Method for performing relay communication in wireless communication system, and device therefor

Abstract

A method for performing communication in a wireless communication system, and a device therefor, according to various embodiments, are disclosed. Disclosed are the device and the method, which: form a first connection with a second relay UE directly connected to a base station for U2N relay communication between the base station and a remote UE; transmit paging monitoring information for the remote UE to the second relay UE through the first connection; and switch from an RRC idle or inactive state to an RRC connected state on the basis that a first message including paging information about the remote UE has been received through the first connection.

Description

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

[0001] A method for performing multi-hop based relay communication in a wireless communication system and a device therefor are provided.

[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 relay UE to perform multi-hop based U2N relay communication 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 first relay UE to perform communication according to one aspect may include: forming a first connection with a second relay UE directly connected to a base station for U2N (UE-to-Network) relay communication between the base station and a remote UE; transmitting paging monitoring information for the remote UE to the second relay UE through the first connection; and switching from an RRC (Radio Resource Control) idle or inactive state to an RRC connected state based on receiving a first message including paging information for the remote UE through the first connection.

[0018] Alternatively, the first message is characterized in that it is a PC5-RRC message for the first relay UE.

[0019] Alternatively, the first message is characterized in that it further includes a local ID (Identifier) ​​for the remote UE.

[0020] Alternatively, the first message is characterized in that it further includes instruction information indicating a transition to the RRC connection state.

[0021] Alternatively, the instruction information is characterized in that it is transmitted by being included in the SRAP (sidelink Relay Adaptation Protocol) header of the first message.

[0022] Alternatively, the first relay UE is characterized in that it forms a second connection with the remote UE or a third relay UE connected to the remote UE, and receives a RemoteUEInformation message including the paging monitoring information through the second connection.

[0023] Alternatively, based on the RRC being in an idle or inactive state, the first relay UE is characterized in that it transmits paging monitoring information for the first relay UE to the second relay UE together with paging monitoring information for the remote UE.

[0024] Alternatively, the paging monitoring information is transmitted to the second relay UE based on the first relay UE transitioning to an RRC idle or inactive state or a common search space (CSS) not being set.

[0025] Alternatively, based on the transition from the RRC idle or inactive state to the RRC connected state and the establishment of a common search space (CSS), the first relay UE transmits a third message requesting release of the paging monitoring information to the second relay UE.

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

[0027] According to another aspect, a first relay 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 first relay UE performing the above-described communication.

[0029] According to another aspect, a method for performing the above-described communication by a second relay UE may include: forming a first connection with a base station and a second connection with a first relay UE for U2N (UE-to-Network) relay communication between the base station and a remote UE; monitoring a paging signal based on paging information for the remote UE; and transmitting a first message for switching the first relay UE, which is in an RRC (Radio Resource Control) idle or inactive state, to an RRC connected state based on detection of the paging signal.

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

[0031] According to one embodiment, a relay UE in a wireless communication system can perform multi-hop based U2N relay communication more accurately and efficiently.

[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 for explaining a method for performing paging monitoring in multi-hop U2N relay communication.

[0048] FIG. 15 and FIG. 16 are diagrams for explaining how a relay UE monitors paging for a remote UE.

[0049] FIG. 17 is a diagram illustrating a method for a first relay UE to transmit information about a paging signal to a remote UE.

[0050] FIG. 18 is a diagram illustrating a method for a second relay UE to transmit information about a paging signal to a remote UE.

[0051] Figure 19 illustrates a communication system applied to the present invention.

[0052] Figure 20 illustrates a wireless device applicable to the present invention.

[0053] Figure 21 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.

[0054] Figure 22 illustrates a vehicle or autonomous vehicle to which the present invention is applied.

[0055] A wireless communication system is a multiple access system that supports communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include 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).

[0056] 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.

[0057] 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.

[0058] 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.

[0059] The following technologies can be used in various wireless communication systems, such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented 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.

[0060] 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.

[0061] For clarity, the description will focus on LTE-A or 5G NR, but the technical ideas of the embodiment(s) are not limited thereto.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

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

[0068] 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.

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

[0070] 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).

[0071] 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).

[0072] 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.

[0073] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 15KHz (u=0)1410130KHz (u=1)1420260KHz (u=2)14404120KHz (u=3)14808240KHz (u=4)1416016

[0074] Table 2 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.

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

[0076] In an NR system, 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.

[0077] 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.

[0078] 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).

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

[0080] As described above, the numerical value of the frequency range of the NR system 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).

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

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

[0083] Referring to 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] New network characteristics in 6G may include:

[0088] - Satellite integrated network

[0089] - 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).

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

[0091] - 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.

[0092] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0093] - small cell networks

[0094] - Ultra-dense heterogeneous network

[0095] - High-capacity backhaul

[0096] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communications is a key feature of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0097] - Softwarization and virtualization

[0098] Below, the core implementation technologies of the 6G system are described.

[0099] - 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.

[0100] - 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.

[0101] 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.

[0102] - Large-scale MIMO technology

[0103] - Hologram beamforming (HBF)

[0104] - Optical wireless technology

[0105] - Free-space optical transmission backhaul network (FSO backhaul network)

[0106] - Quantum communication

[0107] - Cell-free communication

[0108] - Integration of wireless information and power transmission

[0109] - Integration of wireless communication and sensing

[0110] - Integrated access and backhaul network

[0111] - Big data analysis

[0112] - Reconfigurable intelligent surface

[0113] - metaverse

[0114] - Blockchain

[0115] 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.

[0116] - 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.

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

[0118] Below, the SL synchronization signal (Sidelink Synchronization Signal, SLSS) and synchronization information are described.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

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

[0127] 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).

[0128] For example, terminal 1 can select a resource unit corresponding to a specific resource within a resource pool, which represents a set of resources. Then, terminal 1 can transmit an SL signal using the 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.

[0129] 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.

[0130] 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.

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

[0132] 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.

[0133] 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.

[0134] 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:

[0135] (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.

[0136] (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.

[0137] (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.

[0138] Even if the content of the SL signal described above is the same, different resource pools may be used depending on the transmission and reception 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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).

[0144] 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.

[0145] FIG. 12 illustrates a procedure for a terminal to perform V2X or SL communication according to a resource allocation mode, according to an embodiment of the present disclosure. The embodiment of FIG. 12 may be combined with various embodiments of the present disclosure.

[0146] 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.

[0147] 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.

[0148] In step S1210, 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.

[0149] 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 within the set resource pool. For example, the terminal can select a resource 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 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.

[0150] 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.

[0151] 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.

[0152] 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.

[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] In 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] The setup procedure of U2N relay can be performed based on the following RRC messages (see 3GPP TS 38.331).

[0168] (1)RRCSetupRequest

[0169] The RRCSetupRequest message can be used to request the establishment of an RRC connection. The RRCSetupRequest message can be sent in the following manner.

[0170] -Signalling radio bearer: SRB0

[0171] - RLC-SAP: TM

[0172] - Logical channel: CCCH

[0173] - Direction: UE to Network

[0174] The RRCSetupRequest message can be configured as shown in Tables 5 to 7 below.

