Method for performing communication in wireless communication system and apparatus therefor

Abstract

An apparatus according to various embodiments may: transmit, to a second device, configuration information for configuring a first transmission path and a second transmission path related to a split bearer; transmit, to the second device, first data about the first transmission path related to a terrestrial network (TN); and transmit, to the second device, second data about the second transmission path related to a non-terrestrial network (NTN).

Description

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

[0001] This relates to a method for a device to perform communication in a wireless communication system and a device 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, various V2X scenarios regarding V2X communication 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 data 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 first device according to one aspect comprises the steps of: transmitting setting information to a second device for setting a first transmission path and a second transmission path associated with a split bearer; transmitting first data for the first transmission path associated with a terrestrial network (TN) to the second device; and transmitting second data for the second transmission path associated with a non-terrestrial network (NTN) to the second device, and based on the first data and the second data being associated with each other, the transmission timing of the first data may be delayed by a first delay time based on the transmission timing of the second data.

[0018] Alternatively, the first delay time may be determined based on the propagation delay time associated with the NTN.

[0019] Alternatively, based on the fact that the first data and the second data are identical data, the transmission timing of the first data may be delayed by the first delay time based on the transmission timing of the second data.

[0020] Alternatively, based on the fact that the first data and the second data are data duplicated from a single PDCP (Packet Data Convergence Protocol) data, the transmission timing of the first data may be delayed by the first delay time based on the transmission timing of the second data.

[0021] Alternatively, based on the fact that the first data and the second data are data for splitting and transmitting a plurality of SDUs (Service Data Units) associated with a single PDCP (Packet Data Convergence Protocol) data, the transmission timing of the first data may be delayed by the first delay time based on the transmission timing of the second data.

[0022] Alternatively, the delay in the transmission timing of the first data may be performed based on receiving a request message from the second device requesting delayed transmission.

[0023] Alternatively, the request message may be transmitted by the second device based on the buffer or memory state of the second device.

[0024] Alternatively, the method further includes a step of determining whether to approve the request for delayed transmission based on the buffer or memory state of the first device; and the delay in the transmission timing of the first data may be performed based on the approval of the request for delayed transmission.

[0025] Alternatively, it may further include the step of transmitting a release message to the second device for releasing the delayed transmission based on the buffer or memory state of the first device.

[0026] According to another aspect, at least one non-transient computer-readable recording medium comprises instructions for performing operations when executed by at least one processor, said operations include: transmitting setting information for setting a first transmission path and a second transmission path associated with a split bearer to a second device; transmitting first data for the first transmission path associated with a terrestrial network (TN) to the second device; and transmitting second data for the second transmission path associated with a non-terrestrial network (NTN) to the second device, and based on the first data and the second data being associated with each other, the transmission timing of the first data may be delayed by a first delay time based on the transmission timing of the second data.

[0027] According to another aspect, the first device comprises a Radio Frequency (RF) transceiver; and a processor connected to the RF transceiver, wherein the processor transmits setting information to a second device for setting a first transmission path and a second transmission path associated with a split bearer, transmits first data for the first transmission path associated with a terrestrial network (TN) to the second device, transmits second data for the second transmission path associated with a non-terrestrial network (NTN) to the second device, and based on the first data and the second data being associated with each other, the transmission timing of the first data may be delayed by a first delay time based on the transmission timing of the second data.

[0028] According to another aspect, a processing device controlling a first device 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 transmitting setting information to a second device that sets a first transmission path and a second transmission path associated with a split bearer; transmitting first data for the first transmission path associated with a terrestrial network (TN) to the second device; and transmitting second data for the second transmission path associated with a non-terrestrial network (NTN) to the second device, and based on the first data and the second data being associated with each other, the transmission timing of the first data may be delayed by a first delay time based on the transmission timing of the second data.

[0029] A method by a second device according to another aspect comprises the steps of: receiving setting information from a first device for setting a first transmission path and a second transmission path associated with a split bearer; transmitting first data for the first transmission path associated with a terrestrial network (TN) to the first device; and transmitting second data for the second transmission path associated with a non-terrestrial network (NTN) to the first device, and based on the first data and the second data being associated with each other, the transmission timing of the first data may be delayed by a first delay time based on the transmission timing of the second data.

[0030] According to another aspect, a second device comprises an RF (Radio Frequency) transceiver; and a processor connected to the RF transceiver, wherein the processor controls the RF transceiver to receive setting information for setting a first transmission path and a second transmission path associated with a split bearer from the first device, transmits first data for the first transmission path associated with a terrestrial network (TN) to the first device, transmits second data for the second transmission path associated with a non-terrestrial network (NTN) to the first device, and based on the first data and the second data being associated with each other, the transmission timing of the first data may be delayed by a first delay time based on the transmission timing of the second data.

[0031] According to one embodiment of the present invention, data transmission and reception in a wireless communication system can be performed more accurately and efficiently. According to one example, even if a split bearer is configured for a TN path and an NTN path with a large difference in propagation delay for related data, it is possible to effectively prevent an increase in the memory size required for data rearrangement at the receiving device.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0047] Figures 14 to 22 are diagrams illustrating how a UE performs a handover in relation to a satellite gNB.

[0048] Figures 23 and 24 are drawings for explaining the coverage of NTN.

[0049] Figures 25 and 26 are diagrams illustrating a method of transferring SDU from an RLC layer to an upper layer.

[0050] FIGS. 27 to 29 are diagrams illustrating a method for transmitting and receiving data through a split bearer for a TN path and an NTN path.

[0051] FIGS. 30 and 31 are diagrams illustrating a method for a transmitting end to transmit data to an NTN path and a TN path, respectively, taking into account the propagation delay in the NTN path.

[0052] FIG. 32 is a diagram illustrating a method for a first device to transmit data using a TN transmission path and an NTN transmission path.

[0053] FIG. 33 is a diagram illustrating a method for a second device to transmit data using a TN transmission path and an NTN transmission path.

[0054] FIG. 34 illustrates a communication system to which the present invention is applied.

[0055] FIG. 35 illustrates a wireless device that can be applied to the present invention.

[0056] FIG. 36 illustrates another example of a wireless device to which the present invention applies. The wireless device may be implemented in various forms depending on the use-example / service.

[0057] FIG. 37 illustrates a vehicle or autonomous vehicle to which the present invention is applied.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0091] - Satellite Integrated Network

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

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

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

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

[0096] - Small cell networks

[0097] - Ultra-dense heterogeneous network

[0098] - High-capacity backhaul

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

[0100] - Softwarization and virtualization

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

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

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

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

[0105] - Large-scale MIMO technology

[0106] - Hologram beamforming (HBF)

[0107] - Optical wireless technology

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

[0109] - Quantum communication

[0110] - Cell-free communication

[0111] - Integration of wireless information and power transmission

[0112] - Integration of wireless communication and sensing

[0113] - Integrated access and backhaul network

[0114] - Big data analysis

[0115] - Reconfigurable intelligent metasurface

[0116] - Metaverse

[0117] - blockchain

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

[0119] - Autonomous Driving (Self-Driving): V2X (Vehicle to Everything), a core element in building autonomous driving infrastructure, refers to technologies that enable vehicles to communicate and share with various elements on the road for autonomous driving, such as wireless communication between vehicles (Vehicle to Vehicle, V2V) and between vehicles and infrastructure (Vehicle to Infrastructure, V2I). Fast transmission speeds and low-latency technologies are essential to maximize autonomous driving performance and ensure high safety. Furthermore, future autonomous driving may go beyond 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.

