Method for communicating in wireless communication system and device therefor

Abstract

A device according to various embodiments may: receive a first SSB including at least one synchronization signal and a PBCH; receive an SIB on the basis of a satellite identification value included in the first SSB; and perform a RACH procedure with a base station on the basis of the first SSB and the SIB.

Description

Method for performing communication in a wireless communication system and device for the same

[0001] This invention relates to a method for transmitting and receiving signals between a terminal and a base station in a wireless communication system and an apparatus for doing so.

[0002] A wireless communication system is a multiple access system that supports communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access), and MC-FDMA (multi carrier frequency division multiple access) systems.

[0003] Sidelink (SL) refers to a communication method in which User Equipment (UE) establishes a direct link to directly exchange voice or data between terminals without passing through a Base Station (BS). SL is being considered as a solution to address the burden on base stations caused by rapidly increasing data traffic.

[0004] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-equipped objects through wired or wireless communication. V2X can be classified into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through PC5 interfaces and / or Uu interfaces.

[0005] Meanwhile, as more communication devices require larger communication capacities, the need for improved mobile broadband communication compared to existing Radio Access Technology (RAT) is emerging. Accordingly, communication systems considering services or terminals sensitive to reliability and latency are being discussed; next-generation radio access technology that incorporates improved mobile broadband communication, Massive Machine Type Communication (MTC), and Ultra-Reliable and Low Latency Communication (URLC) can be referred to as new radio access technology (new RAT) or new radio (NR). Vehicle-to-everything (V2X) communication can also be supported in NR.

[0006] Figure 1 is a diagram illustrating a comparison between V2X communication based on RAT prior to NR and V2X communication based on NR.

[0007] Regarding V2X communication, prior to NR, RATs mainly discussed methods for providing safety services based on V2X messages such as BSM (Basic Safety Message), CAM (Cooperative Awareness Message), and DENM (Decentralized Environmental Notification Message). V2X messages can include location information, dynamic information, attribute information, etc. For example, a terminal can transmit a CAM of the periodic message type and / or a DENM of the event-triggered message type to another terminal.

[0008] For example, the CAM may include basic vehicle information such as dynamic state information of the vehicle, such as direction and speed, static data of the vehicle, such as dimensions, external lighting conditions, and route history. For example, a terminal may broadcast the CAM, and the latency of the CAM may be less than 100ms. For example, in the event of an unexpected situation such as a vehicle breakdown or accident, the terminal may generate a DENM and transmit it to other terminals. For example, all vehicles within the transmission range of the terminal may receive the CAM and / or DENM. In this case, the DENM may have a higher priority than the CAM.

[0009] Since then, regarding V2X communication, various V2X scenarios have been presented in NR. For example, various V2X scenarios may include vehicle platooning, advanced driving, extended sensors, remote driving, etc.

[0010] For example, based on vehicle platooning, vehicles can dynamically form groups and move together. For example, to perform platoon operations based on vehicle platooning, vehicles belonging to said group can receive periodic data from the lead vehicle. For example, vehicles belonging to said group can use said periodic data to reduce or increase the distance between vehicles.

[0011] For example, based on enhanced driving, vehicles can be semi-automated or fully automated. For example, each vehicle can adjust trajectories or maneuvers based on data acquired from local sensors of nearby vehicles and / or nearby logical entities. Additionally, for example, each vehicle can mutually share driving intentions with nearby vehicles.

[0012] For example, based on extended sensors, raw data or processed data or live video data acquired through local sensors can be exchanged between vehicles, logical entities, pedestrian terminals and / or V2X application servers. Thus, for example, a vehicle can perceive an environment that is enhanced compared to the environment it can detect using its own sensors.

[0013] For example, based on remote driving, a remote driver or V2X application can operate or control a remote vehicle for a person unable to drive or for a remote vehicle located in a dangerous environment. For example, in cases where the route is predictable, such as in public transportation, cloud computing-based driving can be used for the operation or control of the remote vehicle. Additionally, access to a cloud-based back-end service platform, for example, can be considered for remote driving.

[0014] Meanwhile, methods to specify service requirements for various V2X scenarios, such as vehicle platooning, enhanced driving, extended sensors, and remote driving, are being discussed in NR-based V2X communication.

[0015] The technical problem that the present invention aims to solve is to provide a method for transmitting and receiving signals more accurately and efficiently.

[0016] The technical problems are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0017] A method by a UE (User Equipment) according to one aspect comprises the steps of: receiving a first SSB (Synchronization Signal Block) from a base station including at least one synchronization signal and a PBCH (physical broadcast channel); receiving a SIB (System Information Block) based on the first SSB; and performing a RACH (Random Access Channel) procedure with the base station based on the first SSB and the SIB, wherein, based on the first SSB being received through a NTN (Non-Terrestrial Network), the UE obtains a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN from the first SSB, and the SIB may be received based on the cell ID and the first satellite identification value.

[0018] Alternatively, the UE determines a scramble initial value associated with the SIB based on the cell ID and the first satellite identification value, and the SIB can be decoded based on the scramble initial value.

[0019] Alternatively, the scramble initial value may be determined based on the value obtained by adding the first satellite identification value to the cell ID.

[0020] Alternatively, the first satellite identification value may be included in the PBCH.

[0021] Alternatively, the above SIB may be SIB19 containing satellite orbit information for the NTN corresponding to the above first satellite identification value.

[0022] Alternatively, the UE may determine a TA (timing advance) value related to the RACH procedure based on the satellite orbit information.

[0023] Alternatively, the above PBCH may further include information regarding a synchronization raster for receiving a second SSB associated with a second satellite identification value.

[0024] Alternatively, the method further includes the step of receiving configuration information including index values ​​for synchronization rasters of a plurality of satellites from the base station, wherein the PBCH may include an index value among the index values ​​corresponding to a synchronization raster for receiving the second SSB.

[0025] Alternatively, the UE may receive multiple SSBs corresponding to each of the multiple satellites from the base station.

[0026] According to another aspect, at least one non-transient computer-readable recording medium comprises instructions for performing operations when executed by at least one processor, said operations include receiving a first Synchronization Signal Block (SSB) from a base station, which includes at least one synchronization signal and a Physical Broadcast Channel (PBCH); receiving a System Information Block (SIB) based on said first SSB; and performing a Random Access Channel (RACH) procedure with said base station based on said first SSB and said SIB, and based on said first SSB being received through a Non-Terrestrial Network (NTN), said first SSB includes a cell ID (identifier) ​​for said base station and a first satellite identification value associated with said NTN, and said SIB may be received based on said cell ID and said first satellite identification value.

[0027] According to another aspect, a UE (User Equipment) includes an RF (Radio Frequency) transceiver; and a processor connected to the RF transceiver, wherein the processor controls the RF transceiver to receive a first SSB (Synchronization Signal Block) from a base station comprising at least one synchronization signal and a PBCH (physical broadcast channel), receives a SIB (System Information Block) based on the first SSB, performs a RACH (Random Access Channel) procedure with the base station based on the first SSB and the SIB, and, based on the first SSB being received through a NTN (Non-Terrestrial Network), the first SSB includes a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and the SIB may be received based on the cell ID and the first satellite identification value.

[0028] According to another aspect, a processing device controlling a UE (User Equipment) comprises at least one processor; and at least one memory connected to the at least one processor and storing instructions that perform operations when executed by the at least one processor, wherein the operations include receiving a first SSB (Synchronization Signal Block) comprising at least one synchronization signal and a PBCH (physical broadcast channel) from a base station; receiving a SIB (System Information Block) based on the first SSB; and performing a RACH (Random Access Channel) procedure with the base station based on the first SSB and the SIB, wherein, based on the first SSB being received through a NTN (Non-Terrestrial Network), the first SSB includes a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and the SIB may be received based on the cell ID and the first satellite identification value.

[0029] A method by a base station according to another aspect comprises the steps of: transmitting a first SSB (Synchronization Signal Block) comprising at least one synchronization signal and a PBCH (physical broadcast channel); transmitting a SIB (System Information Block) based on the first SSB; and performing a RACH (Random Access Channel) procedure with a UE (user equipment) based on the first SSB and the SIB, wherein the first SSB is transmitted through a NTN (Non-Terrestrial Network), the first SSB includes a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and the SIB may be transmitted based on the cell ID and the first satellite identification value.

[0030] According to another aspect, a base station comprises a Radio Frequency (RF) transceiver; and a processor connected to the RF transceiver, wherein the processor controls the RF transceiver to transmit a Synchronization Signal Block (SSB) comprising at least one synchronization signal and a Physical Broadcast Channel (PBCH), transmits a System Information Block (SIB) based on the first SSB, performs a Random Access Channel (RACH) procedure with a User Equipment (UE) based on the first SSB and the SIB, and wherein the first SSB is transmitted through a Non-Terrestrial Network (NTN), the first SSB comprises a Cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and the SIB may be transmitted based on the Cell ID and the first satellite identification value.

[0031] According to one embodiment, signals can be transmitted and received more accurately and efficiently in a wireless communication system. For example, even in an environment where a base station transmits an SSB corresponding to each satellite through each of a plurality of satellites, a UE can effectively select and receive the SIB for the satellite corresponding to each SSB through the satellite identification value included in the SSB.

[0032] The effects obtainable from various embodiments are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below.

[0033] The drawings attached to this specification are intended to provide an understanding of the present invention, to illustrate various embodiments of the invention, and to explain the principles of the invention together with the description in the specification.

[0034] Figure 1 is a diagram illustrating a comparison between V2X communication based on RAT prior to NR and V2X communication based on NR.

[0035] Figure 2 shows the structure of an LTE system.

[0036] Figure 3 shows the structure of the NR system.

[0037] Figure 4 shows the structure of a wireless frame of NR.

[0038] Figure 5 shows the slot structure of an NR frame.

[0039] FIG. 6 shows a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure.

[0040] FIG. 7 shows an electromagnetic spectrum according to one embodiment of the present disclosure.

[0041] Figure 8 shows the radio protocol architecture for SL communication.

[0042] Figure 9 shows a terminal performing V2X or SL communication.

[0043] Figure 10 shows a resource unit for V2X or SL communication.

[0044] FIG. 11 shows an example of a BWP according to one embodiment of the present disclosure.

[0045] FIG. 12 illustrates a procedure in which a terminal performs V2X or SL communication according to a resource allocation mode, according to one embodiment of the present disclosure.

[0046] FIG. 13 shows an example of a general NTN scenario based on a transparent payload or a regenerated payload according to one embodiment.

[0047] Figures 14 and 15 are drawings for explaining the coverage of NTN.

[0048] Figures 16 and 17 are diagrams illustrating TN and NTN multiple connection scenarios.

[0049] FIG. 18 is a diagram illustrating a method of connecting a UE and a base station through at least one satellite.

[0050] FIG. 19 is a diagram for explaining the structure of an SSB, and FIG. 20 is a diagram for explaining the relationship between SSBs and SIBs received through multiple satellites.

[0051] Figure 21 is a diagram illustrating a method for searching for a synchronization raster for another satellite based on the synchronization of a reference satellite.

[0052] FIG. 22 is a diagram illustrating a method for a UE to perform an initial connection with a base station.

[0053] Figure 23 is a flowchart illustrating how a base station provides satellite-specific SSB and satellite-specific SIB transmissions.

[0054] FIG. 24 illustrates a communication system to which the present invention is applied.

[0055] FIG. 25 illustrates a wireless device that can be applied to the present invention.

[0056] FIG. 26 illustrates another example of a wireless device to which the present invention applies. The wireless device may be implemented in various forms depending on the use-example / service.

[0057] FIG. 27 illustrates a vehicle or autonomous vehicle to which the present invention is applied.

[0058] A wireless communication system is a multiple access system that supports communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access), and MC-FDMA (multi carrier frequency division multiple access) systems.

[0059] Sidelink refers to a communication method in which User Equipment (UE) establishes a direct link to directly exchange voice or data between terminals without passing through a Base Station (BS). Sidelink is being considered as a solution to address the burden on base stations caused by rapidly increasing data traffic.

[0060] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-equipped objects through wired or wireless communication. V2X can be classified into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through PC5 interfaces and / or Uu interfaces.

