Operation method related to cell change in multipath relay in wireless communication system

Abstract

An embodiment relates to an operation method of a remote user equipment (UE) related to a multipath relay in a wireless communication system, the method comprising the steps of: the remote UE reporting a result of a candidate relay UE measurement to a base station; the remote UE receives, from the base station, an RRCReceigation message including the ID of the target relay UE; and the remote UE attempting to establish a PC5 connection with the target relay UE, in which the remote UE transmits, to the base station, information notifying the change of the resident cell of the target relay UE on the basis of the remote UE detecting, by a discovery message transmitted by the candidate relay UE, that the resident cell of the target relay UE has changed or that the target relay UE has performed cell reselection at RRC connection.

Description

Technical Field

[0001] The following description relates to a wireless communication system, and more particularly, to a method and apparatus for operating a remote user equipment (UE) associated with a relay cell change in multipath relay. Background Art

[0002] Wireless communication systems employ various radio access technologies (RATs) such as Long Term Evolution (LTE), Advanced LTE (LTE-A), and Wireless Fidelity (WiFi). The fifth generation (5G) is also included in the RATs. The three key areas of demand for 5G are (1) enhanced mobile broadband (eMBB), (2) massive machine type communications (mMTC), and (3) ultra-reliable low latency communications (URLLC). Some use cases may require multiple dimensions for optimization, while other use cases may focus on only one key performance indicator (KPI). 5G supports these various use cases in a flexible and reliable manner.

[0003] eMBB goes far beyond basic mobile Internet access and covers rich interactive work, media and entertainment applications in the cloud or augmented reality (AR). Data is one of the key drivers of 5G, and in the 5G era, dedicated voice services may not be seen for the first time. In 5G, it is expected that voice will be processed as an application using only the data connectivity provided by the communication system. The main driving force for the increase in traffic is the increase in the number of applications requiring high data rates and the increase in content size. As more and more devices are connected to the Internet, streaming services (audio and video), interactive video and mobile Internet connections will continue to be widely used. Many of these applications require always-on connections to push real-time information and notifications to users. Cloud storage and applications for mobile communication platforms are increasing rapidly. This applies to both work and entertainment. Cloud storage is a specific use case that drives the growth of uplink data rates. 5G will also be used for remote work in the cloud, which requires much lower end-to-end latency when done with a tactile interface to maintain a good user experience. Entertainment (e.g., cloud games and video streaming) is another key driver for increasing demand for mobile broadband capabilities. Entertainment will be critical for smartphones and tablets everywhere, including high-mobility environments such as trains, cars and airplanes. Another use case is augmented reality (AR) for entertainment and information search, which requires very little latency and a large amount of real-time data.

[0004] One of the most anticipated 5G use cases is the ability to actively connect embedded sensors in every field (i.e., mMTC). It is expected that there will be 20.4 billion potential Internet of Things (IoT) devices by 2020. In industrial IoT, 5G is one of the areas that will play a key role in enabling smart cities, asset tracking, smart utilities, agriculture, and secure infrastructure.

[0005] URLLC includes services that will revolutionize industries using ultra-reliable / available low-latency links, such as remote control of critical infrastructure and autonomous vehicles. The levels of reliability and latency are critical for smart grid control, industrial automation, robotics, drone control and coordination, etc.

[0006] Now, a number of use cases will be described in detail.

[0007] 5G can complement fiber-to-the-home (FTTH) and cable-based broadband (or cable data service interface specification (DOCSIS)) as a means of delivering streams with data rates ranging from hundreds of megabits per second to gigabits per second. Such high speeds are required for virtual reality (VR) and AR, as well as TV broadcasts with resolutions of 4K or higher (6K, 8K, or higher). VR and AR applications mainly include immersive sports events. Specific applications may require special network configurations. For example, for VR games, gaming companies may have to integrate core servers with network operators' edge network servers in order to minimize latency.

[0008] The automotive industry is expected to become a very important new driver of 5G, with many use cases for mobile communications in vehicles. For example, entertainment for passengers requires both high-capacity and high-mobility mobile broadband, because future users will expect to always have a high-quality connection, regardless of their location and speed. Other use cases in the automotive industry are AR dashboards. These dashboards display superimposed information on what the driver is seeing through the front window, identify objects in the dark, and inform the driver of the distance and movement of objects. In the future, wireless modules will enable communication between the vehicles themselves, information exchange between the vehicle and the supporting infrastructure, and information exchange between the vehicle and other connected devices (for example, devices carried by pedestrians). Safety systems can guide drivers to take alternative courses of action to enable them to drive more safely and reduce the risk of accidents. The next stage will be remotely controlled or autonomous vehicles. This requires very reliable and very fast communication between different autonomous vehicles and between vehicles and infrastructure. In the future, autonomous vehicles will perform all driving activities while the driver focuses on the elusive traffic anomalies of the vehicle itself. The technical requirements for autonomous vehicles require ultra-low latency and ultra-high reliability, thereby increasing traffic safety to a level that cannot be achieved by humans.

