Random access method and apparatus using subband 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 can be applied to intelligent services (for example, smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail businesses, security- and safety-related services, and the like) on the basis of 5G communication technology and IoT-related technology. The present disclosure relates to a signal transmission / reception method and apparatus for enabling a UE to perform random access by using an SBFD resource in a wireless communication system supporting an 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 operations of a terminal and a base station in a wireless communication system, and more particularly, to a method and device for transmitting and receiving signals to enable 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 (SBFD) technology in some 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 the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

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

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

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] The present disclosure provides a device characterized by a method for transmitting and receiving signals that need to be exchanged between a network and a terminal and a method for selecting resources to enable uplink random access by utilizing the resources when a network in a wireless communication system supports subband full duplex transmission and reception and allocates resources for the same.

[0009] The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0010] An embodiment of the present disclosure includes an operation in which a terminal receives any signal transmitted by a base station and performs random access using subband full duplex resources according to any condition included in the signal.

[0011] In order to solve the above-described problem, a method performed by a terminal of a wireless communication system according to an embodiment of the present invention comprises the steps of: receiving, from a base station, a message including configuration information for performing a random access procedure on a sub-band full duplex (SBFD) resource; determining, based on the configuration information, whether a condition for performing the random access procedure on the SBFD resource is satisfied; and performing the random access procedure on the SBFD resource if the condition for performing the random access procedure on the SBFD resource is satisfied. Whether the condition for performing the random access procedure on the SBFD resource is satisfied may be determined based on at least one of whether information instructing to perform the random access procedure on the SBFD resource is received from the base station or a comparison result between measured channel quality and a preset first threshold value.

[0012] According to an embodiment, the information instructing the base station to perform the random access procedure on the SBFD resource may be included in the message.

[0013] In some embodiments, the first threshold value may be included in the message.

[0014] In some embodiments, the condition may include at least one of: the measured channel quality being better than the first threshold value; or the measured channel quality being worse than the first threshold value.

[0015] In an embodiment, the step of performing the random access procedure on the SBFD resource may further include the step of identifying whether the number of transmissions of the random access preamble on the SBFD resource is equal to a preset second threshold value; and, if the number of transmissions of the random access preamble on the SBFD resource is equal to the preset second threshold value, determining to perform the random access procedure on a non-SBFD resource.

[0016] In order to solve the above-described problem, a method performed by a base station of a wireless communication system according to an embodiment of the present invention comprises the steps of: transmitting to a terminal a message including configuration information for performing a random access procedure on a sub-band full duplex (SBFD) resource; and, based on the configuration information, receiving a random access preamble from the terminal when a condition for performing the random access procedure on the SBFD resource is satisfied, wherein whether the condition for performing the random access procedure on the SBFD resource is satisfied may be determined based on at least one of whether the base station has transmitted information indicating to perform the random access procedure on the SBFD resource or a comparison result between a channel quality measured by the terminal and a preset first threshold value.

[0017] According to an embodiment, the information instructing the base station to perform the random access procedure on the SBFD resource may be included in the message.

[0018] In some embodiments, the first threshold value may be included in the message.

[0019] The above condition may include at least one of the case where the measured channel quality is better than the first threshold value or the case where the measured channel quality is worse than the first threshold value.

[0020] According to an embodiment, a random access preamble may be received in a non-SBFD resource when the number of transmissions of the random access preamble in the SBFD resource is equal to a preset second threshold value.

[0021] In order to solve the above-described problem, according to an embodiment of the present invention, a terminal of a wireless communication system includes a transceiver; and a control unit, wherein the control unit receives a message including configuration information for performing a random access procedure on a sub-band full duplex (SBFD) resource from a base station through the transceiver, determines whether a condition for performing the random access procedure on the SBFD resource is satisfied based on the configuration information, and performs the random access procedure on the SBFD resource if the condition for performing the random access procedure on the SBFD resource is satisfied, and whether the condition for performing the random access procedure on the SBFD resource is satisfied may be determined based on at least one of whether information instructing to perform the random access procedure on the SBFD resource is received from the base station or a comparison result between measured channel quality and a preset first threshold value.

[0022] In order to solve the above-described problem, according to an embodiment of the present invention, a base station of a wireless communication system includes a transceiver; and a control unit, wherein the control unit transmits a message including configuration information for performing a random access procedure on a sub-band full duplex (SBFD) resource to a terminal through the transceiver, and, based on the configuration information, if a condition for performing the random access procedure on the SBFD resource is satisfied, receives a random access preamble from the terminal through the transceiver, and whether the condition for performing the random access procedure on the SBFD resource is satisfied can be determined based on at least one of whether the base station has transmitted information indicating to perform the random access procedure on the SBFD resource or a comparison result between a channel quality measured by the terminal and a preset first threshold value.

[0023] According to one embodiment of the present disclosure, random access can be performed more quickly and with lower delay by performing random access using subband full duplex resources as well as general uplink resources in a wireless communication system.

[0024] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0025] FIG. 1 is a diagram illustrating a next-generation mobile communication system structure that supports subband full duplex transmission and reception according to an embodiment of the present disclosure.

[0026] FIG. 2 is a diagram for explaining the subband full duplex (SBFD) concept of a base station or cell according to one embodiment of the present disclosure.

[0027] FIG. 3 is a diagram illustrating an example of a terminal's SBFD RACH capability reporting procedure according to an embodiment of the present disclosure.

[0028] 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 an example of a procedure for performing SBFD random access by a terminal according to usage conditions.

[0029] FIG. 5 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 an SBFD random access performance procedure of a terminal according to a condition of using SBFD random access and then falling back to general random access.

[0030] FIG. 6 is a diagram illustrating an embodiment of a procedure related to a base station allocating SBFD and non-SBFD RO resources to a terminal for the purpose of performing random access for beam failure recovery (BFR) to the terminal according to an embodiment of the present disclosure and performing SBFD random access by the terminal according to conditions.

[0031] FIG. 7 is a diagram illustrating the structure of a base station according to one embodiment of the present disclosure.

[0032] FIG. 8 is a diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

[0033] The operating principles of the present disclosure are described in detail below with reference to the attached drawings. In the following description of the present disclosure, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0034] The 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, and terms referring to various identification information are provided as examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0035] Hereinafter, the base station is an entity that performs resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included in a system to which the embodiments of the present disclosure may be applied, and 5G below may also 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, as determined by a person skilled in the art, without significantly departing from the scope of the present disclosure. It will be appreciated that each block of the processing flow diagrams and combinations of the flow diagrams can be executed by computer program instructions.

[0036] These computer program instructions may be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, so that the instructions executed by the processor of the computer or other programmable data processing apparatus create means for performing the functions described in the flowchart block(s). These computer program instructions may also be stored in a computer-available or computer-readable memory that can be directed to a computer or other programmable data processing apparatus to implement functions in a particular manner, so that the instructions stored in the computer-available or computer-readable memory can produce an article of manufacture that includes instruction means for performing the functions described in the flowchart block(s). The computer program instructions may also be installed on a computer or other programmable data processing apparatus, so that a series of operational steps are performed on the computer or other programmable data processing apparatus to create a computer-implemented process, so that the instructions executing on the computer or other programmable data processing apparatus can provide steps for performing the functions described in the flowchart block(s).

[0037] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order depending on the corresponding function. In this case, the term '~unit' used in the present embodiment means software or a hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the '~unit' may perform certain roles. However, the '~unit' is not limited to software or hardware. The '~unit' may be configured to be on an addressable storage medium and may be configured to execute one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, the components and '~ units' may be implemented to reproduce one or more CPUs within a device or a secure multimedia card. Also, in an embodiment, the '~ unit' may include one or more processors.

[0038] For convenience of explanation, this disclosure uses terms and names defined in the 5GS and NR standards, which are standards defined by the 3rd Generation Partnership Project (3GPP). However, this disclosure is not limited to these terms and names and can be equally applied to wireless communication networks that comply with other standards. For example, this disclosure can be applied to the 3GPP 5GS / NR (5th generation mobile communication standard).

[0039] Fifth-generation wireless communication systems operate in higher frequency (mmWave) bands, and user equipment (UE) and base stations (gNBs, new radio node Bs, NR gNBs) use beamforming to communicate with each other. Beamforming technology is used to mitigate propagation path loss and increase the propagation range for communications in higher frequency bands. Beamforming improves transmission and reception performance by using high-gain antennas. Beamforming can be categorized into transmit (TX) beamforming, performed at the transmitter, and receive (RX) beamforming, performed at the receiver. TX beamforming typically uses multiple antennas to densely position the area where radio waves reach in a specific direction, thereby increasing directivity. In this context, a set of multiple antennas can be referred to as an antenna array, and each antenna in the array can be referred to as an array element. Antenna arrays can be configured in various configurations, such as linear arrays and planar arrays. The use of TX beamforming increases the directivity of the signal, thereby increasing the propagation range. In addition, since the signal is hardly transmitted in a direction other than the directional direction, signal interference acting on other receivers is greatly reduced. The receiver can perform beamforming on the RX signal using the RX antenna array. RX beamforming increases the strength of the RX signal transmitted in a specific direction by focusing the radio waves in a specific direction, and provides the effect of blocking interference signals by excluding signals transmitted in directions other than the specific direction from the RX signal. Beamforming technology allows the transmitter to create multiple transmit beam patterns in different directions. Each of these transmit beam patterns may 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, each providing coverage to a portion of the cell. The narrower the TX beam, the higher the antenna gain, and thus the longer the propagation range of the transmitted signal using beamforming. The receiver can also generate multiple receive (RX) beam patterns in different directions. Each of these receive patterns may also be referred to as a receive (RX) beam.

[0040] 5th 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 a master node (MN) and the other acts as a secondary node (SN). The MN and SN are connected via a network interface, and at least the MN is connected to the core network. NR also supports multi-RAT dual connectivity (MR-DC) operation, where a UE in the RRC_CONNECTED state (radio resource control connected state) is configured to utilize radio resources provided by two separate schedulers connected via a non-ideal backhaul, providing either E-UTRA (i.e., if the node is an ng-eNB) or NR access (i.e., if the node is a gNB). In NR, a UE in RRC_CONNECTED state that is not configured with carrier aggregation (CA) / DC has only one serving cell, which is the primary cell. For a UE in RRC_CONNECTED state configured with CA / DC, the term 'serving cell' is used to indicate a set of cells that includes a special cell (SpCell) and all secondary cells. In NR, a master cell group (MCG) refers to a group of serving cells associated with a master node, which includes a PCell (primary cell) and optionally one or more SCell(s) (secondary cell(s)).In NR, a secondary cell group (SCG) is a group of serving cells associated with a secondary node, including a primary secondary cell (PSCell) and optionally one or more SCells. In NR, a PCell (primary cell) is a serving cell within an MCG operating on the primary frequency where a UE performs an initial connection setup procedure or initiates a connection re-establishment procedure. For a CA-configured UE, an SCell in NR is a cell that provides additional radio resources on top of a special cell. A PSCell (Primary SCG Cell) is a serving cell within an SCG to which a UE performs random access when performing a Reconfiguration with Sync procedure. For dual connectivity operation, 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.

