Method performed by user equipment, user equipment, processing device and storage medium, and method performed by base station and base station

Abstract

This UE receives DCI including change information about a periodicity for reception of SSBs on a first cell, and starts, from a first half frame within a first frame of a first SFN on the first cell, reception of SSBs according to the periodicity indicated through the DCI. The first frame is within a first frame set for the indicated periodicity, the first frame set for the indicated periodicity has a first SFN offset value associated with the indicated periodicity, relative to SFN 0, the first half frame is within a set of half frames having a first half frame index value associated with the indicated periodicity, and the reception of the SSBs according to the indicated periodicity does not start before a second time unit that is after a predetermined offset after a first time unit in which the DCI is received.

Description

A method performed by a user device, a user device, a processing device and a storage medium, and a method performed by a base station and a base station

[0001] This specification relates to a wireless communication system.

[0002] Various devices and technologies, such as machine-to-machine (M2M) communication, machine type communication (MTC), and devices requiring high data transmission rates like smartphones and tablet PCs (Personal Computers), are emerging and becoming widespread. Consequently, the amount of data required to be processed in cellular networks is increasing very rapidly. To satisfy this rapidly increasing demand for data processing, technologies such as carrier aggregation and cognitive radio are being developed to efficiently utilize more frequency bands, while technologies such as multi-antenna technology and multi-BS cooperation are being developed to increase the data capacity transmitted within a limited frequency range.

[0003] As more communication devices require greater communication capacity, the need for enhanced mobile broadband (eMBB) communication is emerging compared to legacy radio access technology (RAT). In addition, massive machine type communication (mMTC), which connects multiple devices and objects to provide various services anytime and anywhere, is one of the key issues to consider in next-generation communication.

[0004] In addition, discussions are underway regarding communication systems to be designed with user equipment (UE) in mind, which is sensitive to reliability and latency. The introduction of next-generation wireless access technologies is being discussed with consideration of eMBB communication, mMTC, and ultra-reliable and low-latency communication (URLLC).

[0005] As the number of services and UEs that the network must support increases rapidly, the need for energy conservation in the network, as well as power conservation in the UEs, is gradually growing.

[0006] One technical objective of this specification is to provide methods and processes for network energy conservation.

[0007] Another technical objective of this specification is to provide methods and processes for transmitting / controlling downlink / uplink signals to enable network energy saving.

[0008] The technical problems that this specification aims to solve are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art related to this specification from the detailed description below.

[0009] In one aspect of the present specification, a method by means of a user device is provided. In another aspect of the present specification, a user device is provided comprising at least one transceiver; at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations. In yet another aspect of the present specification, a processing device is provided comprising at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations. In yet another aspect of the present specification, a computer-readable non-transitory storage medium is provided for storing at least one program code that includes instructions that, when executed, cause the at least one processor to perform operations. The above method or above operations may include: receiving a synchronization signal block (SSB) adaptation setting for a first cell, said SSB adaptation setting including at least one additional SSB burst periodicity; receiving downlink control information including change information for periodicity for receiving SSBs on the first cell; and expecting to start receiving SSBs according to the period indicated by the downlink control information in a first half frame within a first frame of a first system frame number (SFN) on the first cell.

[0010] In one aspect of the present specification, a method by a base station is provided. In another aspect of the present specification, a BS is provided comprising at least one transceiver; at least one processor; and at least one computer memory operably connectable to the at least one processor and, when executed, stores instructions that cause the at least one processor to perform operations. The method or the operations may include: transmitting a synchronization signal block (SSB) adaptation setting for a first cell, wherein the SSB adaptation setting includes at least one additional SSB burst periodicity; transmitting downlink control information including change information for a periodicity for transmitting SSBs on the first cell; and initiating the transmission of SSBs according to the periodicity indicated by the downlink control information in a first half frame within a first frame of a first system frame number (SFN) on the first cell.

[0011] In each aspect of the specification, the first frame is within a first frame set for the indicated period, the first frame set for the indicated period has a first SFN offset value associated with the indicated period relative to SFN 0, the first half frame is within a set of half frames having a first half frame index value associated with the indicated period, and the transmission / reception of SSBs according to the indicated period does not begin before a second time unit after a predetermined offset after a first time unit after the downlink control information is transmitted / received.

[0012] In each aspect of the present specification, the at least one additional SSB burst cycle may include a first additional SSB burst cycle and a second additional SSB burst cycle that is larger than the first additional SSB burst cycle.

[0013] In each aspect of the specification, the SSB periods of the second additional SSB burst cycle may be a subset of the SSB periods of the first additional SSB burst cycle.

[0014] In each aspect of this specification, the SSB adaptation-related setting may include an SFN offset value for each additional SSB burst cycle.

[0015] In each aspect of this specification, the SSB adaptation-related setting may include a half-frame index value for each additional SSB burst cycle.

[0016] In each aspect of this specification, the predetermined offset may be a predetermined value.

[0017] In each aspect of the specification, the first frame may be a frame in which the candidate SSB time associated with the first transmitted SSB provided by the upper layer parameter ssb-PositionsInBurst among the frames in the first frame set is after the second time unit.

[0018] The above-mentioned problem-solving methods are merely some of the examples of this specification, and various examples reflecting the technical features of this specification can be derived and understood by a person with ordinary knowledge in the relevant technical field based on the detailed description below.

[0019] According to some implementations of this specification, methods and procedures for energy saving of networks, BS and / or UEs may be provided.

[0020] According to some implementations of this specification, methods and procedures for transmitting / controlling downlink / uplink signals can be provided to enable energy saving of the network, BS and / or UE.

[0021] The effects of this specification are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art related to this specification from the detailed description below.

[0022] The attached drawings, included as part of the detailed description to aid in understanding the implementations of this specification, provide examples of the implementations of this specification and describe the implementations of this specification together with the detailed description:

[0023] FIG. 1 illustrates an example of a communication system 1 to which the implementations of the present specification are applied;

[0024] FIG. 2 is a block diagram illustrating examples of communication devices capable of performing the method according to the present specification;

[0025] FIG. 3 illustrates another example of a wireless device capable of performing implementation(s) of the present specification;

[0026] FIG. 4 illustrates an example of a frame structure available in a 3rd generation partnership project (3GPP)-based wireless communication system;

[0027] FIG. 5 illustrates a resource grid of slots;

[0028] FIG. 6 illustrates physical channels used in a 3rd generation partnership project (3GPP)-based communication system, which is an example of a wireless communication system, and the signal transmission / reception process using them;

[0029] FIG. 7 illustrates synchronization signal (SS) / physical broadcast channel (PBCH) blocks (SSB) on a cell.

[0030] FIG. 8 is illustrated to explain the bitmaps used to indicate the SSBs actually being transmitted;

[0031] FIG. 9 illustrates the process of acquiring system information (SI);

[0032] FIG. 10 illustrates an arbitrary connection process that may be applied to the implementation(s) of the present specification;

[0033] FIG. 11 illustrates an example of time-domain resource allocation of a physical downlink shared channel (PDSCH) by a physical downlink control channel (PDCCH) and an example of time-domain resource allocation of a physical uplink shared channel (PUSCH) by a PDCCH;

[0034] FIG. 12 illustrates an operation procedure in a BS that supports network energy saving (NES) technology;

[0035] FIG. 13 is an example of a procedure for carrier aggregation (CA) operation using an SSB-less secondary cell (SCell);

[0036] FIGS. 14 through 16 illustrate custom SIB1 transmission scenarios related to some implementations of the present specification;

[0037] FIG. 17 illustrates adaptation to a RACH occasion (RO);

[0038] FIGS. 18 through 20 are examples of SSB adaptations according to some implementations of the present specification;

[0039] FIGS. 21 through 23 are other examples of SSB adaptations according to some implementations of the present specification;

[0040] FIGS. 24 and 25 are other examples of SSB adaptations according to some implementations of the present specification;

[0041] FIG. 26 illustrates the flow of downlink (DL) signal reception in a UE according to some implementations of the present specification;

[0042] FIG. 27 illustrates the flow of downlink (DL) signal transmission in a BS according to some implementations of the present specification;

[0043] FIG. 28 illustrates the signal transmission / reception flow between a UE and a network according to some implementations of the present specification.

[0044] Implementations according to this specification are described below with reference to the accompanying drawings. The detailed description disclosed below, together with the accompanying drawings, is intended to describe exemplary implementations of this specification and is not intended to represent the only form in which this specification may be practiced. The detailed description below includes specific details to provide a complete understanding of this specification. However, a person skilled in the art will know that this specification may be practiced without such specific details.

[0045] In some cases, to avoid ambiguity regarding the concepts of this specification, known structures and devices may be omitted or depicted in the form of block diagrams focusing on the core functions of each structure and device. Additionally, the same reference numerals are used to describe identical components throughout this specification.

[0046] In this specification, "A or B" may mean "only A," "only B," or "both A and B." Alternatively, in this specification, "A or B" may be interpreted as "A and / or B." For example, in this specification, "A, B or C" may mean "only A," "only B," "only C," or "any combination of A, B and C."

[0047] A slash ( / ) or comma used in this specification may mean "and / or." For example, "A / B" may mean "A and / or B." Accordingly, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B or C."

[0048] In this specification, "at least one of A and B" may mean "only A," "only B," or "both A and B." Additionally, in this specification, the expressions "at least one of A or B" or "at least one of A and / or B" may be interpreted as synonymous with "at least one of A and B."

[0049] Additionally, in this specification, "at least one of A, B and C" may mean "only A," "only B," "only C," or "any combination of A, B and C." Also, "at least one of A, B or C" or "at least one of A, B and / or C" may mean "at least one of A, B and C."

[0050] In addition, terms such as "first," "second," etc. in this specification are used solely for the purpose of distinguishing one component from another and are not used to limit the components, nor do they limit the order or importance of the components unless specifically limited. Accordingly, the first component in one embodiment of this specification may be referred to as the second component in another embodiment, and likewise, the second component in one embodiment may be referred to as the first component in another embodiment.

[0051] In the following explanation, 'when, if, in case of' can be replaced with 'based on'.

[0052] In this specification, information / status / parameters being "configured or pre-configured" may be interpreted as information / status / parameters being provided or pre-provided to the UE through pre-defined signaling from the BS (e.g., system information block (SIB), medium access control (MAC), radio resource control (RRC)). In this specification, information / status / parameters being "defined or pre-defined" may be interpreted as information / status / parameters being known or stored in advance by the BS and the UE without signaling between the base station and the UE.

[0053] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously.

[0054] The techniques, devices, and systems described below can be applied to various wireless multiple access systems. Examples of multiple access systems include CDMA (code division multiple access) systems, FDMA (frequency division multiple access) systems, TDMA (time division multiple access) systems, OFDMA (orthogonal frequency division multiple access) systems, SC-FDMA (single carrier frequency division multiple access) systems, and MC-FDMA (multi carrier frequency division multiple access) systems. CDMA can be implemented in wireless technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented in wireless technologies such as GSM (Global System for Mobile communication), GPRS (General Packet Radio Service), and EDGE (Enhanced Data Rates for GSM Evolution) (i.e., GERAN). OFDMA can be implemented in wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved-UTRA). UTRA is part of UMTS (Universal Mobile Telecommunication System), and 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is part of E-UMTS that utilizes E-UTRA.3GPP LTE adopts OFDMA for the downlink (DL) and SC-FDMA for the uplink (UL). LTE-A (LTE-advanced) is an evolved form of 3GPP LTE.

[0055] For the convenience of explanation, the following description assumes that this specification applies to 3GPP-based communication systems, such as LTE and NR. However, the technical features of this specification are not limited thereto. For example, even though the following detailed description is based on a mobile communication system corresponding to a 3GPP LTE / NR system, it may be applied to any other mobile communication system, except for matters specific to 3GPP LTE / NR.

[0056] For terms and technologies used in this specification that are not specifically described, refer to 3GPP-based standard documents, e.g., 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321, 3GPP TS 36.300, and 3GPP TS 36.331, 3GPP TS 37.213, 3GPP TS 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.214, 3GPP TS 38.215, 3GPP TS 38.300, 3GPP TS 38.304, 3GPP TS 38.321, 3GPP TS You may refer to 38.322, 3GPP TS 38.323, 3GPP TS 38.331, etc.

[0057] In the examples of this specification described below, the expression that the device "assumes" may mean that the entity transmitting the channel transmits the channel in accordance with said "assume." It may mean that the entity receiving the channel receives or decodes the channel in a form that conforms to said "assume," under the premise that the channel was transmitted in accordance with said "assume."

[0058] In this specification, UEs may be fixed or mobile and include various devices that communicate with a base station (BS) to transmit and / or receive user data and / or various control information. A UE may be referred to as Terminal Equipment, Mobile Station (MS), Mobile Terminal (MT), User Terminal (UT), Subscribe Station (SS), wireless device, Personal Digital Assistant (PDA), wireless modem, handheld device, etc. Additionally, in this specification, a BS generally refers to a fixed station that communicates with a UE and / or other BSs, and exchanges various data and control information by communicating with a UE and other BSs. A BS may be referred to by other terms such as Advanced Base Station (ABS), Node-B (NB), eNB (evolved-NodeB), Base Transceiver System (BTS), Access Point, Processing Server (PS), etc. In particular, BSs of UTRAN are called Node-Bs, BSs of E-UTRAN are called eNBs, and BSs of new radio access technology networks are called gNBs. For convenience of explanation, BSs will be collectively referred to as BSs regardless of the type or version of the communication technology.

[0059] In this specification, a node refers to a fixed point capable of transmitting or receiving wireless signals by communicating with a UE. Various types of BSs may be used as nodes regardless of their designation. For example, a BS, NB, eNB, pico-cell eNB (PeNB), home eNB (HeNB), relay, repeater, etc., may serve as a node. Additionally, a node does not have to be a BS. For example, it may be a radio remote head (RRH) or a radio remote unit (RRU). RRHs, RRUs, etc. generally have a power level lower than that of a BS. Since an RRH or RRU (or RRH / RRU) is generally connected to a BS via a dedicated line such as an optical cable, cooperative communication between an RRH / RRU and a BS can be performed more smoothly compared to cooperative communication between BSs connected via wireless lines. At least one antenna is installed at a node. This antenna may refer to a physical antenna, an antenna port, a virtual antenna, or an antenna group. Nodes are also referred to as points.

[0060] In this specification, the term "cell" refers to a specific geographical area where one or more nodes provide communication services. Accordingly, in this specification, communicating with a specific cell may mean communicating with a BS or node that provides communication services to said specific cell. Furthermore, the downlink / uplink signals of a specific cell refer to downlink / uplink signals from to or to the BS or node that provides communication services to said specific cell. A cell that provides uplink / downlink communication services to a UE is specifically referred to as a serving cell. Additionally, the channel state / quality of a specific cell refers to the channel state / quality of the channel or communication link formed between the BS or node providing communication services to said specific cell and the UE. In a 3GPP-based communication system, a UE can measure the downlink channel state from a specific node using the CRS(s) transmitted by the antenna port(s) of the specific node over the CRS (Cell-specific Reference Signal) resource assigned to the specific node and / or the CSI-RS(s) transmitted over the CSI-RS (Channel State Information Reference Signal) resource.

[0061] Meanwhile, 3GPP-based communication systems use the concept of a cell to manage wireless resources, and a cell associated with wireless resources is distinguished from a cell in a geographical area.

[0062] A “cell” of a geographical area can be understood as the coverage over which a node can provide services using a carrier wave, and a “cell” of a wireless resource is associated with the bandwidth (BW), which is the frequency range configured by said carrier wave. Since downlink coverage, which is the range over which a node can transmit a valid signal, and uplink coverage, which is the range over which a valid signal can be received from a UE, depend on the carrier wave carrying the signal, the coverage of a node is also associated with the coverage of the “cell” of the wireless resource used by said node. Therefore, the term “cell” can be used to refer sometimes to the coverage of a service by a node, sometimes to a wireless resource, and sometimes to the range over which a signal using said wireless resource can reach with effective strength.

[0063] Meanwhile, 3GPP communication standards use the concept of a cell to manage radio resources. A "cell" associated with radio resources is defined as a combination of downlink resources (DL resources) and uplink resources (UL resources), that is, a combination of a DL component carrier (CC) and a UL CC. A cell can be configured as a DL resource alone or as a combination of a DL resource and a UL resource. Where carrier aggregation is supported, the linkage between the carrier frequency of a DL resource (or DL ​​CC) and the carrier frequency of a UL resource (or UL CC) can be indicated by system information. For example, the combination of DL resources and UL resources can be indicated by a System Information Block Type 2 (SIB2) linkage. Here, the carrier frequency may be equal to or different from the center frequency of each cell or CC. When Carrier Aggregation (CA) is established, the UE has only one Radio Resource Control (RRC) connection with the network. One serving cell provides Non-Access Stratum (NAS) mobility information during RRC establishment / re-establishment / handover, and one serving cell provides security input during RRC re-establishment / handover. This cell is called a primary cell (Pcell). A Pcell is a cell operating on the primary frequency where the UE performs the initial connection establishment procedure or initiates the connection re-establishment procedure.Depending on the UE capability, secondary cells (Scells) can be configured to form a set of serving cells together with Pcells. Scells can be configured after a Radio Resource Control (RRC) connection is established and are cells that provide additional radio resources in addition to the resources of special cells (SpCells). The carrier corresponding to a Pcell in the downlink is called the Downlink Primary CC (DL PCC), and the carrier corresponding to a Pcell in the uplink is called the UL Primary CC (UL PCC). The carrier corresponding to an Scell ​​in the downlink is called the DL Secondary CC (DL SCC), and the carrier corresponding to the Scell ​​in the uplink is called the UL Secondary CC (UL SCC).

