performed by the receiving unit 201 and / or the transmitting unit 202). 【0259】 For example, the control unit 203 acquires information such as data and control information from the upper layer and outputs it to the transmission unit 202. The control unit 203 also outputs data and control information received from the receiving unit 201 to the upper layer. 【0260】 For example, the control unit 203 controls the transmission of information to be fed back to the gNB100. The information to be fed back to the gNB100 may include, for example, HARQ-ACK, Channel State Information (CSI), or Scheduling Request (SR). The information to be fed back to the gNB100 may be included in the UCI. 【0261】 Here, for example, the control unit 203 of the UE200 sets the type of repetition opportunity based on whether or not it supports switching the type of repetition opportunity for a random access signal (e.g., preamble or Msg1). For example, the type of repetition opportunity for a random access signal may be the legacy RO or additional RO described above. For example, if the control unit 203 does not support switching the type of repetition opportunity for a random access signal, it does not switch the type of repetition opportunity. Also, if the control unit 203 supports switching the type of repetition opportunity for a random access signal, it switches the type at a specific opportunity. The communication unit transmits the signal at an opportunity of the type set by the control unit 203. 【0262】 <Hardware Configuration, etc.> The block diagram used in the description of the above embodiment shows functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may also be realized by combining the above one device or the above multiple devices with software. 【0263】Functions include, but are not limited to, judgment, decision, determination, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. In all cases, as mentioned above, the method of implementation is not particularly limited. 【0264】 For example, a base station, terminal, etc. in one embodiment of the present disclosure may function as a computer that processes the communication method of the present disclosure. Figure 19 is a diagram showing an example of the hardware configuration of a base station and terminal according to one embodiment of the present disclosure. The gNB100 and UE200 described above may be physically configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, bus 1007, etc. 【0265】 In the following explanation, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of gNB100 and UE200 may include one or more of the devices shown in the diagram, or it may be configured to omit some of the devices. 【0266】 Each function in the gNB100 and UE200 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of data reading and writing in the memory 1002 and storage 1003. 【0267】The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may be composed of a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, etc. For example, the control unit 103 and control unit 203 described above may be implemented by the processor 1001. 【0268】 Furthermore, the processor 1001 reads programs (program code), software modules, data, etc., from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. For example, the control unit 203 of the UE200 may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and other functional blocks may be implemented similarly. The above-described various processes have been explained as being executed by one processor 1001, but they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may also be transmitted from a network via a telecommunications line. 【0269】 Memory 1002 is a computer-readable recording medium and may consist of at least one of the following: ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. Memory 1002 may also be called a register, cache, main memory, etc. Memory 1002 can store executable programs (program code), software modules, etc., for implementing a communication method according to one embodiment of the present disclosure. 【0270】Storage 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., Compact Disc, Digital Multipurpose Disc, Blu-ray® Disc), a smart card, flash memory (e.g., a card, stick, key drive), a floppy® disk, a magnetic strip, etc. Storage 1003 may also be called an auxiliary storage device. The above-mentioned storage medium may be, for example, a database, server, or other suitable medium including at least one of memory 1002 and storage 1003. 【0271】 The communication device 1004 is hardware (transmitting / receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc. The communication device 1004 may be configured to include high-frequency switches, duplexers, filters, frequency synthesizers, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmitting unit 101, receiving unit 102, receiving unit 201, and transmitting unit 202 may be implemented by the communication device 1004. 【0272】 The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel). 【0273】Furthermore, each device, such as the processor 1001 and memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device. 【0274】 Furthermore, gNB100 and UE200 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array), and some or all of each functional block may be realized by such hardware. For example, processor 1001 may be implemented using at least one of these hardware components. 【0275】(Supplement to Embodiments) While embodiments of the present disclosure 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, substitutions, etc. Specific numerical examples have been used to facilitate understanding of the invention, but 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 disclosure, and matters described in two or more items may be combined as needed, and matters described in one item may be applied to matters described in another item (as long as they do not contradict each other). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operation of multiple functional units may be physically performed by one part, or the operation of one functional unit may be physically performed by multiple parts. The processing procedures described in the embodiments may be rearranged as long as they do not contradict each other. For the convenience of explaining the processing, base stations and terminals have been described using functional block diagrams, but such devices may be implemented in hardware, software, or a combination thereof. Software operated by a processor in a base station according to embodiments of this disclosure, and software operated by a processor in a terminal according to embodiments of this disclosure, may each be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disks (HDDs), removable disks, CD-ROMs, databases, servers, or any other suitable storage medium. 【0276】<Notification of Information, Signaling> Notification of information is not limited to the embodiments described herein and may be carried out by other means. For example, notification of information may be carried out by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block))), other signals, or combinations thereof. RRC signaling may also be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc. 【0277】<Applicable Systems> The embodiments described herein may be applied to systems utilizing LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (where x is, for example, an integer or decimal)), FRA (Future Radio Access), NR (new Radio), New radio access (NX), Future generation radio access (FX), W-CDMA®, GSM®, CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth®, and other appropriate systems, as well as at least one of the next-generation systems that are extended, modified, created, or defined based on these. Furthermore, multiple systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A with 5G). 【0278】 <Processing Procedures, etc.> The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described in this disclosure may be rearranged in order, as long as there is no contradiction. For example, the methods described in this disclosure present various step elements using exemplary order and are not limited to the specific order presented. 