[0175] -- ASN1START-- TAG-RRCSETUPREQUEST-STARTRRCSetupRequest ::= SEQUENCE {rrcSetupRequest RRCSetupRequest-IEs}RRCSetupRequest-IEs ::= SEQUENCE {ue-Identity InitialUE-Identity,establishmentCause EstablishmentCause,spare BIT STRING (SIZE (1))}InitialUE-Identity ::= CHOICE {ng-5G-S-TMSI-Part1 BIT STRING (SIZE (39)),randomValue BIT STRING (SIZE (39))}EstablishmentCause ::= ENUMERATED {emergency, highPriorityAccess, mt-Access, mo-Signalling,mo-Data, mo-VoiceCall, mo-VideoCall, mo-SMS, mps-PriorityAccess, mcs-PriorityAccess,spare6, spare5, spare4, spare3, spare2, spare1}-- TAG-RRCSETUPREQUEST-STOP-- ASN1STOP

[0176] RRCSetupRequest-IEsfield descriptionsestablishmentCauseProvides the establishment cause for theRRCSetupRequestin accordance with the information received from upper layers. gNB is not expected to reject anRRCSetupRequestdue to unknown cause value being used by the UE.ue-IdentityUE identity included to facilitate contention resolution by lower layers.

[0177] InitialUE-Identityfield descriptionsng-5G-S-TMSI-Part1The rightmost 39 bits of 5G-S-TMSI.randomValueInteger value in the range 0 to 2 39 - 1.

[0178] (2)RRCSetup

[0179] The RRCSetup message can be used to establish SRB1. The RRCSetup message can be transmitted in the following manner.

[0180] -Signalling radio bearer: SRB0

[0181] - RLC-SAP: TM

[0182] - Logical channel: CCCH

[0183] - Direction: Network to UE

[0184] The RRCSetup message can be defined as shown in Tables 8 to 10 below.

[0185] -- ASN1START-- TAG-RRCSETUP-STARTRRCSetup ::= SEQUENCE {rrc-TransactionIdentifier RRC-TransactionIdentifier,criticalExtensions CHOICE {rrcSetup RRCSetup-IEs,criticalExtensionsFuture SEQUENCE {}}}RRCSetup-IEs ::= SEQUENCE {radioBearerConfig RadioBearerConfig,masterCellGroup OCTET STRING (CONTAINING CellGroupConfig),lateNonCriticalExtension OCTET STRING OPTIONAL,nonCriticalExtension RRCSetup-v1700-IEs OPTIONAL}RRCSetup-v1700-IEs ::= SEQUENCE {sl-ConfigDedicatedNR-r17 SL-ConfigDedicatedNR-r16 OPTIONAL,-- Cond L2RemoteUEsl-L2RemoteUE-Config-r17 SL-L2RemoteUE-Config-r17 OPTIONAL, -- Cond L2RemoteUEnonCriticalExtension SEQUENCE {} OPTIONAL}-- TAG-RRCSETUP-STOP-- ASN1STOP

[0186] RRCSetup-IEsfield descriptionsmasterCellGroupThe network configures only the RLC bearer for the SRB1,mac-CellGroupConfig,physicalCellGroupConfigandspCellConfig.radioBearerConfignly SRB1 can be configured in RRC setup.sl-ConfigDedicatedNRContains dedicated configurations for NR sidelink communication. The network configures only the PC5 Relay RLC channel andsl-PHY-MAC-RLC-Configused for the SRB1.sl-L2RemoteUE-ConfigContains dedicated configurations used for L2 U2N relay related operation. The network configures only the SRAP configuration used for the SRB1 and local UE ID.

[0187] Conditional PresenceExplanationL2RemoteUEThe field is mandatory present for L2 U2N Remote UE; otherwise it is absent.

[0188] (3)SL-L2RemoteUE-Config

[0189] IESL-L2RemoteUE-Config can be used to set configurations related to L2 U2N relay operation used in L2 U2N remote UE.

[0190] The SL-L2RemoteUE-Config message can be defined as shown in Tables 11 to 13 below.

[0191] -- ASN1START-- TAG-SL-L2REMOTEUE-CONFIG-STARTSL-L2RemoteUE-Config-r17 ::= SEQUENCE {sl-SRAP-ConfigRemote-r17SL-SRAP-Config-r17OPTIONAL, --Need Msl-UEIdentityRemote-r17 RNTI-ValueOPTIONAL, -- Cond FirstRRCReconfig...}-- TAG-SL-L2REMOTEUE-CONFIG-STOP-- ASN1STOP

[0192] SL-L2RemoteUE-Configfield descriptionssl-SRAP-ConfigRemoteIndicates SRAP configuration used for L2 U2N Remote UE. sl-UEIdentityRemoteIndicates the C-RNTI to the L2 U2N Remote UE.

[0193] Conditional PresenceExplanationFirstRRCReconfigThis field is mandatory present in the firstRRCReconfiguration. Otherwise the field is absent.

[0194] (4)SL-SRAP-Config

[0195] IESL-SRAP-Config can be used to configure configurable SRAP parameters used by L2 U2N relay UEs and L2 U2N remote UEs (see 3GPP TS 38.351).

[0196] The SL-SRAP-Config message can be defined as shown in Table 14 below.

[0197] -- ASN1START-- TAG-SL-SRAP-CONFIG-STARTSL-SRAP-Config-r17 ::= SEQUENCE {sl-LocalIdentity-r17 INTEGER(0..255)OPTIONAL, -- Need Msl-MappingToAddModList-r17 SEQUENCE (SIZE (1..maxLC-ID)) OF SL-MappingToAddMod-r17 OPTIONAL, -- Need Nsl-MappingToReleaseList-r17 SEQUENCE (SIZE (1..maxLC-ID)) OF SL-RemoteUE-RB-Identity-r17 OPTIONAL, -- Need N...}SL-MappingToAddMod-r17 ::= SEQUENCE {sl-RemoteUE-RB-Identity-r17 SL-RemoteUE-RB-Identity-r17, sl-EgressRLC-ChannelUu-r17 Uu-RelayRLC-ChannelID-r17OPTIONAL, -- Cond L2RelayUEsl-EgressRLC-ChannelPC5-r17 SL-RLC-ChannelID-r17OPTIONAL, -- Need N...}SL-RemoteUE-RB-Identity-r17 ::= CHOICE {srb-Identity-r17 INTEGER (0..3),drb-Identity-r17 DRB-Identity,...}-- TAG-SL-SRAP-CONFIG-STOP-- ASN1STOP

[0198] Below, the procedure is additionally described with respect to the operation of the U2N relay UE.

[0199] The following procedure can be used by a UE supporting NR sidelink U2N relay UE operation configured at a higher layer to transmit an NR sidelink discovery message to evaluate AS layer conditions.

