Method and device for transmitting and receiving signals in wireless communication system

Abstract

A method and device for transmitting and receiving signals in a wireless communication system, disclosed in the present specification, can request a change in SSB transmission-related configuration through a specific UL signal / channel when an SSB is transmitted and received between a base station and a terminal.

Description

Method and device for transmitting and receiving signals in a wireless communication system

[0001] The present invention relates to a method and apparatus used in a wireless communication system.

[0002] Wireless communication systems are widely deployed to provide various types of communication services, such as voice and data. Typically, wireless communication systems are multiple access systems that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power). Examples of multiple access systems include Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), and Single Carrier Frequency Division Multiple Access (SC-FDMA).

[0003] The technical problem to be achieved by the present invention is to provide a method for efficiently transmitting and receiving wireless communication signals and a device therefor.

[0004] The technical problems of the present invention are not limited to the technical problems described above, and other technical problems can be inferred from the embodiments of the present invention.

[0005] The present invention provides a method and device for transmitting and receiving signals in a wireless communication system.

[0006] As one aspect of the present invention, a method performed by a terminal in a wireless communication system is provided, comprising: a step of transmitting a physical random access channel (PRACH) at a specific random access channel occasion (RO); and a step of receiving a random access response (RAR) based on the PRACH; wherein the specific RO is associated with a request for setting up a synchronization signal / physical broadcast channel block (SSB).

[0007] As another aspect of the present invention, a device for performing the above method is provided, comprising a terminal, a processor, and a storage medium.

[0008] In another aspect of the present invention, a method performed by a base station in a wireless communication system is provided, comprising: receiving a physical random access channel (PRACH) at a specific random access channel occasion (RO); and transmitting a random access response (RAR) based on the PRACH; wherein the specific RO is associated with a request for setting up a synchronization signal / physical broadcast channel block (SSB).

[0009] As another aspect of the present invention, a device for performing the method is provided, comprising a base station, a processor, and a storage medium.

[0010] The above devices may include at least a terminal, a network, and an autonomous vehicle capable of communicating with other autonomous vehicles other than the above devices.

[0011] The above-described aspects of the present invention are only some of the preferred embodiments of the present invention, and various embodiments reflecting the technical features of the present invention can be derived and understood by a person having ordinary skill in the art based on the detailed description of the present invention described below.

[0012] According to one embodiment of the present invention, when a signal is transmitted and received between communication devices, there is an advantage in that more efficient signal transmission and reception can be performed through operations differentiated from those of the prior art.

[0013] The technical effects of the present invention are not limited to the technical effects described above, and other technical effects can be inferred from the embodiments of the present invention.

[0014] Figure 1 illustrates the structure of a radio frame.

[0015] Figure 2 illustrates a resource grid of slots.

[0016] Figure 3 illustrates the SSB structure.

[0017] Figures 4 and 5 illustrate a random access process.

[0018] FIG. 6 is a drawing for explaining a signal transmission and reception method according to an embodiment of the present invention.

[0019] Figures 7 to 10 illustrate devices according to embodiments of the present invention.

[0020] The following technologies can be used in various wireless access systems, such as CDMA, FDMA, TDMA, OFDMA, and SC-FDMA. CDMA can be implemented using wireless technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented using wireless technologies such as GSM (Global System for Mobile communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented using wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (Evolved UTRA). UTRA is a part of UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is a part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A (Advanced) / LTE-A pro is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A / LTE-A pro.

[0021] For clarity, the description is based on a 3GPP communication system (e.g., LTE, NR), but the technical idea of ​​the present invention is not limited thereto. LTE refers to technology after 3GPP TS 36.xxx Release 8. Specifically, LTE technology after 3GPP TS 36.xxx Release 10 is referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 is referred to as LTE-A pro. 3GPP NR refers to technology after TS 38.xxx Release 15. LTE / NR may be referred to as a 3GPP system. "xxx" refers to a standard document detail number. LTE / NR may be collectively referred to as a 3GPP system. For background technology, terms, abbreviations, etc. used in the description of the present invention, reference may be made to matters described in standard documents published prior to the present invention. For example, reference may be made to the following documents.

