Method and apparatus for contention-based random access in a wireless communication system

Abstract

A method of a terminal for performing a random access (RA) procedure can comprise the steps of: receiving, from a base station, CFRA configuration information for a contention-free RA (CFRA) procedure and a system information request, and CBRA configuration information for a contention-based random access (CBRA) procedure; measuring a reception strength of a synchronization signal block (SSB) received from the base station; determining a number of repetitions for transmitting a message 1 (Msg1) based on the measured reception strength; and repeatedly transmitting the Msg1 according to the determined number of repetitions in a first random access occasion (RO) set determined by the CFRA configuration information and / or the CBRA configuration information.

Description

Technical Field

[0001] This disclosure relates to a random access procedure in a wireless communication system, and more specifically, to a method and apparatus for non-contention-based random access. Background Technology

[0002] With the development of information and communication technologies, various wireless communication technologies have been developed. Typical wireless communication technologies include Long Term Evolution (LTE) and New Radio (NR) as defined in the 3rd Generation Partnership Project (3GPP) standards. LTE can be a type of fourth-generation (4G) wireless communication technology, and NR can be a type of fifth-generation (5G) wireless communication technology.

[0003] 5G communication systems (e.g., NR-enabled systems) using frequency bands higher than those of 4G systems (e.g., 6 GHz or below) are being considered for handling the surge in wireless data following the commercialization of 4G systems (e.g., LTE-enabled systems). 5G systems can support enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), massive machine-type communication (mMTC), and more. Discussions are ongoing regarding sixth-generation (6G) communication systems following 5G.

[0004] In mobile communication systems, non-contention-based random access procedures can be performed for various purposes and environments. However, for purposes such as requesting on-demand system information, and for environments such as non-terrestrial networks (NTN) or multiple transmitter and receiver points (multiple TRP) communication scenarios, many improvements to the non-contention-based random access procedures are needed. Summary of the Invention

[0005] Technical issues This disclosure aims to provide a method and apparatus for performing a non-contention-based random access procedure in a wireless communication system.

[0006] Technical solution According to an exemplary embodiment for achieving the above objectives, a method for a terminal to perform a random access (RA) procedure may include: receiving first RA configuration information and second RA configuration information from a base station, wherein the first RA configuration information is used for a non-contention-based RA procedure or a system information request, and the second RA configuration information is used for a contention-based random access (CBRA) procedure; measuring the received strength of a synchronization signal block (SSB) received from the base station; determining a repetition factor for transmitting message 1 (Msg1) based on the measured received strength; and repeatedly transmitting Msg1 in a first random access opportunity (RO) set determined by the first RA configuration information and / or the second RA configuration information, according to the determined repetition factor.

[0007] The first RO set can be derived from the first RA configuration information, and the first RO set can include ROs independent of the ROs configured by the second RA configuration information for the CBRA process.

[0008] Time offsets may not be applied between RO groups belonging to the first RO group set.

[0009] When no resources for the CFRA process are configured in the first RA configuration information, the first RO group set can be exported through the second RA configuration information, and the time offset between RO groups belonging to the first RO group set can be indicated through the second configuration information.

[0010] The first RA configuration information may include mask information, which can be used to determine the validity of ROs belonging to the first RO set, and Msg1 can be sent among the valid ROs determined based on the mask information.

[0011] Based on the repetition factor, the time offset can be selected from multiple values ​​indicated by the first RA configuration information or the second RA configuration information.

[0012] At least a portion of the configuration information of the first RA can share at least a portion of the configuration information of the second RA.

[0013] The repetition factor can be determined based on the receiver intensity segments obtained by comparing the measured receiver intensity with at least one threshold, wherein the measured receiver intensity belongs to the receiver intensity segment.

[0014] It can perform repeated transmissions of Msg1 to request system information from the base station.

[0015] According to an exemplary embodiment for achieving the above objectives, a method for a base station to perform a random access (RA) procedure may include: sending first RA configuration information and second RA configuration information to a terminal, wherein the first RA configuration information is used for a non-contention-based RA procedure or a system information request, and the second RA configuration information is used for a contention-based random access (CBRA) procedure; sending a synchronization signal block (SSB) to the terminal; and repeatedly receiving message 1 (Msg1) from the terminal in a first random access opportunity (RO) set determined by the first RA configuration information and / or the second RA configuration information, based on a repetition factor determined based on the reception strength of the SSB at the terminal.

[0016] The first RO set can be derived from the first RA configuration information, and the first RO set can include ROs independent of the ROs configured by the second RA configuration information for the CBRA process.

[0017] Time offsets may not be applied between RO groups belonging to the first RO group set.

[0018] When no resources for the CFRA process are configured in the first RA configuration information, the first RO group set can be exported through the second RA configuration information, and the time offset between RO groups belonging to the first RO group set can be indicated through the second configuration information.

[0019] The first RA configuration information may include mask information, which can be used to determine the validity of ROs belonging to the first RO set, and Msg1 can be received in the valid ROs determined based on the mask information.

[0020] Based on the repetition factor, the time offset can be selected from multiple values ​​indicated by the first RA configuration information or the second RA configuration information.

[0021] At least a portion of the configuration information of the first RA can share at least a portion of the configuration information of the second RA.

[0022] According to an exemplary embodiment for achieving the above objectives, a terminal for performing a random access (RA) procedure may include: at least one processor, and the at least one processor is configured to cause the terminal to perform the following operations: receiving first RA configuration information and second RA configuration information from a base station, wherein the first RA configuration information is used for a non-contention-based RA procedure or a system information request, and the second RA configuration information is used for a contention-based random access (CBRA) procedure; measuring the received strength of a synchronization signal block (SSB) received from the base station; determining a repetition factor for transmitting message 1 (Msg1) based on the measured received strength; and repeatedly transmitting Msg1 according to the determined repetition factor in a first random access opportunity (RO) set determined by the first RA configuration information and / or the second RA configuration information.

[0023] The first RO set can be derived from the first RA configuration information, and the first RO set can include ROs independent of the ROs configured by the second RA configuration information for the CBRA process.

[0024] When no resources for the CFRA process are configured in the first RA configuration information, the first RO group set can be exported through the second RA configuration information, and the time offset between RO groups belonging to the first RO group set can be indicated through the second configuration information.

[0025] The first RA configuration information may include mask information, which can be used to determine the validity of ROs belonging to the first RO set, and Msg1 is sent among the valid ROs that can be determined based on the mask information.

[0026] Beneficial effects According to various exemplary embodiments of this disclosure, a non-contention-based random access procedure can be performed suitable for the purpose (such as requesting on-demand system information) and environment (such as NTN or multi-TRP communication scenarios). Therefore, the overall performance of the communication system can be improved. Attached Figure Description

[0027] Figure 1 This is a conceptual diagram illustrating a first exemplary embodiment of a communication system.

[0028] Figure 2 This is a block diagram illustrating a first exemplary embodiment of a communication node constituting a communication system.

[0029] Figure 3 This is a sequence diagram illustrating a method for a terminal to trigger a base station where the terminal is camped to send SIB1 or SIBx using UL DRS, according to an exemplary embodiment of the present disclosure.

[0030] Figure 4 This is a sequence diagram illustrating a method for a terminal to trigger a base station where the terminal is camped to send SIB1 or SIBx using UL DRS, according to another exemplary embodiment of the present disclosure.

[0031] Figure 5 This is a sequence diagram illustrating a response monitoring process for a terminal receiving RAR, SIB1, or SIBx according to another exemplary embodiment of the present disclosure.

[0032] Figure 6 and Figure 7 This is a sequence diagram illustrating the operation of a terminal when SIB1 and / or SIBx are triggered by multiple terminals according to an exemplary embodiment of the present disclosure.

[0033] Figure 8 and Figure 9 This is a timing diagram illustrating a method for determining whether to discard a preamble according to an exemplary embodiment of the present disclosure.

[0034] Figure 10 This is a conceptual diagram showing examples of valid ROs derived from selected SSBs in chronological order.

[0035] Figure 11 and Figure 12 This is a conceptual diagram illustrating an example of overlapping RO sets and how RO sets are represented as their union.

[0036] Figure 13 This is a conceptual diagram illustrating an exemplary embodiment where sets of RO groups overlap in time and are mapped at the boundary of a second period.

[0037] Figure 14This is a conceptual diagram illustrating an exemplary embodiment in which the set of RO groups is mapped in time at the boundary of the second period without overlapping.

[0038] Figure 15 This is a conceptual diagram showing the Rx GoB and Tx GoB of the terminal.

[0039] Figure 16 and Figure 17 This is a conceptual diagram illustrating the relationship between the receiving beam of SSB and the transmitting beam of Msg1.

[0040] Figure 18 This is a conceptual diagram illustrating an improvement in the reception quality of Msg1 based on repeated transmission of Msg1 through the same beam.

[0041] Figure 19 and Figure 20 This is a conceptual diagram illustrating the case where four transmit beams are derived from one receive beam used for Msg1 scanning.

[0042] Figure 21 and Figure 22 This is a conceptual diagram illustrating an example of gaps reflected in the RO group.

[0043] Figure 23 This is a conceptual diagram illustrating the situation where a base station indicates a specific RO within a RO group.

[0044] Figure 24 This is a sequence diagram showing the transmission of Msg5 and the process preceding it. Detailed Implementation

[0045] Because this disclosure is subject to various modifications and has several forms, specific exemplary embodiments will be shown in the accompanying drawings and described in detail in the specific embodiments. However, it should be understood that this is not intended to limit this disclosure to the specific exemplary embodiments, but rather, this disclosure will cover all modifications and alternatives falling within the spirit and scope of this disclosure.

[0046] Relational terms such as first, second, etc., may be used to describe various elements, but these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first component may be named a second component, and a second component may similarly be named a first component. The term "and / or" refers to any one or a combination of multiple related and described items.

[0047] In exemplary embodiments of this disclosure, "at least one of A and B" may refer to "at least one of A or B" or "at least one of a combination of one or more of A and B". Furthermore, "one or more of A and B" may refer to "one or more of A or B" or "one or more of a combination of one or more of A and B".

[0048] When it is said that a component is "combined" or "connected" with another component, it should be understood that the component is directly "combined" or "connected" with the other component, or that another component may be placed between them. Conversely, when it is said that a component is "directly combined" or "directly connected" with another component, it should be understood that no other component is placed between them.

[0049] The terminology used in this disclosure is for describing particular exemplary embodiments only and is not intended to limit the disclosure. Unless the context clearly indicates otherwise, singular expressions include plural expressions. In this disclosure, terms such as “comprising” or “having” are intended to indicate the presence of features, quantities, steps, operations, components, parts, or combinations thereof described in the specification, but it should be understood that these terms do not exclude the presence or addition of one or more features, quantities, steps, operations, components, parts, or combinations thereof.

[0050] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Terms that are commonly used and already in dictionaries shall be interpreted as having the meaning that matches the context in this art. In this specification, terms are not necessarily to be interpreted as having a formal meaning unless explicitly defined.

[0051] The form of this disclosure will be described in detail below with reference to the accompanying drawings. In describing this disclosure, for ease of overall understanding, the same reference numerals refer to the same elements throughout the description of the drawings, and repeated descriptions will be omitted.

[0052] A communication system based on exemplary embodiments of the present disclosure will be described. The communication system based on exemplary embodiments of the present disclosure is not limited to what is described below, and can be applied to various communication systems. Here, "communication system" can be used in the same sense as "communication network".

[0053] In an exemplary embodiment, "configuration of an operation (e.g., a transmission operation)" may mean "signaling for configuration information (e.g., information elements, parameters) for the operation" and / or "signaling of information indicating the execution of the operation." "Configuration of information elements (e.g., parameters)" may mean sending the corresponding information element by signaling. The signaling may be at least one of the following: System Information (SI) signaling (e.g., transmission of System Information Block (SIB) and / or Master Information Block (MIB)), RRC signaling (e.g., transmission of RRC messages, RRC parameters, and / or higher-level parameters), MAC Control Element (CE) signaling (e.g., transmission of MAC messages and / or MAC CE), PHY signaling (e.g., transmission of Downlink Control Information (DCI), Uplink Control Information (UCI), and / or Sidelink Control Information (SCI)) or combinations thereof.

[0054] Figure 1 This is a conceptual diagram illustrating a first exemplary embodiment of a communication system.

[0055] Reference Figure 1 The communication system 100 may include multiple communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Furthermore, the communication system 100 may also include a core network (e.g., a Serving Gateway (S-GW), a Packet Data Network (PDN) Gateway (P-GW), and a Mobility Management Entity (MME)). When the communication system 100 is a 5G communication system (e.g., an NR system), the core network may include Access and Mobility Management Functions (AMF), User Plane Functions (UPF), Session Management Functions (SMF), etc.

[0056] Multiple communication nodes 110 to 130 can support communication protocols defined by the technical specifications of the 3rd Generation Partnership Project (3GPP) (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.). Multiple communication nodes 110 to 130 can support communication protocols based on Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiplexing (OFDM), Filtered OFDM, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Extended OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier FDMA (SC-FDMA), Non-Orthogonal Multiple Access (NOMA), Generalized Frequency Division Multiplexing (GFDM), Filter Bank Multicarrier (FBMC), Universal Filtered Multicarrier (UFMC), and Space Division Multiple Access (SDMA), etc. Each of the multiple communication nodes can have the following structure.

[0057] Figure 2 This is a block diagram illustrating a first exemplary embodiment of a communication node constituting a communication system.

[0058] Reference Figure 2 The communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to a network to perform communication. Furthermore, the communication node 200 may also include an input interface device 240, an output interface device 250, a storage device 260, etc. The various components included in the communication node 200 can communicate with each other when connected via a bus 270.

[0059] However, each component included in communication node 200 may be connected to processor 210 via a separate interface or a separate bus (instead of the common bus 270). For example, processor 210 may be connected to at least one of memory 220, transceiver 230, input interface device 240, output interface device 250, and storage device 260 via a dedicated interface.

[0060] Processor 210 can execute a program stored in at least one of memory 220 and storage device 260. Processor 210 may refer to a central processing unit (CPU), graphics processing unit (GPU), or dedicated processor on which methods according to embodiments of the present disclosure are executed. Each of memory 220 and storage device 260 may be constituted by at least one of volatile storage medium and non-volatile storage medium. For example, memory 220 may include at least one of read-only memory (ROM) and random access memory (RAM).

[0061] Refer again Figure 1 The communication system 100 may include multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell, and each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may be within the cell coverage area of ​​the first base station 110-1. Furthermore, the second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may be within the cell coverage area of ​​the second base station 110-2. Furthermore, the fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 can all fall within the cell coverage area of ​​the third base station 110-3. Additionally, the first terminal 130-1 can fall within the cell coverage area of ​​the fourth base station 120-1, and the sixth terminal 130-6 can fall within the cell coverage area of ​​the fifth base station 120-2.

[0062] Here, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can refer to a NodeB, an evolved NodeB (eNB), a gNB, an Advanced Base Station (ABS), a High Reliability Base Station (HR-BS), a Base Transceiver Station (BTS), a Radio Base Station, a Radio Transceiver, an Access Point, an Access Node, a Radio Access Station (RAS), a Mobile Multi-Hop Relay Base Station (MMR-BS), a Relay Station (RS), an Advanced Relay Station (ARS), a High Reliability Relay Station (HR-RS), a Home NodeB (HNB), a Home eNodeB (HeNB), a Roadside Unit (RSU), a Radio Remote Header (RRH), a Transmitting Point (TP), a Transmitting and Receiving Point (TRP), etc.

[0063] Each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can refer to a User Equipment (UE), Terminal Equipment (TE), Advanced Mobile Station (AMS), High Reliability Mobile Station (HR-MS), Terminal, Access Terminal, Mobile Terminal, Station, Subscriber Station, Mobile Station, Portable Subscriber Station, Node, Device, On-Board Unit (OBU), etc.

