Method for performing communication in wireless communication system and apparatus therefor

Abstract

Disclosed are a method by which a remote UE performs communication in a wireless communication system according to various embodiments, and an apparatus therefor. Disclosed are the method and the apparatus therefor, the method comprising the steps of: establishing a plurality of indirect paths connected to a network through a plurality of relay UEs; receiving, from the network, mapping information regarding a plurality of path IDs mapped to the plurality of relay UEs; receiving, from the network, control information for controlling whether or not to activate the plurality of paths; and on the basis of the mapping information and the control information, activating or deactivating at least one indirect path from among the plurality of indirect paths.

Description

Method for performing communication in a wireless communication system and device therefor

[0001] The present invention relates to a method for a remote terminal to communicate with a network using multipath in a wireless communication system and a device therefor.

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

[0003] Sidelink (SL) refers to a communication method that establishes a direct link between user equipment (UE), allowing voice or data to be exchanged directly between terminals without going through a base station (BS). SL is being considered as a solution to address the burden on base stations due to rapidly increasing data traffic.

[0004] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-based objects through wired / wireless communication. V2X can be divided 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 the PC5 interface and / or Uu interface.

[0005] Meanwhile, as more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed. Next-generation wireless access technologies that consider improved mobile broadband communication, massive machine type communication (MTC), and ultra-reliable and low latency communication (URLLC) can be called new radio access technology (RAT) or new radio (NR). NR can also support vehicle-to-everything (V2X) communication.

[0006] Figure 1 is a diagram for comparing and explaining V2X communication based on RAT before NR and V2X communication based on NR.

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

[0008] For example, a CAM may include basic vehicle information such as dynamic vehicle status information, such as direction and speed, static vehicle data, such as dimensions, external lighting conditions, and route history. For example, a terminal may broadcast a CAM, and the latency of the CAM may be less than 100 ms. For example, in the event of an emergency, such as a vehicle breakdown or accident, a 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 have been proposed in NR in relation to V2X communications. For example, various V2X scenarios may include vehicle platooning, advanced driving, extended sensors, and remote driving.

[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 in the group can receive periodic data from the lead vehicle. For example, vehicles in the group can use this periodic data to narrow or widen the gap between vehicles.

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

[0012] For example, based on extended sensors, raw data, 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 its environment better than it can perceive using its own sensors.

[0013] For example, based on remote driving, a remote driver or V2X application can operate or control the remote vehicle for people who cannot drive or for remote vehicles located in hazardous environments. For example, in cases where the route is predictable, such as public transportation, cloud computing-based driving can be utilized to operate or control the remote vehicle. Additionally, access to a cloud-based back-end service platform, for example, can be considered for remote driving.

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

[0015] The technical problem to be achieved by the present invention is to provide a method for a remote terminal to communicate with a network based on multipath more accurately and efficiently.

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

[0017] A method for a remote UE to perform communication according to one aspect may include: establishing a plurality of indirect paths connected to a network through a plurality of relay UEs (User Equipment); receiving mapping information between IDs (Identifiers) of the plurality of relay UEs and a plurality of path IDs from the network; receiving control information for controlling whether to activate the plurality of paths from the network; and activating or deactivating at least one indirect path among the plurality of indirect paths based on the mapping information and the control information.

[0018] Alternatively, the control information is characterized in that it controls whether to activate the at least one indirect path by using at least one path ID among the plurality of path IDs.

[0019] Alternatively, the at least one indirect path is characterized in that it is determined based on the position of a bit having a specific bit value in a bitmap included in the control information.

[0020] Alternatively, the at least one indirect path is characterized in that it switches from a disabled state to an enabled state or from an enabled state to a disabled state based on the specific bit value.

[0021] Alternatively, the bitmap is characterized in that it includes bits that are mapped in ascending or descending order to the plurality of path IDs.

[0022] Alternatively, based on the activation of the at least one indirect path by the control information, the remaining indirect paths except for the at least one indirect path among the plurality of indirect paths are deactivated.

[0023] Alternatively, the method further comprises a step of reporting information about the transition of the inactive state to at least one relay UE forming the at least one indirect path based on the transition of the at least one indirect path to the inactive state by the control information.

[0024] Alternatively, the method further comprises a step of establishing a direct path directly connected to the network; and a step of receiving a configuration message adding one or more indirect paths from the network through the direct path, wherein the configuration message further includes information for establishing a path along which a response message for adding one or more indirect paths among the direct path and the one or more indirect paths is to be transmitted.

[0025] Alternatively, the method further comprises: setting a direct path directly connected to the network; and receiving setting information for setting a first primary path of a first data volume for the direct path from the network and a second primary path of a second data volume for one indirect path among the plurality of indirect paths.

[0026] According to another aspect, a non-transitory computer-readable storage medium having recorded thereon commands for performing the method for performing communication by the above-described remote UE may be provided.

[0027] According to another aspect, a remote UE may be provided that performs the method for performing the communication described above.

[0028] According to another aspect, a processing device may be provided for controlling a remote UE performing the above-described communication.

[0029] On the other hand, a method for a network to perform communication includes the steps of: establishing a plurality of indirect paths connected to a remote UE through a plurality of relay UEs (User Equipment); transmitting mapping information between IDs (Identifiers) of the plurality of relay UEs and a plurality of path IDs to the remote UE; and transmitting control information for controlling whether to activate the plurality of paths to the remote UE; wherein at least one indirect path among the plurality of indirect paths can be activated or deactivated based on the mapping information and the control information.

[0030] According to another aspect, a network may be provided that performs the method for performing the communication described above.

[0031] According to one embodiment, in a wireless communication system, a remote terminal can communicate with a network more accurately and efficiently based on multipath.

[0032] The effects that can be obtained in various embodiments are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

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

[0034] Figure 1 is a diagram for comparing and explaining V2X communication based on RAT before NR and V2X communication based on NR.

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

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

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

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

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

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

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

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

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

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

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

[0046] Figure 13 is a diagram for explaining the control plane procedure of L2 U2N relay (UE-to-Network Relay).

[0047] Figure 14 is a diagram illustrating how a remote UE adds an indirect path.

[0048] FIG. 15 is a diagram illustrating a method for a remote UE to activate at least one indirect path.

[0049] FIG. 16 is a diagram illustrating a method for a network to activate or deactivate multiple indirect paths formed to a remote UE.

[0050] Figure 17 illustrates a communication system applied to the present invention.

[0051] Figure 18 illustrates a wireless device applicable to the present invention.

[0052] Figure 19 illustrates another example of a wireless device applicable to the present invention. The wireless device may be implemented in various forms depending on the use case / service.

[0053] Figure 20 illustrates a vehicle or autonomous vehicle to which the present invention is applied.

[0054] 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 code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and multi-carrier frequency division multiple access (MC-FDMA).

[0055] Sidelink refers to a communication method that establishes a direct link between user equipment (UE), allowing voice or data to be exchanged directly between terminals without going through a base station (BS). Sidelink is being considered as a solution to address the burden on base stations due to rapidly increasing data traffic.

[0056] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-based objects through wired / wireless communication. V2X can be divided 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 the PC5 interface and / or Uu interface.

[0057] Meanwhile, as more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed. Next-generation wireless access technologies that consider improved mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) can be called new radio access technology (RAT) or new radio (NR). NR can also support V2X (vehicle-to-everything) communication.

[0058] 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 with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, providing 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 a part of E-UMTS (evolved UMTS) that 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.

[0059] 5G NR, the successor to LTE-A, is a new clean-slate mobile communications system featuring high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, mid-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz.

[0060] For clarity, the description will focus on LTE-A or 5G NR, but the technical ideas of the embodiment(s) are not limited thereto.

[0061] Figure 2 illustrates the architecture of an applicable LTE system. This may be referred to as an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) or a Long Term Evolution (LTE) / LTE-A system.

[0062] Referring to FIG. 2, the E-UTRAN includes a base station (20; 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 a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, etc. 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 an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, etc.

[0063] Base stations (20) can be connected to each other via the X2 interface. The base station (20) is connected to an EPC (Evolved Packet Core, 30) via the S1 interface, more specifically, to an MME (Mobility Management Entity) via the S1-MME, and to an S-GW (Serving Gateway) via the S1-U.

[0064] The EPC (30) consists of an MME, an S-GW, and a P-GW (Packet Data Network-Gateway). The MME holds information about terminal access and capabilities, and this information is primarily used for terminal mobility management. The S-GW is a gateway with the E-UTRAN as its endpoint, and the P-GW is a gateway with the PDN as its endpoint.

[0065] The layers of the radio interface protocol between the terminal and the network can be divided into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) based on the three lower layers of the Open System Interconnection (OSI) standard model, which is widely known in communication systems. Among these, the physical layer belonging to Layer 1 provides an information transfer service using a physical channel, and the RRC (Radio Resource Control) layer located in Layer 3 controls radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0066] Figure 3 shows the structure of the NR system.

[0067] Referring to FIG. 3, the NG-RAN may include a gNB and / or an eNB that provides user plane and control plane protocol termination to the UE. FIG. 7 illustrates a case where only a gNB is included. The gNB and eNB are connected to each other via an Xn interface. The gNB and eNB are connected to the 5th generation core network (5G Core Network: 5GC) via the NG interface. More specifically, the gNB is connected to the access and mobility management function (AMF) via the NG-C interface, and the gNB is connected to the user plane function (UPF) via the NG-U interface.

[0068] Figure 4 shows the structure of a radio frame of NR.

[0069] Referring to FIG. 4, radio frames can be used for uplink and downlink transmission in NR. A radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (Half-Frames, HF). A half-frame can include five 1 ms sub-frames (Subframes, SF). A sub-frame can be divided into one or more slots, and the number of slots within a sub-frame can be determined by the Subcarrier Spacing (SCS). Each slot can include 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP).

[0070] When normal CP is used, each slot can contain 14 symbols. When extended CP is used, each slot can contain 12 symbols. Here, the symbols can include OFDM symbols (or CP-OFDM symbols), SC-FDMA (Single Carrier - FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0071] Table 1 below shows the number of symbols per slot ((N)) depending on 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 ) is an example.

[0072] 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

[0073] Table 2 illustrates the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to SCS when extended CP is used.

[0074] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0075] In an NR system, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., subframe, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0076] In NR, multiple numerologies, or SCSs, can be supported to support various 5G services. For example, a 15 kHz SCS can support wide areas in traditional cellular bands, while a 30 kHz / 60 kHz SCS can support dense urban areas, lower latency, and wider carrier bandwidth. A 60 kHz or higher SCS can support bandwidths greater than 24.25 GHz to overcome phase noise.

[0077] The NR frequency band can be defined by two types of frequency ranges. The two types of frequency ranges can be FR1 and FR2. The numerical values ​​of the frequency ranges can be changed, and for example, the two types of frequency ranges can be as shown in Table 3 below. Among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range", and FR2 can mean the "above 6 GHz range" and can be called millimeter wave (mmW).

[0078] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0079] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 4 below. That is, FR1 may include a frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, such as for vehicular communications (e.g., autonomous driving).

[0080] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0081] Figure 5 shows the slot structure of an NR frame.

