Method and apparatus for lower layer control signaling related to synchronization signal in wireless communication system

Abstract

Disclosed are a method and an apparatus for lower layer control signaling related to a synchronization signal in a wireless communication system. A method according to one embodiment of the present disclosure may comprise the steps of: receiving, by a terminal, synchronization signal block configuration information from a network; receiving, by the terminal, indication information for one or more synchronization signal blocks from the network on the basis of the configuration information; and receiving, by the terminal, the one or more synchronization signal blocks from the network on the basis of the indication information. The indication information may include information on an index of one or more specific cells and parameter information on the one or more synchronization signal blocks.

Description

Method and device for lower layer control signaling related to synchronization signal in wireless communication system

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for lower layer control signaling related to a synchronization signal in a wireless communication system.

[0002] The fifth generation (5G) wireless communication system, the successor to 4G LTE (long-term evolution), is a new, clean-slate mobile communication system characterized by high performance, low latency, and high availability. 5G NR (New Radio) can utilize all available spectrum resources, from low-frequency bands below 1 GHz, to intermediate-frequency bands between 1 GHz and 10 GHz, and to high-frequency (or millimeter wave) bands above 24 GHz. 6G wireless communication systems are being developed based on the underlying technologies of 5G wireless communication.

[0003] The 6G wireless communication system is being developed with the goals of (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) reduced energy consumption of battery-free Internet of Things (IoT) devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be divided into four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity. Considering the requirements of the 6G system, such as a peak data rate of 1 Tbps per device, an end-to-end latency of 1 ms, a maximum spectrum efficiency of 100 bps / Hz, support for mobility of 1000 km / h, satellite integration, artificial intelligence (AI), autonomous vehicles, extended reality (XR), and haptic communication, various technologies are being researched.

[0004] The technical problem of the present disclosure is to provide a method and device that support transmitting a synchronization signal block in a specific cell when necessary in a wireless communication system.

[0005] An additional technical problem of the present disclosure is to provide a method and device for indicating in a medium access control (MAC) layer to support transmitting a synchronization signal block in a specific cell when necessary in a wireless communication system.

[0006] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

[0007] A method according to one aspect of the present disclosure may include the steps of: receiving, by a terminal, synchronization signal block configuration information from a network; receiving, by the terminal, from the network, indication information for one or more synchronization signal blocks based on the configuration information; and receiving, by the terminal, from the network, the one or more synchronization signal blocks based on the indication information. The indication information may include information on an index of one or more specific cells and parameter information for the one or more synchronization signal blocks.

[0008] A method according to an additional aspect of the present disclosure may include the steps of: transmitting, by a base station, synchronization signal block configuration information to a terminal; transmitting, by the base station, indication information for one or more synchronization signal blocks to the terminal based on the configuration information; and transmitting, by the base station, the one or more synchronization signal blocks to the terminal based on the indication information. The indication information may include information on an index of one or more specific cells and parameter information for the one or more synchronization signal blocks.

[0009] According to the present disclosure, a method and apparatus for supporting transmitting a synchronization signal block in a specific cell when necessary in a wireless communication system can be provided.

[0010] According to the present disclosure, a method and device for indicating in a medium access control (MAC) layer to support transmitting a synchronization signal block in a specific cell when necessary in a wireless communication system can be provided.

[0011] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0012] The accompanying drawings, which are incorporated in and are part of the detailed description to aid in understanding the present disclosure, provide embodiments of the present disclosure and, together with the detailed description, describe the technical features of the present disclosure.

[0013] Figure 1 illustrates a flexible network topology to which some examples of the present disclosure may be applied.

[0014] FIG. 2 illustrates an example of a communication system to which some examples of the present disclosure may be applied.

[0015] FIG. 3 illustrates an example of a wireless device to which some examples of the present disclosure may be applied.

[0016] FIG. 4 exemplarily illustrates a communication procedure between a first node and a second node to which some examples of the present disclosure may be applied.

[0017] FIG. 5 illustrates a functional framework for AI operations to which some examples of the present disclosure may be applied.

[0018] FIG. 6 illustrates an example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0019] FIG. 7 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0020] FIG. 8 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0021] FIG. 9 illustrates an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0022] FIG. 10 illustrates an example of a system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0023] FIG. 11 exemplarily illustrates a beam management procedure to which some examples of the present disclosure may be applied.

[0024] Figures 12 and 13 illustrate examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0025] FIG. 14 illustrates examples of sensing operations to which some examples of the present disclosure may be applied.

[0026] FIG. 15 illustrates an example of cell DTX / DRX operation to which some examples of the present disclosure may be applied.

[0027] FIG. 16 illustrates an example of carrier aggregation (CA) operation including an SSB-less cell to which some examples of the present disclosure may be applied.

[0028] FIG. 17 illustrates an example of a conditional handover operation to which some examples of the present disclosure may be applied.

[0029] FIG. 18 illustrates an example of a procedure for CSI measurement and reporting to which some examples of the present disclosure may be applied.

[0030] FIG. 19 illustrates examples of on-demand SIB1 operation to which some examples of the present disclosure may be applied.

[0031] FIG. 20 is a drawing for explaining an example of a method performed by a terminal according to the present disclosure.

[0032] FIG. 21 is a drawing illustrating an example of a method performed by a base station according to the present disclosure.

[0033] FIG. 22 is a diagram showing exemplary formats of MAC-CE related to SSB transmission according to the present disclosure.

[0034] FIG. 23 is a diagram showing other exemplary formats of MAC-CE related to SSB transmission according to the present disclosure.

[0035] FIG. 24 is a diagram illustrating further exemplary formats of MAC-CE related to SSB transmission according to the present disclosure.

[0036] FIG. 25 is a diagram illustrating further exemplary formats of MAC-CE related to SSB transmission according to the present disclosure.

[0037] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

[0038] In some cases, to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0039] In the present disclosure, when a component is said to be "connected," "coupled," or "connected" to another component, this may include not only a direct connection but also an indirect connection in which another component exists between them. Furthermore, the terms "comprises" or "has" in the present disclosure specify the presence of the mentioned features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0040] In this disclosure, terms such as “first,” “second,” etc. are used only to distinguish one component from another and are not used to limit the components, and do not limit the order or importance between the components unless specifically stated otherwise. Accordingly, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0041] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0042] In this disclosure, "A or B" can mean "only A," "only B," or "both A and B." In other words, "A or B" in this disclosure can be interpreted as "A and / or B." For example, "A, B or C" in this disclosure can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0043] As used herein, a slash ( / ) or a comma 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."

[0044] In the present disclosure, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in the present disclosure, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”

[0045] Additionally, in the present disclosure, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0046] Additionally, parentheses used in the present disclosure may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be described as an example of "control information." In other words, "control information" in the present disclosure is not limited to "PDCCH," and "PDCCH" may be described as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be described as an example of "control information."

[0047] In the following description, 'when, if, in case of' can be replaced with 'based on'.

[0048] Technical features individually described in one drawing in this disclosure may be implemented individually or simultaneously.

[0049] In the present disclosure, a terminal or user equipment (UE) may be a portable device and may be a first node that receives a signal from a base station / second node / IAB (integrated access backhaul) node.

[0050] In the present disclosure, a base station (BS) may be a second node / IAB node / Transmission-Reception Point (TRP).

[0051] In the present disclosure, higher layer parameters may be parameters configured, pre-configured, or pre-defined for the terminal. For example, a base station or a network may transmit higher layer parameters to the terminal. For example, the higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0052] In the present disclosure, "setting or defining" may be interpreted as being set to a device through predefined signaling (e.g., SIB (system information block), MAC, RRC) from a base station or network. In the present disclosure, "setting or defining" may be interpreted as being set to a device through separate signaling or being defined in advance without separate signaling.

[0053] In the present disclosure, transmitting or receiving a channel means transmitting or receiving information or a signal through the channel. For example, transmitting a control channel means transmitting control information or a signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a signal through the data channel.

[0054] The technology described in the present disclosure can be used in various wireless communication systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), LTE (long term evolution), 5G NR, and the like.

[0055] The technology described in the present disclosure can be implemented with 6G wireless technology and applied to various 6G systems. For example, the 6G system can have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), artificial intelligence (AI) integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0056] Network structure

[0057] Figure 1 illustrates a flexible network topology to which some examples of the present disclosure may be applied.

[0058] To compensate for incomplete network coverage areas, a network topology that allows for more flexible and resilient split radio access networks (RANs) may be considered. For this purpose, various nodes, such as integrated access backhaul (IAB) nodes, relays, and radio frequency (RF) repeaters, as illustrated in Figure 1, may be applied, or a non-terrestrial network (NTN) may be integrated. For example, an IAB node may correspond to a node that provides wireless backhaul. For example, a relay may refer to any intermediate point, and in the case of a sidelink relay where a terminal functions as a relay, it may collectively refer to a terminal-to-network (U2N) relay and a terminal-to-terminal (U2U) relay. For example, an RF repeater may correspond to a node that simply performs the functions of signal amplification and forwarding, or in the case of a network-controlled repeater, it may not only amplify and forward signals but also adjust its transmission and reception settings based on information provided by the network. For example, NTN nodes could be satellites or aircraft that provide NTN coverage that terrestrial networks struggle to provide. Beyond these examples, various intermediate points can be introduced to improve the network topology.

[0059] Referring to Figure 1, a split RAN can support the division of a base station into a centralized unit (CU) and one or more distributed units (DUs). The CU and DU can correspond to logical units. The CU can be further divided into a control plane (CP) portion and one or more user plane (UP) portions. Since a failure in the CU-CP affects not only the CU-UP but also the DUs, various intermediate points can be introduced to compensate for this.

[0060] An intermediate point may correspond to a terminal or a base station, depending on its relationship to other nodes. For example, an IAB node may include a mobile-termination (MT) portion and a unit (DU). The MT may connect the IAB node to a donor node. The unit (DU) of an IAB node may serve other terminals or connect to other IAB nodes to provide multi-hop wireless backhaul to the terminal. For example, an IAB node may correspond to a base station in its relationship to a user-side node, and to a terminal in its relationship to a network-side node.

[0061] In some examples of the present disclosure, the description of a terminal may equally apply not only to a user-side endpoint, but also to an intermediate point corresponding to a terminal in a relative relationship with a network-side endpoint. Similarly, in some examples of the present disclosure, the description of a base station may equally apply not only to a network-side endpoint, but also to an intermediate point corresponding to a base station in a relative relationship with a user-side endpoint. In most cases where there is no additional description of the operations of three or more entities, the communicating entities in the present disclosure are briefly described as terminals and / or base stations (or first nodes and / or second nodes), where the terms terminal and / or base stations (or first nodes and / or second nodes) are interpreted to include / replace any endpoint or any intermediate point in relation to other nodes.

[0062] As such, in some examples of the present disclosure, for the sake of simplicity of explanation, the subjects of the operation may be referred to as terminals and / or base stations (or first nodes and / or second nodes). In addition, the terms terminal and / or base station (or first node and / or second node) may also be interpreted / replaced as in the following examples: For example, the terminal (or first node) and the base station (or second node) may respectively correspond to the first endpoint and the second endpoint; may respectively correspond to the endpoint and the intermediate point; may respectively correspond to the intermediate point and the endpoint; or may respectively correspond to the first intermediate point and the second intermediate point.

[0063] In the present disclosure, there may be zero or more intermediate points between the base station and the terminal. If an intermediate point exists, it may correspond to an IAB node / relay / RF repeater / NTN node, or a node supporting other functions. The intermediate point may be a node with a fixed location or a node with an unfixed location.

[0064] Systems applicable to this disclosure

[0065] FIG. 2 illustrates an example of a communication system to which some examples of the present disclosure may be applied.

[0066] The communication system (100) applied to the present disclosure includes a wireless device (110), a network device (120), and a network (130). Here, the wireless device (110) refers to a device that performs communication using a wireless access technology (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G) and may be referred to as a communication / wireless / 5G / 6G device. Although not limited thereto, the wireless device (110) may include a robot (110a), a vehicle (110b-1, 110b-2), an XR (extended reality) device (110c), a hand-held device (110d), a home appliance (110e), an IoT (Internet of Things) device (110f), and an AI (artificial intelligence) device / server (110g). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle (110b-1, 110b-2) may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device (110c) includes an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device, and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc. The portable device (110d) may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.), etc. The home appliance (110e) may include a TV, a refrigerator, a washing machine, etc. The IoT device (110f) may include a sensor, a smart meter, etc. The wireless device (110) may correspond to a terminal (or first node) or an intermediate point.The network device (120) may correspond to a base station (or second node) or another intermediate point. For example, the network device (120) may also be implemented as a wireless device (110), and a specific wireless device (120a) may act as a network device (120) to another wireless device (110).

[0067] Wireless devices (110a to 110f) can be connected to a network (130) via a network device (120). AI technology can be applied to the wireless devices (110a to 110f), and the wireless devices (110a to 110f) can be connected to an AI server (110g) via a network (130). The network (130) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR), or a 6G network. The wireless devices (110a to 110f) can communicate with each other via the network device (120) / network (130), but can also communicate directly (e.g., sidelink communication) without going through the network device (120) / network (130). For example, vehicles (110b-1, 110b-2) can communicate directly (e.g., V2V (vehicle to vehicle) / V2X (vehicle to everything) communication). Additionally, an IoT device (110f) (e.g., a sensor) can communicate directly with another IoT device (e.g., a sensor) or another wireless device (110a to 110f).

[0068] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (110a to 110f) / network devices (120), network devices (120) / network devices (120). Here, the wireless communication / connection can be established through various wireless access technologies such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between network devices (150c) (e.g., relay, IAB (integrated access backhaul)). Through the wireless communication / connection (150a, 150b, 150c), the wireless device and the network device / wireless device, and the network device and the network device can transmit / receive wireless signals to each other. For example, the wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various descriptions of the present disclosure, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), resource allocation processes, etc., may be performed.

[0069] Device applicable to the present disclosure

[0070] FIG. 3 illustrates an example of a wireless device to which some examples of the present disclosure may be applied.

[0071] Referring to FIG. 3, the wireless device (200) can transmit and receive wireless signals via various wireless access technologies (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G). The wireless device (200) includes at least one processor (202) and at least one memory (204), and may additionally include at least one transceiver (206) and / or at least one antenna (208).

[0072] The processor (202) controls the memory (204) and / or the transceiver (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (206). In addition, the processor (202) may receive a wireless signal including second information / signal via the transceiver (206), and then store information obtained from signal processing of the second information / signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may store software code including instructions for performing some or all of the processes controlled by the processor (202), or for performing the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology. The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via at least one antenna (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF (radio frequency) unit. In the present disclosure, a wireless device may also mean a communication modem / circuit / chip.

[0073] Hereinafter, the hardware elements of the wireless device (200) will be described in more detail. Although not limited thereto, at least one protocol layer may be implemented by at least one processor (202). For example, at least one processor (202) may implement at least one layer (e.g., a functional layer such as physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), radio resource control (RRC), and service data adaptation protocol (SDAP)). At least one processor (202) may generate at least one Protocol Data Unit (PDU) and / or at least one Service Data Unit (SDU) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. At least one processor (202) may generate a message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. At least one processor (202) can generate a signal (e.g., a baseband signal) comprising a PDU, an SDU, a message, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in this document, and provide the signal to at least one transceiver (206). At least one processor (202) can receive a signal (e.g., a baseband signal) from at least one transceiver (206) and obtain the PDU, SDU, message, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document.

[0074] At least one processor (202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The at least one processor (202) may be implemented by hardware, firmware, software, or a combination thereof. For example, at least one application specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in the at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be included in the at least one processor (202), or may be stored in at least one memory (204) and driven by the at least one processor (202). The descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions and / or sets of instructions.

[0075] At least one memory (204) can be connected to at least one processor (202) and can store various forms of data, signals, messages, information, programs, codes, instructions and / or commands. The at least one memory (204) can be configured as a read only memory (ROM), a random access memory (RAM), an erasable programmable read only memory (EPROM), a flash memory, a hard drive, a register, a cache memory, a computer readable storage medium and / or a combination thereof. The at least one memory (204) can be located internally and / or externally to the at least one processor (202). In addition, the at least one memory (204) can be connected to the at least one processor (202) via various technologies such as a wired or wireless connection.

[0076] At least one transceiver (206) can transmit user data, control information, wireless signals / channels, etc., mentioned in the methods and / or flowcharts of this document to at least one other device. At least one transceiver (206) can receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts disclosed in this document from at least one other device. For example, at least one transceiver (206) can be connected to at least one processor (202) and can transmit and receive wireless signals. For example, at least one processor (202) can control at least one transceiver (206) to transmit user data, control information, or wireless signals to at least one other device. Furthermore, at least one processor (202) can control at least one transceiver (206) to receive user data, control information, or wireless signals from at least one other device. Additionally, at least one transceiver (206) may be connected to at least one antenna (208), and at least one transceiver (206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document via at least one antenna (208). In this document, at least one antenna may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). At least one transceiver (206) may convert the received wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using at least one processor (202).At least one transceiver (206) may convert user data, control information, wireless signals / channels, etc. processed by at least one processor (202) from a baseband signal to an RF band signal. For this purpose, at least one transceiver (206) may include an (analog) oscillator and / or filter.

[0077] The components of the wireless device described with reference to FIG. 3 may be referred to by different terms in terms of functionality. For example, the processor (202) may be referred to as a control unit, the transceiver (206) as a communication unit, and the memory (204) as a storage unit. In some cases, the communication unit may be used to mean at least a portion of the processor (202) and the transceiver (206).

[0078] The structure of the wireless device described with reference to FIG. 3 can be understood as the structure of at least a portion of various devices. For example, the structure of the wireless device illustrated in FIG. 3 can be at least a portion of various devices described with reference to FIG. 2 (e.g., a robot (110a), a vehicle (110b-1, 110b-2), an XR device (110c), a portable device (110d), a home appliance (110e), an IoT device (110f), an AI device / server (110g)). Furthermore, according to various embodiments, in addition to the components illustrated in FIG. 3, the device may further include other components.

[0079] For example, the device may be a portable device such as a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), or a portable computer (e.g., a laptop, etc.). In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an interface unit that includes at least one port for connection with another device (e.g., an audio input / output port, a video input / output port), and an input / output unit for inputting and outputting image information / signals, audio information / signals, data, and / or information input from a user.

[0080] For example, the device may be a mobile device such as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, etc. In this case, the device may further include at least one of a driving unit including at least one of an engine, a motor, a power train, wheels, brakes, and a steering unit of the device, a power supply unit including a wired / wireless charging circuit, a battery, etc. that supplies power, a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, an autonomous driving unit that performs functions such as path maintenance, speed control, and destination setting, and a position measurement unit that obtains location information of the mobile device through a global positioning system (GPS) and various sensors.

[0081] For example, the device may be an XR device such as an HMD, a head-up display (HUD) installed in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an input / output unit that obtains control information, data, etc. from the outside and outputs the generated XR object, and a sensor unit that senses status information, environmental information, and user information of the device or the surroundings of the device.

[0082] For example, the device may be a robot that can be classified into industrial, medical, household, military, etc. types depending on the purpose or field of use. In this case, the device may further include at least one of a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, and a driving unit that performs various physical actions, such as moving the robot joints.

[0083] For example, the device may be an AI device such as a TV, a projector, a smartphone, a PC, a laptop, a digital broadcasting terminal, a tablet PC, a wearable device, a set-top box (STB), a radio, a washing machine, a refrigerator, digital signage, a robot, a vehicle, etc. In this case, the device may further include at least one of an input unit that acquires various types of data from the outside, an output unit that generates output related to sight, hearing, or touch, a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, and a training unit that trains a model composed of an artificial neural network using learning data.

[0084] The structure of the wireless device illustrated in FIG. 3 may be understood as a part of a terminal (or first node), or as a part of an intermediate point, or as a part of a base station (or second node). If the device illustrated in FIG. 3 is a base station (or second node), the device may further include a wired transceiver for front haul and / or back haul communications. If the front haul and / or back haul communications are based on wireless communications, at least one transceiver (206) illustrated in FIG. 3 may be used for front haul and / or backhaul communications, and a wired transceiver may not be included.

