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

Abstract

Disclosed are a method and device for transmitting and receiving system information in a wireless communication system. The method according to one embodiment of the present disclosure may comprise the steps in which: a UE receives configuration information from a base station in a first cell, the configuration information including information about one or more parameters for transmitting a PRACH for the UE to request system information about a second cell; and the UE transmits the PRACH for requesting system information about the second cell to the base station on the basis of the configuration information.

Description

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

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and device for transmitting and receiving system information 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 and receiving on-demand system information upon request by a user equipment (UE) in a wireless communication system.

[0005] In addition, an additional technical challenge of the present disclosure is to provide a method and device for requesting on-demand system information while simultaneously performing a random access procedure.

[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 an aspect of the present disclosure may include: receiving, by a user equipment (UE), configuration information from a base station in a first cell, wherein the configuration information includes information on one or more parameters for transmission of a physical random access channel (PRACH) for requesting system information for a second cell by the UE; and transmitting, by the UE, the PRACH for requesting the system information for the second cell to the base station based on the configuration information. Based on the transmission of the PRACH, a first random access procedure for the UE may be initiated.

[0008] A method according to an additional aspect of the present disclosure may include: transmitting, by a base station, configuration information to a user equipment (UE) in a first cell, the configuration information including information on one or more parameters for transmission of a physical random access channel (PRACH) for requesting system information for a second cell by the UE; and receiving, by the base station, the PRACH for requesting the system information for the second cell from the user equipment based on the configuration information. Based on the transmission of the PRACH, a first random access procedure for the UE may be initiated.

[0009] According to an embodiment of the present disclosure, energy of the network can be saved by transmitting on-demand system information upon request of a UE.

[0010] In addition, according to an embodiment of the present disclosure, PRACH, which is used as a wake up signal (WUS) for requesting on-demand system information, can be used as the first message of a random access procedure, thereby reducing the latency of the initial access procedure.

[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 exemplarily illustrates a functional framework for AI / ML operations to which some examples of the present disclosure may be applied.

[0018] FIG. 6 illustrates an example of a communication procedure based on an AI / ML model between a first node and a second node to which some examples of the present disclosure may be applied.

[0019] FIG. 7 illustrates an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0020] FIG. 8 exemplarily illustrates a system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0021] FIG. 9 illustrates an exemplary beam management procedure to which some examples of the present disclosure may be applied.

[0022] Figure 10 illustrates examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0023] Figure 11 illustrates examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0024] FIG. 12 illustrates examples of sensing operations to which some examples of the present disclosure may be applied.

[0025] Figure 13 illustrates a random access process in a wireless communication system to which the present disclosure can be applied.

[0026] Figure 14 illustrates a two-step random access process in a wireless communication system to which the present disclosure can be applied.

[0027] FIG. 15 illustrates an on-demand SIB1 transmission method to which some examples of the present disclosure may be applied.

[0028] FIG. 16 illustrates a random access procedure between a terminal and a base station according to one embodiment of the present disclosure.

[0029] FIG. 17 illustrates a random access procedure between a terminal and a base station according to one embodiment of the present disclosure.

[0030] FIG. 18 illustrates a random access procedure between a terminal and a base station according to one embodiment of the present disclosure.

[0031] FIG. 19 illustrates a random access procedure between a terminal and a base station according to one embodiment of the present disclosure.

[0032] FIG. 20 illustrates the operation of a UE for transmitting and receiving system information according to one embodiment of the present disclosure.

[0033] FIG. 21 illustrates the operation of a base station for a method of transmitting and receiving system information according to one embodiment of the present disclosure.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] In this disclosure, terms such as "first," "second," etc. are used only to distinguish one component from another, are not used to limit the components, and do not limit the order or importance of 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.

[0038] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0039] 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."

[0040] 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."

[0041] 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.”

[0042] 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.”

[0043] 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."

[0044] In the following description, 'when, if, in case of' can be replaced with 'based on'.

[0045] Technical features individually described in one drawing in this disclosure may be implemented individually or simultaneously.

[0046] 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.

[0047] In the present disclosure, a base station (BS) may be a second node / IAB node / Transmission-Reception Point (TRP).

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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), and 5G NR.

[0052] 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.

[0053] Network structure

[0054] Figure 1 illustrates a flexible network topology to which some examples of the present disclosure may be applied.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] Systems applicable to this disclosure

[0062] FIG. 2 illustrates an example of a communication system to which some examples of the present disclosure may be applied.

[0063] 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).

[0064] 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).

[0065] 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.

[0066] Device applicable to the present disclosure

[0067] FIG. 3 illustrates an example of a wireless device to which some examples of the present disclosure may be applied.

[0068] 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).

[0069] 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.

[0070] 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.

[0071] At least one processor (202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The at least one processor (202) may be implemented by hardware, firmware, software, or a combination thereof. For example, at least one application specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in the at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be included in the at least one processor (202), or may be stored in at least one memory (204) and driven by the at least one processor (202). The descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions and / or sets of instructions.

[0072] 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.

[0073] 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.

[0074] 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).

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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 back haul communications, and a wired transceiver may not be included.

[0082] Communication procedures

[0083] 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.

[0084] 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.

[0085] 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).

[0086] 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., 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.

[0087] 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)).

[0088] 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.

[0089] 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.

[0090] 6G system core technologies

[0091] 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.

[0092] artificial intelligence

[0093] 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. This means 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.

[0094] The following describes a functional framework for AI / ML operations.

[0095] Below, to explain AI (or AI / ML) more specifically, the terms can be defined as follows.

[0096] - Data collection: Data collected from network nodes, management entities, or terminals as a basis for AI model training, data analysis, and inference.

[0097] - 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.

[0098] - 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.

[0099] - AI / ML Inference: The process of making predictions or inducing decisions based on collected data and the AI ​​model using a trained AI model.

[0100] Life Cycle Management (LCM) procedures for AI / ML models (i.e., model training, model deployment, model inference, model monitoring, model updates, etc.) can be divided into functionality-based LCM and model-based LCM. In functionality-based LCM, AI / ML models may not be identified by the network, and the network can direct the activation / deactivation / fallback / switching of AI / ML functionality. In model-ID (identifier)-based LCM, AI / ML models can be identified by the network, and the network / terminal can activate / deactivate / select / switch AI / ML models based on the model ID.

[0101] FIG. 5 exemplarily illustrates a functional framework for AI / ML operations to which some examples of the present disclosure may be applied.

[0102] Figure 5 illustrates a general functional architecture relevant to both Functionality-based LCM and Model-based LCM. Some of the functions or some of the data / information / command flows (i.e., arrows) illustrated in Figure 5 may be omitted.

[0103] Referring to FIG. 5, a general functional framework can be configured to include a data collection function (10), a model training function (20), a management function (30), an inference function (40), and a model storage function (50).

[0104] The Data Collection function (10) is a function that provides input data to the Model Training function (20), Management function (30), and Inference function (40). The Data Collection function (10) can perform data preparation based on raw data and provide input data processed through data preparation. Examples of raw data may include received data / measurement data from terminals or other network entities, inference / output of AI / ML models, etc. The Data Collection function (10) may be performed by a single entity (e.g., a terminal, a network node, etc.) or may be performed by multiple entities.

[0105] Here, training data (11) refers to data required as input for the AI / ML Model Training function (20). Monitoring data (12) refers to data required as input for the Management (30) of the AI / ML model or AI / ML function. Inference data (13) refers to data required as input for the AI / ML Inference function (30).

[0106] The Model Training function (20) is a function that performs AI / ML model training, validation, and testing, which can generate model performance metrics that can be used as part of the AI / ML model testing procedure. The Model Training function (20) can perform data preparation (e.g., data pre-processing and cleaning, forming, and transformation) based on the Training Data (11) transferred from the Data Collection function (10), if necessary.

[0107] Trained / Updated Model (21): If there is a Model Storage function (50), it is used to pass a trained, validated and tested AI / ML model to the Model Storage function (50) or to pass an updated version of the model to the Model Storage function (50).

[0108] The Management function (30) is a function that supervises the operation of the AI / ML model or AI / ML function. In addition, the Management function (30) may perform decisions to ensure appropriate inference operations based on data received from the Data Collection function (10) (i.e., Monitoring Data (12)) and / or data received from the Inference function (40) (i.e., Inference Output (41)).

