Method and apparatus for transmitting or receiving various synchronization signals in wireless communication system

Abstract

Disclosed are a method and apparatus for transmitting or receiving various synchronization signals in a wireless communication system. The method according to an embodiment of the present disclosure may comprise the steps of: receiving, by a terminal, a first synchronization signal group transmitted from a first cell; receiving, by the terminal, a second synchronization signal group transmitted from the first cell; and transmitting, by the terminal to a second cell, a report on a measurement result based on one or more of the first synchronization signal group or the second synchronization signal group. Information related to the second synchronization signal group may be provided to the terminal either included in the first synchronization signal group or after the first synchronization signal group is received, and the second synchronization signal group may be received on the basis of the information related to the second synchronization signal group.

Description

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

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting or receiving various synchronization signals 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 for transmitting or receiving various synchronization signal blocks in a wireless communication system.

[0005] An additional technical problem of the present disclosure is to provide a method and device for performing or supporting measurements based on various synchronization signals 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, a first synchronization signal group transmitted from a first cell; receiving, by the terminal, a second synchronization signal group transmitted from the first cell; and transmitting, by the terminal, to the second cell, a report on the result of a measurement based on at least one of the first synchronization signal group or the second synchronization signal group. Information related to the second synchronization signal group may be included in the first synchronization signal group or provided to the terminal after the first synchronization signal group is received, and the second synchronization signal group may be received based on the information related to the second synchronization signal group.

[0008] A method according to an additional aspect of the present disclosure may include the steps of: transmitting, by a base station, a first synchronization signal group of a first cell to one or more terminals; transmitting, by the base station, a second synchronization signal group of the first cell to the one or more terminals; and receiving, by the base station, a report on the result of a measurement based on at least one of the first synchronization signal group or the second synchronization signal group from a first terminal of the one or more terminals via a second cell. Information related to the second synchronization signal group may be included in the first synchronization signal group or provided to the first terminal after the first synchronization signal group is received, and the second synchronization signal group may be transmitted based on the information related to the second synchronization signal group.

[0009] According to the present disclosure, a method and device for transmitting or receiving various synchronization signal blocks in a wireless communication system can be provided.

[0010] According to the present disclosure, a method and device for performing or supporting measurements based on various synchronization signals 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 diagram showing examples of various SSB transmissions to which the present disclosure can be applied.

[0032] FIG. 21 is a diagram showing examples of SMTC-based measurements to which the present disclosure can be applied.

[0033] FIG. 22 is a drawing for explaining an example of a method performed by a terminal according to the present disclosure.

[0034] FIG. 23 is a drawing illustrating an example of a method performed by a base station according to the present disclosure.

[0035] FIG. 24 is a diagram for explaining examples of averaging of SSB measurement results according to the present disclosure.

[0036] FIG. 25 illustrates examples of various periods and transmission locations of SSB transmission according to the present disclosure.

[0037] FIG. 26 is a drawing showing an example of the structure of an SSB to which the present disclosure can be applied.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] The terminology used in this disclosure is for the purpose of describing particular embodiments 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.

[0043] 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."

[0044] 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."

[0045] 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.”

[0046] 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.”

[0047] 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."

[0048] In the following description, 'when, if, in case of' can be replaced with 'based on'.

[0049] Technical features individually described in one drawing in this disclosure may be implemented individually or simultaneously.

[0050] 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.

[0051] In the present disclosure, a base station (BS) may be a second node / IAB node / Transmission-Reception Point (TRP).

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] Network structure

[0058] Figure 1 illustrates a flexible network topology to which some examples of the present disclosure may be applied.

[0059] 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 function 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] Systems applicable to this disclosure

[0066] FIG. 2 illustrates an example of a communication system to which some examples of the present disclosure may be applied.

[0067] 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).

[0068] 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).

[0069] 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.

[0070] Device applicable to the present disclosure

[0071] FIG. 3 illustrates an example of a wireless device to which some examples of the present disclosure may be applied.

[0072] 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).

[0073] 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.

[0074] 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.

[0075] 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 executed 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.

[0076] 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.

[0077] 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.

[0078] 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).

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] Communication procedures

[0087] 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.

[0088] 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.

[0089] 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).

[0090] 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.

[0091] 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)).

[0092] 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.

[0093] 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.

[0094] 6G system core technologies

[0095] 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.

[0096] artificial intelligence

[0097] 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.

[0098] FIG. 5 illustrates a functional framework for AI operations to which some examples of the present disclosure may be applied.

[0099] Below, to explain AI (or AI / ML (machine learning)) in more detail, the terms can be defined as follows.

[0100] - Data collection: Data collected from network nodes, management entities, or terminals as a basis for AI model training, data analysis, and inference.

[0101] - 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.

[0102] - 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.

[0103] - AI / ML inference: The process of making predictions or inducing decisions based on collected data and the AI ​​model using a trained AI model.

[0104] 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).

[0105] Examples of input data may include measurements from terminals or other network entities, feedback from actors, and output from AI models.

[0106] 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.

[0107] 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).

[0108] 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.

[0109] 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).

[0110] 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).

[0111] 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.

[0112] 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.

[0113] Model performance feedback (14) can be used to monitor the performance of the AI ​​model, if available, and this feedback may be omitted.

[0114] 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.

[0115] 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.

[0116] Meanwhile, the definitions of training / validation / test in data sets used in AI / ML can be distinguished as follows.

[0117] - Training data: refers to a data set for learning a model.

[0118] - 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.

[0119] - Test data: This refers to the data set for final evaluation. This data is unrelated to learning.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] Category 0b: Frameworks that involve a wireless interface modified to fit efficient implementation-based AI / ML algorithms, but without collaboration.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.).

[0131] 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.

[0132] Step 2: Network nodes can train AI models using the received training data.

[0133] 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.

[0134] For convenience of explanation, we assume that the AI ​​model is deployed / updated only to RAN node 1.

[0135] Step 4: RAN node 1 can receive input data (e.g., inference data) for AI model inference from the terminal and RAN node 2.

[0136] Step 5: RAN node 1 can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).

[0137] Step 6: If applicable, RAN node 1 may send model performance feedback to the network nodes.

[0138] 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.

[0139] Step 8: RAN node 1 and RAN node 2 can transmit feedback information to the network nodes.

[0140] 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.

[0141] 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.).

[0142] Step 1: The terminal and RAN node 2 can transmit input data (e.g., training data) for AI model training to RAN node 1.

[0143] Step 2: RAN node 1 can train an AI model using the received training data.

[0144] Step 3: RAN node 1 can receive input data (e.g., inference data) for AI model inference from the terminal and RAN node 2.

[0145] Step 4: RAN node 1 can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).

[0146] 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.

[0147] Step 6: RAN node 2 may transmit feedback information to RAN node 1.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] Step 2: RAN nodes can train AI models using the received training data.

[0152] 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.