[0200] (1) NR sidelink U2N relay UE threshold condition

[0201] A UE capable of NR sidelink U2N relay UE operation can:

[0202] 1> If the threshold conditions specified below have not previously been met:

[0203] 2> If threshHighRelay is not configured; or if the RSRP measurement of the PCell or cell on which the UE camps is configured and is lower than threshHighRelay by hystMaxRelay; and

[0204] 2> If threshLowRelay is not configured; or if the RSRP measurement of the PCell or cell on which the UE is camping is configured and is higher than threshLowRelay by hystMinRelay:

[0205] 3> The threshold condition is considered to be met (entry);

[0206] 1> If not:

[0207] 2> If the RSRP measurement value of the PCell or cell on which the UE is camping is higher than threshHighRelay, if configured; or

[0208] 2> If the RSRP measurement value of the PCell or cell where the UE is camping is lower than threshLowRelay, if configured;

[0209] 3> Consider unsatisfied critical conditions (leave);

[0210] (2) Threshold conditions for NR sidelink U2N remote UE

[0211] A UE capable of NR sidelink U2N remote UE operation can:

[0212] 1> If the threshold conditions specified below have not previously been met:

[0213] 2> If threshHighRemote is not configured or if the RSRP measurement of the PCell or cell where the UE is camping is configured and is lower than threshHighRemote by hystMaxRemote or

[0214] 2> If the UE does not have a serving cell:

[0215] 3> The threshold condition is considered to be met (entry);

[0216] 1> If not:

[0217] 2> If the RSRP measurement value of the PCell or cell where the UE is camping is higher than threshHighRemote, as configured:

[0218] 3> Leave the threshold condition as not met;

[0219] The following procedure can be used by an L2 U2N remote UE in RRC_IDLE / RRC_INACTIVE state to inform information about required SIBs and provide paging related information to a connected L2 U2N relay UE.

[0220] (1) Actions related to sending RemoteUEInformationSidelink messages

[0221] When the state transitions to RRC_IDLE or RRC_INACTIVE or the information in RemoteUEInformationSidelink changes in RRC_IDLE or RRC_INACTIVE state, the L2 U2N remote UE can:

[0222] 1> If the UE does not store a valid version of the SIB, does not store one or more required SIBs, and the requested SIB was not previously present in a RemoteUEInformationSidelink message to the L2 U2N Relay UE:

[0223] 2> Include sl-RequestedSIB-List in RemoteUEInformationSidelink to indicate the requested SIBs.

[0224] 1> If the UE has not previously sent sl-PagingInfo-RemoteUE to the L2 U2N Relay UE in the RemoteUEInformationSidelink message, sl-PagingInfo-RemoteUE can be set as follows:

[0225] 2> When L2 U2N Remote UE is in RRC_IDLE:

[0226] 3> Include ng-5G-S-TMSI in sl-PagingIdentityRemoteUE.

[0227] 3> If a UE-specific DRX cycle is configured in the upper layer, set sl-PagingCycleRemoteUE to the UE-specific Uu DRX cycle value configured in the upper layer.

[0228] 2> Otherwise, if the L2 U2N remote UE is RRC_INACTIVE:

[0229] 3> Include ng-5G-S-TMSI and fullI-RNTI in sl-PagingIdentityRemoteUE.

[0230] 3> If a UE-specific DRX cycle is configured in the upper layer

[0231] 4> Set sl-PagingCycleRemoteUE to the minimum value of the UE-specific Uu DRX cycle (configured in upper layers and configured in RRC).

[0232] 3> If not:

[0233] 4> Set sl-PagingCycleRemoteUE to the UE-specific DRX cycle value configured in RRC.

[0234] 1> Submit the RemoteUEInformationSidelink message for transmission to the lower layer.

[0235] When entering RRC_CONNECTED, if the L2 U2N remote UE sends sl-RequestedSIB-List and / or sl-PagingInfo-RemoteUE, the L2 U2N remote UE can:

[0236] 1> If previously requested, set sl-RequestedSIB-List to the value release.

[0237] 1> If previously sent, set sl-PagingInfo-RemoteUE to the release value.

[0238] 1> Submit a RemoteUEInformationSidelink message to the lower layer for transmission.

[0239] (2) Reception of RemoteUEInformationSidelink message by L2 U2N Relay UE

[0240] The L2 U2N Relay UE must:

[0241] 1> If RemoteUEInformationSidelink contains sl-PagingInfo-RemoteUE:

[0242] 2> When the UE is in RRC_CONNECTED state in an active BWP with a common search space configured including pagingSearchSpace; or

[0243] 2> If the UE is in RRC_IDLE or RRC_INACTIVE state:

[0244] 3> If sl-PagingInfo-RemoteUE is set to Enabled:

[0245] 4> Monitor paging messages at the paging time of L2 U2N Remote UE calculated according to sl-PagingIdentityRemoteUE and sl-PagingCycleRemoteUE included in sl-PagingInfo-RemoteUE.

[0246] 3> Otherwise (sl-PagingInfo-RemoteUE is set to off):

[0247] 4> Stop monitoring paging messages when paging L2 U2N Remote UE.

[0248] 4> sl-PagingInfo-Release paging information received from RemoteUE.

[0249] 2> else (if UE is in RRC_CONNECTED state in active BWP with pagingSearchSpace not configured):

[0250] 3> If sl-PagingInfo-RemoteUE is set to setup:

[0251] 4> Include the received sl-PagingIdentityRemoteUE in the SidelinkUEInformationNR message and perform Sidelink UE information transmission according to 5.8.3.

[0252] 3> else (if sl-PagingInfo-RemoteUE is set to release):

[0253] 4> Start sending SidelinkUEInformationNR message to release sl-PagingIdentityRemoteUE of SidelinkUEInformationNR message according to 5.8.3.

[0254] 4> sl-PagingInfo-Release paging information received from RemoteUE.

[0255] 여기서, RemoteUEInformationSidelink message 및 UuMessageTransferSidelink message는 표 15 및 표 16과 같이 정의될 수 있다.

[0256] SL-PagingInfo-RemoteUE-r17 ::= SEQUENCE {sl-PagingIdentityRemoteUE-r17 SL-PagingIdentityRemoteUE-r17,sl-PagingCycleRemoteUE-r17 PagingCycle OPTIONAL -- Need M}

[0257] ASN1START-- TAG-UUMESSAGETRANSFERSIDELINK-STARTUuMessageTransferSidelink-r17 ::= SEQUENCE {criticalExtensions CHOICE {uuMessageTransferSidelink-r17 UuMessageTransferSidelink-r17-IEs,criticalExtensionsFuture SEQUENCE {}}}UuMessageTransferSidelink-r17-IEs ::= SEQUENCE {sl-PagingDelivery-r17OCTET STRING (CONTAINING PagingRecord) OPTIONAL, -- Need Nsl-SIB1-Delivery-r17 OCTET STRING (CONTAINING SIB1) OPTIONAL, -- Need Nsl-SystemInformationDelivery-r17 OCTET STRING (CONTAINING SystemInformation) OPTIONAL, -- Need NlateNonCriticalExtension OCTET STRING OPTIONAL,nonCriticalExtension SEQUENCE {} OPTIONAL}-- TAG-UUMESSAGETRANSFERSIDELINK-STOP-- ASN1STOP

[0258] Below, we describe in detail how to monitor paging in multi-hop based U2N relay communication.

[0259] How to Monitor Paging in Multi-Hop U2N Relay Operation

[0260] Figure 14 is a diagram for explaining a method for performing paging monitoring in multi-hop U2N relay communication.

[0261] Multi-hop U2N relay operation is likely to be handled by rel-19 SL relay. Multi-hop U2N relay operation may be a structure in which data is transmitted / received from the gNB to the remote UE via multiple hops in the existing U2N operation.

