Random access method and apparatus using sub-band full duplex resource in next-generation mobile communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure relates to operations of a UE and a base station in a wireless communication system. Particularly, the present disclosure relates to a signal transmission and reception method and apparatus for enabling a UE to perform random access by using a sub-band full duplex (hereinafter, SBFD) resource if the UE needs to perform random access to a specific cell in a wireless communication system that supports SBFD technology in some frequency resources.

Description

Random access method and device utilizing subband full-duplex resources in next-generation mobile communication systems

[0001] The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a signal transmission and reception method and apparatus for enabling a terminal to perform random access by utilizing SBFD resources when the terminal needs to perform random access to a specific cell in a wireless communication system that supports Sub-Band Full Duplex (hereinafter SBFD) technology in a portion of frequency resources.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in frequency bands below 6 GHz ('Sub 6 GHz'), such as 3.5 gigahertz (3.5 GHz), but also in ultra-high frequency bands called millimeter waves (mmWave), such as 28 GHz and 39 GHz ('Above 6 GHz'). In addition, for 6G mobile communication technology, which is referred to as a system beyond 5G, implementation in the terahertz band (e.g., the 3 terahertz (3 THz) band at 95 GHz) is being considered to achieve transmission speeds 50 times faster and ultra-low latency reduced to one-tenth compared to 5G mobile communication technology.

[0003] In the early stages of 5G mobile communication technology, aiming to satisfy service support and performance requirements for enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), technologies such as beamforming and Massive MIMO to mitigate path loss and increase transmission distance in ultra-high frequency bands, support for various numerologies (such as the operation of multiple subcarrier spacings) and dynamic operation of slot formats for the efficient utilization of ultra-high frequency resources, initial access techniques to support multi-beam transmission and broadband, definition and operation of Band-Width Parts (BWP), Low Density Parity Check (LDPC) codes for high-volume data transmission, new channel coding methods such as Polar Codes for the reliable transmission of control information, and L2 pre-processing (L2 Standardization has been carried out for pre-processing, network slicing which provides a dedicated network specialized for specific services, and other methods.

[0004] Currently, discussions are underway to improve and enhance the performance of the initial 5G mobile communication technology, taking into account the services that the 5G mobile communication technology was intended to support. Additionally, standardization of the physical layer is in progress for technologies such as V2X (Vehicle-to-Everything), which helps autonomous vehicles make driving decisions and enhance user convenience based on their own location and status information transmitted by the vehicle; NR-U (New Radio Unlicensed), which aims for system operation in unlicensed bands to comply with various regulatory requirements; NR terminal low power consumption technology (UE Power Saving); Non-Terrestrial Network (NTN), which is direct terminal-satellite communication for securing coverage in areas where communication with the terrestrial network is impossible; and positioning.

[0005] In addition, standardization is underway in the field of wireless interface architecture / protocols for technologies such as the Industrial Internet of Things (IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) which provides nodes to expand network service areas by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) Handover, and 2-step Random Access (2-step RACH for NR) which simplifies random access procedures. Standardization is also underway in the field of system architecture / services for 5G baseline architectures (e.g., Service based Architecture, Service based Interface) to incorporate Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC), which provides services based on the location of the terminal.

[0006] When such 5G mobile communication systems are commercialized, connected devices, which are increasing explosively, will be connected to communication networks. Accordingly, it is expected that there will be a need to enhance the functionality and performance of 5G mobile communication systems and to integrate the operation of connected devices. To this end, new research is planned to be conducted on 5G performance improvement and complexity reduction, support for AI services, support for metaverse services, and drone communication using eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] Furthermore, the advancement of these 5G mobile communication systems encompasses multi-antenna transmission technologies such as new waveforms to guarantee coverage in the terahertz band of 6G mobile communication technology, Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas; metamaterial-based lenses and antennas to improve terahertz band signal coverage; high-dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum); and Reconfigurable Intelligent Surface (RIS) technology; as well as Full Duplex technology for enhancing frequency efficiency and system networks in 6G mobile communication technology; AI-based communication technologies that realize system optimization by utilizing satellites and AI from the design stage and internalizing end-to-end AI support functions; and the realization of services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could serve as a foundation for the development of next-generation distributed computing technologies.

[0008] The present disclosure aims to provide an apparatus characterized by a method for transmitting and receiving signals and a method for selecting resources that need to be exchanged between a network and a terminal in order to enable uplink random access by utilizing said resources when a network in a wireless communication system supports subband full-duplex transmission and reception and allocates resources for such transmission and reception.

[0009] A terminal according to one embodiment of the present disclosure includes an operation of receiving a signal transmitted by a base station and performing random access utilizing a subband full-duplex resource according to a condition within the signal.

[0010] The technical problems to be solved in the various embodiments of the present disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0011] According to one embodiment of the present disclosure, random access can be performed faster with low latency by utilizing not only general uplink resources but also subband full-duplex resources in a wireless communication system.

[0012] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0013] FIG. 1 is a diagram showing the structure of a next-generation mobile communication system that supports subband full-duplex transmission and reception according to an embodiment of the present disclosure.

[0014] FIG. 2 is a drawing for explaining the concept of a subband full duplex (hereinafter SBFD) of a base station or cell according to one embodiment of the present disclosure.

[0015] FIG. 3 is a diagram illustrating an example of a terminal SBFD RACH capability reporting procedure according to an embodiment of the present disclosure.

[0016] FIG. 4 is a diagram illustrating an example of a procedure for performing SBFD random access by a terminal according to a signal for SBFD random access transmitted by a base station to a terminal and usage conditions.

[0017] FIG. 5 is a diagram illustrating an example of a procedure for performing SBFD random access by a terminal according to a signal for SBFD random access transmitted by a base station to a terminal and usage conditions.

[0018] FIG. 6 is a diagram illustrating an example of a procedure for performing SBFD random access by a terminal according to a signal for SBFD random access transmitted by a base station to a terminal and usage conditions.

[0019] FIG. 7 is a drawing for explaining a random access method of a terminal according to one embodiment of the present disclosure.

[0020] FIG. 8 is a drawing for explaining a random access method of a terminal according to one embodiment of the present disclosure.

[0021] FIG. 9 is a diagram illustrating an example of a fallback or switching method to a different RO type during a random access execution procedure of a terminal according to an embodiment of the present disclosure.

[0022] FIG. 10 is a drawing illustrating the structure of a base station according to one embodiment of the present disclosure.

[0023] FIG. 11 is a drawing illustrating the structure of a terminal according to one embodiment of the present disclosure.

[0024] Fifth-generation wireless communication systems operate in higher frequency (mmWave) bands, and UEs and gNBs communicate with each other using beamforming. Beamforming technology is used to mitigate propagation path loss and increase the propagation distance for communication in higher frequency bands. Beamforming improves transmission and reception performance by using high-gain antennas. Beamforming can be classified into transmission (TX) beamforming, performed at the transmitter, and reception (RX) beamforming, performed at the receiver. Generally, TX beamforming increases directivity by using multiple antennas to densely position the area where radio waves reach in a specific direction. In this context, a collection of multiple antennas can be referred to as an antenna array, and each antenna included in the array can be referred to as an array element. Antenna arrays can be configured in various forms, such as linear arrays or planar arrays. The use of TX beamforming results in increased signal directivity, thereby extending the propagation distance. Furthermore, signal interference acting on other receivers is significantly reduced because the signal is rarely transmitted in directions other than the directed direction. The receiver can perform beamforming on the RX signal using an RX antenna array. RX beamforming increases the strength of the RX signal transmitted in a specific direction by concentrating radio waves in that direction, and provides the effect of blocking interference signals by excluding signals transmitted in non-specific directions from the RX signal. Using beamforming technology, a transmitter can create multiple transmit beam patterns in different directions. Each of these transmit beam patterns can also be referred to as a transmit (TX) beam. Wireless communication systems operating at high frequencies transmit signals within a cell using multiple narrow TX beams, because each narrow TX beam provides coverage to a portion of the cell. The narrower the TX beam, the higher the antenna gain, and consequently, the propagation distance of the signal transmitted using beamforming increases. The receiver can also create multiple receive (RX) beam patterns in different directions.Each of these reception patterns can also be referred to as a reception (RX) beam.

[0025] Fifth-generation wireless communication systems support not only standalone mode operation but also dual connectivity (DC). In DC, multiple Rx / Tx UEs can be configured to utilize resources provided by two different nodes (or NBs) connected via a non-ideal backhaul. One node acts as the Master Node (MN) and the other as the Secondary Node (SN). The MN and SN are connected via network interfaces, and at least the MN is connected to the core network. NR also supports Multi-RAT Dual Connectivity (MR-DC) operation, where UEs in the RRC_CONNECTED state are configured to utilize radio resources provided by two distinct schedulers connected via a non-ideal backhaul, providing E-UTRA (i.e., when the node is an ng-eNB) or NR access (i.e., when the node is a gNB). In NR, UEs in the RRC_CONNECTED state that are not configured as CA / DC have only one serving cell configured as the primary cell. For a UE in the RRC_CONNECTED state configured as a CA / DC, the term 'serving cell' is used to denote a set of cells containing special cells and all sub-cells. In NR, a Master Cell Group (MCG) refers to a group of serving cells associated with a master node; an MCG includes a PCell and may optionally include one or more SCells. In NR, a Secondary Cell Group (SCG) refers to a group of serving cells associated with a secondary node; an SCG includes a PSCell and may optionally include one or more SCells. In NR, a PCell (Primary Cell) refers to a serving cell within an MCG operating at the fundamental frequency where the U performs the initial connection setup procedure or initiates the connection reset procedure. For a UE configured as a CA, an Scell ​​in NR is a cell that provides additional radio resources on top of a special cell.A PSCell (Primary SCG Cell) refers to a serving cell within an SCG that the UE accesses randomly when performing the Reconfiguration with Sync procedure. For dual connectivity operations, a SpCell (i.e., a special cell) refers to a PCell in an MCG or a PSCell in an SCG, otherwise the term special cell refers to a PCell.

[0026] Acquisition of System Information in 5th Generation Wireless Communication Systems: In 5th generation wireless communication systems, a Node B (gNB) or base station broadcasts synchronization signals and PBCH blocks (SSBs), which consist of primary and secondary synchronization signals (PSS, SSS) and system information. System information contains common parameters necessary for communication within a cell. In 5th generation wireless communication systems (also known as next-generation radio or NR), system information (SI) is divided into an MIB and multiple SIBs, where:

[0027] - MIB is always transmitted on BCH at a cycle of 80 ms, repeated within 80 ms, and contains parameters necessary to obtain SIB1 from the cell.

[0028] - SIB1 is transmitted over DL-SCH at a period of 160ms, and the transmission repetition is variable. The default transmission repetition period of SIB1 is 20ms, but the actual transmission repetition period depends on the network implementation. The scheduling information of SIB1 includes the mapping between the SIB and SI messages, the periodicity of each SI message, and the SI window length. The scheduling information of SIB1 includes an indicator for each SI message, indicating whether the corresponding SI message is broadcast. If at least one SI message is not broadcast, SIB1 may include random access resources (PRACH preamble(s) and PRACH resource(s)) that request the gNB to broadcast one or more SI messages.

[0029] - SIBs other than SIB1 are carried in System Information (SI) messages transmitted over the DL-SCH. Only SIBs with the same period can be mapped to the same SI message. Each SI message is transmitted within a time-domain window that occurs periodically (referred to as an SI-window of equal length for all SI messages). Each SI message is associated with an SI-window, and SI-windows of different SI messages do not overlap. That is, only the corresponding SI message is transmitted within a single SI-window. Any SIB other than SIB1 can be configured as cell-specific or region-specific using the markings within SIB1. A cell-specific SIB is applicable only within the cell providing the SIB, while a region-specific SIB is applicable within a region called an SI area, which consists of one or more cells and is identified by the systemInformationAreaID.

[0030] - The UE acquires SIB 1 from the camped cell or serving cell. The UE checks the BroadcastStatus bit in SIB 1 for the SI message it needs to acquire. The SI request configuration for SUL is signaled by the gNB using IE si-RequestConfigSUL in SIB 1. If IE si-RequestConfigSUL does not exist in SIB 1, the UE assumes that the SI request configuration for SUL has not been signaled by the gNB. The SI request configuration for NUL is signaled by the gNB using IE si-RequestConfig in SIB 1. If IE si-RequestConfig does not exist in SIB 1, the UE assumes that the SI request configuration for NUL has not been signaled by the gNB. If the SI message it needs to acquire is not being broadcast (i.e., the BroadcastStatus bit is set to 0), the UE begins transmitting the SI request. The procedure for transmitting the SI request is as follows:

[0031] - The gNB signals the SI request configuration for the SUL, and if the SUL selection criteria are met (i.e., the RSRP derived from the SSB measurement of the camped cell or serving cell is less than rsrp-ThresholdSSB-SUL, where rsrp-ThresholdSSB-SUL is signaled by the gNB (e.g., in a broadcast signaling scheme such as SIB1)), the UE initiates the transmission of the SI request based on the Msg1-based SI request on the SUL. In other words, the UE initiates the random access procedure using the PRACH preamble(s) and PRACH resource(s) within the SI request configuration of the SUL. The UE transmits Msg1 (i.e., the random access preamble) and waits for acknowledgment of the SI request. The random access resources (PRACH preamble(s) and PRACH time(s)) indicated in the SI request configuration of the SUL are used for Msg1. Msg1 is transmitted from the SUL. When an acknowledgment for an SI request is received, the UE monitors the SI window of the requested SI message during one or more SI period(s) of the corresponding SI message.

[0032] - Otherwise, the gNB signals the SI request configuration for the NUL, and if the NUL selection criteria are met (i.e., the SUL is supported in the camped cell or serving cell, and the RSRP derived from the SSB measurement of the camped cell or serving cell is greater than or equal to rsrp-ThresholdSSB-SUL; or the SUL is not supported in the serving cell), the UE initiates the transmission of the SI request based on the Msg1-based SI request on the NUL (350). In other words, the UE initiates a random access procedure using the PRACH preamble(s) and PRACH resource(s) within the SI request configuration of the NUL. The UE transmits Msg1 (i.e., the random access preamble) and waits for acknowledgment of the SI request. The random access resources (PRACH preamble(s) and PRACH time(s)) indicated in the SI request configuration of the NUL are used for Msg1. Msg1 is transmitted from the NUL. When an acknowledgment for an SI request is received, the UE monitors the SI window of the requested SI message during one or more SI period(s) of the corresponding SI message.

