METHOD OF OPERATION ASSOCIATED WITH CELL CHANGE OF RELAY IN MULTIPATH RELAY IN WIRELESS COMMUNICATION SYSTEM - Patent application

Abstract

One embodiment of the present invention is a method for operating a remote UE (User Equipment) associated with a multipath relay in a wireless communication system, the method including the remote UE reporting measurement results for a candidate relay UE to a base station, the remote UE receiving an RRCReconfiguration message including an ID of a target relay UE from the base station, and the remote UE attempting a PC5 connection with the target relay UE, wherein the remote UE determines from the discovery message sent by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, and then transmits information to the base station indicating that the camping cell of the target relay UE has changed.

Description

[Technical Field]

[0001] The following description relates to wireless communication systems, and more particularly to methods and apparatus for operating a remote UE in connection with relay cell changes in multipath relaying. [Background technology]

[0002] Wireless communication systems use various radio access technologies (RATs) such as LTE, LTE-A, and WiFi, including 5G. The three main areas of 5G requirements are (1) enhanced mobile broadband (eMBB), (2) massive machine-type communication (mMTC), and (3) ultra-reliable and low latency communications (URLLC). Some use cases require multiple areas for optimization, while others can focus on only one key performance indicator (KPI). 5G aims to support these various use cases in a flexible and reliable manner.

[0003] eMBB goes beyond basic mobile Internet access to cover rich two-way work, cloud, and augmented reality media and entertainment applications. Data is one of the core drivers of 5G, and for the first time in the 5G era, dedicated voice services will not be seen. In 5G, voice is expected to be handled solely as an application using the data connection provided by the communications system. The primary causes of increased traffic volume are the increasing content size and the growing number of applications requiring high data transmission rates. Streaming services (audio and video), conversational video, and mobile Internet connections will become more widespread as more devices connect to the Internet. These applications require always-on connectivity to push real-time information and notifications to users. Cloud storage and applications are proliferating on mobile communication platforms, applicable to both work and entertainment. Cloud storage is a particular use case driving the growth of uplink data transmission rates. 5G will also be used for cloud remote work, which requires very low end-to-end latency to maintain a superior user experience when haptic interfaces are used. Entertainment, such as cloud gaming and video streaming, is another key driver of increased demand for mobile broadband capabilities. Entertainment is essential on smartphones and tablets everywhere, including in highly mobile environments such as trains, cars, and airplanes. Further use cases include augmented reality and information search for entertainment, where augmented reality requires very low latency and instantaneous data volume.

[0004] One of the most anticipated use cases for 5G is its ability to seamlessly connect embedded sensors across all sectors, or mMTC. It is predicted that there will be 20.4 billion potential IoT devices by 2020. Industrial IoT is one area where 5G will play a key role in enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructure.

[0005] URLLC encompasses new services that will transform industries with ultra-reliable / available low-latency links, such as remote control of key infrastructure and self-driving vehicles. Reliability and latency levels are essential for smart grid control, industrial automation, robotics, and drone control and coordination.

[0006] A number of use cases will now be described in more detail.

[0007] 5G is a means of delivering streams rated at hundreds of megabits per second to gigabits per second, complementing fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS). Such high speeds are required not only for virtual reality and augmented reality, but also for transmitting TV at resolutions above 4K (6K, 8K, and beyond). Virtual reality (VR) and augmented reality (AR) applications include nearly immersive sports competitions. Certain applications may require special network configurations. For example, VR games require game makers to integrate core servers with network operators' edge network servers to minimize latency.

[0008] Automotive is expected to be a key new driver of 5G, with many use cases for mobile communications in vehicles. For example, passenger entertainment requires high concurrent capacity and highly mobile broadband because future users expect high-quality connectivity regardless of their location or speed. Another example in the automotive field is the augmented reality dashboard, which identifies objects in the dark and overlays information on the driver's front window, informing them of their distance and movement. Future wireless modules will enable vehicle-to-vehicle communication, information exchange between vehicles and supporting infrastructure, and information exchange between vehicles and other connected devices (e.g., devices accompanied by pedestrians). Safety systems can reduce the risk of accidents by providing drivers with alternative routes of action for safer driving. The next step will be remotely piloted, or self-driven vehicles. This will require extremely reliable and fast communication between different self-driven vehicles and between vehicles and infrastructure. In the future, self-driven vehicles will perform all driving activities, leaving the driver to focus only on traffic anomalies that the vehicle itself cannot identify. The technical requirements for self-driving vehicles demand ultra-low latency and ultra-fast reliability to increase traffic safety to levels unattainable by humans.

[0009] Smart cities and smart homes, also referred to as smart societies, are embedded in dense wireless sensor networks. A distributed network of intelligent sensors identifies requirements for cost- and energy-efficient maintenance of a city or home. A similar configuration is made for each home: temperature sensors, window and heating controls, burglar alarms, and appliances are all wirelessly linked. Most such sensors typically have low data transmission rates, low power, and low cost. However, real-time HD video, for example, is required for certain types of devices for surveillance.

[0010] The consumption and distribution of energy, including heat and gas, is highly decentralized, requiring automated control of distributed sensor networks. A smart grid interconnects such sensors using digital information and communication technologies to collect and act on information. This information includes supplier and consumer behavior, allowing the smart grid to improve the efficiency, reliability, economy, sustainability of production, and distribution of fuels, such as electricity, in an automated manner. A smart grid can be viewed as another sensor network with low latency.

[0011] The health sector has many applications that benefit from mobile communications. Communications systems support telemedicine, providing clinical care over long distances. This overcomes the barrier of distance and improves access to medical services that are not sustainably available in remote rural areas. It can also be used to save lives in critical care and emergency situations. Mobile-based wireless sensor networks can provide remote monitoring and sensing of parameters such as heart rate and blood pressure.

[0012] Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring is expensive to install and maintain. Therefore, the possibility of replacing cables with wireless links by reconfiguring them is an attractive opportunity in many industrial sectors. However, achieving this requires that wireless links operate with cable-like latency, reliability, and capacity, while also being easy to manage. Low latency and very low error rates are new requirements that need to be coupled with 5G.

[0013] Logistics and freight tracking are important use cases for mobile communications, using location-based information systems to enable inventory and package tracking anywhere. Logistics and freight tracking use cases typically require low data rates, but require wide range and reliable location information.

[0014] Wireless communication systems are multiple access systems that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and multi carrier frequency division multiple access (MC-FDMA) systems.

[0015] Sidelink (SL) is a communication method that establishes a direct link between terminals (User Equipment, UE) and directly transmits voice or data between terminals without going through a base station (BS). SL is one solution to alleviate the burden on base stations due to the rapidly increasing data traffic.

[0016] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-based objects via wired or wireless communication. V2X is divided into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication is provided via the PC5 interface and / or Uu interface.

[0017] Meanwhile, as more communication devices require greater communication capacity, there is an emerging need for improved mobile broadband communication compared to existing radio access technologies (RATs). This has led to discussions about communication systems that take into account reliability- and latency-sensitive services or terminals. Next-generation wireless access technologies that take into account such improved mobile broadband communication, massive MTC, and Ultra-Reliable and Low Latency Communication (URLLC) are called new radio access technologies (RATs) or new radios (NRs). NRs can also support vehicle-to-everything (V2X) communication.

[0018] FIG. 1 is a diagram illustrating a comparison between V2X communication based on a RAT prior to NR and V2X communication based on NR.

[0019] In relation to V2X communication, RATs prior to NR have discussed 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). V2X messages include location information, dynamic information, attribute information, etc. For example, a terminal can send a periodic message type CAM and / or an event-triggered message type DENM to another terminal.

[0020] For example, the CAM includes basic vehicle information such as vehicle dynamic status information such as direction and speed, vehicle static data such as dimensions, exterior lighting status, and route details. For example, a terminal can broadcast the CAM, and the delay of the CAM is less than 100 ms. For example, if an emergency situation such as a vehicle breakdown or accident occurs, the terminal can generate a DENM and transmit it to other terminals. For example, all vehicles within the transmission range of the terminal can receive the CAM and / or the DENM. In this case, the DENM has a higher priority than the CAM.

[0021] Subsequently, various V2X scenarios related to V2X communication have been defined in NR, including vehicle platooning, enhanced driving, extended sensors, remote driving, etc.

[0022] For example, based on platooning vehicles, vehicles dynamically form groups and move together. For example, to perform platooning operations based on platooning vehicles, vehicles belonging to the group receive periodic data from a lead vehicle. For example, the vehicles belonging to the group can use the periodic data to decrease or increase the spacing between vehicles.

[0023] For example, based on enhanced driving, vehicles may be semi-automated or fully automated. Each vehicle may adjust its trajectories or maneuvers based on data obtained from local sensors of nearby vehicles and / or nearby logical entities. For example, each vehicle may share driving intentions with nearby vehicles.

[0024] For example, based on the extended sensor, raw data, processed data, or live video data obtained by local sensors can be exchanged between vehicles, logic elements, pedestrian terminals, and / or V2X application servers. Thus, for example, a vehicle can recognize an environment that is more enhanced than the environment it can sense using its own sensors.

[0025] For example, based on remote driving, a remote driver or V2X application can operate or control a remote vehicle for a person who cannot drive or for a remote vehicle located in a dangerous environment. For example, when the route is predictable, such as in public transportation, cloud computing-based driving can be used to operate or control the remote vehicle. For example, a connection to a cloud-based back-end service platform can be considered for remote driving.

[0026] Meanwhile, methods to specify service requirements for various V2X scenarios, such as platooning vehicles, improved driving, extended sensors, and remote driving, are being discussed for NR-based V2X communications. Summary of the Invention [Problem to be solved by the invention]

[0027] The present disclosure addresses the technical problem of the operation of a remote UE when an IDEL / INACTIVE relay UE selected by the serving base station of the remote UE for the remote UE's multi-path / HO operation accesses a target cell (and / or gNB) different from the one expected by the serving base station of the remote UE. [Means for solving the problem]

[0028] One embodiment is a method for operating a remote UE (User Equipment) associated with a multipath relay in a wireless communication system, the method including the remote UE reporting measurement results for a candidate relay UE to a base station, the remote UE receiving an RRCReconfiguration message including an ID of a target relay UE from the base station, and the remote UE attempting a PC5 connection with the target relay UE, and based on the remote UE finding out from the discovery message sent by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE transmits information to the base station indicating that the camping cell of the target relay UE has changed.

[0029] In a wireless communication system, a remote UE includes at least one processor and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, the operations including reporting measurement results for a candidate relay UE to a base station, receiving an RRCReconfiguration message from the base station including an ID of a target relay UE, and the remote UE attempting a PC5 connection with the target relay UE, and based on the discovery message sent by the candidate relay UE indicating that a camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE transmits information to the base station indicating that the camping cell of the target relay UE has changed.

