Method for communicating in wireless communication system and device therefor

Abstract

A device according to various embodiments may: receive first system information related to a TN cell; receive second system information related to an NTN cell; and initiate a TAU procedure on the basis of at least one TAC included in the second system information not being included in a TAC list of a UE.

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 first system information related to a TN (Terrestrial Network) cell; receiving second system information related to a NTN (Non-Terrestrial Network) cell; and initiating a TAU (Tracking Area Update) procedure based on the fact that at least one TAC (Tracking Area Code) included in the second system information is not included in the TAC list of the UE, and based on the fact that the UE supports dual connection to the TN cell and the NTN cell, the TAU procedure may be performed only through the TN cell and not the NTN cell.

[0018] Alternatively, the TAU procedure may include transmitting a message to the TN cell that includes information about at least one TAC included in the second system information.

[0019] Alternatively, based on the fact that the TAC value is common between the NTN cell and the TN cell, the message may further include information indicating whether the at least one TAC belongs to the TN cell or the NTN cell.

[0020] Alternatively, based on the fact that the TAC list of the UE does not include both the at least one TAC and the TAC included in the first system information, the UE may include the at least one TAC and the TAC together in the message and transmit it to the TN cell.

[0021] Alternatively, the above TAU procedure may be initiated based on the fact that the above TAC list does not include all of the at least one TAC.

[0022] Alternatively, based on (i) the UE supports dual connectivity to the TN cell and the NTN cell, and (ii) being within the coverage of the TN cell, the TAU procedure may be performed only through the TN cell and not the NTN cell.

[0023] Alternatively, the second system information may further include information regarding an effective time interval corresponding to each of the at least one TAC.

[0024] Alternatively, the above UE may be in an RRC (radio resource control) idle or inactive state.

[0025] 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 first system information related to a TN (Terrestrial Network) cell; receiving second system information related to an NTN (Non-Terrestrial Network) cell; and initiating a TAU (Tracking Area Update) procedure based on the fact that at least one TAC (Tracking Area Code) included in the second system information is not included in the TAC list of the UE, and based on the fact that dual connection to the TN cell and the NTN cell is supported, said TAU procedure may be performed only through the TN cell and not the NTN cell.

[0026] According to another aspect, a User Equipment (UE) comprises a Radio Frequency (RF) transceiver; and a processor connected to the RF transceiver, wherein the processor controls the RF transceiver to receive first system information related to a Terrestrial Network (TN) cell and receives second system information related to a Non-Terrestrial Network (NTN) cell, and initiates a Tracking Area Update (TAU) procedure based on the fact that at least one Tracking Area Code (TAC) included in the second system information is not included in the TAC list of the UE, and based on the fact that the UE supports dual connection to the TN cell and the NTN cell, the TAU procedure can be performed only through the TN cell and not the NTN cell.

[0027] 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 first system information related to a TN (Terrestrial Network) cell; receiving second system information related to a NTN (Non-Terrestrial Network) cell; and initiating a TAU (Tracking Area Update) procedure based on the fact that at least one TAC (Tracking Area Code) included in the second system information is not included in the TAC list of the UE, and based on the fact that the UE supports dual connection to the TN cell and the NTN cell, the TAU procedure may be performed only through the TN cell and not the NTN cell.

[0028] A method by a base station according to another aspect comprises the step of transmitting first system information including a TAC (Tracking Area Code) associated with a TN (Terrestrial Network) cell; and the step of receiving a message from a UE (user equipment) including the transmitted TAC information by initiating a TAU (Tracking Area Update) procedure, wherein, based on the UE supporting dual connection to the TN cell and the NTN cell, the message may include information regarding at least one TAC associated with a NTN (Non-Terrestrial Network) cell.

[0029] A base station according to another aspect includes an RF (Radio Frequency) transceiver; and a processor connected to the RF transceiver, wherein the processor controls the RF transceiver to transmit first system information including a TAC (Tracking Area Code) associated with a TN (Terrestrial Network) cell, and receives a message from a UE (user equipment) including the transmitted TAC information by initiating a TAU (Tracking Area Update) procedure, and based on the UE supporting dual connection to the TN cell and the NTN cell, the message may include information regarding at least one TAC associated with a NTN (Non-Terrestrial Network) cell.