[0109] Management Instruction (32) is information required as input to manage the Inference function (40). The relevant information may include selection / (de)activation / switching of an AI / ML model or AI / ML-based function, and may also include fallback to non-AI / ML operations (i.e., not relying on the inference process).

[0110] A Model Transfer / Delivery Request (33) can be used to request model(s) from Model Storage (50).

[0111] A Performance Feedback / Retraining Request (31) refers to information required as input to the Model Training function (20) (e.g., for the purpose of (re)training or updating the model).

[0112] The Inference function (40) is a function that provides output from the process of applying an AI / ML model or AI / ML function using data (i.e., Inference Data (13)) provided by Data Collection (10) as input. Data preparation (e.g., data preprocessing and cleaning, formatting, and transformation) may also be performed based on the Inference Data (13) delivered by Data Collection (10). If necessary, the Inference function (40) may also perform data preparation (e.g., data preprocessing and cleaning, forming, and transformation) based on the Inference Data (13) provided by Data Collection function (10).

[0113] Inference Output (41) is data used in the Management function (30) to monitor the performance of an AI / ML model or AI / ML function. Inference Output (41) may include the inference output of the AI / ML model generated by the Inference function (30), and the details of the inference output may vary depending on the use case.

[0114] The Model Storage function (50) stores a learned / updated model that can be used to perform the Inference function (40). The Model Storage function (50) illustrated in FIG. 2 can be used as a reference point (if any) when applicable to protocol termination, model transmission / delivery, and related processes. Furthermore, the Model Storage function (50) is merely an example and is not intended to limit the storage location of actual AI / ML models, and may be omitted.

[0115] Model Transfer / Delivery (51) is used to transfer AI / ML models to inference functions.

[0116] The level of cooperation can be defined as follows depending on the capability of AI / ML functions between multiple nodes, and variations due to combination of multiple levels or separation of any one level are also possible.

[0117] Cat 0a) No collaboration framework: AI / ML algorithms are purely implementation-based and do not require any changes to the wireless interface.

[0118] Cat 0b) This level corresponds to a framework with a modified wireless interface tailored to efficient implementation-based AI / ML algorithms, but without collaboration.

[0119] Category 1) involves inter-node support to improve the AI / ML algorithms of each node. For example, this applies when a specific node receives support from another node (for training, adaptation, etc.) and vice versa. At this level, model exchange between network nodes is not required.

[0120] Category 2) Joint AI / ML tasks can be performed across multiple nodes. This level requires the exchange of AI / ML model commands or network nodes.

[0121] FIG. 5 is a diagram illustrating an overall functional framework for an AI / ML model, and not all functions and / or all data / information / command signals illustrated in FIG. 5 may be performed within a specific node, but only some of them may be performed.

[0122] AI / ML models can be divided into one-side models and two-side models depending on whether training and / or inference are performed on a single node or jointly / sequentially on multiple nodes.

[0123] A one-side model can refer to an AI / ML model in which inference is performed entirely by a single node (e.g., a terminal or network). Here, AI / ML model training can also be performed entirely by a single node. AI / ML model training and inference can be performed by the same node, or they can be performed by separate nodes.

[0124] A two-side model can refer to an AI / ML model in which joint inference is performed across multiple nodes (e.g., terminals and networks). Joint inference refers to inference being performed jointly across multiple nodes. For example, the first part of the inference may be performed by a first node, and the remaining part by a second node. Two-side models can be categorized into several types depending on the training method of the AI / ML model, as follows:

[0125] - First type: AI / ML models can be trained on a single node. In this case, joint training can be performed. The trained model can then be distributed to other nodes / objects.

[0126] - Second type: Joint training of AI / ML models can be performed on multiple nodes / entities (e.g., networks and terminals). Joint training can mean that model generation (e.g., CSI generation part) and model reconstruction (CSI compression by sub-use case) are trained in the same loop for forward activation and backward gradient. In this type, joint training can include both simultaneous training (i.e., model generation training and model reconstruction training are performed simultaneously) and sequential training (i.e., model reconstruction training is performed after model generation training).

[0127] - Third type: Separate training of AI / ML models can be performed on multiple nodes (e.g., networks and terminals). Separate training may mean that training begins sequentially on one node and continues on other nodes. In this case, the first node first performs the AI / ML model and shares the training data with the second node. The second node can then use the shared training data to perform the AI / ML model. For example, training for the CSI generation part may be performed by the terminal, while CSI reconstruction may be performed by the network.

[0128] FIG. 6 illustrates an example of a communication procedure based on an AI / ML model between a first node and a second node to which some examples of the present disclosure may be applied.

[0129] Step 1: In the description of the present disclosure described below, signaling (e.g., information / data / channel / signal, etc.) or a set of signaling between a specific node (e.g., a terminal, a network, etc.) and another node may be interpreted as the signaling or set of signaling of Step 1 used to perform an operation based on an AI / ML model, even if not otherwise mentioned. For example, it may correspond to training data for training (i.e., generation and / or reconstruction) the AI / ML model of FIG. 2, or correspond to inference data used for inference of the AI / ML model, or correspond to feedback for the AI / ML model, etc. If signaling between nodes is not required prior to an operation based on an AI / ML model in the present disclosure, Step 1 may be omitted. If a one-side model is used in the present disclosure, the unidirectional / bidirectional signaling (set) in the present disclosure may correspond to the signaling of Step 1. In addition, when a two-side model is used in the present disclosure, the one-way / two-way signaling in the present disclosure may correspond to one-stage signaling, and also, a repetitive signaling operation may correspond to one-stage signaling.

[0130] For example, in AI / ML model-based beam management (BM), if a base station predicts (i.e., infers) beam(s) with good quality based on an AI / ML model, the base station can receive quality / intensity information for multiple beams from a terminal. Furthermore, if a terminal predicts (i.e., infers) beam(s) with good quality based on an AI / ML model, the terminal can receive multiple beams from the base station.

[0131] Step 2: In the description of the present disclosure described below, an operation (e.g., calculation, selection, prediction, etc.) in a specific node (e.g., terminal, network, etc.) or a joint operation (e.g., calculation, selection, prediction, etc.) in multiple nodes (e.g., terminal, network, etc.) may correspond to a step 2 operation based on one or more functions in the functional framework of the AI / ML model, even if not mentioned separately. For example, it may correspond to training (i.e., generation and / or reconstruction) of the AI / ML model in FIG. 2, or it may correspond to inference of the AI / ML model, etc. When a one-side model is used, an operation performed by a single node in the present disclosure may correspond to a step 2 operation, and also, when a two-side model is used, a joint operation performed by multiple nodes in the present disclosure may correspond to a step 2 operation.

[0132] For example, in an AI / ML model-based BM, the base station can use quality / intensity information for multiple beams received from the terminal as inference data to predict (i.e., infer) beam(s) with good quality based on the AI / ML model. Furthermore, the terminal can measure multiple beams received from the base station and use the measurement results as inference data to predict (i.e., infer) beam(s) with good quality based on the AI / ML model.

[0133] Step 3: In the description of the present disclosure described below, the signaling (e.g., information / data / channel / signal, etc.) or set of signaling between a specific node (e.g., terminal, network, etc.) and another node may be interpreted as a three-step signaling or set of signaling generated due to (as a result of) an operation based on an AI / ML model, even if not otherwise mentioned. For example, it may correspond to an output resulting from inference of the AI / ML model in FIG. 2. If signaling between nodes is not required as a result of an operation based on an AI / ML model in the present disclosure, Step 3 may be omitted. If a one-side model is used in the present disclosure, the one-way / two-way signaling (set) in the present disclosure may correspond to the three-step signaling. In addition, if a two-side model is used in the present disclosure, the one-way / two-way signaling in the present disclosure may correspond to the three-step signaling, and furthermore, a repetitive signaling operation may correspond to the three-step signaling.

[0134] For example, in an AI / ML model-based BM, the base station can transmit to the terminal the beam(s) predicted based on the AI / ML model as candidates so that the terminal can determine the optimal beam. Furthermore, the terminal can report to the base station the beam(s) predicted based on the AI / ML model to request the base station to transmit the candidate beams as candidates for determining the optimal beam.

[0135] THz communication (terahertz communication)

[0136] 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.

[0137] FIG. 7 illustrates an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0138] 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.

[0139] 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.

[0140] FIG. 8 exemplarily illustrates a system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0141] The example of Fig. 8 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. 8 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. 8.