[0041] Acquiring System Information in 5th Generation Wireless Communication Systems: In 5th generation wireless communication systems, a Node B (gNB) or base station broadcasts a synchronization signal (SS) and a physical broadcast channel (PBCH) block (SSB: SS / PBCH block), which consists of a primary and secondary synchronization signal (PSS, SSS) and a secondary synchronization signal (SSS), and system information. The system information includes common parameters required for communication in a cell. In 5th generation wireless communication systems (also known as next generation radio or NR), system information (SI) is divided into a master information block (MIB) and multiple system information blocks (SIBs), where:

[0042] - MIB is always transmitted on the BCH with a cycle of 80 ms, is repeated within 80 ms, and contains the parameters required to obtain SIB1 from the cell.

[0043] - SIB1 is transmitted on the downlink shared channel (DL-SCH) with a period of 160 ms, and the transmission repetition is variable. The default transmission repetition period of SIB1 is 20 ms, but the actual transmission repetition period depends on the network implementation. The scheduling information of SIB 1 includes the mapping between SIBs and SI messages, the periodicity of each SI message, and the SI window length. The scheduling information of SIB 1 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 (physical random access channel (PRACH) preamble(s) and PRACH resource(s)) requesting the gNB to broadcast one or more SI messages.

[0044] - SIBs other than SIB1 are carried in system information (SI) messages transmitted on the DL-SCH. Only SIBs with the same period can be mapped to the same SI message. Each SI message is transmitted within a periodically occurring time-domain window (referred to as an SI-window of the same length for all SI messages). Each SI message is associated with an SI-window, and the 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 except SIB1 can be configured as cell-specific or region-specific using an indication in SIB1. A cell-specific SIB is applicable only within the cell providing the SIB, and a region-specific SIB is applicable within an area called an SI area, which consists of one or more cells and is identified by the systemInformationAreaID.

[0045] - The UE acquires SIB1 from the camped cell or serving cell. The UE checks the BroadcastStatus bit in SIB1 for the SI message it needs to acquire. The SI request configuration for the supplementary uplink (SUL) is signaled by the gNB using the information element (IE) si-RequestConfigSUL in SIB1. If the IE si-RequestConfigSUL is not present in SIB1, the UE considers that the SI request configuration for the SUL is not signaled by the gNB. The SI request configuration for the normal uplink (NUL) is signaled by the gNB using the IE si-RequestConfig in SIB1. If the IE si-RequestConfig is not present in SIB1, the UE considers that the SI request configuration for the NUL is not signaled by the gNB. If the SI message it needs to acquire is not broadcast (i.e., the BroadcastStatus bit is set to 0), the UE initiates the SI request transmission. The SI request transmission procedure is as follows:

[0046] - When the gNB signals an SI request configuration on the SUL and the SUL selection criteria are met (i.e., the reference signal received power (RSRP) derived from SSB measurements 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 transmission of an SI request based on the SI request based on Msg1 (message 1) on the SUL. In other words, the UE initiates a random access procedure using the PRACH preamble(s) and PRACH resource(s) within the SI request configuration on the SUL. The UE transmits Msg1 (i.e., the random access preamble) and waits for an acknowledgment for the SI request. The random access resources (PRACH preamble(s) and PRACH time(s)) indicated in the SI request configuration on the SUL are used for Msg1. Msg1 is transmitted on the SUL. Upon receiving an acknowledgment for an SI request, the UE monitors the SI window of the requested SI message for one or more SI period(s) of that SI message.

[0047] - Otherwise, if the gNB signals an SI request configuration for NUL and the NUL selection criteria are met (i.e., SUL is supported on the camped cell or serving cell and RSRP derived from SSB measurements on the camped cell or serving cell is greater than or equal to rsrp-ThresholdSSB-SUL; or SUL is not supported on the serving cell), the UE initiates transmission of SI request based on Msg1-based SI request on NUL. In other words, the UE initiates a random access procedure using PRACH preamble(s) and PRACH resource(s) in the SI request configuration on NUL. The UE transmits Msg1 (i.e., random access preamble) and waits for an acknowledgment for the SI request. The random access resources (PRACH preamble(s) and PRACH time(s)) indicated in the SI request configuration on NUL are used for Msg1. Msg1 is transmitted on NUL. Upon receiving an acknowledgment for an SI request, the UE monitors the SI window of the requested SI message for one or more SI period(s) of that SI message.

[0048] - Otherwise, the UE initiates transmission of the SI request based on the SI request based on Msg3 (message 3). In other words, the UE initiates transmission of the RRCSystemInfoRequest message (345). The UE transmits Msg1 (i.e., 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. Based on the UL grant received in the random access response, the UE transmits an RRCSystemInfoRequest message and waits for an acknowledgment (i.e., an RRCSystemInfoRequest message) for the SI request. Once an acknowledgment for the SI request (i.e., an RRCSystemInfoRequest message) is received, the UE monitors the SI window of the requested SI message in one or more SI period(s) of the corresponding SI message. Note that if SUL is configured, the UL (uplink) carrier selection for Msg1 transmission will be selected by the UE in a similar manner to the way it was selected by the UE for the Msg1-based SI request. SUL is a UL carrier selected if the RSRP derived from SSB measurements 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 if the RSRP derived from SSB measurements 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).

[0049] Physical downlink control channel (PDCCH) in 5th generation wireless communication system: In 5th generation wireless communication system, a physical downlink control channel (PDCCH) is used to schedule downlink (DL) transmission on a physical downlink shared channel (PDSCH) and uplink (UL) transmission on a physical uplink shared channel (PUSCH), wherein downlink control information (DCI) on the PDCCH includes downlink allocations including at least modulation and coding format, resource allocation, and hybrid automatic repeat request (HARQ) information related to DL-SCH. In addition to scheduling, the PDCCH may be used to activate and deactivate PUSCH transmissions configured with configured grants, activate and deactivate PDSCH semi-persistent transmissions, notify one or more UEs of a slot format, notify one or more UEs of physical resource block(s) (PRB(s)) and orthogonal frequency-division multiplexing (OFDM) symbol(s) so that the UE can assume that a transmission is not intended, transmit transmit power control (TPC) commands for PUCCH and PUSCH, transmit one or more TPC commands for sounding reference signal (SRS) transmission by one or more UEs, switch the active bandwidth of a UE, and initiate a random access procedure. A UE monitors a set of PDCCH candidates for a configured monitoring case in one or more configured control resource sets (CORESETs) according to a corresponding search space configuration. A CORESET consists of a set of PRBs having a duration of one to three OFDM symbol times.Resource units, resource element groups (REGs) and control channel elements (CCEs), are defined within a CORESET, where each CCE constitutes a REG set. Control channels are formed by aggregating CCEs, and different code rates for control channels are realized by aggregating different numbers of CCEs. Interleaved CCE-to-REG mapping and non-interleaved CCE-to-REG mapping are supported in CORESET. Polar coding is used for the PDCCH. Each resource element group carrying the PDCCH carries its own demodulation reference signal (DMRS). QPSK modulation is used for the PDCCH.

[0050] In 5th generation wireless communication systems, a search space configuration list is signaled by the gNB for the configured bandwidth part (BWP), each search configuration being uniquely identified by an identifier. The identifier is explicitly signaled by the gNB to identify the configuration of the search space to be used for a specific purpose, such as paging reception, SI reception, and random access response reception. The NR search space configuration includes the parameters monitoring periodicity-PDCCH-slot, monitoring offset-PDCCH-slot, monitoring symbol-within-PDCCH-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-within-PDCCH-slot). The PDCCH monitoring case exists in slots from 'x' to x+duration, where slot number 'x' in radio frame number 'y' satisfies the equation below:

[0051] (y*(number of slots in radio frame) + x - monitoring offset-PDCCH-slots) mod (monitoring periodicity-PDCCH-slots) = 0;

[0052] The start symbol of a PDCCH monitoring instance is given by the monitoring symbol-PDCCH-in-slot. The length of a PDCCH monitoring instance (in symbols) is given by the coreset associated with the search space. The search space configuration includes the identifiers of the coreset configurations associated with it. For each configured BWP, there is a list of coreset configurations signaled by the gNB, where each coreset configuration is uniquely identified by its identifier. Note that each radio frame has a duration of 10 ms. A radio frame is identified by its radio frame number or system frame number. Each radio frame consists of multiple slots, and the number of slots and the duration of the slots within the radio frame depend on the subcarrier spacing. The number of slots within the radio frame and the duration of the slots for each supported SCS are predefined in NR. Each coreset configuration is associated with a list of transmission configuration indicator (TCI) states. One DL RS ID (SSB or channel state information reference signal (CSI RS)) is configured for each TCI state. A list of TCI states corresponding to a coreset configuration is signaled by the gNB via RRC signaling. One of the TCI states is activated and indicated to the UE by the gNB via a medium access control (MAC) control element (CE). The TCI state indicates the DL TX beam (the DL TX beam is QCL'd with the SSB / CSI RS of the TCI state) used by the gNB for PDCCH transmission in PDCCH monitoring cases in the search space. 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 coreset ID in the slot is used for the PDSCH. Alternatively, a combination of RRC+MAC CE+DCI is used to indicate the TCI state for the PDSCH.RRC constructs a list of TCI states, MAC CE represents a subset of these TCI states, and DCI represents one TCI state from the list of TCI states indicated in MAC CE.

[0053] Bandwidth Adaptation (BA) in 5G Wireless Communication Systems: 5G wireless communication systems support Bandwidth Adaptation (BA). With BA, a UE's transmit and receive bandwidth need not be as large as the cell's bandwidth and can be adjusted: the width can be instructed to change (e.g., to reduce during periods of low activity to save power); the location can be shifted in the frequency domain (e.g., to increase scheduling flexibility); and the subcarrier spacing can be instructed to change (e.g., to allow for different services). A subset of a cell's total cell bandwidth is called a bandwidth part (BWP). BA is achieved by configuring an RRC-connected UE with BWP(s) and informing the UE which of the configured BWPs is currently active. Once a BA is configured, the UE only needs to monitor the PDCCH on one active BWP. This means that it does not need to monitor the PDCCH on 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 activated serving cell always has one active UL and DL BWP at a time. BWP switching for a serving cell is used to activate an inactive BWP and simultaneously deactivate an active BWP. BWP switching is controlled by a PDCCH indicating a downlink assignment or an uplink grant, and is controlled by the bwp-InactivityTimer, an RRC signal, or the MAC entity at the initiation of a random access procedure. When an SpCell is added or an SCell is activated, the DL BWP and UL BWP indicated by firstActiveDownlinkBWP-Id and firstActiveUplinkBWP-Id, respectively, are activated without receiving a PDCCH indicating a downlink assignment or an uplink grant.The active BWP for a serving cell is indicated by either RRC or 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).

[0054] Random Access in 5G Wireless Communication Systems: 5G wireless communication systems support Random Access (RA). 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 data or control information transmission in the UL by UEs that are connected to RRC but asynchronous.