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

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

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

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

[0124] S-PSS, S-SSS, and PSBCH may be included in a block format that supports periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP lengths) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) within the carrier, and the transmission bandwidth may be within a (pre-)set SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RB (Resource Block). For example, the PSBCH may 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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0144] 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.

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

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

[0147] S-PSS, S-SSS, and PSBCH may be included in a block format that supports periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP lengths) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) within the carrier, and the transmission bandwidth may be within a (pre-)set SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RB (Resource Block). For example, the PSBCH may 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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0170] Split Bearer

[0171] A split bearer may refer to a radio bearer that includes an RLC layer on both the Master Cell Group (hereinafter 'MCG') and the Secondary Cell Group (hereinafter 'SCG') in a Multi-Radio Dual Connectivity (MR-DC) environment. In the split bearer, the Packet Data Convergence Protocol (PDCP) layer is located at the Master Node (MN) in the User Plane and terminates therein, and data below the PDCP layer can be split and transmitted into the RLC / MAC layer of the first transmission path, the MCG, and the RLC / MAC layer of the second transmission path, the SCG. In the case of an MR-DC structure (NGEN-DC, NE-DC, NR-DC) coupled with a 5G core network (5GC), all radio bearers may have a configuration that includes an NR-based PDCP layer.

[0172] Split Bearer is typically established through the Secondary Node Addition or Modification procedure of a Secondary Node (SN) when the User Equipment (UE) is in the RRC_CONNECTED state. This configuration is transmitted to the User Equipment via a Radio Resource Control (RRC) Reconfiguration message.

[0173] The split bearer setup procedure can consist of the following steps.

[0174] (1) MN configuration request step

[0175] - MN determines whether the bearer will be implemented as an MCG bearer, SCG bearer, or split bearer based on the QoS flow.

[0176] - MN can request direct configuration of SCG or split bearer without prior configuration of MCG bearer for a specific QoS flow.

[0177] - For these requests, information including SCG resource configuration, along with E-RAB or QoS flow characteristics, is transmitted to the SN.

[0178] - In the case of a split bearer, an X2-U (EN-DC) or Xn-U (5GC MR-DC) transmission path is established for user plane data transmission between the MN and the SN.

[0179] (2) Resource allocation step of SN

[0180] - The SN allocates the requested SCG radio resources and related transmission network resources, and transmits the result to the MN through RRC configuration messages (such as SN Addition Request Acknowledge).

[0181] - The above message includes configuration information for the RLC bearer corresponding to the second transmission path.

[0182] (3) Terminal setup step

[0183] - The MN transmits an RRCReconfiguration message to the UE, including the SCG configuration received from the SN.

[0184] - The RadioBearerConfig within the message defines that the target DRB is a split bearer, and the moreThanOneRLC field specifies that the PDCP layer is connected to two or more RLC entities.

[0185] - The UE configures the RLC / MAC layer and logical channels on both the MCG and SCG sides based on CellGroupConfig.

[0186] To control the operation of the split bearer more precisely, the following control parameters can be set:

[0187] - primaryPath: If a PDCP entity is associated with multiple RLC entities, specify the cell group ID and logical channel ID of the RLC path to prioritize the transmission of uplink data.

[0188] -PDCP Duplication: The PDCP layer can be configured to duplicate and transmit the same PDCP PDU to all enabled RLC entities (MCG and SCG), which is configured via RRC signaling.

[0189] - ul-DataSplitThreshold: Used as a splitting threshold value when transmitting uplink data, it serves as a criterion for determining which path (MCG or SCG) to select.

[0190] - Split SRB: Not only the Data Radio Bearer (DRB) but also the Signaling Radio Bearer (SRB) can be split, and this is directed by the network during the SN addition or modification procedure.

[0191] Handover related to TN and NTN

[0192] Figures 14 to 22 are diagrams illustrating how a UE performs a handover in relation to a satellite gNB.

[0193] In the following, it is assumed that the UE must always maintain a connected state. While the UE may be connected to the ground-gNB within ground-gNB coverage, when it is outside ground-gNB coverage (e.g., deserts, oceans, mountainous regions), the UE must connect to the ground-gNB via a satellite or maintain connectivity via a satellite-gNB to keep the connection intact. Meanwhile, the above-mentioned UE may be a UAV UE mounted on or included in a UAV flying at high altitudes, and although the following explanation is based on the premise of a UE, it naturally applies to UAV UEs as well.

[0194] Here, being connected to the ground-gNB via a satellite may mean a case where the satellite gNB acts as a relay, enabling an indirect connection between the UE and the ground-gNB. On the other hand, the term satellite-gNB may mean that a gNB (or a device performing the gNB function) is installed on the satellite itself, enabling a direct connection with the UE.

[0195] Previously, satellite-based connections were discussed at 3GPP through NTN WI (work item). The following triggering conditions were added for cases where a ground UE performs an HO from a ground-gNB (A) to another ground-gNB (B) via satellite relay.

[0196] - 이벤트 D1: Distance between UE and a reference locationreferenceLocation1becomes larger than configured thresholddistanceThreshFromReference1and distance between UE and a reference locationreferenceLocation2becomes shorter than configured thresholddistanceThreshFromReference2;

[0197] - 이벤트 D2: Distance between UE and a moving reference location based onmovingReferenceLocationand its corresponding satellite ephemeris and epoch time broadcast inSIB19for the serving cell becomes larger than configured thresholddistanceThreshFromReference1and distance between UE and a moving reference location determined based onreferenceLocation2becomes shorter than configured thresholddistanceThreshFromReference2;

[0198] - 조건 이벤트 D1 (CondEvent D1): Distance between UE and a reference locationreferenceLocation1becomes larger than configured thresholddistanceThreshFromReference1and distance between UE and a reference locationreferenceLocation2of conditional reconfiguration candidate becomes shorter than configured thresholddistanceThreshFromReference2;

[0199] - 조건 이벤트 D2 (CondEvent D2): Distance between UE and a moving reference location determined based onmovingReferenceLocationand its corresponding satellite ephemeris and epoch time broadcast inSIB19for the serving cell becomes larger than configured thresholddistanceThreshFromReference1and distance between UE and a moving reference location determined based onreferenceLocation2of conditional reconfiguration candidate becomes shorter than configured thresholddistanceThreshFromReference2;

[0200] The reason location-based triggering conditions as described above were added in NTN is that signals received via satellite are transmitted over very long distances, making it difficult for the UE to measure changes in signal strength and trigger measurement reporting at an appropriate time.

[0201] For example, referring to FIG. 14, a UE on the ground may move out of coverage without knowing the difference in signal change between receiving a signal at the boundary of satellite_A and receiving a signal at the center of satellite_B. In this case, the continuity of service cannot be maintained with the existing HO triggering method. Considering this problem, a measurement event can be triggered when the UE moves a certain distance away from a defined (or configured) reference location A (reference location(A)) or (and / or) moves a certain distance closer to another defined (or configured) reference location B (reference location(B)), thereby satisfying service continuity. This location-based measurement triggering operation can be applied to the existing basic HO procedure or conditional HO procedure.

[0202] As such, when a UE communicates using a satellite, the role of the satellite can be distinguished into the following scenarios 1 and 2.

[0203] - Scenario 1: The satellite can simply receive a message transmitted by a ground gNB and transmit it transparently to a UE on the ground (transparency mode). Alternatively, it can receive a message from a UE on the ground and transmit it transparently to a gNB on the ground.