[0142] In step S810, the second node (120) (e.g., base station) can transmit system information of cell #1 through 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.

[0143] At step S830, the first node (110) (e.g., a terminal) can acquire synchronization for cell #1. Synchronization can be acquired by detecting a synchronization signal. Typically, synchronization is acquired before receiving system information. However, 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.

[0144] At step S850, 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.

[0145] The procedure described with reference to FIG. 8 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) performs a handover to cell #1 of the second node (120). However, in the case of a 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).

[0146] 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.

[0147] FIG. 9 illustrates an exemplary beam management procedure to which some examples of the present disclosure may be applied.

[0148] Although FIG. 9 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.

[0149] 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.

[0150] In step S910, the second node (120) (e.g., a base station) can set resources for beam management to the first node (110) (e.g., a terminal). Here, the resources may include at least one of time-frequency resources, channels, and spatial resources (e.g., antenna ports). For example, the base station may utilize a beam search signal (BSS) that is transmitted spatially separated from an existing downlink signal / channel for beam search. Here, the BSS may be transmitted based on a dedicated port for beam search. The dedicated port may 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 may be included in the technical concept according to the present embodiment.

[0151] In step S930, the second node (120) (e.g., a 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).

[0152] At step S950, 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 at step S1030.

[0153] In step S970, 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).

[0154] non-terrestrial networks (NTN)

[0155] Figures 10 and 11 illustrate examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0156] NTN can represent a network or network segment that uses radio frequency (RF) resources mounted on a satellite (or unmanned aerial system (UAS) platform).

[0157] Figure 10 shows an example of a typical scenario of an NTN based on a transparent payload, and Figure 11 shows an example of a typical scenario of an NTN based on a regenerative payload.

[0158] Referring to Figure 10, 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.

[0159] Referring to Figure 11, 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.

[0160] Figures 10 and 11 are only 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.

[0161] 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.

[0162] 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).

[0163] Integrated Sensing and Communication (ISAC)

[0164] 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.

[0165] FIG. 12 illustrates examples of sensing operations to which some examples of the present disclosure may be applied.

[0166] Specifically, Fig. 12(a) shows an example of a monostatic sensing operation using a sensing receiver and a sensing transmitter located in the same location. Fig. 12(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 via an entity / service within the 3GPP system.

[0167] Random access behavior and related actions

[0168] When there are no PUSCH transmission resources (i.e., Uplink Grant) allocated by the base station, the UE can perform a random access operation. Random access in the NR system can be initiated when 1) the UE requests or resumes an RRC connection, 2) the UE performs a handover to an adjacent cell or adds a secondary cell group (SCG: Secondary Cell Group) (i.e., SCG addition), 3) the UE makes a scheduling request to the base station, 4) the base station instructs the UE to perform random access using a PDCCH order, or 5) a beam failure or RRC connection failure is detected.

[0169] Figure 13 illustrates a random access process in a wireless communication system to which the present disclosure can be applied. Figure 13(a) illustrates a contention-based random access process, and Figure 13(b) illustrates a dedicated random access process.

[0170] Referring to Fig. 13(a), the contention-based random access process includes the following four steps. Hereinafter, the messages transmitted in steps 1 to 4 may be referred to as messages (Msg) 1 to 4, respectively.

[0171] -Step 1: The terminal transmits a RACH (random access channel) preamble through a PRACH (physical random access channel).

[0172] -Step 2: The terminal receives a random access response (RAR) from the base station through the DL-SCH (downlink shared channel).

[0173] -Step 3: The terminal transmits Layer 2 / Layer 3 messages to the base station through UL-SCH (uplink shared channel).

[0174] -Step 4: The terminal receives a contention resolution message from the base station through the DL-SCH.

[0175] The terminal can receive information about random access from the base station through system information.

[0176] If random access is required, the terminal transmits a RACH preamble to the base station as in step 1. The base station can distinguish each random access preamble through the time / frequency resource (i.e., RACH Occasion (RO)) in which the random access preamble is transmitted and the random access preamble index (PI: Preamble Index).

[0177] When the base station receives a random access preamble from a terminal, the base station transmits a random access response (RAR) message to the terminal as in step 2. To receive the random access response message, the terminal monitors an L1 / L2 control channel (PDCCH) CRC-masked with a Random Access-RNTI (RA-RNTI), which includes scheduling information for the random access response message, within a preset time window (e.g., ra-ResponseWindow). The PDCCH masked with the RA-RNTI can be transmitted only through a common search space. When a scheduling signal masked with the RA-RNTI is received, the terminal can receive a random access response message from a PDSCH indicated by the scheduling information. Thereafter, the terminal checks whether the random access response message includes random access response information indicated to the terminal. Whether or not the random access response information directed to itself exists can be checked by whether or not the RAPID (Random Access Preamble ID) for the preamble transmitted by the terminal exists. The index of the preamble transmitted by the terminal and the RAPID may be the same. The random access response information includes the corresponding random access preamble index, timing offset information for UL synchronization (e.g., Timing Advance Command (TAC)), UL scheduling information for message 3 transmission (e.g., UL grant), and terminal temporary identification information (e.g., TC-RNTI (Temporary-C-RNTI)).

[0178] A terminal that has received random access response information transmits UL-SCH (Shared Channel) data (message 3) via PUSCH according to UL scheduling information and timing offset value as in step 3. The time and frequency resources to which the PUSCH carrying message 3 is mapped / transmitted are defined as PO (PUSCH Occasion). Message 3 may include the ID of the terminal (or the global ID of the terminal). Alternatively, message 3 may include information related to an RRC connection request for initial access (e.g., an RRCSetupRequest message). In addition, message 3 may include a Buffer Status Report (BSR) regarding the amount of data available for transmission by the terminal.

[0179] After receiving UL-SCH data, the base station transmits a contention resolution message (message 4) to the terminal, as in step 4. If the terminal receives the contention resolution message and the contention is successfully resolved, the TC-RNTI is changed to a C-RNTI. Message 4 may include the terminal's ID and / or RRC connection-related information (e.g., an RRCSetup message). If the information transmitted through message 3 does not match the information received through message 4, or if message 4 is not received for a certain period of time, the terminal may consider contention resolution to have failed and retransmit message 3.

[0180] Referring to Fig. 13(b), the dedicated random access process includes the following three steps. Hereinafter, the messages transmitted in steps 0 to 2 may be referred to as messages (Msg) 0 to 2, respectively. The dedicated random access process may be triggered using a PDCCH (hereinafter, PDCCH order) used by the base station to command RACH preamble transmission.

[0181] -Step 0: The base station allocates a RACH preamble to the terminal through dedicated signaling.

[0182] -Step 1: The terminal transmits a RACH preamble through PRACH.

[0183] -Step 2: The terminal receives a random access response (RAR) from the base station through the DL-SCH.

[0184] The operation of steps 1 and 2 of the dedicated random access process may be identical to steps 1 and 2 of the contention-based random access process.

[0185] In NR, DCI format 1_0 is used to initiate a non-contention-based random access process with a PDCCH order. DCI format 1_0 is used to schedule PDSCH in a DL cell. Meanwhile, if the CRC (Cyclic Redundancy Check) of DCI format 1_0 is scrambled with C-RNTI and the bit values ​​of the "Frequency domain resource assignment" field are all 1, DCI format 1_0 is used as a PDCCH order indicating a random access process. In this case, the fields of DCI format 1_0 are set as follows.

[0186] - RA preamble index: 6 bits

[0187] - UL / SUL (Supplementary UL) indicator: 1 bit. If all bit values ​​of the RA preamble index are not 0 and SUL is set for the terminal within the cell, it indicates the UL carrier on which the PRACH is transmitted within the cell. Otherwise, it is not used (reserved).

[0188] - SSB (Synchronization Signal / Physical Broadcast Channel) Index: 6 bits. If the bit values ​​of the RA preamble index are not all 0, it indicates the SSB used to determine the RACH opportunity for PRACH transmission. Otherwise, it is unused (reserved).

[0189] - PRACH Mask Index: 4 bits. If the bit values ​​of the RA Preamble Index are not all 0, it indicates the RACH opportunity associated with the SSB indicated by the SSB Index. Otherwise, it is unused (reserved).