[0082] Referring to Figure 5, a slot includes multiple symbols in the time domain. For example, in the case of a normal CP, one slot may include 14 symbols, but in the case of an extended CP, one slot may include 12 symbols. Alternatively, in the case of a normal CP, one slot may include 7 symbols, but in the case of an extended CP, one slot may include 6 symbols.

[0083] A carrier includes multiple subcarriers in the frequency domain. An RB (Resource Block) can be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) can be defined as multiple consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain, and can correspond to one numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed through activated BWPs. Each element can be referred to as a Resource Element (RE) in the resource grid, and one complex symbol can be mapped to it.

[0084] Meanwhile, the wireless interface between terminals or between terminals and a network may be composed of an L1 layer, an L2 layer, and an L3 layer. In various embodiments of the present disclosure, the L1 layer may refer to a physical layer. Furthermore, for example, the L2 layer may refer to at least one of a MAC layer, an RLC layer, a PDCP layer, and an SDAP layer. Furthermore, for example, the L3 layer may refer to an RRC layer.

[0085] FIG. 6 illustrates a communication structure that can be provided in a 6G system according to an embodiment of the present disclosure. The embodiment of FIG. 6 can be combined with various embodiments of the present disclosure.

[0086] New network characteristics in 6G may include:

[0087] - Satellite integrated network

[0088] - Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is revolutionary, upgrading the wireless evolution from "connected objects" to "connected intelligence." AI can be applied at every stage of the communication process (or at every signal processing step, as described below).

[0089] - Seamless integration of wireless information and energy transfer

[0090] - Ubiquitous super 3D connectivity: Access to networks and core network functions of drones and very low Earth orbit satellites will create super 3D connectivity in 6G ubiquitous.

[0091] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0092] - small cell networks

[0093] - Ultra-dense heterogeneous network

[0094] - High-capacity backhaul

[0095] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communications is a key feature of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0096] - Softwarization and virtualization

[0097] Below, the core implementation technologies of the 6G system are described.

[0098] - Artificial Intelligence: Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analytics to determine how complex target tasks should be performed. This means AI can increase efficiency and reduce processing delays. Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly using AI. AI can also play a crucial role in machine-to-machine (M2M), machine-to-human, and human-to-machine communications. Furthermore, AI can facilitate rapid communication in brain-computer interfaces (BCIs). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0099] - THz communication (terahertz communication): Data rates can be increased by increasing the bandwidth. This can be achieved by using sub-THz communication with wide bandwidths and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz, with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (sub-THz band) is considered a key part of the THz spectrum for cellular communications. Adding the sub-THz band to the mmWave band will increase the capacity of 6G cellular communications. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While part of the optical band, the 300 GHz to 3 THz band lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF.

[0100] Figure 7 illustrates the electromagnetic spectrum according to one embodiment of the present disclosure. The embodiment of Figure 7 can be combined with various embodiments of the present disclosure. Key characteristics of THz communications include (i) a widely available bandwidth to support very high data rates, and (ii) high path loss at high frequencies (highly directional antennas are essential). The narrow beamwidth generated by the highly directional antenna reduces interference. The small wavelength of THz signals allows for a much larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array techniques to overcome range limitations.

[0101] - Large-scale MIMO technology

[0102] - Hologram beamforming (HBF)

[0103] - Optical wireless technology

[0104] - Free-space optical transmission backhaul network (FSO backhaul network)

[0105] - Quantum communication

[0106] - Cell-free communication

[0107] - Integration of wireless information and power transmission

[0108] - Integration of wireless communication and sensing

[0109] - Integrated access and backhaul network

[0110] - Big data analysis

[0111] - Reconfigurable intelligent surface

[0112] - metaverse

[0113] - Blockchain

[0114] Unmanned aerial vehicles (UAVs): UAVs, or drones, will be a key element in 6G wireless communications. In most cases, high-speed data wireless connectivity can be provided using UAV technology. Base stations (BSs) can be installed on UAVs to provide cellular connectivity. UAVs may offer specific capabilities not found in fixed BS infrastructure, such as easy deployment, robust line-of-sight links, and controlled mobility. During emergencies such as natural disasters, deploying terrestrial communications infrastructure is not economically feasible and sometimes cannot provide services in volatile environments. UAVs can easily handle these situations. UAVs will become a new paradigm in wireless communications. This technology facilitates three fundamental requirements for wireless networks: enhanced mobile broadband (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 important technologies for 6G communications.

[0115] - Autonomous driving (self-driving): V2X (vehicle to everything), a key element in building autonomous driving infrastructure, can be a technology that allows cars to communicate and share with various elements on the road for autonomous driving, such as vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) wireless communication. Fast transmission speeds and low-latency technologies are essential to maximize autonomous driving performance and ensure high safety. Furthermore, in the future, autonomous driving will go beyond simply providing warnings or guidance messages to drivers and may require active intervention in vehicle operation and direct control of the vehicle in dangerous situations. To this end, the amount of information that needs to be transmitted and received may become enormous, so 6G is expected to maximize autonomous driving with faster transmission speeds and lower latency than 5G.

[0116] Figure 8 illustrates a radio protocol architecture for SL communication. Specifically, Figure 8 (a) illustrates a user plane protocol stack of NR, and Figure 8 (b) illustrates a control plane protocol stack of NR.

[0117] Below, the SL synchronization signal (Sidelink Synchronization Signal, SLSS) and synchronization information are described.

[0118] SLSS is an SL-specific sequence and may include a Primary Sidelink Synchronization Signal (PSSS) and a Secondary Sidelink Synchronization Signal (SSSS). The PSSS may be referred to as a Sidelink Primary Synchronization Signal (S-PSS), and the SSSS may be referred to as a Sidelink Secondary Synchronization Signal (S-SSS). For example, length-127 M-sequences may be used for the S-PSS, and length-127 Gold sequences may be used for the S-SSS. For example, a terminal may detect an initial signal and acquire synchronization using the S-PSS. For example, a terminal may acquire detailed synchronization and detect a synchronization signal ID using the S-PSS and the S-SSS.

[0119] PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel that transmits basic (system) information that a terminal must know first before transmitting or receiving an SL signal. For example, the basic information may be information related to SLSS, duplex mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, resource pool-related information, type of application related to SLSS, subframe offset, broadcast information, etc. For example, in NR V2X, for evaluating PSBCH performance, the payload size of PSBCH may be 56 bits, including a 24-bit CRC.

[0120] S-PSS, S-SSS and PSBCH may be included in a block format supporting periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter referred to as S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP length) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) in the carrier, and the transmission bandwidth may be within a (pre-)configured SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RBs (Resource Blocks). For example, the PSBCH may span 11 RBs. And, the frequency location of the S-SSB may be (pre-)configured. Therefore, the terminal does not need to perform hypothesis detection in the frequency to discover the S-SSB in the carrier.

[0121] Meanwhile, in the 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 a transmitting terminal to transmit an S-SSB may become shorter. Accordingly, the coverage of the S-SSB may decrease. Therefore, in order to ensure the coverage of the S-SSB, the transmitting terminal may transmit one or more S-SSBs to a receiving terminal within one S-SSB transmission period according to the SCS. For example, the number of S-SSBs that the transmitting terminal transmits to the receiving terminal within one S-SSB transmission period may be pre-configured or configured for the transmitting terminal. For example, the S-SSB transmission period may be 160 ms. For example, an S-SSB transmission period of 160 ms may be supported for all SCSs.

[0122] For example, when the SCS is 15 kHz at FR1, the transmitting terminal can transmit one or two S-SSBs to the receiving terminal within one S-SSB transmission period. For example, when the SCS is 30 kHz at FR1, the transmitting terminal can transmit one or two S-SSBs to the receiving terminal within one S-SSB transmission period. For example, when the SCS is 60 kHz at FR1, the transmitting terminal can transmit one, two, or four S-SSBs to the receiving terminal within one S-SSB transmission period.

[0123] For example, when 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 period. For example, when 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 period.

[0124] Meanwhile, when the SCS is 60 kHz, two types of CP may be supported. In addition, the structure of the S-SSB transmitted by the transmitting terminal to the receiving terminal may be different depending on the CP type. For example, the CP type may be Normal CP (NCP) or Extended CP (ECP). Specifically, for example, when the CP type is NCP, the number of symbols to which the PSBCH is mapped within the S-SSB transmitted by the transmitting terminal may be 9 or 8. On the other hand, for example, when the CP type is ECP, the number of symbols to which the PSBCH is mapped within the S-SSB transmitted by the transmitting terminal may be 7 or 6. For example, the 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 an Automatic Gain Control (AGC) operation in the first symbol section of the S-SSB.

[0125] Figure 9 shows a terminal performing V2X or SL communication.

[0126] Referring to FIG. 9, the term "terminal" in V2X or SL communication may primarily refer to a user's terminal. However, if a network device such as a base station transmits and receives signals according to a 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).

[0127] 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 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 a signal from terminal 1 within the resource pool.

[0128] Here, if terminal 1 is within the connection range of the base station, the base station can 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 can inform terminal 1 of the resource pool, or terminal 1 can use a pre-configured resource pool.

[0129] In general, a resource pool can be composed of multiple resource units, and each terminal can select one or multiple resource units to use for its SL signal transmission.

[0130] Figure 10 shows resource units for V2X or SL communication.

[0131] Referring to Figure 10, the entire frequency resources of the resource pool can be divided into NF units, and the entire time resources of the resource pool can be divided into NT units. Therefore, a total of NF * NT resource units can be defined within the resource pool. Figure 10 illustrates an example where the resource pool repeats with a cycle of NT subframes.

[0132] As shown in Figure 10, a single resource unit (e.g., Unit #0) may appear periodically and repeatedly. Alternatively, to achieve diversity effects in the time or frequency dimensions, 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 resource unit structure, a resource pool may refer to a set of resource units that a terminal wishing to transmit an SL signal can use for transmission.

[0133] Resource pools can be subdivided into several categories. For example, based on the content of the SL signal transmitted from each resource pool, resource pools can be categorized as follows:

[0134] (1) Scheduling Assignment (SA) may be a signal that includes information such as the location of resources used by a transmitting terminal for transmission of an SL data channel, MCS (Modulation and Coding Scheme) or MIMO (Multiple Input Multiple Output) transmission method required for demodulation of other data channels, and TA (Timing Advance). SA may also be transmitted multiplexed with SL data on the same resource unit, in which case the SA resource pool may mean a resource pool in which SA is multiplexed with SL data and transmitted. SA may also be called an SL control channel.

[0135] (2) The SL data channel (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 together with SL data on the same resource unit, only the SL data channel excluding SA information may be transmitted from the resource pool for the SL data channel. In other words, the REs (Resource Elements) that were used to transmit SA information on individual resource units within the SA resource pool may still be used to transmit SL data in the resource pool of the SL data channel. For example, the transmitting terminal may transmit the PSSCH by mapping it to consecutive PRBs.

[0136] (3) A discovery channel may be a resource pool for transmitting terminals to transmit information such as their IDs. Through this, transmitting terminals can enable neighboring terminals to discover them.