[0009] Smart cities and smart homes, often referred to as smart societies, will be embedded with dense wireless sensor networks. Distributed networks of smart sensors will confirm the cost and energy efficiency maintenance conditions of a city or home. A similar setup can be made for each home, where temperature sensors, window and heating controls, burglar alarms, and home appliances are all connected wirelessly. Many of these sensors are typically characterized by low data rates, low power, and low cost, but real-time high-definition (HD) video may be required, for example, in some types of surveillance installations.

[0010] The consumption and distribution of energy, including heat or gas, is becoming highly decentralized, creating a need for automatic control of very decentralized sensor networks. Smart grids interconnect these sensors using digital information and communication technologies to collect and act on information. This information can include information about the behavior of suppliers and consumers, enabling smart grids to improve the efficiency, reliability, economic viability, and sustainability of production of fuels such as electricity in an automated manner. Smart grids can be viewed as another sensor network with less latency.

[0011] The health sector has many applications that can benefit from mobile communications. Communication systems enable telemedicine, which provides clinical care at a distance. It helps to eliminate distance barriers and improve access to medical services that are often not consistently available in remote rural communities. It can also be used to save lives in critical care and emergency situations. Wireless sensor networks based on mobile communications can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

[0012] Wireless and mobile communications are becoming increasingly important for industrial applications. Wires are expensive to install and maintain, and the possibility of replacing cables with reconfigurable wireless links is an attractive opportunity for many industries. However, to achieve this, wireless connections need to operate with latency, reliability, and capacity close to cables, and to be easier to manage. Low latency and very low error probability are new requirements that 5G needs to address.

[0013] Finally, logistics and freight tracking are important use cases for mobile communications to enable tracking of inventory and packages wherever they are located using location-based information systems. Logistics and freight tracking use cases typically require lower data speeds, but wide coverage and reliable location information.

[0014] A wireless communication system is a multiple-access system that supports communication for multiple users by sharing available system resources (bandwidth, transmit power, etc.) Examples of multiple-access systems include CDMA systems, FDMA systems, TDMA systems, OFDMA systems, SC-FDMA systems, and MC-FDMA systems.

[0015] Sidelink (SL) refers to a communication scheme in which a direct link is established between a user equipment (UE) and the UEs and the UEs directly exchange voice or data without intervention of a base station (BS). SL is considered a solution to alleviate the rapidly growing data traffic constraints of the BS.

[0016] Vehicle-to-everything (V2X) is a communication technology in which a vehicle exchanges information with another vehicle, pedestrians, and infrastructure through wired / wireless communications. V2X can be divided into four types: vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). V2X communication can be provided via a PC5 interface and / or a Uu interface.

[0017] As more and more communication devices require greater communication capacity, enhanced mobile broadband communication relative to existing RATs is needed. Therefore, communication systems that take into account services or UEs that are sensitive to reliability and latency are being discussed. The next generation RAT that takes into account eMBB, MTC, and URLLC is called new RAT or NR. In NR, V2X communication can also be supported.

[0018] Figure 1 2 is a diagram illustrating a comparison between V2X communication based on a RAT prior to NR and V2X communication based on NR.

[0019] For V2X communication, the technology of providing security services based on V2X messages such as Basic Security Message (BSM), Collaborative Awareness Message (CAM) and Decentralized Environment Notification Message (DENM) is mainly discussed in the pre-NR RAT. V2X messages may include location information, dynamic information and attribute information. For example, a UE may send a CAM of a periodic message type and / or a DENM of an event-triggered type to another UE.

[0020] For example, CAM may include basic vehicle information, including dynamic status information such as direction and speed, vehicle static data such as size, external lighting status, path details, etc. For example, UE may broadcast CAM, and the waiting time of CAM may be less than 100ms. For example, when an unexpected event such as vehicle damage or accident occurs, UE may generate DENM and send DENM to another UE. For example, all vehicles within the transmission range of UE may receive CAM and / or DENM. In this case, DENM may have a higher priority than CAM.

[0021] Regarding V2X communication, various V2X scenarios are proposed in NR. For example, V2X scenarios include vehicle platooning, advanced driving, extended sensors, and remote driving.

[0022] For example, vehicles can be dynamically grouped and driven together based on vehicle platooning. For example, to perform platooning operations based on vehicle platooning, vehicles in a group can receive periodic data from a leading vehicle. For example, vehicles in a group can widen or narrow their gaps based on the periodic data.

[0023] For example, based on advanced driving, the vehicles can be semi-autonomous or fully autonomous. For example, each vehicle can adjust trajectory or maneuver based on data obtained from nearby vehicles and / or nearby logical entities. For example, each vehicle can also share driving intent with nearby vehicles.