[0064] In a UE where CA is configured and DC is not configured, a Pcell PUCCH group (also referred to as a primary PUCCH group) consisting of a Pcell and zero or more Scells, and an Scell ​​PUCCH group (also referred to as a secondary PUCCH group) consisting only of Scell(s) may be configured. In the case of an Scell, an Scell ​​(hereinafter referred to as a PUCCH Scell) to which a PUCCH associated with that cell is transmitted may be configured. An Scell ​​designated as a PUCCH Scell ​​belongs to the Scell ​​PUCCH group (i.e., secondary PUCCH group), and the PUCCH transmission of the associated UCI is performed on the said PUCCH Scell; an Scell ​​that is not designated as a PUCCH Scell, or an Scell ​​in which the cell designated as a PUCCH transmission cell is a Pcell, belongs to the Pcell PUCCH group (i.e., primary PUCCH group), and the PUCCH transmission of the associated UCI is performed on the said Pcell. In the following, if the UE is configured with an SCG and some implementations of this specification related to PUCCH apply to the SCG, the primary cell may refer to the PSCell of the SCG. If the UE is configured with a PUCCH Scell ​​and some implementations of this specification related to PUCCH apply to a secondary PUCCH group, the primary cell may refer to the PUCCH Scell ​​of the secondary PUCCH group.

[0065] In a wireless communication system, the UE receives information from the BS via the downlink (DL) and transmits information to the BS via the uplink (UL). The information transmitted and / or received by the BS and the UE includes data and various control information, and various physical channels exist depending on the type and purpose of the information they transmit and / or receive.

[0066] 3GPP-based communication standards define downlink physical channels corresponding to resource elements that carry information originating from upper layers, and downlink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from upper layers. For example, the physical downlink shared channel (PDSCH), physical broadcast channel (PBCH), and physical downlink control channel (PDCCH) are defined as downlink physical channels, while the reference signal and synchronization signal are defined as downlink physical signals. The reference signal (RS), also referred to as a pilot, refers to a signal of a specific, predefined waveform known to both the BS and the UE. For example, the demodulation reference signal (DMRS), channel state information RS (CSI-RS), and positioning reference signal (PRS) are defined as downlink reference signals. 3GPP-based communication standards define uplink physical channels corresponding to resource elements that carry information originating from upper layers, and uplink physical signals corresponding to resource elements that are used by the physical layer but do not carry information originating from upper layers.For example, the physical uplink shared channel (PUSCH), physical uplink control channel (PCCH), and physical random access channel (PRACH) are defined as uplink physical channels, and the demodulation reference signal (DMRS) for uplink control / data signals and the sounding reference signal (SRS) used for uplink channel measurement are defined.

[0067] In this specification, PDCCH (Physical Downlink Control Channel) refers to a set of time-frequency resources (e.g., resource elements (REs)) carrying DCI (Downlink Control Information), and PDSCH (Physical Downlink Shared Channel) refers to a set of time-frequency resources carrying downlink data. Additionally, PUCCH (Physical Uplink Control Channel), PUSCH (Physical Uplink Shared Channel), and PRACH (Physical Random Access Channel) respectively refer to sets of time-frequency resources carrying UCI (Uplink Control Information), uplink data, and random access signals. In the following, the expression that a user device transmits / receives PUCCH / PUSCH / PRACH is used to mean that the user device transmits / receives uplink control information / uplink data / random access signals on or through PUCCH / PUSCH / PRACH, respectively. In addition, the expression that BS transmits / receives PBCH / PDCCH / PDSCH is used with the same meaning as transmitting broadcast information / downlink control information / downlink data on or through PBCH / PDCCH / PDSCH, respectively.

[0068] In this specification, radio resources (e.g., time-frequency resources) scheduled or set for a UE by a BS for the transmission or reception of PUCCH / PUSCH / PDSCH are also referred to as PUCCH / PUSCH / PDSCH resources.

[0069] Since the communication device receives a synchronization signal (SS), DMRS, CSI-RS, PRS, PBCH, PDCCH, PDSCH, PUSCH, and / or PUCCH in the form of radio signals on the cell, it is not possible to selectively receive only radio signals containing only a specific physical channel or a specific physical signal through the RF receiver, or to selectively receive only radio signals excluding only a specific physical channel or a specific physical signal through the RF receiver. In actual operation, the communication device first receives radio signals on the cell through the RF receiver, converts the radio signals, which are RF band signals, into baseband signals, and uses one or more processors to decode the physical signals and / or physical channels within the baseband signals. Accordingly, in some implementations of this specification, not receiving a physical signal and / or physical channel may actually mean that the communication device does not receive wireless signals containing the physical signal and / or physical channel at all, but rather does not attempt to recover the physical signal and / or physical channel from the wireless signals, for example, not attempt to decode the physical signal and / or physical channel.

[0070] As more communication devices require larger communication capacities, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Furthermore, Massive Mobile Telecommunications (MTC), which connects multiple devices and objects to provide various services anytime and anywhere, is also one of the key issues to be considered in next-generation communication. In addition, communication system designs that consider reliability and latency-sensitive services / UEs are being discussed. Accordingly, the introduction of next-generation RATs that incorporate advanced mobile broadband communication, Massive MTC, and Ultra-Reliable and Low Latency Communication (URLC) is being discussed. Currently, 3GPP is conducting studies on next-generation mobile communication systems following the EPC. For convenience, this specification refers to the technology as New RAT (NR) or 5G RAT, and systems that use or support NR are referred to as NR systems.

[0071] FIG. 1 illustrates an example of a communication system 1 to which the implementations of the present specification apply. Referring to FIG. 1, the communication system (1) to which the present specification applies includes a wireless device, a BS, and a network. Here, a wireless device refers to a device that performs communication using wireless access technology (e.g., 5G NR (New RAT), LTE (e.g., E-UTRA)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, a 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 Thing) device (100f), and an AI device / server (400). For example, a vehicle may include a vehicle equipped with wireless communication capabilities, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, vehicles may include UAVs (Unmanned Aerial Vehicles) (e.g., drones). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and may be implemented in the form of HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) equipped in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Portable devices may include smartphones, smartpads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops, etc.). Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, BS and networks may be implemented as wireless devices, and specific wireless devices may operate as BS / network nodes to other wireless devices.

[0072] Wireless devices (100a to 100f) can be connected to a network (300) via a BS (200). Artificial Intelligence (AI) technology may 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, or a 5G (e.g., NR) network. The wireless devices (100a to 100f) may communicate with each other via the BS (200) / network (300), but they may also communicate directly (e.g., sidelink communication) without using the BS / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0073] Wireless communication / connection (150a, 150b) may be established between wireless devices (100a~100f) / BS (200) and BS (200) / wireless devices (100a~100f). Here, the wireless communication / connection may be established through uplink / downlink communication (150a) and sidelink communication (150b) (or D2D communication) using various wireless access technologies (e.g., 5G NR). Through the wireless communication / connection (150a, 150b), wireless devices and BS / wireless devices may transmit / receive wireless signals to / from each other. To this end, based on various proposals of the present specification, at least some of the following may be performed: a process for setting various configuration information for transmitting / receiving wireless signals, a process for various signal processing (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and a resource allocation process.

[0074] FIG. 2 is a block diagram illustrating examples of communication devices capable of performing the method according to the present specification. Referring to FIG. 2, a first wireless device (100) and a second wireless device (200) can transmit and / or receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} may correspond to {wireless device (100x), BS (200)} and / or {wireless device (100x), wireless device (100x)} of FIG. 1.

[0075] The first wireless device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memory (104) and / or transceivers (106) and may be configured to implement the functions, procedures and / or methods described / suggested below. For example, the processor (102) may process information within the memory (104) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (106). Additionally, the processor (102) may receive a wireless signal containing a second information / signal through the transceiver (106) and then store information obtained from the signal processing of the second information / signal in the memory (104). Memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, memory (104) may store software code containing instructions for performing some or all of the processes controlled by the processor (102) or for performing the procedures and / or methods described / suggested below. Here, the processor (102) and memory (104) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). A transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals through one or more antennas (108). The transceiver (106) may include a transmitter and / or receiver. The transceiver (106) may be interchangeably used with an RF (Radio Frequency) unit. In this specification, a wireless device may mean a communication modem / circuit / chip.

[0076] The second wireless device (200) includes one or more processors (202) and one or more memories (204), and may additionally include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memory (204) and / or transceivers (206) and may be configured to implement the functions, procedures and / or methods described / suggested below. For example, the processor (202) may process information within the memory (204) to generate a third information / signal and then transmit a wireless signal containing the third information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and then store information obtained from the signal processing of the fourth information / signal in the memory (204). Memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, memory (204) may store software code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the procedures and / or methods described / suggested below. Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through one or more antennas (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeably used with an RF unit. In this specification, a wireless device may mean a communication modem / circuit / chip.

[0077] The wireless communication technology implemented in the wireless device (100, 200) of this specification may include LTE, NR, and 6G, as well as Narrowband Internet of Things for low-power communication. In this case, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented according to standards such as LTE Cat NB1 and / or LTE Cat NB2, but is not limited to the names mentioned above. Additionally, or generally, the wireless communication technology implemented in the wireless device (XXX, YYY) of this specification may perform communication based on LTE-M technology. In this case, for example, LTE-M technology may be an example of LPWAN technology and may be referred to by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented in at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the names mentioned above. Additionally or generally, wireless communication technology implemented in the wireless device (XXX, YYY) of this specification may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) with consideration for low-power communication, and is not limited to the names mentioned above. As an example, ZigBee technology can create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4 and may be referred to by various names.

[0078] Hereinafter, 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 a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, and a service data adaptation protocol (SDAP). One or more processors (102, 202) may generate one or more protocol data units (PDU) and / or one or more service data units (SDU) according to the functions, procedures, proposals and / or methods disclosed in this specification. One or more processors (102, 202) may generate messages, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this specification. One or more processors (102, 202) may generate a signal (e.g., baseband signal) containing a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this specification and provide it to one or more transceivers (106, 206). One or more processors (102, 202) may receive a signal (e.g., baseband signal) from one or more transceivers (106, 206) and may obtain a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this specification.

[0079] One or more processors (102, 202) may be referred to as a controller, microcontroller, microprocessor, or 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 functions, procedures, proposals, and / or methods disclosed in this specification may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the functions, procedures, proposals and / or methods disclosed in this specification may be included in one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The functions, procedures, proposals and / or methods disclosed in this specification may be implemented using firmware or software in the form of code, instructions and / or sets of instructions.

[0080] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memories (104, 204) may be composed of ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0081] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc. of this specification to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the functions, procedures, proposals, methods and / or operation flowcharts, etc. disclosed in this specification from one or more other devices. For example, one or more transceivers (106, 206) may be connected to one or more processors (102, 202) and may transmit and / or receive wireless signals. For example, one or more processors (102, 202) may 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 connected to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and / or receive user data, control information, wireless signals / channels, etc., as mentioned in the functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this specification through one or more antennas (108, 208). In this specification, 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 the received wireless signal / channel, etc. from an RF band signal to a baseband signal in order to process the received user data, control information, wireless signal / channel, etc. using one or more processors (102, 202).One or more transceivers (106, 206) can convert user data, control information, wireless signals / channels, etc. processed using one or more processors (102, 202) from baseband signals to RF band signals. To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters.

[0082] FIG. 3 illustrates another example of a wireless device capable of performing implementation(s) of the present specification. Referring to FIG. 3, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 2 and may be composed of various elements, components, units / parts, 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 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. 2. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 2. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and additional elements (140) and controls the general operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on a program / code / command / information stored in the memory unit (130). Additionally, the control unit (120) may transmit information stored in the memory unit (130) to the outside (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from the outside (e.g., another communication device) via a wireless / wired interface through the communication unit (110) in the memory unit (130).

[0083] The additional element (140) may be configured in various ways depending on the type of 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. 1, 100a), a vehicle (Fig. 1, 100b-1, 100b-2), an XR device (Fig. 1, 100c), a portable device (Fig. 1, 100d), a home appliance (Fig. 1, 100e), an IoT device (Fig. 1, 100f), a UE for digital broadcasting, a holographic device, a public safety device, an MTC device, a medical device, a fintech device (or financial device), a security device, a climate / environment device, an AI server / device (Fig. 1, 400), a BS (Fig. 1, 200), a network node, etc. Depending on the use—e.g., service—the wireless device may be movable or used in a fixed location.

[0084] In FIG. 3, 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 a portion 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 the first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). Additionally, each element, component, unit / part, and / or module within the wireless device (100, 200) may include one or more additional elements. For example, the control unit (120) may be composed of one or more sets of 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, transitory memory, non-transitory memory and / or a combination thereof.

[0085] In this specification, at least one memory (e.g., 104 or 204) may store instructions or programs, and said instructions or programs may, when executed, cause at least one processor operablely connected to said at least one memory to perform operations according to some embodiments or implementations of this specification.

[0086] In this specification, a computer-readable (non-transient) storage medium may store at least one instruction or computer program, and when executed by at least one processor, said at least one instruction or computer program may cause said at least one processor to perform operations according to some embodiments or implementations of this specification.

[0087] In this specification, a processing device or apparatus may include at least one processor and at least one computer memory connectable to said at least one processor. said at least one computer memory may store instructions or programs, and said instructions or programs, when executed, may cause at least one processor operablely connected to said at least one memory to perform operations according to some embodiments or implementations of this specification.

[0088] In this specification, a computer program may include program code stored on at least one computer-readable (non-transient) storage medium and, when executed, perform operations according to some implementations of this specification or cause at least one processor to perform operations according to some implementations of this specification. The computer program may be provided in the form of a computer program product. The computer program product may include at least one computer-readable (non-transient) storage medium.

[0089] A communication device of this specification comprises at least one processor; and at least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations according to the examples(s) of this specification described below.

[0090] Figure 4 illustrates an example of a frame structure available in a 3GPP-based wireless communication system.

[0091] The structure of the frame in Fig. 4 is merely an example, and the number of subframes, slots, and symbols in the frame can be varied. In an NR system, OFDM numerology (e.g., subcarrier spacing (SCS)) may be configured differently among multiple cells aggregated to a single UE. Accordingly, the (absolute time) duration of a time resource (e.g., subframe, slot, or transmission time interval (TTI)) consisting of the same number of symbols may be configured differently among the aggregated cells. Here, symbols may include OFDM symbols (or cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) symbols) and SC-FDMA symbols (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols). In this specification, symbols, OFDM-based symbols, OFDM symbols, CP-OFDM symbols, and DFT-s-OFDM Symbols can be substituted for each other.

[0092] Referring to Fig. 4, uplink and downlink transmissions in an NR system are organized into frames. Each frame is T f = (△f max *N f / 100)*T c = It has a duration of 10 ms and is divided into two half-frames, each with a duration of 5 ms. Here, T is the basic time unit for NR. c = 1 / (△fmax *N f ) and, △f max = 480*10 3 It is Hz, and N f = 4096. For reference, T is the standard time unit for LTE. s = 1 / (△f ref *N f,ref ) and, △f ref = 15*10 3 It is Hz, and N f,ref =2048. T c Wow T s is a constant κ = T s / T c It has a relationship of = 64. Each half-frame consists of 5 subframes, and the period T of a single subframe (SF) sf is 1ms. Subframes are further divided into slots, and the number of slots within a subframe depends on the subcarrier spacing. Each slot consists of 14 or 12 OFDM symbols based on a cyclic prefix. For a normal cyclic prefix (CP), each slot consists of 14 OFDM symbols, while for an extended CP, each slot consists of 12 OFDM symbols. The above numerology is an exponentially scalable subcarrier spacing △f = 2 u It depends on 15 kHz. The following table shows the subcarrier spacing △f = 2 for normalized CP. u *Number of OFDM symbols per slot according to 15 kHz (N slot symb ), number of slots per frame (N frame,u slot ) and the number of slots per subframe (N subframe,u slot It represents ).

[0093]

[0094] The following table shows the subcarrier spacing △f = 2 for extended CP.u This shows the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per subframe according to *15 kHz.

[0095]

[0096] For a subcarrier interval setting u, the slots are arranged in increasing order n within the subframe. u s ∈ {0, ..., nsubframe,u slot - 1} and n in increasing order within the frame u s,f ∈ {0, ..., n frame,u slot - 1} is numbered.