[0030] One embodiment is a non-volatile computer-readable storage medium storing at least one computer program including instructions that, when executed by at least one processor, cause the at least one processor to perform operations for a remote UE, the operations including reporting measurement results for a candidate relay UE to a base station, receiving an RRCReconfiguration message from the base station including an ID of a target relay UE, and attempting a PC5 connection with the target relay UE, and based on the remote UE finding out from the discovery message sent by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE transmits information to the base station informing that the camping cell of the target relay UE has changed.

[0031] One embodiment is a method for operating a relay UE associated with a multipath relay in a wireless communication system, the method including the relay UE transmitting a discovery message and the relay UE receiving a PC5 message for multipath connection from the remote UE, wherein the relay UE rejects an SL connection request associated with the multipath connection of the remote UE based on the camping cell when the relay UE transmits the discovery message being different from the camping cell when the relay UE receives the PC5 message or the RRC connected cell when the relay UE receives the PC5 message, and the remote UE transmits information to the base station indicating that the camping cell of the target relay UE has changed.

[0032] One embodiment is a relay UE in a wireless communication system, comprising at least one processor and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, the operations including transmitting a discovery message and receiving a PC5 message for multipath connection from the remote UE, wherein, based on the camping cell when the relay UE transmits the discovery message being different from the camping cell when the relay UE receives the PC5 message or the RRC-connected cell when the relay UE receives the PC5 message, the relay UE rejects an SL connection request related to the multipath connection of the remote UE, and the remote UE transmits information to the base station indicating that the camping cell of the target relay UE has changed.

[0033] When the remote UE finds out that the camping cell of the target relay UE has changed after establishing the PC5 connection with the target relay UE, the remote UE releases the PC5 connection with the target relay UE.

[0034] Based on the fact that the remote UE has learned from the discovery message sent by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE omits triggering RRCReestablishment.

[0035] The remote UE reports a new candidate relay UE to the base station based on the discovery message sent by the candidate relay UE indicating that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection.

[0036] The camping cell of the target relay UE has changed, or the target relay UE has performed cell reselection during RRC connection, when the ID of the candidate relay UE at the time of reporting the measurement result is different from the ID of the candidate relay UE included in the discovery message.

[0037] The discovery message is received after reporting the measurement results.

[0038] The target relay UE is in RRC IDLE / INACTIVE state.

[0039] The remote UE is in communication with at least one of another UE, a UE associated with an autonomous vehicle, a base station, or a network. [Effects of the Invention]

[0040] According to one embodiment of the present disclosure, the remote UE can take appropriate action to quickly establish a new indirect link. [Brief explanation of the drawings]

[0041] The drawings accompanying this specification are provided to aid in understanding the embodiments, illustrate various embodiments, and together with the description serve to explain the principles.

[0042] [Figure 1] FIG. 1 is a diagram for explaining a comparison between V2X communication based on a RAT prior to NR and V2X communication based on NR. [Figure 2] FIG. 1 illustrates the structure of an LTE system according to one embodiment of the present disclosure. [Figure 3] FIG. 1 illustrates a radio protocol architecture for the user plane and the control plane according to one embodiment of the present disclosure. [Figure 4]FIG. 1 illustrates the structure of an NR system according to one embodiment of this disclosure. [Figure 5] FIG. 1 illustrates a functional division between NG-RAN and 5GC according to one embodiment of the present disclosure. [Figure 6] FIG. 1 is a diagram illustrating a structure of an NR radio frame to which an embodiment can be applied. [Figure 7] FIG. 1 illustrates a slot structure of an NR frame according to one embodiment of the present disclosure. [Figure 8] FIG. 1 illustrates a radio protocol architecture for SL communication according to one embodiment of the present disclosure. [Figure 9] FIG. 1 illustrates a radio protocol architecture for SL communication according to one embodiment of the present disclosure. [Figure 10] FIG. 1 illustrates a V2X synchronization source or synchronization reference according to one embodiment of the present disclosure. [Figure 11] FIG. 10 is a diagram illustrating a procedure in which a terminal performs V2X or SL communication depending on a transmission mode according to one embodiment of the present disclosure. [Figure 12] FIG. 1 illustrates a procedure for a terminal to perform path switching according to one embodiment of the present disclosure. [Figure 13] FIG. 1 illustrates switching from a direct path to an indirect path. [Figure 14] FIG. 10 is a diagram for explaining handover. [Figure 15] FIG. 1 is a diagram for explaining an embodiment. [Figure 16] 1A to 1C are diagrams illustrating various devices to which the embodiment can be applied. [Figure 17] 1A to 1C are diagrams illustrating various devices to which the embodiment can be applied. [Figure 18] 1A to 1C are diagrams illustrating various devices to which the embodiment can be applied. [Figure 19] 1A to 1C are diagrams illustrating various devices to which the embodiment can be applied. [Figure 20] 1A to 1C are diagrams illustrating various devices to which the embodiment can be applied. [Figure 21] 1A to 1C are diagrams illustrating various devices to which the embodiment can be applied. [Figure 22] 1A to 1C are diagrams illustrating various devices to which the embodiment can be applied. DETAILED DESCRIPTION OF THE INVENTION

[0043] In various embodiments of the present invention, " / " and "," indicate "and / or." For example, "A / B" means "A and / or B." Also, "A, B" means "A and / or B." "A / B / C" means "any one of A, B and / or C." Also, "A, B, C" means "any one of A, B and / or C."

[0044] In various embodiments of the present invention, "or" denotes "and / or." For example, "A or B" includes "A only," "B only," and / or "both A and B." In other words, "or" can be interpreted as "also or alternatively."

[0045] The following technologies can be used for various wireless access systems, such as CDMA (Code Division Multiple Access), FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access), OFDMA (Orthogonal Frequency Division Multiple Access), and SC-FDMA (Single Carrier Frequency Division Multiple Access). CDMA can be implemented using radio technologies such as UTRA (Universal Terrestrial Radio Access) and CDMA2000. TDMA can be implemented using radio technologies such as GSM (Global System for Mobile communications), GPRS (General Packet Radio Service), and EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented using radio technologies such as IEEE802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE802-20, and E-UTRA (Evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e. UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (registered trademark) 3rd Generation Partnership Project (3GPP) LTE (long term evolution) is part of E-UMTS (Evolved UMTS) that uses E-UTRA and employs OFDMA on the downlink and SC-FDMA on the uplink. LTE-Advanced (LTE-A) is an evolution of 3GPP LTE.

[0046] 5G NR is the technology that follows LTE-A and is a new clean-slate mobile communication system with characteristics such as high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz to intermediate-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz.

[0047] For clearer explanation, the following description will be focused on LTE-A or 5G NR, but the technical idea according to an embodiment of the present invention is not limited thereto.

[0048] 2 shows the structure of an LTE system according to one embodiment of the present invention, which is also called E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) or LTE (Long Term Evolution) / LTE-A system.

[0049] 2, the E-UTRAN includes a base station 20 that provides a control plane and a user plane to a terminal 10. The terminal 10 may be fixed or mobile, and may also be referred to as a mobile station (MS), user terminal (UT), subscriber station (SS), mobile terminal (MT), wireless device, etc. Generally, the base station 20 is a fixed station that communicates with the terminal 10, and may also be referred to as an evolved NodE-B (eNB), base transceiver system (BTS), access point (AP), etc.

[0050] The base stations 20 are connected to each other via the X2 interface. The base stations 20 are connected to the evolved packet core (EPC) 30 via the S1 interface, more specifically to the mobility management entity (MME) via the S1-MME, and to the serving gateway (S-GW) via the S1-U.

[0051] EPC 30 consists of MME, S-GW, and P-GW (Packet Data Network - Gateway). MME has information about terminal connection information and terminal capabilities, and such information is mainly used for terminal mobility management. S-GW is a gateway with E-UTRAN as its end point, and P-GW is a gateway with PDN (Packet Data Network) as its end point.

[0052] The radio interface protocol layers between a terminal and a network are classified into Layer 1 (L1), Layer 2 (L2), and Layer 3 (L3) based on the bottom three layers of the Open System Interconnection (OSI) reference model, which is well known in communication systems. Among them, the physical layer belonging to Layer 1 provides information transmission services using physical channels, and the Radio Resource Control (RRC) layer belonging to 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.

[0053] FIG. 3(a) illustrates a radio protocol architecture for the user plane according to one embodiment of the present invention.

[0054] 3(b) shows a radio protocol architecture for the control plane according to one embodiment of the present invention. The user plane is a protocol stack for user data transmission, and the control plane is a protocol stack for control signal transmission.

[0055] Referring to Figures 3(a) and A3, the physical layer provides information transmission services to higher layers using physical channels. The physical layer is connected to the higher layer, the Medium Access Control (MAC) layer, via transport channels. Data moves between the MAC layer and the physical layer via the transport channels. Transport channels are classified according to how and with what characteristics data is transmitted over the air interface.

[0056] Data travels between different physical layers, i.e., between the physical layers of a transmitter and a receiver, via physical channels. Physical channels are modulated using Orthogonal Frequency Division Multiplexing (OFDM) and utilize time and frequency as radio resources.

[0057] The MAC layer provides services to the higher-level radio link control (RLC) layer via logical channels. The MAC layer provides a mapping function from multiple logical channels to multiple transmission channels. The MAC layer also provides a logical channel multiplexing function by mapping multiple logical channels to a single transmission channel. The MAC layer provides data transmission services on logical channels.

[0058] The RLC layer performs concatenation, segmentation, and reassembly of RLC SDUs (Serving Data Units). To guarantee various Quality of Service (QoS) requirements for Radio Bearers (RBs), the RLC layer provides three operation modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction through automatic repeat request (ARQ).

[0059] The Radio Resource Control (RRC) layer is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transmission channels, and physical channels in relation to the configuration, reconfiguration, and release of radio bearers. RB refers to the logical path provided by Layer 1 (physical layer or PHY layer) and Layer 2 (MAC layer, RLC layer, PDCP (Packet Data Convergence Protocol) layer) for data transmission between the terminal and the network.

[0060] The functions of the PDCP layer in the user plane include user data transmission, header compression, and ciphering, and the functions of the PDCP layer in the control plane include control plane data transmission and encryption / integrity protection.

[0061] RB configuration refers to the process of defining the radio protocol layer and channel characteristics to provide a specific service and setting their specific parameters and operation methods. RBs are again divided into two types: SRBs (Signaling Radio Bearers) and DRBs (Data Radio Bearers). SRBs are used as paths for transmitting RRC messages in the control plane, and DRBs are used as paths for transmitting user data in the user plane.