[0064] Furthermore, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can operate in the same frequency band or different frequency bands. The multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be interconnected with each other via ideal or non-ideal backhaul, and exchange information with each other via ideal or non-ideal backhaul. Furthermore, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected to the core network via ideal or non-ideal backhaul. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can transmit signals received from the core network to the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6, and transmit signals received from the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 to the core network.

[0065] In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can support multiple-input multiple-output (MIMO) transmission (e.g., single-user MIMO (SU-MIMO), multi-user MIMO (MU-MIMO), massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in unlicensed frequency bands, device-to-device (D2D) communication (or proximity service (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can perform an operation corresponding to the operation of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 (i.e., the operation supported by the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2). For example, the second base station 110-2 can transmit signals to the fourth terminal 130-4 in SU-MIMO mode, and the fourth terminal 130-4 can receive signals from the second base station 110-2 in SU-MIMO mode. Optionally, the second base station 110-2 can transmit signals to the fourth terminal 130-4 and the fifth terminal 130-5 in MU-MIMO mode, and the fourth terminal 130-4 and the fifth terminal 130-5 can receive signals from the second base station 110-2 in MU-MIMO mode.

[0066] The first base station 110-1, the second base station 110-2, and the third base station 110-3 can transmit signals to the fourth terminal 130-4 in CoMP mode, and the fourth terminal 130-4 can receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 in CoMP mode. Furthermore, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can exchange signals with the corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 within its cell coverage area in CA mode. Each of base stations 110-1, 110-2, and 110-3 can control D2D communication between the fourth terminal 130-4 and the fifth terminal 130-5, so the fourth terminal 130-4 and the fifth terminal 130-5 can perform D2D communication under the control of the second base station 110-2 and the third base station 110-3.

[0067] The following describes the operation methods of communication nodes in a communication system. Even when describing a method performed at a first communication node (e.g., sending or receiving data packets), a corresponding second communication node can also perform a method corresponding to the method performed at the first communication node (e.g., receiving or sending data packets). That is, when describing the operation of a terminal, a corresponding base station can perform an operation corresponding to the terminal's operation. Conversely, when describing the operation of a base station, a corresponding terminal can perform an operation corresponding to the base station's operation.

[0068] To reduce the error rate of data, a low modulation and coding scheme (MCS) level (or low MCS index) can be applied. To avoid increasing the size of the field indicated by downlink control information (DCI), frequently used MCSs can be selected. Applying a lower MCS allows for repetitive transmission operations. Applying Quadrature Phase Shift Keying (QPSK) as the lowest modulation rate may further reduce the code rate. Specifically, because transmission power is limited in uplink (UL) transmissions, repetitive transmission operations can be performed in the time domain (rather than in the frequency domain).

[0069] In the cases of eMBB and URLLC services, a lower MCS can be used for different purposes. For example, for eMBB services, a lower MCS may be needed to extend coverage. On the other hand, for URLLC services, a lower MCS may be needed to reduce latency and achieve a lower error rate. Due to the different requirements, eMBB services can be retransmitted even when relatively large delays occur. A new MCS (e.g., a low MCS) can be used (instead of retransmission) for URLLC services. The new MCS can be configured via RRC messages and / or DCI.

[0070] To support repeated transmissions of eMBB services in the time domain, Physical Uplink Shared Channel (PUSCH) repetition (e.g., PUSCH repetition type A) can be introduced. In this case, repeated transmissions are based on time slot allocation of the PUSCH. To extend coverage, time resources can be allocated across multiple time slots. When using PUSCH repetition type A, time resources can be configured via RRC messages and / or DCI. The number of PUSCH repetitions can be indicated by RRC messages, and the time resources used for transmitting the PUSCH in the first time slot can be indicated by DCI (e.g., in the case of type 2 configuration grant (CG) or dynamic grant) or RRC messages (e.g., in the case of type 1 CG).

[0071] Because retransmitting URLLC services incurs latency, it may be unsuitable. However, using a sufficiently low MCS can reduce the latency for decoding URLLC services. That is, with a sufficiently low MCS, the number of resource elements (REs) to which the URLLC service is mapped may increase, and the base station (e.g., the base station's decoder) should wait until all REs are received. In this case, the latency for decoding the URLLC service can be reduced.

[0072] However, when retransmitting PUSCHs with a fairly high MCS, the base station may only utilize a few REs to perform decoding. Therefore, successful decoding in retransmitted PUSCHs (e.g., retransmitted PUSCHs with a slightly high MCS) may occur earlier than in non-retransmitted PUSCHs (e.g., PUSCHs with a low MCS). Unnecessary delays may occur when using PUSCH retransmission type A, and PUSCH retransmission type B can be introduced to reduce delays due to retransmissions. When using PUSCH retransmission type B, PUSCHs based on micro-slot allocation can be retransmitted. When using PUSCH retransmission type B, time resources can be configured via RRC messages and / or DCI. The combination of the reference time resources and the number of retransmissions for a PUSCH instance can be indicated by DCI (e.g., in the case of type 2 CG and / or dynamic granting) or RRC messages (e.g., in the case of type 1 CG).

[0073] To control the transmission power of SRS resources indicated by the Sounding Reference Signal (SRS) Resource Indicator (SRI), the base station can estimate the path loss for each SRS resource. The base station can control the transmission power of SRS resources using a Distributed Control Interface (DCI). The transmission power of SRS resources can be controlled based on the estimated path loss. The DCI can be a scheduling DCI (e.g., DCI format 0_0, DCI format 0_1, DCI format 0_2, DCI format 1_0, DCI format 1_1, or DCI format 1_2) or a Group Common (GC)-DCI (e.g., DCI format 2_2 or DCI format 2_3). The DCI may include fields indicating a Transport Power Control (TPC) command, and the TPC command can be used to control the transmission power of the terminal. For example, the transmission power of the terminal can be increased or decreased based on a TPC command included in the DCI. To determine the transmission power of the PUSCH, the terminal can consider values ​​obtained based on the path loss, values ​​according to the TPC command included in the DCI, and / or the PUSCH bandwidth indicated by the DCI.

[0074] The base station can configure two or more sets to the terminal using higher-layer signaling. The terminal can receive configuration information for two or more sets from the base station. Elements constituting each of the two or more sets can be transmission power parameters and can be indicated to be suitable for different scenarios (e.g., URLLC scenario, eMBB scenario). The terminal can receive a scheduling DCI or activation DCI from the base station for allocating PUSCH resources, and the scheduling DCI or activation DCI can indicate the set used to interpret the transmission power parameters. When the sets of transmission power parameters are different, the magnitude of the increase or decrease in transmission power indicated by the same TPC command can be different.

[0075] When using Type 1 CG or Type 2 CG, the transmission power can be determined based on DCI format 2_3 used for the SRI associated with the PUSCH instance. When using Type 2 CG, activating the DCI indicates the set of transmission power parameters applied to the PUSCH event. The PUSCH event can refer to a PUSCH instance. The terminal can obtain the TPC command for the SRI by receiving the GC-DCI, and can interpret the TPC command as a set of transmission power parameters suitable for the transmission power parameters indicated by the base station, and can derive the transmission power to be applied to the PUSCH instance based on the interpretation result.

[0076] When transmitting dynamically scheduled PUSCHs, the terminal can derive the transmission power applied to the PUSCH instance based on a combination of GC-DCI and scheduling DCI. By receiving GC-DCI, the terminal can identify and store the TCP commands of the SRI. When transmitting dynamically scheduled PUSCHs, the scheduling DCI can be used to indicate the set of transmission power parameters and / or TPC commands applied to the PUSCH timing. The terminal can derive the transmission power to be applied to the PUSCH instance based on the transmission power of the SRI associated with the PUSCH instance.

[0077] Repeated HARQ-ACK transmissions can be indicated (or configured) via higher-layer signaling for each Physical Uplink Control Channel (PUCCH) format. The number of repetitions for PUCCH format i can be set independently. i can be 1, 3, or 4. Terminals can repeatedly transmit the PUCCH format over time slots. In this case, the same time resources can be used to transmit the PUCCH format across all time slots.

[0078] The type of uplink control information (UCI) can be classified according to the type of information included in the UCI. UCI may include at least one of scheduling requests (SR), L1 reference signal received power (L1-RSRP), HARQ-ACK, channel state information (CSI), or combinations thereof. In an exemplary embodiment, UCI and UCI type may have the same meaning. In a UCI retransmission operation, only one UCI type may be transmitted. To support this operation, the priority of each UCI type can be defined in the technical specification. A UCI type may be selected, and a PUCCH including that UCI type may be retransmitted. In this case, the terminal may assume that no other UCI types have been transmitted before the transmission of the corresponding UCI type is completed. To support this operation, the base station may instruct the terminal to transmit a UCI (e.g., SR or HARQ-ACK) after the transmission of the corresponding PUCCH is completed. The waiting time for UCI transmission may be long, and the waiting time can be used as a constraint on the base station's scheduling.

[0079] When an indication is given to transmit HARQ-ACK in the same time slot (or the same sub-time slot), or when PUCCH time resources indicated by DCI and / or RRC messages used for allocating the Physical Downlink Shared Channel (PDSCH) overlap, the terminal may generate a HARQ codebook for transmission on a single PUCCH (e.g., a single PUCCH time resource). In the HARQ codebook, HARQ-ACK bits can be arranged in the order defined in the technical specification. Information bits can be generated through the above operations. The terminal can generate encoded bits by performing an encoding operation on them.

[0080] During encoding operations, Reed-Muller codes or polar codes can be used. The code rate applied during encoding operations can be indicated by higher-level signaling. For example, a value in the PUCCH format can be the code rate and can be indicated to the terminal.

[0081] A codeword can be mapped to a PUCCH. In repeated PUCCH transmissions, a UCI type can be generated as a codeword. When a PUCCH is transmitted once, information bits of one or more UCI types can be concatenated, and the terminal can generate a codeword by performing the same encoding operation on the information bits. Soft combination operations may be difficult to implement when using Reed-Muller codes or polar codes. Therefore, even when PUCCHs are transmitted repeatedly, the same codeword can be transmitted, and the base station can perform append-merge operations on the same codeword. Encoded bits or codewords can refer to a bit stream in which multiple code blocks are concatenated. Modulation operations can be performed on codewords, and the results of the modulation operations can be mapped to resource elements (REs).

[0082] Furthermore, the same UCI type can be considered different information. The same UCI type can be mapped to be considered different information. For example, UCIs can be generated to support services with different priorities. A UCI supporting eMBB services (e.g., SR or HARQ-ACK) can be considered different information from a UCI supporting URLLC services (e.g., SR or HARQ-ACK). In this case, even when the UCI types are the same, they can be distinguished as different information.

[0083] The encoded UCI can be mapped to the PUCCH. During PUCCH transmission operations, the same preprocessing scheme (e.g., spatial information, spatial relationships) can be maintained. Optionally, during PUCCH transmission operations, different preprocessing schemes can be allowed for each PUCCH via RRC signaling from the base station.

[0084] To support URLLC services, it may be preferable for the terminal to perform frequent receive operations in downlink (DL) resources and / or frequent transmit operations in uplink (UL) resources. In Time Division Duplex (TDD) systems, the terminal can operate based on a half-duplex scheme. Therefore, the time for supporting DL and / or UL services can be increased depending on the time slot pattern. On the other hand, in Frequency Division Duplex (FDD) systems, the terminal can utilize both DL and UL resources simultaneously. Therefore, the aforementioned problems in TDD systems may not occur in FDD systems. FDD systems can use two or more carriers. When configuring two or more serving cells for a terminal in a TDD system, the terminal can utilize both DL and UL resources.

[0085] In a communication system that includes at least one carrier using FDD (hereinafter referred to as "FDD carrier"), there may be no issue regarding terminal latency. In a communication system that includes only carriers using TDD (hereinafter referred to as "TDD carrier"), there may be an issue regarding terminal latency. To address this issue, time slots in the TDD carrier can be configured according to different modes.

[0086] Carrier aggregation (CA) can be configured in the terminal, and PCells and SCells can be activated. Cells can be classified as PCells or SCells depending on whether a common search space (CSS) set is included. For example, a PCell may include a CSS set, while an SCell may not. To reduce latency in communication systems supporting URLLC services, time slots with different modes can be configured and / or indicated to the terminal.

[0087] eMBB or URLLC services can be supported in licensed frequency bands, but also in unlicensed frequency bands. Carriers belonging to licensed frequency bands or unlicensed frequency bands can be used individually, but depending on the base station configuration, frequency aggregation can be used to utilize all carriers belonging to licensed and unlicensed frequency bands.

[0088] In an exemplary embodiment, two or more terminals may receive data from one or more TRPs and may send data to one or more TRPs. It may be assumed that a base station or a server performs management and / or scheduling operations on one or more of the multiple TRPs. TRPs may be directly connected to each other. Optionally, TRPs may be connected via a base station. The aforementioned connection may be based on an Xn interface or a radio interface (e.g., a 3GPP NR interface).

[0089] Dead zones can occur between areas supported by TRPs. Therefore, TRPs can resolve dead zones through cooperative transmission. Cooperative transmission can be performed for terminals located between TRPs. Even when no dead zones exist, the quality of the radio link can be improved by installing many TRPs (or base stations) to send and receive large amounts of data.

[0090] Based on the cooperative transmission and reception of TRPs, communication schemes can be classified into Dynamic Point Selection (DPS) and Joint Transmission (JT). For a specific set of Physical Resource Blocks (PRBs), DPS can be a scheme that receives data through one TRP, while JT can be a scheme that receives data through two or more TRPs. Dynamic Point Blanking (DPB) can be a type of JT. When using DPB, the terminal may not receive data from some TRPs and may receive data from the remaining TRPs. JTs can be classified into coherent JPs and incoherent JPs. Coherent JPs or incoherent JPs can be used depending on whether a coherent combining operation is performed on the signals received from the TRPs.

[0091] Depending on the latency and traffic volume of the backhaul network to which the base station or TRP is connected, the TRP may or may not participate in real-time cooperative transmission and reception. A terminal can support JT via a single DCI (i.e., a single DCI (sDCI)). Optionally, a terminal can support JT via multiple DCIs (i.e., multiple DCIs (mDCI)).

[0092] When using sDCI, the terminal can send and receive data using TRPs. With sDCI, it is preferable that the TRPs can cooperate over the backhaul network without latency. With mDCI, the terminal can send and receive data with some TRPs. When the terminal sends and receives data with other TRPs, these TRPs have difficulty cooperating in real time over the backhaul network; therefore, allocating semi-static resources to these TRPs may be preferable.

[0093] In existing technical specifications, CORESET pool indices have been introduced to identify TRPs. A CORESET pool is a collection of CORESETs and can independently indicate to the terminal the Transmission Configuration Indication (TCI) status applied to each CORESET via RRC signaling and / or MAC Control Element (CE) signaling. Therefore, a CORESET pool index may not necessarily correspond to a TRP. More specifically, if a TRP is classified as a Transmitting Point (TxP) and a Receiver Point (RxP), then a CORESET pool index may correspond to an RxP. For example, an Rx beam received from a TxP can be derived from the TCI status, and an uplink signal / channel scheduled by DCI detected in a CORESET belonging to a CORESET pool indicated by a CORESET pool index can be interpreted as being received from the same RxP.

[0094] For a terminal to gain gain through coherent combining, a certain degree of synchronization is required between the TRPs used by the terminal, and CSI reports for the TRPs also need to be shared. When these conditions cannot be met, performing incoherent combining within the terminal is advantageous in terms of performance.

[0095] When the terminal is installed in a vehicle, restrictions on its size and weight can be relaxed. However, when the terminal is carried by a person, portability should be considered.