[0204] - Scenario 2: A method in which a satellite directly performs the functions of a communication gNB. For example, a communication unit capable of performing operations similar to (or the same as) a gNB may be attached to the satellite to receive messages transmitted by a ground gNB, interpret them to generate a message, and transmit the generated message to a UE on the ground (regenerative mode). Alternatively, it may be a method in which a message is received from a UE on the ground, interpreted to generate a message, and transmit the generated message to a gNB on the ground.

[0205] 1. Scenario 1

[0206] (1) Case 1-1

[0207] Referring to Fig. 15, a ground UE connected to gNB(A) can perform an HO procedure to gNB(B) via a transparency satellite (Case 1-1).

[0208] - 1. When a measurement report is triggered, a UE connected to a ground-gNB(A) can measure the signal strength of the current serving cell and neighbor cell and report it to the ground-gNB(A). In this case, the measurement report of the signal strength can be transmitted to the source gNB, the ground-gNB(A), via a satellite (or satellite relay).

[0209] - 2. The ground-gNB (A) can determine the HO and send a message requesting the HO to the target ground-gNB (B).

[0210] - 3. The ground-gNB (A) can receive permission for the HO request or an HO request ACK from the target ground-gNB (B).

[0211] - 4. The ground-gNB(A) can send an RRC message (e.g., RRCReconfiguration message) containing an HO-related command (HO command) to the UE.

[0212] - 5. At this time, the ground-gNB (A) may transmit an SN (Sequence Number) status Transfer message to the target ground-gNB (B). Here, the SN status Transfer message may be a message for transmitting the uplink PDCP SN receiver status and downlink PDCP SN transmitter status for the data radio bearer (DRB).

[0213] - 6. When the UE receives an RRCReconfiguration message, it can perform RACH to the target ground-gNB(B) and send an RRCReconfigurationComplete message to the target ground-gNB(B) to complete the HO procedure.

[0214] - 7. The UE is connected to the target ground-gNB (B), and 8. The target ground-gNB (B) can send a UE context release message to the source ground-gNB (A).

[0215] (2) Case 1-2

[0216] Referring to Fig. 16, a ground UE connected to gNB(B) via a Transparency satellite can perform an HO procedure from ground to gNB(A) (Case 1-2).

[0217] - 1. When a measurement report is triggered for a UE connected to the ground-gNB(B) via the transparency satellite, the UE can report the measurement value to the ground-gNB(B) via the transparency satellite.

[0218] - 2. (source) The ground-gNB(B) can decide on the HO and transmit a request for the HO to the target ground-gNB(A).

[0219] - 3. (source) Ground-gNB(B) can receive a response to the HO request from the target ground-gNB(A).

[0220] - 4. (Source) The ground-gNB(B) can transmit an RRCReconfiguration message to the UE to command HO via the transparency satellite.

[0221] - 5. At this time, the ground-gNB (B) can transmit the SN status transfer to the target ground-gNB (A).

[0222] - 6. After the UE performs the RACH procedure to the target ground-gNB(A) based on the RRCReconfiguration message, it can complete the HO by sending the RRCReconfigurationComplete message to the target ground-gNB(A).

[0223] - 7. The UE is connected to the target ground-gNB(A), and 8. The target ground-gNB(A) can send a UE context release message to the source ground-gNB(A).

[0224] When a UE performs an HO operation as in Case 1-1 and / or Case 1-2, the process of the UE reporting measurements via the transparency satellite and the (Source) ground-gNB transmitting an RRCReconfiguration message related to the measurement report to the UE (and / or the UE transmitting an RRCReconfigurationComplete to the target ground-gNB) can take significantly longer than a typical HO between a ground-gNB and a UE. In this case, the reported measurement values ​​may become out-of-date, which can be disadvantageous for the UE in selecting an appropriate target-gNB. Therefore, it may be more appropriate to apply a Conditional HO (CHO) method to operations related to an HO from a ground-gNB connected to gNB(A) to gNB(B) via the transparency satellite. This is explained in detail in Cases 1-3 and 1-4 below.

[0225] (3) Case 1-3

[0226] Referring to FIG. 17, a ground UE connected to ground-gNB(A) can perform a CHO procedure to ground-gNB(B) via a transparency satellite (Case 1-3).

[0227] - 1. A ground UE connected to the ground-gNB(A) can report a measurement value when a measurement report is triggered. For example, the ground UE can report the measurement value to the ground-gNB(A) via a transparency satellite (or satellite relay).

[0228] - 2. (source) The ground-gNB(A) can determine the HO based on the above-reported measurements and send an HO request message to the candidate target gNB(s).

[0229] - 3. The candidate target gNB(s) that accepted the above HO request may send a response accepting the HO to the (source) ground-gNB(A).

[0230] - 4. (source) The ground-gNB(A) can transmit configuration related to the CHO to the ground UE. For example, the ground-gNB(A) can provide configuration related to the CHO to the ground UE through an RRCReconfiguration message.

[0231] - 5. When the ground UE receives the configuration related to the CHO, it can send RRCReconfigurationComplete to the ground-gNB(A).

[0232] - 6. A ground-gNB(A) may provide an Early status transfer message to a candidate target gNB(s). Here, the Early status transfer message may include information about the RLC and PDCP layer status of the ground UE.

[0233] - 7. The ground UE can perform RACH on the target ground-gNB(B) through the transparency satellite and complete HO with the target ground-gNB(B) when the HO condition is satisfied based on the CHO condition according to the above CHO setting.

[0234] - 8. The target ground-gNB (B) can provide a message related to the success of the HO with the ground UE to the source ground-gNB (A).

[0235] - 9. Source ground-gNB (A) can provide SN status transfer messages to target ground-gNB (B).

[0236] - 10. The source ground-gNB (A) can send a message related to HO cancellation to the remaining candidate target gNBs, excluding the target ground-gNB (B) among the candidate target gNBs.

[0237] (4) Case 1-4

[0238] Referring to FIG. 18, a ground UE connected to a ground-gNB (B) via a Transparency satellite can perform a CHO to a ground-gNB (A) (Case 1-4).

[0239] - 1. When a measurement report is triggered, the ground UE performs a measurement report to the ground-gNB(B) via the transparency satellite (source).

[0240] - 2. (Source) The ground-gNB can determine the CHO and send an HO request message to the candidate target ground-gNB(s) selected by the measurement results.

[0241] - 3. If the candidate target ground-gNB(s) allows HO, it can send a response to it to the (source) ground-gNB(B).

[0242] - 4. (source) Ground-gNB(B) can perform CHO-related settings on the ground UE. For example, (source) Ground-gNB(B) can provide the ground UE with an RRCReconfiguration message containing CHO settings for CHO trigger conditions, etc.

[0243] - 5. A ground UE that has received the configuration for the CHO can send an RRCReconfigurationComplete message to the (source) ground-gNB(B).

[0244] - 6. The ground-gNB(B) can provide an Early status transfer message to candidate target gNB(s).

[0245] - 7. When the ground UE satisfies a specific set HO triggering condition, it can complete the CHO handover procedure by performing RACH to the target gNB(A).

[0246] - 8. The target ground-gNB (A) can provide a message related to the success of the HO with the ground UE to the source ground-gNB (B).

[0247] - 9. The source ground-gNB (B) can provide an SN status transfer message to the target ground-gNB (A).

[0248] - 10. The source ground-gNB(B) can send a message related to HO cancellation to the remaining candidate target gNBs, excluding the target ground-gNB(A) from the candidate target gNB(s).