[0061] Meanwhile, as more communication devices require larger communication capacities, the need for improved mobile broadband communication compared to existing Radio Access Technology (RAT) is emerging. Accordingly, communication systems considering services or terminals sensitive to reliability and latency are being discussed; next-generation radio access technology that incorporates improved mobile broadband communication, Massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) can be referred to as new radio access technology (new RAT) or new radio (NR). Vehicle-to-everything (V2X) communication can also be supported in NR.

[0062] The following technologies 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 using wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented using wireless technologies such as GSM (global system for mobile communications), GPRS (general packet radio service), and EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented using wireless technologies such as IEEE (institute of electrical and electronics engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e. UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is part of E-UMTS (evolved UMTS) which uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink.LTE-A (advanced) is an evolution of 3GPP LTE.

[0063] 5G NR is a successor technology to LTE-A and is a new clean-slate type mobile communication system with characteristics such as high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, ranging from low frequency bands below 1 GHz to mid-frequency bands from 1 GHz to 10 GHz, and high frequency (millimeter wave) bands above 24 GHz.

[0064] For clarity of explanation, the description focuses on LTE-A or 5G NR, but the technical concept of the embodiment(s) is not limited thereto.

[0065] Figure 2 shows the structure of an applicable LTE system. This can be called an E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network), or an LTE (Long Term Evolution) / LTE-A system.

[0066] Referring to FIG. 2, the E-UTRAN includes a base station (20; Base Station, BS) that provides a control plane and a user plane to a terminal (10). The terminal (10) may be fixed or mobile and may be referred to by other terms such as MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), MT (Mobile Terminal), or Wireless Device. The base station (20) refers to a fixed station that communicates with the terminal (10) and may be referred to by other terms such as eNB (evolved-NodeB), BTS (Base Transceiver System), or Access Point.

[0067] Base stations (20) can be connected to each other through an X2 interface. The base station (20) is connected to the EPC (Evolved Packet Core, 30) through the S1 interface, more specifically to the MME (Mobility Management Entity) through the S1-MME and to the S-GW (Serving Gateway) through the S1-U.

[0068] The EPC (30) consists of an MME, an S-GW, and a P-GW (Packet Data Network-Gateway). The MME holds information regarding the terminal's connection information or capabilities, and this information is primarily used for managing the terminal's mobility. The S-GW is a gateway with an E-UTRAN as its endpoint, and the P-GW is a gateway with a PDN as its endpoint.

[0069] The layers of the Radio Interface Protocol between a terminal and a network can be classified into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) based on the lower three layers of the Open System Interconnection (OSI) model, which is widely known in communication systems. Among these, the Physical Layer, belonging to Layer 1, provides Information Transfer Services using a physical channel, while the Radio Resource Control (RRC) layer, located at Layer 3, performs the role of controlling radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0070] Figure 3 shows the structure of the NR system.

[0071] Referring to FIG. 3, the NG-RAN may include gNBs and / or eNBs that provide user plane and control plane protocol termination to terminals. FIG. 7 illustrates a case where only gNBs are included. The gNBs and eNBs are connected to each other via Xn interfaces. The gNBs and eNBs are connected to the 5G Core Network (5GC) via NG interfaces. More specifically, they are connected to the access and mobility management function (AMF) via NG-C interfaces and to the user plane function (UPF) via NG-U interfaces.

[0072] Figure 4 shows the structure of a wireless frame of NR.

[0073] Referring to FIG. 4, radio frames can be used for uplink and downlink transmission in NR. The radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (HF). A half-frame may contain five 1 ms subframes (SF). A subframe may be divided into one or more slots, and the number of slots within a subframe may be determined by the subcarrier spacing (SCS). Each slot may contain 12 or 14 OFDM(A) symbols according to the cyclic prefix (CP).

[0074] When normal CP is used, each slot may contain 14 symbols. When extended CP is used, each slot may contain 12 symbols. Here, the symbols may include OFDM symbols (or CP-OFDM symbols) and SC-FDMA (Single Carrier - FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0075] Table 1 below shows the number of symbols per slot ((N) according to the SCS setting (u) when normal CP is used. slot symb ), number of slots per frame((N frame,u slot ) and the number of slots per subframe((N subframe,u slot ) exemplifies.

[0076] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 15KHz (u=0)1410130KHz (u=1)1420260KHz (u=2)14404120KHz (u=3)14808240KHz (u=4)1416016

[0077] Table 2 shows the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to the SCS when an extended CP is used.

[0078] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0079] In an NR system, the OFDM(A) numerology (e.g., SCS, CP length, etc.) can be configured differently among multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., subframe, slot, or TTI) (collectively referred to as TU (Time Unit) for convenience) composed of the same number of symbols can be configured differently among the merged cells.

[0080] In NR, multiple numerologies or SCSs may be supported to support various 5G services. For example, if the SCS is 15 kHz, a wide area in traditional cellular bands may be supported, and if the SCS is 30 kHz / 60 kHz, dense-urban, lower latency, and wider carrier bandwidth may be supported. If the SCS is 60 kHz or higher, a bandwidth greater than 24.25 GHz may be supported to overcome phase noise.

[0081] The NR frequency band can be defined by two types of frequency ranges. The two types of frequency ranges may be FR1 and FR2. The numerical values ​​of the frequency ranges may change, for example, as shown in Table 3 below. Among the frequency ranges used in an NR system, FR1 may mean "sub 6GHz range" and FR2 may mean "above 6GHz range" and may be referred to as millimeter wave (mmW).

[0082] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0083] As described above, the numerical value of the frequency range of the NR system may change. For example, FR1 may include a band of 410 MHz to 7125 MHz as shown in Table 4 below. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher. For example, the frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, for example, for communication for vehicles (e.g., autonomous driving).

[0084] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0085] Figure 5 shows the slot structure of an NR frame.

[0086] Referring to FIG. 5, a slot contains multiple symbols in the time domain. For example, in the case of a normal CP, one slot may contain 14 symbols, but in the case of an extended CP, one slot may contain 12 symbols. Alternatively, in the case of a normal CP, one slot may contain 7 symbols, but in the case of an extended CP, one slot may contain 6 symbols.

[0087] A carrier includes multiple subcarriers in the frequency domain. A Resource Block (RB) can be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) can be defined as multiple consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed through the active BWPs. Each element can be referred to as a Resource Element (RE) in a resource grid and can be mapped to a single complex symbol.

[0088] Meanwhile, a wireless interface between terminals or a wireless interface between a terminal and a network may be composed of L1, L2, and L3 layers. In various embodiments of the present disclosure, L1 layer may refer to the physical layer. Additionally, for example, L2 layer may refer to at least one of the MAC layer, RLC layer, PDCP layer, and SDAP layer. Additionally, for example, L3 layer may refer to the RRC layer.

[0089] FIG. 6 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure. The embodiment of FIG. 6 can be combined with various embodiments of the present disclosure.

[0090] New network characteristics in 6G may be as follows.

[0091] - Satellite Integrated Network

[0092] - Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is innovative and will update wireless evolution from "connected things" to "connected intelligence." AI can be applied at each stage of the communication process (or at each step of the signal processing described below).

[0093] - Seamless integration of wireless information and energy transfer

[0094] - Ubiquitous Super 3D Connectivity: Connectivity to the network and core network functions of drones and very low Earth orbit satellites will create Super 3D connectivity in 6G ubiquitous.

[0095] Some general requirements regarding the new network characteristics of 6G mentioned above may be as follows.

[0096] - Small cell networks

[0097] - Ultra-dense heterogeneous network

[0098] - High-capacity backhaul

[0099] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communication is one of the functions of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0100] - Softwarization and virtualization

[0101] The core implementation technologies of the 6G system are described below.

[0102] - Artificial Intelligence: Introducing AI into communications can streamline and enhance real-time data transmission. AI can determine how complex target tasks are performed using numerous analyses. In other words, AI can increase efficiency and reduce processing latency. Time-consuming tasks such as handover, network selection, and resource scheduling can be performed instantly using AI. AI can also play a significant role in M2M, machine-to-human, and human-to-machine communication. Furthermore, AI can enable rapid communication in Brain-Computer Interfaces (BCI). 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.

[0103] - THz Communication: Data transmission rates can be increased by expanding bandwidth. This can be achieved by using sub-THz communication with wide bandwidth and applying advanced large-scale MIMO technology. THz waves, also known as sub-millimeter radiation, generally refer to a frequency band between 0.1 THz and 10 THz with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz-300 GHz band range (Sub-THz band) is considered the primary portion of the THz band for cellular communication. Adding the Sub-THz band to the mmWave band increases 6G cellular communication capacity. Among the defined THz bands, the 300 GHz-3 THz band is located in the far-infrared (IR) frequency band. Although the 300 GHz-3 THz band is part of the optical band, it lies at the boundary of the optical band and immediately following the RF band. Therefore, this 300 GHz-3 THz band exhibits similarities to RF.

[0104] FIG. 7 illustrates an electromagnetic spectrum according to one embodiment of the present disclosure. The embodiment of FIG. 7 may be combined with various embodiments of the present disclosure. Key characteristics of THz communication include (i) a widely available bandwidth to support very high data transmission rates, and (ii) high path loss occurring at high frequencies (highly directional antennas are indispensable). The narrow beam width generated by highly directional antennas reduces interference. The small wavelength of THz signals allows a much larger number of antenna elements to be integrated into devices and BSs operating in this band. This enables the use of advanced adaptive array techniques that can overcome range limitations.

[0105] - Large-scale MIMO technology

[0106] - Hologram beamforming (HBF)

[0107] - Optical wireless technology

[0108] - Free Space Optical Transmission Backhaul Network (FSO backhaul network)

[0109] - Quantum communication

[0110] - Cell-free communication

[0111] - Integration of wireless information and power transmission

[0112] - Integration of wireless communication and sensing

[0113] - Integrated access and backhaul network

[0114] - Big data analysis

[0115] - Reconfigurable intelligent metasurface

[0116] - Metaverse

[0117] - blockchain

[0118] - Unmanned Aerial Vehicle (UAV): UAVs or drones will be a critical element in 6G wireless communication. In most cases, high-speed data wireless connectivity can be provided using UAV technology. Base station (BS) entities can be installed on UAVs to provide cellular connectivity. UAVs can possess specific features not found in fixed BS infrastructure, such as easy deployment, robust line-of-sight links, and controlled degrees of freedom for mobility. During emergencies, such as natural disasters, the deployment of ground communication infrastructure is not economically feasible, and sometimes services cannot be provided in volatile environments. UAVs can easily handle these situations. UAVs will become a new paradigm in the field of wireless communication. This technology facilitates the three fundamental requirements of wireless networks: eMBB, URLLC, and mMTC. UAVs can also support various purposes, such as enhancing network connectivity, fire detection, disaster emergency services, security and surveillance, pollution monitoring, parking monitoring, and accident monitoring. Therefore, UAV technology is recognized as one of the most critical technologies for 6G communication.

[0119] - Autonomous Driving (Self-Driving): V2X (Vehicle to Everything), a core element in building autonomous driving infrastructure, refers to technologies that enable vehicles to communicate and share with various elements on the road for autonomous driving, such as wireless communication between vehicles (Vehicle to Vehicle, V2V) and between vehicles and infrastructure (Vehicle to Infrastructure, V2I). Fast transmission speeds and low-latency technologies are essential to maximize autonomous driving performance and ensure high safety. Furthermore, future autonomous driving may go beyond simply delivering warning or guidance messages to the driver to actively intervene in vehicle operation and directly control the vehicle in dangerous situations. Since the amount of information to be transmitted and received may become massive for this purpose, it is expected that 6G will be able to maximize autonomous driving through faster transmission speeds and lower latency compared to 5G.

[0120] Figure 8 illustrates a radio protocol architecture for SL communication. Specifically, Figure 8 (a) shows the user plane protocol stack of NR, and Figure 8 (b) shows the control plane protocol stack of NR.

[0121] The Sidelink Synchronization Signal (SLSS) and synchronization information are described below.