[0096] Small cells or IAB nodes can be deployed to extend signal range. The throughput of small cells or IAB nodes can be affected by the quality of the backhaul link, and protecting the backhaul network can be expensive. As an alternative, wireless repeaters can be deployed to deliver higher quality signals to terminals. Wireless repeaters can be categorized into several types based on the method of signal transmission. As a wireless repeater supports more functions, it can exhibit performance similar to a base station, and as a wireless repeater supports fewer functions, it can be deployed at a lower cost. The wireless repeaters considered in this disclosure can perform the function of beamforming to terminals, but can also perform the minimal function of transmitting data. Base stations need to transmit wireless signals to control these wireless repeaters. These wireless signals can be used to configure appropriate parameters for the wireless repeaters.

[0097] In this disclosure, transmitting a channel can refer to sending messages, data, signals, and / or information through the channel, and receiving a channel can refer to receiving messages, data, signals, and / or information through the channel. The channel may include a Physical Downlink Control Channel (PDCCH), a Physical Downlink Shared Channel (PDSCH), a Physical Uplink Control Channel (PUCCH), a Physical Uplink Shared Channel (PUSCH), a Physical Random Access Channel (PRACH), a Physical Sidelink Broadcast Channel (PSBCH), a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), and / or a Physical Sidelink Feedback Channel (PSFCH).

[0098] In time-division duplex (TDD) communication systems, downlink (DL) and uplink (UL) communication can be performed in different time resources. The ratio between DL time for DL ​​communication and UL time for UL communication can be determined based on the ratio of services (e.g., DL services and / or UL services). For example, since the amount of DL service is typically greater than the amount of UL service in an NR system, more DL time slots can be allocated than UL time slots. For example, time slots (e.g., time slot patterns) can be configured such that the DDDSU pattern is repeated. D can indicate a DL time slot, S can indicate a time slot including DL symbols, flexible (FL) symbols, and UL symbols, and U can indicate a UL time slot. In an S time slot, the order of symbols can be DL symbol-FL symbol-DL symbol. The base station can indicate or configure the time slot pattern to the terminal via signaling (e.g., Radio Resource Control (RRC) signaling). The base station can indicate some FL symbols from the FL symbols configured via RRC signaling as DL symbols or UL symbols. Some FL symbols can be indicated as DL symbols or UL symbols via DCI.

[0099] [Non-contention random access procedure] Terminals located at the edge of a cell can repeatedly transmit uplink (UL) signals / channels to the base station to deliver UL services to the base station. This improves the signal-to-interference-plus-noise ratio (SINR) at the base station and reduces the block error rate (BLER). In this disclosure, UL signals / channels can refer to UL signals and / or UL channels, and downlink (DL) signals / channels can refer to DL signals and / or DL ​​channels. The base station can instruct the terminal to repeatedly transmit UL signals / channels, and the terminal can repeatedly transmit UL signals / channels based on the base station's instructions. The base station can instruct the terminal to repeatedly receive DL signals / channels, and the terminal can repeatedly receive DL signals / channels based on the base station's instructions. When UL time slots are infrequent, the terminal may experience long delays to obtain sufficient UL time slots for repeated transmission. For example, when the configuration mode is "DDDSU" and the subcarrier spacing (SCS) is 30 kHz, UL time slots may occur every 2.5 ms. In this case, the time required for four repeated transmissions of the UL signal / channel could be 10 ms.

[0100] When slight coupling occurs between DL and UL communications, separate Rx filtering or Rx processing operations can be performed in the base station, but separate Tx filtering or Tx processing operations may not be necessary in the terminal. The filtering operation can be a radio frequency (RF) filtering operation. When performing RF filtering operations, spectral emissions affecting adjacent physical resource blocks (PRBs) (e.g., out-of-band (OOB) emissions or adjacent channel leakage ratio (ACLR)) can be reduced, and saturation of RF components can be prevented.

[0101] A base station can establish a Radio Resource Control (RRC) connection with a terminal to handle the terminal's service requests. A large number of unspecified terminals can select or reselect a base station through a cell search process. The base station (or cell) can periodically transmit synchronization signals and / or system information. System information is divided into Master Information Blocks (MIBs) and System Information Blocks (SIBs), and SIBs can be further divided into SIB1, SIB2, etc. Various SIBs can be referred to as SIBx. Terminals can use MIBs and SIBx to camp on a specific base station (or cell). Synchronization signals and MIBs can be combined and transmitted as Synchronization Signal Blocks (SSBs). In the following text, SIBx primarily refers to SIB1, but is not necessarily limited to it.

[0102] When a DL service destined for a specific terminal occurs in a network or base station, the network or base station may send paging messages to a large number of unspecified terminals in order to establish an RRC connection with the specific terminal. The specific terminal may receive the paging message and perform random access with the base station to establish an RRC connection.

[0103] When a UL service is available to be sent from the terminal to the network or base station, the terminal can perform random access to establish an RRC connection with the base station where the terminal is camped. After the RRC connection is established, the terminal can be controlled by the serving cell or base station, and the terminal can send and receive data with the serving cell or base station.

[0104] Since the base station is unaware of the status of the terminals camped on it, it can periodically transmit SSB, SIB1, and / or SIBx, and power consumption may not decrease accordingly. For example, during normal operation, the base station can transmit SIB1 and / or SIBx at predetermined intervals. When operating in low-power mode, the base station can transmit SIB1 and / or SIBx at longer intervals, or it may not transmit SIB1 and / or SIBx at all.

[0105] The base station may transmit SIB1 and / or SIBx upon request from the terminal. Since the SSB is transmitted periodically, information indicating that SIB1 and / or SIBx should not be transmitted can be broadcast via the MIB transmitted along with the SSB. In this case, the MIB may include separate information indicating that SIB1 and / or SIBx should not be transmitted, or it may include implicit information indicating that SIB1 and / or SIBx should not be transmitted. Alternatively, SIB1 and / or SIBx may not be transmitted by not transmitting the control channel (or CORESET 0 and Type0-PDCCH CSS set) used for scheduling SIB1 and / or SIBx.

[0106] In an exemplary embodiment, the MIB may indicate whether the SSB including the MIB is a cell-defined (CD)-SSB or a non-cell-defined (NCD)-SSB. The MIB may include information for deriving a control resource set (CORESET), which includes information derived from... ControlResourceSetZero The configured Type0-PDCCH CSS set and by SearchSpaceZero The configured PDCCH timing. The MIB may include an index indicating the multiplexing mode of the SSB and CORESET, the bandwidth of the CORESET, the number of symbols in the CORESET, and / or the resource block (RB) offset. When the SSB and CORESET are not multiplexed, the SSB may be referred to as the NCD-SSB. In NR systems, when k is used to determine the frequency location of the SSB... SSB When the value is less than a specific value, it is determined by k. SSB SSBs transmitted at a defined frequency location can be classified as CD-SSBs, and the terminal can search the Type 0-PDCCH CSS set. On the other hand, when k SSB When the value of belongs to the remaining range (i.e., equal to or greater than a specific value), it is determined by k. SSBSSBs transmitted at a defined frequency location can be classified as NCD-SSBs, and the terminal may not need to search the Type0-PDCCH CSS set. When the received SSB is an NCD-SSB, the terminal can perform a cell reselection procedure again to receive a CD-SSB. The base station can transmit NCD-SSBs in a mode without transmitting SIB1, and can also transmit CD-SSBs in a mode that transmits SIB1.

[0107] In an exemplary embodiment, the terminal may determine whether to transmit SIB1 and / or SIBx based on the presence of a CORESET demodulation reference signal (DM-RS) (or PDCCH DM-RS). For example, the terminal may assume that SIB1 is transmitted when the CORESET DM-RS (or PDCCH DM-RS) exists, and may assume that SIB1 and / or SIBx are not transmitted when the CORESET DM-RS (or PDCCH DM-RS) does not exist. When SIB1 is not transmitted, the terminal may perform the cell reselection procedure again.

[0108] In an exemplary embodiment, k can be changed relative to the frequency position used to determine the transmission SSB. SSB The specific value or k being compared SSB The value of k. For example, when using a pre-defined counter and the counter expires, a specific value or k can be changed. SSB The value. The changed specific value may indicate CD-SSB or NCD-SSB, and may indicate the type of SSB that is different from the type of SSB indicated by the specific value before the change (e.g., CD-SSB or NCD-SSB).

[0109] Optionally, the k indicating NCD-SSB (or CD-SSB) SSB It can be changed to indicate another k of CD-SSB (or NCD-SSB). SSB In other words, k belongs to the range corresponding to NCD-SSB (or CD-SSB). SSB It can be changed to fall within the range corresponding to CD-SSB (or NCD-SSB). Therefore, the terminal can use the value of the counter or k SSB The changes are used to predict when the base station will transmit SIB1 and / or SIBx.

[0110] According to the above method, the base station may transmit or not transmit SIB1 and / or SIBx as needed. Conditions can be defined for switching from a mode that does not transmit SIB1 and / or SIBx (or a mode that transmits SIB1 and / or SIBx) to a mode that transmits SIB1 and / or SIBx (or a mode that does not transmit SIB1 and / or SIBx), and the base station and / or terminal can determine whether the conditions are met.

[0111] Alternatively or concurrently, the terminal may send a UL Discovery Signal (DRS) or Physical Random Access Channel (PRACH) to the base station to request a change in the transmission mode of SIB1 and / or SIBx. For the terminal to send the UL DRS, it may need to establish an RRC connection with the base station or use PRACH. The base station may need to indicate to the terminal the resources and various configuration information for the UL DRS. Similarly, to send the PRACH, it may need to indicate to the terminal information regarding the Random Access (RA) Timing (RO). The method of changing the transmission mode of SIBx using PRACH (or PRACH preamble) is described in detail below.

[0112] To transmit PRACH, a terminal can generate and modulate a preamble based on the sequence defined in the technical specification and the configuration information of the Information Elements (IEs) included in SIBx, and can allocate appropriate transmission power. Additionally, the terminal can derive information about the RO set from another IE included in SIB1 and / or SIBx, and can select a specific RO from the RO set to transmit PRACH. Therefore, the Random Access Channel (RACH) configuration derived from its PRACH and / or ROs may need to be passed to a large number of unspecified terminals.

[0113] Terminals can derive the resource location of RO in the time domain using the PRACH configuration index. The PRACH configuration index can be interpreted based on the frequency band and duplex scheme of the transmitted PRACH. For example, the PRACH configuration index in a frequency division duplex (FDD) system (e.g., an FDD system supporting frequency range 1 (FR1)) can be interpreted differently from the PRACH configuration index in a time division duplex (TDD) system (e.g., a TDD system supporting FR1). The PRACH configuration index in FR1 can be interpreted differently from the PRACH configuration index in FR2. Table 1 below shows a portion of the PRACH configuration index in a communication system supporting FR1.

[0114] [Table 1]

[0115] Additionally, Table 2 below represents a portion of the PRACH configuration index in communication systems that support FR2.

[0116] [Table 2]

[0117] Because the PRACH configuration index is received via system information, the terminal performing the random access procedure (e.g., the initial access procedure) can interpret the same PRACH configuration index. The base station can indicate one or two PRACH formats to the terminal, and the two PRACH formats can coexist. To enable the coexistence of two PRACH formats, the two PRACH formats may include cyclic prefixes (CP) of different lengths and / or guard times (GT) of different lengths. In this case, the PRACH preambles of the two PRACH formats can have the same length.

[0118] According to Table 1, when the PRACH configuration index is 106 and the result of (System Frame Number (SFN) mod 1) is 0, the terminal can select a subframe with a subframe index from 0 to 9. In Tables 1 and 2, This can represent the system frame number. That is, the terminal can transmit PRACH in all subframes. One subframe can correspond to two PRACH slots, and one PRACH slot can include six ROs. The terminal can transmit PRACH in six locations (e.g., six ROs) within a PRACH slot. PRACH can use the preamble format A1, and the duration of PRACH can correspond to two symbols.

[0119] When instructing PRACH configuration index 114, the terminal may use preamble format A1 or preamble format B1. The number of PRACH locations (e.g., ROs) that can be transmitted within a PRACH time slot can be seven.

[0120] The base station can indicate or configure an association mode period to the terminal. An association mode period can include one or more association periods. An association mode period including RO can be repeated within 160 milliseconds (ms). Here, 160ms can be related to the transmission period of SIB1.

[0121] When an association period is used for a system information request, the base station can indicate the index of the association period to the terminal. This can be done via RRC signaling (e.g., based on...). ssb-PositionsInBurst The minimum value among all integer multiples of the patterns of all ROs corresponding to all SSBs is derived from the number of SSBs indicated to the terminal. The derivable minimum value can be defined in the technical specifications in Table 3 below.

[0122] [Table 3]

[0123] For example, the PRACH configuration period can be derived based on the PRACH configuration index indicated to the terminal. When the PRACH configuration index is indicated as 11 in Table 2, x is 2, therefore, the length of the PRACH configuration period can be considered as 20ms. Subsequently, the time required to map all SSBs to RO can be derived based on the number of SSBs. A value of {1, 2, 4, 8} can be selected from Table 3, and when 4 is selected from Table 3, the length of the period including the four associated periods can be interpreted as 80ms. In this case, the length of each of the four associated periods can be 20ms, and the associated pattern period can be repeated twice.

[0124] A single SSB can be mapped to multiple ROs. Optionally, multiple SSBs can be mapped to a single RO. The base station can indicate the mapping information between SSBs and ROs to the terminal via RRC signaling. Here, the mapping information between SSBs and ROs can be... ssb- perRACH-OccasionAndCB-PreamblesPerSSB The terminal can be based on ssb-perRACH-OccasionAndCB- PreamblesPerSSB The value is derived from (N, R). In (N, R), N can refer to the number of SSBs mapped to a RO, and R can refer to the number of PRACH preambles. N can be equal to or greater than 1. When N > 1, multiple SSBs can be mapped to a single RO. Optionally, N can be less than 1. When N < 1, one SSB can be mapped to multiple ROs.

[0125] According to standard technical specifications, an association period that is an integer multiple of the associated period can constitute an association mode period. An association mode period can be introduced to repeat the same SSB-RO mapping at a maximum period of 160ms based on the radio frame number. However, the association mode period may not exactly match an integer number of associated periods, and some ROs may not be included in the associated period. In this case, the SSB may not be mapped to the corresponding RO. This extends to ROs mapped in Subband Full-Duplex (SBFD) resources. That is, an RO mapped in an SBFD resource is considered a valid RO only if it belongs to an associated period mapped to a UL resource.

[0126] The RA procedure executed by the terminal can be either a contention-based RA (CBRA) or a non-contention-based RA (CFRA). In a non-contention-based RA, the terminal knows information about the generation of the preamble and the resource location of the RO. Furthermore, when the resource location of the RO is not configured or indicated to the terminal during a CFRA, the corresponding RO can be shared with the resources used in a contention-based RA.

[0127] Performing CFRA when the terminal has not yet established an RRC connection with the base station could correspond to, for example, the terminal sending a preamble to the base station where it is camped in order to receive SIBx. On the other hand, performing CFRA when the terminal has already established an RRC connection with the base station could correspond to, for example, the terminal sending a preamble to request the re-establishment of the RRC connection with the serving cell.

[0128] For example, a base station may send SIBx with a very long period or not send SIBx at all, and terminals camped on the base station may receive RACH configuration information via SIB1. When some of these terminals transmit PRACH, the base station may send SIB1 with a shorter period. In other words, terminals transmit PRACH to allow the base station to adjust the transmission period of the SIBs, thereby changing the transmission mode of the SIBs.