[0062] If an RRC connection is established between the RRC layer of the terminal and the RRC layer of the E-UTRAN, the terminal enters the RRC_CONNECTED state; otherwise, it enters the RRC_IDLE state. In the case of NR, the RRC_INACTIVE state is further defined, and a terminal in the RRC_INACTIVE state maintains its connection with the core network but can release its connection with the base station.

[0063] Downlink transmission channels for transmitting data to terminals in a network include a BCH (Broadcast Channel) for transmitting system information and a downlink SCH (Shared Channel) for transmitting user traffic and control messages. Traffic or control messages of downlink multicast or block services are transmitted via the downlink SCH or via a separate downlink MCH (Multicast Channel). On the other hand, uplink transmission channels for transmitting data from terminals to a network include a RACH (Random Access Channel) for transmitting initial control messages and an uplink SCH (Shared Channel) for transmitting user traffic and control messages.

[0064] Logical channels that are above transmission channels and are mapped to transmission channels include BCCH (Broadcast Control Channel), PCCH (Paging Control Channel), CCCH (Common Control Channel), MCCH (Multicast Control Channel), and MTCH (Multicast Traffic Channel).

[0065] A physical channel consists of multiple OFDM symbols in the time domain and multiple subcarriers in the frequency domain. One subframe consists of multiple OFDM symbols in the time domain. A resource block is a resource allocation unit consisting of multiple OFDM symbols and multiple subcarriers. Each subframe can use a specific subcarrier of a specific OFDM symbol (e.g., the first OFDM symbol) of the subframe for the Physical Downlink Control Channel (PDCCH), i.e., the L1 / L2 control channel. A Transmission Time Interval (TTI) is the unit time for subframe transmission.

[0066] FIG. 4 shows the structure of an NR system according to one embodiment of the present invention.

[0067] Referring to FIG. 4, a Next Generation Radio Access Network (NG-RAN) includes a next generation Node BF cell (gNB) and / or an eNB that provides user plane and control plane protocol termination to a terminal. FIG. 4 illustrates a case where only a gNB is included. The gNB and the eNB are connected to each other via an Xn interface. The gNB and the eNB are connected to a 5th generation core network (5G Core Network: 5GC) via an NG interface. More specifically, they are connected to an access and mobility management function (AMF) via an NG-C interface and to a user plane function (UPF) via an NG-U interface.

[0068] FIG. 5 illustrates the functional division between NG-RAN and 5GC according to one embodiment of the present invention.

[0069] Referring to Figure 5, the gNB provides functions such as inter-cell radio resource management (Inter Cell RRM), radio bearer management (RB control), connection mobility control, radio admission control, measurement configuration & provision, and dynamic resource allocation. The AMF provides functions such as non-access stratum (NAS) security and idle state mobility handling. The UPF provides functions such as mobility anchoring and protocol data unit (PDU) processing. The session management function (SMF) provides functions such as terminal IP (Internet Protocol) address allocation and PDU section control.

[0070] FIG. 6 shows the structure of an NR radio frame to which an embodiment of the present invention can be applied.

[0071] Referring to Figure 6, in NR, radio frames are used for uplink and downlink transmission. A radio frame has a length of 10 ms and is defined by two 5 ms half-frames (HF). A half-frame includes five 1 ms subframes (SF). A subframe is divided into one or more slots, and the number of slots within a subframe depends on the subcarrier spacing (SCS). Each slot includes 12 or 14 OFDM(A) symbols depending on the cyclic prefix (CP).

[0072] When a normal CP is used, each slot contains 14 symbols. When an extended CP is used, each slot contains 12 symbols. Here, the symbols include OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or DFT-s-OFDM symbols).

[0073] Table 1 shows the number of symbols per slot (N) depending on the SCS setting (μ) when a general CP is used. slot symbol ), number of slots per frame (N frame,u slot ) and the number of slots per subframe (N subframe,u slot ) is shown below.

[0074] [Table 1]

[0075] Table 2 illustrates the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to the SCS when the extended CP is used.

[0076] [Table 2]

[0077] In an NR system, OFDM(A) pneumatology (e.g., SCS, CP length, etc.) can be configured to be different among multiple cells merged into one UE, and thus the (absolute time) duration of time resources (e.g., subframes, slots, or TTIs) (commonly referred to as TUs (Time Units) for convenience) consisting of the same number of symbols can be configured to be different among the merged cells.

[0078] NR supports multiple pneumothoraxes or SCSs to support various 5G services. For example, a 15 kHz SCS supports wide areas in traditional cellular bands, while a 30 kHz / 60 kHz SCS supports dense urban areas, lower latency, and wider carrier bandwidths. A 60 kHz or higher SCS supports bandwidths greater than 24.25 GHz to overcome phase noise.

[0079] The NR frequency band is defined by two types of frequency ranges. The two types of frequency ranges are FR1 and FR2. The numerical values ​​of the frequency ranges are variable. For example, the two types of frequency ranges are as shown in Table 3 below. Of the frequency ranges used in the NR system, FR1 refers to the "sub 6 GHz range" and FR2 refers to the "above 6 GHz range," also known as millimeter wave (mmW).

[0080] [Table 3]

[0081] As mentioned above, the numerical values ​​of the frequency range of the NR system can be changed. For example, FR1 includes the band from 410 MHz to 7125 MHz, as shown in Table 4 below. That is, FR1 includes frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included in FR1 include unlicensed bands. Unlicensed bands are used for various purposes, such as communications for vehicles (e.g., autonomous driving).

[0082] [Table 4]

[0083] FIG. 7 is a diagram illustrating a slot structure of an NR frame according to one embodiment of the present invention.

[0084] 7, a slot includes a plurality of symbols in the time domain. For example, in the case of the general CP, one slot includes 14 symbols, but in the case of the extended CP, one slot includes 12 symbols. Alternatively, in the case of the general CP, one slot includes 7 symbols, but in the case of the extended CP, one slot includes 6 symbols.

[0085] A carrier includes multiple subcarriers in the frequency domain. An RB (Resource Block) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP is defined as multiple consecutive PRBs (Physical RBs) in the frequency domain and corresponds to one numerology (e.g., SCS, CP length, etc.). A carrier includes up to N (e.g., 5) BWPs. Data communication is performed using activated BWPs. Each element in the resource grid is called a resource element (RE), and one complex symbol can be mapped to it.

[0086] Meanwhile, a wireless interface between terminals or a wireless interface between a terminal and a network is composed of an L1 layer, an L2 layer, and an L3 layer. In various embodiments of the present invention, the L1 layer refers to a physical layer. The L2 layer refers to, for example, any one of a MAC layer, an RLC layer, a PDCP layer, and an SDAP layer. The L3 layer refers to, for example, an RRC layer.

[0087] V2X or SL (sidelink) communication will be explained below.

[0088] Figure 8 illustrates a radio protocol architecture for SL communication according to one embodiment of the present invention. More specifically, Figure 8(a) illustrates the user plane protocol stack for LTE, and Figure 8(b) illustrates the control plane protocol stack for LTE.

[0089] Figure 9 illustrates a radio protocol architecture for SL communication according to one embodiment of the present invention. More specifically, Figure 9(a) illustrates the NR user plane protocol stack, and Figure 9(b) illustrates the NR control plane protocol stack.

[0090] FIG. 10 illustrates a V2X synchronization source or synchronization reference according to one embodiment of the present invention.

[0091] 10, in V2X, a terminal is directly synchronized to a global navigation satellite system (GNSS), or indirectly synchronized to a GNSS by a terminal (inside or outside of network coverage) that is directly synchronized to the GNSS. When the GNSS is set as the synchronization source, the terminal calculates the Direct Frame Number (DFN) and subframe number using Coordinated Universal Time (UTC) and a (pre-set) DFN offset.

[0092] Alternatively, the terminal may be directly synchronized to the base station or synchronized to another terminal that is time / frequency synchronized to the base station. For example, the base station may be an eNB or a gNB. For example, when the terminal is within the network coverage, the terminal receives synchronization information provided by the base station and is directly synchronized to the base station. The terminal then provides synchronization information to other neighboring terminals. When the base station timing is set as the synchronization reference, the terminal follows the cell (if within the cell coverage in frequency), primary cell, or serving cell (if out of the cell coverage in frequency) associated with the frequency for synchronization and downlink measurements.

[0093] The base station (e.g., serving cell) provides synchronization settings for the carrier used for V2X or SL communication. In this case, the terminal follows the synchronization settings received from the base station. If the terminal does not detect any cell on the carrier used for V2X or SL communication and does not receive synchronization settings from the serving cell, the terminal follows the preset synchronization settings.

[0094] Alternatively, the terminal may be synchronized to another terminal for which synchronization information cannot be obtained directly or indirectly from a base station or GNSS. The synchronization source and preference may be preset in the terminal, or may be set by a control message provided by the base station.

[0095] The SL synchronization source is associated with a synchronization priority. For example, the relationship between the synchronization source and the synchronization priority is defined as shown in Table 5 or Table 6. Table 5 or Table 6 is merely an example, and the relationship between the synchronization source and the synchronization priority can be defined in various ways.

[0096] [Table 5]

[0097] [Table 6]

[0098] In Table 5 or Table 6, P0 means the highest priority and P6 means the lowest priority. In Table 5 or Table 6, the base station includes at least one of a gNB or an eNB.

[0099] Whether GNSS-based or base station-based synchronization is used is (pre-configured). In single-carrier operation, the terminal derives its transmission timing from the available synchronization reference with the highest priority.

[0100] The SL synchronization signal (Sidelink Synchronization Signal, SLSS) and synchronization information will be described below.

[0101] The SLSS includes a Primary Sidelink Synchronization Signal (PSSS) and a Secondary Sidelink Synchronization Signal (SSSS) as SL-specific sequences. The PSSS is called a Sidelink Primary Synchronization Signal (S-PSS), and the SSSS is called a Sidelink Secondary Synchronization Signal (S-SSS). For example, length-127 M-sequences are used for the S-PSS, and length-127 Gold sequences are used for the S-SSS. For example, a terminal performs initial signal detection and acquires synchronization using the S-PSS. For example, a terminal acquires detailed synchronization and detects a synchronization signal ID using the S-PSS and S-SSS.

[0102] The PSBCH (Physical Sidelink Broadcast Channel) is a (broadcast) channel that transmits basic (system) information that a terminal must first know before transmitting or receiving an SL signal. For example, the basic information includes information about SLSS, duplex mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, information about the resource pool, the type of application related to SLSS, subframe offset, broadcast information, etc. For example, to evaluate the performance of the PSBCH, in NR V2X, the payload size of the PSBCH is 56 bits including a 24-bit CRC.