[0030] According to one embodiment, signals can be transmitted and received more accurately and efficiently in a wireless communication system. According to one example, when a UE supports dual connections to a TN cell and an NTN cell, power consumption and signaling load caused by TAU procedures performed independently for each TN cell and TNT cell can be minimized by restricting the UE to perform TAU procedures only through the TN cell.

[0031] 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.

[0032] 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.

[0033] Figure 1 is a diagram illustrating a comparison between V2X communication based on RAT prior to NR and V2X communication based on NR.

[0034] Figure 2 shows the structure of an LTE system.

[0035] Figure 3 shows the structure of the NR system.

[0036] Figure 4 shows the structure of a wireless frame of NR.

[0037] Figure 5 shows the slot structure of an NR frame.

[0038] FIG. 6 shows a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure.

[0039] FIG. 7 shows an electromagnetic spectrum according to one embodiment of the present disclosure.

[0040] Figure 8 shows the radio protocol architecture for SL communication.

[0041] Figure 9 shows a terminal performing V2X or SL communication.

[0042] Figure 10 shows a resource unit for V2X or SL communication.

[0043] FIG. 11 shows an example of a BWP according to one embodiment of the present disclosure.

[0044] 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.

[0045] FIG. 13 shows an example of a general NTN scenario based on a transparent payload or a regenerated payload according to one embodiment.

[0046] Figures 14 and 15 are drawings for explaining the coverage of NTN.

[0047] Figures 16 and 17 are diagrams illustrating a TAU procedure based on TN and NTN multiple connections.

[0048] Figures 18 and 19 are diagrams illustrating how a UE capable of dual connection to a TN cell and an NTN cell performs a TAU procedure.

[0049] Figure 20 is a diagram illustrating how a UE performs a TAU procedure.

[0050] Figure 21 is a diagram illustrating how a base station performs a TAU procedure with a UE.

[0051] FIG. 22 illustrates a communication system to which the present invention is applied.

[0052] FIG. 23 illustrates a wireless device that can be applied to the present invention.

[0053] FIG. 24 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.

[0054] FIG. 25 illustrates a vehicle or autonomous vehicle to which the present invention is applied.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] Figure 3 shows the structure of the NR system.

[0068] 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.

[0069] Figure 4 shows the structure of a wireless frame of NR.

[0070] 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).

[0071] 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).

[0072] 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.

[0073] 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

[0074] 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.

[0075] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0076] 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.

[0077] 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.

[0078] 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).

[0079] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0080] 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).

[0081] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0082] Figure 5 shows the slot structure of an NR frame.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] New network characteristics in 6G may be as follows.

[0088] - Satellite Integrated Network

[0089] - 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).

[0090] - Seamless integration of wireless information and energy transfer

[0091] - 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.

[0092] Some general requirements regarding the new network characteristics of 6G mentioned above may be as follows.

[0093] - Small cell networks

[0094] - Ultra-dense heterogeneous network

[0095] - High-capacity backhaul

[0096] - 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.

[0097] - Softwarization and virtualization

[0098] The core implementation technologies of the 6G system are described below.

[0099] - 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.

[0100] - 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.

[0101] 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.

[0102] - Large-scale MIMO technology

[0103] - Hologram beamforming (HBF)

[0104] - Optical wireless technology

[0105] - Free Space Optical Transmission Backhaul Network (FSO backhaul network)

[0106] - Quantum communication

[0107] - Cell-free communication

[0108] - Integration of wireless information and power transmission

[0109] - Integration of wireless communication and sensing

[0110] - Integrated access and backhaul network

[0111] - Big data analysis

[0112] - Reconfigurable intelligent metasurface

[0113] - Metaverse

[0114] - blockchain

[0115] - 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.

[0116] - 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 merely 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.

[0117] FIG. 8 illustrates a radio protocol architecture for SL communication. Specifically, FIG. 8 (a) shows the user plane protocol stack of NR, and FIG. 8 (b) shows the control plane protocol stack of NR.