[0085] Communication procedures

[0086] FIG. 4 exemplarily illustrates a communication procedure between a first node and a second node to which some examples of the present disclosure may be applied.

[0087] FIG. 4 illustrates operations of a first node (110) (e.g., a terminal) and a second node (120) (e.g., a base station) transmitting and / or receiving data and operations performed prior thereto.

[0088] In step S101, the first node (110) and the second node (120) can perform synchronization. For example, the terminal (110) performs an initial cell search operation. Specifically, the terminal (110) can detect at least one synchronization signal transmitted from the base station (120) according to a predefined rule. Here, the synchronization signal can include a plurality of synchronization signals (e.g., a primary synchronization signal, a secondary synchronization signal) classified according to a structure or purpose. Through this, the terminal (110) can confirm the boundaries of the frame, subframe, slot, and / or symbol of the base station (120) and obtain information (e.g., a cell identifier) ​​about the base station (120).

[0089] In step S103, the first node (110) can obtain system information transmitted from the second node (120). For example, the system information is information related to the properties, characteristics, and / or capabilities of the base station (120) required to access the base station (120) and use the service, and can be classified according to the content (e.g., whether it is essential for access), transmission structure (e.g., the channel used, whether it is provided in an on-demand manner), etc., and can be classified into, for example, a master information block (MIB) and a system information block (SIB). If necessary, the terminal (110) can transmit a signal requesting system information before receiving the system information. Such requesting and providing of system information may be performed after a random access procedure described below.

[0090] In step S105, the first node (110) and the second node (120) can perform a random access procedure. For example, the terminal (110) can transmit and / or receive at least one message (e.g., a random access preamble, a random access response (RAR) message, etc.) for a random access procedure based on information related to a random access channel of the base station (120) obtained through system information (e.g., channel position, channel structure, structure of a supported preamble, etc.). For example, the terminal (110) may transmit a preamble (e.g., message 1 (MSG1)) over a random access channel, receive a random access response (RAR) message (e.g., message 2 (MSG2)), transmit a message (e.g., message 3 (MSG3)) including information related to the terminal (110) (e.g., identification information) using scheduling information included in the RAR message to the base station (120), and receive a message for contention resolution and / or connection establishment (e.g., message 4 (MSG4)). As another example, MSG1 and MSG3 may be transmitted and received as one message (e.g., message A (MSG A)), or MSG2 and MSG4 may be transmitted and received as one message (e.g., message B (MSG B)).

[0091] In step S107, the first node (110) and the second node (120) can perform signaling of control information. For example, the control information can be defined in various layers, such as a layer that controls a connection (e.g., a radio resource control (RRC) layer), a layer that handles mapping between logical channels and transmission channels (e.g., a media access control (MAC) layer), and a layer that handles physical channels (e.g., a physical (PHY) layer). For example, the terminal (110) and the base station (120) can perform at least one of signaling for establishing a connection, signaling for determining settings related to communication, and signaling for indicating allocated resources.

[0092] In step S109, the first node (110) and the second node (120) can transmit and / or receive data. For example, the terminal (110) and the base station (120) can process, transmit, and / or receive data based on signaling of control information. For example, when transmitting data, the terminal (110) or the base station (120) can perform at least one of channel encoding, rate matching, scrambling, constellation mapping, layer mapping, waveform modulation, antenna mapping, and resource mapping on information bits. For example, when receiving data, the terminal (110) or the base station (120) can perform at least one of signal extraction from resources, waveform demodulation for each antenna, signal arrangement considering layer mapping, constellation demapping, descrambling, and channel decoding.

[0093] 6G system core technologies

[0094] As core implementation technologies of the 6G system, technologies such as artificial intelligence (AI), THz (terahertz) communication, optical wireless technology, free space optics (FSO) backhaul network, massive MIMO (multiple input multiple output) technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS) can be adopted.

[0095] artificial intelligence

[0096] Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analytics to determine how complex target tasks should be performed. AI can increase efficiency and reduce processing delays. Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly using AI. AI can also play a crucial role in machine-to-machine (M2M), machine-to-human, and human-to-machine communications. Furthermore, AI can facilitate rapid communication in brain-computer interfaces (BCIs). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0097] FIG. 5 illustrates a functional framework for AI operations to which some examples of the present disclosure may be applied.

[0098] Below, to explain AI (or AI / ML (machine learning)) in more detail, the terms can be defined as follows.

[0099] - Data collection: Data collected from network nodes, management entities, or terminals as a basis for AI model training, data analysis, and inference.

[0100] - AI model: A data-driven algorithm that applies AI technology to generate a set of outputs containing predictive information and / or decision parameters based on a set of inputs.

[0101] - AI / ML training: An online or offline process of training an AI model by learning features and patterns that best represent the data and obtain a trained AI / ML model for inference.

[0102] - AI / ML inference: The process of making predictions or inducing decisions based on collected data and the AI ​​model using a trained AI model.

[0103] Referring to FIG. 5, the data collection function (10) is a function that collects input data and provides processed input data to the model training function (20) and the model inference function (30).

[0104] Examples of input data may include measurements from terminals or other network entities, feedback from actors, and output from AI models.

[0105] The data collection function (10) performs data preparation based on input data and provides input data processed through the data preparation. Here, the data collection function (10) does not perform data preparation specific to each AI algorithm (e.g., data pre-processing and cleaning, formatting, and transformation), but can perform data preparation common to all AI algorithms.

[0106] After the data preparation process is performed, the data collection function (10) may provide training data (11) to the model training function (20) and may provide inference data (12) to the model inference function (30). Here, the training data (11) may correspond to data required as input for the AI ​​model training function (20), and the inference data (12) may correspond to data required as input for the AI ​​model inference function (30).

[0107] The data collection function (10) may be performed by a single entity (e.g., a terminal, a RAN node, a network node, etc.), but may also be performed by multiple entities. In this case, training data (11) and inference data (12) may be provided to the model training function (20) and model inference function (30), respectively, from multiple entities.

[0108] The model training function (20) may correspond to a function that performs AI model training, validation, and testing, which can generate model performance metrics as part of the AI ​​model testing procedure. If necessary, the model training function (20) may also be responsible for data preparation (e.g., data pre-processing and cleaning, formatting, and transformation, etc.) based on training data (11) provided by the data collection function (10).

[0109] Here, model deployment / update (13) can be used to initially deploy a trained, validated and tested AI model to the model inference function (30) or to provide an updated model to the model inference function (30).

[0110] The model inference function (30) may correspond to a function that provides AI model inference output (16) (e.g., prediction or decision). If applicable, the model inference function (30) may provide model performance feedback (14) to the model training function (20). In addition, the model inference function (30) may also be responsible for data preparation (e.g., data pre-processing and cleaning, formatting and transformation, etc.) based on inference data (12) provided by the data collection function (10), if necessary.

[0111] Here, output (16) refers to the inference output of the AI ​​model generated by the model inference function (30), and the details of the inference output may vary depending on the use case.

[0112] Model performance feedback (14) can be used to monitor the performance of the AI ​​model, if available, and this feedback may be omitted.

[0113] An actor function (40) is a function that receives an output (16) from a model inference function (30) and triggers or performs a corresponding task / action. The actor function (40) can trigger tasks / actions for other entities (e.g., one or more terminals, one or more RAN nodes, one or more network nodes, etc.) or for itself.

[0114] Feedback (15) can be used to derive training data (11), inference data (12), or to monitor the performance of the AI ​​model, its impact on the network, etc.

[0115] Meanwhile, the definitions of training / validation / test in data sets used in AI / ML can be distinguished as follows.

[0116] - Training data: refers to a data set for learning a model.

[0117] - Validation data: This refers to a dataset used to validate a model that has already completed training. Validation data can typically be used to prevent overfitting of the training data set. It can also be used to select the best model among the various models learned during the training process. Therefore, validation can be considered a type of learning.

[0118] - Test data: This refers to the data set for final evaluation. This data is unrelated to learning.

[0119] For example, the training and validation data can be divided into an 8:2 or 7:3 ratio within the entire data set. Alternatively, the training data:validation data:test data can be divided into a 6:2:2 ratio within the entire data set.

[0120] The level of cooperation can be defined as follows depending on whether the base station and the terminal have capabilities for AI / ML functions, and variations due to combination of multiple levels or separation of any one level are also possible.

[0121] Category 0a: This category corresponds to a no-collaboration framework. In this case, AI / ML algorithms are purely implementation-based and may not require any changes to the wireless interface.

[0122] Category 0b: Frameworks that involve a wireless interface modified to fit efficient implementation-based AI / ML algorithms, but without collaboration.

[0123] Category 1: This category applies to cases where inter-node support is required to improve the AI / ML algorithms of each node. For example, this applies when a terminal receives support from a base station (for training, adaptation, etc.), and vice versa. At this level, model exchange between network nodes is not required.

[0124] Category 2: This applies to cases where joint ML tasks can be performed between terminals and base stations. This level requires exchange of AI / ML model commands or network nodes.

[0125] The functions exemplified in FIG. 5 above may be implemented in a RAN node (e.g., a base station, a TRP, a CU of a base station, etc.), a network node, an OAM (operation administration maintenance) of a network operator, or a terminal.

[0126] Alternatively, two or more entities, such as a RAN, a network node, a network operator's OAM, or a terminal, may cooperate to implement the functions illustrated in FIG. 5. For example, one entity may perform some of the functions of FIG. 5, and another entity may perform the remaining functions. In this way, since some of the functions illustrated in FIG. 5 are performed by a single entity (e.g., a terminal, a RAN node, a network node, etc.), the transmission / provision of data / information between each function may be omitted. For example, if the model training function (20) and the model inference function (30) are performed by the same entity, the transmission / provision of model deployment / update (13) and model performance feedback (14) may be omitted.

[0127] Alternatively, any one of the functions illustrated in FIG. 5 may be performed collaboratively by two or more entities, including a RAN, a network node, a network operator's OAM, or a terminal. This may be referred to as a split AI operation.

[0128] FIG. 6 illustrates an example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0129] For example, the AI ​​model training function may be performed by a network node (e.g., a core network node, an OAM of a network operator, etc.), and the AI ​​model inference function may be performed by a RAN node (e.g., a base station, a TRP, a CU of a base station, etc.).

[0130] Step 1: RAN node 1 and RAN node 2 can transmit input data (e.g., training data) for AI model training to the network node. Here, RAN node 1 and RAN node 2 can also transmit data collected from the terminal (e.g., terminal measurements related to RSRP (reference signal received power), RSRQ (reference signal received quality), SINR (signal to interference-plus-noise ratio) of the serving cell and neighboring cells, terminal location, speed, etc.) to the network node.

[0131] Step 2: Network nodes can train AI models using the received training data.

[0132] Step 3: The network node may distribute / update the AI ​​model to RAN node 1 and / or RAN node 2. RAN node 1 (and / or RAN node 2) may also continue model training based on the received AI model.

[0133] For convenience of explanation, we assume that the AI ​​model is deployed / updated only to RAN node 1.

[0134] Step 4: RAN node 1 can receive input data (e.g., inference data) for AI model inference from the terminal and RAN node 2.

[0135] Step 5: RAN node 1 can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).

[0136] Step 6: If applicable, RAN node 1 may send model performance feedback to the network nodes.

[0137] Step 7: RAN node 1, RAN node 2, and the terminal (or 'RAN node 1 and the terminal', or 'RAN node 1 and RAN node 2') may perform actions based on the output data. For example, in the case of a load balancing operation, the terminal may move from RAN node 1 to RAN node 2.

[0138] Step 8: RAN node 1 and RAN node 2 can transmit feedback information to the network nodes.

[0139] FIG. 7 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0140] For example, both AI model training functions and AI model inference functions can be performed by RAN nodes (e.g., base stations, TRPs, CUs of base stations, etc.).

[0141] Step 1: The terminal and RAN node 2 can transmit input data (e.g., training data) for AI model training to RAN node 1.

[0142] Step 2: RAN node 1 can train an AI model using the received training data.

[0143] Step 3: RAN node 1 can receive input data (e.g., inference data) for AI model inference from the terminal and RAN node 2.

[0144] Step 4: RAN node 1 can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).

[0145] Step 5: RAN node 1, RAN node 2, and the terminal (or 'RAN node 1 and the terminal', or 'RAN node 1 and RAN node 2') may perform actions based on the output data. For example, in the case of a load balancing operation, the terminal may move from RAN node 1 to RAN node 2.

[0146] Step 6: RAN node 2 may transmit feedback information to RAN node 1.

[0147] FIG. 8 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0148] For example, the AI ​​model training function may be performed by a RAN node (e.g., a base station, a TRP, a CU of a base station, etc.), and the AI ​​model inference function may be performed by a terminal.

[0149] Step 1: The terminal may transmit input data (e.g., training data) for AI model training to the RAN node. Here, the RAN node may collect data (e.g., terminal measurements related to RSRP, RSRQ, SINR of the serving cell and neighboring cells, terminal location, speed, etc.) from various terminals and / or from other RAN nodes.

[0150] Step 2: RAN nodes can train AI models using the received training data.

[0151] Step 3: The RAN node can distribute / update the AI ​​model to the terminal. The terminal can also continue model training based on the received AI model.

[0152] Step 4: Input data (e.g., inference data) for AI model inference can be received from the terminal and RAN node (and / or from another terminal).

[0153] Step 5: The terminal can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).

[0154] Step 6: If applicable, the terminal may send model performance feedback to the RAN node.

[0155] Step 7: The terminal and RAN node can perform actions based on the output data.

[0156] Step 8: The terminal may transmit feedback information to the RAN node.

[0157] THz communication (terahertz communication)

[0158] Data transmission rates can be increased by increasing bandwidth. This can be achieved by utilizing sub-THz communications with wide bandwidths and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz, with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (the sub-THz band) is considered a key part of the THz spectrum for cellular communications. Adding the sub-THz band to the mmWave band will increase 6G cellular capacity. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While part of the optical band, the 300 GHz to 3 THz band lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF.

[0159] FIG. 9 illustrates an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0160] Key characteristics of THz communications include (i) the widely available bandwidth to support very high data rates, and (ii) the high path loss at high frequencies (which necessitates highly directional antennas). The narrow beamwidths generated by highly directional antennas reduce interference. The small wavelength of THz signals allows for a significantly larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array technologies to overcome range limitations.

[0161] Transmitting system information (e.g., MIB) in a cell in the THz frequency band can be inefficient because the beam width in high-frequency bands narrows, requiring more beam sweeps to cover the entire cell area. This method is particularly inefficient when there are only a few users within the cell.

[0162] FIG. 10 illustrates an example of a system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0163] The example of Fig. 10 is applicable not only to THz communication environments but also to 6G communication environments where THz communication is not applicable. Furthermore, the procedure illustrated in Fig. 10 can be combined with various embodiments of the present disclosure described below. For example, the embodiments described below can be performed based on system information acquired through the procedure illustrated in Fig. 10.

[0164] In step S1010, the second node (120) (e.g., base station) can transmit system information of cell #1 via cell #2. For example, the base station provides at least two cells, cell #1 uses a THz frequency band, and cell #2 uses a frequency band other than the THz frequency band. Here, the system information may include at least one of an SFN (system frame number), a PDCCH configuration for SIB1, cell barring, cell re-selection, and subcarrier spacing generated in a higher layer, and may include at least one of an SFN, a half frame indicator, and an SSB index (synchronization signal / PBCH (physical broadcast channel) block index) generated in a physical layer. For this purpose, as an example, cell #1 and cell #2 may have a relationship of a secondary cell and a primary cell.

[0165] At step S1030, the first node (110) (e.g., terminal) can acquire synchronization for cell #1. Synchronization can be acquired by detecting a synchronization signal. Typically, synchronization is acquired before receiving system information, but since the system information for cell #1 is received from cell #2, synchronization acquisition for cell #1 can be performed after receiving the system information. For example, the terminal can acquire synchronization based on the system information. Alternatively, synchronization acquisition can be performed before step S1010.

[0166] At step S1050, the first node (110) may transmit a signal for accessing cell #1. For example, the signal may include a random access preamble. The structure of this signal and the resources (e.g., channels) for transmitting the signal may be identified through system information. Thereafter, at step S1070, the first node (110) and the second node (120) may perform an access procedure for cell #1 and communicate.

[0167] The procedure described with reference to FIG. 10 may be performed when the first node (110) initially connects to cell #1 of the second node (120). Alternatively, a similar procedure may be performed when the first node (110) hands over to cell #1 of the second node (120). However, in the case of handover, the system information of cell #1 may be received from a cell of a base station other than cell #2 of the second node (120).

[0168] Communications in the THz band are expected to experience extremely severe path loss, and to overcome this, terminals and base stations may be required to use very sharp beams. The use of sharp beams means that terminals and base stations must perform beam control in addition to beamforming, and the number of beams used increases significantly. Consequently, it takes a very long time to align the transmit and receive beams between the base station and terminals. Furthermore, if the beam alignment between the base station and terminals is misaligned due to movement or movement of the terminals, frequent re-alignment is required, which can lead to link instability.

[0169] FIG. 11 exemplarily illustrates a beam management procedure to which some examples of the present disclosure may be applied.

[0170] Although FIG. 11 illustrates an example of a procedure for searching and / or selecting beams for THz communication, this procedure is not limited to a THz environment and can also be applied to a 6G communication environment where THz communication is not applied.

[0171] Here, beam may be interpreted as other terms having equivalent technical meanings that can distinguish beams, such as 'spatial domain filter', 'spatial domain transmit filter', 'spatial domain receive filter', reference signal (RS) resource that distinguishes beams, SSB index, etc.

[0172] In step S1110, the second node (120) (e.g., base station) can set resources for beam management to the first node (110) (e.g., terminal). Here, the resources can include at least one of time-frequency resources, channels, and spatial resources (e.g., antenna ports). For example, the base station can utilize a beam search signal (BSS) that is transmitted spatially separated from an existing downlink signal / channel for beam search. Here, the BSS can be transmitted based on a dedicated port for beam search. The dedicated port can be a different port from a port for transmitting an existing downlink signal / channel (e.g., SSB, PDSCH (physical downlink shared channel), etc.). BSS is a term defined for convenience of explanation, and the technical concept according to the present embodiment is not limited to the term BSS itself. For example, a signal transmitted based on a dedicated port defined / set for beam search can be included in the technical concept according to the present embodiment.

[0173] In step S1130, the second node (120) (e.g., base station) transmits measurement signals using a plurality of transmission beams. For example, the measurement signals may include at least one of a reference signal and a synchronization signal. At this time, the measurement signals may be transmitted as many times as the number of beams that require measurement, and may also be transmitted in a multi-beam transmission method that forms a plurality of beams simultaneously to reduce sweeping time. Here, the multi-beam transmission may be performed based on at least one of a multi-panel, a sub-array, and a true time delay (TTD).

[0174] In step S1050, a first node (110) (e.g., a terminal) may transmit a feedback signal to a second node (120) (e.g., a base station). The feedback signal may indicate at least one beam selected by the terminal. The terminal may select at least one preferred beam based on the measurement signals received in step S1030.

[0175] In step S1070, the first node (110) and the second node (120) can perform communication. For example, the second node (120) can perform transmission to the first node (110) using the reception beam of the first node (110) selected in step S1050. If channel reciprocity is established, the transmission beam of the first node (110) can also be determined through steps S1030 and S1050, so that the transmission operation from the first node (110) can also be performed using a beam that has a reciprocal relationship with the beam selected in step S1050. If channel reciprocity is not established, a procedure including transmission of measurement signal(s) by the first node (110) and transmission of feedback signal(s) by the second node (120) may be performed first to determine the transmission beam of the first node (110).

[0176] non-terrestrial networks (NTN)

[0177] Figures 12 and 13 illustrate examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0178] NTN can represent a network or network segment that uses radio frequency (RF) resources mounted on a satellite (or unmanned aerial system (UAS) platform).

[0179] Figure 12 shows an example of a typical scenario of NTN based on transparent payload, and Figure 13 shows an example of a typical scenario of NTN based on regenerative payload.