[0153] 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).

[0154] Step 5: The terminal can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).

[0155] Step 6: If applicable, the terminal may send model performance feedback to the RAN node.

[0156] Step 7: The terminal and RAN node can perform actions based on the output data.

[0157] Step 8: The terminal may transmit feedback information to the RAN node.

[0158] THz communication (terahertz communication)

[0159] 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.

[0160] FIG. 9 illustrates an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0161] 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.

[0162] 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.

[0163] FIG. 10 illustrates an example of a system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] 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.

[0168] 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).

[0169] 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.

[0170] FIG. 11 exemplarily illustrates a beam management procedure to which some examples of the present disclosure may be applied.

[0171] 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.

[0172] 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.

[0173] 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.

[0174] 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).

[0175] 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.

[0176] 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).

[0177] non-terrestrial networks (NTN)

[0178] Figures 12 and 13 illustrate examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0179] NTN can represent a network or network segment that uses radio frequency (RF) resources mounted on a satellite (or unmanned aerial system (UAS) platform).

[0180] 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.

[0181] 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.

[0182] 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.

[0183] 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.

[0184] 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.

[0185] 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).

[0186] Integrated Sensing and Communication (ISAC)

[0187] 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.

[0188] FIG. 14 illustrates examples of sensing operations to which some examples of the present disclosure may be applied.

[0189] 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.

[0190] Network Energy Saving (NES)

[0191] 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).

[0192] 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.

[0193] 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.

[0194] 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.).

[0195] 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.

[0196] 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.

[0197] Examples of NES solutions that can be implemented using these procedures include:

[0198] 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).

[0199] Inter-system energy savings: NG-RAN nodes that own capacity booster cells can autonomously transition those cells to an inactive state.

[0200] 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.

[0201] 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 suspended 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 suspended during the cell DRX inactivity period. Cell DTX / DRX can be activated / deactivated via RRC signaling or L1 (layer 1) group common signaling.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] Cell DTX / DRX

[0206] 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.

[0207] FIG. 15 illustrates an example of cell DTX / DRX operation to which some examples of the present disclosure may be applied.

[0208] 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).

[0209] 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.

[0210] 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.

[0211] 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.).

[0212] 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.

[0213] 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.

[0214] 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.

[0215] SSB-less cells

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] Conditional Handover (CHO)

[0221] FIG. 17 illustrates an example of a conditional handover operation to which some examples of the present disclosure may be applied.

[0222] The order of the operations illustrated in Fig. 17 may vary depending on the case.

[0223] 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.

[0224] 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.

[0225] 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.

[0226] 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.

[0227] Channel State Information (CSI) Measurement and Reporting

[0228] FIG. 18 illustrates an example of a procedure for CSI measurement and reporting to which some examples of the present disclosure may be applied.

[0229] 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.

[0230] 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).

[0231] 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)).

[0232] 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.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] 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.

[0237] 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.

[0238] 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.

[0239] 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.

[0240] 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.

[0241] 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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] 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.

[0248] 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.

[0249] 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.

[0250] 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.

[0251] 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).

[0252] 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.

[0253] 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).

[0254] 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.

[0255] 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.

[0256] 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.

[0257] 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.

[0258] Improved NES

[0259] For enhancement of NES technology, on-demand SSB, on-demand SIB1, and adaptation of common signal / channel transmissions are being discussed.

[0260] Below we describe on-demand SSB.

[0261] 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.

[0262] These on-demand SSB processes can be triggered by one or more of the following examples:

[0263] - 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).

[0264] - 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.

[0265] - Signaling whether SSB transmission of the corresponding SCell is possible through SCell activation / deactivation signaling.

[0266] 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.

[0267] Below, we describe On-Demand SIB1.

[0268] 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.

[0269] 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.

[0270] 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.

[0271] 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).

[0272] 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).

[0273] 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).

[0274] Below we describe the adaptation of common signal / channel transmission.

[0275] 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.

[0276] 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.

[0277] 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.

[0278] Types of synchronization signals

[0279] The examples of the present disclosure assume two types of synchronization signals and explain them. 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."

[0280] 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.

[0281] 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.

[0282] 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.

[0283] 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.

[0284] 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.

[0285] 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.

[0286] 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.

[0287] 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.

[0288] 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.

[0289] 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.

[0290] Measurements based on various synchronization signals

[0291] This disclosure describes various examples for improving SSB transmission related to NES in 6G systems. Although the structure and features of SSB (i.e., SS / PBCH block) as in 5G systems are not directly applicable in 6G systems, the term "SSB" described in this disclosure may be replaced with a group of synchronization signals or a group including a synchronization signal and other physical signals / channels, and the term "SSB" is used for convenience of explanation.

[0292] As mentioned above, the SSB can be operated by the base station by distinguishing it into the first SSB (or SSB1, AO SSB, etc.) and the second SSB (or SSB2, OD SSB, etc.). SSB1 can be defined as an SSB that the base station transmits constantly or periodically. SSB2 can be defined as an SSB that the base station transmits or does not transmit depending on the situation. The base station can transmit SSB1 minimally and additionally transmit SSB2 when necessary. For example, in order to minimize the energy consumption of the base station, the base station can transmit SSBs corresponding to SSB1, and then additionally transmit SSB2 when there is internal energy left (or when SSB transmission with a relatively shorter period than the SSB1 period is required). The terminal can perform the initial access through SSB1 or SSB2. For example, when the terminal generally switches from power-off to power-on, the terminal can determine whether the cell to be accessed is accessible and whether it is barred through a combination of received SSBs. In this case, the terminal may need to know whether the SSB detected / received is SSB1 or SSB2.

[0293] The present disclosure describes a method for a base station to explicitly or implicitly inform a terminal of which SSB the terminal is receiving in an RRC idle or RRC inactive state (or even in an RRC connected state) after initial access in which the terminal has received a synchronization signal (e.g., PSS, SSS) and broadcast information (e.g., MIB provided via PBCH), and a method for the terminal to recognize information about such SSB.

[0294] For example, when a terminal performs measurements on a serving cell and a neighboring cell, assuming that the serving cell supports transmission of SSB1 and SSB2, and that the neighboring cell also supports transmission of SSB1 and SSB2, transmission of SSB2 can be activated or deactivated in each cell. Therefore, a method for the terminal to perform measurements on the serving cell and the neighboring cell by considering whether or not SSB2 is transmitted needs to be defined. In the examples below, it is assumed that SSB1 and SSB2 are distinguishable, and the method itself for SSB1 and SSB2 is not described.