[0118] The Sidelink Synchronization Signal (SLSS) and synchronization information are described below.

[0119] 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-SSSS to obtain detailed synchronization and detect a synchronization signal ID.

[0120] 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.

[0121] 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 span 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] Figure 9 shows a terminal performing V2X or SL communication.

[0127] 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).

[0128] 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.

[0129] 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.

[0130] 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.

[0131] Figure 10 shows a resource unit for V2X or SL communication.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] (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.

[0136] (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.

[0137] (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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] A BWP can be configured by point A, an offset from point A (NstartBWP), and a bandwidth (NsizeBWP). 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 on that carrier) is aligned. For example, the offset may be the PRB interval between the lowest subcarrier in a given numerology and point A. For example, the bandwidth may be the number of PRBs in a given numerology.

[0142] 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-SSSS to obtain detailed synchronization and detect the synchronization signal ID.

[0143] 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).

[0144] 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 span 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] FIG. 13 shows an example of a general NTN scenario based on a transparent payload or a regenerated payload according to one embodiment.

[0154] 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).

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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).

[0159] 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.

[0160] 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.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] Figures 14 and 15 are drawings for explaining the coverage of NTN.

[0168] 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.

[0169] 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).

[0170] 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.

[0171] 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.

[0172] 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.

[0173] 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.

[0174] TAU (Tracking Area Update)

[0175] In mobile communication systems, UEs connect to the network via a radio access network (RAN), and the concept of a Tracking Area (TA) is introduced to efficiently manage the location of terminals. In order for terminals to maintain location information and receive appropriate services even while moving, the network performs procedures to track and update the location of terminals. To this end, 3GPP defines the Tracking Area Identity (TAI) and Tracking Area Update (TAU) procedures.

[0176] A TAI is an identifier used to globally identify a specific tracking area where a terminal is located, and consists of a PLMN ID, which is an identifier for a Public Land Mobile Network (PLMN), and a Tracking Area Code (TAC). Here, the PLMN ID consists of a Mobile Country Code (MCC) and a Mobile Network Code (MNC), and the TAC is a code that identifies an individual tracking area within the corresponding PLMN. In other words, the TAI has a structure of “MCC + MNC + TAC,” and even if the TAC is the same, it can be distinguished as a different TAI in different PLMNs.

[0177] The terminal receives and stores a TAI list (or TAC list) from the network, and may move within a Tracking Area included in this list without a separate location update procedure. However, if the terminal moves to a TAI not included in its TAI list, it must immediately perform a TAU procedure to notify the network of its current Tracking Area. Additionally, the TAU may be triggered when the terminal's wireless connection status changes, when a timer (such as T3412) managing the location update cycle expires, or by a request from the network.

[0178] The TAU procedure may be initiated by the terminal generating a TAU request message and transmitting it to the core network (MME or AMF in the case of 5G) via the base station. The TAU request message may include the TAI where the terminal is currently located, the terminal identifier (GUTI or IMSI), the request type (period update, update due to movement, etc.), terminal status information, security information, etc. The network receives such information, checks whether the terminal's location has changed and its status, and can perform authentication and security reset if necessary.

[0179] If the network determines that the terminal's TAU request is valid, it may allocate a new TAI List to the terminal and generate and transmit a TAU Accept message to the terminal. The TAU Accept message may include a list of newly allowed tracking areas, along with EPS bearer settings, session information, and DRX-related parameters. Upon receiving this message, the terminal can complete the TAU procedure by transmitting a TAU Complete message to the network. Through this TAU procedure, the terminal can continuously maintain its location information up to date even while moving, and the network can efficiently utilize wireless resources by performing paging only on the area where the terminal is located. For example, TAI enables the global identification of the terminal's location across the entire PLMN, allowing for consistent location tracking and mobility control even in a multi-operator environment. Furthermore, the TAU procedure can be linked with DRX settings that consider the terminal's battery life and can contribute to reducing signaling load by being executed conditionally based on the terminal's state.