[0097] FIG. 5 illustrates a resource grid of a slot. A slot contains multiple (e.g., 14 or 12) symbols in the time domain. For each numerator (e.g., subcarrier interval) and carrier, a common resource block (CRB) N indicated by upper-layer signaling (e.g., radio resource control (RRC) signaling) start,u grid Starting from,N size,u grid,x *N RB sc individual subcarriers and N subframe,u symb A resource grid of N OFDM symbols is defined. Here, N size,u grid,x is the number of resource blocks (RB) in the resource grid, and the subscript x is DL for downlinks and UL for uplinks. RB sc is the number of subcarriers per RB, and in 3GPP-based wireless communication systems, N RB scis typically 12. There is one resource grid for a given antenna port p, subcarrier spacing configuration u, and transmission direction (DL or UL). Carrier bandwidth N for subcarrier spacing configuration u. size,u grid This is given to the UE by upper-layer parameters (e.g., RRC parameters) from the network. Each element within the resource grid for antenna port p and subcarrier spacing u is referred to as a resource element (RE), and one complex symbol can be mapped to each resource element. Each resource element within the resource grid is uniquely identified by an index k in the frequency domain and an index l indicating the symbol position relative to a reference point in the time domain. In an NR system, RBs are defined by 12 consecutive subcarriers in the frequency domain. In an NR system, RBs can be classified into Common Resource Blocks (CRBs) and Physical Resource Blocks (PRBs). CRBs are numbered upwards from 0 in the frequency domain for subcarrier spacing u. The center of subcarrier 0 of CRB 0 for subcarrier spacing u coincides with 'Point A', which is the common reference point for the resource block grids. The PRBs for the subcarrier spacing setting u are defined within the bandwidth part (BWP), and range from 0 to N size,u BWP,i Numbered up to -1, where i is the number of the above bandwidth part. Common resource block n u CRB and physical resource block n within bandwidth part i PRB The relationships between them are as follows: n u PRB = n u CRB +N start,u BWP,i , here N start,u BWP,iis a common resource block where the above bandwidth part starts relative to CRB 0. A BWP contains multiple consecutive RBs in the frequency domain. For example, a BWP is a given numerator u within a BWP i on a given carrier. i It is a subset of contiguous CRBs defined for. The carrier may contain up to N (e.g., 5) BWPs. A UE may be configured to have one or more BWPs on a given component carrier. Data communication is performed through the enabled BWPs, and only a predetermined number (e.g., 1) of the BWPs configured for the UE may be enabled on the carrier.

[0098] For each serving cell within a set of DL BWPs or UL BWPs, the network establishes at least an initial DL BWP and one initial UL BWP (if the serving cell is configured with an uplink) or two initial UL BWPs (if using a supplementary uplink). The network may also establish additional ULs and DL BWPs for the serving cell. For each DL BWP or UL BWP, the UE is provided with the following parameters for the serving cell: i) subcarrier spacing, ii) circular prefix, iii) N start BWP Assuming = 275, offset RB set and length L RB CRBN provided by the RRC parameter locationAndBandwidth, which indicates as the resource indicator value (RIV). start BWP =O carrier +RB start and the number of contiguous RBs N size BWP =L RB , and O provided by the RRC parameter offsetToCarrier for the subcarrier spacing carrier; Index within the set of the above DL BWPs or UL BWPs; set of BWP-common parameters and set of BWP-exclusive parameters.

[0099] Switching between configured BWPs may occur using RRC signaling, DCI, an inactivity timer, or upon the initiation of a random connection. If an inactivity timer is configured for a serving cell, the expiration of the inactivity timer associated with said serving cell switches the active BWP to the default BWP configured by the network.

[0100] Virtual resource blocks (VRBs) are defined within the bandwidth part and range from 0 to N size,u BWP,i Numbered up to -1, where i is the number of the above bandwidth part. VRBs are mapped to physical resource blocks (PRBs) according to interleaved or non-interleaved mapping. In some implementations, for non-interleaved VRB-to-PRB mapping, VRB n can be mapped to PRB n.

[0101] NR frequency bands are defined as two types of frequency ranges, FR1 and FR2, where FR2 is also referred to as millimeter wave (mmW). The following table illustrates the frequency ranges in which NR can operate.

[0102]

[0103] Figure 6 illustrates physical channels used in a 3GPP-based communication system, which is an example of a wireless communication system, and the signal transmission / reception process using them.

[0104] A UE that has been turned on again after being turned off or has lost connection with a wireless communication system first performs an initial cell search process, such as searching for a suitable cell to camp on and synchronizing with said cell or the BS of said cell (S11). During the initial cell search process, the UE receives a synchronization signal block (SSB) (also called an SSB / PBCH block) from the BS. The SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). Based on the PSS / SSS, the UE synchronizes with the BS and obtains information such as the cell identifier (ID). Additionally, the UE can obtain broadcast information within the cell based on the PBCH. Meanwhile, during the initial cell search process, the UE can receive a downlink reference signal (DL RS) to check the downlink channel status.

[0105] After completing the initial cell search, the UE can camp on the cell. After camping on the cell, the UE monitors the PDCCH on the cell and receives the PDSCH according to the downlink control information (DCI) carried by the PDCCH to obtain more specific system information (S12).

[0106] Subsequently, the UE may perform a random access procedure to complete access to the BS (S13 to S16). For example, during the random access procedure, the UE may transmit a preamble through a physical random access channel (PRACH) (S13) and receive a random access response (RAR) for the preamble through a PDCCH and a corresponding PDSCH (S14). If the reception of the RAR for the UE fails, the UE may attempt to re-transmit the preamble. In the case of contention-based random access, a contention resolution procedure (S16) may be performed, which includes transmitting a PUSCH based on the UL resource allocation included in the RAR (S15) and receiving a PDCCH and a corresponding PDSCH.

[0107] A UE that has performed the procedure described above may subsequently perform the reception of PDCCH / PDSCH (S17) and the transmission of PUSCH / PUCCH (S18) as part of a general uplink / downlink signal transmission process. The control information transmitted by the UE to the BS is collectively referred to as uplink control information (UCI). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK) (also called HARQ-ACK), scheduling request (SR), channel state information (CSI), etc. CSI may include channel quality indicator (CQI), precoding matrix indicator (PMI), and / or rank indicator, etc. UCI is generally transmitted via PUCCH, but may be transmitted via PUSCH if control information and traffic data need to be transmitted simultaneously. In addition, the UE can transmit UCI atypically via PUSCH based on network requests / instructions.

[0108] Figure 7 illustrates SS / PBCH blocks (SSB) on a cell.

[0109] In 3GPP-based systems, each SSB is associated with each beam. For example, during a half-frame, different SSBs may be transmitted in different spatial directions (using different beams that span the cell's coverage area). The possible time positions of SSBs within a half-frame are determined by the subcarriers, and the periododicity of the half-frames in which the SSBs are transmitted is set by the network. Multiple SSBs may be transmitted within the carrier frequency span. Different indices of SSBs transmitted / detected on a single cell may correspond to different BS (wide) Tx beams. Multiple SSBs may be transmitted within the carrier frequency span. The physical (layer) cell identifiers (PCIs) of SSBs transmitted at different frequency locations do not need to be unique, and different SSBs in the frequency domain may have different PCIs. When an SSB is associated with remaining minimum system information (RMSI), the SSB is referred to as a cell-defining SSB (CD-SSB), and the PCell is always associated with a CD-SSB located on a synchronization raster (sync raster).If an SSB is not associated with an RMSI, the said SSB is referred to as a non-cell defining SSB (NCD-SSB), which can be used to perform radio link monitoring (RLM), beam failure detection (BFD), and radio resource management (RRM) measurements, and measurements for random access resource selection within an active DL BWP if the active DL BWP does not include the said CD-SSB. In 3GPP-based systems, multi-beam operation is based on beam switching / beam scanning, which transmits / receives signals while changing the beam direction over time. Beam sweeping refers to the transmission and reception point (TRP) (e.g., BS / cell) changing the beam (direction) of the radio signal over time. In this specification, beam and beam direction may be used interchangeably. An SSB may be transmitted periodically using beam sweeping. In this case, the SSB index is implicitly linked to the SSB beam. The SSB beam can be changed by an SSB (index) unit or by an SSB (index) group unit. In the latter case, the SSB beam remains the same within the SSB (index) group. For example, referring to Fig. 7, a set of SSBs can be transmitted within a 5 ms half-frame. A set of SSBs transmitted within a 5 ms half-frame is called an SSB burst, and the entire set of bursts that are repeated at each period set by the BS is called an SSB burst set. SSBs within an SSB burst can be transmitted in different beam directions. L. max is the maximum number of SSB indices within a cell, and the maximum number of SSBs transmitted within a half-frame is L. max is. The maximum number of SSB transmissions L within an SSB burst.max has a value of 4, 8, or 64 depending on the frequency band to which the carrier belongs. For example, L is the maximum number of SSBs in an SSB burst set. max It can be given as follows.

[0110] - For frequency range up to 3 GHz, L max = 4

[0111] - For frequency range from 3GHz to 6 GHz, L max = 8

[0112] - For frequency range from 6 GHz to 52.6 GHz, L max = 64

[0113] The actual number of transmitted SSBs can be configured, with a maximum number L max It can be smaller. If multi-beam transmission is not applied, the number of SSB beams is 1.

[0114] The UE can perform DL synchronization acquisition (e.g., OFDM symbol / slot / half-frame boundary detection), cell ID (Identifier) ​​acquisition (e.g., Physical Cell Identifier, PCID), beam alignment for initial connection, MIB acquisition, DL measurement, etc. based on the SSB. The UE can identify the frame number to which the detected SSB belongs using system frame number (SFN) information within the PBCH, and identify the half-frame number to which the detected SSB belongs using PBCH DMRS and / or half-frame indication information (hereinafter HF) within the PBCH. For example, if the UE detects a PBCH DMRS generated based on HF=0 or a PBCH containing HF=0, it can determine that the SSB to which the PBCH belongs belongs to the first half-frame within the frame, and if the UE detects a PBCH DMRS generated based on HF=1 or a PBCH containing HF=1, it can determine that the SSB to which the PBCH belongs belongs to the second half-frame within the frame.

[0115] Figure 8 is illustrated to explain the bitmaps used to indicate the SSBs actually being transmitted.

[0116] Maximum L within SSB burst max SSBs may be transmitted, and the number / locations of the SSBs actually transmitted may vary depending on the BS / cell. The number / locations of the SSBs actually transmitted are used for rate-matching and measurement, and information regarding the SSBs actually transmitted (e.g., RRC setting ssb-PositionsInBurst) may be indicated as follows.

[0117] - In the case of rate-matching: This may be indicated via UE-specific RRC signaling or RMSI. UE-specific RRC signaling includes a full (e.g., length L) bitmap in both the below 6 GHz and above 6 GHz frequency ranges. On the other hand, the remaining minimum system information (RMSI) (i.e., SIB1) includes a full bitmap in the below 6 GHz range and a bitmap in a compressed form as described above 6 GHz. Specifically, information regarding the SSB actually transmitted may be indicated using a group-bitmap (8-bit) and an in-group bitmap (8-bit). Here, the resources indicated via UE-specific RRC signaling or RMSI (e.g., resource elements (REs)) are reserved for SSB transmission, and PDSCH / PUSCH, etc., may be rate-matched with respect to the SSB resources.

[0118] - In relation to measurement: When in RRC_CONNECTED mode, the network (e.g., BS) can specify the set of SSBs to be measured within the measurement interval. The set of SSBs can be specified by frequency layer. If no specification is given for the set of SSBs, the default set of SSBs is used. The default set of SSBs includes all SSBs within the measurement interval. The set of SSBs is the full of RRC signaling (e.g., length L max It can be specified using a bitmap. If in RRC_IDLE mode, the default SSB set is used.

[0119] Figure 9 illustrates the system information (SI) acquisition process. A UE can acquire AS- / NAS- information through the SI acquisition process. The SI acquisition process can be applied to UEs in the RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states. RRC_CONNECTED is a state in which the UE has established an RRC connection with the network. RRC_IDLE is a state in which the UE is not registered with a specific cell and has not received the access stratum (AS) context and other information received from the network. RRC_INACTIVE is a state in which the UE remains in CM-CONNECTED, a state in which it has a signaling connection with the core network for connection management (CM), and can move within an area set by the RAN (e.g., BS(s)) without notifying the radio access network (RAN). CM_CONNECTED is a state in which the UE has a non-access stratum (NAS) signaling connection with the core network, and CM_IDLE is a state in which the UE has no NAS signaling.

[0120] In 3GPP-based systems, SI can be divided into a master information block (MIB) and multiple system information blocks (SIBs). The MIB and multiple SIBs can be further divided into minimum SI and other SI. Here, the minimum SI may consist of an MIB and SystemInformationBlock1 (SIB1), and includes basic information required for initial connection and information for obtaining other SI. Here, SIB1 may be referred to as remaining minimum system information (RMSI). For details, refer to the following.

[0121] - The MIB is always transmitted over a BCH with a periododicity of 80 ms and repetitions created within 80 ms. The MIB contains information / parameters related to SIB1 reception and is transmitted via the SSB's PBCH. During initial cell selection, the UE assumes that half-frames containing the SSB(s) repeat with a period of 20 ms. Based on the MIB, the UE can determine whether a control resource set (CORESET) exists for the Type0-PDCCH common search space. For example, the field ssb-SubcarrierOffset within the MIB is k, which is a frequency domain offset in units of the number of subcarriers between the SSB and the overall resource block grid. SSB Corresponds to. Upon detection of an SS / PBCH block, the UE, in the case of FR1, k SSB If < 24, or in the case of FR2, k SSBIf < 12, it can be determined that a CORESET exists for the Type-0 PDCCH common search space (CSS) set, and for FR1, k SSB If > 23, or in the case of FR2, k SSB If > 11, it can be determined that a Type-0 PDCCH CSS set does not exist. The Type-0 PDCCH common seek space is a type of PDCCH seek space and is used to transmit PDCCHs that schedule SI messages. If a Type-0 PDCCH common seek space exists, the UE can determine (i) multiple consecutive RBs and one or more consecutive symbols that constitute a CORESET and (ii) the PDCCH time (i.e., the time domain location for receiving the PDCCH) based on information within the MIB (e.g., pdcch-ConfigSIB1). If a Type-0 PDCCH common seek space does not exist, pdcch-ConfigSIB1 provides information regarding frequency locations where SSB / SIB1 exists and frequency ranges where SSB / SIB1 does not exist.

[0122] - SIB1 is transmitted over a downlink shared channel (DL-SCH) with a periododicity of 160 ms and a variable transmission repetition period within 160 ms. The default transmission repetition period of SIB1 is 20 ms, but the actual transmission repetition period may vary depending on the network implementation. SIB1 contains information regarding the availability and scheduling (e.g., transmission period, SI-window size) of the remaining SIBs (hereinafter SIBx, where x is an integer greater than or equal to 2). For example, SIB1 can indicate whether SIBx is broadcast periodically or provided on-demand by a UE's request. If SIBx is provided on-demand, SIB1 may contain information necessary for the UE to perform an SI request. SIB1 is a cell-specific SIB. The PDCCH scheduling SIB1 is transmitted through the Type0-PDCCH common seek space, and SIB1 is transmitted through the PDSCH directed by the said PDCCH.

[0123] - SIBx is included in SI messages and transmitted via PDSCH. Each SI message is transmitted within a time window (i.e., SI window) that occurs periodically according to SI scheduling information provided by SIB1.

[0124] FIG. 10 illustrates a random connection process that can be applied to the implementation(s) of the present specification. In particular, FIG. 10(a) illustrates a four-step random connection process, and FIG. 10(b) illustrates a two-step random connection process.

[0125] The random access process can be used for various purposes, such as initial access, uplink adjustment, resource allocation, handover, reconfiguration after a wireless link failure, and location measurement. Random access processes are classified into contention-based and dedicated (i.e., non-contention-based) processes. Contention-based random access processes are generally used for initial access, while dedicated random access processes are used for handover, when downlink data reaches the network, and when reconfiguring uplink synchronization for location measurement. In a contention-based random access process, the UE randomly selects a random access (RA) preamble. Therefore, it is possible for multiple UEs to transmit the same RA preamble simultaneously, which necessitates a subsequent contention resolution process. In contrast, in a dedicated random access process, the UE uses an RA preamble uniquely assigned to it by the BS. Consequently, the UE can perform the random access process without conflicts with other UEs.

[0126] Referring to FIG. 10(a), the contention-based random access process includes the following four steps. Hereinafter, the messages transmitted in steps 1 through 4 may be referred to as Msg1 through Msg4, respectively.

[0127] - Step 1: The UE transmits the RA preamble via PRACH.

[0128] - Step 2: The UE receives a random access response (RAR) from the BS via PDSCH.

[0129] - Step 3: The UE transmits UL data to the BS via PUSCH based on RAR. Here, the UL data includes Layer 2 and / or Layer 3 messages.

[0130] - Step 4: The UE receives a contention resolution message from the BS via PDSCH.

[0131] The UE can receive information regarding random access from the BS through system information. For example, information regarding RACH times associated with SSBs on the cell may be provided through system information. The UE can select an SSB among those received on the cell for which the reference signal received power (RSRP) measured based on the SSB exceeds a threshold, and transmit an RA preamble through the PRACH associated with the selected SSB. For example, if random access is required, the UE transmits Msg1 (e.g., preamble) to the BS on the PRACH. The BS can distinguish each random access preamble through the time / frequency resource (RA Occasion, RO) and the random access preamble index (Preamble Index, PI). When the BS receives a random access preamble from the UE, the BS transmits a RAR message to the UE on the PDSCH. To receive a RAR message, the UE monitors a L1 / L2 control channel (PDCCH) masked with a cyclic redundancy check (CRC) by a Random Access-RnTI (RA-RNTI) containing scheduling information for the RAR message within a preset time window (e.g., ra-ResponseWindow). If scheduling information is received through the PDCCH masked with the RA-RNTI, the UE may receive a RAR message from the PDCCH indicated by the scheduling information. Subsequently, the UE determines whether there is a RAR for itself in the RAR message. Whether a RAR for itself exists can be determined by whether a Random Access preamble ID (RAPID) exists for the preamble transmitted by the UE. The index of the preamble transmitted by the UE and the RAPID may be the same.A RAR includes a corresponding random access preamble index, timing offset information for UL synchronization (e.g., a timing advance command (TAC)), UL scheduling information for sending Msg3 (e.g., a UL grant), and temporary UE identification information (e.g., Temporary-C-RNTI, TC-RNTI). Upon receiving the RAR, the UE sends Msg3 via PUSCH according to the UL scheduling information and timing offset values ​​within the RAR. Msg3 may include the UE's ID (or the UE's global ID). Additionally, Msg3 may include information related to an RRC connection request for initial access to the network (e.g., an RRCSetupRequest message). After receiving Msg3, the BS sends Msg4, a contention resolution message, to the UE. If the UE receives the contention resolution message and the contention is successfully resolved, TC-RNTI is changed to C-RNTI. Msg4 includes the UE's ID and / or It may include information related to the RRC connection (e.g., RRCSetup message). If the information transmitted via Msg3 does not match the information received via Msg4, or if Msg4 is not received for a certain period of time, the UE may report that the contention resolution failed and retransmit Msg3.