[0033] - Otherwise, the UE initiates the transmission of the SI request based on the Msg3-based SI request. In other words, the UE initiates the transmission of the RRCSystemInfoRequest message (345). The UE transmits Msg1 (i.e., the random access preamble) and waits for a random access response. Common random access resources (PRACH preamble(s) and PRACH time(s)) are used for Msg1. Upon the UL acknowledgment received in the random access response, the UE transmits the RRCSystemInfoRequest message and waits for an acknowledgment for the SI request (i.e., the RRCSystemInfoRequest message). When an acknowledgment for the SI request (i.e., the RRCSystemInfoRequest message) is received, the UE monitors the SI window of the requested SI message during one or more SI period(s) of the corresponding SI message. Note that if SUL is configured, the UL carrier selection for the transmission of Msg1 will be selected by the UE in a manner similar to the way the UE selected for the Msg1-based SI request. SUL is a UL carrier selected when the RSRP derived from the SSB measurement of the camped cell or serving cell is less than rsrp-ThresholdSSB-SUL, where rsrp-ThresholdSSB-SUL is signaled by the gNB (e.g., in a broadcast signaling scheme such as SIB1). NUL is a UL carrier selected when the RSRP derived from the SSB measurement of the camped cell or serving cell is greater than or equal to rsrp-ThresholdSSB-SUL, where rsrp-ThresholdSSB-SUL is signaled by the gNB (e.g., in a broadcast signaling scheme such as SIB1).

[0034] PDCCH in a 5th generation wireless communication system: In a 5th generation wireless communication system, a physical downlink control channel (PDCCH) is used to schedule DL transmissions on the PDSCH and UL transmissions on the PUSCH, wherein downlink control information (DCI) on the PDCCH includes at least modulation and coding formats, resource allocations, and downlink allocations including hybrid ARQ information related to the DL-SCH. In addition to scheduling, the PDCCH may be used to enable and disable PUSCH transmissions configured with configured grants, enable and disable PDSCH semi-persistent transmissions, notify one or more UEs of slot formats, notify one or more UEs of PRB(s) and OFDM symbol(s) so that the UEs may assume there is no intention to transmit, transmit TPC commands for PUCCH and PUSCH, transmit one or more TPC commands for SRS transmissions by one or more UEs, switch the active bandwidth of the UEs, and initiate random access procedures. The UE monitors a set of PDCCH candidates for monitoring cases configured in a CORESET, which is one or more configured sets of control resources according to the corresponding search space configuration. A CORESET consists of a set of PRBs with 1 to 3 OFDM symbol time durations. Resource units, namely Resource Element Groups (REGs) and Control Channel Elements (CCEs), are defined within a CORESET where each CCE constitutes a set of REGs. Control channels are formed by sets of CCEs, and different code rates for control channels are realized by assembling different numbers of CCEs. Interleaved CCE-to-REG mapping and non-interleaved CCE-to-REG mapping are supported in the CORESET. Polar coding is used for the PDCCH. Each resource element group carrying the PDCCH carries its own DMRS. QPSK modulation is used for the PDCCH.

[0035] In 5th generation wireless communication systems, a list of search space configurations is signaled by the GNB for a configured BWP, which is uniquely identified by an identifier for each search configuration. An identifier to identify the configuration of the search space to be used for specific purposes, such as paging reception, SI reception, and random access response reception, is explicitly signaled by the gNB. The NR search space configuration includes the parameters monitoring periodicity-PDCCH-slot, monitoring offset-PDCCH-slot, monitoring symbol-PDCCH-in-slot, and duration. The UE determines the PDCCH monitoring case within a slot using the parameters PDCCH monitoring periodicity (monitoring periodicity-PDCCH-slot), PDCCH monitoring offset (monitoring offset-PDCCH-slot), and PDCCH monitoring pattern (monitoring symbol-PDCCH-in-slot). The PDCCH monitoring case exists in slots from 'x' to x+duration, where the slot at number 'x' in the radio frame at number 'y' satisfies the following equation:

[0036] (y*(number of slots in radio frame) + x - monitoring offset-PDCCH-slot) mod (monitoring periodicity-PDCCH-slot) = 0;

[0037] The start symbol of the PDCCH monitoring case is given by the monitoring symbol-PDCCH-in-slot. The length (in symbols) of the PDCCH monitoring case is given by the core set associated with the search space. The search space configuration includes the identifier of the associated core set configuration. For each configured BWP, there is a list of core set configurations signaled by the GNB, where each core set configuration is uniquely identified by an identifier. Each radio frame has a duration of 10 ms. Radio frames are identified by a radio frame number or a system frame number. Each radio frame consists of multiple slots, and the number of slots within the radio frame and the duration of the slots depend on the subcarrier interval. The number of slots within the radio frame and the duration of the slots for each supported SCS are predefined in the NR. Each core set configuration is associated with a list of TCI (Transmission Configuration Indicator) states. A single DL RS ID (SSB or CSI RS) is configured per TCI state. A list of TCI states corresponding to the core set configuration is signaled by the gNB via the RRC signal. One of the TCI states in the list is activated and indicated to the UE by the gNB via MAC CE. The TCI state indicates the DL TX beam (the DL TX beam is QCLed with the SSB / CSI RS of the TCI state) used by the GNB for the transmission of the PDCCH in the search space PDCCH monitoring cases. For the PDSCH, the TCI state of the scheduling PDCCH can be used for the scheduled PDSCH. Alternatively, the TCI state of the PDCCH for the lowest core set ID in the slot is used for the PDSCH. Alternatively, the RRC+MAC CE+DCI combination is used to indicate the TCI state for the PDSCH.RRC constitutes a list of TCI states, MAC CE represents a subset of these TCI states, and DCI represents a single TCI state from the list of TCI states indicated in MAC CE.

[0038] Bandwidth Adaptation (BA) in 5th Generation Wireless Communication Systems: Bandwidth adaptation (BA) is supported in 5th generation wireless communication systems. With BA, the transmit and receive bandwidth of a UE does not need to be as large as the cell's bandwidth and can be adjusted: the width can be commanded to change (e.g., to be reduced during periods of low activity to save power); the position can be shifted in the frequency domain (e.g., to increase scheduling flexibility); and the subcarrier spacing can be commanded to change (e.g., to allow for different services). A subset of the cell's total bandwidth is called the bandwidth part (BWP). BA is implemented by configuring RRC-connected UEs into BWP(s) and informing the UE which of the configured BWPs is currently active. Once BA is configured, the UE only needs to monitor the PDCCH from one active BWP. In other words, there is no need to monitor the PDCCH across the entire DL frequency of the serving cell. In the RRC connected state, the UE is configured with one or more DL and UL BWPs for each configured serving cell (i.e., PCell or SCell). An active serving cell always has one active UL and DL BWP at any given time. BWP switching for a serving cell is used to enable inactive BWPs and simultaneously disable active BWPs. BWP switching is controlled by a PDCCH indicating a downlink allocation or uplink grant, and by a MAC entity at the start of a bwp-InactivityTimer, RRC signal, or random access procedure. When a SpCell is added or a SCell is enabled, the DL BWP and UL BWP indicated by firstActiveDownlinkBWP-Id and firstActiveUplinkBWP-Id, respectively, are enabled without receiving a PDCCH indicating a downlink allocation or uplink grant.The active BWP for the serving cell is directed by either the RRC or the PDCCH. For unpaired spectrum, the DL BWP is paired with the UL BWP, and BWP switching is common for both UL and DL. When the BWP inactivity timer expires, the UE switches the active DL BWP to the default DL BWP or the initial DL BWP (if the default DL BWP is not configured).

[0039] Random Access in 5th Generation Wireless Communication Systems: Random Access (RA) is supported in 5G wireless communication systems. RA is used to achieve Uplink (UL) time synchronization. RA is used for UE Initial Access, Handover, Radio Resource Control (RRC) Connection Re-establishment procedures, Scheduling Request transmission, Secondary Cell Group (SCG) addition / modification, Beam Failure Recovery, and the transmission of data or control information from the UL by UEs that are connected to the RRC but in an asynchronous state.

[0040] CBRA (Contention Based Random Access): This is also referred to as 4-Step CBRA or 4-Step Random Access. In this type of random access, the UE first transmits a Random Access Preamble (Msg1) and then waits for a Random Access Response (RAR) in the RAR window. The RAR is also referred to as Msg2. The next-generation node B (gNB) transmits the RAR on the Physical Downlink Shared Channel (PDSCH). The PDCCH that schedules the PDSCH carrying the RAR is addressed by the RA-RNTI (RA-radio network temporary identifier). The RA-RNTI identifies the time-frequency resource (also referred to as PRACH (Physical RA Channel) occasion, PRACH(TX) occasion, or RACH(RACH) occasion, or RO) at which the RA preamble was detected by the gNB. RA-RNTI is calculated as RA-RNTI=1 + s_id + 14*t_id + 14*80*f_id + 14*80*8*ul_carrier_id, where s_id is the index of the first Orthogonal Frequency Division Multiplexing (OFDM) symbol of the PRACH occision in which the UE transmitted Msg1, i.e., the RA preamble (0 s_id<14). t_id is the index of the first slot of the PRACH occasion(0 t_id < 80), and f_id is the index of the PRACH Occasion in the frequency domain within the slot (0 f_id < 8). Also, ul_carrier_id is the UL carrier used for Msg1 transmission, having a value of 0 for a Normal UL carrier and 1 for a Supplementary UL (SUL) carrier. Multiple RARs for various Random Access Preambles detected by the gNB may be multiplexed by the gNB in ​​the same RAR Media Access Control (MAC) Protocol Data Unit (PDU). A RAR in the MAC PDU is considered to correspond to the terminal's RA Preamble transmission if it contains the RA Preamble Identifier (RAPID) of the RA Preamble transmitted by the terminal. If the UE does not receive a RAR corresponding to its RA Preamble transmission within the RAR window and has not yet transmitted the RA Preamble a set number of times (set by the gNB in ​​the RACH configuration), the UE returns to the first step, namely the Random Access Resource selection step, selects a preamble / RACH occasion, and transmits the RA Preamble. Backoff may be applied before returning to that first step.

[0041] When the terminal receives a RAR corresponding to its RA Preamble transmission, it transmits Message 3 (Msg3) from the UL grant received in the RAR. Msg3 includes messages such as an RRC connection request, an RRC connection re-establishment request, an RRC handover confirm, a scheduling request, and an SI request, and may include a UE identity (e.g., a cell-radio network temporary identifier (C-RNTI), an SAE (system architecture evolution) - temporary mobile subscriber identity (S-TMSI), or a random number). After transmitting Msg3, the UE starts a contention resolution timer. While the Contention Resolution Timer is running, if the UE receives a PDCCH (Physical Downlink Control Channel) directed to the C-RNTI included in Msg3, it is determined that the contention resolution has been successful, the contention resolution timer is stopped, and the RA procedure is completed. When the Contention Resolution Timer receives a Contention Resolution MAC Control Element (CE) containing the UE's Contention Resolution Identity (the first X bit of the Common Control Channel (CCCH) Service Data Unit (SDU) transmitted in Msg3) while the Contention Resolution Timer is running, the Contention Resolution is considered successful, the Contention Resolution Timer is stopped, and the RA procedure is completed.If the Contention Resolution Timer expires and the terminal fails to transmit the RA Preamble a configurable number of times, the terminal may return to the first step, Random Access Resource (Preamble / RACH occision), to transmit the RA Preamble. Backoff may be applied before returning to the first step.

[0042] Contention-free random access (CFRA): This is also referred to as legacy CFRA or 4-step CFRA. The CFRA procedure is used in scenarios requiring low latency, such as handover, timing advance establishment for a secondary cell (Scell), and when a gNB (node ​​B) assigns a UE-dedicated random access preamble. The UE transmits a dedicated RA preamble. The gNB transmits a RAR for the PDSCH addressed by RA-RNTI. The RAR carries the RA preamble identifier and timing alignment information. The RAR may also include UL grants. The RAR is transmitted within the RAR window, similar to the Contention-Based RA (CBRA) procedure. CFRA is considered successfully completed upon receiving a RAR containing the RA Preamble Identifier (RAPID) of the RA preamble transmitted by the terminal. When RA is initiated for beam failure recovery, CFRA is considered to have successfully completed when it receives a PDCCH addressed to C-RNTI in the search space for beam failure recovery. If the UE does not receive a RAR until the RAR window expires, it considers the RA not to have completed successfully, and if it has not repeated the RA preamble a sufficient number of times (set as gNB in ​​the RACH configuration), it retransmits the RA preamble.

[0043] In the event of specific events such as handover and beam failure recovery, if dedicated preamble(s) are assigned to the UE, during the first phase of random access—that is, during the selection of random access resources for Msg1 transmission—the UE may decide whether to transmit the dedicated or non-dedicated preamble. Dedicated preambles are generally provided for a subset of SSBs / CSI RSs. If, among the SSBs / CSI RSs for which contention-free random access resources (i.e., dedicated preambles / ROs) are provided by the GNB, there are no SSBs / CSI RSs whose DL RSRP is above the threshold, the UE selects the non-dedicated preamble. Otherwise, the UE selects the dedicated preamble. Therefore, during the RA procedure, one random access attempt may be a CFRA and another random access attempt may be a CBRA.

[0044] Two-Step Contention-Based Random Access (2-Step CBRA): In the first step, the UE transmits a random access preamble on PRACH and a payload (i.e., MAC PDU) on PUSCH. The transmission of the random access preamble and payload is also referred to as MsgA. In the second step, after transmitting MsgA, the UE monitors for a response from the network (i.e., gNB) within the configured window. This response is also referred to as MsgB. The next-generation node B (gNB) transmits MsgB on the physical downlink shared channel (PDSCH). The PDCCH scheduling the PDSCH carrying MsgB is addressed by the MsgB-Radio Network Temporal Identifier (MSGB-RNTI). The MSGB-RNTI identifies the time-frequency resource at which the RA frame was detected by the gNB (also referred to as the physical RA channel (PRACH) time, the PRACH transmission (TX) time, or the RA channel (RACH) time). MSGB-RNTI is calculated as follows: RA-RNTI 1 + s_id + 14 * t_id + 14 * 80 * f_id + 14 * 80 * 8 * ul_carrier_id + 14 x 80 x 8 x 2, where s_id is the index of the first Orthogonal Frequency Division Multiplexing (OFDM) symbol at the time of PRACH when the UE transmitted Msg1, i.e., the RA preamble (0 <= s_id < 14), t_id is the index of the first slot at the time of PRACH (0 <= t_id < 80), f_id is the index of the time of PRACH within the slot in the frequency domain (0 <= f_id < 8), and ul_carrier_id is the UL carrier used for Msg1 transmission (0 for normal UL (NUL) carrier, 1 for supplementary UL (SUL) carrier).

[0045] If a CCCH SDU is transmitted as the MsgA payload, the UE performs contention resolution using the contention resolution information in MsgB. If the contention resolution ID received in MsgB matches the first 48 bits of the CCCH SDU transmitted in MsgA, contention resolution is successful. If a C-RNTI is transmitted as the MsgA payload, contention resolution is successful if the UE receives a PDCCH addressed to the C-RNTI. If contention resolution is successful, the random access procedure is considered to have been successfully completed. Instead of contention resolution information corresponding to the transmitted MsgA, MsgB may contain fallback information corresponding to the random access preamble transmitted in MsgA. If fallback information is received, the UE transmits Msg3 and performs contention resolution using Msg4 as in the CBRA procedure. If contention resolution following the fallback fails (i.e., by transmitting Msg3), the UE retransmits MsgA. If, after sending MsgA, the configuration window for the UE to monitor network responses expires and the UE does not receive MsgB containing contention resolution or fallback information as described above, the UE resends MsgA. If the random access procedure is not successfully completed even after sending the message a configurable number of times, the UE returns to the 4-Step RACH procedure. That is, the UE sends only the PRACH preamble.