[0103] The S-PSS, S-SSS, and PSBCH are included in a block format (e.g., an SL Synchronization Signal (SS) / PSBCH block, hereinafter referred to as an S-SSB (Sidelink-Synchronization Signal Block)) that supports periodic transmission. The S-SSB has the same pneumatics (i.e., SCS and CP length) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) in a carrier, and the transmission bandwidth is within a (pre-set) SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB is 11 RBs (Resource Blocks). For example, the PSBCH spans 11 RBs. In addition, the frequency location of the S-SSB is (pre-set). Therefore, the terminal does not need to perform hypothesis detection in frequency to find the S-SSB in the carrier.

[0104] Meanwhile, in an NR SL system, multiple pneumothorologies with different SCS and / or CP lengths are supported. Here, as the SCS increases, the length of time resources for a transmitting terminal to transmit S-SSBs decreases. This reduces S-SSB coverage. Therefore, to ensure S-SSB coverage, a transmitting terminal transmits 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 a transmitting terminal transmits to a receiving terminal within one S-SSB transmission period is pre-configured or configured in the transmitting terminal. For example, the S-SSB transmission period is 160 ms. For example, an S-SSB transmission period of 160 ms is supported for all SCSs.

[0105] For example, if the SCS is 15 kHz in FR1, the transmitting terminal transmits one or two S-SSBs to the receiving terminal within one S-SSB transmission period. For example, if the SCS is 30 kHz in FR1, the transmitting terminal transmits one or two S-SSBs to the receiving terminal within one S-SSB transmission period. For example, if the SCS is 60 kHz in FR1, the transmitting terminal transmits one, two, or four S-SSBs to the receiving terminal within one S-SSB transmission period.

[0106] 11 illustrates a procedure in which a terminal performs V2X or SL communication according to a transmission mode according to one embodiment of the present invention. The embodiment of FIG. 11 can be combined with various embodiments of the present disclosure. In various embodiments of the present invention, a transmission mode is also referred to as a mode or a resource allocation mode. Hereinafter, for convenience of explanation, a transmission mode in LTE is also referred to as an LTE transmission mode, and a transmission mode in NR is also referred to as an NR resource allocation mode.

[0107] For example, Figure 11(a) shows terminal operation related to LTE transmission mode 1 or LTE transmission mode 3. For example, Figure 11(a) shows terminal operation related to NR resource allocation mode 1. For example, LTE transmission mode 1 can be applied to general SL communication, and LTE transmission mode 3 can be applied to V2X communication.

[0108] For example, FIG. 11(b) illustrates terminal operation associated with LTE transmission mode 2 or LTE transmission mode 4. Or, for example, FIG. 11(b) illustrates terminal operation associated with NR resource allocation mode 2.

[0109] 11(a), in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, a base station schedules SL resources to be used by a terminal for SL transmission. For example, in step S8000, the base station transmits information related to SL resources and / or information related to UL resources to a first terminal. For example, the UL resources include PUCCH resources and / or PUSCH resources. For example, the UL resources are resources for reporting SL HARQ feedback to the base station.

[0110] For example, the first terminal receives information about DG (dynamic grant) resources and / or information about CG (configured grant) resources from the base station. For example, the CG resources include CG type 1 resources or CG type 2 resources. In this specification, the DG resources are resources that the base station configures / assigns to the first terminal via DCI (downlink control information). In this specification, the CG resources are (periodic) resources that the base station configures / assigns to the first terminal via DCI and / or RRC messages. For example, in the case of CG type 1 resources, the base station transmits an RRC message including information about the CG resources to the first terminal. For example, in the case of CG type 2 resources, the base station transmits an RRC message including information about the CG resources to the first terminal, and the base station transmits a DCI regarding activation or release of the CG resources to the first terminal.

[0111] In step S8010, the first terminal transmits a PSCCH (e.g., SCI (Sidelink Control Information) or 1st-stage SCI) to the second terminal based on resource scheduling. In step S8020, the first terminal transmits a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S8030, the first terminal receives a PSFCH related to the PSCCH / PSSCH from the second terminal. For example, HARQ feedback information (e.g., NACK information or ACK information) is received from the second terminal via the PSFCH. In step S8040, the first terminal transmits / reports the HARQ feedback information to the base station via the PUCCH or PUSCH. For example, the HARQ feedback information reported to the base station is 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 is information generated by the first terminal based on a preset rule. For example, the DCI is DCI for SL scheduling. For example, the format of the DCI is DCI format 3_0 or DCI format 3_1. Table 7 shows an example of DCI for SL scheduling.

[0112] [Table 7]

[0113] Referring to FIG. 11(b), in LTE transmission mode 2, LTE transmission mode 4, or NR resource allocation mode 2, a terminal determines SL transmission resources within SL resources configured by a base station / network or pre-configured SL resources. For example, the configured SL resources or pre-configured SL resources are a resource pool. For example, a terminal autonomously selects or schedules resources for SL transmission. For example, a terminal self-selects resources within a configured resource pool and performs SL communication. For example, a terminal performs sensing and resource (re)selection procedures and self-selects resources within a selection window. For example, this sensing is performed on a subchannel basis. For example, in step S8010, a first terminal that self-selects resources within a resource pool transmits a PSCCH (e.g., SCI (Sidelink Control Information) or 1st-stage SCI) to a second terminal using the resources. In step S8020, the first terminal transmits a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S8030, the first terminal receives a PSFCH related to the PSCCH / PSSCH from the second terminal.

[0114] 11(a) or 11(b), for example, the first terminal transmits an SCI to the second terminal on the PSCCH. Or, for example, the first terminal transmits two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal on the PSCCH and / or PSSCH. In this case, the second terminal decodes the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first terminal. In this specification, the SCI transmitted on the PSCCH is referred to as the 1st SCI, the first SCI, the 1st-stage SCI, or the 1st-stage SCI format, and the SCI transmitted on the PSSCH is referred to as the 2nd SCI, the second SCI, the 2nd-stage SCI, or the 2nd-stage SCI format. For example, the 1st-stage SCI format includes SCI format 1-A, and the 2nd-stage SCI format includes SCI format 2-A and / or SCI format 2-B. Table 8 shows an example of the 1st-stage SCI format.

[0115] [Table 8]

[0116] Table 9 shows an example of the 2nd-stage SCI format.

[0117] [Table 9]

[0118] 11(a) or 11(b), in step S8030, the first terminal receives a PSFCH based on Table 10. For example, the first terminal and the second terminal determine a PSFCH resource based on Table 10, and the second terminal transmits HARQ feedback to the first terminal using the PSFCH resource.

[0119] [Table 10]

[0120] Referring to FIG. 11(a), in step S8040, the first terminal transmits SLHARQ feedback to the base station via PUCCH and / or PUSCH according to Table 11.

[0121] [Table 11]

[0122] Meanwhile, the following Table 12 shows the contents regarding the selection and reselection of sidelink relay UEs disclosed in 3GPP TS 36.331. The contents of Table 12 are used as the prior art of the present invention, and the necessary details related thereto are referred to 3GPP TS 36.331.

[0123] [Table 12]

[0124] Figure 12 shows the connection management and direct to indirect path switching process captured in the TR document (3GPP TR 38.836) for Rel-17 NR SL. The remote UE must establish its own PDU session / DRB with the network before transmitting user plane data.

[0125] The PC5 unicast link setup procedure of the PC5-RRC aspect of Rel-16 NR V2X is reused to set up a secure unicast link for L2 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.

[0126] For both in-coverage and out-of-coverage, when the remote UE initiates the first RRC message for connection setup with the gNB, the PC5 L2 configuration for transmission between the remote UE and the UE-to-Network Relay UE is based on the RLC / MAC configuration defined in the standard. The establishment of the Uu SRB1 / SRB2 and DRB for the remote UE follows the legacy Uu configuration procedure for L2 UE-to-Network Relay.

[0127] The higher level connection setup procedure shown in FIG. 12 is applied to L2 UE-to-Network Relay.

[0128] In step S1200, the remote and relay UEs perform a discovery procedure and establish a PC5-RRC connection in step S1201 based on the conventional Rel-16 procedure.

[0129] In step S1202, the remote UE sends an initial RRC message (i.e., RRCSetupRequest) for connection setup with the gNB via the relay UE using the PC5 basic L2 configuration. The gNB responds with an RRC Setup message to the remote UE (S1203). The RRC Setup message transmission to the remote UE uses the PC5 basic configuration. If the relay UE does not start from RRC_CONNECTED, it needs to perform its own connection setup when it receives a message for the PC5 basic L2 configuration. In this step, details for the relay UE to transmit the RRCSetupRequest / RRCSetup message to the remote UE are discussed in the WI step.

[0130] In step S1204, 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 sets up an RLC channel to relay SRB1 to the remote UE via PC5. This step prepares the relay channel for SRB1.

[0131] In step S1205, a remote UE SRB1 message (e.g., an RRCSetupComplete message) is sent to the gNB via the relay UE using the SRB1 relay channel via PC5, and the remote UE is RRC connected via Uu.

[0132] In step S1206, the remote UE and the gNB establish security according to legacy procedures, and security messages are transmitted via the relay UE.

[0133] In step S1210, the gNB establishes an 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 RLC channel between the remote UE and the relay UE for traffic relay. The gNB sends RRCReconfiguration to the remote UE via the relay UE to establish a relay SRB2 / DRB. The remote UE sends RRCReconfigurationComplete to the gNB via the relay UE as a response.

[0134] In addition to the concatenation setup procedure, for L2 UE-to-Network Relay:

[0135] The RRC reconfiguration and RRC disconnection procedures reuse the legacy RRC procedures with the message content / configuration design remaining in the WI step.

[0136] The RRC connection re-establishment and RRC connection resumption procedures reuse the conventional RRC procedure as a baseline, taking into account the aforementioned L2 UE-to-Network Relay connection establishment procedure to handle relay-specific parts along with message content / configuration design. Message content / configuration will be defined in the future.

[0137] An example of a path switch from direct to indirect is shown in Figure 13. For service continuity of L2 UE-to-Network Relay, when a remote UE switches to an indirect relay UE, it follows the procedure in Figure 13.

[0138] 13, in step S1301, after the remote UE measures / discovers candidate relay UEs, the remote UE reports one or more candidate relay UEs. The remote UE filters suitable relay UEs that meet upper layer criteria when reporting. The report includes the relay UE ID and SL RSRP information, and details regarding PC5 measurement will be determined in the future.

[0139] In step S1302, the gNB decides to switch to the target relay UE, and a target (re)configuration is selectively sent to the relay UE.

[0140] In step S1304, the RRC reconfiguration message to the remote UE includes the ID of the target relay UE, the target Uu and the PC5 configuration.

[0141] In step S1305, if a connection has not been established yet, the remote UE establishes a connection between the target relay UE and PC5.