[0137] 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 properties of the SL signal. For example, even if it is the same SL data channel or discovery message, it may be again divided into different resource pools depending on the transmission timing determination method of the SL signal (for example, whether it is transmitted at the time of reception of a synchronization reference signal or whether it is transmitted by applying a certain timing advance at the time of reception), the resource allocation method (for example, whether the base station designates transmission resources for individual signals to individual transmitting terminals or whether individual transmitting terminals independently select individual signal transmission resources within the resource pool), the signal format (for example, the number of symbols each SL signal occupies in one subframe or the number of subframes used for transmission of one SL signal), the signal strength from the base station, the transmission power strength of the SL terminal, etc.

[0138] FIG. 11 illustrates an example of a BWP according to an embodiment of the present disclosure. The embodiment of FIG. 11 can be combined with various embodiments of the present disclosure. In the embodiment of FIG. 11, it is assumed that there are three BWPs.

[0139] Referring to Figure 11, a common resource block (CRB) may be a carrier resource block numbered from one end of a carrier band to the other. Furthermore, a PRB may be a numbered resource block within each BWP. Point A may indicate a common reference point for the resource block grid.

[0140] The BWP can be set by Point A, an offset from Point A (NstartBWP), and a bandwidth (NsizeBWP). For example, Point A can be an outer reference point of a PRB of a carrier where subcarrier 0 of all numerologies (e.g., all numerologies supported by the network on that carrier) are aligned. For example, the offset can be the PRB spacing between the lowest subcarrier in a given numerology and Point A. For example, the bandwidth can be the number of PRBs in a given numerology.

[0141] SLSS (Sidelink Synchronization Signal) is a SL (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 detect an initial signal (signal detection) and obtain synchronization using S-PSS. For example, the terminal can obtain detailed synchronization using S-PSS and S-SSS and detect a synchronization signal ID.

[0142] PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel that transmits basic (system) information that a terminal must know first before transmitting or receiving an SL signal. For example, the basic information may be information related to SLSS, duplex mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, resource pool-related information, type of application related to SLSS, subframe offset, broadcast information, etc. For example, in order to evaluate PSBCH performance, in NR V2X, the payload size of PSBCH may be 56 bits, including a 24-bit CRC (Cyclic Redundancy Check).

[0143] S-PSS, S-SSS and PSBCH may be included in a block format supporting periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter referred to as S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP length) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) in the carrier, and the transmission bandwidth may be within a (pre-)configured SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RBs (Resource Blocks). For example, the PSBCH may span 11 RBs. And, the frequency location of the S-SSB may be (pre-)configured. Therefore, the terminal does not need to perform hypothesis detection in the frequency to discover the S-SSB in the carrier.

[0144] FIG. 12 illustrates a procedure for a terminal to perform 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.

[0145] Referring to (a) of FIG. 12, 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.

[0146] For example, a first terminal may receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from a base station. For example, a CG resource may include a CG type 1 resource or a CG type 2 resource. In this specification, a DG resource may be a resource that a base station configures / allocates to the first terminal via downlink control information (DCI). In this specification, a CG resource may be a (periodic) resource that a base station configures / allocates to the first terminal via DCI and / or an RRC message. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message including 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 including information related to the CG resource to the first terminal, and the base station may transmit a DCI related to activation or release of the CG resource to the first terminal.

[0147] In step S1510, the first terminal may transmit a PSCCH (e.g., Sidelink Control Information (SCI) 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.) related to the PSCCH to the second terminal. In step S1230, the first terminal may receive a PSFCH related to 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 HARQ feedback information to the base station via a PUCCH or a PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on the 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 rule set in advance. For example, the DCI may be DCI for scheduling SL.

[0148] Referring to (b) of FIG. 12, in resource allocation mode 2, a terminal can determine an SL transmission resource within the SL resources set by the base station / network or within the preset SL resources. For example, the set SL resources or the preset SL resources may be a resource pool. For example, the terminal can autonomously select or schedule resources for SL transmission. For example, the terminal can perform SL communication by selecting a resource by itself within the set resource pool. For example, the terminal can select a resource by itself within a selection window by performing sensing and resource (re)selection procedures. For example, the sensing can be performed on a subchannel basis. For example, in step S1210, a first terminal that has selected a resource by itself within the resource pool can transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to a second terminal using the resource. In step S1220, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S1230, the first terminal may receive a PSFCH related to the PSCCH / PSSCH from the second terminal.

[0149] Referring to (a) or (b) of FIG. 12, for example, a first terminal may transmit an SCI to a second terminal on a PSCCH. Or, for example, the first terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal on the PSCCH and / or the 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 on a PSCCH may be referred to as a 1st SCI, a 1st SCI, a 1st-stage SCI, or a 1st-stage SCI format, and an SCI transmitted on a PSSCH may be referred to as a 2nd SCI, a 2nd SCI, a 2nd-stage SCI, or a 2nd-stage SCI format.

[0150] Referring to (a) or (b) of FIG. 12, in step S1530, the first terminal may receive a PSFCH. For example, the first terminal and the second terminal may determine PSFCH resources, and the second terminal may use the PSFCH resources to transmit HARQ feedback to the first terminal.

[0151] Referring to (a) of FIG. 12, in step S1540, the first terminal may transmit SL HARQ feedback to the base station via PUCCH and / or PUSCH.

[0152] Meanwhile, the aforementioned sidelink can be defined as terminal-to-terminal communication or direct terminal-to-terminal communication. In this case, the PSCCH can be defined as a physical control channel for direct terminal-to-terminal communication, the PSSCH as a physical data channel or physical shared channel for direct terminal-to-terminal communication, and the PSFCH as a physical feedback transmission channel for direct terminal-to-terminal communication.

[0153] Figure 13 is a diagram for explaining the control plane procedure of L2 U2N relay (UE-to-Network Relay).

[0154] The PC5-RRC aspect PC5 unicast link establishment procedure of Rel-16 NR V2X can be reused to establish a secure unicast link for L2 U2N relay (layer 2 UE-to-Network relaying) between the remote UE and the relay UE before the remote UE establishes a Uu RRC connection with the network via the relay UE.

[0155] For both in-coverage and out-of-coverage scenarios, when a remote UE initiates the first RRC message to establish a connection with a gNB, the PC5 L2 configuration for transmissions between the remote UE and the U2N relay UE can be based on the RLC / MAC configuration defined in the standard. The establishment of Uu SRB1 / SRB2 and DRB of the remote UE follows the legacy Uu configuration procedure for the L2 U2N relay.

[0156] A given scenario (TS 38.300) describes the control plane procedures of an L2 U2N relay as follows:

[0157] In step S1300, the remote UE and the relay UE can perform a discovery procedure and establish a PC5-RRC connection in step S1301 based on the existing Rel-16 procedure.

[0158] At step S1302, the remote UE can transmit the first RRC message (i.e., RRCSetupRequest) to establish a connection with the gNB via the relay UE using the default L2 configuration of PC5. The gNB responds to the remote UE with an RRCSetup message (S1303). The RRCSetup delivery to the remote UE uses the default configuration of PC5. If the relay UE is not initiated in RRC_CONNECTED, it must perform its own connection establishment upon receiving the message for the default L2 configuration of PC5.

[0159] In step S1304, the gNB and the relay UE perform a relay channel setup procedure via Uu. Depending on the configuration of the gNB, the relay / remote UE establishes an RLC channel for relaying SRB1 to the remote UE via PC5. This step prepares the relay channel for SRB1.

[0160] In step S1305, a remote UE SRB1 message (e.g., an RRCSetupComplete message) is transmitted to the gNB via the relay UE using the SRB1 relay channel over PC5. The remote UE is then RRC connected over Uu.

[0161] In steps S1306 and S1307, the remote UE and the gNB establish security according to legacy procedures, and the security message is transmitted through the Relay UE.

[0162] In steps S1308 and S1309, the gNB transmits RRCReconfiguration to the remote UE via the relay UE to set up the relay SRB2 / DRB. The remote UE responds by transmitting RRCReconfigurationComplete to the gNB via the relay UE.

[0163] In step S1310, the gNB establishes an additional RLC channel between the gNB and the relay UE for traffic relay. Depending on the configuration of the gNB, the relay / remote UE establishes an additional RLC channel between the remote UE and the relay UE for traffic relay.

[0164] In the above scenario, in addition to the connection setup procedure, for L2 UE-to-Network relay:

[0165] - RRC reconfiguration and RRC disconnection procedures can reuse legacy RRC procedures with message content / configuration design left in the WI phase.

[0166] - The RRC connection re-establishment and RRC connection resumption procedures can be reused as a baseline by considering the connection establishment procedure of the L2 U2N relay above to handle relay-specific parts along with the message content / structure design. The message content / structure can be defined later.

[0167] Below, we describe in detail how a U2N remote UE acquires system information.

[0168] U2N remote UE obtains system information from base station

[0169] A U2N remote UE can obtain system information from a network connected via a relay UE. The method by which such a U2N remote UE obtains system information is detailed in a given scenario (see section 16.12.5.5 of 3GPP TS 38.300). For example, a U2N remote UE can obtain system information in the following manner.

[0170] An in-coverage L2 U2N remote UE (or U2N remote UE) can obtain all required SIBs over the Uu interface, independent of the PC5 connection to the L2 U2N relay UE (or U2N relay UE). An L2 U2N remote UE can also receive system information from the L2 U2N relay UE after establishing a PC5 connection with the L2 U2N relay UE. An L2 U2N remote UE in RRC_CONNECTED can request SIBs through the L2 U2N relay UE using the SIB-on-demand framework. An L2 U2N remote UE in RRC_IDLE or RRC_INACTIVE can inform the L2 U2N relay UE of the requested SIB type via a PC5-RRC message. Then, the L2 U2N relay UE can trigger an on-demand SI / SIB collection procedure according to its own RRC state, if necessary, and transmit the collected SI(s) / SIB(s) to the L2 U2N remote UE via PC5-RRC message.

[0171] Any SIB that an RRC_IDLE or RRC_INACTIVE L2 U2N remote UE needs to use (e.g., SIB for relay purpose) can be requested from an L2 U2N remote UE (either from the L2 U2N relay UE or from the network). The L2 U2N relay UE can forward updated SIBs to the L2 U2N remote UE if there are updates to the SIBs requested by the L2 U2N remote UE. For an RRC_CONNECTED L2 U2N remote UE, if a SIB is updated, the network needs to forward the updated SIBs to the L2 U2N remote UE. Meanwhile, when the L2 U2N remote UE transitions from RRC_IDLE or RRC_INACTIVE state to RRC_CONNECTED state, the L2 U2N remote UE can release the configuration for SI requests with the L2 U2N relay UE.

[0172] With respect to SIB1 forwarding to L2 U2N remote UEs, both request-based SIB1 forwarding (i.e., SIB1 request from U2N remote UE) and non-request-based SIB1 forwarding can be supported by L2 U2N relay UEs. When SIB1 associated with L2 U2N remote UEs in RRC_IDLE or RRC_INACTIVE state is changed, L2 U2N relay UE always needs to forward the changed SIB1 to L2 U2N remote UEs.