[0046] The MsgA payload may include one or more of the Common Control Channel (CCCH) Service Data Unit (SDU), Dedicated Control Channel (DCCH) SDU, Dedicated Traffic Channel (DTCH) SDU, Buffer Status Reporting (BSR) MAC Control Element (CE), Power Headroom Reporting (PHR) MAC CE, SSB information, C-RNTI MAC CE, or padding. In the first stage, the MsgA may include a UE ID (e.g., Random ID, S-TMSI, C-RNTI, Resume ID, etc.) along with a preamble. The UE ID may be included within the MAC PDU of the MsgA. UE IDs such as C-RNTI may be carried in the MAC CE, and the MAC CE is included in the MAC PDU. Other UE IDs (Random ID, S-TMSI, C-RNTI, Resume ID, etc.) may be carried in the CCCH SDU. The UE ID may be a Random ID, S-TMSI, C-RNTI, Resume ID, IMSI, Idle Mode ID, Inactive Mode ID, etc. The UE ID may differ in different scenarios where the UE performs the RA procedure. When the UE performs the RA after powering on (before connecting to the network), the UE ID is a random ID. When the UE performs the RA while idle after connecting to the network, the UE ID is S-TMSI. If the UE has a C-RNTI assigned (e.g., connected state), the UE ID is C-RNTI. If the UE is in an inactive state, the UE ID is the resumption ID. In addition to the UE ID, some additional control information may be sent to the MsgA. This control information may be included in the MAC PDU of the MsgA. This control information may include connection request indications, connection resumption request indications, SI request indications, buffer status indications, beam information (such as one or more DL TX beam IDs or SSB IDs), beam failover indications / information, data indicators, cell / BS / TRP switching indications, connection re-establishment indications, reconfiguration complete or handover complete messages, etc.

[0047] 2-Step Contentless Random Access (2-Step CFRA): In this case, the gNB allocates dedicated random access preamble(s) and PUSCH resource(s) for MsgA transmission to the UE. RO(s) to be used for preamble transmission may also be specified. In the first step, the UE uses the contentless random access resources (i.e., dedicated preamble / PUSCH resource / RO) to transmit the random access preamble to PRACH and the payload to PUSCH. In the second step, after MsgA transmission, the UE monitors for a response from the network (i.e., gNB) within the configured window. This response is also referred to as MsgB.

[0048] The next-generation node B (gNB) transmits MsgB over the physical downlink shared channel (PDSCH). The PDCCH that schedules the PDSCH carrying MsgB is addressed by the MsgB-radio network temporal identifier (MSGB-RNTI). The MSGB-RNTI identifies the time-frequency resource at which the RA frame was detected by the gNB (also referred to as the physical RA channel (PRACH) time, or the PRACH transmission (TX) time, or the RA channel (RACH) time). MSGB-RNTI is calculated as follows: RA-RNTI = 1 + s_id + 14 * t_id + 14 * 80 * f_id + 14 * 80 * 8 * ul_carrier_id + 14 x 80 x 8 x 2, where s_id is the index of the first Orthogonal Frequency Division Multiplexing (OFDM) symbol at the PRACH time when the UE transmitted Msg1, i.e., the RA preamble, and 0 <= s_id < 14; t_id is the index of the first slot at the PRACH time (0 <= t_id < 80), f_id is the index of the PRACH time within the slot in the frequency domain (0 <= f_id < 8), and ul_carrier_id is the UL carrier used for Msg1 transmission (0 for normal UL (NUL) carrier, 1 for supplementary UL (SUL) carrier).

[0049] If the UE receives a PDCCH addressed to C-RNTI, the random access procedure is considered to have been successfully completed. If the UE receives fallback information corresponding to the transmitted preamble, the random access procedure is considered to have been successfully completed.

[0050] In the case of specific events such as handover and beam failure recovery where dedicated preamble(s) and PUSCH resource(s) are assigned to the UE, the UE decides whether to transmit a dedicated preamble or a non-dedicated preamble during the first step of random access, namely, the selection of random access resources for MsgA transmission. Dedicated preambles are typically provided to a subset of SSBs / CSI RSs. If, among the SSBs / CSI RSs for which contention-free random access resources (i.e., dedicated preamble / ROs / PUSCH resources) are provided by the gNB, there are no SSBs / CSI RSs with a DL RSRP above a threshold, the UE selects a non-dedicated preamble. Otherwise, the UE selects a dedicated preamble. Thus, during the RA procedure, one random access attempt may be a 2-Step CFRA and another random access attempt may be a 2-Step CBRA.

[0051] When a random access procedure is initiated, the UE first selects a carrier (SUL or NUL). If the carrier to be used for the random access procedure is explicitly signaled by the gNB, the UE selects the signaled carrier to perform the random access procedure. If the carrier to be used for the random access procedure is not explicitly signaled by the gNB, and if the serving cell for the random access procedure is configured to have a supplementary uplink and the RSRP of the downlink path loss reference is less than rsrp - ThresholdSSB - SUL, the UE selects a SUL carrier to perform the random access procedure. Otherwise, the UE selects a NUL carrier to perform the random access procedure. After selecting the UL carrier, the UL and DL BWP for the random access procedure are determined as specified in Section 5.15 of TS 38.321. The UE then determines whether to perform a 2-Step or 4-Step RACH for this random access procedure.

[0052] - If this random access procedure is initiated by the PDCCH order and the ra-PreambleIndex explicitly provided by the PDCCH is not 0b000000, the UE selects 4Step RACH.

[0053] - Otherwise, if a 2-step contention-free random access resource for this random access procedure is signaled by gNB, the UE selects 2-step RACH.

[0054] - Otherwise, if a 4-step contention-free random access resource for this random access procedure is signaled by gNB, the UE selects 4-step RACH.

[0055] - Otherwise, if the UL BWP selected for this random access procedure consists only of 2-Step RACH resources, the UE selects 2-Step RACH.

[0056] - Otherwise, if the UL BWP selected for this random access procedure consists only of 4-Step RACH resources, the UE selects 4-Step RACH.

[0057] - Otherwise, if the UL BWP selected for this random access procedure consists of both 2-Step and 4-Step RACH resources, the UE selects 2-Step RACH.

[0058] - If the RSRP of downlink path loss is below the configured threshold, the UE selects 4-Step RACH. Otherwise, the UE selects 2-Step RACH.

[0059] Paging in 5th Generation Wireless Communication Systems: In 5th generation (also known as NR or New Radio) wireless communication systems, a UE can be in one of the following RRC states: RRC IDLE, RRC INACTIVE, and RRC CONNECTED. RRC states can be further characterized as follows:

[0060] - In the RRC_IDLE state, a UE-specific DRX can be configured by the upper layer (i.e., NAS). The UE monitors short messages transmitted to the P-RNTI via the DCI; monitors the paging channel for CN paging using 5G-S-TMSI; performs neighbor cell measurement and cell (re)selection; and can acquire system information and send SI requests (if configured).

[0061] - In the RRC_INACTIVE state, a UE-specific DRX can be configured by the upper layer or the RRC layer. In this state, the UE stores the UE inactive AS context. The RAN-based alert region is configured by the RRC layer. The UE monitors short messages transmitted to P-RNTI via DCI; monitors paging channels for RAN paging using 5G-S-TMSI and fullI-RNTI; performs neighbor cell measurement and cell (re)selection; performs RAN-based alert region updates periodically and when moving out of the configured RAN-based alert region; can acquire system information and send SI requests (if configured).

[0062] - In RRC_CONNECTED, the UE stores the AS context. Unicast data is transmitted and received with the UE. At the lower layer, the UE can be configured with a UE-specific DRX. If configured, the UE monitors short messages transmitted to the P-RNTI via the DCI; monitors the control channel associated with the shared data channel to determine if data is scheduled for it; provides channel quality and feedback information; performs neighbor cell measurements and measurement reports; and acquires system information.

[0063] A 5G or Next-Generation Radio Access Network (NG-RAN) based on NR consists of NG-RAN nodes, where the NG-RAN node acts as a gNB, providing NR user plane and control plane protocol endpoints to the UE. The gNB is also connected to the 5GC, more specifically the Access and Mobility Management Function (AMF), via the NG-C interface, and to the User Plane Function (UPF) via the NG-U interface. In 5th generation (also known as NR or New Radio) radio communication systems, the UE may use Discontinuous Receive (DRX) in the RRC_IDLE and RRC_INACTIVE states to reduce power consumption. In the RRC_IDLE / RRC_INACTIVE state, the UE wakes up briefly at regular intervals (i.e., each DRX cycle) to receive paging, SI update notifications, and emergency notifications. Paging messages are transmitted using the Physical Downlink Shared Channel (PDSCH). The Physical Downlink Shared Control Channel (PDCCH) is addressed as P-RNTI when there is a paging message on the PDSCH. P-RNTI is common to all UEs. To indicate paging for a specific UE, the UE identity (i.e., S-TMSI for RRC_IDLE UEs or I-RNTI for RRC_INACTIVE UEs) is included in the paging message. Paging messages can be paged to multiple UEs by including multiple UE identities. Paging messages are broadcast (i.e., the PDCCH is masked by P-RNTI) and are transmitted over the data channel (i.e., PDSCH). SI updates and emergency notifications are included in the DCI, and the PDCCH carrying this DCI is addressed by the P-RNTI. In RRC idle / inactive mode, the UE monitors one Paging Opportunity (PO) per DRX cycle. In RRC idle / inactive mode, the UE monitors the PO in the initial DL BWP. In the RRC connected state, the UE monitors one or more POs to receive SI update notifications and emergency notifications.In the RRC connection state, the UE can monitor any PO of the paging DRX cycle and monitors at least one PO during the SI modification period. In the RRC idle / inactive mode, the UE monitors a PO for each DRX cycle in the active DL BWP. A PO is a set of 'S' PDCCH monitoring opportunities, which is the number of SSBs (Synchronization Signals and PBCH Blocks) transmitted from the cell. The UE first determines a paging frame (PF) and determines a PO for the determined PF. One PF is a radio frame (10ms).

[0064] - A PF for a UE is a radio frame with system frame number 'SFN' satisfying the equation (SFN + PF_offset) mod T = (T div N) * (UE_ID mod N).

[0065] - The index (i_s) representing the index of the PO is determined by i_s = floor(UE_ID / N) mod Ns.

[0066] - T is the UE's DRX cycle.

[0067] - In the RRC_INACTIVE state, T is determined by the minimum of the UE-specific DRX value configured by RRC, the UE-specific DRX value configured by NAS, and the default DRX value broadcast from system information.

[0068] - In the RRC_IDLE state, T is determined by the minimum of the UE-specific DRX value configured by the NAS and the default DRX value broadcast from the system information. If the UE-specific DRX is not configured by the upper layer (i.e., the NAS), the default value is applied.

[0069] - N: Total number of paging frames in T

[0070] - Ns: Number of paging opportunities for PF

[0071] - PF_offset: Offset used to determine PF

[0072] - UE_ID: 5G-S-TMSI mod 1024

[0073] - Ns, nAndPagingFrameOffset, and the default DRX cycle length are signaled in SIB1. The values ​​for N and PF_offset are derived from the nAndPagingFrameOffset parameter as defined in TS 38.331. If there is no 5G-S-TMSI, such as when the UE is not yet registered with the network, the default identity UE_ID = 0 must be used in the above PF and i_s formulas.

[0074] - The opportunity for PDCCH monitoring for paging is determined based on the paging-SearchSpace configuration signaled by the gNB.

[0075] - If SearchSpaceId = 0 is configured for pagingSearchSpace, the PDCCH monitoring opportunity for paging is for the RMSI, as defined in Clause 13 of TS 38.213. If SearchSpaceId = 0 is configured for pagingSearchSpace, Ns is 1 or 2. If Ns = 1, there is only one PO starting from the first PDCCH monitoring opportunity for paging in the PF. If Ns = 2, the PO is in the first frame (i_s = 0) or second frame (i_s = 1) of the PF.

[0076] - If a non-zero SearchSpaceId is configured for pagingSearchSpace, the UE monitors the (i_s + 1)th PO. The PDCCH monitoring opportunities for paging are determined based on the paging-SearchSpace configuration signaled by the gNB. The PDCCH monitoring opportunities do not overlap with the UL symbols determined by tdd-UL-DL-ConfigurationCommon, and they are numbered sequentially starting from the first PDCCH monitoring opportunity for paging in the PF. The gNB can signal the firstPDCCH-MonitoringOccasionOfPO parameter for each PO corresponding to each PF. If firstPDCCH-MonitoringOccasionOfPO is signaled, the (i_s + 1)th PO is a set of 'S' consecutive PDCCH monitoring opportunities for paging starting from the PDCCH monitoring opportunity number indicated by firstPDCCH-MonitoringOccasionOfPO (i.e., the (i_s + 1)th value of the firstPDCCH-MonitoringOccasionOfPO parameter). Otherwise, the (i_s + 1)th PO is a set of 'S' consecutive PDCCH monitoring opportunities starting from the (i_s * S)th PDCCH monitoring opportunity for paging. 'S' is the number of actual transmitted SSBs determined by the parameter ssb-PositionsInBurst signaled in SystemInformationBlock1 received from the gNB. The first-PDCCH-MonitoringOccasionOfPO parameter is signaled in SIB1 for paging in the initial DL BWP. For paging in DL BWPs other than the initial DL BWP, the first-PDCCH-MonitoringOccasionOfPO parameter is signaled in the corresponding BWP configuration.

[0077]

[0078] The operating principles of the present disclosure will be described in detail below with reference to the attached drawings. In describing the present disclosure below, specific descriptions of related known functions or configurations will be omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the present disclosure. Furthermore, the terms described below are defined in consideration of their functions in the present disclosure, and these may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0079] Terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc., are examples provided for the convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

[0080] Hereinafter, a base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, eNode B, Node B, BS (Base Station), radio access unit, base station controller, or a node on a network. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. In this disclosure, a downlink (DL) refers to a wireless transmission path of a signal transmitted by a base station to a terminal, and an uplink (UL) refers to a wireless transmission path of a signal transmitted by a terminal to a base station. Furthermore, while an LTE or LTE-A system may be described as an example below, embodiments of this disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included in a system to which embodiments of this disclosure can be applied, and the 5G below may be a concept that includes existing LTE, LTE-A, and other similar services. Furthermore, the present disclosure may be applied to other communication systems with some modifications made at the discretion of a person with skilled technical knowledge, without departing significantly from the scope of the present disclosure. In this case, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams may be executed by computer program instructions.

[0081] Since these computer program instructions can be loaded onto the processor of a general-purpose computer, a computer for special purposes, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means for performing the functions described in the flowchart block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement functions in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing means of instruction for performing the functions described in the flowchart block(s). Since the computer program instructions can also be loaded onto the computer or other programmable data processing equipment, the instructions that perform a series of operation steps on the computer or other programmable data processing equipment to create a computer-executable process can also provide steps for performing the functions described in the flowchart block(s).