[0132] Meanwhile, the dedicated random access process includes the following three steps. Hereinafter, the messages transmitted in steps 0 to 2 may be referred to as Msg0 to Msg2, respectively. The dedicated random access process may be triggered by the UE by the BS using a PDCCH (hereinafter referred to as the PDCCH order) for commanding the transmission of an RA preamble.

[0133] - Step 0: BS assigns the RA preamble to the UE via dedicated signaling.

[0134] - Step 1: The UE transmits the RA preamble via PRACH.

[0135] - Step 2: The UE receives the RAR via the PDSCH from the BS.

[0136] The operations of steps 1 to 2 of a dedicated random access process may be the same as steps 1 to 2 of a contention-based random access process.

[0137] In NR systems, lower latency than in existing systems may be required. Additionally, a four-stage random access process may not be desirable, particularly for latency-sensitive services such as URLLC. A low-latency random access process may be required within various scenarios of NR systems. When the implementation(s) of this specification are performed with a random access process, to reduce latency in the random access process, the implementation(s) of this specification may be performed with the following two-stage random access process.

[0138] Referring to FIG. 10(b), the two-stage random access process may consist of two stages: the transmission of MsgA from the UE to the BS and the transmission of MsgB from the BS to the UE. The transmission of MsgA may include the transmission of an RA preamble via PRACH and the transmission of a UL payload via PUSCH. In the transmission of MsgA, PRACH and PUSCH may be transmitted using time division multiplexing (TDM). Alternatively, in the transmission of MsgA, PRACH and PUSCH may be transmitted using frequency division multiplexing (FDM).

[0139] A BS that receives MsgA may send MsgB to a UE. MsgB may include a RAR for said UE.

[0140] A message related to an RRC connection request (e.g., RRCSetupRequest message) requesting to establish a connection between the RRC layer of the BS and the RRC layer of the UE may be transmitted by being included in the payload of MsgA. In this case, MsgB may be used to transmit RRC connection-related information (e.g., RRCSetup message). Alternatively, the RRC connection request message (e.g., RRCSetupRequest message) may be transmitted via PUSCH transmitted based on a UL grant within MsgB. In this case, the RRC connection-related information (e.g., RRCSetup message) related to the RRC connection request may be transmitted via PDSCH associated with said PUSCH transmission after the PUSCH transmission based on MsgB.

[0141] Below, physical channels that can be used in 3GPP-based wireless communication systems are described in more detail.

[0142] A PDCCH carries a DCI. For example, a PDCCH (i.e., a DCI) carries the transmission format and resource allocation of the downlink shared channel (DL-SCH), resource allocation information for the uplink shared channel (UL-SCH), paging information for the paging channel (PCH), system information on the DL-SCH, resource allocation information for control messages of the layer above the physical layer (hereinafter referred to as the upper layer) among the protocol stacks of the UE / BS, such as random access response (RAR) transmitted on the PDSCH, transmission power control commands, and the activation / deactivation of configured scheduling (CS). A DCI containing resource allocation information for the DL-SCH is also called a PDSCH scheduling DCI, and a DCI containing resource allocation information for the UL-SCH is also called a PUSCH scheduling DCI. The DCI includes a cyclic redundancy check (CRC), and the CRC is masked / scrambled with various identifiers (e.g., radio network temporary identifier (RNTI)) depending on the owner or use of the PDCCH. For example, if the PDCCH is for a specific UE, the CRC is masked with the UE identifier (e.g., cell RNTI (C-RNTI)). If the PDCCH is for paging, the CRC is masked with the paging RNTI (P-RNTI). If the PDCCH is for system information (e.g., system information block (SIB)), the CRC is masked with the system information RNTI (SI-RNTI). If the PDCCH is for a random access response, the CRC is masked with the random access RNTI (RA-RATI).

[0143] The scheduling of a PDCCH on one serving cell to a PDSCH or PUSCH on another serving cell is called cross-carrier scheduling. Cross-carrier scheduling using a carrier indicator field (CIF) may allow a PDCCH on a serving cell to schedule resources on another serving cell. Meanwhile, the scheduling of a PDSCH or PUSCH on a serving cell to a serving cell is called self-carrier scheduling. When cross-carrier scheduling is used in a cell, the BS may provide the UE with information regarding the cell scheduling said cell. For example, the BS may provide the UE with whether the serving cell is scheduled by a PDCCH on another (scheduling) cell or by said serving cell, and if said serving cell is scheduled by another (scheduling) cell, which cell signals downlink assignments and uplink grants for said serving cell. In this specification, a cell carrying a PDCCH is referred to as a scheduling cell, and a cell in which the transmission of a PUSCH or PDSCH is scheduled by a DCI included in the PDCCH, that is, a cell carrying a PUSCH or PDSCH scheduled by the PDCCH, is referred to as a scheduled cell.

[0144] PDSCH is a physical layer DL channel for DL ​​data transport. PDSCH carries downlink data (e.g., DL-SCH transport blocks) and applies modulation methods such as QPSK (Quadrature Phase Shift Keying), 16 QAM (Quadrature Amplitude Modulation), 64 QAM, and 256 QAM. Codewords are generated by encoding transport blocks (TB). PDSCH can carry up to two codewords. Scrambling and modulation mapping are performed for each codeword, and the modulation symbols generated from each codeword can be mapped to one or more layers. Each layer is mapped to a radio resource along with DMRS to generate an OFDM symbol signal, which is then transmitted through the corresponding antenna port.

[0145] The UE must have uplink resources available to it for UL-SCH data transmission and downlink resources available to it for DL-SCH data reception. Uplink resources and downlink resources are assigned to the UE through resource allocation by the BS. Resource allocation may include time domain resource allocation (TDRA) and frequency domain resource allocation (FDRA). In this specification, uplink resource allocation is also referred to as uplink grant, and downlink resource allocation is also referred to as downlink assignment. Uplink grant is dynamically received by the UE on the PDCCH or within the RAR, or is semi-persistently set to the UE by RRC signaling from the BS. Downlink assignment is dynamically received by the UE on the PDCCH, or is semi-persistently set to the UE by RRC signaling from the BS.

[0146] In UL, the BS can dynamically allocate uplink resources to the UE via PDCCH(s) addressed to a cell radio network temporary Identifier (C-RNTI). The UE monitors the PDCCH(s) to find available uplink grant(s) for UL transmission. Additionally, the BS can allocate uplink resources to the UE using configured grants. Two types of configured grants, Type 1 and Type 2, may be used. In the case of Type 1, the BS directly provides the configured uplink grant (including periodicity) via RRC signaling. In the case of Type 2, the BS sets the period of the RRC-configured uplink grant via RRC signaling and can signal and activate or deactivate the configured uplink grant via a PDCCH addressed to a configured scheduling RNTI (CS-RNTI). For example, in the case of Type 2, the PDCCH addressed by CS-RNTI indicates that the corresponding uplink grant may be implicitly reused according to the period set by RRC signaling until it is deactivated.

[0147] In DL, the BS can dynamically allocate downlink resources to the UE via PDCCH(s) addressed by C-RNTI. The UE monitors the PDCCH(s) to identify potential downlink assignments. Additionally, the BS can allocate downlink resources to the UE using semi-persistent scheduling (SPS). The BS can set the period of the configured downlink assignments via RRC signaling and signal and enable or disable the configured downlink assignments via PDCCHs addressed by CS-RNTI. For example, a PDCCH addressed by CS-RNTI indicates that the corresponding downlink assignment may be implicitly reused according to the period set by RRC signaling until it is disabled.

[0148] Figure 11 illustrates an example of PDSCH time domain resource allocation by PDCCH and an example of PUSCH time domain resource allocation by PDCCH.

[0149] The DCI carried by PDCCH to schedule PDSCH or PUSCH includes a time domain resource assignment (TDRA) field, said TDRA field provides a value m for row index m+1 to the allocation table for PDSCH or PUSCH. A predefined default PDSCH time domain assignment is applied as the allocation table for PDSCH, or a PDSCH time domain resource assignment table set by BS via RRC signaling pdsch-TimeDomainAllocationList is applied as the allocation table for PDSCH. A predefined default PUSCH time domain assignment is applied as the allocation table for PUSCH, or a PUSCH time domain resource assignment table set by BS via RRC signaling pdsch-TimeDomainAllocationList is applied as the allocation table for PUSCH. The PDSCH time domain resource allocation table to be applied and / or the PUSCH time domain resource allocation table to be applied may be determined according to fixed / predefined rules (e.g., see 3GPP TS 38.214).

[0150] In the PDSCH time domain resource settings, each indexed row defines the DL allocation-to-PDSCH slot offset K0, the start and length indicator value SLIV (or directly the starting position of the PDSCH within the slot (e.g., start symbol index S) and the allocation length (e.g., number of symbols L)), and the PDSCH mapping type. In the PUSCH time domain resource settings, each indexed row defines the UL grant-to-PUSCH slot offset K2, the starting position of the PUSCH within the slot (e.g., start symbol index S) and the allocation length (e.g., number of symbols L), and the PUSCH mapping type. K0 for PDSCH or K2 for PUSCH indicates the difference between the slot containing the PDSCH and the slot containing the PDSCH or PUSCH corresponding to said PDSCH. SLIV is a joint indicator of the starting symbol S relative to the start of the slot containing the PDSCH or PUSCH and the number of consecutive symbols L counted from said symbol S. For PDSCH / PUSCH mapping types, there are two mapping types: one is mapping type A and the other is mapping type B. In the case of PDSCH / PUSCH mapping type A, the demodulation reference signal (DMRS) is mapped to the PDSCH / PUSCH resource based on the start of the slot, and depending on other DMRS parameters, one or two symbols from the PDSCH / PUSCH resource may be used as DMRS symbol(s). For example, in the case of PDSCH / PUSCH mapping type A, the DMRS is located at the third symbol (symbol #2) or the fourth symbol (symbol #3) in the slot according to RRC signaling. In the case of PDSCH / PUSCH mapping type B, the DMRS is mapped based on the first OFDM symbol of the PDSCH / PUSCH resource, and depending on other DMRS parameters, one or two symbols starting from the first symbol of the PDSCH / PUSCH resource may be used as DMRS symbol(s).For example, in the case of PDSCH / PUSCH mapping type B, DMRS is located at the first symbol allocated for PDSCH / PUSCH. In this specification, PDSCH / PUSCH mapping types may be referred to as mapping types or DMRS mapping types. For example, in this specification, PUSCH mapping type A may be referred to as mapping type A or DMRS mapping type A, and PUSCH mapping type B may be referred to as mapping type B or DMRS mapping type B.

[0151] The above scheduling DCI includes a frequency domain resource assignment (FDRA) field that provides assignment information regarding resource blocks used for PDSCH or PUSCH. For example, the FDRA field provides the UE with information regarding a cell for PDSCH or PUSCH transmission, information regarding a BWP for PDSCH or PUSCH transmission, and information regarding resource blocks for PDSCH or PUSCH transmission.

[0152] A control resource set (CORESET), which is a set of time-frequency resources that allows the UE to monitor PDCCHs, may be defined and / or configured. The CORESET consists of a set of physical resource blocks (PRBs) with a duration of one to three OFDM symbols. The PRBs constituting the CORESET and the CORESET duration may be provided to the UE through upper-layer (e.g., RRC) signaling. Within the configured CORESET(s), a set of PDCCH candidates is monitored according to the corresponding search space sets. In this specification, monitoring may imply decoding (also known as blind decoding) each PDCCH candidate according to the monitored DCI formats. The master information block (MIB) on the PBCH provides the UE with parameters (e.g., setting CORESET#0) for monitoring the PDCCH to schedule the PDSCH carrying the system information block (SIB1). The PBCH may also indicate that there is no associated SIB1; in this case, the UE may be instructed on a frequency range where it can assume there is no SSB associated with SIB1, as well as other frequencies to search for the SSB associated with SIB1. At least CORESET#0, which is the CORESET for scheduling SIB1, can be set via the MIB or dedicated RRC signaling.

[0153] One or more CORESETs can be configured for the UE, and multiple CORESETs can overlap in the time / frequency domain.

[0154] The set of PDCCH candidates monitored by the UE is defined in terms of PDCCH search space sets. A search space set can be a common search space (CSS) set or a UE-specific search space (USS) set. Each CORESET setting is associated with one or more search space sets, and each search space set is associated with one CORESET setting.

[0155] A set of PDCCH candidates can be monitored in one or more CORESETs on an active DL BWP on each active serving cell where PDCCH monitoring is configured, wherein monitoring implies receiving each PDCCH candidate and decoding it according to the monitored DCI formats.

[0156] SS sets can be configured via system information (e.g., MIB) or UE-specific upper layer (e.g., RRC) signaling. Each DL BWP in a serving cell may have up to S (e.g., 10) SS sets configured. For example, the following parameters / information may be provided for each SS set. Each SS set is associated with one CORESET, and each CORESET configuration may be associated with one or more SS sets.

[0157] -searchSpaceId: Represents the ID of the SS set.

[0158] -controlResourceSetId: Represents the CORESET associated with the SS set.

[0159] -monitoringSlotPeriodicityAndOffset: Represents the PDCCH monitoring period interval (in slots) and the PDCCH monitoring interval offset (in slots).

[0160] -monitoringSymbolsWithinSlot: Represents the first OFDMA symbol(s) for PDCCH monitoring within the slot where PDCCH monitoring is enabled. It is indicated by a bitmap, where each bit corresponds to each OFDMA symbol within the slot. The MSB of the bitmap corresponds to the first OFDMA symbol within the slot. The OFDMA symbol(s) corresponding to bit(s) with a bit value of 1 correspond to the first symbol(s) of the CORESET within the slot.

[0161] -nrofCandidates: AL={1, 2, 4, 8, 16} represents the number of star PDCCH candidates (e.g., one of 0, 1, 2, 3, 4, 5, 6, 8).

[0162] -searchSpaceType: Indicates whether the SS type is CSS or USS.

[0163] - DCI Format: Indicates the DCI format of the PDCCH candidate.

[0164] Based on the CORESET / SS set configuration, the UE can monitor PDCCH candidates from one or more SS sets within the slot. The occasion (e.g., time / frequency resources) when PDCCH candidates must be monitored is defined as a PDCCH (monitoring) time. One or more PDCCH (monitoring) times can be configured within the slot.

[0165] The current standard document 3GPP TS 38.213 discloses the random access process and PRACH configuration as follows. For a more detailed description of the RRC parameters mentioned below, refer to 3GPP TS 38.331.

[0166] Prior to the initiation of the physical random access process, Layer 1 receives a set of SS / PBCH block indices from the upper layers and provides the corresponding set of RSRP measurements to the upper layers.

[0167] Prior to the initiation of the physical random access process, Layer 1 may receive an indication from the upper layers to perform a Type-1 random access process or a Type-2 random access process.

[0168] Prior to the initiation of the physical random access process, Layer 1 receives the following information from the upper layers:

[0169] - Physical Random Access Channel (PRACH) transmission parameters (PRACH preamble format, time resources, and frequency resources for PRACH transmission).

[0170] - Parameters for determining the root sequences within the PRACH preamble sequence set and their cylic shifts (index to logical root sequence table, cylic shifts (N CS ), and set type (unrestricted, restricted set A, or restricted set B)).

[0171] From a physical layer perspective, the type-1 L1 random access process includes the transmission of a random access preamble (Msg1) in a PRACH, a random access response (RAR) with a PDCCH / PDSCH (Msg2), and, when applicable, a PUSCH scheduled by a RAR UL grant, and a transmission of a PDSCH for contention resolution.

[0172] From a physical layer perspective, the above-mentioned type-2 L1 random access process includes a random access preamble in a PRACH and the transmission of a PUSCH (MsgA), the reception of a RAR message with a PDCCH / PDSCH (MsgB), and, if applicable, the transmission of a PDSCH for contention resolution with a PUSCH scheduled by a fallback RAR UL grant.

[0173] When a random access process for a UE is initiated by a PDCCH order, the PRACH transmission has the same subcarrier spacing (SCS) as the PRACH transmission initiated by the upper layers.

[0174] When a UE is configured to have two UL carriers for a serving cell and the UE detects a PDCCH command, the UE determines the UL carrier for the corresponding PRACH transmission using the UL / supplementary (supplementary UL, SUL) indicator field value from the detected PDCCH command.

[0175] The physical random access process for the UE is triggered upon a request for a PRACH transmission by upper layers or by a PDCCH command to the cell. Configuration by upper layers for a PRACH transmission includes the following:

[0176] - Settings for PRACH transmission on the above cell.

[0177] - Preamble Index, Preamble SCS, PRACH Target Reception Power P PRACH,target , when applicable, the corresponding RA-RNTI, PRACH resource for the above cell.

[0178] - If the UE would transmit the PRACH with repetitions, N for transmitting the PRACH rep preamble >1 Number of preamble iterations.