[0173] For L2 U2N remote UEs in RRC_IDLE or RRC_INACTIVE, short messages over the Uu interface may not be delivered from the L2 U2N relay UE to the L2 U2N remote UE. The L2 U2N relay UE may deliver PWS SIBs to the connected L2 U2N remote UE.

[0174] RAN sharing may be supported for L2 U2N relay UEs. In particular, L2 U2N relay UEs may convey cell access-related information via discovery messages before establishing a PC5-RRC connection.

[0175] Below, we describe in detail the case where a U2N remote UE forms a multipath (MP) including an indirect path and a direct path to the network.

[0176] Multi Path (MP) relay

[0177] The following advantages may exist for multipathing: Operation of multipathing via relay connections (or indirect paths) and direct connections (or direct paths) (including both Scenarios 1 and 2) can provide efficient path switching between direct and indirect paths. Remote UEs operating based on multipathing can enjoy improved user data throughput and reliability compared to single-link operations. The gNB can offload the signaling load for congested remote UEs' direct connections / direct paths to indirect connections via relay UEs (e.g., in different intra-frequency / inter-frequency cells).

[0178] Multipath-based remote UE operation can improve throughput and reliability / robustness for relay and UE aggregation (e.g., for UEs at the cell edge and UEs with limited UL transmit power). The terms "relay UE" and "remote UE" are used in Scenarios 1 and 2.

[0179] The remote UE in Scenario 1 and the remote UE in Scenario 2 can perform the following operations. In Scenario 1, the remote UE can be connected to the same gNB using one direct path and one indirect path via a Layer-2 UE-to-Network relay. In Scenario 2, the remote UE can be connected to the same gNB using one direct path and one indirect path via another UE (assuming ideal UE-UE interconnection).

[0180] The following cell deployment scenarios for multipath relaying can be supported in a given scenario (3GPP TS38.331 Rel-18). Scenario C1 allows the relay UE and remote UE to be served from the same cell. Scenario C2 allows the relay UE and remote UE to be served from cells within different frequencies of the same gNB. Scenario C3 allows the relay UE and remote UE to be served from cells across different frequencies of the same gNB.

[0181] Additionally, the following sidelink scenarios can be supported for multipath: Scenario S1, SL TX / RX and Uu can share the same carrier in the remote UE. Scenario S2, SL TX / RX and Uu can use different carriers in the remote UE. Scenario S3, SL TX / RX and Uu can share the same carrier in the relay UE. Scenario S4, SL TX / RX and Uu can use different carriers in the relay UE.

[0182] In multipath communication, direct bearer (bearer mapped to the direct path of Uu), indirect bearer (bearer mapped to the indirect path via relay UE), and MP split bearer (bearer mapped to both paths based on the existing split bearer framework) can be supported.

[0183] For MP split bearer in Scenario 1, a PDCP entity of a remote UE can be configured with one direct Uu RLC channel and one indirect PC5 RLC channel. For upstream, the PDCP entity can forward to the PC5 RLC entity with the Uu RLC entity and the SRAP entity on the remote UE side. For downstream, the PDCP entity can receive from the PC5 RLC entity with the Uu RLC entity and the SRAP entity on the remote UE side.

[0184] Specifically, in Scenario 1, the following cases can be supported:

[0185] A. A remote UE that operates only on a direct path can add an indirect path to the same gNB.

[0186] B. A remote UE operating only on an indirect path can add a direct path from the same gNB.

[0187] C. A remote UE operating in multipath can directly release the indirect path.

[0188] D. A remote UE operating in multi-path can directly release the path.

[0189] G. A remote UE operating in multi-path can change an existing relay UE for an indirect path to a new relay UE while maintaining a direct path to the same gNB.

[0190] Meanwhile, the following cases may not be supported for Scenario 1 as group mobility scenarios.

[0191] F. A remote UE configured with multipath maintains a serving relay UE for the indirect path and maintains the serving cell of the remote UE for the direct path, while the serving relay UE changes the serving cell of the relay UE in the same gNB.

[0192] The following cases can be supported through separate releases and additions for Scenario 1 (B+D in separate reconfigurations):

[0193] E. Remote UEs operating in multipath can change their path directly to other cells in the same gNB, while using a serving relay UE for indirect paths in the same gNB.

[0194] In the above-described scenario 2, the following cases can be supported:

[0195] A-1. A remote UE configured only on a direct path can add an indirect path on the same gNB.

[0196] B-1. A remote UE configured with multi-path can directly release the indirect path.

[0197] Meanwhile, in Scenario 2, the following cases may not be supported:

[0198] C-1. When a remote UE configured with multipath maintains the serving relay UE of the indirect path and the serving cell of the direct path, while the serving relay UE changes the serving cell of the relay UE in the same gNB.

[0199] For Scenario 1, SRB1 (Signaling Radio Bearer 1) and SRB2 can be configured for either the direct path or the indirect path, or for both the direct path and the indirect path with minimal redundancy. For Scenario 2, SRB1 and SRB2 can be configured for at least the direct path.

[0200] PDCP DRB replication can be supported based on the existing framework (3GPP TS38-compliant framework) for MP Split Bearer in Scenario 1. PDCP DRB replication can be supported based on the existing framework for MP Split Bearer in Scenario 2. In Scenario 2, a relay UE can be restricted to serving only one relay UE.

[0201] For Scenario 2, different Uu logical channels are configured to identify data transmitted to or initiated by the relay UE and data relayed or relayed from the remote UE via the Uu link in the indirect path (same as 3GPP TS38 V17).

[0202] In Scenario 2, it may be assumed that PDCP PDUs can be delivered to PDCP entities or RLC entities intended to support more than one RB over the inter-UE link, depending on the UE implementation, without an adaptation layer over a non-3GPP link. In Scenario 2, if the relay UE can serve only one remote UE and can assume different Uu RLC channels for the remote UE and the relay UE, UE identification on the Uu link may not be required.

[0203] Multipath relay can be applied to RRC_CONNECTED remote UEs for Scenario 1 and Scenario 2. Multipath relay may not be applied to RRC_IDLE remote UEs for Scenario 1 and Scenario 2. For multipath relay, RRC_IDLE / RRC_INACTIVE target relay UEs can be supported for path switching scenarios with addition of indirect paths or changes in indirect paths.

[0204] When the UE operates in a multipath relay, Radio link monitoring (RLM) can be performed on the Uu interface in Scenario 1 and Scenario 2. Sidelink radio link failure (RLF) detection can be performed on the PC5 interface in Scenario 1 according to the Rel-16 V2X specification.

[0205] When paging is applied to RRC_CONNECTED, the R17 mechanism for paging forwarding to the R18 U2N relay of the indirect path and the legacy mechanism of the direct path may be reused in the multipath configuration. The multipath relay may not be applied to the RRC configuration procedures of Scenarios 1 and 2.

[0206] Multipath relay may not be applicable to RRC_INACTIVE remote UEs in Scenario 1 and Scenario 2. Multipath relay may not be applicable to the RRC resumption procedure in Scenario 1 and Scenario 2. A UE operating in multipath relay may also perform an RRC reestablishment procedure.

[0207] For both Scenario 1 and Scenario 2, PCell can be supported on the direct path only when the UE performs multipath-based operation. The following situations can be considered for Scenario 2: Bearer identification other than LCID in L2 PDUs over Uu links in Scenario 2 may not be required. For the indirect path, only 1:1 bearer mapping over Uu links may be supported. Without an adaptation layer over Uu links in Scenario 2, PDCP PDUs can be delivered to the intended PDCP entity or RLC entity to support multiple RBs over Uu links. For example, a 1:1 bearer mapping and a different Uu RLC channel can be configured for the local traffic of a relay UE and the relay traffic for PDU delivery.

[0208] In principle, Mode 1 RA can be supported for remote UEs configured with multipath in Scenario 1. For both scenarios, split SRBs can be configured with or without overlap as a baseline (assuming support in Scenario 2 as suggested elsewhere).

[0209] For Scenario 2, non-split SRB1 / 2 can be configured on the direct path. The remote UE saving the configuration of the indirect path (e.g., SRAP and PC5-RLC channel configuration) and directly resuming with the configuration of the multipath may not be supported in Scenario 1. If a Common Search Space (CSS) for system information (SI) is configured within the active BWP of the PCell, the remote UE can acquire system information directly from the PCell as specified in the given scenario (3GPP TS 38.331). Additionally, SIBs can be conveyed over SRB1 configured on the direct and / or indirect path as specified in the given scenario (3GPP TS 38.331) using dedicated signaling. If an RLF failure defined in a given scenario is detected on a path and SRB1 for a remote UE (configured as MP) is configured on an alternate path or a split SRB1 is configured, the remote UE may report the path failure via the alternate available path. Meanwhile, PDCP control PDUs may not be replicated.

[0210] (Scenario 1) If split SRB1 is configured to transition an idle / inactive relay UE to RRC_CONNECTED, the behavior of the existing scenario (3GPP TS38 Rel-17 behavior) is not disabled for adding an indirect path. In other cases, the PC5-RRC trigger can be specified. If both the remote UE and the relay UE are in RRC_CONNECTED state, the remote UE can report the ID of the relay UE to the gNB for adding an indirect path.

[0211] Below, we describe in detail how a remote UE adds an indirect path.

[0212] Figure 14 is a diagram illustrating how a remote UE adds an indirect path.

[0213] A remote UE can transmit and receive UL / DL data / channels to and from the network via a direct path (Uu link) that is directly connected to the network.

[0214] 1. The remote UE and the relay UE can perform measurements based on the measurement settings. The remote UE can report the measurement results when a specific event is satisfied (e.g., event Y2 (when the measured signal quality for the candidate L2 U2N relay UE is above a specific threshold value)).

[0215] 2. The gNB may decide to add an indirect path to the remote UE. The cell providing the direct path and the cell providing the relay UE in the indirect path belong to the same gNB, but may be the same or different.

[0216] 3. The gNB can send an RRCReconfiguration message to the relay UE to establish an indirect path to the remote UE.

[0217] 4. The gNB may send an RRCReconfiguration message to the remote UE regarding the addition of an indirect path. The RRCReconfiguration message may include information about the target relay UE, the additional configuration of the indirect path, RLC channel configuration, bearer mapping, and associated radio bearers.

[0218] 5. If the remote UE does not have a PC5 unicast link with the target relay UE, the remote UE can establish a PC5 unicast link with the target relay UE. If the remote UE sends the RRCReconfigurationComplete message only through the direct path in step 6 below, the remote UE can send a PC5-RRC message to the target relay UE. If the relay UE is not in the RRC_CONNECTED state, the relay UE can initiate the RRC connection establishment upon receiving the PC5-RRC message.

[0219] - Meanwhile, additional conditions for triggering a PC5-RRC message (e.g., based on the RRC state of the relay UE), the PC5-RRC message used for this purpose (e.g., a new message or an existing message), and the content of the PC5-RRC message (e.g., triggering an RRC configuration) may be required.

[0220] 6a. The remote UE may send an RRCReconfigurationComplete message to the gNB via the direct path to complete the additional procedures of the indirect path.