[0180] Referring to Figure 12, a satellite (or UAS platform) can establish a service link with a terminal. The satellite (or UAS platform) can be connected to a gateway via a feeder link. The satellite can be connected to a data network via the gateway. The beam footprint can refer to the area where the signal transmitted by the satellite can be received.

[0181] Referring to Figure 13, a satellite (or UAS platform) can establish a service link with a terminal. A satellite (or UAS platform) connected to a terminal can be connected to another satellite (or UAS platform) via an inter-satellite link (ISL). The other satellite (or UAS platform) can be connected to a gateway via a feeder link. Based on the regenerated payload, the satellite can be connected to a data network through another satellite and the gateway. If an ISL does not exist between the satellite and another satellite, a feeder link between the satellite and the gateway may be required.

[0182] Figures 12 and 13 are merely examples of NTN scenarios, and NTN can be implemented based on various scenarios. For example, a satellite (or UAS platform) can implement a transparent or regenerative (e.g., with onboard processing) payload. For example, a satellite (or UAS platform) can generate multiple beams across a designated service area depending on the field of view of the satellite (or UAS platform). For example, the field of view of the satellite (or UAS platform) can vary depending on the onboard antenna diagram and the minimum elevation angle.

[0183] For example, a transparent payload may include radio frequency filtering, frequency conversion, and amplification. Therefore, the waveform signal repeated by the payload may remain unchanged.

[0184] For example, a regenerative payload may include radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, and coding / modulation. For example, a regenerative payload may be substantially equivalent to mounting all or part of a base station function on a satellite (or UAS platform).

[0185] Integrated Sensing and Communication (ISAC)

[0186] Wireless sensing is a technology that uses radio frequencies to determine the instantaneous linear velocity, angle, distance (or range) of an object, and thus obtain information about the characteristics of the environment and / or objects within the environment. Because radio frequency sensing does not require a networked device to connect to the object, it can provide a service for object positioning without a device. The ability to obtain range, velocity, and angle information from radio frequency signals can enable a wide range of new capabilities, such as various object detection, object recognition (e.g., vehicles, humans, animals, UAVs), and high-precision localization, tracking, and activity recognition. Wireless sensing services can provide information to a variety of industries (e.g., drones, smart homes, V2X, factories, railways, public safety, etc.), enabling applications such as intruder detection, assisted vehicle steering and navigation, trajectory tracking, collision avoidance, traffic management, and health and traffic management. In some cases, wireless sensing can utilize non-3GPP type sensors (e.g., radar, cameras) to further support 3GPP-based sensing. For example, the operation of wireless sensing services, such as sensing operations, may depend on the transmission, reflection, and scattering of wireless sensing signals. Therefore, wireless sensing offers an opportunity to enhance existing communication systems from a communications network to a wireless communication and sensing network.

[0187] FIG. 14 illustrates examples of sensing operations to which some examples of the present disclosure may be applied.

[0188] Specifically, Fig. 14(a) shows an example of a monostatic sensing operation using a sensing receiver and a sensing transmitter located in the same location. Fig. 14(b) shows an example of a bistatic sensing operation using a sensing receiver and a sensing transmitter located in separate locations. A sensing signal transmitted from a sensing transmitter is reflected / scattered by a sensing object, and the sensing receiver can receive the signal, and extract / obtain sensing data based on the received signal. A sensing result can be generated / determined through appropriate processing of the sensing data. The sensing result can be provided to a trusted third-party entity / service outside the 3GPP system through an entity / service within the 3GPP system.

[0189] Network Energy Saving (NES)

[0190] Energy conservation at base stations is a key consideration in wireless communication systems, including 3GPP, as it can contribute to building eco-friendly networks by reducing carbon emissions and reducing operational expenditures (OPEX) for telecommunications providers. In particular, the introduction of 5G communications will require higher transmission rates, necessitating base stations to be equipped with more antennas and provide services over wider bandwidths and frequency bands. Consequently, recent studies have shown that base station energy costs have reached as high as 20% of total OPEX. For example, various technologies for reducing energy consumption in 5G wireless communication systems are being discussed under the term "network energy savings" (NES).

[0191] Depending on the application of NES technology, the base station can perform operations such as controlling on / off for a certain time duration in the time domain, controlling transmission / reception resources for terminal-common or terminal-specific signals / channels, changing the amount of frequency domain resources, controlling transmission power, or turning on / off an antenna port, transmission-reception point (TRP), etc. in the spatial domain.

[0192] For example, a base station may identify the NES solution(s) to be applied, perform signaling to the NES, and perform actions on the NES.

[0193] NES solution(s) may be related to control of signal transmission and reception (e.g., on / off), beam operation, handover procedures, channel measurement, and reporting. The NES solution(s) to be applied may be adaptively selected or predefined based on current conditions (e.g., cell load level, characteristics of connected terminals, etc.).

[0194] A base station that has identified NES solution(s) performs signaling for the NES. The specific signaling procedure may vary depending on the identified NES solution(s). For example, the base station may transmit common information about the NES solution(s), transmit configuration information necessary for NES operation to at least one terminal, or transmit control information regarding the progress of NES operation to at least one terminal. In addition, the base station may receive capability information related to the NES from at least one terminal.

[0195] Based on the signaled NES-related information, the base station can perform operations for the NES. For example, based on system information, configuration information, and control information conveyed via signaling, the base station can turn on / off transmission and reception of specific signals, turn on / off elements in the spatial domain, or adjust resources for transmission and reception of measurement signals.

[0196] Examples of NES solutions that can be implemented using these procedures include:

[0197] Intra-system energy saving: A RAN node may request a neighboring RAN node to switch at least one SSB beam into its inactive cell, or may perform paging using a limited set of beams to an inactive terminal (e.g., a stationary terminal).

[0198] Inter-system energy savings: NG-RAN nodes that own capacity booster cells can autonomously transition those cells to an inactive state.

[0199] SSB-less cells: If SSB or SSB-based RRM (radio resource management) measurement timing configuration (SMTC) configuration is not provided for a specific cell (e.g., secondary cell (SCell) or primary cell (PCell)), the UE may obtain timing reference and automatic gain control (AGC) source from another serving cell. In frequency range 1 (FR1) or FR2, the base station may configure intra-band carrier aggregation (CA) or inter-band CA including cells without SSB transmission, in which case SSB / SIB transmission may be triggered by a wake up signal (WUS) of the UE. Accordingly, since the period of common channels / signals such as SSB is increased, the base station may stay in sleep state for a longer time.

[0200] Cell DTX (discontinuous transmission) / DRX (discontinuous reception): In order to reduce the downlink transmission / uplink reception activity time of the base station, a periodic cell DTX / DRX pattern (e.g., active and inactive periods) may be commonly configured for terminals within a cell having the 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 a semi-persistent scheduling (SPS) opportunity or monitoring a PDCCH may be stopped during the cell DTX inactivity period. When cell DRX is configured and activated, at least one of transmission on a configured grant (CG) resource or transmission of a scheduling request (SR) may be stopped during the cell DRX inactivity period. Cell DTX / DRX can be activated / deactivated via RRC signaling or L1 (layer 1) group common signaling.

[0201] Parameters such as active duration and cycle may be configured for cell DTX / DRX. Active duration is the period during which the UE receives a PDCCH or SPS opportunity and waits to transmit SR or CG, and cycle may specify the periodic repetition of the active duration and inactive duration. When both cell DTX and cell DRX are configured, parameters such as active duration and cycle may be common. If the base station recognizes 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 configuration so as not to affect the service. In addition, at least some overlap may be required between the active period of the connected mode DRX of the UE and the active period of the cell DTX / DRX. For example, the connected mode DRX cycle of the UE may be a multiple of the cell DTX / DRX cycle, or vice versa.

[0202] Conditional handover (CHO): A CHO procedure performed in a manner in which the execution of a handover is determined by the UE may be used while NES technology is applied (e.g., when the cell activates or deactivates cell DTX / DRX). In this case, the UE may use an NES-specific CHO event to initiate CHO to a candidate cell, and reception of a DCI activating the CHO condition(s) set by the NES event indication may be applied as an additional triggering condition for this.

[0203] Spatial and Power Domain Adaptation: To support the base station for transceiver muting and / or transmit power adaptation, the UE may be configured to report multiple CSI quantities in a CSI report based on multiple sub-configurations. Each sub-configuration corresponds to a spatial domain adaptation pattern (e.g., a subset of available spatial elements) and / or a power offset between a data channel (e.g., PDSCH) and CSI-RS. Depending on the application of the spatial and power domain adaptation solution, the CSI configuration, measurement, and / or reporting behavior may be affected.

[0204] Cell DTX / DRX

[0205] To enable base stations to operate in sleep mode for relatively long periods of time without frequent wake-ups, base station DTX / DRX has been introduced for NES purposes. The base station can reduce energy consumption by utilizing DTX transmission under low system load conditions by configuring cell DTX and setting the on-duration of terminals' C-DRX within the active period of the cell DTX.

[0206] FIG. 15 illustrates an example of cell DTX / DRX operation to which some examples of the present disclosure may be applied.

[0207] A second node (120) (e.g., a base station) can transmit system information to a first node (110) (e.g., a terminal). Accordingly, the first node (110) can check information related to the cell DTX / DRX of the second node (120).

[0208] For example, system information may include MIB, SIB1, etc. In relation to NES technology, MIB may include information related to cell barring (e.g., cellBarred), and SIB1 may include information related to cell barring state (e.g., cellBarredNES). For example, if cellBarred included in MIB is set to a value indicating that it is not barred (e.g., notBarred), a terminal may determine that the cell is not barred, regardless of whether it supports NES cell DTX / DRX. For example, if cellBarred included in received MIB is set to a value indicating that the cell is barred (e.g., barred), a terminal that does not support NES cell DTX / DRX may determine that the cell is barred.

[0209] For example, if a terminal has a capability to support NES cell DTX / DRX, the terminal can check SIB1 to determine a cell barring status. For example, if cellBarred of MIB is set to barred and cellBarredNES is absent in SIB1, a terminal supporting NES cell DTX / DRX can treat the cell as barred and perform cell reselection to another cell. For example, if cellBarred of MIB is set to barred and cellBarredNES is included in SIB1, a terminal supporting NES cell DTX / DRX can determine that the cell is not barred.

[0210] In the example of FIG. 15, it is assumed that the terminal has the capability to support NES cell DTX / DRX, and cellBarred of MIB is set to notBarred, or cellBarred of MIB is set to barred and SIB1 includes cellBarredNES. Accordingly, the terminal can perform a random access procedure to connect to the base station, and then perform communication. For example, the base station can perform a cell DTX / DRX operation, and transmit configuration information related to the cell DTX / DRX operation to the terminal. The configuration information related to the cell DTX / DRX operation (e.g., CellDTXDRX-Config) includes at least one parameter related to the cell DTX / DRX, and may include, for example, at least one of an on-duration timer, a cycle start offset, a slot offset, a configuration type (e.g., DTX, DRX, or DTX-DRX), and an activation state of the DTX / DRX (e.g., active, inactive). Additionally, the configuration information may further include information for receiving and interpreting cell DRX / DRX-related control information (e.g., cellDTRX-RNTI included in physicalCellGroupConfig, DCI-related information such as the size of DCI format 2_9, etc.).

[0211] Thereafter, the base station can transmit control information related to cell DTX / DRX to the terminal. The control information related to cell DTX / DRX can include DCI having a designated format (e.g., DCI format 2_9). If an operation for a serving cell according to at least one of a cell DTX operation and a cell DRX operation is configured by configuration information (e.g., cellDTXDRX-Config included in servingcell-config), the terminal can check a set of search spaces (e.g., a Type3-PDCCH CSS set) for monitoring a PDCCH conveying control information of a designated format during an active time through a higher layer parameter (e.g., SearchSpace included in PDCCH-Config), and can obtain a location of information about the serving cell within the control information through a higher layer parameter (e.g., positionInDCI-cellDTRX included in ServingCell-config). Then, the terminal can obtain control information based on the identified set of search spaces and the location.

[0212] Control information related to cell DTX / DRX may be used to indicate activation or deactivation of cell DTX and / or cell DRX, and / or to provide NES-mode indicators (e.g., NES-specific CHO execution conditions, etc.), and may include, for example, at least one block including a cell DTX / DRX indicator and an NES-mode indicator. In this case, when the serving cell is configured as a supplementary uplink (SUL) carrier, the indication of activation or deactivation of cell DRX by the cell DTX / DRX indicator may be applied to both the uplink (UL) carrier and the SUL carrier.

[0213] After that, the terminal and the base station can perform communication based on the cell DTX / DRX. Specifically, the base station can turn on / off the transmission and reception of signals according to the settings related to the cell DTX / DRX, so that the terminal can selectively monitor the signal from the base station. During the DTX-OFF duration, the base station can enter a sleep mode to reduce energy consumption. For example, the base station DTX cycle can be aligned with the cycle of the terminal DRX. The base station DTX-ON duration can completely cover the DRX-ON duration of the terminal. Furthermore, the base station can align the transmission on Xn (base station-to-base station interface) / NG (interface between 5G RAN and 5G core network) and the transmission on Uu (interface between terminal and network) for NES purposes. The DTX / DRX mechanism triggers switching of reference signal resource sets, and the base station can perform a dormancy-like behavior of rarely or not transmitting SSB, SIB, and CSI-RS to reduce energy consumption. The terminal can rarely or not receive downlink signals / channels depending on the configuration of the base station. Once the base station DTX / DRX operation is triggered, the terminal can discontinuously receive the corresponding CSI-RS, SSB, or PDCCH during the DTX / DRX OFF duration.

[0214] SSB-less cells

[0215] FIG. 16 illustrates an example of carrier aggregation (CA) operation including an SSB-less cell to which some examples of the present disclosure may be applied.

[0216] In the example of Figure 16, it is assumed that the SSB-less cell is an SCell in the CA, but the SSB-less cell may also be a PCell in the CA.

[0217] A second node (120) (e.g., a base station) can transmit configuration information for an SCell to a first node (110) (e.g., a terminal). For example, the base station can transmit configuration information for CA to provide a service to the terminal 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 an SCell may include information (e.g., sCellToAddModList) including information for adding an SCell, 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. Accordingly, the terminal can determine the configuration for the CA operation and perform communication using the PCell and SCell of the base station.

[0218] For example, the terminal 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 related parameters. For example, the terminal can determine that the SCell is an SSB-less SCell by checking the presence of a parameter indicating that the SCell is an SSB-less SCell (e.g., SSBlessSCell), and can check the timing reference and AGC source for the SCell based on information about the reference cell (e.g., referenceCell). In the example of Fig. 16, the reference cell can be the PCell. Therefore, the terminal can use the PCell as a timing reference and AGC source for communication in the SCell. For example, the reference of the SSB-less cell can be (another) cell, TRP, CORESET pool (control resource set pool), (additional) PCI (physical cell ID), etc.

[0219] Conditional Handover (CHO)

[0220] FIG. 17 illustrates an example of a conditional handover operation to which some examples of the present disclosure may be applied.

[0221] The order of the operations illustrated in Fig. 17 may vary depending on the case.

[0222] A second node (120) (e.g., a base station) can transmit configuration information for CHO to a first node (110) (e.g., a terminal). The configuration information for CHO can include information related to conditional reconfiguration (e.g., ConditionalReconfiguration, CondReconfigToAddModList), information related to configuration for reporting (e.g., ReportConfigNR). For example, the information related to configuration for reporting can include information related to events related to reporting, identifiers of the events (e.g., condEventId), information indicating whether it is a NES-specific CHO event (e.g., nesEvent), etc. In the example of FIG. 17, it is assumed that event information indicating that it is a NES-specific CHO event is received.

[0223] A base station may transmit information for enabling an NES-specific CHO execution condition to a terminal. The information for enabling the NES-specific CHO execution condition may be transmitted via control information of a specified format (e.g., DCI format 2_9). The information for enabling the NES-specific CHO execution condition may be referred to as an NES-mode indicator, and may be, for example, 1-bit information that indicates enabling the NES-specific CHO execution condition when a related upper layer parameter (e.g., nesEvent) is set and a serving cell of a related block in the DCI is a primary cell.

[0224] Afterwards, the terminal can perform measurements and transmit a measurement report to the base station. The base station can determine a CHO based on the measurement report and perform signaling for a handover request with the adjacent / neighboring base station(s) indicated by the measurement report. The base station can determine the adjacent base station(s) that have confirmed admission through signaling as candidate base station(s) and transmit information about the candidate base station(s) to the terminal. Accordingly, the terminal can evaluate the CHO execution conditions for the candidate base station(s). Based on the evaluation result, if a candidate cell satisfying the conditions is determined, the terminal can perform detachment for the old cell and synchronization for the new cell.

[0225] For example, based on event information indicating that the event is an NES-specific CHO event received by the terminal in the previous procedure and information enabling an NES-specific CHO execution condition, the terminal can determine whether the event is satisfied. For example, if an NES-mode indicator is received through a lower layer and conditional triggering configuration information (e.g., condTriggerConfig) includes information indicating that the event is an NES-specific CHO event (e.g., nesEvent), the terminal can determine that the event associated with the corresponding measurement identifier (e.g., measId) is satisfied, and thus, determine that the CHO execution condition is satisfied.

[0226] Channel State Information (CSI) Measurement and Reporting

[0227] FIG. 18 illustrates an example of a procedure for CSI measurement and reporting to which some examples of the present disclosure may be applied.

[0228] A second node (120) (e.g., a base station) can transmit configuration information for CSI to a first node (110) (e.g., a terminal). The configuration information for CSI can include information related to a reference signal (e.g., a CSI-RS) resource or a resource set for CSI (e.g., time-frequency resource information, sequence information, power information, etc.), information related to CSI reporting (e.g., report item (quantity) information, report type information, report resource information, codebook information, etc.), information related to CSI measurement, etc.

[0229] For example, to assist the base station with transceiver muting and / or transmit power adaptation of the base station, the terminal may be configured to report multiple CSI entries in a CSI report based on multiple sub-configurations. For example, each sub-configuration may correspond to a spatial domain adaptation pattern (e.g., a subset of available spatial elements) and / or a power offset. With respect to CSI reporting, a higher layer parameter included in the configuration information (e.g., CSI-ReportConfig) may include a list of sub-configurations, and each sub-configuration may be identified by an identifier (e.g., csi-ReportSubConfigID). For example, each sub-configuration may correspond to a list of at least one CSI-RS resource, or may correspond to a subset of CSI-RS antenna ports, and / or may correspond to power-related parameters of the CSI-RS resource(s) (e.g., power control offset-related parameters (e.g., powerControlOffset) and / or power offset for a PDSCH associated with the CSI-RS).

[0230] For example, an information element (IE) for an aperiodic trigger state list for CSI may include a trigger list parameter for a CSI reporting sub-configuration. This parameter may include a list of sub-configuration ID(s) of N sub-configuration(s) among L configured sub-configurations within a CSI reporting configuration that are associated with triggering states for aperiodic CSI reporting on an uplink data channel (e.g., a physical uplink shared channel (PUSCH)).

[0231] For example, an IE for a CSI reporting configuration may include parameters for a list of CSI reporting sub-configuration ID(s) to be added / modified or released. Port subset indicators and a list of non-zero power (NZP) CSI-RS resources may not be configured simultaneously in the same CSI reporting configuration.

[0232] For example, an IE for a CSI reporting sub-configuration may include a port-subset indicator parameter, an NZP CSI-RS resource list parameter, and a power offset parameter.

[0233] The port-subset indicator parameter may indicate the number of ports of the NZP CSI-RS resources indicated in the NZP CSI-RS resource list (the value of which is equal to the number of ports of the corresponding NZP CSI-RS resources) and the (sub)set of CSI-RS antenna ports used for CSI calculation of the sub-configuration. Each bit in the bit string of the port-subset indicator corresponds to an antenna port, and if any bit is set to 1, the corresponding port may be enabled for CSI calculation corresponding to the sub-configuration, and if any bit is set to 0, the corresponding port may not be enabled for CSI calculation corresponding to the sub-configuration.