[0022] 3GPP NR

[0023] - 38.211: Physical channels and modulation

[0024] - 38.212: Multiplexing and channel coding

[0025] - 38.213: Physical layer procedures for control

[0026] - 38.214: Physical layer procedures for data

[0027] - 38.300: NR and NG-RAN Overall Description

[0028] - 38.331: Radio Resource Control (RRC) protocol specification

[0029] Figure 1 illustrates the structure of a radio frame used in NR.

[0030] In NR, uplink (UL) and downlink (DL) transmissions are structured as frames. A radio frame is 10ms long and is defined as two 5ms half-frames (HF). Each half-frame is defined as five 1ms subframes (SF). A subframe is divided into one or more slots, and the number of slots in a subframe depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 OFDM(A) symbols, depending on the cyclic prefix (CP). When normal CP is used, each slot contains 14 symbols. When extended CP is used, each slot contains 12 symbols. Here, the symbols can include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or DFT-s-OFDM symbols).

[0031] Table 1 illustrates that when CP is normally used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

[0032] [Table 1]

[0033]

[0034] Table 2 illustrates that when extended CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

[0035] [Table 2]

[0036]

[0037] In an NR system, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single user equipment (UE). Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (conveniently referred to as a TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0038] NR supports multiple Orthogonal Frequency Division Multiplexing (OFDM) numerologies (e.g., subcarrier spacing, SCS) to support various 5G services. For example, a 15 kHz SCS supports wide areas in traditional cellular bands, while a 30 kHz / 60 kHz SCS can support dense urban areas, lower latency, and wider carrier bandwidth.

[0039] The NR frequency band is defined by two types of frequency ranges (FR) (FR1 / FR2). FR1 / FR2 can be configured as shown in Table 3 below. FR2 can also refer to millimeter wave (mmW).

[0040] [Table 3]

[0041]

[0042] Figure 2 illustrates the slot structure of an NR frame.

[0043] A slot contains multiple symbols in the time domain. For example, for a normal CP, one slot contains 14 symbols, and for an extended CP, one slot contains 12 symbols. A carrier contains multiple subcarriers in the frequency domain. An RB (Resource Block) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. Multiple RB interlaces (simply, interlaces) can be defined in the frequency domain. An interlace m ∈ {0, 1, ..., M-1} can be composed of (common) RBs {m, M+m, 2M+m, 3M+m, ...}. M represents the number of interlaces. A BWP (Bandwidth Part) is defined as multiple consecutive RBs (e.g., physical RBs, PRBs) in the frequency domain, and can correspond to one OFDM numerology (e.g., SCS(u), CP length, etc.). A carrier can contain up to N (e.g., 5) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for a single terminal within a single cell / carrier. Each element in the resource grid is referred to as a Resource Element (RE), to which a single modulation symbol can be mapped.

[0044] In a wireless communication system, a terminal receives information from a base station via the downlink (DL), and the terminal transmits information to the base station via the uplink (UL). The information transmitted and received between the base station and the terminal includes data and various control information, and various physical channels / signals exist depending on the type / purpose of the information they transmit and receive. A physical channel corresponds to a set of resource elements (REs) that carry information derived from a higher layer. A physical signal corresponds to a set of resource elements (REs) used by the physical layer (PHY), but does not carry information derived from a higher layer. The higher layers include the Medium Access Control (MAC) layer, the Radio Link Control (RLC) layer, the Packet Data Convergence Protocol (PDCP) layer, and the Radio Resource Control (RRC) layer.

[0045] DL physical channels include Physical Broadcast Channel (PBCH), Physical Downlink Shared Channel (PDSCH), and Physical Downlink Control Channel (PDCCH). DL physical signals include DL Reference Signal (RS), Primary Synchronization Signal (PSS), and Secondary Synchronization Signal (SSS). DL RS includes Demodulation RS (DM-RS), Phase-tracking RS (PT-RS), and Channel-state information RS (CSI-RS). UL physical channels include Physical Random Access Channel (PRACH), Physical Uplink Shared Channel (PUSCH), and Physical Uplink Control Channel (PUCCH). UL physical signals include UL RS. UL RS includes DM-RS, PT-RS, and Sounding RS (SRS).

[0046] In the present invention, the base station may be, for example, a gNodeB.

[0047] Figure 3 illustrates the SSB structure. Based on SSB, a terminal can perform cell search, system information acquisition, beam alignment for initial access, and DL measurements. SSB is used interchangeably with the SS / PBCH (Synchronization Signal / Physical Broadcast channel) block.