[0180] TAU operation method in NTN-TN multiple connections

[0181] Figures 16 and 17 are diagrams illustrating a TAU procedure based on TN and NTN multiple connections.

[0182] 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).

[0183] 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.

[0184] 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.

[0185] 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.

[0186] The following describes in detail how to perform the TAU procedure when a single UE has multi-connection capabilities and has multiple connections to the TN (or TN cell) and NTN (or NTN cell).

[0187] Figures 18 and 19 are diagrams illustrating how a UE capable of dual connection to a TN cell and an NTN cell performs a TAU procedure.

[0188] As described above, the UE may be capable of dual connectivity for TN cells and NTN cells. The geographical TA layout of the TN may be applied / used identically for the NTN cells. For example, the network may be configured to use the same TAC value for TN cells and NTN cells. Referring to FIG. 18 (a), when an NTN cell (e.g., a moving cell) enters the area corresponding to TAC 5 and TAC 6 at time T1, the NTN cell may broadcast TAC information for TAC 5 and TAC 6 via SIB1 (or SIB 19). As illustrated in FIG. 18 (b), when the NTN cell moves to the left and enters the area corresponding to TAC 3 and TAC 4 at time T2, the NTN cell may broadcast TAC information for TAC 3, TAC 4, TAC 5, and TAC 6 via SIB1 (or SIB 19). At this time, if a UE located in a geographical area corresponding to TAC4 has a TAC list of {TAC1, TAC2, TAC3, TAC4}, the UE may not need to perform a TAC update in relation to the NTN cell. This is because the network (e.g., core network; CN) can broadcast a paging message via satellite to the area to which the UE belongs, and the IDLE / INACTIVE UE can become RRC CONNECTED upon receiving the paging message.

[0189] Alternatively, referring to FIG. 19 (a) and (b), TACs for TN cells (or, TN) and NTN cells (NTN) can be assigned / placed / set independently of each other for the same geographical area.

[0190] Specifically, referring to FIG. 19 (a), there may be no overlap between the TAC values ​​for the TN cell and the TAC values ​​for the NTN cell (Case 1). For example, if a UE located in the TAC4 area and having a TAC list of {TAC1, TAC2, TAC3, TAC4} moves to the TAC6 area, the UE may receive information about TAC6 from the TN cell (or TN gNB) via SIB1, and may receive information about TAC7 and TAC8 from the NTN cell (or NTN gNB) via SIB1. In this case, the UE must be able to update the TACs included in the TAC list to the TAC6, TAC7, and TAC8 values.

[0191] Alternatively, referring to FIG. 19 (b), there may be overlap between the TAC value for the TN cell and the TAC value for the NTN cell (Case 2). This may be similar to Case 1 described above, but the TAC value of the NTN cell may be placed to overlap with the TAC value of the nearby cell. For example, the TAC value of the NTN cell may overlap with the TAC value of the nearby cell for the TN cell. In this case, the UE performs a TAC update procedure, but it may be necessary to indicate whether the TAC value for the TAC update belongs to the TN cell (or TN) or the NTN cell (or NTN). For example, when the UE reports a TAC value recognized / received from the TN cell to the NTN cell, or reports a TAC value recognized / received from the NTN cell to the TN cell, an indication of which cell the TAC value belongs to may be required. In the case where a gNB that has received a report on such a TAC value sets an appropriate TAI list for the UE, it must also be distinguished whether the setting of the TAI list is a TAC value corresponding to TN or a TAC value corresponding to NTN.

[0192] In at least one of the cases illustrated in FIG. 18 and / or FIG. 19, a UE having multi-connection capability (e.g., dual connection capability for TN cells and NTN cells) can perform the following operations.

[0193] If a TAC value that does not exist in the current UE's TAC list is received through a TN cell (or TN gNB) (legacy operation), or if multiple TAC values ​​broadcast by an NTN cell (NTN gNB) are not all included in the current UE's TAC list, the UE may report the TAC value received through the TN cell or the TAC values ​​received from the NTN cell (or TN or NTN) (to the network). For example, if an NTN cell broadcasts multiple TACs, the UE may report all of the multiple TACs (or multiple TAC values) received from the NTN cell if none of the TAC values ​​corresponding to the multiple TACs are included in its TAC list.