[0055] CBRA (Contention Based Random Access): This is also called 4-Step CBRA, 4-Step (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 called message 2 (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 with the RA-radio network temporary identifier (RA-RNTI). The RA-RNTI identifies the time-frequency resource (also called a Physical RA Channel (PRACH) occasion or PRACH(TX) occasion or RO) on 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 occlusion 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). In addition, ul_carrier_id is a UL carrier used for transmitting Msg1, and has a value of 0 for a Normal UL carrier and 1 for a Supplementary UL (SUL) carrier.Multiple RARs for different random access preambles detected by the gNB can be multiplexed by the gNB into the same RAR media access control (MAC) protocol data unit (PDU). An RAR in a MAC PDU is considered to correspond to an RA preamble transmission by the UE if it contains the RA preamble identifier (RAPID) of the RA preamble transmitted by the UE. If the UE does not receive an RAR corresponding to its RA preamble transmission within the RAR window and has not yet transmitted the RA preamble a configured number of times (configured by the gNB in ​​the RACH configuration), the UE returns to the first step, i.e., selecting a Random Access Resource, to select a preamble / RACH occasion and transmit the RA preamble. A backoff may be applied before returning to the first step.

[0056] When the UE receives the RAR corresponding to its RA Preamble transmission, it transmits message 3 (Msg3) in 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 UE identity (e.g., a cell-radio network temporary identifier (C-RNTI) or a system architecture evolution (SAE)-temporary mobile subscriber identity (S-TMSI) or a random number). The UE starts a contention resolution timer after transmitting Msg3. 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, the contention resolution is determined to be successful, so the contention resolution timer is stopped and the RA procedure is completed. When a CE (contention resolution MAC control element) containing the UE's contention resolution identity (the first X bits of the common control channel (CCCH) service data unit (SDU) transmitted in Msg3) is received 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 UE fails to transmit the RA preamble a configurable number of times, the UE may return to the first step, selecting a random access Rrsource (preamble / RACH occlusion) and transmitting the RA preamble. A backoff may be applied before returning to the first step.

[0057] Contention-free random access (CFRA): Also known as legacy CFRA or 4-Step CFRA. The CFRA procedure is used in scenarios such as handover requiring low latency, timing advance establishment for secondary cells (Scells), and gNB (node ​​B) allocation of a UE-dedicated random access preamble. The UE transmits a dedicated RA preamble. The gNB transmits an RAR on the PDSCH addressed to the RA-RNTI. The RAR carries the RA preamble identifier and timing alignment information. The RAR may also include an UL grant. The RAR is transmitted in an RAR window, similar to the Contention-Based RA (CBRA) procedure. CFRA is considered successfully completed after receiving an RAR containing the RA Preamble Identifier (RAPID) of the RA Preamble transmitted by the UE. When RA is initiated for beam failure recovery, the CFRA is considered to be successfully completed when a PDCCH addressed to the C-RNTI in the search space is received for beam failure recovery. If the UE does not receive an RAR by the time the RAR window expires, the RA is considered to be not successfully completed, and if the RA preamble has not been repeatedly transmitted enough times as configured (configured by the gNB in ​​the RACH configuration), the RA preamble is retransmitted.

[0058] For certain events such as handover and Beam Failure Recovery, if dedicated preamble(s) are allocated to the UE, during the first phase of random access, i.e., during random access resource selection for Msg1 transmission, the UE can decide whether to transmit a dedicated preamble or a non-dedicated preamble. Dedicated preambles are typically provided for a subset of SSBs / CSI RSs. If there is no SSB / CSI RS with DL RSRP greater than a threshold among the SSBs / CSI RSs for which contention-free random access resources (i.e., dedicated preambles / ROs) are provided by the gNB, the UE selects a non-dedicated preamble. Otherwise, the UE selects a dedicated preamble. Therefore, during the RA procedure, one random access attempt may be a CFRA and another may be a CBRA.

[0059] Two-step contention-based random access (2-step CBRA): In the first step, the UE transmits a random access preamble on the PRACH and a payload (i.e., MAC PDU) on the PUSCH. The random access preamble and payload transmission is also referred to as message A (MsgA). In the second step, after transmitting MsgA, the UE monitors a response from the network (i.e., gNB) within a configured window. This response is also referred to as message B (MsgB). The next generation Node B (gNB) transmits MsgB on the Physical Downlink Shared Channel (PDSCH). The PDCCH that schedules the PDSCH carrying MsgB is addressed with the MsgB-Radio Network Temporary Identifier (MSGB-RNTI). The MSGB-RNTI identifies the time-frequency resource (also referred to as the physical RA channel (PRACH) point in time or the PRACH transmit (TX) point in time or the RA channel (RACH) point in time) on which the RA frame was detected by the gNB. 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 of the PRACH occasion 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), f_id is the index of the PRACH occasion within the slot in the frequency domain (0 <= f_id < 8), and ul_carrier_id is the UL carrier used for transmitting Msg1 (0 for normal UL (NUL) carrier, 1 for supplementary UL (SUL) carrier).

[0060] If the CCCH SDU is transmitted in 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 the C-RNTI is transmitted in 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 completed successfully. Instead of the contention resolution information corresponding to the transmitted MsgA, MsgB may include 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 by fallback fails (i.e., by transmitting Msg3), the UE retransmits MsgA. If the configuration window during which the UE monitors network responses expires after transmitting MsgA and MsgB containing contention resolution information or fallback information is not received as described above, the UE retransmits MsgA. If the random access procedure is not successfully completed even after transmitting the message a configurable number of times, the UE reverts to the 4-Step RACH procedure. That is, the UE only transmits the PRACH preamble.

[0061] The MsgA payload may include one or more of a common control channel (CCCH) service data unit (SDU), a dedicated control channel (DCCH) SDU, a dedicated traffic channel (DTCH) SDU, a buffer status report (BSR) MAC control element (CE), a power headroom report (PHR) MAC CE, SSB information, a C-RNTI MAC CE, or padding. The MsgA may include a UE ID (e.g., random ID, S-TMSI, C-RNTI, resume ID, etc.) along with a preamble in the first step. The UE ID may be included in the MAC PDU of the MsgA. A UE ID such as a C-RNTI may be carried in a MAC CE, and the MAC CE may be included in a 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. In different scenarios where the UE performs the RA procedure, the UE ID may be different. When the UE performs RA after powering on (before attaching to the network), the UE ID is a random ID. When the UE performs RA in idle state after attaching to the network, the UE ID is the S-TMSI. If the UE has an assigned C-RNTI (e.g., in connected state), the UE ID is the C-RNTI. When the UE is in inactive state, the UE ID is the resume ID. In addition to the UE ID, some additional control information may be sent in MsgA. The control information may be included in the MAC PDU of MsgA. The control information may include a connection request indication, a connection resume request indication, an SI request indication, a buffer status indication, beam information (such as one or more DL TX beam IDs or SSB IDs), beam failure recovery indication / information, data indicators, cell / BS / TRP transition indications, connection re-establishment indications, reconfiguration complete or handover complete messages, etc.

[0062] 2-Step Contention-Free Random Access (2-Step CFRA): In this case, the gNB allocates the UE dedicated random access preamble(s) and PUSCH resource(s) for MsgA transmission. The RO(s) to be used for preamble transmission may also be indicated. In the first step, the UE transmits the random access preamble on the PRACH and the payload on the PUSCH using the contention-free random access resources (i.e., dedicated preamble / PUSCH resources / RO). In the second step, after transmitting the MsgA, the UE monitors for a response from the network (i.e., gNB) within a configured window. This response is also referred to as MsgB.

[0063] The next-generation Node B (gNB) transmits MsgB on the Physical Downlink Shared Channel (PDSCH). The PDCCH that schedules the PDSCH carrying MsgB is addressed by the MsgB-Radio Network Temporary Identifier (MSGB-RNTI). The MSGB-RNTI identifies the time-frequency resource where the RA frame was detected by the gNB (also referred to as the physical RA channel (PRACH) time, the PRACH transmit (TX) time, or the RA channel (RACH) time). MSGB-RNTI is computed 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 of the PRACH occasion in which the UE transmits Msg1, i.e., the RA preamble, and 0 <= s_id < 14; t_id is the index of the first slot of the PRACH occasion (0 <= t_id < 80), f_id is the index of the PRACH occasion within the slot in the frequency domain (0 <= f_id < 8), and ul_carrier_id is the UL carrier used to transmit Msg1 (0 for normal UL (NUL) carrier, 1 for supplementary UL (SUL) carrier).

[0064] If the UE receives a PDCCH addressed to the C-RNTI, the random access procedure is considered to have completed successfully. If the UE receives fallback information corresponding to the transmitted preamble, the random access procedure is considered to have completed successfully.

[0065] For certain events such as handover and beam failure recovery where dedicated preamble(s) and PUSCH resource(s) are allocated to the UE, the UE decides whether to transmit a dedicated preamble or a non-dedicated preamble during the first step of random access, i.e., random access resource selection for MsgA transmission. Dedicated preambles are typically provided on a subset of SSBs / CSI RSs. If none of the SSBs / CSI RSs for which the gNB provides contention-free random access resources (i.e., dedicated preambles / ROs / PUSCH resources) has a DL RSRP greater than or equal to 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.

[0066] 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 with a supplementary uplink and the RSRP of the downlink path loss reference is less than rsrp-ThresholdSSB-SUL, the UE selects the SUL carrier to perform the random access procedure. Otherwise, the UE selects the NUL carrier to perform the random access procedure. After selecting the UL carrier, the UE determines the UL and DL BWP for the random access procedure 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.

[0067] - 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 the 4-Step RACH.

[0068] - Otherwise, if 2-Step contention-free random access resources are signaled by the gNB for this random access procedure, the UE selects 2-Step RACH.

[0069] - Otherwise, if 4-Step contention-free random access resources are signaled by the gNB for this random access procedure, the UE selects 4-Step RACH.

[0070] - Otherwise, if the UL BWP selected for this random access procedure consists of only 2 Step RACH resources, the UE selects 2 Step RACH.

[0071] - Otherwise, if the UL BWP selected for this random access procedure consists of only 4 Step RACH resources, the UE selects 4 Step RACH.

[0072] - Otherwise, if the UL BWP selected for this random access procedure consists of both 2-Step and 4-Step RACH resources,

[0073] - If the RSRP of the downlink path loss is less than or equal to the configured threshold, the UE selects 4-Step RACH. Otherwise, the UE selects 2-Step RACH.

[0074] 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. The RRC states can be further characterized as follows:

[0075] - In RRC_IDLE state, UE-specific DRX can be configured by higher layers (i.e., NAS). The UE monitors short messages transmitted with P-RNTI via DCI; monitors paging channels for CN paging using 5G-S-TMSI; performs neighbor cell measurements and cell (re)selection; acquires system information and can send SI requests (if configured).

[0076] - In RRC_INACTIVE state, UE specific DRX can be configured by higher layers or RRC layer. In this state, UE stores UE inactive AS context. RAN based notification area is configured by RRC layer. UE monitors short messages transmitted with P-RNTI over DCI; monitors paging channel for RAN paging using 5G-S-TMSI and fullI-RNTI; performs neighbor cell measurements and cell (re)selection; performs RAN based notification area updates when moving out of configured RAN based notification area and periodically; acquires system information and can send SI requests (if configured).

[0077] - In RRC_CONNECTED, the UE stores the AS context. Unicast data is transmitted and received with the UE. At lower layers, the UE can be configured with UE-specific DRX. The UE monitors short messages transmitted with the P-RNTI via DCI, if configured; 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.