[0190] - Unused (reserved): 10 bits

[0191] If DCI format 1_0 does not correspond to a PDCCH command, DCI format 1_0 consists of fields used to schedule PDSCH (e.g., Time domain resource assignment (TDRA), Modulation and Coding Scheme (MCS), HARQ process number, PDSCH-to-HARQ_feedback timing indicator, etc.).

[0192] NR systems may require lower latency than legacy systems. Furthermore, if a random access process occurs in the U-band, the terminal and base station must sequentially succeed in LBT throughout all four steps of the random access process to complete the random access process and resolve contention. If LBT fails at any step of the four-step random access process, resource efficiency deteriorates and latency increases. In particular, if LBT fails during the scheduling / transmission process associated with Message 2 or Message 3, resource efficiency may decrease and latency may increase significantly. Even in the L-band, a low-latency random access process may be required in various NR system scenarios. Therefore, a two-step random access process can also be performed on the L-band.

[0193] Figure 14 illustrates a two-step random access process in a wireless communication system to which the present disclosure can be applied.

[0194] As illustrated in Fig. 14(a), the 2-step random access process can be composed of two steps: transmission of an uplink signal (referred to as message A, corresponding to PRACH preamble + Msg3 PUSCH) from a terminal to a base station, and transmission of a downlink signal (referred to as message B, corresponding to RAR + Msg4 PDSCH) from a base station to a terminal.

[0195] Additionally, in a non-contentious random access process, the random access preamble and PUSCH part may be transmitted together as illustrated in FIG. 14(b).

[0196] Although not shown in FIG. 14, a PDCCH for scheduling message B may be transmitted from the base station to the terminal, which may be referred to as Msg. B PDCCH.

[0197] Meanwhile, the PRACH format for transmitting the PRACH preamble in the NR system consists of a format consisting of a sequence of length 839 (referred to as a long RACH format for convenience) and a format consisting of a sequence of length 139 (referred to as a short RACH format for convenience). For example, in FR1, the SCS of the short RACH format is defined as 15 or 30 kHz.

[0198] The base station can inform the UE through higher layer signaling (e.g., RRC signaling or MAC CE or DCI) (e.g., prach-ConfigurationIndex or msgA-PRACH-ConfigurationIndex) which PRACH format can be transmitted at a specific timing for a specific duration, and even how many ROs (RACH occasions or PRACH occasions) are present in the slot. Tables for random access configurations are defined in TS 38.211, and the PRACH transmission time domain resources can be determined according to the PRACH configuration index indicated by the higher layer signaling.

[0199] Table 1 illustrates a portion of the table for random access settings.

[0200] PRACH setting index preamble format N f mod x = y slot number starting symbol number of PRACH slots in a 60 kHz slot N t RA,slot ,N number of time-domain PRACH opportunities (RO) within the PRACH slot dur RA, PRACH Durationxy81A1104,9016282A1107,97132100A21099114101A21090134127A3104,90126128A3107,97116142B1104,92162143B1 107,98132221A1 / B1104,92162222A1 / B1107,98132235A2 / B2104,90134236A2 / B2107,96124251A3 / B3104,90126252A3 / B3107,92126

[0201] Referring to Table 1, how many ROs are defined in each RACH slot for each preamble format (N t RA,slot : The number of time domain PRACH occasions in a PRACH slot), how many OFDM symbols are occupied by the PRACH preamble of each preamble format (N dur RA : The PRACH duration can be known. In addition, since the starting symbol of the first RO can be indicated for each preamble format, information on the point in time from which the RO starts in the corresponding RACH slot can also be provided to the terminal.

[0202] Network Energy Saving (NES) related operations

[0203] 1) On-demand synchronization signal block (SSB) (or SS / PBCH block)

[0204] A method to reduce energy consumption by not transmitting SSB when the base station transmits SSB on a specific cell through the on-demand SSB process and when there is no on-demand SSB process on the cell can be discussed. In the existing NR system, SSB must be transmitted periodically and always for purposes such as time / frequency synchronization or radio resource management (RRM) measurement, so it was difficult to reduce energy consumption even when the base station had no data to receive or send. Considering this, the base station can reduce base station energy consumption by not performing SSB transmission until the on-demand SSB process is involved and then performing SSB transmission. The on-demand SSB process can be triggered by one of the following methods:

[0205] - The terminal requests SSB transmission from the base station by transmitting an uplink signal / channel (e.g., PRACH, PUCCH, PUSCH, SRS in the NR system).

[0206] - Requesting SSB transmission from base station (or TRP) #1 to base station (or TRP) #2 via an interface between base stations (e.g., Xn interface in NR system) or backhaul signaling.

[0207] - Signaling whether SSB transmission is possible for the corresponding Scell ​​through Scell ​​activation / deactivation signaling.

[0208] Considering coexistence with existing NR terminals, it may be limited to on-demand SSB operation for connected mode terminals and SCells. And / or, on-demand SSB operation (for SSB transmission on PCell) considering inactive or idle mode terminals or initially connected terminals may be defined. In addition, carrier aggregation (CA) including the SCell may be applied to both intra-band CA and inter-band CA, and the SSB on the SCell transmitted through the on-demand SSB process may be utilized for functions such as time / frequency synchronization, L1 / L3 measurement, and SCell deactivation at least.

[0209] 2) On-demand system information block 1 (SIB1)

[0210] A method to reduce energy consumption by not transmitting SIB1 for a specific cell when the on-demand SIB1 process is not available can be discussed. In the existing NR system, SIB1 containing system information, random access information, etc. for initial access or idle mode UEs to access a cell must be provided periodically, making it difficult to reduce energy consumption even when the UE has no data to receive or send. Considering this, the UE can reduce energy consumption by not performing SIB1 transmission until the on-demand SIB1 process is involved and then performing SIB1 transmission. The on-demand SIB1 process can trigger SIB1 transmission of the UE when the UE transmits an uplink signal / channel (e.g., PRACH in an NR system). Specifically, the following scenarios can be considered, but are not limited to the following scenarios.

[0211] FIG. 15 illustrates an on-demand SIB1 transmission method to which some examples of the present disclosure may be applied.

[0212] - Scenario 1: When a terminal recognizes that SIB1 is not transmitted on cell#1 by receiving SSB (and / or other downlink signal / channel) from cell#1 as shown in FIG. 15(a), the terminal may trigger SIB1 transmission by transmitting a signal requesting SIB1 (for convenience, the signal is referred to as a wake-up signal (WUS) in this disclosure) based on information provided in the SSB (and / or other downlink signal / channel) and / or predetermined information. The base station that receives the WUS may transmit a specific DL signal / channel on cell#1 in response thereto, and may transmit SIB1 on cell#1 (or without transmitting the DL signal / channel).

[0213] - Scenario 2: As shown in Fig. 15(b), a UE that receives an SSB (and / or other downlink signal / channel such as SIB1) from cell#1 and recognizes that SIB1 is not transmitted on cell#2 may attempt to camp on cell#2. The UE may trigger SIB1 transmission for cell#2 by transmitting a signal (i.e., WUS) requesting SIB1 on cell#1 based on information provided in the received SSB (and / or other downlink signal / channel such as SIB1) and / or predetermined information. The base station that receives the WUS may transmit a specific DL signal / channel (on cell#1 or cell#2) in response thereto, and may transmit SIB1 for cell#2 on cell#1 or cell#2 (or without transmitting the DL signal / channel).

[0214] Scenario 3: As shown in Fig. 15(c), a UE that receives an SSB (and / or other downlink signal / channel such as SIB1) from cell#1 and recognizes that SIB1 is not transmitted on cell#2 may attempt to camp on cell#2. The UE may trigger SIB1 transmission for cell#2 by transmitting a signal requesting SIB1 (i.e., WUS) on cell#2 based on information provided in the received SSB (and / or other downlink signal / channel such as SIB1) and / or predetermined information. The base station that receives the WUS may transmit a specific DL signal / channel (on cell#1 or cell#2) in response thereto, and may transmit SIB1 for cell#2 on cell#1 or cell#2 (or without transmitting the DL signal / channel).

[0215] When multiple cells are involved in on-demand SIB1 operation, such as in Scenario 2 or 3 above, Cell#1 and Cell#2 can be defined as follows.

[0216] - Cell A (=Cell#1): A cell that periodically transmits at least its own SIB1.

[0217] - NES Cell (=Cell#2): A cell that can transmit SIB1 transmission in response to UL WUS from UE.