[0234] The NZP CSI-RS resource list parameter may indicate a list of NZP CSI-RS resources for a sub-configuration, which is a (sub)set of NZP CSI-RS resource(s) of a CSI-RS resource set for channel measurements associated with the sub-configuration of the CSI reporting configuration. The values ​​0, 1, 2, ... may mean the first, second, third, ... NZP CSI-RS resources of the CSI-RS resource set.

[0235] When the power offset parameter is set for an NZP CSI-RS resource, it may indicate that a power offset is applied between the PDSCH RE (resource element) and the NZP CSI-RS RE by the difference in the value of the power offset parameter from the value of the power control offset parameter.

[0236] When a configuration for CSI includes multiple sub-configurations, when interpreting the configuration information for CSI, the terminal may determine CSI-RS resources, CSI-RS port mapping, power offset, codebook type, report items, etc. by considering the sub-configurations. When configuration information related to CSI reporting including sub-configurations (e.g., CSI-ReportConfig) is provided to the terminal, the terminal may not expect that a higher layer parameter related to a report item (e.g., reportQuantity) is set to 'cri-RSRP', 'cri-SINR', 'cri-SINR-Index', 'cri-RSRP-Index', 'none', 'ssb-Index-RSRP', 'ssb-Index-SINR', 'ssb-Index-RSRP-Index', 'ssb-Index-SINR-Index' or 'tdcp' (wherein CRI corresponds to a CSI-RS resource index, and tdcp corresponds to time domain channel properties). Additionally, when the type of CSI reporting is set to semi-persistent CSI reporting or aperiodic CSI reporting, the base station can activate / trigger only some of the sub-configurations configured for the UE through MAC-CE (control element) or DCI (downlink control information). For example, the trigger state of aperiodic CSI reporting can be configured as needed, and whether semi-static CSI reporting is activated can be controlled by an activation command.

[0237] For example, with respect to the configuration of a report quantity, the terminal may determine the CSI-RS port index(es) for each CSI-RS resource based on information related to a port subset per sub-configuration (hereinafter referred to as a "port subset indicator"). The port subset indicator may include a bitmap for specifying some of the antenna ports for the corresponding CSI-RS resource. Accordingly, the terminal may identify at least one antenna port for the corresponding sub-configuration based on the positions of bits set to positive values ​​(e.g., 1) in the port subset indicator.

[0238] For example, with respect to the configuration of report items (report quantity), the terminal may determine the codebook type based on the presence or absence of sub-configurations. Specifically, if sub-configurations are configured for CSI reporting, the terminal may exclude the configuration of at least one codebook type. For example, if the terminal's capabilities support it, at least one codebook type may be configured.

[0239] For example, in relation to the configuration of the report quantity, a power offset value and an NZP CSI-RS resource set may be configured for each sub-configuration. For example, depending on whether a power offset value is configured for each sub-configuration and whether an NZP CSI-RS resource set is configured, the interpretation of the NZP CSI-RS resource set for each sub-configuration may vary.

[0240] When determining the channel quality indicator (CQI), a higher-layer parameter related to time restrictions for channel measurements (e.g., timeRestrictionForChannelMeasurements) may be configured. In this case, the terminal can derive a channel estimate for determining CSI based on the most recent CSI reference resource. For example, if cell DTX is activated for the base station, the cell DTX activation time, etc., may be considered to determine the CSI reference resource, etc.

[0241] CSI is derived based on CSI reference resources. A CSI reference resource is defined as a group of downlink physical resource blocks corresponding to a band related to the CSI derived in the frequency domain, and is defined as a single downlink slot determined based on higher-layer parameters and subcarrier spacing in the time domain. After receiving a CSI-RS, a UE can transmit a CSI report no later than the CSI reference resource. For example, if sub-configurations are configured for a CSI report, a CSI reference resource may be considered for each sub-configuration.

[0242] When at least one of a CQI index, a precoding matrix index (PMI), and a rank indicator (RI) is set to be reported, in the CSI reference resource, the terminal may assume specific values ​​for the symbol positions and number occupied by control signaling, the number of PDSCH and demodulation reference signal (DMRS) symbols, the subcarrier spacing of the bandwidth part (BWP), the bandwidth for CQI reporting, the length and subcarrier spacing of the cyclic prefix (CP) of the reference resource, and the redundancy version (RV), for the purpose of deriving at least one of the CQI index, PMI, and RI. At this time, when sub-configurations are set for the CSI reporting, assumptions about the antenna port, EPRE (energy per resource element), etc. may be determined based on the sub-configurations.

[0243] Based on the aforementioned configuration, the base station can transmit at least one CSI-RS to the terminal. Based on the aforementioned configuration, the terminal can receive at least one CSI-RS and perform measurement on it. For example, the at least one CSI-RS can be transmitted via a CSI-RS resource or resource set configured by the configuration information.

[0244] When the terminal is set to DRX (discontinuous reception), the terminal can perform measurements as follows. For example, when the terminal is set to monitor power saving related control information (e.g., DCI format 2_6) and the DRX related timer (e.g., drx-onDurationTimer) has not been started by a higher layer parameter (e.g., ps-TransmitOtherPeriodicCSI), and is set to report CSI using a reporting configuration type set to periodic reporting and a reporting item set to an item other than cri-RSRP and ssb-index-RSRP, the most recent CSI measurement opportunity occurs during the time indicated by drx-onDurationTimer in the DRX related configuration information (e.g., DRX-Config) other than the DRX active time or the DRX active time for the CSI to be reported. As another example, if the terminal is configured to monitor power saving related control information (e.g., DCI format 2_6) and is configured to report L1-RSRP using a report configuration type set to periodic reporting and a report item set to cri-RSRP in a situation where drx-onDurationTimer has not started by a higher layer parameter (e.g., ps-TransmitPeriodicL1-RSRP), the most recent CSI measurement opportunity occurs during a time indicated by drx-onDurationTimer in DRX-related configuration information (e.g., DRX-Config) other than the DRX active time or the DRX active time for the CSI to be reported. In addition, the most recent CSI measurement opportunity occurs within the DRX active time for the CSI to be reported.

[0245] A base station may perform cell DTX and / or cell DRX operations. In this case, during the inactive period of cell DTX, a terminal configured as cell DTX may not expect to receive periodic CSI-RS and semi-static CSI-RS, at least as configured in a CSI reporting configuration associated with a report item including RI. When cell DTX is activated for a serving cell, the most recent CSI measurement opportunity of a semi-static CSI-RS resource or a periodic CSI-RS resource may occur within the active periods of cell DTX for CSI reporting, at least as configured by configuration information (e.g., CSI-ReportConfig) related to CSI reporting associated with a report item including RI.

[0246] A terminal that receives at least one CSI-RS can determine CSI. For example, the terminal can perform CSI calculations. The terminal can perform CSI calculations based on CSI processing criteria. The terminal can indicate the number of supported concurrent CSI calculations, for example, the number of CSI processing units (CPUs) that can be performed simultaneously, called NCPUs. The terminal can determine the number of CPUs for a given CSI report based on at least one of the NCPUs, the number of CPUs for each CSI report, the number of CPUs currently occupied, and the settings of the report items. For example, for configuration information (e.g., CSI-ReportConfig) related to CSI reporting that includes a report item parameter (e.g., reportQuantity) that is not set to 'none', the CPU(s) may be occupied for at least one orthogonal frequency division multiplexing (OFDM) symbol, wherein the number of at least one symbol may be determined based on CSI-RS resources or CSI-IM (interference measurement) resources associated with the sub-configurations.

[0247] When configuration information related to CSI reporting (e.g., CSI-ReportConfig) includes multiple sub-configurations, the number of CPUs occupied by the CSI report may be determined based on the number of CSI-RS resources corresponding to the sub-configurations. For example, the number of CSI-RS resources may be determined based on the number of times they are referred in the configuration information related to CSI reporting (e.g., CSI-ReportConfig) or the number of sub-configurations referencing the corresponding CSI-RS resources.

[0248] A terminal that has determined CSI can transmit a CSI report to a base station. The terminal can transmit CSI(s) for at least one sub-configuration according to a report item parameter (e.g., reportQuantity) configured for configuration information related to the CSI report (e.g., CSI-ReportConfig). For example, the CSI report can include at least one of PMI, CQI, RI, CRI, SSBRI (SSB resource index), LI (layer indicator), and RSRP. In this case, the CSI report can include a Part 1 CSI report and a Part 2 CSI report. In addition, the CSI report can be transmitted via at least one of a physical uplink control channel (PUCCH) or a PUSCH.

[0249] When a terminal multiplexes a CSI report including a Part 2 CSI report on a PUCCH resource, the terminal determines the number of PUCCH resources and physical resource blocks (PRBs) for the PUCCH resource or the number of Part 2 CSI reports, assuming that each CSI report or each CSI sub-report included in the CSI report indicates rank 1 or the rank combination {1, 1}. When a higher layer parameter related to the CSI reporting mode (e.g., csi-ReportMode) is set to 'Mode2', the terminal determines the PUCCH resource and the number of PRBs for the PUCCH resource or the number of Part 2 CSI reports, assuming that each CRI of the CSI report is associated with a resource pair.

[0250] When a CSI report on PUSCH includes two parts, the UE may omit some of the Part 2 CSI. The omission of Part 2 CSI is in priority order. When omitting Part 2 CSI information for a particular priority level, the UE shall exclude all information for that priority level, except when the corresponding CSI report includes at least one CSI sub-report including Part 2, which corresponds to a sub-configuration from a list of sub-configurations provided by a higher layer parameter (e.g., csi-ReportSubConfigList) included in information related to the CSI report (e.g., CSI-ReportConfig).

[0251] For a report configuration related to information related to a CSI report (e.g., CSI-ReportConfig) that includes a list of sub-configurations, the following processing is possible: For a corresponding CSI report that includes at least one CSI sub-report, omission of Part 2 CSI is performed at the sub-configuration level within the same priority level, where a sub-configuration with a lower index value has a higher priority.

[0252] If a CSI report consists of two parts, a UE may omit some of the Part 2 CSI. The omission of Part 2 CSI is based on a priority order. For a report configuration related to information related to a CSI report (e.g., CSI-ReportConfig) that includes a list of sub-configurations, for a given CSI report that includes at least one CSI sub-report, the omission of Part 2 CSI may be applied according to the CSI reporting procedure using PUSCH. Part 2 CSI may be omitted starting from the lowest priority level up to the Part 2 CSI coding rate that is less than or equal to the coding rate set by the higher layer parameter (e.g., maxCodeRate).

[0253] Additionally, if the CQI request (or CSI request) field in the DCI triggers CSI report(s) on the PUSCH, the first uplink symbol carrying the CSI report(s) may not precede a symbol specified after a certain interval from the last symbol of the PDCCH carrying the corresponding DCI. Accordingly, the CSI calculation time may be guaranteed. For example, if multiple sub-configurations are configured for the CSI report, the starting position of the aforementioned certain interval may be determined based on all triggered sub-configurations.

[0254] CSI is transmitted via PUCCH or PUSCH and can be expressed as a bit string of a fixed size. When CSI is transmitted via PUCCH, if a parameter (e.g., csi-ReportSubConfig) indicating sub-configuration-specific settings for CSI reports is configured, the mapping order of CSI fields for each CSI sub-report can be applied according to predefined rules.

[0255] When CSI is transmitted via PUSCH, if a parameter indicating sub-configuration-specific configuration for CSI reporting (e.g., csi-ReportSubConfig) is set, for each CSI sub-report, the mapping order of CSI fields can be applied according to a predefined rule.

[0256] Some or all of the examples of FIGS. 1 to 18 described above may be combined with some or all of the examples of the present disclosure described below, and such combined examples are included within the scope of the present disclosure.

[0257] Improved NES

[0258] For enhancement of NES technology, on-demand SSB, on-demand SIB1, and adaptation of common signal / channel transmissions are being discussed.

[0259] Below we describe on-demand SSB.

[0260] On-demand SSB is a NES scheme that transmits SSB when triggered in a specific cell and does not transmit SSB when not triggered. Existing NR systems require periodic, constant transmission of SSB for purposes such as time / frequency synchronization and RRM measurement, making it difficult to reduce energy consumption even when the base station has no data to receive or send. Considering this, energy consumption at the base station can be reduced by not performing SSB transmission at all and only performing SSB transmission when the on-demand SSB process is performed.

[0261] These on-demand SSB processes can be triggered by one or more of the following examples:

[0262] - The terminal requests SSB transmission from the base station by transmitting an uplink signal / channel (e.g., PRACH (physical random access channel), PUCCH, PUSCH, SRS (sounding reference signal) in the 5G NR system, and may be a signal / channel with a different name in the 6G system).

[0263] - The first base station (or TRP) requests SSB transmission from the second base station (or TRP) through an interface between base stations (e.g., Xn interface in 5G NR system, interface with different name in 6G system) or backhaul signaling, etc.

[0264] - Signaling whether SSB transmission of the corresponding SCell is possible through SCell activation / deactivation signaling.

[0265] Considering coexistence with existing NR terminals, on-demand SSB operation may be limited to connected mode terminals and SCells. In subsequent releases or next-generation communication systems, on-demand SSB operation considering inactive or idle mode terminals or initially connected terminals (e.g., on-demand SSB support on PCell) may be defined. In addition, carrier aggregation (CA) including SCells applicable to on-demand SSB may be applied to both intra-band CA and inter-band CA. SSB on SCells transmitted through on-demand SSB may be utilized at least for time / frequency synchronization, L1 / L3 measurements, SCell activation, etc.

[0266] Below, we describe On-Demand SIB1.

[0267] On-demand SIB1 corresponds to a NES scheme that transmits SIB1 when triggered on a specific cell and does not transmit SIB1 when not triggered. In the existing NR system, in order to support access to a cell by an initial access terminal or an idle mode terminal, it is required to periodically and always transmit SIB1 containing system information, random access information, etc., making it difficult to reduce energy consumption even when the base station has no data to receive or send. By allowing the base station to not perform SIB1 transmission and to perform SIB1 transmission only when the on-demand SIB1 process is performed, the energy consumption of the base station can be reduced.

[0268] This on-demand SIB1 process may include the terminal transmitting an uplink signal / channel (e.g., PRACH in a 5G NR system, or a signal / channel with a different name in a 6G system) that triggers the base station's SIB1 transmission.

[0269] FIG. 19 illustrates examples of on-demand SIB1 operations to which some examples of the present disclosure may be applied. FIG. 19 merely illustrates examples, and on-demand SIB1 operations are not limited to the examples of FIG. 19.

[0270] In (a) of FIG. 19, the terminal may receive an SSB (and / or other downlink signal / channel) from the first cell (cell#1) and recognize that SIB1 is not transmitted on the corresponding cell#1. The terminal may trigger SIB1 transmission on cell#1 by transmitting a signal requesting SIB1 (e.g., a wake-up signal (WUS)) based on information provided in the SSB (and / or other downlink signal / channel) and / or predetermined information. For example, the base station that received the WUS may transmit a specific DL signal / channel (e.g., ACK) on cell#1 in response thereto and transmit SIB1 on cell#1. Alternatively, the base station may transmit SIB1 on cell#1 without transmitting a specific DL signal / channel (e.g., ACK).

[0271] In (b) of FIG. 19, the terminal may receive an SSB (and / or other downlink signal / channel such as SIB1) from the first cell (cell#1) and recognize that SIB1 is not transmitted from the second cell (cell#2). The terminal may attempt to camp on cell#2. The terminal may trigger SIB1 transmission for cell#2 by transmitting a signal (e.g., WUS) requesting SIB1 on cell#1 based on information provided in the SSB (and / or other downlink signal / channel such as SIB1) received from cell#1 and / or predetermined information. For example, the base station receiving the WUS may transmit a specific DL signal / channel (e.g., ACK) on cell#1 (or on cell#2) in response thereto, and transmit SIB1 for cell#2 on cell#1 (or on cell#2). Alternatively, the base station may transmit SIB1 for cell#2 on cell#1 (or on cell#2) without transmitting a specific DL signal / channel (e.g., ACK).

[0272] In (c) of FIG. 19, the terminal may receive an SSB (and / or other downlink signal / channel such as SIB1) from the first cell (cell#1) and recognize that SIB1 is not transmitted from the second cell (cell#2). The terminal may attempt to camp on cell#2. The terminal may trigger SIB1 transmission for cell#2 by transmitting a signal (e.g., WUS) requesting SIB1 on cell#2 based on information provided in the SSB (and / or other downlink signal / channel such as SIB1) received from cell#1 and / or predetermined information. For example, the base station receiving the WUS may transmit a specific DL signal / channel (e.g., ACK) on cell#2 (or on cell#1) in response thereto, and transmit SIB1 for cell#2 on cell#2 (or on cell#1). Alternatively, the base station may transmit SIB1 for cell#2 on cell#2 (or on cell#1) without transmitting a specific DL signal / channel (e.g., ACK).

[0273] Below we describe the adaptation of common signal / channel transmission.

[0274] Base stations can apply NES schemes that control the transmission of common signals / channels such as SSB, PRACH, and paging. Energy consumption can be reduced more significantly when SSB is not transmitted completely but is transmitted as needed. However, if SSB that supports time / frequency synchronization or RRM measurement is not transmitted completely, stable operation of terminals for the corresponding cell may not be guaranteed. Considering this, energy saving effects of the base station can be achieved by controlling / changing the SSB transmission pattern (e.g., transmission period, period by SSB candidate index(es), SSB candidate index(es) transmitted within one transmission period, transmission power, etc.) according to the situation.

[0275] In the case of PRACH resources, in the case of contention-based random access, since the base station does not know when the terminal will transmit the PRACH, it is required to always attempt reception within the PRACH resources set for the terminal, which may increase network energy consumption. Considering this, a method for controlling the amount of PRACH resources can be applied. For example, the period of the PRACH resources can be adjusted to be longer so that the base station attempts PRACH reception less frequently. For example, the number of PRACH resources can be adjusted to be smaller, such as a method of pre-configuring PRACH resource sets #1 and #2 and activating only one of the two sets or activating both sets. For example, the amount of RACH resources corresponding to each SSB index can be provided uniformly or non-uniformly.

[0276] In the case of paging, it is defined that paging frames (PF) and / or paging occasions (PO) are distributed on the time axis within a DRX cycle (or paging cycle), and the terminal attempts to receive paging at a specific PF / PO derived from a formula based on its own identification information. If the base station wants to transmit paging to multiple terminals simultaneously, it may need to frequently transmit paging messages according to various terminal identification information values. As a method for reducing the base station energy consumption due to this, a method such as arranging the PF and / or PO as close as possible on the time axis or arranging them on distinct frequency resources within the same time resource can be applied.

[0277] Types of synchronization signals

[0278] The examples of the present disclosure assume two types of synchronization signals. While the term "SSB" is used as an example of a synchronization signal in the following description, the scope of the present disclosure is not limited by that term, and other units with different names that include synchronization signals may replace "SSB."

[0279] For example, assuming on-demand SSB on a specific cell where transmission is initiated by a base station instruction or a terminal request, Type-1 SSB and Type-2 SSB can be distinguished as follows.

[0280] Type-1 SSB may refer to an SSB transmitted periodically on a first cell or on a second cell. If a period, etc. for the SSB is determined / defined / set, the SSB may be continuously transmitted according to the period. Continuous transmission may include transmission without distinction between on and off periods for SSB transmission, or without activation or deactivation. If Type-1 SSB refers to an SSB transmitted on a first cell, the first cell may correspond to a timing reference cell. If Type-1 SSB refers to an SSB transmitted on a second cell, the second cell may be in an intra-band CA or inter-band CA relationship with the first cell. For example, (especially in an inter-band CA environment) the second cell may be set as a timing reference cell for the first cell, or (in an intra-band CA environment) the second cell may be determined / defined as a timing reference cell for the first cell (e.g., a specific cell within the same timing advance group or a PCell or PSCell (primary secondary cell, i.e., a primary cell within a secondary cell group (SCG)). Also, only Type-2 SSBs may be transmitted on a specific cell without Type-1 SSBs.