[0262] Referring to Fig. 14 (a), in multi-hop U2N relay communication / operation, relay UE1 is directly connected to gNB and is SL-connected or directly connected to relay UE2, and relay UE2 is SL-connected or directly connected to relay UE1 toward gNB and is directly connected to remote UE. Here, relay UE1 may be defined as a Uu-SL relay UE or last relay UE directly connected to gNB, and relay UE2 may be defined as an SL-SL relay UE or an intermediate relay UE.

[0263] Additionally, the connection of multi-hop U2N relays may also be possible in a topology where bearers / channels are multiplexed as illustrated in FIG. 14 (b) and FIG. 14 (c).

[0264] In the existing Rel-17 SL relay operation, the relay UE can perform the operation of monitoring the paging of the remote UE. In addition, when the remote UE makes a SIB request to the relay UE, the relay UE can transmit the stored SIB value to the remote UE if it has a valid SIB (value) among the SIB (values) requested from the remote UE. If it does not have a valid SIB, the relay UE can transmit an SIB request message to the gNB on behalf of the remote UE.

[0265] Below, the operation method for paging monitoring and SIB requests in multi-hop U2N relay operation is described in detail.

[0266] FIG. 15 and FIG. 16 are diagrams for explaining how a relay UE monitors paging for a remote UE.

[0267] 1. Paging monitoring

[0268] A remote UE in IDLE / INACTIVE state can transmit information for paging monitoring (paging ID and paging cycle (or DRX information)) to a relay UE connected to SL or directly connected to itself. The relay UE can transmit the transmitted information for paging monitoring of the remote UE to a UE (e.g., relay UE1) that can be directly connected to the gNB via multiple hops. At this time, the transmitted value or information for paging monitoring of the remote UE may be identical to the value or information transmitted in rel-17.

[0269] A remote UE can transmit a message containing values / information for paging monitoring toward relay UE1 using a SRAP header. The SRAP header can include the (L2 / local) ID of relay UE1 and / or the (L2 / local) ID of remote UE. Each intermediate relay UE (e.g., relay UE2) can use the (L2 / local) ID of relay UE1 and / or remote UE included in the SRAP to determine to which relay UE to forward the received message (or packet).

[0270] In this case, the relay UE1, which has received the value / information for monitoring paging of the remote UE, can monitor the paging or paging signal of the remote UE. If the paging signal of the remote UE is detected / received (e.g., if paging of the remote UE is received from the gNB via an RRC dedicated message), the relay UE1 can transmit paging information for the detected / received paging signal to the remote UE. In this case as well, the relay UE1 can include the (L2 / local) ID of the relay UE1 and / or the (L2 / local) ID of the remote UE in the SRAP header.

[0271] Alternatively, as described above, the following methods may be considered for the remote UE to transmit paging monitoring information (e.g., identification, DRX information, etc.) for its own paging monitoring to the relay UE1.

[0272] (1) Method 1

[0273] In order for the remote UE to transmit information for its own paging monitoring (hereinafter, paging monitoring information) to the relay UE1, the gNB may inform the remote UE of the local ID of the relay UE1. For example, the gNB may allocate a local ID of the relay UE1 (e.g., a relay UE that can be directly connected to a gNB that is multi-hop connected to the remote UE) and a local ID indicating the remote UE together. At this time, the local ID values ​​of the relay UE1 / remote UE may be included in a message for connection establishment for the remote UE (e.g., RRCSetup, RRCReestablishment, RRCResume message), and an (end-to-end / current-hop) bearer between the relay UE1 and the remote UE for transmitting and receiving the paging monitoring information using the local ID values ​​between the relay UE1 and the remote UE may also be configured.

[0274] Referring to Fig. 15 (a), such an operation may be problematic when a relay UE2 (or one intermediate relay UE) is connected to multiple relay UEs (e.g., relay UE1 (a), relay UE1 (b)). For example, from the intermediate relay UE's perspective, it is necessary to distinguish to which relay UE among relay UE1 (a) and relay UE2 (b) the paging monitoring information for paging of the remote UE should be delivered. For example, when the relay UE connected for the indirect path of remote UE A is relay UE1 (a), the remote UE A needs to inform the intermediate relay UE that it will deliver the paging monitoring information to relay UE1 (a).

[0275] Alternatively, the local ID of the relay UE assigned by the gNB may also be the local ID for relay UE2, which serves as the local ID for the UE that monitors paging for the remote UE. For example, if relay UE2 is in coverage, relay UE2 may perform paging monitoring for the remote UE. This may have the effect of reducing the latency required to wake up the remote UE. From the remote UE's perspective, the paging monitoring information for paging monitoring can be transmitted to the assigned local ID.

[0276] Meanwhile, when relay UE1(a) receives (or monitors) a paging signal, a paging message, or paging information (hereinafter, paging information) for remote UE A, relay UE1(a) can transmit the paging information to remote UE A. During this transmission process, it is necessary to transition intermediate relay UEs (e.g., relay UE2 and / or relay UE3) in RRC IDLE / INACTIVE state to RRC CONNECTED state. When the state transition of the intermediate relay UE is also performed in this manner, the time for remote UE A to enter RRC CONNECTED state can be significantly reduced. To this end, at least one of the following options may be considered. Meanwhile, the following options may also be applied to Method 2 described below.

[0277] - Option 1

[0278] When relay UE2 (or relay UE1) is in IDLE / INACTIVE state, as an implementation example of the gNB, the gNB can transmit a paging message to the intermediate relay UE among the intermediate relay UEs that constitute multi-hops between the remote UE and the gNB, which is in IDLE / INACTIVE state. For this operation, the intermediate relay UE needs to report its hop count, (SRC / DST) L2 ID pair of the connected relay UE / remote UE, etc. to the gNB in ​​advance using a message such as SUI. In this case, the gNB can determine the order of the intermediate relay UEs between the gNB and the remote UE based on the information included in the SUI reported by the intermediate relay UE.

[0279] - Option 2

[0280] When a relay UE (or relay UE1) monitors paging of a remote UE, the relay UE may wake up at least one intermediate relay UE connected to the remote UE. For example, the relay UE1 may transmit a PC5-RRC message (e.g., including paging information for the remote UE) to the relay UE2, which indicates an RRC state transition of the relay UE2 (or for waking up the relay UE2). The relay UE2 (or the intermediate relay UE) receiving the PC5-RRC message may forward a PC5-RRC message to the relay UE3, which wakes up (or for transitioning to an RRC connected state) the next intermediate relay UE (e.g., relay UE3) directed to the remote UE. The PC5-RRC message may include information about a local ID of the remote UE to identify whether the remote UE is the next relay UE directed to the remote UE. An intermediate relay UE receiving this has a setting for the local ID (e.g., a local ID for a remote UE) and can trigger an RRC state transition to an RRC connected state if it is in an IDLE / INACTIVE state.

[0281] - Option 3

[0282] When a relay UE transmits a message containing paging information (e.g., a PC5-RRC message), the SRAP header of the message may additionally include a 1-bit indication. The intermediate relay UE may, when in an IDLE / INACTIVE state, switch its RRC state to an RRC connected state based on the indication included in the SRAP header of the received / transmitted message.

[0283] (2) Method 2

[0284] Referring to FIG. 15 (b), remote UE A is connected to the gNB via relay UE2 (intermediate relay UE) and relay UE1, and remote UE B can also be connected to the gNB via relay UE2 (intermediate relay UE) and relay UE1.