[0221] 6b. If a duplicated split SRB1 is configured, the remote UE can also send the RRCReconfigurationComplete message to the gNB through an indirect path with the relay UE. If the relay UE is not in RRC_CONNECTED state, the relay UE can initiate the RRC connection setup and send the RRCReconfigurationComplete message to the gNB.

[0222] - Meanwhile, there is a need for additional discussion on how to handle cases where a relay UE establishes an RRC connection with a gNB different from the gNB providing the target cell.

[0223] U2N relay operation in a specific scenario (3GPP TS38 Rel-19) may consider the following scenarios:

[0224] - When there is one direct path and multiple indirect paths to the remote UE (i.e., the remote UE can be connected to the gNB through multiple relay UEs).

[0225] - When only multiple indirect paths exist to the remote UE (i.e., the remote UE can be connected to the gNB only through multiple indirect paths via multiple relay UEs without forming a direct path).

[0226] Below, the operation of the base station and the remote UE is described in detail when multiple indirect paths are additionally added to one direct path and / or one indirect path.

[0227] Path addition method for remote UEs performing multi-path operation

[0228] A base station can provide control information for a command (i.e., RRCReconfiguration, MAC CE) for adding at least one indirect path to a remote UE via a preset direct path or indirect path. A remote UE connected via a direct / indirect path can report multiple candidate relay UEs to the base station. In this case, the reported values ​​may be L2 IDs, cell IDs, SL measurement values ​​(SL-RSRP / SD-RSRP) for the candidate relay UEs, etc. Here, the reporting may be configured to be performed only via the direct path. Alternatively, when only multiple indirect paths exist for the remote UE, the base station can configure a specific indirect path for the reporting among the multiple indirect paths for the remote UE (e.g., a primary (indirect) path). This is because the direct path (and / or the primary indirect path) may be the most advantageous path in terms of latency and signal stability. When a remote UE reports information about candidate relay UEs to the base station, the remote UE may also report information about the number of indirect paths it prefers and which candidate relay UEs it prefers. By informing the base station of the (maximum / minimum) number of (indirect) paths that the remote UE prefers in terms of power saving degree and capability of the remote UE, the base station can perform configuration for adding indirect paths suitable for the remote UE.

[0229] Alternatively, the remote UE may request the base station to add a new path (e.g., an indirect path). For example, if the measured signal strength for an existing connected serving relay UE is below a certain threshold, the remote UE may be configured to trigger a measurement event to request the base station to add a path for the remote UE. If there are multiple existing indirect paths for the remote UE and the signal strength for at least one of the multiple indirect paths is below the certain threshold, the remote UE may trigger a measurement report for adding the indirect path.

[0230] A base station may use a single RRCReconfiguration message to add multiple indirect paths. That is, the base station may configure the remote UE to add multiple indirect paths for multiple relay UEs through a single RRC configuration message. In this case, the remote UE may transmit an RRCReoncconfigurationComplete message through the path (indirect path or direct path) through which the RRC configuration message (e.g., the RRCReconfiguration message) was received when all SL connections (i.e., indirect paths) with the relay UEs included in the RRC configuration message are completed. Alternatively, the RRCReconfigurationComplete message may be configured to be transmitted through the newly added indirect path. Alternatively, the operation of transmitting the RRCReconfigurationComplete message for indirect paths may be applied only when a split bearer is configured for the remote UE. Alternatively, the base station (or gNB) may configure non-split SRB1 / 2 on other (some / one) indirect paths in addition to the direct path. In this case, the RRCReconfigurationComplete message may be transmitted only through the indirect paths on which non-split SRB1 / 2 is configured. Alternatively, the base station may directly configure a path on which the RRCReconfigurationComplete message is transmitted among multiple paths formed to the remote UE. Meanwhile, if the configuration information for adding multiple paths is transmitted through one RRCReconfigurationComplete message, the SL connection with the relay UE for some of the multiple paths may fail.In this case, the RRCReconfigurationComplete message may additionally include information about the path on which the connection failed (e.g., including the (L2 / local) ID of the failed relay UE, or the path ID).

[0231] When the base station uses a single RRCReconfiguration message ( / MAC CE) to add multiple indirect paths, it may also notify the RRC status of the relay UE for adding the indirect paths along with the (L2 / local) ID of the relay UE. For example, if the relay UE to be connected is in IDLE / INACTIVE state, the remote UE may trigger the relay UE to enter RRC CONNECTED state by sending a PC5-RRC message to the relay UE.

[0232] Alternatively, the RRCReconfigurationComplete message may be configured to be transmitted along the path through which the RRCReconfiguration message for adding an indirect path was received. In this case, the remote UE may transmit the RRCReconfigurationComplete message along the path through which the RRCReconfiguration message was received after completing the SL connection with the relay UE for which addition was requested.

[0233] Alternatively, the remote UE may receive an RRCRconfiguration message for adding an indirect path via a direct path. In this case, the RRCRconfiguration message may include information for configuring to transmit an RRCReconfigurationComplete message for a specific indirect path (e.g., a primary indirect path) among the indirect paths (including a newly added indirect path). In this case, the remote UE does not need to set the relay UE of the indirect path to which the RRCReconfigurationComplete message is to be transmitted to the CONNECTED state via the PC5-RRC message even if the relay UE is in the IDLE / INACTIVE state. This is because the transmission of the RRCReconfigurationComplete message may trigger a transition to the RRC CONNECTED state for the relay UE. However, even in this case, the RRCReconfigurationComplete message may be configured to be transmitted after an SL connection with another relay UE other than the relay UE is completed.

[0234] Alternatively, the remote UE may be configured to receive the RRCReconfiguration message for adding an indirect path as a direct path, and transmit the RRCReconfigurationComplete message through all indirect paths being added (e.g., when split bearer is configured and duplication is activated). In this case, even if the base station has configured the addition of multiple indirect paths through multiple relay UEs, when the SL connection for one of the multiple indirect paths is completed, the remote UE may transmit the RRCReconfigurationComplete message through the one indirect path to notify that the SL connection or addition of the indirect path is completed. That is, the remote UE may transmit the RRCReconfigurationComplete message when the SL connection for one of the indirect paths is completed even if the SL connections for the additionally requested indirect paths are not all completed. In this case, the base station may determine that the addition of the indirect path has failed for at least one path among the multiple indirect paths for which the RRCReconfigurationComplete message is not transmitted.

[0235] Alternatively, if no direct path is established for the remote UE (i.e., only an indirect path is established), another indirect path may be added. In this case, the remote UE may perform the above-described operations by replacing the aforementioned direct path with the previously connected (primary) indirect path.

[0236] Meanwhile, when the base station transmits a single RRCReconfiguration message for adding multiple indirect paths, the remote UE may fail to add at least one of the multiple indirect paths. In this case, the remote UE may transmit an RRCReconfigurationFailure message to the base station instead of an RRCReconfigurationComplete message. For example, the base station may instruct the remote UE to add multiple indirect paths through multiple relay UEs, but the SL connection to at least one of the multiple relay UEs may fail (i.e., the addition of the indirect path may fail). In this case, the remote UE may report the failure to add the indirect path to at least one relay UE using the RRCReconfigurationFailure message. For example, the remote UE may transmit the RRCReconfigurationFailure message through the path through which the RRCReconfiguration message was received. In this case, the RRCReconfigurationFailure message may only include information about the ID of the at least one relay UE. Meanwhile, the RRCReconfigurationFailure message may also include information about the ID of the successful relay UE with which the SL connection was successful, along with separate indication information.

[0237] Alternatively, the remote UE may fail to add a specific indirect path among the additionally instructed multiple indirect paths (or SL connections with multiple relay UEs) (or fail to establish an SL connection with a specific relay UE). In this case, the remote UE may report an SL RLF for the specific indirect path (or the specific relay UE) to the base station via SUI or the like, and may stop the operation of the running T304( / T420) timer. For example, if the T304( / T420) timer expires, the remote UE may need to perform re-establishment for the SL connection. However, since SL connections for other indirect paths may already be successful / completed, the failure of the indirect path for the specific relay UE may not require the re-establishment operation for the indirect path. Therefore, the remote UE needs to report SL RLF for the specific relay UE to the base station through SUI, etc., and stop the operation of the running T304( / T420) timer.

[0238] Alternatively, a T304( / T420) timer that operates independently for each of the additionally indicated multiple indirect paths may be set. In this case, the remote UE may perform an SL connection re-establishment operation only for the specific indirect path (i.e., the indirect path for which addition has failed). Alternatively, the T304( / T420) timer may be operated independently for each indirect path, and when the T304( / T420) timer expires, it may be determined that the path addition has failed for the indirect path.

[0239] Alternatively, the remote UE may report to the base station a specific indirect path for which path addition failed via the RRCReconfigurationFailure message or SUI. In this case, the remote UE may also report information about the UE ID of the relay UE for the specific indirect path via the RRCReconfigurationFailure message or SUI. Alternatively, if the remote UE fails to add paths for two or more indirect paths, the remote UE may report information about the failure of path addition for the two or more indirect paths at once. Such reporting may be performed only while the T304 / T420 timer is running.

[0240] In this way, the proposed method can effectively add multiple indirect paths formed through multiple relay UEs. Furthermore, the proposed method can configure the addition of multiple indirect paths through a single RRC configuration message, and can simultaneously provide information regarding the success or failure of path addition for the multiple indirect paths through a single message, thereby being efficient in terms of signaling load.

[0241] Below, a method for setting / indicating at least one indirect path to be activated / deactivated among multiple indirect paths formed for a remote UE is described in detail.

[0242] Path activation and deactivation of remote UEs performing multi-path operation

[0243] Currently, in dual connectivity, RLC channel activation / deactivation (path activation / deactivation) can be controlled via RRC configuration or MAC (Medium Access Control) CE (Control Element). When activation / deactivation is performed via MAC CE, path activation / deactivation can be controlled more quickly and dynamically.

[0244] In this way, the base station can control the activation / deactivation of multiple indirect paths / direct paths configured / formed for the remote UE through RRC configuration and / or MAC CE. Hereinafter, activation / deactivation of a path may mean activation / deactivation of an RLC channel. Alternatively, if SL connections connected to different relay UEs are determined to be different indirect paths, each indirect path (or direct path) itself may be subject to activation / deactivation of the path. In other words, activation / deactivation of a path may mean activation / deactivation of an RLC channel of the corresponding path or activation / deactivation of the path itself.

[0245] Alternatively, the remote UE and / or the relay UE may report information about its activation / deactivation preference to the base station during a procedure for a multi-path connection (or a path addition / path change) (or after performing a procedure for a multi-path connection). For example, the remote UE may report preference information including preference / non-preference information related to activation / deactivation (e.g., information about preferred / non-preferred path ID and number), etc., to the base station based on the number of RLC NACK( / ACK) times, the number of PHY NACK( / NAC) times, the result of SL measurement, the load status of the relay UE, the power that the remote UE has to consume ( / remaining power), the degree of beam alignment in case of using FR2, etc. The base station may determine which path among the plurality of paths formed in the remote UE to activate or deactivate based on the above preference information, and transmit an RRC setting or MAC CE for the determined activation / deactivation (to the remote UE and / or relay UE).