[0194] Alternatively, if the UE is located within the cell coverage of the TN, the UE may report both the TAC information of the TN and the TAC information of the NTN only to the TN cell (or TN). For example, if a UE capable of connecting to both the NTN cell and the TN cell is located within the coverage of the TN cell, TAC reporting from the UE may be restricted to being performed only to the TN cell (e.g., the TAU procedure may be performed only through the TN cell). For example, if the UE connects to a gNB of a TN to report TAC information, the AMF of the CN may roughly determine where the UE is located. For example, if the UE connects to a gNB of a TN to report TAC information and reports TAC information, the AMF of the CN may roughly determine where the UE is located through the reported TAC information. This is because, from the perspective of the CN AMF, the cell coverage of NTN is much larger than that of TN, making it easier to estimate the location of the UE when the UE performs the TAC update (or TA update) through TN rather than the NTN cell.

[0195] Accordingly, if a UE with multi-connection capabilities is within the cell coverage of a TN, the UE may perform a TAC update through the TN, and may also update the TAC information of the NTN through the TN. For example, if a UE with multi-connection capabilities is within the cell coverage of a TN, the UE may report to the TN (or TN cell) even if the TAC information is for the NTN. Conversely, if the UE is in the OoC (e.g., in an area outside the coverage of a TN cell), it may perform a TAC update through the NTN cell. For example, if the UE is in the OoC (e.g., in an area outside the coverage of a TN cell), it may perform a TAC update by reporting the TAC information of the NTN cell to the NTN cell.

[0196] The method of reporting TAC information for such TAC updates has the technical effect of effectively reducing the power and effort required for TAC updates compared to existing methods (e.g., updating TAC recognized by TN only through TN, and updating TAC recognized by NTN only through NTN), in that a UE capable of simultaneous link connection to both TN cells and NTN cells reports TAC for the other using either TN or NTN. For example, the proposed method described above can effectively reduce the energy / power required for TAU by a UE in an RRC IDLE / INACTIVE state with multi-connection capabilities.

[0197] Figure 20 is a diagram illustrating how a UE performs a TAU procedure.

[0198] The UE receives system information containing information regarding TAC from the network / base station while in an RRC idle or inactive state, and can determine whether to initiate the TAU procedure based on the information regarding the TAC. Below, based on the content described in the section "Method for TAU Operation in NTN-TN Multiple Connections," a method for performing the TAU procedure in the UE is described in more detail when the UE has the capability to enable dual connections to both an NTN cell (or an NTN base station or NTN) and a TN cell (or a TN base station or TN).

[0199] Referring to FIG. 20, the UE can receive first system information related to a TN (Terrestrial Network) cell (S201). Here, the first system information may include information on mobility and area identification parameters (e.g., TAC, RANAC (RAN Area Code), PLMN Identity List, etc.), information on identification and connection control parameters (e.g., Cell Identity, NR Cell Global Identity, gNB-ID-Length, Cell Barred, etc.), and information on radio resources and physical layer parameters (NR Frequency Band, SSB, SMTC (SSB Measurement Timing Configuration), etc.).

[0200] Next, the UE may receive second system information related to a Non-Terrestrial Network (NTN) cell (S203). Here, the second system information may include SIB1 and / or SIB19. In the case of SIB1, it may include a cellBarredNTN field for network type identification, a trackingAreaList field for at least one TAC, etc., and in the case of SIB19, it may include orbit information, common TA, scheduling offset, synchronization validity period and reference time, service duration (t-Service), etc. as described above. Meanwhile, the UE may receive the first system information after receiving the second system information, or may receive the first and second system information simultaneously, and the content of the proposed invention is not limited by the order of receiving the two information.

[0201] Alternatively, the second system information may further include information regarding a valid time interval corresponding to each of the at least one TAC. In this case, the UE can determine a valid TAC among the at least one TAC based on the valid time interval.