【0279】<Base Station Operation> The specific operations described in this disclosure as being performed by a base station may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal can be performed by the base station and at least one other network node (for example, an MME or S-GW, but not limited to these). The above example illustrates the case where there is one other network node besides the base station, but it may also be a combination of multiple other network nodes (for example, an MME and an S-GW). 【0280】 <Direction of Input / Output> Information, etc. (see the section on <Information, Signals>) can be output from a higher layer (or lower layer) to a lower layer (or higher layer). Input and output may also occur via multiple network nodes. 【0281】 <Handling of Input / Output Information, etc.> Input and output information, etc. may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information, etc. may be overwritten, updated, or appended to. Output information, etc. may be deleted. Input information, etc. may be transmitted to other devices. 【0282】 <Determination Method> The determination may be made by a value represented by one bit (0 or 1), by a boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value). 【0283】 <Variations of Embodiments, etc.> Each embodiment / appearance described in this disclosure may be used individually, in combination, or switched between during implementation. Furthermore, notification of predetermined information (for example, notification that "it is X") is not limited to explicit notification, but may also be implicit (for example, by not providing notification of the predetermined information). 【0284】Although the present disclosure has been described in detail above, it will be 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 intent and scope of the present disclosure as defined by the claims. Therefore, the descriptions in the present disclosure are illustrative and not intended to be restrictive in any way. 【0285】 <Software> Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc., whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name. 【0286】 Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium. 【0287】 <Information, Signals> The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc., which may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof. 【0288】In addition, terms used 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 the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc. 【0289】 <Systems and Networks> The terms “systems” and “networks” as used in this disclosure are interchangeable. 【0290】 <Parameters, Channel Names> Furthermore, the information, parameters, etc. described in this disclosure may be expressed using absolute values, relative values ​​from a predetermined value, or other corresponding information. For example, wireless resources may be indicated by an index. 【0291】 The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way. 【0292】<Base Station> In this disclosure, terms such as "Base Station (BS)", "wireless 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. 【0293】 A base station can accommodate one or more (e.g., three) cells. If a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, each of which may also be provided with communication services by a base station subsystem (e.g., a Remote Radio Head (RRH)). The terms “cell” or “sector” refer to part or all of the coverage area of ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage. 【0294】 In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform control or operation based on the information. 【0295】 <Mobile Station> In this disclosure, terms such as "Mobile Station (MS)", "user terminal", "User Equipment (UE)", and "terminal" may be used interchangeably. 【0296】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 several other appropriate terms. 【0297】 <Base Station / Mobile Station> At least one of a base station and a mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of a base station and a mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body refers to a movable object, and its speed of movement is arbitrary. This also includes cases where the mobile body is stationary. The mobile body includes, but is not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and items mounted on them. The mobile body may also be a mobile body that moves autonomously based on operation commands. It may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Furthermore, at least one of the base station and the mobile station may 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. 【0298】Furthermore, the term "base station" in this disclosure may be interpreted as "terminal." For example, the embodiments of this disclosure may be applied to a configuration in which communication between a base station and a terminal is replaced with communication between multiple terminals (which may be called, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the terminal may have the functions that the base station has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc., may be interpreted as side channel. 【0299】 Similarly, the term "terminal" in this disclosure may be replaced with "base station." In this case, the base station may be configured to have the same functions as the terminal described above. 【0300】 Figure 20 shows an example of the configuration of vehicle 2001. As shown in Figure 20, 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 this disclosure may be applied to a communication device mounted on vehicle 2001, for example, to the communication module 2013. 【0301】 The drive unit 2002 consists of, for example, 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, which is operated by the user. 【0302】 The electronic control unit 2010 consists of a microprocessor 2031, memory (ROM, RAM) 2032, and communication ports (IO ports) 2033. Signals from various sensors 2021 to 2029 installed in the vehicle 2001 are input to the electronic control unit 2010. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit). 【0303】 Signals from various sensors 2021 to 2029 include current signals from current sensor 2021 which senses motor current, front and rear wheel rotation speed signals obtained by rotation speed sensor 2022, front and rear wheel air pressure signals obtained by air pressure sensor 2023, vehicle speed signals obtained by vehicle speed sensor 2024, acceleration signals obtained by acceleration sensor 2025, accelerator pedal depression signals obtained by accelerator pedal sensor 2029, brake pedal depression signals obtained by brake pedal sensor 2026, shift lever operation signals obtained by shift lever sensor 2027, and detection signals obtained by object detection sensor 2028 for detecting obstacles, vehicles, pedestrians, etc. 【0304】 The Information Services Unit 2012 consists of various devices for providing (outputting) various types of information such as driving information, traffic information, and entertainment information, including a car navigation system, audio system, speakers, television, and radio, and one or more ECUs that control these devices. The Information Services Unit 2012 uses information acquired from external devices via a communication module 2013, etc., to provide various multimedia information and multimedia services to the occupants of the vehicle 2001. 【0305】 The Information Services Unit 2012 may include input devices that accept input from external sources (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) and output devices that output to external sources (e.g., displays, speakers, LED lamps, touch panels, etc.). 【0306】The driver assistance system unit 2030 consists of various devices that provide functions to prevent accidents or reduce the driver's workload, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS), 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 driver assistance system unit 2030 also sends and receives various information via the communication module 2013 to realize driver assistance functions or autonomous driving functions. 【0307】 The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via its communication port. For example, the communication module 2013 sends and receives data via its communication port 2033 between the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, the microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 2029 provided in the vehicle 2001. 