[0246] Meanwhile, in order to distinguish which path the activation / deactivation indicated through the RRC setting or MAC CE is for, the RRC setting or MAC CE may include the (L2 / local / C-RNTI) ID of the relay UE related to the indirect path to be activated / deactivated. However, since the MAC CE should be expressed in a simple and short message format to be advantageous in terms of latency, it may not be appropriate to indicate the indirect path to be activated / deactivated through the UE ID of the relay UE. Therefore, when using the MAC CE, it may be appropriate for the base station to indicate at least one indirect path to be activated / deactivated using the path ID associated with the ID of the relay UE. To this end, the base station may preset mapping information associating the ID (or UE ID or L2 ID) of the relay UE with the path ID to the remote UE through a dedicated RRC message. In other words, the base station can map in advance the IDs and path IDs of a plurality of relay UEs related to a plurality of indirect paths set / formed to the remote UE, and provide mapping information on the mapping relationship between the IDs of the plurality of relay UEs and the path IDs to the remote UE in advance through a dedicated RRC message.

[0247] In addition, a MAC CE that can indicate activation and deactivation simultaneously may be defined. For example, one MAC CE may be defined that activates a path with a path ID of 1 and deactivates a path with a path ID of 2. In this case, the path ID may be a value that is sequentially mapped to the MAC CE. For example, when an 8-bit MAC CE is used, it may be assumed that the path IDs are mapped / assigned in LSB( / MSB) order. In addition, it may be applied in a toggling manner. For example, when the first bit of the MAC CE is set to 1 and the path ID mapped to the first bit is 1, the MAC CE may indicate activation / deactivation for an indirect path corresponding to path ID=1 (e.g., an indirect path formed via a relay UE having a relay UE ID mapped to path ID=1). In this case, the remote UE can transition to a de-active state if the current state (or previous state) of the indirect path with path ID 1 is active, and transition to an active state if the current state (or previous state) is de-active. In contrast, if the first bit of MAC CE is set to 0, the remote UE can maintain the current state (or previous state) of the path with path ID 1 (e.g., if it was active, it will remain active, and if it was de-active, it will remain de-active).

[0248] Alternatively, if the path indicated for activation is an indirect path, the RRC / MAC CE may further include information about the RRC state (IDLE / INACTIVE / CONNECTED) of the relay UE corresponding to the indirect path to be activated. In this case, if the relay UE indicated for activation is in IDLE / INACTIVE state, the remote UE needs to transmit a separate message (e.g., a PC5 RRC message) to switch the relay UE to RRC_CONNECTED state.

[0249] Alternatively, when multiple indirect paths are formed in the remote UE, the MAC CE may activate only one indirect path among the multiple indirect paths. That is, when an activation instruction for one indirect path is received by the MAC CE, the remote UE may switch to a deactivated state all indirect paths except for the one indirect path for which activation was instructed among the multiple indirect paths. In other words, the remote UE may activate only the indirect path indicated by the MAC CE and deactivate the remaining indirect paths (i.e., only one indirect path is always in an activated state).

[0250] Alternatively, when the base station transmits a MAC CE to the remote UE for activation / deactivation of an indirect path (or, direct path), the remote UE may also inform the relay UE of the information about the activation / deactivation indicated by the MAC CE. This is because the relay UE may also need to know whether the path with the remote UE connected to it has been deactivated ( / activated) in order to operate at low power. Alternatively, the base station may inform the relay UE of the deactivation ( / activation) of the indirect path formed with the remote UE through the MAC CE, etc., and the relay UE may inform the remote UE of the deactivation / activation information of the indirect path transmitted from the base station. In this case, the remote UE may recognize that at least one indirect path among a plurality of indirect paths has been deactivated ( / activated) through the MAC CE transmitted by the relay UE. Meanwhile, if the base station connected via the direct path and the base station connected via the indirect path are different, the remote UE can report information on deactivation / activation of at least one indirect path transmitted via the relay UE via the indirect path to the base station connected via the direct path.

[0251] Alternatively, measurement reporting may be triggered for any one of the indirect paths (or SL connections) involved in the multi-path relay (i.e., when the signal strength of the SL connection between the remote UE and any one of the relay UEs is below a certain threshold). In this case, the remote UE may also be configured to report the measurement results for all other indirect paths (or SL connections) as well. Such reporting may provide the base station with useful information to activate a better path.

[0252] Alternatively, a beam failure may occur in at least one indirect path (or SL connection) among a plurality of indirect paths (or a plurality of SL connections) formed in the remote UE (e.g., when FR2 is used for SL communication between the remote UE and the relay UE). In this case, the remote UE may report information about the beam failure of at least one indirect path (or SL connection) to the base station (or, the remote UE may directly deactivate at least one indirect path in which the beam failure occurred). At this time, the report format may use SUI (sidelink UE information) or MAC CE. If the beam of the indirect path (or SL connection) in which the beam failure occurred is recovered, the remote UE may directly activate the indirect path (or SL connection) in which the beam was recovered, and report information about the beam recovery and activation for the indirect path (or SL connection) to the base station. Alternatively, the remote UE may keep the beam-recovered indirect path (or SL connection) in a deactivated state if there is no activation / deactivation instruction via a new MAC CE from the base station even if the beam-recovered indirect path (or SL connection) has been restored (because a new path may have been activated after the existing indirect path (or SL connection) was deactivated). On the other hand, in this case as well, the remote UE needs to report to the base station information that the beam has been restored after the beam failure of the indirect path (or SL connection) is detected.

[0253] Alternatively, a beam failure may occur for at least one indirect path among multiple indirect paths (or multiple SL connections) formed in the remote UE, and the beam recovery procedure for the beam failure may fail. In this case, the remote UE may consider that an RLF has occurred for the at least one indirect path. However, the remote UE may notify the base station that the SL beam recovery failure has occurred with a cause value. Alternatively, if a beam failure is detected in FR2 SL (e.g., if the upper layer receives an instruction (BFI (beam failure instance)) from the PHY layer), the remote UE may report the beam failure detection to the base station (meanwhile, whether the base station will control the SL beam has not been decided at this time in the FR2 SL discussion). Such reporting of beam failure may be performed only for activated indirect paths (or, such reporting of beam failure may be a value that is reported only for activated relay UEs). This may be to reduce the complexity that may arise when the base station is involved in SL beam recovery. Alternatively, the remote UE may also report to the base station the occurrence of beam failure detection and / or information about the beam recovery failure for a deactivated indirect path. This is to maintain the alive state of the deactivated indirect path even for the deactivated indirect path so that the base station can dynamically direct / control activation / deactivation.

[0254] When a remote UE reports a beam recovery failure or beam failure for an indirect path to a base station, the remote UE may also report values ​​such as a path index ( / ID) corresponding to the indirect path, the (L2 / local / C-RNTI) ID of the relay UE, etc. This may be to inform the base station of which relay UE the indirect path on which the beam recovery failure / beam failure occurred is related. In addition, such reports of beam recovery failure or beam failure may be reported to the base station via MAC CE.

[0255] Such a proposed method can effectively and dynamically direct activation / deactivation of at least one path among multiple paths formed in a remote UE.

[0256] Below, a method for setting a primary path among multiple paths formed in a remote UE and a method for performing communication based on the set primary path are described in detail.

[0257] Setting the primary path for a remote UE performing multi-path operation

[0258] The MAC CE for activation / deactivation of the above-described path can be transmitted only through the direct path (and / or the primary indirect path). For example, if a split bearer is configured, or if non-split SRB1 / 2 is configured on one or more paths, the MAC CE for activation / deactivation of the above-described path can be transmitted only through the direct path. This is because the direct path (and / or the primary indirect path) may be the most reliable path. In addition, the direct path is advantageous in terms of latency, and it may be easy for the base station (gNB) to confirm whether it has properly transmitted to the remote UE.

[0259] In contrast, if the MAC CE for activating / deactivating a path is transmitted to the remote UE via an indirect path, there may be a problem of whether the relay UE should report back to the base station whether the MAC CE was properly transmitted to the remote UE. For example, the base station may transmit the MAC CE for activating / deactivating a path via the primary indirect path. In this case, if the relay UE receives an ACK ( / NACK) from the remote UE after forwarding the MAC CE to the remote UE, the relay UE may need to inform the base station of information about the ACK. This is because the base station may need to know whether the MAC CE for activating / deactivating a path was properly transmitted to the remote UE via the relay UE.

[0260] Here, the primary indirect path may refer to one indirect path set by the base station as the primary path among multiple indirect paths formed / set in the remote UE. Alternatively, the base station may set non-split 1 / 2 for only one path among the multiple indirect paths. In this case, the above-described MAC CE and / or RRC settings may be transmitted via non-split 1 / 2 or a split bearer.

[0261] Meanwhile, the remote UE may use multipath to improve reliability through duplication, but it may also use multipath to increase the throughput of data transmission. The method of increasing throughput using multipath may be similar to the DC (Dual Connectivity) method, but may differ in that there are multiple indirect paths. In the case of the existing DC, data can be transmitted primarily through the primary RLC in a situation where one or more RLC sub-layers exist. However, if the data volume threshold set for the primary RLC channel is exceeded, the data can be configured to be transmitted through another RLC channel.

[0262] The way a remote UE with multiple indirect paths established / formed operates using multi-path may be as follows.

[0263] The base station and the remote UE primarily transmit data via a direct path (or, if only an indirect path exists, a configured primary indirect path), but may transmit the data via another path if the data volume exceeds a predefined / configured data volume threshold for the direct path. At this time, a data volume threshold may be configured for each of a plurality of indirect paths, and data may be configured to be transmitted via the next indirect path only if the data volume exceeds the data volume threshold. For example, a data volume threshold A may be configured for a direct path, a data volume threshold B may be configured for a first indirect path (path ID=2), and a data volume threshold C may be configured for a second indirect path (path ID=3). In this case, the base station or the remote UE may transmit data via the direct path until the data volume threshold A is exceeded, and when the data exceeds the data volume threshold A, may transmit data via the first indirect path (path ID=2) until the data volume threshold B is exceeded. When the base station or the remote UE transmits data exceeding the data volume threshold B on the first indirect path (path ID=2), the base station or the remote UE may transmit the data via the second indirect path (path ID=3). In this way, the base station may configure which indirect path the remote UE will sequentially use and extend to transmit data (e.g., direct path -> first indirect path -> second indirect path). Alternatively, the remote UE may implicitly interpret which path it will sequentially use to transmit data based on the data volume thresholds configured by the base station for each path. For example, the remote UE may determine the order of the indirect paths on which the data will be sequentially transmitted based on the data volume thresholds configured for the plurality of indirect paths in descending order.

[0264] Alternatively, only the data volume threshold for the direct path (or, if only an indirect path exists, the configured primary indirect path) may be determined. In this case, if the data transmitted by the base station or remote UE exceeds the data volume threshold, the remote UE may transmit the remaining data through an (other) indirect path activated by the base station (via RRC / MAC CE). In this case, there may be only one (1) activated (other) indirect path.