[0295] As described above, the term SSB may refer to a group of signals / channels involved in the process of obtaining the most basic information of a cell through system information (e.g., checking information of contents or bit fields through decoding of MIB / PBCH) after a terminal finds an OFDM symbol boundary through a primary synchronization signal (e.g., PSS detection), finds cell identification information through a secondary synchronization signal (e.g., SSS detection), and then the system information. The primary synchronization signal, secondary synchronization signal, and system information included in the synchronization signal group may be transmitted in continuous time resources or may be transmitted discontinuously (e.g., at time intervals, or at different cycles). For example, all three elements (e.g., PSS, SSS, and PBCH) may be transmitted at each SSB transmission opportunity, or some combination of the three elements (e.g., only PSS, or a combination of PSS and PBCH, or PSS and SSS, etc.) may be transmitted at some transmission opportunities. For example, by predefining specific instructions or signaling information for three elements, a terminal can determine whether an SSB corresponds to SSB1 or SSB2. If all three elements are transmitted, it corresponds to SSB1, and if some are transmitted, it corresponds to SSB2.

[0296] Here, elements within SSB may be referred to in various ways, such as signal / channel / information / part, etc.

[0297] FIG. 20 is a diagram showing examples of various SSB transmissions to which the present disclosure can be applied.

[0298] Figure 20(a) exemplarily illustrates the transmission opportunities for SSB1 and SSB2. SSB1 can be transmitted at relatively long intervals, while SSB2 can be transmitted at relatively short intervals. SSB1 is always transmitted, while SSB2 may or may not be transmitted at any given transmission opportunity.

[0299] As shown in Figure 20(b), the elements of the SSB transmitted in different SSB2 transmission opportunities may not be identical. For example, in one SSB2 transmission opportunity, the PSS, SSS, and PBCH may all be transmitted. In another SSB2 transmission opportunity, only the PSS and SSS may be transmitted. In another SSB2 transmission opportunity, only the PSS may be transmitted. In another SSB2 transmission opportunity, only the SSS may be transmitted. The elements included in the SSB may be explicitly or implicitly indicated / signaled.

[0300] For example, different combinations of elements included in an SSB may be applied to different services / purposes. Accordingly, two or more SSBs may be defined and referred to, for example, as SSBn (n=1, 2, 3, ...).

[0301] Different SSBs (e.g., SSB1 and SSB2) may exist in the same frequency location (e.g., bandwidth / band), but may be distinguished by different sets / orders of REs to which they are mapped, or by the order in which the elements of the SSB are mapped.

[0302] When a base station operates at low power for purposes such as NES, a method for distinguishing different SSBn may be required. For example, different SSBn can be distinguished using the existing PSS and SSS. PSS and SSS can be detected and received by finding the sequence by attempting to decode the sequence in a trial and error manner using a sequence correlator, rather than by decoding the channel based on the reference signal. Therefore, through PSS and SSS, the UE can not only identify the existing cell but also determine whether the SSB is an AO SSB or an OD SSB. If PSS and SSS are used for synchronization and cell identification as before, the UE can use the bit field information in the PBCH to distinguish the SSB. Alternatively, a short sample sequence can be added and decoded to distinguish whether the SSB is an AO SSB or an OD SSB. Furthermore, SSB1, SSB2, SSB3, ... can be distinguished by service, and in this case, various methods for distinguishing SSBs from each other can be applied.

[0303] In the examples of the present disclosure, the first SSB and the second SSB are transmitted at the same frequency location and have corresponding contents, but the examples may also include SSBs that are transmitted at different periods. The examples below mainly describe a method in which various SSBs are utilized to perform measurements on a serving cell and neighboring cells when measurement-related information is obtained by receiving a SIB after the terminal is switched from power-off to power-on. After receiving the SIBs, the terminal can periodically perform measurements on the serving cell and neighboring cells based on an SSB Measurement Time Configuration (SMTC) period (or cycle).

[0304] FIG. 21 is a diagram showing examples of SMTC-based measurements to which the present disclosure can be applied.

[0305] In the example of Fig. 21(a), SSB1 corresponds to AO SSB, so SSB is always transmitted in all transmission opportunities, and in SSB2, since the cell can turn transmission on / off, SSB may not be transmitted in some transmission opportunities. If the terminal performs measurement in a transmission opportunity where there is no SSB2 transmission, the measurement result may not be derived correctly. For example, if the terminal is given an SMTC period for SSB2, in a transmission opportunity where there is no SSB, it may be unclear from the terminal's perspective whether the terminal is actually out of cell coverage and thus the SSB is not detected / received, or the terminal is within cell coverage but the cell does not transmit the SSB, so the SSB is not detected / received at the terminal.

[0306] Even if the SMTC period is given between SSB1 and SSB2 in the example of Fig. 21(b), the measurement result for SSB2 may not be able to distinguish whether SSB2 is off or out of coverage even when SSB2 is on.

[0307] Therefore, in these cases, a method is needed that allows the terminal to clearly recognize whether or not SSB is being transmitted. This disclosure describes various examples of enabling the terminal to correctly perform SSB-based measurements by explicitly or implicitly indicating / signaling whether or not SSB2 is being transmitted to the terminal, or by defining restrictions on the SSB transmission method.

[0308] For example, in RRC_IDLE state or RRC_CONNECTED state, SMTC can be assumed to be aligned with the time when the terminal wakes up from the DRX operation. Each neighboring cell can inform the system information whether it is a cell that transmits only SSB1 or a cell that can transmit both SSB1 and SSB2. Alternatively, when setting the information for performing measurements on neighboring cells to the terminal, the base station can provide the terminal with a list of one or more cells, and can distinguish whether the cell transmits only SSB1 or whether the cell can transmit SSB1 / SSB2 for each cell list. For example, the terminal can recognize that only SSB1 is transmitted for a PCI (physical cell identifier) ​​belonging to cell list #1, and the terminal can recognize that SSB1 / SSB2 can be transmitted for a PCI belonging to cell list #2. When a terminal performs measurements on the SSB2 of a base station for cells where SSB2 can be transmitted, it may be unclear whether the terminal receives the SSB2. Therefore, it is necessary to define how the terminal will perform measurements on cells where SSB2 is transmitted when it receives SSB1 and SSB2 at a specific frequency. The averaging process of the measurements can be said to be the process of deriving a value for judging the mobility criterion based on previously accumulated data by utilizing the coefficient of the L3 measurement.

[0309] FIG. 22 is a drawing for explaining an example of a method performed by a terminal according to the present disclosure.

[0310] In step S2210, the terminal can receive a first synchronization signal group transmitted from the first cell and a second synchronization signal group transmitted from the first cell.

[0311] For example, information related to the second synchronization signal group may be provided to the terminal as part of the first synchronization signal group, or may be provided to the terminal after the first synchronization signal group is received. Accordingly, the second synchronization signal group may be received based on information related to the second synchronization signal group.

[0312] In some examples, information related to the second synchronization signal group may be included in the broadcast information of the first synchronization signal group. For example, information related to the second synchronization signal group may include information about the presence, period, period candidate, and / or resource size of the second synchronization signal group. For example, the broadcast information may be provided via a physical broadcast channel. For example, the broadcast information may correspond to system information.