[0129] SIB1, transmitted at a very long interval or upon request from the terminal, may contain only simplified information. That is, SIB1 may not include all the information used to perform random access and may only include the information required to derive the PRACH for the SIB1 request and its associated RO set. SIB1 can be a simplified SIB, can be defined separately, and can be the information required for PRACH transmission. When the terminal transmits PRACH in a specific RO, the base station may subsequently transmit SIB1 at a shorter interval, or may begin transmitting SIB1.

[0130] Figure 3 This is a sequence diagram illustrating a method for a terminal to trigger a base station where the terminal is camped to send SIB1 or SIBx using UL DRS, according to an exemplary embodiment of the present disclosure.

[0131] Reference Figure 3 The configuration information of the UL DRS or RACH preamble can be indicated from the base station to the terminal via DCI, RRC signaling, SSB and / or SIB1 (S310).

[0132] For example, a base station may transmit a separate DCI format to provide unspecified terminals with the information needed to derive the PRACH sequence and a set of ROs that can be derived from the RACH configuration. The proposed DCI format may or may not be scheduled for PDSCH. The proposed DCI format can be scrambled using System Information-RNTI (SI-RNTI), or a separate RNTI can be applied to the proposed DCI format. For example, a CORESET or search space set including the DCI format can be derived from the time resources (e.g., time slots or symbols) of the received DCI format. Optionally, values ​​transmitted by signaling from higher layers can be applied.

[0133] Resources receiving the proposed DCI format may belong to the Type 0-PDCCH CSS set and may be received over a period of two radio frames. Alternatively, resources may be received over a single period. For example, the proposed DCI format may have different reception periods in systems operating at FR1 and FR2. In the case of system operation at FR2, the reception period of the proposed DCI format may be the same as the reception period of the SSB. Here, the SSB can provide quasi-co-location (QCL) information or receive beam-related information associated with the DCI format.

[0134] The proposed DCI format may include at least preamble information, UL symbol location information, RO set information, and SSB index. Since the proposed DCI format indicates the PRACH and RO sets used to trigger SIB1 transmission, it can be configured to provide simplified information compared to SIB1. For example, when a base station triggers SIB1 transmission via an on / off keying (OOK) scheme, there may be no need to resolve conflicts between unspecified terminals. Optionally, even when a conflict occurs, this can be considered a non-contention RA (CFRA). Therefore, the preamble index can be indicated in the DCI.

[0135] The PRACH configuration index indicates the UL resources from which ROs can be transmitted. By deriving the UL symbol positions in the UL resources indicated by the PRACH configuration index based on information about the time slot mode, only valid ROs can be selected. Furthermore, by individually indicating the frequency resources of the ROs, it is possible to derive how many ROs can be frequency-division multiplexed (FDM) within the same time resources. Through this process, the terminal can identify the required parameters, derive the RO set, and select the RO corresponding to the selected SSB (S320). Here, the required parameters can be derived from the RACH configuration information and obtained from the information included in SIB1. However, when configuring the PRACH and ROs to change the transmission mode of SIB1, simplified information may be sufficient.

[0136] Additionally, the terminal can send a RACH preamble (Msg1) or UL DRS to the base station in the selected RO (S330), and can receive SSB / DCI / SIB1 / SIBx from the base station in response to Msg1 (S340).

[0137] Furthermore, the proposed DCI format can indicate whether SIB1 or SIBx will be sent later or is currently being sent. For this purpose, a separate information field can be used in the DCI, or the information can be derived by using another value from an existing information field. For example, the information indicating that SIB1 or SIBx will be sent can be represented as a counter. In this case, when the counter expires, the transmission of SIB1 or SIBx can be expected.

[0138] Furthermore, a transmission time window for SIB1 or SIBx can be defined. For example, based on the length of the time window (e.g., 160ms) and the radio frame offset or subframe offset, SIB1 or SIBx may not be transmitted within the time window in which the DCI is received, but can be expected to be transmitted in the next time window when a specific information field of the DCI has a specific value. By using such information, even when SIB1 or SIBx is not received, the terminal can wait for the next time window without transmitting PRACH. Here, the length of the time window can be the reception period P of SIB1 or the reception period of the Type 0-PDCCH CSS set derived from existing technical specifications.

[0139] In another method, when the terminal triggers the base station where the terminal is camped to send SIB1 or SIBx by using UL DRS (or PRACH preamble), the base station can respond to UL DRS or PRACH preamble by sending SIB1 or SIBx to the terminal.

[0140] Figure 4 This is a sequence diagram illustrating a method for a terminal to trigger a base station where the terminal is camped to send SIB1 or SIBx using UL DRS, according to another exemplary embodiment of the present disclosure.

[0141] Figure 4 The process is similar to the CFRA process. In the CFRA process, the terminal sends a PRACH preamble to the base station where it is camped, enabling the base station to transmit Other System Information (OSI) according to standard technical specifications. According to these specifications, when the base station receives the PRACH preamble from the terminal, it sends a Random Access Response (RAR), and the terminal can anticipate the OSI transmission by receiving the RAR. If no RAR is received within a predetermined time, the terminal can retransmit the preamble to the base station.

[0142] In the proposed method, it can be combined with Figure 3 Steps S410 and S420 are performed in the same or similar manner as steps S310 and S320. The terminal may execute the CFRA procedure to send a preamble (S430). The response to the CFRA executed by the terminal may be received as SIBx in message 2 (Msg2) (S440).

[0143] The stationary base station can send SIB1 or SIBx to the terminal, enabling the terminal to receive SIB1 or SIBx. The terminal can then determine the appropriate method for receiving SIBx. searchSpaceSIB1 or searchSpaceOtherSystemInformation To monitor the search space and decode the scheduled SIBx, but not to monitor the search space used for RAR reception. ra-SearchSpace .

[0144] In another proposed method, the response to the CFRA executed by the terminal can be received as SIB1, SIBx, or RAR.

[0145] Figure 5 This is a sequence diagram illustrating a response monitoring process for a terminal receiving RAR, SIB1, or SIBx according to another exemplary embodiment of the present disclosure.

[0146] Reference Figure 5 The terminal can send a preamble to the base station (S510) and can receive SIB1, SIBx, or RAR from the base station in response to the preamble (S520). The terminal can monitor the... ra-SearchSpace , searchSpaceSIB1 or searchSpace OtherSystemInformation The indicated search space is used to receive responses to the preamble sent to the base station. The terminal may consider the reception of a RAR, SIB1, or SIBx as a reception of a response. When a response is received, the terminal may not monitor another search space to search for a response to trigger the transmission of the SIB or SIBx within a predetermined time after the reception time of that response. Here, the predetermined time can be derived in association with the processing time used by the terminal to demodulate and / or decode the DCI that schedules the RAR, SIB1, or SIBx.

[0147] In the proposed method, when the terminal repeatedly sends the preamble, the terminal can monitor the search space of the scheduling response based on the first RO.

[0148] The terminal can receive SSBs from the base station, and when the received strength of the SSB (e.g., Reference Signal Received Power (RSRP) or Reference Signal Received Quality (RSRQ)) exceeds a certain threshold, the terminal can receive SIB1 or SIBx. Optionally, when the RSRP or RSRQ derived by the terminal does not exceed the certain threshold, the terminal may not receive SIB1 or SIBx.

[0149] Here, the threshold applied to SIBx can be derived from the base station's SIB1. When the terminal cannot receive SIB1 or SIBx from the base station, the terminal may be unable to camp on the base station. Optionally, the threshold applied to SIB1 or SIBx can be determined by the terminal based on the value derived from SIB1 or SIBx received from another base station.

[0150] Therefore, the terminal can derive a specific SSB index. A threshold can be used by the terminal to determine the RO set during a random access procedure. Optionally, the threshold can be used to determine the number of preamble transmissions during random access.

[0151] For example, the terminal can derive the number of preamble transmissions and / or the size of the RO group corresponding to the selected SSB index by using multiple thresholds. The number of transmissions can include at least 1, 2, 4, and 8. The RO group can consist of valid ROs and can consist of the same number of ROs as the number of transmissions.

[0152] Valid ROs belonging to the RO group can have the same frequency resources or can have temporally continuous resources. However, depending on the parameters and slot patterns associated with the SSB-RO mapping, valid ROs may not necessarily have continuous temporal resources.

[0153] Figure 6 and Figure 7 This is a sequence diagram illustrating the operation of a terminal when SIB1 and / or SIBx are triggered by multiple terminals according to an exemplary embodiment of the present disclosure.

[0154] Reference Figure 6 The first terminal may send a preamble to the base station (S610). The first terminal may be configured to send the preamble at least twice. Optionally, the first terminal may send the preamble at least once. The base station may send a response (e.g., RAR, SIB1, and / or SIBx) to the first terminal and the second terminal (S620, S630). The RAR, SIB1, and / or SIBx transmitted in steps S620 and S630 may be RAR, SIB1, and / or SIBx transmitted via triggering by the second terminal, and the second terminal may receive the response.

[0155] Regardless of step S610, the first terminal can receive a response (S620). However, the RAR, SIB1, and / or SIBx transmitted in step S620 may be independent of the triggering by the first terminal according to step S610. Therefore, the first terminal needs to send the preamble at least again, and in step S640, all or part of the remaining preamble may then be sent.

[0156] On the other hand, although the RAR, SIB1, and / or SIBx transmitted in step S620 are not triggered by step S610, the response may include the same content as the information requested by the first terminal based on the triggering in step S610. For example, the presence of the response (RAR, SIB1, and / or SIBx) received and decoded in layer 1 (L1) of the first terminal may be notified to layer 2 (L2) of the first terminal. Thus, L2 of the first terminal may instruct L1 of the first terminal to discard the additional preamble transmission.

[0157] Reference Figure 7The first terminal may discard the remaining preamble to be transmitted after receiving a response to the preamble transmission (S610) (S650). According to the proposed method, when the operation of discarding the preamble transmission is performed, although all or part of the preamble in the first terminal is discarded, the discarding may not affect the power ramp counter, backoff indicator, another timer, or another counter.

[0158] Refer again Figure 6 and Figure 7 The response demodulated and decoded by the first terminal can be a response to the second terminal. When the response can be considered as SIB1 and / or SIBx, the response can be a downlink shared channel (DL-SCH) scheduled by DCI scrambled with system information RNTI (SI-RNTI). When the response can be considered as RAR, the response can be a DL-SCH scheduled by DCI scrambled with random access RNTI (RA-RNTI). That is, the first terminal can receive the response by deriving an RNTI independent of step S610, which transmits the preamble. Therefore, in order to receive a response to a preamble transmitted by the second terminal, the first terminal may need to separately monitor the search space and apply a separate RNTI.

[0159] Furthermore, regarding the preamble index, the first terminal can receive a response from the base station by using all or part of the preamble index that is not used by the first terminal but is considered to be used by the second terminal. For example, the first terminal can determine the validity of the RAR by using two or more Random Access Preamble Identifiers (RAPIDs).

[0160] Figure 8 and Figure 9 This is a timing diagram illustrating a method for determining whether to discard a preamble according to an exemplary embodiment of the present disclosure.

[0161] Reference Figure 8When CFRA is triggered, the first terminal can select a first SSB and can transmit a preamble twice using RO 2 and RO 10, which belong to the RO set associated with the first SSB. Between time slot 810 for transmitting RO 2 and time slot 830 for transmitting RO 10, time slot 820 for receiving SIB1, SIBx, and / or RAR can appear. According to the proposed method, the terminal can transmit the preamble in RO 10 or discard the preamble based on the value of Δ, which is the interval between time slots 820 and 830. Δ can include not only the processing time required for the terminal to demodulate and decode the DCI and respond, but also the time required to indicate the presence of the response and the subsequent procedures to be performed from the terminal's layer 1 (L1) to the terminal's layer 2 (L2). The value Δ can be determined in the technical specification for each subcarrier interval (SCS), or a value can be determined for a reference SCS and converted to an appropriate value by applying the SCS of the activated DL / UL BWP, or the value Δ can be indicated to the terminal via RRC signaling.

[0162] Reference Figure 9 Time slot 910 for receiving SIB1, SIBx, and / or RAR may occur before time slot 920, when the first terminal begins transmitting a preamble at least once using RO 2, which belongs to the RO set associated with the selected first SSB. In this case, the terminal may transmit the preamble in RO 2 or may discard the preamble. According to the method described above, the terminal may transmit the preamble in RO 2 or may discard the preamble based on the value of Δ, which is the interval between time slots 910 and 920. The conditions for deriving Δ or the method for indicating Δ have been described above. Here, the terminal may transmit the preamble more than once. In this case, RO 2 may represent the RO that performs the first transmission of the preamble.

[0163] After CFRA is triggered, the terminal can receive scheduling information for SIB1 and / or SIBx after a predetermined first time T1 since the transmission of the preamble. Additionally, upon receiving RAR, the terminal can receive scheduling information for SIB1 and / or SIBx after a predetermined second time T2 since the transmission of the preamble.

[0164] For example, T1 and T2 can be different from each other. T1 can be related to the time required for the stationary base station to demodulate the preamble, perform modulation and coding processes for SIB1 and / or SIBx, and schedule SIB1 and / or SIBx. Alternatively, the stationary base station can transmit SIB1 and / or SIBx in response to a trigger for SIB1 and / or SIBx from another terminal, rather than receiving a preamble from that terminal. Therefore, T1 can be the same as the time corresponding to the gap symbol between SSB and RO.

[0165] T2 can be related to the time required for the stationary base station to demodulate the preamble, perform modulation and encoding processes for the RAR, and schedule the RAR. Optionally, the stationary base station can transmit the RAR in response to a trigger for SIB1 and / or SIBx from another terminal, rather than receiving the preamble from that terminal.

[0166] Figure 10 This is a conceptual diagram showing examples of valid ROs derived from selected SSBs in chronological order.

[0167] Reference Figure 10 This shows the set of ROs derived from the selected first SSB. Here, RO 1 can represent the index that restarts when the mapping cycle restarts. Figure 10 For ease of description, only one frequency resource is shown defined, but the exemplary embodiments of this disclosure are not limited thereto. When the number of transmissions is 2, 4, or 8, in order to perform CFRA, the terminal may use RO 1 to RO 2, RO 1 to RO 4, or RO 1 to RO 8 as RO groups.

[0168] During CFRA, it may be possible to individually indicate the time offset to the terminal via RRC signaling or to derive the time offset from SIB1 or SIBx. In this case, the time offset can be indicated as a separate value for the number of preamble transmissions (i.e., the RO group size). Here, the time offset can represent the interval between the first ROs of the RO group. For example, the time offset can be derived from... msg1-RepetitionTimeOffsetROGroup instruct.

[0169] A group of origin (RO) can consist of ROs belonging to the previous mapping period and ROs belonging to another mapping period. However, even if two adjacent RO groups have different mapping periods, the time offset interval can be maintained. Therefore, even if the mapping period restarts, the RO group may not start mapping from RO 1. However, to save base station power consumption, a function is needed to align the starting ROs of the RO groups with each other. That is, although the set of RO groups (i.e., the RO group set, the RO group grid) is derived differently for each transmission, when the mapping period restarts, it may be preferable that the starting ROs of the RO group set are aligned with each other, even if the RO groups are different in size.

[0170] Figure 11 and Figure 12 This is a conceptual diagram illustrating an example of overlapping RO sets and how RO sets are represented as their union.

[0171] When the terminal selects the first SSB and derives the number of transmissions accordingly, the size of the RO group can be determined. Therefore, when performing the CFRA procedure, the terminal can select a set of RO groups based on the mapping period and can transmit the preamble in RO groups starting from RO 1. When the size of the RO group is large and the mapping period is short, an RO group can be included in two or more mapping periods.

[0172] Reference Figure 11 When the CFRA procedure is triggered in the first mapping cycle, the terminal can transmit the preamble by using the RO group belonging to RO group set 1120. Here, the selected RO group can start from RO 1. Similarly, when the CFRA procedure is triggered in the second mapping cycle, the terminal can transmit the preamble by using the RO group belonging to RO group set 1130. Here, the selected RO group can start from RO 1.

