Terminal, wireless communication method, and base station

Abstract

A terminal according to one embodiment of the present disclosure is provided with: a reception unit that receives one or more first reference signals; and a control unit that determines, on the basis of the received power of the one or more first reference signals, whether to perform a single random access channel transmission or a plurality of random channel transmission in an attempt of random access channel transmission, and at least one of the number of random access channel transmissions in the attempt, when the attempt fails, at least one of the transmission power to be re-attempted and the maximum number of random access channel transmissions is determined on the basis of the determination.

Description

TECHNICAL FIELD

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

[0002] In a Universal Mobile Telecommunications System (UMTS) network, Long Term Evolution (LTE) is standardized for the purpose of further higher-speed data rates, lower delay, and so on (Non-Patent Literature 1). Further, LTE-Advanced (3GPP Rel. 10-14) is standardized for the purpose of further larger capacity, higher density, and so on of LTE (Third Generation Partnership Project (3GPP (registered trademark)) Release (Rel.) 8, 9).

[0003] A subsequent system of LTE (for example, also referred to as a 5th generation mobile communication system (5G), 5G+, a 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 15 onwards, and so on) is also under study.

[0004] PRIOR ART DOCUMENTS

[0005] NON-PATENT LITERATURE

[0006] Non-Patent Literature 1: 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] In a future wireless communication system (for example, NR), improvement of coverage is under study.

[0009] However, a random access procedure for coverage improvement is not clear. If such a random access procedure is not clear, there is a concern that communication throughput decreases.

[0010] Therefore, one of the objects of the present disclosure is to provide a terminal, a wireless communication method, and a base station that improve coverage of a random access procedure.

[0011] Means for solving the problem

[0012] The terminal according to an aspect of the present disclosure includes a reception unit that receives one or more first reference signals, and a control unit that determines at least one of whether to perform single random access channel transmission or multiple random access channel transmission in an attempt of random access channel transmission, and the number of random access channel transmissions in the attempt, based on reception power of the one or more first reference signals, and determines at least one of a reattempt transmission power and a maximum number of random access channel transmissions based on the determination in a case where the attempt fails.

[0013] Effects of the Invention

[0014] According to an aspect of the present disclosure, it is possible to improve coverage of a random access procedure. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 An example of RACH configuration information element is shown.

[0016] Figure 2A And Figure 2B An example of association of PRACH occasion and beam is shown.

[0017] Figure 3 An example of RAR window is shown.

[0018] Figure 4 An example of RO group is shown.

[0019] Figure 5A And Figure 5B An example of a set of RSRP thresholds for UE power class is shown.

[0020] Figure 6 An example of the relationship of RSRP range and parameter set is shown.

[0021] Figure 7 An example of option 1 of embodiment C-1 is shown.

[0022] Figure 8 An example of embodiment C-3 is shown.

[0023] Figure 9 An example of multiple RACH attempts is shown.

[0024] Figure 10 An example of Option 1 of Embodiment 1-1 is shown.

[0025] Figure 11 An example of Option 2 of Embodiment 1-1 is shown.

[0026] Figure 12 An example of K=2 and Option 1-1 of Embodiment 2-1 is shown.

[0027] Figure 13 An example of K=2 and Option 1-2 of Embodiment 2-1 is shown.

[0028] Figure 14 An example of K=2 and Option 1-3 of Embodiment 2-1 is shown.

[0029] Figure 15 An example of K=2 and Option 1-4 of Embodiment 2-1 is shown.

[0030] Figure 16 An example of K=4 and Option 1-1 and Option 1-3 of Embodiment 2-1 is shown.

[0031] Figure 17 An example of K=4 and Option 1-2 and Option 1-4 of Embodiment 2-1 is shown.

[0032] Figure 18 An example of K>1 and Option 1-5 of Embodiment 3-1 is shown.

[0033] Figure 19 FIG. 1 is an example of a diagram showing an outline configuration of a wireless communication system according to an embodiment.

[0034] Figure 20 FIG. 2 is an example of a diagram showing a configuration of a base station according to an embodiment.

[0035] Figure 21 FIG. 3 is an example of a diagram showing a configuration of a user terminal according to an embodiment.

[0036] Figure 22 FIG. 4 is an example of a diagram showing a hardware configuration of a base station and a user terminal according to an embodiment.

[0037] Figure 23 FIG. 5 is an example of a diagram showing a vehicle according to an embodiment. DETAILED DESCRIPTION

[0038] (TCI, Spatial Relation, QCL)

[0039] In NR, it is being studied to control at least one of reception processing (for example, at least one of reception, demapping, demodulation, decoding) and transmission processing (for example, at least one of transmission, mapping, precoding, modulation, coding) of a signal and a channel (expressed as signal / channel) in the UE based on a transmission configuration indication state (TCI state).

[0040] The TCI state can also indicate an element applied to a signal / channel of the downlink. An element equivalent to the TCI state applied to a signal / channel of the uplink can also be expressed as a spatial relation.

[0041] The so-called TCI state is information on Quasi-Co-Location (QCL) of a signal / channel, and can also be referred to as a spatial reception parameter, spatial relation information, etc. The TCI state can also be set to the UE per channel or per signal.

[0042] The so-called QCL is an indicator indicating a statistical property of a signal / channel. For example, it can mean that, in a case where a certain signal / channel is in a QCL relationship with other signal / channels, at least one of a Doppler shift, a Doppler spread, an average delay, a delay spread, a spatial parameter (for example, a spatial Rx parameter) can be assumed to be the same among the different plurality of signal / channels (as to at least one of them being QCL).

[0043] In addition, the spatial reception parameter can also correspond to a reception beam (for example, a reception analog beam) of the UE, and the beam can also be determined based on spatial QCL. The QCL (or at least one element of the QCL) in the present disclosure can also be rewritten as sQCL (spatial QCL).

[0044] The QCL can also be defined in multiple types (QCL types). For example, four QCL types A-D can be set in which parameters (or sets of parameters) that can be assumed to be the same are different, and the following table represents the parameters (which can also be referred to as QCL parameters):

[0045] • QCL Type A (QCL-A): Doppler shift, Doppler spread, average delay, and delay spread;

[0046] • QCL Type B (QCL-B): Doppler shift and Doppler spread;

[0047] • QCL Type C (QCL-C): Doppler shift and average delay;

[0048] • QCL Type D (QCL-D): Spatial receive parameters.

[0049] The case where a UE can be assumed a certain control resource set (Control Resource Set (CORESET)), channel or reference signal to be in a specific QCL (e.g., QCL Type D) relationship with other CORESETs, channels or reference signals can also be referred to as a QCL assumption.

[0050] The UE can also determine at least one of a transmission beam (Tx beam) and a reception beam (Rx beam) of a signal / channel based on a TCI state or a QCL assumption of the signal / channel.

[0051] The TCI state can be, for example, information related to a QCL between a channel (in other words, a reference signal (RS) for the channel) that is the object and other signals (e.g., other RSs). The TCI state can be configured (indicated) through higher layer signaling, physical layer signaling, or a combination thereof.

[0052] The physical layer signaling can be, for example, downlink control information (Downlink Control Information (DCI)).

[0053] The channel for which the TCI state or spatial relation is configured (indicated) can be, for example, at least one of a downlink shared channel (Physical Downlink Shared Channel (PDSCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), an uplink shared channel (Physical Uplink Shared Channel (PUSCH)), and an uplink control channel (Physical Uplink Control Channel (PUCCH)).

[0054] Further, the RS in the QCL relationship with the channel can be, for example, at least one of a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), a reference signal for measurement (sounding reference signal (SRS)), a CSI-RS for tracking (also referred to as a tracking reference signal (TRS)), and a reference signal for QCL detection (also referred to as a QRS).

[0055] The SSB is at least one signal block including a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a broadcast channel (physical broadcast channel (PBCH)). The SSB can also be referred to as an SS / PBCH block.

[0056] The RS of the QCL type X of the TCI state can also mean an RS in a QCL type X relationship with (the DMRS of) a certain channel / signal, which can also be referred to as a QCL source of the QCL type X of the TCI state.

[0057] (initial access procedure)

[0058] In the initial access procedure, the UE (RRC_IDLE mode) performs reception of an SS / PBCH block (SSB), transmission of Msg. 1 (PRACH / random access preamble / preamble), reception of Msg. 2 (PDCCH / PDSCH including a random access response (RAR)), transmission of Msg. 3 (PUSCH scheduled by the RAR UL grant), and reception of Msg. 4 (PDCCH / PDSCH including a UE contention resolution identity). Thereafter, if an ACK is transmitted from the UE for Msg. 4 based on the base station (network), an RRC connection is established (RRC_CONNECTED mode).

[0059] The reception of the SSB includes PSS detection, SSS detection, PBCH-DMRS detection, and PBCH reception. In the PSS detection, detection of a part of the physical cell ID (PCI), detection of OFDM symbol timing (synchronization), and (coarse) frequency synchronization are performed. The SSS detection includes detection of the physical cell ID. The PBCH-DMRS detection includes detection of the SSB index (a part of) within a half radio frame (5 ms). The PBCH reception includes detection of the system frame number (SFN) and radio frame timing (SSB index), reception of the setting information for the reception of the remaining minimum system information (RMSI, SIB1), and identification of whether the UE can camp on the cell (carrier).

[0060] The SSB has a band of 20 RBs and a time of 4 symbols. The transmission period of the SSB can be set from {5, 10, 20, 40, 80, 160} ms. In a half frame, a plurality of symbol positions of the SSB are specified based on the frequency range (FR1, FR2).

[0061] The PBCH has a payload of 56 bits. N repetitions of the PBCH are transmitted within a period of 80 ms. N depends on the SSB transmission period.

[0062] The system information is constituted by the MIB carried by the PBCH, the RMSI (SIB1), and other system information (OSI). The SIB1 includes information for performing RACH setting, RACH procedure. The relationship of the resource of the time / frequency between the SSB and the PDCCH monitoring resource of the SIB1 is set by the PBCH.

[0063] The base station using beam correspondence transmits a plurality of SSBs using a plurality of beams respectively per SSB transmission period. The plurality of SSBs respectively have a plurality of SSB indexes. The UE that detected one SSB transmits PRACH in the RACH occasion associated with the SSB index and receives RAR in the RAR window.

[0064] (PRACH setting)

[0065] As Figure 1As shown, the common RACH configuration (RACH-ConfigCommon) can also contain the generic RACH configuration (rach-ConfigGeneric), the total number of RA preambles (totalNumberOfRA-Preambles), the SSB per RACH occasion, and the contention-based (CB) preambles per SSB (ssb-perRACH-OccasionAndCB-PreamblesPerSSB). The rach-ConfigGeneric can also contain the PRACH configuration index (prach-ConfigurationIndex) and the message 1 FDM (msg1-FDM, the number of PRACH occasions that are FDM within one time instance). The ssb-perRACH-OccasionAndCB-PreamblesPerSSB can also be the SSB number per RACH occasion 1 / 8 (oneEighth, one SSB is associated with 8 RACH occasions) containing the number of CB preambles per SSB.

[0066] For Type 1 random access procedure (4-step random access procedure, message 1 / 2 / 3 / 4), the UE can also be applied by ssb-perRACH-OccasionAndCB-PreamblesPerSSB the number N of SS / PBCH blocks associated with one PRACH occasion, and the number R of CB preambles per valid PRACH occasion, per SS / PBCH block.

[0067] For Type 1 random access procedure, or for Type 2 random access procedure (2-step random access procedure, message A / B) with configured PRACH occasions independent of Type 1 random access procedure, if one SS / PBCH block is mapped to 1 / N consecutive valid RACH occasions in case of N < 1, R CB preambles with consecutive indices associated with SS / PBCH block index are from preamble index 0 per valid PRACH occasion. If one SS / PBCH block is mapped to 1 / N consecutive valid RACH occasions in case of N >= 1, R CB preambles with consecutive indices associated with SS / PBCH block index n (0 <= n < -N-1) are from preamble index n-N_preamble^total / N per valid PRACH occasion. Here, N_preamble^total is given by totalNumberOfRA-Preambles for Type 1 random access procedure, and by msgA-TotalNumberOfRA-Preambles for Type 2 random access procedure with configured PRACH occasions independent of Type 1 random access procedure. N_preamble^total is a multiple of N.

[0068] From frame 0, the association period for mapping SS / PBCH blocks to PRACH occasions is the minimum value within the set determined by PRACH configuration period, such that N Tx SSB is mapped to PRACH occasions at least once within the association period. Here, UE derives N Tx SSB from the value of ssb-PositionsInBurst within SIB1 or within ServingCellConfigCommon for the common serving cell configuration, if the value of ssb-PositionsInBurst is not configured. Tx SSBIn case of a set of PRACH occasions or PRACH preambles per SS / PBCH block index, one SS / PBCH block index is not mapped to the set of PRACH occasions or PRACH preambles. The association pattern contains more than one association period during the association pattern and is decided to make the pattern between PRACH occasions and SS / PBCH block index repeat at most every 160 ms. If there is a PRACH occasion after an integer number of association periods that is not associated with a SS / PBCH block index, the PRACH occasion is not used for PRACH.

[0069] In case of PRACH transmission triggered by higher layer (PRACH transmission not triggered by PDCCH order), if ssb-ResourceList is provided, the PRACH mask index is represented by ra-ssb-OccasionMaskIndex. The ra-ssb-OccasionMaskIndex represents the PRACH occasions that are used for PRACH transmission associated with the selected SS / PBCH block index.

[0070] The PRACH occasions are mapped consecutively for each of the corresponding SS / PBCH block index. The index of the PRACH occasions represented by the mask index value is reset per mapping period of consecutive PRACH occasions per SS / PBCH block index. The UE selects the PRACH occasion represented by the PRACH mask index value for the indicated SS / PBCH block index in the first mapping period available for use for PRACH transmission.

[0071] The order of the PRACH occasions for the indicated preamble index is the following.

[0072] • First, the increasing order of the frequency resource index of the PRACH occasions for frequency multiplexing.

[0073] • Second, the increasing order of the time resource index of the PRACH occasions for time multiplexing within a PRACH slot.

[0074] • Third, the ascending order of the index of the PRACH slot.

[0075] In case of PRACH transmission triggered according to the request from higher layer, if the value of ra-OccasionList represents a list of PRACH occasions for PRACH transmission in case that csirs-ResourceList is provided, the PRACH occasions are associated with the CSI-RS index represented by the csi-RS and selected. The index of the PRACH occasions represented by ra-OccasionList is reset per association pattern period.

[0076] For PRACH settings of 10, 20, 40, 80, and 160 [msec], the associated periods are {1, 2, 4, 8, 16}, {1, 2, 4, 8}, {1, 2, 4}, {1, 2}, and {1}, respectively.

[0077] The value of the PRACH mask index (msgA-SSB-SharedRO-MaskIndex) is associated with the allowed PRACH timings of the SSB (the value of the PRACH timing index).

[0078] Figure 2A This illustrates an example (mapping 1) of the association between PRACH timing (RACH timing (RO)) and beam (SSB / CSI-RS) based on the higher-level parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB. In the case where ssb-perRACH-OccasionAndCB-PreamblesPerSSB represents oneHalf, n16 (half, n16) (N=1 / 2, R=16), and msg1-FDM is 4, in one time instance, 4 ROs are FDMed, and one SSB is mapped to 2 ROs. Preamble indices 0 to 15 are associated with 2 ROs, and preamble indices 0 to 15 are associated with SSB0. In this way, when N<1, one SSB is mapped to multiple ROs. This increases the capacity of the ROs for each beam.

[0079] Figure 2B This illustrates another example (mapping 2) of the association between ROs and beams based on the higher-level parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB. In the case where ssb-perRACH-OccasionAndCB-PreamblesPerSSB represents n4, n16 (N=4, R=16), msg1-FDM is 4, and N_preamble^total is 64, in one time instance, 4 ROs are FDMed, and 4 SSBs are mapped to one RO. SSB#0 through #3 are associated with one RO. Preamble indices #0 through #15 are associated with SSB#0, preamble indices #16 through #31 are associated with SSB#1, preamble indices #32 through #47 are associated with SSB#2, and preamble indices #48 through #63 are associated with SSB#3. In this way, the same RO is associated with different SS / PBCH block indices, and different preambles use different SS / PBCH block indices. The base station can distinguish the associated SS / PBCH block index through the received PRACH.

[0080] The random access preamble can only be transmitted within the time resources specified in the random access configuration of the specification, depending on whether it is FR1 or FR2, and the spectrum type (paired spectrum / supplementary uplink (SUL) / unpaired spectrum). The PRACH configuration index is given by the higher-layer parameter prach-ConfigurationIndex, or by msgA-PRACH-ConfigurationIndex if it is set. In the specification, each value of the PRACH configuration index is associated with at least one of the following: preamble format, x and y in n_f (frame number) mod x = y, subframe number, start symbol, number of PRACH slots in the subframe, number of time-domain PRACH slots N_t^RA,slot in the PRACH slot, and PRACH duration N_dur^RA.

[0081] The type of RACH process that is triggered varies depending on the purpose, such as whether the PRACH repetition can be applied to a particular scenario. The type of RACH process can also be at least one of the following.

[0082] • Contention-free random access (CFRA), PDCCH ordered RA (PDCCH ordered RA, RA initiated by PDCCH command), beam failure recovery (BFR) using CFRA, system information (SI) request using CFRA, and reconfiguration with sync using CFRA, etc.

[0083] • Contention-based random access (CBRA), RA triggered by MAC entities, RA triggered by RRCs associated with events, CBRA for BFR, etc.

[0084] • 4-step RACH.

[0085] • 2-step RACH.

[0086] (PDCCH command)

[0087] DCI format 1_0 includes the identifier field of the DCI format, a bit field that is always set to 1, and a frequency domain resource assignment field. With the cyclic redundancy check (CRC) of DCI format 1_0 scrambled by C-RNTI and all bits in the frequency domain resource assignment field set to 1, this DCI format 1_0 is used for random access procedures initiated by the PDCCH command. The remaining fields are the random access preamble, the UL / supplementary uplink (SUL) indicator, the SS / PBCH index (SSB index), the PRACH mask index, and reserved bits (12 bits).

[0088] In the case of PRACH transmission triggered by the PDCCH command, when the value of the random access preamble index field is not zero, the PRACH mask index field indicates that the PRACH timing is the PRACH timing associated with the SS / PBCH block index represented by the SS / PBCH block index field of the PDCCH command.

[0089] (Random Access Procedure in MAC Entities: MAC Protocol Specification: Random Access Procedure Initialization)

[0090] The random access procedure is initiated by a PDCCH command, the MAC entity itself, or an RRC for a compliant event. Within a MAC entity, there is only one random access procedure in progress at any given time. The random access procedure for an SCell is initiated only by a PDCCH command accompanied by a ra-PreambleIndex other than 0b000000.

[0091] When a random access procedure is initiated on the serving cell, the MAC entity performs the following operations.

[0092] • When the random access procedure is started by a PDCCH command and the ra-PreambleIndex explicitly provided by the PDCCH is not 0b000000, or when the random access procedure is started for the purpose of reconfiguration accompanying synchronization and, for the BWP selected for the random access procedure, a contention-free random access resource of type 4-step RA is explicitly provided by rach-ConfigDedicated, set RA_TYPE to 4-step RA.

[0093] When the selected RA_TYPE is set to 4-step RA, the MAC entity performs the following operations.

[0094] • If ra-PreambleIndex is explicitly provided by PDCCH and ra-PreambleIndex is not 0b000000, set PREAMBLE_INDEX to the notified ra-PreambleIndex and select the SSB notified by PDCCH.

[0095] • When an SSB is selected as described above, the next available PRACH opportunity is determined from the PRACH opportunities corresponding to the selected SSB, which are permitted by the constraints given by ra-ssb-OccasionMaskIndex (the MAC entity randomly selects a PRACH opportunity with equal probability from consecutive PRACH opportunities, corresponding to the selected SSB, according to the specification. The MAC entity may also consider the possibility of generating a measurement gap when determining the next available PRACH opportunity corresponding to the selected SSB).

[0096] (Time between PDCCH command reception and PRACH transmission)

[0097] If a random access procedure is initiated via a PDCCH command, and if requested via a higher layer, the UE, as described in the specification, transmits PRACH within the selected PRACH timing if the time between the last symbol received from the PDCCH command and the first symbol transmitted from the PRACH is N_(T,2) + Δ_BWPSwitching + Δ_Delay + T_switch[msec] or more (time condition). Here, N_(T,2) is the duration of the N_2 symbol corresponding to the PUSCH preparation time of UE processing capability 1. It is assumed that μ corresponds to the minimum SCS setting between the subcarrier spacing (SCS) setting of the PDCCH command and the corresponding SCS setting of the PRACH transmission. Δ_BWPSwitching = 0 if the UL BWP activation remains unchanged; otherwise, Δ_BWPSwitching is defined in the specification. In FR1, Δ_delay = 0.5 msec, and in FR2, Δ_delay = 0.25 msec. T_switch is the duration of the switching gap as defined in the specification.

[0098] (SSB / CSI-RS selection: MAC protocol specification: Random Access Resource selection)

[0099] When the RA type (RA_TYPE) is set to 4-step RA, the MAC entity performs the following operations:

[0100] - When the RA process is initiated for SpCell beam failure recovery, and the beam failure recovery timer is operational or not set, the CFRA resource for beam failure recovery requests associated with at least one SSB / CSI-RS is explicitly provided via RRC, and at least one of the SSBs in the candidateBeamRSList with an SS-RSRP exceeding the SS-RSRP threshold (rsrp-ThresholdSSB) and at least one of the CSI-RSs in the candidateBeamRSList with an SS-RSRP exceeding the CSI-RSRP threshold (rsrp-ThresholdCSI-RS) is available, the MAC entity performs the following operations.

[0101] -- The MAC entity selects either one of the multiple SSBs in candidateBeamRSList that has an SS-RSRP exceeding rsrp-ThresholdSSB, or one of the multiple CSI-RSs in candidateBeamRSList that has a CSI-RSRP exceeding rsrp-ThresholdCSI-RS.

[0102] -- If a CSI-RS is selected and there exists a RA preamble index (ra-PreambleIndex) associated with the selected CSI-RS, the MAC entity sets the preamble index (PREAMBLE_INDEX) to: the ra-PreambleIndex in candidateBeamRSList corresponding to the quasi-colocated SSB of the selected CSI-RS that is QCL.

[0103] -- Otherwise, set PREAMBLE_INDEX to: the ra-PreambleIndex corresponding to the SSB or CSI-RS selected from the set of RA preambles used for beam failure recovery requests.

[0104] - Otherwise, if ra-PreambleIndex is explicitly provided by PDCCH and is not 0b000000, the MAC entity sets PREAMBLE_INDEX to the notified ra-PreambleIndex and selects the SSB notified by PDCCH.

[0105] - Otherwise, if the CFRA resources associated with multiple SSBs are explicitly provided in a dedicated RACH setting (rach-ConfigDedicated), and at least one SSB with an SS-RSRP exceeding rsrp-ThresholdSSB is available, the MAC entity selects one of the associated multiple SSBs with an SS-RSRP exceeding rsrp-ThresholdSSB and sets PREAMBLE_INDEX to the ra-PreambleIndex corresponding to the selected SSB.

[0106] - Otherwise, if the CFRA resources associated with multiple CSI-RS are explicitly provided in a dedicated RACH setting (rach-ConfigDedicated), and at least one CSI-RS among the multiple CSI-RS with a CSI-RSRP exceeding rsrp-ThresholdCSI-RS is available, the MAC entity selects one of the associated multiple CSI-RS with a CSI-RSRP exceeding rsrp-ThresholdCSI-RS and sets PREAMBLE_INDEX to the ra-PreambleIndex corresponding to the selected CSI-RS.

[0107] - Otherwise, if the RA process is initiated for an SI request and the SI request is explicitly provided via RRC using RA resources, the MAC entity performs the following operations.

[0108] -- If at least one SSB of an SS-RSRP with more than rsrp-ThresholdSSB is available, the MAC entity selects one SSB of the SS-RSRP with more than rsrp-ThresholdSSB.

[0109] -- Otherwise, the MAC entity selects any SSB.

[0110] -- The MAC entity selects the RA preamble corresponding to the selected SSB from the RA preambles that are verified according to the RA preamble start index (ra-PreambleStartIndex), and sets PREAMBLE_INDEX to the selected RA preamble.

[0111] - Otherwise (CBRA preamble selection), the MAC entity performs the following operations.

[0112] -- If at least one SSB of an SS-RSRP with more than rsrp-ThresholdSSB is available, the MAC entity selects one SSB of the SS-RSRP with more than rsrp-ThresholdSSB.

[0113] -- Otherwise, the MAC entity selects any SSB.

[0114] (Conditions for the validity / invalidity of PRACH timing (valid conditions))

[0115] In paired spectrum (FDD) or SUL band domain, all PRACH timings are valid. In unpaired spectrum (TDD), PRACH timings may also follow rules 1 and 2 below.

[0116] [Rule 1]

[0117] If the UE is not provided with tdd-UL-DL-ConfigurationCommon, the PRACH timing within the PRACH slot does not precede the SS / PBCH blocks within the PRACH slot, but is valid if it begins at least N_gap symbols after the last SS / PBCH block reception symbol. Here, N_gap is specified in the specification. When channelAccessMode=semistatic is provided, the set of consecutive symbols preceding the start of the next channel occupancy time before which the UE does not transmit does not overlap. The candidate SS / PBCH block index corresponds to the SS / PBCH block index provided by ssb-PositionsInBurst in SIB1 or ServingCellConfigCommon.

[0118] [Rule 2]

[0119] When the UE is provided with tdd-UL-DL-ConfigurationCommon, the PRACH timing within the PRACH slot is valid under the following conditions.

[0120] • The PRACH timing is within the UL code. Alternatively,

[0121] The PRACH timing does not precede the SS / PBCH blocks within the PRACH slot, but begins at least N_gap symbols after the last DL symbol and at least N_gap symbols after the last SS / PBCH block symbol. Here, N_gap is specified in the specification. If channelAccessMode=semistatic is provided, the PRACH timing, as described in the specification, does not overlap with the set of consecutive symbols preceding the start of the next channel occupancy period without any transmission. The candidate SS / PBCH block indexes, as described in the specification, correspond to the SS / PBCH block indexes provided by ssb-PositionsInBurst within SIB1 or ServingCellConfigCommon.

[0122] (PRACH transmit power control: physical layer procedures for control / uplink power control / physical random access channel)

[0123] The actual PRACH transmit power is determined based on the target preamble reception power, RS path loss, and maximum output power limit.

[0124] Based on the DL RS for serving cell c within transmission timing i, the UE determines the (actual) transmit power P of the PRACH on the active UL BWP b of serving cell c, as shown in the following formula. PRACH,b,f,c (i).

[0125] P PRACH,b,f,c (i) = min{P CMAX,f,c (i), P PRACH,target,f,c +PL b,f,c [dBm]

[0126] P CMAX,f,c (i) is the maximum output power set to the UE for carrier f of serving cell c within transmission timing i. PRACH,target,f,c This refers to the activation of the UL BWP b on carrier f of serving cell c, and the target receive power PREAMBLE_RECEIVED_TARGET_POWER provided by the higher layers via PRACH. b,f,c The path loss of the active UL BWP b for carrier f is calculated by the UE as (reference signal power (SS-PBCH-Block Power) [dBm] - RSRP after higher layer filtering [dBm]) [dB], based on the DL RS associated with the PRACH transmission on the active DL BWP of serving cell c. When the active DL BWP is the initial DL BWP and is used in SS / PBCH block and CORESET multiplexing mode 2 or 3, the UE determines the PL based on the SS / PBCH block associated with the PRACH transmission. b,f,c .

[0127] The DL RS used for path loss calculation can also be called path loss (PL)-RS, path loss reference RS, etc.

[0128] In the existing RACH process, if the UE sends a PRACH and does not receive the network's RAR or contention / conflict resolution Msg4 within a specific time window, and the random access procedure is not completed, the UE will retransmit the PRACH after the random backoff time.

[0129] (Target preamble receive power: MAC protocol specification / MAC procedures / Random Access procedure)

[0130] The UE calculates the transmit power based on the target preamble received power set by the network and the value of the preamble power ramping counter (power lifting / ramping mechanism).