[0218] That is, Cell A may refer to a cell on which SIB1 information for the corresponding cell is periodically transmitted, and may also be expressed as Cell#1 or an anchor cell. In addition, NES cell may refer to a cell on which SIB1 is provided in response to an uplink WUS from a terminal, and may also be expressed as Cell#2 or a non-anchor cell.

[0219] The way a terminal discovers a cell and knows that the cell is a NES cell (requiring on-demand SIB1 operation) can be at least one or a combination of the following methods:

[0220] - The terminal can recognize that it is a NES cell through SIB and / or WUS configuration information (provided from Cell A).

[0221] - The terminal can recognize that it is an NES cell through information such as the center frequency of the PBCH (physical broadcast channel) / MIB (master information block) / SSB (synchronization signal block) (received from the NES cell).

[0222] - The terminal can recognize that it is a NES cell through DCI information (received from the NES cell). The terminal can receive the DCI in the control resource set (CORESET: control resource set) / search space configured in the PBCH / MIB / SSB (received from the NES cell). In addition, a separate RNTI (radio network temporary identifier) ​​value for the DCI can be set / defined in advance.

[0223] - If a terminal attempts to receive SIB1 of a cell and fails to receive SIB1 for a certain period of time, the terminal can recognize that it is a NES cell.

[0224] Meanwhile, the terminal may be provided with a configuration for an uplink WUS requesting SIB1 for an NES cell through at least one or a combination of the following methods.

[0225] - RRC messages transmitted from Cell A (e.g. SIB1 or other system information blocks, RRC release messages)

[0226] - DCI transmitted on Cell A or NES cell

[0227] - msg2 / msg4 (in a 4-step random access procedure) or msgB (in a 2-step random access procedure) transmitted from Cell A

[0228] - Center frequency of PBCH / MIB / SSB transmitted on NES cell

[0229] - Information predefined / pre-configured in the standard specification in advance

[0230] 3) Adaptive common signal / channel transmission

[0231] Methods for reducing energy consumption by having the base station adjust the transmission of common signals / channels such as SSB, PRACH, and paging can be discussed. While completely disabling SSB can significantly reduce the energy consumption of the base station, the absence of SSB, which performs functions such as time / frequency synchronization or RRM measurement, may not guarantee stable operation for the corresponding cell from the terminal's perspective. Considering this, energy savings at the base station can be achieved by changing the SSB transmission pattern (e.g., transmission period, period per SSB candidate index(es), SSB candidate index(es) transmitted within a transmission period, transmission power, etc.) according to the situation.

[0232] In the case of PRACH resources, since the base station does not know when the UE will transmit the PRACH in the case of contention-based random access, energy consumption may increase because the base station always attempts to receive within the configured PRACH resources. Considering this, energy of the base station can be saved by applying a method of adjusting the amount of PRACH resources (e.g., adjusting the period of PRACH resources, adjusting the amount of resources by pre-configuring PRACH resource sets #1 and #2 and indicating whether to activate only one of the two sets or both sets, or providing the corresponding RACH resource amount uniformly or non-uniformly for each SSB index).

[0233] In the case of paging, paging frames (PF) and / or paging occasions (PO) were previously distributed along the time axis within a discontinuous reception (DRX) cycle (or paging cycle), and the terminal attempted to receive paging at a specific PF / PO derived from a formula based on its ID. If the base station wanted to transmit paging to multiple terminals simultaneously, it may have to wake up frequently and transmit paging. As a method for reducing base station energy consumption due to this, it may be considered to place the PF and / or PO for paging reception as close to the time axis as possible or to place different frequency axis resources within the same time.

[0234] How to set up a random access procedure (or RACH (random access channel) procedure) using WUS

[0235] In the present disclosure, in an on-demand SIB1 technology for network energy saving, a method is proposed for performing an initial access procedure using a wake-up signal (WUS: wake-up signal) when the PRACH preamble (or RACH preamble, message 1) is considered / used.

[0236] Although the present disclosure primarily describes a 4-step random access procedure (i.e., RACH procedure) for the sake of convenience in explaining RACH opportunities, the proposed method of the present disclosure is not limited thereto. That is, if operations similar to the proposed method of the present disclosure are applied to a 2-step RACH procedure, the methods of considering RACH opportunities (or RO or RACH resources, etc.) in the present disclosure can be similarly applied to RACH opportunities and / or PUSCH opportunities in the 2-step RACH procedure.

[0237] The NES RO referred to in the present disclosure may be a set of RACH opportunities established through an additional RACH configuration separate from the legacy RACH configuration. That is, the NES RO may refer to all or some of the SSB beams / indexes used within the cell and ROs where SSB-to-RO mapping is performed.

[0238] For convenience of explanation, in this disclosure, a cell where legacy UEs and NES UEs coexist is referred to as cell A. The base station can provide information necessary for NES cell operation (e.g., settings related to WUS, etc.) through upper layer signaling of cell A (e.g., SIB1, etc.). In addition, in this disclosure, an NES cell may refer to a cell to which only NES UEs are permitted to access.

[0239] Hereinafter, the present disclosure describes the proposed method mainly targeting a system that supports network energy saving features by referring to NES UE and / or NES RO and / or NES cell, but the proposed method described in the present disclosure can also be applied to a system that supports other technologies (e.g., coverage enhancement, wake-up signal, ambient IoT (ambient Internet of Things), duplex enhancement, etc.).

[0240] In this disclosure, ' / ' means 'and', 'or', or 'and / or' depending on the context. In addition, examples of the proposed method described in this disclosure may also be included as one of the implementation methods of this specification, and thus may be regarded as a type of proposed method. In addition, the proposed methods described in this disclosure may be implemented independently, but may also be implemented in the form of a combination (or merge) of some of the proposed methods. Information on whether the proposed methods described in this disclosure are applicable (or information on the rules of the proposed methods) may be notified by the base station to the terminal through a predefined signal (e.g., a physical layer signal or a higher layer signal). In this disclosure, the higher layer may include, for example, one or more of functional layers such as MAC (medium access control), RLC (radio link control), PDCP (packet data convergence protocol), RRC (radio resource control), and SDAP (service data adaptation protocol).

[0241] Below, the method of setting up the RACH procedure using WUS is described.

[0242] For on-demand SIB1 operation, the base station can configure / instruct a wake-up signal (WUS). The terminal can request on-demand SIB1 transmission from the base station by transmitting the WUS configured / instructed by the base station. Here, the PRACH preamble can be considered / used as the WUS. For example, a PRACH used for WUS can be configured separately.

[0243] Accordingly, the present disclosure proposes a method in which, when a terminal transmits a corresponding PRACH preamble (i.e., WUS) to a base station, it also requests the base station to transmit on-demand SIB1, while simultaneously performing a RACH procedure for initial access of the terminal.

[0244] Hereinafter, in the description of the present disclosure, a WUS configuration (i.e., a PRACH configuration) may mean a configuration of PRACH transmission parameters set for a WUS, including at least one of a PRACH preamble format for a PRACH, a time resource for PRACH transmission, a frequency resource for PRACH transmission, a number of preamble repetitions, a maximum number of preamble transmissions, a power ramping step of a PRACH, etc.

[0245] FIG. 16 illustrates a random access procedure between a terminal and a base station according to one embodiment of the present disclosure.

[0246] Referring to FIG. 16, in a specific proposed method of the present disclosure, when the base station configures / instructs the WUS configuration (i.e., the configuration of the PRACH used for WUS), parameters required for the RACH procedure, such as parameters for msg3 PUSCH transmission and / or HARQ-ACK PUCCH transmission for msg4 PDSCH (i.e., PUCCH transmission carrying HARQ-ACK information for msg4 PDSCH), may be configured / instructed together. Here, the WUS configuration may be configured / instructed via SIB1 of cell A (i.e., a cell on which both legacy UEs and / or NES UEs can camp on), or may be predefined in the standard. Alternatively, parameters for msg3 PUSCH transmission and / or HARQ-ACK PUCCH transmission for msg4 PDSCH may be provided in the WUS configuration, or some or all of the parameters may be predefined in the standard. For example, parameters for msg3 PUSCH transmission may include information related to the waveform of msg3 PUSCH, repetition number of msg3 PUSCH, etc. As another example, parameters for HARQ-ACK PUCCH transmission for msg4 PDSCH may include information related to common PUCCH resource set value (i.e., upper layer parameter pucch-ResourceCommon), repetition number, frequency hopping, etc.