[0078] 5G or Next Generation Radio Access Network (NG-RAN) based on NR consists of NG-RAN nodes, where the NG-RAN nodes are gNBs, which provide NR user plane and control plane protocol termination towards the UE. The gNBs are also connected to the 5G core (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) wireless communication systems, the UE can use discontinuous reception (DRX) in RRC_IDLE and RRC_INACTIVE states to reduce power consumption. In the RRC_IDLE / RRC_INACTIVE states, the UE wakes up briefly at regular intervals (i.e., each DRX cycle) to receive paging, SI update notification, and emergency notification. Paging messages are transmitted using the Physical Downlink Shared Channel (PDSCH). The Physical Downlink Common Control Channel (PDCCH) is addressed with a paging RNTI (P-RNTI) when a paging message is carried on the PDSCH. The P-RNTI is common to all UEs. To indicate paging for a specific UE, the paging message includes the UE identity (i.e., S-TMSI for an RRC_IDLE UE or I-RNTI for an RRC_INACTIVE UE). A paging message can page multiple UEs by including multiple UE identities. The paging message is broadcast (i.e., the PDCCH is masked with the P-RNTI) and is transmitted over the data channel (i.e., the PDSCH). SI updates and emergency notifications are contained in DCIs, and the PDCCH carrying these DCIs is addressed with the P-RNTI.In RRC idle / inactive mode, the UE monitors one paging occasion (PO) per DRX cycle. In RRC idle / inactive mode, the UE monitors a PO in the initial DL BWP. In RRC connected state, the UE monitors one or more POs to receive SI update notification and emergency notification. In RRC connected state, the UE can monitor any PO in a paging DRX cycle and monitors at least one PO during the SI modification period. In RRC idle / inactive mode, the UE monitors a PO in each DRX cycle in the active DL BWP. A PO is a set of 'S' PDCCH monitoring occasions, which is the number of SSBs (synchronization signal and PBCH blocks) transmitted in the cell. The UE first determines a paging frame (PF) and then determines a PO for the determined PF. One PF is a radio frame (10 ms).

[0079] - PF for UE is a radio frame having a system frame number 'SFN' satisfying the formula (SFN + PF_offset) mod T = (T div N)*(UE_ID mod N).

[0080] - The index (i_s) representing the index of PO is determined by i_s = floor (UE_ID / N) mod Ns.

[0081] - T is the DRX cycle of the UE.

[0082] - In 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 (non-access stratum), and the default DRX value broadcast in the system information.

[0083] - In RRC_IDLE state, T is determined by the minimum of the UE-specific DRX value configured by NAS and the default DRX value broadcast in the system information. If the UE-specific DRX is not configured by the upper layer (i.e., NAS), the default value is applied.

[0084] - N: Total number of paging frames in T

[0085] - Ns: Number of paging opportunities for PF

[0086] - PF_offset: Offset used to determine PF

[0087] - UE_ID: 5G-S-TMSI mod 1024

[0088] - Ns, nAndPagingFrameOffset, and the default DRX cycle length are signaled in SIB1. The N and PF_offset values ​​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 shall be used in the above PF and i_s formulas.

[0089] - The PDCCH monitoring opportunity for paging is determined based on the paging search space configuration (paging-SearchSpace) signaled by the gNB.

[0090] - If SearchSpaceId = 0 is configured for pagingSearchSpace, the PDCCH monitoring opportunity for paging is for 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 half of the frame (i_s = 0) or the second half of the frame (i_s = 1) of the PF.

[0091] - If a non-zero SearchSpaceId is configured for pagingSearchSpace, the UE monitors the (i_s + 1)th PO. PDCCH monitoring opportunities for paging are determined based on the paging search space configuration (paging-SearchSpace) signaled by the gNB. PDCCH monitoring opportunities do not overlap with UL symbols determined according to tdd-UL-DL-ConfigurationCommon, and they are numbered consecutively starting from the first PDCCH monitoring opportunity for paging in the PF. The gNB may signal the firstPDCCH-MonitoringOccasionOfPO parameter for each PO corresponding to each PF. If the 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 for paging starting from the (i_s * S)th PDCCH monitoring opportunity for paging. 'S' is the number of actual transmitted SSBs determined according to 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 a DL BWP other than the initial DL BWP, the first-PDCCH-MonitoringOccasionOfPO parameter is signaled in the corresponding BWP configuration.

[0092] FIG. 1 is a diagram illustrating a next-generation mobile communication system structure that supports subband full duplex transmission and reception according to an embodiment of the present disclosure.

[0093] Referring to FIG. 1, a next-generation mobile communication system supporting subband full duplex transmission and reception may be configured with a next-generation base station (1-01, g Node B, hereinafter referred to as gNB, Node B or base station), a cell (1-06, 1-07, 1-08), a terminal (1-09, User Equipment (UE)), etc. Here, the gNB (1-01) may include a CU (1-02, Central Unit) and one or more DUs (1-03, 1-04, Distributed Unit).

[0094] One CU (1-02) can support one or more DUs (1-03, 1-04), 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).

[0095] UE (1-09) can access an external network via gNB (1-01) through cell (1-06, 1-07, 1-08).

[0096] FIG. 2 is a diagram for explaining the subband full duplex (SBFD) concept of a base station or cell according to one embodiment of the present disclosure.

[0097] Referring to FIG. 2, a base station (2-1) performs wireless communication (2-2) with a terminal (2-4), and for this purpose, determines frequency and time resources (2-3) and can allocate (schedule) downlink (DL) and uplink (UL) resources to the terminal within the resources. Conventionally, the resources (2-3) allocated to the terminal (2-4) could be configured as one 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 (subband full duplex), it has become possible to set up an SBFD slot (or SBFD D+U slot) (2-6, 2-7, 2-8) in which downlink and uplink resources are mixed between a base station (2-1) and a terminal (2-4) that can use SBFD. SBFD slots (2-6, 2-7, 2-8) can be set not only in the same positions as in Fig. 2, but can also be set in any slot that the base station (2-1) wishes to set, for example, the downlink slot of 2-5. For example, the SBFD slots (2-6, 2-7, 2-8) may have downlink and uplink regions in the frequency domain, and a guard band may exist between the downlink band and the uplink band.

[0098] In this situation, in order to support random access of the terminal (2-4), the base station (2-1) can allocate an uplink physical layer random access channel (PRACH) capable of transmitting and receiving a preamble for random access within the SBFD slots (2-6, 2-7, 2-8) instead of the existing uplink slot (2-9), and can also allocate a RACH occasion (RO) (2-10). The SBFD RO (2-10) may be included in the SBFD slots (2-6, 2-7, 2-8), for example, as shown in FIG. 2, and may exist across one or more SBFD slots (2-7, 2-8), and may exist across not only one or more SBFD slots but also a normal uplink slot (2-9).

[0099] Through these SBFD ROs (2-10), terminals (2-4) capable of using SBFD gain additional RO opportunities in addition to the existing legacy RO, thereby enabling random access with even less delay and collision.

[0100] FIG. 3 is a diagram illustrating an example of a terminal's SBFD RACH capability reporting procedure according to an embodiment of the present disclosure.

[0101] Referring to FIG. 3, in step 3-3, the terminal (3-1) can receive a signal requesting terminal capability information from the serving cell base station (3-2) to which the terminal (3-1) is connected (connected). The requesting signal may be a UE capability enquiry message. In response thereto, in step 3-4, the terminal (3-1) can transmit a capability signal including Random Access performance capability information via SBFD possessed by the terminal (3-1) to the base station (3-2). The response message may be a UE capability information message.

[0102] According to one embodiment of the present disclosure, the terminal (3-1) can inform the serving cell (3-2) through the signal of step 3-4 that the terminal (3-1) can use SBFD, or has a function to support the use of SBFD Random Access through SBFD, and for example, the terminal (3-1) can inform that it supports all or part of the following functions.

[0103] The terminal capability can be expressed as a combination of features that can use any Random Access resource, as follows:

[0104] For example, any SBFD capability contained in a FeatureCombination IE (information element) such as [Table 1] and [Table 2] below may indicate a feature or combination of features to be associated with a set of Random Access resources (i.e., an instance of FeatureCombinationPreambles). This may be linked with other IEs FeatureCombinationPreambles to associate a set of preambles with a feature combination. The terminal (3-1) may apply the corresponding field value when performing Random Access using the preamble in this featureCombinationPreambles for the parameters that can be provided in this IE, or may apply the corresponding value as specified in the corresponding Need Code. In a specific BWP, there may be at most one preamble set associated with a given feature combination per RA type (i.e., a given specific combination). (4-step RACH or 2-step RACH)

[0105] FeatureCombination information element-- ASN1START-- TAG-FEATURECOMBINATION-STARTFeatureCombination-r17 ::= SEQUENCE {redCap-r17 ENUMERATED {true} OPTIONAL, -- Need RsmallData-r17 ENUMERATED {true} OPTIONAL, -- Need Rnsag-r17 NSAG-List-r17 OPTIONAL, -- Need Rmsg3-Repetitions-r17 ENUMERATED {true} OPTIONAL, -- Need RSBFD-r19 ENUMERATED {true} OPTIONAL, -- Need Rspare3 ENUMERATED {true} OPTIONAL, -- Need Rspare2 ENUMERATED {true} OPTIONAL, -- Need Rspare1 ENUMERATED {true} OPTIONAL -- Need R}NSAG-List-r17 ::= SEQUENCE (SIZE (1.. maxSliceInfo-r17)) OF NSAG-ID-r17-- TAG-FEATURECOMBINATION-STOP-- ASN1STOP

[0106] FeatureCombination field descriptionsSBFDIf present, this field indicates that Subband Full Duplex is part of this feature combination.redCapIf present, this field indicates that RedCap is part of this feature combination.smallDataIf present, this field indicates that Small Data is part of this feature combination.nsagIf present, this field indicates NSAG(s) that are part of this feature combination.msg3-RepetitionsIf present, this field indicates that signaling of msg3 repetition is part of this feature combination. This field is not configured in a set of preambles that is configured with 2-step random-access type.

[0107] The terminal capability may be a per-band capability that allows the terminal (3-1) to indicate availability / unavailability for each frequency bandwidth, or a per-band combination capability corresponding to a combination of frequency bandwidths.

[0108] The terminal capability may be a per UE capability that can be utilized by the terminal (3-1) regardless of the frequency bandwidth.

[0109] 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 an example of a procedure for performing SBFD random access by a terminal according to usage conditions.

[0110] Referring to FIG. 4, in step 4-3, the base station (4-2) can transmit to the terminal (4-1) a signal (message) including SBFD resource information, configuration information of ROs that may exist in the SBFD, and at least one of any condition(s) that the terminal must satisfy in order to use the SBFD RO.

[0111] The SBFD resource information included in the signal transmitted from the base station (4-2) in step 4-3 above may be resource information of a form identical or similar to that illustrated in FIG. 2. For example, it may be a resource characterized by a frame structure composed of some or all of general uplink or downlink slots, flexible or special slots, and SBFD slots in which uplink and downlink coexist.

[0112] The SBFD RACH occasion information included in the signal transmitted from the base station (4-2) in the above step 4-3 may be resource information of the same or similar form as that illustrated in FIG. 2. For example, the SBFD RACH occasion information may be an uplink RO resource allocated across one or more SBFD slots, or may be an uplink RO resource allocated across not only the SBFD slots but also any adjacent uplink slots. In addition, the information may include parameters required for the terminal (4-1) to perform random access through the RO, for example, the following SBFD random access dedicated parameters.