[0285] In this case, the remote UE (remote UE A and / or remote UE B) can forward a message including its paging monitoring information (paging ID / DRX related information) and its local ID to the relay UE (e.g., relay UE2 toward the gNB) without assigning a local ID to the relay UE1 (assuming / presupposing that a bearer and other settings for forwarding the message including the paging monitoring information and local ID are set by the gNB). The relay UE (e.g., relay UE2) receiving this can forward the paging monitoring information to another relay UE connected to it (e.g., relay UE1 toward the gNB). When the relay UE (e.g., relay UE2) receives paging monitoring information from multiple remote UEs (or other relay UEs), the relay UE may merge or list-up the paging monitoring information for multiple remote UEs by matching paging monitoring information (e.g., DRX-related information) by remote UE ID (e.g., local ID, paging ID, and / or 5G-S-TMSI (Temporary Mobile Subscriber Identity)). The relay UE may forward the merged or listed-up merged paging monitoring information to its previous relay UE (e.g., the relay UE toward the gNB).

[0286] Alternatively, when a remote UE transmits paging monitoring information to an intermediate relay UE, the (IDLE / INACTIVE) intermediate relay UE may also (or separately) transmit / forward paging monitoring information for its own paging monitoring to a relay UE (e.g., relay UE1) that can directly perform paging monitoring. When the relay UE that can directly perform paging monitoring is in an RRC connection state, it may report the paging monitoring information or the merged paging monitoring information to the gNB. This is so that the relay UE can receive a paging message from the gNB as an RRC message in the same manner as before.

[0287] Meanwhile, Method 2 may be a method that, unlike Method 1, does not use two local IDs (SRC local ID, DST local ID) in the SRAP header, but rather uses only one local ID (the remote UE's local ID) in the SRAP header, similar to the existing Rel-17 U2N. This method may also be applied only when the relay UE is not connected to the gNB through multiple other relay UEs, as in Fig. 15 (b).

[0288] In this way, the gNB can notify the paging information for multiple remote UEs and / or multiple relay UEs to the relay UE (e.g., relay UE1) directly connected to it in a single RRC message. In this case, the local ID of each remote UE and / or relay UE can be used as a value that can identify each remote UE and / or relay UE. For this purpose, the gNB may also allocate a local ID for an intermediate relay UE in advance. When the paging information for multiple remote UEs and / or multiple relay UEs is received, the relay UE (e.g., relay UE1, relay UE2, and / or relay UE3) may split the paging information / paging message for each remote UE and / or relay UE to which the paging information / paging message is to be delivered, and may deliver only the necessary information to each remote UE and / or relay UE. This is to prevent paging information of remote UE B from being transmitted to remote UE A (e.g., to prevent unnecessary information from being transmitted to each remote UE).

[0289] Below, we describe in detail how to transmit paging information via RemoteUEInformationSidelink or UuMessageTransferSidelink messages.

[0290] Upon receipt of a RemoteUEInformationSidelink message by an L2 U2N relay UE, the L2 U2N relay UE shall:

[0291] 1>If RemoteUEInformationSidelink contains sl-PagingInfo-RemoteUE:

[0292] 2> When the UE is in RRC_CONNECTED state in an active BWP with a common search space configured including pagingSearchSpace; or

[0293] 2> If the UE is in RRC_IDLE or RRC_INACTIVE state:

[0294] 3>If sl-PagingInfo-RemoteUE is set to setup:

[0295] 4> Monitors paging messages at the paging time of L2 U2N remote UE calculated according to sl-PagingCycleRemoteUE included in sl-PagingIdentityRemoteUE and sl-PagingInfo-RemoteUE.

[0296] 3> Otherwise (sl-PagingInfo-RemoteUE is set to release):

[0297] 4> Stop monitoring paging messages when paging the L2 U2N remote UE.

[0298] 4>sl-PagingInfo-Release paging information received from RemoteUE.

[0299] 2> else (if UE is in RRC_CONNECTED state in active BWP without pagingSearchSpace configured):

[0300] 3>If sl-PagingInfo-RemoteUE is set to setup:

[0301] 4> The received sl-PagingIdentityRemoteUE is included in the SidelinkUEInformationNR message to perform Sidelink UE information transmission.

[0302] 3> else (if sl-PagingInfo-RemoteUE is set to release):

[0303] 4> Start transmitting the SidelinkUEInformationNR message to release the sl-PagingIdentityRemoteUE of the SidelinkUEInformationNR message according to 5.8.3.

[0304] 4> sl-PagingInfo-Release paging information received from RemoteUE.

[0305] Here, the RemoteUEInformationSidelink message can be used to request SIB(s) or provide paging-related information.

[0306] - Signal radio bearer: SL-SRB3

[0307] - RLC-SAP: AM

[0308] - Logical Channel: SCCH

[0309] - Direction: From L2 U2N remote UE to L2 U2N relay UE

[0310] The RemoteUEInformationSidelink message can be defined as shown in Table 17.

[0311] RemoteUEInformationSidelink-r17 ::= SEQUENCE {criticalExtensions CHOICE {remoteUEInformationSidelink-r17 RemoteUEInformationSidelink-r17-IEs,criticalExtensionsFuture SEQUENCE {}}}RemoteUEInformationSidelink-r17-IEs ::= SEQUENCE {sl-RequestedSIB-List-r17 SetupRelease { SL-RequestedSIB-List-r17} OPTIONAL, -- Need Msl-PagingInfo-RemoteUE-r17SetupRelease { SL-PagingInfo-RemoteUE-r17} OPTIONAL, -- Need MlateNonCriticalExtension OCTET STRING OPTIONAL,nonCriticalExtension RemoteUEInformationSidelink-v1800-IEs OPTIONAL}SL-PagingInfo-RemoteUE-r17 ::= SEQUENCE {sl-PagingIdentityRemoteUE-r17 SL-PagingIdentityRemoteUE-r17,sl-PagingCycleRemoteUE-r17 PagingCycle OPTIONAL -- Need M}

[0312] In the actions related to the transmission of a UuMessageTransferSidelink message, the L2 U2N relay UE initiates the transmission procedure of the Uu message if one or more of the following conditions are met:

[0313] 1> When a paging message related to a L2 U2N remote UE connected to the network is received (including a paging message within an RRCReconfiguration message);

[0314] For each associated L2 U2N remote UE, the L2 U2N relay UE shall set the content of the UuMessageTransferSidelink message as follows:

[0315] 1> If the paging message received from the network contains the ue-Identity of the L2 U2N remote UE, include sl-PagingDelivery.

[0316] Below, a method for providing paging information based on the above-described messages is described in detail.

[0317] Referring to FIG. 16, remote UE A may form an indirect path connecting relay UE3 - relay UE2 - relay UE1-gNB, remote UE B may form an indirect path connecting relay UE3 - relay UE2a -gNB, remote UE C may form an indirect path connecting relay UE2 - relay UE1 -gNB, and remote UE D may form an indirect path connecting relay UE1 -gNB.