[0122] SLSS is an SL-specific sequence that may include PSSS (Primary Sidelink Synchronization Signal) and SSSS (Secondary Sidelink Synchronization Signal). The PSSS may be referred to as S-PSS (Sidelink Primary Synchronization Signal), and the SSSS may be referred to as S-SSS (Sidelink Secondary Synchronization Signal). For example, length-127 M-sequences may be used for S-PSS, and length-127 Gold sequences may be used for S-SSS. For example, a terminal may use S-PSS to detect a primary signal and obtain synchronization. For example, a terminal may use S-PSS and S-SSS to obtain detailed synchronization and detect a synchronization signal ID.

[0123] PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel through which basic (system) information that a terminal must know first is transmitted before transmitting or receiving SL signals. For example, the basic information may include information related to SLSS, Duplex Mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, information related to resource pools, types of applications related to SLSS, subframe offsets, broadcast information, etc. For example, to evaluate PSBCH performance, in NR V2X, the payload size of PSBCH may be 56 bits, including a 24-bit CRC.

[0124] S-PSS, S-SSS, and PSBCH may be included in a block format that supports periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP lengths) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) within the carrier, and the transmission bandwidth may be within a (pre-)set SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RB (Resource Block). For example, the PSBCH may be transmitted with a bandwidth corresponding to the 11 RB. Additionally, the frequency position of the S-SSB may be (pre-)set. Therefore, the terminal does not need to perform hypothesis detection at the frequency to discover the S-SSB in the carrier.

[0125] Meanwhile, in an NR SL system, multiple numerologies having different SCS and / or CP lengths may be supported. In this case, as the SCS increases, the length of the time resource for the transmitting terminal to transmit S-SSBs may decrease. Consequently, the coverage of S-SSBs may decrease. Therefore, to ensure S-SSB coverage, the transmitting terminal may transmit one or more S-SSBs to the receiving terminal within a single S-SSB transmission cycle according to the SCS. For example, the number of S-SSBs transmitted by the transmitting terminal to the receiving terminal within a single S-SSB transmission cycle may be pre-configured or configured for the transmitting terminal. For example, the S-SSB transmission cycle may be 160ms. For example, an S-SSB transmission cycle of 160ms may be supported for all SCSs.

[0126] For example, if the SCS is 15 kHz at FR1, the transmitting terminal may transmit one or two S-SSBs to the receiving terminal within one S-SSB transmission cycle. For example, if the SCS is 30 kHz at FR1, the transmitting terminal may transmit one or two S-SSBs to the receiving terminal within one S-SSB transmission cycle. For example, if the SCS is 60 kHz at FR1, the transmitting terminal may transmit one, two, or four S-SSBs to the receiving terminal within one S-SSB transmission cycle.

[0127] For example, if the SCS is 60 kHz at FR2, the transmitting terminal can transmit 1, 2, 4, 8, 16, or 32 S-SSBs to the receiving terminal within one S-SSB transmission cycle. For example, if the SCS is 120 kHz at FR2, the transmitting terminal can transmit 1, 2, 4, 8, 16, 32, or 64 S-SSBs to the receiving terminal within one S-SSB transmission cycle.

[0128] Meanwhile, when the SCS is 60 kHz, two types of CP may be supported. Additionally, depending on the CP type, the structure of the S-SSB transmitted by the transmitting terminal to the receiving terminal may differ. For example, the CP type may be Normal CP (NCP) or Extended CP (ECP). Specifically, for example, if the CP type is NCP, the number of symbols mapping PSBCH within the S-SSB transmitted by the transmitting terminal may be 9 or 8. On the other hand, for example, if the CP type is ECP, the number of symbols mapping PSBCH within the S-SSB transmitted by the transmitting terminal may be 7 or 6. For example, PSBCH may be mapped to the first symbol within the S-SSB transmitted by the transmitting terminal. For example, the receiving terminal receiving the S-SSB may perform Automatic Gain Control (AGC) operation during the first symbol interval of the S-SSB.

[0129] Figure 9 shows a terminal performing V2X or SL communication.

[0130] Referring to FIG. 9, in V2X or SL communication, the term terminal may primarily refer to a user's terminal. However, if network equipment such as a base station transmits and receives signals according to the communication method between terminals, the base station may also be considered a type of terminal. For example, terminal 1 may be a first device (100), and terminal 2 may be a second device (200).

[0131] For example, terminal 1 can select a resource unit corresponding to a specific resource within a resource pool, which represents a set of resources. Then, terminal 1 can transmit an SL signal using the said resource unit. For example, terminal 2, which is a receiving terminal, can be configured with a resource pool in which terminal 1 can transmit a signal, and can detect terminal 1's signal within said resource pool.

[0132] Here, if terminal 1 is within the connection range of the base station, the base station may inform terminal 1 of the resource pool. On the other hand, if terminal 1 is outside the connection range of the base station, another terminal may inform terminal 1 of the resource pool, or terminal 1 may use a pre-configured resource pool.

[0133] Generally, a resource pool can be composed of multiple resource units, and each terminal can select one or more resource units to use for its SL signal transmission.

[0134] Figure 10 shows a resource unit for V2X or SL communication.

[0135] Referring to FIG. 10, the total frequency resources of the resource pool can be divided into NF units, and the total time resources of the resource pool can be divided into NT units. Thus, a total of NF * NT resource units can be defined within the resource pool. FIG. 10 illustrates an example where the resource pool is repeated in a period of NT subframes.

[0136] As shown in FIG. 10, a single resource unit (e.g., Unit #0) may appear repeatedly over time. Alternatively, to obtain diversity effects in the time or frequency dimension, the index of the physical resource unit to which a single logical resource unit is mapped may change in a predetermined pattern over time. In this structure of resource units, a resource pool may refer to a set of resource units that a terminal intending to transmit an SL signal can use for transmission.

[0137] Resource pools can be subdivided into several types. For example, depending on the content of the SL signals transmitted from each resource pool, resource pools can be classified as follows.

[0138] (1) A Scheduling Assignment (SA) may be a signal containing information such as the location of the resource used by the transmitting terminal for transmission of the SL data channel, the Modulation and Coding Scheme (MCS) or Multiple Input Multiple Output (MIMO) transmission method required for demodulation of the data channel, and Timing Advance (TA). The SA may also be multiplexed and transmitted together with the SL data on the same resource unit, in which case the SA resource pool may refer to a resource pool in which the SA is multiplexed and transmitted together with the SL data. The SA may also be called the SL control channel.

[0139] (2) A Physical Sidelink Shared Channel (PSSCH) may be a resource pool used by a transmitting terminal to transmit user data. If SA is multiplexed and transmitted along with SL data on the same resource unit, only the form of the SL data channel excluding SA information can be transmitted from the resource pool for the SL data channel. In other words, REs (Resource Elements) that were used to transmit SA information on individual resource units within the SA resource pool can still be used to transmit SL data in the resource pool of the SL data channel. For example, the transmitting terminal can transmit by mapping the PSSCH to a succession of PRBs.

[0140] (3) The discovery channel may be a resource pool for a transmitting terminal to transmit information such as its ID. Through this, the transmitting terminal can enable adjacent terminals to discover it.

[0141] Even if the content of the SL signal described above is the same, different resource pools may be used depending on the transmission and reception attributes of the SL signal. For example, even if the same SL data channel or discovery message is used, it may be divided into different resource pools depending on the method of determining the transmission timing of the SL signal (e.g., whether it is transmitted at the time of reception of the synchronization reference signal or whether it is transmitted by applying a certain timing advance at the time of reception), the method of resource allocation (e.g., whether the base station assigns the transmission resource of an individual signal to the individual transmission terminal or whether the individual transmission terminal selects the individual signal transmission resource itself from within the resource pool), the signal format (e.g., the number of symbols occupied by each SL signal in one subframe, or the number of subframes used for the transmission of one SL signal), the signal strength from the base station, the transmission power strength of the SL terminal, etc.

[0142] FIG. 11 illustrates an example of a BWP according to an embodiment of the present disclosure. The embodiment of FIG. 11 may be combined with various embodiments of the present disclosure. In the embodiment of FIG. 11, it is assumed that there are three BWPs.

[0143] Referring to FIG. 11, the common resource block (CRB) may be a numbered carrier resource block extending from one end of the carrier band to the other. And, the PRB may be a numbered resource block within each BWP. Point A may indicate a common reference point for the resource block grid.

[0144] BWP is point A, offset from point A ( ) and bandwidth( It can be set by ). For example, point A may be an external reference point of the PRB of a carrier where the subcarrier 0 of all numerologies (e.g., all numerologies supported by the network in that carrier) is aligned. For example, offset may be the PRB interval between the lowest subcarrier in a given numerology and point A. For example, bandwidth may be the number of PRBs in a given numerology.

[0145] SLSS (Sidelink Synchronization Signal) is a sidelink-specific sequence and may include PSSS (Primary Sidelink Synchronization Signal) and SSSS (Secondary Sidelink Synchronization Signal). The PSSS may be referred to as S-PSS (Sidelink Primary Synchronization Signal), and the SSSS may be referred to as S-SSS (Sidelink Secondary Synchronization Signal). For example, length-127 M-sequences may be used for S-PSS, and length-127 Gold sequences may be used for S-SSS. For example, a terminal may use S-PSS to detect the initial signal and obtain synchronization. For example, a terminal may use S-PSS and S-SSS to obtain detailed synchronization and detect the synchronization signal ID.

[0146] The PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel through which basic (system) information that the terminal must know first is transmitted before transmitting or receiving SL signals. For example, the basic information may include information related to SLSS, Duplex Mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, information related to resource pools, types of applications related to SLSS, subframe offsets, broadcast information, etc. For example, to evaluate PSBCH performance, in NR V2X, the payload size of the PSBCH may be 56 bits, including a 24-bit CRC (Cyclic Redundancy Check).

[0147] S-PSS, S-SSS, and PSBCH may be included in a block format that supports periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP lengths) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) within the carrier, and the transmission bandwidth may be within a (pre-)set SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RB (Resource Block). For example, the PSBCH may be transmitted with a bandwidth corresponding to the 11 RB. Additionally, the frequency position of the S-SSB may be (pre-)set. Therefore, the terminal does not need to perform hypothesis detection at the frequency to discover the S-SSB in the carrier.

[0148] FIG. 12 illustrates a procedure in which a terminal performs V2X or SL communication according to a resource allocation mode, according to one embodiment of the present disclosure. The embodiment of FIG. 12 may be combined with various embodiments of the present disclosure.

[0149] Referring to FIG. 12(a), in resource allocation mode 1, the base station may schedule SL resources to be used by the terminal for SL transmission. For example, in step S1200, the base station may transmit information related to SL resources and / or information related to UL resources to the first terminal. For example, the UL resources may include PUCCH resources and / or PUSCH resources. For example, the UL resources may be resources for reporting SL HARQ feedback to the base station.

[0150] For example, the first terminal may receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from the base station. For example, the CG resource may include a CG type 1 resource or a CG type 2 resource. In this specification, the DG resource may be a resource that the base station sets / assigns to the first terminal via downlink control information (DCI). In this specification, the CG resource may be a (periodic) resource that the base station sets / assigns to the first terminal via DCI and / or RRC messages. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message containing information related to the CG resource to the first terminal. For example, in the case of a CG type 2 resource, the base station may transmit an RRC message containing information related to the CG resource to the first terminal, and the base station may transmit DCI related to the activation or release of the CG resource to the first terminal.

[0151] In step S1210, the first terminal may transmit a PSCCH (e.g., Sidelink Control Information or 1st-stage SCI) to the second terminal based on the resource scheduling. In step S1220, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) associated with the PSCCH to the second terminal. In step S1230, the first terminal may receive a PSFCH associated with the PSCCH / PSSCH from the second terminal. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second terminal via the PSFCH. In step S1240, the first terminal may transmit / report the HARQ feedback information to the base station via a PUCCH or PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on HARQ feedback information received from the second terminal. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on a pre-set rule. For example, the DCI may be a DCI for scheduling SL.