[0048] Referring to Figure 3, SSB is composed of PSS, SSS, and PBCH. SSB is composed of four consecutive OFDM symbols, and PSS, PBCH, SSS / PBCH, and PBCH are transmitted for each OFDM symbol. PSS and SSS are each composed of one OFDM symbol and 127 subcarriers, and PBCH is composed of three OFDM symbols and 576 subcarriers. Polar coding and QPSK (Quadrature Phase Shift Keying) are applied to PBCH. PBCH is composed of data RE and DMRS (Demodulation Reference Signal) RE for each OFDM symbol. There are three DMRS REs for each RB, and three data REs exist between DMRS REs.

[0049] Referring to FIG. 4, the contention-based random access process includes the following four steps. Hereinafter, the messages transmitted in steps 1 to 4 may be referred to as messages (Msg) 1 to 4, respectively.

[0050] -Step 1: The terminal transmits a RACH preamble through PRACH.

[0051] -Step 2: The terminal receives a random access response (RAR) from the base station through the DL-SCH.

[0052] -Step 3: The terminal transmits a Layer 2 / Layer 3 message to the base station via UL-SCH.

[0053] -Step 4: The terminal receives a contention resolution message from the base station through the DL-SCH.

[0054] To reduce latency during the random access process, a random access process can be used. As illustrated in Figure 5, the two-step random access process can be comprised of two steps: transmitting an uplink signal (referred to as message A) from a terminal to a base station, and transmitting a downlink signal (referred to as message B) from the base station to the terminal.

[0055] NES (Network energy saving)

[0056] The contents discussed above can be applied in combination with the methods proposed in the present invention described below, or can be supplemented to clarify the technical features of the methods proposed in the present invention.

[0057] In addition, the methods described below can be equally applied to the NR system (licensed band) or shared spectrum described above, and the technical ideas proposed in this specification can be modified or replaced to fit the terms, expressions, structures, etc. defined in each system so that they can be implemented in the corresponding systems.

[0058] As higher data rates are demanded, base stations must be equipped with more antennas and provide services across wider bandwidths and frequency bands. Recent studies indicate that base station energy costs can reach as high as 20% of total operational expenditure (OPEX). To build eco-friendly networks by reducing carbon emissions and lowering operating expenses (OPEX) for telecommunications operators, energy conservation at base stations is a key consideration in wireless communication systems, including 3GPP.

[0059] This increased interest in base station energy savings led to the approval of a new study item in 3GPP NR release 18 called “study on network energy savings”, and the technologies specified in subsequent work items included SSB-less S-Cell operation for inter-band CA of FR1 and co-located cells, improvements to the Cell DTX / DRX mechanism including alignment of Cell DTX / DRX and UE DRX in RRC_CONNECTED mode, and inter-node information exchange of Cell DTX / DRX. It also includes spatial domain and power domain techniques that enable efficient adaptation of spatial elements, efficient adaptation of power values ​​between PDSCH and CSI-RS, mechanisms to prevent camping of legacy UEs in cells adopting Rel-18 NES technology, improvements to CHO procedures, inter-node beam activation and improvements to limit paging in limited areas, and corresponding RRM / RF core requirements.

[0060] Meanwhile, there are other technologies that have been identified as useful through research but are not yet specified in Rel-18. Rel-19 WI aims to adopt additional technologies that can achieve network energy savings, targeting beneficial techniques studied but not yet adopted in Rel-18, such as on-demand SSB and on-demand SIB1 transmission, and adaptation of common signaling / channel transmission.

[0061] The present invention proposes methods for achieving energy savings by allowing a base station to adjust SSB cycles and other parameters based on feedback from a terminal based on pre-configured conditions / resources from the base station. Furthermore, in a multi-carrier / cell configuration, methods are also proposed for conserving energy at the base station by adjusting SSBs based on feedback from the base station or from the terminal.

[0062] In the present invention, ' / ' means 'and / or'. For example, SSB index / SSB index group means SSB index and / or SSB index group.

[0063] [Method #1] A method of requesting SSB transmission control (e.g., period of SSB burst / SSB index / SSB index group) to the base station through a message transmitted by the terminal within the RACH procedure (i.e., message 1 / message 3 / message A) or a specific field / bit within the message.