[0313] In some examples, information related to the second synchronization signal group may be included in signaling common to the terminal group including the terminal, or may be included in signaling specific to the terminal. For example, information related to the second synchronization signal group may include information regarding activation or deactivation of the second synchronization signal group, the number of transmissions, the start time, and / or the end time. For example, such signaling may be layer 1 (L1) signaling or layer 2 (L2) signaling.

[0314] In step S2220, the terminal may transmit a report on the results of measurements based on the first synchronization signal group and / or the second synchronization signal group to the second cell.

[0315] In some examples, the measurement of the terminal may be based on an average of a first measurement result for the first synchronization signal group and a second measurement result for the second synchronization signal group.

[0316] In some examples, the measurement of the terminal may be based on an average of measurement results having a quality above a certain threshold value among the first measurement result for the first synchronization signal group and the second measurement result for the second synchronization signal group.

[0317] In some examples, the report of the results of the terminal's measurement may further include information about a first time associated with a first measurement for a first synchronization signal group, and / or information about a second time associated with a second measurement for a second synchronization signal group.

[0318] The method described in the example of FIG. 22 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 a first synchronization signal group transmitted from a first cell via one or more transceivers (206), receive a second synchronization signal group transmitted from the first cell via one or more transceivers (206), and transmit a report on the results of a measurement based on one or more of the first synchronization signal group or the second synchronization signal group to the second cell via one or more transceivers (206). Furthermore, one or more memories (204) of the wireless device (200) may store instructions for performing the method described in the example of FIG. 22 or the examples described below when executed by one or more processors (202).

[0319] FIG. 23 is a drawing illustrating an example of a method performed by a base station according to the present disclosure.

[0320] In step S2310, the base station can transmit a first synchronization signal group of the first cell to one or more terminals, and can transmit a second synchronization signal group of the first cell to one or more terminals.

[0321] For example, information related to a second synchronization signal group may be included in a first synchronization signal group and provided to one or more terminals, or may be provided to one or more terminals after the first synchronization signal group is transmitted. Accordingly, the second synchronization signal group may be transmitted based on the information related to the second synchronization signal group.

[0322] In step S2320, the base station can receive a report on the measurement results of the first terminal based on the first synchronization signal group and / or the second synchronization signal group from the first terminal through the second cell.

[0323] In the example of Fig. 23, the specific features related to the first synchronization signal group, the second synchronization signal group, information related to the second synchronization signal group, measurement results, and reporting of measurement results are the same as the description referring to the example of Fig. 22, so redundant descriptions are omitted.

[0324] The method described in the example of FIG. 23 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 a first synchronization signal group of a first cell to one or more terminals via one or more transceivers (206), transmit a second synchronization signal group of the first cell to one or more terminals via one or more transceivers (206), and receive a report on the results of measurements based on the first synchronization signal group and / or the second synchronization signal group from a first terminal among the one or more terminals via one or more transceivers (206) in the second cell. Furthermore, one or more memories (204) of the wireless device (200) may store instructions for performing the method described in the example of FIG. 23 or the examples described below when executed by one or more processors (202).

[0325] In the examples of FIGS. 22 and 23, the first cell may be a neighboring cell, and the second cell may be a serving cell. For example, the first synchronization signal group may correspond to (AO) SSB, and the second synchronization signal group may correspond to OD SSB. For example, the synchronization signal group may include one or more synchronization signals (e.g., PSS and / or SSS) and / or system information (e.g., PBCH).

[0326] Hereinafter, more specific examples of the present disclosure regarding transmission and reception methods of various synchronization signals and measurement methods based thereon will be described. In the examples below, the terms SSB1 and SSB2 are used for clarity, but SSB corresponds to a group of synchronization signals including one or more synchronization signals and / or system information (broadcast information) of any structure, and the number of SSBs is not limited to two, and the examples below can also be applied to three or more SSBs.

[0327] Example 1

[0328] This embodiment is about a method of applying averaging to measurements for SSB1 and SSB2 based on whether SSB2 is transmitted.

[0329] Depending on the various methods for distinguishing between SSB1 and SSB2 when a terminal receives an SSB, the terminal performing the measurement can determine whether the received SSB is SSB1 or SSB2. For cells belonging to the list of cells capable of transmitting SSB, when the terminal attempts to receive SSB2 during the SMTC period, if there is no specific instruction / signaling in advance regarding whether to transmit SSB2, the terminal may not be able to clearly determine whether or not the SSB2 has been received. If an SSB below / below a specific threshold is measured during the SMTC period, it may be difficult for the terminal to distinguish whether the base station did not transmit SSB2 or whether the base station transmitted SSB2 but the reception quality was poor. Similarly, for SSB1, there may be uncertainty as to whether the base station transmitted SSB when the terminal performs the measurement. Therefore, a method to solve this problem is needed.

[0330] Example 1-1

[0331] The terminal may perform measurements and apply averaging for SSB regardless of whether SSB2 is transmitted or not (or regardless of whether SSB1 / SSB2 is distinguished or detected) during the SMTC period.

[0332] As another example, if the terminal can determine whether the SSB on which the current measurement is performed is SSB1 or SSB2, instead of always performing measurement and averaging, the terminal can perform measurement and averaging based on the period of SSB1 estimated by the terminal, instead of the SMTC period given to the terminal. For example, if the SMTC period is given as 80 ms, and measurement for SSB is performed based on 80 ms, then assuming that the SSB measured at the first 80 ms transmission opportunity is SSB1, SSB2 is measured at the 160 ms and 240 ms transmission opportunities, and SSB1 is measured at the 320 ms transmission opportunity, the terminal can estimate that SSB1 is transmitted with a period of at least 320 ms. In this case, the terminal can regard the 320 ms period corresponding to the period of SSB1, rather than the SMTC period / period, as a time region in which measurement and averaging can be performed, and thus the measurement can be performed stably.

[0333] As another example, if SSB1 is detected while the SMTC period / cycle is set to 80 ms, after detecting SSB1, the terminal can expect reception of SSB1 in the section where the period of SSB1 (e.g., 160 ms, or a predefined value or the pre-set period of SSB1) overlaps with the SMTC period. In the remaining section where the period of SSB1 and the SMTC period do not overlap, the terminal can check whether SSB2 is transmitted and then perform measurement on the SSB2 whose transmission is confirmed. Alternatively, the terminal may receive and perform measurement of SSB1 only in the section where the period of SSB1 and the SMTC period overlap, and not perform measurement in the remaining section where the period of SSB1 and the SMTC period do not overlap.

[0334] In cases where both SSB1 and SSB2 are transmittable, and SSB1 transmission can be guaranteed by utilizing multiples of the SMTC cycle, the terminal can perform measurements, and apply different coefficients for SSB1 and SSB2 (e.g., the network can signal information about the coefficients to the terminal) so that the terminal can process SSB2 between SSB1 transmissions differently from SSB1. Accordingly, cases where SSB2 is averaged and cases where SSB1 is averaged can be distinguished.