[0281] Type-2 SSB may refer to an SSB in which transmission on a specific cell is activated through a configuration / instruction of the base station (via RRC / MAC-CE / DCI, etc.) or upon a request of the terminal. For an activated SSB, SSB deactivation may be explicitly configured / instructed via RRC / MAC-CE / DCI, etc. Alternatively, for an SSB in which the number of transmissions or transmission intervals are configured / instructed in the RRC / MAC-CE / DCI instructing SSB activation, the SSB may be deactivated when the corresponding number of transmissions or transmission intervals have expired. Alternatively, if there is a pre-configured / defined number of transmissions or transmission intervals, the SSB may be deactivated when the corresponding number of transmissions or transmission intervals have expired after SSB activation. Alternatively, (if a specific cell is an SCell) the SSB may be deactivated when activation for the specific cell is completed (or when CSI reporting for the specific cell is successfully completed). Alternatively, SSB may be deactivated when the specific cell is deactivated (if the specific cell is an SCell). Alternatively, SSB may be deactivated after a handover from the specific cell to another cell (if the specific cell is a PCell). Alternatively, SSB may be deactivated at the request of the UE.

[0282] As another example, it can be assumed that one or more SSB configurations are configured among different SSB configurations with at least different SSB cycle values, and an SSB corresponding to one of the SSB configurations is transmitted at the base station's instruction or the terminal's request. In this case, adaptation to the SSB cycle can be performed by varying the activated SSB configuration. In this case, Type-1 SSB and Type-2 SSB can be distinguished as follows.

[0283] Type-1 SSB may refer to a reference SSB setting among the configured SSB setting(s). For example, the reference SSB setting may correspond to the SSB setting having the largest SSB period value. For example, if an SSB setting corresponding to a Type-2 SSB is not activated, an SSB setting corresponding to a Type-1 SSB may be activated. Alternatively, if an SSB setting corresponding to a Type-2 SSB is activated, an SSB setting corresponding to a Type-1 SSB may be deactivated. Alternatively, if SSB opportunities specified based on a particular SSB setting (e.g., the reference SSB setting) among the configured SSB settings are a subset of SSB opportunities specified based on other SSB settings (e.g., "extended SSB opportunities"), the reference SSB opportunities may be defined as a Type-1 SSB (regardless of the actual activated SSB setting). In this case, Type-2 SSB can be defined as the remaining SSB opportunities among the extended SSB opportunities (included in the actual activated SSB configuration) excluding the reference SSB opportunities.

[0284] For Type-2 SSB, in addition to the SSB configuration corresponding to Type-1 SSB, one or more SSB configurations for Type-2 SSB can be configured. When an SSB configuration corresponding to Type-2 SSB is activated, all SSBs belonging to the activated SSB configuration can be defined as Type-2 SSBs. Alternatively, if SSB opportunities configured based on a specific SSB configuration (e.g., a reference SSB configuration) among the configured SSB configurations (hereinafter, referred to as "reference SSB opportunities" for convenience) are a subset of SSB opportunities configured based on other configurations (hereinafter, referred to as "extended SSB opportunities" for convenience), the reference SSB opportunities can be defined as Type-1 SSBs (regardless of the actual activated SSB configuration), in which case Type-2 SSBs can be defined as the remaining SSB opportunities among the extended SSB opportunities (in the actual activated configuration) excluding the reference SSB opportunities. One or more SSB configurations may be activated by a configuration / instruction (via RRC / MAC-CE / DCI) of the base station or by a request of the terminal. For an activated SSB configuration, SSB deactivation may be explicitly configured / instructed via RRC / MAC-CE / DCI, etc. Alternatively, for an SSB activated by configuring / instructing the number of transmissions or transmission intervals in the RRC / MAC-CE / DCI instructing the activation of the SSB configuration, when the corresponding number of transmissions or transmission intervals expire, the SSB may be deactivated. Alternatively, if there is a pre-configured / defined number of transmissions or transmission intervals, the SSB may be deactivated when the corresponding number of transmissions or transmission intervals expire after the SSB is activated. Alternatively, (if a specific cell is an SCell) the SSB may be deactivated when activation for the specific cell is completed (or CSI reporting for the specific cell is successfully completed). Alternatively, (if a specific cell is an SCell) the SSB may be deactivated when the specific cell is deactivated.Alternatively, SSB may be deactivated after a handover from a specific cell to another cell (if the specific cell is a PCell). Alternatively, SSB may be deactivated at the request of the terminal.

[0285] As another example, it can be assumed that one or more SSB configurations are configured and an SSB corresponding to one of the SSB configuration(s) is transmitted at the instruction of the base station or upon the request of the terminal. In this case, there is an SSB (e.g., Type-1 SSB) that continues to be transmitted periodically regardless of the activation / deactivation of the corresponding SSB configuration(s), and an SSB configuration to be transmitted in addition to this SSB can be activated / deactivated. At least the SSB period value or SSB time pattern can be different between different SSB configurations. In this case, adaptation to the SSB period can be performed by varying the activated SSB configuration. In this case, Type-1 SSB and Type-2 SSB can be distinguished as follows.

[0286] Type-1 SSB may mean an SSB corresponding to the default SSB setting, and continuous periodic transmission may be guaranteed for Type-1 SSB regardless of the activation / deactivation of the SSB setting(s) corresponding to Type-2 SSB.

[0287] One or more SSB configurations for Type-2 SSB can be configured. One of the one or more SSB configurations can be activated by a configuration / instruction from a base station (via RRC / MAC-CE / DCI) or a request from a terminal. For an activated SSB configuration, SSB deactivation can be explicitly configured / instructed via RRC / MAC-CE / DCI, etc. Alternatively, for an SSB activated by configuring / instructing the number of transmissions or transmission intervals in the RRC / MAC-CE / DCI indicating the activation of the SSB configuration, when the number of transmissions or transmission intervals has expired, the SSB can be deactivated. Alternatively, if there is a pre-configured / defined number of transmissions or transmission intervals, the SSB can be deactivated when the number of transmissions or transmission intervals has expired after the SSB is activated. Alternatively, the SSB can be deactivated when activation for the specific cell is completed (or when CSI reporting for the specific cell is successfully completed) (if the specific cell is an SCell). Alternatively, SSB may be deactivated when the specific cell is deactivated (if the specific cell is an SCell). Alternatively, SSB may be deactivated after a handover from the specific cell to another cell (if the specific cell is a PCell). Alternatively, SSB may be deactivated at the request of the UE.

[0288] In the various examples described above, Type-1 SSB may correspond to an SSB that can assume continuous periodic transmission, and Type-2 SSB may correspond to an SSB that cannot assume continuous periodic transmission. In some of the examples described below, the always-on SSB may correspond to or be replaced by the Type-1 SSB described above, and the on-demand SSB may correspond to or be replaced by the Type-2 SSB described above.

[0289] Lower layer control signaling related to synchronization signals

[0290] The present disclosure describes various methods for notifying a requesting UE of information regarding SSB transmission at the L2 or MAC layer when the base station determines that SSB transmission is necessary when the UE makes an on-demand SSB request. Examples of the present disclosure primarily include methods for notifying / indicating information / parameters regarding SSB transmission to the UE via MAC-CE.

[0291] The present disclosure may also include a method in which information related to SSB transmission is included for synchronization or QCL (quasi co-location) information when a specific cell (e.g., SCell) is activated, or a method in which MAC-CE information including reference cell-related information is directly designated. In the present disclosure, triggering or instructions related to on-demand SSB transmission may be used with the same meaning. In the present disclosure, activation / triggering for on-demand SSB transmission corresponds to a description from a base station perspective, and this can be understood as activation / triggering for reception of on-demand SSB from a terminal perspective.

[0292] FIG. 20 is a drawing for explaining an example of a method performed by a terminal according to the present disclosure.

[0293] In step S2010, the terminal can receive synchronization signal block setting information from the network.

[0294] For example, the synchronization signal block configuration information may include one or more parameter lists (or combinations of parameter(s)) for the synchronization signal block. Different parameter lists may include distinct indexes. Accordingly, the index of a parameter list may indicate one or more parameters configured for the corresponding parameter list.

[0295] For example, the configuration information may correspond to RRC signaling or RRC information elements.

[0296] In step S2020, the terminal may receive instruction information for one or more synchronization signal blocks from the network based on the configuration information.

[0297] For example, the instruction information may include information regarding the index of one or more specific cells and parameter information regarding one or more synchronization signal blocks. Instruction information based on the configuration information may refer to information indicating one or more targets among the target(s) set for the terminal by the configuration information. For example, the instruction information may include information indicating the index of one or more parameter lists among the parameter list(s) set for the terminal.

[0298] For example, parameter information for a specific cell and a synchronization signal block indicated by the instruction information may be associated with each other. For example, parameter information for a synchronization signal to be transmitted / activated in a specific cell to be activated may be indicated to the terminal.

[0299] For example, information about the index of one or more specific cells included in the indication information may correspond to an SCell index bitmap. In addition, parameter information included in the indication information may include an index field of a synchronization signal block parameter list associated with an SCell set to a specific value (e.g., 1) in the SCell index bitmap. If the bitmap is set to a specific value for a plurality of SCells, the index field of the synchronization signal block parameter list may be associated with each of the plurality of SCells. Alternatively, if transmission of a synchronization signal block is not performed for some / all of the plurality of SCells indicated by the bitmap, the index of the synchronization signal block parameter list may not be associated with the corresponding SCell(s).

[0300] For example, information about the index of one or more specific cells included in the indication information may correspond to one or more SCell index fields. In addition, parameter information included in the indication information may include one or more index fields of a parameter list corresponding to one or more SCell index fields, respectively. For example, when multiple SCell index fields are included, an index field of a synchronization signal block parameter list may be associated with each of the multiple SCells. Alternatively, if transmission of a synchronization signal block is not performed for some / all of the multiple SCells indicated by the multiple SCell index fields, an index of a synchronization signal block parameter list may not be associated with the corresponding SCell(s).

[0301] For example, such indication information may be included in a single MAC-CE. For example, a MAC-CE indicating a specific cell(s) and a MAC-CE indicating synchronization signal block parameter information may not be configured separately, but may be integrated and configured as a single MAC-CE.

[0302] For example, the parameter information included in the instruction information may include the parameter(s) indicated by the index of the parameter list as described above. Alternatively, some of the parameter information included in the instruction information may correspond to the parameter(s) indicated by the index of the parameter list, and the remaining part may include the respective values ​​of the parameter(s) that are not set as a parameter list (e.g., are not included in the parameter list and are dynamically indicated). Alternatively, the parameter information included in the instruction information may include the respective values ​​of the parameter(s) that are not set as a parameter list (e.g., are not included in the parameter list and are dynamically indicated).

[0303] For example, parameter information included in the instruction information may include information on the number of transmissions of a burst of a synchronization signal block. Candidates for the number of transmissions may include a natural number, a value of 0, a non-numeric value, etc. A natural number corresponds to the number of transmissions as is, a value of 0 corresponds to no transmission of a synchronization signal block, and a non-numeric value may correspond to a case where there is no limit to the number of transmissions of a synchronization signal block (or infinite or continuous transmission).

[0304] For example, if the number of transmissions of a finite natural number of values ​​is set / indicated, the synchronization signal block may be deactivated when the number of transmissions expires. If the number of transmissions of a finite natural number of values, or a non-numeric value corresponding to infinity, is set / indicated, the synchronization signal block may be deactivated based on a deactivation instruction for the synchronization signal block before the number of transmissions expires (or while transmissions are being performed without a limit on the number of transmissions).

[0305] For example, the synchronization signal block to which the configuration information of step S2010 and the instruction information of step S2020 are associated may correspond to the aforementioned Type-2 SSB (e.g., on-demand SSB). The synchronization signal block (Type-2 SSB or on-demand SSB) transmitted based on the configuration / instruction in this way can be distinguished from the Type-1 SSB (e.g., always-on SSB or legacy SSB) that is always transmitted without the configuration / instruction. The number of transmissions of such synchronization signal blocks may also be indicated or assumed based on the presence or absence of the Type-1 SSB (e.g., always-on SSB or legacy SSB). For example, when the legacy SSB (or Type-1 SSB or always-on SSB) exists in a specific cell / BWP, information on the number of transmissions of a burst for the synchronization signal block (or Type-2 SSB or on-demand SSB) may be set to a finite value and included in the instruction information. For example, if legacy SSB (or type-1 SSB or always-on SSB) does not exist in a particular cell / BWP, information about the number of transmissions of a burst of synchronization signal blocks may not be included in the indication information, and the number of transmissions of synchronization signal blocks may be assumed to be unlimited (e.g., infinite or perpetual).

[0306] For example, a synchronization signal block activated by instruction information may be deactivated based on the deactivation of a specific cell with which the activated synchronization signal block is associated. For example, a synchronization signal block may be deactivated in response to the deactivation of a specific cell with which it is associated, even without an instruction to deactivate the synchronization signal block.

[0307] In step S2030, the terminal may receive one or more synchronization signal blocks from the network based on the instruction information.

[0308] For example, the terminal can receive a synchronization signal block based on parameter information indicated by the instruction information on a specific cell indicated by the instruction information.

[0309] In the example of FIG. 20, the synchronization signal block may correspond to the aforementioned Type-2 SSB or On-Demand SSB.

[0310] The method described in the example of FIG. 20 may be performed by the wireless device (200) of FIG. 3 corresponding to the first node (110) of FIG. 2 described above. For example, one or more processors (202) of the wireless device (200) of FIG. 3 may be configured to receive synchronization signal block configuration information from a network through one or more transceivers (206), receive instruction information for one or more synchronization signal blocks from the network through one or more transceivers (206) based on the configuration information, and receive one or more synchronization signal blocks from the network through one or more transceivers (206) based on the instruction information. Furthermore, one or more memories (204) of the wireless device (200) may store commands for performing the method described in the example of FIG. 20 or the examples described below when executed by one or more processors (202).

[0311] FIG. 21 is a drawing illustrating an example of a method performed by a base station according to the present disclosure.

[0312] In step S2110, the base station can transmit synchronization signal block setting information to the terminal.

[0313] For example, a base station may transmit synchronization signal block setup information to all terminals within a cell or to some terminal(s).

[0314] In step S2120, the base station may transmit indication information for one or more synchronization signal blocks to the terminal based on the configuration information.

[0315] For example, the base station may transmit indication information for a synchronization signal block to some / all of the terminal(s) that received the configuration information.

[0316] In step S2130, the base station may transmit one or more synchronization signal blocks to the terminal based on the instruction information.

[0317] For example, a base station may transmit a synchronization signal block to all or some terminals indicating activation on a particular cell where activation is indicated in the instruction information.

[0318] The specific features of the synchronization signal block and its setting information and instruction information are the same as those described with reference to the example of Fig. 20, so redundant descriptions are omitted.

[0319] The method described in the example of FIG. 21 may be performed by the wireless device (200) of FIG. 3 corresponding to the second node (120) of FIG. 2 described above. For example, one or more processors (202) of the wireless device (200) of FIG. 3 may be configured to transmit synchronization signal block configuration information to a terminal via one or more transceivers (206), transmit instruction information for one or more synchronization signal blocks to the terminal via one or more transceivers (206) based on the configuration information, and transmit one or more synchronization signal blocks to the terminal via one or more transceivers (206) based on the instruction information. Furthermore, one or more memories (204) of the wireless device (200) may store commands for performing the method described in the example of FIG. 21 or the examples described below when executed by one or more processors (202).

[0320] Below, various examples of the present disclosure for lower layer (e.g., MAC layer) control signaling related to synchronization signals are described.

[0321] FIG. 22 is a diagram showing exemplary formats of MAC-CE related to SSB transmission according to the present disclosure.

[0322] Figure 22(a) shows an exemplary format of MAC-CE for conventional SCell activation / deactivation compared to examples of the present disclosure. For example, when activating or deactivating a certain SCell, the index of each SCell (C1 to C) is input through the MAC-CE of Figure 22(a). 31 ) can activate or deactivate up to 31 SCell(s) simultaneously. Each SCell index can be represented by one bit of the bitmap. For example, C1 to C 31 Among them, the SCell(s) corresponding to the bits set to a value of 1 may be indicated to be activated, and the SCell(s) corresponding to the bits set to a value of 0 may be indicated to be deactivated. Although not shown, when the number of SCells is 7 or less, SCell activation / deactivation may be indicated through the bitmap of C1-C7, and examples of C1 to C 31 Examples of may be replaced with examples of C1-C7.

[0323] For example, one could consider adding SSB transmission related information immediately after the SCell enable / disable MAC-CE. Alternatively, a MAC-CE indicating SSB transmission related information could be defined independently of the SCell enable / disable MAC-CE.

[0324] Information related to SSB transmission may include some or all of the parameters listed in the table below, or may additionally include parameters not listed in the table. Some or all of these parameters may be preset via the RRC Information Element (IE), while others may be dynamically indicated via the MAC-CE.

[0325] Parameter Name Description SSB Burst Transmission Count (or Window Size or Timer) This parameter can indicate how many times the burst is transmitted, considering that sweeping from SSB#0 to SSB#x is one transmission (i.e., one SSB burst). If the number of transmissions is 2, SSB#0 to SSB#x can be transmitted and then SSB#0 to SSB#x can be transmitted again after a predetermined time interval. The number of transmissions can be set / indicated as 1 or 2 or more. In addition, the number of transmissions can be replaced by a time window size or a timer (dividing the time remaining until the time window size or timer expires by the SSB transmission cycle corresponds to the number of transmissions). SSB Transmission Status This parameter is 1-bit information that indicates whether the SSB is transmitted or not. The SSB Transmit On parameter can be associated with a specific ID indicating not to transmit SSB, in which case the SSB Transmit On parameter may not be required. SSB#x ID This parameter is an identification (ID) assigned to an SSB in a specific direction. For a Type-2 SSB (e.g., on-demand SSB), a new type of identification that is distinct from the identification for a Type-1 SSB (e.g., conventional always-on SSB) may be assigned. For example, the new SSB ID may be notified in a bitmap format, and the maximum number of bits may be 64, so that an SSB ID supports 64 SSBs. Candidate values ​​for the new SSB ID may include a value indicating not to transmit SSB, or a value indicating to transmit once for all SSB IDs configured on the cell (i.e., sweeping). SSB Group ID This parameter is a group ID for managing SSB IDs in a specific direction as a group. For example, SSB Group ID#0={SSB0,SSB1,SSB2}, SSB Group ID#1={SSB3,SSB4,SSB5}, ...SSB Group ID#x can be defined as {SSBx,SSBy,SSBz}. The number of SSB IDs belonging to multiple groups may be the same or different. The SSB IDs belonging to each group may be continuous or some / all may be discontinuous. The SSB Transmission Time This parameter is information indicating the time interval (or offset) between the reference time point when a command instructing SSB transmission (e.g., SSB trigger / activation instruction information such as MAC-CE) is received and the time point when the SSB according to the command is transmitted. For example, the reference time point may be the time point when the SSB instruction information is received, or may be defined as another time point. Reference Cell ID (or Index) This parameter is information indicating another cell when setting / instructing not to transmit SSB in a specific cell and performing operations such as synchronization by referring to the SSB of another cell. For example, the reference cell ID may be defined as a new type of cell identifier (or TRP identifier, CORESET full index, (additional) PCI, etc.) different from the existing serving cell index or SCell index. SSB Transmission Duration This parameter may indicate the time period during which the SSB transmission is maintained. For example, the SSB transmission duration may be indicated as a multiple of the SSB transmission period (e.g., for a number of periods). BWP ID This parameter may indicate the BWP during which on-demand SSB activation / deactivation is applied.