[0202] Next, the UE may initiate a Tracking Area Update (TAU) procedure based on at least one of the first system information and the second system information (S205). For example, if a TAC included in the first system information or at least one TAC (or TAI) included in the second system information is not included in the UE's TAC list (or TAI list), the UE may initiate a TAU procedure for updating the TAC list, etc. Here, the UE may initiate the TAU procedure only when all of the plurality of TACs included in the second system information for the NTN cell are not included in the TAC list. For example, if any one of the plurality of TACs is included in the TAC list, the UE may not initiate the TAU procedure.

[0203] When the above TAU procedure is initiated, the UE may perform the TAU procedure with the cell associated with the TAC requiring update among the NTN cell and the TN cell. However, if the UE supports dual connections to the TN cell and the NTN cell, the UE may perform the TAC procedure only through the TN cell and not the NTN cell, even if the TAC information to be updated by the TAU procedure pertains to the NTN cell. In this case, the UE may transmit a message containing information regarding at least one TAC included in the second system information to the TN cell. For example, the UE may transmit a message containing the TAC information only to the TN cell, even if the TAC information to be transmitted pertains to the NTN cell.

[0204] Alternatively, as described above, if the second system information includes information regarding the valid time interval, the UE may determine whether to initiate the TAU procedure by considering only the remaining TACs among the at least one TAC, excluding the TACs that are invalid based on the valid time interval. For example, the UE may perform the TAU procedure only if none of the remaining TACs are included in the TAC list. For example, the UE may not consider whether the excluded TACs are included in the TAC list.

[0205] Alternatively, the UE may additionally consider whether it is within the coverage of the TN cell. For example, if the UE supports dual connectivity to the TN cell and the NTN cell and is located within the coverage of the TN cell, the UE may perform the TAC procedure only through the TN cell and not the NTN cell.

[0206] Alternatively, the message transmitted for the TAU procedure may further include indication information regarding whether the at least one TAC belongs to the TN cell or the NTN cell. For example, as illustrated in FIG. 18, if the TAC values ​​are assigned commonly or identically between the NTN cell and the TN cell, the UE may inform the TN cell that the at least one TAC belongs to the NTN cell through the indication information.

[0207] Alternatively, the TAC list of the UE may not include both the at least one TAC and the TAC included in the first system information. In this case, the UE supporting TN / NTN dual connection / multiple connection may perform the TAU procedure only through the TN cell, and may transmit the at least one TAC and a single message including the TAC together to the TN cell.

[0208] Figure 21 is a diagram illustrating how a base station performs a TAU procedure with a UE.

[0209] Referring to FIG. 21, the base station may be a TN cell which is a ground base station, and may transmit / broadcast first system information related to the TN cell as described above (S211). Here, the first system information may include information on mobility and area identification parameters (e.g., TAC, RANAC (RAN Area Code), PLMN Identity List, etc.), information on identification and connection control parameters (e.g., Cell Identity, NR Cell Global Identity, gNB-ID-Length, Cell Barred, etc.), and information on wireless resources and physical layer parameters (NR Frequency Band, SSB, SMTC (SSB Measurement Timing Configuration), etc.).

[0210] Next, the base station may receive a message from the UE containing TAC information transmitted by initiating the TAU procedure (S213). As described above, if the UE supports TN / NTN multiple / duplex connections, the base station may receive a message containing information about at least one TAC related to an NTN cell rather than a TN cell. For example, if at least one TAC included in the second system information received from the NTN cell is not included in the TAC list, the UE may initiate the TAU procedure. In this case, as described above, even if the TAU procedure was initiated based on at least one TAC for the NTN cell, the UE may perform the TAU procedure only through the base station which is a TN cell rather than an NTN cell. In this case, the base station may perform the TAU procedure based on a message containing information about at least one TAU from the UE. For example, the base station may perform an operation to update the TAC information for the UE based on the at least one TAU. In addition, based on the updated TAC information, a paging message for a UE that is in an RRC idle or inactive state can be sent to the UE.