[0082] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). Also, it should be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For example, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may be executed in reverse order depending on the corresponding function. In this case, the term "part" as used in this embodiment refers to software or hardware components such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), and the "part" may perform certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or configured to run one or more processors. Accordingly, as an example, 'part' includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or further separated into additional components and 'parts'. Furthermore, the components and 'parts' may be implemented to utilize one or more CPUs within a device or secure multimedia card. Additionally, in an embodiment, 'part' may include one or more processors.

[0083] For convenience of explanation, the present disclosure uses terms and names defined in the 5GS and NR specifications, which are standards defined by the 3GPP (The 3rd Generation Partnership Project). However, the present disclosure is not limited to the above terms and names and may be applied equally to wireless communication networks conforming to other standards. For example, the present disclosure may be applied to 3GPP 5GS / NR (5th generation mobile communication standard).

[0084] FIG. 1 is a diagram showing the structure of a next-generation mobile communication system that supports subband full-duplex transmission and reception according to an embodiment of the present disclosure.

[0085] Referring to FIG. 1, a next-generation mobile communication system supporting subband full-duplex transmission and reception may be composed of a next-generation base station (1-01, g Node B, hereinafter gNB, Node B or base station), a cell (1-06, 1-07, 1-08), and a terminal (1-09, User Equipment (UE)). Here, the gNB may include a CU (1-02, Central Unit) and one or more DUs (1-03, 1-04, Distributed Units).

[0086] One CU can support one or more DUs, and one DU (1-03, 1-04) can support one cell (1-06, 1-07, 1-08) or one or more cells (1-06, 1-07, 1-08).

[0087] UE (1-09) can access the external network through the cell via the gNB.

[0088] FIG. 2 is a drawing for explaining the concept of a subband full duplex (hereinafter SBFD) of a base station or cell according to one embodiment of the present disclosure.

[0089] Referring to FIG. 2, a base station (2-1) performs wireless communication (2-2) with a terminal (2-4). To this end, frequency and time resources (2-3) are determined, and downlink (DL) and uplink (UL) resources are scheduled to the terminal within the resources. In the past, the resources (2-3) allocated to the terminal could be composed of a downlink slot (2-5), an uplink slot (2-9), and a flexible or special slot allocated when changing the downlink / uplink direction. Now, with the introduction of SBFD, it has become possible to set up an SBFD slot (2-6) in which downlink and uplink resources are mixed between a base station capable of using SBFD and a terminal. Of course, the SBFD slot (2-6) can be set up not only in the same location as in FIG. 2, but also in any slot that the base station wishes to set up, such as the Downlink slot of 2-5.

[0090] In this situation, to support random access of the terminal, the base station can allocate an uplink physical layer Random Access Channel (PRACH) capable of transmitting and receiving a preamble for random access within an SBFD slot, rather than the existing uplink slot (2-9), and can allocate a RACH occasion (RO) (2-10). The SBFD RO may be contained within an SBFD slot as shown in FIG. 2, may exist across one or more SBFD slots, and may exist across not only one or more SBFD slots but also a normal Uplink slot (2-9).

[0091] Through this SBFD RO (2-10), terminals capable of using SBFD gain additional RO opportunities in addition to existing legacy RO, thereby enabling random access with even less latency and collision.

[0092] FIG. 3 is a diagram illustrating an example of a terminal SBFD RACH capability reporting procedure according to an embodiment of the present disclosure.

[0093] Referring to FIG. 3, the terminal (3-1) can receive a signal (3-3) requesting capability information of the terminal from the serving cell base station (3-2) to which the terminal (3-1) is connected, and in response to this, can transmit a capability signal to the base station including capability information for performing Random Access through the SBFD that the terminal has.

[0094] According to one embodiment of the present disclosure, the terminal (3-1) may inform the serving cell through a signal (3-4) that the terminal's SBFD is available for use, or that there is a function that supports SBFD Random Access through the SBFD, and specifically, that it supports all or part of the following functions.

[0095] The terminal capability can be represented as a combination of features that enable the use of any Random Access resource, as follows.

[0096] For example, the following FeatureCombination IE (information element) is used to associate a feature or combination of features with a set of Random Access resources (i.e., an instance of a single FeatureCombinationPreambles). The IE FeatureCombinationPreambles can define a set of preambles corresponding to a specific feature combination. For the parameters specified in this IE, if the UE performs Random Access using the preambles defined by FeatureCombinationPreambles, the corresponding field value is applied. Conversely, if the UE does not use the preambles defined by FeatureCombinationPreambles, the value is applied as determined by the relevant Need Code. In a specific BWP, there may be at most one set of preambles associated with a given feature combination per RA type (i.e., a given feature combination) (4-step RACH or 2-step RACH).

[0097] FeatureCombination information element

[0098]

[0099]

[0100] The terminal capability may be a per-band capability that allows the terminal to indicate availability for each frequency band, or a per-band combination capability corresponding to a combination of frequency bands.

[0101] The terminal capability may be a per UE capability that the terminal can utilize regardless of frequency bandwidth.

[0102] FIG. 4 is a diagram illustrating an example of a signal for SBFD random access transmitted by a base station to a terminal according to an embodiment of the present disclosure and a procedure for performing SBFD random access by the terminal according to usage conditions.

[0103] Referring to FIG. 4, the base station (4-2) can transmit a signal (4-3) to the terminal (4-1) that includes SBFD resource information, configuration information of RO that may exist within the SBFD, and any condition(s) that the terminal must satisfy to use the SBFD RO.

[0104] The SBFD resource information included in the signal 4-3 transmitted from the base station may be resource information of the same or similar form as illustrated in FIG. 2. For example, it may be a resource characterized by a frame structure consisting of some or all of general uplink or downlink slots, flexible or special slots, and SBFD slots in which uplink and downlink coexist.

[0105] The SBFD RACH Occasion information included in the signal 4-3 transmitted from the base station may be resource information of the same or similar form as illustrated in FIG. 2. For example, it may be an uplink RO resource allocated across one or more SBFD slots, or an uplink RO resource allocated across any adjacent uplink slot as well as SBFD slots. In addition, the information may include parameters necessary for the terminal to perform random access through the RO, such as the following SBFD random access-specific parameters.

[0106] - prach-ConfigurationIndex_SBFD: An available set of SBFD PRACH OCCASIONS (RO) for transmitting the Random Access Preamble, which also applies to MSGA PRACH when SBFD PRACH OCCASIONS (RO) are shared between 2-Step and 4-Step RA types.

[0107] - msgA-PRACH-ConfigurationIndex_SBFD : This is the set of available SBFD PRACH OCCASION (RO) for Random Access Preamble transfer for MSGA of 2-Step RA type.

[0108] - preambleReceivedTargetPower_SBFD : Initial Random Access Preamble Power of the 4-Step RA type performed as an SBFD RO.

[0109] - msgA-PreambleReceivedTargetPower_SBFD : Initial Random Access Preamble power of the 2-Step RA type performed as an SBFD RO.

[0110] - rsrp-ThresholdSSB_SBFD: This is the RSRP threshold for SSB selection for the 4-Step RA type performed with SBFD RO. When a random access procedure is initiated for beam failure recovery, the rsrp-ThresholdSSB_SBFD used for SSB selection within the candidate BeamRSList refers to the rsrp-ThresholdSSB_SBFD within BeamFailureRecoveryConfig IE.

[0111] - rsrp-ThresholdCSI-RS_SBFD: This is the RSRP threshold for CSI-RS selection for 4-Step RA types performed with SBFD RO. If a random access procedure is initiated for beam failure recovery, rsrp-ThresholdCSI-RS_SBFD is equivalent to rsrp-ThresholdSSB_SBFD within BeamFailureRecoveryConfig IE.

[0112] - msgA-RSRP-ThresholdSSB_SBFD : This is the RSRP threshold for SSB selection for the 2-Step RA type performed with SBFD RO.

[0113] - rsrp-ThresholdSSB-SUL_SBFD : RSRP threshold for selection between NUL carriers and SUL carriers in random access performed with SBFD RO.

[0114] - msgA-RSRP-Threshold_SBFD: This is the RSRP threshold for selecting between the 2-Step RA type and the 4-Step RA type when both 2-Step and 4-Step RA types performed by SBFD RO are configured in the UL BWP.

[0115] - rsrp-ThresholdMsg3_SBFD: RSRP threshold for MSG3 repetitions performed with SBFD RO. (see clause 5.1.1b)

[0116] - featurePriorities_SBFD: The priority for features such as RedCap, NSAG(s), etc., performed by SBFD RO. (see clasue 5.1.1d)

[0117] - msgA-TransMax_SBFD : This is the maximum number of MSGA transfers when both 4-Step and 2-Step RA type random access resources are configured to perform SBFD RO.

[0118] - candidateBeamRSList_SBFD: A list of reference signals (CSI-RS and / or SSB) that identify candidate beams associated with random access parameters related to beam recovery performed with SBFD RO.

[0119] - recoverySearchSpaceId_SBFD : This is a search space ID for monitoring the response to a Veeam failure recovery request performed with SBFD RO.

[0120] - powerRampingStep_SBFD : This is the power-ramping step performed by SBFD RO.

[0121] - msgA-PreamblePowerRampingStep_SBFD : This is the power ramping step for the MSGA preamble performed by SBFD RO.

[0122] - powerRampingStepHighPriority_SBFD : This is the power-ramping step for a prioritized random access procedure performed as an SBFD RO.

[0123] - scalingFactorBI_SBFD : Scaling factor for a prioritized random access procedure performed as an SBFD RO.

[0124] - ra-PreambleIndex_SBFD : This is the random access preamble ID performed with SBFD RO.

[0125] - ra-ssb-OccasionMaskIndex_SBFD: Defines the PRACH OCCASION (RO) associated with the SSB through which the MAC entity can transmit the random access preamble for random access performed with the SBFD RO. (See TS 38.321 Section 7.4)

[0126] - msgA-SSB-SharedRO-MaskIndex_SBFD: Represents a subset of 4-Step RA type PRACH OCCASION (RO) mapped to each SSB when 2-Step and 4-Step RA type PRACH OCCASION (RO) are shared for each SSB in random access performed with SBFD RO. If 2-Step RA type PRACH OCCASION (RO) is shared with 4-Step RA type PRACH OCCASION (RO) and msgA-SSB-SharedRO-MaskIndex is not configured, all 4-Step RA type PRACH OCCASION (RO) are available for 2-Step RA types. (See TS 38.321 Section 7.4)

[0127] - ra-OccasionList_SBFD : Defines a PRACH OCCASION (RO) associated with CSI-RS where the MAC entity can transmit a random access preamble for random access performed by SBFD RO.

[0128] - ra-PreambleStartIndex_SBFD : This is the starting index of the random access preamble for on-demand SI requests in random access performed with SBFD RO.

[0129] - startPreambleForThisPartition_SBFD : The first preamble associated with the set of random access resources applied to the random access procedure in random access performed by SBFD RO.

[0130] - preambleTransMax_SBFD : The maximum number of random access preamble transmissions in random access performed with SBFD RO.

[0131] - ssb-perRACH-OccasionAndCB-PreamblesPerSSB_SBFD : Defines the number of SSBs mapped to each PRACH OCCASION (RO) and the number of contention-based random access preambles mapped to each SSB for 4-Step RA types in random access performed with SBFD RO.

[0132] - msgA-CB-PreamblesPerSSB-PerSharedRO_SBFD : Defines the number of contention-based random access preambles for 2-Step RA types mapped to each SSB when PRACH OCCASION (RO) is shared between 2-Step and 4-Step RA types in random access performed with SBFD RO.

[0133] - msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB_SBFD : Defines the number of SSBs mapped to each PRACH OCCASION (RO) and the number of contention-based random access preambles mapped to each SSB for 2-Step RA types in random access performed with SBFD RO.

[0134] - numberOfPreamblesForThisPartition_SBFD : The number of consecutive preambles associated with the set of random access resources applied to the random access procedure in random access performed by SBFD RO.

[0135] - msgA-PUSCH-ResourceGroupA_SBFD : Defines the MSGA PUSCH resource that the UE must use when performing an MSGA transfer using the random access preamble of group A for random access performed with SBFD RO.

[0136] - msgA-PUSCH-ResourceGroupB_SBFD : Defines the MSGA PUSCH resource that the UE must use when performing an MSGA transfer using the random access preamble of group B for random access performed with SBFD RO.

[0137] - msgA-PUSCH-Resource-Index_SBFD : Identifies the index of the PUSCH resource used in the 2-Step RA type for contention-free random access in random access performed with SBFD RO.

[0138] - groupBconfigured_SBFD: For random access performed with SBFD RO, if groupBconfigured is configured, random access preamble group B is configured for the 4-Step RA type.

[0139] - groupB-ConfiguredTwoStepRA_SBFD: For random access performed with SBFD RO, if groupB-ConfiguredTwoStepRA is configured, random access preamble group B is configured for the 2-Step RA type.

[0140] - numberOfRA-PreamblesGroupA_SBFD : In random access performed with SBFD RO, among the contention-based random access preambles associated with SSB, the first numberOfRA-PreamblesGroupA included in the group B configured random access preamble belongs to random access preamble group A, and the remaining random access preambles associated with SSB belong to random access preamble group B (if configured).

[0141] - groupB-ConfiguredTwoStepRA_SBFD: For random access performed with SBFD RO, if groupB-ConfiguredTwoStepRA is configured, random access preamble group B is configured for the 2-Step RA type.

[0142] - numberOfRA-PreamblesGroupA_SBFD : In random access performed with SBFD RO, among the contention-based random access preambles associated with SSB, the first numberOfRA-PreamblesGroupA included in the groupB-ConfiguredTwoStepRA random access preamble belongs to random access preamble group A, and the remaining random access preambles associated with SSB belong to random access preamble group B (if configured).

[0143] - The above parameters and the measurement values ​​used in this patent may be indicators of various power quantities such as RSRP, RSRQ, CQI, SNR, SINR, etc., and may be expressed interchangeably.

[0144] The UE uses the parameters received above to set and initialize the following parameters managed by the terminal for SBFD execution. In the case of parameters having the same name as the parameters set by the base station, they may have the same value, and in the case of counters, they are initialized with a starting value (e.g., 1) and then the number gradually increases.

[0145] - PREAMBLE_INDEX_SBFD;

[0146] -PREAMBLE_TRANSMISSION_COUNTER_SBFD;

[0147] -PREAMBLE_POWER_RAMPING_COUNTER_SBFD;

[0148] -PREAMBLE_POWER_RAMPING_STEP_SBFD;

[0149] -PREAMBLE_RECEIVED_TARGET_POWER_SBFD;

[0150] - PREAMBLE_BACKOFF_SBFD;

[0151] - PCMAX_SBFD;

[0152] - SCALING_FACTOR_BI_SBFD;

[0153] - TEMPORARY_C-RNTI_SBFD;

[0154] - RA_TYPE_SBFD;

[0155] - POWER_OFFSET_2STEP_RA_SBFD;

[0156] - MSGA_PREAMBLE_POWER_RAMPING_STEP_SBFD.

[0157] - RO Type

[0158] The above parameters may be configured as dedicated parameters for SBFD and used by the terminal, or in the case of some parameters, they may be used by the terminal as Legacy random access parameters other than SBFD. The terminal may recognize these parameters in the following ways.