[0024] For example, based on the extended sensor, raw or processed data or real-time video data obtained by local sensors can be exchanged between vehicles, logical entities, pedestrian terminals and / or V2X application servers. Therefore, the vehicle can perceive a high-level environment relative to the environment that can be perceived by the vehicle's sensors.

[0025] For example, based on remote driving, remote drivers or V2X applications can operate or control remote vehicles on behalf of people who are unable to drive or are in dangerous environments. For example, cloud-based driving can be used to operate or control remote vehicles when the path can be predicted as in public transportation. For example, access to a cloud-based backend service platform can also be used for remote driving.

[0026] In NR-based V2X communications, schemes for specifying service requirements for various V2X scenarios including vehicle platooning, advanced driving, extended sensors, and remote driving are discussed. Summary of the invention

[0027] Technical issues

[0028] The present disclosure is intended to provide an operation method of a remote user equipment (UE) when a relay UE in an IDLE / INACTIVE state selected by a serving base station (BS) (or a next-generation Node B (gNB) of a remote user equipment (UE) for multipath / handover (HO) operation) accesses a target cell (and / or gNB) different from the target cell (and / or gNB) desired by the serving gNB of the remote UE.

[0029] Technical Solution

[0030] In one embodiment, a method for operating a remote UE associated with multipath relay in a wireless communication system is provided herein. The method may include the following steps: the remote UE reports measurement results for a candidate relay UE to a base station; the remote UE receives an RRCReconfiguration message including an identifier (ID) of the target relay UE from the base station; and the remote UE attempts to establish a PC5 connection with the target relay UE. Based on the remote UE learning that the target relay UE's resident cell has changed or the target relay UE has performed cell reselection during a radio resource control RRC connection through a discovery message sent by the candidate relay UE, the remote UE may send information notifying the base station of the change in the resident cell of the target relay UE.

[0031] In one embodiment, a remote UE in a wireless communication system is provided herein. The remote UE may include: at least one processor; and at least one computer memory, the at least one computer memory being operatively connected to the at least one processor, the computer memory being configured to store instructions, which, when executed, cause the at least one processor to perform operations. These operations may include: reporting measurement results for candidate relay UEs to a base station; receiving an RRCReconfiguration message including an ID of a target relay UE from a base station; and attempting to establish a PC5 connection with a target relay UE. Based on the remote UE learning through a discovery message sent by a candidate relay UE that a target relay UE's resident cell has changed or that the target relay UE has performed a cell reselection during a radio resource control RRC connection, the remote UE may send information to the base station notifying the target relay UE of a resident cell change.

[0032] In one embodiment, a non-volatile computer-readable storage medium is provided herein, which is configured to store at least one computer program, the 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. These operations may include: reporting measurement results for a candidate relay UE to a base station; receiving an RRCReconfiguration message including an ID of a target relay UE from a base station; and attempting to establish a PC5 connection with a target relay UE. Based on the remote UE learning that the target relay UE's resident cell has changed through a discovery message sent by the candidate relay UE or that the target relay UE has performed a cell reselection during a radio resource control RRC connection, the remote UE may send information to the base station notifying the target relay UE of a resident cell change.

[0033] In one embodiment, a method for operating a relay UE associated with multipath relay in a wireless communication system is provided herein. The method may include the following steps: a discovery message is sent by the relay UE; and the relay UE receives a PC5 message for multipath connection from a remote UE. Based on the fact that the resident cell of the relay UE when sending the discovery message is different from the resident cell when receiving the PC5 message or different from the RRC connection cell when receiving the PC5 message, the relay UE may reject a side link (SL) connection request associated with the multipath connection from the remote UE, and the remote UE may send information to the base station notifying the target relay UE of the change of the resident cell.

[0034] In one embodiment, a relay UE in a wireless communication system is provided herein. The relay UE may include: at least one processor; and at least one computer memory, at least one computer memory being operatively connected to at least one processor, the computer memory being configured to store instructions that, when executed, cause at least one processor to perform operations. These operations may include: sending a discovery message by the relay UE; and receiving a PC5 message for multipath connection by the relay UE from a remote UE. Based on the fact that the resident cell of the relay UE when sending the discovery message is different from the resident cell when receiving the PC5 message or from the RRC connection cell when receiving the PC5 message, the relay UE may reject the SL connection request associated with the multipath connection from the remote UE, and the remote UE may send information to the base station notifying the target relay UE of the change in the resident cell.

[0035] Based on the fact that the remote UE learns that the camping cell of the target relay UE has changed after establishing the PC5 connection with the target relay UE, the remote UE may release the PC5 connection with the target relay UE.

[0036] Based on the remote UE learning through the discovery message sent by the candidate relay UE that the camped cell of the target relay UE has changed or the target relay UE has performed cell reselection during the RRC connection, the remote UE may skip triggering RRC reestablishment.

[0037] Based on the remote UE learning through the discovery message sent 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 the RRC connection, the remote UE may report a new candidate relay UE to the base station.