[0326] In the absence of SMTC configuration in a specific cell, periodic SSB transmission may not be easy. For example, assuming SMTC is configured, in an SSB-less SCell, it is sufficient for the base station to transmit SSB only when there is a request for on-demand SSB in the uplink (e.g., from a UE). Assuming SMTC is not configured, information such as the SSB transmission time in Table 1 may be required to clearly determine when to transmit SSB in response to an on-demand SSB request. If the SSB transmission period of the SMTC configuration is included in the RRC parameters, when there is a request for on-demand SSB according to the period, SSB can be transmitted from the time when the next period returns. In the present disclosure, an SSB configuration ID may be assigned to a list including on-demand SSB-related parameters (e.g., parameters in Table 1) configured by a higher layer (e.g., RRC). For example, a set of SSB-related parameters corresponds to a parameter list, and one or more parameter lists can be configured. Different parameter lists are assigned different IDs / indexes, which are referred to as SSB configuration IDs in the present disclosure. In a lower layer (e.g., L1 or L2), the SSB configuration ID can be used to indicate one of the configured parameter lists. The parameter list indicated by the SSB configuration ID can include parameters for an SSB burst related to SSB-PositionsInBurst (bitmap), which is an RRC parameter for a group of SSB IDs, rather than for individual SSB transmissions.

[0327] In the present disclosure, two sub-states can be defined for the SCell activation state. The SCell state from the last slot in which MAC-CE or RRC signaling containing a command to activate the SCell is received to the first slot in which a CSI report is transmitted for the SCell can be referred to as the SCell activating state. The SCell state after the first slot in which a CSI report is transmitted for the SCell can be referred to as the activated state.

[0328] In the present disclosure, the number of transmissions may be replaced with the concepts of a timer or window size. For example, the number of transmissions, the timer, and the window size may be interchangeable in that they indicate the activation of on-demand SSB transmission while also indicating when transmission will end (or that transmission will only be performed within a finite number of times / interval).

[0329] In this disclosure, various examples of the number of transmissions for an SSB burst (sweeping that transmits SSB beams one at a time) are described. In this regard, the number of transmissions of an SSB burst can be expressed as N. N can include an infinite or permanent value, in which case on-demand SSB can be deactivated (e.g., transmission / reception is stopped) only when explicitly indicated, and after an indication (e.g., triggering or activation) of on-demand SSB, transmission / reception of SSB can be maintained without an explicit deactivation indication. The infinite or permanent value is not limited to a specific value and may also be defined or referred to as a non-numerical value having the corresponding meaning.

[0330] In the examples below, when PCell and SCell are referred to as cells without distinction, activation / deactivation for cells is assumed to apply to SCells. In other cases, cells are assumed to correspond to PCells and / or SCells.

[0331] In the description of the present disclosure, the fact that some action / information is predefined may include the meaning that the terminal assumes that the action / information is applied without separate signaling from the network.

[0332] Example 1

[0333] This embodiment relates to a method of setting and indexing a list of SSB transmission related parameters by a higher layer (e.g., RRC) and indicating the corresponding information through MAC-CE.

[0334] The list of SSB transmission related parameters may include some or all of the parameters included in Table 1 described above, or may include parameters with one or more parameters not included in Table 1 added.

[0335] When adding an SSB configuration via RRC signaling, an index may be assigned to the parameter list. For example, the index may correspond to an SSB configuration ID. There may be 256 such indices or IDs, and their values ​​may range from 0 to 255. For example, 256 different combinations of parameters may be configured. The number of configurable parameter lists, 256, is merely an example, and other values ​​in the form of powers of 2, such as 128 or 64, may also be applied.

[0336] For example, an SSB related IE via an RRC message may have the following information structure: {{SSB ID #1, Transmission time #1, Number of transmissions #1}, {SSB ID #2, Transmission time #2, Number of transmissions #2}, {SSB ID #3, Transmission time #3, Number of transmissions #3}, ...}}. Here, {SSB ID #x, Transmission time #x, Number of transmissions #x} may correspond to a parameter list, and the index or ID of the parameter list may correspond to x. In the above example, an index is assigned to a grouped list of multiple parameters, and the number of parameters included in one list is 3, but fewer or more parameters than 3 may be included in one list.

[0337] Additionally, parameters related to an aperiodic-tracking reference signal (A-TRS) may be included in the SSB transmission-related parameters. In this case, information about SSB and A-TRS may be indicated simultaneously.

[0338] In this way, when the SSB parameter list(s) are set through RRC signaling, the index of the SSB parameter list (or SSB setting ID) can be indicated through MAC-CE.

[0339] In (b) of Fig. 22, an example of concatenating the index of the SSB parameter list to the SCell activation / deactivation MAC-CE (example of (a) of Fig. 22) is shown.

[0340] One of the SSB parameter list indices indicated through MAC-CE can indicate one combination of various RRC configured parameters (e.g., transmission time, number of transmissions, SSB ID(s), SSB group ID (or SSBpositionInBurst), reference cell ID, etc.). For an activated SSB-less SCell, if an SSB parameter list index is indicated, the terminal can receive SSB and attempt synchronization, etc. based on each value of the parameters of the combination indicated by the index.

[0341] The size of one SSB parameter index field can be assumed to be 8 bits (or 1 octet). In this case, one octet can correspond to one SCell index. If the size of one SSB parameter index field is 4 bits, one octet can correspond to two SCell indices. For example, N octets from Oct 5 to Oct N+4 can indicate N SSB parameter list indices (or SSB configuration IDs).

[0342] In some of the examples described below, the UE may assume that a MAC-CE indicating on-demand SSB activation / triggering is valid when the SCell is inactive or a command related to SCell deactivation is instructed. The UE may ignore a MAC-CE indicating on-demand SSB activation / triggering received while the SCell is active or active. Alternatively, the UE may expect that the base station will not instruct activation / triggering for on-demand SSB via a MAC-CE when the SCell is active.

[0343] In some of the examples described below, the UE may assume that a MAC-CE related to SSB activation / triggering is valid only if the command to activate the SCell while the SCell is disabled is received at the same time (e.g., slot, symbol, etc.), in the same transport block (TB), or in the same MAC PDU as the MAC-CE indicating SSB activation / triggering. The UE may ignore a MAC-CE indicating on-demand SSB activation / triggering that is received while the SCell is activated or while it is activated. Alternatively, the UE may expect that the base station will not indicate activation / triggering for on-demand SSB via a MAC-CE while the SCell is activated.

[0344] In some examples described below, the terminal does not distinguish between the activation (activating or activated) or deactivation state of the SCell, and the terminal does not ignore the MAC-CE related to on-demand SSB deactivation, and can operate according to the SSB deactivation state based on the MAC-CE.

[0345] Example 1-1

[0346] An SSB parameter list index can be defined that corresponds to not transmitting SSB. For example, index 0 or the lowest or highest index value can indicate a parameter combination that does not transmit SSB.

[0347] When activating an SCell, if the cell is already known or the base station knows to some extent the directionality of the transmission beam, an SSB parameter list index indicating that SSB is not transmitted for that cell may be indicated. No SSB transmission may also imply that ongoing SSB transmission is stopped.

[0348] Example 1-2

[0349] An index of the SSB transmission related parameter list set by a higher layer (e.g. RRC) can be connected only to a cell (e.g. SCell) whose activation is indicated in MAC-CE.

[0350] Since information about SSB transmission is not required for disabled cells, the octet indicating the SSB transmission related parameter index for disabled cells does not need to be additionally concatenated to MAC-CE.

[0351] Additionally, if a particular cell is not an SSB-free cell, a parameter list for SSB transmission may not be required. In this case, the SSB parameter list index may not be included in the MAC-CE for that cell. Alternatively, information indicating no SSB transmission for that cell (e.g., SSB parameter list index 0, the lowest index, or the highest index) may be indicated.

[0352] When the SSB parameter list index field is added only for activated and also SSB-less cells, the octets from Oct 5 to Oct N+4 of (a) of Fig. 22 may correspond to the activated SCell indices (e.g., one octet sequentially corresponds to one SCell index). In this case, N may correspond to the number of activated cells. If the size of one SSB parameter index field is 4 bits, each octet from Oct 5 to Oct N+4 may correspond to two activated SCell indices. In this case, 2*N may correspond to the number of activated cells or the number of activated cells + 1.

[0353] Example 1-3

[0354] The index of the SSB transmission related parameter list set by the upper layer (e.g. RRC) can be connected to all (configured) cells without distinguishing between cells whose activation is indicated in MAC-CE (e.g. SCell) and cells whose activation is not indicated.

[0355] For cells that require on-demand SSB even in the disabled state, the SSB parameter list index can be indicated.

[0356] In the example of (b) of Fig. 22, activation / deactivation by SCell index is performed using a bitmap (C1-C 31 ) format, the activation / deactivation of on-demand SSB can also be indicated in bitmap format. For example, bitmap(C1-C 31 ) may indicate that on-demand SSB is enabled for the SCell index corresponding to the bit set to 1, and may indicate that on-demand SSB is disabled for the SCell index corresponding to the bit set to 0. The SSB parameter list index fields linked to the bitmap may be added in the order of the indexes of the SCell. If on-demand SSB is disabled (e.g., the corresponding bit position is set to 0), the corresponding SSB parameter list index field may not be included in the MAC-CE.

[0357] In the example of (b) of Fig. 22, the bit position indicated by R is newly defined as corresponding to the PCell, and SSB activation / deactivation may be indicated for the PCell. For example, the PCell may also be configured as an SSB-less cell, and SSB transmission may be performed only when on-demand SSB is activated.

[0358] The enhanced SCell Activation / Deactivation MAC-CE is defined in a format in which TRS field(s) are concatenated to the SCell index bitmap. According to the present disclosure, the enhanced SCell Activation / Deactivation MAC-CE may additionally be concatenated with SSB Parameter List Index field(s).

[0359] Example 1-4

[0360] Figure 22(c) shows an example of a new MAC-CE that indicates the on-demand SSB parameter list index per cell, separately from the SCell activation / deactivation MAC-CE.

[0361] When SSB parameter list index #x is indicated for cell index #a, SSB may be indicated to be activated / triggered based on parameter(s) belonging to one of the SSB parameter lists configured by RRC in the corresponding cell. For example, the cell index may be an SCell index or a PCell index.

[0362] The bit size of the cell index field and the bit size of the SSB parameter list index may be the same or different. A single cell index field may be defined in octet units, including reserved bits. The number of cell index fields may correspond to the number of cells indicating SSB-related information. Accordingly, the MAC-CE payload size may vary.

[0363] Unlike the example in (b) of Fig. 22, SSB-related information can be signaled to the terminal via an L2 control message (e.g., MAC-CE) at any time other than the SCell activation or deactivation time.

[0364] Depending on the value of the SSB parameter list index, activation / triggering of on-demand SSB may be indicated for a specific cell, or no SSB transmission (or deactivation of on-demand SSB being transmitted) may be indicated for a specific cell.

[0365] Example 1-5

[0366] If the size of the field indicating SSB configuration related information is constant, the lower layer information (e.g., MAC-CE) may be defined in a format that includes only the ID (e.g., SSB parameter list index)(s) of the SSB configuration related information, omitting the cell index corresponding to the SSB.

[0367] Fig. 22 (d) exemplarily shows a new MAC-CE format that includes only SSB configuration related information field(s).

[0368] For example, assuming that 16 SSB parameter lists are set, the SSB parameter list index can be indicated by a 4-bit field. In this case, the 4-bit SSB configuration-related information field can be set to a value indicating the SSB parameter list index for the corresponding cell according to the cell index order. For example, the order or position of the SSB configuration-related information field can correspond to the cell index or implicitly indicate the cell index.

[0369] For cells having an index corresponding to a sequence of fields set to an index value indicating no SSB transmission (e.g., 0000 for the lowest index, or 1111 for the highest index), no SSB transmission (or deactivation of ongoing SSB transmission) may be indicated.

[0370] In this case, the size of the MAC-CE indicating SSB activation / triggering is reduced compared to other examples, but the SCell activation / deactivation MAC-CE and the SSB activation / triggering MAC-CE can be defined and used as separate MAC-CEs.

[0371] Example 2

[0372] This embodiment describes a method for directly indicating the value of the SSB parameter in MAC-CE.

[0373] In the aforementioned embodiment 1, it can be said that this is a method in which the values ​​of the parameter(s) included in the SSB parameter list set by the upper layer are indirectly indicated by indicating the SSB parameter list index in the MAC-CE.

[0374] FIG. 23 is a diagram showing other exemplary formats of MAC-CE related to SSB transmission according to the present disclosure.

[0375] C1-C in (a) of Fig. 23 31 is the same as the example of (b) of Fig. 22, and one or more sets of connected A1-A4 fields may be connected as many times as the number of activated cells, or may be connected as many times as the number of set cells without distinguishing between activated and deactivated.

[0376] Additionally, the R field may indicate whether SSB is enabled for the PCell, and a set of parameter fields corresponding to the R field may be linked.

[0377] A1, A2, A3, and A4 can correspond to parameters related to SSB transmission. For example, A1 can be set to a parameter value for the SSB ID, A2 to the number of transmissions, A3 to the transmission cycle, and A4 to the reference cell ID.

[0378] Some of A1-A4 are indexed by a higher layer (e.g. RRC), so that the corresponding field indicates the index, and the value of the parameter set in relation to the index may be indirectly indicated to the terminal.

[0379] For example, after the number of transmissions is set in a list format by RRC, the index of the list can be indicated through MAC-CE. If the number of transmissions is predefined only as 1 or 2, the number of transmissions can be indicated as 1 bit to indicate one of the two cases. If the number of transmissions is indicated as 0 or an index indicating no transmission is indicated, it can be indicated that SSB transmission is not performed or is disabled in the corresponding cell.

[0380] For example, for a reference cell ID, the value of a specific field can be directly set to the value corresponding to the ID via MAC-CE. Alternatively, for (some) candidates for the reference cell ID, a list can be set by RRC, and then the index of the list can be indicated via MAC-CE.

[0381] Similarly, the SSB transmission time can be directly indicated by the value through MAC-CE, or the index of the RRC configured list can be indicated through MAC-CE.

[0382] The example of Fig. 23(a) exemplifies a case where the total size of one parameter field set (A1-A4) is one octet in size, but one parameter field set may be defined with a size of two or more octets.

[0383] Also, the number of fields included in one parameter field set being four is just an example, and one parameter field set may be defined as one field or as multiple fields.

[0384] In (b) of Fig. 23, the cell index field is the same as the example in (c) of Fig. 22, and instead of the SSB parameter list index being indicated in Fig. 22, the parameter field can be indicated directly in Fig. 23.

[0385] The parameter field included in the aforementioned MAC-CE may include information related to cell activation / deactivation, or may include information related to activation / deactivation of on-demand SSB.

[0386] In (c) of Fig. 23, the cell-specific parameter field set may include fields that directly indicate the parameter values ​​of the corresponding cell, instead of the cell-specific parameter list index of Fig. 22(d). Alternatively, in (b) of Fig. 23, the cell index field may be omitted, and another parameter may be directly indicated at the corresponding bit position. For example, when the maximum number of configurable cells is 8, 3 bits indicating the cell index, or when the maximum number of configurable cells is 32, 5 bits indicating the cell index, may be used as a field that directly indicates the SSB ID.

[0387] For example, the size of one parameter field set is X bits, and parameter field sets of the same size can correspond to multiple cells. Parameter field sets corresponding to the number of indicated cells can be included in the MAC-CE.

[0388] Even in this case, if the number of transmissions is indicated as 0 or an index indicating no transmission is indicated, it may be indicated that SSB transmission is not performed or is disabled in the corresponding cell. For example, instead of the index of on-demand SSB directly indicating no transmission, the number of transmissions or the transmission window size may be indicated as 0, thereby indicating no SSB transmission. Alternatively, by setting a value meaning persistent for the number of transmissions / transmission window / timer, it may be indicated that SSB is transmitted continuously (until explicitly disabled). Instead of the number of transmissions or the transmission window, information indicating the disablement or deactivation of on-demand SSB may be defined as one of the fields in a set of parameter fields (e.g., A1-A4).

[0389] In this example, the number of fields included in a parameter field set is four, but this is merely an example. A parameter field set can be defined as a single field or multiple fields. If the sum of the sizes of the parameter fields included in a parameter field set is less than a multiple of an octet, it can be defined as a size that is a multiple of an octet by including additional reserved bits.

[0390] For the examples described above, the UE may assume that the MAC-CE indicating on-demand SSB activation / triggering is valid when the SCell is inactive or a command related to SCell deactivation is instructed. The UE may ignore the MAC-CE indicating on-demand SSB activation / triggering received while the SCell is active or active. Alternatively, the UE may expect that the base station will not indicate activation / triggering for on-demand SSB via the MAC-CE when the SCell is active.

[0391] For the examples described above, the UE may assume that the MAC-CE related to SSB activation / triggering is valid only if the command to activate the SCell while the SCell is inactive is received at the same time (e.g., slot, symbol, etc.), in the same TB (transport block), or in the same MAC PDU as the MAC-CE indicating SSB activation / triggering. The UE may ignore the MAC-CE indicating on-demand SSB activation / triggering received while the SCell is active or activated. Alternatively, the UE may expect that the base station will not indicate activation / triggering for on-demand SSB through the MAC-CE while the SCell is active.

[0392] For the examples described above, the terminal does not distinguish between the activation (activating or activated) or deactivation state of the SCell, and the terminal does not ignore the MAC-CE related to on-demand SSB deactivation, and can operate according to the SSB deactivation state based on the MAC-CE.

[0393] Example 3

[0394] This embodiment is about a method in which some of the SSB configuration related information indicated through MAC-CE indicates an index of a parameter list set by RRC, and other parts are directly indicated by parameter field values.

[0395] In this embodiment, the description of Embodiment 1 may be applied to the index of the parameter list, and the description of Embodiment 2 may be applied to the direct indication of the parameter field value. For example, among the parameters in Table 1, the index set by RRC for the list of combinations of some parameter(s) may be indicated through MAC-CE, and other parameter(s) may be indicated directly through MAC-CE.

[0396] FIG. 24 is a diagram illustrating further exemplary formats of MAC-CE related to SSB transmission according to the present disclosure.

[0397] In (a) of Fig. 24, A1 corresponds to the number of transmissions or transmission time information, and the SSB parameter list index can indicate a specific combination of some / all of the remaining parameters excluding the parameter corresponding to A1.

[0398] For example, relatively static information can be managed by pre-setting a list of various combinations in advance through RRC and indicating the combination using the index of the list, and relatively dynamic information can be managed by directly indicating the value of the information through the MAC-CE field in order to control it in real time by reflecting the situation of the terminal or base station at that time.

[0399] If the sum of the size of the SSB Parameter List Index field defined per cell in the MAC-CE format and the size of A1 (or the additional direct instruction parameter field(s)) is not a multiple of an octet, additional reserved bits may be included to make it a multiple of an octet.

[0400] C1-C of (a) of Fig. 24 31 Each bit in the bitmap may instead indicate SSB enable / disable for the corresponding cell, and the R bit may indicate SSB enable / disable for the PCell.

[0401] Figure 24 (b) corresponds to a method for indicating SSB information using a new MAC-CE format that is not linked to the SCell activation / deactivation MAC-CE. For example, a set of a cell index field, an SSB parameter list index field, and a direct indication parameter field(s) is defined, and one or more of the sets may be included in the MAC-CE. The size of one set may be defined as a multiple of an octet.

[0402] In the examples described above, when the A1 field is defined to indicate the number of transmissions, it may indicate a finite number of on-demand SSB transmissions, no transmission (e.g., 0), or continuous transmission. For example, when the size of A1 is 2 bits, it may indicate one of 0, 1, 2, or a non-numeric value (wherein the non-numeric value may mean infinite or perpetual transmission). If a non-numeric value is indicated, SSB transmission may be maintained until deactivation is indicated for on-demand SSB via MAC-CE or L1 DCI.

[0403] The A1 field may be defined as information indicating SCell activation / deactivation, or as information indicating on-demand SSB activation / deactivation.

[0404] The directly indicated field is not limited to one of A1, and multiple fields corresponding to multiple parameters not included in the SSB parameter list may be included in the MAC-CE as directly indicated fields.

[0405] Alternatively, in (b) of Fig. 24, the cell index field may be omitted, and another parameter may be directly indicated at the corresponding bit position. For example, if the maximum number of configurable cells is 8, the 3 bits indicating the cell index, or if the maximum number of configurable cells is 32, the 5 bits indicating the cell index, may be used as a field directly indicating the SSB ID.