[0211] Thus, the proposed invention can minimize power consumption and signaling load caused by TAU procedures performed independently for each TN cell and TNT cell by restricting the TAU procedure to be performed only through the TN cell when the UE is capable of dual connection to the TN cell and the NTN cell. And / or, the proposed invention can enable the AMF of the core network to more easily estimate the location of the UE by having the TAU procedure related to the NTN cell also be performed through the TN cell, which has a narrower coverage than the NTN cell.

[0212] Example of a communication system to which the invention is applied

[0213] 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.

[0214] 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.

[0215] FIG. 22 illustrates a communication system to which the present invention is applied.

[0216] Referring to FIG. 22, 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.

[0217] 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).

[0218] 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.

[0219] Example of a wireless device to which the present invention is applied

[0220] FIG. 23 illustrates a wireless device that can be applied to the present invention.

[0221] Referring to FIG. 23, 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. 22.

[0222] 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.

[0223] 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 the embodiments proposed in the section “Method of TAU operation in NTN-TN multiple connection” in FIGS. 16 to 21. The operations include receiving first system information related to a TN (Terrestrial Network) cell, receiving second system information related to an NTN (Non-Terrestrial Network) cell, and initiating a TAU (Tracking Area Update) procedure based on the fact that at least one TAC (Tracking Area Code) included in the second system information is not included in the TAC list of the UE, and based on the fact that dual connection to the TN cell and the NTN cell is supported, the TAU procedure may be performed only through the TN cell and not the NTN cell.

[0224] Alternatively, a processing device may be configured including a processor (102) and a memory (104) that control 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 first system information related to a TN (Terrestrial Network) cell, receiving second system information related to a NTN (Non-Terrestrial Network) cell, and initiating a TAU (Tracking Area Update) procedure based on the fact that at least one TAC (Tracking Area Code) included in the second system information is not included in the TAC list of the UE, and based on the fact that dual connection to the TN cell and the NTN cell is supported, the TAU procedure may be performed only through the TN cell and not the NTN cell.

[0225] 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 sequence diagrams 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.

[0226] 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 of TAU operation in NTN-TN multiple connection” in FIGS. 16 to 21. The operations include controlling the RF transceiver to transmit first system information including a TAC (Tracking Area Code) related to a TN (Terrestrial Network) cell, receiving a message from a UE (user equipment) containing the transmitted TAC information by initiating a TAU (Tracking Area Update) procedure, and based on the UE supporting dual connection to the TN cell and the NTN cell, the message may include information regarding at least one TAC related to an NTN (Non-Terrestrial Network) cell.

[0227] 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.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] Examples of wireless device applications to which the present invention is applied

[0232] FIG. 24 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. 22).

[0233] Referring to FIG. 24, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 23 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. 24. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 23. 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).

[0234] 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. 22, 100a), a vehicle (Fig. 22, 100b-1, 100b-2), an XR device (Fig. 22, 100c), a portable device (Fig. 22, 100d), a home appliance (Fig. 22, 100e), an IoT device (Fig. 22, 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. 22, 400), a base station (Fig. 22, 200), a network node, etc. Wireless devices can be used in a movable or fixed location depending on the use—e.g., service.

[0235] In FIG. 24, 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 partially 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 connected via a wire, and the control unit (120) and the first unit (e.g., 130, 140) may be connected wirelessly 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.

[0236] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0237] FIG. 25 illustrates a vehicle or autonomous vehicle to which the present invention applies. The vehicle or autonomous vehicle may be implemented as a mobile robot, vehicle, train, manned / unmanned aerial vehicle (AV), ship, etc.

[0238] Referring to FIG. 25, 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 each correspond to blocks 110 / 130 / 140 of FIG. 24.

[0239] 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.

[0240] 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.

[0241] 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.

[0242] 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.

[0243] 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).

[0244] 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.

[0245] 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.

[0246] 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 above detailed description should not be interpreted restrictively in all respects and 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.

[0247] 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 first system information related to a TN (Terrestrial Network) cell; A step of receiving second system information related to an NTN (Non-Terrestrial Network) cell; and Based on the fact that at least one TAC (Tracking Area Code) included in the second system information is not included in the TAC list of the UE, the method includes the step of initiating a TAU (Tracking Area Update) procedure. A method in which, based on the UE supporting dual connectivity to the TN cell and the NTN cell, the TAU procedure is performed only through the TN cell and not the NTN cell.