[0038] A change of a camped cell of the target relay UE or a cell reselection performed by the target relay UE during an RRC connection may occur based on that the ID of the selected relay UE is different from the ID of the candidate relay UE included in the discovery message when reporting the measurement result.

[0039] The discovery message may be received after the measurement results are reported.

[0040] The target relay UE may be in RRC IDLE / INACTIVE state.

[0041] The remote UE may communicate with at least one of another UE, a UE associated with the autonomous vehicle, a base station, or a network.

[0042] Beneficial Effects

[0043] According to one embodiment of the present disclosure, a remote user equipment (UE) may perform appropriate operations to quickly establish a new indirect link. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. In the drawings:

[0045] Figure 1 is a diagram for illustrating a comparison between vehicle-to-everything (V2X) communication based on a pre-new radio (NR) access technology (RAT) and NR-based V2X communication.

[0046] Figure 2 The structure of a Long Term Evolution (LTE) system according to an embodiment of the present disclosure is illustrated.

[0047] Figure 3 The radio protocol architecture of the user plane and the control plane according to the embodiments of the present disclosure is illustrated.

[0048] Figure 4 A structure of a New Radio (NR) system according to an embodiment of the present disclosure is illustrated.

[0049] Figure 5 The functional split between the next generation radio access network (NG-RAN) and the fifth generation core network (5GC) according to an embodiment of the present disclosure is illustrated.

[0050] Figure 6 The structure of a radio frame of NR to which the embodiment is applicable is illustrated.

[0051] Figure 7 The structure of a time slot in an NR frame according to an embodiment of the present disclosure is illustrated.

[0052] Figure 8 A radio protocol architecture for side link (SL) communication according to an embodiment of the present disclosure is illustrated.

[0053] Fig. 9 A radio protocol architecture for SL communication according to an embodiment of the present disclosure is illustrated.

[0054] Fig.10 A synchronization source or synchronization reference of V2X according to an embodiment of the present disclosure is illustrated.

[0055] Fig.11 A process in which a user equipment (UE) performs V2X or SL communication according to a transmission mode according to an embodiment of the present disclosure is illustrated.

[0056] Fig.12 A process in which a UE performs a path switching according to an embodiment of the present disclosure is illustrated.

[0057] Fig.13 Direct to indirect path switching is illustrated.

[0058] Fig.14 is a diagram for explaining switching.

[0059] Fig.15 It is a schematic diagram for explaining one embodiment.

[0060] Figures 16 to 22 The diagrams are for explaining various devices to which the embodiments are applicable. DETAILED DESCRIPTION

[0061] In various embodiments of the present disclosure, " / " and "," should be interpreted as "and / or". For example, "A / B" may mean "A and / or B". In addition, "A, B" may mean "A and / or B". In addition, "A / B / C" may mean "at least one of A, B and / or C". In addition, "A, B, C" may mean "at least one of A, B and / or C".

[0062] In various embodiments of the present disclosure, "or" should be interpreted as "and / or". For example, "A or B" may include "only A", "only B", or "both A and B". In other words, "or" should be interpreted as "additionally or alternatively".

[0063] The technology described herein can be used for various wireless access systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), etc. CDMA can be implemented as a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented as a radio technology such as Global System for Mobile Communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rate for GSM Evolution (EDGE). OFDMA can be implemented as a radio technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Evolved UTRA (E-UTRA), etc. IEEE802.16m is an evolution of IEEE 802.16e, providing backward compatibility with systems based on IRRR802.16e. UTRA is part of Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a part of Evolved UMTS (E-UMTS) using Evolved UTRA (E-UTRA). 3GPP LTE adopts OFDMA for downlink (DL) and SC-FDMA for uplink (UL). LTE Advanced (LTE-A) is an evolution of 3GPP LTE.

[0064] The successor to LTE-A - the 5th generation (5G) new radio access technology (NR) is a new clean-state mobile communication system characterized by high performance, low latency and high availability. 5G NR can use all available spectrum resources, including low frequency bands below 1 GHz, mid-frequency bands between 1 GHz and 10 GHz, and high frequency (millimeter) bands of 24 GHz or above.

[0065] Although the following description is mainly given in the context of LTE-A or 5G NR for the sake of clarity, the technical ideas of the embodiments of the present disclosure are not limited thereto.

[0066] Figure 2 The structure of the LTE system according to the embodiment of the present disclosure is illustrated. This may also be referred to as an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) or an LTE / LTE-A system.

[0067] Reference Figure 2, E-UTRAN includes an evolved Node B (eNB) 20 that provides a control plane and a user plane to UE 10. UE 10 may be fixed or mobile, and may also be referred to as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), or a wireless device. eNB 20 is a fixed station that communicates with UE 10, and may also be referred to as a base station (BS), a base transceiver system (BTS), or an access point.

[0068] The eNBs 20 may be connected to each other via an X2 interface. The eNBs 20 are connected to an Evolved Packet Core (EPC) 39 via an S1 interface. More specifically, the eNBs 20 are connected to a Mobility Management Entity (MME) via an S1-MME interface, and to a Serving Gateway (S-GW) via an S1-U interface.