[0249] The CHO procedure according to the method of Case 1-3 and / or Case 1-4 can receive settings related to HO for several candidate target ground-gNBs in advance and trigger HO based on measurements taken by the ground UE. In this case, compared to the general HO procedure, it has the advantage of being able to determine HO based on currently measured values.

[0250] 2. Scenario 2

[0251] (1) Case 2-1

[0252] Referring to Fig. 19, a ground UE connected to gNB(A) can perform HO to the satellite-gNB(B).

[0253] - 1. (source) A ground UE connected to the ground-gNB(A) can perform measurement reporting to the (source) ground-gNB(A).

[0254] - 2. (source) Ground-gNB(A) can determine the HO based on the measured report value and send an HO request message to (target) satellite-gNB(B).

[0255] - 3. The ground-gNB(A) can receive a response message from the satellite-gNB(B) that it allows HO.

[0256] - 4. The ground-gNB(A) can send an RRCReconfiguration message containing an HO command to the ground UE.

[0257] - 5. The ground-gNB (A) can send an SN status Transfer message to the satellite-gNB (B).

[0258] - 6. After receiving an RRCReconfiguration message containing an HO command, the ground UE can perform an HO to the target satellite-gNB(B) and complete the HO procedure by transmitting an RCReconfigurationComplete message to the ground-gNB(A).

[0259] - 7. The UE is connected to the target satellite-gNB(B), and 8. the target satellite-gNB(B) can send a UE context release message to the source ground-gNB(A).

[0260] (1) Case 2-2

[0261] Referring to Fig. 20, a ground UE connected to the satellite-gNB (B) can perform HO to the ground-gNB (A).

[0262] - 1. A ground UE connected to the satellite-gNB(B) can perform a measurement report to the satellite-gNB(B) when a measurement report is triggered.

[0263] - 2. The satellite-gNB(B) can determine the HO based on the above measurement report, determine the target ground-gNB(A), and send an HO request message to the target ground-gNB(A).

[0264] - 3. The satellite-gNB(B) can receive a response from the target ground-gNB(A) that it allows HO.

[0265] - 4. (source) The satellite-gNB(B) can send an RRCReconfiguration message containing an HO command to the ground UE.

[0266] - 5. (source) The satellite-gNB(B) can send an SN status transfer message to the target ground-gNB(A).

[0267] - 6. After receiving an RRCReconfiguration message containing an HO command, the ground UE can perform an HO to the Target ground-gNB (A) and transmit an RRCReconfigurationComplete message to the satellite-gNB (B) to complete the HO procedure.

[0268] - 7. The UE is connected to the Target ground-gNB (A), and 8. The Target ground-gNB (A) can send a UE context release message to the source satellite-gNB (B).

[0269] In Cases 2-1 and 2-2, similar to the HO case in the aforementioned Scenario 1, the time required for the ground UE to transmit measured values ​​to the satellite-gNB, for the satellite-gNB to request an HO from the ground-gNB and receive admission (and / or for the ground UE to transmit measured values ​​to the ground-gNB, but for the ground-gNB to request an HO from the satellite-gNB and receive admission) may be significantly longer than in the case of a standard HO. In this case, the measured values ​​from the ground UE may be out-of-date, and determining the HO based on them may be unsuitable for achieving good performance. Therefore, a conditional HO (CHO) may be a more appropriate operation for HOs used in satellite communication. This will be explained in detail below in Cases 2-3 and 2-4.

[0270] (3) Case 2-3

[0271] Referring to Fig. 21, a ground UE connected to a ground-gNB (A) can perform a CHO procedure with a satellite-gNB (B).

[0272] - 1. When a measurement report is triggered, the ground UE can report the measurement value to (source) ground-gNB(A).

[0273] - 2. (source) The ground-gNB(A) can send an HO request message to the candidate satellite-gNB(s) based on the above measurement report.

[0274] - 3. (source) The ground-gNB(A) can receive admission for HO ( / HO Request ACK) from the candidate satellite-gNB(s).

[0275] - 4. The (source) ground-gNB(A) that receives this can send an RRCReconfiguration message to the ground UE for CHO-related configuration for multiple candidate satellite-gNB(s).

[0276] - 5. If the ground UE receives the configuration related to the CHO, it can send RRCReconfigurationComplete to the (source) ground-gNB(A).

[0277] - 6. A ground-gNB(A) may provide an Early status transfer message to a candidate target satellite-gNB(s). Here, the Early status transfer message may include information about the RLC and PDCP layer status of the ground UE.

[0278] - 7. When a conditional HO (CHO) is triggered based on a set value, the UE can perform an HO by selecting one target satellite-gNB from among the candidate target satellite-gNB(s) and performing the RACH procedure.

[0279] - 8. The target satellite-gNB(B) can provide a message related to the success of the HO with the ground UE to the ground-gNB(A).

[0280] - 9. The ground-gNB (A) can provide SN status transfer messages to the target satellite-gNB (B).

[0281] - 10. Ground-gNB(A) can send a message related to HO cancellation to the remaining candidate target satellite-gNBs, excluding the target satellite-gNB(B) from the candidate target satellite-gNB(s).

[0282] (4) Case 2-4

[0283] Referring to Fig. 22, a ground UE connected to the satellite-gNB (B) can perform a CHO procedure with the ground-gNB (A).

[0284] - 1. When a measurement report is triggered, the ground UE performs a measurement report to the satellite-gNB(B).

[0285] - 2. The satellite-gNB(B) can determine the CHO and send an HO request message to the candidate target ground-gNB(s) selected by the measurement results.

[0286] - 3. If the candidate target ground-gNB(s) allows HO, it can transmit a response to the satellite-gNB(B).

[0287] - 4. The satellite-gNB(B) can perform CHO-related settings on the ground UE. For example, the satellite-gNB(B) can provide the ground UE with an RRCReconfiguration message containing CHO settings for CHO trigger conditions, etc.

[0288] - 5. A ground UE that has received the configuration for the CHO can send an RRCReconfigurationComplete message to the satellite-gNB(B).

[0289] - 6. The satellite-gNB(B) can provide an Early status transfer message to candidate target ground-gNB(s).

[0290] - 7. When the ground UE satisfies a specific set HO triggering condition, it performs a RACH procedure to a selected target ground-gNB(A) among the candidate target ground-gNB(s), and can complete a CHO procedure with the target ground-gNB(A) through the RACH procedure.

[0291] - 8. The target ground-gNB (A) can provide a message related to the success of the HO with the ground UE to the satellite-gNB (B).

[0292] - 9. The satellite-gNB(B) can provide SN status transfer messages to the target ground-gNB(A).

[0293] - 10. Satellite-gNB(B) can send a message related to HO cancellation to the remaining candidate target ground-gNBs, excluding the target ground-gNB(A) from the candidate target ground-gNB(s).

[0294] Figures 23 and 24 are drawings for explaining the coverage of NTN.

[0295] 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.

[0296] 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. 23 (a), coverage based on a Quasi-Earth fixed cell (deployed by LEO satellite) as shown in FIG. 23 (b), and coverage based on an Earth moving cell (deployed by LEO satellite).

[0297] 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. 23 (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.

[0298] 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. 24 (b) in the region corresponding to the edge of the cell coverage.

[0299] For example, as illustrated in FIG. 24 (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.

[0300] 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.

[0301] Storage space distribution for data buffering in TN-NTN dual-connect structure

[0302] Below, the in-order delivery method on the RLC layer is explained in detail, taking into account the aforementioned NTN system.