[0113] - prach-ConfigurationIndex_SBFD: Available set of SBFD PRACH OCCASION(RO) for transmitting Random Access Preamble, this also applies to MSGA PRACH when SBFD PRACH OCCASION(RO) is shared between 2 Step RA and 4 Step RA types.

[0114] - msgA-PRACH-ConfigurationIndex_SBFD: Available set of SBFD PRACH OCCASION (RO) for transmitting Random Access Preamble for MSGA of 2 Step RA type.

[0115] - preambleReceivedTargetPower_SBFD: Initial Random Access Preamble power of 4 Step RA type performed with SBFD RO.

[0116] - msgA-PreambleReceivedTargetPower_SBFD: Initial Random Access Preamble power of 2 Step RA type performed with SBFD RO.

[0117] - rsrp-ThresholdSSB_SBFD: RSRP threshold for SSB selection for 4-Step RA type performed with SBFD RO. When the random access procedure is initiated for beam failure recovery, rsrp-ThresholdSSB_SBFD used when selecting SSB within candidate BeamRSList can refer to rsrp-ThresholdSSB_SBFD within BeamFailureRecoveryConfig IE.

[0118] - rsrp-ThresholdCSI-RS_SBFD: RSRP threshold for CSI-RS selection for 4-Step RA type performing SBFD RO. If the random access procedure is initiated for beam failure recovery, rsrp-ThresholdCSI-RS_SBFD can be the same as rsrp-ThresholdSSB_SBFD in the BeamFailureRecoveryConfig IE.

[0119] - msgA-RSRP-ThresholdSSB_SBFD: RSRP threshold for SSB selection for 2 Step RA type performed with SBFD RO.

[0120] - rsrp-ThresholdSSB-SUL_SBFD: RSRP threshold for selection between NUL and SUL carriers in random access performed with SBFD RO.

[0121] - msgA-RSRP-Threshold_SBFD: RSRP threshold for selecting between 2 Step RA type and 4 Step RA type when both 2 Step RA and 4 Step RA types are configured in UL BWP performing SBFD RO.

[0122] - rsrp-ThresholdMsg3_SBFD: RSRP threshold for MSG3 repetition performed with SBFD RO (see Section 5.1.1b).

[0123] - featurePriorities_SBFD: Priority for features such as RedCap, NSAG(s), etc., performed by SBFD RO. (See Section 5.1.1d)

[0124] - msgA-TransMax_SBFD: The maximum number of MSGA transmissions when both 4 Step RA and 2 Step RA type random access resources are configured to perform SBFD RO.

[0125] - 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.

[0126] - recoverySearchSpaceId_SBFD: Search space ID for monitoring responses to beam failure recovery requests performed by SBFD RO.

[0127] - powerRampingStep_SBFD: Power-ramping step performed by SBFD RO.

[0128] - msgA-PreamblePowerRampingStep_SBFD: Power ramping step for MSGA preamble performed with SBFD RO.

[0129] - powerRampingStepHighPriority_SBFD: Power-ramping step for prioritized random access procedures performed with SBFD RO.

[0130] - scalingFactorBI_SBFD: Scaling factor for prioritized random access procedures performed with SBFD RO.

[0131] - ra-PreambleIndex_SBFD: Random access preamble Id performed with SBFD RO.

[0132] - ra-ssb-OccasionMaskIndex_SBFD: Defines the PRACH OCCASION (RO) associated with the SSB on which the MAC entity can transmit the random access preamble for random accesses performed with SBFD ROs. (See TS 38.321 Section 7.4)

[0133] - msgA-SSB-SharedRO-MaskIndex_SBFD: Indicates a subset of 4-Step RA type PRACH OCCASION(RO) mapped to each SSB when both 2-Step RA and 4-Step RA type PRACH OCCASION(RO) are shared for each SSB for random accesses 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)

[0134] - ra-OccasionList_SBFD: Defines the PRACH OCCASION (RO) associated with the CSI-RS on which the MAC entity can transmit the random access preamble for random access performed with SBFD RO.

[0135] - ra-PreambleStartIndex_SBFD: Start index of the random access preamble for on-demand SI requests in random access performed with SBFD RO.

[0136] - startPreambleForThisPartition_SBFD: The first preamble associated with the random access resource set applied to the random access procedure for random access performed with SBFD RO.

[0137] - preambleTransMax_SBFD: The maximum number of random access preamble transmissions for random access performed with SBFD RO.

[0138] - 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 type random access performed with SBFD RO.

[0139] - 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 RA and 4 Step RA types for random access performed with SBFD RO.

[0140] - 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 type random access performed with SBFD RO.

[0141] - numberOfPreamblesForThisPartition_SBFD: The number of consecutive preambles associated with the random access resource set applied to the random access procedure for random access performed with SBFD RO.

[0142] - msgA-PUSCH-ResourceGroupA_SBFD: Defines the MSGA PUSCH resource that should be used when the UE performs MSGA transmission using the random access preamble of group A in random access performed with SBFD RO.

[0143] - msgA-PUSCH-ResourceGroupB_SBFD: Defines the MSGA PUSCH resource that should be used when the UE performs MSGA transmission using the random access preamble of group B in random access performed with SBFD RO.

[0144] - msgA-PUSCH-Resource-Index_SBFD: For contention-free random access performed with SBFD RO, identifies the index of the PUSCH resource used in the 2 Step RA type.

[0145] - groupBconfigured_SBFD: If groupBconfigured is configured for random access performed with SBFD RO, random access preamble group B is configured for 4 Step RA type.

[0146] - groupB-ConfiguredTwoStepRA_SBFD: For random access performed with SBFD RO, if groupB-ConfiguredTwoStepRA is configured, random access preamble group B is configured for 2 Step RA type.

[0147] - numberOfRA-PreamblesGroupA_SBFD: For random access performed with SBFD RO, the first numberOfRA-PreamblesGroupA included in the group B configured random access preamble among the contention-based random access preambles associated with SSB 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).

[0148] - groupB-ConfiguredTwoStepRA_SBFD: For random access performed with SBFD RO, if groupB-ConfiguredTwoStepRA is configured, random access preamble group B is configured for 2 Step RA type.

[0149] - numberOfRA-PreamblesGroupA_SBFD: For random access performed with SBFD RO, the first numberOfRA-PreamblesGroupA contained in the groupB-ConfiguredTwoStepRA random access preamble among the contention-based random access preambles associated with SSB 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).

[0150] The terminal (4-1) can use the parameters set above to set and initialize the following parameters managed by the terminal (4-1) for performing SBFD. In the case of parameters having the same name as the parameters set by the base station (4-2), they may have the same value, and in the case of a counter, the number may gradually increase after being initialized with a starting value (e.g., 1).

[0151] - PREAMBLE_INDEX_SBFD;

[0152] -PREAMBLE_TRANSMISSION_COUNTER_SBFD;

[0153] -PREAMBLE_POWER_RAMPING_COUNTER_SBFD;

[0154] -PREAMBLE_POWER_RAMPING_STEP_SBFD;

[0155] -PREAMBLE_RECEIVED_TARGET_POWER_SBFD;

[0156] - PREAMBLE_BACKOFF_SBFD;

[0157] - PCMAX_SBFD;

[0158] - SCALING_FACTOR_BI_SBFD;

[0159] - TEMPORARY_C-RNTI_SBFD;

[0160] - RA_TYPE_SBFD;

[0161] - POWER_OFFSET_2STEP_RA_SBFD;

[0162] - MSGA_PREAMBLE_POWER_RAMPING_STEP_SBFD.

[0163] The above parameters are set as dedicated parameters for SBFD and can be used by the terminal (4-1). In some cases, legacy random access parameters other than SBFD can be used as they are. These parameters can be recognized by the terminal in the following manner.

[0164] - If the parameters required to perform random access using SBFD RO are not included in the configuration signal that sets the SBFD parameter set, the terminal (4-1) can implicitly use legacy random access parameters other than SBFD.

[0165] - If the terminal (4-1) receives from the base station (4-1) an indication that any parameter required for performing random access using SBFD RO is not included in the configuration signal that sets the SBFD parameter set and that the corresponding parameter is to be used as a legacy random access parameter other than SBFD, the terminal (4-1) may use the legacy random access parameter other than SBFD for the corresponding parameter.

[0166] ■ The indicator that allows the legacy random access parameters to be used as they are can be individually assigned to each parameter and transmitted from the base station (4-2) to the terminal (4-1). For example, the indicator can be set in a format that includes each parameter name, or the indicator can be set in a bitmap format and each parameter can be assigned to the position of each bit.

[0167] ■ An instruction to use the legacy random access parameters as they are can be transmitted from the base station (4-2) to the terminal (4-1) as a single bit, etc., so that it can be applied to all parameters. For example, if the bit is set to on (or 1) and transmitted, the terminal (4-1) can understand that it has been instructed to use the legacy random access parameters as they are, not SBFD, and can perform this if the required parameters are not included in the configuration signal that sets the SBFD parameter set.

[0168] The message (signal) transmitted in the above step 4-3 may be an RRC signal using MR transmitted to a specific terminal or a specific terminal group, for example, an RRC signal such as RRC Configuration, RRC Reconfiguration, RRC Release, RRC resume, or RRC setup received by the terminal (4-1) in the RRC Connected mode (state), or may be any MAC CE signal, or may be any PHY DCI signal.

[0169] In addition, the signal transmitted in the above step 4-3 may be a type of broadcast signal transmitted to any unspecified number of terminals, and may be a type of Master Information Block (MIB) or System Information Block (SIB) transmitted and received via MR.

[0170] Additionally, the signal transmitted in the above step 4-3 may be a type of PDCCH order signal as a downlink signal that triggers random access transmitted by the base station (4-2) to a specific terminal.

[0171] The signal transmitted from the base station (4-2) in the above step 4-3 may include conditions that must be met when the terminal (4-1) transmits a random access preamble in the uplink through the SBFD RO and performs random access.

[0172] Alternatively, in one embodiment, the signal transmitted in step 4-3 may be composed of different signals, one signal setting the SBFD RO and another signal including conditions to be met when performing random access through the SBFD RO.

[0173] These conditions may be all or part of the conditions below, each of which may be expressed as a value having some indicator or numerical value.

[0174] - When the representative value of the cell measured by the terminal is greater than a certain threshold1.

[0175] Threshold1 can be transmitted by being included in the signal transmitted in step 4-3 above.

[0176] - When the measurement value of any RS, such as SSB or CSI-RS, in a Quasi Co-Location (QCL) relationship with the RO that the terminal wants to transmit is greater than a certain threshold2. Threshold2 and the RS type can be included in the signal transmitted in step 4-3.

[0177] Alternatively, the RS type can be fixed to one (e.g., SSB) and only Threshold2 can be included in the signal transmitted in step 4-3 and transmitted.

[0178] - A condition that forces the terminal to use the RO of the earliest available SBFD slot or normal slot.

[0179] An indicator allowing the above conditions can be transmitted by including it in the signal transmitted in step 4-3.

[0180] - A condition to always give priority to SBFD RO when a terminal can use SBFD.

[0181] An indicator indicating the above conditions can be transmitted by including it in the signal transmitted in step 4-3.

[0182] - When the representative value of the cell measured by the terminal is less than (or equal to) a certain threshold3, the base station can mitigate interference by inducing the transmission of a RACH preamble within the SBFD of a terminal relatively far from the base station through this condition.