[0335] From the perspective of terminal measurement, if the measured SSB1 and SSB2 values ​​are low according to the current SMTC period, additional examples are described below to enable the terminal to distinguish whether the terminal is out of coverage or whether SSB2 is not transmitted by the cell.

[0336] Example 1-2

[0337] FIG. 24 is a diagram for explaining examples of averaging of SSB measurement results according to the present disclosure.

[0338] As in the example of Fig. 24(a), if the first measurement result in a certain SMTC period is greater than or equal to a certain threshold, the second measurement result in the next SMTC period is less than / below a certain threshold, and the third measurement result in the next SMTC period is greater than or equal to a certain threshold, the terminal may consider the second measurement result to be a measurement result in the case where SSB2 is not transmitted, and may not include the second measurement result in the averaging process.

[0339] As in the example of Fig. 24(b), if the first measurement result in a certain SMTC period is above a certain threshold value, the second measurement result in the next SMTC period is below / below a certain threshold value, and the third measurement result in the next SMTC period is below a certain threshold value, the second measurement result and the third measurement result may be included in the averaging process.

[0340] Although not shown, thresholds for the lower boundary may also be defined in addition to defining only one upper boundary threshold. The threshold(s) corresponding to one or both boundaries may be provided through system information for the list of cells capable of transmitting SSB2, or may be predefined without separate signaling.

[0341] Referring to the example of Fig. 24(c), if the SSB measurement result in the previous SMTC period / cycle is above / below the threshold value, the value of the counter K can be decreased by 1 if the SSB measurement value in the current SMTC period / cycle is below / below the threshold value. For example, the value of K can be decreased by 1 for each time the SSB measurement result is below / below the threshold value within the SMTC period / cycle. If an SSB measurement result above / below the threshold value occurs before the value of K becomes 0, the SSB measurement result values ​​retained / stored while decreasing the value of the counter K within the corresponding SMTC period can be initialized without being included in the averaging. If SSB measurement result values ​​below / below the threshold value occur within the corresponding SMTC period even after the value of the counter K becomes 0, the corresponding SSB measurement result values ​​can be temporarily retained / stored as targets for inclusion in the averaging. If an SSB measurement result value above / beyond the threshold value occurs within the SMTC cycle, the K value is initialized, and the temporarily held / saved SSB measurement result values ​​are not included in the averaging. In this case, the terminal can assume that SSB2 is not transmitted. Alternatively, if no SSB measurement result value above / beyond the threshold value occurs within the SMTC cycle, averaging can be performed including SSB measurement result values ​​below / below the threshold value. In this case, the terminal can assume that SSB2 is transmitted but is at the cell edge or out of coverage.

[0342] The value of K can be greater than 1 and signaled via system information. Figure 24(b) illustrates the case where K = 2, and Figure 24(c) illustrates the case where K = 4. The base station may also set a different value of K depending on the network status.

[0343] Example 1-3

[0344] The terminal can store the measurement time for SSB measurement and report the measurement time together with the measurement result when reporting the measurement result.

[0345] For example, when a terminal reports a measurement result, it may also report information related to the time at which the SSB2 was measured (e.g., SFN (system frame number), subframe index, slot index) together with the measurement result of SSB2. For example, the range of SFN may be 0 to 1023, the range of the subframe index may be 0 to 9, and the range of the slot index may be 0 to 13. The base station already knows the time at which the terminal transmitted SSB2, and can more accurately determine the SSB measurement situation of the terminal by considering the measurement time of the terminal and the measurement value at that time from the report of the terminal.

[0346] This behavior may be limited to terminals in an RRC connected state. Alternatively, it may also apply to measurement reports triggered for terminals in an RRC idle or RRC inactive state. For example, reporting on measurement results and measurement times may be applied even in non-RRC connected states, such as RRC idle or RRC inactive.

[0347] Information indicating whether SSB is being transmitted can be placed around the SSB so that the terminal can determine whether SSB is currently being transmitted through the information.

[0348] Example 1-4

[0349] When performing measurements on a neighboring cell capable of transmitting both SSB1 and SSB2, the SMTC period / cycle can be set to a value that is an integer multiple of the period of SSB1.

[0350] In the examples of FIG. 21 described above, when setting the SMTC period / cycle, there may be a case where one or both of the start and end points correspond to SSB2 transmission opportunities. In this case, since ambiguity may arise in the measurement operation depending on whether the terminal transmits SSB2, the start and end points of the SMTC cycle may be restricted to correspond to SSB1 and not SSB2. Accordingly, in the case of measurements for neighboring cells, the SSB measured at the start and end points of the SMTC cycle is always a transmission opportunity for the transmitted SSB, so that the terminal can perform measurements more clearly (for example, if no SSB is detected in the transmission opportunity, it is certain that the terminal is outside of cell coverage).

[0351] In a cell capable of transmitting both SSB1 and SSB2, the period of SSB1 may often be longer than the period of the general SSB. In this case, the period / period of the SMTC window for the cell may be restricted to be equal to the period of SSB1 or an integer multiple of the period of SSB1.

[0352] Example 1-5

[0353] When applying averaging to SSB measurement results within the size of the SSB measurement window, adjustment / setting of the coefficient can be applied so that measurement result values ​​below / below a certain threshold are excluded from or included in the averaging.

[0354] When a terminal performs SSB measurement during a predetermined duration corresponding to an SSB measurement window, unlike in the case of SSB1-based measurement, there may be cases where the base station for SSB2-based measurement does not transmit SSB2, and therefore the reliability of the SSB measurement result of the terminal may not be high. Therefore, the terminal may receive the size of the SSB measurement window from the base station for SSB measurement, and measure SSB during the corresponding period and apply averaging. Instead of the SSB measurement value for a time instance, the terminal may use the SSB measurement values ​​during the window / time duration for cell reselection or report the measurement result to the base station.

[0355] These SSB measurement windows may not be fixed in length and / or position but may be variable. The length and / or position of the measurement window may be specified by the base station or determined by the terminal. In cases where the terminal determines the length and position (e.g., start and end points) of the measurement window, the measurement result report may include information about the length and position of the measurement window.

[0356] The base station may also inform the terminal of the minimum guaranteed number of SSB2 transmissions within the size of the measurement window (e.g., an integer multiple of SMTC).

[0357] Instead of measurements for time instances, thresholds to be applied for values ​​averaged over one or more SMTC periods (e.g. triggered measurement reports, or cell (re)selection related thresholds) may be signaled to the UE in addition to the existing thresholds, taking into account the transmission opportunity of SSB2.

[0358] Example 1-6

[0359] In the process of performing measurement and averaging while distinguishing between SSB1 and SSB2, the terminal may be signaled to apply different coefficients to SSB1 and SSB2.