[0173] Reference Figure 12 RON-1, RON, RO1, and RO2 can constitute an RO group. Since the mapping cycle restarts, the indexes for ROs can start from 1 again according to the restarted mapping cycle. Optionally, ROs can be indexed within each RO group set, and the indexes of ROs belonging to RO groups can be indexed as RON-1, RON, RON+1, and RON+2.

[0174] A CFRA procedure can be executed to trigger the transmission of SIB1 or SIBx. According to the proposed method, when triggering the transmission of SIB1 or SIBx, a time offset can be taken into account, and the time offset can be reapplied when the mapping period changes.

[0175] In another proposed method, a separate DCI format can be defined, including information indicating that SIB1 or SIBx will be scheduled, instead of including separate information in the existing DCI format. The search space set for monitoring the DCI format can be either the Type0-PDCCH CSS set or the Type0A-PDCCH CSS set, or a separate search space set for monitoring the DCI format can be indicated to the terminal. For example, when no search space set is indicated, either the Type0-PDCCH CSS set or the Type0A-PDCCH CSS set can be used, but even when a search space set is indicated, either the Type0-PDCCH CSS set or the Type0A-PDCCH CSS set can be used. For example, even when a search space set is indicated, the terminal can monitor either the Type0-PDCCH CSS set or the Type0A-PDCCH CSS set to monitor both search space sets.

[0176] When the number of transmissions is fixed at a value L, the set of RO groups can be considered in a first period N, in which the RO groups associated with all SSBs are mapped at least once. The first period can vary for each number of transmissions L. A second period can be formed by multiple first periods. The second period can be a period that maps RO groups to all SSBs at least once for all transmissions. Therefore, the second period can be interpreted as a minimum period that includes at least one or more integer multiples of the first period N, and in this case, the integer multiples can be derived differently for each number of transmissions L. The second period can occur periodically based on the radio frame number or SFN. In this case, the terminal can derive the second period without indicating a time offset, or even if a time offset is indicated, the terminal can derive the second period without considering the time offset.

[0177] When considering the second cycle, the terminal may take into account the time offset. When a different time offset is indicated for each transmission count, the terminal may not use some of the RO groups in the final first cycle constituting the second cycle. These RO groups may be determined as valid RO groups, but the terminal may not use them to transmit the preamble.

[0178] Unused RO groups can be RO groups that cross the boundaries of the second period. That is, in a set of ROs that repeat in the second period, some RO groups can be distributed across the boundaries of the second period. For example, an RO group can belong to different second periods, and different second periods can belong to different SFNs.

[0179] Figure 13 This is a conceptual diagram illustrating an exemplary embodiment where sets of RO groups overlap in time and are mapped at the boundary of a second period.

[0180] Reference Figure 13 Although RO groups are represented as RON-1, RON, RO1, and RO2, they can be mapped to the boundaries of the second period. Such RO groups may not be used by the terminal. This is because isolated ROs exist due to time offset considerations. In this case, the terminal can use RO groups belonging to the new second period (i.e., RO1, RO2, RO3, and RO4) to transmit the preamble.

[0181] When the number of transmissions constituting an RO group is given as one of 2, 4, or 8, the individual RO groups corresponding to different transmission numbers may be derived to overlap with each other. That is, ROs overlapping between RO groups correspond to ROs shared between RO groups, and the number of transmissions can be considered as different combinations of characteristics. A time offset can be indicated for each transmission number, and the time offset can be given as an integer multiple of the number of transmissions. In particular, the time offset can have constraints based on the number of transmissions L. For example, when L=8, the time offset can be 16. For example, when L=4, the time offset can be 8 or 16. For example, when L=2, the time offset can be 4, 8, or 16.

[0182] When considering the second cycle, it is possible to Figure 14 The example below shows the final set of RO groups.

[0183] Figure 14 This is a conceptual diagram illustrating an exemplary embodiment in which the set of RO groups is mapped in time at the boundary of the second period without overlapping.

[0184] Reference Figure 14 In the case of a typical set of RO groups, the time offset can be indicated differently for cases with 2, 4, or 8 transmissions. For example, the time offset for cases with 2, 4, or 8 transmissions can be 8 (the difference between RO group 10 and RO group 20), 16 (the difference between RO group 60 and RO group 70), and 16 (the difference between RO group 90 and RO group 100), respectively.

[0185] However, the time offset for the final RO groups 30, 40, 50, 70, 80, 100, and 110 belonging to the second cycle can be derived differently from the aforementioned time offset (8 or 16). This is because, although the second cycle is derived by applying the same number of associated cycles or associated pattern cycles (i.e., the first cycle mentioned above), unused ROs appear in the associated cycles or associated pattern cycles. Because the number of ROs required for each RO group corresponding to each transmission number is different, the final RO groups in the second cycle may not be nested.

[0186] Refer again Figure 14 When the number of transmissions is 2, the difference between the starting RO of RO group 40 and the starting RO of RO group 50 is 6, which may differ from the time offset 8 mentioned above. When the number of transmissions is 4, the difference between the starting RO of RO group 70 and the starting RO of RO group 80 is 14, which may differ from the time offset 16 mentioned above. When the number of transmissions is 8, the difference between the starting RO of RO group 100 and the starting RO of RO group 110 is 14, which may differ from the time offset 16 mentioned above.

[0187] In other words, according to the proposed method, the difference between the starting RO of the last RO group in the second cycle and the starting RO of the first RO group may be different from the time offset determined based on the number of transmissions.

[0188] According to another proposed method, the time offset can be considered based on the number of transmissions, thereby deriving a set of RO groups. A timing period can then be derived from the set of RO groups.

[0189] When this approach is applied, things like... may not occur. Figure 14 The situation is as follows. Because the value of the time offset allowed according to the number of transmissions can be interpreted as another number of transmissions, the set of RO groups corresponding to different number of transmissions can be aligned with the boundary of the second period.

[0190] When CFRA is triggered, a time offset value can be configured or indicated to the terminal via RRC signaling. When the terminal transmits the same preamble two or more times, the mask index may not be configured or indicated. Optionally, even if the mask index is indicated, the terminal may ignore it. Here, CFRA can be interpreted as including... ReconfigurationWithSync , SI- RequestConfig or SI-RequestConfigRepetition The concept of process.

[0191] Table 4 shows examples of time offsets that can be applied in specific cases for CBRA and CFRA. According to this table, time offsets can be... msg1-RepetitionTimeOffsetROGroup This indicates that a single time offset value can be derived based on one or more combinations of features supported by the terminal or BWP in the CBRA environment.

[0192] Resources performing CFRA may belong to a separately indicated first RO group set. Optionally, resources performing CFRA may belong to a second RO group set indicating that CBRA will be performed. This distinction can be determined from the CFRA-related configuration information indicated to the terminal. When CFRA is performed in the first RO group set, a time offset (hereinafter, the first time offset) may be configured separately in the CFRA configuration information, which may differ from the time offset in the CBRA configuration information, or the time offset may not be configured in the CFRA configuration information. When CFRA is performed in the second RO group set, a value corresponding to a specific number of CBRA transmissions (hereinafter, the second time offset) may be directly applied to the CFRA.

[0193] According to the proposed method, when CFRA is performed in the first RO group set, a first time offset can be applied if it is configured. When CFRA is performed in the second RO group set, a second time offset, which is a separate unused value in the CFRA, can preferably be applied. Here, the terminal can be configured not to perform CFRA in the first RO group set. Optionally, the terminal can be configured to perform CFRA in the first RO group set and a first time offset can be configured. Optionally, the terminal can be configured to perform CFRA in the first RO group set and a first time offset can be left unconfigured. The time offset configuration schemes can be combined and applied together.

[0194] Table 5 shows exemplary embodiments of time offsets that can be applied in specific cases of CFRA.

[0195] When the terminal performs CFRA in the set of the first RO group, it can indicate including occasions The Cfra IE. In this case, it can be based on the... occasions and technical specifications RACH-ConfigGeneric To derive the set of the corresponding RO groups (i.e., the set of the first RO groups).

[0196] On the other hand, when the instruction does not include occasions When using Cfra IE, the terminal can be configured based on the first activated ULBWP (i.e., the initially activated UL BWP). RACH-ConfigCommon And use the technical specifications to derive the set of the second RO group.

[0197] According to the proposed method, the terminal can... RACH-ConfigCommon The derived time offset is applied to the set of the second RO group, and this time offset may correspond to the second time offset mentioned above. When indicating multiple transmission counts, the second time offset and the first time offset may be applied as time offset values ​​corresponding to the same number of transmissions.

[0198] The terminal can select an RO group from the exported set of RO groups and perform CFRA. Based on the CFRA configuration information, this may include not only information about the RO set but also identifiers or indices of one or more SSBs or CSI-RSs, indicating which RO group within the RO set is associated with the SSB or CSI-RS to select. When performing the CFRA procedure after the terminal has established an RRC connection, the CSI-RS identifier can be indicated, and Msg1 can be sent in the RO or RO group associated with the corresponding CSI-RS. When the terminal performs CFRA before establishing an RRC connection, re-establishes an RRC connection, or requests SIB1 and / or SIBx from the base station, the CFRA procedure using the SSB can be performed.

[0199] CFRA configuration information can be indicated in the form of a mask or mask index, specifying which resources in the RO set and associated with a particular SSB or CSI-RS are allowed or not allowed to be sent by Msg1. The terminal can determine from the mask whether an RO in the RO set is valid for the CFRA process or not.

[0200] The mask can indicate the RO group or the index of the RO, and can be reset and assigned for each mapping period derived from the PRACH associated index. The order in which the RO indexes are assigned follows the technical specifications used for mapping SSBs and ROs, and can be derived from the indexes of the RO's frequency and time resources.

[0201] According to another proposed method, the terminal can include cfra The individual time offset in IE is applied to the set of the second RO group, instead of from... RACH-ConfigCommon The exported time offset is applied to the set of the second RO group. In this case, the applied time offset may correspond to the third time offset.

[0202] Depend on cfra The information indicated by the IE can be applied to the parameters required for a single transmission. The camped cell can configure or indicate three or fewer parameters to the terminal. cfra IE, and can be accessed via ReconfigurationWithSync Process exported RACH- ConfigDedicated IE configuration cfra IE.

[0203] When configured SI-RequestConfig IE or SI-RequestConfigRepetition In Internet Explorer, you can select from the options included in the corresponding IE browser. RACH-ConfigGeneric Export RO groups. However, according to standard technical specifications, it may be difficult to explicitly export RO groups configured in this way.

[0204] A method could be proposed in which the terminal originates from... SI-RequestConfig IE or SI- RequestConfigRepetition IE exports the collection of the first RO group. Time offsets can be included. SI- RequestConfigRepetition In IE, it can be considered as the first time offset.

[0205] Furthermore, different first time offsets can be included for each number of transmissions. Table 6 shows exemplary embodiments of time offsets that can be applied in specific cases of SI requests. According to Table 6, transmission numbers of 2, 4, 8, or combinations thereof can be supported, and time offsets can be configured in a one-to-one correspondence according to such combinations.

[0206] According to another proposed method, the time offset can be indicated as a single value and can be applied collectively regardless of the number of transmissions. In this case, the time offset... value It can be given as an integer multiple of the maximum number of transmissions, such that the integer multiple relationship is satisfied under all transmission count conditions.

[0207] According to another proposed method, it is not possible to... SI-RequestConfigRepetition The value in IE indicates the time offset, and the time offset value applied in CBRA can be reused.

[0208] When indicating multiple transmission counts to the terminal, the applied time offset can be limited to the same number of transmissions indicated in the SI request as the number of transmissions for which the time offset is applied in the CBRA. In other words, for different transmission counts, the time offset applied to the SI request can be a value derived from the time offset of the CBRA method with the same number of transmissions.

[0209] Referring again to Tables 5 and 6, Cond Msg1Rep3 to Cond Msg1Rep6 This indicates the conditions under which the time offset can be included in the IE. Here, Cond Msg1Rep3 Indicator msg1-Repetitions Included Feature Combination The situation in the middle. Cond Msg1Rep4 to Cond Msg1Rep6 It can indicate the corresponding number of transmissions. si- RequestResourcesRepetitionNum2 to si-RequestResourcesRepetitionNum8 Conditions that can be included in IE.

[0210] [Table 4]

[0211]

[0212] [Table 5]

[0213]

[0214] [Table 6]

[0215] [Msg1 scan] The terminal can measure the RSRP of an SSB and select one SSB. The RSRP of the selected SSB can belong to one of several segments defined by multiple boundary values. For example, when boundary values ​​1 to 3 are indicated to the terminal in ascending order, if the RSRP of the selected SSB belongs to the segment from boundary value 0 to boundary value 1, the number of transmissions can be determined as 1; if the RSRP belongs to the segment from boundary value 1 to boundary value 2, the number of transmissions can be determined as 2; if the RSRP belongs to the segment from boundary value 2 to boundary value 3, the number of transmissions can be determined as 3; and if the RSRP belongs to the segment with boundary value 3 or greater, the number of transmissions can be determined as 4. Here, the number of transmissions can indicate the number of times the terminal repeatedly sends Msg1 to the camped base station (or serving base station). Here, the number of transmissions from 1 to 4 can be arranged in ascending order, and all can have a value greater than 1. The number of transmissions and boundary values ​​can be indicated to the terminal via RRC signaling. The number of transmissions and boundary values ​​can be included in SIB1 and can be indicated to the terminal in the RRC idle state.

[0216] For example, the value used for Msg1 repetition can be reused as a boundary value and can also be applied to the Msg1 scan. For example, the boundary value can be indicated independently of the boundary value used for Msg1 repetition and can be applied to the Msg1 scan.

[0217] The terminal can determine the RO group corresponding to the number of transmissions of Msg1. The RO group can consist of multiple ROs located at different times and existing at the same frequency, and multiple ROs can be associated with the same SSB.

[0218] Here, an RO can be interpreted as a unit of resource that a terminal can send once for Msg1, and for an RO group, only valid ROs according to the standard technical specifications can be considered.

[0219] The terminal can maintain the same transmit beam in different ROs. Optionally, the terminal can apply different transmit beams to different ROs. According to standard technical specifications, the terminal can maintain the same transmit beam in all ROs belonging to the RO group.

[0220] The base station can gain gain during reception processing by combining and demodulating all Msg1s corresponding to the number of transmissions. On the other hand, the terminal may not be able to maintain the same transmit beam in some ROs belonging to the RO group. Optionally, the terminal may intentionally apply different transmit beams to transmit Msg1s.

[0221] The base station can attempt Msg1 demodulation in the RO corresponding to each transmit beam, and in doing so, the base station can identify the RO that provides the best reception quality. The identified RO can be interpreted as corresponding to the best transmit beam among the transmit beams used by the terminal.

[0222] Here, the "optimal transmit beam" can be determined in various ways depending on the implementation. For example, the transmit beam with the highest RSRP value in a specific RO can be determined as the optimal transmit beam. Alternatively, the transmit beam with the highest value measured based on a predetermined metric can be determined as the optimal transmit beam. The optimal transmit beam is preferably a transmit beam that can be received at high receive power at the receiving end of the base station.

[0223] The terminal can perform a repeating Msg1 transmission operation while maintaining the transmission beam, and a Msg1 scanning operation that does not maintain the transmission beam and transmits Msg1 with a different beam. Optionally, the terminal can perform only one of the repeating Msg1 transmission operation and the Msg1 scanning operation.

[0224] For example, the operating scheme can be determined based on the terminal's capabilities. In another example, the operating scheme can be determined based on the frequency range (FR) of the system in which the terminal operates. For example, in a system operating in FR1, repeated Msg1 transmissions can be performed, and in a system operating in FR2, Msg1 scanning can be performed.