[0318] At this time, each of the relay UEs can support all RRC states, but the RRC state of the relay UE may be restricted in relation to the RRC state of the relay UE of the previous hop (e.g., the relay UE connected SL toward the gNB). For example, if relay UE3 is in RRC_CONNECTED state, relay UE2 (or the previous relay UE) cannot be in RRC_IDLE / INACTIVE state. In this case, relay UE2 may only be allowed to be in RRC_CONNECTED state. As another example, if relay UE3 is in RRC_INACTIVE state, relay UE2 cannot be in RRC_IDLE state. If relay UE3 is in RRC_INACTIVE state, relay UE2 may only be allowed to be in RRC_CONNECTED / RRC_INACTIVE state. It can be assumed that this follows the principle of the existing Rel-17.

[0319] When remote UE A / B is in RRC_IDLE / INACTIVE state, it can request monitoring of its own paging information from the relay UE connected to it. At this time, remote UE A / B can request paging monitoring from the relay UE using RemoteUEInformation of Rel-17 (or RemoteUEInformationSidelink of Table 17). The RemoteUEInformationmessage can include UE identification information (e.g., 5G-S-TMSI) for requesting paging monitoring and paging monitoring information such as DRX cycle. When the RemoteUEInformation message is received, the relay UE (e.g., relay UE3) can perform the following actions.

[0320] - If relay UE3 is in OoC (Out of coverage) and receives a request message (e.g., RemoteUEInformationmessage) containing paging monitoring information for a remote UE (or another relay UE) transmitted by a remote UE (or another relay UE), the relay UE3 may forward the request message to a relay UE of a previous hop connected to it (e.g., relay UE2 or relay UE2a).

[0321] - If the relay UE3 or the remote UE is in RRC_CONNECTED state and the common search space (CSS) is not configured, the relay UE3 may transmit the request message received (from the remote UE or another relay UE) to the relay UE of its previous hop (e.g., relay UE2 or relay UE2a). Alternatively, the relay UE3 (or the relay UE) may transmit the request message including its local ID in the SRAP header to the gNB (via multiple relay UEs) using the SUI as if it were requesting paging monitoring.

[0322] Alternatively, when the relay UE3 or remote UE is in RRC_CONNECTED state and CSS is set, the relay UE3 can directly monitor the paging signal for the remote UE (or relay UE) based on the request message. However, even when the relay UE3 is in RRC_CONNECTED state and CSS is set, a situation may arise where the paging cannot be directly monitored due to the mobility of the relay UE3 (e.g., through Uu-RSRP measurement, etc.). In this case, the relay UE3 can forward the paging monitoring request message received from the remote UE (or relay UE) to the relay UE of the previous hop (e.g., relay UE2 or relay UE2a). Alternatively, the relay UE3 may transmit a SUI (SidelinkUEinformation message) including an SRAP header including its local ID to the gNB (via multiple relay UEs) as if requesting its own paging monitoring.

[0323] Alternatively, a relay UE that was in RRC_CONNECTED state (e.g., a relay UE that is in RRC_CONNECTED state and can directly monitor paging by receiving configuration for CSS from the gNB) may enter RRC_IDLE / INACTIVE state while performing paging monitoring for a remote UE (and / or another relay UE). In this case, the relay UE may transmit first paging monitoring information for its own paging monitoring and second paging monitoring information (information previously requested for paging monitoring) for paging monitoring of the remote UE (and / or another relay UE) to the relay UE of its previous hop. Alternatively, a relay UE that was receiving paging information for itself and other relay UEs (and / or remote UEs) via a dedicated RRC message from the gNB (e.g., a relay UE that is in RRC_CONNECTED state and has not received configuration for a common search space from the gNB) may enter RRC_IDLE / INACTIVE state. In this case, the relay UE may transmit paging monitoring information for its own paging monitoring and paging monitoring information for paging monitoring of a remote UE (and / or another relay UE) to the relay UE of its previous hop. This may be applied only when the relay UE has transitioned from an RRC_CONNECTED state to an RRC_IDLE / INACTIVE state and cannot perform direct paging monitoring. For example, when it has transitioned to an RRC_IDLE / INACTIVE state but can perform direct paging monitoring, the relay UE may not transmit paging monitoring information for paging monitoring received from itself and a remote UE (and / or another relay UE) to the relay UE of its previous hop.

[0324] Thereafter, when the relay UE transitions from RRC_IDLE / INACTIVE state to RRC_CONNECTED state, the relay UE may request its previous hop relay UE to release paging monitoring according to paging monitoring information for itself or another relay UE (or request release of paging monitoring information (UE-identification, cycle) transmitted for paging monitoring). In this case, the relay UE may request release of paging monitoring information of the next hop relay UE (and / or remote UE) connected to itself as well as paging monitoring information for its own paging monitoring. For example, the relay UE in IDLE / INACTIVE state may transfer paging monitoring information for the relay UE and / or another relay UE (and / or remote UE) to the previous hop relay UE. After this, when the relay UE transitions to the RRC_CONNECTED state, the relay UE can request the release of paging monitoring information previously transmitted to the relay UE of the previous hop or paging monitoring based on the paging monitoring information, and can directly perform paging monitoring for other relay UEs and / or remote UEs.

[0325] Alternatively, a relay UE in RRC_CONNECTED state and with CSS configured can directly monitor paging of itself and other relay UEs (and / or remote UEs). Alternatively, if the relay UE is in RRC_CONNECTED state but CSS is not configured, the relay UE may transmit paging monitoring information for paging monitoring to the gNB through the SUI, and directly receive paging information / paging messages through a dedicated RRC message from the gNB. Alternatively, if the relay UE is in RRC_CONNECTED state and CSS is configured but determines that it cannot directly monitor paging of itself and other relay UEs (and / or remote UEs), the relay UE may transmit paging monitoring information for paging monitoring to the gNB through the SUI, and directly receive paging information / paging messages through a dedicated RRC message from the gNB. This operation has the advantage of significantly reducing latency compared to requesting paging monitoring from the relay UE of the previous hop (the previous relay UE toward the gNB), receiving paging information from the previous relay UE, and forwarding it to another relay UE or a remote UE. Latency can be reduced only when a relay UE close to the remote UE can directly monitor paging, and thus the relay UE in RRC_IDLE / INACTIVE state can request the previous relay UE to release paging monitoring only when it has changed to RRC_CONNECTED state and CSS is set.

[0326] Alternatively, only relay UE1 (capable of direct Uu link connection with gNB) may be configured to perform paging monitoring for other relay UEs and / or remote UEs. In this case, the following actions may be performed.

[0327] - An SL-SL relay UE (a relay UE that cannot be directly connected to the gNB) that has received a paging request message for paging monitoring from another remote UE and / or relay UE may forward the paging monitoring information to the relay UE of the previous hop via a PC5-RRC message (even if the SL-SL relay UE is in RRC_CONNECTED state). This operation may be performed until the paging monitoring information for paging monitoring is forwarded to the relay UE1. During this operation, if paging monitoring information for paging monitoring is received from multiple remote UEs and / or multiple relay UEs, the relay UE may forward the merged paging monitoring information, which is the paging monitoring information received from the multiple remote UEs and / or multiple relay UEs, to the relay UE of the previous hop as a single message. The relay UE1, which has received the single message, may forward the merged paging monitoring information included in the single message to the gNB via the SUI if it is in RRC_CONNECTED state and CSS is not set. Alternatively, if the relay UE1 is in RRC_CONNECTED state and CSS is set, it can perform paging monitoring for multiple remote UEs and / or multiple relay UEs.