[0179] The UE, on the designated PRACH resource or N rep preamble For preamble iterations, use the same spatial filter to N rep preamble On a determined set of resources, transmission power P as described in Section 7.4 of 3GPP TS 38.214 PRACH,b,f,c (i) A UE transmits a PRACH on a cell using the selected PRACH format with transmission power P PRACH,b,f,c (i), as described in section 7.4 of 3GPP TS 38.214, on the indicated PRACH resource or on a determined set of N rep preamble resources using a same spatial filter in case of N rep preamble preamble repetitions.)

[0180] For a Type-1 random access process, the UE is provided by the RRC parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB with the number N of SS / PBCH block indexes associated with a single PRACH occasion and the number R of contention-based preambles per SS / PBCH block index per valid PRACH occasion.

[0181] In the case of a Type-1 random access process having a common configuration of PRACH times, the UE is provided with the number of SS / PBCH block indices N associated with one PRACH time by the RRC parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB and the number of contention-based preambles Q per SS / PBCH block index per valid PRACH time by the RRC parameter msgA-CB-PreamblesPerSSB-PerSharedRO. PRACH transmission may take place on a subset of PRACH times associated with the same SS / PBCH block index within an SSB-RO mapping cycle for a UE provided with a PRACH mask index by the RRC parameter msgA-SSB-SharedRO-MaskIndex in accordance with 3GPP TS 38.321.

[0182] For a Type-2 random access procedure with a separate configuration of PRACH occasions with a Type-1 random access procedure, the UE is provided with the number of SS / PBCH block indices N associated with a single PRACH occasion and the number of contention-based preambles R per SS / PBCH block index per valid PRACH occasion by the RRC parameter msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB when provided, and otherwise by ssb-perRACH-OccasionAndCB-PreamblesPerSSB.

[0183] For a random access process associated with a feature combination indicated by the RRC information element FeatureCombinationPreambles (which associates a set of feature combinations with preambles), the UE is provided with the number of SS / PBCH block indices N associated with one PRACH time by the RRC parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB or, if provided, msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB, and the number of contention-based preambles S per SS / PBCH block index per valid PRACH time by the RRC parameter startPreambleForThisPartition and the RRC parameter numberOfPreamblesPerSSB-ForThisPartition. PRACH transmission is a PRACH associated with the same SS / PBCH block index within an SSB-RO mapping cycle for a UE provided with a PRACH mask index by ssb-SharedRO-MaskIndex in accordance with 3GPP TS 38.321. It can be done on subsets of periods.

[0184] For a Type-1 random access process, or for a Type-2 random access process having a separate configuration of PRACH periods from the Type-1 random access process, if N < 1, one SS / PBCH block index is mapped to 1 / N consecutive valid PRACH periods, and per valid PRACH period, R contention-based preambles with consecutive indices associated with the said SS / PBCH block index start from preamble index 0. If N ≥ 1, per valid PRACH period, R contention-based preambles with consecutive indices associated with the SS / PBCH block index n start from preamble index n*N total preamble Starting from / N, 0≤n≤N-1, and Ntotal preamble is provided by totalNumberOfRA-Preambles for a type-1 random connection process, or by msgA-TotalNumberOfRA-Preambles for a type-2 random connection process that has a separate configuration of PRACH times from the type-1 random connection process, and is an integer multiple of N.

[0185] For a Type-2 random access process having common settings for PRACH periods with a Type-1 random access process, if N < 1, a single SS / PBCH block index is mapped to 1 / N consecutive valid PRACH periods, and Q contention-based preambles having consecutive indices associated with the said SS / PBCH block index per valid PRACH period start from preamble index R. If N ≥ 1, Q contention-based preambles having consecutive indices associated with the SS / PBCH block index n per valid PRACH period start from preamble index n*N total preamble Starting from / N + R, where 0 ≤ n ≤ N-1 and N total preamble The type-1 random connection process is provided by totalNumberOfRA-Preambles.

[0186] In the case of link recovery, the UE is provided with N SS / PBCH block indices associated with a single PRACH time by the RRC parameter ssb-perRACH-Occasion in the RRC configuration BeamFailureRecoveryConfig. In the case of a dedicated RACH configuration provided by the RRC configuration RACH-ConfigDedicated, if parameters cfra for contention-free random access to a given target cell are provided, the UE is provided with N SS / PBCH block indices associated with a single PRACH time by the parameter ssb-perRACH-Occasion regarding random access times for contention-free random access. If N < 1, a single SS / PBCH block index is mapped to 1 / N consecutive valid PRACH times. If N ≥ 1, all N consecutive SS / PBCH block indices are associated with a single PRACH time.

[0187] The SS / PBCH block indices provided by ssb-PositionsInBurst in SIB1 or RRC configuration ServingCellConfigCommon are mapped to valid PRACH times in the following order, and the parameters are described in 3GPP TS 38.211.

[0188] First, in the increasing order of preamble indices within a single PRACH period

[0189] Second, in increasing order of frequency resource indices for frequency-multiplexed PRACH periods

[0190] Third, in increasing order of time resource indices for time-multiplexed PRACH periods within the PRACH slot

[0191] Fourth, in increasing order of the indices for the PRACH slots

[0192] The association period, starting from frame 0, for mapping SS / PBCH block indexes to PRACH periods is N SSB Tx an association period, starting from frame 0, for mapping SS / PBCH block indexes to PRACH occasions is the smallest integer number in the set determined by the PRACH configuration period according to the following table such that N SSB Tx SS / PBCH block indexes are mapped at least once to the PRACH occasions within the association period), where UE is N from the value of ssb-PositionsInBurst in SIB1 or ServingCellConfigCommon SSB Tx Gets.

[0193] The following table illustrates the mapping between the PRACH setting period and the association period between the SS / PBCH block and the PRACH occasion.

[0194]

[0195] In the case of a PRACH transmission by a UE triggered by a PDCCH command, if the value of the Random Connection Preamble Index field is not zero, the PRACH Mask Index field indicates the PRACH timing for said PRACH transmission, wherein the PRACH timings are associated with the SS / PBCH block index indicated by the SS / PBCH Block Index field of said PDCCH command, and if any, the Cell Indicator field indicates the cell for the PRACH transmission (see 3GPP TS 38.212). The UE K by the RRC parameter cellSpecificKoffset cell,offset If provided, the above PRACH time is slot n + 2 u ·K cell,offset After, and here n is T TA Assuming = 0, it is a slot in the UL BWP for a PRACH transmission that overlaps with the end of the PDCCH command reception, and u is the SCS setting for said PRACH transmission. If the PDCCH reception for a PDCCH command contains two PDCCH candidates from two linked sets of searchspaces based on the RRC parameter searchSpaceLinkingId used to link two searchspaces of the same type within the same BWP, the last symbol of said PDCCH reception is the last symbol of the PDCCH candidate that ends later, as described in Section 10.1 of 3GPP TS 38.213. said PDCCH reception contains said two PDCCH candidates even when the UE is not required to monitor one of said two PDCCH candidates, as described in Section 10 (excluding Section 10.4), 11.1, 11.1.1, and 17.2 of 3GPP 38.213.

[0196] In the case of a PRACH transmission triggered by upper layers, if the RRC parameter ssb-ResourceList is provided, the PRACH mask index is indicated by the RRC parameter ra-ssb-OccasionMaskIndex, which indicates the PRACH timing for the PRACH transmission.

[0197] PRACH periods are mapped consecutively per corresponding SS / PBCH block index. The indexing of the PRACH periods indicated by the mask index value is reset per mapping cycle of consecutive PRACH periods per SS / PBCH block index. Within the first available mapping cycle, the UE selects the PRACH period indicated by the PRACH mask index value for the indicated SS / PBCH block index for PRACH transmission.

[0198] For the preamble index indicated above, the ordering of the PRACH periods is

[0199] First, regarding the frequency-multiplexed PRACH periods, in increasing order of frequency resource indices

[0200] Second, regarding the time-multiplexed PRACH periods within the PRACH slot, in increasing order of time resource indices

[0201] Third, for the PRACH slots, in increasing order of the indices

[0202] N rep preamble For a PRACH transmission with multiple preamble repetitions, the set is continuous in time and uses the same frequency resources, and is associated with one or more identical SS / PBCH block index(s), N rep preambleIt consists of valid PRACH periods, and each SS / PBCH block index is associated with the same preamble index within all valid PRACH periods in the set.

[0203] In the case of a PRACH transmission with preamble repetitions, the time interval starting from frame 0 is the above N SSB Tx For a PRACH transmission with preamble repetitions, a time period, starting from frame 0, is the smallest integer number of association pattern periods such that at least one set of valid PRACH occasions for each of the N SS / PBCH block indices can be determined within the time period for all set number of preamble repetitions. SSB Tx SS / PBCH block indexes can be determined within the time period for all configured number of preamble repetitions. The set(s) of valid PRACH occasions for each configured number of preamble repetitions repeat every time period.

[0204] Within the time interval, N rep preamble N for PRACH transmission with dog preamble iterations rep preamble For a set of valid preamble iterations

[0205] The first valid PRACH time of the first set is the first valid PRACH time.

[0206] If any, the first valid PRACH time of the subsequent sets is determined according to the ordering of the valid PRACH times.

[0207] First, in increasing order of frequency resource indices for frequency-multiplexed PRACH periods

[0208] Second, in increasing order of the time resource indices of the time multiplexing PRACH periods

[0209] Here, for each frequency resource index for the frequency-multiplexed PRACH periods

[0210] The first valid PRACH time of the first set is the first valid PRACH time.

[0211] If any, the first valid PRACH time of subsequent sets is

[0212] If the RRC parameter msg1-RepetitionTimeOffsetROGroup is provided, it is msg1-RepetitionTimeOffsetROGroup consecutive valid PRACH periods after the first valid PRACH period of the previous set, where each PRACH period is associated with the same SS / PBCH block index(s) and each SS / PBCH block index is associated with the same preambles.

[0213] If the RRC parameter msg1-RepetitionTimeOffsetROGroup is not provided, it is after the PRACH time of the previous set mentioned above.

[0214] In the case of a PRACH transmission triggered by a request from upper layers, if the RRC parameter csiirs-ResourceList is provided, the value of the RRC parameter ra-OccasionList indicates a list of PRACH times for said PRACH transmission, wherein said PRACH times are associated with a selected CSI-RS index indicated by the RRC parameter csi-RS. The indexing of the PRACH times indicated by ra-OccasionList is reset for each associated pattern interval.

[0215] For paired spectra or supplementary uplink bands, all PRACH periods are valid.

[0216] In the case of an unpaired spectrum,

[0217] If the UE is not provided with the RRC configuration tdd-UL-DL-ConfigurationCommon, the PRACH time within the PRACH slot does not precede the SS / PBCH block within the said PRACH slot, and at least N after the last SS / PBCH block received symbol. gap If it starts after the dog symbols, it is valid, where N gap It is provided in the following table, and if the RRC parameter channelAccessMode ="semiStatic" is provided, it does not overlap with the set of consecutive symbols before the start of the next channel occupancy time (see 3GPP TS 37.213) that the UE does not transmit.

[0218] >> The candidate SS / PBCH block index for the SS / PBCH block corresponds to the SS / PBCH block index provided by ssb-PositionsInBurst in SIB1 or ServingCellConfigCommon as described in Section 4.1 of 3GPP TS 38.213.

[0219] If the UE is provided with tdd-UL-DL-ConfigurationCommon, the PRACH timing within the PRACH slot is valid in the following cases.

[0220] If it is within the UL symbol, or

[0221] >> It does not precede the SS / PBCH block within the aforementioned PRACH slot, and at least N after the last downlink symbol gap After the dog symbols and after the last SS / PBCH block symbol, at least N gap If you start after the dog symbols, here N gap It is provided in the following table, and if channelAccessMode = "semiStatic" is provided, it does not overlap with a set of consecutive symbols before the start of the next channel occupancy time, which must not have any transmissions, as described in 3GPP TS 37.213 (it does not precede a SS / PBCH block in the PRACH slot and starts at least N gap symbols after a last downlink symbol and at least N gap symbols after a last SS / PBCH block symbol, where N_gap is provided in Table 8.1-2, and ifchannelAccessMode= "semiStatic" is provided, does not overlap with a set of consecutive symbols before the start of a next channel occupancy time where there shall not be any transmissions, as described in 3GPP TS 37.213.

[0222] >>> The candidate SS / PBCH block index of the above SS / PBCH block corresponds to the SS / PBCH block index provided by ssb-PositionsInBurst in SIB1 or ServingCellConfigCommon as described in Section 4.1 of 3GPP TS 38.213.

[0223] The following table shows N for different preamble SCS u. gap These are examples of values.

[0224]

[0225] Energy conservation in BSs is considered important in wireless communication systems, including 3GPP, because it can contribute to building eco-friendly networks by reducing carbon emissions and lowering the operational expenditure (OPEX) of telecommunication operators. In particular, as the introduction of 5G communication requires high transmission rates, BSs must equip a larger number of antennas and provide services through wider bandwidths and frequency bands. As a result, energy costs for BSs have reportedly reached 20% of total OPEX, according to recent studies. Due to this increased interest in BS energy conservation, a new study item titled "study on network energy savings" was approved in 3GPP NR release 18. For example, to improve energy saving capabilities in terms of transmission and reception of BS, this study investigates how to achieve more efficient operation of transmission and / or reception with one or more network energy saving techniques in time, frequency, space, and power domains, dynamically and / or semi-statically, and with finer granularity adaptation, using potential support / feedback and potential UE support information of the UE.

[0226] The following enhancement techniques may be considered.

[0227] Specify SSB-less SCell operation for inter-band CA for FR1 and co-located cells, where a UE measures SSB transmitted on PCell or another SCell for an SCell's time / frequency synchronization (including downlink AGC), and L1 / L3 measurements, including potential enhancement on SCell activation procedures if necessary.

[0228] Specify enhancement on cell DTX / DRX mechanism including the alignment of cell DTX / DRX and UE DRX in RRC_CONNECTED mode, and inter-node information exchange on cell DTX / DRX

[0229] Specify the following techniques in spatial and power domains

[0230] Specify necessary enhancements on CSI and beam management related procedures, including measurement and report, and signaling, to enable efficient adaptation of spatial elements (e.g., antenna ports, active transceiver chains).

[0231] Specify necessary enhancements on CSI-related procedures, including measurement and report, and signaling, to enable efficient adaptation of power offset values ​​between PDSCH and CSI-RS.

[0232] Specify mechanism(s) to prevent legacy UEs camping on cells adopting the Rel-18 NES techniques, if necessary.

[0233] Specify conditional handover (CHO) procedure enhancement(s) in case source / target cell is in NES mode.

[0234] Specify inter-node beam activation and enhancements on restricting paging in a limited area.

[0235] If necessary, specify the corresponding radio resource management / radio frequency (RRM / RF) core requirements for the above features.

[0236] BS can apply techniques such as adjusting the on / off duration in the time axis for NES purposes, adjusting transmit / receive resources for UE-common or UE-specific signals / channels, changing the amount of resources in the frequency axis, adjusting the transmission power, or turning on / off antenna port(s) or TRP(s), etc. in the spatial domain. The state in which such techniques(s) (hereinafter referred to as NES_tech for convenience) are applied is called NES mode or NES state.

[0237] Figure 12 illustrates the operation procedure in a BS that supports network energy saving (NES) technology.

[0238] Referring to FIG. 12, the BS identifies or determines the NES solution(s) to be applied (S1201). The NES solution(s) may be related to the control of signal transmission / reception (e.g., on / off), beam operation, handover procedures, channel measurement and reporting, etc. Which NES solution(s) to apply may be adaptedly selected based on the current situation (e.g., cell load level, characteristics of connected UEs, etc.) or may be predefined. The BS that has identified (or determined) the NES solution(s) may perform signaling for the NES (S1203). The specific signaling procedure may vary depending on the identified NES solution(s). For example, the BS may transmit common information regarding the NES solution(s), transmit configuration information necessary for NES operation to at least one UE, or transmit control information regarding the progress of NES operation to at least one UE. Additionally, the BS may receive capability information related to the NES from at least one UE. Afterward, BS can perform operations for NES (S1205). At this time, BS can perform operations for NES based on the signaling performed earlier. For example, depending on the system information, configuration information, and control information transmitted through the signaling, BS can turn on or off the transmission / reception of a specific signal, turn on / off elements of the spatial domain, or adjust resources for the transmission / reception of a measurement signal.

[0239] NES technology can be performed through a procedure as shown in Fig. 12. Examples of NES solutions that can be performed by a procedure as shown in Fig. 12 are as follows.

[0240] Intra-system energy saving solution: A radio access network (RAN) node may request a neighbor RAN node to switch at least one SSB beam into its deactivated cell, or perform paging using a limited set of beams to an inactive UE (e.g., stationary UE).

[0241] Inter-system energy saving solution: An NG-RAN node owning a capacity booster cell can autonomously switch the cell to an inactive state.

[0242] > SSB-less SCell solution: If an SSB measurement timing configuration (SMTC), which is an SSB-based radio resource management (RRM) measurement timing configuration, is not provided for the SCell, the UE can obtain timing reference and automatic gain control (AGC) sources from other serving cells. In FR1 or FR2, the BS can set up intra-band carrier aggregation (CA) or inter-band CA including the SCell without SSB transmission, in which case SSB / SIB transmission can be triggered by the UE's wake-up signal (WUS). Accordingly, as the periododicity of common channels / signals such as SSB increases, the BS can remain in a sleep state for a longer time.