[0131] `preambleReceivedTargetPower` is the initial random access preamble power for a 4-step RA type. `DELTA_PREAMBLE` is associated with the preamble format. `PREAMBLE_POWER_RAMPING_COUNTER` is the number of power lifts. `PREAMBLE_POWER_RAMPING_STEP` is the step size for power lifting / ramping.

[0132] For each RA preamble, the MAC entity performs the following operations:

[0133] - If the selected SSB or CSI-RS has not been changed since the last RA preamble was sent,

[0134] -- Increment PREAMBLE_POWER_RAMPING_COUNTER by 1;

[0135] - Select the value of DELTA_PREAMBLE;

[0136] - Set PREAMBLE_RECEIVED_TARGET_POWER to preambleReceivedTargetPower +DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER-1) × PREAMBLE_POWER_RAMPING_STEP + POWER_OFFSET_2STEP_RA.

[0137] If a valid downlink allocation is received on the PDCCH for RA-RNTI and the received TB is successfully decoded, the reception of RAR is considered successful. If the RAR does not contain a MAC subPDU accompanied only by RAPID, the MAC entity applies the following operations for the serving cell where the RAR preamble was sent:

[0138] - Process the received timing advance command;

[0139] - Indicates the preambleReceivedTargetPower to the lower bit level and the amount of power increment applied to the final RA preamble transmission (i.e., PREAMBLE_POWER_RAMPING_COUNTER - 1) × PREAMBLE_POWER_RAMPING_STEP).

[0140] - Ignore received UL clearances when performing a RA procedure for an Scell ​​on an uplink carrier where pusch-Config is not configured.

[0141] As described above, if the selected SSB / CSI-RS has not been changed since the last SSB / CSI-RS selection, the UE increments the power ramp-up counter (PREAMBLE_POWER_RAMPING_COUNTER).

[0142] PREAMBLE_POWER_RAMPING_STEP is set via powerRampingStep {0dB, 2dB, 4dB, 6dB} within RRC IE RACH-ConfigGeneric.

[0143] (Maximum number of preamble transmissions: MAC protocol specification / MAC procedures / Random Access procedure)

[0144] preambleTransMax is the maximum number of random access preambles that can be sent.

[0145] In the event of a failure to receive a listen before talk (LBT) signal from the lower layer for random access preamble transmission, and if lbt-FailureRecoveryConfig is not set, the MAC entity performs the following operations:

[0146] - The MAC entity increments the preamble transmission counter (PREAMBLE_TRANSMISSION_COUNTER) by 1.

[0147] - In the case of PREAMBLE_TRANSMISSION_COUNTER = preambleTransMax + 1:

[0148] -- In the event that a random access preamble is sent on SpCell, the MAC entity indicates a problem with the RA to the higher layer. If the RA process was triggered by an SI request, the MAC entity considers the completion of the RA process to have failed.

[0149] -- If the random access preamble is sent on the SCell, the MAC entity considers the completion of the RA process to have failed.

[0150] - If the RA process is not completed, the MAC entity will proceed with the RA resource selection process.

[0151] If the ra-ResponseWindow set in BeamFailureRecoveryConfig expires and the PDCCH transmission via recoverySearchSpaceId to C-RNTI is not received on the serving cell where the preamble was sent, or if the ra-ResponseWindow set in RACH-ConfigCommon expires and the RAR containing the random access preamble identifier consistent with the sent PREAMBLE_INDEX is not received, the MAC entity performs the following operations:

[0152] - This MAC entity is considered a failure of RAR reception;

[0153] - Increment PREAMBLE_TRANSMISSION_COUNTER by 1;

[0154] - In the case of PREAMBLE_TRANSMISSION_COUNTER = preambleTransMax + 1:

[0155] -- In the event that a random access preamble is sent on SpCell, the MAC entity indicates a problem with the RA to higher layers, and if the RA process is triggered by an SI request, the MAC entity considers the completion of the RA process to have failed.

[0156] -- If the random access preamble is sent on the SCell, the MAC entity considers the completion of the RA process to have failed.

[0157] If contention resolution is deemed a failure, the MAC entity refreshes (clears) the HARQ buffer used for sending the MAC PDU in the Msg3 buffer, increments PREAMBLE_TRANSMISSION_COUNTER by 1, and indicates a problem with the RA to higher layers. If the RA process was triggered by an SI request, the MAC entity considers the completion of the RA process to have failed.

[0158] (RAR window)

[0159] The RA Response Window (ra-ResponseWindow) is a time window used to monitor RA responses (RARs) (SpCell only). The RA Contention Resolution Timer (ra-ContentionResolutionTimer) is a timer for RA contest resolution (SpCell only). The Msg.B Response Window is a time window used to monitor RA responses (RARs) for 2-step RA types (SpCell only).

[0160] In this disclosure, SpCell, primary cell (PCell) and primary secondary cell (PSCell) can also be rewritten to each other.

[0161] If the RA preamble is sent, the MAC entity performs the following operations 1 to 3, regardless of the possibility of a measurement gap being generated.

[0162] [Operation 1]

[0163] If the contention-free RA preamble for the BFR request is sent through this MAC entity, the MAC entity performs the following operations 1-1 and 1-2.

[0164] [[Operation 1-1]] The MAC entity begins to set the ra-ResponseWindow in the BFR setting (BeamFailureRecoveryConfig) at the initial PDCCH timing after the end of the RA preamble transmission.

[0165] [[Operation 1-2]] During the operation of the ra-ResponseWindow, the MAC entity monitors the PDCCH transmission in the search space indicated by the BFR of the SpCell identified by C-RNTI using the search space ID (recoverySearchSpaceId).

[0166] [Operation 2]

[0167] Otherwise, the MAC entity performs the following operations 2-1 and 2-2.

[0168] [[Operation 2-1]] The MAC entity begins to set the ra-ResponseWindow in the common RACH settings (RACH-ConfigCommon) during the initial PDCCH timing after the RA preamble is sent.

[0169] [[Operation 2-2]] During the operation of ra-ResponseWindow, the MAC entity monitors the PDCCH transmission of the SpCell used by RAR identified by RA-RNTI.

[0170] [Operation 3]

[0171] If the ra-ResponseWindow set in BeamFailureRecoveryConfig expires and a PDCCH sent via recoverySearchSpaceId to C-RNTI is received on the serving cell where the preamble was sent, or if the ra-ResponseWindow set in RACH-ConfigCommon expires and a RAR containing RA preamble identifiers consistent with the preamble index (PREAMBLE_INDEX) is received, the MAC entity considers the RAR reception a failure and increments the preamble transmission counter (PREAMBLE_TRANSMISSION_COUNTER) by 1.

[0172] The MAC entity can also stop the ra-ResponseWindow after successfully receiving a RAR containing RA preamble identifiers that match the sent PREAMBLE_INDEX (and can also stop monitoring for RAR).

[0173] For PDCCH monitoring within the RA response window, there are two scenarios: PDCCH used for the base station's response to the BFR, and PDCCH used for the RAR. The following content can also be applied to both scenarios.

[0174] If the MSGA (Msg.A) preamble is sent, the MAC entity performs the following operations 4 to 6, regardless of the possibility of a measurement gap being generated.

[0175] [Operation 4]

[0176] The MAC entity starts the Msg.B response window (msgB-ResponseWindow) in the PDCCH monitoring window specified in the specification.

[0177] The msgB-ResponseWindow can also begin with the first symbol of the earliest CORESET of the PDCCH for a Type 1-PDCCH CSS set when the UE is configured to receive it, wherein this symbol is at least one symbol following the last symbol of the PRACH timing corresponding to the PRACH transmission. The length of the msgB-ResponseWindow can also correspond to the SCS used for the Type 1-PDCCH CSS set.

[0178] [Operation 5]

[0179] The MAC entity monitors the PDCCH transmission of the SpCell used by the RAR, identified by MSGB-RNTI, during the operation of the msgB-ResponseWindow.

[0180] [Operation 6]

[0181] If the MSGA contains a C-RNTI MAC CE, the MAC entity monitors the PDCCH transmission of the SpCell used by the RAR identified by the C-RNTI during the operation of the msgB-ResponseWindow.

[0182] (RA-RNTI: MAC protocol specification / Random Access Preamble transmission)

[0183] The RA-RNTI associated with the PRACH timing of sending the RA preamble is calculated as follows.

[0184] RA-RNTI = 1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

[0185] Here, s_id is the index of the initial OFDM symbol of the PRACH timing (0 <= s_id < 14 (number of symbols in the time slot)). t_id is the index of the initial time slot of the PRACH timing within the system frame (0 <= t_id < 80 (number of time slots in the system frame with an SCS of 120 kHz)). The subcarrier spacing (SCS) used to determine t_id is based on the value of μ. f_id is the index of the PRACH timing in the frequency domain (0 <= f_id < 8 (maximum number of FDM PRACH timings)). ul_carrier_id is the UL carrier used for RA preamble transmission (0 for normal uplink (NUL) carrier, 1 for supplementary uplink (SUL) carrier). RA-RNTI is calculated according to the specification. RA-RNTI is the RNTI used for 4-step RACH.

[0186] The MSGB-RNTI associated with the PRACH timing of sending the RA preamble is calculated as follows.

[0187] MSGB-RNTI = 1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id+14×80×8×2

[0188] Here, s_id is the index of the initial OFDM symbol of the PRACH timing (0 <= s_id < 14). t_id is the index of the initial slot of the PRACH timing within the system frame (0 <= t_id < 80). The subcarrier spacing (SCS) used to determine t_id is based on the value of μ. f_id is the index of the PRACH timing in the frequency domain (0 <= f_id < 8). ul_carrier_id is the UL carrier used for RA preamble transmission (0 for normal uplink (NUL) carrier, 1 for supplementary uplink (SUL) carrier). MSGB-RNTI is the RNTI used for two-step RACH.

[0189] The total number of RA-RNTI values ​​(the total number of PRACH opportunities within a system frame) is 14 × 80 × 8 × 2. The formula for MSGB-RNTI is the formula for RA-RNTI plus the total number of RA-RNTI values. According to this formula, conflicts between MSGB-RNTI and RA-RNTI can be avoided.

[0190] (RAR surveillance)

[0191] According to the PRACH transmission, the UE attempts to detect DCI format 1_0 with CRC scrambled by the corresponding RA-RNTI within a window controlled by the aforementioned higher layers. This window begins in the initial symbol of the earliest CORESET of the PDCCH for the Type 1-PDCCH CSS set, i.e., after at least one symbol of the last symbol of the PRACH timing corresponding to the PRACH transmission. This symbol period corresponds to the SCS for the Type 1-PDCCH CSS set. The length of this window, based on the SCS for the Type 1-PDCCH CSS set, is provided by ra-responseWindow as the number of time slots.

[0192] If the UE detects a DCI format 1_0 containing a CRC scrambled by the corresponding RA-RNTI and the LSBs of the SFN field in the DCI format that are the same as the least significant bits (LSBs) of the system frame number (SFN) of the PRACH sent by the UE, and the UE receives a transport block in the corresponding PDSCH, regardless of whether the UE is provided with a TCI-State for receiving a PDCCH with the CORESET accompanying the DCI format 1_0, the UE can also envision the same DMRS antenna port QCL properties for the SS / PBCH block or CSI-RS resources used by the UE in the association of the PRACH.

[0193] If the UE attempts to detect DCI format 1_0 accompanied by a CRC scrambled by the corresponding RA-RNTI when sending a PRACH initiated by a PDCCH command that triggers a CFRA procedure for the SpCell, the UE may also assume that the PDCCH containing this DCI format 1_0 and the PDCCH command have the same DMRS antenna port QCL properties. Similarly, if the UE attempts to detect DCI format 1_0 accompanied by a CRC scrambled by the corresponding RA-RNTI when sending a PRACH initiated by a PDCCH command that triggers a CFRA procedure for the subcell, the UE may also assume that the DMRS antenna port QCL properties associated with the CORESET for receiving the PDCCH containing this DCI format 1_0 are valid.

[0194] RAR UL licenses may also include at least one of the following fields: frequency hopping flag field, PUSCH frequency resource allocation field, PUSCH time resource allocation field, modulation and coding scheme (MCS) field, PUSCH TPC command field, CSI request field, and channel access - cyclic prefix extension (CPext) field.

[0195] In single-cell operation or operation accompanied by carrier aggregation within the same frequency band, if the qcl-Type of the 'typeD' property setting of the DMRS used for monitoring PDCCH in the type 1-PDCCHCSS set is not set to be the same as the qcl-Type of the 'typeD' property setting of the DMRS used for monitoring PDCCH in the type 0 / 0A / 0B / 2 / 3-PDCCHCSS set or the USS set, and the PDCCH or associated PDSCH overlaps with the PDCCH or associated PDSCH monitored by the UE in the type 1-PDCCHCSS set at least in one symbol, the UE does not intend to monitor the PDCCH in the type 0 / 0A / 0B / 2 / 3-PDCCHCSS set or the USS set.

[0196] If the UE is provided with one or more search space sets via PDCCH-Config, through searchSpaceZero, searchSpaceSIB1, searchSpaceOtherSystemInformation, pagingSearchSpace, peiSearchSpace, ra-SearchSpace, and CSS sets, and is provided with SI-RNTI, P-RNTI, PEI-RNTI, RA-RNTI, MsgB-RNTI, SFI-RNTI, INT-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, or TPC-SRS-RNTI, in each time slot, the UE does not intend to process information from more than one DCI format from the CRC scrambled with the use of that RNTI.

[0197] (Message 3 PUSCH (Msg3 PUSCH))

[0198] The UE transmits transport blocks in the PUSCH scheduled by the RAR UL permission within the corresponding RAR message. The UE transmits transport blocks in time slot n+k2+Δ+2. μ ·K cell,offset Within, send the PUSCH. K cell,offset The value is provided via CellSpecific_Koffset; if not provided, K... cell,offset =0.

[0199] k2 is the slot offset, determined based on the row index m+1 of the configuration table provided by the PUSCH time resource allocation field value m (permitted by RAR UL) and the PUSCH subcarrier spacing μPUSCH. Δ is the additional subcarrier spacing-specific slot delay value used for the initial transmission of PUSCHs scheduled via RAR, specific to the PUSCH subcarrier spacing μPUSCH, and applies Δ in addition to K2.

[0200] If the UE repeatedly requests PUSCH transmissions, the UE will cross N PUSCH repeat Each time slot is used to send PUSCH. Here, N... PUSCH repeat In other words, it is indicated from the set of 4 values ​​provided by numberOfMsg3Repetitions, or from {1, 2, 3, 4} if numberOfMsg3Repetitions is not provided, by the 2MSB of the MCS field within the RAR UL license or DCI format 0_0.

[0201] The UE determines whether to apply Msg3 repeat based on RSRP. If Msg repeat is set and the RSRP referenced for DL ​​path loss is less than rsrp-ThresholdMsg3 (threshold), the MAC entity assumes that message 3 repeat can be applied to the current random access (RA) procedure.

[0202] The UE can request Msg3PUSCH repetition via dedicated PRACH resources. The MAC entity selects RA resources in the following situations: that is, there exists more than one set of available RA resources, and one of these sets is used in the indications for all functions triggering the RA procedure; and that there exists a set of more than one available RA resources scheduled with indications for a subset of all functions triggering the RA procedure. When Msg3 repetition is configured for a set of RA resources, the MAC entity considers that set of RA resources unusable for the RACH procedure if Msg3 repetition is not available.

[0203] RA resources can also be partitioned for each function. A function can include at least one of Msg3 repetition, reduced capacity (RedCap) , small data transmission (SDT) , or RAN slicing.

[0204] The following information is notified within SIB1 transmitted via the base station.

[0205] • Function priority (featurePriorities-r17). This priority is used to determine which FeatureCombinationPreamble the UE should use if a function is mapped to more than one FeatureCombinationPreamble (feature combination preamble setting).

[0206] • Add RO settings. These settings include available functions (which are associated with multiple functions), RA resources (e.g., preamble index), and mask indexes used to distinguish ROs.

[0207] The UE depends on this function to determine which RO to use.

[0208] SIB1 contains ServingCellConfigCommonSIB. It contains UplinkConfigCommonSIB. It contains BWP-UplinkCommon (UL BWP common settings).

[0209] BWP-UplinkCommon can also contain RACH common settings (RACH-ConfigCommon or MsgA-ConfigCommon) and additionalRACH-ConfigList-r17 (additional RACH settings list). additionalRACH-ConfigList-r17 can also contain rsrp-ThresholdMsg3-r17 (threshold).

[0210] The RACH public settings can also include FeatureCombinationPreambles. FeatureCombinationPreambles associate a set of preambles (partitions) with a feature combination. FeatureCombinationPreambles can also include FeatureCombination (feature combination setting), startPreambleForThisPartition (index of the initial preamble), numberOfPreamblesPerSSB-ForThisPartition (number of preambles), and ssb-SharedRO-MaskIndex-r17 (PRACH mask index). FeatureCombination includes at least one of redCap, smallData (SDT), sliceGroup (RAN slicing), and msg3-Repetition (Msg3 repetition). The partition is given by the index of the initial preamble and the number of preambles.

[0211] The available ROs are explicitly set using the PRACH mask index. Utilizing the relationship between the PRACH mask index and the permitted PRACH opportunities (ROs) of the SSB (MAC protocol specification / PRACH mask index value table), at least one of PRACH opportunity indices 1 to 8 can be set.

[0212] The number of Msg3 repeats is indicated by the two most significant bits (MSB) of the modulation and coding scheme (MCS) field within the RAR UL license.

[0213] In PUSCH repetition type A, when a PUSCH is sent that is scheduled via RAR UL permission, the 2MSB of the MCS information field of that RAR UL permission provides code points for determining the repetition number K based on whether the higher-layer parameter numberOfMsg3Repetitions is set, according to the relationship between the value of the 2MSB of the MCS information field (code points) and the repetition number K (table). The number of time slots N used to determine the transport block size (TBS) is equal to 1.

[0214] In PUSCH repetition type B, when transmitting PUSCH scheduled via DCI format 0_0, where DCI format 0_0 is accompanied by CRC scrambled via TC-RNTI, the 2MSB of the MCS information field of this DCI format, based on whether the higher-layer parameter numberOfMsg3Repetitions is set, provides code points for determining the repetition number K according to the relationship (table) between the value of the 2MSB of the MCS information field (code points) and the repetition number K. The number of time slots N used for TBS determination is equal to 1.

[0215] (Contention resolution)

[0216] If Msg3 is sent, the MAC entity follows steps 1 through 4 below.

[0217] [Operation 1] If Msg3 is sent on a non-terrestrial network, the MAC entity starts the ra-ContentionResolutionTimer and restarts the HARQ retransmission of the initial symbol after the UE-gNB RTT is estimated by the UE at the end of Msg3.

[0218] [Operation 2] Otherwise, if the Msg3 transmission (initial transmission or HARQ retransmission) is scheduled to be accompanied by repeated A PUSCH, the MAC entity starts or restarts the ra-ContentionResolutionTimer within the first symbol after all repeated Msg3 transmissions have ended.

[0219] [Operation 3] Otherwise, the MAC entity starts or restarts the ra-ContentionResolutionTimer within the first symbol after the Msg3 transmission ends.

[0220] [Operation 4] During the period when the ra-ContentionResolutionTimer is operating, the MAC entity monitors the PDCCH regardless of the possibility of a measurement gap occurring.

[0221] Step 4 (Msg4) of the RA process in Rel. 16 NR follows the steps in Step 4 below.

[0222] [Step 4]

[0223] Without providing the UE with a C-RNTI, based on the PUSCH transmission scheduled via RAR UL permission, the UE attempts to detect: a PDSCH containing the UE contention resolution identity, accompanied by a DCI format 1_0 scrambled with the corresponding TCI-RNTI. Upon receiving the PDSCH containing the UE contention resolution identity, the UE transmits HARQ-ACK information within the PUCCH. The PUCCH transmission occurs within the same active UL BWP as the PUSCH transmission. The minimum time between the last symbol of the received PDSCH and the first symbol of the corresponding PUCCH transmission containing the HARQ-ACK information is equal to N_T,1 [msec]. N_T,1 is the duration of the N_T,1 symbol, equivalent to the PDSCH processing time of UE processing capability 1 with appended PDSCH DM-RS configured. For μ=0, the UE assumes N_T,1=14.

[0224] When detecting the DCI format, either by sending a PUSCH according to a PUSCH scheduled via RAR UL permission or by retransmitting the corresponding PUSCH according to DCI format 0_0 with a CRC scrambled by the TC-RNTI provided in the corresponding RAR message, regardless of whether the TCI state of the CORESET for the PDCCH with the DCI format received by the UE is provided to the UE, the UE may also envision the same DM-RS antenna port QCL properties for the PDCCH carrying the DCI format as for the DM-RS antenna port quasi co-location (QCL) properties used by the UE for the SS / PBCH block associated with PRACH.

[0225] (Type 2 RA process)

[0226] During the MsgA transmission within a Type 2 RA procedure (2-step RA procedure), the UE transmits the following pair:

[0227] - Within the MsgA RACH timing (RO), there is a preamble with a preamble index.

[0228] - Within each MsgA PUSCH time (PO) set by MsgA PUSCH, there is one PUSCH accompanied by one PUSCH resource unit (PRU).

[0229] MsgA PRACH has the structure of MsgA preamble index (symbol field resource) within the MsgA RACH timing (time domain resource / frequency domain resource).

[0230] MsgA PUSCH has the structure of MsgA PUSCH resource units (symbol domain resources / spatial domain resources) within the MsgA PUSCH setting (RRC setting) and the MsgA PUSCH timing (time domain resources / frequency domain resources).

[0231] Within the MsgA PUSCH timeframe (time domain resources / frequency domain resources), multiple PRUs can be multiplexed using DMRS ports / DMRS sequences. Only in CP-OFDM can more than one DMRS sequence be configured.

[0232] (MsgA PUSCH timing within Type 2 RA process)

[0233] The MsgA PUSCH timing (PO) that overlaps with the valid RO used for the type 1 / 2RA process is an invalid PO.

[0234] A PUSCH timing is valid if it does not overlap in time or frequency with any valid PRACH timing associated with a Type 1 RA procedure or a Type 2 RA procedure. For current spectrum (TDD) blocks and SS / PBCH blocks accompanied by an index provided via ssb-PositionsInBurst or ServingCellConfigCommon within SIB1, the UE follows several operations.

[0235] - If the UE is not provided with tdd-UL-DL-ConfigurationCommon, the PUSCH timing is valid if the following conditions are met.

[0236] -- This PUSCH timing precedes the SS / PBCH blocks within this PUSCH time slot, and,

[0237] -- The PUSCH timing is at least N from the last SS / PBCH block symbol. gap Starting after a symbol, when channelAccessMode="semiStatic" is provided, the timing of this PUSCH does not overlap with the set of consecutive symbols preceding the start of the next channel occupancy period in which the UE does not transmit. Here, N gap It is provided in a standard form.

[0238] - When the UE is provided with tdd-UL-DL-ConfigurationCommon, the PUSCH timing is valid if the following conditions are met.

[0239] -- The timing of this PUSCH is within the UL symbol, or,

[0240] -- This PUSCH timing precedes the SS / PBCH blocks within this PUSCH time slot, and,

[0241] -- The PUSCH timing is at least N from the last DL symbol. gap After the symbol, and starting from the last SS / PBCH block symbol at least N gap Starting after a symbol, when channelAccessMode="semiStatic" is provided, the timing of this PUSCH does not overlap with the set of consecutive symbols preceding the start of the next channel occupancy period in which the UE does not transmit. Here, N gap It is provided in a standard form.

[0242] (PRACH conflict: Physical layer procedures for control / slot configuration)

[0243] In operation on a single carrier within the current spectrum (TDD), if the UE transmits SRS, PUCCH, PUSCH, or PRACH within a set of symbols configured in a time slot by a higher layer, and the UE detects the DCI format of the received CSI-RS or PDSCH from a subset of symbols in that set of symbols, the UE follows the following operation:

[0244] - If the UE does not have the ability to indicate partial cancellation, the UE will follow these steps:

[0245] -- The first symbol in the set of symbols starts from the last symbol of the CORESET in the DCI format detected by the UE. proc,2 In the event of an event occurring within the specified range, the UE does not expect to cancel the transmission of PUCCH, PUSCH, or PRACH within the set of symbols. Otherwise, the UE cancels the transmission of PUCCH, PUSCH, actual repetition of PUSCH, or PRACH within the set of symbols.

[0246] - If the UE indicates the ability to perform partial cancellation, the UE will follow these steps:

[0247] -- The UE does not expect to cancel the initial symbol from the set of symbols starting from the last symbol of the CORESET in the DCI format detected by the UE. proc,2 The UE cancels the transmission of PUCCH, PUSCH, or PRACH within the set of symbols that occurs within the set of symbols.

[0248] That is, if a PRACH triggered / set by a higher layer overlaps with a symbol scheduled for DL ​​reception via DCI, the UE cancels the PRACH.

[0249] In the case of operation on a single carrier within the current spectrum (TDD), and transmission of any symbol from the set of symbols in a time slot to which reception of a particular SS / PBCH block is indicated to the UE, the UE shall not transmit PUSCH, PUCCH, or PRACH in that time slot, nor shall the UE transmit SRS in that set of symbols in that time slot. The specific SS / PBCH block is: an SS / PBCH block based on ssb-PositionsInBurst within SIB1 (SystemInformationBlockType1); or an SS / PBCH block based on ssb-PositionsInBurst within ServingCellConfigCommon; or, if the UE is not provided with dl-OrJoint-TCIStateList, an SS / PBCH block based on ssb-PositionsInBurst within SSB-MTCAdditionalPCI associated with the physical cell ID accompanying the active TCI state for PDCCH or PDSCH; or an SS / PBCH block for the set of symbols corresponding to the time slot of the SS / PBCH block set for L1 beam measurement / reporting. When tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated is provided to the UE, the set of symbols in that time slot is not expected to be indicated as uplink through tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated.

[0250] In UE

[0251] - Multiple serving cells are configured, and the set of serving cells among these multiple serving cells is provided with directionalCollisionHandling-r16 = 'enabled', and,

[0252] - Indicates support for the half-DuplexTDD-CA-SameSCS-r16 capability, and,

[0253] - If no PDCCH for monitoring DCI format 2_0 detection is configured on any of the multiple serving cells, the UE follows the procedure below:

[0254] - In the set of symbols of the time slot indicated to the UE for receiving a specific SS / PBCH block in the initial cell of the multiple serving cells, if the transmission overlaps with any symbol from the set of symbols, the UE will not transmit PUSCH, PUCCH, or PRACH in that time slot, and the UE will not transmit SRS in that set of symbols in that time slot of the specific cell. The specific SS / PBCH block is: an SS / PBCH block based on ssb-PositionsInBurst within SIB1 (SystemInformationBlockType1); or an SS / PBCH block based on ssb-PositionsInBurst within ServingCellConfigCommon; or, if the UE is not provided with dl-OrJoint-TCIStateList, an SS / PBCH block based on ssb-PositionsInBurst within SSB-MTCAdditionalPCI associated with the physical cell ID accompanying the active TCI state for PDCCH or PDSCH; or an SS / PBCH block for the set of symbols corresponding to the time slot of the SS / PBCH block set for L1 beam measurement / reporting. The specific cell is: any one of the plurality of serving cells that does not have the simultaneous transmission and reception capability indicated by simultaneousRxTxInterBandCA; and any one of the cells that corresponds to the same band as the original cell, regardless of the capability indicated by simultaneousRxTxInterBandCA.

[0255] That is, if the PRACH triggered / set by a higher layer overlaps with the SSB symbol, the UE will not send the PRACH.

[0256] (PRACH conflict: Physical layer procedures for control / UE procedure for determining slot format)

[0257] In the case where tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated are provided, the UE is indicated to the UE as a flexible time slot through the set of symbols indicated by tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated; or in the case where tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated are not provided, or in the case where the UE detects DCI format 2_0 with a time slot format value other than 255 for that time slot, the UE follows the following operation:

[0258] - If the SFI index field value m in DCI format 2_0 indicates that the set of symbols in this time slot is flexible, and the UE does not receive a DCI format indicating PDSCH or CSI-RS to the UE, or does not receive a DCI format indicating PUSCH, PUCCH, PRACH or SRS to the UE, RAR UL permission, fallback RAR UL permission or success RAR in the set of symbols in this time slot, the UE will neither transmit nor receive in the set of symbols in this time slot.

[0259] That is, if a PRACH without a PDCCH command overlaps with a symbol indicated as flexible by SFI, the UE will not send the PRACH.