[0406] For example, the size of the set of SSB parameter list index and direct indication parameter field(s) for one cell may be X bits, and sets of the same size may correspond to multiple cells. A set corresponding to the number of indicated cells may be included in the MAC-CE. Here, no on-demand SSB transmission may be indicated when the value of the SSB parameter list index is a specific value (e.g., 0, or the lowest index, or the highest index).

[0407] For the examples described above, the UE may assume that the MAC-CE indicating on-demand SSB activation / triggering is valid when the SCell is inactive or a command related to SCell deactivation is instructed. The UE may ignore the MAC-CE indicating on-demand SSB activation / triggering received while the SCell is active or active. Alternatively, the UE may expect that the base station will not indicate activation / triggering for on-demand SSB via the MAC-CE when the SCell is active.

[0408] For the examples described above, the UE may assume that the MAC-CE related to SSB activation / triggering is valid only if the command to activate the SCell while the SCell is inactive is received at the same time (e.g., slot, symbol, etc.), in the same TB (transport block), or in the same MAC PDU as the MAC-CE indicating SSB activation / triggering. The UE may ignore the MAC-CE indicating on-demand SSB activation / triggering received while the SCell is active or activated. Alternatively, the UE may expect that the base station will not indicate activation / triggering for on-demand SSB through the MAC-CE while the SCell is active.

[0409] For the examples described above, the terminal does not distinguish between the activation (activating or activated) or deactivation state of the SCell, and the terminal does not ignore the MAC-CE related to on-demand SSB deactivation, and can operate according to the SSB deactivation state based on the MAC-CE.

[0410] Example 4

[0411] This embodiment relates to a method for indicating some SSB beam information in a reference cell for SSB transmission.

[0412] FIG. 25 is a diagram illustrating further exemplary formats of MAC-CE related to SSB transmission according to the present disclosure.

[0413] One way to indicate SSB information is to provide information about the reference cell, while another is to transmit SSB directly from that cell. For example, information about the reference cell may be provided to the UE, and some SSB information from a reference cell other than the UE's current serving cell may be provided to the UE. In this case, the SSB information may be indicated by an index value in a grouped list.

[0414] In the example of Fig. 25, the SSB (group) field may indicate the ID of a single SSB beam when not grouped, or may indicate the SSB group ID when grouped. The reference cell information field may indicate the identification information of a specific cell (or TRP ID, CORESET full index, (additional) PCI), or may indicate the index of a specific list preset by RRC. The reference cell may also be referred to as an anchor cell.

[0415] Figure 25 (a) corresponds to an example of indicating reference cell information and SSB (group) information together with SCell activation / deactivation indication information, and (b) corresponds to an example of indicating reference cell information and SSB (group) information by cell index without SCell activation / deactivation indication information.

[0416] For example, when instructing a terminal to refer to / receive only some SSBs of a reference cell, the information can be set as a list with indexes assigned in advance in a higher layer (e.g., RRC, L3), and only the indexes can be indicated through an L2 control command such as MAC-CE (or an L1 control command such as PDCCH).

[0417] Alternatively, in (b) of Fig. 25, the cell index field may be omitted, and another parameter may be directly indicated at the corresponding bit position. For example, if the maximum number of configurable cells is 8, the 3 bits indicating the cell index, or if the maximum number of configurable cells is 32, the 5 bits indicating the cell index, may be used as a field directly indicating the SSB (group) ID.

[0418] For example, the size of the set of reference cell information and SSB (group) information for one cell may be X bits, and sets of the same size may correspond to multiple cells. The sets corresponding to the number of indicated cells may be included in the MAC-CE. Here, no on-demand SSB transmission may be indicated when the SSB (group) ID has a specific value (e.g., 0, or the lowest index, or the highest index).

[0419] Example 5

[0420] In the aforementioned embodiments, when SSB-related information is transmitted together with the SCell activation / deactivation MAC-CE, SSB-related information may be indicated only for the activated cell. In this case, SSB-related information may be additionally restricted by the upper layer to be indicated only for SSB-free cells.

[0421] Alternatively, for a cell in which deactivation is indicated in the SCell activation / deactivation MAC-CE in the aforementioned embodiments (the bit value corresponding to the cell is set to 0), an index of on-demand SSB-related information corresponding to the cell may be associated. In addition, if on-demand SSB is required even when the cell is deactivated, an index of SSB-related information may be associated.

[0422] In the embodiments described above, the size of each field is not limited, and the total size of the fields indicating SSB-related information (including reference cell-related information) indicated for each cell can be defined in units of multiples of octets from the MAC-CE format perspective. If the total size of the fields does not fit in units of multiples of octets, padding or reserved bits may be added.

[0423] For on-demand SSB for multiple SSB bursts, it can be assumed that multiple SSB parameter lists are set through a combination of various parameters such as SSB groups (SSB_PostionsInBurst) and the number of transmissions, transmission periods, etc. In addition, the scope of the present disclosure also includes a case where only one SSB parameter list is set. In this case, when a single SSB parameter list is set, SSB can be activated / triggered (according to the respective values ​​of the parameters included in one list) upon cell activation, even without triggering / activating on-demand SSB through a lower layer.

[0424] When SSB transmission related information is linked to the cell activation / deactivation MAC-CE and transmitted as a single MAC-CE, the SSB related information may be included in the MAC-CE only for cells that are activated (e.g., the value of the bit corresponding to the cell is set to 1), and the SSB related information may not be included in the MAC-CE for cells that are deactivated (e.g., the value of the bit corresponding to the cell is set to 0). If the activated cell is a cell that can be designated as a reference cell that transmits SSB without a request for on-demand SSB, the SSB related information for such a cell may not be included in the MAC-CE (similarly to the way that SSB related information for a deactivated cell is not included in the MAC-CE).

[0425] Additionally or alternatively, after on-demand SSB transmission starts from a certain point in time on a certain cell (until a separate on-demand SSB deactivation instruction or a deactivation instruction for the cell in question), the terminal may assume that on-demand SSB transmission continues periodically. Even if the number of transmissions / transmission window size / timer length in the present disclosure are set to values ​​corresponding to permanent / infinite, it may be assumed that SSB transmission continues as above.

[0426] Example 5-1

[0427] When SSB related information is connected to the cell activation / deactivation MAC-CE and indicated, if a specific cell where SSB is always transmitted is activated, the value of the index that is set / defined as a specific SSB that is always transmitted can be indicated for that cell.

[0428] For MAC-CE formats that refer to a reference cell for SSB, cell-related information can be added to the MAC-CE.

[0429] Example 5-2

[0430] When SSB related information is indicated by being connected to the cell activation / deactivation MAC-CE, for SSB-less cells (or cells that do not always transmit SSB), SSB related information indicating no SSB transmission may be included.

[0431] If the cell for which activation is indicated is a non-SSB cell, SSB-related information for that cell (information indicating no SSB transmission) may be included in the MAC-CE.

[0432] Example 5-3

[0433] In relation to MAC (or L2) indication / control of on-demand SSB, in the above-described examples linked to cell activation / deactivation MAC-CE, on-demand SSB related information may be included in the MAC-CE only when activation for a specific cell is indicated.

[0434] If the UE fails to synchronize time / frequency through the SSB received based on the information indicated by the MAC-CE after the L2 SSB-related MAC-CE is transmitted, the cell may be switched to inactive if the cell is active or has been activated, and the synchronization failure state may be reported to the base station through the uplink channel. For example, if SSB-related information for a specific cell is transmitted through the downlink and then the UE requests SSB transmission for the cell again, the cell may be assumed to be in an inactive state. In this case, if the SSB-related MAC-CE is transmitted to the UE in the PDSCH, the UE may feed back a NACK (non-acknowledgement) for the PDSCH to the base station or may not provide any feedback, and the UE may request on-demand SSB from the base station again.

[0435] If a terminal transmits an uplink signal / channel requesting SSB transmission on a specific cell, but is signaled that SSB is not transmitted on the cell through a cell activation message (e.g., via RRC signaling or MAC-CE), the terminal may have problems acquiring time / frequency synchronization and / or setting AGC and / or applying QCL source for the cell. Alternatively, although a reference cell for a specific cell is indicated through a cell activation message (e.g., via RRC signaling or MAC-CE), it may be difficult for the terminal receiving the signaling to apply the time / frequency synchronization information acquired from the reference cell to the cell. In this situation, the actions taken by the terminal after receiving the cell activation message can be defined as follows. In the first method, the terminal can trigger an on-demand SSB process (without performing activation for the cell) to (re)transmit an uplink signal / channel requesting SSB transmission on the cell. In a second way, the UE can feed back HARQ-ACK (hybrid automatic repeat request-acknowledgement) information corresponding to NACK to the base station (even though it has successfully received a cell activation message). In a third way, the UE can operate by determining a default cell (which can be pre-configured or defined, and can be a PCell, PSCell, or an SCell belonging to the same TAG (timing advance group) if it is determined by a rule in advance) as the reference cell. In a fourth way, the UE can consider the cell to be inactive (even though it has received a cell activation message for the cell).

[0436] When SSB-related information is indicated with an L2 command together with or separately from the cell activation / deactivation MAC-CE, the SSB-related information of the corresponding cell or the reference cell information may be indicated to the UE. When a UE requests on-demand SSB upon cell activation, rather than providing SSB-related information or reference cell information to the UE in response to this, the base station may provide SSB-related information to the UE via downlink without a request from the UE. Alternatively, instead of notifying the UE of SSB-related information upon cell activation with an L2 command, the base station may trigger on-demand SSB to the UE. For example, when a cell is activated, the base station may indicate to the UE 1-bit information indicating whether SSB triggering is permitted. In this case, the cell activation / deactivation MAC-CE information may include information indicating whether on-demand SSB operation due to UE triggering is permitted / enabled / supported for each cell. If the UE has been instructed that on-demand SSB operation is allowed / enabled / supported for a specific cell due to UE triggering, the UE may trigger an on-demand SSB procedure for an SSB request on the cell. If the UE has been instructed that on-demand SSB operation is not allowed / disabled / not supported for a specific cell due to UE triggering, the UE may not trigger an on-demand SSB procedure for an SSB request on the cell.

[0437] Example 5-4

[0438] The MAC-CE can be used to notify the UE on a cell-by-cell basis of whether the process of requesting on-demand SSB is triggered. In this case, it can be linked to the aforementioned cell activation indication MAC-CE, or a new MAC-CE containing the cell index and corresponding information can be defined.

[0439] Example 5-5

[0440] In all examples of the present disclosure where on-demand SSB related information is linked to a cell activation / deactivation MAC-CE, on-demand SSB related information may be added only when the cell is activated.

[0441] In the present disclosure, when instructing on-demand SSB in L2 MAC-CE, there are various examples including cases where it is connected to a cell activation / deactivation MAC-CE, cases where it is not connected and a cell index is indicated, and cases where it is not connected and a corresponding cell is indicated according to a bit position without a cell index. In addition, on-demand SSB can be indicated through L1 DCI. Since cell activation commands are defined in L3 or L2 but not in L1, only the command related to on-demand SSB can be newly defined, or control signaling including an on-demand SSB command together with a cell activation command through L1 DCI can be newly defined. In addition, as in MAC-CE, SSB triggering and deactivation can be controlled using an index for whether or not to transmit on-demand SSB (for example, when the parameter list index, transmission count, window size, and timer length set by RRC are indicated as 0).

[0442] Example 5-6

[0443] When indicating on-demand SSB through terminal-specific L1 DCI, the cell index can be notified in advance in bitmap form and on-demand SSB information for each cell can be indicated.

[0444] In the case of bitmap, if up to 31 SCells are supported, the number of PDCCH bits in L1 DCI may be too large, so it may be limited to only up to 7 or 8 SCells that can be indicated.

[0445] Information of such on-demand SSB may have an index value predefined to indicate no transmission of on-demand SSB.

[0446] Controlling the triggering and deactivation of on-demand SSB via terminal-specific L1 DCI is only possible when the corresponding cell is active. In addition to the terminal-specific C-RNTI (radio network temporary identifier)-based PDCCH for existing SCells, control information such as on-demand SSB-related indexes, transmission counts, and deactivation instructions can be included.

[0447] Example 5-6-1

[0448] Triggering / activation or deactivation of on-demand SSB for the currently activated cell may also be indicated in terminal-specific L1 DCI without cell index.

[0449] Example 5-7

[0450] When indicating on-demand SSB via group-common L1 DCI, the block can be composed of multiple blocks to allow for application even when cell indices differ for each terminal. Each block contains on-demand SSB information for a specific cell, and the base station can set a mapping relationship for each block corresponding to the cell index for each terminal in advance.

[0451] Information of such on-demand SSB may have an index value predefined to indicate no transmission of on-demand SSB.

[0452] Example 5-8

[0453] In the case where there is an already activated first on-demand SSB, a specific index or a specific bit may be preset / defined to indicate that when transmission of a second on-demand SSB is triggered, the settings (e.g., period, transmission type, etc.) for the first on-demand SSB are applied to the second on-demand SSB as is.

[0454] When setting SSB related information in RRC, related parameters may not be included in the list for the specific indexes mentioned above.

[0455] If an on-demand SSB transmission is performed according to the specific index described above, a second on-demand SSB transmission may not be performed if there is no previous first on-demand SSB transmission.

[0456] Example 5-8-1

[0457] In the L1 DCI method, similarly to the examples of embodiments 1 to 3 described above, the index of the list for some combination of SSB-related parameters may be indicated, or the index for each parameter may be indicated directly.

[0458] When triggering / activating on-demand SSB transmission is indicated via MAC-CE, each cell information may be configured to be aligned in units of multiples of octets (or units of multiples of half an octet (i.e., 4 bits)). If not aligned in units of multiples of octets or half an octet, padding or reserved bits may be included.

[0459] While the first on-demand SSB is being transmitted, a triggering / activation instruction for the second on-demand SSB may be issued without signaling to stop transmitting the first on-demand SSB. In this case, it may be defined that the transmission of the first on-demand SSB is stopped and the newly indicated second on-demand SSB is transmitted. Alternatively, if the first on-demand SSB and the second on-demand SSB do not overlap each other in the time axis and frequency axis, both the first and second on-demand SSBs may be transmitted. Alternatively, which on-demand SSB is to be transmitted may be predefined or configured in the terminal.

[0460] Example 5-9

[0461] By specifying a specific index value among the indexes of the lists set in the upper layer used for transmission of a specific on-demand SSB, the on-demand SSB indicated by the index value can be continuously transmitted regardless of the triggering of transmission of a new on-demand SSB later.

[0462] Example 5-10

[0463] It is permitted to transmit both the first and second on-demand SSBs, but one of the first and second on-demand SSBs may be dropped if they overlap in time and frequency. In this case, the on-demand SSB transmitted as the non-cell defining (NCD)-SSB may be dropped.

[0464] Example 5-11

[0465] When dropping one of the first and second on-demand SSBs, the UE may be signaled as to whether to drop the first on-demand SSB that is already being transmitted or the newly indicated second on-demand SSB. If the two overlap, the UE may be informed as to which on-demand SSB to drop.

[0466] When triggering or indicating on-demand SSB in L2 or L1 control signaling, one index from the list of on-demand SSB transmission related parameters set by L3 RRC can be indicated. If on-demand SSB is triggered or indicated directly from L3 RRC, an index indicating that SSB is triggered / indicated through L3 RRC through a specific parameter, with or without indicating the list index, can be indicated, and additional information can also be provided.

[0467] Example 5-12

[0468] If the specific parameter value mentioned above (e.g., an index value indicating that SSB is triggered / indicated via L3 RRC) is not indicated, triggering / indication may be made via L2 MAC-CE or L1 DCI for on-demand SSB transmission.

[0469] Example 5-13

[0470] When RRC directly instructs the transmission of on-demand SSB, it can be limited to cases where there is no always-on SSB. Alternatively, when RRC directly instructs the transmission of on-demand SSB, it can be limited to cases where there is always-on SSB.

[0471] In this case, on-demand SSB transmission can be performed periodically and continuously (indefinitely / permanently).

[0472] Example 5-14

[0473] When triggering / instructing on-demand SSB through lower layer L1 or L2 control signaling, it can be limited to cases where there is always-on SSB. Alternatively, when triggering / instructing on-demand SSB through lower layer L1 or L2 control signaling, it can be limited to cases where there is no always-on SSB.

[0474] In this case, the transmission of on-demand SSB may not be performed continuously and periodically, but may be performed for a number of times / time windows / timers of N (e.g., N is a finite value greater than or equal to 1). Information about N may not be included in the RRC parameter list, but may be included in the L2 MAC-CE or L1 DCI.

[0475] A value of 0 for N may mean that on-demand SSB is not transmitted.

[0476] The value of N may be such that the periodic transmissions can be maintained for the number of times / intervals / times until the value of N is reached, before the SSB transmission stop signaling is indicated. Alternatively, a specific value of N (e.g., a non-numeric value) may be defined to continue the periodic SSB transmissions indefinitely / perpetually, until the SSB transmission stop / disable signaling is indicated.

[0477] In the absence of always-on SSB (or in the absence of a reference cell), one may limit oneself to performing SSB transmissions periodically (indefinitely / perpetually until signaling to stop / deactivate transmission).

[0478] Additional information for stopping / disabling transmission of on-demand SSB may also be included in the L1 / L2 control signaling.

[0479] Example 5-15

[0480] If persistent transmission of on-demand SSB is indicated through L2 MAC-CE or L1 DCI, information for deactivating SSB transmission may be indicated through L2 MAC-CE or L1 DCI. Alternatively, deactivation of SSB transmission may be defined to be performed automatically (or without separate instruction) when the state of the cell changes (e.g., activated state or completion of active state, or start and end of deactivation, cell release, etc.) during persistent transmission of on-demand SSB.

[0481] Example 5-16

[0482] When SSB deactivation is indicated through L2 MAC-CE or L1 DCI while on-demand SSB is triggered, the values ​​of other field(s) in the information within L2 MAC-CE or L1 DCI other than on-demand SSB related information may be set to NULL.

[0483] For example, if the on-demand SSB index value is set to 0 in L2 MAC-CE or L1 DCI to indicate deactivation, other information such as the number of transmissions may be set to NULL values.

[0484] For example, if the value of the number of on-demand SSB transmissions in L1 MAC-CE or L1 DCI is set to 0 to indicate deactivation, the remaining information may be set to NULL values.

[0485] Example 5-17

[0486] When triggering of on-demand SSB is indicated through L1 DCI, if it is not indicated which of the multiple settings (e.g., SSB parameter lists) set in the upper layer for on-demand SSB of the corresponding cell of the DCI is to be used and a default index (e.g., 0) is indicated, whether or not the on-demand SSB is triggered / deactivated can be indicated by a specific bit in the DCI.

[0487] In particular, when L1 DCI is indicated terminal-specifically, one bit (or multiple bits) in the existing C-RNTI-based DCI can be predefined to indicate whether to trigger / deactivate on-demand SSB. In this case, triggering / deactivating on-demand SSB can be indicated through a specific bit in the DCI, without having to set or pre-designate a specific index by the upper layer.

[0488] In case of group-common L1 DCI, triggering and / or deactivation of on-demand SSB can be indicated in bitmap form for multiple cells using a new RNTI.

[0489] For the number of transmissions of on-demand SSB triggered in this way, persistent transmission can be applied without reset or separate instruction.

[0490] Example 5-18

[0491] When disabling on-demand SSB is indicated through L1 DCI, L1 DCI may be used only for the limited purpose of disabling. For this purpose, a 1-bit field may be included in the DCI, and if the value of the 1-bit field is a first value (e.g., 0 or 1), the existing state is maintained, and if the value is a second value (e.g., 1 or 0), the triggered on-demand SSB may be disabled.

[0492] Specifically for terminal-specific DCI, one bit in the existing C-RNTI-based DCI may indicate the deactivation of on-demand SSB triggered for one cell. Alternatively, multiple bits within the DCI may indicate the deactivation of on-demand SSB triggered for multiple cells.

[0493] In case of group-common DCI, deactivation of on-demand SSB triggered in bitmap form for multiple cells can be indicated using a new RNTI.