[0360] For example, if there is only one SSB, there is only one coefficient for the L3 measurement, and the coefficient value can be applied from the perspective of how it will be included in the averaging with respect to past measurement values. If the coefficients applied to the filtering of each L3 measurement for SSB1 and SSB2 are signaled independently or separately, the reflection ratio for the averaging of SSB2 can be set relatively low, and the reflection ratio for the averaging of SSB1 can be set high. Accordingly, the proportion reflected in the averaging of the measurement results for SSB2, whose transmission status is flexible, can be reduced.

[0361] Example 2

[0362] The present embodiment relates to a method for performing SSB measurement based on system information of a synchronization signal group (e.g., a bit field of a PBCH).

[0363] For the serving cell and neighboring cells, decoding of PBCH within SSB is not mandatory, but may be required depending on the situation. In the present disclosure, the SMTC period can be set based on SSB1 (e.g., an integer multiple of the SSB1 period). In addition, information related to SSB2 that can be transmitted between SSB1 transmission opportunities through the terminal capability can also be utilized for terminal measurement. For example, a terminal supporting a specific capability can utilize additional information in SIB1 and MIB to auxiliary utilize SSB2 even in periods outside the SMTC period, thereby performing fast measurements. In this case, the serving cell's system information can notify the terminal of a list of neighboring cells where SSB2 can be transmitted, and the SSB2 transmission period in the corresponding cell, through a higher layer.

[0364] Example 2-1

[0365] The PBCH bit field information of SSB1 can indicate whether an SSB following the corresponding SSB1 is transmitted.

[0366] As illustrated in the example of Fig. 20(a), there may be one or more (e.g., two) SSB2 transmission opportunities between consecutive SSB1 transmission opportunities. In the present disclosure, it may be assumed that SSB transmission and measurement information from the serving cell and neighboring cells are provided to the terminal through SIB1.

[0367] Whether to transmit the subsequent SSB2 (e.g., the first SSB2) can be indicated / signaled through the PBCH included in the first SSB1. Furthermore, whether to transmit the subsequent SSB2 (e.g., the second SSB2) can be indicated / signaled through the PBCH included in the first SSB2. Since the second SSB2 is followed by an opportunity to transmit SSB1, and SSB1 is assumed to always be transmitted, the PBCH of SSB2 may not include information regarding whether to transmit the subsequent SSB1.

[0368] SSB1 may include information indicating how many subsequent SSB2 transmissions are actually performed (e.g., not the number of transmission opportunities, but how many actual transmissions are performed across transmission opportunities). If 2 is indicated, this may correspond to the case where SSB2 is transmitted in both SSB2 transmission opportunities in the example of Fig. 20(a). If 1 is indicated, this may correspond to the case where only the first SSB2 is transmitted in the example of Fig. 20(a). If 0 is indicated, this may correspond to the case where no SSB2 transmissions occur before the next SSB1 transmission.

[0369] SSB1 may include information in the form of a bitmap indicating whether or not SSB2 transmission opportunities are actually transmitted until the next SSB1 is transmitted. If there are two SSB2 transmission opportunities between SSB1s, this can be indicated through a bitmap of 2 bits. A bitmap value of 00 may correspond to a case where SSB2 is not transmitted. A bitmap value of 01 may correspond to a case where only the second SSB2 is transmitted. A bitmap value of 10 may correspond to a case where only the first SSB2 is transmitted. A bitmap value of 11 may correspond to a case where both the first and second SSB2 are transmitted.

[0370] For example, let's assume that the period of SSB1 is 80 ms, SSB2 can be transmitted at 20 ms intervals between SSB1s, and SMTC period is set to 40 ms. If the value of the bitmap included in SSB1 is 001, the terminal can know that SSB2 will be OFF after 20 ms, OFF after 40 ms, and ON after 60 ms, and since SMTC window size is 40 ms, the terminal knows that the next SSB2 will be OFF and can not perform measurement / averaging. Alternatively, if the value of the bitmap included in SSB1 is 011, the terminal can know that SSB2 will be OFF after 20 ms, ON after 40 ms, and ON after 60 ms, and the terminal knows that the SSB2 to be transmitted in the next SMTC window period will be ON, and can perform measurement / averaging.

[0371] Example 2-2

[0372] The PBCH of SSB1 may include information indicating that the period of SSB2 is 1 / N of the original SSB1 period (N is an integer) or that there is no transmission of SSB2.

[0373] In general, when the terminal is in an RRC connection state for a neighboring cell and a serving cell, or even when in an RRC idle / inactive state, the terminal can perform measurements based on the SMTC cycle. In this case, if the SMTC cycle interval is set based on the SSB1 cycle (e.g., an integer multiple of the SSB1 cycle), the cycle of SSB2 transmission between two consecutive SSB1s may be set differently.

[0374] FIG. 25 illustrates examples of various periods and transmission locations of SSB transmission according to the present disclosure.

[0375] In the example of Fig. 25(a), the first SSB1 may include information indicating that the period of the subsequent SSB2s is 1 / 5 of the period of the SSB1 (e.g., N=5). The second SSB1 may include information indicating that the period of the subsequent SSB2s is 1 / 2 of the period of the SSB1 (e.g., N=2).

[0376] Instead of the N value for the period ratio, it could be more specifically signaled / controlled at which SSB2 transmission opportunity at which location the SSB2 is actually transmitted, through information such as bitmap or number of transmissions.

[0377] For example, the first index value of the variable period related information of SSB2 included in SSB1 can be set to a value of 0 when SSB2 is not transmitted, or a value of 1. If N=1, it indicates that the period of SSB2 is the same as the period of SSB1, which may correspond to the case where SSB2 is not transmitted. For example, the time offsets for the transmission start times of SSB1 and SSB2 are the same, and SSB2 can be defined as being transmitted when SSB1 is not transmitted.

[0378] Example 2-3

[0379] If the contents included in the PBCH of SSB1 and the PBCH of SSB2 are not the same (for example, if they are composed of different bit fields rather than the same bit fields being set to different values), the number and / or positions of PRBs occupied by the PBCH in SSB1 and SSB2, the number and / or positions of OFDM symbols, and the number and / or positions of REs may be different.

[0380] For example, SSB1 may have 20 PRBs in the PBCH, and SSB2 may have 16 PRBs in the PBCH. For example, SSB1 may have 3 OFDM symbols in the PBCH, and SSB2 may have 2 OFDM symbols in the PBCH.

[0381] To enable the terminal to recognize these differences and attempt PBCH decoding, the PBCH structure may be signaled to the terminal by sequence detection or other means, or the PBCH structure may be predefined without separate signaling.

[0382] Example 2-4

[0383] The system information (e.g., SIB) may inform the terminal of a list of candidates for the cycle of SSB2, and may inform the terminal of one cycle from the list through SSB1 (PBCH).