[0328] - Alternatively, if the SL-SL relay UE is RRC_CONNECTED, the SL-SL relay UE may transmit paging monitoring information for paging monitoring received from a remote UE and / or another relay UE via a PC5-RRC message to the gNB using SUI. If the gNB configures CSS for the relay UE1 so that the relay UE1 can directly perform paging monitoring, the gNB may additionally inform the relay UE1 of paging monitoring information that the relay UE1 should monitor based on the SUI value received via the SL-SL relay UE. This is because the relay UE1 cannot know the paging monitoring information for paging monitoring that the SL-SL relay UE directly transmitted to the gNB via SUI. When the gNB receives paging monitoring information for paging monitoring from the SL-SL relay UE via the SUI, and the relay UE1 performs paging monitoring based on the paging monitoring information (e.g., provided by the gNB), the gNB may also configure which SL connection the paging monitoring result will be transmitted through, or which local ID (which may be the local ID of the SL-SL relay UE in the CONNECTED state) the paging monitoring result will be transmitted using, etc. This is to inform the relay UE1 to which relay UE (or remote UE) the paging monitoring result should be transmitted. Such an operation may be applicable not only to the relay UE1 but also to other relay UEs for which CSS is configured.

[0329] Alternatively, the request message for paging monitoring transmitted by the relay UE to the previous relay UE may include paging monitoring information for its own paging monitoring in addition to paging monitoring information for paging monitoring of other remote UEs or relay UEs connected to the relay UE.

[0330] The relay UE of the aforementioned previous hop may refer to a relay UE that is SL-connected in the direction close to or toward the gNB. Furthermore, the relay UE of the aforementioned next hop may refer to a relay UE (or remote UE) that is SL-connected in the direction toward the remote UE (or away from the gNB).

[0331] FIG. 17 is a diagram illustrating a method for a first relay UE to transmit information about a paging signal to a remote UE.

[0332] The first relay UE can support U2N relay communication / operation between the base station and the remote UE. As described above, the first relay UE can be an intermediate relay UE or SL-SL relay UE that is SL-connected to a second relay UE (or a last relay UE or a Uu-SL relay UE) that is directly connected to the base station for U2N relay communication / operation, and is connected to a remote UE or another relay UE (or a third relay UE) that is SL-connected to the remote UE.

[0333] Specifically, referring to FIG. 17, a first relay UE may form a first connection, which is an SL connection, with a second relay UE directly connected to the base station for U2N (UE-to-Network) relay communication between the base station and a remote UE (S171). In addition, the first relay UE may form a second connection, which is an SL connection, with the third relay UE or the remote UE for U2N relay communication.

[0334] Next, the first relay UE can transmit / send paging monitoring information for the remote UE to the second relay UE via the first connection (S173). Specifically, the first relay UE can transmit or receive paging monitoring information for the remote UE via the second connection. Here, the paging monitoring information may include information for paging monitoring, such as identification information and DRX cycle related to the remote UE as described above. For example, the paging monitoring information may be transmitted via the RemoteUEInformation message described above. The first relay UE can transmit / forward the received paging monitoring information to the second relay UE via the first connection. At this time, when the first relay UE is in an RRC idle state or an RRC inactive state, the first relay UE can also transmit paging monitoring information for its own paging monitoring to the second relay UE. Alternatively, when the first relay UE is in an RRC idle state or an RRC inactive state, the first relay UE may transmit merged paging monitoring information, which is a merged combination of paging monitoring information for its own paging monitoring and paging monitoring information for the remote UE, to the second relay UE. Here, the merged paging monitoring information may include paging monitoring information mapped to each of the ID of the first relay UE and the ID of the remote UE, or may include a merged DRX pattern, which is a merged combination of a DRX pattern for the first relay UE and a DRX pattern for the remote UE.

[0335] Alternatively, if the first relay UE is connected to a plurality of remote UEs and receives the paging monitoring information from the plurality of remote UEs, the first relay UE may transmit merged paging monitoring information, which is the merged paging monitoring information of the plurality of remote UEs, to the second relay UE. Alternatively, the first relay UE may additionally merge its own paging monitoring information into the merged paging monitoring information of the plurality of remote UEs.

[0336] Alternatively, the first relay UE may determine whether to forward the paging monitoring information to the second relay UE based on whether it can directly perform paging monitoring for the remote UE. For example, if the first relay UE is in an RRC connection state and a CSS related to paging monitoring is configured, the first relay UE may directly monitor paging information for the remote UE without forwarding the paging monitoring information to the second relay UE. Alternatively, for example, if the first relay UE is not in an RRC connection state or a CSS related to paging monitoring is not configured, the first relay UE may forward the paging monitoring information for the remote UE to the second relay UE.

[0337] Next, the first relay UE may transition from an RRC (Radio Resource Control) idle or inactive state to an RRC connected state based on reception of a first message via the first connection (S175). Here, the first message may be a message including paging information for the remote UE when the second relay UE detects paging information for the remote UE. In this case, the first message may include a local ID for the remote UE, and the first relay UE may specify a next relay UE based on the local ID of the remote UE and forward the first message to the specified next relay UE.

[0338] Alternatively, the first message may be a message including instruction information (1-bit instruction) in the SRAP (sidelink Relay Adaptation Protocol) header that instructs the RRC state of the first relay UE to be switched to an RRC connected state.

[0339] Alternatively, the first relay UE may be switched to an RRC connected state after transmitting the paging monitoring information to the second relay UE. At this time, if the CSS is set for the first relay UE and paging monitoring for a remote UE is possible directly from the base station, the first relay UE may transmit a third message to the second relay UE for releasing the paging monitoring information or requesting release of paging monitoring for the remote UE (and / or the first relay UE, another relay UE, another remote UE). In this case, the first relay UE may directly perform paging monitoring for the remote UE (and / or the first relay UE, another relay UE, another remote UE).

[0340] FIG. 18 is a diagram illustrating a method for a second relay UE to transmit information about a paging signal to a remote UE.

[0341] Referring to FIG. 18, the second relay UE may form a third connection directly connected to the base station for U2N (UE-to-Network) relay communication between the base station and the remote UE. In addition, the second relay UE may form a fourth connection, which is an SL connection, with the second relay UE for U2N relay communication (S181).

[0342] Next, the second relay UE can transmit / receive paging monitoring information for the remote UE from the first relay UE via the fourth connection (S183). Here, the paging monitoring information may include information for paging monitoring, such as identification information and DRX cycle related to the remote UE as described above. For example, the paging monitoring information may be transmitted via the RemoteUEInformation message described above. Alternatively, when the first relay UE is in an RRC idle state or an RRC inactive state, the second relay UE may receive paging monitoring information for the first relay UE as well as paging monitoring information for the remote UE. In this case, merged paging information, in which paging information for the remote UE and the first relay UE are merged, may be transmitted. As described above, the merged paging information may include information about a merged DRX pattern for the remote UE and the first relay UE, and the second relay UE may monitor paging information for the remote UE and the first relay UE based on the merged DRX pattern.

[0343] Next, the second relay UE may transmit a first message to the first relay UE via the fourth connection, instructing the first relay UE to switch to an RRC connected state when paging information for the remote UE is detected (S185). Alternatively, the first message may be a PC5-RRC message targeting the first relay UE. Here, the first message may be a message including paging information for the remote UE. Alternatively, the first message may be a message including indication information (1-bit indication) in the SRAP (sidelink Relay Adaptation Protocol) header, instructing the first relay UE to switch the RRC state to an RRC connected state.