[0303] Figures 25 and 26 are diagrams illustrating a method of transferring SDU from an RLC layer to an upper layer.

[0304] Referring to FIG. 25, the RLC layer can deliver Service Data Units (SDUs) to an upper layer (e.g., PDCP) based on a sequential delivery method. Here, the sequential delivery method may be a method in which the RLC layer delivers SDUs to an upper layer by ordering them according to the data order. In this case, the RLC layer delivers incoming SDUs to the upper layer by sorting them according to the order (e.g., the sequence number (SN) assigned to the data), but when the 't-Reordering' timer expires, SDUs that do not match the assigned SN may also be delivered to the upper layer. For example, referring to FIG. 25, SDU5 may be delivered to the upper layer after the 't-Reordering' timer expires, even if SDU4 has not yet been delivered to the upper layer. Meanwhile, SDUs received by the RLC layer after the 't-Reordering' timer expires may be removed without being delivered to the upper layer. For example, as illustrated in Fig. 25, SDU4 delivered / received to the RLC layer after the 't-Reordering' timer expires may be discarded without being delivered to the upper layer.

[0305] Referring to FIG. 26, the RLC layer can deliver SDUs to the upper layer without sorting them according to data order based on an out-of-order delivery method. For example, when an out-of-order delivery method is applied, the RLC layer can deliver the received SDUs directly to the upper layer without sorting them according to data order. For example, as shown in FIG. 26, even if the RLC layer receives SDU5 after receiving SDU1 and SDU2, it can deliver the received SDU5 directly to the upper layer. Meanwhile, SDUs received after the 't-Reordering' timer expires may be discarded without being delivered to the upper layer.

[0306] It can be assumed that the reason SDUs received after the 't-Reordering' timer expires are not forwarded to the upper layer is that even if the received SDUs were sent to the upper layer, they would no longer be usable by the upper layer. This 't-Reordering' value may be related to the service's QoS requirement (e.g., latency).

[0307] The t-Reordering value currently defined in the specified scenario (3GPP TS38.331) is set as shown in Table 5 below, and the currently set value can be set to a long value of up to 3 seconds.

[0308] - t-Reordering ENUMERATED {ms0, ms1, ms2, ms4, ms5, ms8, ms10, ms15, ms20, ms30, ms40,ms50, ms60, ms80, ms100, ms120, ms140, ms160, ms180, ms200, ms220, ms240, ms260, ms280, ms300, ms500, ms750, ms1000, ms1250, ms1500, ms1750, ms2000, ms2250, ms2500, ms2750, ms3000, spare28, spare27, spare26, spare25, spare24, spare23, spare22, spare21, spare20, spare19, spare18, spare17, spare16, spare15, spare14, spare13, spare12, spare11, spare10, spare09, spare08, spare07, spare06, spare05, spare04, spare03, spare02, spare01}

[0309] This 't-Reordering' value is set by the upper layer to the AS layer and can be configured according to the UE's implementation.

[0310] Meanwhile, as described above, in the case of NTN communication (NTN scenario), the transmission distance is longer compared to TN communication, so a larger propagation delay may be required than in the case of TN. When a single gNB or different gNBs are connected via TN and NTN, the gNB or UE receives a message through the NTN path after passing through a much larger propagation delay compared to TN. For example, when a single gNB or different gNBs are connected via TN and NTN, it may be a case of CA (in the case of existing CA operation, it means the case where one UE is connected to one gNB) or DC (in the case of existing DC operation, it means the case where one UE is connected to different gNBs).

[0311] In the following, it can be assumed that the TN path and the NTN path can be connected in the same way as the existing DC (dual connectivity). For example, even if UEs are connected to the same gNB, a DC can be established through both the TN path and the NTN path. In this case, it is necessary to reorder the transmitted RLC packets to account for the long propagation delay of the NTN path. Below, we explain in detail a method to minimize the increase in the memory / buffer size at the receiving end or to minimize / prevent the increase in power consumption when applying the aforementioned sequential or non-sequential delivery methods, even when a DC is established through the TN path and the NTN path.

[0312] FIGS. 27 to 29 are diagrams illustrating a method for transmitting and receiving data through a split bearer for a TN path and an NTN path.

[0313] A base station may establish separate bearers for the TN path and NTN path, respectively, to transmit data / packets for different services for each path, or establish the TN path and NTN path through an existing split bearer. For example, if the base station provides different services for each path, it may establish separate bearers for the TN path and NTN path for the UE, respectively, or it may establish the TN path and NTN path through a split bearer to increase reliability or throughput for the same service. When establishing a split bearer, it may be configured for the purpose of improving reliability or throughput, as in the past. In this case, a situation may occur where a single gNB carries an RLC entity for the TN path and an RLC entity for the NTN path separately.

[0314] Specifically, as described above, a split bearer-related architecture applicable when using a TN-NTN dual path can be configured as shown in FIG. 27 (a).

[0315] When the NTN path and the TN path are connected between the gNB and the UE, a significant difference in propagation delay may occur between the NTN path and the TN path. For example, as shown in Fig. 27 (b), when the NTN path and the TN path are connected, the difference between the time it takes for a data packet transmitted by the UE via a split bearer to reach the gNB via the satellite (NTN path) and the time it takes to reach the gNB via the TN path can be substantial. Alternatively, in the case of DL, the difference between the time it takes for a data packet transmitted by the gNB via a split bearer to reach the UE via the satellite (NTN path) and the time it takes to reach the UE via the TN path can be substantial.

[0316] In this way, when there is a large difference in propagation delay between the NTN path and the TN path, if the current RLC realignment method is applied as is, the realignment method can be performed at the receiving end.

[0317] For example, referring to FIG. 28, a transmitting end (e.g., gNB) can transmit the same data / data packet (e.g., PDCP data packet) through a split bearer to improve reliability, and a receiving end (e.g., UE) can receive the data / data packet. As illustrated in FIG. 28, even if the transmitting end transmits the data / data packet simultaneously through the TN path and the NTN path, the receiving end may receive the data through the NTN path after a considerable amount of time has passed since receiving the data through the TN path. In this case, since the 't-reorder' value used in the receiving end's RLC is much larger than the propagation delay, there may be no data / data packets that are removed, but it may be necessary to receive some of the data that was not received through the TN path (e.g., SDU) through the NTN path. At this time, the receiver may face a memory burden of having to store a large amount of data for a long period of time (e.g., during the propagation delay of the NTN) for the aforementioned reordering. For example, as illustrated in FIG. 28, the receiver may not receive an SDU4 packet through the TN path. In this case, in order to receive the same SDU4 packet from the NTN path, the receiver must store data for a period of time corresponding to the difference in propagation delay values ​​received after SDU4 in the RLC layer (in the case of the in-order method) or upper layer (in the case of the out-of-order method) (e.g., the time taken to receive the SDU4 transmitted through the NTN path). If the SDU4 transmitted through the NTN path is retransmitted, the amount of data that needs to be stored may increase further.

[0318] Alternatively, different data may be transmitted through a split bearer to improve transmission capacity. For example, as shown in FIG. 29, among SDUs 1 to 7 for a single PDCP data packet, SDUs 1, 2, 3, 6, and 7 may be transmitted via the TN path, and SDUs 4 and 5 may be transmitted via the NTN path. In this way, when SDUs 1, 2, 3, 6, and 7 are transmitted via the TN path and SDUs 4 and 5 are transmitted via the NTN path, SDUs 4 and 5 may be received at the receiver by the NTN propagation delay. In this case, it may be assumed that the RLC layer (in the case of sequential delivery) or the upper layer (in the case of out-of-delay) at the receiver must store the data packets after SDU 6 received via the TN path (e.g., SDU 7) until SDUs 4 and 5 are received via the NTN path.