[0247] In this way, the base station can set / instruct the parameters required for the RACH procedure together with the WUS configuration. Here, the base station can set the NES terminal to transmit the WUS to cell A or to transmit the WUS to the NES cell. That is, the terminal can be defined to transmit the WUS in cell A and / or the NES cell according to the WUS configuration provided by the base station. If the RACH procedure is started while transmitting the WUS in cell A, the terminal can be set to perform the RACH procedure in cell A until the RACH attempt for the corresponding msg1 preamble is terminated. Similarly, if the RACH procedure is started while transmitting the WUS in the NES cell, the terminal can be set to perform the RACH procedure in the NES cell until the RACH attempt for the corresponding msg1 preamble is terminated.

[0248] Afterwards, the base station that successfully receives the WUS transmitted from the terminal can transmit msg2 RAR to the terminal and can configure the RAR MAC-CE to include scheduling information for msg3 PUSCH through UL grant. Afterwards, the terminal can transmit msg3 PUSCH based on the UL grant information of the RAR and the msg3 transmission related parameters included in the WUS configuration (or defined in advance). The base station that receives msg3 can transmit msg4 PDCCH / PDSCH to the terminal. Afterwards, if the terminal succeeds in contention resolution, the terminal can transmit HARQ-ACK PUCCH (msg5) for msg4 PDSCH based on the information indicated by msg4 PDCCH and the HARQ-ACK PUCCH transmission related parameters for msg4 PDSCH included in the WUS configuration (or defined in advance) and complete the RACH procedure.

[0249] If the UE completes the RACH procedure using WUS in cell A, when handing over to the NES cell thereafter, it may perform a contention-free random access (CFRA) procedure in the NES cell (to newly acquire UL timing advance (TA)), but it may be configured / defined that UL transmission is continued using the UL TA value acquired in cell A without a separate random access procedure (i.e., RACH procedure) (i.e., RACH-less handover (RACH-less HO)).

[0250] Meanwhile, i) if the terminal transmits a WUS and fails to receive a RAR from the base station within the RAR window, or ii) if the terminal receives a RAR and also transmits a msg3 PUSCH but fails to receive a msg4 PDSCH and thus fails to resolve the contention (i.e., in a RACH failure situation), the terminal can operate in two cases depending on whether the on-demand SIB1 requested by the terminal is being transmitted from the NES cell.

[0251] Case 1: It is determined whether the on-demand SIB1 requested by the terminal is being transmitted from the NES cell, and if the on-demand SIB1 has not yet been transmitted from the NES cell, the terminal can be defined to retransmit the WUS to Cell A or the NES cell through power ramping (similar to the existing RACH procedure). An example related to the random access procedure between the terminal / base station is shown in Fig. 17.

[0252] FIG. 17 illustrates a random access procedure between a terminal and a base station according to one embodiment of the present disclosure.

[0253] FIG. 17 illustrates a case where a terminal transmits a WUS (i.e., msg1) for requesting on-demand SIB1 of an NES cell and receives msg2 RAR from a base station in response thereto, but the on-demand SIB1 requested by the terminal is not transmitted from the NES cell.

[0254] In this case, if the UE was performing the RACH procedure using the existing WUS in Cell A, the UE can be configured to continue the RACH procedure using the WUS in Cell A (i.e., retry the RACH procedure). Also, if the UE was performing the RACH procedure using the existing WUS in the NES cell, the UE can be configured to continue the RACH procedure using the WUS in the NES cell (i.e., retry the RACH procedure).

[0255] Here, the PRACH transmission counter and / or power ramping counter used in the RACH procedure using WUS previously can be defined to be used continuously in the subsequent RACH procedure using WUS without being initialized.

[0256] Case 2: It is determined whether the on-demand SIB1 requested by the terminal is being transmitted from the NES cell, and if it is confirmed that the on-demand SIB1 is being transmitted from the NES cell, parameters for a new PRACH configuration and msg3 PUSCH transmission, HARQ-ACK PUCCH transmission for msg4 PDSCH, etc. can be received through the on-demand SIB1. An example related to the random access procedure between the terminal / base station is shown in Fig. 18.

[0257] FIG. 18 and FIG. 19 illustrate a random access procedure between a terminal and a base station according to one embodiment of the present disclosure.

[0258] FIG. 18 and FIG. 19 illustrate a case where a terminal transmits a WUS (i.e., msg1) for requesting on-demand SIB1 of an NES cell, receives msg2 RAR from a base station in response thereto, and also, on-demand SIB1 requested by the terminal is being transmitted from the NES cell.

[0259] FIG. 18 shows an example of a case where a RACH procedure using WUS for requesting on-demand SIB1 of an NES cell is performed in cell A, and FIG. 19 shows an example of a case where a RACH procedure using WUS for requesting on-demand SIB1 of an NES cell is performed in an NES cell.

[0260] Thereafter, the terminal can set to continue the RACH procedure in the NES cell (i.e., attempt the RACH procedure in the NES cell) using parameters related to the RACH procedure provided through the on-demand SIB1 (e.g., parameters for PRACH configuration and msg3 PUSCH transmission, HARQ-ACK PUCCH transmission for msg4 PDSCH, etc.).

[0261] If the UE was performing the RACH procedure using the existing WUS in cell A, the UE may be configured to move to the NES cell and perform the RACH procedure in the NES cell using the RACH procedure-related parameters received through the on-demand SIB1 of the NES cell. In addition, if the UE was performing the RACH procedure using the existing WUS in the NES cell, the UE may be configured to continue performing the RACH procedure in the NES cell using the RACH procedure-related parameters received through the on-demand SIB1 of the NES cell.

[0262] Here, the PRACH transmission counter and / or power ramping counter used in the RACH procedure using WUS previously may be defined to be used continuously in the subsequent RACH procedure without being initialized. Alternatively, the PRACH transmission counter and / or power ramping counter used in the RACH procedure using WUS previously may be defined to start from 0 in the subsequent RACH procedure after being initialized. Alternatively, the base station may set / indicate whether to initialize the PRACH transmission counter and / or power ramping counter via NES cell SIB1 (or cell A SIB1).

[0263] In the proposed method described above, the operation of transmitting WUS in NES cells can be applied when the base station sets / instructs dedicated WUS settings for each NES cell.

[0264] Meanwhile, when the base station configures / instructs the WUS configuration to the terminal, it may also configure / instruct the terminal with parameters for msg3 PUSCH transmission, but may not configure / instruct the terminal with parameters for HARQ-ACK PUCCH transmission for msg4 PDSCH. In this case, the terminal may configure / instruct the terminal with information about parameters for HARQ-ACK PUCCH transmission for msg4 PDSCH through the msg4 PDSCH payload, or may configure / instruct the terminal with DCI format 1_0 having a CRC (cyclic redundancy check) scrambled by the TC-RNTI (or C-RNTI) that schedules the msg4 PDSCH. In other words, the base station may configure / instruct the UE through the msg4 PDSCH payload for parameters for HARQ-ACK PUCCH transmission for msg4 PDSCH (e.g., common PUCCH resource set value (i.e., pucch-ResourceCommon), repetition count, hopping-related information), or may configure / instruct the UE through DCI format 1_0 having a CRC (cyclic redundancy check) scrambled by the TC-RNTI (or C-RNTI) that schedules the msg4 PDSCH. In addition, in this case, considering the time required for the terminal to obtain parameter information for HARQ-ACK PUCCH transmission for Msg4 PDSCH through the msg4 PDSCH payload, a specific offset value (e.g., X slot(s) or Y ms) can be set / defined for the terminal to understand / regard by adding a value indicated by DCI format 1_0 (i.e., HARQ feedback timing indicator, e.g., K1) with CRC (cyclic redundancy check) scrambled by TC-RNTI (or C-RNTI), which is the DCI scheduling Msg4 PDSCH.