[0069] The EPC 30 includes an MME, an S-GW, and a packet data network gateway (P-GW). The MME has access information or capability information about the UE, which is mainly used for mobility management of the UE. The S-GW is a gateway with the E-UTRAN as an endpoint, and the P-GW is a gateway with a packet data network (PDN) as an endpoint.

[0070] Based on the lowest three layers of the open system interconnection (OSI) reference model known in communication systems, the radio protocol stack between the UE and the network can be divided into layer 1 (L1), layer 2 (L2), and layer 3 (L3). These layers are defined in pairs between the UE and the evolved UTRAN (E-UTRAN) for data transmission via the Uu interface. The physical (PHY) layer at L1 provides information transfer services on physical channels. The radio resource control (RRC) layer at L3 is used to control radio resources between the UE and the network. For this purpose, the RRC layer exchanges RRC messages between the UE and the eNB.

[0071] Figure 3 (a) in FIG. 1 illustrates a user plane radio protocol architecture according to an embodiment of the present disclosure.

[0072] Figure 3 (b) in FIG. 1 illustrates a control plane radio protocol architecture according to an embodiment of the present disclosure. The user plane is a protocol stack for user data transmission, and the control plane is a protocol stack for control signal transmission.

[0073] Reference Figure 3 (a) and Figure 3In (b), the PHY layer provides information transfer services to its higher layer on the physical channel. The PHY layer is connected to the medium access control (MAC) layer through a transport channel, and data is transferred between the MAC layer and the PHY layer on the transport channel. The transport channel is divided according to the characteristics used to send data via the radio interface.

[0074] Data is transmitted on a physical channel between different PHY layers (ie, the PHY layers of a transmitter and a receiver). The physical channel may be modulated by orthogonal frequency division multiplexing (OFDM) and uses time and frequency as radio resources.

[0075] The MAC layer provides services to the higher layer, Radio Link Control (RLC), on logical channels. The MAC layer provides the function of mapping from multiple logical channels to multiple transport channels. In addition, the MAC layer provides a logical channel multiplexing function by mapping multiple logical channels to a single transport channel. The MAC sublayer provides data transmission services on logical channels.

[0076] The RLC layer performs concatenation, segmentation, and reassembly of RLC service data units (SDUs). To guarantee various quality of service (QoS) requirements for each radio bearer (RB), 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).

[0077] The RRC layer is defined only in the control plane, and controls logical channels, transport channels, and physical channels in relation to configuration, reconfiguration, and release of RBs. RBs refer to logical paths for data transmission between UEs and networks provided by L1 (PHY layer) and L2 (MAC layer, RLC layer, and Packet Data Convergence Protocol (PDCP) layer).

[0078] The user plane functions of the PDCP layer include user data transmission, header compression and encryption. The control plane functions of the PDCP layer include control plane data transmission and encryption / integrity protection.

[0079] RB establishment is equivalent to the process of defining radio protocol layers and channel characteristics and configuring specific parameters and operation methods in order to provide specific services. RB can be divided into two types - signaling radio bearer (SRB) and data radio bearer (DRB). SRB is used as a path for sending RRC messages on the control plane, while DRB is used as a path for sending user data on the user plane.

[0080] Once an RRC connection is established between the RRC layer of the UE and the RRC layer of the E-UTRAN, the UE is in the RRC_CONNECTED state, otherwise the UE is in the RRC_IDLE state. In NR, the RRC_INACTIVE state is additionally defined. A UE in the RRC_INACTIVE state can maintain a connection with the core network while releasing the connection from the eNB.

[0081] The DL transport channels that carry data from the network to the UE include a broadcast channel (BCH) on which system information is sent and a DL shared channel (DL SCH) on which user traffic or control messages are sent. Traffic or control messages for DL ​​multicast or broadcast services may be sent on a DL-SCH or a DL multicast channel (DL MCH). The UL transport channels that carry data from the UE to the network include a random access channel (RACH) on which initial control messages are sent and a UL shared channel (UL SCH) on which user traffic or control messages are sent.

[0082] Logical channels above and mapped to the transport channels include a Broadcast Control Channel (BCCH), a Paging Control Channel (PCCH), a Common Control Channel (CCCH), a Multicast Control Channel (MCCH), and a Multicast Traffic Channel (MTCH).

[0083] A physical channel includes multiple OFDM symbols in the time domain multiplied by multiple subcarriers in the frequency domain. A subframe includes multiple OFDM symbols in the time domain. An RB is a resource allocation unit defined by multiple OFDM symbols multiplied by multiple subcarriers. In addition, each subframe may use a specific subcarrier of a specific OFDM symbol (e.g., the first OFDM symbol) in the corresponding subframe for a physical DL control channel (PDCCH), i.e., an L1 / L2 control channel. A transmission time interval (TTI) is a unit time for subframe transmission.