[0319] In addition, as the amount of data to be stored in memory / buffer for the reordering described above increases, the power consumed by the reordering operation may also increase.

[0320] To resolve such problems, when a split bearer is configured to transmit and receive data using TN and NTN paths, it may be appropriate for the transmitter to partially bear the amount of memory consumed for data storage at the receiver, taking into account propagation delay. In this case, it may be advantageous in terms of the size of the memory chip at the receiver and power consumption. Below, a method for the transmitter to partially bear the amount of memory consumed for data storage at the receiver, taking into account propagation delay, is explained in detail when a split bearer is configured to transmit and receive data using TN and NTN paths.

[0321] FIGS. 30 and 31 are diagrams illustrating a method for a transmitting end to transmit data to an NTN path and a TN path, respectively, taking into account the propagation delay in the NTN path.

[0322] The transporter (e.g., TX UE, gNB) can reorder the data / data packets to be transmitted at the RLC layer (or at the upper layer) before transmission, taking into account the propagation delay. For example, when transmitting the same data (e.g., data from an SDU or PDCP) through the TN path and the NTN path respectively to improve reliability, the transporter can store the data to be transmitted (through the TN path) in memory, taking into account the propagation delay of the NTN, and then transmit the stored data through the TN path after the considered propagation delay time has elapsed.

[0323] For example, referring to FIG. 30, when the same data is transmitted to both the TN path and the NTN path to improve reliability, the transmitting end may delay the data in the TN path by the propagation delay time of the NTN path before transmitting it. In this case, the receiving end may receive the data transmitted through the TN path and the data transmitted through the NTN path at similar times. If the receiving end fails to receive data through either the TN path or the NTN path, it may receive the lost data through the other path. In this case, since the receiving end does not need to store the data received through either path for the propagation delay time, the amount of memory used by the receiving end can be significantly reduced.

[0324] Similarly, the method described above can be similarly applied when different data packets are transmitted to the TN path and the NTN path, respectively, in order to increase the data transmission rate. For example, in this case as well, if the data transmitted through the TN path is delayed by the propagation delay of the NTN path, the receiving end may not need to store the amount of the propagation delay. For example, referring to FIG. 31, the transmitting end (or transmission device) can transmit data in the TN path after transmitting data in the NTN path (e.g., based on the time of data transmission in the NTN path), and then delay the transmission of data in the TN path by the NTN propagation delay time. In this case, the need for the receiving end to use memory corresponding to the propagation delay for rearranging the data received from the two paths can be significantly reduced.

[0325] As such, if the transmitting end (e.g., gNB or UE) delays data for the TN path by the propagation delay before transmission, the memory burden on the transmitting end may increase. However, if data is transmitted using the TN path and the NTN path without such transmission delay at the transmitting end, the problem of requiring additional memory capacity to account for the NTN propagation delay (or the difference in propagation delay between the TN path and the NTN path) may be greater at the receiving end, in addition to the memory required to apply the existing reordering method. Furthermore, even if the memory burden for transmission increases slightly when the transmitting end is a gNB, it may be more appropriate to reduce the memory burden on the UE, which has a large memory size limit.

[0326] Therefore, by applying the proposed method described above, it may be more appropriate to maintain the amount of memory at the receiver for existing reordering or to minimize the increase in the amount of memory. For example, according to the proposed method described above, the gNB may delay the transmission of data for the TN path by a time corresponding to the NTN propagation delay in the NTN path. In this case, even if data transmission is performed through the TN path and the NTN path, the storage period of data for the TN path at the receiver due to the NTN propagation delay may not increase. Conversely, if a dual pass of the TN path and the NTN path is applied without the application of the proposed operation, the memory required by the terminal may require not only memory for existing reordering but also additional memory space to store data received during the NTN propagation delay time.

[0327] Meanwhile, a method of delaying data transmission by the NTN propagation delay for the gNB's TN path, as proposed, may be applied at the request of the terminal. For example, if the terminal has sufficient memory capacity, the gNB configured with a split bearer can transmit data to the terminal via the TN path and the NTN path without delaying or / or buffering the data on the TN path. However, if the terminal does not have sufficient memory capacity for any reason, the terminal may request the gNB to delay the transmission of data on the TN path by the propagation delay time. Since this involves the gNB's memory usage, the gNB may also allow the request from the terminal if it has spare memory compared to the data it is processing.

[0328] Alternatively, the proposed method described above may also be applied to the UE's TN path. This may be a method that uses more of the UE's memory, but if the amount of data to be processed by the gNB suddenly increases for any reason, the gNB may request the UE to delay the transmission of data through the TN path by the propagation delay time.

[0329] Alternatively, if the entity that allowed the delayed transmission of data in the TN path by the propagation delay time (e.g., the entity that requested permission at the receiving end's request) determines that its own (e.g., the transmitting end's) memory space is insufficient, it may send a message to the requesting entity to cancel / release the operation according to the proposed method.

[0330] Alternatively, since the use of less memory may be associated with power consumption, a low-power UE or a UE with low residual power may optionally be allowed to request the gNB to perform an operation according to the proposed method described above. For example, even if the UE's memory size is sufficient, the UE may request the gNB to delay the transmission of data on the TN path according to the proposed method due to the UE's power condition.

[0331] Meanwhile, the aforementioned upper layer may refer to a PDCP layer existing above the RLC layer in the AS layer or an upper layer of the AS layer.

[0332] When a split bearer is established via the TN path and the NTN path, the receiver needs to store data received via the TN path for a duration equal to the propagation delay time to reorder data packets, such as SDUs, from the aforementioned RLC entity or PDCP entity. In this case, since data received via the TN path must be stored in memory until data is received via the NTN path, an increase in memory size may be required. To apply the TN-NTN split bearer without such an increase in memory (for example, so that only the amount of memory required when using only the existing TN is utilized), the transmitter needs to transmit the data from the TN path after a delay equal to the propagation delay time (after buffering), as described above. In this case, additional memory usage at the receiver can be reduced. Furthermore, the amount of available memory can be dynamically adjusted by requesting or allowing the use of each other's memory based on the memory load situation of the transmitter and receiver.

[0333] FIG. 32 is a diagram illustrating a method for a first device to transmit data using a TN transmission path and an NTN transmission path.

[0334] The following describes the operation related to the proposed method described in the section "Distribution of storage space for data buffering in TN-NTN dual connection structure." The first device is a transmission unit or transmission device that transmits data as described above, and may be a base station or a gNB. The first device may transmit data / signals to the second device through a first transmission path (e.g., TN transmission path; primary path) directly connected to the second device in relation to a split bearer, and a second transmission path (e.g., NTN transmission path; secondary path) connected to the second device through the NTN.

[0335] Specifically, referring to FIG. 32, the first device may transmit configuration information to the second device for setting a first transmission path and a second transmission path associated with a split bearer (S321). For example, the configuration information may include information for configuring a split bearer for data transmission and reception with the second device, or may include information for setting a first transmission path (or primary path) for TN and a second transmission path (or secondary path) for NTN for an already configured split bearer. For example, the configuration information may define and configure an RLC entity and a MAC logical channel associated with the first transmission path in relation to the split bearer, and configure an RLC entity and a MAC logical channel associated with the second transmission path. Additionally, the configuration information may set the first transmission path as the primary path.