[0152] Referring to FIG. 12(b), in resource allocation mode 2, the terminal can determine an SL transmission resource within an SL resource set by the base station / network or a preset SL resource. For example, the set SL resource or the preset SL resource may be a resource pool. For example, the terminal may autonomously select or schedule a resource for SL transmission. For example, the terminal may perform SL communication by selecting a resource itself within the set resource pool. For example, the terminal may select a resource itself within a selection window by performing a sensing and resource (re)selection procedure. For example, the sensing may be performed on a subchannel basis. For example, in step S1210, the first terminal, having selected a resource itself within the resource pool, may use the resource to transmit PSCCH (e.g., SCI (Sidelink Control Information) or 1st-stage SCI) to the second terminal. In step S1220, the first terminal can transmit PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) associated with the PSCCH to the second terminal. In step S1230, the first terminal can receive PSFCH associated with the PSCCH / PSSCH from the second terminal.

[0153] Referring to FIG. 12 (a) or (b), for example, the first terminal may transmit an SCI to the second terminal over the PSCCH. Or, for example, the first terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal over the PSCCH and / or PSSCH. In this case, the second terminal may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first terminal. In this specification, an SCI transmitted over the PSCCH may be referred to as the 1st SCI, the 1st SCI, the 1st-stage SCI, or the 1st-stage SCI format, and an SCI transmitted over the PSSCH may be referred to as the 2nd SCI, the 2nd SCI, the 2nd-stage SCI, or the 2nd-stage SCI format.

[0154] Referring to FIG. 12 (a) or (b), in step S1230, the first terminal can receive PSFCH. For example, the first terminal and the second terminal can determine a PSFCH resource, and the second terminal can use the PSFCH resource to transmit HARQ feedback to the first terminal.

[0155] Referring to FIG. 12(a), in step S1240, the first terminal can transmit SL HARQ feedback to the base station via PUCCH and / or PUSCH.

[0156] FIG. 13 shows an example of a general NTN scenario based on a transparent payload or a regenerated payload according to one embodiment.

[0157] Non-terrestrial networks (NTN): NTN may represent a network or network segment that uses RF (radio frequency) resources mounted on a satellite (or UAS (unmanned aerial system) platform).

[0158] Specifically, with reference to FIG. 13 (a), an example of a typical NTN scenario based on a transparent payload is shown, and FIG. 13 (b) shows an example of a typical NTN scenario based on a regenerative payload according to an embodiment of the present disclosure. The embodiment of FIG. 13 (a) or FIG. 13 (b) may be combined with various embodiments of the present disclosure.

[0159] Specifically, referring to FIG. 13 (a), a satellite (or UAS platform) can establish a service link with a UE. 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. A beam footprint may refer to an area where signals transmitted by the satellite can be received.

[0160] Alternatively, referring to FIG. 13 (b), a satellite (or UAS platform) can establish a service link with a UE. A satellite (or UAS platform) connected to a UE can be connected to another satellite (or UAS platform) via inter-satellite links (ISL). Another satellite (or UAS platform) can be connected to a gateway via a feeder link. Based on a replay payload, the satellite can be connected to a data network via another satellite and a gateway. If no ISL exists between the satellite and another satellite, a feeder link between the satellite and the gateway may be required.

[0161] Meanwhile, FIG. 13 is merely an example of an NTN scenario, and NTN can be implemented based on various scenarios. For example, a satellite (or UAS platform) can implement a regenerative (with on-board 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) may vary depending on the on-board antenna diagram and the minimum elevation angle. For example, a regenerative payload may include radio frequency filtering, frequency conversion, and amplification. Thus, the waveform signal repeated by the payload may not be altered. 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, the playback payload can be substantially the same as carrying all or part of the base station functions on a satellite (or UAS platform).

[0162] The Next Generation Radio Access Network (NG-RAN) is a Radio Access Network (RAN) for 5G that supports a configuration in which 5G base stations (gNB) are divided into a Central Unit (CU) and a Distributed Unit (DU). Various options for NTN-based NG-RAN architectures were reviewed, and it was concluded that there were no technical obstacles to supporting the identified architecture options.

[0163] The upper-layer protocol stack of NR is divided into the User Plane (UP) and the Control Plane (CP). The User Plane is responsible for data transmission, while the Control Plane is responsible for signal processing. In the case of the User Plane, long-distance propagation delay in an NTN environment has a significant impact; accordingly, the effects on the MAC, RLC, PDCP, and SDAP layers were analyzed. The analysis revealed that improvements are needed in the MAC layer for functions such as random access, discontinuous reception (DRX), scheduling requests, and HARQ (Hybrid Automatic Repeat Request). In the RLC layer, emphasis was placed on status reporting functions and the utilization of sequence numbers, while in the PDCP layer, the discarding of Service Data Units (SDU) and sequence number management were considered. For the SDAP layer, it was assessed that no separate modifications are required to support NTN.

[0164] In the control plane, mobility management procedures were reviewed with particular focus on the rapid mobility of LEO (Low Earth Orbit) satellites. For IDLE mode, the introduction of NTN-specific system information is required, and frequent Tracking Area Updates (TAU) can be prevented by introducing an Earth-fixed tracking area. Additionally, it may be beneficial to add auxiliary information for cell selection and re-selection. In Connected mode, improvements to the handover procedure were discussed to mitigate the problem of frequent handovers caused by rapid satellite movement.

[0165] From a physical layer perspective, link-level and system-level evaluations were performed in the S-band and Ka-band. According to the evaluation results, when appropriate satellite beam placement is applied, portable user terminals (UEs) can be serviced via LEO and GEO satellites in the S-band, and user terminals equipped with high-gain transmit / receive antennas (e.g., VSAT, phased array antennas) can be serviced by LEO and GEO satellites in the Ka-band as well as the S-band. Despite issues such as long-range propagation delay, large Doppler shift, and mobile cells in the NTN environment, it was concluded that the NR functions defined in Rel-15 and Rel-16 provide a sufficient foundation for supporting NTN. However, it was found that further functional improvements are needed in terms of timing relationships, uplink timing and frequency synchronization, and HARQ processing methods.

[0166] The NR NTN research topic in Release-17 aims to specify functional improvements for LEO and GEO-based NTN, while simultaneously considering implicit support for High Altitude Platform Systems (HAPS) and Air-to-Ground networks. The research topic includes the physical layer, protocols, and network architecture, as well as radio resource management, RF requirements, and frequency bands used. This study targets transparent payload architectures and Frequency Division Duplex (FDD) systems based on Earth fixed tracking zones, and assumes that all user terminals possess Global Navigation Satellite System (GNSS) capabilities.

[0167] Rel-16 NR performs continuous transmission based on up to 16 stop-and-wait HARQ processes. Since a single HARQ process cannot be reused until feedback is received regarding the previous transmission, in NTN environments with long Round-Trip Times (RTT), all HARQ processes wait for feedback, causing transmission congestion and consequently degrading communication efficiency. To mitigate this congestion, the number of HARQ processes has been expanded to 32, which can cover some Air-to-Ground scenarios. However, considering the RTTs of LEO and GEO-based NTNs, 32 HARQ processes alone are insufficient. Since further expanding the number of HARQ processes is undesirable, a method must be implemented that allows the same HARQ process to be reused before the entire RTT has elapsed. For downlink transmissions, if a HARQ process is reused before the RTT, HARQ feedback becomes unnecessary, and thus the feedback is disabled. There is no HARQ feedback in the uplink, and the gNB can dynamically decide whether to reuse the HARQ process before RTT by sending a grant for new data or retransmission.

[0168] For HARQ processes with HARQ feedback disabled, terminals do not need to wait for retransmission assignments after a certain period to conserve energy. If HARQ is not used for retransmission, link adaptation can be set to a target low block error rate, but a higher RLC retransmission rate and more frequent RLC status reporting are required to ensure overall reliability.

[0169] Considering the long-range RTT of NTN, some MAC and RLC timers are extended, and the terminal needs to (re)select a new satellite depending on the movement of the satellite. In this case, satellite selection is based on existing criteria, but may include new criteria such as the point in time when the satellite no longer provides service at the terminal location. Conditional handover is strengthened with new conditions based on the terminal location and the satellite coverage time for that location, and the measurement procedure can be improved with a terminal location-based triggering function.

[0170] Figures 14 and 15 are drawings for explaining the coverage of NTN.

[0171] NTN (Non-terrestrial Networks) operation typically refers to an operation that performs communication via a satellite. However, NTN operation is not limited to communication via a satellite. For example, NTN operation may also include communication via HAPs (high altitude platforms). In certain scenarios (3GPP), NTN operation is defined as operation via a satellite. For example, in certain scenarios, configuration information related to the NTN or NTN cell may be provided through system information (SIB19). Specifically, SIB19 may be a system information block containing essential satellite assistance information for NTN (Non-Terrestrial Network) access. This information is used by the UE to connect to and maintain a connection with a cell in an NTN environment and may include detailed NTN-related configuration and timing information such as ntn-Config, t-Service, referenceLocation, movingReferenceLocation, distanceThresh, epochTime, ntn-RS-TimingInfo, ssb-TimeOffset, and satellite ephemeris (see TS38.331). The above system information may be information broadcast directly from the NTN cell. The following description assumes that NTN operations are operations via satellite.

[0172] Cell coverage using satellites as an NTN operation can be defined into three types: coverage based on an Earth fixed cell (deployed by GEO satellite) as shown in FIG. 14 (a), coverage based on a Quasi-Earth fixed cell (deployed by LEO satellite) as shown in FIG. 14 (b), and coverage based on an Earth moving cell (deployed by LEO satellite) as shown in FIG. 14 (c).

[0173] Among the three types mentioned above, in the case of a quasi-Earth fixed cell, the coverage of the cell (or NTN, NTN cell) may change due to satellite movement. For example, as illustrated in FIG. 14 (b), the coverage of the NTN at the first time (t1) may shift / change to the coverage of the NTN at the second time (t2). In this case, from the perspective of the UE, the cell coverage changes suddenly. Therefore, a method may be required to ensure that measurements can be started / triggered at the UE connected to the NTN (and / or the UE camped on the serving cell) before the cell coverage changes. As described above, t-Service has been introduced as a value for starting / triggering such measurements. T-Service may be the time indicating that the serving cell (or serving NTN cell) will no longer operate in the serving area (e.g., the time when the coverage of the serving cell moves from a specific geographic area to another geographic area). T-Service is a value provided only for NTN or NTN cells based on quasi-earth fixed cells and can be included in SIB19 and broadcast. If a t-Service value exists in SIB19, t-Service indicates that operation as a serving cell in the corresponding area will cease after the time elapsed according to t-Service.

[0174] Meanwhile, the distance between the satellite (or NTN cell) and the UE may be significantly longer than the distance between the existing gNB and the UE. Therefore, the signal received by the UE via the satellite may have a lower signal strength compared to the signal received from the ground gNB. As such, the relatively low signal strength may have characteristics as shown in Fig. 15 (b) in the region corresponding to the edge of the cell coverage.

[0175] For example, as illustrated in FIG. 15 (b), when the UE is located at the edge of the cell coverage of the NTN cell, the signal strength may not differ significantly from the signal strength when the UE is located at the center of the cell coverage of the NTN cell (e.g., the rate of signal strength reduction within the cell coverage is low). Therefore, the method of triggering a measurement report based solely on the signal strength value of the UE, as in conventional TN, may not be sufficient or appropriate for NTN.

[0176] Considering the signal attenuation characteristics of NTN, measurement reporting can be triggered in a location-based manner within NTN. For example, 'referenceLocation' and 'distanceThresh' values ​​can be set for the UE via SIB19, dedicated RRC messages, etc. The UE may perform cell reselection or trigger measurement reporting based on the 'referenceLocation' and / or 'distanceThresh' values. In this case, the referenceLocation value represents a specific point (geographic location value) within the coverage of the serving cell, and distanceThresh may represent a value for the threshold distance at which location-based measurement begins / is triggered. Specifically, measurement action / measurement reporting may be triggered if the UE is located at a location further away than distanceThresh relative to the referenceLocation value. For example, a measurement report may be triggered if the distance between a specific geographic location based on the referenceLocation value and the UE's own location is greater than or equal to distanceThresh. For example, a measurement report ( / measurement initiation) may be triggered when the degree of signal strength reduction or the absolute signal strength value is less than a defined threshold strength (e.g., in the case of a measurement report for a ground gNB), but in the case of an NTN, a measurement-related action may be triggered when the UE is located farther away than a set distance (e.g., distanceThresh) relative to the referenceLocation.