【0308】 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 external devices. For example, it can send and receive various types of information to and from external devices 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 or a mobile station. 【0309】The communication module 2013 may transmit at least one of the following to an external device via wireless communication: signals from the various sensors 2021 to 2029 input to the electronic control unit 2010, information obtained based on said signals, and information based on input from an external source (user) obtained via the information service unit 2012. The electronic control unit 2010, the various sensors 2021 to 2029, the information service unit 2012, etc., may also be called input units that accept input. For example, the PUSCH transmitted by the communication module 2013 may include information based on the above input. 【0310】 The communication module 2013 receives various information (traffic information, signal information, inter-vehicle information, etc.) transmitted from an external device and displays it on the information service unit 2012 provided in the vehicle 2001. The information service unit 2012 may also be called an output unit, which outputs information (for example, outputs information to devices such as displays and speakers based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 2013). The communication module 2013 also stores the various information received from the external device in a memory 2032 that is available to the microprocessor 2031. Based on the information stored in 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 2021-2029, etc., provided in the vehicle 2001. 【0311】<Meaning and Interpretation of Terms> As used in this disclosure, the terms “determining” and “determining” may encompass a wide variety of actions. “Determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., searching in tables, databases or other data structures), and ascertaining. “Determining” may also include, for example, receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, and accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having "judgmented" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having "judgmented" or "decided" about some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering." 【0312】The terms “connected,” “coupled,” and any variations thereof mean 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” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain. 【0313】 <Reference Signal> The reference signal can also be abbreviated as RS (Reference Signal), and may be called a pilot depending on the applicable standard. 【0314】 <Meaning of "based on"> As used in this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on". 【0315】 <"First", "Second"> Any reference to elements using the designations "first", "second", etc. as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to first and second elements do not imply that only two elements may be adopted, or that the first element must precede the second element in any way. 【0316】 <Means> The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc. 【0317】<Open Format> Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to be exclusive OR. 【0318】 <Time units such as TTI, frequency units such as RB, and radio frame configuration> A radio frame may consist 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 consist 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. 【0319】 Numerology may be communication parameters applied to at least one of the transmission and reception of a signal or channel. Numerology may include, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain. 【0320】 A slot may consist of one or more symbols in the time domain (such as OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.). A slot may also be a time unit based on neurology. 【0321】A slot may include multiple mini-slots. Each mini-slot may consist of one or more symbols in the time domain. Mini-slots may also be called sub-slots. Mini-slots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a mini-slot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may be called PDSCH (or PUSCH) mapping type B. 【0322】 Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Different names may be used for each of these terms. 【0323】 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 mini-slot may be called a TTI. In other words, at least one of a subframe and a TTI may be a subframe in existing LTE (1 ms), 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, mini-slot, etc., instead of a subframe. 【0324】 Here, TTI refers to, for example, the smallest unit of time for scheduling in wireless communication. For example, in an LTE system, the base station schedules each user terminal to allocate wireless resources (such as the frequency bandwidth and transmission power available to each user terminal) in TTI units. However, the definition of TTI is not limited to this. 【0325】TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Note that when a TTI is given, the actual time interval (e.g., number of symbols) in which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI. 【0326】 Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute the minimum time unit of scheduling may be controlled. 【0327】 A TTI with a time length of 1 ms may also be called a normal TTI, long TTI, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may also be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini slot, sub slot, slot, etc. 【0328】 Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more. 【0329】 A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology. 【0330】Furthermore, the time domain of RB may contain one or more symbols and may be the length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc., may each consist of one or more resource blocks. 【0331】 One or more RBs may also be called Physical RBs (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc. 【0332】 Furthermore, a resource block may consist of one or more resource elements (REs). For example, one RE may be a radio resource area comprising one subcarrier and one symbol. 【0333】 A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a given neurology in a given carrier. These common RBs may be identified by an index of the RBs relative to a common reference point of the carrier. The PRBs may be defined and numbered within a given BWP. 【0334】 A BWP may include BWPs for UL (UL BWP) and BWPs for DL ​​(DL BWP). One or more BWPs may be configured within a single carrier for a UE. 【0335】 At least one of the configured BWPs may be active, and the UE does not need to assume that it will send or receive a given signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP". 【0336】The structures described above, such as wireless frames, subframes, slots, minislots, and symbols, are merely illustrative. For example, the number of subframes included in a wireless frame, the number of slots per subframe or wireless 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, and the number of symbols, symbol length, and cyclic prefix (CP) length within the TTI can be varied in various ways. 【0337】 <Maximum Transmit Power> The term "maximum transmit power" as used in this disclosure may mean the maximum value of the transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power. 【0338】 <Articles> In this disclosure, if articles are added by translation, such as a, an, and the in English, this disclosure may also include the fact that the noun following these articles is plural. 【0339】 <"Different"> In this 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 "combine" may be interpreted similarly to "different." 【0340】 This patent application claims priority based on Japanese Patent Application No. 2024-215953, filed on 10 December 2024, and the entire contents of Japanese Patent Application No. 2024-215953 are incorporated herein by reference. 【0341】 One aspect of this disclosure is useful for wireless communication systems. 【0342】 10 Wireless communication system 20 NG-RAN 100 Base station (gNB) 200 Terminal (UE) 101, 202 Transmitter 102, 201 Receiver 103, 203 Control unit