[0384] Candidates included in this list may also apply a specific period of time during which the terminal does not measure SSB2 at all from a cell perspective. For example, this time period may be indicated through SFN values.

[0385] Example 3

[0386] Information related to SSB2 can be provided to terminals via group-common signaling or terminal-specific signaling. Group-common / terminal-specific signaling can be L1 signaling or L2 signaling.

[0387] For example, in a serving cell, information related to SSB2 (e.g., ON / OFF of SSB transmission, etc.) can be notified about neighboring cell(s) specified in the current serving cell or SIB information, etc., through group-common L1 signaling distinguished by a specific radio network temporary identifier (RNTI), or group-common DCI, or paging DCI (e.g., DCI including scheduling information of a PDSCH including paging information), or paging message (e.g., PDSCH including paging information). Such signaling may be transmitted to the terminal at a specific cycle. For example, the L1 signaling may include signaling through a PDCCH.

[0388] SSB1 / SSB2 transmission-related information corresponding to multiple cells (or PCIs) can be indicated through a single signaling. When SSB1 / SSB2 transmission information for each cell / PCI is indicated through a specific field in the DCI or PDSCH, cell / PCI-related index or ID-related information associated with each field may be preset through SIB, etc.

[0389] Example 3-1

[0390] Activation / deactivation of SSB2 transmission of a specific cell can be indicated on PDCCH / PDSCH.

[0391] Information related to the transmission of each SSB2 may be transmitted together with multiple specific cell IDs or indices.

[0392] For example, if it is indicated through PDCCH / PDSCH that SSB2 transmission of a specific cell is enabled, the terminal can know that SSB2 transmission will occur after a specific offset (e.g., defined in symbol / slot units, and the value can be 0, 1, 2, ...), and can perform measurement and averaging by considering SSB2 transmission for SMTC cycles from that point onward. If it is indicated through PDCCH / PDSCH that SSB2 transmission of a specific cell is disabled, the terminal can know that SSB2 transmission will not occur after a specific offset, and can perform measurement and averaging by considering that SSB2 is not transmitted for SMTC cycles from that point onward (e.g., SSB measurement results corresponding to SSB2 will not be included in averaging).

[0393] Example 3-2

[0394] When information related to SSB2 of a specific cell is signaled through PDCCH / PDSCH, the number of times SSB2 is to be transmitted (or the number of times SSB2 is not transmitted) from the time the signaling is provided may be indicated.

[0395] Instead of the number of transmissions or non-transmissions, bitmap information for SSB2 transmissions, such as the examples described above, may be applied. For example, such a bitmap may be defined as a bit field of the PDCCH / DCI.

[0396] After receiving that signaling, there may or may not be a predetermined number of SSB2 transmissions for a specific period of time.

[0397] Information related to the transmission of each SSB2 may also be transmitted together with multiple specific cell IDs or indices.

[0398] As described in Example 3-1, after a certain offset from the transmission of the PDCCH / PDSCH containing information related to SSB2, the measurement results for SSB2 may or may not be included in the measurement and averaging.

[0399] Example 3-3

[0400] When a terminal is in an RRC connection state, SSB2-related information may be provided to the terminal via terminal-specific DCI or terminal-specific L2 signaling (e.g., MAC CE) instead of group-common L1 signaling. Examples of SSB2-related information may be applied in the same manner as described in Embodiments 3-1 and 3-2.

[0401] Alternatively, SSB2-related long-term information may be indicated / signaled to the terminal via an L3 RRC message. The time associated with such SSB2-related information may be signaled using the SFN value.

[0402] Example 3-4

[0403] Signaling containing SSB2-related information may also include information about the start and end times at which the SSB2-related information applies.

[0404] After detecting / decoding a PDCCH / PDSCH containing SSB2-related information, it may be defined not to attempt to detect / decode SSB2-related information for a predetermined length of time or a predetermined absolute length of time. This can reduce the complexity and power consumption of terminal operation.

[0405] In general, in the case of cell (re)selection, since it is performed in a terminal in RRC idle / deactivated state, when SSB2-related information is notified to the terminal through group-common signaling for cells that have notified the terminal that SSB2 is capable of transmission, the time point at which the signaling is to be applied may be specified. For example, a specific time point or time offset (e.g., SFN / frame / subframe / slot / symbol) related to SSB2 transmission may be provided to the terminal, and SSB2 transmission may start or stop in the corresponding cell at that time.

[0406] Information about a specific duration can be provided to the UE via higher-layer signaling, allowing the UE to assume / expect that SSB2 will not be transmitted during that duration. While SSB2 transmission can be indicated via L1 / L2 signaling, power consumption can be reduced by preventing the UE from attempting to detect / decode SSB2 in certain situations, such as during an RRC reset.

[0407] A candidate list of SSB2 transmission cycles may be provided to the terminal through upper layer signaling, and the transmission of SSB2 in one of the candidate cycles may be indicated to the terminal through L1 / L2 signaling.

[0408] Example 4

[0409] If the terminal recognizes that an additional SSB (e.g., SSB2) exists between the cycles of SSBs (e.g., SSB1) while performing neighbor cell measurements based on SMTC, the terminal may be instructed to perform measurements for the additional SSB. Measurements for the additional SSBs may be configured through the SMTC interval.

[0410] Example 4-1

[0411] For terminals having the capability to support these additional SSB measurements, an SMTC interval for the additional SSB measurements can be set.

[0412] In the examples of Figures 25(b) and 25(c), SSB2 can be transmitted once between SSB1 transmission cycles, and the transmission cycle of SSB2 can be applied identically to the transmission cycle of SSB1. In this case, the transmission start time of SSB2 can be specified by a time offset referenced to the transmission time of SSB1.

[0413] Example 4-2

[0414] SSB1 may contain information indicating whether an SSB2 following the SSB1 is to be transmitted.

[0415] SSB2 may contain information such as the time offset of the SSB2 following the SSB2.

[0416] Example 4-3

[0417] In the examples of FIG. 25(b) and FIG. 25(c), a cycle (e.g., an integer multiple of the SSB1 cycle) with the cycle of SSB1 as a reference may be set in the SMTC setting, and information on the cycle of SSB2 may not be set.

[0418] Since SSB2 is transmitted after a time offset in the corresponding cycle, the terminal can decide whether to include SSB2 in the measurement and averaging.

[0419] Example 4-4

[0420] When some of the elements included in SSB2 (e.g., PSS, SSS, PBCH) are transmitted, the transmission period of each element may be separately indicated within SSB1 or SSB2.

[0421] FIG. 26 is a drawing showing an example of the structure of an SSB to which the present disclosure can be applied.

[0422] In the SSB structure, there are unused PRBs in the high and low frequency directions of the PRBs where PSS is transmitted. Information indicating whether each SSB2 element is to be transmitted can be placed in these unused PRBs and transmitted.