[0084] Figure 4 The structure of the NR system according to an embodiment of the present disclosure is illustrated.

[0085] Reference Figure 4 , the next generation radio access network (NG-RAN) may include next generation Node Bs (gNBs) and / or eNBs that provide user plane and control plane protocol terminations to the UE. Figure 4 In the figure, for example, NG-RAN is shown as including only gNB. gNB and eNB are connected to each other via Xn interface. gNB and eNB are connected to 5G core network (5GC) via NG interface. More specifically, gNB and eNB are connected to access and mobility management function (AMF) via NG-C interface, and to user plane function (UPF) via NG-U interface.

[0086] Figure 5 The functional division between NG-RAN and 5GC according to an embodiment of the present disclosure is illustrated.

[0087] Reference Figure 5 , gNB can provide functions including inter-cell radio resource management (RRM), radio admission control, measurement configuration and provision, and dynamic resource allocation. AMF can provide functions such as non-access stratum (NAS) security and idle state mobility processing. UPF can provide functions including mobility anchoring and protocol data unit (PDU) processing. Session management function (SMF) can provide functions including UE Internet Protocol (IP) address allocation and PDU session control.

[0088] Figure 6 The radio frame structure in NR to which the embodiments of the present disclosure are applicable is illustrated.

[0089] Reference Figure 6 , a radio frame can be used for UL transmission and DL transmission in NR. The length of a radio frame is 10ms and can be defined by two 5ms half frames. HF may include five 1ms subframes. A subframe may be divided into one or more slots, and the number of slots in a SF may be determined according to a subcarrier spacing (SCS). Each slot may include 12 or 14 OFDM (A) symbols depending on a cyclic prefix (CP).

[0090] In the case of normal CP (NCP), each time slot may include 14 symbols, and in the case of extended CP (ECP), each time slot may include 12 symbols. Herein, a symbol may be an OFDM symbol (or CP-OFDM symbol) or an SC-FDMA symbol (or DFT-s-OFDM symbol).

[0091] Table 1 below lists the number of symbols N per time slot according to the SCS configuration μ in the NCP case 时隙 符号 , the number of time slots per frame N 帧,u 时隙 And the number of time slots N in each subframe 子帧,u 时隙 .

[0092] [Table 1]

[0093] <![CDATA[SCS(15×2 u )]]> <![CDATA[N 时隙 符号 ]]> <![CDATA[N 帧,u 时隙 ]]> <![CDATA[N 子帧,u 时隙 ]]> 15KHz(u=0) 14 10 1 30KHz(u=1) 14 20 2 60KHz(u=2) 14 40 4 120KHz(u=3) 14 80 8 240KHz(u=4) 14 160 16

[0094] The following Table 2 lists the number of symbols per time slot, the number of time slots per frame, and the number of time slots per subframe according to SCS in the ECP case.

[0095] [Table 2]

[0096] SCS(15×2^u) <![CDATA[N 时隙 符号 ]]> <![CDATA[N 帧,u 时隙 ]]> <![CDATA[N 子帧,u 时隙 ]]> 60KHz(u=2) 12 40 4

[0097] In the NR system, different OFDM(A) parameter sets (e.g., SCS, CP length, etc.) may be configured for multiple cells aggregated for one UE. Therefore, the (absolute time) duration of a time resource (e.g., a subframe, a time slot, or a TTI) (collectively referred to as a time unit (TU) for convenience) including the same number of symbols may be configured to be different for the aggregated cells.

[0098] In NR, various parameter sets or SCS can be supported to support various 5G services. For example, with 15kHz SCS, wide areas in traditional cellular bands can be supported, while with 30kHz / 60kHz SCS, dense urban areas, lower latency and wide carrier bandwidth can be supported. With 60kHz or higher SCS, bandwidths greater than 24.25GHz can be supported to overcome phase noise.

[0099] The NR frequency band may be defined by two types of frequency ranges FR1 and FR2. The values ​​in each frequency range may vary. For example, two types of frequency ranges may be given in Table 3. In the NR system, FR1 may be a "range below 6 GHz" and FR2 may be a "range above 6 GHz" known as millimeter wave (mmW).

[0100] [Table 3]

[0101] Frequency range specification Corresponding frequency range Subcarrier Spacing (SCS) FR1 450MHz–6000MHz 15, 30, 60kHz FR2 24250MHz–52600MHz 60, 120, 240kHz

[0102] As mentioned above, in the NR system, the values ​​in the frequency range can be changed. For example, as listed in Table 4, the range of FR1 can be from 410 MHz to 7125 MHz. That is, FR1 can include frequency bands of 6 GHz (or 5850, 5900, and 5925 MHz) or above. For example, frequency bands of 6 GHz (or 5850, 5900, and 5925 MHz) or above can include unlicensed frequency bands. Unlicensed frequency bands can be used for various purposes, for example, vehicle communications (e.g., autonomous driving).