[0260] When a UE transmits SRS, PUCCH, PUSCH, or PRACH within a set of symbols configured by a higher layer, and the UE detects that the time slot format accompanying a subset of symbols from that set of symbols is indicated as downlink or a flexible DCI format with a time slot format value other than 255, or the UE receives a DCI format indicating the reception of CSI-RS or PDSCH from a subset of symbols in that set of symbols, the UE performs the following operations:

[0261] - If the UE does not have the ability to indicate partial cancellation, the UE will follow these steps:

[0262] -- The first symbol in this set of symbols starts from the last symbol of the CORESET in the DCI format detected by the UE. proc,2 In the event of an event occurring within the specified range, the UE does not expect to cancel the transmission of PUCCH, PUSCH, or PRACH within the set of symbols. Otherwise, the UE cancels the transmission of PUCCH, PUSCH, actual repetition of PUSCH, or PRACH within the set of symbols.

[0263] - If the UE indicates the ability to perform partial cancellation, the UE will follow these steps:

[0264] -- The UE does not expect cancellation of PUCCH, PUSCH, or PRACH transmissions from the following set of symbols: the first symbol in the set starting from the last symbol of the CORESET in the DCI format detected by the UE. proc,2 This occurs within the set of symbols. The UE cancels the actual repetition of PUCCH, PUSCH, or PUSCH, or PRACH transmissions within the remaining symbols of this symbol set.

[0265] That is, if a PRACH set by a higher layer overlaps with a symbol indicated as DL or flexible by SFI, the UE cancels the PRACH.

[0266] If tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated are provided, and the UE indicates to the UE the set of symbols that constitute a flexible time slot through tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated, or if tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated are not provided, and the UE does not detect DCI format 2_0 providing a time slot format for that time slot, the UE follows the following operation:

[0267] - If the UE is configured to transmit via SRS, PUCCH, PUSCH, or PRACH through a higher layer, and the UE is not provided with enableConfiguredUL, the UE will follow the following operations:

[0268] -- If the UE does not have the ability to indicate partial cancellation, the UE will follow these steps:

[0269] --- The initial symbol of the PUCCH, or PUSCH, or the actual repetition of the PUSCH, or the PRACH, begins from the last symbol of the CORESET set by the UE for monitoring the PDCCH in DCI format 2_0. proc,2 If the event occurs within the time slot, the UE does not expect the cancellation of the transmission of PUCCH, PUSCH, or actual repetition of PUSCH, or PRACH within that time slot. Otherwise, the UE cancels the transmission of PUCCH, PUSCH, or actual repetition of PUSCH, or PRACH within that time slot.

[0270] -- If the UE indicates the ability to perform partial cancellation, the UE will follow these steps:

[0271] --- This UE does not expect cancellation of the following PUCCH, PUSCH, or actual repetition of PUSCH, or PRACH transmissions within the following symbols: from the last symbol of the CORESET monitored by the UE for DCI format 2_0. proc,2 The set of symbols occurring within this time slot. The UE cancels the actual repetition of PUCCH, or PUSCH, or PUSCH, or PRACH transmission within this time slot. The UE cancels the PUCCH, or PUSCH, or PUSCH, or PRACH transmission within the remaining symbols from this set of symbols.

[0272] That is, if a PRACH triggered / set by a higher layer overlaps with a flexible symbol set to semi-static, and the UE does not detect DCI format 2_0, the UE cancels the PRACH.

[0273] (Beam and coverage)

[0274] In high-frequency bands, if beamforming is not applied to the synchronization / reference signals, the coverage area narrows, making it difficult for the UE to detect the base station. Conversely, if beamforming is applied to the synchronization / reference signals to ensure coverage, strong signals will arrive in specific directions, but signals will become more difficult to reach in other directions. At the base station before the UE connects, if the UE's location is unclear, it's impossible to use beams only in the appropriate direction to transmit the synchronization / reference signals. Consider the following approach: the base station transmits multiple synchronization / reference signals with beams in different directions, and the UE identifies which beam it has detected. If a thin (narrow) beam is used for coverage, more synchronization / reference signals need to be transmitted, thus raising concerns about increased overhead and reduced frequency utilization efficiency.

[0275] If a coarse (wide) beam is used to reduce overhead by minimizing the number of beams (synchronization / reference signals), the coverage area will be narrowed.

[0276] In future wireless communication systems (e.g., 6G), the utilization of frequency bands such as millimeter waves and terahertz waves is expected to be further developed. The idea is to provide communication services by using a large number of thin beams to construct cell areas / coverage.

[0277] Consider using existing FR2 to expand the region, or using a higher frequency band than existing FR2. To achieve these goals, in addition to improving multi-TRP, reconfigurable intelligent surface (RIS), etc., improved beam management is preferred.

[0278] PRACH coverage enhancement is under investigation. For example, it is being investigated to use multiple PRACH transmissions with the same beam during a 4-step RACH process (multiple repetitions of PRACH), and multiple PRACH transmissions with different beams during a 4-step RACH process. This PRACH enhancement can be applied to either frequency range (FR)2 or FR1. This PRACH extension can be applied to both short PRACH formats and other formats.

[0279] For multiple PRACH transmissions with the same beam, a single RAR window can be used for each PRACH transmission. This RAR window can also follow existing designs. Alternatively, for multiple PRACH transmissions with the same beam, a single RAR window can be used for all of the multiple PRACH transmissions.

[0280] The UE can also use different multiple transmit (Tx) beams in the transmission of multiple PRACHs across multiple ROs associated with the same SSB / CSI-RS.

[0281] (Multiple PRACH transmissions use PRACH resources)

[0282] Investigating: Multiple PRACH transmissions (multiple PRACH transmissions) are transmitted on separate ROs (separate ROs, ROs separated for multiple PRACH transmissions and ROs separated for a single PRACH transmission) separated from a single PRACH transmission (single PRACH transmission); multiple PRACH transmissions are transmitted on ROs shared with a single PRACH transmission (shared ROs) using preambles separated from a single PRACH transmission (separate preambles).

[0283] To distinguish between multiple PRACH transmissions using the same Tx beam and a single PRACH transmission, research is underway to support multiple PRACH transmissions being transmitted on separate ROs.

[0284] To distinguish between multiple PRACH transmissions using the same Tx beam and a single PRACH transmission, research is underway to support multiple PRACH transmissions being transmitted using separate preambles on a shared RO.

[0285] In multiple PRACH transmissions using the same Tx beam, a “RO group” is envisioned for at least one of the separate preambles on a shared RO and multiple PRACH transmissions on separate ROs.

[0286] - All ROs within an RO group are associated with more than one of the same SSBs.

[0287] - Shared RO / preamble means that the RO / preamble is shared with a single PRACH transmission.

[0288] - Separate RO / preamble means that the RO / preamble is separated from a single PRACH.

[0289] - Effective Returns (ROs) are defined in existing specifications. Effective ROs can also follow the validity conditions of the aforementioned PRACH timing.

[0290] (RAR monitoring for multiple PRACH)

[0291] In RAR monitoring of multiple PRACH transmissions using the same transmit beam within a single RACH attempt, research is underway to support only a single RAR window.

[0292] The UE repeatedly transmits Msg1 on K random access opportunities (RO) / RO resources. Afterwards, the UE waits for the detection of Msg2 on a preamble in a predefined type 1 PDCCH opportunity. In this disclosure, the repeated transmission of the preamble in the K RO / RO resources is sometimes referred to as an RO group. Figure 3 This is an example of timing multiple PRACH transmissions. In this example, the size of the RO group (the number of ROs within the RO group) is K. A RAR window begins after an RO group.

[0293] In this disclosure, a RO group can also be defined as consisting of K valid ROs that are TDM'd, each having a separate RO in the frequency domain for each time slot. In other words, if an RO group is selected, the ROs used for each PRACH transmission are determined. Figure 4 In the example, with repetition number K=2, the RO group consists of two consecutive ROs that are TDMed.

[0294] (Research)

[0295] Investigating: Supporting {2, 4, 8} as the number of PRACH transmissions in multiple PRACH transmissions using the same Tx beam. Investigating: In multiple PRACH transmissions using the same Tx beam, at least for the initial RACH attempt, using more than one SSB-RSRP threshold to determine the number of PRACH transmissions.

[0296] Under investigation: Switching (fallback) from a single PRACH send to multiple PRACH sendes (PRACH repetition) is not supported. For example, under investigation: Switching between a single PRACH send and multiple PRACH sendes within a single RACH procedure is not supported.

[0297] (Analysis 1)

[0298] Following existing PRACH transmit power calculation rules, for a specific PRACH format in the initial RACH attempt (i.e., the case where the power ramp-up counter equals 0), the following is recognized:

[0299] - Without considering the maximum UE output power limit (i.e., only considering (P) PRACH,target,f,c +PL b,f,c In the case of PRACH transmission power, since path loss is compensated when determining PRACH transmission power, the target preamble receive power on the base station side is equal to (preambleReceivedTargetPower + DELTA_PREAMBLE) set / indicated by the SIB, regardless of the SSB / CSI-RS measured on the UE side.

[0300] - Considering the maximum UE output power limit (i.e., considering min(P) CMAX,f,c (i), P PRACH,target,f,c +PL b,f,c In the case of a very low SINR, the path loss is very large, meaning that even with a very low detected SINR, it becomes much larger / higher (P). PRACH,target,f,c +PL b,f,c PRACH transmit power is limited by the maximum UE output power limit, and the PRACH receive power on the base station side may be lower than (preambleReceivedTargetPower + DELTA_PREAMBLE).

[0301] According to this view, it is preferable that the limit on multiple PRACH transmissions may be triggered only when the transmission power reaches (exceeds) the maximum UE output power limit.

[0302] (Analysis 2)

[0303] Multiple PRACH transmissions can potentially create an unfair situation. For example, consider a scenario where the RSRP of the SSB selected in UE#1 is higher than that of the SSB selected in UE#2 (e.g., there is a 2dB gap between them), and UE#1 performs a single PRACH transmission while UE#2 performs two PRACH transmissions. As a result, considering the base station-side synthesis gain (e.g., a synthesis gain of 3dB for the two PRACH transmissions), the target performance for the UE#2 preamble is better than the target performance for the UE#1 preamble. This differs from the motivation for supporting multiple PRACH transmissions in Rel. 18.

[0304] The motivation for sending multiple PRACHs is to compensate for the poor performance of a few UEs so that they can match the same target preamble performance with other UEs under better channel conditions. For example, the total / effective preamble receive power of these few UEs is equal to or close to the target (preambleReceivedTargetPower + DELTA_PREAMBLE) for other UEs.

[0305] According to this viewpoint, it is preferable to adjust the number of PRACH transmissions in relation to the target preamble reception power.

[0306] (Analysis 3)

[0307] Based on the aforementioned Analysis 1, the likelihood of applying multiple PRACH transmissions may decrease if they are triggered solely by the transmission power reaching the maximum UE output power limit. Under investigation: For both multiple PRACH transmissions and single PRACH transmissions, the utilization rate of separate PRACH resources (separate RO resources / separate preamble resources) for multiple PRACH transmissions may be very low. From a system perspective, this is inefficient. In such cases, the condition of reaching the maximum UE output power limit is not preferred.

[0308] The overall / effective target preamble reception power can be matched to the different numbers of PRACH transmissions. That is, according to Analysis 2 and its solution, no limitation is required. As a result, it is similar whether the UE performs a single PRACH transmission with a larger target preamble reception power or multiple PRACH transmissions with a reduced target preamble reception power.

[0309] According to this viewpoint, for each RSRP range, it is preferable that the UE has multiple options.

[0310] (Analysis 4)

[0311] There has been insufficient research on how to determine the number of PRACH transmissions used for retransmission. Furthermore, the rule being studied for determining the number of PRACH transmissions based on SSB-RSRP and at least one other factor is only applied to the initial RACH attempt. The determination of the repetition level for subsequent RACH attempts, taking into account the number of PRACH transmissions within previous RACH attempts (repetition level, the determined number of PRACH transmissions), has not been sufficiently studied.

[0312] (Analysis 5)

[0313] The limitations of multiple RACH attempts within a single RACH process have not been adequately studied.

[0314] If a single PRACH transmission is determined for the initial RACH attempt, it is considered that a single PRACH transmission should also be applied to any RACH re-attempt within that RACH process. If the SSB / CSI-RS selection follows existing rules, the UE can select an SSB / CSI-RS with an RSRP lower than the RSRP threshold used to trigger multiple PRACH transmissions. In this case, if a single PRACH transmission is considered to be applied to RACH re-attempts, PRACH performance will be poor. Enhanced SSB / CSI-RS selection is preferred. Enhancements to power escalation are also considered. For example, in RACH re-attempts using RSRPs corresponding to multiple PRACH transmissions, power escalation may be necessary if the UE selects an SSB / CSI-RS.

[0315] If multiple PRACH transmissions are determined for the initial RACH attempt, it is unclear whether the repetition factor is maintained for subsequent RACH attempts within that RA process. Similarly, enhancements to the SSB / CSI-RS selection rules and power escalation rules are considered. A limit on the maximum number of preamble transmissions for multiple PRACH transmissions within a single RACH attempt is also taken into account.

[0316] Therefore, if operations related to RACH retry have not been fully studied, there are concerns that this could lead to reduced communication throughput.

[0317] Therefore, the inventors of this invention conceived of operations related to RACH retry.

[0318] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, the following embodiments (e.g., various scenarios) can be used individually or in combination of at least two.

[0319] In this disclosure, "A / B" and "at least one of A and B" may be rewritten as each other. In addition, in this disclosure, "A / B / C" may also mean "at least one of A, B and C".

[0320] In this disclosure, terms such as notification, activation, deactivation, indication (or indication), selection, configuration, update, and determination can be overridden. Similarly, terms such as support, control, ability to control, operation, and ability to operate can also be overridden.

[0321] In this disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher-level parameters, fields, Information Elements (IE), settings, etc., can also be modified interchangeably. In this disclosure, Medium Access Control (MAC) control elements (CE), update commands, activation / deactivation commands, etc., can also be modified interchangeably.

[0322] In this disclosure, higher-layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, other messages (e.g., positioning protocol messages (e.g., NR Positioning Protocol A (NRPPa) / LTE Positioning Protocol (LPP) messages, etc. from the core network), or a combination thereof.

[0323] In this disclosure, MAC signaling may also use, for example, a MAC Control Element (MACCE) or a MAC Protocol Data Unit (PDU). Broadcast information may also be, for example, a Master Information Block (MIB), a System Information Block (SIB), a Minimum System Information (Remaining Minimum System Information (RMSI)), or Other System Information (OSI).

[0324] In this disclosure, physical layer signaling may also be, for example, downlink control information (DCI), uplink control information (UCI), etc.

[0325] The following abbreviations may also be used in this disclosure.

[0326] Time division multiplexing (TDM);

[0327] - Time-division-multiplexed: TDM;

[0328] - Frequency division multiplexing (FDM);

[0329] - Frequency-division-multiplexed: FDM.

[0330] In this disclosure, a b The expressions a, a_b, and a with b appended to the lower right can also be rewritten interchangeably. In this disclosure, a c The expressions a, a^c, and a with c appended to the upper right can also be rewritten interchangeably. In this disclosure, a b c The expressions a_b^c and a with b appended to the lower right and c appended to the upper right can also be rewritten. In this disclosure, the ceil(x), ceiling function, and ceiling (rounding up) function can also be rewritten. In this disclosure, the floor(x), floor function, and floor (rounding down) function can also be rewritten.

[0331] In this disclosure, the reference signal (RS), downlink reference signal (DL-RS), and SSB / CSI-RS can be interchanged. In this disclosure, RSRP and SS-RSRP / CSI-RSRP can also be interchanged. In this disclosure, RS accompanied by RSRP, RS corresponding to RSRP, RS used for RSRP measurement, SSB accompanied by SS-RSRP, and CSI-RS accompanied by CSI-RSRP can also be interchanged.

[0332] In this disclosure, beam, SSB, SSB index, CSI-RS, CSI-RS resource, CSI-RS resource index, reference signal (RS), QCL concept, TCI state, unified TCI state, DL or joint TCI state, UL TCI state, UL Tx spatial filter, spatial domain filter, spatial domain transmit filter, spatial domain receive filter, antenna port QCL parameters, QCL parameters, Tx beam, and spatial filter can also be rewritten.

[0333] In this disclosure, RACH resources, RA resources, PRACH preamble, timing, RACH timing (RO), PRACH timing, repetition resources, repetition setting resources, resources set for RO / repetition, time instances and frequency instances, time resources and frequency resources, RO / preamble resources, repetition, PRACH resources, time / frequency resources used for PRACH, preamble setting / index, main setting / index, and PRACH setting can also be overridden.

[0334] In this disclosure, the terms "time opportunity," "time domain position," "time location," "PRACH opportunity," "PRACH slot," "period," "period," "cycle," "symbol / slot / subframe / frame," at least one of their indices, "time domain index," and "T#" can be interchanged. Similarly, the terms "frequency domain position," "frequency location," "subcarrier / RE / RB / CC," at least one of their indices, "frequency domain index," and "F#" can also be interchanged. Furthermore, the terms "RO," "RO index," and "RO#" can also be interchanged.

[0335] In this disclosure, the number of PRACH transmissions, the number of repetitions, the repetition factor, the aggregation factor, and K can be rewritten interchangeably. In this disclosure, multiple PRACH transmissions, more than one PRACH transmission, and multiple PRACH repetitions can also be rewritten interchangeably. In this disclosure, a single PRACH transmission and a PRACH transmission count of 1 can also be rewritten interchangeably.

[0336] In this disclosure, multiple PRACH transmissions, multiple PRACH transmissions using the same Tx beam, multiple PRACH transmissions using different Tx beams, and multiple PRACH transmissions including multiple PRACH transmissions using the same Tx beam and multiple PRACH transmissions using different Tx beams can also be rewritten to each other.

[0337] In this disclosure, individual PRACH transmissions, existing PRACH transmissions, and existing PRACH resource settings can also be overwritten.

[0338] In this disclosure, multiple PRACH transmissions, new PRACH transmissions, and multiple PRACH resource settings can also be mutually modified. In this disclosure, separate ROs, new ROs, appended ROs, multiple ROs for PRACH transmissions, and ROs obtained by separating from existing ROs for PRACH transmissions can also be mutually modified.

[0339] In this disclosure, existing ROs may also include ROs that are set / determined via RACH-ConfigCommon / RACH-ConfigGeneric / RACH-ConfigDedicated / AdditionalRACH-Config-r17 / additionalRACH-ConfigList-r17.

[0340] In this disclosure, the determination of the number of PRACH transmissions may also include whether to perform a single PRACH transmission or multiple PRACH transmissions. The number of PRACH transmissions may also include 1 (a single PRACH transmission).

[0341] In this disclosure, multiple actual PRACH transmissions may also mean more than one actual number of PRACH transmissions after taking into account the possibility of dropping / canceling the PRACH transmission due to at least one conflict defined in the existing specification and other conflicts (e.g., conflicts in implementation B1 / implementation B2).

[0342] In this disclosure, multiple nominal PRACH transmissions may also refer to a repetition level of more than 1.

[0343] In this disclosure, a RACH attempt, a single PRACH transmission, and multiple PRACH transmissions can be rewritten interchangeably. In this disclosure, an attempt, an initial transmission RACH attempt, the first RACH attempt, a previous RACH attempt, and a completed RACH attempt can also be rewritten interchangeably. In this disclosure, a re-attempt, a retransmission RACH attempt, a later RACH attempt, a RACH attempt other than the initial RACH attempt, a second or subsequent RACH attempt, a scheduled transmission RACH attempt, the current RACH attempt, and a RACH attempt following more than one RACH attempt can also be rewritten interchangeably.

[0344] In this disclosure, the repetition level, the number of PRACH transmission decisions, the number of PRACH transmissions decided, the number of ROs in the RO group selected for multiple PRACH transmissions, the repetition factor in the RA process, the repetition factor in the initial RACH attempt, the number of PRACH transmissions decided for the initial RACH attempt, and the number of valid ROs in the RO group selected for the initial RACH attempt can also be rewritten from each other.

[0345] In this disclosure, the actual number of PRACH transmissions, the number of PRACH transmissions sent, the actual number of PRACH transmissions sent, the number of PRACH transmissions actually sent, and the number of PRACH transmissions sent after being dropped due to a drop group can also be rewritten to each other.

[0346] In this disclosure, the maximum transmit power, the UE maximum transmit power, the maximum output power, and the UE maximum output power can also be rewritten in different ways.

[0347] In this disclosure, the received power range, RSRP range, SSB / CSI-RS set, whether a specific RSRP threshold is exceeded, RSRP range divided by RSRP threshold, RSRP corresponding to a single PRACH transmission or multiple PRACH transmissions, and RSRP corresponding to a specific repetition factor can also be rewritten.

[0348] (Wireless communication method)

[0349] <Implementation Method A1>

[0350] This implementation involves analysis 1.

[0351] In determining the number of PRACH transmissions, the UE power level is considered in addition to the RSRP threshold. According to this implementation, the problem in Analysis 1 (i.e., the triggering conditions for multiple PRACH transmissions considering the maximum UE output power limit) can be addressed.

[0352] - Example

[0353] To determine the number of PRACH transmissions, multiple sets of RSRP thresholds can be set / indicated. Each set of RSRP thresholds can also correspond to a UE power level. For example, if the number of supported UE power levels is X, X sets of RSRP thresholds can be set / indicated. The UE can also use the set corresponding to its power level.

[0354] exist Figure 5A as well as Figure 5B In the example, the maximum transmit power for power levels PC1, PC1.5, PC2, and PC3 are 31dBm, 29dBm, 26dBm, and 23dBm, respectively. Figure 5A The example represents the set of RSRP thresholds for PC2: {RSRP_0_PC2, RSRP_1_PC2, RSRP_2_PC2}. Figure 5BThe example represents the set of RSRP thresholds for PC3: {RSRP_0_PC3, RSRP_1_PC3, RSRP_2_PC3}. UEs using PC2 use the set of RSRP thresholds for PC2, and UEs using PC3 use the set of RSRP thresholds for PC3. The RSRP thresholds within the set for PC3 can also be lower than the RSRP thresholds within the set for PC2. Here, x in RSRP_0_x can be any of PC1, PC1.5, PC2, or PC3. In this example, if the RSRP (measurement result) of SSB / CSI-RS is above RSRP_0_x, the UE determines the number of PRACH transmissions N to be 1. If the RSRP (measurement result) of SSB / CSI-RS is below RSRP_0_x but above RSRP_1_x, the UE determines the number of PRACH transmissions N to be 2. If the RSRP (measurement result) of SSB / CSI-RS is lower than RSRP_1_x but higher than RSRP_2_x, the UE will determine the number of PRACH transmissions N to be 4. If the RSRP (measurement result) of SSB / CSI-RS is lower than RSRP_2_x, the UE will determine the number of PRACH transmissions N to be 8.

[0355] - Change 0

[0356] To determine the number of PRACH transmissions, multiple sets of RSRP thresholds can be set / indicated. Each set of RSRP thresholds can also correspond to a specific range of UE power levels and the number of previously failed RACH attempts. For example, if the number of supported UE power levels is X, Y sets of RSRP thresholds (>X) can also be set / indicated. A power level can also correspond to more than one set. In the case where a power level corresponds to multiple sets of RSRP thresholds, each set of RSRP thresholds can also correspond to a specific range of the number of previously failed RACH attempts. The UE can also use the set corresponding to its power level and the number of previously failed RACH attempts.

[0357] - Change 1

[0358] In the above operations, the number of PRACH transmissions can also be determined using at least one of the following parameters instead of the UE power level. The sets of RSRP thresholds can also correspond to at least one specific range of that parameter and the number of previously failed RACH attempts.

[0359] -- Change 1-1: Current UE Power Class. Since UEs with high power capabilities (e.g., UE power class 1 / 1.5 / 2) need to fall back to UE power class 3 depending on the situation, the current UE power class is considered.

[0360] -- Change 1-2: ΔP PowerClass This parameter represents the amount of power reduction when falling back to power level 3, so consider using this parameter.

[0361] -- Change 1-3: P-MPR (P-MPR) c Power management maximum power reduction.

[0362] UE power level, a specific range of the number of previously failed RACH attempts, current UE power level, ΔP PowerClass Two or more combinations within P-MPR can also be used to determine the number of PRACH transmissions.

[0363] The UE can also determine the number of PRACH transmissions through a combination of this implementation method and implementation method C.

[0364] According to this implementation, the UE can appropriately determine the number of PRACH transmissions.

[0365] (ΔP) PowerClass )

[0366] ΔP PowerClass Alternatively, you can follow these steps.

[0367] - If P-max is indicated to be below 23dBm, or if the UE capability maxUplinkDutyCycle-PC2-FR1 field is absent, and the UE capability maxUplinkDutyCycle-MPE-FR1 field is absent, and the percentage of uplink symbols transmitted during a certain evaluation period is greater than 50%, or if the UE capability maxUplinkDutyCycle-PC2-FR1 field exists, and the percentage of uplink symbols transmitted during a certain evaluation period is greater than maxUplinkDutyCycle-PC2-FR1 (strict evaluation period is more than 1 radio frame), or if the UE capability maxUplinkDutyCycle-MPE-FR1 field exists, and half of the percentage of uplink symbols transmitted during a certain evaluation period is greater than maxUplinkDutyCycle-MPE-FR1 (strict evaluation period is more than 1 radio frame), ΔP PowerClass The UE has a power level of 3dB for power level 2 capability and a power level of 6dB for power level 1.5 capability.

[0368] - If the P-max is indicated to be between 23dBm and 26dBm, or if the UE capability maxUplinkDutyCycle-PC2-FR1 field is absent, and the UE capability maxUplinkDutyCycle-MPE-FR1 field is absent, and the percentage of uplink symbols transmitted during a certain evaluation period is between 25% and 50%, or if the UE capability maxUplinkDutyCycle-PC2-FR1 field exists, and the percentage of uplink symbols transmitted during a certain evaluation period is between maxUplinkDutyCycle-PC2-FR1 and maxUplinkDutyCycle-PC2-FR1 / 2 (strict evaluation period is more than 1 radio frame), or if the UE capability maxUplinkDutyCycle-MPE-FR1 field exists, and the percentage of uplink symbols transmitted during a certain evaluation period is greater than maxUplinkDutyCycle-MPE-FR1 (strict evaluation period is more than 1 radio frame), ΔP PowerClass The UE has a power rating of 3dB for power level 1.5 capability.

[0369] - When the UE is configured with supplementary uplink (SUL) and the default power level requirement is applied in the band domain representing power level 2, ΔP PowerClass It is 3dB.

[0370] - In the case of a PC2-capable UE with txDiversity-r16 capability or a PC1.5-capable UE further indicating SRS-TxSwitch capability 't1r2' or 't1r4' or 't1r1-t1r2' or 't1r1-t1r2-t1r4', ΔP in the SRS transmission timing for the SRS resource set with 'antennaSwitching' purpose, where an SRS resource consisting of one SRS port is configured in each SRS resource set. PowerClass 3dB was applied.

[0371] Otherwise, ΔP PowerClass It is 0dB.

[0372] (P-MPR)

[0373] P-MPR c It can also be used for the maximum power drop in power management for the following a and b.

[0374] (a) In the case of simultaneous transmission on multiple RATs used in scenarios outside the scope of the specification, comply with the applicable electromagnetic energy absorption requirements and ensure compliance with the requirements for unwanted emission / selfdesense.

[0375] (b) In cases where proximity detection is used to address requirements such as lower maximum output power, the electromagnetic energy absorption requirements that can be applied shall be followed.

[0376] The UE applies P-MPR for serving cell c only in the above scenarios. c In the suitability test conducted via UE, P-MPR c 0dB. P-MPR c Imported into P CMAX,f,c The formula enables the UE to report the maximum available output transmit power to the base station. P-MPR c This could potentially impact the maximum uplink performance of the selected UL transmission path.

[0377] <Implementation Method A2>

[0378] This implementation relates to Analysis 2. According to this implementation, for different numbers of PRACH transmissions, it is possible to match the overall / effective target preamble reception power / performance on the base station side.

[0379] Implementation Method A2-1

[0380] It is also possible to import the target preamble receive power (separate target preamble receive power) that is separated from the single PRACH transmission for multiple (actual / nominal) PRACH transmissions. The separate target preamble receive power can also follow at least one of the following options.