[0344] Alternatively, the second relay UE may receive a third message from the first relay UE requesting the release of the paging monitoring information or the release of the request for paging monitoring for the remote UE (and / or the first relay UE, another relay UE, another remote UE). In this case, the second relay UE may stop paging monitoring for the remote UE (and / or the first relay UE, another relay UE, another remote UE).

[0345] In this way, the proposed invention can effectively and quickly transition an intermediate relay UE in an RRC idle or inactive state to an RRC connected state by transmitting detection information of a paging signal to a remote UE. Alternatively, the proposed invention can significantly reduce delays that may occur in reestablishing an RRC connection of a remote UE following transmission of the paging signal by ensuring a rapid transition of the RRC connection state of the intermediate relay UE.

[0346] Examples of communication systems to which the invention applies

[0347] 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.

[0348] 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.

[0349] Figure 19 illustrates a communication system applied to the present invention.

[0350] Referring to FIG. 19, 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.

[0351] 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).

[0352] 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.

[0353] Examples of wireless devices to which the present invention is applied

[0354] Figure 20 illustrates a wireless device applicable to the present invention.

[0355] Referring to FIG. 20, 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. 19.

[0356] 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.

[0357] Specifically, the first wireless device or first relay 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 18.

[0358] The processor (102) controls the transceiver (106) to form a first connection with a second relay UE directly connected to the base station for U2N (UE-to-Network) relay communication between the base station and a remote UE, transmit paging monitoring information for the remote UE to the second relay UE through the first connection, and can switch from an RRC (Radio Resource Control) idle or inactive state to an RRC connected state based on receiving a first message including paging information for the remote UE through the first connection.

[0359] Alternatively, a processing device may be configured including a processor (102) and a memory (104). 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 first relay UE to: form a first connection with a second relay UE directly connected to the base station for U2N (UE-to-Network) relay communication between the base station and the remote UE, transmit paging monitoring information for the remote UE to the second relay UE through the first connection, and transition from an RRC (Radio Resource Control) idle or inactive state to an RRC connected state based on receiving a first message including paging information for the remote UE through the first connection.

[0360] 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.

[0361] Specifically, the second wireless device or second relay UE (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 18.

[0362] The processor (202) controls the transceiver (206) to form a first connection with the base station and a second connection with the first relay UE for U2N (UE-to-Network) relay communication between the base station and the remote UE, monitors paging information based on paging monitoring information for the remote UE, and transmits a first message to switch the first relay UE, which is in an RRC (Radio Resource Control) idle or inactive state, to an RRC connected state based on the paging information being detected.

[0363] 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.

[0364] 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.

[0365] 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.

[0366] 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.

[0367] Examples of wireless devices to which the present invention is applied

[0368] Figure 21 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 19).

[0369] Referring to FIG. 21, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 20 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. 21. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 20. 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).

[0370] 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. 19, 100a), a vehicle (Fig. 19, 100b-1, 100b-2), an XR device (Fig. 19, 100c), a portable device (Fig. 19, 100d), a home appliance (Fig. 19, 100e), an IoT device (Fig. 19, 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. 19, 400), a base station (Fig. 19, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0371] In FIG. 21, 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.

[0372] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0373] Figure 22 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.

[0374] Referring to FIG. 22, 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. 21, respectively.

[0375] 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.

[0376] 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.

[0377] 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.

[0378] 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.

[0379] 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).

[0380] 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.

[0381] 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.

[0382] 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.

[0383] The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims

1. In a method using a first relay UE (User Equipment), A step of forming a first connection with a second relay UE directly connected to the base station for U2N (UE-to-Network) relay communication between the base station and the remote UE; A step of transmitting paging monitoring information for the remote UE to the second relay UE through the first connection; and A method comprising the step of transitioning from an RRC (Radio Resource Control) idle or inactive state to an RRC connected state based on receiving a first message including paging information for the remote UE through the first connection.

2. In paragraph 1, A method, characterized in that the first message is a PC5-RRC message for the first relay UE.

3. In paragraph 1, A method, characterized in that the first message further includes a local ID (Identifier) for the remote UE.

4. In paragraph 1, A method, characterized in that the first message further includes instruction information indicating a transition to the RRC connection state.

5. In paragraph 4, A method characterized in that the above instruction information is transmitted by being included in the SRAP (sidelink Relay Adaptation Protocol) header of the first message.

6. In paragraph 1, A method characterized in that the first relay UE forms a second connection with the remote UE or a third relay UE connected to the remote UE, and receives a RemoteUEInformation message including the paging monitoring information through the second connection.

7. In paragraph 6, A method characterized in that, based on the RRC being in an idle or inactive state, the first relay UE transmits paging monitoring information for the first relay UE to the second relay UE together with paging monitoring information for the remote UE.

8. In paragraph 1, A method characterized in that the paging monitoring information is transmitted to the second relay UE based on the first relay UE transitioning to an RRC idle or inactive state or a common search space (CSS) not being set.

9. In paragraph 1, A method characterized in that, based on transitioning from an RRC idle or inactive state to the RRC connected state and establishment of a common search space (CSS), the first relay UE transmits a third message requesting release of the paging monitoring information to the second relay UE.

10. A computer-readable recording medium recording a program for performing the method described in paragraph 1.

11. In the first relay UE (User Equipment), RF (Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, A first relay UE, wherein the processor controls the RF transceiver to form a first connection with a second relay UE directly connected to the base station for U2N (UE-to-Network) relay communication between the base station and the remote UE, transmits paging monitoring information for the remote UE to the second relay UE through the first connection, and switches from an RRC (Radio Resource Control) idle or inactive state to an RRC connected state based on receiving a first message including paging information for the remote UE through the first connection.

12. In paragraph 11, A first relay UE, characterized in that the first message is a PC5-RRC message for the first relay UE.

13. In a processing device controlling the first relay 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 first relay UE causes: A processing device that forms a first connection with a second relay UE directly connected to a base station for U2N (UE-to-Network) relay communication between the base station and a remote UE, transmits paging monitoring information for the remote UE to the second relay UE through the first connection, and switches from an RRC (Radio Resource Control) idle or inactive state to an RRC connected state based on receiving a first message including paging information for the remote UE through the first connection.

14. In a method using a second relay UE (User Equipment), A step of forming a first connection with the base station and a second connection with the first relay UE for U2N (UE-to-Network) relay communication between the base station and the remote UE; A step of monitoring paging information for the remote UE based on paging monitoring information for the remote UE; and A method comprising: a step of transmitting a first message for switching the first relay UE, which is in an RRC (Radio Resource Control) idle or inactive state, to an RRC connected state based on the detection of the paging information; 15. In the second relay UE (User Equipment), RF (Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, A second relay UE, wherein the processor controls the RF transceiver to form a first connection with the base station and a second connection with the first relay UE for U2N (UE-to-Network) relay communication between the base station and the remote UE, monitors paging information for the remote UE based on paging monitoring information for the remote UE, and transmits a first message for switching the first relay UE, which is in an RRC (Radio Resource Control) idle or inactive state, to an RRC connected state based on detection of the paging information.

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