[0183] Threshold3 can be transmitted by being included in the signal transmitted in step 4-3 above.

[0184] A terminal (4-1) that needs to perform random access checks whether the conditions for using the SBFD RO are satisfied in step 4-4, and if the conditions are satisfied, the terminal (4-1) can start performing random access using SBFD by transmitting a random access preamble through the SBFD RO in step 4-6. In addition, if the conditions are not satisfied, the terminal (4-1) can start performing random access by transmitting a random access preamble using a legacy RO instead of SBFD in step 4-5.

[0185] In the scenario of the above-described FIG. 4, the SBFD RO may be allocated for the purpose of random access performed by the base station (4-2) to the terminal (4-1) for beam failure recovery (BFR). The base station (4-1) may allocate the SBFD RO to the terminal (4-1) for use in BFR through a signal transmitted in step 4-3, and may cause the terminal (4-1) to perform SBFD random access according to conditions set from among various conditions as in the scenario of the above-described FIG. 4 when BFR occurs.

[0186] In the scenario of FIG. 4, the SBFD RO can be allocated for the purpose of supporting the operation of the base station (4-2) to change the random access operation using the non-SBFD RO to the random access operation using the SBFD RO for the terminal (4-1). The base station (4-2) allocates the SBFD RO to the terminal (4-1) for use in BFR through a signal transmitted in step 4-3, and the terminal (4-1) that was performing the random access operation using the non-SBFD RO can perform the SBFD random access according to the set conditions among various conditions as in the scenario of FIG. 4. In this case, how to operate the preamble transmission count counter for determining the random access failure of the terminal (4-1) performing the random access operation by switching between non-SBFD and SBFD and the power ramping counter for determining the transmission power, etc., will be described below with reference to FIG. 5.

[0187] In the scenario of the above-described Figure 4, it is obvious that the terminal (4-1) can be configured with only an SBFD RO without any conditions for using a separate SBFD RO and can perform random access using only the SBFD RO. In this case, it is also obvious that there may not be any resource configuration for using a non-SBFD RO.

[0188] FIG. 5 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 an SBFD random access performance procedure of a terminal according to a condition of using SBFD random access and then falling back to general random access.

[0189] Referring to FIG. 5, in step 5-3, the base station (5-2) can transmit to the terminal (5-1) a signal (message) containing at least one of SBFD resource information, configuration information of ROs that may exist in the SBFD, and information on certain condition(s) that the terminal (5-1) must satisfy in order to fallback from SBFD random access to general random access.

[0190] Alternatively, in one embodiment, the signal transmitted in step 5-3 may be composed of different signals, one signal setting the SBFD RO and another signal including certain condition(s) that the terminal must satisfy in order to fallback from SBFD random access to normal random access.

[0191] The SBFD resource information included in the signal transmitted from the base station (5-2) in step 5-3 above may be resource information of a form identical or similar to that illustrated in FIG. 2. For example, it may be a resource characterized by a frame structure composed of some or all of general uplink or downlink slots, flexible or special slots, and SBFD slots in which uplink and downlink coexist.

[0192] The SBFD RACH Occasion information included in the signal transmitted from the base station (5-2) in the above step 5-3 may be resource information of the same or similar form as that illustrated in FIG. 2. For example, the SBFD RACH occasion information may be an uplink RO resource allocated across one or more SBFD slots, or may be an uplink RO resource allocated across not only the SBFD slots but also any adjacent uplink slots. In addition, the information may include parameters necessary for the terminal (5-1) to transmit a preamble through the RO, for example, SBFD-only parameters such as those described in FIG. 4.

[0193] The signal transmitted in the above step 5-3 may be an RRC signal using MR transmitted to a specific terminal or a specific terminal group, for example, an RRC signal such as RRC Config, RRC Reconfig, or RRC Release received by the terminal (5-1) in RRC Connected mode, or may be any MAC CE signal, or may be any PHY DCI signal.

[0194] In addition, the signal transmitted in the above step 5-3 may be a type of broadcast signal transmitted to any unspecified number of terminals, and may be a type of Master Information Block (MIB) or System Information Block (SIB) transmitted and received via MR.

[0195] Additionally, the signal transmitted in the above step 5-3 may be a type of PDCCH order signal as a downlink signal that triggers random access transmitted by a base station (5-2) to a specific terminal (5-1).

[0196] The signal transmitted from the base station (5-2) in the above step 5-3 may include conditions that must be satisfied in order to determine when the terminal (5-1) needs to fallback to performing random access through a non-SBFD, for example, legacy RO while transmitting a random access preamble in the uplink through the SBFD RO. These conditions may be all or part of the conditions below, and each may be expressed as a value having some indicator or numerical value.

[0197] - When the Random Access Preamble transmission attempted through SBFD RO fails a certain number of times (or more).

[0198] The number of times may be any new parameter included in the signal that the base station (5-2) transmits to the terminal (5-1) in step 5-3, or may be any parameter that the base station (5-2) sets to the terminal as described in FIG. 4, for example, preambleTransMax_SBFD, as one of the existing parameters.

[0199] - When the representative value of the cell measured by the terminal (5-1) is less than (or less than or equal to) a certain threshold1.

[0200] Threshold1 can be transmitted by being included in the signal transmitted in step 5-3 above.

[0201] - When the representative value of any reference signal (or reference signals) set by the base station (5-2) and measured by the terminal (5-1) is smaller than (or smaller than or equal to) a certain threshold2. For example, the reference signal may be included in the signal transmitted in step 5-3 and transmitted as any RS set by the base station (5-2) among various RSs such as SSB (Synchronization Signal Block), CSI-RS (Channel Side Information-RS), DMRS (Demodulation RS).

[0202] The ID or RS type information and / or Threshold2 of the RS that the base station (5-2) sets for the terminal (5-1) to measure and compare with Threshold2 may be included in the signal transmitted in step 5-3 and transmitted.

[0203] - When the measurement value of any RS, such as SSB or CSI-RS, in a Quasi Co-Location (QCL) relationship with the RO that the terminal (5-1) wants to transmit is smaller than a certain threshold2. Threshold2 and the RS type can be included in the signal transmitted in step 5-3.

[0204] Alternatively, the RS type can be fixed to one (e.g., SSB) and only Threshold2 can be included in the signal transmitted in step 5-3 and transmitted.

[0205] The terminal (5-1) performing random access through the SBFD RO in step 5-4 can check whether the fallback condition is satisfied in step 5-5. If the condition is satisfied based on the result of checking the fallback condition, the terminal (5-1) can start performing random access using the legacy Uplink RO other than SBFD by transmitting a random access preamble through the non-SBFD RO in step 5-7. If the condition is not satisfied, the terminal (5-1) can continuously perform SBFD random access through the SBFD RO in step 5-6 (maintain or retry RA in SBFD).

[0206] The terminal (5-1) attempts to retransmit the preamble only up to a certain parameter value set by the base station (5-2), and if the preamble transmission fails until the number of retransmissions reaches that number, the random access can be considered to have failed. The corresponding procedure for existing terminals is as follows.

[0207] If any condition is met that indicates that the ongoing random access is unsuccessful, the terminal (5-1) increases the PREAMBLE_TRANSMISSION_COUNTER by 1 to restart the random access and re-transmit the preamble. Any condition that increases the PREAMBLE_TRANSMISSION_COUNTER by 1 may be all or part of the following:

[0208] - If the terminal (5-1) receives an LBF failure indication from a lower layer after transmitting a random access preamble and lbt-FailureRecoveryConfig is not set.

[0209] (If lbt-FailureRecoveryConfig is set, the Random Access Resource selection procedure is performed again.)

[0210] - When the terminal (5-1) transmits MSGA for 2-step random access and then receives an LBF failure indication from the lower layer, and lbt-FailureRecoveryConfig is not set.

[0211] (If lbt-FailureRecoveryConfig is set, the Random Access Resource selection procedure is performed again for 2-step RA.)

[0212] - If, after the terminal (5-1) transmits a random access preamble, the ra-ResponseWindow within the RACH configuration set by the network has expired and a Random Access Response (RAR) containing a Random Access Preamble identifier called PREAMBLE_INDEX transmitted by the terminal (5-1) is not received during the period, the RAR reception is considered unsuccessful.

[0213] - If the terminal (5-1) transmits MSGA for 2-step RA, and the msgB-ResponseWindow within the RACH configuration set by the network expires and the MSGB containing the Random Access Preamble identifier called PREAMBLE_INDEX transmitted by the terminal (5-1) is not received during the period, the RAR reception is considered unsuccessful.

[0214] - When the Contention Resolution of the terminal (5-1) is deemed unsuccessful:

[0215] ■ For example, when the terminal (5-1) that sent msg3 has not successfully received msg4, contention resolution message until the ra-ContentionResolutionTimer expires (until the expiration)

[0216] If the terminal (5-1) satisfies one of the above conditions, it increases the PREAMBLE_TRANSMISSION_COUNTER by 1, and if the value is equal to preambleTransMax + 1, which is a parameter set by the base station (5-2), it can recognize that the random access has failed.

[0217] If the random access procedure was attempted on a Special Cell (SpCell), such as a Primary Cell (PCell) or Primary Secondary Cell (PSCell), the terminal (5-1) may report this to upper layers (indicate a Random Access problem to upper layers). Furthermore, if the random access procedure was intended to update system information (SI), the terminal (5-1) may consider the random access procedure to have been terminated unsuccessfully.

[0218] If the random access procedure was attempted on a secondary cell (SCell), the terminal (5-1) may consider that the random access procedure was terminated unsuccessfully.

[0219] However, since the above existing procedure does not take into account the newly set preambleTransMax_SBFD, in order to specify this and clarify the terminal operation by linking it with fallback, etc., the present patent proposes the following various possible scenarios and the operation of the terminal (5-1).

[0220] 1. PREAMBLE_TRANSMISSION 1) A method of operating independent parameters and procedures for SBFD random access and non-SBFD random access.

[0221] ■ In this method, we propose the following method that utilizes a parameter set independent of existing parameters:

[0222] If the terminal (5-1) satisfies any condition that the random access using the ongoing SBFD RO is unsuccessful, it restarts the random access using the SBFD RO and increases the PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 to re-perform preamble transmission. Any condition that increases the PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 may be all or part of the following:

[0223] - When the terminal (5-1) transmits a random access preamble to SBFD and then receives an LBF failure indication from a lower layer, and lbt-FailureRecoveryConfig is not set.

[0224] (If lbt-FailureRecoveryConfig is set, the SBFD Random Access Resource selection procedure is performed again.)

[0225] - When the terminal (5-1) transmits MSGA for 2-step SBFD random access and then receives an LBF failure indication from the lower layer, and lbt-FailureRecoveryConfig is not set.

[0226] (If lbt-FailureRecoveryConfig is set, the Random Access Resource selection procedure is performed again for 2-step SBFD RA.)

[0227] - If the terminal (5-1) transmits a random access preamble through the SBFD RO, and the ra-ResponseWindow_SBFD within the RACH configuration set by the network expires and the terminal (5-1) does not receive a Random Access Response (RAR) containing a Random Access Preamble identifier matching the PREAMBLE_INDEX transmitted during the period, the terminal (5-1) considers that the RAR reception was not successful.