[0336] Next, the first device transmits first data for the first transmission path related to the TN (terrestrial network) to the second device based on the split bearer (S323), and can transmit second data for the second transmission path related to the NTN (non-terrestrial network) to the second device (S325). As described above, the first device may transmit the same data through the two paths to improve reliability, or transmit different data through the two paths to improve transmission volume. For example, the first data and the second data may be identical data as data duplicated from a single PDCP (Packet Data Convergence Protocol) data. Alternatively, the first data and the second data may be first SDUs and second SDUs obtained by splitting a plurality of SDUs included in a single PDCP (Packet Data Convergence Protocol) data. In this case, the first data and the second data may be for a single PDCP (Packet Data Convergence Protocol) data, even if they include different SDUs.

[0337] For example, if the replication function in PDCP is applied in relation to a split bearer, the PDCP layer of the first device may submit the same PDCP PDU multiple times. This replicated PDU may be transmitted once to each of the RLC entities for the first transmission path and the second transmission path that are enabled for the split bearer (or split SRB or split DRB). Each RLC entity of the first device may independently transmit the replicated PDU to the second device (e.g., UE) through the corresponding transmission path.

[0338] At this time, the first data of the first transmission path may be transmitted with a delay of a predetermined amount compared to the transmission timing of the second data of the second transmission path. For example, if the first data and the second data are related to each other, the first data may be transmitted at a transmission timing delayed by a first delay time based on the transmission timing of the second data. Here, the first delay time may be determined based on the propagation delay time required for the data transmitted through the second transmission path to reach the receiving device (e.g., propagation delay time related to NTN). For example, the first delay time may be determined as the propagation delay time in the second transmission path, or as the time obtained by subtracting the propagation delay time in the first transmission path from the propagation delay time in the second transmission path.

[0339] Here, the association between the first data and the second data may mean that the first data and the second data are data that require reordering according to the sorting order of the data at the receiving end. For example, the first data and the second data may be data replicated by PDCP replication as shown in FIG. 30, or data intended for split transmission of SDUs associated with a single PDCP data as shown in FIG. 31.

[0340] Delayed transmission of data in such a first transmission path may be performed upon a request by the second device. For example, the second device may transmit a request message to the first device requesting delayed transmission of data in the first transmission path when, based on its memory state or power state, the amount of memory required to buffer data in one transmission path by the difference in propagation delay time between the first transmission path and the second transmission path is insufficient or there is a power burden. In this case, the first device may determine whether to apply delayed transmission of data in the first transmission path according to the request message by considering the memory state of the first device, and if it decides to apply delayed transmission of data in the first transmission path, it may transmit an approval message to the second device. Subsequently, if the first device predicts that its memory capacity will be insufficient, it may transmit a release message to the second device to release the application of delayed transmission of data in the first transmission path. In this case, the first device may transmit the first data in the first transmission path without delayed transmission of data in the first transmission path. For example, in the first transmission path, the first data is transmitted at a timing that is the same as or corresponds to the transmission timing of the second data in the second transmission path, and is not transmitted with a delay according to the first delay time.

[0341] FIG. 33 is a diagram illustrating a method for a second device to transmit data using a TN transmission path and an NTN transmission path.

[0342] The second device may be a UE, as a transmission unit or transmission device that transmits data as described above. The second device may transmit the same data or different data to the first device (e.g., base station, gNB) by simultaneously using the first transmission path and the second transmission path.

[0343] Specifically, referring to FIG. 33, the second device may receive setting information from the first device for setting a first transmission path and a second transmission path associated with a split bearer (S331). For example, the setting information may include information for configuring a split bearer for data transmission and reception with the first device, or may set a first transmission path (or main path) for TN and a second transmission path (or auxiliary path) for NTN for the split bearer that is pre-set.

[0344] Next, the second device can transmit first data for the first transmission path related to the TN (terrestrial network) to the first device based on the split bearer (S333), and transmit second data for the second transmission path related to the NTN (non-terrestrial network) to the first device (S335). As described above, the second device may transmit the same data through each of the two paths to improve reliability, or transmit different data through the two paths to improve transmission volume. For example, the first data and the second data may be identical data as data duplicated from a single PDCP (Packet Data Convergence Protocol) data. Alternatively, the first data and the second data may be first SDUs and second SDUs obtained by splitting a plurality of SDUs included in a single PDCP (Packet Data Convergence Protocol) data. In this case, the first data and the second data may be for a single PDCP (Packet Data Convergence Protocol) data, even if they include different SDUs.

[0345] At this time, the first data of the first transmission path may be transmitted with a delay of a predetermined amount compared to the transmission timing of the second data of the second transmission path. For example, if the first data and the second data are related to each other, the first data may be transmitted at a transmission timing delayed by a first delay time based on the transmission timing of the second data. Here, the first delay time may be determined based on the propagation delay time required for the data transmitted through the second transmission path to reach the receiving device (e.g., propagation delay time related to NTN). For example, the first delay time may be determined as the propagation delay time in the second transmission path, or as the time obtained by subtracting the propagation delay time in the first transmission path from the propagation delay time in the second transmission path.

[0346] Here, the association between the first data and the second data may mean that the first data and the second data are data that require reordering according to the sorting order of the data at the receiving end. For example, the first data and the second data may be data replicated by PDCP replication as shown in FIG. 30, or data intended for split transmission of SDUs associated with a single PDCP data as shown in FIG. 31.

[0347] Meanwhile, delayed transmission of data in the first transmission path may be performed at the request of the first device. For example, the first device may transmit a request message to the second device requesting delayed transmission of data in the first transmission path if, based on its memory state or power state, the amount of memory required to buffer data in one transmission path by the difference in propagation delay time between the first transmission path and the second transmission path is insufficient or if there is a power burden. In this case, the second device may determine whether to apply delayed transmission of data in the first transmission path according to the request message by considering the memory state of the first device, and if it decides to apply delayed transmission of data in the first transmission path, it may transmit an approval message to the first device. Subsequently, if the second device predicts that its memory capacity will be insufficient, it may transmit a release message to the first device to release the application of delayed transmission of data in the first transmission path. In this case, the second device may transmit the first data in the first transmission path without delayed transmission of data in the first transmission path. For example, in the first transmission path, the first data is transmitted at a timing that is the same as or corresponds to the transmission timing of the second data in the second transmission path, and is not transmitted with a delay according to the first delay time.

[0348] In this way, the proposed invention can effectively prevent an increase in the memory size required for rearrangement at the receiving device, even if a split bearer is configured for the TN path and NTN path, which have a large difference in propagation delay of related data.

[0349] Alternatively, the proposed invention can ensure that data from both paths is received at a similar time by delaying data transmission in the TN path among the TN path and the NTN path, taking into account NTN propagation delay, and can minimize memory burden and increased power consumption in the receiving device.

[0350] Example of a communication system to which the invention is applied

[0351] 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.

[0352] 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.

[0353] FIG. 34 illustrates a communication system to which the present invention is applied.

[0354] Referring to FIG. 34, 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.

[0355] 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).

[0356] 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.

[0357] Example of a wireless device to which the present invention is applied

[0358] FIG. 35 illustrates a wireless device that can be applied to the present invention.

[0359] Referring to FIG. 35, 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. 34.

[0360] 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.