[0381] - Option 2-1-1

[0382] The separate target preamble receive power parameter (e.g., preambleReceivedTargetPower-Multi-PRACH) for multiple PRACH transmissions is set / indicated.

[0383] The PREAMBLE_RECEIVED_TARGET_POWER for multiple (actual / nominal) PRACH transmissions can also be calculated using the following formula.

[0384] PREAMBLE_RECEIVED_TARGET_POWER = preambleReceivedTargetPower-Multi-PRACH + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) × PREAMBLE_POWER_RAMPING_STEP

[0385] - Option 2-1-2

[0386] The power drop offset (e.g., Multi-PRACH-offset) can be set / indicated via RRC IE / SIB or defined via the specification.

[0387] The PREAMBLE_RECEIVED_TARGET_POWER for multiple (actual / nominal) PRACH transmissions can also be calculated using the following formula.

[0388] PREAMBLE_RECEIVED_TARGET_POWER = preambleReceivedTargetPower - Multi-PRACH-offset + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) ×PREAMBLE_POWER_RAMPING_STEP

[0389] Implementation Method A2-2

[0390] It is also possible to import different numbers of split-target preamble receive powers for multiple (actual / nominal) PRACH transmissions. The split-target preamble receive power can also follow at least one of the following options.

[0391] - Option 2-2-1

[0392] The different numbers of split target preamble receive power parameters (e.g., preambleReceivedTargetPower-PRACH-Rep2, preambleReceivedTargetPower-PRACH-Rep4, preambleReceivedTargetPower-PRACH-Rep8) for multiple (actual / nominal) PRACH transmissions are set / indicated.

[0393] In the presence of 4 (actual / nominal) PRACH transmissions, PREAMBLE_RECEIVED_TARGET_POWER can also be calculated using the following formula.

[0394] PREAMBLE_RECEIVED_TARGET_POWER = preambleReceivedTargetPower-PRACH-Rep4 + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) × PREAMBLE_POWER_RAMPING_STEP

[0395] When the preamble receive power parameter for K (actual / nominal) PRACH transmissions is expressed as preambleReceivedTargetPower-PRACH-RepK, the PREAMBLE_RECEIVED_TARGET_POWER for K (actual / nominal) PRACH transmissions can also be calculated using the following formula.

[0396] PREAMBLE_RECEIVED_TARGET_POWER = preambleReceivedTargetPower-PRACH-RepK + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) × PREAMBLE_POWER_RAMPING_STEP

[0397] - Option 2-2-2

[0398] Different numbers of power drop offsets (e.g., Multi-PRACH-offset-Rep2, Multi-PRACH-offset-Rep4, Multi-PRACH-offset-Rep8) transmitted across multiple (actual / nominal) PRACHs can be set / indicated via RRC IE / SIB or defined by the specification. For example, Multi-PRACH-offset-Rep2 could be 3dB, Multi-PRACH-offset-Rep4 6dB, and Multi-PRACH-offset-Rep8 9dB.

[0399] In the presence of 4 (actual / nominal) PRACH transmissions, PREAMBLE_RECEIVED_TARGET_POWER can also be calculated using the following formula.

[0400] PREAMBLE_RECEIVED_TARGET_POWER = preambleReceivedTargetPower - Multi-PRACH-offset-Rep4 + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) ×PREAMBLE_POWER_RAMPING_STEP

[0401] When the received power parameter of the split target preamble for K (actual / nominal) PRACH transmissions is expressed as Multi-PRACH-offset-RepK, the PREAMBLE_RECEIVED_TARGET_POWER for K (actual / nominal) PRACH transmissions can also be calculated using the following formula.

[0402] PREAMBLE_RECEIVED_TARGET_POWER = preambleReceivedTargetPower - Multi-PRACH-offset-RepK + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) ×PREAMBLE_POWER_RAMPING_STEP

[0403] According to this implementation, the UE can determine the appropriate target preamble receive power for multiple PRACH transmissions.

[0404] <Implementation Method A3>

[0405] This implementation relates to analysis 3. According to this implementation, it is possible to mitigate the limitation that multiple PRACH transmissions can be triggered simply by reaching the maximum UE output power limit through transmission power.

[0406] Alternatively, for multiple PRACH transmissions, one or more RSRP thresholds are set / indicated, and a specific RSRP range corresponds to multiple operation candidates. The UE selects an operation from the multiple operation candidates corresponding to the RSRP.

[0407] Multiple operation candidates can also refer to a set of multiple parameters, including the number of PRACH transmissions, the target preamble receive power, and the preamble receive power offset (power drop offset).

[0408] exist Figure 6In the example, by setting RSRP thresholds {RSRP_0, RSRP_1, RSRP_2}, there are ranges 0 (RSRP above RSRP_0), 1 (RSRP below RSRP_0 but above RSRP_1), 2 (RSRP below RSRP_1 but above RSRP_2), and 3 (RSRP below RSRP_2). The number of PRACH transmissions is denoted as N, and the target preamble reception power is denoted as target_power_x. Range 0 corresponds to a parameter set {N=1} (single PRACH transmission). Range 1 corresponds to three parameter sets {N=1, target_power_1}, {N=2, target_power_2}, and {N=4, target_power_4}. Range 2 corresponds to three parameter sets {N=2, target_power_2a}, {N=4, target_power_4a}, and {N=8, target_power_8a}. Range 3 corresponds to three parameter sets: {N=2, target_power_2b}, {N=4, target_power_4b}, and {N=8, target_power_8b}. The UE can also select a range from ranges 0, 1, 2, and 3 that corresponds to the RSRP measurement results, and choose one parameter set from more than one parameter sets corresponding to that range, applying that parameter set to PRACH transmission.

[0409] The UE can also determine the number of PRACH transmissions through a combination of this implementation method and implementation method C.

[0410] According to this implementation, the UE can apply an appropriate set of parameters to the PRACH transmission based on the situation.

[0411] <Implementation Method B1>

[0412] Considering the possibility of RO collisions in multiple PRACH transmissions using the same Tx beam, UE operation may also follow at least one of the following options.

[0413] - Option 1

[0414] The UE does not expect the first or last (valid) RO within a RO group to be accompanied by a conflict. Alternatively, the UE does not expect the first or last (valid) RO within any RO group to be accompanied by a conflict.

[0415] - Option 2

[0416] When the UE selects the RO group, conflicts are taken into account. The UE may also follow at least one of the following options.

[0417] -- Option 2-1: The UE will not decide / select the RO group with the first or last (valid) RO that has a conflict as the RO group for multiple PRACH transmissions.

[0418] -- Option 2-2: If the number of conflicting (valid) ROs is greater than a specific value X, or is above a specific value X, the UE will not decide / select the RO group as the RO group for multiple PRACH transmissions. Here, the value of X can be specified by the specification or set by the base station.

[0419] -- Option 2-3: If the number of valid ROs without conflicts is less than a specific value Y, or is below a specific value Y, the UE will not decide / select the RO group as the RO group for multiple PRACH transmissions. Here, the value of Y can be specified by the specification or set by the base station.

[0420] - Option 3

[0421] When the UE selects the RO group, conflicts are not considered. The UE operation after the RO group selection is defined. The UE may also follow at least one of the following options.

[0422] -- Option 3-1: If any (valid) RO within the RO group is conflicted, the UE will not send PRACH on that RO, or will cancel PRACH transmission. The UE may also send PRACH on the remaining (unconflicted) valid ROs within the RO group.

[0423] -- Option 3-2: If the first or last (valid) RO in a RO group is accompanied by a conflict, the UE shall not send PRACH in that RO group, or cancel PRACH sending.

[0424] -- Option 3-3: If the number of conflicting (valid) ROs within the selected RO group is greater than a specific value X, or is above a specific value X, the UE will not send PRACH within that RO group, or will cancel PRACH transmission. Here, the value of X can be specified by the standard or set by the base station.

[0425] -- Option 3-4: If the number of non-conflicting (valid) ROs within the selected RO group is less than a specific value Y, or is below a specific value Y, the UE will not send PRACH within that RO group, or will cancel PRACH transmission. Here, the value of Y can be specified by the standard or set by the base station.

[0426] According to this implementation, even if there is a possibility of conflict, the UE can properly control the transmission of multiple PRACH.

[0427] <Implementation Method B2>

[0428] The definition of "conflict" in "with conflict" / "without conflict" in this disclosure may also include at least one of the following conflict scenarios.

[0429] - Any symbol indicated as DL by tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated overlaps with this RO.

[0430] - Any symbol indicated by ssb-PositionsInBurst in SIB1 or ssb-PositionsInBurst in ServingCellConfigCommon that is used for the reception of SS / PBCH blocks overlaps with this RO.

[0431] - Any symbol indicated as DL by DCI format 2_0 / SFI overlaps with this RO.

[0432] - By means of DCI format 2_0 / SFI, it is indicated that the symbol overlaps with the RO as flexible and arbitrary.

[0433] - Any symbol used for receiving PDSCH / CSI-RS that overlaps with the RO is indicated by the detected DCI.

[0434] - When tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated are set, and any symbol is set to flexible by tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated, and the UE is set to monitor DCI format 2_0 / SFI, and the UE does not detect that the symbol overlaps with the RO in the case of DCI format 2_0 / SFI.

[0435] - In the time / frequency domain, any valid RO associated with a type 1 RA procedure for a single PRACH transmission overlaps with this RO.

[0436] - In the time / frequency domain, any valid RO associated with a type 2 RA process overlaps with this RO.

[0437] - In the time / frequency domain, any valid PUSCH timing associated with a Type 2 RA process overlaps with this RO.

[0438] Whether a conflict situation is included among the above-mentioned conflict situations can be specified by the standard or set by the base station.

[0439] According to this embodiment, the UE can properly handle conflicts.

[0440] <Changes to Implementation Method B1 / Implementation Method B2>

[0441] Implementation method B1 / Implementation method B2 can be applied to situations where multiple PRACH transmissions are used with different multiple Tx beams.

[0442] For cases where multiple PRACHs are transmitted using the same Tx beam and cases where multiple PRACHs are transmitted using different Tx beams, different options in Implementation Method B1 / Implementation Method B2 can also be applied. The options in Implementation Method B1 / Implementation Method B2 that apply to each case can be specified by the standard or set by the base station.

[0443] Implementation method B1 / Implementation method B2 can be applied to multiple PRACH transmissions accompanied by a specific RACH type. The specific RACH type can also be a specific RACH triggering method, a specific RACH purpose, etc.

[0444] - Example: Implementation method B1 / Implementation method B2 can also be applied to a specific RACH triggering method. A specific RACH triggering method can also be an RA process that is started / triggered by a PDCCH / MAC entity / RRC.

[0445] - Example: Implementation method B1 / Implementation method B2 can also be applied to a specific RACH purpose. The specific RACH purpose method can also be, for example, at least one of initial access, SI request, SpCell BFR, and reconfiguration with synchronization.

[0446] <Implementation Method C>

[0447] This implementation involves determining the number / number of PRACH transmissions.

[0448] - Implementation method C-1

[0449] The decision on the number of PRACH transmissions using the same Tx beam can also follow at least one of the following options.

[0450] -- Option 1

[0451] The UE can also determine the number of PRACH transmissions based on the selected SSB / CSI-RS and a set RSRP threshold. This RSRP threshold can also be set to determine the number of PRACH transmissions using the same Tx beam.

[0452] -- Option 2

[0453] The UE can also determine the number of PRACH transmissions based on the selected SSB / CSI-RS, the set RSRP threshold, and the number of past failed attempts. The RSRP threshold can also be set to determine the number of PRACH transmissions using the same Tx beam. This attempt can be either an attempt using the same Tx beam or an attempt targeting the same selected SSB / CSI-RS.

[0454] -- Option 3

[0455] The UE can also determine the number of PRACH transmissions based on the number of PRACH transmissions in past attempts, the number of failed past attempts, and at least one of the RSRPs of the selected SSB / CSI-RS. The number of PRACH transmissions can be either the number of PRACH transmissions using the same Tx beam or the number of PRACH transmissions targeting the same selected SSB / CSI-RS.

[0456] -- Example 1 based on option 1

[0457] The base station can also set up to m values ​​for the number of PRACH transmissions using the same Tx beam, and set (m+1) RSRP thresholds for the SSB / CSI-RS used to determine the number of PRACH transmissions using the same Tx beam. The m values ​​for the number of PRACH transmissions can also be candidate values ​​N_1, N_2, ..., N_m. Here, it can also be N_m > ... > N_2 > N_1 > 1. The (m+1) RSRP thresholds can also be RSRP_0, RSRP_1, RSRP_2, ..., RSRP_m. Here, it can also be RSRP_0 > RSRP_1 > RSRP_2 > ... > RSRP_m.

[0458] like Figure 7 As in the example, if the RSRP of the selected SSB / CSI-RS is greater than RSRP_0 (above RSRP_0), the UE can also decide to send a single PRACH.

[0459] If the RSRP of the selected SSB / CSI-RS is greater than RSRP_i (above RSRP_i) and less than RSRP_i-1 (below RSRP_i-1), the UE can also determine the number of PRACH transmissions as N_i. The UE can also use PRACH resources set for multiple PRACH transmissions using the same Tx beam, or use PRACH resources set for a specific number of N_i, to transmit multiple PRACHs.

[0460] The base station can also set m RSRP thresholds for the SSB / CSI-RS used to determine the number of PRACH transmissions using the same Tx beam. The m RSRP thresholds can also be RSRP_1, RSRP_2, ..., RSRP_m. Here, it can also be RSRP_1 > RSRP_2 > ... > RSRP_m. If the RSRP of the selected SSB / CSI-RS is greater than RSRP_1 (above RSRP_1), the UE can also decide to transmit a single PRACH. If the RSRP of the selected SSB / CSI-RS is greater than RSRP_(i+1) (above RSRP_(i+1)) and less than RSRP_i (below RSRP_i), the UE can also determine the number of PRACH transmissions as N_i. The UE can also use PRACH resources set for multiple PRACH transmissions using the same Tx beam, or use PRACH resources set for a specific number of N_i, to transmit multiple PRACHs.

[0461] -- Example 2-1 based on option 2

[0462] The base station can also set up to m values ​​for the number of PRACH transmissions using the same Tx beam, and set (m+1) RSRP thresholds for the SSB / CSI-RS used to determine the number of PRACH transmissions using the same Tx beam. The m values ​​for the number of PRACH transmissions can also be candidate values ​​N_1, N_2, ..., N_m. Here, it can also be N_m > ... > N_2 > N_1 > 1. The (m+1) RSRP thresholds can also be RSRP_0, RSRP_1, RSRP_2, ..., RSRP_m. Here, it can also be RSRP_0 > RSRP_1 > RSRP_2 > ... > RSRP_m.

[0463] If the RSRP of the selected SSB / CSI-RS is greater than RSRP_0 (above RSRP_0), the UE may also follow at least one of the following operations.

[0464] --- If the number of failed attempts in the past is less than a certain value Z (below Z), the UE may also decide to transmit a single PRACH. This attempt can be either an attempt using the same Tx beam or an attempt targeting the same selected SSB / CSI-RS. Z can be defined in the specification or set via RRC IE.

[0465] --- If the number of failed attempts in the past is greater than a certain value Z, the UE can also determine the number of PRACH transmissions using the same Tx beam as N_1. This attempt can be an attempt using the same Tx beam or an attempt targeting the same selected SSB / CSI-RS. Z can be defined in the specification or set via RRC IE.

[0466] --- Variation: A set of (m+1) values ​​for Z (Z_1, Z_2, ..., Z_i, ...) can also be set / defined. For example, if the number of failed attempts in the past is greater than Z_i, the UE can also determine the number of PRACH transmissions using the same Tx beam as N_i. This attempt can be an attempt using the same Tx beam or an attempt for the same selected SSB / CSI-RS. Z can be defined in the specification or set via RRC IE.

[0467] If the RSRP of the selected SSB / CSI-RS is greater than RSRP_i (above RSRP_i) and less than RSRP_i-1 (below RSRP_i-1), the UE may also follow at least one of the following operations.

[0468] --- If the number of failed attempts in the past is less than a specific value Z (below Z), the UE can also determine the number of PRACH transmissions using the same Tx beam as N_i. This attempt can be either an attempt using the same Tx beam or an attempt targeting the same selected SSB / CSI-RS. Z can be defined in the specification or set via RRC IE.

[0469] --- If the number of failed past attempts is greater than a specific value Z, the UE can also determine the number of PRACH transmissions using the same Tx beam as N_i+1 if i < m, and the UE can also determine the number of PRACH transmissions using the same Tx beam as N_m if i = m. This attempt can be either an attempt using the same Tx beam or an attempt targeting the same selected SSB / CSI-RS. Z can be defined in the specification or set via RRC IE.

[0470] --- Variation: A set of (m+1) values ​​for Z (Z_1, Z_2, ..., Z_j, ...) can also be set / defined. For example, if the number of failed attempts in the past is greater than Z_j, if (i+j) ≤ m, the number of PRACH transmissions using the same Tx beam by the UE is determined to be N_(i+j), and if (i+j) > m, the number of PRACH transmissions using the same Tx beam by the UE is determined to be N_m. This attempt can be an attempt using the same Tx beam or an attempt for the same selected SSB / CSI-RS. Z can be defined in the specification or set via RRC IE.

[0471] -- Example 2-2 based on option 2

[0472] The base station can also set up to m values ​​for the number of PRACH transmissions using the same Tx beam, and set multiple sets of RSRP thresholds for the SSB / CSI-RS used to determine the number of PRACH transmissions using the same Tx beam. The m values ​​for the number of PRACH transmissions can also be candidate values ​​N_1, N_2, ..., N_m. Here, it can also be N_m > ... > N_2 > N_1 > 1. Each set can also contain (m+1) RSRP thresholds RSRP_0, RSRP_1, RSRP_2, ..., RSRP_m. Here, it can also be RSRP_0 > RSRP_1 > RSRP_2 > ... > RSRP_m.

[0473] --- If two sets of RSRP thresholds are set, the UE may also use the first set of RSRP thresholds in the determination of the number of PRACH transmissions if the number of failed attempts in the past is greater than a certain value Z (greater than Z). This follows the procedure in Example 1 of Option 1.

[0474] --- Variation: More than two sets of RSRP thresholds can also be set / defined, representing a set of (m+1) values ​​of Z (Z_1, Z_2, ..., Z_i, ...). For example, if the number of failed attempts in the past is greater than Z_i, the UE can also use the (i+1)th set of RSRP thresholds, following the procedure in Example 1 of Option 1.

[0475] -- Example 3 based on option 3

[0476] A new counter for the number of PRACH transmissions using the same Tx beam can also be imported. This counter can be, for example, PRACH_TRANSMISSION_NUMBER. The candidate values ​​for this counter can also be the same as the candidate values ​​for the number of PRACH transmissions (e.g., N_1, N_2, ...). The UE can also gradually increment the number of PRACH transmissions (repetition count).

[0477] In the first PRACH attempt (where the value of PRACH_TRANSMISSION_NUMBER is equal to 1 (or 0)), the UE can also determine the number N of PRACH to be sent based on option 1 (e.g., Example 1) and set the value of PRACH_TRANSMISSION_NUMBER to N.

[0478] In the k-th (k>1) PRACH attempt (where the value of PRACH_TRANSMISSION_NUMBER is equal to k1 (or k-1)), if PRACH_TRANSMISSION_NUMBER does not reach the maximum candidate value of PRACH transmission (the maximum number of PRACH transmissions), the UE may also follow at least one of the following examples.

[0479] ---Example 3-1

[0480] PRACH_TRANSMISSION_NUMBER is maintained / incremented based on PRACH_TRANSMISSION_COUNTER.

[0481] ---- PRACH_TRANSMISSION_NUMBER can also be set to the next candidate value for the number of PRACH transmissions if at least one of the following conditions is met: k is greater than a specific value K_thres (above the specific value K_thres), the RSRP of the selected SSB / CSI-RS is less than a specific value RSRP-thres (below the specific value RSRP-thres), or the selected SSB / CSI-RS has not been changed since the last attempt.

[0482] ---- Otherwise, PRACH_TRANSMISSION_NUMBER can also be maintained.

[0483] ---- Variation: The values ​​of K_thres and at least one of RSRP-thres can be defined in the specification or set via RRC IE. The values ​​of K_thres and at least one of RSRP-thres can also differ depending on the value of PRACH_TRANSMISSION_NUMBER.

[0484] ---Example 3-2

[0485] You can also import new counters (failure counters, Multi_PRACH_TRANSMISSION_FAILURE). The initial value of Multi_PRACH_TRANSMISSION_FAILURE can also be 0. PRACH_TRANSMISSION_NUMBER is maintained / incremented based on Multi_PRACH_TRANSMISSION_FAILURE.

[0486] ---- If at least one of the following conditions is met: Multi_PRACH_TRANSMISSION_FAILURE is greater than a specific value K_fail (above K_fail), the RSRP of the selected SSB / CSI-RS is less than a specific value RSRP-thres (below RSRP-thres), or the selected SSB / CSI-RS has not been changed since the last attempt, PRACH_TRANSMISSION_NUMBER can also be set to the next candidate value for the number of PRACH transmissions, and Multi_PRACH_TRANSMISSION_FAILURE can also be reset to 0.

[0487] Alternatively, PRACH_TRANSMISSION_NUMBER can be maintained, and Multi_PRACH_TRANSMISSION_FAILURE can be incremented by 1.

[0488] --- Changes: For at least one value of PRACH_TRANSMISSION_NUMBER and Multi_PRACH_TRANSMISSION_FAILURE, the value can be defined in the specification, set via RRC IE, or retained for each SSB / CSI-RS. The value of at least one value of K_thres and RSRP-thres can also be defined in the specification or set via RRC IE. The value of at least one of K_thres and RSRP-thres can also differ depending on the value of PRACH_TRANSMISSION_NUMBER.

[0489] In the k-th (k>1) PRACH attempt (when the value of PRACH_TRANSMISSION_NUMBER is equal to k1 (or k-1)), the value of PRACH_TRANSMISSION_NUMBER can be maintained even if PRACH_TRANSMISSION_NUMBER has not reached the maximum candidate value of PRACH transmission (the maximum number of PRACH transmissions).

[0490] -- Change

[0491] If the UE has the capability to report the maximum number (supported number) of PRACHs transmitted using the same Tx beam (the UE has the capability to transmit up to X PRACHs using the same Tx beam), the UE can also follow options 1 / 2 / 3 to determine the number N of PRACHs transmitted using the same Tx beam.

[0492] --- If X≤N, the UE can also determine the number of PRACH transmissions using the same Tx beam as X.

[0493] --- If X > N, the UE can also determine the number of PRACH transmissions using the same Tx beam as N.

[0494] - Implementation method C-2

[0495] Option 1 / 2 / 3 of implementation C-1 can also be applied to the determination of the number of PRACH transmissions using different Tx beams by rewriting "using the same Tx beam" as "using different multiple Tx beams".

[0496] -- Change

[0497] If the UE has the capability to report the maximum number (supported number) of PRACH transmissions using different multiple Tx beams (the UE has the capability to transmit up to X PRACHs using different multiple Tx beams), the UE can also follow options 1 / 2 / 3 of implementation method C-1 to determine the number N of PRACH transmissions using different multiple Tx beams.

[0498] --- If X≤N, the UE can also determine the number of PRACH transmissions using multiple different Tx beams as X.

[0499] --- If X > N, the UE can also determine the number of PRACH transmissions using multiple different Tx beams as N.

[0500] - Implementation method C-3

[0501] The UE can also determine, based on the RSRP of the selected SSB / CSI-RS, the procedure for a single PRACH transmission, the procedure for a specific number of PRACH transmissions using the same Tx beam, or the procedure for a specific number of PRACH transmissions using multiple different Tx beams.

[0502] --example

[0503] The base station can also set a maximum of m values ​​for the number of PRACH transmissions using the same Tx beam, a maximum of n values ​​for the number of PRACH transmissions using multiple different Tx beams, and set (m+n+1) RSRP thresholds. The m values ​​for the number of PRACH transmissions can also be candidate values ​​K_1, K_2, ..., K_m. Here, it can also be K_m > ... > K_2 > K_1 > 1. The n values ​​for the number of PRACH transmissions can also be candidate values ​​K'_1, K'_2, ..., K'_n. Here, it can also be K'_n > ... > K'_2 > K'_1 > 1. The UE can also determine any one of the following processes by comparing the RSRP of the selected SSB / CSI-RS with multiple RSRP thresholds: a single PRACH transmission process, a specific number of PRACH transmissions using the same Tx beam, or a specific number of PRACH transmissions using multiple different Tx beams.

[0504] like Figure 8 As in the example, the (m+n+1) RSRP thresholds can also be RSRP_0, RSRP_1, RSRP_2, ..., RSRP_n, RSRP_n+1, RSRP_n+2, ..., RSRP_n+m. Here, it can also be RSRP_0 > RSRP_1 > RSRP_2 > ... > RSRP_n > RSRP_n+1 > RSRP_n+2 > ... > RSRP_n+m. When the RSRP of the selected SSB / CSI-RS is greater than RSRP_0 (above RSRP_0), the procedure for transmitting a single PRACH can also be determined. When the RSRP of the selected SSB / CSI-RS is less than RSRP_(i-1) and greater than RSRP_i (above RSRP_i), the procedure for transmitting K'_i PRACHs using multiple different Tx beams can also be determined. If the RSRP of the selected SSB / CSI-RS is less than RSRP_(n+i-1) and greater than RSRP_(n+i) (above RSRP_(n+i)), it is also possible to decide to use K_i PRACH transmissions of the same Tx beam.

[0505] The base station can also set a maximum of m values ​​for the number of PRACH transmissions using the same Tx beam, a maximum of n values ​​for the number of PRACH transmissions using multiple different Tx beams, and set (m+n) RSRP thresholds. The m values ​​for the number of PRACH transmissions can also be candidate values ​​K_1, K_2, ..., K_m. Here, it can also be K_m > ... > K_2 > K_1 > 1. The n values ​​for the number of PRACH transmissions can also be candidate values ​​K'_1, K'_2, ..., K'_n. Here, it can also be K'_n > ... > K'_2 > K'_1 > 1. The (m+n) RSRP thresholds can also be RSRP_1, RSRP_2, ..., RSRP_n, RSRP_n+1, RSRP_n+2, ..., RSRP_n+m. Here, it can also be that RSRP_1 > RSRP_2 > ... > RSRP_n > RSRP_n+1 > RSRP_n+2 > ... > RSRP_n+m. If the RSRP of the selected SSB / CSI-RS is greater than RSRP_1 (above RSRP_1), the procedure for transmitting a single PRACH can also be determined. If the RSRP of the selected SSB / CSI-RS is less than RSRP_i (less than RSRP_i) but greater than RSRP_(i+1) (above RSRP_(i+1)), the procedure for transmitting K'_i PRACHs using multiple different Tx beams can also be determined. If the RSRP of the selected SSB / CSI-RS is less than RSRP_(n+i) (less than RSRP_(n+i)) but greater than RSRP_(n+i+1) (above RSRP_(n+i+1)), the procedure for transmitting K_i PRACHs using the same Tx beam can also be determined.

[0506] A UE that has the capability to transmit multiple PRACHs using the same Tx beam but not the capability to transmit multiple PRACHs using different Tx beams may also follow at least one of the following operations.

[0507] --- The UE may also use only (m+1) values ​​from the beginning / end within a range of RSRP thresholds in either the decision of a single PRACH transmission process or a process of a specific number of PRACH transmissions using the same Tx beam.

[0508] --- If the UE has the ability to report the maximum number (supported number) of PRACH transmissions using the same Tx beam (the UE has the ability to transmit up to X PRACHs using the same Tx beam), the UE can also decide the number N of PRACH transmissions using the same Tx beam.

[0509] If X≤N, the UE can also determine the number of PRACH transmissions using the same Tx beam as X.

[0510] If X > N, the UE can also determine the number of PRACH transmissions using the same Tx beam as N.

[0511] A UE that has the capability to transmit multiple PRACHs using different Tx beams but not multiple PRACHs using the same Tx beam can also follow at least one of the following operations.

[0512] --- The UE may also use only (n+1) values ​​from the beginning / end within a range of RSRP thresholds in either the decision of a single PRACH transmission process or a specific number of PRACH transmissions using different Tx beams.