[0159] - If the parameters required to perform random access using SBFD RO are not included in the setting signal that sets the SBFD parameter set, the terminal may implicitly use legacy random access parameters other than SBFD.

[0160] - If a terminal receives from a base station any indicator that causes a parameter required to perform random access using SBFD RO not to be included in a setting signal that sets the SBFD parameter set, and the terminal uses a legacy random access parameter other than SBFD for that parameter, the terminal may use a legacy random access parameter other than SBFD for that parameter.

[0161] ■ An indicator that allows the above-mentioned legacy random access parameters to be used as is can be individually assigned to each parameter and transmitted from the base station to the terminal. For example, the indicator may be set in a format including each parameter name, or the indicator may be set in a bitmap format and each parameter may be assigned to the position of each bit.

[0162] ■ An indicator to use the legacy random access parameters as they are may be assigned as a single bit, etc., and transmitted from the base station to the terminal so as to be applied to all parameters. For example, if the bit is set to ON (or 1) and transmitted, the terminal may understand that it has been instructed to use legacy random access parameters as they are, rather than SBFD, when the required parameters are not included in the setting signal that sets the SBFD parameter set, and may perform this.

[0163] The above 4-3 signal may be an RRC signal using MR transmitted to any specific terminal or a specific group of terminals, for example, an RRC signal such as RRC Config, RRC Reconfig, RRC Release received by the terminal in RRC Connected mode, any MAC CE signal, or any PHY DCI signal.

[0164] In addition, the above 4-3 signal may be a type of Master Information Block (MIB) or System Information Block (SIB) transmitted and received via MR as a type of broadcast signal transmitted to any unspecified number of terminals.

[0165] In addition, the above 4-3 signal may be a type of PDCCH order signal as a downlink signal that triggers random access transmitted by the base station to a specific terminal.

[0166] The signal 4-3 transmitted from the above base station may include conditions that must be met when the terminal transmits a Random access preamble to the uplink through the SBFD RO and intends to perform random access.

[0167] Alternatively, in one embodiment, the 4-3 signal may be composed of different signals, such as one signal for setting the SBFD RO and another signal containing conditions that must be met when performing random access through the SBFD RO.

[0168] These conditions may be all or part of the following conditions, and each may be expressed as a value having any indicator or numerical value.

[0169] - When the representative value of the cell or beam (SSB or CSI-RS) measured by the terminal is greater than (or smaller than) any threshold1.

[0170] Threshold1 is included in the above signal 4-3 and transmitted.

[0171] - When the measured value of any RS, e.g., SSB or CSI-RS, that has a Quasi Co Location (QCL) relationship with the RO the terminal intends to transmit is greater than any threshold2. The threshold2 and RS type are included in the above signal 4-3 and transmitted.

[0172] Alternatively, fix the RS type to one (e.g., SSB) and transmit only Threshold2 included in 4-3.

[0173] - Condition to use the RO of the earliest available SBFD slot or normal slot.

[0174] Transmit by including an indicator allowing the above conditions in the above signal 4-3.

[0175] - An indicator that always prioritizes the use of SBFD RO if the terminal is capable of using SBFD.

[0176] The relevant directive may refer to SBFD RO or Legacy RO.

[0177] Transmit by including an indicator indicating the above conditions in the above signal 4-3.

[0178] - When the representative value of a cell or beam (SSB or CSI-RS) measured by the terminal is smaller than (or smaller than or equal to) any threshold3. Through these conditions, the base station can mitigate interference by inducing the transmission of a RACH preamble within the SBFD of a terminal located at a relatively long distance from the base station.

[0179] Threshold3 is included in the above signal 4-3 and transmitted.

[0180] - Case where only threshold value(s) are present

[0181] ■ The terminal compares all or part of the set threshold(s) with the measurement of the corresponding cell or beam, and if the measurement is higher than the threshold (or higher or equal to), it may perform random access using the SBFD RO corresponding to that cell or beam. This is used to increase the success rate by allowing the terminal in the center of the cell to use the SBFD RO.

[0182] ■ In another embodiment, the terminal compares all or part of the set threshold value(s) with the measurement value of the corresponding cell or beam, and if the measurement value is lower than the threshold value (or lower than or equal to it), it may perform random access using the SBFD RO corresponding to the cell or beam. This is used to increase the relative success rate of the SBFD and expand the coverage of the network by utilizing the characteristics of the SBFD, which has a narrower frequency bandwidth than the legacy RO, by allowing terminals in the periphery of the cell to use the SBFD RO.

[0183] - If it has threshold(s) and indicators

[0184] ■ The indicator is an indicator that includes information (e.g., 1 bit) indicating whether to use SBFD RO if the measured value (RSRP, RSRQ, CQI, SNR, SINR, etc.) of a cell (or beam, SSB, CSI-RS) measured by the terminal is greater than (or greater than or equal to) the threshold value set by the network, or whether to use SBFD RO if the measured value is smaller than (or less than or equal to) the threshold value.

[0185] ■ The terminal may perform random access using the SBFD RO corresponding to the cell or beam by comparing all or part of the set threshold value(s) with the measurement value of the corresponding cell or beam, and if the measurement value is higher than (or higher than or equal to) the threshold value when the indicator is 1 (or 0), for example, if the indicator is 0 (or 1) and the measurement value is lower than (or lower than or equal to) the threshold value. This allows the base station to control the settings that enable the SBFD based on the location of the terminal.

[0186] ■ In another embodiment, the terminal compares all or part of the set threshold value(s) with the measurement value of the corresponding cell or beam, and if the measurement value is higher than (or higher than or equal to) the threshold value according to an indicator, for example, if an indicator exists, or if it is lower than (or lower than or equal to) the threshold value when no indicator exists, it may perform random access using the SBFD RO corresponding to the cell or beam. This is used to further increase the success rate by allowing the terminal in the center of the cell to use the SBFD RO.

[0187] In one embodiment, the thresholds may be any parameter included in the signal 4-3, for example, rsrp-ThresholdSSB_SBFD, rsrp-ThresholdCSI-RS_SBFD, or a threshold value set by any network.

[0188] In one embodiment, the thresholds and some indicators may be used in combination with priority. For example, if an indicator prioritizing a certain RO type set by the network is set, the terminal may always utilize it; if there is no such indicator, if there is a threshold set to select an RO type according to a condition, the terminal may utilize it to set the RO type; and if the priority type indicator and threshold values ​​are not set, the terminal may follow an indicator set to use the RO of the earliest arriving SBFD slot or normal slot available to the terminal, or the terminal may resolve this through implementation.

[0189] A terminal that needs to perform random access checks whether the conditions for using the SBFD RO are satisfied (4-4), and depending on the result, if the conditions are satisfied, it starts performing random access using SBFD by transmitting a random access preamble through the SBFD RO (4-6), and if the conditions are not satisfied, it starts performing random access by transmitting a random access preamble using a legacy RO instead of SBFD (4-5).

[0190] In the scenario of FIG. 4 above, the SBFD RO can be allocated by the base station to the terminal for the purpose of performing random access for beam failure recovery (BFR). The base station allocates the SBFD RO to the terminal for use in BFR through the signal (4-3), and when BFR occurs, the terminal can perform SBFD random access according to the set condition among various conditions as in the scenario of FIG. 4 above.

[0191] In the scenario of FIG. 4 above, the SBFD RO can be assigned for the purpose of supporting the base station in switching from performing a random access operation using non-SBFD RO to a random access operation using SBFD RO. The base station assigns the SBFD RO to the terminal for use with BFR via signal (4-3), and the terminal, which was performing a random access operation using non-SBFD RO, can be made to perform SBFD random access according to a set condition among various conditions as in the scenario of FIG. 4 above. At this time, how to operate the preamble transmission count counter for determining the random access failure of the terminal performing random access while switching between non-SBFD and SBFD, and the power ramping counter for determining the transmission power, will be explained together with FIG. 5 below.

[0192] In the scenario of Figure 4 above, it goes without saying that the terminal may receive only an SBFD RO without any specific conditions for using an SBFD RO and perform random access using only that SBFD RO. In this case, there may not be any resource settings for using a non-SBFD RO.

[0193] In the SBFD configuration signal 4-3 transmitted from the base station, various threshold values ​​that serve as criteria for judgment may be set to enable the repeated transmission of msg1, a random access preamble signal transmitted by the terminal to perform random access, and msg3, a third message transmitted in response to a random access response (RAR) message in the random access procedure, and these may have different values ​​from the threshold values ​​used in the existing legacy RO.

[0194] - Threshold values ​​for determining msg1 / msg3 repetition availability / applicability for Legacy RO:

[0195]

[0196] - Threshold values ​​for determining msg1 / msg3 repetition availability for SBFD RO:

[0197]

[0198] In the case where the terminal receives a threshold value and an indicator set by the network as conditions for selecting the SBFD RO in the above signal 4-3, the value range of the settable values ​​of the threshold values ​​set for the SBFD RO can be determined based on the received content.

[0199] - For example, in one embodiment, if the network is configured to use SBFD when the threshold value(s) and indicator are used when the measurement value of the cell (or beam) measured by the terminal (e.g., RSRP) is greater than threshold1, then naturally, the threshold values ​​of msg1 and msg3 must also be configured to have values ​​greater than threshold1.

[0200] - For example, in one embodiment, if the network is configured to use SBFD when the threshold value(s) and indicator are set so that the measured value of the cell (or beam) measured by the terminal (e.g., RSRP) is less than threshold2, then naturally, the threshold values ​​of msg1 and msg3 must also be set to have values ​​less than threshold2.

[0201] These constraints may be specified in the RAN1 or RAN2 specifications.

[0202] FIG. 5 is a diagram illustrating an example of a procedure for performing SBFD random access by a terminal according to a signal for SBFD random access transmitted by a base station to a terminal and usage conditions.

[0203] Referring to FIG. 5, the base station (5-2) can transmit a signal (5-3) to the terminal (5-1) that includes SBFD resource information, configuration information of RO that may exist within the SBFD, and any condition(s) that the terminal must satisfy in order to use the SBFD RO.

[0204] The SBFD resource information included in the signal 5-3 transmitted from the base station may be resource information of the same or similar form as illustrated in FIG. 2. For example, it may be a resource characterized by a frame structure consisting of some or all of general uplink or downlink slots, flexible or special slots, and SBFD slots in which uplink and downlink coexist.

[0205] The SBFD RACH Occasion information included in the signal 5-3 transmitted from the base station may be resource information of the same or similar form as illustrated in FIG. 2. For example, it may be an uplink RO resource allocated across one or more SBFD slots, or an uplink RO resource allocated across any adjacent uplink slot as well as SBFD slots. In addition, the information may include parameters necessary for the terminal to perform random access through the RO, such as some or all of the various parameters included in the signal in FIG. 4-3.

[0206] The above 5-3 signal may be an RRC signal using MR transmitted to any specific terminal or a specific group of terminals, for example, an RRC signal such as RRC Config, RRC Reconfig, RRC Release received by the terminal in RRC Connected mode, any MAC CE signal, or any PHY DCI signal.

[0207] In addition, the above 5-3 signal may be a type of Master Information Block (MIB) or System Information Block (SIB) transmitted and received via MR as a type of broadcast signal transmitted to any unspecified number of terminals.

[0208] In addition, the above 5-3 signal may be a type of PDCCH order signal as a downlink signal that triggers random access transmitted by the base station to a specific terminal.

[0209] The signal 5-3 transmitted from the above base station may include conditions that must be met when the terminal transmits a Random access preamble to the uplink through the SBFD RO and intends to perform random access.

[0210] Alternatively, in one embodiment, the 5-3 signal may be composed of different signals, such as one signal for setting the SBFD RO and another signal containing conditions that must be met when performing random access through the SBFD RO.

[0211] In one embodiment, the thresholds may be any parameter included in the signal 4-3, for example, rsrp-ThresholdSSB_SBFD, rsrp-ThresholdCSI-RS_SBFD, or a threshold value set by any network.

[0212] In one embodiment, the thresholds and some indicators may be used in combination with priority. For example, if an indicator prioritizing a certain RO type set by the network is set, the terminal may always utilize it; if there is no such indicator, if there is a threshold set to select an RO type according to a condition, the terminal may utilize it to set the RO type; and if the priority type indicator and threshold values ​​are not set, the terminal may follow an indicator set to use the RO of the earliest arriving SBFD slot or normal slot available to the terminal, or the terminal may resolve this through implementation.

[0213] For example, the terminal can determine whether an indicator prioritizing a specific RO type is set in the signal 5-3 (5-4). If an indicator prioritizing a specific RO type is set in the signal, the terminal can prioritize random access with that RO type accordingly (5-5).

[0214] If an indicator prioritizing a specific RO type is not set in the above signal 5-3, the terminal can determine in step 5-6 whether a specific threshold condition for using SBFD RO is set.

[0215] The threshold condition may have a configuration and operation similar to signal 4-3 in Fig. 4 above.

[0216] In one embodiment, the network may set a threshold value to allow the terminal to specify an RO type, or if not specified, to use at least an SBFD RO. In other words, in this case, if the terminal satisfies the condition in step 5-7, it can perform random access through the satisfied RO type. For example, it can perform random access through an SBFD RO. If the condition is not satisfied, it can perform random access through an unsatisfied RO type. For example, it can perform random access through a Legacy RO (5-8).

[0217] The above operation can be captured as the following MAC operation.

[0218]

[0219] or

[0220]

[0221] or

[0222]

[0223] or

[0224]

[0225] FIG. 6 is a diagram illustrating an example of a procedure for performing SBFD random access by a terminal according to a signal for SBFD random access transmitted by a base station to a terminal and usage conditions.

[0226] Referring to FIG. 6, the base station (6-2) can transmit a signal (6-3) to the terminal (6-1) that includes SBFD resource information, configuration information of RO that may exist within the SBFD, and any condition(s) that the terminal must satisfy to use the SBFD RO.

[0227] The SBFD resource information included in the signal 6-3 transmitted from the base station may be resource information of the same or similar form as illustrated in FIG. 2. For example, it may be a resource characterized by a frame structure consisting of some or all of the SBFD slots in which general uplink or downlink slots, flexible or special slots, and uplink and downlink coexist.

[0228] The SBFD RACH Occasion information included in the signal 5-3 transmitted from the base station may be resource information of the same or similar form as illustrated in FIG. 2. For example, it may be an uplink RO resource allocated across one or more SBFD slots, or an uplink RO resource allocated across any adjacent uplink slot as well as SBFD slots. In addition, the information may include parameters necessary for the terminal to perform random access through the RO, such as some or all of the various parameters included in the signal in FIG. 4-3.

[0229] The above 6-3 signal may be an RRC signal using MR transmitted to any specific terminal or a specific group of terminals, for example, an RRC signal such as RRC Config, RRC Reconfig, RRC Release received by the terminal in RRC Connected mode, any MAC CE signal, or any PHY DCI signal.

[0230] In addition, the above 6-3 signal may be a type of Master Information Block (MIB) or System Information Block (SIB) transmitted and received via MR as a type of broadcast signal transmitted to any unspecified number of terminals.