[0494] Example 5-19

[0495] When the number of on-demand SSB transmissions is directly indicated in MAC-CE or L1 DCI, the number of transmissions may be limited to one of a finite number of transmissions that are predefined or (e.g., configurable by a higher layer). For example, if the value of the field indicating the number of transmissions is set to 0, 1, or 2, it can indicate 5, 10, or 20 transmissions, respectively.

[0496] This restriction can only be applied when there is no SSB that must always be transmitted in the cell (or when there is no indication from the reference cell).

[0497] Example 5-20

[0498] In relation to the on-demand SSB configuration, when on-demand SSB is currently being transmitted and the terminal is receiving, only some of the on-demand SSB transmission-related information (e.g., period, SSBpositionInBurst, number of transmissions, SCS (subcarrier spacing), frequency, etc.) may be instructed to be changed.

[0499] For example, in relation to the triggering / activation of on-demand SSB in the embodiments described above, in the extended format or new MAC-CE format of the cell activation / deactivation MAC-CE, it can be defined that only specific information(s) are applied when the cell is activated or in the process of being activated. For example, the specific information(s) may be preset or may be predefined without separate signaling. The specific information(s) may include a transmission period. For example, when the cell is in the activation (activating or activated) state, only the transmission period may be applied / changed to a newly indicated value when triggering on-demand SSB, and the remaining parameters may be maintained at the existing values.

[0500] A new MAC-CE may be defined that supports modifying only specific parameters of on-demand SSB. In this case, similar to the examples described above, the MAC-CE may be defined in the form of a MAC-CE that includes a cell index field and a parameter field associated with the cell index, or a MAC-CE in which parameters at specific bit positions are defined for a specific cell. Specific parameters may include a period. In this case, a specific ID value may be predefined / set to indicate that the currently applied period should be maintained without modification.

[0501] When changing a specific parameter (e.g., period), a bit field may be added to the terminal-specific L1 DCI for one cell to which the L1 DCI is associated, or multiple bit fields may be added for multiple cells. In this case, the value of the bit field may be set to a value indicating that the currently applied period is maintained without change.

[0502] The examples described above may be limited to apply only when there is always-on SSB, or to apply only when there is no always-on SSB.

[0503] Example 5-21

[0504] When a cell activation MAC-CE is indicated in cell-inactive state and the MAC-CE corresponds to a SCell activation / deactivation MAC-CE that may or may not include legacy A-TRS triggering information (e.g., a legacy SCell activation / deactivation MAC-CE that does not include on-demand SSB related information), the following actions may be defined.

[0505] When a legacy SCell enable / disable MAC-CE indicates activation of the SCell in the SCell disabled state, the on-demand SSB can be automatically disabled while on-demand SSB is being received. This behavior can be predefined or configured to be applied only to cases where SCell activation is indicated through the legacy SCell enable / disable MAC-CE (or a MAC-CE that does not trigger A-TRS).

[0506] Alternatively, if a legacy SCell enable / disable MAC-CE is indicated, the state (e.g., enabled or disabled) of the on-demand SSB in the previous SCell disable state may be maintained.

[0507] When legacy SCell enable / disable MAC-CE is indicated in SCell disabled state, certain configurations (e.g., certain combinations of values ​​of parameters such as period, frequency, number of transmissions, SCS, SSB PostioninBusrt, etc.) among the configuration(s) of on-demand SSB may be applied. These behaviors may be predefined or may be preset to be applied only when legacy SCell enable / disable MAC-CE is indicated (or when A-TRS is not triggered). In addition, they may be predefined or may be preset to be applied only when on-demand SSB is disabled in SCell disabled state, or may be applied only when on-demand SSB is enabled in SCell disabled state.

[0508] The examples described above may be limited to apply only when there is always-on SSB, or to apply only when there is no always-on SSB.

[0509] The following examples 5-22, 5-23, and 5-24 can be applied to cases where on-demand SSB can be set by BWP unit rather than cell unit by upper layer.

[0510] Example 5-22

[0511] In the embodiments described above, activation / deactivation of on-demand SSB for the corresponding BWP can be indicated by adding information about the BWP ID within the MAC-CE.

[0512] Example 5-23

[0513] If the MAC-CE that triggers / activates on-demand SSB is signaled while the cell is inactive, a BWP may be configured in RRC to perform SSB transmission operation while the cell is inactive, or on-demand SSB may be triggered at a predefined BWP (e.g., first active downlink BWP (firstactivedownlinkBWP)).

[0514] It can be assumed that the MAC-CE that triggers / activates on-demand SSB is signaled together with the cell activation command. In this case, the BWP indicating information included in the MAC-CE may be set to indicate the BWP corresponding to the firstactivedownlinkBWP, or on-demand SSB may be triggered / activated in the BWP corresponding to the firstActiveDownlinkBWP set for the terminal, regardless of the BWP indicating information included in the MAC-CE.

[0515] Example 5-24

[0516] When on-demand SSB triggering / activation is indicated without indicating BWP ID via MAC-CE, it can be applied that on-demand SSB related to (currently) active BWP is indicated in cell-activated state, and on-demand SSB related to FirstactivedownlinkBWP is indicated in cell-deactivated state.

[0517] We will explain two ways to enable on-demand SSB.

[0518] According to the first method (e.g., type-1 activation), the number of SSB transmissions N or the SSB transmission interval T is directly indicated by an activation signal, and after the N transmissions or the T intervals, the on-demand SSB transmission can be deactivated (without a separate deactivation signal).

[0519] According to the second method (e.g., type-2 activation), when on-demand SSB transmission is activated without any indication of the number of transmissions N or the transmission interval T, SSB transmission can be performed continuously until a separate deactivation signal is received (or until the activation process of the cell is terminated, or until the cell is deactivated).

[0520] If the signal (or signaling) that activates on-demand SSB is L2 MAC-CE (or L1 DCI), both Type-1 and Type-2 activation schemes may be supported, or support for each may be selectively preset. If the signal (or signaling) that activates on-demand SSB is L3 RRC signaling, only Type-2 activation scheme may be supported / indicated.

[0521] As an example of Type-2 activation, when on-demand SSB is activated via RRC signaling, the number of transmissions N can be restricted to always be set to a value corresponding to permanent (or infinite). Since the number of transmissions of the triggered on-demand SSB when triggering on-demand SSB in RRC is permanent (or infinite), the parameter for the number of transmissions can be omitted in the signaling. In addition, the restriction on the number of transmissions as above can be defined to be applied only when there is always-on SSB in the corresponding cell, or only when there is no always-on SSB.

[0522] As a concrete example, if the number of on-demand SSB transmissions that can be set / indicated in RRC / MAC is not included in RRC signaling or MAC-CE, the number of on-demand SSB transmissions is assumed to correspond to a non-numeric value that means infinite (or permanent) or infinite / permanent as described above, and the on-demand SSB can be continuously transmitted until deactivated through separate signaling.

[0523] When on-demand SSB is activated / triggered via RRC signaling and includes a parameter for the number of transmissions N, continuous (or infinite) transmissions of on-demand SSB triggered / activated by RRC may be allowed only when there is no always-on SSB. For example, when there is no always-on SSB, even if the number of transmissions N for on-demand SSB is set to a specific value in RRC signaling, the continuous (or infinite) number of on-demand SSB transmissions may be maintained. For example, when there is always-on SSB, if the number of transmissions N for on-demand SSB is set to a specific value in RRC signaling, a finite number of on-demand SSB transmissions may be performed according to the specific value.

[0524] Example 5-25

[0525] The action of disabling / deactivating the L2 MAC-CE instruction while the on-demand SSB is being transmitted can be defined to be applied only when the number of transmissions (or window size / timer length) of the on-demand SSB being transmitted is infinite / permanent.

[0526] For example, if a terminal is instructed to deactivate / disable on-demand SSB transmissions 5 times after receiving the activated on-demand SSB transmissions with a finite number of transmissions N of 10, the terminal may ignore the deactivation / disable instruction and attempt to receive SSB until the initially configured 10 transmissions are completed. This behavior may be predefined, or its application may be preconfigured.

[0527] Example 6

[0528] This embodiment relates to a method for linking on-demand SSB activation / deactivation with respect to cell deactivation.

[0529] There are two scenarios where a cell can transition from an activated state to a deactivated state. For example, a cell can be deactivated if a deactivation instruction / signaling is provided to the UE via MAC-CE / RRC signaling. Alternatively, a cell can be deactivated if no uplink / downlink data transmission or reception is scheduled for the cell until the cell deactivation timer expires.

[0530] If cell deactivation is indicated while the cell is active, on-demand SSB may be deactivated simultaneously with the cell deactivation. Accordingly, if cell deactivation is indicated / signaled while on-demand SSB is active / triggered, or if the cell deactivation timer expires, the terminal may stop receiving the on-demand SSB being transmitted, or the network may stop transmitting the on-demand SSB.

[0531] Here, cell deactivation may be indicated for individual cells, or for all cells included in a cell group (e.g., a secondary cell group (SCG)) via the value of the SCG-state. In this way, even in the case of deactivation for a cell group, deactivation of on-demand SSB in each cell included in the cell group may be applied.

[0532] Example 6-1

[0533] When cell deactivation is indicated through upper layer signaling of L1 (e.g., L2 MAC-CE or L3 RRC signaling) and triggered to deactivate on-demand SSB, whether or not to apply SSB deactivation can be determined differently depending on specific conditions. For example, specific conditions can be preset through RRC signaling or MAC-CE to determine whether to maintain or deactivate on-demand SSB activation depending on cell deactivation.

[0534] For example, for a specific cell, a UE can perform deactivation for the cell by receiving a cell deactivation instruction via MAC-CE, and can also perform deactivation for all cells (including the cell) within the SCG by receiving an scg-state parameter via an RRC message. When performing such cell deactivation, whether to deactivate the on-demand SSB in the cell that is activated can be defined in advance or configured separately. If the deactivation of the on-demand SSB due to cell deactivation for the cell is defined / configured in advance, the UE can also deactivate the on-demand SSB when performing cell deactivation according to MAC-CE or RRC signaling. Alternatively, if the deactivation of the on-demand SSB due to cell deactivation for the cell is not defined / configured in advance, the UE can assume / expect that the currently activated on-demand SSB will continue to be transmitted even if cell deactivation is performed according to MAC-CE or RRC signaling.

[0535] Rather than deactivation instruction / signaling for individual cells, whether or not to deactivate on-demand SSB in response to cell deactivation can be preset / defined on a cell-group basis for all cells included in a cell group (e.g., SCG). Alternatively, if whether or not to deactivate on-demand SSB in response to cell deactivation is preset / defined on a cell-by-cell basis, and if deactivation is applied to a cell group based on an SCG-status parameter, on-demand SSB may be deactivated only for the cell(s) preset / defined to deactivate on-demand SSB in response to cell deactivation, and on-demand SSB may not be deactivated for the remaining cell(s).

[0536] For example, if a SCG contains 10 SCells, and on-demand SSB is pre-configured to be disabled along with SCell deactivation for 5 of them, when the SCG is deactivated according to the SCG-state parameter, on-demand SSB is disabled only for the 5 SCells that are configured for the association, and on-demand SSB can remain enabled for the remaining 5 SCells even when the SCells are deactivated.

[0537] Example 6-2

[0538] When a cell is deactivated due to expiration of the cell deactivation timer while the cell is active, whether or not to deactivate the on-demand SSB triggered in the cell can be preset or predefined via RRC signaling or MAC-CE.

[0539] For example, for a specific cell, a terminal may deactivate the cell due to expiration of a cell deactivation timer. When performing such cell deactivation, if there is an on-demand SSB activated in the cell, whether to deactivate the on-demand SSB may be defined in advance or configured separately. If the deactivation of the on-demand SSB has been defined / configured in advance for the cell, the terminal may also deactivate the on-demand SSB when performing cell deactivation due to expiration of the cell deactivation timer. Alternatively, if the deactivation of the on-demand SSB has not been defined / configured in advance for the cell, the terminal may assume / expect that the currently activated on-demand SSB will continue to be transmitted even when performing cell deactivation due to expiration of the cell deactivation timer.

[0540] Example 6-3

[0541] In the case where a cell transitions from an activated state to a deactivated state, the operation of applying the deactivation of an already activated / triggered on-demand SSB in conjunction with the deactivation may be limited to being applied only when there is an always-on SSB. For example, in the case where a cell is deactivated as in embodiments 6-1 and 6-2, the operation of pre-defining / setting whether to deactivate an activated on-demand SSB in conjunction with the deactivation may be limited to when there is an always-on SSB transmitted on the cell.

[0542] Additionally, even in the absence of an always-on SSB, if the cell is not QCL'd with a reference cell or no reference cell is indicated for the cell, the on-demand SSB that is activated / triggered may not be deactivated even when transitioning from an activated state to a deactivated state. Whether or not such an operation is applied may be preset / defined.

[0543] Example 6-4

[0544] When a cell transitions from an activated state to a deactivated state due to L2 / L3 signaling or timer instruction / setting related to the aforementioned cell deactivation, whether or not to deactivate the on-demand SSB being transmitted or received may be applied depending on whether or not there is always-on SSB. For example, if there is always-on SSB in the corresponding BWP or cell, the on-demand SSB being transmitted or received may be deactivated due to cell deactivation. Alternatively, if there is no always-on SSB in the corresponding BWP or cell, the on-demand SSB being transmitted or received may be maintained due to cell deactivation. These actions may be predefined, or whether or not to apply them may be predefined.

[0545] For example, when a cell is transitioned from an active state to an inactive state (e.g., by L2 MAC-CE or L3 RRC signaling, or by a timer expiration), if there is an active BWP or an always-on SSB is being transmitted in that cell, the on-demand SSB may be deactivated / disabled, and if there is no always-on SSB, the on-demand SSB may be kept enabled. This behavior may be predefined, or its application may be preset.

[0546] According to some examples of the present disclosure described above, since SSB is transmitted only during the time period required for a specific cell / BWP, the purpose of energy saving and / or interference reduction can be achieved. In addition, according to some examples of the present disclosure, time / frequency synchronization in another cell can be performed using SSB transmitted from a reference cell (or anchor cell, TRP, CORESET pool, (additional) PCI). In addition, according to some examples of the present disclosure, information about on-demand SSB or reference cell can be efficiently and accurately provided to a terminal through lower layer control signaling such as MAC-CE, thereby facilitating the implementation of an SSB-less cell.

[0547] The embodiments described above are combinations of components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form embodiments of the present disclosure by combining some components and / or features. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form embodiments or incorporated as new claims through post-application amendments.

[0548] It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics thereof. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present disclosure are intended to be included within the scope of the present disclosure.

[0549] The scope of the present disclosure includes software or machine-executable instructions (e.g., an operating system, an application, firmware, a program, etc.) that cause operations according to the methods of various embodiments to be executed on a device or a computer, and a non-transitory computer-readable medium having such software or instructions stored thereon and executable on the device or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure can be stored on / in a storage medium or a computer-readable storage medium, and a computer program product including such a storage medium can be used to implement the features described in the present disclosure. The storage medium can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices, and can include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices remotely located from the processor(s). The memory or, alternatively, the non-volatile memory device(s) within the memory comprise a non-transitory computer-readable storage medium. The features described in this disclosure may be incorporated into software and / or firmware stored on any of the machine-readable media, which may control the hardware of the processing system and allow the processing system to interact with other mechanisms that utilize results according to embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0550] Here, the wireless communication technology implemented in the device of the present disclosure may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the device of the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by 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 above-described names. Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PAN) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0551] The method proposed in this disclosure is explained with a focus on examples applied to 3GPP LTE / LTE-A, 5G, and 6G systems, but can be applied to various wireless communication systems in addition to 3GPP LTE / LTE-A, 5G, and 6G systems.

Claims

1. A step of receiving synchronization signal block setting information from a network by a terminal; A step of receiving, by the terminal, from the network, instruction information for one or more synchronization signal blocks based on the above setting information; and A step of receiving, by the terminal, one or more synchronization signal blocks from the network based on the instruction information, A method wherein the above instruction information includes information about an index of one or more specific cells and parameter information about one or more synchronization signal blocks.

2. In paragraph 1, The above configuration information includes one or more parameter lists for the synchronization signal block, A method wherein one or more of the above parameter lists include distinct indices.

3. In paragraph 1, A method in which information about the index of one or more specific cells included in the above instruction information corresponds to a secondary cell (SCell) index bitmap.

4. In paragraph 3, The parameter information included in the above instruction information is: A method comprising an index field of a parameter list associated with an SCell set to a specific value in the above SCell index bitmap.

5. In paragraph 1, A method wherein information about the index of one or more specific cells included in the above instruction information corresponds to one or more SCell index fields.

6. In paragraph 5, The parameter information included in the above instruction information is: A method comprising one or more index fields of a parameter list each corresponding to one or more SCell index fields.

7. In paragraph 1, A method wherein the above instruction information is included in one MAC-CE (medium access control-control element).

8. In paragraph 1, The above parameter information included in the above instruction information is: Contains information about the index of the parameter list; or Information about the index of the above parameter list, and each value of one or more parameters not included in the above parameter list; or A method comprising the values ​​of each of one or more parameters associated with said one or more synchronization signal blocks.

9. In paragraph 1, The parameter information included in the above instruction information is: A method comprising information about the number of transmissions of bursts of the above synchronization signal block.

10. In paragraph 9, The candidates for the above transmission count include at least one of 0 or a non-numeric value, The above non-numeric value corresponds to an unlimited number of transmissions of the synchronization signal block.

11. In paragraph 9, A method wherein the synchronization signal block is deactivated based on the expiration of the number of transmissions.

12. In paragraph 9, A method wherein, before the expiration of the number of transmissions, the synchronization signal block is deactivated based on a deactivation instruction for the synchronization signal block.

13. In paragraph 1, Information about the number of transmissions of a burst of the synchronization signal block, which is set to a finite value based on the presence of a legacy SSB (synchronization signal / PBCH (physical broadcast channel) block) in a specific cell or a specific bandwidth portion (BWP), is included in the instruction information, Based on the absence of the SSB in the specific cell or the specific BWP, information on the number of transmissions of the burst of the synchronization signal block is not included in the instruction information, and the number of transmissions of the synchronization signal block is not limited. The above legacy SSB is a method in which an SSB is always transmitted without any setup or instruction.

14. In paragraph 1, A method in which a synchronization signal block activated by the above instruction information is deactivated based on the deactivation of a specific cell to which the activated synchronization signal block is associated.

15. In paragraph 1, The above synchronization signal block is an on-demand SSB (synchronization signal / PBCH (physical broadcast channel) block).

16. One or more transceivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Receive synchronization signal block setup information from the network via one or more of the transceivers; Receiving instruction information for one or more synchronization signal blocks from the network through the one or more transceivers based on the above setting information; and Based on the above instruction information, the one or more synchronization signal blocks are set to be received from the network through the one or more transceivers, A terminal, wherein the above instruction information includes information about an index of one or more specific cells and parameter information about one or more synchronization signal blocks.

17. A step of transmitting synchronization signal block setting information to a terminal by a base station; A step of transmitting, by the base station, to the terminal, instruction information for one or more synchronization signal blocks based on the above setting information; and A step of transmitting, by the base station, the one or more synchronization signal blocks to the terminal based on the above instruction information, A method wherein the above instruction information includes information about an index of one or more specific cells and parameter information about one or more synchronization signal blocks.

18. One or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Transmitting synchronization signal block setting information to a terminal via one or more of the transceivers; Transmitting instruction information for one or more synchronization signal blocks to the terminal through the one or more transceivers based on the above setting information; and Based on the above instruction information, the one or more synchronization signal blocks are set to be transmitted to the terminal through the one or more transceivers, A base station, wherein the above instruction information includes information about an index of one or more specific cells and parameter information about the one or more synchronization signal blocks.

19. One or more processors; and A processing device comprising one or more computer memories operatively connected to said one or more processors and storing instructions for performing a method according to any one of claims 1 to 15 based on execution by said one or more processors.

20. One or more non-transitory computer-readable media storing one or more instructions that are executed by one or more processors to control the performance of a method according to any one of claims 1 to 15.

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