[0265] In addition, when the base station configures / instructs the WUS configuration, it may also configure / instruct the UE with parameters for msg3 PUSCH transmission, but may not configure / instruct the UE with parameters for HARQ-ACK PUCCH transmission for msg4 PDSCH. In this case, the base station may configure / instruct parameters for HARQ-ACK PUCCH transmission for msg4 PDSCH (e.g., common PUCCH resource set value (i.e., pucch-ResourceCommon), repetition count, hopping-related information), etc., through the on-demand SIB1 of the NES cell. In this way, when parameters for HARQ-ACK PUCCH transmission for msg4 PDSCH are transmitted through the on-demand SIB1 of the NES cell, the UE can operate as follows: The UE can transmit msg3 PUSCH based on the RAR UL grant configured / instructed by the base station and the parameters for msg3 PUSCH transmission included in the WUS configuration (or defined in advance). Afterwards, the UE can receive parameters for HARQ-ACK PUCCH transmission for msg4 PDSCH by receiving the on-demand SIB1 of the NES cell. Afterwards, the UE can transmit HARQ-ACK PUCCH for msg4 PDSCH based on the parameters and the information indicated through the PDCCH that schedules the msg4 PDSCH (if reception for msg4 PDSCH is successful). Here, it is necessary to additionally define the point in time when the contention resolution timer (CR timer) starts.For example, in the above case (previously, the UE starts the CR timer immediately after transmitting Msg3 PUSCH), considering the time required for the UE to acquire parameter information for HARQ-ACK PUCCH transmission for msg4 PDSCH through SIB1, the CR timer can be defined to start after the time point at which the UE receives the on-demand SIB1 of the NES cell (for example, the point at which the transmission of the last (or first) OFDM symbol of the last (or first) frame in which the on-demand SIB1 is transmitted ends (or the point at which the transmission of the OFDM symbol starts)) or after a specific time set / indicated by the base station from that point. As a result, it can be defined that the UE understands / considers the point in time when the CR timer starts as the point in time when the on-demand SIB1 of the NES cell is received (e.g., the point in time when the transmission of the last (or the first) OFDM symbol of the last (or the first) frame in which the on-demand SIB1 is transmitted ends (or the point in time when the transmission of the OFDM symbol starts)), or as a time after a specific time set / indicated by the base station from that point in time. In addition, considering the time required for the UE to obtain parameter information for HARQ-ACK PUCCH transmission for msg4 PDSCH through the on-demand SIB1 of the NES cell, the UE can determine the point in time when the value indicated in the DCI format 1_0 with the CRC (cyclic redundancy check) scrambled by the TC-RNTI (or C-RNTI), which is the DCI scheduling the Msg4 PDSCH, is applied (i.e., the HARQ feedback timing indicator, e.g., K1).That is, the time point at which the value indicated in DCI format 1_0 with CRC scrambled by TC-RNTI (or C-RNTI) (i.e., HARQ feedback timing indicator, e.g., K1) is applied can be set to be applied at the time point of receiving on-demand SIB1 of the NES cell (e.g., the point at which the transmission of the last (or first) OFDM symbol of the last (or first) frame in which on-demand SIB1 is transmitted ends (or the point at which the transmission of the OFDM symbol starts)).

[0266] Also, when a slot containing CORESET#0 corresponding to the last SSB index (among the time domain positions of SS blocks transmitted within a half frame having SS / PBCH blocks set by the RRC parameter ssb-PositionsInBurst) or a PDSCH reception slot scheduled with a DCI having a CRC scrambled with SI-RNTI in the corresponding CORESET#0 is defined as slot n, the CR timer may be configured / defined to start from slot n (or slot n+k, where the value of k may be a predefined or configured value). Alternatively, the slot n (or slot n+k) may be configured / defined to be the start slot of a value indicated by DCI format 1_0 having a CRC scrambled by TC-RNTI (or C-RNTI), which is a DCI scheduling Msg4 PDSCH (i.e., a HARQ feedback timing indicator, for example, K1).

[0267] FIG. 20 illustrates the operation of a UE for transmitting and receiving system information according to one embodiment of the present disclosure.

[0268] FIG. 20 illustrates the operation of a UE based on the proposed methods in the embodiments described above. The example in FIG. 20 is provided for convenience of explanation and does not limit the scope of the present disclosure. Some of the step(s) illustrated in FIG. 20 may be omitted depending on the situation and / or setting. Furthermore, the UE in FIG. 20 is merely an example and may be implemented as the device illustrated in FIG. 3. For example, the processor (202) in FIG. 3 may control the transmission and reception of channels / signals / data / information, etc. using the transceiver (206), and may also control the storage of transmitted or received channels / signals / data / information, etc. in the memory (204).

[0269] Additionally, the operation of FIG. 20 may be processed by one or more processors (202) of FIG. 3. Additionally, the operation of FIG. 20 may be stored in a memory (e.g., one or more memories (204) of FIG. 3) in the form of a command / program (e.g., an instruction, an executable code) for driving at least one processor (e.g., 202) of FIG. 3.

[0270] Referring to FIG. 20, the UE receives configuration information in the first cell from the base station (S2001).

[0271] Here, the configuration information may include information about one or more parameters for transmission of a PRACH (i.e., WUS) for the UE to request system information (e.g., on-demand SIB1) for the second cell.

[0272] Additionally, the configuration information may include information about one or more parameters for transmission of a PUSCH scheduled by a random access response and information about one or more parameters for transmission of a PUCCH carrying HARQ-ACK information for a PDSCH received in response to transmission of the PUSCH.

[0273] Additionally, the configuration information may include information about one or more parameters for transmission of a PUSCH scheduled by a random access response. That is, information about one or more parameters for transmission of a PUCCH carrying HARQ-ACK information for a PDSCH received in response to transmission of the PUSCH may not be included.

[0274] The UE transmits a PRACH to the base station to request system information for the second cell based on the configuration information (S2002).

[0275] Here, based on the transmission of the PRACH, a first random access procedure for the UE can be initiated.

[0276] Based on the above configuration information, the PRACH may be transmitted from the first cell or the second cell to request the system information for the second cell, and the first random access procedure may be initiated for the cell to which the PRACH is transmitted. Here, based on the UE handing over to the second cell after the first random access procedure is completed for the first cell, uplink transmission may be performed in the second cell using a timing advance value acquired in the first cell.

[0277] Additionally, based on the failure of the first random access procedure to be completed successfully, a second random access procedure may be initiated subsequent to the first random access procedure, depending on whether the system information for the second cell requested by the UE is transmitted in the second cell.

[0278] For example, based on the fact that the system information for the second cell is not transmitted, the second random access procedure may be initiated in the cell in which the first random access procedure was performed using the PRACH. In this case, the PRACH transmission counter and / or power ramping counter used in the first random access procedure may not be initialized and may be subsequently used in the second random access procedure. As another example, based on the fact that the system information for the second cell is transmitted, the second random access procedure may be initiated in the second cell based on the system information for the second cell. In this case, the PRACH transmission counter and / or power ramping counter used in the first random access procedure may not be initialized and may be subsequently used in the second random access procedure.

[0279] Information about one or more parameters for transmission of a PUCCH carrying HARQ-ACK information for a PDSCH received in response to transmission of the PUSCH may be transmitted in the PDSCH or in downlink control information scheduling the PDSCH. Here, an offset value may be added to a value indicated in the downlink control information scheduling the PDSCH to determine the transmission timing of the PUCCH.

[0280] In addition, information about one or more parameters for transmission of a PUCCH carrying HARQ-ACK information for a PDSCH received in response to transmission of the PUSCH may be transmitted in the system information for the second cell. Here, the contention resolution timer for the first random access procedure may be started at a first time point at which the system information for the second cell is received or after a predetermined time from the first time point. In addition, a value indicated in the downlink control information for scheduling the PDSCH may be applied from the time point at which the system information for the second cell is received.

[0281] FIG. 21 illustrates the operation of a base station for a method of transmitting and receiving system information according to one embodiment of the present disclosure.

[0282] FIG. 21 illustrates the operation of a base station based on the proposed methods in the embodiments described above. The example in FIG. 21 is provided for convenience of explanation and does not limit the scope of the present disclosure. Some of the step(s) illustrated in FIG. 21 may be omitted depending on circumstances and / or settings. In addition, the base station in FIG. 21 is merely an example and may be implemented with the device illustrated in FIG. 3. For example, the processor (202) in FIG. 3 may control the transceiver (206) to transmit and receive channels / signals / data / information, etc., and may also control the storage of transmitted or received channels / signals / data / information, etc., in the memory (204).

[0283] Additionally, the operation of FIG. 21 may be processed by one or more processors (202) of FIG. 3. Additionally, the operation of FIG. 21 may be stored in a memory (e.g., one or more memories (204) of FIG. 3) in the form of a command / program (e.g., an instruction, an executable code) for driving at least one processor (e.g., 202) of FIG. 3.