[0064] A terminal can receive RACH resources for SSB transmission control from a base station through SIB1 for RACH (random access channel) configuration or terminal-specific RRC signaling. In this case, SSB transmission control can mean controlling the cycle of an SSB burst / SSB index / SSB index group or turning ON / OFF (or activating / deactivating) specific SSB settings / parameters.

[0065] PRACH resources for SSB transmission control can be configured to use specific RO / RAPID(s) among RO (random access channel occasion) / RAPID (random access preamble identifier) ​​for CBRA (contention based random access) or RO / RAPID configured for CFRA (contention free random access). This may mean that the terminal performs the random access procedure while also requesting SSB control.

[0066] Separate RO / RAPIDs for SSB transmission control may also be configured. RO / RAPIDs configured for SSB transmission control can be configured by the base station to associate each RO / RAPID with a specific SSB transmission control request. For example, a specific RAPID=60 may be preset / agreed to be a RAPID requesting to change the period of SSB index #1 to 40ms, and RAPID=61 may be preset / agreed to be a RAPID requesting to change the period of SSB index #1 to 80ms.

[0067] Meanwhile, the terminal can also request the base station to adjust SSB transmission through Message 3 or the PRACH / PUSCH of Message A. This may be similar to the method in which the terminal includes the RRCSystemInfoRequest message in Message 3 and transmits it in CBRA, one of the on-demand SI (system information) related procedures.

[0068] For example, if a terminal transmits a message including the 'SSB-periodicityadaptRequest' message in message 3 or message A, the base station may consider that the terminal has requested SSB transmission adjustment.

[0069] Alternatively, a terminal can request SSB transmission adjustment from the base station using a combination of Message 1 and Message 3 (or Message A PRACH and Message A PUSCH). For example, a terminal can request an SSB index (or SSB index group) using Message 1 and a specific period value using Message 3.

[0070] Certain fields / bits of existing Message 3 or Message A may be pre-configured / defined to indicate that a certain state requests SSB transmission control.

[0071] When a terminal transmits an SSB transmission control request signal (i.e., message 1 / message 3 / message A) in a specific beam direction, the SSB settings / parameters of the SSB burst / SSB index / SSB group linked to the beam direction may be controlled (period / pattern / activation / deactivation may be controlled).

[0072] When multiple SSB transmission related settings / parameters are set for a terminal, the terminal's message 1 / message 3 / message A can be used to request activation / deactivation of specific SSB settings / parameters. As an example of an SSB transmission related setting / parameter request operation, when a relatively long-period sparse SSB setting and a relatively short-period dense SSB setting are set for a terminal, the terminal / base station operates based on the sparse SSB setting in order to save energy of the base station, and when a shorter-period SSB is required due to reasons such as synchronization, measurement, cell selection / cell reselection, or access delay, the terminal can request the base station to activate the dense SSB setting through message 1 / message 3 / message A.

[0073] [Method #2] A method in which a terminal requests SSB transmission control (e.g., period of SSB burst / SSB index / SSB index group) using a specific UL signal / channel (PUCCH, SRS, CG-PUSCH, P-PUSCH, SP-PUSCH, P-PUCCH, SP-PUCCH, etc.)

[0074] In addition to Message 1 / Message 3 / Message A, the UE can use specific UL signals / channels, such as PUCCH, SRS, CG (configured grant)-PUSCH, periodic / semi-persistent PUCCH or PUSCH, to request SSB transmission modulation from the base station. Existing SR (scheduling request) PUCCH resources for receiving UL scheduling may be used to request SSB transmission modulation, or separate PUCCH resources for SSB transmission modulation may be configured. Alternatively, specific PUCCH resources among PUCCH resources configured for HARQ-ACK (hybrid automatic repeat request acknowledgment) transmission may be used to request SSB transmission modulation, or separate PUCCH resources for SSB modulation may be configured.

[0075] Different SSB indices (or SSB index groups) correspond to each SR PUCCH resource, and request information about the period and SSB index can be included through the PUSCH (or MAC-CE within the PUSCH) scheduled by the SR. Alternatively, the SR PUCCH can be used to notify that UL resources are needed for an SSB transmission control request, and request information about the actual period and SSB index (or SSB index group) can be included in the PUSCH (or MAC-CE within the PUSCH) scheduled through the SR.