[0142] In step S1306, the remote UE uses the target configuration provided by RRCReconfiguration to feed back RRCReconfigurationComplete to the gNB via the target path.

[0143] In step S1307, the data path is switched.

[0144] The contents of the following Tables 13 to 18 are disclosed in the 3GPP TS 38.423 standard document related to handover and are used as prior art for the contents of this disclosure. In Table 14, Figure 8.2.1.2-1 corresponds to Figure 14, and other matters refer to the standard document 3GPP TS 38.423.

[0145] [Table 13-1] [Table 13-2]

[0146] [Table 14-1] [Table 14-2]

[0147] [Table 15-1] [Table 15-2]

[0148] [Table 16-1] [Table 16-2]

[0149] [Table 17-1] [Table 17-2]

[0150] [Table 18-1] [Table 18-2]

[0151] Based on Tables 13 to 18, the HO process of a general UE will be described as follows. The UE reports Uu link measurement results (Uu link signal strength of its own serving cell and Uu link signal strength of surrounding neighbor cells) to the base station, and the base station selects a target cell using the measurement results reported by the UE. The serving base station (Serving gNB) can request an HO request from a target base station (hereinafter referred to as the target base station (gNB)) to which the target cell belongs, and if the target base station allows HO, it transmits an RRCReconfiguration(withSync) message for HO via the serving base station.

[0152] Table 19 below is "New Rel-18 WID on NR sidelink relay enhancements" and is prior art for this disclosure.

[0153] [Table 19]

[0154] The relay operation being prepared in 3GPP NR Rel-18 allows a remote UE to activate both a direct path and an indirect path via a relay UE, and in this case, the connection between the remote UE and the relay UE becomes an SL or ideal link.

[0155] In multipath operation, the RRC state of the relay UE selected by the remote UE is the RRC IDLE / INACTIVE / CONNECTED state. When a remote UE (and / or the remote UE's serving base station) having a direct (and / or indirect) link determines a relay UE to establish an SL connection, the selected relay UE is in the RRC IDLE / INACTIVE state. In this case, the relay UE enters the CONNECTED state (and / or performs RACH) in a cell (and / or gNB) different from the cell (and / or gNB) that it broadcasted as the cell (and / or gNB) it was camping on via a discovery message or the like before establishing the SL connection with the remote UE. Alternatively, a relay UE in the RRC IDLE / INACTIVE state can establish an SL connection with the remote UE, which can be a trigger condition for the relay UE to enter the RRC_CONNECTED state. In this case, we discuss how the remote UE should behave when the relay UE, for which the RRC_CONNECTED state was triggered, enters the CONNECTED state in a cell (and / or gNB) different from the cell (and / or gNB) that it broadcast via a conventional discovery message, etc.

[0156] Therefore, the following describes a method for solving the above-mentioned problems that may arise when a remote UE having a direct / indirect link establishes a connection for multipath relay with a relay UE in an RRC IDLE / INACTIVE state.

[0157] A remote UE having a direct (and / or indirect) link may establish an SL connection with a relay UE in the RRC_IDLE / INACITVE state. When a certain condition is triggered, a remote UE having a direct / indirect link can report the IDs, cell IDs, SD-RSRP, RRC status, etc. of surrounding candidate relay UEs to its serving base station (serving gNB, serving cell) depending on the gNB's measurement configuration. The serving base station of the remote UE receiving this information can select and notify the remote UE of a relay UE. In this case, the selected relay UE can be in any of the RRC_CONNECTED, IDLE, and INACTIVE states. This operation is necessary for the remote UE to set up an indirect link for multipath relay operation or when performing HO over the indirect link.

[0158] According to one embodiment, a remote UE reports measurement results for candidate relay UEs to a base station (S1501 in FIG. 15). The remote UE receives an RRCReconfiguration message including the ID of a target relay UE from the base station (S1502). Then, the remote UE attempts a PC5 connection with the target relay UE (S1503).

[0159] Here, when the remote UE determines from the discovery message transmitted by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE transmits information notifying the base station that the camping cell of the target relay UE has changed.When the remote UE determines from the discovery message transmitted by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE omits triggering an RRCReestablishment.

[0160] The remote UE reports a new candidate relay UE to the base station based on the discovery message sent by the candidate relay UE indicating that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection.

[0161] That is, if a remote UE receives a command for multipath (and / or HO) operation from its serving base station and detects that the cell (gNB) ID of the relay UE is different from the previous cell (gNB) ID (e.g., the cell (gNB) ID of the relay UE when making a measurement report), the remote UE can report to its current serving base station without triggering RRC re-establishment. In this case, the remote UE can also search for new candidate relay UEs and report them to the base station.

[0162] The target relay UE is in an RRC IDLE / INACTIVE state, i.e., before the relay UE establishes an SL connection with the remote UE, the relay UE becomes RRC_CONNECTED by accessing (RACH) a cell (and / or gNB) different from the cell (and / or gNB) on which it previously informed itself via a discovery message, or the like, or the cell on which the relay UE in the IDLE / INACTIVE state is camped is changed.

[0163] The discovery message is received after reporting the measurement results. In this regard, the camping cell of the target relay UE has changed or the target relay UE has performed cell reselection during RRC connection when the ID of the candidate relay UE at the time of reporting the measurement results is different from the ID of the candidate relay UE included in the discovery message.

[0164] Subsequently, if a remote UE establishes an SL connection for relaying before the relay UE broadcasts the newly changed cell (and / or gNB) via a discovery message or the like, the relay UE anticipates that the remote UE will not know the cell (and / or gNB) of the changed relay UE and transmits a rejection (and / or RRCReconfigurationFailure) message to the SL connection of the remote UE. At this time, a cause value may be used to indicate that the new cell (and / or gNB) is different from the previous cell (and / or gNB). The message used at this time may be a PC5-S message instead of an SL message. This operation may be limited to cases where the remote UE has a direct (and / or indirect) connection (connection for multipath relay) or where the remote UE performs HO over an indirect link in a direct / indirect connection. In this case, when the operation is restricted, the remote UE may indicate at the time of the SL connection that the connection is for multipath relay or that HO is being performed over an indirect link when establishing an SL connection with the relay UE.

[0165] If the relay UE notifies, for example, by a discovery message, that the cell (and / or gNB) ID is different from before, a remote UE attempting an SL connection thereafter can assume that it knows the new cell (and / or gNB) ID of the relay UE. In this case, the relay UE can establish an SL connection with the remote UE, because it can assume that the remote UE already knows that the cell (and / or gNB) ID of the relay UE has changed.

[0166] When a remote UE having a direct / indirect link establishes an SL connection (PC5-S / RRC) with a relay UE in IDLE / INACTIVE state due to SL multipath (or HO), it can inform the relay UE of its current cell (and / or gNB) ID. If the cell (and / or gNB) ID of the remote UE is different from the cell / gNB value on which the relay UE is currently camped (or the serving cell if the relay UE is RRC_CONNECTED), the relay UE can also reject the SL connection with the remote UE due to this reason.

[0167] Meanwhile, if the remote UE finds out that the camping cell of the target relay UE has changed after establishing the PC5 connection with the target relay UE, the remote UE can release the PC5 connection with the target relay UE. This occurs when the remote UE establishes an SL connection with a relay UE selected by a gNB due to multipath (and / or HO), etc., but the relay UE accesses (RACH) a cell (and / or gNB) different from the cell (and / or gNB) on which it previously camped via a discovery message, etc., and becomes RRC_CONNECTED. In this case, the remote UE can report to the gNB that the cell (and / or gNB) ID value of the relay UE determined by the serving base station has changed without triggering RRC re-establishment. Alternatively, the remote UE can notify the serving base station of the remote UE that the SL connection has failed. This is different from the re-establishment that is always performed when a conventional handover fails because the connection with the previous cell has been severed due to a handover command. Of course, in the present disclosure, the remote UE can also perform RRC re-establishment.

[0168] If the remote UE has activated an indirect link via a relay UE, the remote UE can deactivate the indirect link, or the remote UE can release the SL with the relay UE and report the SL RLF to the base station. Since the SL connection has been released, it can also report this in the SUI.

[0169] Alternatively, the remote UE may deactivate the indirect connection and wait for RRCReconfiguration from the base station before receiving a release command for the indirect link from the base station. At this time, the remote UE may also search for and report a new relay UE.

[0170] The operation procedure is that after the remote UE deactivates the indirect link, it searches for a new relay UE and reports it to the base station, or after deactivating the indirect link, it may report a failure (RLF) to the base station and search for a new relay UE (and / or report a new candidate relay UE).

[0171] Alternatively, if there is no connection from the relay UE selected by the serving / target base station of the relay UE after a predetermined time, the serving / target base station may perform RRC Reconfiguration again to the remote UE to select and notify a new relay UE, or release the connection with the currently established relay UE. For example, if a gNB that selected and notified a relay UE for multipath relay operation does not receive a connection from the selected relay UE after a predetermined time, it sets a new RRC Reconfiguration to the remote UE. In the case of HO, if there is no connection from the relay UE that the target cell decided to connect to it, the gNB may notify the serving base station, and the serving base station may select another relay UE and perform an HO procedure for it. That is, it may determine HO for the newly selected relay UE and send an HO request to the target cell of the determined relay UE.

[0172] If the remote UE is configured to establish an SL connection with a relay UE selected by the gNB due to reasons such as multipath (and / or HO), and attempts but fails to establish the SL connection, the remote UE will perform RRC re-establishment if the remote UE's serving base station fails to establish an SL connection with the relay UE selected due to reasons such as multipath (and / or HO).

[0173] Alternatively, the remote UE may not trigger RRC re-establishment and may report to the base station that it failed to establish an SL connection with the relay UE. In this case, if the relay UE notifies the reason for SL rejection using a cause value, etc., the remote UE may report this to the base station. Alternatively, if the remote UE detects that the cell (gNB) ID value included in the relay UE's discovery message is different from the value used in the previous measurement report to its own serving base station, it may not establish an SL connection with the relay UE determined by the serving base station and may report to the gNB that the cell (and / or gNB) ID value of the selected relay UE has changed.

[0174] According to the present disclosure, the remote UE can take appropriate action to quickly establish a new indirect link.

[0175] In the above, it was explained that the relay UE for the indirect link of the remote UE is selected by the serving base station of the remote UE, but the same operation can also be applied when the serving base station transmits information about the candidate relay UEs to the target base station and the target gNB selects the final relay UE.

[0176] The above content also applies when a remote UE receives a notification message from a relay UE. In this case, the notification message may refer to a message that a relay UE transmits to a remote UE in a rel-17 relay operation (3GPP TS38.331). It also applies when a remote UE detects RLF on the sidelink.