[0177] Figures 16 and 17 are diagrams illustrating TN and NTN multiple connection scenarios.

[0178] FIG. 16 (a) illustrates an exemplary case of multi-connectivity including a transparent NTN-based NG-RAN and a cellular NG-RAN, FIG. 16 (b) illustrates an exemplary case of multi-connectivity between two transparent NTN-based NG-RANs, and FIG. 16 (c) illustrates an exemplary case of multi-connectivity between two regenerative NTN-based NG-RANs (including a substrate-mounted gNB).

[0179] Generally, a terrestrial UE in an RRC IDLE / INACTIVE state can receive TAC (Tracking Area Code) and PLMN (Public Land Mobile Network) values ​​broadcast from its cell via the SIB (System Information Block). If the received TAC and PLMN values ​​do not exist in its TAI (Tracking Area Identity, TAC + PLMN) list or TAC list, the terrestrial UE can initiate / execute the TA Update (Tracking Area Update, TAU) procedure. The Network (NW) can perform a registration update using the TAI value received from the UE and can transmit a new TAI list to the UE. Assuming that the RRC IDLE / INACTIVE UE exists within an area belonging to the TAI list, the Network can broadcast the paging message to the TAC area configured for the UE when it needs to send a paging message to the said RRC IDLE / INACTIVE UE. A single TAC value can be used per cell. For example, a single cell broadcasts only one TAC value, which can be a geographically determined value. UEs in an RRC IDLE / INACTIVE state connected to an NTN (Non-Terrestrial Network) must also perform a TAU operation to receive paging messages. If an NTN moving cell broadcasts a single TAC value per cell, UEs located at the cell boundary must execute the TAU procedure whenever they receive a new TAC value. This can be burdensome for UEs in a fast-moving NTN environment.

[0180] Specifically, referring to FIG. 17, TAU fluctuation can occur in the case of a UE in a fixed position, as the TAC value continues to change, such as when a UE belonging to TAC2 at time T1 belongs to TAC1 at time T2 and belongs to another TAC2 at time T3. In this regard, NTN can use a locally fixed TAC value (or TA value), just as TN. For example, a locally determined TAC (layout) value may already exist at the location where the satellite passes, and a satellite passing through a specific geographical area can broadcast the TAC value of said specific geographical area. Since the satellite's cell coverage covers a wide area, a single satellite cell (or NTN cell) can broadcast multiple TAC values.

[0181] Additionally, in an NTN moving cell environment, considering that the satellite is constantly moving, the TAC list may also include time bounds applicable to each TAC value. In this case, the UE can determine whether to execute the TAU procedure by judging that the set TAC value is valid only within the time interval corresponding to the aforementioned time bounds.

[0182] A method for distinguishing multiple satellites within the same carrier

[0183] FIG. 18 is a diagram illustrating a method of connecting a UE and a base station through at least one satellite.

[0184] Referring to FIG. 18 (a), the current transparent payload satellite operation assumes a case where one satellite is connected to one gNB. In this case, the satellite operating in transparent mode can transmit the signal received from the gNB directly to the UE. At this time, the satellite can perform only signal amplification and relay functions. When there is only one satellite connected to the gNB, the UE can measure the quality or reception strength of the SSB of the signal (e.g., the signal from the gNB received through the satellite), identify the PCell ID based on the SSB, and decode the SIB19 (or SBI19 received via a downlink channel scrambled with the PCell ID) based on the PCell ID. In this case, the UE can obtain the satellite's orbit and other satellite-related information through the SIB19, transmit a RACH toward the satellite, and establish a connection with the gNB by making an initial connection to a general TN.

[0185] However, multiple satellites may subsequently exist in the same coverage area, and in this case, multiple satellites may also be connected to a single gNB. For example, as illustrated in FIG. 18 (b) or FIG. 18 (c), a single gNB may be connected to multiple satellites to provide services through the multiple satellites. The UE may select one of the multiple satellites and connect to the gNB through the selected satellite, or be connected to the gNB through multiple satellites.

[0186] In this case, the UE needs to identify which of the aforementioned satellites the signal (e.g., SSB) it received and measured signal strength from originated from. Below, we will explain in detail how the UE can identify multiple satellites with the same cell ID (PCell ID) when multiple satellites are connected to the same gNB. Here, multiple satellites may be used for a single gNB to extend the coverage of the same cell ID.

[0187] The following describes in detail a method for transmitting a PBCH (or SSB) containing a flag (using a reserved bit) to identify satellites when multiple satellites are used for a single gNB to extend the coverage of the same cell ID.

[0188] FIG. 19 is a diagram for explaining the structure of an SSB, and FIG. 20 is a diagram for explaining the relationship between SSBs and SIBs received through multiple satellites.

[0189] The gNB can transmit each identical SSB via a feeder link. Here, identical SSB may refer to an SSB used in the same cell. In this case, the PBCH of the SSB may include a flag that can identify the satellite. For example, if the SSB is configured as shown in FIG. 19, the PBCH transmitted through SAT1 may include {sat_indication=1}, the PBCH transmitted through SAT2 may include {sat_indication=2}, and the PBCH transmitted through STA3 may include {sat_indication=3}. For example, a gNB that intends to connect with multiple satellites in relation to a single cell may transmit an SSB signal with a different sat_indication value (e.g., an SSB containing a PBCH with a different sat_indication value) to each satellite.

[0190] Based on the sat_indication value included in the PBCH of the received SSB, the UE can identify which satellite the measured SSB signal strength was received from and the PCell ID (or PCI). In this case, the PCell ID for the SSB received from each of the multiple satellites may all be the same (e.g., when the same gNB uses multiple satellites for NTN communication for the same cell).

[0191] A UE can receive at least one SSB having the same cell ID through multiple satellites. In this case, the UE can select one of the multiple satellites based on the reception quality of the at least one SSB and perform initial access through the selected satellite. For example, the UE can select one satellite (or the satellite corresponding to the SSB with the best reception quality among the received SSBs) based on the SSB signal strength (RSRP / RSRQ / SINR, etc.) and connect to the gNB through the selected satellite. In order for the UE to perform initial access, it is necessary to know the orbit information of the selected satellite. Since the satellite's propagation delay consumes a longer value than the TN, it is necessary to derive a TA (Timing Advance) value based on the satellite's position information even during initial access, and the RACH procedure can be performed based on the derived TA value. A UE capable of satellite communication can be assumed to be a UE capable of GNSS, and if the UE is aware of the satellite's orbit information, the UE can calculate an initial TA value based on its own position and the satellite's position, and can perform RACH based on the initial TA value. Therefore, when the UE selects a satellite based on at least one SSB, the UE must be able to decode SIB19 (a SIB containing information about the satellite) in order to know the position information of the selected satellite. For example, the UE needs to receive / decode SIB19 related to the selected satellite in order to determine / calculate an initial TA value related to the selected satellite.

[0192] In the case of general TN operation, one SSB may be provided per cell, and a SIB can be decoded using the PCell ID obtained by decoding the single SSB. For example, the SIB can be decoded / received based on the PCell ID. For example, the SIB can generally be received via a scrambled downlink channel (e.g., PDSCH) using the PCell ID included in the SSB. In this case, when the PCell is identical (e.g., when the gNB can provide services to the UE using multiple satellites), the SIB19 corresponding to each satellite may not be distinguishable. Therefore, as in the proposed method described above, if the PCell ID is identical but the sat_indication value of the SSB is different, the location information of the corresponding satellite must be obtainable through the SIB19 for each satellite with a different sat_indication. For example, in the case where there are multiple SSBs with the same PCell ID but different sat_indication values ​​as in the proposed method, the downlink channel (or SIB19) containing SIB19 needs to be scrambled so that the UE can obtain location information of each satellite distinguished by sat_indication value through SIB19.

[0193] In other words, in an NTN environment where a gNB can provide services to a UE using multiple satellites, the SSBs transmitted by the gNB to each of the multiple satellites may contain the same Pcell ID (e.g., PCI). In this case, if the UE receives / decodes the SIB (e.g., SIB19) based solely on the Pcell ID, the UE may not be able to distinguish the SIB19 (e.g., satellite position information) corresponding to each satellite. Therefore, even if the Pcell IDs are identical, if the sat_indication values ​​included in the SSB differ, it is necessary to configure the SIB so that the UE can obtain the satellite information corresponding to each sat_indication value via the SIB19. To this end, the SIB19 or the downlink channel carrying the SIB19 may be configured to be scrambled based on the sat_indication value as well as the Pcell ID. For example, if multiple SSBs have the same Pcell ID but differ only in sat_indication values, the UE determines descrambling parameters (e.g., initial scramble sequence values) based on the PCI and sat_indication values, and uses this to receive and decode SIB19 corresponding to the satellite associated with each SSB (or the SSB selected for initial access based on the reception quality of the SSB).

[0194] Specifically, as illustrated in FIG. 20, the SIB that needs to be decoded may differ depending on the SSB. When a UE measures the signal strength for an SSB (sat_indication=1) and intends to connect to a gNB via the satellite, the UE must be able to decode SIB19 (for sat1) for initial connection. Therefore, the SSB (sat_indication=1) may require a resource location where SIB19 is transmitted and / or a scrambled input value or initial value capable of decoding SIB19. As in the case of a general TN, the SIB19 (for sat1) (or the downlink channel where the SIB19 is received; e.g., PDSCH)) may be scrambled based on the value of “PCell ID + 1”, and when an SSB (sat_identification = 2) is selected, the SIB19 (for sat2) (or the downlink channel where the SIB19 is received; e.g., PDSCH) may be scrambled based on the value of “PCell ID + 2”. The above method is merely an example, and for each SSB, the PBCH and / or SIB information may be decoded and / or descrambled based on a different identifier (or value) that can replace the PCell ID. For example, for each SSB, the SIB information may be decoded based on a different identifier (or value) that can replace the PCell ID.

[0195] Meanwhile, the UE may operate in a multi-path manner by adding an NTN path while maintaining a TN path. For this operation, the UE may report the received signal strength (e.g., SSB measurement) for at least one candidate satellite to the gNB via the TN path. Based on the reported signal strength value, the gNB may select one of the at least one satellite and determine / set configuration information to establish an NTN connection with the selected satellite. In this case, when the UE reports at least one candidate satellite, the UE may report including the PCell ID, sat_indication value, and measured signal value. Based on the above report, the gNB may select one of the at least one candidate satellite and transmit the orbit information of the selected satellite to the UE along with a path addition command.

[0196] Therefore, if a UE reports a satellite in the same PCell as a TN path as a candidate satellite for adding an NTN path, the UE may not need to decode the SIB19 information for said candidate satellite. This is because the gNB can transmit part and / or all of the information contained in the satellite's SIB19 to the UE during the process of setting up the path addition configuration. Additionally, this can be similarly applied even if the satellite selected for adding an NTN path belongs to a different cell and / or a different gNB. For example, upon a path addition request, the gNB can obtain part and / or all of the information contained in the selected satellite's SIB19 from another gNB (or cell) and provide it to the UE.

[0197] Therefore, in the operation where a UE maintaining a TN route searches for a satellite to add a route and reports the satellite to a gNB, SIB19 decoding by the UE according to the proposed method may be unnecessary.

[0198] Even if there are multiple satellites connected to the same gNB and / or cell according to the method described above, the UE can easily identify the satellite corresponding to the SSB by obtaining a value (sat_indication) related to the identification of each satellite from the SSB, and can effectively determine which satellite to use to establish a connection with the gNB.

[0199] Below, we explain in detail how to distinguish other satellites based on the synchronization of the First priority ( / basic / anchor) satellite.

[0200] Figure 21 is a diagram illustrating a method for searching for a synchronization raster for another satellite based on the synchronization of a reference satellite.