[0076] The pre-configured SRS resources of the UE may be used for the SSB throttling request, or separate SRS resources may be configured for the SSB throttling request. In the case of CG-PUSCH, an SSB transmission throttling message may be directly included in the PUSCH payload. Alternatively, in the case of CG-PUSCH (for unlicensed bands), SSB transmission throttling may be requested (additionally) through specific fields / bits in the CG-UCI that are always multiplexed and transmitted together with the CG-PUSCH. Alternatively, if the UE is configured with UTO-UCI (unused transmission occasion(s) indicated by uplink control information), SSB transmission throttling may be requested to the base station by configuring and transmitting specific fields / bits in the UTO-UCI in a specific state.

[0077] In case of P (periodic)-PUSCH / SP (semi-persistent)-PUSCH / P-PUCCH / SP-PUCCH, an SSB transmission throttling message can be directly included in the payload of a PUSCH / PUCCH (e.g., CSI report) configured to be transmitted periodically or semi-persistently. Since an SSB transmission throttling request is not required for every P-PUSCH / SP-PUSCH / P-PUCCH / SP-PUCCH opportunity, if the UE has nothing to request, it can indicate that there is nothing to transmit by using another UL signal / channel (e.g., SRS / PRACH) located before the opportunity. If an SSB transmission throttling request can be transmitted together with a CSI report, the UE can indicate whether there is an SSB transmission request by using a specific field in CSI Part 1. Rather than transmission being performed at every opportunity on the P-PUSCH / SP-PUSCH / P-PUCCH / SP-PUCCH resources configured for SSB throttling request, an SSB transmission request can be triggered through a specific resource (or opportunity) among the configured resources only when a specific condition (e.g., when the number of SSBs exceeding a threshold is X or more, where X can be configured in advance) is satisfied.

[0078] When SSB transmission control is requested through a specific PUCCH, SRS, CG-PUSCH, P-PUSCH, SP-PUSCH, P-PUCCH, SP-PUCCH itself or a specific field / bit, the period of a specific UL signal / channel and a specific SSB burst / SSB index / SSB index group is set in advance, so that when a specific UL signal / channel is received by the base station, it can be interpreted that transmission control of the linked SSB has been requested.

[0079] For example, if a terminal is configured with only one SRS for SSB transmission control (default SSB is set / promised to 20ms in advance and linked with SRS resources), the terminal's transmission of that SRS can be implicitly interpreted as a request to the base station to fallback the transmission period of the SSB burst to the transmission period of the default SSB.

[0080] Different SSB transmission periods may be set and linked for each of multiple SRS resource sets set for the terminal or each of multiple SRS resource indexes within the SRS resource set, and pre-linked SSB transmission adjustment may be requested according to the SRS resource set or SRS resource index of the SRS transmitted by the terminal.

[0081] When a terminal transmits a specific UL signal / channel for SSB transmission control request in a specific beam direction, the SSB settings / parameters of the SSB burst / SSB index / SSB index group linked to the beam direction may be controlled (cycle / pattern / activation / deactivation controlled).

[0082] When multiple SSB transmission related settings / parameters are set, specific UL signals / channels of the terminal can be used to request activation / deactivation of specific SSB settings / parameters. As an example of a request operation for SSB transmission related settings / parameters, when a sparse SSB setting with a relatively long period and a dense SSB setting with a relatively short period are set for the terminal, the terminal / base station operates based on the sparse SSB setting in order to save energy of the base station, and when an SSB with a shorter period is required due to reasons such as synchronization, measurement, cell selection / cell reselection, or access delay, the terminal can request the base station to activate the dense SSB setting through specific UL signals / channels.

[0083] [Method #3] When a terminal requests SSB transmission control through a specific UL signal / channel that has been set / promised in advance, the base station's response procedure / method and SSB transmission / reception method

[0084] Even if the terminal requests the base station to adjust SSB transmission through the above methods #1 and #2, the actual SSB transmission adjustment may be determined by the judgment / implementation of the base station. In other words, even if the base station receives a pre-arranged / defined SSB transmission adjustment request from the terminal, the base station may ignore the request and transmit SSB as before. In addition, after requesting SSB transmission adjustment to the base station, the terminal must confirm whether the request has been properly delivered to the base station through a response (e.g., ACK) in order to expect SSB reception of the changed cycle. Therefore, in this proposed method, when the terminal requests SSB transmission adjustment, we propose a response procedure / method of the base station and an SSB transmission / reception method between the base station and the terminal.