2. In Paragraph 1, The above TAU procedure comprises transmitting a message to the TN cell that includes information about at least one TAC included in the second system information.

3. In Paragraph 2, A method based on the fact that the TAC value is common between the NTN cell and the TN cell, wherein the message further includes indication information regarding whether the at least one TAC belongs to the TN cell or the NTN cell.

4. In Paragraph 2, A method in which, based on the fact that the TAC list of the UE does not include both the at least one TAC and the TAC included in the first system information, the UE includes the at least one TAC and the TAC together in the message and transmits it to the TN cell.

5. In Paragraph 1, The above TAU procedure is a method initiated based on the fact that the above TAC list does not include all of the above at least one TAC.

6. In Paragraph 1, (i) the UE supports dual connectivity to the TN cell and the NTN cell, and (ii) based on belonging to the coverage of the TN cell, the TAU procedure is performed only through the TN cell and not the NTN cell, a method.

7. In Paragraph 1, A method in which the second system information further includes information on an effective time interval corresponding to each of the at least one TAC.

8. In Paragraph 1, A method in which the above UE is in an RRC (radio resource control) idle or inactive state.

9. 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, Receive first system information related to a TN (Terrestrial Network) cell; Receiving second system information related to an NTN (Non-Terrestrial Network) cell; and It includes initiating a TAU (Tracking Area Update) procedure based on the fact that at least one TAC (Tracking Area Code) included in the second system information is not included in the TAC list of the UE, and Based on the fact that dual connection to the TN cell and the NTN cell is supported, at least one non-transient computer-readable recording medium in which the TAU procedure is performed only through the TN cell and not the NTN cell.

10. 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 first system information related to a TN (Terrestrial Network) cell and second system information related to a NTN (Non-Terrestrial Network) cell, and initiates a TAU (Tracking Area Update) procedure based on the fact that at least one TAC (Tracking Area Code) included in the second system information is not included in the TAC list of the UE, Based on the fact that the above UE supports dual connectivity to the TN cell and the NTN cell, the TAU procedure is performed only through the TN cell and not the NTN cell, in a UE.

11. In Paragraph 10, A UE that transmits a message to the TN cell containing information about at least one TAC included in the second system information based on the initiation of the TAU procedure.

12. In Paragraph 11, Based on the fact that the TAC value is common between the NTN cell and the TN cell, the message further includes indication information regarding whether the at least one TAC belongs to the TN cell or the NTN cell, UE.

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 at least one processor and performing operations when executed by the at least one processor, The above operations are, Receive first system information related to a TN (Terrestrial Network) cell; Receiving second system information related to an NTN (Non-Terrestrial Network) cell; and It includes initiating a TAU (Tracking Area Update) procedure based on the fact that at least one TAC (Tracking Area Code) included in the second system information is not included in the TAC list of the UE, and A processing device in which, based on the fact that the UE supports dual connectivity to the TN cell and the NTN cell, the TAU procedure is performed only through the TN cell and not the NTN cell.

14. In the method using a base station, A step of transmitting first system information including a TAC (Tracking Area Code) associated with a TN (Terrestrial Network) cell; and The method includes the step of receiving a message from the UE (user equipment) containing TAC information transmitted by initiating the TAU (Tracking Area Update) procedure, A method based on the fact that the UE supports dual connectivity for the TN cell and the NTN cell, wherein the message contains information about at least one TAC associated with the NTN (Non-Terrestrial Network) cell.

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 first system information including a TAC (Tracking Area Code) associated with a TN (Terrestrial Network) cell, and receives a message from the UE (user equipment) including the transmitted TAC information by initiating a TAU (Tracking Area Update) procedure, Based on the fact that the UE supports dual connectivity for the TN cell and the NTN cell, the message is a base station containing information about at least one TAC associated with the NTN (Non-Terrestrial Network) cell.

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