[0201] The frequency (start) range (e.g., sync raster) for the UE to search for the sync of a first priority satellite may be a value (pre)set based on cell ID and / or carrier / BWP, etc. Alternatively, a default frequency range (e.g., default sync raster) for searching for a first priority satellite regardless of the above information may be (pre)set.

[0202] The UE can decode the SSB by performing a sync search in a (pre)configured frequency range. The UE derives a PCell ID from the value of the decoded SSB and can decode the PBCH using the PCell ID (e.g., de-scrambling using the PCell ID). A structure can be considered in which the PBCH includes a sync raster value for detecting the sync of other satellites, so that a UE that has decoded the first priority satellite can decode the sync and PBCH of other satellites. Two specific methods for performing such operations can be considered as follows.

[0203] (1) Method 1: Where the PBCH includes information that can identify the satellite

[0204] Assuming sync raster1 is the default raster (e.g., a location where sync information of a first-priority satellite exists), the UE can prioritize the operation of searching for sync within the default raster. At this time, the sync block detected by the UE can be assumed to be SSB1. The UE can measure the signal quality (e.g., RSRP / RSRQ / SINR) of SSB1 using the PSS / SSS / DMRS information of SSB1 and decode the PBCH corresponding to SSB1. Additionally, upon decoding the PBCH, the UE can obtain the sync raster location information of SSB2 (e.g., the sync raster location information of SSB2 may be included in the PBCH). Based on the sync raster location information of SSB2, the UE can detect SSB2 and similarly obtain the sync raster location information of SSB3 by decoding the PBCH of SSB2. In this case, each SSB1 / SSB2 / SSB3 includes a PBCH value, and as described above, “sync raster-related information for searching for the next satellite” may be included in the PBCH. FIG. 21(a) illustrates a method for searching for the next satellite or the SSB corresponding to the next satellite sequentially in this manner.

[0205] FIG. 21(a) illustrates a method for sequentially searching for the SSB of the next satellite, but is not limited thereto. For example, SSB1 or the PBCH of SSB1 may contain all sync raster position information of SSB2 and SSB3 (e.g., sync raster position information for searching for all other satellites excluding SSB1). This information may be provided by being included in the PBCH of SSB1. In such a case, since SSB1 contains all the sync raster information for searching for other satellites, SSB2, SSB3, etc. may contain only PSS / SSS for satellite detection without a PBCH (e.g., SSB2 and SSB3 are provided only with signals for synchronization detection, and additional information may be provided through SSB1).

[0206] Additionally, the sync raster-related information included in SSB1 may include the total number of sync rasters to be searched (or the number of satellites to be identified). For example, the UE may require information regarding which position (or index / order) the currently searched satellite corresponds to among a total of multiple satellites. Alternatively, the UE can use the total number information to determine how many sync rasters need to be searched in total, whether to search for the next sync raster after the current search, and / or whether to terminate the search procedure without further searching. For example, SSB1 may provide a list of each sync raster (or index-location mapping information) along with the total number of satellites, and the UE can efficiently identify candidate satellites by performing PSS / SSS-based detection on the corresponding sync rasters sequentially or selectively until the total number of satellites is reached.

[0207] The bit size that can be included in a PBCH is limited, and expansion may not be easy. Therefore, the information that can be included in a PBCH is necessarily limited. Accordingly, the information included in the PBCH may be provided in a simple index format. For example, specific frequency information of sync rasters (capable of detecting satellites) can be recognized by the UE through pre-setting and / or SIB, etc., and the PBCH may provide only an index value indicating which number among the multiple sync rasters it corresponds to.

[0208] In addition, in addition to the sync raster information described above, offset information for detecting the next SSB may be included in the PBCH. For example, if the sync raster information refers to position information in the frequency domain, the offset information may refer to position information in the time domain. As a method of providing offset information, when indicating the next SSB sequentially, the UE may indicate the time interval at which the next SSB is separated from the time position of the SSB it detected (e.g., relative offset). Alternatively, when indicating the positions of other SSB2 and / or SSB3 together through SSB1, the time offset of SSB2 and / or SSB3 relative to SSB1 (e.g., relative offset relative to SSB1) may be indicated.

[0209] In current general UE operations, the UE can obtain a PCell ID after decoding and / or descrambling SSS / PSS sync information. The UE can decode the PBCH based on the said PCell ID, and the PCell ID can also be used to decode the SIB information associated with each SSB. If existing operations are inherited assuming that all SSBs in each raster have the same PCell ID, the PBCH and associated SIB information (or downlink channels containing SIB information) of each SSB must be encoded and / or scrambled using the same PCell ID. However, such operations may be difficult to accept or undesirable. This is because, when the UE obtains sync through a specific SSB, the PCell ID is utilized for scrambling to distinguish (identify) whether the PBCH and SIB information correspond to that SSB. Therefore, in general operation, it may be natural for each SSB to have a distinct PCell ID value. On the other hand, as considered in the proposed method, when multiple satellites are connected to a single cell, decoding and / or descrambling the PBCH / SIB information of each SSB based on the (identical) PCell ID may not be desirable.

[0210] In order to enable decoding and / or descrambling of the PBCH and SIB information of SSB1, SSB2, and SSB3 transmitted by satellites 1, 2, and 3 belonging to the same cell, respectively, based on different seed values ​​rather than “different PCell IDs” even when they all have the same PCell ID, the following method may be considered. For example, the decoding of the PBCH of SSB1, which corresponds to the first priority satellite, and the SIB for satellite 1 may be performed based on the PCell ID obtained from the SSS / PSS. When the UE searches for / detects the sync of SSB2 based on the information contained in the PBCH of SSB1, the UE may use a value corresponding to “PCell ID + 1” (e.g., a value set as an offset based on the PCell ID) as a seed to decode the PBCH of SSB2 and the SIB information for satellite 2. Likewise, if the UE detects / detects the sync of SSB3 based on the information contained in the PBCH of SSB2 (or based on the information contained in the PBCH of SSB1), the UE can use the value corresponding to “PCell ID + 2” as a seed to decode the PBCH of SSB3 and the SIB information for Satellite 3.

[0211] (2) Method 2: Where the SIB (e.g., SIB19) includes information that can identify the satellite

[0212] As in Method 1 described above, if information for identifying satellites other than the first priority satellite (e.g., information for searching for other satellites) is included in the PBCH, constraints may arise due to the limitation on the number of bits allowed in the PBCH. Therefore, a method of including the relevant information in the SIB information of the first priority satellite (e.g., SIB19) may be considered.

[0213] In such cases, the SIB19 of the first priority satellite may include information for identifying other satellites belonging to the same cell. For example, the SIB19 of the first priority satellite may include sync raster (and / or carrier / BWP) information regarding the transmission of the SSB of other satellites in the same cell, and information regarding the position (time axis and / or frequency axis) at which the transmission occurs with an offset relative to the first priority satellite's SSB. Additionally, the information may be included in the SIB19 of the first priority satellite in the form of a list, enumerating all information regarding other satellites belonging to the same cell.

[0214] If the SIB19 of the first priority satellite also includes SIB19 information for other satellites, the transmission of SSB2 and SSB3 may be transmitted with only PSS / SSS included, excluding PBCH. This is because relevant information for satellites 2 and 3 may already be included in the SIB19 associated with SSB1. In this case, the UE can measure the sync and signal strength (e.g., RSRP / RSRQ / SINR) of the satellites using the SSB information (or PSS / SSS( / PBCH) information) for satellites 2 and 3, and the information for satellites 2 and 3 (e.g., information included in the SIB19) may also be obtained through the SIB19 information associated with the first priority satellite. And / or, since the UE can obtain information about other satellites belonging to the same cell (e.g., position and orbit information) through the SIB19 of the first priority satellite, it may not be necessary to transmit separate SIB19 information for those satellites via SSB2 and SSB3. In this case, the UE can decode and / or descramble the SIB19 using the PCell ID obtained from the PSS / SSS of the first priority satellite.

[0215] However, in cases where separate SIB19 information for satellite 2 and satellite 3 is transmitted respectively as in Method 1 described above, the SIB19 can be decoded and / or descrambled using a value obtained by adding an offset value to the PCell ID, as described in Method 1. For example, in the case of satellite 2 (where sync is obtained using SSB2), the SIB19 associated with SSB2 can be decoded and / or descrambled using a value corresponding to “PCell ID + 1,” and in the case of satellite 3 (where sync is obtained using SSB3), the SIB19 associated with SSB3 can be decoded and / or descrambled using a value corresponding to “PCell ID + 2.” For example, as shown in FIG. 21(b), only PSS / SSS may be transmitted for satellite 2 and satellite 3.

[0216] Thus, according to the method described above, a method is provided in which a UE can distinguish between multiple satellites even when there are multiple satellites connected to a single cell. The UE measures the signal strength of each satellite and, based on the measurement results, can effectively select which satellite to use to connect to the cell.

[0217] FIG. 22 is a diagram illustrating a method for a UE to perform an initial connection with a base station.

[0218] As described above, a base station may provide services to a UE using multiple satellites. For example, the base station may generate an SSB corresponding to each of the multiple satellites and transmit each SSB to the UE via the corresponding satellite. Accordingly, the UE may receive at least one SSB among the SSBs corresponding to each of the multiple satellites from the base station. The UE may select one SSB for initial connection based on the signal quality (e.g., RSRP, RSRQ, SINR, etc.) of the at least one SSB, and may perform a RACH procedure with the base station via the satellite corresponding to the selected SSB. At this time, the UE needs to receive a SIB (e.g., SIB19) containing satellite information based on the SSB in order to determine a TA (timing advance) value related to the transmission of a PRACH or RACH preamble for initiating the RACH procedure. Meanwhile, the multiple SSBs received through the multiple satellites may include the same PCell ID (or PCI) in that they are signals corresponding to the same base station / gNB. Therefore, the UE needs to identify and receive a SIB (e.g., SIB19) containing satellite information for the satellite associated with the selected SSB among the SIBs for each of the multiple satellites. Below, a method for identifying a SIB containing satellite information corresponding to the selected SSB for the execution of the RACH procedure is described in detail.

[0219] Referring to FIG. 22, the UE receives a Synchronization Signal Block (SSB) containing at least one synchronization signal and a Physical Broadcast Channel (PBCH) (S221), receives a System Information Block (SIB) based on the SSB (S223), and can perform a Random Access Channel (RACH) procedure with a base station based on the SSB and the SIB (S225). Here, the SSB is a reference signal block for the UE to search for a cell and perform initial access, and may include a PBCH along with synchronization signals such as a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) (see FIG. 19), and may provide basic parameters or related instruction information for receiving system information through the PBCH.

[0220] As described above, a base station / gNB can support the provision of services through each of multiple satellites. In such a Non-Terrestrial Network (NTN) environment, the same cell ID (e.g., physical cell ID, PCI) may be shared across multiple satellite links (or multiple satellites / beams). In such an environment, if a UE obtains a SIB (e.g., SIB19) using only the cell ID acquired from the SSB, it may be difficult to distinguish and receive different system information (e.g., satellite orbit / position-related information) for each satellite, or there may be a possibility that system information from different satellites corresponding to the same cell ID may be mixed. Therefore, as described above, the UE needs to reliably receive and interpret SIBs that are distinguished by satellite by additionally using a satellite identification value associated with the NTN (hereinafter referred to as the “satellite identification value”) in addition to the cell ID.

[0221] Specifically, if the SSB is transmitted from a base station via an NTN or satellite, the SSB may further include a satellite identification value for the satellite. For example, if the SSB is transmitted via an NTN or satellite, the UE may obtain a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN (or satellite) from the SSB. For example, the first satellite identification value may be included in the PBCH and may be represented according to specific fields / bits of the PBCH payload, reserved resources, or pre-agreed mapping rules. The UE obtains the cell ID and the first satellite identification value by decoding the PBCH and can use this to proceed with the reception procedure of the SIB for the satellite corresponding to the first satellite identification value.