[0361] Specifically, the first wireless device or the first device (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 described in the section “Distribution of storage space for data buffering in a TN-NTN dual-link structure”. The operations include transmitting configuration information to the second device for setting a first transmission path and a second transmission path related to a split bearer, transmitting first data for the first transmission path related to a TN (terrestrial network) to the second device, and transmitting second data for the second transmission path related to a NTN (non-terrestrial network) to the second device, and based on the first data and the second data being related to each other, the transmission timing of the first data may be delayed by a first delay time based on the transmission timing of the second data.

[0362] Alternatively, a processing device may be configured including a processor (102) and a memory (104) for controlling the first device. 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 transmitting setting information to the second device for setting a first transmission path and a second transmission path associated with a split bearer, transmitting first data for the first transmission path associated with a terrestrial network (TN) to the second device, and transmitting second data for the second transmission path associated with a non-terrestrial network (NTN) to the second device, and based on the first data and the second data being associated with each other, the transmission timing of the first data may be delayed by a first delay time based on the transmission timing of the second data. Alternatively, at least one non-transient computer-readable medium may be configured for storing programs / instructions for performing the above-described operations.

[0363] 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.

[0364] Specifically, the second wireless device or second device (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 described in the section “Distribution of storage space for data buffering in a TN-NTN dual-link structure”. The operations include receiving configuration information from the first device for setting a first transmission path and a second transmission path related to a split bearer, transmitting first data for the first transmission path related to a TN (terrestrial network) to the first device, and transmitting second data for the second transmission path related to a NTN (non-terrestrial network) to the first device, and based on the first data and the second data being related to each other, the transmission timing of the first data may be delayed by a first delay time based on the transmission timing of the second data.

[0365] 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.

[0366] 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.

[0367] 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, codes, 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.

[0368] 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.

[0369] Examples of wireless device applications to which the present invention is applied

[0370] FIG. 36 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. 34).

[0371] Referring to FIG. 36, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 35 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. 36. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 35. 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).

[0372] 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. 34, 100a), a vehicle (Fig. 34, 100b-1, 100b-2), an XR device (Fig. 34, 100c), a portable device (Fig. 34, 100d), a home appliance (Fig. 34, 100e), an IoT device (Fig. 34, 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. 34, 400), a base station (Fig. 34, 200), a network node, etc. Wireless devices can be used in a movable or fixed location depending on the use—e.g., service.

[0373] In FIG. 36, 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.

[0374] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0375] FIG. 37 illustrates a vehicle or autonomous vehicle to which the present invention applies. The vehicle or autonomous vehicle may be implemented as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, etc.

[0376] Referring to FIG. 37, a vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a driving unit (140a), a power supply unit (140b), a sensor unit (140c), and an autonomous driving unit (140d). The antenna unit (108) may be configured as part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 36, respectively.

[0377] 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.

[0378] 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.

[0379] 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.

[0380] 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.

[0381] 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).

[0382] 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.

[0383] 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.

[0384] It is obvious to those skilled in the art that the present invention may be embodied in other specific forms without departing from the features of the invention. Accordingly, the foregoing detailed description should not be interpreted restrictively in all respects but should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention.

[0385] The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims

1. In the method using the first device, A step of transmitting setting information to a second device for setting a first transmission path and a second transmission path associated with a split bearer; A step of transmitting first data for the first transmission path associated with the TN (terrestrial network) to the second device; and The method includes the step of transmitting second data for the second transmission path associated with the NTN (non-terrestrial network) to the second device. A method in which, based on the first data and the second data being related to each other, the transmission timing of the first data is delayed by a first delay time based on the transmission timing of the second data.

2. In Paragraph 1, The above first delay time is determined based on the propagation delay time associated with the NTN, in a method.

3. In Paragraph 1, A method in which, based on the fact that the first data and the second data are identical data, the transmission timing of the first data is delayed by the first delay time based on the transmission timing of the second data.

4. In Paragraph 1, A method in which, based on the fact that the first data and the second data are data duplicated from a single PDCP (Packet Data Convergence Protocol) data, the transmission timing of the first data is delayed by the first delay time based on the transmission timing of the second data.

5. In Paragraph 1, A method in which, based on the fact that the first data and the second data are data for splitting and transmitting a plurality of SDUs (Service Data Units) associated with a single PDCP (Packet Data Convergence Protocol) data, the transmission timing of the first data is delayed by the first delay time based on the transmission timing of the second data.

6. In Paragraph 1, A method in which the delay in the transmission timing of the first data is performed based on receiving a request message requesting delayed transmission from the second device.

7. In Paragraph 6, The above request message is transmitted by the second device based on the buffer or memory state of the second device.

8. In Paragraph 6, The method further includes the step of determining whether to approve the request for the delayed transmission based on the buffer or memory state of the first device; A method in which the delay in the transmission timing of the first data is performed based on the approval of the request for the delayed transmission.

9. In Paragraph 6, A method further comprising the step of transmitting a release message to the second device for releasing the delayed transmission based on the buffer or memory state of the first device.

10. In at least one non-transient computer-readable recording medium, Includes instructions that perform operations when executed by at least one processor, The above operations are, Transmitting setting information to a second device for setting a first transmission path and a second transmission path associated with a split bearer; Transmitting first data for the first transmission path associated with the TN (terrestrial network) to the second device; and It includes transmitting second data for the second transmission path associated with the NTN (non-terrestrial network) to the second device, At least one non-transient computer-readable recording medium, wherein the transmission timing of the first data is delayed by a first delay time based on the transmission timing of the second data, based on the first data and the second data being related to each other.

11. In the first device, RF (Radio Frequency) transceiver; and It includes a processor connected to the above RF transceiver, and The processor controls the RF transceiver to set up a first transmission path and a second transmission path associated with a split bearer and transmits setting information to a second device, transmits first data for the first transmission path associated with a terrestrial network (TN) to the second device, and transmits second data for the second transmission path associated with a non-terrestrial network (NTN) to the second device. A first device in which, based on the first data and the second data being related to each other, the transmission timing of the first data is delayed by a first delay time based on the transmission timing of the second data.

12. In Paragraph 11, The first device, the first delay time is determined based on the propagation delay time associated with the NTN.

13. In a processing device that controls the first device, 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, Transmitting setting information to a second device for setting a first transmission path and a second transmission path associated with a split bearer; Transmitting first data for the first transmission path associated with the TN (terrestrial network) to the second device; and It includes transmitting second data for the second transmission path associated with the NTN (non-terrestrial network) to the second device, A processing device in which, based on the first data and the second data being related to each other, the transmission timing of the first data is delayed by a first delay time based on the transmission timing of the second data.

14. In the method using the second device, A step of receiving setting information from a first device for setting a first transmission path and a second transmission path associated with a split bearer; A step of transmitting first data for the first transmission path associated with the TN (terrestrial network) to the first device; and The method includes the step of transmitting second data for the second transmission path associated with the NTN (non-terrestrial network) to the first device. A method in which, based on the first data and the second data being related to each other, the transmission timing of the first data is delayed by a first delay time based on the transmission timing of the second data.

15. In the second device, RF (Radio Frequency) transceiver; and It includes a processor connected to the above RF transceiver, and The processor controls the RF transceiver to receive configuration information from the first device for establishing a first transmission path and a second transmission path associated with a split bearer, transmits first data for the first transmission path associated with a terrestrial network (TN) to the first device, and transmits second data for the second transmission path associated with a non-terrestrial network (NTN) to the first device. A second device in which, based on the first data and the second data being related to each other, the transmission timing of the first data is delayed by a first delay time based on the transmission timing of the second data.

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