[0243] Cell DTX / DRX Solution: To reduce the downlink transmission / uplink reception active time of a BS, periodic cell DTX / DRX patterns (e.g., active and inactive periods) may be configured commonly for UEs within a cell having the corresponding feature. Here, the cell DTX pattern and the cell DRX pattern may be configured and activated separately, and up to two cell DTX / DRX patterns may be configured per MAC entity. When cell DTX is configured and activated, at least one of monitoring for semi-persistent scheduling (SPS) occasions or PDCCH monitoring may be suspended during the cell DTX inactive period. When cell DRX is configured and activated, at least one of transmission or scheduling request (SR) transmission from a configured grant (CG) resource may be suspended during the cell DRX inactive period. Cell DTX / DRX can be enabled / disabled via RRC signaling or L1 group common signaling (e.g., PDCCH over CSS). Parameters such as active duration and cycle can be set for Cell DTX / DRX. The active duration is the period during which the UE waits to transmit an SR or CG after receiving a PDCCH or SPS occasion, and the cycle specifies the periodic repetition of the active and inactive periods. When both Cell DTX and Cell DRX are enabled, parameters such as the active duration and cycle are common.If the BS detects an emergency call or a public safety-related service (e.g., multimedia priority service (MPS) or mission critical service (MCS)), the network may release or deactivate the cell DTX / DRX settings so as not to affect the service. Additionally, at least some overlap is required between the active period of the UE's connected mode DRX and the active period of the cell DTX / DRX. For example, the UE's connected mode DRX periododicity may be a multiple of the cell DTX / DRX periododicity, or vice versa.

[0244] Conditional Handover (CHO) Solution: A CHO procedure, performed in such a way that the execution of a handover is determined by the UE, is used while NES technology is applied (e.g., when a cell enables or disables Cell DTX / DRX). In this case, the UE may use NES-specific CHO events to execute a CHO for a candidate cell, and as an additional triggering condition for this, the reception of a DCI that enables CHO condition(s) set as NES event indications may be applied.

[0245] Spatial and power domain adaptation solution: To support BS for transceiver muting and / or transmission power adaptation, the UE can be configured to report multiple CSI entries in CSI reporting based on multiple sub-configurations. Each sub-configuration can correspond to a spatial domain adaptation pattern (e.g., a subset of available spatial elements) and / or a data channel (e.g., PDSCH) and power offset between CSI-RSs. Depending on the application of the spatial and power domain adaptation solution, CSI configuration, measurement, and / or reporting behavior may be affected.

[0246] DCI format 2_9

[0247] DCI Format 2_9 is used to enable or disable cell DTX and / or DRX settings of one or more serving cells for one or more UEs, or to provide NES-mode instructions for primary cells for one or more UEs. The following information is transmitted via DCI Format 2_9 with a CRC scrambled by cellDTRX, which is a parameter provided to the UE via upper layer (e.g., RRC) signaling.

[0248] Block number 1, block number 2, ..., block number N, where the starting position of each block associated with the serving cell is determined by positionInDCI-cellDTRX, a parameter provided to the UE through upper layer (e.g., RRC) signaling.

[0249] If the UE is configured to monitor DCI 2_9 with a CRC scrambled with cellDTRX-RNTI, which is a parameter provided to the UE via upper-layer signaling, one or more blocks are configured for said UE by upper-layer signaling, having the following fields defined for each block:

[0250] Cell DTX / DRX indication - The number of bits is determined by the following:

[0251] If the upper layer parameter cellDTXDRX-L1activation is set:

[0252] If cellDTXDRXconfigType is set to dtxdrx for the serving cell associated with that block, 2 bits as defined in Section 11.5 of 3GPP TS 38.213, where the most significant bit (MSB) corresponds to the cell DTX setting and the least significant bit (LSB) corresponds to the cell DRX setting;

[0253] If cellDTXDRXconfigType is set to either dtx or drx for the serving cell associated with that block, 1 bit as defined in Section 11.5 of 3GPP TS 38.213;

[0254] Otherwise, 0 bit.

[0255] NES-mode indication - 1 bit indicating an NES-specific CHO execution condition as defined in Section 11.5 of 3GPP TS 38.213 if the upper layer parameter nesEvent is set and the associated serving cell of the block is a primary cell; otherwise, 0 bit.

[0256] The size of DCI format 2_9 is determined by the upper layer parameter sizeDCI-2-9.

[0257] SSB-less SCell

[0258] Figure 13 is an example of a process for carrier aggregation (CA) operation using an SSB-less secondary cell (SCell).

[0259] Referring to FIG. 13, the BS can transmit configuration information for SCells to be aggregated through a SCell already configured to the PCell or UE (S1301). For example, the BS can transmit configuration information for CA to provide services to the UE through a CA operation. Here, the CA operation may be an intra-band CA or an inter-band CA. For example, the configuration information for SCells may include information containing information for adding SCells (e.g., sCellToAddModList), and specifically, may include a cell index, a physical cell identifier, information related to DL-UL configuration, information related to BWP, information related to cell DTX / DRX, information related to downlink frequency (e.g., FrequencyInfoDL), etc. Subsequently, the UE determines the configuration for the CA operation (S1303) and can perform communication using the BS's PCell and SCell (S1305a, S1305b). In some implementations, the UE can determine that the SCell is an SSB-less SCell based on information related to the downlink frequency included in the configuration information and can check the relevant parameters. For example, the UE can determine that the SCell is an SSB-less SCell by checking for the presence of a parameter indicating that it is an SSB-less SCell (e.g., SSBlessSCell) and can determine the timing reference and AGC source for the SCell based on information about the reference cell (e.g., referenceCell). In the example of FIG. 13, the reference cell may be a PCell. In this case, the UE can use the PCell as the timing reference and AGC source for communication in the SCell.

[0260] The following table illustrates a portion of the RRC information element (IE) FrequencyInfoDL, which provides the downlink carrier and the basic parameters of transmission on said downlink carrier.

[0261]

[0262] The above IEFrequencyInfoDL may be included in the RRC configuration DownlinkConfigCommon or DownlinkConfigCommonSIB, which provides common downlink parameters for the cell.

[0263] In the table above, the field absoluteFrequencySSB indicates the frequency of the SSB to be used for this serving cell, and SSB-related parameters provided for the serving cell (e.g., SSB index) refer to this SSB frequency unless otherwise noted. The cell-defining SSB (CD-SSB) of the PCell is always on the sync raster. If frequencies are identifiable by their GSCN values, they are considered to be on the sync raster. If the field absoluteFrequencySSB is absent in the IEFrequencyInfoDL, the SSB-related parameters (e.g., ssb-PositionsInBurst, ssb-periodicityServingCell, and subcarrierSpacing in ServingCellConfigCommonIE) are absent. If the above field absoluteFrequencySSB is absent, the UE may obtain a timing reference from an applicable SpCell or SCell, from the SpCell or SCell indicated by the referenceCell, or from a default cell. This is supported when the SCell from which the UE obtains the timing reference is within the same or different frequency band as the cell from which the UE obtains the timing reference (e.g., the respective SpCell or SCell).

[0264] In the table above, the field referenceCell can indicate a reference cell, which is a cell that provides timing references and AGC sources for SCells without SSB. If the reference cell is an SCell or PSCell, it is an active SCell or active PSCell. If this field is absent, the default cell is the reference cell.

[0265] The UE may receive the periododicity of half frames for receiving SSBs for that serving cell per serving cell via the RRC parameter ssb-perodicityServingCell. If the UE is not set the periododicity of half frames for receiving SSBs, the UE assumes a periododicity of half frames. The UE may assume that the periododicity is the same for all SSBs within the serving cell. For initial cell selection, the UE may assume that half frames containing SSBs occur at a period of two frames.

[0266] On-demand SSB

[0267] In some implementations, a method to reduce energy consumption may be considered in which the BS transmits an SSB on a specific cell through an on-demand SSB process, and does not transmit an SSB on said specific cell when there is no on-demand SSB process. For convenience, SSBs transmitted for a certain period or interval upon request by a UE are referred to as on-demand SSBs below. In existing NR systems, it was difficult to reduce energy consumption even when the BS had no data to receive or send, as SSBs had to be transmitted periodically at all times for purposes such as time / frequency synchronization or RRM measurement. Considering this, in some implementations, BS energy consumption can be reduced by allowing the BS to refrain from transmitting SSBs and only perform transmissions when an on-demand SSB process is involved. The above on-demand SSB process can be triggered through one of the following methods.

[0268] 1) The UE requests the BS's SSB transmission by transmitting an uplink signal / channel (e.g., PRACH, PUCCH, PUSCH, SRS, etc. in 3GPP-based systems);

[0269] 2) Requesting the transmission of the SSB from BS (or TRP) #1 to BS (or TRP) #2 via an interface between BSs (e.g., Xn interface in NR-based systems) or backhaul signaling; or

[0270] 3) Signal whether SSB is transmitted for the corresponding SCell through SCell activation / deactivation signaling.

[0271] Considering coexistence with UEs according to existing NR standards, some scenarios (e.g., 3GPP Release 19) may be limited to on-demand SSB operations for connected mode UEs and SCells. However, in future releases or next-generation communication systems, on-demand SSB operations (for SSB transmission on a PCell) may be defined for inactive or idle mode UEs or initial connection UEs. Additionally, CA including the SCell may be applied to both intra-band CA and inter-band CA, and the SSB on the SCell transmitted through the on-demand SSB process may be utilized for at least time / frequency synchronization, layer 1 (L1) / layer 3 (L3) measurement, and SCell activation.

[0272] SIB1 transmission on demand

[0273] In some implementations, a method to reduce energy consumption may be considered in which the BS transmits an on-demand SIB1 for a specific cell through an on-demand SIB1 process, and does not transmit the SIB1 for that cell when there is no on-demand SIB1 process. For convenience, the SIB1 transmitted for a certain period or interval upon request by a UE is referred to as an on-demand SIB1 below. In existing NR systems, it was difficult to reduce energy consumption even when the BS had no data to receive or send, because it was always necessary to periodically provide SIB1s containing system information and random connection information for UEs in initial connection or idle mode to connect to a cell. Considering this, some implementations allow the BS to refrain from transmitting SIB1s and only perform transmissions when an on-demand SIB1 process is involved, thereby reducing BS energy consumption. During this on-demand SIB1 process, the BS's SIB1 transmission can be triggered by the UE transmitting an uplink signal / channel (e.g., PRACH in 3GPP-based systems).

[0274] FIGS. 14 through 16 illustrate custom SIB1 transmission scenarios related to some implementations of the present specification.

[0275] The following scenarios may be considered in relation to custom SIB1 transmission according to some implementations of this specification, but some implementations of this specification may not be limited to the following scenarios.

[0276] 1) Scenario 1: As illustrated in FIG. 14, a UE that receives an SSB (and / or other downlink signal / channel) at Cell #1 and recognizes that SIB1 is not being transmitted on Cell #1 can trigger the transmission of SIB1 by transmitting a signal requesting SIB1 (hereinafter, for convenience, a wake-up signal (WUS)) based on information provided by the SSB (and / or other downlink signal / channel) and / or predetermined information. A BS that receives the WUS can transmit a specific DL signal / channel on Cell #1 (corresponding to an ACK for the WUS) in response, or transmit SIB1 on Cell #1 (or without transmitting the DL signal / channel).

[0277] 2) Scenario 2: As illustrated in FIG. 15, a UE that receives an SSB (and / or other downlink signal / channel such as SIB1) at Cell #1 and realizes that SIB1 is not being transmitted on Cell #2 may attempt to camp-on through Cell #2. The UE may trigger the transmission of SIB1 to Cell #2 by transmitting a signal (e.g., WUS) requesting SIB1 on Cell #1 based on the information provided by the received SSB (and / or other downlink signal / channel such as SIB1) and / or predetermined information. A BS that receives the WUS may, in response, transmit a specific DL signal / channel (corresponding to an ACK for the WUS) on Cell #1 or Cell #2, or transmit SIB1 to Cell #2 on Cell #1 or Cell #2 (or without transmitting the DL signal / channel).

[0278] 3) Scenario 3: As illustrated in FIG. 16, a UE that receives an SSB (and / or other downlink signal / channel such as SIB1) at Cell #1 and realizes that SIB1 is not being transmitted on Cell #2 may attempt to camp-on through Cell #2. The UE may trigger the transmission of SIB1 for Cell #2 by transmitting a signal (e.g., WUS) requesting SIB1 on Cell #2 based on the information provided in the received SSB (and / or other downlink signal / channel such as SIB1) and / or predetermined information. A BS that receives the WUS may, in response, transmit a specific DL signal / channel (corresponding to an ACK for the WUS) on Cell #1 or Cell #2, or transmit SIB1 for Cell #2 on Cell #1 or Cell #2 (or without transmitting the DL signal / channel).

[0279] In cases where multiple cells are involved for on-demand SIB1 operation, as in the above scenarios 2 or 3, Cell#1 and Cell#2 can be defined as follows.

[0280] - Cell A (= Cell#1): A cell that is periodically transmitting at least its own SIB1.

[0281] - NES cell (= Cell#2): A cell that may transmit SIB1 in response to UL WUS from a UE.

[0282] For example, Cell A may refer to a cell where SIB1 information for that cell is periodically transmitted over that cell, and may also be expressed as Cell #1 or an anchor cell. Additionally, NES cell may refer to a cell where SIB1 is provided in response to an uplink WUS from the UE, and may also be expressed as Cell #2 or a non-anchor cell.

[0283] The UE can discover a cell and recognize that the cell is an NES cell (requiring on-demand SIB1 operation) through at least one or a combination of the following methods.

[0284] - The UE can recognize that it is an NES cell through the SIB and / or WUS configuration information (provided by Cell A).

[0285] - The UE can identify that it is an NES cell through information such as the center frequency of the PBCH / MIB / SSB (received from the NES cell).

[0286] - The UE can identify an NES cell through the DCI (received from the NES cell). The DCI can be received in the CORESET / scan space configured via the PBCH, MIB, or SSB (received from the NES cell). Additionally, a separate RNTI value for the DCI can be pre-configured / defined.

[0287] - If the UE attempts to receive SIB1 of the cell but fails to receive SIB1 for a certain period of time or longer, it can recognize that it is an NES cell.

[0288] Meanwhile, the UE may receive configuration for an uplink WUS requesting SIB1 for an NES cell through at least one of the following methods or a combination thereof.

[0289] - RRC messages transmitted from Cell A (e.g., SIB1 or other system information block, RRC release message),

[0290] - DCI transmitted over Cell A or NES cell,

[0291] - Msg2 / Msg4 (via the 4-stage random access process) or MsgB (via the 2-stage random access process) transmitted from Cell A

[0292] - The center frequency of the PBCH / MIB / SSB transmitted over the NES cell, or

[0293] - Information that is pre-defined / pre-configured in the specifications.

[0294] Since there are technologies found to be useful through research that are not yet specified in the 3GPP communication standard document, some implementations of this specification are provided below that can obtain network energy saving benefits based on beneficial techniques that have not yet been adopted.

[0295] BS can save energy through symbol muting when there is no data to send. However, since common signal(s) and channel(s) such as SSB or SIB are always-on signal(s) / channel(s) that must always be transmitted, it is difficult to achieve energy saving (ES) effects through symbol muting for these symbols. In NR, SSB / SIB can be transmitted via beam sweeping through multiple beams and specific subcarrier spacing (SCS) for each frequency range (FR), and the number of beams increases as the FR increases. Therefore, the amount of time resources used for common signal / channel transmission, such as SSB / SIB1, becomes relatively larger in FR2 compared to FR1, and consequently, the proportion of energy consumption in BS at which common signal / channel transmission occurs in FR2 may also be higher than in FR1. In order to reduce energy consumption caused by constant signal transmission such as BS's SSB / SIB, the period of the SSB / SIB may be set to a long duration, but in this case, the time required for the UE to connect to the cell may be prolonged, and problems such as legacy UEs failing to properly discover the cell may occur.

[0296] Accordingly, in one way, in some implementations of this specification, a connection mode UE may receive an SSB period set through a UE-specific RRC in addition to the SSB period set through SIB1. In this case, one or more SSB burst period candidates may be set (to the UE(s) in the cell) for energy saving of the BS, and control instructions regarding the SSB burst period (for the cell) may be provided quickly (relatively compared to RRC reconfiguration) through a group-common DCI or MAC CE, taking into account the conditions within the cell (e.g., load / number of connection mode UEs / traffic in a specific beam direction, etc.). For example, if a UE is set to four SSB burst periods such as {80ms, 160ms, 320ms, 640ms}, it can be dynamically directed to one of the four SSB period candidates through a 2-bit field in the group-common (GC) DCI (e.g., 80ms if 00, 160ms if 01) in a low load situation where there is little data activity, such as during the early morning hours.

[0297] FIG. 17 illustrates RACH occasion (RO) adaptation. The UE receives information necessary to transmit a PRACH (e.g., information regarding time / frequency resources) through the BS's SIB1 or UE-specific RRC signaling, and can transmit a PRACH at determined / set RACH occasions (RO) based on said information. The BS must wake up at each RO to receive the PRACH that the UE may transmit and wait for PRACH reception. Therefore, if the RO period set for the UE is short, the energy consumption of the BS may be relatively greater compared to when the RO period is set long. However, if ROs are set with too long a period to save energy for the BS, if there is no RO resource near the time when the UE needs to transmit a PRACH for cell connection, it may wait until the next RO resource becomes available before transmitting, which can increase connection delay. This leads to scheduling delays and may result in performance degradation of the UE. In addition, the BS can save energy by switching to sleep mode when the number of connected mode UEs is low or there is a time period with no temporary data activity depending on the situation within the cell; however, since it must frequently wake up to receive and check for PRACH transmitted by UEs in the RO configured in the cell, it cannot remain in sleep mode for a long time, and it is difficult to expect significant energy saving benefits. Therefore, in such cases, setting a long RO periodicity can be advantageous in terms of BS energy saving.However, according to current standards, since only semi-static methods (such as SI modification) are possible to change settings such as the cell's RO cycle, it is relatively time-consuming and may be difficult to quickly respond to opportunities for energy saving.