[0085] First, if the terminal uses message 1 / message 3 / message A for SSB transmission control, the base station can respond by sending RAR (random access response) / message 4 / message B to confirm whether it has properly received the terminal's SSB control request.

[0086] When a terminal requests SSB transmission control through a specific RAPID as in Method #1, the terminal can determine that the SSB transmission control request is successful if the RAPID it transmitted is included in the RAR sent by the base station. The terminal can expect that SSB will be transmitted with a changed transmission cycle after a pre-configured / promised time (e.g., T ms / slot) from the time of receiving the RAR (or during a certain time window from that time), or that a specific SSB setting / parameter will be activated / deactivated, and can receive the SSB.

[0087] When the terminal uses Message 3 / Message A, the base station notifies the terminal whether it has properly received the terminal's SSB transmission adjustment request through Message 4 / Message B (or a specific field / bit included in the message). The terminal can expect SSB to be transmitted at a changed transmission cycle after a pre-configured / promised time from the time of receiving Message 4 / Message B, or expect that a specific SSB setting / parameter is activated / deactivated, and can receive SSB.

[0088] The base station's response message (RAR / Message 4 / Message B) may contain information about the SSB transmission to be changed (e.g., one of the pre-configured period candidate indices of the SSB burst), or may contain an activation / deactivation instruction for the SSB settings / parameters.

[0089] When a terminal uses a specific UL signal / channel such as method #2 for SSB transmission modulation, the base station can directly indicate the SSB period or SSB configuration / parameter to be changed by transmitting GC (group-common)-DCI or MAC-CE to respond to the terminal whether or not an SSB modulation request has been received. At the same time, the base station can directly indicate the SSB period or SSB configuration / parameter to be changed. The terminal can expect that the SSB will be transmitted with the changed transmission period or that the specific SSB configuration / parameter will be activated / deactivated after a pre-configured / agreed time (e.g., T ms / slot) from the time of receiving the GC-DCI or MAC-CE (or during a certain time window from the time point). In addition, the GC-DCI or MAC-CE transmitted by the base station can include information about the SSB transmission to be changed (e.g., one of the pre-configured SSB burst period candidate indices), or an activation / deactivation instruction and a change time point for the SSB configuration / parameter (one of the pre-agreed time point candidate indices) can be included.

[0090] If a cell where a UE is camped on is currently operating on-demand SSB / SIB1, and the UE has been configured with a UL signal / channel for an SSB / SIB1 request, 1) if the base station is already transmitting SSB / SIB1 and the UE transmits a UL signal / channel for an SSB / SIB1 transmission request, the UL signal / channel may be interpreted as a SSB transmission adjustment request or a request for activation / deactivation of SSB configuration / parameters, and 2) the UE may utilize the UL signal / channel for the SSB / SIB1 transmission request to request SSB period adjustment or activation / deactivation of SSB configuration / parameters together. A request field for SSB period adjustment and / or a request field for activation / deactivation of SSB configuration / parameters may be added to the UL signal / channel. If there are multiple SSB periods, the request field for SSB period adjustment may indicate an index corresponding to a specific period.

[0091] Meanwhile, the present invention is not limited to the transmission and reception of uplink and / or downlink signals. For example, the present invention can also be used in direct communication between terminals. Furthermore, the base station in the present invention may include not only a base station but also a relay node. For example, the base station operations in the present invention may be performed by the base station, but may also be performed by a relay node.

[0092] It is clear that the examples of the proposed methods described above can also be considered as a type of proposed methods, as they can be included as one of the implementation methods of the present invention. In addition, the proposed methods described above can be implemented independently, but can also be implemented in the form of a combination (or merge) of some of the proposed methods. Information on whether the proposed methods are applicable (or information on the rules of the proposed methods) can be defined by a rule so that the base station notifies the terminal or the transmitting terminal notifies the receiving terminal through a predefined signal (e.g., a physical layer signal or a higher layer signal).

[0093] Implementation example

[0094] Figure 6 is a flowchart of a signal transmission and reception method according to one embodiment of the present invention.