[0103] [Table 4]

[0104] Frequency range specification Corresponding frequency range Subcarrier Spacing (SCS) FR1 410MHz–7125MHz 15, 30, 60kHz FR2 24250MHz–52600MHz 60, 120, 240kHz

[0105] Figure 7 The time slot structure in the NR frame according to an embodiment of the present disclosure is illustrated.

[0106] Reference Figure 7, a time slot includes multiple symbols in the time domain. For example, a time slot may include 14 symbols in the NCP case and 12 symbols in the ECP case. Alternatively, a time slot may include 7 symbols in the NCP case and 6 symbols in the ECP case.

[0107] A carrier includes multiple subcarriers in the frequency domain. An RB can be defined by multiple (e.g., 12) consecutive subcarriers in the frequency domain. A bandwidth part (BWP) can be defined by multiple consecutive (physical) RBs ((P)RBs) in the frequency domain and corresponds to a parameter set (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed in an activated BWP. Each element can be referred to as a resource element (RE) in a resource grid, and a complex symbol can be mapped to an RE.

[0108] The radio interface between UEs or the radio interface between UE and the network may include L1, L2 and L3. In various embodiments of the present disclosure, L1 may refer to a PHY layer. For example, L2 may refer to at least one of a MAC layer, an RLC layer, a PDCH layer or an SDAP layer. For example, L3 may refer to an RRC layer.

[0109] Now, a description will be given of the side link (SL) communication.

[0110] Figure 8 The radio protocol architecture for SL communication according to an embodiment of the present disclosure is illustrated. Specifically, Figure 8 (a) in FIG. 1 illustrates a user plane protocol stack in LTE, and Figure 8 (b) in FIG. 1 illustrates an example of the control plane protocol stack in LTE.

[0111] Fig. 9 The radio protocol architecture for SL communication according to an embodiment of the present disclosure is illustrated. Specifically, Fig. 9 (a) in FIG. 1 illustrates an example of a user plane protocol stack in NR, and Fig. 9 (b) in FIG. 4 illustrates the control plane protocol stack in NR.

[0112] Fig.10 A synchronization source or synchronization reference of V2X according to an embodiment of the present disclosure is illustrated.

[0113] refer to Fig.10In V2X, the UE can synchronize directly with the Global Navigation Satellite System (GNSS). Alternatively, the UE can synchronize indirectly with the GNSS through another UE (in or out of network coverage). If GNSS is configured as the synchronization source, the UE can calculate the direct frame number (DFN) and subframe number based on the Coordinated Universal Time (UTC) and the configured (preconfigured) DFN offset.

[0114] Alternatively, the UE may be synchronized directly with the BS or may be synchronized with another UE that is synchronized with the BS in time / frequency. For example, the BS may be an eNB or a gNB. For example, when the UE is within network coverage, the UE may receive synchronization information provided by the BS and may be synchronized directly with the BS. Next, the UE may provide synchronization information to another neighboring UE. If the timing of the BS is configured as a synchronization reference, the UE may follow the cell associated with the corresponding frequency (when the UE is within the cell coverage on the frequency) or the primary cell or serving cell (when the UE is not within the cell coverage on the frequency) for synchronization and DL measurements.

[0115] The BS (e.g., serving cell) may provide a synchronization configuration of a carrier for V2X / SL communication. In this case, the UE may comply with the synchronization configuration received from the BS. If the UE fails to detect any cell in the carrier for V2X / SL communication and fails to receive a synchronization configuration from the serving cell, the UE may comply with the preset synchronization configuration.

[0116] Alternatively, the UE may synchronize with another UE that fails to directly or indirectly acquire synchronization information from the BS or GNSS. The synchronization source and preference may be preconfigured for the UE. Alternatively, the synchronization source and preference may be configured via a control message provided by the BS.

[0117] The SL synchronization source may be associated with the synchronization priority. For example, the relationship between the synchronization source and the synchronization priority may be defined as shown in Table 14 or Table 15. Table 5 or Table 6 is only an example, and the relationship between the synchronization source and the synchronization priority may be defined in various ways.

[0118] [Table 5]

[0119] Priority GNSS-based synchronization BS-based synchronization (eNB / gNB-based synchronization) P0 Global Navigation Satellite System Base Station P1 All UEs synchronize directly with GNSS All UEs synchronize directly with the BS P2 All UEs are synchronized indirectly with GNSS All UEs are synchronized with the BS indirectly P3 All other UEs Global Navigation Satellite System P4 not applicable All UEs synchronize directly with GNSS P5 not applicable All UEs are synchronized indirectly with GNSS P6 not applicable All other UEs

[0120] [Table 6]

[0121]

[0122] In Table 5 or Table 6, P0 may represent the highest priority and P6 may represent the lowest priority. In Table 5 or Table 6, the BS may include at least one of a gNB or an eNB.