[0231] In addition, the above 6-3 signal is a downlink signal transmitted by a base station to trigger random access to a specific terminal, and may be a type of PDCCH order signal.

[0232] The signal 5-3 transmitted from the above base station may include conditions that must be met when the terminal transmits a Random access preamble to the uplink through the SBFD RO and intends to perform random access.

[0233] Alternatively, in one embodiment, the 6-3 signal may be composed of a signal for setting the SBFD RO and different signals including conditions that must be met when performing random access through the SBFD RO.

[0234] In one embodiment, the thresholds may be any parameter included in the signal 4-3, for example, rsrp-ThresholdSSB_SBFD, rsrp-ThresholdCSI-RS_SBFD, or a threshold value set by any network.

[0235] In one embodiment, the thresholds and certain indicators may be used in combination with priority. For example, if an indicator prioritizing a specific RO type set by the network is set, the terminal may always utilize it. If there is no such indicator, and a threshold is set to select an RO type based on conditions, the RO type may be set using this. If the priority type indicator and threshold values ​​are not set, the terminal may follow an indicator set to use the RO of the earliest available SBFD slot or normal slot, or the terminal may resolve this through implementation.

[0236] For example, the terminal can determine whether an indicator prioritizing a specific RO type is set in the signal 6-3 (6-4). If an indicator prioritizing a specific RO type is set in the signal, the terminal can prioritize random access with that RO type accordingly (6-5).

[0237] If an indicator prioritizing a specific RO type is not set in the above signal 6-3, the terminal can determine whether a specific threshold condition for using SBFD RO is set in the signal 6-3.

[0238] The threshold condition may have some or all of the configuration and operation of steps 5-6 described in Figure 5 above.

[0239] If the above threshold condition is set, the terminal can perform random access through the satisfying RO type if the condition is satisfied in steps 6-7. For example, random access can be performed through the SBFD RO. If the condition is not satisfied, random access can be performed through the non-satisfying RO type. For example, random access can be performed through the Legacy RO.

[0240]

[0241] If the above threshold value condition is not set, the terminal can determine in steps 6-8 whether there is an indicator that allows the terminal to use the RO type that arrives first among the available ROs, and perform an operation accordingly.

[0242] In step 6-8, if the signal 6-3 received from the network contains an indicator that allows the terminal to use the first RO type among the available ROs, the terminal can perform random access through the first RO type among the available ROs (6-9).

[0243] If, in step 6-8, the terminal does not have an indicator in the signal 6-3 received from the network that allows the terminal to use the first RO type among the available ROs, the terminal may arbitrarily select and use any RO type preferred by the terminal (6-10).

[0244] Alternatively, if the specification in Step 6-10 specifies that SBFD RO (or legacy RO) must always be used, SPFD RO (or legacy RO) may be used according to the specification.

[0245] In one embodiment, steps 6-8 may be omitted. For example, the terminal may not determine the presence or absence of an indicator and may use the first RO type that arrives among the available ROs. In this case, the indicator may not be included in signal 6-3.

[0246] In one embodiment, steps 6-8 may be omitted. For example, the terminal may not determine the presence or absence of an indicator and may arbitrarily select and use any preferred RO type. In this case, the indicator may not be included in signal 6-3.

[0247] In one embodiment, steps 6-8 may be omitted. For example, the terminal may always use the SBFD RO (or legacy RO) without determining the presence or absence of the indicator. In this case, the indicator may not be included in signal 6-3.

[0248] The SBFD RO selection process of such a terminal applies only when the network sets the SBFD RO, and only when the terminal can use SBFD.

[0249] The above operation can be captured as the following MAC operation.

[0250]

[0251] or

[0252]

[0253] or

[0254]

[0255] or

[0256]

[0257] or

[0258]

[0259] or

[0260]

[0261] or

[0262]

[0263] or

[0264]

[0265] or

[0266]

[0267] or

[0268]

[0269] or

[0270]

[0271] or

[0272]

[0273]

[0274] FIG. 7 is a drawing for explaining a random access method of a terminal according to one embodiment of the present disclosure.

[0275] Referring to FIG. 7, the terminal can perform a random access process to transition from an RRC_Idle or Inactive state to an RRC_CONNECTED state when certain conditions are satisfied.

[0276] In step 7-1, the terminal can perform a cell selection (or re-selection) process. Through this process, the terminal selects a cell to perform random access.

[0277] In step 7-2, the terminal can perform a carrier selection process. If a supplementary uplink (SUL) is set, the terminal can select one of the SUL and a normal uplink (NUL) to perform random access.

[0278] In step 7-3, the terminal can perform a BWP selection process. For example, the terminal can perform random access in the initial uplink BWP.

[0279] In step 7-4, the terminal can select an RO type for performing random access. To do this, the base station must have set up an SBFD resource through SIB1 or an RRC signal, and the terminal must be a terminal capable of supporting SBFD. A terminal satisfying these conditions selects one of the appropriate SBFD RO or legacy RACH RO types according to the standardized and implemented operation and the conditions set and transmitted by the network in the flowcharts of FIGS. 4 to 7.

[0280] In step 7-5, the terminal may select a suitable RA resource set by referring to the selected RO type and the RACH configuration of the BWP, and considering one or more Feature(s) applicable to the RA process (e.g., (e) RedCap, and / or Slicing and / or SDT (small data transmission) and / or MSG3 repetition and / or MSG1 repetition and / or SBFD). At this time, the terminal may use different parameter values ​​depending on the selected RO type, and if an SBFD RO is selected, the following procedure may be performed, for example.

[0281]

[0282]

[0283]

[0284]

[0285]

[0286]

[0287]

[0288] A terminal that has selected an RA resource set can select an RA type in step 7-6. More specifically, the terminal can determine whether it is a 2-step RA or a 4-step RA. In one embodiment, if there is an RA type that is not supported by the RO type selected by the terminal, the terminal must exclude the RA type that is not supported by the RO type selected by the terminal. For example, if the RO type selected by the terminal is SBFD RO and the SBFD RO type does not support 2-step RA, the terminal excludes the 2-step RA and determines the 4-step RA.

[0289] Subsequently, in step 7-7, the terminal can select a synchronization signal block, a random access occasion (RO), and a preamble.

[0290] In one embodiment of the present disclosure, the terminal may select an RA resource set in steps 7-8 by applying the method of [Table 1] below.

[0291] [Table 1]

[0292]

[0293] In one embodiment of the present disclosure, if the SBFD field is set to true for an RA resource set, the RA resource set may be considered not available for RA processes for which SBFD is not applicable.

[0294] In one embodiment of the present disclosure, a base station may add a featurePriorities field to a specific SIB (e.g., SIB1).

[0295] For example, the featurePriorities field may additionally include a field indicating the priority of the SBFD (e.g., sbfd-Priority-r19) in addition to the priority of the existing feature.

[0296] For example, the above field can be defined to have an integer value between [0, 7]. If one or more available RA resource sets are set for only some of the features that triggered the RA process, the terminal can select one of the RA resource sets based on the priority order of the features.

[0297] In one embodiment of the present disclosure, if a terminal supporting SBFD satisfies a specific CBRA (or CFRA) SBFD RA condition, the terminal may perform an SBFD RA (e.g., transmitting Preamble / MSG1 / MSGA through a Valid SBFD RO (if configured / present)) during the said CBRA (or CFRA) random access process. For example, the CBRA (or CFRA) SBFD RA condition may be as follows. The present disclosure does not limit the SBFD RA condition to the following conditions.

[0298] - An SBFD-enabled terminal may be configured to perform an SBFD RA (e.g., transmit a CBRA (or CFRA) Preamble using a Valid SBFD RO (if configured / existing)) when the RSRP value of the downlink pathloss reference received from the cell is compared to a specific threshold value and is greater or less than the threshold value. The threshold value may include sbfd-RSRP-ThresholdSSB and / or sbfd-RSRP-ThresholdCsi-RS.

[0299] For example, the base station may include thresholds / parameters associated with the above SBFD RA conditions (e.g., sbfd-RSRP-ThresholdSSB, sbfd-RSRP-ThresholdCsi-RS) in a specific SIB (e.g., SIB1) or RRC message (e.g., RRCReconfiguration) and transmit them to the terminal.

[0300] For example, the above threshold / parameter (e.g., sbfd-RSRP-ThresholdSSB, sbfd-RSRP-ThresholdCsi-RS) may be included in existing RACH common settings (e.g., BWP-UplinkCommon->rach-ConfigCommon or sub-field, BWP-UplinkCommon->msgA-ConfigCommon->rach-ConfigCommonTwoStepRA or sub-field) and / or SBFD-only RACH settings (e.g., BWP-UplinkCommon->rach-ConfigCommonSBFD or sub-field).

[0301] In one embodiment of the present disclosure, the CBRA 2-Step RA conditions to be satisfied to perform 2-Step RA in CBRA may include at least one of the following conditions.

[0302] - if the BWP selected for Random Access procedure is configured with both 2-step and 4-step RA type Random Access Resources within the selected set of Random Access resources (as specified in TS 38.321 clause 5.1.1b) and the RSRP of the downlink pathloss reference is above msgA-RSRP-Threshold

[0303] - if the BWP selected for Random Access procedure is only configured with 2-step RA type Random Access resources within the selected set of Random Access resources according to TS 38.321 clause 5.1.1b

[0304] In FIG. 7 and the above embodiment, the terminal can select resources according to the RACH resources that are separately set (or distinguished in the settings) according to the RO type by selecting the RO type before the RA resource set selection step (7-4). Therefore, there is an advantage in that one does not have to worry about selecting resources of other RO types.

[0305] FIG. 8 is a drawing for explaining a random access method of a terminal according to one embodiment of the present disclosure.

[0306] Referring to FIG. 8, the terminal can perform a random access process to transition from an RRC_Idle or Inactive state to an RRC_CONNECTED state, for example, when certain conditions are satisfied.

[0307] In step 8-1, the terminal can perform a cell selection (or re-selection) process. Through this process, the terminal selects a cell to perform random access.

[0308] In step 8-2, the terminal can perform a carrier selection process. If a supplementary uplink (SUL) is set, the terminal can select one of the SUL and a normal uplink (NUL) to perform random access.

[0309] In step 8-3, the terminal can perform a BWP selection process. For example, the terminal can perform random access on the initial uplink BWP.

[0310] In one embodiment of the present patent, the terminal may select a suitable RA resource set by referring to the RACH configuration of the selected BWP in step 8-4 and considering one or more Feature(s) applicable to the RA process (e.g., (e) RedCap, and / or Slicing and / or SDT (small data transmission) and / or MSG3 repetition and / or MSG1 repetition and / or SBFD). At this time, the terminal may use different parameter values ​​according to various different RO types and may store different parameter values ​​for subsequent RO type configuration.

[0311] After selecting the RA resource set, the terminal can select an RO type in step 8-5. In this case, the terminal can select a suitable RO type by considering the previously selected RA feature, resource, and parameters. To do this, the base station must have set the SBFD resource through SIB1 or RRC signals, and the terminal must be a terminal capable of supporting SBFD. A terminal satisfying these conditions may select one of the suitable SBFD RO or legacy RACH RO types according to the standardized and implemented operation and the conditions set and transmitted by the network during the flowcharts of FIGS. 4 to 7.

[0312] In this way, where the selection of the RA resource set is prioritized and the RO type is selected later, the terminal can select the RO type after first knowing whether there is a resource suitable for the feature(s) desired by the terminal and what RO type that resource supports. For example, if SBFD RO is not among the RO types supported by an RA that can support the feature(s) desired by the terminal, the terminal can exclude SBFD RO when selecting the RO type by reflecting this.

[0313] In another embodiment of the present patent, the terminal may perform the operation of selecting an RA feature and a resource set (8-4) and the operation of selecting an RO type (8-5) in combination, either simultaneously or in combination.

[0314] The above terminal can select a suitable RA resource set by referring to the selected RO type and the RACH configuration of the BWP, and considering one or more Feature(s) applicable to the RA process (e.g., (e) RedCap, and / or Slicing and / or SDT (small data transmission) and / or MSG3 repetition and / or MSG1 repetition and / or SBFD). At this time, the terminal may use different parameter values ​​depending on the selected RO type, and, for example, may perform the following procedure.

[0315]

[0316]

[0317]

[0318]

[0319] As can be seen from the above procedure, the terminal may have different RO type and RA Resource set selection orders for each feature, such as selecting the RO type simultaneously or immediately before resource set selection for a specific feature to perform RA Resource Set selection in special cases, and selecting the RO type immediately after resource set selection for other features.

[0320] In one embodiment, regarding a feature in which a msg1 repetition is set and used, the terminal first determines whether such a feature is used and determines and decides that the feature is used. Then, it can select an RO type and select an RA Resource set suitable for the RO type.

[0321] In one embodiment, the terminal may first select an RO type for a feature other than the special feature (after determining only that it is not the special feature), and then select a specific feature and a corresponding RA resource set.

[0322] In one embodiment, the terminal may select an RA resource set for a different RO type for a certain feature, and then select an RO type to determine an RA Resource set for that RO type.

[0323] In another embodiment of the present patent, the terminal may simultaneously select an RO type when selecting an RA type at step 8-6. More specifically, the terminal may determine whether the RO type is SBFD or Legacy RO and whether the RA type is 2-step RA or 4-step RA, based on threshold values ​​set by the network and the judgment results described in FIGS. 4 to 6.

[0324] In another embodiment of the present patent, the terminal may select an RO type after selecting an RA type at step 8-6. In this case, if a 2-step RACH can be selected first, the terminal may decide to select it first to proceed with faster random access, and then select an RO type.

[0325] FIG. 9 is a diagram illustrating an example of a fallback or switching method to a different RO type during a random access execution procedure of a terminal according to an embodiment of the present disclosure.

[0326] Referring to FIG. 9, the base station (9-2) can transmit an SBFD configuration to the terminal (9-1) that includes SBFD resource information, configuration information of ROs that may exist within the SBFD, and any condition(s) that the terminal must satisfy to use the SBFD RO. Additionally, it can transmit a configuration signal (9-3) that includes conditions for fallback or switching to perform random access using a different RO type while performing random access using a certain RO type, terminal operation accordingly, and a limitation defining the limit of fallback / switching.

[0327] The SBFD configuration information included in signal 9-3 transmitted from the base station may be all or part of the information included in signal 4-3, signal 5-3, or signal 6-3 described in FIGS. 4 to 6.

[0328] Alternatively, in one embodiment, the 9-3 signal may be composed of one signal for setting the SBFD RO and different signals including any condition(s) that the terminal must satisfy to perform fallback / switching to change the RO type.

[0329] Signal 9-3 transmitted from the base station may include conditions that must be satisfied to determine when a terminal needs to fallback / switch to perform random access through another RO type, e.g., legacy RO, while performing random access by transmitting a random access preamble over the uplink through one RO type, e.g., SBFD RO. These conditions may be all or part of the following conditions, each of which may be expressed as a value having some indicator or numerical value.

[0330] - When Random Access Preamble transmissions attempted through a single RO type, e.g., SBFD RO, fail a certain number of times (or more than a certain number of times).

[0331] The number may be any new parameter included in the signal 9-3 transmitted by the terminal, or any parameter set by the base station for the terminal, for example, preambleTransMax_SBFD, preambleTransMax, or preambleTransMax_legacy.