[0095] FIG. 6 is an example of a combination of some steps of FIG. 4 and / or FIG. 5 and one or more of Methods #1 to #3, and the operation for combining with one or more of Methods #1 to #3 may be an operation corresponding to part or all of FIG. 4 and / or FIG. 5 in addition to the operation of FIG. 6. Instead of the operation corresponding to part or all of FIG. 4 and / or FIG. 5, an operation of setting / scheduling a specific UL signal / channel of Method #2 may be combined with the operation of Method #2 and / or Method #3.

[0096] Referring to FIG. 6, a signal transmission and reception method according to an embodiment of the present invention may be performed by a terminal and may be configured to include a step (S501) of transmitting a PRACH in a specific RO, and a step (S503) of receiving an RAR based on the PRACH. A signal transmission and reception method from a base station perspective according to an embodiment of the present invention may be configured to include a step (S501) of receiving a PRACH in a specific RO, and a step (S503) of transmitting an RAR based on the PRACH.

[0097] In addition to the operation of FIG. 6, one or more of the operations described through Method #1 to Method #3 may be performed.

[0098] For example, referring to method #1, SSB transmission control may be requested through a specific RO through which a PRACH transmitted in message 1 or message A of a random access process is transmitted. The request (or request for SSB configuration) includes at least one of a request for changing the period of SSB related to the SSB configuration and a request for activating the SSB configuration.

[0099] ROs for PRACH transmission are divided into a first set of ROs associated with SSB requests and a second set not associated with SSB configurations. ROs in the first set of ROs may contain requests with different content based on their respective resource locations. Since the RAPID associated with a PRACH varies depending on the resource location of the RO, each RAPID contains requests with different content.

[0100] The content of the request for SSB configuration may be determined based on the combination of the RO in which the PRACH is transmitted and the PUSCH transmitted in Message 3 or Message A. The SSB configuration whose period, etc., is changed or activated / deactivated by the request may be an SSB configuration associated with the beam direction in which the PRACH is transmitted.

[0101] A request for SSB configuration may be a request to activate a second SSB configuration (dense SSB configuration) in addition to the previously activated first SSB configuration (sparse SSB configuration).

[0102] Referring to Method #3, a RAR corresponding to a PRACH transmitted via the RO can be received. If the RAR includes a RAPID corresponding to the transmitted RO, the terminal determines that the SSB configuration has been changed by the request transmitted by the RO. The change in SSB configuration may be applied some time after the RAR is received.

[0103] Examples of communication systems to which the present invention is applied

[0104] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts of the present invention disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0105] Hereinafter, more specific examples will be provided with reference to the drawings. In the drawings / descriptions below, the same drawing reference numerals may represent identical or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise described.

[0106] Figure 7 illustrates a communication system (1) applied to the present invention.

[0107] Referring to FIG. 7, a communication system (1) applied to the present invention includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0108] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0109] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or, D2D communication), and communication between base stations (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present invention.

[0110] Examples of wireless devices to which the present invention is applied

[0111] Figure 8 illustrates a wireless device applicable to the present invention.

[0112] Referring to FIG. 8, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the base station (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 7.

[0113] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0114] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0115] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0116] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0117] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0118] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0119] Examples of wireless devices to which the present invention is applied

[0120] Figure 9 illustrates another example of a wireless device applicable to the present invention. The wireless device may be implemented in various forms depending on the use case / service (see Figure 7).

[0121] Referring to FIG. 9, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 8 and may be composed of various elements, components, units / units, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 8. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 8. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0122] The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 7, 100a), a vehicle (Fig. 7, 100b-1, 100b-2), an XR device (Fig. 7, 100c), a portable device (Fig. 7, 100d), a home appliance (Fig. 7, 100e), an IoT device (Fig. 7, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 7, 400), a base station (Fig. 7, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0123] In FIG. 9, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and a first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of a set of one or more processors. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and / or a combination thereof.

[0124] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0125] Figure 10 illustrates a vehicle or autonomous vehicle applicable to the present invention. The vehicle or autonomous vehicle may be implemented as a mobile robot, a car, a train, a manned or unmanned aerial vehicle (AV), a ship, or the like.

[0126] Referring to FIG. 10, a vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a driving unit (140a), a power supply unit (140b), a sensor unit (140c), and an autonomous driving unit (140d). The antenna unit (108) may be configured as a part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 8, respectively.