[0225] Terminal capabilities can be reported to the serving base station via RRC signaling. However, a terminal in RRC idle state may not be able to share information about its capabilities with the cell it is camped in or the serving base station. Therefore, the terminal can transmit its capability information to the serving base station using the Msg1 preamble.

[0226] The serving base station can specify a set or group of preambles that a terminal can use. When a terminal uses a preamble belonging to a specific set or group, the base station can assume that the terminal supports a specific function (e.g., Msg1 scan operation). Such an operation can be applied when assigning a separate combination of features to Msg1 scan.

[0227] When a separate feature combination is assigned and activated in the corresponding uplink BWP, the terminal can select one of the preamble sets or preamble groups configured by the base station. Subsequently, the terminal can select and use a specific Msg1 preamble from the selected preamble set or preamble group. Additionally, the terminal can select a set of boundary values ​​corresponding to the selected preamble set or preamble group. That is, when performing repeated Msg1 transmissions or Msg1 scans, the terminal can identify which boundary values ​​need to be applied.

[0228] Repeated Msg1 transmissions and Msg1 scans can be defined within the same RO group. Optionally, repeated Msg1 transmissions and Msg1 scans can be defined separately in different RO groups. When repeated Msg1 transmissions and Msg1 scans are defined within the same RO group, the terminal can use different preambles for the repeated Msg1 transmissions and Msg1 scans.

[0229] The terminal can determine a receive beam (Rx beam) by selecting the SSB. The terminal can then determine the transmit beam (Tx beam) to be used for Msg1 transmission based on the determined receive beam.

[0230] When the number of transmitting antennas (Tx antennas) of a terminal is less than the number of receiving antennas (Rx antennas), the area represented by the Rx beam on the beam grid (GoB) and the area represented by the Tx beam on the GoB can be configured to have different sizes.

[0231] Figure 15 This is a conceptual diagram showing the Rx GoB and Tx GoB of the terminal.

[0232] Reference Figure 15 According to Rx GoB, a beam can be formed that maps to a smaller area, and according to Tx GoB, a beam can be formed that maps to a larger area.

[0233] When the terminal has the same number of transmit and receive antennas, Tx GoB and Rx GoB can consist of beams of the same size. Here, the first and second axes of the angle can be defined according to the configuration type of the array antennas or antenna panels arranged in the terminal.

[0234] For example, even when a terminal has x receive antenna ports (Rx antenna ports) and y transmit antenna ports (Tx antenna ports), the transmit antenna ports alone may not form an orthogonal Tx GoB. In this case, Figure 15 In this context, beams on a Tx GoB can be represented as overlapping regions. Alternatively, only the main lobe of each transmitted beam can be used to represent a beam belonging to the Tx GoB.

[0235] Refer again Figure 15 Even when the terminal performs uplink beam management (UL BM) or when it does not perform UL BM according to the terminal's capabilities, reciprocity between DL beams and UL beams can be established on the terminal side.

[0236] When a terminal determines a receive beam in the Rx GoB, it can select the corresponding transmit beam in the Tx GoB, and the receive beam and transmit beam can have a beam reciprocity relationship.

[0237] Figure 16 and Figure 17 This is a conceptual diagram illustrating the relationship between the receiving beam of SSB and the transmitting beam of Msg1.

[0238] like Figure 16As shown, when there is no beam reciprocity relationship, the terminal can independently derive the receive beam and the transmit beam. The terminal can send Msg1 with a transmit beam applied, and can send Msg1 once in a RO.

[0239] like Figure 17 As shown, according to standard technical specifications, a terminal can transmit Msg1 once and can derive the transmit beam for Msg1 from the selected SSB. When performing repeated Msg1 transmissions, it can be assumed that the terminal can derive a suitable transmit beam from the receive beam of the selected SSB.

[0240] Reference Figure 17 The terminal can derive transmit beam 1, but because UL BM is not implemented, transmit beam 1 can correspond to a wider angular range than the receive beam. Therefore, methods can be applied to further improve the beam gain or directivity.

[0241] Figure 18 This is a conceptual diagram illustrating an improvement in the reception quality of Msg1 based on repeated transmission of Msg1 through the same beam.

[0242] Reference Figure 18 Preferably, the terminal repeatedly applies the transmit beam 1 to improve the reception quality of Msg1 at the base station.

[0243] On the other hand, when performing a Msg1 scan, the terminal can derive two or more suitable transmit beams and can apply one transmit beam based on feedback from the base station.

[0244] Figure 19 and Figure 20 This is a conceptual diagram illustrating the case where four transmit beams are derived from one receive beam used for Msg1 scanning.

[0245] Reference Figure 19 The terminal can derive four transmit beams from one receive beam (i.e., transmit beams 0 to 3). The terminal can repeatedly transmit Msg1 in an RO group consisting of at least four ROs.

[0246] Reference Figure 20 Different transmission beams can be applied to the transmission of Msg1 in different ROs.

[0247] Transmit beam 0 can be selected from the four transmit beams based on feedback from the base station. Feedback from the base station will be described later. The terminal can assume that UL BM has been performed, and transmit beam 0 can be applied when transmitting PUSCH in another phase of initial access. For example, transmit beam 0 can be applied to transmit Msg3 and / or Msg5. Optionally, transmit beam 0 can be applied to transmit PUCCH for HARQ-ACK against Msg4.

[0248] When a terminal performs a Msg1 scan or repeated Msg1 transmission, it can transmit Msg1 by applying the same or different transmission beams in different time-mapped ROs or RO groups. Examples related to repeated Msg1 transmissions can be found in [reference needed]. Figure 18 Examples related to Msg1 scans can be found in [reference needed]. Figure 20 .

[0249] The terminal can apply four different transmit beams in the effective ROs and transmit Msg1 in each RO belonging to the RO group. The ROs included in the RO group can be arranged continuously in time or at time intervals.

[0250] The terminal can change the transmit beam to perform a Msg1 scan. Alternatively, the terminal can perform a Msg1 scan by using two or more transmit panels (Tx panels). In this case, the terminal uses only one transmit panel to transmit Msg1 in one RO, and only one transmit panel is involved in the corresponding RO. Therefore, the terminal can perform a Msg1 scan by switching transmit panels.

[0251] For example, the terminal can use the first transmit beam of the first transmit panel to transmit Msg1 in the first RO of the RO group, while preparing the second transmit beam of the second transmit panel. Subsequently, in the second RO of the RO group, the terminal can use the second transmit beam of the second transmit panel to transmit Msg1, while preparing the third transmit beam of the first or third transmit panel. This operation can be repeated for all ROs in the RO group. In this case, the terminal may not need a separate time for switching transmit panels.

[0252] The terminal can perform Msg1 scanning or repeated Msg1 transmissions. When Msg1 scanning and repeated Msg1 transmissions have the same number of transmissions, they may not be distinguishable from each other in the technical specifications. This is because, although the transmission beam applied to Msg1 by a terminal performing repeated Msg1 transmissions can always be the same, in practice, the transmission beam may differ partially during the derivation process. This can be considered a generalized Msg1 scanning.

[0253] The terminal can derive the repetition factor by comparing the RSRP (or RSRQ) derived from the received SSB with boundary values. Similarly, the same RSRP (or RSRQ) can be used to derive the scan factor. The boundary values ​​required for deriving the repetition factor or scan factor can be indicated to the terminal via system information.

[0254] For example, the boundary value used to derive the scanning factor may be the same as the boundary value used to derive the repetition factor. Even if no separate boundary value is indicated to the terminal, when deriving the repetition factor or the scanning factor, the terminal may derive the RO group to which the repetition factor or the scanning factor is applied, and may determine whether to perform repeated Msg1 transmission or Msg1 scanning.

[0255] In another example, the boundary value used to derive the scanning factor and the boundary value used to derive the repetition factor may be different from each other. In this case, for the same RSRP (or RSRQ), the derived repetition factor L and scanning factor L' may be different from each other.

[0256] According to the proposed method, the terminal may select a method that can transmit Msg1 faster. For example, when L>L', the terminal may determine to perform Msg1 scanning. When L<L', the terminal may determine to perform repeated Msg1 transmission. When L=L', the terminal may determine to perform any operation. For example, when L=L', the terminal may determine to perform Msg1 scanning or repeated Msg1 transmission.

[0257] When the terminal that determines to perform Msg1 scanning fails to receive an RAR from the base station, the terminal may perform Msg1 scanning again. The maximum number of times to perform Msg1 scanning may be indicated through system information. For example, when the number of Msg1 scanning failures of the terminal exceeds the maximum number of times, the terminal may increase the Msg1 scanning factor. When the increased Msg1 scanning factor exceeds the maximum value, the terminal may perform repeated Msg1 transmission instead of Msg1 scanning. In another example, the terminal may perform repeated Msg1 transmission regardless of Msg1 scanning, and in this case, the repetition factor may be the same as the Msg1 scanning factor.

[0258] When the terminal performs Msg1 scanning, the magnitude of the power applied for each Msg1 transmission may be the same. When the terminal fails to receive the RAR in the search space ra-SearchSpaceSet (or the Type1-PDCCH CSS set or the RAR window), retransmission of Msg1 scanning may be performed, and in this case, the magnitude of the power applied to Msg1 may be increased. In this case, the increase amount may be a ramp-up value separately indicated to the terminal in system information, or the ramp-up value applied in the process of performing repeated Msg1 transmission may be reused.

[0259] A method is proposed for determining transmission power when the terminal switches from Msg1 scanning to repeated Msg1 transmission or from repeated Msg1 transmission to Msg1 scanning.

[0260] For example, even if the terminal changes the transmission scheme of Msg1, the ramp value can remain unchanged. To do this, the value of the ramp counter can remain unchanged. Alternatively, the ramp counter can be reset, but the ramp value can simply be kept as is.

[0261] In another example, when the terminal changes the transmission scheme of Msg1, the ramp value can be reset and treated as 0.

[0262] Furthermore, the terminal may have only one transmit panel, or even when the terminal has two or more transmit panels, Msg1 scanning can be performed simultaneously within a single transmit panel while changing the transmit beam. In this case, according to conventional technical specifications, the terminal may require a certain processing time for transmit beam switching. This time may be the time required to activate the transmit panel. Alternatively, the time may be the time required to adjust the parameters of the RF circuitry to change the transmit beam within an already activated transmit panel. The processing time can be set to different values ​​depending on the UL BWP or subcarrier spacing.

[0263] According to the proposed scheme, gaps may occur during Msg1 scanning. The terminal may have one or more transmitting panels, but it is not necessary to use a single receiving panel (Rx panel) to receive an SSB. Here, the Rx panel and transmitting panel may have such a structure that the same physical panel is used for either Rx or Tx purposes.

[0264] According to standard technical specifications, because the terminal repeatedly transmits Msg1 while maintaining the same transmission beam, it can transmit continuously within adjacent ROs. However, when performing a Msg1 scan, the terminal may need some time to switch to another transmission beam. Therefore, a Msg1 scan may not always be performed within adjacent ROs.

[0265] Figure 21 and Figure 22 This is a conceptual diagram illustrating an example of gaps reflected in the RO group.

[0266] Reference Figure 21 and Figure 22 Adjacent Returning Objects (ROs) can be considered a subgroup. For example, Msg1 can be sent only in one RO. Alternatively, Msg1 can be sent in a fixed RO. In another example, Msg1 can be sent in all ROs belonging to a subgroup.

[0267] One transmit beam can correspond to one RO subgroup. For example, when two ROs are considered as one subgroup, Msg1 can be transmitted in one RO or in all ROs.

[0268] Reference Figure 21This describes whether gaps exist between RO subgroups. Gaps may be required between RO subgroups, but in the case of the last subgroup within an RO group, gaps may not be necessary.

[0269] When the scan factor is 2, the terminal may need three ROs to transmit two transmit beams. When the scan factor is 4, it may need seven ROs, and when the scan factor is 8, it may need fifteen ROs.

[0270] Reference Figure 22 This describes the scenario where RO subgroups always require gaps. All RO subgroups can be configured to the same size. In this case, an RO subgroup consisting of four ROs can be used when the scan factor is 2. An RO subgroup consisting of eight ROs can be used when the scan factor is 4, and an RO subgroup consisting of sixteen ROs can be used when the scan factor is 8.

[0271] When two Original Routers (ROs) form a subgroup, the terminal may send Msg1 in only one RO. In this case, it may be preferable for the base station to more clearly indicate which RO in the RO subgroup needs to be used (e.g., the first RO or the second RO). This indication can be derived from specific fields in the RARUL authorization. For example, the CSI request field can indicate the corresponding information through specific values.

[0272] According to standard technical specifications, a terminal can use an RO group consisting of up to eight ROs. Based on this configuration, the time period can be determined. Because repeated Msg1 transmissions are performed, the same transmission beam can be applied to all ROs belonging to the RO group.

[0273] Based on the above scheme, up to 16 ROs may be required. However, according to the scheme proposed below, only a maximum of 8 ROs can be used to scan up to 4 transmit beams. In this case, the association period, association mode period, and time period can be derived by reusing the Msg1 repetition process defined in the conventional technical specifications.

[0274] According to the proposed method, Msg1 scanning can be performed within a group of up to eight ROs. When gaps are required, the terminal can use seven or eight of the eight ROs.

[0275] The terminal can perform Msg1 scanning by using a subgroup consisting of up to 4 ROs (i.e., up to 4 transmit beams). Additionally, when the RAR UL-licensed MCS field is partitioned, up to 2 bits can be used to identify the optimal transmit beam for Msg1 transmission.

[0276] Msg1 can be used to indicate the use of one of several preamble formats. According to standard technical specifications, various information related to Msg1 can be derived from an index included in SIB1, and this information can indicate the preamble format.

[0277] According to standard technical specifications, preamble formats can be classified into long and short formats. In the case of a long format, this means that Msg1 is sent once within a time interval of 1 ms or longer. On the other hand, in the case of a short format, Msg1 can be sent once within a time interval of less than 1 ms.

[0278] Preamble formats classified as short formats can be configured to have a cyclic prefix (CP), a sequence, and a guard period (GP), and in some cases the GP can be omitted.

[0279] Therefore, in configurations using preamble formats including GP, it may not be necessary to allocate separate gaps (ROs) to interpret RO subgroups within an RO group. In this case, as in standard technical specifications, the size k of the RO group can be equal to the number of times Msg1 is sent (k).

[0280] According to the proposed method, RO groups, including or excluding gap ROs, can be derived based on the preamble format. Therefore, even for the same scan factor k, the required size of the RO group can vary depending on the preamble format. Thus, the size of the RO group can be set to 2k, 2k-1, or k. Here, the scan factor k can be one or more of 2, 4, and 8, and a value equal to or greater than 16 can be indicated as the maximum value.

[0281] According to standard technical specifications, since preamble formats B1, B2, B3, B4 and preamble formats C0, C1, and C2 may include GPs, at least some of these formats can be configured to have RO groups without gaps ROs. On the other hand, in the case of other preamble formats, RO groups including gaps ROs can be configured. The terminal can determine the presence of gap ROs based on information included in SIB1.

[0282] After the terminal sends Msg1, the base station can send Msg2 based on it. According to standard technical specifications, when the terminal performs repeated Msg1 transmissions, the base station can derive the RA-RNTI based on the last RO belonging to the RO group.

[0283] According to the proposed method, even when the terminal performs a Msg1 scan, the base station can derive the RA-RNTI based on the last RO belonging to the RO group. Furthermore, the start time of the RA search space set can be the same whether a Msg1 scan is performed or repeated Msg1 transmissions are performed.

[0284] [Msg3 repeated] When a terminal performs a Msg1 scan, the camped base station or serving base station can select the optimal transmission beam from the transmission beams used by the terminal for Msg1. The selected transmission beam can also be used when the terminal transmits Msg3 or transmits a PUCCH for HARQ-ACK against Msg4. Therefore, the base station can indicate to the terminal the transmission beam to be applied.