[0298] With this in mind, as in the example of FIG. 17, the BS can set up a sparse RO (in the time domain) and a dense RO that can be dynamically activated or deactivated (for a cell or BWP), and normally operate only according to the sparse RO to save energy, but when certain conditions are met, such as when the initial connection delay of a UE increases or congestion occurs due to an increase in the number of UEs transmitting RACH from one RO, the dense RO (in the time domain) is activated based on a request from the UE(s) or a dynamic instruction by the BS (e.g., through a group common DCI and / or MAC control element, CE), thereby providing an opportunity to save energy of the BS while minimizing performance degradation.

[0299] A method to reduce energy consumption by controlling SSB transmission in the BS may be considered. However, while completely turning off the SSB on the cell can significantly reduce energy consumption in the BS, stable operation of the cell may not be guaranteed from the UE's perspective without an SSB that performs functions such as time / frequency synchronization or radio resource management (RRM) measurement in the cell. Considering this, it may be considered to achieve energy saving effects in the BS by changing the transmission pattern of the SSB (e.g., transmission period, periodicity per SSB candidate index(s), SSB candidate index(s) transmitted within one transmission period, transmission power, etc.) depending on the situation.

[0300] When SSB adaptation is introduced, the UE cannot know when the BS changes the SSB cycle for the cell. Even if the BS explicitly provides an SSB adaptation instruction to the UE through explicit signaling, it is necessary to clarify when the adapted SSB transmission is applied. Furthermore, since the SSB transmission pattern and / or SSB timing(s) on the cell may differ depending on whether SSB adaptation is present, for the energy saving efficiency of the UE and / or BS, the UE and BS must be able to assume the same SSB transmission pattern and / or SSB timing(s) regardless of the presence or absence of the SSB adaptation instruction. In addition, a method is required to ensure that critical problems do not occur in communication through the cell even if the UE fails to detect the SSB adaptation instruction transmitted by the BS.

[0301] Some implementations of this specification are described below for determining the transmission location of an SSB burst of a changed period when one or more additional SSB (index) group(s) / burst period(s) are pre-configured for UE(s) for SSB (index) group period adaptation and / or SSB burst period adaptation for a specific cell, and when period switching is dynamically indicated via (GC-)DCI (or MAC CE). Also described below are some implementations of this specification for determining the reference time point at which the actual additional SSB location(s) become available when additional SSB location(s) (also referred to as SSB time(s)) are configured for SSB adaptation and when the availability of the additional SSB time(s) is dynamically indicated via (GC-)DCI, and some implementations of this specification for explicitly activating the additional SSB location(s).

[0302] <Method #1> A method for determining the SSB reception location of a changed period when an SSB period is dynamically instructed via (GC-)DCI (or MAC CE), and for receiving parameters such as N (≥1) additional SSB periods for SSB adaptation (e.g., SSB burst period adjustment) and (SFN) offset and half-frame index for a specific cell (e.g., SCell) from the BS.

[0303] When a UE initially connects to a cell, it attempts to receive a primary synchronization signal (PSS) for the entire time domain for time / frequency synchronization. When the PSS is detected, it receives a secondary synchronization signal (SSS) and a PBCH, thereby identifying the half-frame index, SFN information, and SSB index contained within the PBCH. Although the UE cannot immediately know the exact SSB period upon detecting the SSB, it receives SIB1 based on the received SSB and obtains the SSB period information contained within SIB1. By combining the SFN information and / or half-frame (HF) index with the SSB period information within SIB1, the UE can accurately identify and receive the SSB location of the PCell. For example, based on the time / frequency synchronization procedure performed during the UE's initial connection procedure and information such as the HF index and SSB period, it can determine which frame and which half-frame the SSB burst is located in.

[0304] In the case of SCell, the SSB period, SSB frequency position, and physical cell ID can be pre-configured, and the UE moves to the SCell to attempt SSB reception based on this information. Since the SCell is aligned with the PCell at the slot boundary, it attempts SSB detection once per half-frame boundary without the synchronization procedure required in the PCell. For example, if a UE moves to the SCell starting from SFN#0 and begins SSB monitoring, and an SSB is received at SFN#3, the UE can assume that SSBs will continue to be received at every pre-configured SSB period starting from SFN#3.

[0305] In some implementations, for a cell to which SSB adaptation is applied, one or more SSB periods may be configured for said cell. In some implementations, legacy parameters (e.g., ssb-Periodicity) previously configured via the RRC information element (IE)ServingCellConfigCommon are configured identically for legacy UEs, and one or more additional SSB period(s) may be configured for UE(s) that support SSB adaptation (e.g., R19 NES-capable UEs). However, if only additional SSB periods are configured for a cell to which SSB adaptation is applied, but parameter(s) for the UE(s) to receive the SSB of the changed period (e.g., offset, half-frame index) after SSB adaptation for said cell is indicated are not configured separately, the UE cannot know where the first SSB of the changed period will be transmitted when it is indicated for SSB adaptation via (GC-)DCI (or MAC CE).

[0306] Accordingly, when BS sets one or more SSB period candidates for SSB adaptation and directs a change from SSB period #A to SSB period #B via (GC-)DCI (or MAC CE), in some implementations of this specification, the time domain location where the UE can assume the first reception of the SSB of the changed period may be set or defined (in the standard, etc.) largely by one of the following methods, and long-period SSB occasions may be set in a form that is a subset of short-period SSB occasions.

[0307] Option 1) The UE receives a (GC-)DCI (or MAC CE) instructing SSB adaptation, and SSB transmission of the modified cycle begins immediately after the processing time. In some implementations, the processing time may be pre-defined in standard documents, etc.

[0308] > Option 2) The UE receives (GC-)DCI (or MAC CE) instructing SSB adaptation, and SSB transmission of the modified period begins after a (SFN) offset defined in a pre-configured / standard, etc. (after processing time). In some implementations, different offset values ​​may be set for each SSB period configured for SSB adaptation, and the first SSB of the modified period may be configured to be transmitted after the (GC-)DCI processing time.

[0309] Some implementations of this specification regarding the time domain location where the UE can assume the first reception of an SSB of a changed period are described in more detail below. In the following description, an SSB period may refer to the period of an SSB of a single SSB index, or the period of an SSB burst containing a set of SSBs of different SSB indices. For convenience of explanation, the period of an SSB burst is primarily referred to as an SSB period in this specification.

[0310] FIGS. 18 through 20 are examples of SSB adaptations according to some implementations of the present specification. In the following description with reference to FIGS. 18 through 20, SSB may mean a single SSB or may mean an SSB burst comprising SSBs of different SSB indices. For example, in the examples of FIGS. 18 through 20, a box representing an SSB may include multiple SSB (candidate) times of different SSB indices. In the examples of FIGS. 18 through 20, it is assumed that an SSB adaptation instruction to an SSB (burst) cycle in (GC-)DCI from an SSB (burst) cycle of 20 ms to an SSB (burst) cycle of 80 ms is indicated through (GC-)DCI.

[0311] For Option 1 described above, referring to Fig. 18, for example, {20ms, 80ms} are set in advance as SSB period candidates for the UE, and if a change instruction to an 80ms period is given via (GC-)DCI (e.g., DCI format 2_9) while the SSB is being transmitted at a 20ms period before SSB adaptation, the UE can expect to receive the first SSB of the changed period starting from the earliest time among the 20ms period SSB times after the (GC-)DCI processing time. Conversely, if a change to a 20ms period is given via (GC-)DCI while the SSB is being transmitted at an 80ms period, the UE can expect to receive the first SSB of the changed period starting from the earliest time among the 80ms period SSB times after the (GC-)DCI processing time.

[0312] For Option 2 described above, referring to FIG. 19 and FIG. 20, for example, {20ms, 80ms} are set in advance as SSB period candidates for the UE, and if there is a change instruction to an 80ms period via (GC-)DCI (e.g., DCI format 2_9) while the SSB is being transmitted at a 20ms period before SSB adaptation, the UE can expect to receive the first SSB of the changed period from the time when the (GC-)DCI is received (see FIG. 19), or from the time when the SSB is at which the offset value is added in advance or defined in the standard based on the start or end time of the SFN where the (GC-)DCI is received (see FIG. 20). In the examples of FIGS. 19 and 20, at the 20ms period SSB time immediately following the reception of (GC-)DCI (e.g., the SSB time following the reception of DCI in FIG. 19 and the SSB time located at SFN 2 in FIG. 20), the SSB may or may not be transmitted according to the setting / instruction by BS (or definition in standard documents, etc.).

[0313] In some implementations, the offset value may be set differently for each SSB cycle configured for SSB adaptation, and the first SSB of the modified cycle may be configured to be transmitted after the (GC-)DCI processing time. Alternatively, multiple candidate offset values ​​may be set in advance (or defined in standard documents, etc.), and one of them may be dynamically indicated via the DCI that directs SSB adaptation. Additionally, the reference point to which the offset value is added may be set / defined based on 1) the first or last symbol of the slot where the (GC-)DCI was received, or 2) the first / last symbol of the CORESET where the (GC-)DCI was received. If such an offset value is set in advance (or defined in standard documents, etc.), it can have the effect of determining the SSB timing for each SSB cycle. For example, if an offset value is pre-set or defined (in a standard document) for each additional SSB burst cycle, the position of the SSB burst for that cycle can be determined because the SSB times corresponding to that cycle start periodically after the offset value from a specific reference point for each SSB burst cycle. In some implementations of this specification, if SSB adaptation is indicated by (GC-)DCI, the change may be applied starting from the nearest position among the defined SSB times after the first processing time (or predetermined offset) following the (GC-)DCI.

[0314] Regarding the time domain location where the UE can assume the first reception of the SSB of the changed period, the following may be considered.

[0315] > Option 3) Based on a reference SFN point (e.g., an SFN satisfying (SFN index * 10) modulo (addl-SSB periodicity) = 0), a set of SFNs is defined in which candidate SSB periods for which an SSB can be transmitted are located for each (additional) SSB period set for SSB adaptation, and after the (GC-)DCI (or MAC CE) indicating SSB adaptation is transmitted / received, transmission / reception of the SSB of the changed period may begin starting from the closest SFN among the set of SFNs of the SSB period to be changed after a processing time (or a preset / predefined offset). Here, "addl-SSB periodicity" means the transmission interval or transmission cycle of the additional SSB period.

[0316] FIGS. 21 through 23 are other examples of SSB adaptation according to some implementations of the present specification. In particular, FIGS. 21 through 23 are examples for illustrating SSB adaptation according to Option 3. In the examples of FIGS. 21 through 23, SSB may mean a single SSB or may mean an SSB burst containing SSBs of different SSB indices. In some implementations, for Option 3, for example, an SFN satisfying (SFN index * 10) modulo (OD-SSB periodicity) = 0 may be determined to be the SFN to be used as a reference point. In some implementations, a set of SFNs may be defined from the SFN used as a reference point, in which an SSB may be located for each additional SSB period set for SSB adaptation. For example, through the SSB adaptation settings for a cell, when an additional SSB period and an SFN offset value and a half-frame value associated with said additional SSB period are set, a set of SFNs that may have SSB times according to said additional SSB period can be determined. Referring to FIG. 21, when the reference SFN is SFN#0 and the additional SSB period set for SSB adaptation is 80ms, the set of SFNs that can transmit an SSB of the 80ms period (e.g., for candidate SSB times) can be defined as SFN#0, #8, #16, ..., when the period is 40ms, it can be defined as SFN#0, #4, #8, ..., and when the period is 20ms, it can be defined as SFN#0, #2, #4, #6, #8, ...,. Here, a shifted set of SFNs can be determined by applying an SFN offset and half-frame index that are pre-set (for the UE(s)) or dynamically indicated via (GC-)DCI or MAC CE (or defined in standard documents, etc.).For example, referring to FIG. 22, when the SFN offset value is 1, the candidate SSB timings for the 80ms period in the example of FIG. 21 may be located at SFN#1, #9, #17, ..., when the period is 40ms, the candidate SSB timings may be located at SFN#1, #5, #9, ..., and when the period is 20ms, the candidate SSB timings may be located at SFN#1, #3, #5, #7, #9, ...,.

[0317] FIG. 23 illustrates a change in the SSB (burst) transmission location when the exemplified SSB period(s) of FIG. 22 are set as candidate SSB period(s) for a cell, and there is an SSB adaptation instruction to change the 20ms period for said cell to an 80ms period. Referring to FIG. 23, when the UE receives a (GC-)DCI (or MAC CE) that triggers SSB adaptation from a 20ms period to an 80ms period and applies a processing time (or offset) at SFN#6, it can be expected that the changed 80ms period SSB will be received at the location where the half-frame index is applied in SFN#9, which is the closest (i.e., earliest) SFN after SFN#6 among the transitioned SFN set {SFN#9, #17, #25, #33, ...} corresponding to the 80ms period SSB. According to Option 1 or Option 2, the changed SSB period is applied from the earliest frame after the processing time or (SFN) offset from the symbol / slot / SFN boundary where the SSB adaptation instruction triggering the SSB period change is received. Therefore, in the case of Option 1 or Option 2, referring to FIG. 23, if the time at which the UE receives the (GC-)DCI (or MAC CE) that triggers SSB adaptation from a 20ms period to an 80ms period and applies the processing time or offset is within SFN#6 or at the end of SFN#6, the UE can expect to receive an SSB (burst) with an 80ms period starting from SFN#7, which is the earliest SFN after SFN#6 among the SSG (burst) periods of 20ms period.Therefore, according to Option 1 or Option 2, if the SSB period is changed from a longer SSB period to a shorter SSB period, there is a risk that the interval between SSB transmission times will suddenly become too short, and since the set of SFNs to which an SSB can be transmitted varies depending on when the SSB adaptation instruction is transmitted / received, there is a risk that if the UE does not successfully receive the SSB adaptation instruction transmitted by the BS, the BS and the UE will perceive the SSB transmission locations differently. In contrast, according to some implementations of Option 3 described above or below, since the sets of SFNs to which an SSB can be transmitted are in a mutually inclusive relationship depending on the period, no major problem may occur even if the UE and the BS do not understand different SFNs as SFNs where an SSB may be present or understand them differently. Additionally, according to Option 3, when a UE moving from another cell to a cell that supports SSB adaptation needs to perform blind detection of the SSB location, it may be easy to detect the SSB because the set of SFNs to which an SSB can be transmitted is fixed.

[0318] In Option 1, Option 2, and / or Option 3, the UE may determine candidate SSB (burst) times in which an SSB of a changed period may be transmitted by applying a (SFN) offset and a half-frame index that are pre-configured or dynamically indicated via (GC-)DCI or MAC CE (or defined in standard documents, etc.). For example, in Option 3, a shifted set of SFNs may be determined by applying a pre-configured SFN offset value. As previously described, since long-period SSB (burst) times must satisfy the relationship of being a subset of short-period SSB times, in some implementations of this specification, except for 5ms period SSBs where an SSB burst always exists within 5ms, the UE may assume that all half-frame indices carried in / reflected in the MIB / PBCH payload / PBCH-DMRS sequence are the same. If a UE receives / recognizes a half-frame index value (e.g., HF = 1) of an SSB (from the MIB / PBCH payload / PBCH-DMRS sequence) corresponding to one or more period values, it may assume / expect that the half-frame index value (from the MIB / PBCH payload / PBCH-DMRS sequence) of an SSB(s) corresponding to other period values ​​is the same as HF = 1.