[0265] Alternatively, among the multiple indirect paths formed / configured in the remote UE, one indirect path may be configured as an additional primary path. For example, while the direct path is still the primary path, an additional primary path may be configured for one of the multiple indirect paths, and the additionally configured primary path for the one indirect path may be defined as a secondary primary path. In this case, the data volume threshold may be configured only for the direct path and the one indirect path. In this case, when data is transmitted through the direct path and the amount of data transmitted exceeds the data volume threshold configured for the direct path, the base station or the remote UE may change the transmission path of the data from the direct path to one indirect path configured as the secondary primary path. However, if the data volume threshold configured for the secondary primary path is also exceeded, the remote UE may change the transmission path of the data from the one indirect path to another indirect path activated by the base station (via RRC / MAC CE). This is based on the premise that the base station activates at least two indirect paths among the indirect paths.

[0266] Alternatively, even if the primary path and / or the secondary primary path are set, a MAC CE may be additionally defined to dynamically change the primary path or the secondary primary path. Here, the MAC CE may be different from the MAC CE indicating activation / deactivation of the above-described path. In addition, the base station may provide the remote UE with information about ranks / priorities among multiple indirect paths in relation to changing the primary path. For example, when an RLF occurs in the direct path that is the primary path (or the primary indirect path if only indirect paths exist), the remote UE may determine / set the next primary path based on the information about the rank / priority. For example, when an RLF occurs in the existing primary path, the remote UE may determine / set the indirect path with the highest rank / priority among the multiple indirect paths (or the indirect path indicated by the first rank) as the next primary path, and report the RLF detection of the direct path through the indirect path set as the next primary path.

[0267] Alternatively, in FR2 operation, if a beam failure occurs on the direct path, the remote UE may report the beam failure of the direct path via the indirect path. For example, the remote UE and the relay UE may use different FR1 and FR2. In this case, it may be reliable for the remote UE to report the beam failure of the direct path via the indirect path. For example, the direct path of the remote UE may use FR2 and the direct path of the relay UE (or the indirect path of the remote UE) may use FR1. In this case, the remote UE may report information about the beam failure / BLF for the direct path via the indirect path when it detects a beam failure (i.e., Uu Beam failure) for the direct path (or when an RLF occurs due to a failure in beam recovery for the direct path). A similar operation may be applied to the U2U relay UE. For example, in U2U relay operation, if there is a direct path (e.g., a path directly connecting a source remote UE and a target remote UE) and an indirect path, the remote UE may detect a beam failure (i.e., Uu Beam failure) for the direct path, or if an RLF occurs due to a failure in beam recovery for the direct path, report information about the beam failure / BLF for the direct path to the target remote UE through the indirect path.

[0268] In this way, the proposed invention can effectively improve data throughput by establishing a primary path among multiple indirect paths formed in a remote UE. Furthermore, the proposed method described above can be applied by extending the relay UE to include gNBs, IAB nodes, and the like.

[0269] FIG. 15 is a diagram illustrating a method for a remote UE to activate at least one indirect path.

[0270] Referring to FIG. 15, a remote UE can establish multiple indirect paths connecting to a network via multiple relay UEs (S151). Furthermore, the remote UE can establish a direct path directly connected to the network, and perform multi-path operations based on the direct path and the multiple indirect paths.

[0271] Next, the remote UE can receive mapping information between the plurality of relay UEs and the plurality of path IDs from the network (S153). For example, the network can one-to-one map IDs (L2 IDs) of the plurality of relay UEs associated with the plurality of indirect paths formed in the remote UE and the plurality of path IDs. The network can generate mapping information for the IDs of the plurality of relay UEs and the plurality of path IDs, and provide the generated mapping information to the remote UE. Alternatively, the network can provide the remote UE with mapping information about whether the IDs of the plurality of relay UEs are mapped to the plurality of path IDs (e.g., integers sequentially increasing by "1" from 0 to N-1, or from 1 to N) in ascending or descending order of the IDs of the plurality of relay UEs.

[0272] Next, the remote UE can receive control information from the network to control whether to activate or deactivate the plurality of paths (S155). As described in the section "Path Activation and Deactivation of a Remote UE Performing Multi-Path Operation", the network can control / instruct the remote UE to activate or deactivate at least one of the plurality of paths via an RRC configuration message or MAC-CE. Here, the control information can indicate at least one path to be activated or deactivated using a path ID according to the mapping information.

[0273] Next, the remote UE can activate or deactivate at least one indirect path among the plurality of indirect paths based on the mapping information and the control information (S157). For example, the remote UE can determine the at least one indirect path to be activated / deactivated based on at least one path ID indicated in the control information and the mapping information. For example, the remote UE can identify at least one indirect path corresponding to at least one path ID included in the control information, and activate / deactivate the identified at least one indirect path based on the control information.

[0274] Alternatively, the control information may include a bitmap of a predetermined length. In this case, the remote UE may determine the at least one indirect path to be activated / deactivated based on the position of a bit on the bitmap where a specific bit value (e.g., bit value 1) is set. For example, path IDs may be pre-mapped in ascending or descending order according to the positions of the bits on the bitmap. In this case, the remote UE may identify which bit among the bits included in the bitmap has a specific bit value set, and determine a path ID corresponding to the position of the identified bit. The remote UE may determine / specify an indirect path formed with a relay UE having an ID of the relay UE mapped to the determined path ID according to the mapping information. Here, the specific bit value may indicate a change in the current state of the indirect path. For example, the remote UE may transition to an active state if an indirect path mapped to a path ID corresponding to a bit position having the specific bit value is in an inactive state, and transition to an inactive state if an indirect path mapped to a path ID corresponding to a bit position having the specific bit value is in an active state. An indirect path corresponding to a bit position having a bit value other than the specific bit value (e.g., bit value 0) may maintain its current state.

[0275] Alternatively, the control information may indicate a path ID for an indirect path to be activated among the plurality of indirect paths, while indicating deactivation of the remaining indirect paths. For example, if the control information indicates only the first path ID mapped to the first indirect path, the remote UE may activate only the first indirect path among the plurality of indirect paths and deactivate the remaining indirect paths.

[0276] Alternatively, the remote UE may additionally report information about the transition of the indirect path to a deactivation state to a relay UE forming the one or more indirect paths when one or more indirect paths among the plurality of indirect paths are deactivated by the control information.

[0277] Alternatively, the remote UE may receive a configuration message that configures to add one or more indirect paths via a direct path directly connected to the network. In this case, the remote UE may additionally form / configure one or more additionally indicated indirect paths, and transmit a response message including information about the success or failure of adding one or more indirect paths among the direct paths and the one or more indirect paths indicated by the configuration message. Alternatively, the remote UE may perform operations related to the method of receiving the configuration for adding an indirect path and transmitting a response message about the success or failure of adding an indirect path, as described in the section “Path addition method of a remote UE performing multipath operation”.

[0278] Alternatively, the remote UE may receive configuration information from the network that sets a first primary path of the first data volume for the direct path and a second primary path of the second data volume for one of the plurality of indirect paths. In this case, when the remote UE transmits data more than the first data volume through the first primary path, the remote UE may switch the path for transmitting the data to the second primary path and transmit the data. In addition, the remote UE may perform an operation of transmitting and receiving data based on the configuration of the primary path and the configured primary path as described in “Configuration of a Primary Path for a Remote UE Performing Multipath Operation.”

[0279] FIG. 16 is a diagram illustrating a method for a network to activate or deactivate multiple indirect paths formed to a remote UE.

[0280] Referring to FIG. 16, the network can establish multiple indirect paths connecting to a remote UE via multiple relay UEs (User Equipment) (S161). Additionally, the network can also form / establish a direct path connecting directly to the remote UE.

[0281] Next, the network may transmit mapping information for a plurality of path IDs mapped to the plurality of relay UEs to the remote UE (S163). For example, the network may map IDs (L2 IDs) of a plurality of relay UEs associated with a plurality of indirect paths formed in the remote UE on a one-to-one basis with a plurality of path IDs. The network may generate mapping information for the IDs of the plurality of relay UEs and the plurality of path IDs, and provide the generated mapping information to the remote UE. Alternatively, the network may provide mapping information to the remote UE as to whether the IDs of the plurality of relay UEs are mapped to a plurality of path IDs (e.g., integers sequentially increasing by "1" from 0 to N-1, or from 1 to N) in ascending or descending order of the IDs of the plurality of relay UEs.

[0282] Next, the network can transmit control information to the remote UE for activating or deactivating at least one indirect path among the plurality of indirect paths (S165). As described in the section “Path Activation and Deactivation of Remote UE Performing Multi-Path Operation”, the network can control / instruct the remote UE to activate or deactivate at least one of the plurality of paths through an RRC configuration message or MAC-CE. Here, the control information can instruct whether to activate or deactivate the at least one path using a path ID according to the mapping information.

[0283] For example, when indicating with the MAC-CE, the network may indicate the at least one path using a plurality of path IDs according to the mapping information rather than the UE ID of the relay UE corresponding to the at least one path, taking into account the size limitation of the MAC-CE. For example, the network may include in the MAC-CE at least one path ID corresponding to at least one indirect path to be switched to the activated or deactivated state based on the mapping information.

[0284] Alternatively, the network may indicate whether to activate / deactivate the at least one indirect path through control information including a bitmap having a predetermined length. For example, the network may map path IDs by bit positions in a bitmap (or a fixed size of 8 bits) including predetermined bits (e.g., a number of bits corresponding to the number of a plurality of indirect paths formed in the remote UE). For example, the network may map the plurality of path IDs and the bits of the bitmap respectively in ascending or descending order of the plurality of path IDs. For example, when the plurality of path IDs are set from 1 to 4, the first bit of the bitmap may be mapped to a first path ID, the second bit of the bitmap may be mapped to a second path ID, the third bit of the bitmap may be mapped to a third path ID, and the fourth bit of the bitmap may be mapped to a fourth path ID. At this time, the network may set a specific bit value (e.g., 1) in a bit on the bitmap corresponding to at least one path ID to be indicated for activation / deactivation, and transmit control information including the bitmap to indicate whether to activate / deactivate the at least one indirect path. For example, if an indirect path corresponding to a position of a bit in which the specific bit value is set in the bitmap is in an inactive state, it may be switched to an activated state, and if it is in an activated state, it may be switched to an inactive state. An indirect path corresponding to a position of a bit in which a bit value other than a specific value (e.g., 0) is set in the bitmap may maintain its existing state as is.

[0285] Alternatively, the network may transmit a configuration message that configures adding one or more indirect paths via a direct path directly connected to the remote UE. In this case, the configuration message may further include information indicating a path along which a response message regarding whether the addition of the one or more indirect paths was successful or failed will be transmitted. For example, the network may configure one of the direct path and the one or more indirect paths (or, the plurality of indirect paths) as a path along which the response message will be transmitted via the configuration message. Alternatively, the network may perform operations related to receiving a configuration for adding an indirect path and transmitting a response message regarding the success or failure of the addition of the indirect path, as described in the section “Path addition method of a remote UE performing multipath operation”.