[0332] - When the representative value of the cell measured by the terminal is smaller than any threshold1 (or smaller than or equal to, or larger than, or larger than or equal to).

[0333] Threshold1 can be transmitted by being included in the above signal 9-3.

[0334] - When the representative value of any reference signal (or reference signals) set by the base station and measured by the terminal is smaller than any threshold2 (or smaller than or equal to, or larger than, or greater than or equal to). For example, the above reference signal may be any RS set by the base station among various RSs such as SSB (Synchronization Signal Block), CSI-RS (Channel Side Information-RS), DMRS (Demodulation RS), etc., and may be included in the above signal 9-3 and transmitted.

[0335] The ID or RS type information of the RS that the base station measures and sets to compare with Threshold2, and / or Threshold2, may be included in the above signal 9-3 and transmitted.

[0336] - When the measured value of any RS, e.g., SSB or CSI-RS, which is in a Quasi Co Location (QCL) relationship with the RO belonging to the current RO type selected by the terminal to perform random access, is less than (or less than or equal to, or greater than, or greater than or equal to) any threshold2. The threshold2 and RS type are included in the above signal 9-3 and transmitted.

[0337] Or, fix the RS type to one (e.g., SSB) and transmit only Threshold2 included in 5-3.

[0338] Signal 9-3 transmitted from the base station may include a condition that a specific limit on the number of fallbacks / switchings must be satisfied to prevent excessive fallbacks / switchings when a terminal needs to fallback / switch to perform random access through another RO type, e.g., legacy RO, while performing random access by transmitting a random access preamble over the uplink through one RO type, e.g., SBFD RO. Such conditions may be all or part of the following conditions, each of which may be expressed as a value having an indicator or numerical value. (9-6)

[0339] - When limiting the total number of fallback / switching operations. For example, set rotypeSwitchingMax, and the terminal increments rotypeSwitchingCounter by 1 whenever a rotype switching / fallback occurs, and when this value becomes greater than or equal to rotypeSwitchingMax, it no longer performs fallback / switching. The above rotypeSwitchingCounter is initialized to 0 when random access is triggered.

[0340] - When limiting the number of fallback / switching operations from a specific RO type. For example, set rotypeSwitchingMax_SBFD or rotypeSwitchingMax_legacy, and the terminal, while using a specific RO type, increments rotypeSwitchingCounter_SBFD or rotypeSwitchingMax_legacy by 1 whenever switching / fallback occurs, and stops performing fallback / switching when this value becomes greater than or equal to rotypeSwitchingMax_SBFD or rotypeSwitchingMax_legacy. The above rotypeSwitchingCounter_SBFD or rotypeSwitchingMax_legacy is initialized to 0 when random access is triggered.

[0341] - Cases where only a single fallback / switching is allowed. For example, set ROtypeFallbackFlag, and when ROtype switching / fallback occurs, the terminal turns the flag on / enables it and no longer performs fallback / switching. The above ROtypeFallbackFlag is initialized to 0 when random access is triggered.

[0342] A terminal that was performing random access through one RO type (9-4) checks whether it has reached the constraint for performing fallback / switching (9-5), and if it has reached the constraint, it performs continuous random access through the current RO type (9-8).

[0343] If the constraint condition has not yet been reached, the terminal checks whether the fallback / switching condition is satisfied (9-6). If the condition is satisfied, the fallback / switching counter or flag is incremented or changed (9-7), and random access is started by transmitting a random access preamble through a different type of RO (9-9).

[0344] If the terminal checks whether the above fallback / switching condition is satisfied (9-6) and the condition is not satisfied, the terminal performs continuous random access through the current RO type (9-8). In one embodiment, when a terminal using a legacy RO performs a switching operation to use an SBFD RO, the operation of FIG. 9 may be changed as follows.

[0345] After the condition checked in step 9-6 is satisfied, the terminal may proceed to step 9-7 and change the RO type to SBFD RO only when the condition for selecting the SBFD RO set by the base station in the 9-3 signal is additionally satisfied.

[0346] For example, a terminal that performs random access through legacy RO may, after the random access fails for the number of times preambleTransMax_legacy set by the network, compare the current network measurement value (e.g., SSB RSRP) with the set threshold based on a threshold value to compare with the measurement value set by the network in signal 9-3 and an indicator indicating when to use SBFD RO, such as when the measurement value is greater than or less than the threshold value, and if the conditions for using SBFD RO are satisfied, perform a subsequent operation and change the RO type to SBFD RO.

[0347] In another embodiment, even if the conditions checked in step 9-6 are not all satisfied, if the conditions for selecting the SBFD RO set by the base station in the 9-3 signal are satisfied for every Random Access attempt, the terminal may determine that step 9-6 is satisfied immediately, proceed to step 9-7, and then change the RO type to SBFD RO.

[0348] For example, a terminal performing random access via a legacy RO may, even if random access fails for the number of times preambleTransMax_legacy set by the network, perform a subsequent operation and change the RO type to SBFD RO if random access via the current legacy RO fails, in order to select the SBFD RO set by the network in signal 9-3, compare the current network measurement value (e.g., SSB RSRP) with a set threshold based on a threshold value to compare with the measurement value and an indicator indicating when to use the SBFD RO, whether when the measurement value is greater than or less than the threshold value. If the conditions regarding the use of the SBFD RO are satisfied, the network may perform a subsequent operation and change the RO type to SBFD RO. Furthermore, for this purpose, the network may set any indicator that permits such an operation to the terminal within the above signal 9-3.

[0349] The terminal attempts to retransmit the preamble only up to a certain parameter value set by the base station, and if the preamble transmission fails until that number is reached, the random access can be considered to have failed. The corresponding procedure for existing terminals is as follows.

[0350] If the terminal satisfies a specific condition for determining that the ongoing random access is unsuccessful, it increments PREAMBLE_TRANSMISSION_COUNTER by 1 to restart the random access and re-perform the preamble transmission. Any condition for incrementing PREAMBLE_TRANSMISSION_COUNTER by 1 may be all or part of the following:

[0351] - After the terminal transmits a random access preamble, it receives an LBF failure indication from a lower layer, and if lbt-FailureRecoveryConfig is not configured.

[0352] (If lbt-FailureRecoveryConfig is configured, run the Random Access Resource selection procedure again.)

[0353] - After the terminal transmits MSGA for 2-step random access, it receives an LBF failure indication from the lower layer, and if lbt-FailureRecoveryConfig is not configured.

[0354] (If lbt-FailureRecoveryConfig is configured, the Random Access Resource selection procedure is executed again for 2-step RA.)

[0355] - If, after the terminal transmits a random access preamble, the ra-ResponseWindow within the RACH setting configured by the network expires and the Random Access Response (RAR) containing the Random Access Preamble identifier called PREAMBLE_INDEX transmitted by the terminal is not received during that period, the reception of the RAR is considered unsuccessful.

[0356] - If, after the terminal transmits MSGA for 2-step RA, the msgB-ResponseWindow within the RACH setting configured by the network expires and the terminal does not receive MSGB containing the Random Access Preamble identifier called PREAMBLE_INDEX transmitted during that period, the RAR reception is considered unsuccessful.

[0357] - When the terminal's Contention Resolution is deemed unsuccessful:

[0358] ■ For example, when the terminal that sent msg3 subsequently has its ra-ContentionResolutionTimer expire (when it has not successfully received msg4, the contention resolution message, until expiration)

[0359] If the terminal satisfies one of the above conditions, it increments PREAMBLE_TRANSMISSION_COUNTER by 1, and if the value is equal to preambleTransMax + 1, a parameter previously set by the base station, it recognizes that random access has failed.

[0360] If the random access procedure was attempted on a Special Cell (SpCell), such as a Primary Cell (PCell) or Primary Secondary Cell (PSCell), it is reported to the upper layers (indicate a Random Access problem to upper layers). And if the random access procedure was for updating system information (SI), the random access procedure is considered to have terminated unsuccessfully.

[0361] If the random access procedure was attempted on a Secondary Cell (SCell), the random access procedure is considered to have terminated unsuccessfully.

[0362] However, since the aforementioned existing procedure does not take into account newly configured preambleTransMax_SBFD, preambleTransMax_legacy, etc., in order to clarify terminal operations in conjunction with fallback / switching, this patent proposes the following various possible scenarios and terminal operations.

[0363] 1. PREAMBLE_TRANSMISSION 1) A method for distinguishing between SBFD random access and non-SBFD random access and operating independent parameters and procedures for each.

[0364] ■ This method proposes the following method utilizing a set of parameters independent of existing parameters:

[0365] If the terminal satisfies a specific condition for determining that the ongoing random access using SBFD RO is unsuccessful, it increments PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 to restart the random access using SBFD RO and re-perform the preamble transmission. Any condition for incrementing PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 may be all or part of the following:

[0366] - If the terminal sends a random access preamble to the SBFD and receives an LBF failure indication from a lower layer, and lbt-FailureRecoveryConfig is not configured.

[0367] (If lbt-FailureRecoveryConfig is configured, run the SBFD Random Access Resource selection procedure again.)

[0368] - If the terminal transmits MSGA for 2-step SBFD random access and receives an LBF failure indication from the lower layer, and lbt-FailureRecoveryConfig is not configured.

[0369] (If lbt-FailureRecoveryConfig is configured, the Random Access Resource selection procedure is executed again for 2-step SBFD RA.)

[0370] - If, after the terminal transmits a random access preamble via the SBFD RO, the ra-ResponseWindow_SBFD within the RACH setting configured by the network expires and the terminal does not receive a Random Access Response (RAR) containing a Random Access Preamble identifier that matches the PREAMBLE_INDEX transmitted by the terminal during that period, the reception of the RAR is considered unsuccessful.

[0371] - If, after the terminal transmits MSGA for 2-step SBFD RA, msgB-ResponseWindow_SBFD within the RACH setting configured by the network expires and the terminal does not receive MSGB containing a Random Access Preamble identifier that matches the PREAMBLE_INDEX transmitted during that period, the RAR reception is considered unsuccessful.

[0372] - When the terminal's Contention Resolution is deemed unsuccessful:

[0373] ■ For example, when the terminal that sent msg3 subsequently has ra-ContentionResolutionTimer_SBFD expire (when it has not successfully received msg4, the contention resolution message, until expiration)

[0374] If the terminal satisfies one of the above conditions, it increments PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1, and if the value is equal to preambleTransMax_SBFD + 1, which is a parameter set by the base station, it recognizes that random access has failed.

[0375] If the random access procedure was attempted on a Special Cell (SpCell), such as a Primary Cell (PCell) or Primary Secondary Cell (PSCell), it is reported to the upper layers (indicate a Random Access problem to upper layers). And if the random access procedure was for updating system information (SI), the random access procedure is considered to have terminated unsuccessfully.

[0376] If the random access procedure was attempted on a Secondary Cell (SCell), the random access procedure is considered to have terminated unsuccessfully.

[0377] In the above procedure, a series of parameters may reuse the same parameters as non-SBFD. For example, ra-ResponseWindow_SBFD may be replaced with ra-ResponseWindow, msgB-ResponseWindow_SBFD with msgB-ResponseWindow, and ra-ContentionResolutionTimer_SBFD with ra-ContentionResolutionTimer. Alternatively, the terminal may be instructed by the base station to use the same parameters.

[0378] 1. PREAMBLE_TRANSMISSION 2) A method for operating preamble transmission attempts by combining SBFD random access and non-SBFD random access without distinguishing between them.

[0379] ■ This method proposes the following method that integrates and utilizes existing parameters and a new set of parameters:

[0380] If the terminal satisfies a specific condition for determining that an ongoing random access is unsuccessful, regardless of whether it is SBFD or non-SBFD, it increments PREAMBLE_TRANSMISSION_COUNTER by 1 to restart the random access and re-perform the preamble transmission. Any condition for incrementing PREAMBLE_TRANSMISSION_COUNTER by 1 may be all or part of the following:

[0381] - After the terminal transmits a random access preamble, it receives an LBF failure indication from a lower layer, and if lbt-FailureRecoveryConfig is not configured.

[0382] (If lbt-FailureRecoveryConfig is configured, run the Random Access Resource selection procedure again.)

[0383] - After the terminal transmits MSGA for 2-step random access, it receives an LBF failure indication from the lower layer, and if lbt-FailureRecoveryConfig is not configured.

[0384] (If lbt-FailureRecoveryConfig is configured, the Random Access Resource selection procedure is executed again for 2-step RA.)

[0385] - If, after the terminal transmits a random access preamble through the RO, the ra-ResponseWindow (or ra-ResponseWindow_SBFD in the case of SBFD) within the RACH setting configured by the network has expired and the terminal has not received a Random Access Response (RAR) containing a Random Access Preamble identifier that matches the PREAMBLE_INDEX transmitted by the terminal during that period, the reception of the RAR is considered unsuccessful.

[0386] - After the terminal transmits MSGA for 2-step RA, if the msgB-ResponseWindow (or msgB-ResponseWindow_SBFD in the case of SBFD) within the RACH setting configured by the network has expired and the terminal has not received an MSGB containing a Random Access Preamble identifier that matches the PREAMBLE_INDEX transmitted during that period, the RAR reception is considered unsuccessful.

[0387] - When the terminal's Contention Resolution is deemed unsuccessful:

[0388] ■ For example, when the terminal that sent msg3 subsequently has its ra-ContentionResolutionTimer (or ra-ContentionResolutionTimer_SBFD) expire (when it has not successfully received the msg4, contention resolution message, until expiration)

[0389] If the terminal satisfies one of the above conditions, it increments PREAMBLE_TRANSMISSION_COUNTER by 1, and if the value is equal to preambleTransMax + 1, a parameter previously set by the base station, it recognizes that random access has failed.

[0390] If the random access procedure was attempted on a Special Cell (SpCell), such as a Primary Cell (PCell) or Primary Secondary Cell (PSCell), it is reported to the upper layers (indicate a Random Access problem to upper layers). And if the random access procedure was for updating system information (SI), the random access procedure is considered to have terminated unsuccessfully.

[0391] If the random access procedure was attempted on a Secondary Cell (SCell), the random access procedure is considered to have terminated unsuccessfully.

[0392] 2. PREAMBLE_TRANSMISSION 3) A method that distinguishes between SBFD random access and non-SBFD random access, but combines the number of preamble transmission attempts of both types when determining random access failure.

[0393] ■ This method proposes the following method that integrates and utilizes existing parameters and a new set of parameters:

[0394] In addition to the counter procedure of the existing standard above, if the terminal satisfies a specific condition for determining that the ongoing SBFD random access is unsuccessful, it increments PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 to restart the random access and re-perform the preamble transmission. Any condition for incrementing PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 may be all or part of the conditions proposed in the first embodiment above.

[0395] If the terminal satisfies one of the above conditions, it increments PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1, and if the sum of the two counter values ​​currently held by the terminal, e.g., PREAMBLE_TRANSMISSION_COUNTER + PREAMBLE_TRANSMISSION_COUNTER_SBFD, is equal to preambleTransMax + 1, a parameter set by the base station, it recognizes that random access has failed.