[0177] for example,

[0178] (option 1) A remote UE performing multipath relay operation can report notification / SL-RLF to the base station without triggering re-establishment.

[0179] (Option 2) The remote UE can deactivate the indirect link (and / or connection) with the relay UE. In multipath relay operation, the remote UE and relay UE belong to the same gNB. Therefore, if a situation occurs in which the relay UE sends a notification message to the remote UE, the gNB may be aware of this relay UE situation even if the remote UE does not specifically report it. Therefore, the gNB can receive a new RRC Reconfiguration for indirect link release. However, the remote UE can deactivate the indirect link and expect a new RRC Reconfiguration message to be sent from the base station before receiving a new RRC Reconfiguration from the base station.

[0180] (Option 3) The remote UE may also autonomously release the indirect link if such a situation occurs, without the instruction of the base station.

[0181] (Option 4) The remote UE can search for new candidate relay UEs and report them to the base station along with the measurement results. That is, such a situation can be an event that triggers measurement and reporting.

[0182] (Option 5) Because the remote UE and relay UE are connected to the same gNB, the gNB assumes that it knows the status of the remote UE and waits until it receives a new RRC Reconfiguration. However, even in this case, it must report an SL RLF. If a new RRC Reconfiguration is not received from the gNB within a predetermined time after receiving a notification from the relay UE or reporting an SL RLF, the remote UE can trigger an RRC Reestablishment. A separate timer may be required for the predetermined time. For example, the timer starts when the relay UE receives a notification or reports an SL RLF, and stops when it receives a new RRC Reconfiguration. Furthermore, when the timer expires, the remote UE performs an RRC Reestablishment.

[0183] The above options can be applied in combination with each other. For example, the remote UE does not trigger re-establishment, and after the indirect link is deactivated, reports the failure to the base station and finds a new candidate relay UE and reports it to the base station. Alternatively, the remote UE does not trigger re-establishment, and finds a new candidate relay UE and reports it to the base station.

[0184] A remote UE relevant to the above description includes at least one processor and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, the operations including the remote UE reporting measurement results for candidate relay UEs to a base station, the remote UE receiving an RRCReconfiguration message from the base station including an ID of a target relay UE, and the remote UE attempting a PC5 connection with the target relay UE, and based on the remote UE finding out from the discovery message sent by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE transmits information to the base station indicating that the camping cell of the target relay UE has changed.

[0185] Also, a non-volatile computer-readable storage medium storing at least one computer program including instructions, which when executed by at least one processor, cause the at least one processor to perform operations for a remote UE, the operations including the remote UE reporting measurement results for a candidate relay UE to a base station, the remote UE receiving an RRCReconfiguration message from the base station including an ID of a target relay UE, and the remote UE attempting a PC5 connection with the target relay UE, and based on the remote UE finding out from the discovery message sent by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE transmitting information to the base station indicating that the camping cell of the target relay UE has changed.

[0186] Further, the operation method of the relay UE includes the relay UE transmitting a discovery message and the relay UE receiving a PC5 message for multipath connection from the remote UE, and based on the fact that a camping cell when the relay UE transmits the discovery message is different from a camping cell when the relay UE receives the PC5 message or an RRC-connected cell when the relay UE receives the PC5 message, the relay UE rejects an SL connection request related to the multipath connection of the remote UE, and the remote UE transmits information to the base station indicating that the camping cell of the target relay UE has changed.

[0187] The relay UE also includes at least one processor and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, the operations including transmitting a discovery message and receiving a PC5 message for multipath connection from the remote UE, and based on the camping cell when the relay UE transmits the discovery message being different from the camping cell when the relay UE receives the PC5 message or the RRC-connected cell when the relay UE receives the PC5 message, the relay UE rejects an SL connection request related to the multipath connection of the remote UE, and the remote UE transmits information to the base station indicating that the camping cell of the target relay UE has changed.

[0188] On the other hand, in multipath operation, if the remote UE has an indirect link, it can establish a new connection via the indirect link. In this case, the remote UE reports information about the candidate relay UEs (e.g., candidate relay UE IDs and measurements (SD-RSRP, remote / relay UE Uu RSRP, etc.), relay UE serving cell / campon cell ID, PLMN ID, etc.) to the serving gNB via the direct link. The serving gNB can send one or more relay lists from among the candidate relay UEs to the remote UE via the direct link. This can be conveyed via an RRCReconfiguration message. Upon receiving this, the remote UE establishes an SL with the relay UE included in the RRCReconfiguration and sends an RRCReconfigurationComplete message to the serving base station (serving gNB or serving cell) via the indirect link via the relay UE.

[0189] In the HO operation of a remote UE, the remote UE may have a direct link and an indirect link. When a remote UE having a direct / indirect link accesses a target base station (target gNB or target cell) via the direct / indirect link, the operation is similar to the multipath operation described above. The remote UE reports candidate relay UEs to its serving base station and receives RRC Reconfiguration related to HO from the serving base station. The remote UE establishes an SL connection with the relay UE included in the RRC Reconfiguration and sends an RRC Reconfiguration Complete message via the indirect link via the relay UE.

[0190] The RRC state of a relay UE that can be selected by the serving base station and / or target base station of a remote UE can be any of IDLE, INACTIVE, and CONNECTED. When the RRC state of the relay UE is RRC_CONNECTED, the serving gNB of the remote UE can pre-configure the relay UE for an indirect link with the remote UE. For example, the serving gNB of the remote UE can perform RRC Reconfiguration related to multipath (and / or HO) on the remote UE while performing configuration (e.g., bearer mapping) for the indirect link with the remote UE on the relay UE in the RRC_CONNECTED state.

[0191] However, if the relay UE is configured to prepare for an indirect connection with the remote UE, and the remote UE fails to establish an SL connection with the relay UE due to an SL connection failure or other reasons, the relay UE's behavior must be specified. The following proposes the behavior of the relay UE in this case.

[0192] In multipath (and / or HO) operation, if the relay UE selected for the remote UE by the serving base station and / or target base station of the remote UE is in RRC_CONNECTED state and the serving base station and / or target base station performs RRC Reconfiguration for the remote UE on the relay UE (i.e., if it receives RRC Reconfiguration related to a remote UE that is not yet connected to SL), the following embodiments are possible.

[0193] (Option 1) After the relay UE completes the SL connection with the (intended) remote UE included in the RRCReconfiguration, it sends an RRCReconfigurationComplete message to the base station. Alternatively, after receiving an RRCReconfigurationComplete message completing multipath (and / or HO) from the (intended) remote UE included in the RRCReconfiguration, the relay UE can also send an RRCReconfigurationComplete message indicating that it has received configuration for the remote UE. If the relay UE does not establish an SL connection with the intended remote UE or does not receive an RRCReconfigurationComplete message from the remote UE, it reports a failure to the gNB.

[0194] In this case, the relay UE may send a completion / failure message to the (serving / target) gNB for only partial configuration. For example, if the relay UE does not receive an SL connection, RRCReconfigurationComplete, from the remote UE for which a connection is scheduled, it may send a completion message for only the other configurations, excluding the configuration for the remote UE. Alternatively, it may send a failure for only the configuration for the remote UE, and complete the other configurations.

[0195] (Option 2) When the relay UE receives RRC Reconfiguration for the intended remote UE, regardless of whether it is connected to the intended remote UE, it can also send an RRC Reconfiguration Complete message to the base station. The base station has a timer for the remote UE, and if the remote UE does not send an RRC Reconfiguration Complete message via the relay UE until the timer expires, it releases the configuration related to the intended remote UE. The relay UE does not take any action related to it, expecting the gNB to release it itself.

[0196] (Option 3) When the relay UE receives configuration for the intended remote UE from the base station, it operates a timer (e.g., T304, T304-like, T420, T420-like, T400, etc.) that is expected to be running in the remote UE. If the timer expires and the SL connection with the intended remote UE is not established (completed) (and / or an RRCReconfigurationComplete message is not received from the remote UE), the relay UE can notify the base station of this. Alternatively, the relay UE can send an RRCReconfiguration failure message to the gNB only for the intended remote UE.

[0197] In multipath (and / or HO) operation, if the relay UE selected for the remote UE by the serving base station of the remote UE and / or the target base station is in RRC_IDLE / INACTIVE state and the relay UE performs a connection establishment operation for multipath (and / or HO) operation but does not access the target base station (in the case of multipath), the target base station also becomes the serving gNB of the remote UE.

[0198] When a remote UE sends an RRCReconfigurationComplete message via a relay UE to the gNB with which the relay UE has completed connection establishment (the serving gNB of the relay UE), the serving gNB of the relay UE may not be able to recognize the RRCReconfigurationComplete message sent by the remote UE. This is because the RRCReconfigurationComplete message sent by the remote UE via the relay UE is a message encrypted by the target base station for security reasons. Therefore, if unknown (unreadable) data is sent via the relay UE, the serving gNB of the relay UE can send a command to the relay UE to release the SL with the remote UE. Upon receiving this command, the relay UE releases the SL with the remote UE.

[0199] In the above, when a remote UE performs an operation related to multipath (and / or HO), the conditions for stopping the timer for multipath (and / or HO) and the timer to be applied when both the setting via a direct link and the setting for an indirect link are allowed are proposed. This allows the timer operation and multipath (and / or HO) operation of the remote UE to be performed efficiently.

[0200] An example of a communication system to which the present invention is applied

[0201] Without being limited thereto, the various descriptions, functions, procedures, suggestions, methods and / or flow charts of the present invention disclosed in this specification may be applied to various fields requiring wireless communication / connectivity between devices (e.g., 5G).

[0202] Hereinafter, a more detailed description will be given with reference to the drawings. In the following drawings / description, the same reference numerals indicate the same or corresponding hardware blocks, software blocks or function blocks unless otherwise specified.

[0203] FIG. 16 illustrates a communication system 1 to which the present invention is applied.

[0204] Referring to FIG. 16, a communication system 1 applicable to the present invention includes wireless devices, base stations, and a network. Here, the wireless devices refer to devices that communicate using wireless connection technologies (e.g., 5G NR, LTE), and are also referred to as communication / wireless / 5G devices. The wireless devices include, but are not limited to, a robot 100a, vehicles 100b-1 and 100b-2, an XR (eXtended Reality) device 100c, a handheld device 100d, a home appliance 100e, an IoT (Internet of Things) device 100f, and an AI device / server 400. For example, the vehicles include vehicles equipped with wireless communication capabilities, autonomous vehicles, vehicles capable of vehicle-to-vehicle communication, etc. Here, the vehicles include unmanned aerial vehicles (UAVs) (e.g., drones). XR devices include Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR) devices, and are embodied in the form of Head-Mounted Devices (HMDs), Head-Up Displays (HUDs) mounted on vehicles, TVs, smartphones, computers, wearable devices, home appliances, digital billboards, vehicles, robots, etc. Mobile devices include smartphones, smart pads, wearable devices (e.g., smart watches, smart glasses), computers (e.g., laptops, etc.), etc. Home appliances include TVs, refrigerators, washing machines, etc. IoT devices include sensors, smart meters, etc. For example, base stations and networks may also be embodied as wireless devices, and a specific wireless device 200a may operate as a base station / network node for other wireless devices.