[0286] Alternatively, the network may transmit configuration information to the remote UE, considering that multiple indirect paths are formed to the remote UE, for setting not only the first primary path of the first data volume for the direct path, but also the second primary path of the second data volume for one indirect path among the multiple indirect paths. In this case, when the network transmits data more than the first data volume through the first primary path, the network may switch the path for transmitting the data to the second primary path and transmit the data. In addition, the network may perform an operation of transmitting and receiving data based on the configuration of the primary path and the configured primary path as described in “Configuration of a Primary Path for a Remote UE Performing Multipath Operation”.

[0287] In this way, the proposed invention can effectively control or instruct whether to activate an indirect path for a remote UE in which a multi-path is formed. Alternatively, the proposed invention can dynamically control or instruct whether to activate an indirect path through MAC-CE using a path ID. Alternatively, the proposed invention can minimize the signaling load for adding indirect paths by adding multiple indirect paths through a single configuration message. Alternatively, the proposed invention can effectively improve data throughput for a remote UE by setting an additional primary path for one of the multiple indirect paths.

[0288] Examples of communication systems to which the invention applies

[0289] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts of the present invention disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0290] Hereinafter, more specific examples will be provided with reference to the drawings. In the drawings / descriptions below, the same drawing reference numerals may represent identical or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise described.

[0291] Figure 17 illustrates a communication system applied to the present invention.

[0292] Referring to FIG. 17, a communication system (1) applied to the present invention includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a 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 Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle 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 HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0293] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can 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). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0294] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (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 communication between base stations (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 each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present invention.

[0295] Examples of wireless devices to which the present invention is applied

[0296] Figure 18 illustrates a wireless device applicable to the present invention.

[0297] Referring to FIG. 18, 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)} can correspond to {the wireless device (100x), the base station (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 17.

[0298] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from 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 perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts 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 via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present invention, a wireless device may also mean a communication modem / circuit / chipset.

[0299] Specifically, the first wireless device or remote UE (100) may include a processor (102) and a memory (104) connected to a transceiver (106). The memory (104) may include at least one program capable of performing operations related to the embodiments described in FIGS. 14 to 16. For example, the memory (104) may include at least one program capable of performing operations related to the embodiments described in the above-described "Path addition method of a remote UE performing multipath operation", "Path activation and deactivation of a remote UE performing multipath operation" and / or "Establishment of a primary path for a remote UE performing multipath operation".

[0300] The processor (102) controls the transceiver (106) to set up a plurality of indirect paths connected to the network through a plurality of relay UEs (User Equipment), receives mapping information for a plurality of path IDs mapped to the plurality of relay UEs, receives control information for controlling whether to activate the plurality of paths, and can activate or deactivate at least one indirect path among the plurality of indirect paths based on the mapping information and the control information.

[0301] Alternatively, a processing device including a processor (102) and a memory (104) may be configured. In this case, at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions, based on being executed by the at least one processor, cause the remote UE to: set a plurality of indirect paths connected to a network through a plurality of relay UEs (User Equipments), receive mapping information for a plurality of path IDs mapped to the plurality of relay UEs, receive control information for controlling whether to activate the plurality of paths, and activate or deactivate at least one indirect path among the plurality of indirect paths based on the mapping information and the control information.

[0302] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals 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 perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts 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 via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0303] Specifically, the second wireless device or network (200) may include a processor (202) and a memory (204) connected to a transceiver (206). The memory (204) may include at least one program capable of performing operations related to the embodiments described in FIGS. 14 to 16. For example, the memory (204) may include at least one program capable of performing operations related to the embodiments described in the above-described “Path addition method of a remote UE performing multipath operation”, “Path activation and deactivation of a remote UE performing multipath operation” and / or “Establishment of a primary path for a remote UE performing multipath operation”.

[0304] The processor (202) controls the transceiver (206) to set up a plurality of indirect paths connected to a remote UE through a plurality of relay UEs (User Equipment), transmit mapping information for a plurality of path IDs mapped to the plurality of relay UEs to the remote UE, and transmit control information for controlling whether to activate the plurality of paths to the remote UE. Here, at least one indirect path among the plurality of indirect paths can be activated or deactivated based on the mapping information and the control information.

[0305] Hereinafter, the 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 one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts 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 operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0306] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a 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 operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0307] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0308] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can 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 coupled 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, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via 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 received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0309] Examples of wireless devices to which the present invention is applied

[0310] Figure 19 illustrates another example of a wireless device applicable to the present invention. The wireless device may be implemented in various forms depending on the use case / service (see Figure 17).

[0311] Referring to FIG. 19, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 18 and may be composed of various elements, components, units / units, 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 a 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. 19. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 18. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0312] The additional element (140) may be configured in various ways depending on the type of the 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. 17, 100a), a vehicle (Fig. 17, 100b-1, 100b-2), an XR device (Fig. 17, 100c), a portable device (Fig. 17, 100d), a home appliance (Fig. 17, 100e), an IoT device (Fig. 17, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 17, 400), a base station (Fig. 17, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0313] In FIG. 19, 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 some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and a first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of a set of one or more 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.

[0314] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0315] Figure 20 illustrates a vehicle or autonomous vehicle applicable to the present invention. The vehicle or autonomous vehicle may be implemented as a mobile robot, car, train, manned / unmanned aerial vehicle (AV), ship, etc.

[0316] Referring to FIG. 20, 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 a part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 19, respectively.

[0317] 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, road side units, etc.), and servers. The control unit (120) can control elements of the vehicle or autonomous vehicle (100) to perform various operations. The control unit (120) can include an ECU (Electronic Control Unit). The drive unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The drive unit (140a) can include an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and can include a wired / wireless charging circuit, a battery, 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 incline sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / backward 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 a technology for maintaining a driving lane, a technology for automatically controlling speed such as adaptive cruise control, a technology for automatically driving along a set path, a technology for automatically setting a path and driving when a destination is set, etc.

[0318] 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 route and driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or autonomous vehicle (100) moves along the autonomous driving route according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can irregularly / periodically acquire the latest traffic information data from an external server and can acquire surrounding traffic information data from surrounding vehicles. In addition, 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 route and driving plan based on newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving route, driving plan, etc. to the external server. External servers can predict traffic information data in advance using AI technology or other technologies based on information collected from vehicles or autonomous vehicles, and provide the predicted traffic information data to the vehicles or autonomous vehicles.

[0319] Here, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. At this time, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification may perform communication based on LTE-M technology. At this time, for example, LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create PAN (personal area networks) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0320] The embodiments described above are combinations of components and features of the present invention in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form an embodiment 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 self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form an embodiment or may be incorporated as a new claim through a post-application amendment.

[0321] In this document, embodiments of the present invention have been described primarily focusing on the signal transmission and reception relationship between a terminal and a base station. This transmission and reception relationship is equally / similarly extended to signal transmission and reception between a terminal and a relay or a base station and a relay. Certain operations described as being performed by a base station in this document may, in some cases, be performed by its upper node. That is, it is obvious that various operations performed for communication with a terminal in a network composed 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. In addition, the terminal may be replaced by terms such as UE (User Equipment), MS (Mobile Station), MSS (Mobile Subscriber Station).

[0322] Embodiments of the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0323] When implemented via firmware or software, an embodiment of the present invention may be implemented in the form of modules, procedures, functions, etc. that perform the functions or operations described above. The software code may be stored in a memory unit and executed by a processor. The memory unit may be located within or outside the processor and may exchange data with the processor via various known means.

[0324] It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the scope of the invention. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present invention are intended to be included within the scope of the present invention.

[0325] The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims

1. A step of establishing multiple indirect paths connected to a network through multiple relay UEs (User Equipment); A step of receiving mapping information between IDs (Identifiers) of the plurality of relay UEs and a plurality of path IDs from the network; A step of receiving control information for controlling whether to activate the plurality of paths from the network; and A method comprising a step of activating or deactivating at least one indirect path among the plurality of indirect paths based on the mapping information and the control information.

2. In paragraph 1, A method characterized in that the control information controls whether to activate at least one indirect path using at least one path ID among the plurality of path IDs.

3. In paragraph 1, A method, characterized in that the at least one indirect path is determined based on the position of a bit having a specific bit value in a bitmap included in the control information.

4. In paragraph 3, A method characterized in that at least one indirect path is switched from a disabled state to an enabled state or from an enabled state to a disabled state based on the specific bit value.

5. In paragraph 3, A method, characterized in that the bitmap includes bits mapped in ascending or descending order to the plurality of path IDs.

6. In paragraph 1, A method characterized in that, based on the activation of the at least one indirect path by the control information, the remaining indirect paths except for the at least one indirect path among the plurality of indirect paths are deactivated.

7. In paragraph 1, A method characterized in that it further comprises a step of reporting information about the transition of the at least one indirect path to at least one relay UE forming the at least one indirect path based on the transition of the at least one indirect path to the inactive state by the control information.

8. In paragraph 1, A step of establishing a direct route directly connected to the above network; and Further comprising the step of receiving a setup message adding one or more indirect routes from the network through the direct route, A method, characterized in that the above setup message further includes information for setting a path along which a response message for addition of the one or more indirect paths among the direct path and the one or more indirect paths is to be transmitted.

9. In paragraph 1, A step of establishing a direct route directly connected to the above network; and A method characterized in that it further comprises the step of receiving configuration information for setting a first primary path of a first data volume for the direct path from the network and a second primary path of a second data volume for one indirect path among the plurality of indirect paths.

10. A computer-readable recording medium recording a program for performing the method described in paragraph 1. 11.RF(Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, A remote UE in which the processor controls the RF transceiver to establish a plurality of indirect paths connected to a network through a plurality of relay UEs (User Equipment), receives mapping information between IDs (Identifiers) of the plurality of relay UEs and a plurality of path IDs, receives control information for controlling whether to activate the plurality of paths, and activates or deactivates at least one indirect path among the plurality of indirect paths based on the mapping information and the control information.

12. In paragraph 11, A remote UE, characterized in that the control information controls whether to activate at least one indirect path using at least one path ID among the plurality of path IDs.

13. In a processing device that controls a remote UE (User Equipment), at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said remote UE: A processing device that sets up a plurality of indirect paths connected to a network through a plurality of relay UEs, receives mapping information between IDs (Identifiers) of the plurality of relay UEs and a plurality of path IDs, receives control information for controlling whether to activate the plurality of paths, and activates or deactivates at least one indirect path among the plurality of indirect paths based on the mapping information and the control information.

14. A step of establishing multiple indirect paths connected to a remote UE through multiple relay UEs (User Equipment); A step of transmitting mapping information between the IDs (Identifiers) of the plurality of relay UEs and the plurality of path IDs to the remote UE; and A step of transmitting control information for controlling whether to activate the plurality of paths to the remote UE, A method wherein at least one indirect path among the plurality of indirect paths is activated or deactivated based on the mapping information and the control information. 15.RF(Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, The processor controls the RF transceiver to set up a plurality of indirect paths connected to a remote UE through a plurality of relay UEs (User Equipment), transmits mapping information between IDs (Identifiers) of the plurality of relay UEs and a plurality of path IDs to the remote UE, and transmits control information for controlling whether to activate the plurality of paths to the remote UE. A network, wherein at least one indirect path among the plurality of indirect paths is activated or deactivated based on the mapping information and the control information.

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