[0228] - If the terminal (5-1) transmits MSGA for 2-step SBFD RA, and msgB-ResponseWindow_SBFD within the RACH configuration set by the network expires and MSGB containing a Random Access Preamble identifier matching the PREAMBLE_INDEX transmitted by the terminal (5-1) is not received during the period, the terminal (5-1) considers that RAR reception is not successful.

[0229] - When the Contention Resolution of the terminal (5-1) is deemed unsuccessful:

[0230] ■ For example, when the terminal (5-1) that sent msg3 has not successfully received msg4, contention resolution message until the ra-ContentionResolutionTimer_SBFD expires (until the expiration)

[0231] If the terminal (5-1) satisfies one of the above conditions, it increases 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 (5-2), it can recognize that random access has failed.

[0232] If the random access procedure was attempted on a Special Cell (SpCell), such as a Primary Cell (PCell) or Primary Secondary Cell (PSCell), the terminal (5-1) may report this to upper layers (indicate a Random Access problem to upper layers). Furthermore, if the random access procedure was intended to update system information (SI), the terminal (5-1) may consider the random access procedure to have been terminated unsuccessfully.

[0233] If the random access procedure was attempted on a secondary cell (SCell), the terminal (5-1) may consider that the random access procedure was terminated unsuccessfully.

[0234] In the above procedure, a series of parameters may be reused as the same parameters as non-SBFD. For example, ra-ResponseWindow_SBFD may be replaced with ra-ResponseWindow, msgB-ResponseWindow_SBFD may be replaced with msgB-ResponseWindow, and ra-ContentionResolutionTimer_SBFD may be replaced with ra-ContentionResolutionTimer, or may be instructed to use the same parameters.

[0235] 2. PREAMBLE_TRANSMISSION 2) A method of operating a preamble transmission attempt by combining SBFD random access and non-SBFD random access without distinguishing between them.

[0236] ■ In this method, we propose the following method that integrates existing parameters and a new parameter set:

[0237] If any condition is met that indicates that the ongoing random access is unsuccessful, regardless of whether it is SBFD or non-SBFD, the terminal (5-1) restarts the random access and increases the PREAMBLE_TRANSMISSION_COUNTER by 1 to re-transmit the preamble. Any condition that increases the PREAMBLE_TRANSMISSION_COUNTER by 1 may be all or part of the following:

[0238] - If the terminal (5-1) receives an LBF failure indication from a lower layer after transmitting a random access preamble and lbt-FailureRecoveryConfig is not set.

[0239] (If lbt-FailureRecoveryConfig is set, the Random Access Resource selection procedure is performed again.)

[0240] - When the terminal (5-1) transmits MSGA for 2-step random access and then receives an LBF failure indication from the lower layer, and lbt-FailureRecoveryConfig is not set.

[0241] (If lbt-FailureRecoveryConfig is set, the Random Access Resource selection procedure is performed again for 2-step RA.)

[0242] - If the terminal (5-1) transmits a random access preamble through the RO, and the ra-ResponseWindow (or ra-ResponseWindow_SBFD in the case of SBFD) within the RACH configuration set by the network expires and a Random Access Response (RAR) containing a Random Access Preamble identifier matching the PREAMBLE_INDEX transmitted by the terminal (5-1) is not received during the period, the terminal (5-1) considers that the RAR reception was not successful.

[0243] - If the terminal (5-1) transmits MSGA for 2-step RA, and the msgB-ResponseWindow (or msgB-ResponseWindow_SBFD in case of SBFD) within the RACH configuration set by the network expires and the terminal (5-1) does not receive an MSGB containing a Random Access Preamble identifier matching the PREAMBLE_INDEX transmitted during the period, the terminal (5-1) considers that the RAR reception was not successful.

[0244] - When the Contention Resolution of the terminal (5-1) is deemed unsuccessful:

[0245] ■ For example, when the terminal (5-1) that sent msg3 has not successfully received msg4, contention resolution message until ra-ContentionResolutionTimer (or ra-ContentionResolutionTimer_SBFD) expires (until expiration)

[0246] If the terminal (5-1) satisfies one of the above conditions, it increases the PREAMBLE_TRANSMISSION_COUNTER by 1, and if the value is equal to preambleTransMax + 1, which is a parameter set by the base station (5-2), the terminal (5-1) can recognize that the random access has failed.

[0247] If the random access procedure was attempted on a Special Cell (SpCell), such as a Primary Cell (PCell) or Primary Secondary Cell (PSCell), the terminal (5-1) may report this to upper layers (indicate a Random Access problem to upper layers). Furthermore, if the random access procedure was intended to update system information (SI), the terminal (5-1) may consider the random access procedure to have been terminated unsuccessfully.

[0248] If the random access procedure was attempted on a secondary cell (SCell), the terminal (5-1) may consider that the random access procedure was terminated unsuccessfully.

[0249] 3. PREAMBLE_TRANSMISSION 3) A method of distinguishing between SBFD random access and non-SBFD random access, but combining the number of preamble transmissions of both types to determine random access failure and operating the preamble transmission attempt.

[0250] ■ In this method, we propose the following method that integrates existing parameters and a new parameter set:

[0251] In addition to the counter procedure of the above existing standard, the terminal (5-1) may increase PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 in order to restart the random access and re-perform preamble transmission when any condition is satisfied that the ongoing SBFD random access is not successful. Any condition for increasing the PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 may be all or part of the conditions proposed in the above embodiment 1.

[0252] If the terminal (5-1) satisfies one of the conditions above, it increases PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1, and if the sum of the two counter values ​​that the terminal (5-1) currently has, for example, the value of PREAMBLE_TRANSMISSION_COUNTER + PREAMBLE_TRANSMISSION_COUNTER_SBFD, is equal to preambleTransMax + 1, which is a parameter set by the base station (5-2), the terminal (5-1) recognizes that the random access has failed.

[0253] If the random access procedure was attempted on a Special Cell (SpCell), such as a Primary Cell (PCell) or Primary Secondary Cell (PSCell), the terminal (5-1) may report this to upper layers (indicate a Random Access problem to upper layers). Furthermore, if the random access procedure was intended to update system information (SI), the terminal (5-1) may consider the random access procedure to have been terminated unsuccessfully.

[0254] If the random access procedure was attempted on a secondary cell (SCell), the terminal (5-1) may consider that the random access procedure was terminated unsuccessfully.

[0255] In the above procedure, a series of parameters may be reused as the same parameters as non-SBFD. For example, ra-ResponseWindow_SBFD may be replaced with ra-ResponseWindow, msgB-ResponseWindow_SBFD may be replaced with msgB-ResponseWindow, and ra-ContentionResolutionTimer_SBFD may be replaced with ra-ContentionResolutionTimer, or may be instructed to use the same parameters.

[0256] 4. PREAMBLE_TRANSMISSION 4) A method of distinguishing between SBFD random access and non-SBFD random access, but when determining random access failure, considering the number of preamble transmissions of both types and attempting to transmit preambles for a larger number of transmissions.

[0257] ■ In this method, we propose the following method that integrates existing parameters and a new parameter set:

[0258] In addition to the counter procedure of the above existing standard, the terminal (5-1) may increase PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 in order to restart the random access and re-perform preamble transmission when any condition is satisfied that the ongoing SBFD random access is not successful. Any condition for increasing the PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1 may be all or part of the conditions proposed in the above embodiment 1.

[0259] If the terminal (5-1) satisfies one of the conditions above, it increases PREAMBLE_TRANSMISSION_COUNTER_SBFD by 1, and if the larger value of the two counter values ​​currently held by the terminal (5-1), for example, the value of max(PREAMBLE_TRANSMISSION_COUNTER, PREAMBLE_TRANSMISSION_COUNTER_SBFD), is equal to preambleTransMax + 1, which is a parameter set by the base station (5-2), the terminal (5-1) can recognize that the random access has failed.

[0260] If the random access procedure was attempted on a Special Cell (SpCell), such as a Primary Cell (PCell) or Primary Secondary Cell (PSCell), the terminal (5-1) may report this to upper layers (indicate a Random Access problem to upper layers). Furthermore, if the random access procedure was intended to update system information (SI), the terminal (5-1) may consider the random access procedure to have been terminated unsuccessfully.

[0261] If the random access procedure was attempted on a secondary cell (SCell), the terminal (5-1) may consider that the random access procedure was terminated unsuccessfully.

[0262] In the above procedure, a series of parameters may be reused as the same parameters as non-SBFD. For example, ra-ResponseWindow_SBFD may be replaced with ra-ResponseWindow, msgB-ResponseWindow_SBFD may be replaced with msgB-ResponseWindow, and ra-ContentionResolutionTimer_SBFD may be replaced with ra-ContentionResolutionTimer, or may be instructed to use the same parameters.

[0263] In the same context as the above PREAMBLE_TRANSMISSION_COUNTER, the PREAMBLE_POWER_RAMPING_COUNTER can also be specified due to the addition of SBFD random access via SBFD RO.

[0264] The terminal (5-1) operates the PREAMBLE_POWER_RAMPING_COUNTER immediately before each random access preamble transmission attempt to determine the transmission power for the transmission. In the existing procedure, the terminal (5-1) increases the PREAMBLE_POWER_RAMPING_COUNTER by 1 if the selected SSB or CSI-RS reference signal measurement value has not changed compared to the previous preamble transmission before transmitting the preamble. Thereafter, the terminal (5-1) can set the DELTA_PREAMBLE value according to Section 7.3 of the standard document (TS) 38.321 and set the PREAMBLE_RECEIVED_TARGET_POWER according to the following formula:

[0265] For 4-step RA, set as follows:

[0266] - preambleReceivedTargetPower + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) × PREAMBLE_POWER_RAMPING_STEP + POWER_OFFSET_2STEP_RA;

[0267] For 2-step RA, set as follows:

[0268] - msgA-PreambleReceivedTargetPower + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) × PREAMBLE_POWER_RAMPING_STEP;

[0269] However, since the above existing procedure does not take into account preamble transmission utilizing the newly established SBFD, in order to specify this and clarify terminal operation in connection with fallback, etc., this patent proposes the following various possible scenarios and operation of the terminal (5-1).

[0270] 1. PREAMBLE_POWER_RAMPING 1) A method of operating independent parameters and procedures by distinguishing between SBFD random access and non-SBFD random access.

[0271] ■ In this method, we propose the following method that utilizes a parameter set independent of existing parameters:

[0272] The terminal (5-1) may operate the PREAMBLE_POWER_RAMPING_COUNTER_SBFD to determine the transmission power for the transmission immediately before attempting to transmit a random access preamble using SBFD. In the existing procedure, the terminal (5-1) increases the PREAMBLE_POWER_RAMPING_COUNTER_SBFD by 1 if the selected SSB or CSI-RS reference signal measurement value has not changed compared to the previous preamble transmission before transmitting the preamble. Thereafter, the terminal (5-1) may set the DELTA_PREAMBLE value according to Section 7.3 of the standard document (TS) 38.321 and set the PREAMBLE_RECEIVED_TARGET_POWER_SBFD according to the following formula:

[0273] For 4-step SBFD RA, set as follows:

[0274] - preambleReceivedTargetPower_SBFD + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER_SBFD - 1) × PREAMBLE_POWER_RAMPING_STEP_SBFD + POWER_OFFSET_2STEP_RA;

[0275] For 2-step SBFD RA, set as follows:

[0276] - msgA-PreambleReceivedTargetPower_SBFD + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER_SBFD - 1) × PREAMBLE_POWER_RAMPING_STEP_SBFD;

[0277] 2. PREAMBLE_POWER_RAMPING 2) How to operate parameters and procedures by mixing SBFD random access and non-SBFD random access.