[0513] --- If the UE has the ability to report the maximum number (supported number) of PRACH transmissions using multiple different Tx beams (the UE has the ability to transmit up to Y PRACHs using multiple different Tx beams), the UE decides to transmit N PRACHs using multiple different Tx beams.

[0514] If Y≤N, the UE can also determine the number of PRACH transmissions using different Tx beams as Y.

[0515] If Y > N, the UE can also determine the number of PRACH transmissions using multiple different Tx beams as N.

[0516] - Implementation method C-4

[0517] The UE can also determine the process of sending a single PRACH or any of the processes of sending multiple PRACHs.

[0518] -- Option 1

[0519] The UE can also determine any one of the processes for sending a single PRACH or multiple PRACHs based on the RSRP of the selected SSB / CSI-RS and the set RSRP threshold.

[0520] -- Option 2

[0521] The UE can also determine the process of sending a single PRACH or multiple PRACHs based on the RSRP of the selected SSB / CSI-RS, the set RSRP threshold, and the number of past failed attempts.

[0522] -- Example 1 based on option 1

[0523] The base station can also set an RSRP threshold for the SSB / CSI-RS used to determine the process of a single PRACH transmission or any of the processes of multiple PRACH transmissions.

[0524] --- If the RSRP of the selected SSB / CSI-RS is greater than the set RSRP threshold (above the set RSRP threshold), the UE can also decide the procedure for sending a single PRACH.

[0525] --- If the RSRP of the selected SSB / CSI-RS is below the set RSRP threshold (less than the set RSRP threshold), the UE can also determine the process of sending multiple PRACHs.

[0526] -- Example 2-1 based on option 2

[0527] The base station can also set an RSRP threshold for the SSB / CSI-RS used to determine the process of a single PRACH transmission or any of the processes of multiple PRACH transmissions.

[0528] --- If the RSRP of the selected SSB / CSI-RS is greater than the set RSRP threshold (above the set RSRP threshold), the UE may also follow at least one of the following operations.

[0529] If the number of failed attempts in the past is less than a specific value Z (below Z), the UE can also determine the procedure for a single PRACH transmission. This attempt can be either an attempt using the same Tx beam or an attempt targeting the same selected SSB / CSI-RS. Z can be defined in the specification or set via RRC IE.

[0530] If the number of failed attempts in the past exceeds a certain value Z, the UE can also determine the procedure for multiple PRACH transmissions. This attempt can be either using the same Tx beam or targeting the same selected SSB / CSI-RS. Z can be defined in the specification or set via RRC IE.

[0531] -- Example 2-2 based on option 2

[0532] The base station can also set multiple RSRP thresholds for the SSB / CSI-RS to determine the process of a single PRACH transmission or any of the multiple PRACH transmission processes. Each RSRP threshold can also be applied to different numbers of past failed attempts.

[0533] --- When two RSRP thresholds are set, if the number of failed past attempts is greater than / less than a specific value Z (above / below the specific value Z), the UE may also use the first RSRP threshold in either a single PRACH transmission procedure or a multiple PRACH transmission procedure. This attempt can be an attempt using the same Tx beam or an attempt targeting the same selected SSB / CSI-RS. Z can be defined in the specification or set via RRC IE.

[0534] --- Variation: More than two RSRP thresholds can also be set / defined, or a set of ((m+1)) values ​​of Z (Z_1, Z_2, ..., Z_i, ...). For example, if the number of failed attempts in the past is greater than Z_i, the UE can also use the (i+1)th RSRP threshold in either the decision of a single PRACH transmission or multiple PRACH transmissions.

[0535] According to this implementation, the UE can determine the appropriate amount of PRACH to be sent.

[0536] <Implementation Method D0>

[0537] This implementation relates to a method for determining the number (repetition level) of PRACH transmissions in RACH attempts other than the initial RACH attempt.

[0538] The determination of the repetition level of RACH attempts other than the initial RACH attempt can also follow at least one of the following options.

[0539] - Option 0: The repetition level of each RACH attempt is determined independently, following the same rules as those used to determine the repetition level of the initial RACH attempt.

[0540] - Option 1: The repetition level of the RACH resend attempt depends on the repetition level of the last or the first RACH attempt.

[0541] - Option 2: For the repetition level of a retransmission RACH attempt, if there is a last or first RACH attempt with the same SSB / CSI-RS (reference signal / Tx beam / TCI state) selection as the retransmission RACH attempt, then the repetition level of the RACH attempt is used.

[0542] A retransmission RACH attempt can also include any RACH attempt other than the initial RACH attempt. A retransmission RACH attempt can also be a RACH attempt accompanied by a preamble transmission counter (PREAMBLE_TRANSMISSION_COUNTER) greater than 1. A retransmission RACH attempt can also be triggered by a failure of RAR reception or a failure of contention-resolved reception.

[0543] Figure 9 This represents an example of multiple RACH attempts. After the 1st to (n+1st)th RACH attempts (and after the 1st to (n+1st)th RACH attempts failed), the UE performs the (n+2nd)th RACH attempt. In the 1st and (n+1st)th RACH attempts, the UE can also select SSB / CSI-RS#1 and use the Tx beam (TCI state) based on this reference signal for each PRACH transmission within that RACH attempt. In the nth and (n+2nd)th RACH attempts, the UE can also select SSB / CSI-RS#2 and use the Tx beam (TCI state) based on this reference signal for each PRACH transmission within that RACH attempt. In option 0, the repetition level for the (n+2nd)th RACH attempt is determined independently (following the same decision rules) as the previous RACH attempts (up to the (n+1st)th). In Option 1, where the repetition level of a retransmission RACH attempt depends on the repetition level of the last RACH attempt, the repetition level for the (n+2)th RACH attempt is determined based on the last ((n+1)th) RACH attempt. In Option 2, where the repetition level of a retransmission RACH attempt depends on the repetition level of the last RACH attempt with the same SSB / CSI-RS selection, the repetition level for the (n+2)th RACH attempt with SSB / CSI-RS#2 selected is determined based on the last (nth) RACH attempt with the same SSB / CSI-RS#2.

[0544] <Implementation Method D1>

[0545] This embodiment relates to the details of option 1 of embodiment D0.

[0546] In Option 1, the UE may also follow at least one of the following operational scenarios.

[0547] - Scenario 1: The case where the repetition level of the last or first RACH attempt is equal to 1 (determined to be a single PRACH transmission in the last or first RACH attempt).

[0548] In this scenario, the UE can also determine the repetition level of the current RACH attempt based on the decision rules used to determine the repetition level of the initial RACH attempt. These decision rules can also be based on at least one of the following: SSB-RSRP, UE power level, and UE maximum transmit power.

[0549] - Scenario 2: The repetition level of the last or first RACH attempt is greater than 1 (multiple PRACH transmissions are determined in the last or first RACH attempt).

[0550] In this scenario, the UE may also determine the repetition level of the current RACH attempt based on the repetition level of the last or first RACH attempt. The repetition level of the current RACH attempt may also follow at least one of the following options.

[0551] -- Option 1-1: The repetition level of the RACH retransmission attempt can also be the same as the repetition level of the last or first RACH attempt.

[0552] -- Option 1-2: The repetition level of a RACH retransmission attempt can also be increased based on the repetition level of the last or first RACH attempt.

[0553] Implementation Method D1-1

[0554] In scenario 2 described above, the application of option 1-1 or option 1-2 can also be determined based on conditions. For example, option 1-2 can be applied if a specific condition (the condition for increasing the repetition level) is met, otherwise option 1-1 is applied. When option 1-2 is applied, the repetition level of the RACH attempt can also be increased (the repetition level of the current RACH attempt can also be increased from the repetition level of the last or first RACH attempt). When option 1-1 is applied, the repetition level of the RACH attempt can also be maintained (the repetition level of the current RACH attempt can also be equal to the repetition level of the last or first RACH attempt). The specific condition can also be obtained through an AND / OR operation of one of the following conditions, or at least two of the following conditions.

[0555] - Condition 1: The number of repetitions in the last or first RACH attempt did not reach the maximum number set for the number of RACH sends.

[0556] Example: If the repetition level X of the last or first RACH attempt reaches the maximum number set for the number of PRACH transmissions, the repetition level of the current RACH attempt will not increase from X (it will remain equal to X); otherwise, the repetition level of the current RACH attempt will increase from X.

[0557] - Condition 2: The selected SSB / CSI-RS has not changed compared to the selection of the SSB / CSI-RS in the last or initial RACH attempt.

[0558] Example: If the selected SSB / CSI-RS remains unchanged compared to the last or first RACH attempt, the repetition level of the current RACH attempt increases from the repetition level X of the last or first RACH attempt; otherwise, the repetition level of the current RACH attempt does not increase from X.

[0559] - Condition 3: The actual number of PRACH transmissions in the last or first RACH attempt is equal to Y (or greater than Y, or less than Y). Here, the value of Y can be defined in the specification or set / indicated by the base station. For example, it can be Y=1 or a number greater than 1.

[0560] Example: If the actual number of PRACH transmissions Z in the last or first RACH attempt is greater than or less than Y, the repetition level of the current RACH attempt will not increase from the repetition level X of the last or first RACH attempt; otherwise, the repetition level of the current RACH attempt will increase from X.

[0561] - Condition 4: The actual number of PRACH transmissions within the last or first RACH attempt is equal to (or less than) the repetition level of the last or first RACH attempt.

[0562] For example, if the actual number of PRACH transmissions Z in the last or first RACH attempt is less than the repetition level X of the last or first RACH attempt (at least one PRACH transmission was dropped due to a drop rule), the repetition level of the current RACH attempt will not increase from X; otherwise, the repetition level of the current RACH attempt will increase from X. Drop rules can also be specified in the specification for random access channels that control physical layer procedures.

[0563] - Condition 5: The transmit power reaches the maximum transmit power during the last RACH attempt.

[0564] Example: If the transmission power reaches the maximum transmission power in the last RACH attempt, the repetition level of the current RACH attempt will not increase from the repetition level X of the last or first RACH attempt; otherwise, the repetition level of the current RACH attempt will increase from X.

[0565] - Condition 6: The transmission power in the current RACH attempt reaches the maximum transmission power, which is determined by assuming that the repetition level of the current RACH attempt is the same as that of the last or first RACH attempt.

[0566] Example: If the transmission power in the current RACH attempt reaches the maximum transmission power, and the decision number for PRACH transmission in the current RACH attempt is determined by assuming that the repetition level of the current RACH attempt is the same as that of the last or first RACH attempt, then the repetition level of the current RACH attempt does not increase from the repetition level X of the last or first RACH attempt; otherwise, the repetition level of the current RACH attempt increases from X.

[0567] The condition for increasing the repetition level in scenario 2 described above can also be any combination of conditions 1 / 2 / 3 / 4 / 5 / 6. This combination of conditions can also include at least one of the following examples.

[0568] - Example: Condition 1 and (AND) Condition 2

[0569] If the SSB or CSI-RS selected in the current RACH attempt has not changed compared to the SSB or CSI-RS selected in the last or first RACH attempt, and the repetition level of the last or first RACH attempt is less than the maximum number set for the number of PRACH transmissions, the repetition level of the current RACH attempt increases from the repetition level X of the last or first RACH attempt; otherwise, the repetition level of the current RACH attempt is equal to X.

[0570] - Example: Condition 1 AND Condition 2 AND Condition 4

[0571] If the SSB or CSI-RS selected in the current RACH attempt is unchanged from the SSB or CSI-RS selected in the last or first RACH attempt, and the repetition level of the last or first RACH attempt is less than the maximum number set for the number of PRACH transmissions, and the actual number of PRACH transmissions in the last or first RACH attempt is equal to the repetition level X of the last or first RACH attempt, then the repetition level of the current RACH attempt increases from the repetition level X of the last or first RACH attempt; otherwise, the repetition level of the current RACH attempt remains equal to X.

[0572] - Example: Condition 1 AND Condition 2 AND Condition 5

[0573] If the SSB or CSI-RS selected in the current RACH attempt is unchanged from the SSB or CSI-RS selected in the last or first RACH attempt, and the repetition level of the last or first RACH attempt is less than the maximum number set for the number of PRACH transmissions, and the transmission power in the last RACH attempt reaches the maximum transmission power, then the repetition level of the current RACH attempt increases from the repetition level X of the last or first RACH attempt; otherwise, the repetition level of the current RACH attempt is equal to X.

[0574] - Example: Condition 1 AND Condition 2 AND Condition 6

[0575] If the SSB or CSI-RS selected in the current RACH attempt remains unchanged compared to the SSB or CSI-RS selected in the last or first RACH attempt, and the repetition level of the last or first RACH attempt is less than the maximum number set for the number of PRACH transmissions, and the transmission power in the current RACH attempt reaches the maximum transmission power, as determined by assuming that the repetition level of the current RACH attempt is the same as that of the last or first RACH attempt, then the repetition level of the current RACH attempt increases from the repetition level X of the last or first RACH attempt; otherwise, the repetition level of the current RACH attempt is equal to X.

[0576] Implementation Methods D1-2

[0577] In the case of applying option 1-2 (increased repetition level) in scenario 2 above, the determination of the increased repetition level can also follow at least one of the following options.

[0578] - Option 1-2a: The repetition level of the current RACH attempt is increased to the lowest repetition level among the multiple candidate repetition levels that is greater than the repetition level of the last or first RACH attempt.

[0579] For example, the candidate repetition levels {K0, K1, K2, K3} (K0 < K1 < K2 < K3) used for multiple PRACH transmissions can also be set by the base station. If the repetition level of the last or first RACH attempt is K1 and the repetition level increase condition is met, the UE will determine the repetition level of the current RACH attempt as K2.

[0580] - Option 1-2b: If, among the multiple candidate repetition levels set, there exists one or more candidate repetition levels (greater than the repetition level of the last or first RACH attempt, and) obtained by assuming that the calculated transmission power does not exceed the UE's maximum transmission power, then the repetition level of the current RACH attempt is increased to the lowest repetition level among those one or more candidate repetition levels.

[0581] Alternatively, if none of the set candidate repetition levels meet the condition that the PRACH transmission power does not exceed the UE's maximum transmission power, the added repetition level is determined as the maximum repetition level among the set candidate repetition levels.

[0582] For example, if the base station sets candidate repetition levels {K0, K1, K2, K3} (K0 < K1 < K2 < K3) for multiple PRACH transmissions, and the repetition level of the last or first RACH attempt is K0, and the repetition level increase condition is met, the UE may also follow at least one of the following operations.

[0583] Alternatively, if the repetition level of the current RACH attempt is assumed to be K1, and the determined transmission power exceeds the UE's maximum transmission power, and if the repetition level of the current RACH attempt is assumed to be K2 or K3, and the determined transmission power does not exceed the UE's maximum transmission power, then the UE will determine the repetition level of the current RACH attempt to be K2.

[0584] - Alternatively, if the repetition level of the current RACH attempt is assumed to be K1, K2, or K3, and the determined transmission power exceeds the UE's maximum transmission power, the UE will determine the repetition level of the current RACH attempt to be K3.

[0585] "change"

[0586] If the specific conditions (repetition level increase conditions) in implementation method D1-1 are met, the UE may also determine the repetition level of the current RACH attempt based on the determination rule used to determine the repetition level of the initial RACH attempt. This determination rule may also be based on at least one of SSB-RSRP, UE power level, and UE maximum transmit power to determine the repetition level.

[0587] According to this implementation, the UE can appropriately determine the repetition level of the retransmission RACH attempt based on the repetition level of the last or the first RACH attempt.

[0588] <Implementation Method D2>

[0589] This implementation relates to the details of option 2 of implementation D0.

[0590] In option 2, the UE may also follow at least one of the following operational scenarios.

[0591] - Scenario 1: There is no previous RACH attempt with the same SSB / CSI-RS selection as the current RACH attempt.

[0592] In this scenario, the UE can also determine the repetition level of the current RACH attempt based on the decision rule used to determine the repetition level of the initial RACH attempt. This decision rule can also be based on at least one of the following: SSB-RSRP, UE power level, and UE maximum transmit power.

[0593] - Scenario 2: There is a previous RACH attempt with the same SSB / CSI-RS selection as the current RACH attempt, and the repetition level of the last or first RACH attempt with the same SSB / CSI-RS selection is equal to 1 (determining a single PRACH transmission in the last or first RACH attempt with the same SSB / CSI-RS selection).

[0594] In this scenario, the UE can also determine the repetition level of the current RACH attempt based on the decision rule used to determine the repetition level of the initial RACH attempt. This decision rule can also be based on at least one of the following: SSB-RSRP, UE power level, and UE maximum transmit power.

[0595] - Scenario 3: There is a previous RACH attempt with the same SSB / CSI-RS selection as the current RACH attempt, and the repetition level of the last or first RACH attempt with the same SSB / CSI-RS selection is greater than 1 (multiple PRACH transmissions are determined in the last or first RACH attempt with the same SSB / CSI-RS selection).

[0596] In this scenario, the UE may also determine the repetition level of the current RACH attempt based on the repetition level of the last or first RACH attempt with the same SSB / CSI-RS selection. Alternatively, the UE may determine the repetition level of the current RACH attempt by following at least one of the following options.

[0597] -- Option 2-1: The repetition level of a retransmission RACH attempt (the current RACH attempt) may also be the same as the repetition level of the last or first RACH attempt with the same SSB / CSI-RS selection.

[0598] -- Option 2-2: The repetition level of a retransmission RACH attempt (the current RACH attempt) can also be increased based on the repetition level of the last or first RACH attempt with the same SSB / CSI-RS selection.

[0599] In scenario 3, whether to maintain or increase the repetition level based on the repetition level of the last or first RACH attempt with the same SSB / CSI-RS selection can also be conditional. For example, option 2-2 can be applied if a specific condition (repetition level increase condition) is met, otherwise option 2-1 is applied. When option 2-2 is applied, the repetition level of the RACH attempt can also be increased (the current RACH attempt's repetition level can also be increased from the repetition level of the last or first RACH attempt with the same SSB / CSI-RS selection). When option 2-1 is applied, the repetition level of the RACH attempt can also be maintained (the current RACH attempt's repetition level can also be equal to the repetition level of the last or first RACH attempt with the same SSB / CSI-RS selection). The specific condition can also be reused / converted by replacing "last or first RACH attempt" with "last or first RACH attempt with the same SSB / CSI-RS selection," thus reusing / converting the specific condition of implementation D1-1.

[0600] In scenario 3, when applying option 2-2 (increased repetition level), the decision of the increased repetition level can also replace "last or first RACH attempt" with "last or first RACH attempt with the same SSB / CSI-RS selection" to reuse / reuse the decision method of implementation method D1-2.

[0601] "change"

[0602] Replacing "last or first RACH attempt" with "last or first RACH attempt with the same SSB / CSI-RS selection," the UE can also determine the repetition level of the current RACH attempt based on the decision rule used to determine the repetition level of the initial RACH attempt, provided that the specific conditions in Implementation D1-1 are met. This decision rule can also determine the repetition level based on at least one of SSB-RSRP, UE power level, and UE maximum transmit power.

[0603] According to this implementation, the UE can appropriately determine the repetition level of the retransmission RACH attempt based on the last or first RACH attempt that has the same SSB / CSI-RS selection as the RACH retransmission attempt.

[0605] <Implementation Method 0>

[0606] In the following embodiments, the following operations performed by the UE for a certain RACH attempt may also follow at least one of the above embodiments A to D: for a certain RACH attempt, determining whether to perform a single PRACH transmission or multiple PRACH transmissions based on the RSRP of the SSB / CSI-RS; for a certain RACH attempt, determining the number of PRACH transmissions based on the RSRP of the SSB / CSI-RS.

[0607] <Implementation Method 1>

[0608] This implementation involves determining the transmission of a single PRACH.

[0609] Alternatively, the specification may stipulate that, in the case where a single PRACH transmission is determined for the initial RACH attempt, a single PRACH transmission may be applied for more than one RACH attempt within that RA process. This operation may also follow at least one of the following implementation methods 1-x.

[0610] <<Implementation Method 1-1>>

[0611] In this scenario, the SSB / CSI-RS selection during the RACH retry can also follow at least one of the following options.

[0612] - Option 0: SSB / CSI-RS selection is the same as the existing SSB / CSI-RS selection rules.

[0613] -- The existing SSB / CSI-RS selection rules are as follows:

[0614] --- If an SSB / CSI-RS with an RSRP exceeding the threshold (rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS) exists, the UE selects that SSB / CSI-RS; otherwise, the UE selects any SSB / CSI-RS.

[0615] -- The UE can select an SSB / CSI-RS with an RSRP lower than the RSRP threshold used for triggering multiple PRACH transmissions. In this case, PRACH performance is poor if it is treated as a single PRACH transmission applied to RACH retry.

[0616] Option 1: The UE preferentially has an SSB / CSI-RS corresponding to the RSRP of a single PRACH transmission, and secondly, preferentially has an SSB / CSI-RS corresponding to the RSRP of multiple PRACH transmissions. In other words, the UE preferentially has an SSB / CSI-RS with an RSRP exceeding the threshold corresponding to a single PRACH transmission, and secondly, preferentially has an SSB / CSI-RS with an RSRP exceeding the threshold corresponding to multiple PRACH transmissions. In this case, the UE may also follow at least one of the following examples.

[0617] -- Example 1: such as Figure 10 As in the example, the UE can also set / define: an existing threshold rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS; and a higher threshold RSRP_thr0. Alternatively, in the initial RACH attempt, if there is an SSB / CSI-RS with an RSRP exceeding RSRP_thr0, the UE decides to send a single PRACH for the initial RACH attempt. Alternatively, in the initial RACH attempt, if there is no SSB / CSI-RS with an RSRP exceeding RSRP_thr0, the UE decides to send multiple PRACHs for the initial RACH attempt. The UE can also follow at least one of the following examples.

[0618] Example 1-1: If there exists at least one (associated) SSB / CSI-RS with an RSRP exceeding RSRP_thr0, the UE may also select an SSB / CSI-RS with an RSRP exceeding RSRP_thr0. Otherwise, if there exists at least one (associated) SSB / CSI-RS with an RSRP exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, the UE may also select an SSB / CSI-RS with an RSRP exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS. Otherwise, the UE may also select any SSB / CSI-RS.

[0619] Example 1-2: SSB / CSI-RS with an RSRP exceeding RSRP_thr0 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with an RSRP not exceeding RSRP_thr0 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with an RSRP not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #2. Alternatively, if an SSB / CSI-RS exists within SSB / CSI-RS set #0 for SSB / CSI-RS selection, the UE prioritizes SSB / CSI-RS set #0. If no SSB / CSI-RS exists within SSB / CSI-RS set #0, the UE prioritizes SSB / CSI-RS set #1. If no SSB / CSI-RS exists in SSB / CSI-RS set #1, the UE can choose any SSB / CSI-RS or SSB / CSI-RS in SSB / CSI-RS set #2.

[0620] -- Example 2: Alternatively, an existing threshold rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, and a lower threshold RSRP_thr0, can be set / defined. Alternatively, in the initial RACH attempt, if there is an SSB / CSI-RS with an RSRP exceeding the threshold rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, the UE decides to send a single PRACH for the initial RACH attempt. Alternatively, in the initial RACH attempt, if there is no SSB / CSI-RS with an RSRP exceeding the threshold rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, the UE decides to send multiple PRACHs for the initial RACH attempt. The UE can also follow at least one of the following examples.

[0621] Example 2-1: Alternatively, if there exists at least one (associated) SSB / CSI-RS with an RSRP exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, the UE selects an SSB / CSI-RS with an RSRP exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS. Otherwise, if there exists at least one (associated) SSB / CSI-RS with an RSRP exceeding RSRP_thr0, the UE may also select an SSB / CSI-RS with an RSRP exceeding RSRP_thr0. Otherwise, the UE may also select any SSB / CSI-RS.

[0622] - Option 2: The UE prioritizes the SSB / CSI-RS with the RSRP corresponding to a single PRACH transmission, and secondly, prioritizes the SSB / CSI-RS with the RSRP corresponding to a smaller repetition factor. In this case, the UE can also follow the example below.

[0623] -- Example 1: such as Figure 11 As in the example, the following can also be set / defined: the existing threshold rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, the higher threshold RSRP_thr2, the higher threshold RSRP_thr1, and the higher threshold RSRP_thr0. Alternatively, in the initial RACH attempt, if there is an SSB / CSI-RS with an RSRP exceeding RSRP_thr0, the UE decides to send a single PRACH for the initial RACH attempt. Alternatively, in the initial RACH attempt, if there is no SSB / CSI-RS with an RSRP exceeding RSRP_thr0, the UE decides to send multiple PRACHs for the initial RACH attempt. Alternatively, in the initial RACH attempt, if there is an SSB / CSI-RS with an RSRP exceeding RSRP_thr1 but not exceeding RSRP_thr0, the UE determines the number of PRACH transmissions to be 2 for the initial RACH attempt. Alternatively, in the initial RACH attempt, if there is an SSB / CSI-RS with an RSRP that is greater than RSRP_thr1 but greater than RSRP_thr2, the UE determines the PRACH transmission count to be 4 for the initial RACH attempt. Alternatively, if there is no SSB / CSI-RS with an RSRP greater than RSRP_thr2, the UE determines the PRACH transmission count to be 8 for the initial RACH attempt. The UE may also follow at least one of the following examples.

[0624] Example 1-1: Alternatively, if at least one (associated) SSB / CSI-RS has an RSRP greater than RSRP_thr0, the UE selects an SSB / CSI-RS with an RSRP greater than RSRP_thr0. Otherwise, if at least one (associated) SSB / CSI-RS has an RSRP greater than RSRP_thr1, the UE selects an SSB / CSI-RS with an RSRP greater than RSRP_thr1. Alternatively, if at least one (associated) SSB / CSI-RS has an RSRP greater than RSRP_thr2, the UE selects an SSB / CSI-RS with an RSRP greater than RSRP_thr2. Alternatively, if there exists at least one (associated) SSB / CSI-RS with an RSRP exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, the UE selects an SSB / CSI-RS with an RSRP exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS. Otherwise, the UE may select any SSB / CSI-RS.

[0625] --- Example 1-2: SSB / CSI-RS with RSRPs exceeding RSRP_thr0 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with RSRPs not exceeding RSRP_thr0 but exceeding RSRP_thr1 can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with RSRPs not exceeding RSRP_thr1 but exceeding RSRP_thr2 can also be identified as SSB / CSI-RS set #2. SSB / CSI-RS with RSRPs not exceeding RSRP_thr2 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #3. SSB / CSI-RS with RSRPs not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #4. Alternatively, if an SSB / CSI-RS exists within SSB / CSI-RS set #0 for SSB / CSI-RS selection, the UE prioritizes SSB / CSI-RS set #0. Alternatively, if no SSB / CSI-RS exists within SSB / CSI-RS set #0, the UE prioritizes SSB / CSI-RS set #1. Alternatively, if neither SSB / CSI-RS exists within SSB / CSI-RS sets #0 nor #1, the UE prioritizes SSB / CSI-RS set #2. Alternatively, if neither SSB / CSI-RS exists within SSB / CSI-RS sets #0 to #2, the UE prioritizes SSB / CSI-RS set #3. If neither SSB / CSI-RS exists within SSB / CSI-RS sets #0 to #3, the UE can choose any SSB / CSI-RS or one from SSB / CSI-RS set #4.

[0626] -- Example 2: Alternatively, the following can be set / defined: an existing threshold rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, a lower threshold RSRP_thr1, a lower threshold RSRP_thr2, and a higher threshold RSRP_thr3. Alternatively, in the initial RACH attempt, if there is an SSB / CSI-RS with an RSRP exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, the UE decides to send a single PRACH for the initial RACH attempt. Alternatively, in the initial RACH attempt, if there is no SSB / CSI-RS with an RSRP exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, the UE decides to send multiple PRACHs for the initial RACH attempt. Alternatively, in the initial RACH attempt, if there is an SSB / CSI-RS with an RSRP exceeding RSRP_thr1 but not exceeding rsrp_ThresholdSSB / rsrp_ThresholdCSI-RS, the UE determines the PRACH transmission count to be 2 for the initial RACH attempt. Alternatively, in the initial RACH attempt, if there is an SSB / CSI-RS with an RSRP exceeding RSRP_thr1 but not exceeding RSRP_thr2, the UE determines the PRACH transmission count to be 4 for the initial RACH attempt. Alternatively, if there is no SSB / CSI-RS with an RSRP exceeding RSRP_thr2, the UE determines the PRACH transmission count to be 8 for the initial RACH attempt. The UE may also follow at least one of the following examples.