[0319] FIGS. 24 and 25 are further examples of SSB adaptation according to some implementations of the present specification. In Option 1, Option 2, and / or Option 3, a time point after processing time following (GC-)DCI reception or after applying the (SFN) offset may occur in the middle of a specific SSB period. For example, referring to FIG. 24 or 25, if the time between the location where SSB index #0 is transmitted and the location where SSB index #1 is transmitted within an SSB burst is the processing time after (GC-)DCI reception or the time point obtained by applying the (SFN) offset, it is necessary to set / instruct (or define in a standard document, etc.) in advance from the BS whether an SSB of a modified period will be transmitted from that SSB period or from the next SSB period. For example, in Option 1, Option 2, or Option 3, if the point in time when the UE adds the processing time or (SFN) offset at the time the (GC)-DCI is received is located between SSB index #0 and SSB index #1 within the (candidate) SSB burst position within SFN#9 in the example of FIG. 24 or 25, the UE may assume that if SSB index #0 is an actually transmitted SSB index (e.g., an SSB index for which transmission is set / directed by a higher-level parameter such as ssb-PositionsInBurst), the first SSB of the changed period from the next SSB time will be transmitted, and if SSB index #1 is an actually transmitted SSB, the first SSB of the changed period from that SSB time will be transmitted. This is because not all SSB indices within the SSB burst are actually transmitted SSB indices.The UE assumes that if the processing time d or the time after the (SFN) offset value d (hereinafter, time unit m+d) after the time when the SSB adaptation instruction is received (hereinafter, time unit m) is between candidate SSB locations of different SSB indices within the SSB burst, and if all of the SSB locations corresponding to the indices of the actually transmitted SSBs among the SSB locations within the SSB burst are after the time unit m+d, then an SSB of the changed SSB period is transmitted from that SSB (burst) time, and otherwise, an SSB of the changed period is transmitted from the next SSB (burst) time. In this case, even if the time unit m+d is between the candidate SSBs of the SSB burst, if the actually transmitted SSBs are after the time unit m+d, the transmission of SSBs according to the changed SSB period begins from the SFN containing the time unit m+d among the SFNs that may have SSBs of the changed period, and if there is an SSB transmission time corresponding to the SSB actually transmitted before the time unit m+d in the SFN containing the time unit m+d, the transmission of SSBs of the changed period begins from the SFN next to the SFN that is not the SFN containing the time unit m+d among the SFNs that may have SSBs of the changed period, so that all actually transmitted SSBs of the SSB burst can be transmitted with the same period.For example, when a UE receives a DCI instructing a change for receiving SSBs on a cell in slot m, the UE may expect that the transmission of SSBs according to the period indicated by the DCI will start from a slot (hereinafter, the first slot) satisfying the following: i) the first slot includes a candidate SSB corresponding to the first transmitted SSB provided by ssb-PositionInBurst among candidate SSB positions within a half frame (hereinafter, the first half frame) satisfying the following for the indicated period; ii) the half frame is within a set of half frames having a half frame index provided / set / defined / instructed for SSB adaptation, and has an SFN offset provided / set / defined / instructed for SSB adaptation relative to a reference SFN (e.g., SFN #0); and iii) does not start before the start of slot m+d, where d is a pre-set / pre-defined / instructed or provided offset for SSB adaptation. For example, referring to FIGS. 23 and 24, an SSB burst for a cell may include 8 SSBs, and candidate SSBs corresponding to SSB indices #0 to #7 are set as the actual transmitted SSBs by ssb-PositionInBurst, and an additional SSB period of 80 ms, SFN offset = 1, and half-frame index = 1 are set, and when a DCI notifying an 80 ms SSB period for the cell is received, if the UE, after receiving the DCI, processes the time or offset after the time (subsequently, the time at which SSB adaptability is possible) between the candidate SSB of SSB index #0 within the half-frame of SFN#9 and the candidate SSB of SSB index #0, then the SFN set {SFN#9, #17, #25, #33, ...Among them, transmission of SSBs according to an 80ms period can be expected in half frame 1 of SFN#17, which has the earliest candidate SSB burst timing after SFN#9. As another example, referring to FIG. 23 and FIG. 25, an SSB burst for a cell may include 8 SSBs, and candidate SSBs corresponding to SSB index #1 to SSB index #7 are set as the actual transmitted SSBs by ssb-PositionInBurst, and an additional SSB period of 80 ms, SFN offset = 1, and half-frame index = 1 are set, and when a DCI announcing an 80 ms SSB period for the cell is received, the UE can expect transmission of SSBs according to the 80 ms period in half-frame 1 of SFN#9 among the SFN set {SFN#9, #17, #25, #33, ...} corresponding to the 80 ms period and SFN offset = 1, if the time after processing time or offset (subsequently, the time when SSB adaptability is possible) after receiving the DCI is between the candidate SSB of SSB index #0 in half-frame of SFN#9 and the candidate SSB of SSB index #0.

[0320] Although some implementations of this specification have been described above with the example of an SSB period being adapted between a 20ms period and an 80ms period, in the case of adaptation from a long period to a short period, for example, from an 80ms period to a 20ms period, it can be determined in accordance with Option 1, Option 2, and / or Option 3 at a processing time and / or (SFN) offset after the UE receives an SSB adaptation instruction at a location where the changed 20ms period SSB reception can be expected.

[0321] In some implementations of this specification, SSB adaptation for a cell may be configured such that larger period SSB transmission times for SSB adaptation for the cell are a subset of shorter period SSB transmission times for the cell. For example, when an SFN offset value from a reference SFN point is configured / indicated / defined as in Option 3 to determine the SSB position of the changed period, the SFN offset value and half-frame index may be configured only for the largest SSB periodicity among one or more additional SSB periods configured for SSB adaptation. In this case, a UE instructed to adapt SSB via (GC-)DCI (or MAC CE) can calculate the actual location of the SSB of the changed period by assuming that the locations where the SSB of the remaining shorter periods can be transmitted are confined within the set of SFNs where the longest SSB period is located, after calculating the locations where the SSB of the changed period can be transmitted using the SFN offset and half-frame index set for the longest SSB period. For example, if the additional SSB periods set for adapting SSB are {20ms, 40ms, 80ms}, the longest SSB period among them is 80ms, and the SFN offset value (and half-frame index) can be pre-set only for the 80ms SSB period.When the UE is instructed to adapt SSB with a 20ms period from 40ms via (GC-)DCI in SFN#12, when determining the location (e.g., SSB (burst) timing) where the 20ms period SSB transmission begins after the processing time following the (GC-)DCI reception (or the preset / predefined offset to be applied to (GC-)DCI), based on the SFN set {SFN#2, #10, #18, #26, #34, ...} where the 80ms period SSB can be located when applying the SFN offset value 2 set for the 80ms period SSB to the reference SFN point (e.g., SFN#0) (since the relationship that the long period SSB (burst) timing is a subset of the short period SSB timing must be satisfied), the SFN set {SFN#2, #4, #6, #8, #10, #12, #14, #16, ...} can be determined, and since (GC-)DCI was received at SFN#12, the reception of SSB according to the period changed to a 20ms period (at the same half-frame index) starting from the SSB time located at the earliest SFN#14 after the processing time (or offset) can be expected.

[0322] The methods or implementations of the aforementioned specification may be applied independently, but may also be applied in the form of a combination (or merger) of some proposed methods. Information regarding the application of the methods / implements of the aforementioned specification (or information regarding the rules of the methods / implements of the aforementioned specification) may be provided by the BS to the UE via a predefined signal (e.g., a physical layer signal or an upper layer signal). In the aforementioned specification, the upper layer may include one or more of functional layers such as MAC, RLC, PDCP, RRC, SDAP, etc.

[0323] According to some implementations of this specification, when SSB adaptation is introduced, the UE can know when the BS changes the SSB period for the cell. Additionally, according to some implementations of this specification, if the BS explicitly provides an SSB adaptation instruction to the UE through explicit signaling, the UE and the BS can have the same expectation / assuming regarding when the adapted SSB transmission is applied. According to some implementations of this specification, even if the UE fails to detect the SSB adaptation instruction transmitted by the BS, a critical problem may not occur in communication through the cell.

[0324] FIG. 26 illustrates the flow of receiving a downlink (DL) signal in a UE according to some implementations of the present specification.

[0325] A UE may perform operations according to some implementations of this specification in relation to DL signal transmission. A UE may include at least one transceiver; at least one processor; and at least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations according to some implementations of this specification. A processing device for a UE may include at least one processor; and at least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations according to some implementations of this specification. A computer-readable (non-transient) storage medium may store at least one computer program including instructions that, when executed by said at least one processor, cause said at least one processor to perform operations according to some implementations of this specification. A computer program or computer program product is written on at least one computer-readable (non-transient) storage medium and may include instructions that, when executed, cause (at least one processor) to perform operations according to some implementations of this specification.

[0326] In a method performed by the above UE, or in the above UE, the processing device, the computer-readable (non-transient) storage medium, and / or the computer program product, the operations may include: receiving a synchronization signal block (SSB) adaptation related setting for a first cell (S2601), said SSB adaptation related setting including at least one additional SSB burst periodicity; receiving downlink control information including change information for the periodicity for receiving SSBs on the first cell (S2603); and expecting to start receiving SSBs according to the period indicated by the downlink control information in a first half frame within a first frame of a first system frame number (SFN) on the first cell (S2605).

[0327] FIG. 27 illustrates the flow of downlink (DL) signal transmission in BS according to some implementations of the present specification.

[0328] A BS may perform operations according to some implementations of this specification in relation to DL signal transmission. A BS may include at least one transceiver; at least one processor; and at least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations according to some implementations of this specification. A processing device for a BS may include at least one processor; and at least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations according to some implementations of this specification. A computer-readable (non-transient) storage medium may store at least one computer program including instructions that, when executed by said at least one processor, cause said at least one processor to perform operations according to some implementations of this specification. A computer program or computer program product is written on at least one computer-readable (non-transient) storage medium and may include instructions that, when executed, cause (at least one processor) to perform operations according to some implementations of this specification.

[0329] In a method performed by the above BS, or in the above BS, the processing device, the computer-readable (non-transient) storage medium, and / or the computer program product, the operations may include: transmitting a synchronization signal block (SSB) adaptation related setting for a first cell (S2601), said SSB adaptation related setting including at least one additional SSB burst periodicity; transmitting downlink control information including change information for the periodicity for transmitting SSBs on the first cell (S2603); and initiating the transmission of SSBs according to the period indicated by said downlink control information in the first half frame within the first frame of the first system frame number (SFN) on the first cell (S2605).

[0330] FIG. 28 illustrates a signal transmission / reception flow between a UE and a network according to some implementations of the present specification. Referring to FIG. 28, a network (e.g., BS) may transmit (S2801) an SSB adaptation setting for a first cell, and a UE may receive (S2801) the SSB adaptation setting for the first cell. The SSB adaptation setting may include at least one additional SSB burst periodicity. The network may transmit (S2803) downlink control information including change information for the periodicity for transmitting SSBs on the first cell. The UE may receive (S2803) the downlink control information to obtain the periodicity to be changed for the first cell. The above network can start the transmission of SSBs according to the indicated period on the first cell in the first half frame within the first frame of the first SFN through the downlink control information (S2805), and the UE can expect to start the reception of SSBs according to the indicated period on the first cell in the first half frame within the first frame (S2805).

[0331] In some implementations related to FIG. 26, FIG. 27, or FIG. 28, the first frame is within a first frame set for the indicated period, the first frame set for the indicated period has a first SFN offset value associated with the indicated period relative to SFN 0, the first half frame is within a set of half frames having a first half frame index value associated with the indicated period, and the transmission / reception of SSBs according to the indicated period does not begin before a second time unit after a predetermined offset after a first time unit after the downlink control information is transmitted / received.

[0332] In some implementations related to FIG. 26, FIG. 27, or FIG. 28, the at least one additional SSB burst cycle may include a first additional SSB burst cycle and a second additional SSB burst cycle that is larger than the first additional SSB burst cycle.

[0333] In some implementations related to FIG. 26, FIG. 27, or FIG. 28, the SSB periods of the second additional SSB burst cycle may be a subset of the SSB periods of the first additional SSB burst cycle.

[0334] In some implementations related to FIG. 26, FIG. 27, or FIG. 28, the SSB adaptation related settings may include an SFN offset value for each additional SSB burst period.

[0335] In some implementations related to FIG. 26, FIG. 27, or FIG. 28, the SSB adaptation related settings may include half-frame index values ​​for each additional SSB burst cycle.

[0336] In some implementations related to FIG. 26, FIG. 27, or FIG. 28, the predetermined offset may be a predetermined value.

[0337] In some implementations related to FIG. 26, FIG. 27, or FIG. 28, the first frame may be a frame in which the candidate SSB time associated with the first transmitted SSB provided by the upper layer parameter ssb-PositionsInBurst among the frames in the first frame set is after the second time unit.

[0338] As described above, the examples of this specification disclosed are provided to enable a person skilled in the art related to this specification to implement and practice this specification. Although the foregoing has been described by reference to the examples of this specification, a person skilled in the art may modify and change the examples of this specification in various ways. Accordingly, this specification is not intended to be limited to the examples described herein, but to be given the broadest possible scope consistent with the principles and novel features disclosed herein.

[0339] Implementations of this specification may be used in wireless communication systems, BS or user devices, and other equipment.

Claims

1. In a method performed by a user device, Receive a synchronization signal block (SSB) adaptation setting for a first cell, said SSB adaptation setting includes at least one additional SSB burst periodicity; Receiving downlink control information including change information for the periododicity for receiving SSBs on the first cell; and It includes receiving SSBs according to the period indicated by the downlink control information above in the first half frame within the first frame of the first system frame number (SFN) on the first cell, and The first frame above is within the first frame set for the indicated cycle, and The first frame set for the indicated period has a first SFN offset value associated with the indicated period that is relative to SFN 0, and The first half-frame is within a set of half-frames having a first half-frame index value associated with the indicated period, and The reception of SSBs according to the above-mentioned period does not begin before the second time unit after a predetermined offset following the first time unit after the downlink control information is received, method.

2. In Paragraph 1, The above at least one additional SSB burst cycle includes a first additional SSB burst cycle and a second additional SSB burst cycle larger than the first additional SSB burst cycle, and The SSB periods of the second additional SSB burst cycle are a subset of the SSB periods of the first additional SSB burst cycle, method.

3. In Paragraph 2, The above SSB adaptation settings include SFN offset values ​​for each additional SSB burst cycle, method.

4. In Paragraph 2, The above SSB adaptation-related settings include half-frame index values ​​for each additional SSB burst cycle, method.

5. In Paragraph 1, The above predetermined offset is a predetermined value, method.

6. In Paragraph 1, The first frame is a frame in which the candidate SSB time associated with the first transmitted SSB, provided by the upper layer parameter ssb-PositionsInBurst among the frames in the first frame set, is after the second time unit, method.

7. At least one transmitter / receiver; At least one processor; and It includes at least one computer memory operablely connectable to the at least one processor and, when executed, stores instructions that cause the at least one processor to perform operations, wherein the operations are: Receive a synchronization signal block (SSB) adaptation setting for a first cell, said SSB adaptation setting includes at least one additional SSB burst periodicity; Receiving downlink control information including change information for the periododicity for receiving SSBs on the first cell; and It includes receiving SSBs according to the period indicated by the downlink control information above in the first half frame within the first frame of the first system frame number (SFN) on the first cell, and The first frame above is within the first frame set for the indicated cycle, and The first frame set for the indicated period has a first SFN offset value associated with the indicated period that is relative to SFN 0, and The first half-frame is within a set of half-frames having a first half-frame index value associated with the indicated period, and The reception of SSBs according to the above-mentioned period does not begin before the second time unit after a predetermined offset following the first time unit after the downlink control information is received, User device.

8. At least one processor; and It includes at least one computer memory operablely connectable to the at least one processor and, when executed, stores instructions that cause the at least one processor to perform operations, wherein the operations are: Receive a synchronization signal block (SSB) adaptation setting for a first cell, said SSB adaptation setting includes at least one additional SSB burst periodicity; Receiving downlink control information including change information for the periododicity for receiving SSBs on the first cell; and It includes receiving SSBs according to the period indicated by the downlink control information above in the first half frame within the first frame of the first system frame number (SFN) on the first cell, and The first frame above is within the first frame set for the indicated cycle, and The first frame set for the indicated period has a first SFN offset value associated with the indicated period that is relative to SFN 0, and The first half-frame is within a set of half-frames having a first half-frame index value associated with the indicated period, and The reception of SSBs according to the above-mentioned period does not begin before the second time unit after a predetermined offset following the first time unit after the downlink control information is received, Processing unit.

9. In a computer-readable non-transitory storage medium, The above storage medium stores at least one program code including instructions that cause at least one processor to perform operations when executed, and said operations are: Receive a synchronization signal block (SSB) adaptation setting for a first cell, said SSB adaptation setting includes at least one additional SSB burst periodicity; Receiving downlink control information including change information for the periododicity for receiving SSBs on the first cell; and It includes receiving SSBs according to the period indicated by the downlink control information above in the first half frame within the first frame of the first system frame number (SFN) on the first cell, and The first frame above is within the first frame set for the indicated cycle, and The first frame set for the indicated period has a first SFN offset value associated with the indicated period that is relative to SFN 0, and The first half-frame is within a set of half-frames having a first half-frame index value associated with the indicated period, and The reception of SSBs according to the above-mentioned period does not begin before the second time unit after a predetermined offset following the first time unit after the downlink control information is received, Storage medium.

10. In a method performed by a base station, Transmitting synchronization signal block (SSB) adaptation settings for a first cell, wherein the SSB adaptation settings include at least one additional SSB burst periodicity; Transmitting downlink control information including change information for the periodicity for transmitting SSBs on the first cell; and It includes initiating the transmission of SSBs according to the period indicated by the downlink control information above in the first half frame within the first frame of the first system frame number (SFN) on the first cell, and The first frame above is within the first frame set for the indicated cycle, and The first frame set for the indicated period has a first SFN offset value associated with the indicated period that is relative to SFN 0, and The first half-frame is within a set of half-frames having a first half-frame index value associated with the indicated period, and The transmission of SSBs according to the above-mentioned period does not begin before the second time unit after a predetermined offset following the first time unit in which the downlink control information was transmitted, method.

11. At least one transmitter / receiver; At least one processor; and It includes at least one computer memory operablely connectable to the at least one processor and, when executed, stores instructions that cause the at least one processor to perform operations, wherein the operations are: Transmitting synchronization signal block (SSB) adaptation settings for a first cell, wherein the SSB adaptation settings include at least one additional SSB burst periodicity; Transmitting downlink control information including change information for the periodicity for transmitting SSBs on the first cell; and It includes initiating the transmission of SSBs according to the period indicated by the downlink control information above in the first half frame within the first frame of the first system frame number (SFN) on the first cell, and The first frame above is within the first frame set for the indicated cycle, and The first frame set for the indicated period has a first SFN offset value associated with the indicated period that is relative to SFN 0, and The first half-frame is within a set of half-frames having a first half-frame index value associated with the indicated period, and The transmission of SSBs according to the above-mentioned period does not begin before the second time unit after a predetermined offset following the first time unit in which the downlink control information was transmitted, Base station.

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