[0285] According to the proposed method, the base station can select the optimal transmission beam from multiple transmission beams used for Msg1 transmission and can indicate the transmission beam to be used by the terminal for Msg3 transmission. In this case, since the terminal transmits multiple UL beams to the base station and receives feedback from the base station indicating the selection of one UL beam, from the terminal's perspective, UL BM can be considered to have been performed.

[0286] Therefore, decoding can be facilitated even if the base station receives Msg3 only once. The terminal can avoid performing repeated Msg3 transmissions. Alternatively, even if repeated Msg3 transmissions are performed, a higher MCS can be used by applying the optimal transmission beam, and thus, uplink resources can be saved.

[0287] The base station can explicitly or implicitly indicate information about the transmission beam to the terminal. For example, when the base station notifies the terminal of a specific RO within a group of ROs selected by the terminal, the terminal can deduce the transmission beam used during the transmission of the corresponding RO.

[0288] According to standard technical specifications, when performing repeated Msg3 transmissions, some bits (the higher 2 bits, 2 MSB) of the MCS field included in the RAR UL authorization indicate the number of Msg3 transmissions, and the remaining bits (the lower 2 bits, 2 LSB) indicate the MCS of Msg3. Furthermore, even when scheduling Msg3 using DCI format 0_0 scrambled with TC-RNTI, the higher 2 bits of the MCS field still indicate the number of Msg3 transmissions.

[0289] In this case, fields other than the UL-authorized MCS field can be used instead of the MCS field. Furthermore, the bit order in the MCS field can be changed so that the number of times Msg3 is sent is indicated by the lower bits.

[0290] According to the proposed method, an index of one of the ROs included in the RO group can be derived using a portion of the MCS field. In this case, the terminal can avoid performing duplicate Msg3 transmissions. That is, the index can be used to indicate which RO was selected within the RO group chosen by the terminal.

[0291] Figure 23 This is a conceptual diagram illustrating the situation where a base station indicates a specific RO within a RO group.

[0292] Reference Figure 23 When 2 bits of information are available, one of up to 4 ROs can be indicated. When the scan factor of Msg1 is 4, an RO belonging to the RO group can be indicated.

[0293] When the scan factor is 2, 1 bit of information may be needed to indicate that the terminal uses one of the two ROs. When the scan factor is 8, 3 bits of information may be needed to indicate that the terminal uses one of the eight ROs.

[0294] According to the proposed method, scan factors of 2 or 4 can be supported. In this case, the terminal can use only 2 bits to determine a specific RO within the RO group.

[0295] In the above Figure 21 and Figure 22 The RO group configurations for four or two transmit beams have already been described. (Refer to...) Figure 21 or Figure 22 When the RO group includes or excludes gap ROs, 2 bits of information can be used to select one of up to 4 ROs.

[0296] Alternatively, the location of the RO can be indicated by using a portion of the MCS field authorized by RAR UL, and in this case, 2 bits can be used.

[0297] According to the proposed method, scan factors of 2, 4, and 8 can be supported. Even in this case, the location of the RO can be indicated to the terminal by using a portion of the MCS field. To indicate the location of the RO, 3 bits or fewer bits can be used, and to indicate the MCS, 1 bit or more bits can be used.

[0298] For example, when the scan factor is 8, the MCS can be represented using only 1 bit. In this case, the MCS can be restricted to one of two values.

[0299] For example, other fields besides the MCS field in the RAR UL authorization can also be used. According to standard technical specifications, the CSI Request field is reserved, and the terminal may not need to refer to its value. According to the proposed method, 3 bits of information can be indicated to the terminal by combining some bits from the CSI Request field and the MCS field. In this case, one of the eight ROs can be selected, thus supporting a scan factor of 8.

[0300] When interstitial ROs are present, the size of the RO group may increase. For example, with a scan factor of K, 2K-1 or 2K ROs may be required. With a scan factor of 8, refer to... Figure 21 or Figure 22The size of the RO group can be configured to be 15 or 16. In this case, 3 bits of information may be needed to indicate one of the 8 ROs.

[0301] On the other hand, even when gap ROs are present, the maximum size of the RO group can be limited to 4. When the scan factor is 4, refer to... Figure 21 or Figure 22 The size of the RO group can be configured to 7 or 8. In this case, 2 bits of information may be needed to indicate one of the 4 ROs.

[0302] This is the same size (2 bits) as the information used in the standard technical specifications to indicate the Msg1 repeat factor, and therefore can be similarly applied to schemes that partition the MCS field in RAR UL licenses or DCI format 0_0.

[0303] The scheduling information for the initial transmission of Msg3 can be included in the RAR UL authorization. The terminal can send Msg3 to the base station using TC-RNTI. When the base station successfully decodes Msg3 and the CRC of TB matches (e.g., in the ACK case), the terminal can perform the initial access procedure.

[0304] On the other hand, when the base station fails to check the CRC of the TB (e.g., in a NACK situation), the base station can retransmit the scheduling information for retransmission based on the TC-RNTI. The causes of TB CRC errors can vary. For example, in a contention situation where multiple terminals are sending Msg3 using the same RA-RNTI, the base station may receive multiple Msg3s simultaneously, leading to a CRC error. Alternatively, CRC errors may occur due to radio channel fading or incorrect MCS indication.

[0305] The base station can send DCI format 0_0 to the terminal, which includes scheduling information for Msg3 retransmission.

[0306] According to the proposed method, the TCI status and transmission count (i.e., repetition factor or scan factor) can be indicated to the terminal from the scheduling information of Msg3. In another example, only the TCI status can be indicated and the transmission count can be omitted, and in this case, the terminal can interpret that Msg3 will be sent once.

[0307] In order to apply the TCI state to Msg3, the terminal can store the transmit beam used in the previous Msg1 scan.

[0308] According to another proposed method, the scheduling information of Msg3 is categorized for initial transmissions and retransmissions, and in each case, may include only one of the TCI status or the number of transmissions. For example, the TCI status may be indicated from the scheduling information of the initial transmission, and the number of transmissions may be indicated from the scheduling information of the retransmission. Alternatively, the number of transmissions may be indicated in the scheduling information of the initial transmission, and the TCI status may be indicated in the scheduling information of the retransmission.

[0309] The scheduling information for the initial transmission can be included in the RAR UL license, and according to the proposed method, information indicating the TCI status can be included by dividing specific fields. For example, the higher bit (MSB) of the MCS field can indicate the TCI status, and the lower bit (LSB) can indicate the MCS.

[0310] Retransmission scheduling information can be included in DCI format 0_0, and according to the proposed method, information indicating the number of transmissions can be included by dividing specific fields. For example, the MSB of the MCS field can indicate the number of transmissions, and its LSB can indicate the MCS.

[0311] When the base station indicates the number of transmissions, the terminal can repeatedly transmit Msg3 while maintaining the same TCI state. According to conventional technical specifications, Msg3 can be repeatedly transmitted without a TCI state. However, the proposed method implements UL BM and supports the ability to transmit Msg3 two or more times by applying a selected transmit beam.

[0312] During retransmission, the MCS can be configured by changing the modulation order. In this case, the TB encoding process is not performed again, and only rate matching or subsequent processes can be performed.

[0313] Tables 7 and 8 are examples of MCS tables used to illustrate the MCS tables according to standard technical specifications. When the terminal does not apply transform precoding in PUSCH transmission, a Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) waveform is applied, and in this case, Table 7 can be applied. On the other hand, when transform precoding is applied, a Discrete Fourier Transform-Extended Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) waveform is applied, and in this case, Table 8 can be applied.

[0314] The modulation order used for retransmission can be represented as three values ​​in Table 7, and as three or four values ​​in Table 8. For example, the value q is provided to the terminal via separate RRC signaling, and when indicated... tp-piBPSK In this case, q can be interpreted as 1 or 2. Therefore, a maximum of four MCS values ​​can be available, and these MCS values ​​can be represented using 2 bits.

[0315] [Table 7]

[0316] [Table 8]

[0317] To distinguish whether scheduling information is used for initial transmission or retransmission, the New Data Indicator (NDI) field can be used. When the value of the NDI field is switched for the same HARQ process number (HPN) or HARQ process ID (HPID), the terminal can recognize that the corresponding TB has been initially transmitted.

[0318] Therefore, the terminal can treat existing TBs stored in the circular buffer as previous transmission data, or it can reconfigure the circular buffer based on new TBs. On the other hand, when the value of the NDI field is not changed and is retained, the terminal can reuse the TBs stored in the circular buffer and can perform rate matching or subsequent processes based on the received scheduling information.

[0319] For Msg3, the NDI field is typically not used. Information based on TC-RNTI scheduling can be considered as retransmitted information. This is because the terminal is in the process of performing the initial access procedure, and apart from the initial transmission of Msg3, the terminal has no PUSCH transmission history; therefore, the terminal does not need to refer to HARQ HPN or RV.

[0320] When the TCI status for Msg3 is indicated in the RAR UL authorization, the indicated TCI status can also be applied to the retransmission of Msg3. For this purpose, the terminal can store the transmit beam used during the Msg1 scan until the process associated with Msg3 is complete.

[0321] For example, the terminal can apply the same TCI state applied to Msg3 to transmit Msg5. Similarly, in this case, the terminal can store the transmit beam used during the Msg1 scan until the process associated with Msg5 is complete.

[0322] Taking into account the capability information reported by the terminal in Msg5, the serving base station can indicate individual TCI status, spatial relationship information or other relevant information to the terminal.

[0323] As a scheme for indicating the number of transmissions, predetermined fields included in DCI format 0_0 or RAR UL authorization can be used. For example, the predetermined field can be an MCS field. Optionally, two or more fields can be combined and used as information for deriving the number of transmissions. According to the proposed method, the partitioning scheme of the MCS field can vary according to the number of transmissions (i.e., scan factor or repetition factor).

[0324] When the number of transmissions is 2, 1 bit in the MCS field can be used to indicate RO, and the remaining bits can be used to indicate MCS.

[0325] When the number of transmissions is 4, 2 bits in the MCS field can be used to indicate RO, and the remaining bits can be used to indicate MCS.

[0326] When the number of transmissions is 8, if the serving cell or BWP supports this number of transmissions, 3 bits in the MCS field can be used to indicate RO, and the remaining bits can be used to indicate MCS.

[0327] Here, the number of transmissions can be a value that the terminal can determine based on RSRP, and the base station can also identify the number of transmissions through feature combinations of Msg1 or preambles. Therefore, the MCS field partitioning scheme can be derived from the number of transmissions without separate RRC signaling.

[0328] The number of PUCCH transmissions for Msg4 can be set to some or all of 2, 4, 8, or values ​​greater than 8. The serving base station can send or broadcast a list of allowed values ​​for the number of PUCCH transmissions for Msg4 via SIB1.

[0329] The value included in the DAI field of DCI format 1_0 scrambled with TC-RNTI can be interpreted as the number of PUCCH transmissions, and this can also be applied to the number of PUCCH transmissions for Msg4.

[0330] According to the proposed method, the terminal can transmit Msg4 PUCCH two or more times in specific mobile communication scenarios and general mobile communication scenarios.

[0331] The time resources for the PUCCH used for Msg4 can be defined by the start symbol and the number of symbols within a time slot, and this configuration can be applied similarly to multiple time slots corresponding to the repetition factor. This configuration can be applied not only to the PUCCH used for Msg4, but also to situations where the terminal transmits a PUCCH without indicating a dedicated PUCCH resource configuration via RRC signaling.

[0332] The information provided in SIB1 and / or the information included in the scheduling DCI format can be combined to correspond to the PUCCH resource configuration defined in the technical specification, and thus, a single PUCCH resource can be derived.

[0333] According to standard technical specifications, it is not necessary to specify a separate transmit beam for the PUCCH used for Msg4. For example, the terminal may use the transmit beam of Msg1 or Msg3 as the transmit beam for the PUCCH used for Msg4. In another example, depending on the terminal implementation, the transmit beam for the PUCCH used for Msg4 may be determined, and this transmit beam may be the transmit beam of Msg1 or Msg3, or it may be a different transmit beam.

[0334] Furthermore, conventional technical specifications assume that the terminal needs to maintain the same transmit beam for the PUCCH used for Msg4. However, according to the proposed method, the terminal may not necessarily maintain the same transmit beam for the PUCCH used for Msg4.

[0335] According to the proposed method, when the terminal performs a Msg1 scan, it can select the optimal transmission beam from the transmission beams of Msg1 and configure it as the transmission beam for transmitting the PUCCH for Msg4. In this case, the selected transmission beam can be the same as the transmission beam used for Msg3 transmission, and the transmission beam can be interpreted as a TCI state and applied as the TCI state for the PUCCH for Msg4.

[0336] Additionally, the DAI field of DCI format 1_0 for scheduling Msg4 can be interpreted as the number of transmissions for the PUCCH used for Msg4. For example, when the terminal performs a Msg1 scan and a repeated Msg3 transmission, the terminal can consider UL BM to have been performed and can apply a repeated transmission procedure for the PUCCH used for Msg4.

[0337] According to another proposed method, the scanning process can also be applied to the PUCCH used for Msg4. That is, similar to the scanning for Msg1, the scanning can be applied to the PUCCH used for Msg4.

[0338] The terminal can derive two or more transmit beams from the selected SSB and can sequentially apply the transmit beams to transmit PUCCH for Msg4.

[0339] The DAI field of DCI format 1_0 for scheduling Msg4 can be interpreted as the number of times the Msg4 PUCCH is transmitted. This scheme can be applied not only to Msg4 but also to situations where the dedicated PUCCH resource configuration is not indicated to the terminal via RRC signaling. In this case, the terminal can transmit HARQ-ACKs for the PDSCH used for scheduling two or more times.

[0340] According to the proposed method, the number of PUCCH transmissions can be indicated by the DAI field. That is, for general PDSCHs other than Msg4, the DAI field can be used to indicate the number of PUCCH transmissions, while also indicating the number of HARQ-ACK bits. In this case, the number of PUCCH transmissions can increase proportionally to the number of HARQ-ACK bits.

[0341] According to another proposed method, the terminal can derive the transmit beam to be used for the HARQ-ACK transmission of Msg4 from the TCI state of the CORESET of the DCI that is detected scheduling Msg4. Since this scheme derives the transmit beam from the receive beam, it can be applied to terminals that support beam reciprocity even when UL BM is not performed.

[0342] When a terminal is capable of transmitting PUCCH for Msg4 two or more times, it can perform repeated transmissions while maintaining the transmit beam derived from CORESET. Alternatively, the terminal can perform a scan by applying different transmit beams without needing to maintain a single transmit beam.

[0343] [Msg5 repeated] Figure 24 This is a sequence diagram showing the transmission of Msg5 and the process preceding it.

[0344] Reference Figure 24 Duplicate or scan can be performed during Msg1 transmission (S2410). In another example, duplicate can be performed during Msg3 transmission (S2420). Additionally, duplicate or scan can be performed during PUCCH transmission for Msg4 (S2430). This operation can be performed independently or in combination.

[0345] In addition, the Msg5 PUSCH includes information transmitted during the initial access procedure and may include at least the terminal's capability report. For example, besides the terminal's capability information, other information required during the initial access procedure (such as security) may be included in the Msg5 PUSCH. This information may be mapped to a UL-SCH and transmitted via a single schedule through the Msg5 PUSCH. Alternatively, this information may be mapped to two or more UL-SCHs and transmitted via multiple Msg5 PUSCHs using two or more schedules. For ease of description, the term "Msg5" may be considered to refer to Msg5 PUSCH.