[0627] Example 2-1: Alternatively, if there exists at least one (associated) SSB / CSI-RS with an RSRP exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS, the UE selects one SSB / CSI-RS with an RSRP exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS. Otherwise, if there exists at least one (associated) SSB / CSI-RS with an RSRP exceeding RSRP_thr1, the UE selects one SSB / CSI-RS with an RSRP exceeding RSRP_thr1. Alternatively, if there exists at least one (associated) SSB / CSI-RS with an RSRP exceeding RSRP_thr2, the UE selects one SSB / CSI-RS with an RSRP exceeding RSRP_thr2. Alternatively, if there exists at least one (associated) SSB / CSI-RS with an RSRP exceeding RSRP_thr3, the UE selects an SSB / CSI-RS with an RSRP exceeding RSRP_thr3. Otherwise, the UE may select any SSB / CSI-RS.

[0628] <<Implementation Methods 1-2>>

[0629] The power ramp-up in the RACH retry in this scenario can also follow at least one of the following options.

[0630] - Option 1: Able to reuse / repurpose existing power ramp rules.

[0631] -- The existing power ramping rules are as follows:

[0632] --- If the selected SSB / CSI-RS remains unchanged compared to the last RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by 1. If the selected SSB / CSI-RS changes compared to the last RACH attempt, the UE maintains PREAMBLE_POWER_RAMPING_COUNTER.

[0633] - Option 2: Apply an enhanced power ramp-up rule based on the RSRP threshold used to determine the number of PRACH transmissions, and the RSRP of the selected SSB / CSI-RS. The UE may also follow the following rules.

[0634] -- Rule: Alternatively, if the RSRP of the selected SSB / CSI-RS corresponds to multiple PRACH transmissions, the UE shall follow at least one of the following operations. As in Implementation 1-1, whether the RSRP corresponds to multiple PRACH transmissions or a single PRACH transmission can also be determined based on a threshold.

[0635] --- Alternatively, if the selected SSB / CSI-RS remains unchanged compared to the last RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by X. Here, X can be either equal to 1 or greater than 1. X can be defined by the specification or indicated / set by the base station.

[0636] --- Alternatively, if the selected SSB / CSI-RS changes compared to the last RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by Y. Here, Y can be either equal to 0 or greater than 0. Y can be defined by the specification or indicated / set by the base station.

[0637] --- Variation: The values ​​of X and Y can also depend on the value of the repetition factor corresponding to the selected SSB / CSI-RS (the values ​​of X and Y can also differ for different values ​​of the repetition factor).

[0638] -- The RSRP of the selected SSB / CSI-RS does not necessarily exceed the threshold for a single PRACH transmission. This enhancement enables power increases even when no SSB / CSI-RS has an RSRP exceeding the threshold corresponding to a single PRACH transmission.

[0639] According to this implementation, when a single PRACH transmission is determined for the initial RACH attempt, the UE is able to appropriately perform at least one SSB / CSI-RS selection and power ramping for more than one RACH attempt within the RA process.

[0640] <Implementation Method 2>

[0641] This implementation relates to maintaining the number of PRACH transmissions during RACH retry when multiple PRACH transmissions are determined.

[0642] Alternatively, the specification may stipulate that if multiple PRACH transmissions are determined for the initial RACH attempt, multiple PRACH transmissions may be applied for more than one RACH attempt within the RA process, and the number of PRACH transmissions in the RACH retry shall be the same as the number of PRACH transmissions in the initial RACH attempt. This operation may also follow at least one of the following implementation methods 2-x.

[0643] <<Implementation Method 2-1>>

[0644] In this scenario, the SSB / CSI-RS selection during the RACH retry can also follow at least one of the following options.

[0645] - Option 1-0: SSB / CSI-RS selection is the same as the existing SSB / CSI-RS selection rules.

[0646] -- The existing SSB / CSI-RS selection rules are as follows:

[0647] --- If an SSB / CSI-RS with an RSRP exceeding the threshold (rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS) exists, the UE selects that SSB / CSI-RS; otherwise, the UE selects any SSB / CSI-RS.

[0648] -- The UE can select an SSB / CSI-RS with an RSRP lower than the RSRP threshold used for triggering multiple PRACH transmissions. In this case, PRACH performance is poor if it is treated as a single PRACH transmission applied to RACH retry.

[0649] - Option 1-1: The UE has priority to have an SSB / CSI-RS with an RSRP corresponding to a repetition factor equal to the repetition factor in the initial RACH attempt; secondly, it has priority to have an SSB / CSI-RS with an RSRP corresponding to the closest repetition factor that is less than the repetition factor in the initial RACH attempt; and thirdly, it has priority to have an SSB / CSI-RS with an RSRP corresponding to the closest repetition factor that is greater than the repetition factor in the initial RACH attempt.

[0650] - Option 1-2: The UE prioritizes the SSB / CSI-RS corresponding to the RSRP of the repetition factor below the repetition factor in the initial RACH attempt, and secondly, prioritizes the SSB / CSI-RS corresponding to the RSRP of the repetition factor that is greater than the repetition factor in the initial RACH attempt and is closest to it.

[0651] - Options 1-3: The UE has priority for the SSB / CSI-RS corresponding to the RSRP of the repetition factor that is equal to the repetition factor in the initial RACH attempt; secondly, it has priority for the SSB / CSI-RS corresponding to the RSRP of the repetition factor that is smaller than the repetition factor in the initial RACH attempt and is the closest to it; and thirdly, it has priority for the SSB / CSI-RS corresponding to the RSRP of the repetition factor that is larger than the repetition factor in the initial RACH attempt.

[0652] - Options 1-4: The UE has priority for the SSB / CSI-RS corresponding to the RSRP of the repetition factor below the repetition factor in the initial RACH attempt, and secondly, priority for the SSB / CSI-RS corresponding to the RSRP of the repetition factor above the repetition factor in the initial RACH attempt.

[0653] <<<Specific Examples of Each Choice>>>

[0654] In the following specific examples, as mentioned above Figure 11 As in the example, the following can also be set / defined: the existing threshold rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS; a higher threshold RSRP_thr2; a higher threshold RSRP_thr1; and a higher threshold RSRP_thr0. In the initial RACH attempt, whether a single PRACH transmission or multiple PRACH transmissions are performed, and the repetition factor K in multiple PRACH transmissions, are associated with the RSRP threshold. Alternatively, in the initial RACH attempt, if there is an SSB / CSI-RS with an RSRP exceeding RSRP_thr0, a single PRACH transmission is selected. Alternatively, in the initial RACH attempt, if there is no SSB / CSI-RS with an RSRP exceeding RSRP_thr0, multiple PRACH transmissions are selected. In the initial RACH attempt, if there is an SSB / CSI-RS with an RSRP exceeding RSRP_thr1 but not exceeding RSRP_thr0, K=2 is determined. In the initial RACH attempt, if there exists an SSB / CSI-RS with an RSRP that does not exceed RSRP_thr1 but exceeds RSRP_thr2, then K=4 is determined. In the initial RACH attempt, if there is no SSB / CSI-RS with an RSRP that exceeds RSRP_thr2, then K=8 is determined.

[0655] - Example: With K=2 and option 1-1, the UE can also follow the following operation.

[0656] -- like Figure 12As in the examples, SSB / CSI-RS with RSRPs exceeding RSRP_thr0 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with RSRPs not exceeding RSRP_thr0 but exceeding RSRP_thr1 can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with RSRPs not exceeding RSRP_thr1 but exceeding RSRP_thr2 can also be identified as SSB / CSI-RS set #2. SSB / CSI-RS with RSRPs not exceeding RSRP_thr2 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #3. SSB / CSI-RS with RSRPs not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #4.

[0657] -- If the repetition factor K=2 in the initial RACH attempt, the priority order of the SSB / CSI-RS sets selected in the SSB / CSI-RS selection is SSB / CSI-RS sets #1, #0, #2, #3, #4. If an SSB / CSI-RS exists in SSB / CSI-RS set #1, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS set #1, but an SSB / CSI-RS exists in SSB / CSI-RS set #0, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in either SSB / CSI-RS set #1 or #0, but an SSB / CSI-RS exists in SSB / CSI-RS set #2, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS sets #1, #0, and #2, but an SSB / CSI-RS exists in SSB / CSI-RS set #3, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS sets #1, #0, #2, and #3, the UE selects any SSB / CSI-RS.

[0658] - Example: When K=2 and options 1-2 are available, the UE can also follow the following operation.

[0659] -- like Figure 13As in the examples, SSB / CSI-RS with RSRPs exceeding RSRP_thr1 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with RSRPs not exceeding RSRP_thr1 but exceeding RSRP_thr2 can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with RSRPs not exceeding RSRP_thr2 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #2. SSB / CSI-RS with RSRPs not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #3.

[0660] -- If the repetition factor K=2 in the initial RACH attempt, the priority order of the SSB / CSI-RS sets selected in the SSB / CSI-RS selection is SSB / CSI-RS sets #0, #1, #2, #3. If an SSB / CSI-RS exists in SSB / CSI-RS set #0, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS set #0, but an SSB / CSI-RS exists in SSB / CSI-RS set #1, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in either SSB / CSI-RS set #0 or #1, but an SSB / CSI-RS exists in SSB / CSI-RS set #2, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in the sets #0, #1, and #2, the UE selects any SSB / CSI-RS.

[0661] - Example: When K=2 and options 1-3 are available, the UE can also follow the following operations.

[0662] -- like Figure 14As in the examples, SSB / CSI-RS with RSRPs exceeding RSRP_thr0 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with RSRPs not exceeding RSRP_thr0 but exceeding RSRP_thr1 can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with RSRPs not exceeding RSRP_thr1 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #2. SSB / CSI-RS with RSRPs not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #3.

[0663] -- If the repetition factor K=2 in the initial RACH attempt, the priority order of the SSB / CSI-RS sets selected in the SSB / CSI-RS selection is SSB / CSI-RS set #1, #0, #2, #3. If an SSB / CSI-RS exists in SSB / CSI-RS set #1, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS set #1, but an SSB / CSI-RS exists in SSB / CSI-RS set #0, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in either SSB / CSI-RS set #1 or #0, but an SSB / CSI-RS exists in SSB / CSI-RS set #2, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in the sets #1, #0, and #2, the UE selects any SSB / CSI-RS.

[0664] - Example: When K=2 and options 1-4 are available, the UE can also follow the following operations.

[0665] -- like Figure 15As in the example, SSB / CSI-RS with an RSRP exceeding RSRP_thr1 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with an RSRP not exceeding RSRP_thr1 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with an RSRP not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #2.

[0666] -- If the repetition factor K=2 in the initial RACH attempt, the priority order of the SSB / CSI-RS sets selected in the SSB / CSI-RS selection is SSB / CSI-RS set #0, #1, #2. If an SSB / CSI-RS exists in SSB / CSI-RS set #0, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS set #0, but an SSB / CSI-RS exists in SSB / CSI-RS set #1, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in either SSB / CSI-RS set #0 or #1, the UE selects any SSB / CSI-RS.

[0667] - Example: With K=4 and option 1-1, the UE can also follow the following operation.

[0668] -- like Figure 16 As in the examples, SSB / CSI-RS with RSRPs exceeding RSRP_thr0 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with RSRPs not exceeding RSRP_thr0 but exceeding RSRP_thr1 can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with RSRPs not exceeding RSRP_thr1 but exceeding RSRP_thr2 can also be identified as SSB / CSI-RS set #2. SSB / CSI-RS with RSRPs not exceeding RSRP_thr2 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #3. SSB / CSI-RS with RSRPs not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #4.

[0669] -- If the repetition factor K=4 in the initial RACH attempt, the priority order of the SSB / CSI-RS sets selected in the SSB / CSI-RS selection is: SSB / CSI-RS sets #2, #1, #0, #3, #4. If an SSB / CSI-RS exists in SSB / CSI-RS set #2, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS set #2, but an SSB / CSI-RS exists in SSB / CSI-RS set #1, the UE selects that SSB / CSI-RS. If neither SSB / CSI-RS exists in SSB / CSI-RS sets #2 nor #1, but an SSB / CSI-RS exists in SSB / CSI-RS set #0, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS sets #2, #1, and #0, but an SSB / CSI-RS exists in SSB / CSI-RS set #3, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS sets #2, #1, #0, and #3, the UE selects any SSB / CSI-RS.

[0670] - Example: With K=4 and options 1-2, the UE can also follow the following operations.

[0671] -- like Figure 17 As in the example, SSB / CSI-RS with an RSRP exceeding RSRP_thr2 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with an RSRP not exceeding RSRP_thr2 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with an RSRP not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #2.

[0672] -- If the repetition factor K=4 in the initial RACH attempt, the priority order of the SSB / CSI-RS sets selected in the SSB / CSI-RS selection is SSB / CSI-RS set #0, #1, #2. If an SSB / CSI-RS exists in SSB / CSI-RS set #0, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS set #0, but an SSB / CSI-RS exists in SSB / CSI-RS set #1, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in either SSB / CSI-RS set #0 or #1, the UE selects any SSB / CSI-RS.

[0673] - Example: When K=4 and options 1-3 are available, the UE can also follow the following operations.

[0674] -- As mentioned above Figure 16 As in the examples, SSB / CSI-RS with RSRPs exceeding RSRP_thr0 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with RSRPs not exceeding RSRP_thr0 but exceeding RSRP_thr1 can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with RSRPs not exceeding RSRP_thr1 but exceeding RSRP_thr2 can also be identified as SSB / CSI-RS set #2. SSB / CSI-RS with RSRPs not exceeding RSRP_thr2 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #3. SSB / CSI-RS with RSRPs not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #4.

[0675] -- If the repetition factor K=4 in the initial RACH attempt, the priority order of the SSB / CSI-RS sets selected in the SSB / CSI-RS selection is: SSB / CSI-RS sets #2, #1, #0, #3, #4. If an SSB / CSI-RS exists in SSB / CSI-RS set #2, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS set #2, but an SSB / CSI-RS exists in SSB / CSI-RS set #1, the UE selects that SSB / CSI-RS. If neither SSB / CSI-RS exists in SSB / CSI-RS sets #2 nor #1, but an SSB / CSI-RS exists in SSB / CSI-RS set #0, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS sets #2, #1, and #0, but an SSB / CSI-RS exists in SSB / CSI-RS set #3, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS sets #2, #1, #0, and #3, the UE selects any SSB / CSI-RS.

[0676] - Example: When K=4 and options 1-4 are available, the UE can also follow the following operations.

[0677] -- As mentioned above Figure 17 As in the example, SSB / CSI-RS with an RSRP exceeding RSRP_thr2 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with an RSRP not exceeding RSRP_thr2 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with an RSRP not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #2.

[0678] -- If the repetition factor K=4 in the initial RACH attempt, the priority order of the SSB / CSI-RS sets selected in the SSB / CSI-RS selection is SSB / CSI-RS set #0, #1, #2. If an SSB / CSI-RS exists in SSB / CSI-RS set #0, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS set #0, but an SSB / CSI-RS exists in SSB / CSI-RS set #1, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in either SSB / CSI-RS set #0 or #1, the UE selects any SSB / CSI-RS.

[0679] <<Implementation Method 2-2>>

[0680] The power ramp-up in the RACH retry in this scenario can also follow at least one of the following options.

[0681] - Option 1: If the selected SSB / CSI-RS remains unchanged compared to the last RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by 1. If the selected SSB / CSI-RS changes compared to the last RACH attempt, the UE maintains PREAMBLE_POWER_RAMPING_COUNTER.

[0682] - Option 2: Apply an enhanced power ramping rule based on the RSRP threshold used for determining the number of PRACH transmissions, and the RSRP of the selected SSB / CSI-RS. As in Implementation 2-1, the repetition factor corresponding to RSRP can also be determined based on a threshold. The UE can also follow at least one of the following rules.

[0683] -- Rule 1: Alternatively, if the RSRP of the selected SSB / CSI-RS corresponds to a repetition factor greater than the repetition factor in the last RACH attempt, the UE shall follow at least one of the following operations.

[0684] --- Alternatively, if the selected SSB / CSI-RS remains unchanged compared to the last RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by X. Here, X can be either equal to 1 or greater than 1. X can be defined by the specification or indicated / set by the base station.

[0685] --- Alternatively, if the selected SSB / CSI-RS changes compared to the last RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by Y. Here, Y can be equal to 0 or greater than 0. Y can be defined by the specification or indicated / set by the base station.

[0686] --- Variation: The values ​​of X and Y can also depend on the determined repetition factor and the gap between the repetition factors corresponding to the selected SSB / CSI-RS (the values ​​of X and Y will vary depending on the value of this gap).

[0687] -- Rule 2: Alternatively, if the RSRP of the selected SSB / CSI-RS corresponds to a repetition factor less than the repetition factor in the last RACH attempt, the UE may also follow several of the following operations.

[0688] --- Alternatively, if the selected SSB / CSI-RS remains unchanged compared to the last RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by X. Here, X can be equal to or greater than 0 or 1. X can be defined by the specification or indicated / set by the base station.

[0689] --- Alternatively, if the selected SSB / CSI-RS changes compared to the last RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by Y. Here, Y can be equal to 0 or greater than 0. Y can be defined by the specification or indicated / set by the base station.

[0690] --- Variation: The values ​​of X and Y can also depend on the difference between the determined repetition factor and the repetition factor corresponding to the selected SSB / CSI-RS (the values ​​of X and Y can also vary depending on the value of this difference).

[0691] You can also set / indicate specific power ramp-up step sizes for different ramp factors. You can also apply a power ramp-up step size specific to a particular ramp factor during a RA process. For example, for RA processes using ramp factors of 2, 4, and 8, you can set / indicate RRC IE powerRampingStep-Rep2, powerRampingStep-Rep4, and powerRampingStep-Rep8 respectively. If the ramp factor in the RA process is 2, you can also apply powerRampingStep-Rep2 for that RA process.

[0692] <<Implementation Methods 2-3>>

[0693] The maximum value of the preamble transmission counter (the maximum number of random access preamble transmissions) in this case can also follow the settings / instructions below.

[0694] - The maximum number of random access preambles to be transmitted (preambleTransMax) can be set / indicated individually for different repetition factors. Within a specific random access preamble (RA) process, the maximum number of RA preambles to be transmitted (limited) corresponding to the repetition factor for that RA process can also be applied. For example, for RA processes using repetition factors of 2, 4, and 8, RRC IE preambleTransMax-Rep2, preambleTransMax-Rep4, and preambleTransMax-Rep8 can be set / indicated respectively. If the repetition factor in the RA process is 2, preambleTransMax-Rep2 can also be applied to that RA process.

[0695] According to this implementation, when multiple PRACH transmissions are determined for the initial RACH attempt and the number of PRACH transmissions is maintained during RACH retry, the UE can appropriately perform at least one of SSB / CSI-RS selection, power ramp-up, and preamble transmission counter for more than one RACH attempt within the RA process.

[0696] <Implementation Method 3>

[0697] This implementation relates to a situation where the number of PRACH transmissions is not maintained during RACH retry when multiple PRACH transmissions are determined.

[0698] Alternatively, the specification may stipulate that if multiple PRACH transmissions are determined for the initial RACH attempt, a single PRACH transmission shall be applied for more than one RACH attempt within the RA process, and the number of PRACH transmissions in the RACH retry may be the same as or different from the number of PRACH transmissions in the initial RACH attempt.

[0699] Alternatively, the specification can stipulate that if multiple PRACH transmissions are determined for the initial RACH attempt, a single PRACH transmission shall be applied for more than one RACH attempt within the RA process. The number of PRACH transmissions in the RACH retry shall be the same as, greater than, or less than the number of PRACH transmissions in the initial RACH attempt.

[0700] The operation of this situation can also follow at least one of the following implementation methods 3-x.

[0701] <<Implementation Method 3-1>>

[0702] In this scenario, the SSB / CSI-RS selection during the RACH retry can also follow at least one of the following options.

[0703] - Option 1-0: Same as implementation method 2-1.

[0704] - Option 1-1: Same as implementation method 2-1.

[0705] - Option 1-2: Same as implementation method 2-1.

[0706] - Options 1-3: Same as implementation method 2-1.

[0707] - Options 1-4: Same as implementation method 2-1.

[0708] - Options 1-5: The UE has priority to have an SSB / CSI-RS with RSRP corresponding to multiple PRACH transmissions, and secondly, has priority to have an SSB / CSI-RS with RSRP corresponding to a single PRACH transmission.

[0709] <<<Specific examples>>>

[0710] In the following specific examples, similar to the specific examples of each option in implementation 2-1, the following can also be set / defined: the existing threshold rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS; a higher threshold RSRP_thr2; a higher threshold RSRP_thr1; and a higher threshold RSRP_thr0.

[0711] - Example: When K>1 and options 1-5 are available, the UE can also follow the following operations.

[0712] -- like Figure 18 As in the example, SSB / CSI-RS with an RSRP exceeding RSRP_thr0 can also be identified as SSB / CSI-RS set #0. SSB / CSI-RS with an RSRP not exceeding RSRP_thr0 but exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #1. SSB / CSI-RS with an RSRP not exceeding rsrp-ThresholdSSB / rsrp-ThresholdCSI-RS can also be identified as SSB / CSI-RS set #2.

[0713] -- If the repetition factor K > 1 in the initial RACH attempt, the priority order of the SSB / CSI-RS sets selected in the SSB / CSI-RS selection is SSB / CSI-RS set #1, #0, #2. If an SSB / CSI-RS exists in SSB / CSI-RS set #1, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in SSB / CSI-RS set #1, but an SSB / CSI-RS exists in SSB / CSI-RS set #0, the UE selects that SSB / CSI-RS. If no SSB / CSI-RS exists in either SSB / CSI-RS set #1 or #0, the UE selects any SSB / CSI-RS.

[0714] <<Implementation Method 3-2>>

[0715] The power ramp-up in the RACH retry in this scenario can also follow at least one of the following options.

[0716] - Option 1: If the selected SSB / CSI-RS remains unchanged compared to the last RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by 1. If the selected SSB / CSI-RS changes compared to the last RACH attempt, the UE maintains PREAMBLE_POWER_RAMPING_COUNTER.

[0717] - Option 2: Whether to perform power easing depends on whether to perform iterative factor easing (change / increase of the iterative factor). The UE may also follow at least one of the following rules.

[0718] -- Rule 1: Alternatively, if the determined repetition factor is greater than the repetition factor in the last RACH attempt, the UE maintains PREAMBLE_POWER_RAMPING_COUNTER regardless of whether the SSB / CSI-RS selected in the last RACH attempt is the same as or different from the selected SSB / CSI-RS.

[0719] -- Rule 2: Alternatively, if the determined repetition factor is less than the repetition factor in the final RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by X. Here, for the SSB / CSI-RS selection in the final RACH attempt, the value of X can also be different depending on whether the selected SSB / CSI-RS is the same or different.

[0720] -- Rule 3: If the determined repetition factor is the same as the repetition factor in the last RACH attempt, the UE may also follow at least one of the following operations.

[0721] --- If the selected SSB / CSI-RS remains unchanged compared to the last RACH attempt, the UE increments PREAMBLE_POWER_RAMPING_COUNTER by 1.

[0722] --- If the selection of the SSB / CSI-RS changes compared to the last RACH attempt, the UE maintains PREAMBLE_POWER_RAMPING_COUNTER.

[0723] - Variation: A dedicated power ramp-up step size can also be set / indicated for both multiple PRACH transmissions and a single PRACH transmission. For RA procedures using multiple PRACH transmissions (RA procedures where multiple PRACH transmissions are determined in the initial RACH attempt within that RA procedure), a power ramp-up step size set / indicated for multiple PRACH transmissions can also be applied. For example, for RA procedures using multiple PRACH transmissions (different from the RRC IE for RA procedures using a single PRACH transmission), the RRC IE powerRampingStep-MultiPRACH can also be set / indicated. If multiple PRACH transmissions are determined in the RA procedure (in the initial RACH attempt within that RA procedure), powerRampingStep-MultiPRACH can also be applied to that RA procedure.

[0724] <<Implementation Method 3-3>>

[0725] The maximum value of the preamble transmission counter (the maximum number of random access preamble transmissions) in this case can also follow the settings / instructions below.

[0726] - The maximum number of random access preamble transmissions (preambleTransMax) can be set / indicated individually for both multiple PRACH transmissions and a single PRACH transmission. For RA procedures using multiple PRACH transmissions (RA procedures where multiple PRACH transmissions are determined in the initial RACH attempt within that RA procedure), the maximum number of random access preamble transmissions (limited) set / indicated for multiple PRACH transmissions can also be applied. For example, for RA procedures using multiple PRACH transmissions (different from the RRC IE for RA procedures using a single PRACH transmission), RRC IEpreambleTransMax-MultiPRACH can also be set / indicated. If multiple PRACH transmissions are determined in the RA procedure (in the initial RACH attempt within that RA procedure), preambleTransMax-MultiPRACH can also be applied to that RA procedure.

[0727] According to this implementation, when multiple PRACH transmissions are determined for the initial RACH attempt, and the number of PRACH transmissions is not necessarily maintained in the RACH retry, the UE can appropriately perform at least one of SSB / CSI-RS selection, power ramp-up, and preamble transmission counter for more than one RACH attempt within the RA process.

[0728] <Supplement>

[0729] [Information notification to UE]

[0730] In the above embodiments, any information (e.g., notification from the base station (BS) to the UE) (in other words, the reception of any information from the BS in the UE) can also be delivered using physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), specific signals / channels (e.g., PDCCH, PDSCH, reference signals), or combinations thereof.

[0731] When the above notification is made via MAC CE, the MAC CE can also be identified by including a new Logical Channel ID (LCID) in the MAC sub-header that is not specified in the existing standard.

[0732] When the above notification is made by a DCI, the notification can also be made through specific fields of the DCI, the Radio Network Temporary Identifier (RNTI) used in the scrambling of the Cyclic Redundancy Check (CRC) bits assigned to the DCI, the format of the DCI, etc.

[0733] Furthermore, the notification of any information to the UE in the above embodiments can also be performed periodically, semi-persistently, or non-periodically.

[0734] [Notification from UE]

[0735] In the above embodiments, any information notification from the UE (to the NW) (in other words, the transmission / reporting of any information in the UE to the BS) can also be performed using physical layer signaling (e.g., UCI), higher layer signaling (e.g., RRC signaling, MAC CE), specific signals / channels (e.g., PUCCH, PUSCH, PRACH, reference signals), or combinations thereof.

[0736] In the case of notification by a MAC CE, the MAC CE can also be identified by including a new LCID in the MAC sub-header that is not specified in the existing standard.

[0737] When the above notification is made by the UCI, the notification may also be sent using PUCCH or PUSCH.

[0738] Furthermore, notifications of any information from the UE in the above embodiments can also be performed periodically, semi-persistently, or non-periodically.

[0739] [Regarding the application of each implementation method]

[0740] At least one of the above-described implementation methods can also be applied under certain conditions. These specific conditions can be specified in the standard or notified to the UE / BS using higher-layer signaling / physical-layer signaling.

[0741] At least one of the above-described embodiments can be applied to at least one of the following random access (RA) systems, or it can be limited to only at least one of the following RA systems.

[0742] · CBRA.

[0743] CFRA.

[0744] • The RA who was ordered to PDCCH.

[0745] • RA used for system information acquisition (SI acquisition).

[0746] At least one of the above-described implementation methods may also be applied only to UEs that have reported a specific UE capability or support that specific UE capability.

[0747] This specific UE capability can also represent at least one of the following:

[0748] • Supports at least one specific processing / operation / control / information related to the above implementation.

[0749] • Supports changing (increasing / decreasing) the number of PRACH transmissions within a single RA procedure.

[0750] • Supports SSB / CSI-RS selection that takes into account the RSRP threshold indicated / set for determining the amount of PRACH transmissions.

[0751] • Supports dedicated power increment step sizes for different numbers of RA processes sent using PRACH within a single RACH attempt.

[0752] • For RA procedures that use multiple PRACHs to transmit within each RACH attempt and for RA procedures that use a single PRACH to transmit within each RACH attempt, dedicated power ramp-up step sizes are supported.

[0753] • Supports a maximum number of dedicated preamble transmission counters for different numbers of RA procedures sent using PRACH within a single RACH attempt.

[0754] • For RA procedures that use multiple PRACH transmissions within each RACH attempt and RA procedures that use a single PRACH transmission within each RACH attempt, a dedicated preamble transmission counter is supported for a maximum number of times.