[0284] Referring to FIG. 21, the base station transmits configuration information in the first cell to the UE (S2101).

[0285] Here, the configuration information may include information about one or more parameters for transmission of a PRACH (i.e., WUS) for the UE to request system information (e.g., on-demand SIB1) for the second cell.

[0286] Additionally, the configuration information may include information about one or more parameters for transmission of a PUSCH scheduled by a random access response and information about one or more parameters for transmission of a PUCCH carrying HARQ-ACK information for a PDSCH received in response to transmission of the PUSCH.

[0287] Additionally, the configuration information may include information about one or more parameters for transmission of a PUSCH scheduled by a random access response. That is, information about one or more parameters for transmission of a PUCCH carrying HARQ-ACK information for a PDSCH received in response to transmission of the PUSCH may not be included.

[0288] The base station receives a PRACH for requesting system information for a second cell based on configuration information from the UE (S2102).

[0289] Here, based on the transmission of the PRACH, a first random access procedure for the UE can be initiated.

[0290] Based on the above configuration information, the PRACH may be transmitted from the first cell or the second cell to request the system information for the second cell, and the first random access procedure may be initiated for the cell to which the PRACH is transmitted. Here, based on the UE handing over to the second cell after the first random access procedure is completed for the first cell, uplink transmission may be performed in the second cell using a timing advance value acquired in the first cell.

[0291] Additionally, based on the failure of the first random access procedure to be completed successfully, a second random access procedure may be initiated subsequent to the first random access procedure, depending on whether the system information for the second cell requested by the UE is transmitted in the second cell.

[0292] For example, based on the fact that the system information for the second cell is not transmitted, the second random access procedure may be initiated in the cell in which the first random access procedure was performed using the PRACH. In this case, the PRACH transmission counter and / or power ramping counter used in the first random access procedure may not be initialized and may be subsequently used in the second random access procedure. As another example, based on the fact that the system information for the second cell is transmitted, the second random access procedure may be initiated in the second cell based on the system information for the second cell. In this case, the PRACH transmission counter and / or power ramping counter used in the first random access procedure may not be initialized and may be subsequently used in the second random access procedure.

[0293] Information about one or more parameters for transmission of a PUCCH carrying HARQ-ACK information for a PDSCH received in response to transmission of the PUSCH may be transmitted in the PDSCH or in downlink control information scheduling the PDSCH. Here, an offset value may be added to a value indicated in the downlink control information scheduling the PDSCH to determine the transmission timing of the PUCCH.

[0294] In addition, information about one or more parameters for transmission of a PUCCH carrying HARQ-ACK information for a PDSCH received in response to transmission of the PUSCH may be transmitted in the system information for the second cell. Here, the contention resolution timer for the first random access procedure may be started at a first time point at which the system information for the second cell is received or after a predetermined time from the first time point. In addition, a value indicated in the downlink control information for scheduling the PDSCH may be applied from the time point at which the system information for the second cell is received.

[0295] 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.

[0296] 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.

[0297] 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.

[0298] 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.

[0299] 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 configuration information from a base station in a first cell by a user equipment (UE), wherein the configuration information includes information on one or more parameters for transmission of a physical random access channel (PRACH) for requesting system information for a second cell by the UE; and A step of transmitting, by the UE, the PRACH for requesting the system information for the second cell to the base station based on the configuration information, A method in which a first random access procedure for the UE is initiated based on transmission of the PRACH.

2. In paragraph 1, A method wherein the above configuration information includes information about one or more parameters for transmission of a physical uplink shared channel (PUSCH) scheduled by a random access response and information about one or more parameters for transmission of a physical uplink control channel (PUCCH) carrying hybrid automatic repeat request-acknowledgement (HARQ-ACK) information for a physical shared channel (PDSCH) received in response to transmission of the PUSCH.

3. In paragraph 2, The PRACH is transmitted from the first cell or the second cell to request the system information for the second cell based on the setting information, A method in which the first random access procedure is initiated for a cell in which the PRACH is transmitted.

4. In paragraph 3, A method in which uplink transmission is performed in the second cell using a timing advance value obtained in the first cell based on the UE handing over to the second cell after the first random access procedure is completed for the first cell.

5. In paragraph 3, A method in which a second random access procedure is initiated subsequent to the first random access procedure based on whether the system information for the second cell requested by the UE is transmitted in the second cell based on the failure of the first random access procedure to be completed successfully.

6. In paragraph 5, A method in which the second random access procedure is initiated in a cell in which the first random access procedure was performed using the PRACH based on the fact that the system information for the second cell is not transmitted.

7. In paragraph 6, A method in which the PRACH transmission counter and / or power ramping counter used in the first random access procedure are not initialized and are subsequently used in the second random access procedure.

8. In paragraph 5, A method wherein the second random access procedure is initiated in the second cell based on the system information for the second cell, based on the system information for the second cell.

9. In paragraph 8, A method in which the PRACH transmission counter and / or power ramping counter used in the first random access procedure are not initialized and are subsequently used in the second random access procedure.

10. In paragraph 1, A method wherein the above configuration information includes information on one or more parameters for transmission of a PUSCH scheduled by a random access response.

11. In paragraph 10, A method wherein information about one or more parameters for transmission of a PUCCH carrying HARQ-ACK information for a PDSCH received in response to transmission of the PUSCH is transmitted in the PDSCH or in downlink control information scheduling the PDSCH.

12. In paragraph 11, A method in which an offset value is added to a value indicated in downlink control information scheduling the PDSCH to determine the transmission timing of the PUCCH.

13. In paragraph 10, A method in which information about one or more parameters for transmission of a PUCCH carrying HARQ-ACK information for a PDSCH received in response to transmission of the PUSCH is transmitted in the system information for the second cell.

14. In paragraph 13, A method wherein the contention resolution timer for the first random access procedure is started at a first time point when the system information for the second cell is received or after a predetermined time from the first time point.

15. In paragraph 13, A method in which the value indicated in the downlink control information for scheduling the PDSCH is applied from the time when the system information for the second cell is received.

16. User equipment (UE): One or more transceivers for transmitting and receiving wireless signals; and comprising one or more processors controlling one or more of the above transceivers, One or more of the above processors: Receive configuration information from a base station in a first cell, wherein the configuration information includes information on one or more parameters for transmission of a physical random access channel (PRACH) used by the UE to request system information for a second cell; and It is configured to transmit the PRACH to request the system information for the second cell to the base station based on the above setting information, A user device, wherein a first random access procedure for the UE is initiated based on transmission of the PRACH.

17. One or more non-transitory computer-readable media storing one or more instructions, The one or more instructions are executed by one or more processors so that the user device: Receive configuration information from a base station in a first cell, wherein the configuration information includes information on one or more parameters for transmission of a physical random access channel (PRACH) used by the UE to request system information for a second cell; and Control to transmit the PRACH to request the system information for the second cell to the base station based on the above setting information, A computer-readable medium in which a first random access procedure for the UE is initiated based on transmission of the PRACH.

18. In a processing device configured to control a user device, the processing device: one or more processors; and One or more computer memories operatively connected to said one or more processors and storing instructions for performing operations based on execution by said one or more processors, The above actions are: A step of receiving configuration information from a base station in a first cell, wherein the configuration information includes information on one or more parameters for transmission of a physical random access channel (PRACH) used by the UE to request system information for a second cell; and A step of transmitting the PRACH to request the system information for the second cell to the base station based on the setting information, A processing device, wherein a first random access procedure for the UE is initiated based on transmission of the PRACH.

19. A step of transmitting configuration information from a base station to a user equipment (UE) in a first cell, wherein the configuration information includes information on one or more parameters for transmission of a physical random access channel (PRACH) for the UE to request system information for a second cell; and A step of receiving, by the base station, the PRACH for requesting the system information for the second cell based on the configuration information from the user device, A method in which a first random access procedure for the UE is initiated based on transmission of the PRACH.

20. The base station: One or more transceivers for transmitting and receiving wireless signals; and comprising one or more processors controlling one or more of the above transceivers, One or more of the above processors: Transmitting configuration information to a user equipment (UE) in a first cell, wherein the configuration information includes information on one or more parameters for transmission of a physical random access channel (PRACH) for the UE to request system information for a second cell; and It is configured to receive the PRACH for requesting the system information for the second cell from the user device based on the above setting information, A base station, wherein a first random access procedure for the UE is initiated based on transmission of the PRACH.

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