[0205] The wireless devices 100a to 100f are connected to a network 300 via a base station 200. The wireless devices 100a to 100f are equipped with AI (Artificial Intelligence) technology, and are connected to an AI server 400 via the network 300. The network 300 is configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices 100a to 100f can communicate with each other via the base station 200 / network 300, but can also communicate directly without going through the base station / network (e.g., sidelink communication). For example, vehicles 100b-1 and 100b-2 can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). IoT devices (e.g., sensors) can also communicate directly with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0206] Wireless communication / connections 150a, 150b, and 150c are performed between the wireless devices 100a to 100f and the base stations 200, and between the base stations 200. Here, the wireless communication / connections are performed using various wireless connection technologies such as uplink / downlink communication 150a, sidelink communication 150b (or D2D communication), and inter-base station communication 150c (e.g., relay, Integrated Access Backhaul (IAB)) (e.g., 5G NR). Through the wireless communication / connections 150a, 150b, and 150c, the wireless devices and the base stations, and the base stations and the base stations, can transmit / receive wireless signals with each other. For example, the wireless communication / connections 150a, 150b, and 150c can transmit / receive signals via various physical channels. To this end, according to various proposals of the present invention, any one of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes is performed.

[0207] Examples of wireless devices to which the present invention is applied

[0208] FIG. 17 illustrates a wireless device to which the present invention is applied.

[0209] 17, a first wireless device 100 and a second wireless device 200 transmit and receive wireless signals using various wireless access technologies (e.g., LTE, NR), where {first wireless device 100, second wireless device 200} corresponds to {wireless device 100x, base station 200} and / or {wireless device 100x, wireless device 100x} in FIG.

[0210] The first wireless device 100 includes one or more processors 102 and one or more memories 104, and further includes one or more transceivers 106 and / or one or more antennas 108. The processor 102 is configured to control the memory 104 and / or the transceiver 106 to implement the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. For example, the processor 102 processes information in the memory 104 to generate first information / signals and then transmits a wireless signal including the first information / signals via the transceiver 106. The processor 102 also receives a wireless signal including second information / signals via the transceiver 106 and then stores information obtained from signal processing of the second information / signals in the memory 104. The memory 104 is coupled to the processor 102 and stores various information related to the operation of the processor 102. For example, the memory 104 stores software code including instructions for performing some or all of the processes controlled by the processor 102 or for implementing the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. Here, the processor 102 and memory 104 are part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver 106 is coupled to the processor 102 and transmits and / or receives wireless signals via one or more antennas 108. The transceiver 106 includes a transmitter and / or a receiver. The transceiver 106 may also be referred to as an RF (radio frequency) unit. In the present invention, a wireless device may also refer to a communication modem / circuit / chip.

[0211] The second wireless device 200 includes one or more processors 202 and one or more memories 204, and further includes one or more transceivers 206 and / or one or more antennas 208. The processor 202 is configured to control the memory 204 and / or the transceiver 206 to implement the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. For example, the processor 202 processes information in the memory 204 to generate third information / signal, and then transmits a wireless signal including the third information / signal via the transceiver 206. The processor 202 also receives a wireless signal including fourth information / signal via the transceiver 206, and then stores information obtained from signal processing of the fourth information / signal in the memory 204. The memory 204 is coupled to the processor 202 and stores various information related to the operation of the processor 202. For example, the memory 204 stores software code including instructions for performing some or all of the processes controlled by the processor 202 or for implementing the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. Here, the processor 202 and memory 204 are part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver 206 is coupled to the processor 202 and transmits and / or receives wireless signals via one or more antennas 208. The transceiver 206 includes a transmitter and / or a receiver. The transceiver 206 may also be referred to as an RF unit. In the present invention, a wireless device may also refer to a communication modem / circuit / chip.

[0212] The hardware elements of the wireless devices 100, 200 are described in more detail below. Without limitation, 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, and SDAP). The 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, suggestions, methods, and / or flowcharts disclosed herein. The one or more processors 102, 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. The one or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, procedures, suggestions, and / or methods disclosed herein and provide them to the one or more transceivers 106, 206. The one or more processors 102, 202 may receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and derive the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein.

[0213] The one or more processors 102, 202 may also be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102, 202 may be implemented using hardware, firmware, software, or a combination thereof. For example, the one or more processors 102, 202 may include 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). The descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein may be implemented using firmware or software, and the firmware or software may be embodied to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein may be included in the one or more processors 102, 202 or may be stored in one or more memories 104, 204 and executed by the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and / or flow charts disclosed in this specification may be embodied using firmware or software in the form of code, instructions and / or sets of instructions.

[0214] The one or more memories 104, 204 are coupled to the one or more processors 102, 202 and store various types of data, signals, messages, information, programs, code, instructions, and / or commands. The one or more memories 104, 204 may be comprised of 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 internal and / or external 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 techniques, such as wired or wireless connections.

[0215] One or more transceivers 106, 206 may transmit user data, control information, wireless signals / channels, etc., as described in the methods and / or flowcharts herein to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, suggestions, methods and / or flowcharts herein from one or more other devices. For example, one or more transceivers 106, 206 may be coupled to one or more processors 102, 202 to transmit and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Also, 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. One or more transceivers 106, 206 are coupled to one or more antennas 108, 208, and are configured to transmit and receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein via the one or more antennas 108, 208. In this specification, one or more antennas may refer to multiple physical antennas or multiple logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 convert the received user data, control information, radio signals / channels, etc., from RF band signals to baseband signals for processing by one or more processors 102, 202. The one or more transceivers 106, 206 convert the user data, control information, radio signals / channels, etc., processed by one or more processors 102, 202, from baseband signals to RF band signals. For this purpose, the one or more transceivers 106, 206 may include an (analog) oscillator and / or a filter.

[0216] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0217] 18 illustrates an example of a vehicle or an autonomous vehicle to which the present invention is applied. The vehicle or the autonomous vehicle may be embodied as a mobile robot, a car, a train, an aerial vehicle (AV), a ship, or the like.

[0218] 18, a vehicle or autonomous vehicle 100 includes an antenna unit 108, a communication unit 110, a control unit 120, a drive unit 140a, a power supply unit 140b, a sensor unit 140c, and an autonomous driving unit 140d. The antenna unit 108 is configured as a part of the communication unit 110.

[0219] The communication unit 110 transmits and receives signals (e.g., data, control signals, etc.) to and from external devices such as other vehicles, base stations (e.g., base stations, roadside units, etc.), and servers. The control unit 120 controls elements of the vehicle or autonomous vehicle 100 to perform various operations. The control unit 120 includes an ECU (Electronic Control Unit). The driving unit 140a causes the vehicle or autonomous vehicle 100 to move on the ground. The driving unit 140a includes an engine, a motor, a powertrain, wheels, brakes, a steering device, etc. The power supply unit 140b supplies power to the vehicle or autonomous vehicle 100 and includes wired / wireless charging circuits, a battery, etc. The sensor unit 140c can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit 140c includes an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit 140d implements technologies such as lane maintenance while driving, technology for automatically adjusting speed such as adaptive cruise control, technology for automatically driving along a predetermined route, and technology for automatically setting a route and driving when a destination is set.

[0220] For example, the communication unit 110 receives map data, traffic information data, etc. from an external server. The autonomous driving unit 140d generates an autonomous driving route and a driving plan based on the obtained data. The control unit 120 controls the driving unit 140a (e.g., adjusting speed / direction) so that the vehicle or autonomous vehicle 100 moves along the autonomous driving route according to the driving plan. The communication unit 110 aperiodically obtains the latest traffic information data from an external server during autonomous driving and also obtains surrounding traffic information data from surrounding vehicles. In addition, the sensor unit 140c obtains vehicle status and surrounding environment information during autonomous driving. The autonomous driving unit 140d updates the autonomous driving route and driving plan based on the newly obtained data / information. The communication unit 110 transmits information regarding the vehicle position, autonomous driving route, driving plan, etc. to an external server. The external server can predict traffic information data using AI technology based on information collected from the vehicle or autonomous vehicle and provide the predicted traffic information data to the vehicle or autonomous vehicle.

[0221] Examples of AR / VR and vehicles to which the present invention is applied

[0222] 19 shows an example of a vehicle to which the present invention is applied. The vehicle may be embodied as a transportation means, a train, an aircraft, a ship, etc.

[0223] Referring to FIG. 19, a vehicle 100 includes a communication unit 110, a control unit 120, a memory unit 130, an input / output unit 140a, and a position measurement unit 140b.

[0224] The communication unit 110 transmits and receives signals (e.g., data, control signals, etc.) to and from external devices such as other vehicles or base stations. The control unit 120 controls the components of the vehicle 100 to perform various operations. The memory unit 130 stores data / parameters / programs / codes / instructions that support various functions of the vehicle 100. The input / output unit 140a outputs AR / VR objects based on information in the memory unit 130. The input / output unit 140a includes a HUD. The position measurement unit 140b can obtain position information of the vehicle 100. The position information includes absolute position information of the vehicle 100, position information within a driving line, acceleration information, position information relative to surrounding vehicles, etc. The position measurement unit 140b includes a GPS and various sensors.

[0225] For example, the communication unit 110 of the vehicle 100 receives map information, traffic information, etc. from an external server and stores it in the memory unit 130. The position measurement unit 140b obtains vehicle position information using GPS and various sensors and stores it in the memory unit 130. The control unit 120 generates a virtual object based on the map information, traffic information, and vehicle position information, and the input / output unit 140a displays the generated virtual object in a window inside the vehicle (1410, 140a). The control unit 120 also determines whether the vehicle 100 is operating correctly within the driving line based on the vehicle position information. If the vehicle 100 abnormally deviates from the driving line, the control unit 120 displays a warning in a window inside the vehicle via the input / output unit 140a. The control unit 120 also broadcasts a warning message regarding the driving abnormality to surrounding vehicles via the communication unit 110. Depending on the situation, the control unit 120 may also transmit the vehicle position information and information regarding the driving / vehicle abnormality to relevant authorities via the communication unit 110.

[0226] Examples of XR devices to which this invention can be applied

[0227] 20 illustrates an example of an XR device to which the present invention is applied. The XR device may be implemented in the form of an HMD, a head-up display (HUD) installed in a vehicle, a TV, a smartphone, a computer, a wearable device, a home appliance, a digital sign, a vehicle, a robot, etc.