[0755] Furthermore, the aforementioned specific UE capabilities can be applied across the entire frequency range (commonly independent of frequency), or per frequency (e.g., one or a combination of cells, bands, band combinations, BWPs, component carriers, etc.), or per frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), or per subcarrier spacing (SCS), or per feature set (FS) or per CC feature set (FSPS).

[0756] Furthermore, the aforementioned specific UE capabilities can be either capabilities that are applied in all duplex modes (common regardless of the duplex mode) or capabilities that are applicable to each duplex mode (e.g., Time Division Duplex (TDD) and Frequency Division Duplex (FDD)).

[0757] Furthermore, at least one of the above embodiments can also be applied when the UE is set / activated / triggered by specific information associated with the above embodiments (or performs the operation of the above embodiments) via higher-layer signaling / physical layer signaling. For example, the specific information may be information indicating activation of at least one operation of the above embodiments, arbitrary RRC parameters for a specific version (e.g., Rel. 18 / 19), etc.

[0758] In Rel.YY (for example, YY is 18 or higher), the RRC parameter of the activation operation XXX can also be represented as XXX_rYY (XXX-rYY).

[0759] Even if at least one of the specific UE capabilities mentioned above is not supported or the specific information mentioned above is not set, the UE may still apply the operation of Rel.15 / 16, for example.

[0760] (Postscript)

[0761] With respect to one embodiment of this disclosure, the following invention is noted.

[0762] [Appendix 1]

[0763] The terminal has:

[0764] The receiving unit receives one or more first reference signals; and

[0765] The control unit determines, based on the received power of one or more first reference signals, at least one of the following: whether to perform a single random access channel transmission or multiple random channel transmissions in an attempt to transmit via a random access channel, and the number of random access channel transmissions in the attempt; and, in the event that the attempt fails, selects a third reference signal for determining the resources to be used for retrying based on the received power of one or more second reference signals and the determination.

[0766] [Appendix 2]

[0767] The terminal described in Appendix 1,

[0768] In the first attempt, the control unit decides to perform a single random access channel transmission. If the first attempt fails, the control unit decides to perform a single random access channel transmission in the second attempt, prioritizing a reference signal within the receive power range corresponding to the single random access channel transmission, and selecting the third reference signal from the more than one second reference signal.

[0769] [Appendix 3]

[0770] The terminal described in Appendix 1 or Appendix 2,

[0771] In the attempt, it is decided to perform multiple random access channel transmissions, and if the attempt fails, the control unit decides to perform multiple random access channel transmissions in the re-attempt, the same number of random access channel transmissions as the number of random access channel transmissions in the attempt, prioritizing a reference signal in the receive power range corresponding to the number of random access channel transmissions in the attempt, or a reference signal in the receive power range corresponding to a number less than the number of random access channel transmissions in the attempt, and selects the third reference signal.

[0772] [Appendix 4]

[0773] The terminal described in any one of Appendix 1 to Appendix 3,

[0774] In the attempt, it is decided to perform multiple random access channel transmissions, and if the attempt fails, the control unit determines the number of random access channel transmissions to be performed in the re-attempt, and the number of random access channel transmissions in the re-attempt, prioritizing a reference signal that is in the receive power range corresponding to the number of random access channel transmissions in the attempt, or a reference signal that is in the receive power range corresponding to a number less than the number of random access channel transmissions in the attempt, and selects the third reference signal.

[0775] (Postscript)

[0776] With respect to one embodiment of this disclosure, the following invention is noted.

[0777] [Appendix 1]

[0778] The terminal has:

[0779] The receiving unit receives one or more first reference signals; and

[0780] The control unit, based on the received power of the one or more first reference signals, determines at least one of the following in an attempt to transmit via a random access channel: whether to transmit via a single random access channel or multiple random access channels, and the number of random access channel transmissions in the attempt. If the attempt fails, the control unit determines at least one of the following based on the decision: the transmission power for a subsequent attempt and the maximum number of random access channel transmissions.

[0781] [Appendix 2]

[0782] The terminal described in Appendix 1,

[0783] In the first attempt, the control unit decides to perform a single random access channel transmission. If the first attempt fails, the control unit decides to perform a single random access channel transmission in the second attempt. Based on the received power of the more than one second reference signal, the control unit selects a third reference signal for determining the resources for the second attempt. The control unit then determines the transmission power for the second attempt based on the received power threshold for determining the number of random access channel transmissions, the received power of the third reference signal, and the transmission power of the first attempt.

[0784] [Appendix 3]

[0785] The terminal described in Appendix 1 or Appendix 2,

[0786] In the initial attempt, the control unit decides to perform multiple random access channel transmissions. If the initial attempt fails, the control unit decides to perform multiple random access channel transmissions in the retry, the same number as the number of random access channel transmissions in the initial attempt. Based on the received power of the more than one second reference signal, a third reference signal is selected for determining the resources for the retry. The transmission power of the retry is determined based on the received power threshold for determining the number of random access channel transmissions, the received power of the third reference signal, and the transmission power of the initial attempt.

[0787] [Appendix 4]

[0788] The terminal described in any one of Appendix 1 to Appendix 3,

[0789] In the initial attempt, the control unit decides to perform multiple random access channel transmissions. If the initial attempt fails, the control unit determines the number of random access channel transmissions to be performed in the re-attempt, as well as the number of random access channel transmissions in the re-attempt, and determines the transmission power of the re-attempt based on the number of random access channel transmissions in the re-attempt and the transmission power of the initial attempt.

[0790] (Wireless communication system)

[0791] The structure of a wireless communication system according to one embodiment of this disclosure will now be described. In this wireless communication system, communication is performed using any one or a combination of the wireless communication methods according to the above embodiments of this disclosure.

[0792] Figure 19 This is a diagram illustrating an example of the schematic structure of a wireless communication system according to one embodiment. The wireless communication system 1 (also referred to simply as System 1) may also be a system that uses Long Term Evolution (LTE) or 5th generation mobile communication system New Radio (5GNR) as standardized by the Third Generation Partnership Project (3GPP).

[0793] Furthermore, the wireless communication system 1 can also support dual connectivity between multiple radio access technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC can also include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

[0794] In EN-DC, the LTE (E-UTRA) base station (eNB) is the Master Node (MN), and the NR base station (gNB) is the Secondary Node (SN). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0795] Wireless communication system 1 can also support dual connectivity between multiple base stations within the same RAT (e.g., MN and SN are dual connectivity between NR base stations (gNB) (NR-NR Dual Connectivity (NN-DC))).

[0796] The wireless communication system 1 may also include: a base station 11 forming a macro cell C1 with a relatively wide coverage area; and a base station 12 (12a-12c) configured within the macro cell C1 and forming a small cell C2 narrower than the macro cell C1. The user terminal 20 may also be located within at least one cell. The configuration and number of each cell and the user terminal 20 are not limited to the arrangement shown in the figure. Hereinafter, without distinguishing between base stations 11 and 12, they will be collectively referred to as base station 10.

[0797] User terminal 20 may also connect to at least one of multiple base stations 10. User terminal 20 may also utilize at least one of carrier aggregation (CA) using multiple component carriers (CC) and dual connectivity (DC).

[0798] Each CC can also be included in at least one of the first frequency band (Frequency Range 1 (FR1)) and the second frequency band (Frequency Range 2 (FR2)). Macro cell C1 can also be included in FR1, and small cell C2 can also be included in FR2. For example, FR1 can also be a frequency band below 6 GHz (sub-6 GHz), and FR2 can also be a frequency band above 24 GHz (above-24 GHz). In addition, the frequency bands, definitions, etc. of FR1 and FR2 are not limited to these; for example, FR1 can also be equivalent to a frequency band higher than FR2.

[0799] In addition, in each CC, the user terminal 20 may also use at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) for communication.

[0800] Multiple base stations 10 can also be connected via wired (e.g., fiber optic, X2 interface, etc. based on Common Public Radio Interface (CPRI)) or wireless (e.g., NR communication). For example, when NR communication between base stations 11 and 12 is used as a backhaul, base station 11, which is equivalent to a host station, can also be referred to as an Integrated Access Backhaul (IAB) donor, and base station 12, which is equivalent to a relay station, can also be referred to as an IAB node.

[0801] Base station 10 may also be connected to core network 30 via other base stations 10 or directly. Core network 30 may include, for example, at least one of Evolved Packet Core (EPC), 5G Core Network (5GCN), Next Generation Core (NGC), etc.

[0802] The core network 30 may also include, for example, network functions (NFs) such as User Plane Function (UPF), Access and Mobility Management Function (AMF), Session Management Function (SMF), Unified Data Management (UDM), Application Function (AF), Data Network (DN), Location Management Function (LMF), and Operation, Administration and Maintenance (Management) (OAM). Alternatively, multiple functions can be provided through a single network node. Furthermore, communication with external networks (e.g., the Internet) can also be achieved via the DN.

[0803] User terminal 20 can also be at least one terminal that supports communication methods such as LTE, LTE-A, and 5G.

[0804] In wireless communication system 1, wireless access methods based on Orthogonal Frequency Division Multiplexing (OFDM) can also be used. For example, in at least one of the downlink (DL) and uplink (UL) links, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), and Single Carrier Frequency Division Multiple Access (SC-FDMA) can also be used.

[0805] The wireless access method can also be referred to as a waveform. In addition, in the wireless communication system 1, other wireless access methods (e.g., other single-carrier transmission methods, other multi-carrier transmission methods) can also be used in the wireless access methods of UL and DL.

[0806] As a downlink channel, the wireless communication system 1 can also use downlink shared channels (Physical Downlink Shared Channel (PDSCH)), broadcast channels (Physical Broadcast Channel (PBCH)), downlink control channels (Physical Downlink Control Channel (PDCCH)) and so on, which are shared among the user terminals 20.

[0807] In addition, as uplink channels, the wireless communication system 1 may also use uplink shared channels (Physical Uplink Shared Channel (PUSCH)), uplink control channels (Physical Uplink Control Channel (PUCCH)), random access channels (Physical Random Access Channel (PRACH)) and so on, which are shared by each user terminal 20.

[0808] User data, high-level control information, and System Information Blocks (SIBs) are transmitted via the PDSCH. User data and high-level control information can also be transmitted via the PUSCH. In addition, the Master Information Block (MIB) can also be transmitted via the PBCH.

[0809] Lower-layer control information can also be transmitted via PDCCH. Lower-layer control information may include, for example, downlink control information (DCI), which includes scheduling information for at least one of PDSCH and PUSCH.

[0810] Additionally, the DCI that schedules PDSCH can also be called DL allocation, DL DCI, etc., and the DCI that schedules PUSCH can also be called UL authorization, UL DCI, etc. Furthermore, PDSCH can be rewritten as DL data, and PUSCH can be rewritten as UL data.

[0811] In PDCCH detection, a Control Resource Set (CORESET) and a search space can also be utilized. A CORESET corresponds to the resources used to search for DCIs. The search space corresponds to the search area and search method for PDCCH candidates. A CORESET can also be associated with one or more search spaces. The UE can also monitor CORESETs associated with a specific search space based on search space settings.

[0812] A search space can also correspond to a PDCCH candidate corresponding to one or more aggregation levels. One or more search spaces can also be referred to as a search space set. In addition, the terms "search space", "search space set", "search space setting", "search space set setting", "CORESET", and "CORESET setting" in this disclosure can be rewritten interchangeably.

[0813] At least one uplink control message (uplink control information (UCI)) containing channel state information (CSI), delivery confirmation information (such as Hybrid Automatic Repeat reQuest ACK knowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR) can also be transmitted via PUCCH. The random access preamble used to establish a connection with the cell can also be transmitted via PRACH.

[0814] In addition, in this disclosure, downlink, uplink, etc., may be described without the word "link". Furthermore, various channels may be described without the word "physical".

[0815] In wireless communication system 1, synchronization signals (SS) and downlink reference signals (DL-RS) can also be transmitted. As DL-RS, wireless communication system 1 can also transmit cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), positioning reference signals (PRS), phase tracking reference signals (PTRS), etc.

[0816] Synchronization signals can be, for example, at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). A signal block containing SS (PSS, SSS) and PBCH (and DMRS for PBCH) can also be called an SS / PBCH block, SS block (SSB), etc. In addition, SS, SSB, etc. can also be called reference signals.

[0817] Furthermore, as an uplink reference signal (UL-RS), measurement reference signals (sounding reference signals (SRS)) and demodulation reference signals (DMRS) can also be transmitted in the wireless communication system 1. Additionally, DMRS can also be referred to as a user terminal-specific reference signal (UE-specific reference signal).

[0818] (Base station)

[0819] Figure 20 This diagram illustrates an example of the structure of a base station according to one embodiment. The base station 10 includes a control unit 110, a transmit / receive unit 120, a transmit / receive antenna 130, and a transmission path interface (transmission line interface) 140. Alternatively, the control unit 110, the transmit / receive unit 120, the transmit / receive antenna 130, and the transmission path interface 140 may each be provided in more than one manner.

[0820] Furthermore, in this example, only the functional blocks of the characteristic parts of this embodiment are shown. It can also be imagined that the base station 10 also has other functional blocks required for wireless communication. Some of the processing of each unit described below can also be omitted.

[0821] The control unit 110 performs overall control of the base station 10. The control unit 110 can be composed of a controller, control circuit, etc., which are described based on common knowledge in the art to which this disclosure pertains.

[0822] The control unit 110 can also control signal generation and scheduling (e.g., resource allocation, mapping). The control unit 110 can also control transmission, reception, and measurement using the transmit / receive unit 120, transmit / receive antenna 130, and transmission path interface 140. The control unit 110 can also generate data, control information, sequences, etc., to be transmitted as signals and forward them to the transmit / receive unit 120. The control unit 110 can also perform call processing (setting, releasing, etc.) of the communication channel, status management of the base station 10, and management of wireless resources.

[0823] The transmitting / receiving unit 120 may also include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may also include a transmitting processing unit 1211 and a receiving processing unit 1212. The transmitting / receiving unit 120 may be composed of transmitters / receivers, RF circuits, baseband circuits, filters, phase shifters, measurement circuits, transmitting / receiving circuits, etc., as described based on common knowledge in the art to which this disclosure pertains.

[0824] The transmitting and receiving unit 120 can be configured as a single integrated transmitting and receiving unit, or it can be composed of a transmitting unit and a receiving unit. The transmitting unit can also be composed of a transmitting processing unit 1211 and an RF unit 122. The receiving unit can also be composed of a receiving processing unit 1212, an RF unit 122, and a measurement unit 123.

[0825] The transmitting and receiving antenna 130 can be constructed from an antenna, such as an array antenna, as described based on common knowledge in the art to which this disclosure pertains.

[0826] The transmitting / receiving unit 120 can also transmit the aforementioned downlink channel, synchronization signal, downlink reference signal, etc. The transmitting / receiving unit 120 can also receive the aforementioned uplink channel, uplink reference signal, etc.

[0827] The transmitting and receiving unit 120 may also use digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc., to form at least one of the transmitting beam and the receiving beam.

[0828] The transmitting and receiving unit 120 (transmitting processing unit 1211) can also perform processing at the Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer (e.g., RLC retransmission control), and Medium Access Control (MAC) layer (e.g., HARQ retransmission control) on data and control information obtained from the control unit 110, and generate a bit string to be transmitted.

[0829] The transmitting and receiving unit 120 (transmitting processing unit 1211) can also perform transmission processing such as channel coding (which may also include error correction coding), modulation, mapping, filter processing (filtering processing), Discrete Fourier Transform (DFT) processing (as needed), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output the baseband signal.

[0830] For baseband signals, the transmitting and receiving unit 120 (RF unit 122) can also perform modulation, filtering, amplification, etc., to the wireless frequency band, and transmit the wireless frequency band signals through the transmitting and receiving antenna 130.

[0831] On the other hand, the transmitting and receiving unit 120 (RF unit 122) can also amplify, filter, and demodulate the baseband signal for the wireless frequency band signal received by the transmitting and receiving antenna 130.

[0832] The transmitting and receiving unit 120 (receiving and processing unit 1212) can also perform receiving and processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (as needed), filter processing, demapping, demodulation, decoding (which may also include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing on the acquired baseband signal, and acquire user data, etc.

[0833] The transmitting / receiving unit 120 (measurement unit 123) can also perform measurements related to the received signal. For example, the measurement unit 123 can also perform radio resource management (RRM) measurements, channel state information (CSI) measurements, etc., based on the received signal. The measurement unit 123 can also measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results can also be output to the control unit 110.

[0834] The transmission path interface 140 can also transmit and receive signals (backhaul signaling) between the device included in the core network 30 (e.g., the network node providing the NF), other base stations 10, etc., and can also acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0835] In addition, the transmitting unit and receiving unit of the base station 10 in this disclosure may also be composed of at least one of a transmitting / receiving unit 120, a transmitting / receiving antenna 130, and a transmission path interface 140.

[0836] The transmit / receive unit 120 may also transmit more than one first reference signal. The control unit 110 may also control the reception of a retry if a random access channel transmission attempt fails. Alternatively, based on the received power of the more than one first reference signal, at least one of the following may be determined: whether a single random access channel transmission or multiple random channel transmissions are performed in the attempt, and the number of random access channel transmissions in the attempt. Alternatively, in the event of a failed attempt, a third reference signal may be selected based on the received power of more than one second reference signal and the determination made therein, for determining the resources used in the retry.

[0837] The transmit / receive unit 120 may also transmit more than one first reference signal. The control unit 110 may also control a retry reception if a random access channel transmission attempt fails. Alternatively, based on the received power of the one or more first reference signals, at least one of the following may be determined: whether a single random access channel transmission or multiple random channel transmissions are performed in the attempt, and the number of random access channel transmissions in the attempt. Alternatively, in the event of a failed attempt, based on the determination, at least one of the retry transmission power and the maximum number of random access channel transmissions is determined.

[0838] (User terminal)

[0839] Figure 21 This diagram illustrates an example of the structure of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transmitting / receiving unit 220, and a transmitting / receiving antenna 230. Alternatively, the control unit 210, the transmitting / receiving unit 220, and the transmitting / receiving antenna 230 may each be provided as one or more.

[0840] Furthermore, while this example primarily illustrates the functional blocks of the characteristic portions of this embodiment, it is also conceivable that the user terminal 20 may also have other functional blocks required for wireless communication. Some of the processing of each unit described below may also be omitted.

[0841] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be composed of a controller, control circuit, etc., which are described based on common knowledge in the technical field to which this disclosure pertains.

[0842] The control unit 210 can also control signal generation, mapping, etc. The control unit 210 can also control transmission, reception, measurement, etc., using the transmission / reception unit 220 and the transmission / reception antenna 230. The control unit 210 can also generate data, control information, sequences, etc., to be transmitted as signals and forward them to the transmission / reception unit 220.

[0843] The transmitting / receiving unit 220 may also include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may also include a transmitting processing unit 2211 and a receiving processing unit 2212. The transmitting / receiving unit 220 may be composed of transmitters / receivers, RF circuits, baseband circuits, filters, phase shifters, measurement circuits, transmitting / receiving circuits, etc., as described based on common knowledge in the art to which this disclosure pertains.

[0844] The transmitting and receiving unit 220 can be configured as a single integrated transmitting and receiving unit, or it can be composed of a transmitting unit and a receiving unit. The transmitting unit can also be composed of a transmitting processing unit 2211 and an RF unit 222. The receiving unit can also be composed of a receiving processing unit 2212, an RF unit 222, and a measurement unit 223.

[0845] The transmitting and receiving antenna 230 can be constructed from an antenna, such as an array antenna, as described based on common knowledge in the art to which this disclosure pertains.

[0846] The transmitting / receiving unit 220 can also receive the downlink channel, synchronization signal, downlink reference signal, etc., mentioned above. The transmitting / receiving unit 220 can also transmit the uplink channel, uplink reference signal, etc., mentioned above.

[0847] The transmitting and receiving unit 220 may also use digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc. to form at least one of the transmitting beam and the receiving beam.

[0848] For example, the transmitting and receiving unit 220 (transmitting processing unit 2211) can also perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control) on data and control information obtained from the control unit 210, and generate the bit string to be transmitted.

[0849] For the bit string to be transmitted, the transmitting and receiving unit 220 (transmission processing unit 2211) can also perform channel coding (which may include error correction coding), modulation, mapping, filter processing (filtering processing), DFT processing (as needed), IFFT processing, precoding, digital-to-analog conversion and other transmission processing, and output the baseband signal.

[0850] Furthermore, the decision to apply DFT processing can be based on the transform precoding settings. For a specific channel (e.g., PUSCH), if transform precoding is enabled, the transmit / receive unit 220 (transmit processing unit 2211) can perform DFT processing as described above for transmitting the channel using the DFT-s-OFDM waveform; otherwise, the transmit / receive unit 220 (transmit processing unit 2211) can perform DFT processing as described above for transmitting the channel without performing DFT processing.

[0851] For baseband signals, the transmitting and receiving unit 220 (RF unit 222) can also perform modulation, filtering (filtering), amplification, etc., to the wireless frequency band, and transmit the wireless frequency band signals through the transmitting and receiving antenna 230.

[0852] On the other hand, the transmitting and receiving unit 220 (RF unit 222) can also amplify, filter (filter processing), demodulate baseband signals, etc., for the wireless frequency band signals received by the transmitting and receiving antenna 230.

[0853] For the acquired baseband signal, the transmitting and receiving unit 220 (receiving and processing unit 2212) can also perform receiving and processing such as analog-to-digital conversion, FFT processing, IDFT processing (as needed), filter processing, demapping, demodulation, decoding (which may also include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing, and acquire user data.

[0854] The transmitting / receiving unit 220 (measurement unit 223) can also perform measurements related to the received signal. For example, the measurement unit 223 can also perform RRM measurements, CSI measurements, etc., based on the received signal. The measurement unit 223 can also measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results can also be output to the control unit 210.

[0855] Additionally, the measurement unit 223 can also derive channel measurements for CSI calculation based on channel measurement resources. Channel measurement resources can be, for example, non-zero power (NZP) CSI-RS resources. Furthermore, the measurement unit 223 can also derive interference measurements for CSI calculation based on interference measurement resources. Interference measurement resources can be at least one of NZP CSI-RS resources for interference measurement, CSI-Interference Measurement (IM) resources, etc. Additionally, CSI-IM can also be referred to as CSI-Interference Management (IM), and can be interchanged with zero power (ZP) CSI-RS. Furthermore, in this disclosure, CSI-RS, NZPCSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc., can also be interchanged.

[0856] Alternatively, the transmitting and receiving units of the user terminal 20 in this disclosure may also be composed of at least one transmitting / receiving unit 220 and transmitting / receiving antenna 230.

[0857] The transmit / receive unit 220 may also receive more than one first reference signal (e.g., more than one SSB / CSI-RS for determining resources for the initial RACH attempt). The control unit 210 may also determine, based on the received power (e.g., RSRP) of the more than one first reference signal, whether to perform a single random access channel transmission or multiple random channel transmissions in the random access channel transmission attempt (e.g., the initial RACH attempt), and at least one of the number of random access channel transmissions in the attempt, and in the event that the attempt fails, select a third reference signal (e.g., the SSB / CSI-RS selected in the retry) for determining resources for the retry based on the received power of more than one second reference signal (e.g., more than one SSB / CSI-RS for determining resources for the RACH retry) and the decision.

[0858] Alternatively, in the attempt, the control unit 210 decides to perform a single random access channel transmission, and if the attempt fails, the control unit 210 decides to perform a single random access channel transmission in the re-attempt, prioritizing a reference signal that is within the received power range corresponding to the single random access channel transmission (e.g., whether it exceeds a specific RSRP threshold, SSB / CSI-RS set), and selecting the third reference signal from the more than one second reference signal.

[0859] Alternatively, in the attempt, it is decided to perform multiple random access channel transmissions, and if the attempt fails, the control unit 210 decides to perform multiple random access channel transmissions in the re-attempt, equal to the number of random access channel transmissions in the attempt, prioritizing a reference signal in the receive power range corresponding to the number of random access channel transmissions in the attempt, or a reference signal in the receive power range corresponding to a number less than the number of random access channel transmissions in the attempt, and selecting the third reference signal.

[0860] Alternatively, in the attempt, it is decided to perform multiple random access channel transmissions, and if the attempt fails, the control unit 210 determines the number of random access channel transmissions to be performed in the re-attempt, prioritizing a reference signal within the receive power range corresponding to the number of random access channel transmissions in the attempt, or a reference signal within the receive power range corresponding to a number less than the number of random access channel transmissions in the attempt, and selects the third reference signal.

[0861] The transmitting / receiving unit 220 may also receive more than one first reference signal. The control unit 210 may also determine, based on the received power of the more than one first reference signal, whether to perform a single random access channel transmission or multiple random channel transmissions in a random access channel transmission attempt, and the number of random access channel transmissions in the attempt, at least one of these, and if the attempt fails, based on the decision, to determine at least one of the transmission power (e.g., power escalation) for a subsequent attempt and the maximum number of random access channel transmissions.

[0862] Alternatively, in the attempt, the control unit 210 decides to perform a single random access channel transmission, and if the attempt fails, the control unit 210 decides to perform a single random access channel transmission in the retry, and selects a third reference signal for determining the resources for the retry based on the received power of the more than one second reference signal, and determines the transmission power of the retry based on the received power threshold for determining the number of random access channel transmissions, the received power of the third reference signal, and the transmission power of the attempt.

[0863] Alternatively, in the attempt, it is decided to perform multiple random access channel transmissions, and if the attempt fails, the control unit 210 decides to perform multiple random access channel transmissions in the retry, the same number as the number of random access channel transmissions in the attempt, selects a third reference signal for determining the resources for the retry based on the received power of the more than one second reference signal, and determines the transmission power of the retry based on the received power threshold for determining the number of random access channel transmissions, the received power of the third reference signal, and the transmission power of the attempt.

[0864] Alternatively, in the attempt, it is decided to perform multiple random access channel transmissions, and if the attempt fails, the control unit 210 determines the number of random access channel transmissions to be performed in the re-attempt, the number of random access channel transmissions in the re-attempt, and the transmission power of the re-attempt based on the number of random access channel transmissions in the re-attempt and the transmission power of the attempt.

[0865] (Hardware structure)

[0866] Furthermore, the block diagrams used in the description of the above embodiments illustrate functional units. These functional blocks (structural units) are implemented through any combination of at least one of hardware and software. Moreover, the implementation method of each functional block is not particularly limited. That is, each functional block can be implemented using a single device that is physically or logically combined, or it can be implemented by directly or indirectly (e.g., using wired, wireless, etc.) connecting two or more physically or logically separate devices. A functional block can also be implemented by combining the aforementioned single device or multiple devices with software.

[0867] Here, the functions include judgment, decision, determination, calculation, calculation, processing, export, investigation, search, confirmation, receiving, sending, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, regard as, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning, but are not limited to these. For example, a functional block (structural unit) that implements the sending function can also be called a transmitting unit, transmitter, etc. Each of these, as described above, is not particularly limited in its implementation method.

[0868] For example, in one embodiment of this disclosure, the base station, user terminal, etc., can also function as a computer for processing the wireless communication method of this disclosure. Figure 22 This diagram illustrates an example of the hardware structure of a base station and a user terminal according to one embodiment. The base station 10 and the user terminal 20 described above can also be physically configured as a computer device including a processor 1001, a memory 1002, a storage device 1003, a communication device 1004, an input device 1005, an output device 1006, and a bus 1007.

[0869] Furthermore, in this disclosure, terms such as apparatus, circuit, device, section, and unit can be interchanged. The hardware structure of base station 10 and user terminal 20 can be configured to include one or more of the apparatuses shown in the figures, or it can be configured not to include any of the apparatuses.

[0870] For example, only one processor 1001 is shown, but there can be multiple processors. Furthermore, processing can be performed by one processor, or simultaneously, sequentially, or by two or more processors using other methods. Additionally, processor 1001 can be implemented using more than one chip.

[0871] Regarding the functions in base station 10 and user terminal 20, for example, by reading specific software (programs) into hardware such as processor 1001 and memory 1002, so that processor 1001 performs calculations and controls communication via communication device 1004, or by controlling at least one of reading and writing data in memory 1002 and storage device 1003.

[0872] The processor 1001 enables the operating system to operate and control the computer as a whole. The processor 1001 may also be a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic devices, registers, etc. For example, at least a portion of the control unit 110 (210), the transmit / receive unit 120 (220), etc., described above may also be implemented by the processor 1001.