[0222] For example, the above SIB may be received based on the cell ID and the first satellite identification value. Here, “received based on the cell ID and the satellite identification value” may include the UE deriving parameters necessary for receiving / decoding the SIB from the cell ID and the satellite identification value, and using the parameters to obtain the SIB (or the downlink channel / signal carrying the SIB) by scrambling and / or decoding. For example, the UE may determine a scramble initial value associated with the SIB (e.g., a scramble sequence initial value or an ID for calculating the same) based on the cell ID and the first satellite identification value, and may receive the SIB for the satellite corresponding to the first satellite identification value based on the scramble initial value. Alternatively, the scramble initial value may be determined based on the value obtained by adding the first satellite identification value to the cell ID. By using the initial scrambling value determined in this way, different scrambling / scrambling conditions can be formed for links with different satellite identification values ​​even if they have the same cell ID, and the UE can select and receive a SIB corresponding to the satellite associated with the selected SSB based on the reception quality of at least one received SSB.

[0223] In addition, the above SIB may be a SIB19 that includes satellite orbit information for an NTN or satellite corresponding to the first satellite identification value. For example, the SIB19 may include satellite orbit parameters, expected position / velocity, or information that the UE can use to correct for propagation delay and Doppler effects. For example, the UE can obtain satellite orbit information, such as Ephemeris, network control common delay value, such as Common TA, and reference point for these parameters, such as Epoch Time, through the ntn-Config field of SIB19, and the terminal can calculate the unidirectional common propagation delay (Delay common (t)) at the current point in time (t) using the ta-Common, ta-CommonDrift, and ta-CommonDriftVariant parameters of SIB19, and based on this, calculate the distance between itself and the satellite by comparing its own position with the orbit information (satellite position and velocity vector, etc.) of SIB19, and calculate the individual propagation delay time accordingly, and calculate the final TA value (related to RACH procedures such as PRACH or RACH preamble transmission) by summing the common delay component and the terminal-specific delay component.

[0224] Alternatively, the PBCH may further include information regarding a synchronization raster for receiving a second SSB associated with a second satellite identification value. Here, a “synchronization raster” may refer to a candidate frequency location (or set of candidate resources) that the UE considers for searching for / receiving an SSB, and different synchronization rasters may be configured corresponding to multiple satellites or multiple satellite identification values. Alternatively, the UE may receive configuration information from a base station that includes index values ​​for the synchronization rasters of multiple satellites, and the PBCH may include an index value among the index values ​​that corresponds to the synchronization raster for receiving the second SSB. Accordingly, the UE can quickly identify an SSB search / reception location corresponding to a specific satellite identification value (e.g., a second satellite identification value) through the PBCH, thereby reducing unnecessary search ranges or shortening SSB search time.

[0225] In this way, the UE can receive multiple SSBs corresponding to each of multiple satellites from the base station. For example, if there are multiple SSBs that have the same cell ID (e.g., PCI) but different satellite identification values, the UE can obtain the satellite identification value corresponding to the satellite from each SSB and receive and interpret the corresponding SIB (e.g., SIB19) using the initial scramble value determined for each satellite identification value. As a result, the UE can obtain system information that is distinguished by satellite even in the same cell ID environment, and can improve initial connection performance and stability in the NTN environment by utilizing satellite orbit information, etc., to more appropriately set RACH-related parameters (e.g., TA).

[0226] Figure 23 is a flowchart illustrating how a base station provides satellite-specific SSB and satellite-specific SIB transmissions.

[0227] Referring to FIG. 23, a base station (e.g., gNB) may generate and transmit a Synchronization Signal Block (SSB) containing at least one synchronization signal and a Physical Broadcast Channel (PBCH) (S231), and based on the SSB, a UE may transmit a System Information Block (SIB) (S233) and perform a Random Access Channel (RACH) procedure (S235) for initial connection with the UE. Here, the SSB is a reference signal block for the UE to search for a cell and perform initial connection, and may include a PBCH along with the synchronization signal, and the base station may provide basic parameters or related instruction information for receiving system information through the PBCH.

[0228] As described above, a base station / gNB can support the provision of services through each of multiple satellites. In such a Non-Terrestrial Network (NTN) environment, the base station may be configured to share (reuse) the same cell ID (e.g., PCell ID, or PCI) across multiple satellite links (or multiple satellites / beams). In this case, if the UE obtains a SIB (e.g., SIB19) using only the cell ID acquired from the SSB, it may be difficult for the UE to distinguish and receive different system information (e.g., satellite orbit / position-related information) specific to each satellite, or there may be a possibility of system information from different satellites corresponding to the same cell ID being mixed. Therefore, the base station needs to provide a configuration capable of reliably receiving and interpreting satellite-specific SIBs so that the UE can additionally utilize satellite identification values ​​related to the NTN in addition to the cell ID.

[0229] Specifically, when an SSB is provided to a UE via an NTN or a satellite, the base station may configure the SSB to include a satellite identification value for said satellite. For example, when configuring the SSB, the base station may include a first satellite identification value associated with the NTN (or satellite) along with a cell ID (identifier) ​​for the base station. Accordingly, the UE can obtain the cell ID and the first satellite identification value by decoding the PBCH, and the base station may support the UE in proceeding with the procedure to receive a System Information Block (SIB) for the satellite corresponding to said first satellite identification value.

[0230] A base station may configure SIB transmission so that the SIB can be received based on the cell ID and the first satellite identification value (or the first satellite identification value). Here, configuring to be “received based on the cell ID and the satellite identification value” may include the base station setting scrambling conditions for the SIB (or the downlink channel / signal carrying the SIB) according to parameters derivable from the cell ID and the satellite identification value, so that the UE obtains the corresponding SIB through scrambling and / or decoding. For example, the base station may set a scrambling initial value associated with the SIB (e.g., a scrambling sequence initial value or an ID for calculating the same) based on the cell ID and the first satellite identification value, and scrambling and transmitting the SIB for the satellite corresponding to the first satellite identification value or the PDSCH through which the SIB is transmitted based on the scrambling initial value. Alternatively, the scrambling initial value may be configured to be set based on the value obtained by adding the first satellite identification value to the cell ID. In this way, by configuring SIB transmission so that different scrambling conditions are formed according to the satellite identification value, it is possible to support the selective reception of the SIB corresponding to the desired satellite (e.g., the satellite corresponding to the SSB with the best reception quality) for links with different satellite identification values, even if they have the same cell ID.

[0231] In addition, the base station may be configured so that the SIB is provided as SIB19, which includes satellite orbit information for the NTN or satellite corresponding to the first satellite identification value. For example, the base station may provide satellite orbit information (Ephemeris), a network control common delay value (Common TA), and an epoch time information, which is a reference point for these parameters, to the UE through the ntn-Config field of the SIB19.

[0232] Alternatively, the base station may be configured to include additional information regarding a synchronization raster for receiving a second SSB associated with a second satellite identification value in the PBCH. Additionally, the base station may provide the UE with configuration information including index values ​​for synchronization rasters of multiple satellites, and the PBCH may be configured to include an index value among said index values ​​that corresponds to the synchronization raster for receiving the second SSB. Accordingly, the UE can quickly identify the SSB search / reception location corresponding to a specific satellite identification value (e.g., the second satellite identification value) based on the PBCH, and the base station can support reducing unnecessary searches by the UE, thereby reducing SSB search time and system information acquisition delay.

[0233] Based on the method described above, the base station may be configured to provide the UE with multiple SSBs corresponding to each of the multiple satellites. For example, if there are multiple SSBs with the same cell ID but different satellite identification values, the base station may be configured to include a satellite identification value corresponding to the corresponding satellite in each SSB, and by transmitting a corresponding SIB (e.g., SIB19) according to a scramble initial value distinguished by each satellite identification value, the base station may support the UE in reliably obtaining system information distinguished by satellite. As a result, the base station may improve initial connection performance and stability in an NTN environment by enabling the UE to obtain system information distinguished by satellite even in the same cell ID environment, and may support the UE in more appropriately setting RACH-related parameters (e.g., TA) by utilizing satellite orbit information, etc.

[0234] Thus, the proposed invention enables the effective selection and reception of SIBs for satellites corresponding to each SSB through satellite identification values ​​included in the SSBs, even in environments where a base station transmits SSBs corresponding to each satellite via each of the multiple satellites. Alternatively, the proposed invention can mitigate system information conflict or mixing issues that may occur in environments where SSBs for multiple satellites (including those with the same cell ID) are transmitted, by having the UE apply different initial scramble values ​​based on the cell ID and satellite identification values. Alternatively, the proposed invention can reduce the initial cell search and system information acquisition delays by allowing the UE to obtain satellite identification values ​​and synchronization raster-related information for receiving the second SSB through the PBCH, thereby reducing the search range for SSBs corresponding to multiple satellites or shortening the search time.

[0235] Example of a communication system to which the invention is applied

[0236] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods, and / or flowcharts of the invention disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0237] Examples are provided in more detail below with reference to the drawings. In the following drawings and descriptions, the same reference numerals may represent the same or corresponding hardware blocks, software blocks, or function blocks unless otherwise described.

[0238] FIG. 24 illustrates a communication system to which the present invention is applied.

[0239] Referring to FIG. 24, the communication system (1) to which the present invention applies includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Thing) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with wireless communication functions, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and can be implemented in the form of HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) equipped in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Portable devices may include smartphones, smartpads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops, etc.). Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, base stations and networks may be implemented as wireless devices, and a specific wireless device (200a) may operate as a base station / network node to other wireless devices.

[0240] Wireless devices (100a to 100f) can be connected to a network (300) through a base station (200). Artificial Intelligence (AI) technology may be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) through the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices (100a to 100f) may communicate with each other through the base station (200) / network (300), but they may also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0241] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base station (200) and base station (200) / base station (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR), such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and inter-base station communication (150c) (e.g., relay, IAB (Integrated Access Backhaul)). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various proposals of the present invention, at least some of the following may be performed: 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.

[0242] Example of a wireless device to which the present invention is applied

[0243] FIG. 25 illustrates a wireless device that can be applied to the present invention.

[0244] Referring to FIG. 25, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} may correspond to {wireless device (100x), base station (200)} and / or {wireless device (100x), wireless device (100x)} of FIG. 24.

[0245] The first wireless device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memory (104) and / or transceivers (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or flowcharts of operation disclosed in this document. For example, the processor (102) may process information within the memory (104) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (106). Additionally, the processor (102) may receive a wireless signal containing a second information / signal through the transceiver (106) and then store information obtained from the signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may store software code containing instructions for performing some or all of the processes controlled by the processor (102) or for performing the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chipset designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals through one or more antennas (108). The transceiver (106) may include a transmitter and / or receiver. The transceiver (106) may be combined with an RF (Radio Frequency) unit. In the present invention, the wireless device may refer to a communication modem / circuit / chipset.

[0246] Specifically, the first wireless device or UE (100) may include a processor (102) connected to a transceiver (106) and a memory (104). The memory (104) may include at least one program capable of performing operations related to embodiments proposed in the section “Method for distinguishing multiple satellites within the same carrier” in FIGS. 18 to 21. The operations include controlling the transceiver (106) to receive a first SSB (Synchronization Signal Block) containing at least one synchronization signal and a PBCH (physical broadcast channel) from a base station; and receiving a SIB (System Information Block) based on the first SSB. and perform a RACH (Random Access Channel) procedure with the base station based on the first SSB and the SIB, and based on the first SSB being received through an NTN (Non-Terrestrial Network), the first SSB includes a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and the SIB can be received based on the cell ID and the first satellite identification value.

[0247] Alternatively, a processing device may be configured including a processor (102) and a memory (104) that controls the UE (100). In this case, the processing device may include at least one processor; and at least one memory connected to the at least one processor and storing instructions that perform operations when executed by the at least one processor. The operations include receiving a first SSB (Synchronization Signal Block) containing at least one synchronization signal and a PBCH (physical broadcast channel) from a base station; receiving a SIB (System Information Block) based on the first SSB; and performing a RACH (Random Access Channel) procedure with the base station based on the first SSB and the SIB, and based on the first SSB being received through a NTN (Non-Terrestrial Network), the first SSB may include a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and the SIB may be received based on the cell ID and the first satellite identification value.