[0396] If the random access procedure was attempted on a Special Cell (SpCell), such as a Primary Cell (PCell) or Primary Secondary Cell (PSCell), it is reported to the upper layers (indicate a Random Access problem to upper layers). And if the random access procedure was for updating system information (SI), the random access procedure is considered to have terminated unsuccessfully.

[0397] If the random access procedure was attempted on a Secondary Cell (SCell), the random access procedure is considered to have terminated unsuccessfully.

[0398] In the above procedure, a series of parameters may reuse the same parameters as non-SBFD. For example, ra-ResponseWindow_SBFD may be replaced with ra-ResponseWindow, msgB-ResponseWindow_SBFD with msgB-ResponseWindow, and ra-ContentionResolutionTimer_SBFD with ra-ContentionResolutionTimer. Alternatively, the terminal may be instructed by the base station to use the same parameters.

[0399] 3. PREAMBLE_TRANSMISSION 4) A method that distinguishes between SBFD random access and non-SBFD random access, but when determining random access failure, considers the number of preamble transmissions of both types and operates preamble transmission attempts for the larger number of transmissions.

[0400] ■ This method proposes the following method that integrates and utilizes existing parameters and a new set of parameters:

[0401] In addition to the counter procedure of the above-mentioned existing standard, if the terminal satisfies a specific condition for determining that the ongoing SBFD random access is unsuccessful, it increments PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 to restart the random access and re-perform the preamble transmission. Any condition for incrementing PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 may be all or part of the conditions proposed in the above-mentioned embodiment 1.

[0402] If the terminal satisfies one of the above conditions, it increments PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1, and if the larger of the two counter values ​​currently held by the terminal, for example, max(PREAMBLE_TRANSMISSION_COUNTER, PREAMBLE_TRANSMISSION_COUNTER_SBFD), is equal to preambleTransMax + 1, a parameter set by the base station, it recognizes that random access has failed.

[0403] If the random access procedure was attempted on a Special Cell (SpCell), such as a Primary Cell (PCell) or Primary Secondary Cell (PSCell), it is reported to the upper layers (indicate a Random Access problem to upper layers). And if the random access procedure was for updating system information (SI), the random access procedure is considered to have terminated unsuccessfully.

[0404] If the random access procedure was attempted on a Secondary Cell (SCell), the random access procedure is considered to have terminated unsuccessfully.

[0405] In the above procedure, a series of parameters may reuse the same parameters as non-SBFD. For example, ra-ResponseWindow_SBFD may be replaced with ra-ResponseWindow, msgB-ResponseWindow_SBFD with msgB-ResponseWindow, and ra-ContentionResolutionTimer_SBFD with ra-ContentionResolutionTimer. Alternatively, the terminal may be instructed by the base station to use the same parameters.

[0406] In the same context as the above PREAMBLE_TRANSMISSION_COUNTER, PREAMBLE_POWER_RAMPING_COUNTER resulting from the addition of SBFD random access via SBFD RO can also be materialized.

[0407] The terminal operates PREAMBLE_POWER_RAMPING_COUNTER immediately prior to each attempt to transmit a random access preamble to determine the transmit power for that transmission. In the existing procedure, before transmitting the preamble, if the selected SSB or CSI-RS reference signal measurement has not changed compared to the previous preamble transmission, the terminal increments PREAMBLE_POWER_RAMPING_COUNTER by 1. Subsequently, the DELTA_PREAMBLE value is set in accordance with Section 7.3 of Standard Document (TS) 38.321, and PREAMBLE_RECEIVED_TARGET_POWER is set according to the following formula:

[0408] For 4-step RA, configure as follows:

[0409] - preambleReceivedTargetPower + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) × PREAMBLE_POWER_RAMPING_STEP + POWER_OFFSET_2STEP_RA;

[0410] For 2-step RA, configure as follows:

[0411] - msgA-PreambleReceivedTargetPower + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) × PREAMBLE_POWER_RAMPING_STEP;

[0412] However, since the above existing procedure does not consider preamble transmission utilizing the newly established SBFD, in order to clarify terminal operation in conjunction with fallback, etc., this patent proposes the following various possible scenarios and terminal operations.

[0413] 1. PREAMBLE_POWER_RAMPING 1) A method of distinguishing between SBFD random access and non-SBFD random access and operating independent parameters and procedures for each.

[0414] ■ This method proposes the following method utilizing a set of parameters independent of existing parameters:

[0415] Immediately prior to attempting to transmit a random access preamble using SBFD, the terminal operates PREAMBLE_POWER_RAMPING_COUNTER_SBFD to determine the transmit power for the transmission. In the existing procedure, before transmitting the preamble, if the selected SSB or CSI-RS reference signal measurement has not changed compared to the previous preamble transmission, the terminal increments PREAMBLE_POWER_RAMPING_COUNTER_SBFD by 1. Subsequently, the DELTA_PREAMBLE value is set in accordance with Section 7.3 of Standard Document (TS) 38.321, and PREAMBLE_RECEIVED_TARGET_POWER_SBFD is set according to the following formula:

[0416] For 4-step SBFD RA, configure as follows:

[0417] - preambleReceivedTargetPower_SBFD + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER_SBFD - 1) × PREAMBLE_POWER_RAMPING_STEP_SBFD + POWER_OFFSET_2STEP_RA;

[0418] For 2-step SBFD RA, configure as follows:

[0419] - msgA-PreambleReceivedTargetPower_SBFD + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER_SBFD - 1) × PREAMBLE_POWER_RAMPING_STEP_SBFD;

[0420]

[0421] 2. PREAMBLE_POWER_RAMPING 2) A method for operating parameters and procedures by combining SBFD random access and non-SBFD random access.

[0422] ■ This method proposes the following method that combines existing parameters with an independent set of parameters:

[0423] Immediately prior to any attempt to transmit a random access preamble, the terminal operates a counter to determine the transmit power for the transmission. Following existing procedures, the terminal compares the reference signal measurement with the existing value and increments PREAMBLE_POWER_RAMPING_COUNTER or PREAMBLE_POWER_RAMPING_COUNTER_SBFD by 1. Then, PREAMBLE_POWER_RAMPING_COUNTER_Calc is set to max(PREAMBLE_POWER_RAMPING_COUNTER, PREAMBLE_POWER_RAMPING_COUNTER_SBFD). Subsequently, the DELTA_PREAMBLE value is set in accordance with Section 7.3 of Standard Document (TS) 38.321, and PREAMBLE_RECEIVED_TARGET_POWER_SBFD is set according to the following formula:

[0424] For 4-step RA, configure as follows:

[0425] - preambleReceivedTargetPower(or preambleReceivedTargetPower_SBFD) + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER_Calc - 1) × PREAMBLE_POWER_RAMPING_STEP(or PREAMBLE_POWER_RAMPING_STEP_SBFD)+ POWER_OFFSET_2STEP_RA;

[0426] For 2-step RA, configure as follows:

[0427] - msgA-PreambleReceivedTargetPower_SBFD + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER_Calc - 1) × PREAMBLE_POWER_RAMPING_STEP_SBFD;

[0428] In the above scenario, the terminal may be configured with only an SBFD RO without any specific conditions for using an SBFD RO, and may perform random access using only that SBFD RO. In this case, there may also be no resource configuration for using a non-SBFD RO.

[0429] In another embodiment, the terminal may determine whether the fallback / switching condition is satisfied, or simultaneously with the determination (9-6), determine whether the limit / flag is exceeded (9-5), and accordingly perform the fallback / switching operation only when the limit / flag is not exceeded.

[0430] FIG. 10 is a drawing illustrating the structure of a base station according to one embodiment of the present disclosure.

[0431] Referring to FIG. 10, a base station may include a transceiver, a control unit, and a storage unit. The transceiver, control unit, and storage unit may operate according to the communication method of the base station described above. Additionally, a network device may also correspond to the structure of the base station. However, the components of the base station are not limited to the examples described above. For example, the base station may include more components or fewer components than the components described above. For example, the base station may include a transceiver and a control unit. Furthermore, the transceiver, control unit, and storage unit may be implemented in the form of a single chip.

[0432] The transceiver unit is a collective term for the receiver and the transmitter of a base station and can transmit and receive signals with terminals, other base stations, or other network devices. At this time, the signals transmitted and received may include control information and data. For example, the transceiver unit can transmit system information to a terminal and can transmit synchronization signals or reference signals. To this end, the transceiver unit may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver unit, and the components of the transceiver unit are not limited to an RF transmitter and an RF receiver. The transceiver unit may include a wired / wireless transceiver unit and may include various configurations for transmitting and receiving signals. Additionally, the transceiver unit may receive a signal through a communication channel (e.g., a wireless channel) and output it to a control unit, and transmit the signal output from the control unit through the communication channel. In addition, the transceiver receives a communication signal and outputs it to a processor, and can transmit the signal output from the processor to a terminal, another base station, or another entity via a wired or wireless network.

[0433] The storage unit can store programs and data necessary for the operation of the base station. Additionally, the storage unit can store control information or data included in signals acquired from the base station. The storage unit may be composed of a storage medium or a combination of storage media, such as ROM, RAM, a hard disk, CD-ROM, and DVD. Additionally, the storage unit can store at least one of information transmitted and received through the transceiver and information generated through the control unit.

[0434] In the present disclosure, the control unit may be defined as a circuit or an application-specific integrated circuit or at least one processor. The processor may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as applications. The control unit may control the overall operation of a base station according to an embodiment proposed in the present disclosure. For example, the control unit may control the signal flow between each block to perform operations according to the flowchart described above.

[0435] FIG. 11 is a drawing illustrating the structure of a terminal according to one embodiment of the present disclosure.

[0436] Referring to FIG. 11, the terminal may include a transceiver, a control unit, and a storage unit. The transceiver, control unit, and storage unit may operate according to the communication method of the terminal described above. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. For example, the terminal may include a transceiver and a control unit. Furthermore, the transceiver, control unit, and storage unit may be implemented in the form of a single chip.

[0437] The transceiver unit collectively refers to the receiver and transmitter of a terminal and can transmit and receive signals with a base station, another terminal, or a network entity. The signals transmitted and received with the base station may include control information and data. For example, the transceiver unit may receive system information from the base station and may receive synchronization signals or reference signals. To this end, the transceiver unit may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver unit, and the components of the transceiver unit are not limited to an RF transmitter and an RF receiver. Furthermore, the transceiver unit may include a wired / wireless transceiver unit and may include various configurations for transmitting and receiving signals. Additionally, the transceiver unit may receive a signal via a wireless channel and output it to a control unit, and transmit the signal output from the control unit via a wireless channel. In addition, the transceiver receives a communication signal and outputs it to a processor, and can transmit the signal output from the processor to a network entity through a wired or wireless network.

[0438] The storage unit can store programs and data necessary for the operation of the terminal. Additionally, the memory can store control information or data included in signals obtained from the terminal. The storage unit may be composed of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media.

[0439] In the present disclosure, the control unit may be defined as a circuit or an application-specific integrated circuit or at least one processor. The processor may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as applications. The control unit may control the overall operation of the terminal according to the embodiments proposed in the present disclosure. For example, the control unit may control the signal flow between each block to perform operations according to the flowchart described above.

[0440] Methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0441] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of this disclosure.

[0442] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disc storage devices, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0443] Additionally, the above program may be stored on an attachable storage device that can be accessed via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

[0444] In the specific embodiments of the present disclosure described above, the components included in the disclosure are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, or even if a component is expressed in the singular form, it may be composed of a plural form.

[0445] Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, it is understood that various modifications are possible within the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof.

[0446] Among the conditions and mathematical comparisons described in the present disclosure and embodiments, inequality signs may be replaced with inequality signs including equality signs. For example, "greater than" may be replaced with "greater than or equal to," and "less than" may be replaced with "less than or equal to." Furthermore, inequality signs may be replaced with inequality signs of the opposite direction. This implies that the network may set up cases where the expected effect is opposite if desired.

Claims

1. In a method of a terminal in a communication system, A step of receiving configuration information related to the RO (random access channel occasion) type from a base station; A step of identifying the RO type associated with PRACH; and It includes the step of transmitting the PRACH based on the above RO type, and A method characterized in that, when the above RO type-related setting information includes instruction information for the above RO type, the above RO type is determined based on the instruction information for the above RO type.

2. In Paragraph 1, A method characterized in that, when the setting information related to the RO type does not include instruction information for the RO type but includes threshold information for the RO type, the RO type is determined based on the threshold information for the RO type.

3. In Paragraph 1, A method characterized in that, when the above RO type related setting information does not include instruction information for the above RO type and does not include threshold information for the above RO type, the above RO type is determined based on the implementation of the terminal.

4. In Paragraph 1, A method characterized by selecting a set of RA (random access) resources associated with the above PRACH after the above RO type is determined.

5. In the method of a base station in a communication system, A step of transmitting configuration information related to the RO (random access channel occasion) type to the terminal; It includes the step of receiving the PRACH based on the above RO type, and A method characterized in that, when the above RO type-related setting information includes instruction information for the above RO type, the above RO type is determined based on the instruction information for the above RO type.

6. In Paragraph 5, A method characterized in that, when the setting information related to the RO type does not include instruction information for the RO type but includes threshold information for the RO type, the RO type is determined based on the threshold information for the RO type.

7. In Paragraph 5, A method characterized in that, when the above RO type related setting information does not include instruction information for the above RO type and does not include threshold information for the above RO type, the above RO type is determined based on the implementation of the terminal.

8. In Paragraph 5, A method characterized by selecting a set of RA (random access) resources associated with the above PRACH after the above RO type is determined.

9. In a terminal in a communication system, Transmitter / receiver; and Receive configuration information related to RO (random access channel occasion) type from the base station, and Identify the RO type related to PRACH, and It includes a control unit configured to transmit the PRACH based on the above RO type, and A terminal characterized in that, when the above RO type-related setting information includes instruction information for the above RO type, the above RO type is determined based on the instruction information for the above RO type.

10. In Paragraph 9, A terminal characterized in that, when the above RO type related setting information does not include instruction information for the above RO type but includes threshold information for the above RO type, the above RO type is determined based on the threshold information for the above RO type.

11. In Paragraph 9, A terminal characterized in that, when the above RO type related setting information does not include instruction information for the above RO type and does not include threshold information for the above RO type, the above RO type is determined based on the implementation of the terminal.

12. In Paragraph 9, A terminal characterized by selecting a set of RA (random access) resources associated with the above PRACH after the above RO type is determined.

13. In a base station of a communication system, Transmitter / receiver; and Transmit configuration information related to the RO (random access channel occasion) type to the terminal, and It includes a control unit configured to receive the PRACH based on the above RO type, and A base station characterized in that, when the above RO type-related setting information includes instruction information for the above RO type, the above RO type is determined based on the instruction information for the above RO type.

14. In Paragraph 13, A base station characterized in that, when the above RO type-related setting information does not include instruction information for the above RO type but includes threshold information for the above RO type, the above RO type is determined based on the threshold information for the above RO type.

15. In Paragraph 13, A base station characterized in that, when the above RO type related setting information does not include instruction information for the above RO type and does not include threshold information for the above RO type, the above RO type is determined based on the implementation of the terminal.

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