[0228] Referring to FIG. 20, the XR device 100a includes a communication unit 110, a control unit 120, a memory unit 130, an input / output unit 140a, a sensor unit 140b, and a power supply unit 140c.

[0229] The communication unit 110 can transmit and receive signals (e.g., media data, control signals, etc.) to and from external devices such as other wireless devices, mobile devices, or media servers. Media data includes videos, images, sounds, etc. The control unit 120 controls the components of the XR device 100a to perform various operations. For example, the control unit 120 is configured to control and / or perform procedures such as video / image acquisition, (video / image) encoding, and metadata generation and processing. The memory unit 130 stores data / parameters / programs / codes / commands required to operate the XR device 100a and generate XR objects. The input / output unit 140a obtains control information, data, etc. from the outside and outputs the generated XR objects. The input / output unit 140a includes a camera, microphone, user input unit, display unit, speaker, and / or haptic module. The sensor unit 140b obtains the XR device status, surrounding environment information, user information, etc. The sensor unit 140b includes a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, and / or a radar, etc. The power supply unit 140c supplies power to the XR device 100a and includes a wired / wireless charging circuit, a battery, etc.

[0230] For example, the memory unit 130 of the XR device 100a stores information (e.g., data) necessary for generating an XR object (e.g., an AR / VR / MR object). The input / output unit 140a can receive commands from a user to operate the XR device 100a, and the control unit 120 drives the XR device 100a according to the user's commands. For example, when a user uses the XR device 100a to watch a movie or news, the control unit 120 can transmit content request information to another device (e.g., the mobile device 100b) or a media server via the communication unit 130. The communication unit 130 can download / stream content such as a movie or news from another device (e.g., the mobile device 100b) or a media server to the memory unit 130. The control unit 120 controls and / or performs procedures such as video / image acquisition, (video / image) encoding, and metadata generation / processing for the content, and generates / outputs an XR object based on information about the surrounding space or real objects obtained by the input / output unit 140a / sensor unit 140b.

[0231] The XR device 100a is wirelessly connected to the mobile device 100b via the communication unit 110, and the operation of the XR device 100a is controlled by the mobile device 100b. For example, the mobile device 100b operates as a controller for the XR device 100a. To this end, the XR device 100a can obtain three-dimensional position information of the mobile device 100b, and then generate and output an XR individual corresponding to the mobile device 100b.

[0232] Examples of robots to which the present invention is applied

[0233] Figure 21 shows an example of a robot to which the present invention is applied. Robots can be classified into industrial, medical, domestic, military, etc. depending on the purpose or field of use.

[0234] Referring to FIG. 21, the robot 100 includes a communication unit 110, a control unit 120, a memory unit 130, an input / output unit 140a, a sensor unit 140b, and a driving unit 140c.

[0235] The communication unit 110 transmits and receives signals (e.g., driving information, control signals, etc.) to and from external devices such as other wireless devices, other robots, or control servers. The control unit 120 controls the components of the robot 100 to perform various operations. The memory unit 130 stores data, parameters, programs, codes, and instructions that support various functions of the robot 100. The input / output unit 140a receives information from outside the robot 100 and outputs information to outside the robot 100. The input / output unit 140a includes a camera, a microphone, a user input unit, a display unit, a speaker, and / or a haptics module. The sensor unit 140b receives internal information of the robot 100, information about the surrounding environment, user information, etc. The sensor unit 140b includes a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, a radar, etc. The drive unit 140c performs various physical operations, such as moving the robot joints. The driving unit 140c can move the robot 100 on the ground or fly it in the air. The driving unit 140c includes an actuator, a motor, wheels, brakes, propellers, and the like.

[0236] Examples of AI devices to which this invention can be applied

[0237] 22 shows examples of AI devices to which the present invention can be applied. AI devices can be embodied as fixed or mobile devices such as TVs, projectors, smartphones, PCs, notebook computers, digital broadcasting terminals, tablet PCs, wearable devices, set-top boxes (STBs), radios, washing machines, refrigerators, digital signage, robots, and vehicles.

[0238] Referring to FIG. 22, the AI ​​device 100 includes a communication unit 110, a control unit 120, a memory unit 130, an input / output unit 140a / 140b, a running processor unit 140c, and a sensor unit 140d.

[0239] The communication unit 110 transmits and receives wired and wireless signals (e.g., sensor information, user input, learning model, control signal, etc.) to and from external devices such as other AI devices (e.g., 100x, 200, 400 in FIG. 16) and AI servers (e.g., 400 in FIG. 16) using wired and wireless communication technology. To this end, the communication unit 110 transmits information in the memory unit 130 to external devices or transfers signals received from external devices to the memory unit 130.

[0240] The control unit 120 determines one of the executable actions of the AI ​​device 100 based on information determined or generated using a data analysis algorithm or a machine learning algorithm. The control unit 120 can also control the components of the AI ​​device 100 to perform the determined action. For example, the control unit 120 can request, search, receive, or use data from the running processor unit 140c or the memory unit 130, and control the components of the AI ​​device 100 to perform a predicted or desirable action among one of the executable actions. The control unit 120 can also collect history information, including the operation details of the AI ​​device 100 and user feedback on the operation, and store it in the memory unit 130 or the running processor unit 140c, or transmit it to an external device such as an AI server (400, FIG. 17). The collected history information is used when updating a learning model.

[0241] The memory unit 130 stores data that supports various functions of the AI ​​device 100. For example, the memory unit 130 stores data obtained from the input unit 140a, data obtained from the communication unit 110, output data of the running processor unit 140c, and data obtained from the sensing unit 140. The memory unit 130 also stores control information and / or software code required for the operation / execution of the control unit 120.

[0242] The input unit 140a obtains various types of data from outside the AI ​​device 100. For example, the input unit 140a obtains learning data for model learning and input data to which a learning model is applied. The input unit 140a includes a camera, a microphone, and / or a user input unit. The output unit 140b generates output related to vision, hearing, or touch. The output unit 140b includes a display unit, a speaker, and / or a haptics module. The sensing unit 140 obtains any one of internal information of the AI ​​device 100, information about the surrounding environment of the AI ​​device 100, and user information using various sensors. The sensing unit 140 includes a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, and / or a radar.

[0243] The running processor unit 140c uses the training data to train a model composed of an artificial neural network. The running processor unit 140c performs AI processing together with the running processor unit of the AI ​​server (FIG. 17, 400). The running processor unit 140c processes information received from an external device via the communication unit 110 and / or information stored in the memory unit 130. In addition, the output value of the running processor unit 140c is / is transmitted to an external device via the communication unit 110 and stored in the memory unit 130. [Industrial Applicability]

[0244] The above embodiment can be applied to various mobile communication systems.

Claims

1. 1. A method of operating a remote User Equipment (UE) associated with a multi-path relay in a wireless communication system, comprising: the remote UE reporting measurement results for candidate relay UEs to a base station; the remote UE receiving an RRCReconfiguration message from the base station, the RRCReconfiguration message including a target relay UE ID; and The remote UE attempts a PC5 connection with the target relay UE; Including, The method includes the step of: based on the remote UE finding out from the discovery message transmitted by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE transmitting information to the base station informing that the camping cell of the target relay UE has changed.

2. The method of claim 1, wherein the remote UE releases the PC5 connection with the target relay UE based on the remote UE finding that the camping cell of the target relay UE has changed after establishing the PC5 connection with the target relay UE.

3. 2. The method of claim 1, wherein the remote UE omits triggering an RRCReestablishment based on the fact that the remote UE has learned from the discovery message transmitted by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection.

4. 2. The method of claim 1, wherein the remote UE reports a new candidate relay UE to the base station based on the fact that the camping cell of the target relay UE has changed or the target relay UE has performed cell reselection during RRC connection, based on the fact that the remote UE has found out from the discovery message transmitted by the candidate relay UE that the camping cell of the target relay UE has changed or the target relay UE has performed cell reselection during RRC connection.

5. The method of claim 1, wherein the camping cell of the target relay UE has changed or the target relay UE has performed cell reselection during RRC connection when an ID of the candidate relay UE at the time of reporting the measurement result is different from an ID of the candidate relay UE included in the discovery message.

6. The method of claim 1 , wherein the discovery message is received after reporting the measurement results.

7. The method of claim 1 , wherein the target relay UE is in an RRC IDLE / INACTIVE state.

8. In a wireless communication system, a remote UE comprises: at least one processor; and at least one computer memory operatively connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The operation is reporting measurement results for candidate relay UEs to the base station; receiving an RRCReconfiguration message from the base station, the RRCReconfiguration message including a target relay UE ID; and Attempting a PC5 connection with the target relay UE; Including, Based on the remote UE finding out through the discovery message sent by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE transmits information to the base station informing that the camping cell of the target relay UE has changed.

9. 10. The remote UE of claim 8, wherein the remote UE communicates with at least one of another UE, a UE associated with an autonomous vehicle, a base station, or a network.

10. a non-volatile computer-readable storage medium storing at least one computer program comprising instructions that, when executed by at least one processor, cause the at least one processor to perform an operation for a remote UE; The operation is reporting measurement results for candidate relay UEs to the base station; receiving an RRCReconfiguration message from the base station, the RRCReconfiguration message including a target relay UE ID; and Attempting a PC5 connection with the target relay UE; Including, A storage medium in which, based on the remote UE finding out through a discovery message sent by the candidate relay UE that the camping cell of the target relay UE has changed or that the target relay UE has performed cell reselection during RRC connection, the remote UE transmits information to the base station informing that the camping cell of the target relay UE has changed.

11. 1. A method of operating a relay UE in connection with a multipath relay in a wireless communication system, comprising: the relay UE sending a discovery message; The relay UE receives a PC5 message for multipath connection from the remote UE; Including, A method in which the relay UE rejects an SL connection request related to the multipath connection of the remote UE based on the fact that the camping cell when the relay UE transmits the discovery message is different from the camping cell when the relay UE receives the PC5 message or the RRC-connected cell when the relay UE receives the PC5 message, and the remote UE transmits information to the base station indicating that the camping cell of the target relay UE has changed.

12. In a wireless communication system, a relay UE, at least one processor; and at least one computer memory operatively connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The operation is sending a discovery message; receiving a PC5 message for multipath connection from the remote UE; Including, Based on the fact that the camping cell when the relay UE transmits the discovery message is different from the camping cell when the relay UE receives the PC5 message or the RRC-connected cell when the relay UE receives the PC5 message, the relay UE rejects the SL connection request related to the multipath connection of the remote UE, and the remote UE transmits information to the base station informing that the camping cell of the target relay UE has changed.

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