[0248] The second wireless device (200) includes one or more processors (202) and one or more memories (204), and may additionally include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memory (204) and / or transceivers (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or operation sequences disclosed in this document. For example, the processor (202) may process information within the memory (204) to generate a third information / signal and then transmit a wireless signal containing the third information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and then store information obtained from the signal processing of the fourth information / signal in the memory (204). 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 containing 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 operation sequences disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through one or more antennas (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeable with an RF unit. In the present invention, the wireless device may refer to a communication modem / circuit / chip.

[0249] Specifically, the second wireless device or base station (200) may include a processor (202) and a memory (204) connected to a transceiver or RF transceiver (206). The memory (204) may include at least one program capable of performing operations related to the embodiments proposed in the section “Method for distinguishing multiple satellites within the same carrier” of FIGS. 16 to 21. The above operations control an RF transceiver (206) to transmit a first SSB (Synchronization Signal Block) including at least one synchronization signal and a PBCH (physical broadcast channel), transmit a SIB (System Information Block) based on the first SSB, perform a RACH (Random Access Channel) procedure with a UE (user equipment) based on the first SSB and the SIB, and based on the first SSB being transmitted through a NTN (Non-Terrestrial Network), the first SSB includes a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and the SIB can be transmitted based on the cell ID and the first satellite identification value.

[0250] Hereinafter, hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate a signal (e.g., baseband signal) containing a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this document and provide it to one or more transceivers (106, 206). One or more processors (102, 202) may receive a signal (e.g., baseband signal) from one or more transceivers (106, 206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document.

[0251] One or more processors (102, 202) may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or 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. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be contained in one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0252] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memories (104, 204) may be composed of ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0253] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc., of this document to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc., disclosed in this document from one or more other devices. For example, one or more transceivers (106, 206) may be connected to one or more processors (102, 202) and may transmit and receive wireless signals. For example, one or more processors (102, 202) may control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be connected to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document through one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert the received wireless signal / channel, etc. from an RF band signal to a baseband signal in order to process the received user data, control information, wireless signal / channel, etc. using one or more processors (102, 202).One or more transceivers (106, 206) can convert user data, control information, wireless signals / channels, etc. processed using one or more processors (102, 202) from baseband signals to RF band signals. To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters.

[0254] Examples of wireless device applications to which the present invention is applied

[0255] FIG. 26 illustrates another example of a wireless device to which the present invention applies. The wireless device may be implemented in various forms depending on the use-example / service (see FIG. 24).

[0256] Referring to FIG. 26, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 25 and may be composed of various elements, components, units / parts, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 26. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 25. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and additional elements (140) and controls the general operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on a program / code / command / information stored in the memory unit (130). Additionally, the control unit (120) may transmit information stored in the memory unit (130) to an external (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external (e.g., another communication device) via a wireless / wired interface through the communication unit (110) in the memory unit (130).

[0257] The additional element (140) can be configured in various ways depending on the type of wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 24, 100a), a vehicle (Fig. 24, 100b-1, 100b-2), an XR device (Fig. 24, 100c), a portable device (Fig. 24, 100d), a home appliance (Fig. 24, 100e), an IoT device (Fig. 24, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or financial device), a security device, a climate / environment device, an AI server / device (Fig. 24, 400), a base station (Fig. 24, 200), a network node, etc. Wireless devices can be used in a movable or fixed location depending on the use—e.g., service.

[0258] In FIG. 26, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least a portion may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and the first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). Additionally, each element, component, unit / part, and / or module within the wireless device (100, 200) may include one or more additional elements. For example, the control unit (120) may be composed of one or more sets of processors. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an Electronic Control Unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory and / or a combination thereof.

[0259] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0260] FIG. 27 illustrates a vehicle or autonomous vehicle to which the present invention applies. The vehicle or autonomous vehicle may be implemented as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, etc.

[0261] Referring to FIG. 27, a vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a driving unit (140a), a power supply unit (140b), a sensor unit (140c), and an autonomous driving unit (140d). The antenna unit (108) may be configured as part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 26, respectively.

[0262] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, roadside base stations (Roadside units), etc.), and servers. The control unit (120) can perform various operations by controlling elements of the vehicle or autonomous vehicle (100). The control unit (120) may include an Electronic Control Unit (ECU). The driving unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The driving unit (140a) may include an engine, motor, power train, wheels, brakes, steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and may include wired / wireless charging circuits, batteries, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement technologies such as maintaining the driving lane, technologies for automatically adjusting speed such as adaptive cruise control, technologies for automatically driving along a predetermined path, and technologies for automatically setting a path and driving when a destination is set.

[0263] For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving path and a driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or the autonomous vehicle (100) moves along the autonomous driving path according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can acquire the latest traffic information data from an external server non-periodically and can acquire surrounding traffic information data from surrounding vehicles. Additionally, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving path and the driving plan based on the newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving path, driving plan, etc. to an external server. An external server can predict traffic information data in advance using AI technology, etc., based on information collected from vehicles or autonomous vehicles, and can provide the predicted traffic information data to vehicles or autonomous vehicles.

[0264] Here, the wireless communication technology implemented in the wireless device (XXX, YYY) of this specification may include LTE, NR, and 6G, as well as 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 according to standards such as LTE Cat NB1 and / or LTE Cat NB2, but is not limited to the names mentioned above. Additionally, or generally, the wireless communication technology implemented in the wireless device (XXX, YYY) of this specification may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be referred to by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented in at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the names mentioned above. Additionally or generally, wireless communication technology implemented in the wireless device (XXX, YYY) of this specification may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) with consideration for low-power communication, and is not limited to the names mentioned above. As an example, ZigBee technology can create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and may be referred to by various names.

[0265] The embodiments described above are combinations of the components and features of the present invention in a specific form. Each component or feature should be considered optional unless otherwise explicitly stated. Each component or feature may be implemented in a form not combined with other components or features. Additionally, it is possible to construct embodiments of the present invention by combining some components and / or features. The order of operations described in the embodiments of the present invention 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 obvious that embodiments may be constructed by combining claims that do not have an explicit citation relationship in the claims, or that new claims may be included by amendment after filing.

[0266] In this document, embodiments of the present invention are described primarily with a focus on the signal transmission and reception relationship between a terminal and a base station. This transmission and reception relationship is extended in the same or similar manner to signal transmission and reception between a terminal and a relay or between a base station and a relay. Specific operations described in this document as being performed by a base station may, in some cases, be performed by an upper node. That is, it is self-evident that various operations performed for communication with a terminal in a network consisting of multiple network nodes including a base station may be performed by the base station or other network nodes other than the base station. The base station may be replaced by terms such as fixed station, Node B, eNode B (eNB), and access point. Additionally, the terminal may be replaced by terms such as User Equipment (UE), Mobile Station (MS), and Mobile Subscriber Station (MSS).

[0267] Embodiments according to the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of implementation by hardware, one embodiment of the present invention may be implemented by one or more ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), processors, controllers, microcontrollers, microprocessors, etc.

[0268] In the case of implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc., that performs the functions or operations described above. Software code may be stored in a memory unit and executed by a processor. The memory unit may be located inside or outside the processor and may exchange data with the processor by various means already known.

[0269] It is obvious to those skilled in the art that the present invention may be embodied in other specific forms without departing from the features of the invention. Accordingly, the foregoing detailed description should not be interpreted restrictively in all respects but should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention.

[0270] The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims

1. In a method using UE (User Equipment), A step of receiving a first SSB (Synchronization Signal Block) including at least one synchronization signal and a PBCH (physical broadcast channel) from a base station; A step of receiving a SIB (System Information Block) based on the first SSB; and It includes the step of performing a RACH (Random Access Channel) procedure with the base station based on the first SSB and the SIB, and Based on the fact that the first SSB is received via an NTN (Non-Terrestrial Network), the UE obtains a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN from the first SSB, and A method in which the above SIB is received based on the cell ID and the first satellite identification value.

2. In Paragraph 1, The above UE determines a scramble initial value associated with the SIB based on the cell ID and the first satellite identification value, and A method in which the above SIB is decoded based on the above scrambled initial value.

3. In Paragraph 2, A method in which the above scramble initial value is determined based on the value obtained by adding the first satellite identification value to the cell ID.

4. In Paragraph 1, The above first satellite identification value is included in the above PBCH, method.

5. In Paragraph 1, A method in which the above SIB is SIB19 containing satellite orbit information for the above NTN corresponding to the above first satellite identification value.

6. In Paragraph 5, A method in which the above UE determines a TA (timing advance) value related to the RACH procedure based on the above satellite orbit information.

7. In Paragraph 1, The above PBCH further includes information for a synchronization raster for receiving a second SSB associated with a second satellite identification value.

8. In Paragraph 7, The method further includes the step of receiving configuration information from the base station that includes index values ​​for synchronization rasters of a plurality of satellites. A method in which the above PBCH includes an index value among the above index values ​​that corresponds to a synchronization raster for receiving the second SSB.

9. In Paragraph 1, A method in which the above UE receives a plurality of SSBs corresponding to each of the plurality of satellites from the base station.

10. In at least one non-transient computer-readable recording medium, Includes instructions that perform operations when executed by at least one processor, The above operations are, Receiving a first SSB (Synchronization Signal Block) from a base station, comprising at least one synchronization signal and a PBCH (physical broadcast channel); Receiving a SIB (System Information Block) based on the above-mentioned first SSB; and It includes performing a RACH (Random Access Channel) procedure with the base station based on the first SSB and the SIB, and Based on the fact that the first SSB is received via an NTN (Non-Terrestrial Network), the first SSB includes a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and The above SIB is at least one non-transient computer-readable recording medium received based on the cell ID and the first satellite identification value.

11. Regarding UE (user equipment), RF (Radio Frequency) transceiver; and It includes a processor connected to the above RF transceiver, and The processor controls the RF transceiver to receive a first SSB (Synchronization Signal Block) from a base station comprising at least one synchronization signal and a PBCH (physical broadcast channel), receives a SIB (System Information Block) based on the first SSB, and performs a RACH (Random Access Channel) procedure with the base station based on the first SSB and the SIB. Based on the fact that the first SSB is received via an NTN (Non-Terrestrial Network), the first SSB includes a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and The above SIB is a UE received based on the cell ID and the first satellite identification value.

12. In Paragraph 11, The processor determines a scramble initial value associated with the SIB based on the cell ID and the first satellite identification value, and The above SIB is a UE that is decoded based on the above scrambled initial value.

13. In a processing device for controlling UE (user equipment), At least one processor; and It includes at least one memory that stores instructions connected to the above-mentioned at least one processor and performing operations when executed by the at least one processor, The above operations are, Receiving a first SSB (Synchronization Signal Block) from a base station, comprising at least one synchronization signal and a PBCH (physical broadcast channel); Receiving a SIB (System Information Block) based on the above-mentioned first SSB; and It includes performing a RACH (Random Access Channel) procedure with the base station based on the first SSB and the SIB, and Based on the fact that the first SSB is received via an NTN (Non-Terrestrial Network), the first SSB includes a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and The above SIB is a processing device received based on the cell ID and the first satellite identification value.

14. In the method using a base station, A step of transmitting a first SSB (Synchronization Signal Block) comprising at least one synchronization signal and a PBCH (physical broadcast channel); A step of transmitting a SIB (System Information Block) based on the first SSB above; and It includes the step of performing a RACH (Random Access Channel) procedure with UE (user equipment) based on the first SSB and the SIB, and Based on the fact that the first SSB is transmitted through an NTN (Non-Terrestrial Network), the first SSB includes a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and A method in which the above SIB is transmitted based on the cell ID and the first satellite identification value.

15. Regarding base stations, RF (Radio Frequency) transceiver; and It includes a processor connected to the above RF transceiver, and The processor controls the RF transceiver to transmit a first SSB (Synchronization Signal Block) comprising at least one synchronization signal and a PBCH (physical broadcast channel), transmits a SIB (System Information Block) based on the first SSB, and performs a RACH (Random Access Channel) procedure with a UE (user equipment) based on the first SSB and the SIB. Based on the fact that the first SSB is transmitted through an NTN (Non-Terrestrial Network), the first SSB includes a cell ID (identifier) ​​for the base station and a first satellite identification value associated with the NTN, and The above SIB is a base station that is transmitted based on the cell ID and the first satellite identification value.

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