[0873] 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 performs various processes accordingly. As a program, a program that causes the computer to perform at least a portion of the operations described in the above embodiments can be used. For example, the control unit 110 (210) can also be implemented by a control program stored in the memory 1002 and operated in the processor 1001; similar implementations can be made for other functional blocks.

[0874] The memory 1002 may also be a computer-readable recording medium, such as being composed of at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), or other suitable storage media. The memory 1002 may also be referred to as a register, cache, main memory (main storage device), etc. The memory 1002 is capable of storing executable programs (program code), software modules, etc., for implementing the wireless communication method according to an embodiment of this disclosure.

[0875] Storage device 1003 may also be a computer-readable recording medium, such as a flexible disc, floppy disk, optical disk (e.g., a compact disc ROM), digital multifunction disk, Blu-ray disc, removable disk, hard disk drive, smart card, flash memory device (e.g., a card, stick, key drive), magnetic stripe, database, server, or at least one other suitable storage medium. Storage device 1003 may also be referred to as an auxiliary storage device.

[0876] The communication device 1004 is hardware (transmitting and receiving device) used for communication between computers via at least one of a wired network and a wireless network. It is also referred to as a network device, network controller, network interface card (NIC), communication module, etc. To implement at least one of, for example, Frequency Division Duplex (FDD) and Time Division Duplex (TDD), the communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. For example, the aforementioned transmit / receive unit 120 (220) and transmit / receive antenna 130 (230) may also be implemented by the communication device 1004. The transmit / receive unit 120 (220) may also be implemented by physically or logically separating the transmit unit 120a (220a) and the receive unit 120b (220b).

[0877] Input device 1005 is an input device that receives input from external sources (e.g., keyboard, mouse, microphone, switch, button, sensor, etc.). Output device 1006 is an output device that performs output to external sources (e.g., display, speaker, light-emitting diode (LED) lamp, etc.). Alternatively, input device 1005 and output device 1006 can also be an integrated structure (e.g., a touch panel).

[0878] Furthermore, the processor 1001, memory 1002, and other devices are connected via a bus 1007 for communication of information. The bus 1007 can be configured as a single bus or as different buses between the devices.

[0879] Furthermore, the base station 10 and the user terminal 20 can also be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA), and can also use this hardware to implement part or all of the functional blocks. For example, the processor 1001 can also be implemented using at least one of these hardware components.

[0880] (Modified example)

[0881] Furthermore, the terms described in this disclosure, as well as those necessary for understanding this disclosure, may be replaced with terms that have the same or similar meanings. For example, channel, symbol, and signal (signal or signaling) may be interchanged. Additionally, a signal may also be a message. A reference signal can also be abbreviated as RS, and may be referred to as pilot, pilot signal, etc., depending on the applied standard. Furthermore, a component carrier (CC) may also be referred to as cell, frequency carrier, carrier frequency, etc.

[0882] A radio frame can also be composed of one or more periods (frames) in the time domain. Each of these periods (frames) that constitute a radio frame can also be called a subframe. Furthermore, a subframe can also be composed of one or more time slots in the time domain. A subframe can also be a fixed time length (e.g., 1 ms) independent of the parameter set (numerology).

[0883] Here, the parameter set can also be communication parameters applied in at least one of the transmission and reception of a signal or channel. For example, the parameter set can also represent 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 structure, specific filtering processing performed by the transmitter and receiver in the frequency domain, and specific windowing processing performed by the transmitter and receiver in the time domain.

[0884] In the time domain, a time slot can also be composed of one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.). In addition, a time slot can also be a time unit based on a set of parameters.

[0885] A time slot can also contain multiple mini-time slots. Each mini-time slot can also consist of one or more symbols in the time domain. Furthermore, a mini-time slot can also be called a sub-time slot. A mini-time slot can also consist of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a mini-time slot can also be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using mini-time slots can also be called PDSCH (PUSCH) mapping type B.

[0886] Radio frames, subframes, time slots, mini-time slots, and symbols all represent time units for transmitting signals. Radio frames, subframes, time slots, mini-time slots, and symbols can also use their respective other names. Furthermore, the time units such as frames, subframes, time slots, mini-time slots, and symbols in this disclosure can be interchanged.

[0887] For example, a subframe can also be called a TTI, multiple consecutive subframes can also be called a TTI, and a time slot or a mini-time slot can also be called a TTI. That is, at least one of a subframe and a TTI can be a subframe in existing LTE (1ms), a period shorter than 1ms (e.g., 1-13 symbols), or a period longer than 1ms. In addition, the unit representing TTI may not be called a subframe, but rather a time slot, mini-time slot, etc.

[0888] Here, TTI refers, for example, to the smallest unit of time for scheduling in wireless communication. For instance, in an LTE system, the base station schedules radio resources (frequency bandwidth, transmit power, etc., available to each user terminal) in TTI units. However, the definition of TTI is not limited to this.

[0889] TTI can also be a unit of time for transmitting channel-coded data packets (transmission blocks), code blocks, codewords, etc., and can also be a unit of processing such as scheduling and link adaptation. In addition, when a TTI is given, the actual time interval (e.g., the number of symbols) mapped to transmission blocks, code blocks, codewords, etc. can be shorter than the TTI.

[0890] Additionally, where a time slot or a mini-time slot is referred to as a TTI, more than one TTI (i.e., more than one time slot or more than one mini-time slot) can also serve as the minimum time unit for scheduling. Furthermore, the number of time slots (mini-time slots) constituting the minimum time unit of the schedule can also be controlled.

[0891] A TTI with a duration of 1ms can also be referred to as a normal TTI (TTI in 3GPPRel.8-12), a standard TTI, a long TTI, a normal subframe, a standard subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI can also be referred to as a shortened TTI, a short TTI, a partial TTI (partial or fractional TTI), a shortened subframe, a short subframe, a mini time slot, a sub-time slot, a time slot, etc.

[0892] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) can also be rewritten as a TTI with a duration of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) can also be rewritten as a TTI with a duration of less than a long TTI but more than 1 ms.

[0893] A resource block (RB) is a unit of resource allocation in both the time and frequency domains. In the frequency domain, it can also contain one or more consecutive subcarriers. The number of subcarriers in an RB can be the same regardless of the parameter set, for example, it can be 12. The number of subcarriers in an RB can also be determined based on the parameter set.

[0894] Furthermore, an RB can contain one or more symbols in the time domain, and can also be a time slot, a mini-time slot, a subframe, or the length of a TTI. A TTI, a subframe, etc., can also be composed of one or more resource blocks.

[0895] In addition, one or more RBs can also be referred to as Physical Resource Blocks (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc.

[0896] In addition, a resource block can also consist of one or more resource elements (REs). For example, an RE can also be a radio resource area consisting of a subcarrier and a symbol.

[0897] The Bandwidth Part (BWP) (also referred to as partial bandwidth, etc.) can also represent a subset of consecutive common resource blocks (RBs) used for a certain parameter set in a certain carrier. Here, common RBs can also be determined by the index of RBs based on the common reference point of the carrier. PRBs can also be defined in a BWP and appended with numbers within that BWP.

[0898] A BWP can also include a UL BWP (the BWP used by UL) and a DL BWP (the BWP used by DL). For a UE, one or more BWPs can also be set within a single carrier.

[0899] At least one of the configured BWPs can be active, and the UE may not intend to transmit or receive specific signals / channels outside of the active BWPs. Additionally, terms such as "cell" and "carrier" in this disclosure may be replaced with "BWP".

[0900] Furthermore, the structures described above, such as radio frames, subframes, time slots, mini-time slots, and symbols, are merely illustrative. For example, the number of subframes contained in a radio frame, the number of time slots in each subframe or radio frame, the number of mini-time slots contained within a time slot, the number of symbols and RBs contained in a time slot or mini-time slot, the number of subcarriers contained in an RB, and the number of symbols in a TTI, symbol length, and cyclic prefix (CP) length can be varied in many ways.

[0901] Furthermore, the information, parameters, etc., described in this disclosure can be represented by absolute values, relative values ​​with respect to a specific value, or other corresponding information. For example, wireless resources can also be indicated by a specific index.

[0902] In this disclosure, the names used for parameters, etc., are not limiting names in any respect. Furthermore, the mathematical expressions, etc., using these parameters may differ from those explicitly disclosed in this disclosure. Various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name; therefore, the various names assigned to these various channels and information elements are not limiting names in any respect.

[0903] The information, signals, etc., described in this disclosure can also be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc., which may be mentioned throughout the above description, can also be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

[0904] Furthermore, information, signals, etc., can be output in at least one of the following directions: from higher level (upper layer) to lower level (lower layer), and from lower layer to higher level. Information, signals, etc., can also be input and output via multiple network nodes.

[0905] Input and output information, signals, etc., can be stored in a specific location (e.g., memory) or managed using a management table. Input and output information, signals, etc., can be overwritten, updated, or appended. Output information, signals, etc., can also be deleted. Input information, signals, etc., can also be sent to other devices.

[0906] The notification of information is not limited to the methods / implementations described in this disclosure, and may also be carried out by other methods. For example, the notification of information in this disclosure may also be implemented by physical layer signaling (e.g., downlink control information (DCI), uplink control information (UCI), etc.), higher layer signaling (e.g., radio resource control (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB) etc.), medium access control (MAC) signaling), other signals, or combinations thereof.

[0907] In addition, physical layer signaling can also be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signals), L1 control information (L1 control signals), etc. Furthermore, RRC signaling can also be referred to as RRC messages, such as RRC connection setup messages, RRC connection reconfiguration messages, etc. Additionally, MAC signaling can also be notified using, for example, the MAC control element (CE).

[0908] Furthermore, notification of specific information (e.g., a notification of “is X”) is not limited to explicit notification, but can also be implicit (e.g., by not providing that specific information, or by providing other information).

[0909] The determination can be made by a value represented by a single bit (0 or 1), by a true or false value (boolean), or by a numerical comparison (e.g., a comparison with a specific value).

[0910] Whether software is called software, firmware, middleware, microcode, hardware description language, or any other name, it should be broadly interpreted to refer to 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.

[0911] Furthermore, software, instructions, and information can also be sent and received via a transmission medium. For example, when software is sent from a website, server, or other remote source using at least one of wired technologies (coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL) etc.) and wireless technologies (infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0912] The terms “system” and “network” as used in this disclosure are interchangeable. “Network” may also mean devices included in a network (e.g., base stations).

[0913] In this disclosure, the terms “precoding”, “precoder”, “weight (precoding weight)”, “quasi-co-location (QCL)”, “transmission configuration indication state (TCI state)”, “spatial relation”, “spatial domain filter”, “transmit power”, “phase rotation”, “antenna port”, “layer”, “number of layers”, “rank”, “resource”, “resource set”, “beam”, “beamwidth”, “beam angle”, “antenna”, “antenna element”, “panel”, “UE panel”, “transmitting entity”, and “receiving entity” are used interchangeably.

[0914] Furthermore, in this disclosure, the antenna port can also be rewritten with an antenna port used for any signal / channel (e.g., a DeModulation Reference Signal (DMRS) port). In this disclosure, the resources can also be rewritten with resources used for any signal / channel (e.g., reference signal resources, SRS resources, etc.). Additionally, the resources may also include time / frequency / code / space / power resources. Moreover, the spatial domain transmission filter may include at least one of a spatial domain transmission filter and a spatial domain reception filter.

[0915] The aforementioned groups may include, for example, at least one of the following: spatial relation group, code division multiplexing (CDM) group, reference signal (RS) group, control resource set (CORESET) group, PUCCH group, antenna port group (e.g., DMRS port group), layer group, resource group, beam group, antenna group, panel group, etc.

[0916] Furthermore, in this disclosure, beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, Codeword (CW), Transport Block (TB), RS, etc., can also be rewritten to each other.

[0917] Furthermore, in this disclosure, the TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, and joint TCI state can also be rewritten to each other.

[0918] Furthermore, in this disclosure, terms such as "QCL", "QCL concept", "QCL relationship", "QCL type information", "QCL property (QCLproperty / properties)", "specific QCL type (e.g., type A, type D) property", and "specific QCL type (e.g., type A, type D)" can be rewritten interchangeably.

[0919] In this disclosure, indexes, identifiers (IDs), indicators, indications, resource IDs, etc., can be interchanged. Sequences, lists, sets, groups, clusters, subsets, etc., can also be interchanged.

[0920] Furthermore, the spatial relationship information Identifier (ID) (TCI state ID) and spatial relationship information (TCI state) can be interchanged. "Spatial relationship information (TCI state)" can also be interchanged with "a set of spatial relationship information (TCI states)," "one or more spatial relationship information," etc. TCI state and TCI can also be interchanged. Spatial relationship information and spatial relationships can also be interchanged.

[0921] In this disclosure, the terms "Base Station (BS)", "Wireless Base Station", "Fixed Station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "Access Point", "Transmission Point (TP)", "Reception Point (RP)", "Transmission / Reception Point (TRP)", "Panel", "Cell", "Sector", "Cell Group", "Carrier", and "Component Carrier" are used interchangeably. There are also instances where the terms macro cell, small cell, femtocell, and picocell are used to refer to a base station.

[0922] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, its overall coverage area can be divided into several smaller areas, each of which can also provide communication services through a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). Terms such as "cell" or "sector" refer to a portion or all of the coverage area of ​​at least one of the base station and base station subsystem providing communication services within that coverage area.

[0923] In this disclosure, the act of a base station sending information to a terminal can also be rewritten in relation to the act of the base station instructing the terminal to perform control / operation based on that information.

[0924] In this disclosure, the terms “Mobile Station (MS)”, “user terminal”, “user equipment (UE)”, and “terminal” are used interchangeably.

[0925] There are also instances where mobile stations are referred to as subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals, handsets, user agents, mobile clients, clients, or several other appropriate terms.

[0926] At least one of the base station and the mobile station can also be referred to as a transmitting device, a receiving device, a wireless communication device, etc. Additionally, at least one of the base station and the mobile station can also be a device mounted on a moving object, the moving object itself, etc.

[0927] The term "mobile body" refers to a movable object whose speed is arbitrary, including situations where the body is stationary. Examples of such mobile bodies include vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships (ships and other watercraft), airplanes, rockets, artificial satellites, drones, multicopters, quadcopters, hot air balloons, and objects carried on them, but are not limited to these. Furthermore, the mobile body can also be a mobile body that moves autonomously based on operational commands.

[0928] The mobile entity can be a means of transportation (e.g., a vehicle, an airplane, etc.), a mobile entity moving in an unmanned manner (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanized or unmanned). Additionally, at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station can also be an Internet of Things (IoT) device such as a sensor.

[0929] Figure 23 This is a diagram illustrating an example of a vehicle according to one embodiment. The vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, an axle 48, an electronic control unit 49, various sensors (including a current sensor 50, a speed sensor 51, a pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

[0930] The drive unit 41 is comprised of at least one of an engine, a motor, or a combination of an engine and a motor. The steering unit 42 is configured to include at least a steering wheel (also called a steering handle) that steers at least one of the front wheels 46 and the rear wheels 47 based on operation of the steering wheel by the user.

[0931] The electronic control unit 49 consists of a microprocessor 61, a memory (ROM, RAM) 62, and a communication port (e.g., an input / output (IO) port) 63). Signals from various sensors 50-58 present in the vehicle are input to the electronic control unit 49. The electronic control unit 49 can also be referred to as an electronic control unit (ECU).

[0932] The signals from various sensors 50-58 include the following: current signal from current sensor 50 sensing the current of the motor; rotational speed signal of front wheel 46 / rear wheel 47 obtained by speed sensor 51; air pressure signal of front wheel 46 / rear wheel 47 obtained by air pressure sensor 52; vehicle speed signal obtained by vehicle speed sensor 53; acceleration signal obtained by acceleration sensor 54; accelerator pedal 43 depress amount signal obtained by accelerator pedal sensor 55; brake pedal 44 depress amount signal obtained by brake pedal sensor 56; shift lever 45 operation signal obtained by shift lever sensor 57; and detection signal obtained by object detection sensor 58 for detecting obstacles, vehicles, pedestrians, etc.

[0933] The information service unit 59 consists of various devices for providing (outputting) various information such as driving information, traffic information, and entertainment information, including navigation systems, audio systems, speakers, displays, televisions, and radios, as well as one or more ECUs for controlling these devices. The information service unit 59 uses information obtained from external devices via the communication module 60, etc., to provide various information / services (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0934] The information service unit 59 may include input devices (e.g., keyboard, mouse, microphone, switch, button, sensor, touch panel, etc.) that accept input from the outside, and output devices (e.g., display, speaker, LED light, touch panel, etc.) that implement output to the outside.

[0935] The driver assistance system unit 64 comprises various devices used to provide functions for preventing accidents or reducing the driver's workload, such as millimeter-wave radar, light detection and ranging (LiDAR), cameras, positioning detectors (e.g., Global Navigation Satellite System (GNSS), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyroscope systems (e.g., Inertial Measurement Unit (IMU), Inertial Navigation System (INS), etc.), artificial intelligence (AI) chips, and AI processors, and one or more ECUs that control these devices. Furthermore, the driver assistance system unit 64 sends and receives various information via communication module 60 to realize driver assistance functions or autonomous driving functions.

[0936] The communication module 60 can communicate with the microprocessor 61 and the structural elements of the vehicle 40 via the communication port 63. For example, the communication module 60 sends and receives data (information) with the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, gear shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49 of the vehicle 40, and various sensors 50-58 via the communication port 63.

[0937] The communication module 60 can be controlled by the microprocessor 61 of the electronic control unit 49 and is a communication device capable of communicating with external devices. For example, it can transmit and receive various types of information with external devices via wireless communication. The communication module 60 can be located both inside and outside the electronic control unit 49. The external device can be, for example, the aforementioned base station 10, user terminal 20, etc. Furthermore, the communication module 60 can be, for example, at least one of the aforementioned base station 10 and user terminal 20 (or it can function as at least one of the base station 10 and user terminal 20).

[0938] The communication module 60 can also wirelessly transmit at least one of the signals input to the electronic control unit 49 from the various sensors 50-58 described above, the information obtained based on these signals, and the information based on input from an external (user) source obtained via the information service unit 59 to an external device. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc., can also be referred to as input units that receive input. For example, the PUSCH transmitted via the communication module 60 can also contain information based on the aforementioned inputs.

[0939] The communication module 60 receives various information (traffic information, signal information, workshop information, etc.) sent from external devices and displays it on the vehicle's information service unit 59. The information service unit 59 can also be referred to as an output unit that outputs information (for example, outputs information to devices such as displays and speakers based on the PDSCH received by the communication module 60 (or the data / information decoded from the PDSCH).

[0940] Furthermore, the communication module 60 stores various types of information received from external devices into a memory 62 that can be utilized by the microprocessor 61. Based on the information stored in the memory 62, the microprocessor 61 can also control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, gear shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, and various sensors 50-58, etc., of the vehicle 40.

[0941] Furthermore, the base station in this disclosure can also be rewritten as a user terminal. For example, various methods / implementations of this disclosure can be applied to structures where communication between the base station and the user terminal is replaced by communication between multiple user terminals (e.g., also referred to as device-to-device (D2D) or vehicle-to-everything (V2X)). In this case, it can also be configured such that the user terminal 20 has the functions of the base station 10 described above. In addition, terms such as "uplink" and "downlink" can be rewritten as terms corresponding to inter-terminal communication (e.g., "sidelink"). For example, uplink channel, downlink channel, etc., can also be rewritten as sidelink channel.

[0942] Similarly, the user terminal in this disclosure can also be rewritten as a base station. In this case, it can also be configured such that the base station 10 has the functions of the user terminal 20 described above.

[0943] In this disclosure, actions are assumed to be performed by the base station, and sometimes, depending on the circumstances, by its upper node. In a network containing one or more network nodes having a base station, the various operations performed for communication with a terminal can obviously be performed by the base station, one or more network nodes other than the base station (e.g., consider a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc., but not limited to these), or combinations thereof.

[0944] The various methods / implementations described in this disclosure can be used individually or in combination, and can be switched as needed during execution. Furthermore, the processing procedures, timing sequences, flowcharts, etc., of the various methods / implementations described in this disclosure can be rearranged as long as they do not contradict each other. For example, for the method described in this disclosure, the illustrated order is used to indicate various steps, but the order in which they are indicated is not limited.

[0945] The various methods / implementations described in this disclosure can also be applied to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG, where x is, for example, an integer or a decimal)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New Radio Access (NX), Futuregeneration Radio Access (FX), Global System for Mobile Communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE This includes 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-Wideband (UWB)), Bluetooth (registered trademark), systems utilizing other suitable wireless communication methods, and next-generation systems derived from, modified, generated, or specified based on these methods. Furthermore, multiple systems can be combined (e.g., LTE or LTE-A, combinations with 5G, etc.) for application.

[0946] As used in this disclosure, the term "based on" does not mean "based on only" unless otherwise specified. In other words, the term "based on" means both "based on only" and "based on at least".

[0947] Any reference to an element using the designations "first," "second," etc., as used in this disclosure does not comprehensively limit the quantity or order of these elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Therefore, reference to the first and second elements does not imply that only two elements may be used, or that the first element must take precedence over the second element in some form.

[0948] The term "determining" as used in this disclosure can encompass a wide variety of operations. For example, "determining" can also refer to judging, calculating, computing, processing, deriving, investigating, looking up (search, inquiry) (e.g., searching in a table, database or other data structure), and ascertaining.

[0949] In addition, "judgment (decision)" can also refer to receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, accessing (e.g., accessing data in memory), etc., as situations where "judgment (decision)" is performed.

[0950] Furthermore, "judgment (decision)" can also refer to situations where resolving, selecting, choosing, establishing, or comparing are considered as making a "judgment (decision)". That is, "judgment (decision)" can also refer to certain operations as situations where a "judgment (decision)" is made. In this disclosure, "judgment (decision)" can also be rewritten in relation to the operations described above.

[0951] Furthermore, in this disclosure, "determine / determining" can also be interchanged with "assume / assuming," "expect / expecting," "consider / considering," etc. Additionally, in this disclosure, "not assuming to proceed..." can also be interchanged with "assuming not to proceed..."

[0952] In this disclosure, "expect" can also be interchanged with "be expected." For example, "expect(s) ..." ("..." can also be expressed using a "that" clause, an indefinite "to", etc.) can be interchanged with "be expected ...." "Does not expect..." can also be interchanged with "be not expected...". Furthermore, "An apparatus A is not expected..." can also be interchanged with "Apparatus B other than apparatus A does not expect..." (for example, if apparatus A is a UE, apparatus B can also be a base station).

[0953] The term "maximum transmit power" as used in this disclosure may refer to the maximum value of the transmit power, the nominal maximum transmit power (the nominal UE maximum transmit power), or the rated maximum transmit power (the rated UE maximum transmit power).

[0954] As used in this disclosure, the terms “connected,” “coupled,” or all variations thereof, refer to all direct or indirect connections or combinations between two or more elements, and can include cases where there is one or more intermediate elements between two mutually “connected” or “coupled” elements. The connections or combinations between elements can be physical, logical, or a combination thereof. For example, “connection” can also be rewritten as “access.”

[0955] In this disclosure, when two elements are connected, it is possible to consider using more than one wire, cable, printed electrical connection, etc. to be "connected" or "combined" with each other, and as several non-limiting and non-exclusive examples, to use electromagnetic energy with wavelengths having wireless frequency domain, microwave region, light (both visible and invisible) region to be "connected" or "combined" with each other.

[0956] In this disclosure, the term "A is different from B" can also mean "A and B are different from each other." Additionally, the term can also mean "A and B are each different from C." Terms such as "separate" and "combined" can also be interpreted in the same way as "different."

[0957] When the terms "include," "including," and variations thereof are used in this disclosure, these terms, like the term "comprising," mean inclusive. Furthermore, the term "or" as used in this disclosure does not mean XOR.

[0958] In this disclosure, for example, in cases where articles are added through translation, such as a, an, and the in English, the disclosure may also include cases where the noun following these articles is in a plural form.

[0959] In this disclosure, words such as "below," "less than," "above," "more," and "equal to" can be interchanged. Furthermore, in this disclosure, words meaning "good," "bad," "large," "small," "high," "low," "early," "slow," "wide," and "narrow," etc., are not limited to the positive, comparative, and superlative degrees, and can be interchanged. Additionally, in this disclosure, words meaning "good," "bad," "large," "small," "high," "low," "early," "slow," "wide," and "narrow," etc., as expressions appended with "the i-th" (where i is any integer), are not limited to the positive, comparative, and superlative degrees, and can be interchanged (for example, "highest" can also be interchanged with "the i-th highest").

[0960] In this disclosure, "of", "for", "regarding", "related to", "associated with", etc., can also be rewritten interchangeably.

[0961] In this disclosure, phrases such as "when A, B", "if A, then B", "B upon A", "in response to A", "based on A", "during / while A", "before A", "at (the same time as) / on A", "after A", "since A", and "until A" can be rewritten interchangeably. Furthermore, A and B can be replaced with nouns, gerunds, or ordinary sentences depending on the context. Additionally, the time difference between A and B can be approximately 0 (immediately after or immediately before). Moreover, a time offset can be applied to the time A occurs. For example, "A" can be rewritten interchangeably with "before / after the time offset of A". This time offset (e.g., more than one symbol / slot) can be predetermined or determined by the UE based on the information it is notified of.

[0962] In this disclosure, timing, moment, time, time instance, arbitrary time unit (e.g., time slot, sub-time slot, symbol, subframe), period, opportunity, resource, etc., can also be overridden.

[0963] The inventions disclosed herein have been described in detail above. However, it will be apparent to those skilled in the art that the inventions disclosed herein are not limited to the embodiments described herein. The description herein is for illustrative purposes only and is not intended to limit the inventions disclosed herein in any way.

Claims

1. A terminal, comprising: The receiving unit receives one or more first reference signals; and The control unit, based on the received power of the one or more first reference signals, determines at least one of the following in an attempt to transmit via a random access channel: whether to transmit via a single random access channel or multiple random access channels, and the number of random access channel transmissions in the attempt. If the attempt fails, the control unit determines at least one of the following based on the decision: the transmission power for a subsequent attempt and the maximum number of random access channel transmissions.

2. The terminal according to claim 1, wherein, If a single random access channel transmission is decided upon in the first attempt and the first attempt fails, the control unit decides to perform a single random access channel transmission in the second attempt, and selects a third reference signal for determining the resources for the second attempt based on the received power of the more than one second reference signal, and determines the transmission power of the second attempt based on the received power threshold for determining the number of random access channel transmissions, the received power of the third reference signal, and the transmission power of the first attempt.

3. The terminal according to claim 1, wherein, If multiple random access channel transmissions are decided upon in the initial attempt and the attempt fails, the control unit decides to perform multiple random access channel transmissions in the retry, the same number as the number of random access channel transmissions in the initial attempt. Based on the received power of the more than one second reference signal, a third reference signal is selected for determining the resources for the retry. The transmission power for the retry is determined based on the received power threshold for determining the number of random access channel transmissions, the received power of the third reference signal, and the transmission power of the initial attempt.

4. The terminal according to claim 1, wherein, If multiple random access channel transmissions are decided upon in the initial attempt and the attempt fails, the control unit determines the number of random access channel transmissions to be performed in the re-attempt, as well as the number of random access channel transmissions in the re-attempt, and determines the transmission power of the re-attempt based on the number of random access channel transmissions in the re-attempt and the transmission power of the initial attempt.

5. A wireless communication method for a terminal, comprising: The step of receiving more than one first reference signal; Based on the received power of the one or more first reference signals, a step is taken to determine, in an attempt to transmit via a random access channel, whether to perform a single random access channel transmission or multiple random channel transmissions, and the number of random channel transmissions in the attempt; and In the event that the attempt fails, the step of determining at least one of the following: the transmission power for retrying and the maximum number of transmissions via the random access channel, based on the decision.

6. A base station, comprising: The transmitting unit transmits one or more first reference signals; and The control unit controls the retry reception if the initial attempt to transmit via the random access channel fails. Based on the received power of the one or more first reference signals, at least one of the following is determined: whether to perform a single random access channel transmission or multiple random channel transmissions in the attempt, and the number of random access channel transmissions in the attempt. In the event that the attempt fails, based on the decision, at least one of the following is determined: the transmission power of the retry and the maximum number of transmissions via the random access channel.

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