[0127] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, road side units, etc.), and servers. The control unit (120) can control elements of the vehicle or autonomous vehicle (100) to perform various operations. The control unit (120) can include an ECU (Electronic Control Unit). The drive unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The drive unit (140a) can include an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and can include a wired / wireless charging circuit, a battery, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an incline sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement a technology for maintaining a driving lane, a technology for automatically controlling speed such as adaptive cruise control, a technology for automatically driving along a set path, a technology for automatically setting a path and driving when a destination is set, etc.

[0128] For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving route and driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or autonomous vehicle (100) moves along the autonomous driving route according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can irregularly / periodically acquire the latest traffic information data from an external server and can acquire surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving route and driving plan based on newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving route, driving plan, etc. to the external server. External servers can predict traffic information data in advance using AI technology or other technologies based on information collected from vehicles or autonomous vehicles, and provide the predicted traffic information data to the vehicles or autonomous vehicles.

[0129] It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the scope of the invention. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present invention are intended to be included within the scope of the present invention.

[0130] As described above, the present invention can be applied to various wireless communication systems.

Claims

1. In a method performed by a terminal in a wireless communication system, Steps for transmitting a physical random access channel (PRACH) at a specific random access channel occasion (RO): and A step of receiving a random access response (RAR) based on the above PRACH; The above specific RO is associated with a request for SSB (synchronization signal / physical broadcast channel block) setup. method.

2. In paragraph 1, The above specific RO is one of the ROs available for the random access process, The ROs available for the above random access process are divided into a first set of ROs associated with a request for SSB setup and a second set not associated with a request for SSB setup. method.

3. In paragraph 1, The request includes at least one of a request for changing the period of the SSB related to the SSB setting and a request for activating the SSB setting. method.

4. In paragraph 1, The content of the request transmitted by the terminal is determined based on the resource location of the specific RO. method.

5. In paragraph 1, Based on the RAPID determined by the above specific RO, the content of the request is determined, method.

6. In paragraph 5, Based on the above RAR including the RAPID, the terminal determines that the SSB setting has been changed by the request. method.

7. In paragraph 6, SSB is received based on the changed SSB setting after a certain point in time from the time the above RAR is received. method.

8. In paragraph 1, The content of the request is determined based on the combination of the PUSCH transmitted within the above specific RO and random access process. method.

9. In paragraph 1, The above SSB setting is an SSB setting associated with the beam direction in which the PRACH is transmitted. method.

10. In paragraph 1, The request for the above SSB setting is a request to activate the second SSB setting in addition to the previously activated first SSB setting. method.

11. In a terminal operating in a wireless communication system, At least one transceiver; at least one processor; and At least one memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform a specific operation; The above specific actions are: Steps for transmitting a physical random access channel (PRACH) at a specific random access channel occasion (RO): and A step of receiving a random access response (RAR) based on the above PRACH; The above specific RO is associated with a request for SSB (synchronization signal / physical broadcast channel block) setup. Terminal.

12. In a device for a terminal, at least one processor; and At least one computer memory operably connected to said at least one processor and configured to, when executed, cause said at least one processor to perform operations, said operations comprising: Steps for transmitting a physical random access channel (PRACH) at a specific random access channel occasion (RO): and A step of receiving a random access response (RAR) based on the above PRACH; The above specific RO is associated with a request for SSB (synchronization signal / physical broadcast channel block) setup. device.

13. A computer-readable non-volatile storage medium comprising at least one computer program that causes a terminal including at least one processor to perform an operation, the operation comprising: Steps for transmitting a physical random access channel (PRACH) at a specific random access channel occasion (RO): and A step of receiving a random access response (RAR) based on the above PRACH; The above specific RO is associated with a request for SSB (synchronization signal / physical broadcast channel block) setup. Storage media.

14. In a method performed by a base station in a wireless communication system, Steps for receiving a PRACH (physical random access channel) at a specific RO (random access channel occasion): and A step of transmitting a random access response (RAR) based on the above PRACH; The above specific RO is associated with a request for SSB (synchronization signal / physical broadcast channel block) setup. method.

15. In a base station operating in a wireless communication system, At least one transceiver; at least one processor; and At least one memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform a specific operation; The above specific actions are: Steps for receiving a PRACH (physical random access channel) at a specific RO (random access channel occasion): and A step of transmitting a random access response (RAR) based on the above PRACH; The above specific RO is associated with a request for SSB (synchronization signal / physical broadcast channel block) setup. Base station.

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