Claims

1. A terminal comprising: a control unit that sets the type of repetition opportunity based on whether or not it supports switching the type of repetition opportunity for a random access signal; and a communication unit that transmits the signal in the type of opportunity set by the control unit.

2. The terminal according to claim 1, wherein the control unit determines the number of repetitions in the first type of machine before switching the type of machine from the first type to the second type, based on a parameter set for the first type or the second type.

3. The terminal according to claim 1, wherein the control unit determines the timing for switching the type of the machine from a first type to a second type based on a first parameter set for the case in which the repetition is performed, or a second parameter set for the case in which the repetition is not performed.

4. The terminal according to claim 1, wherein the control unit determines the number of repetitions in the second type of the opportunity after switching the type of the opportunity from a first type to a second type, based on at least one of the number of opportunities, the number of repetitions in the first type of opportunity before switching from the first type to the second type, one or more values ​​available for the number of repetitions, the result of comparing the communication quality with a threshold used to determine the number of repetitions, and a specific method.

5. A wireless communication system comprising: a terminal that transmits the signal in the set type of opportunity; and a base station that receives the signal, setting the type of opportunity of the repetition of the random access signal based on whether or not it supports switching of the type of opportunity of the repetition of the signal.

6. A wireless communication method comprising setting the type of repetition opportunity based on whether the terminal supports switching the type of repetition opportunity for a random access signal, and transmitting the signal during the set type of opportunity.

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