[0346] After receiving Msg5, which includes the terminal's capability information, the serving base station can indicate the PUSCH repetition type (Type A or Type B) to the terminal. According to standard technical specifications, the serving base station can indicate PUSCH repetition type A or Type B to the terminal in RRC connection status. This is because the PUSCH repetition scheme can be configured after the terminal reports its capabilities to the base station via Msg5.

[0347] However, since Msg5 transmitted by the terminal itself can also be transmitted in an environment with limited coverage, it may be preferable to perform repeated transmission or scanning of Msg5 (S2440).

[0348] For terminals that have already performed a Msg1 scan, since a specific level of UL BM has been performed, the base station can achieve sufficient reception quality by applying specific TCI status or spatial relationship information to the terminal and having the terminal transmit Msg5 only once. On the other hand, if this condition is not met, a function that indicates two or more transmission counts for Msg5 may be required.

[0349] Additionally, when a terminal has already performed repeated Msg3 transmissions, the base station can identify that the terminal is located at the edge of cell coverage. In this case, the base station can explicitly instruct the transmission count for Msg5 to enhance Msg5 transmission through repetition and / or scanning.

[0350] According to standard technical specifications, the terminal can derive the number of scheduled PUSCH transmissions from the Time Domain Resource Allocation (TDRA) used for PUSCH. The TDRA can be applied by selecting an index from multiple configurations indicated by RRC signaling via scheduling information, and based on the selected TDRA, the starting symbol, the number of symbols, and / or the number of consecutive time slots to which the PUSCH is mapped can be determined.

[0351] According to the proposed method, when DCI format 0_0 is scrambled with C-RNTI or MCS-C-RNTI and transmitted, some bits of the MCS field of the DCI format can be used to derive the number of transmissions of the PUSCH. The remaining bits can be used to derive the MCS of the PUSCH.

[0352] According to another proposed method, the field can be interpreted differently in the case of initial transmission and in the case of retransmission. Whether PUSCH is an initial transmission can be determined by whether the NDI field is switched. When scheduling a TB that will be the initial transmission, the entire MCS field can be used to derive the MCS.

[0353] On the other hand, when a TB to be retransmitted is scheduled, some bits of the MCS field can be used to derive the number of PUSCH transmissions, and the remaining bits can be used to derive the MCS. This is because the MCS information used for retransmission typically only includes modulation order change information.

[0354] For example, when using an MCS table supporting three modulation schemes—QPSK, 16QAM, and 64QAM—only three values, 29, 30, and 31, are allowed in the MCS field for the DCI used for retransmission. In another example, when using an MCS table supporting four modulation schemes—QPSK, 16QAM, 64QAM, and 256QAM—only four values, 28, 29, 30, and 31, are allowed in the MCS field for the DCI used for retransmission.

[0355] The value 0b11100 is calculated as 16 + 8 + 4 = 28, and values ​​subsequently expressed in the form 0b000xx can be interpreted as the lower 2 bits (2 LSBs). For example, the lower 2 bits of the MCS field indicate the MCS, and the higher 3 bits (3 MSBs) indicate the number of PUSCH transmissions. PUSCHs applying this scheme can be scheduled using one of the following: a DCI format searched in the Common Search Space (CSS set), a DCI format searched in the Private Search Space (USS set), DCI format 0_0, or DCI format 0_1. The proposed scheme can be applied using one or a combination of these. For example, PUSCHs applying this scheme can be scheduled using DCI format 0_0 searched in the CSS set.

[0356] For example, in the proposed scheme, the number of transmissions can be indicated only for Msg5. Since Msg5 includes the terminal's capability information, after the base station successfully receives Msg5, the number of transmissions for PUSCH used for general data transmission can be derived from TDRA. In subsequent scheduling, the appropriate number of transmissions can be indicated to the terminal.

[0357] To apply the proposed method, the terminal needs to store information about the transmit beam used for Msg1 transmission. Subsequently, when a value is indicated in the RAR's UL authorization, the terminal can treat that value as a TCI state and apply it to the transmit beams of Msg3 and / or Msg5.

[0358] If the base station fails to decode the initial transmission of Msg3, it can reschedule Msg3 to the terminal using a DCI format scrambled with TC-RNTI. In this case, the maximum time the terminal can store the transmit beam can be determined based on the terminal's capabilities. If the base station indicates a TCI state after this time, the terminal may not apply the transmit beam derived from the Msg1 scan.

[0359] According to another proposed method, the transmit beam for Msg1 and the transmit beam used for PUCCH transmission of Msg4 can correspond one-to-one. That is, the transmission count for Msg1 and the transmission count for PUCCH transmission of Msg4 can be the same, and each transmit beam can be applied in the same way or correspondingly. Therefore, the terminal can transmit PUCCH for Msg4 in multiple time slots or sub-time slots.

[0360] [Maintaining the upward slope] During the process of a terminal transmitting Msg1 to a base station by performing a repetition of a single transmission of Msg1, a repeated transmission of Msg1, or a repetition of a Msg1 scan, the terminal can determine the magnitude of the transmission power applied to the Msg1 preamble. For example, when performing a retransmission, in addition to applying path loss and using values ​​derived from various offsets indicated by higher-layer signaling, a ramp value can also be applied.

[0361] The transmission power of Msg1 can be derived from Equation 1 below.

[0362] [Equation 1] [dBm] The difference between the transmission power of Msg1 and the transmission power of PUSCH lies in the fact that the target transmission power value can be determined based on the value indicated by the higher layer (PREAMBLE_RECEIVED_TARGET_POWER). As for the ramp counter, this value can be derived from the fixed value of the transmission power (preambleReceivedTargetPower + DELTA_PREAMBLE) and the product of the ramp counter value and the ramp step size ((PREAMBLE_POWER_RAMPING_COUNTER - 1) × PREAMBLE_POWER_RAMPING_STEP). Therefore, the target transmission power value can be interpreted as a value proportional to the ramp counter. Here, the ramp counter can refer to a counter that increments by 1 when the terminal transmits Msg1 and fails to receive Msg2 from the base station within a suitable time.

[0363] The interpretation of the ramp value can be derived differently when performing a Msg1 scan and when performing repeated Msg1 transmissions. This can involve the interpretation of the ramp value (or ramp counter) or the number of ramp values ​​(ramp counters).

[0364] When the transmission scheme used in Msg1 is consistently applied (i.e., only Msg1 scanning or only repeated Msg1 transmissions are performed), the standard technical specifications can be applied.

[0365] When performing both a Msg1 scan and a repeated Msg1 transmission, the ramp value (or ramp counter) can be reused or reset so that a different ramp value (or ramp counter) is applied. For example, regardless of the Msg1 transmission scheme, the ramp value (or ramp counter) can be applied so that even when performing a repeated Msg1 transmission, the ramp value (or ramp counter) derived during the Msg1 scan can be the same.

[0366] When the Msg1 transmission scheme is changed, the ramp value can be reset. In this case, the terminal needs to start the Msg1 scan again or repeat the Msg1 transmission to find the appropriate transmission power. To reduce the delay time that occurs in this process, a power offset can be introduced.

[0367] When the transmission scheme of Msg1 is changed by using a separate power offset, the amount of power derived from the power offset can be subtracted from the ramp value. In this case, the transmission power is reduced but has the advantage of starting from a non-zero value, and this achieves the goal of reducing latency.

[0368] If the ramp counter remains unchanged, a situation may arise where the maximum power value of PUSCH is exceeded when the transmission scheme of Msg1 is changed. When the power offset applies in this situation, the transmission power of PUSCH may again be less than the maximum power value.

[0369] For the transmission of Msg3, the power control of the application can be given by Equation 2 below, and its dynamic update part can be examined in detail.

[0370] [Equation 2] [dBm], [dBm] here, or It can indicate the power value configured for the terminal. In the serving cell. carrier Transmit PUSCH in the middle, and Can indicate the first Each TCI state. The transmission time of PUSCH can be expressed as... And this can be an index used in dynamic updates. It can be a value indicated by a higher layer, and when the terminal performs random access, it can be represented as... . It can be represented as . It can be related to the transmission power of Msg1, and can be communicated via higher-layer signaling ( preambleReceivedTargetPower ) to indicate, and It could be that the application uses higher-level signaling ( msg3-DeltaPreamble or deltaPreamble The value indicated by ) or, if such a value does not exist, can be It is considered as 0.

[0371] Can be regarded as And it can be applied through higher layers ( msg3-Alpha The value indicated to the terminal, or when no such value is indicated, can be considered as 1.

[0372] This can represent the number of RBs allocated to PUSCH. It can be a value indicating path loss, and can be obtained by using RS indicated from the base station. To measure.

[0373] According to the value indicated by a higher level ( deltaMCS or ), It can be 0 or .when When, it can be applied Furthermore, the BPRE can be derived from the number of REs scheduled for PUSCH and the number of code blocks. When When, it is differentiable 0.

[0374] exist In the calculation, Can be regarded as . It can be determined as . It can have one of four values. This can be the cumulative value of power control commands received during a predetermined time period. This applies to the transmission time (or timing) of the PUSCH. Transmission time of PUSCH The symbols can be considered separately. Previous time T1 and symbol The previous time T2. Power control commands received between T2 and T1 can be accumulated.

[0375] When the transmission power of the PUSCH becomes less than 0 or exceeds the maximum allowable value, accumulation is not permitted. .

[0376] For Msg3, a separate accumulation may not be necessary and can be expressed as Power control commands can be applied based on the fields included in the RAR. . It can be interpreted in more complex ways and can be represented as a first value or a second value.

[0377] The first value is satisfied. and And it can be equal to or greater than 0. The second value can satisfy... and And it can be equal to or greater than 0.

[0378] here, It can be a value indicated by a higher layer and can correspond to the power ramp derived by the terminal from the initial to the final transmission of Msg1.

[0379] The operation of the method according to exemplary embodiments of this disclosure can be implemented as a computer-readable program or code in a computer-readable recording medium. The computer-readable recording medium may include all kinds of recording devices for storing data readable by a computer system. Furthermore, the computer-readable recording medium may store and execute programs or code that may be distributed across computer systems connected via a network and read in a distributed manner by a computer.

[0380] Computer-readable recording media may include hardware devices specifically configured to store and execute program commands, such as ROM, RAM, or flash memory. Program commands may include not only machine language code created by a compiler, but also high-level language code that can be executed by a computer using an interpreter.

[0381] Although some aspects of this disclosure have been described in the context of the device, these aspects may refer to the corresponding description according to the method, and blocks or devices may correspond to steps or features of the method. Similarly, aspects described in the context of the method may be expressed as features of corresponding blocks or items or corresponding devices. Some or all of the steps of the method may be performed by (or using) hardware devices such as microprocessors, programmable computers, or electronic circuits. In some embodiments, one or more of the most important steps of the method may be performed by such devices.

[0382] In some exemplary embodiments, a programmable logic device, such as a field-programmable gate array (FPGA), may be used to perform some or all of the functions of the methods described herein. In some exemplary embodiments, the FPGA may operate in conjunction with a microprocessor to perform one of the methods described herein. Typically, these methods are preferably performed by a hardware device.

[0383] The description in this disclosure is merely exemplary in nature, and therefore, changes that do not depart from the essence of this disclosure are intended to fall within its scope. These changes should not be considered as departing from the spirit and scope of this disclosure. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope defined by the following claims.

Claims

1. A method for a terminal to perform a random access (RA) procedure, comprising: Receive first RA configuration information and second RA configuration information from the base station, wherein the first RA configuration information is used for non-contention RA CFRA procedure or system information request, and the second RA configuration information is used for contention-based random access CBRA procedure; Measure the received strength of the synchronization signal block (SSB) received from the base station; Based on the measured received strength, determine the repetition factor for sending message 1 Msg1; and In the first random access opportunity (RO) group determined by the first RA configuration information and / or the second RA configuration information, Msg1 is repeatedly transmitted according to the determined repetition factor.

2. The method as described in claim 1, wherein, The first RO set is derived from the first RA configuration information, and the first RO set includes ROs independent of the ROs configured by the second RA configuration information for the CBRA process.

3. The method as described in claim 2, wherein, No time offset is applied between RO groups that belong to the first RO group set.

4. The method of claim 1, wherein, When no resources for the CFRA process are configured in the first RA configuration information, the first RO group set is derived through the second RA configuration information, and the time offset between RO groups belonging to the first RO group set is indicated through the second configuration information.

5. The method of claim 4, wherein, The first RA configuration information includes mask information. Based on the mask information, the validity of ROs belonging to the first RO group is determined, and Msg1 is sent to the valid ROs determined based on the mask information.

6. The method of claim 4, wherein, Based on the repetition factor, the time offset is selected from a plurality of values ​​indicated by the first RA configuration information or the second RA configuration information.

7. The method of claim 1, wherein, At least a portion of the first RA configuration information shares at least a portion of the second RA configuration information.

8. The method of claim 1, wherein, The repetition factor is determined based on a range of received intensity obtained by comparing the measured received intensity with at least one threshold, wherein the measured received intensity belongs to the range of received intensity.

9. The method of claim 1, wherein, Repeated transmission of Msg1 is performed to request system information from the base station.

10. A method for a base station in a random access (RA) procedure, comprising: Send first RA configuration information and second RA configuration information to the terminal, wherein the first RA configuration information is used for non-contention RA CFRA procedure or system information request, and the second RA configuration information is used for contention-based random access CBRA procedure; Send a synchronization signal block (SSB) to the terminal; and In the first random access opportunity (RO) group set determined by the first RA configuration information and / or the second RA configuration information, message 1 Msg1 from the terminal is repeatedly received based on a repetition factor determined based on the reception strength of the SSB at the terminal.

11. The method of claim 10, wherein, The first RO set is derived from the first RA configuration information, and the first RO set includes ROs independent of the ROs configured by the second RA configuration information for the CBRA process.

12. The method of claim 11, wherein, No time offset is applied between RO groups that belong to the first RO group set.

13. The method of claim 11, wherein, When no resources for the CFRA process are configured in the first RA configuration information, the first RO group set is exported through the second RA configuration information, and the time offset between RO groups belonging to the first RO group set is indicated through the second RA configuration information.

14. The method of claim 13, wherein, The first RA configuration information includes mask information. Based on the mask information, the validity of ROs belonging to the first RO set is determined, and Msg1 is received in the valid ROs determined based on the mask information.

15. The method of claim 13, wherein, Based on the repetition factor, the time offset is selected from a plurality of values ​​indicated by the first RA configuration information or the second RA configuration information.

16. The method of claim 13, wherein, At least a portion of the first RA configuration information shares at least a portion of the second RA configuration information.

17. A terminal that performs a random access (RA) procedure, comprising at least one processor, in, The at least one processor is configured to cause the terminal to perform the following operations: Receive first RA configuration information and second RA configuration information from the base station, wherein the first RA configuration information is used for non-contention RA CFRA procedure or system information request, and the second RA configuration information is used for contention-based random access CBRA procedure; Measure the received strength of the synchronization signal block (SSB) received from the base station; Based on the measured received strength, determine the repetition factor for sending message 1 Msg1; and In the first random access opportunity (RO) group determined by the first RA configuration information and / or the second RA configuration information, Msg1 is repeatedly transmitted according to the determined repetition factor.

18. The terminal as claimed in claim 17, wherein, The first RO set is derived from the first RA configuration information, and the first RO set includes ROs independent of the ROs configured by the second RA configuration information for the CBRA process.

19. The terminal as claimed in claim 17, wherein, When no resources for the CFRA process are configured in the first RA configuration information, the first RO group set is derived through the second RA configuration information, and the time offset between RO groups belonging to the first RO group set is indicated through the second configuration information.

20. The terminal as claimed in claim 19, wherein, The first RA configuration information includes mask information. Based on the mask information, the validity of ROs belonging to the first RO group is determined, and Msg1 is sent to the valid ROs determined based on the mask information.

Images