[0278] ■ In this method, we propose the following method that combines existing parameters with an independent parameter set:

[0279] The terminal (5-1) may operate a counter to determine the transmission power for a random access preamble transmission attempt immediately before the transmission attempt. The terminal (5-1) compares the reference signal measurement value with the existing value according to the existing procedure and increases the PREAMBLE_POWER_RAMPING_COUNTER or PREAMBLE_POWER_RAMPING_COUNTER_SBFD by 1. Then, the terminal (5-1) determines the PREAMBLE_POWER_RAMPING_COUNTER_Calc as max(PREAMBLE_POWER_RAMPING_COUNTER, PREAMBLE_POWER_RAMPING_COUNTER_SBFD). Thereafter, the terminal (5-1) may set the DELTA_PREAMBLE value according to Section 7.3 of the standard document (TS) 38.321 and set the PREAMBLE_RECEIVED_TARGET_POWER_SBFD according to the following formula:

[0280] For 4-step RA, set as follows:

[0281] - 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;

[0282] For 2-step RA, set as follows:

[0283] - msgA-PreambleReceivedTargetPower_SBFD + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER_Calc - 1) × PREAMBLE_POWER_RAMPING_STEP_SBFD;

[0284] In the scenario of the above-described Figure 5, it is obvious that the terminal (5-1) can be configured with only an SBFD RO without any conditions for using a separate SBFD RO and can perform random access using only the SBFD RO. In this case, it is also obvious that there may not be any resource configuration for using a non-SBFD RO.

[0285] FIG. 6 is a diagram illustrating an embodiment of a procedure related to a base station allocating SBFD and non-SBFD RO resources to a terminal for the purpose of performing random access for beam failure recovery (BFR) to the terminal according to an embodiment of the present disclosure and performing SBFD random access by the terminal according to conditions.

[0286] Referring to FIG. 6, in step 6-3, the base station (6-2) may transmit to the terminal (6-1) a signal (message) that includes at least one of the conditions that must be satisfied to use SBFD random access, setting SBFD resource information and RO configuration information that may exist in SBFD, and resources that can be used to resolve a Beam Failure Recovery situation when it occurs, for non-SBFD (normal) and SBFD.

[0287] The signal transmitted in the above step 6-3 may be an RRC signal using MR transmitted to a specific terminal or a specific terminal group, such as a signal transmitted in step 5-3 of the embodiment of FIG. 5 and / or a signal transmitted in step 4-3 of the embodiment of FIG. 4, for example, an RRC signal such as RRC Config, RRC Reconfig, or RRC Release received by the terminal (6-1) in RRC Connected mode, or may be any MAC CE signal, or may be any PHY DCI signal.

[0288] In addition, the signal transmitted in the above step 6-3 may be a type of broadcast signal transmitted to any unspecified number of terminals, and may be a type of Master Information Block (MIB) or System Information Block (SIB) transmitted and received via MR.

[0289] In addition, the signal transmitted in the above step 6-3 may be a type of PDCCH order signal as a downlink signal that triggers random access transmitted by a base station (6-2) to a specific terminal (6-1).

[0290] According to the setting, the terminal (6-1) that detected the BFR in step 6-4 can check whether the conditions for using the SBFD RO are satisfied in step 6-5. If the conditions are satisfied based on the result, the terminal (6-1) can perform SBFD random access by transmitting a random access preamble through the SBFD RO in step 6-7. If the conditions are not satisfied, the terminal (6-1) can perform random access through a non-SBFD RO in step 6-6.

[0291] FIG. 7 is a diagram illustrating the structure of a base station according to one embodiment of the present disclosure.

[0292] Referring to Figure 7, 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. In addition, network devices 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 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.

[0293] The transceiver refers to the receiver and transmitter of the base station, and can transmit and receive signals with terminals, other base stations, or other network devices. At this time, the transmitted and received signals may include control information and data. For example, the transceiver can transmit system information to the terminal, and can transmit a synchronization signal or a reference signal. To this end, the transceiver may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-converts the received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver. The transceiver may include wired and wireless transceivers, and may include various configurations for transmitting and receiving signals. In addition, the transceiver may receive a signal through a communication channel (e.g., a wireless channel), output it to the control unit, and transmit the signal output from the control unit through the communication channel. Additionally, the transceiver unit can receive a communication signal and output it to the processor, and transmit the signal output from the processor to a terminal, another base station, or another entity via a wired or wireless network.

[0294] The storage unit can store programs and data required for the operation of the base station. Furthermore, the storage unit can store control information or data included in signals acquired from the base station. The storage unit can be configured as a storage medium, such as a ROM, RAM, hard disk, CD-ROM, or DVD, or a combination of storage media. Furthermore, the storage unit can store at least one of information transmitted and received through the transceiver unit and information generated through the control unit.

[0295] In the present disclosure, the control unit may be defined as a circuit, 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 application programs. The control unit may control the overall operation of the base station 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.

[0296] FIG. 8 is a diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

[0297] Referring to FIG. 8, 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 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.

[0298] The transceiver 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 may receive system information from the base station, and may receive a synchronization signal or a reference signal. To this end, the transceiver may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-downconverts the received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver. In addition, the transceiver may include wired and wireless transceivers, and may include various components for transmitting and receiving signals. In addition, the transceiver may receive a signal through a wireless channel and output it to a control unit, and transmit a signal output from the control unit through the wireless channel. Additionally, the transceiver unit can receive a communication signal and output it to the processor, and transmit the signal output from the processor to a network entity via a wired or wireless network.

[0299] The storage unit can store programs and data necessary for the operation of the terminal. Additionally, the memory can store control information or data contained in signals acquired from the terminal. The storage unit can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of storage media.

[0300] In the present disclosure, the control unit may be defined as a circuit, 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 application programs. The control unit may control the overall operation of a terminal 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.

[0301] The 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.

[0302] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The 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 the present disclosure.

[0303] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0304] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a 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 via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0305] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0306] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

[0307] Inequalities in the conditions and mathematical comparisons described in this disclosure and embodiments can be replaced with inequalities that include equal signs. For example, "greater than" can be replaced with "greater than or equal to," and "smaller than" can be replaced with "smaller than or equal to." Furthermore, inequalities can be applied by replacing them with inequalities in the opposite direction. This means that the network can set conditions where desired, even when the expected effect is opposite.

Claims

1. In a method performed by a terminal of a wireless communication system, A step of receiving a message from a base station including configuration information for performing a random access procedure in SBFD (sub-band full duplex) resources; A step of determining whether the conditions for performing the random access procedure are satisfied in the above SBFD resource based on the above setting information; If the condition for performing the random access procedure on the SBFD resource is satisfied, a step of performing the random access procedure on the SBFD resource is included, A method characterized in that whether a condition for performing the random access procedure on the SBFD resource is satisfied is determined based on at least one of whether information instructing to perform the random access procedure on the SBFD resource has been received from the base station or a comparison result between the measured channel quality and a preset first threshold value.

2. In paragraph 1, A method characterized in that the information instructing the base station to perform the random access procedure on the SBFD resource is included in the message.

3. In paragraph 1. The above first threshold value is included in the above message, A method characterized in that the above condition includes at least one of the cases where the measured channel quality is better than the first threshold value or the case where the measured channel quality is worse than the first threshold value.

4. In the first paragraph, the step of performing the random access procedure in the SBFD resource is: A step of identifying whether the number of transmissions of a random access preamble in the above SBFD resource is equal to a preset second threshold value; and A method characterized in that it further comprises a step of determining to perform the random access procedure in a non-SBFD resource when the number of transmissions of the random access preamble in the SBFD resource is equal to the preset second threshold value.

5. In a method performed by a base station of a wireless communication system, A step of transmitting a message including configuration information for performing a random access procedure in SBFD (sub-band full duplex) resources to a terminal; and Based on the above setting information, if the condition for performing the random access procedure in the SBFD resource is satisfied, a step of receiving a random access preamble from the terminal is included. A method characterized in that whether a condition for performing the random access procedure in the SBFD resource is satisfied is determined based on at least one of whether the base station has transmitted information indicating to perform the random access procedure in the SBFD resource or a comparison result between the channel quality measured by the terminal and a preset first threshold value.

6. In paragraph 5, A method characterized in that the information instructing the base station to perform the random access procedure on the SBFD resource is included in the message.

7. In paragraph 5. The above first threshold value is included in the above message, A method characterized in that the above condition includes at least one of the cases where the measured channel quality is better than the first threshold value or the case where the measured channel quality is worse than the first threshold value.

8. In paragraph 5, A method characterized in that a random access preamble is received in a non-SBFD resource when the number of transmissions of the random access preamble in the SBFD resource is equal to a preset second threshold value.

9. In the terminal of a wireless communication system, Transmitter and receiver; and comprising a control unit, wherein the control unit is: Receive a message including setup information for performing a random access procedure in SBFD (sub-band full duplex) resources from a base station through the transceiver, It is determined based on the above setting information whether the conditions for performing the above random access procedure are satisfied in the above SBFD resource, If the condition for performing the random access procedure on the SBFD resource is satisfied, the random access procedure is performed on the SBFD resource, A terminal characterized in that whether a condition for performing the random access procedure in the SBFD resource is satisfied is determined based on at least one of whether information instructing to perform the random access procedure in the SBFD resource has been received from the base station or a comparison result between the measured channel quality and a preset first threshold value.

10. In paragraph 9, A terminal characterized in that the information instructing the base station to perform the random access procedure on the SBFD resource is included in the message.

11. In paragraph 9. The above first threshold value is included in the above message, A terminal characterized in that the above condition includes at least one of a case where the measured channel quality is better than the first threshold value or a case where the measured channel quality is worse than the first threshold value.

12. In paragraph 9, the control unit, Identify whether the number of transmissions of a random access preamble in the above SBFD resource is equal to a preset second threshold value, A terminal characterized in that it is determined to perform the random access procedure in a non-SBFD resource when the number of transmissions of the random access preamble in the SBFD resource is equal to the preset second threshold value.

13. In a base station of a wireless communication system, Transmitter and receiver; and comprising a control unit, wherein the control unit is: Transmitting a message including configuration information for performing a random access procedure in SBFD (sub-band full duplex) resources to a terminal through the transceiver, Based on the above setting information, if the condition for performing the random access procedure in the SBFD resource is satisfied, a random access preamble is received from the terminal through the transceiver, A base station characterized in that whether a condition for performing the random access procedure in the SBFD resource is satisfied is determined based on at least one of whether the base station has transmitted information indicating to perform the random access procedure in the SBFD resource or a comparison result between the channel quality measured by the terminal and a preset first threshold value.

14. In paragraph 13, The information instructing the base station to perform the random access procedure on the SBFD resource is included in the message, The above first threshold value is included in the above message, A base station characterized in that the above condition includes at least one of a case where the measured channel quality is better than the first threshold value or a case where the measured channel quality is worse than the first threshold value.

15. In paragraph 13, A base station characterized in that a random access preamble is received in a non-SBFD resource when the number of transmissions of the random access preamble in the SBFD resource is equal to a preset second threshold value.

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