[0423] Example 4-5

[0424] In existing SSB, PSS, SSS, and PBCH DMRS are defined as sequences. Additionally, a new terminal sequence can be defined to include information indicating whether SSB2 transmission is required within the SSB structure.

[0425] In the example of Fig. 26, a new terminal sequence may be placed in an unused PRB of a PSS transmission OFDM symbol. In this case, the maximum power boosting value of the PSS may be limited depending on the number of PRBs in which the new terminal sequence is placed. For example, in the existing SSB structure, an additional power boosting of 0 to 3 dB may be applied to the PSS compared to the SSS or PBCH, but the maximum power boosting range may be reduced in proportion to the number of PRBs in which the new terminal sequence is placed. For example, if the new terminal sequence is placed in two PRBs, a power boosting of 0 to 2 dB may be applied to the PSS. For example, if the new terminal sequence is placed in four PRBs, a power boosting of 0 to 1 dB may be applied to the PSS. For example, if the number of PRBs in which the new terminal sequence is placed is five or more, the same power as that of the SSS or PBCH may be applied to the PSS. In this way, a scaling value for power boosting according to the number of PRBs in which a new terminal sequence is placed may be introduced, or a power boosting value corresponding to the number of PRBs may be defined in advance in the form of a table.

[0426] According to the various examples of the present disclosure described above, when a terminal performs SSB-based measurements on a serving cell or a neighboring cell (mainly in an RRC idle / inactive state, but also applicable to an RRC connected state), the ambiguity regarding how to utilize the measurement results for SSB2 in a situation where the terminal cannot know in advance whether SSB2 is transmitted is eliminated, so that accurate and efficient measurement and averaging of the terminal can be applied. As described above, since the terminal can assume that SSB1 is always transmitted, the measurement can be limited to be performed based on SSB1 only. However, for NES, SSB1-based measurements transmitted at very large intervals may cause a delay that does not reflect the current state. Therefore, in order to appropriately utilize one or more SSB2 transmissions between SSB1 transmission intervals for the terminal's measurements, related information such as whether SSB2 is transmitted can be provided to the terminal. Accordingly, the terminal can perform measurements quickly and efficiently by additionally utilizing SSB2 in addition to SSB1. Furthermore, by considering the transmission of SSBs for energy conservation not only in the RRC connected / idle / deactivated states of the terminal, but also in the initial access state, cell energy savings can be significantly improved. Furthermore, if the network continuously transmits the default signal, not only does it suffer from network energy consumption, but it also causes interference in cell overlapping areas. As demand for high-frequency bands increases, the installation of narrower and more numerous cells / base stations is required, resulting in higher cell density and a greater need for inter-cell interference reduction.Therefore, for the purpose of reducing inter-cell interference as well as NES, more efficient network operation may be achieved by applying various examples of the present disclosure related to SSB transmission to minimize transmission of AO SSB and transmit additional OD SSB (or SSB with some elements missing) as needed, while allowing terminals to accurately perform measurements based on various SSBs.

[0427] 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.

[0428] 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.

[0429] 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.

[0430] 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.

[0431] 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 a first synchronization signal group transmitted from a first cell by a terminal; A step of receiving, by the terminal, a second synchronization signal group transmitted from the first cell; and A step of transmitting, by the terminal, to the second cell a report on the result of a measurement based on at least one of the first synchronization signal group or the second synchronization signal group, Information related to the second synchronization signal group is included in the first synchronization signal group or is provided to the terminal after the first synchronization signal group is received, A method wherein the second synchronization signal group is received based on information related to the second synchronization signal group.

2. In paragraph 1, A method wherein information related to the second synchronization signal group is included in the broadcast information of the first synchronization signal group.

3. In paragraph 2, A method wherein information related to the second synchronization signal group includes information about one or more of the presence, period, period candidate, or resource size of the second synchronization signal group.

4. In paragraph 2, A method wherein the above broadcast information is provided through a physical broadcast channel.

5. In paragraph 1, A method wherein information related to the second synchronization signal group is included in signaling common to a terminal group including the terminal or signaling specific to the terminal.

6. In paragraph 5, A method wherein information related to the second synchronization signal group includes information about one or more of activation or deactivation, number of transmissions, start time, or end time of the second synchronization signal group.

7. In paragraph 5, A method wherein the above signaling is first layer (L1) or second layer (L2) signaling.

8. In paragraph 1, A method wherein the measurement is based on an average of a first measurement result for the first synchronization signal group and a second measurement result for the second synchronization signal group.

9. In paragraph 1, A method wherein the measurement is based on an average of measurement results having a quality greater than a certain threshold value among the first measurement results for the first synchronization signal group and the second measurement results for the second synchronization signal group.

10. In paragraph 1, A method wherein the report of the results of the measurement includes at least one of information about a first time associated with a first measurement for the first synchronization signal group, or information about a second time associated with a second measurement for the second synchronization signal group.

11. In paragraph 1, The above first cell is a neighboring cell, A method wherein the second cell is a serving cell of the terminal.

12. In paragraph 1, A method wherein the second synchronization signal group is transmitted based on an on-demand SSB setting.

13. In paragraph 1, A method wherein the above synchronization signal group comprises one or more synchronization signals or one or more system information.

14. One or more transceivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Receiving a first synchronization signal group transmitted from a first cell through said one or more transceivers; Receiving a second synchronization signal group transmitted from the first cell through the one or more transceivers; A report on the results of a measurement based on at least one of the first synchronization signal group or the second synchronization signal group is set to be transmitted to the second cell through the at least one transceiver, Information related to the second synchronization signal group is included in the first synchronization signal group or is provided after the first synchronization signal group is received, The second synchronization signal group is a terminal that is received based on information related to the second synchronization signal group.

15. A step of transmitting a first synchronization signal group of a first cell to one or more terminals by a base station; a step of transmitting a second synchronization signal group of the first cell to the one or more terminals by the base station; and A step of receiving, by the base station, a report on the result of a measurement based on at least one of the first synchronization signal group or the second synchronization signal group from a first terminal among the one or more terminals through a second cell, Information related to the second synchronization signal group is included in the first synchronization signal group or is provided to the first terminal after the first synchronization signal group is received, A method wherein the second synchronization signal group is transmitted based on information related to the second synchronization signal group.

16. 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 a first synchronization signal group of a first cell to one or more terminals via the one or more transceivers; Transmitting a second synchronization signal group of the first cell to the one or more terminals through the one or more transceivers; and A report on the result of a measurement based on at least one of the first synchronization signal group or the second synchronization signal group is set to be received in a second cell from a first terminal among the at least one terminal through the at least one transceiver, Information related to the second synchronization signal group is included in the first synchronization signal group or is provided to the first terminal after the first synchronization signal group is received, A base station, wherein the second synchronization signal group is transmitted based on information related to the second synchronization signal group.

17. 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 13 based on execution by said one or more processors.

18. 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 13.

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