[0123] It can be (pre)configured whether GNSS-based synchronization or eNB / gNB-based synchronization is used. In single carrier operation, the UE can derive its transmission timing from the available synchronization reference with the highest priority.

[0124] Hereinafter, a side link synchronization signal (SLSS) and synchronization information will be described.

[0125] As a SL specific sequence, the SLSS may include a primary side link synchronization signal (PSSS) and a secondary side link synchronization signal (SSSS). The PSSS may be referred to as a side link primary synchronization signal (S-PSS), and the SSSS may be referred to as a side link secondary synchronization signal (S-SSS). For example, an M sequence of length 127 may be used for the S-PSS, and a gold sequence of length 127 may be used for the S-SSS. For example, the UE may use the S-PSS to detect an initial signal and obtain synchronization. In addition, the UE may use the S-PSS and the S-SSS to obtain detailed synchronization and detect a synchronization signal ID.

[0126] The physical sidelink broadcast channel (PSBCH) may be a (broadcast) channel for sending default (system) information that the UE needs to know first before sending and receiving SL signals. For example, the default information may include information related to SLSS, duplex mode (DM), time division duplex (TDD) UL / DL configuration, information related to resource pools, application types related to SLSS, subframe offsets, broadcast information, etc. For example, to evaluate the PSBCH performance in NR V2X, the payload size of the PSBCH may be 56 bits, including a 24-bit CRC.

[0127] S-PSS, S-SSS, and PSBCH may be included in a block format (e.g., SL synchronization signal (SS) / PSBCH block) that supports periodic transmission (hereinafter, the SLSS / PSBCH block is referred to as a sidelink synchronization signal block (S-SSB)). The S-SSB may have the same parameter set (i.e., SCS and CP length) as the physical sidelink control channel (PSCCH) / physical sidelink shared channel (PSSCH) on the carrier, and the transmission bandwidth may exist within a configured (or preconfigured) SL BWP. For example, the S-SSB may have a bandwidth of 11 RBs. For example, the PSBCH may span 11 RBs. In addition, the frequency position of the S-SSB may be configured (preconfigured). Therefore, the UE does not need to perform hypothetical detection of the frequency to discover the S-SSB on the carrier.

[0128] The NR SL system can support multiple parameter sets with different SCSs and / or different CP lengths. In this case, as the SCS increases, the length of the time resources used by the transmitting UE to send the S-SSB can be reduced. Therefore, the coverage of the S-SSB may be reduced. Therefore, in order to ensure the coverage of the S-SSB, the transmitting UE can send one or more S-SSBs to the receiving UE within an S-SSB transmission period based on the SCS. For example, the number of S-SSBs sent by the transmitting UE to the receiving UE within one S-SSB transmission period can be pre-configured or configured for the transmitting UE. For example, the S-SSB transmission period can be 160ms. For example, an S-SSB transmission period of 160ms can be supported for all SCSs.

[0129] For example, when the SCS in FR1 is 15kHz, the transmitting UE can send one or two S-SSBs to the receiving UE in one S-SSB transmission period. For example, when the SCS in FR1 is 30kHz, the transmitting UE can send one or two S-SSBs to the receiving UE in one S-SSB transmission period. For example, when the SCS in FR1 is 60kHz, the transmitting UE can send one, two, or four S-SSBs to the receiving UE in one S-SSB transmission period.

[0130] Fig.11 A process of performing V2X or SL communication by a UE according to a transmission mode according to an embodiment of the present disclosure is illustrated. Fig.11 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure. In various embodiments of the present disclosure, the transmission mode may be referred to as a mode or a resource allocation mode. For the convenience of the following description, the transmission mode in LTE may be referred to as an LTE transmission mode, and the transmission mode in NR may be referred to as an NR resource allocation mode.

[0131] For example, Fig.11 (a) illustrates UE operation associated with LTE transmission mode 1 or LTE transmission mode 3. Or, for example, Fig.11 (a) illustrates UE operations 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.

[0132] For example, Fig.11 (b) illustrates UE operation associated with LTE transmission mode 2 or LTE transmission mode 4. Or, for example, Fig.11 (b) illustrates UE operations associated with NR resource allocation mode 2.

[0133] refer to Fig.11(a), in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, the BS may schedule SL resources to be used by the UE for SL transmission. For example, in step S8000, the BS may send information related to SL resources and / or information related to UE resources to the first UE. For example, the UL resources may include PUCCH resources and / or PUSCH resources. For example, the UL resources may be resources for reporting SL HARQ feedback to the BS.

[0134] For example, the first UE may receive information related to dynamic grant (DG) resources and / or information related to configuration grant (CG) resources from the BS. For example, the CG resources may include CG type 1 resources or CG type 2 resources. In the present specification, the DG resources may be resources that the BS configures / allocates to the first UE in downlink control information (DCI). In the present specification, the CG resources may be (periodic) resources that the BS configures / allocates to the first UE in the DCI and / or RRC message. For example, for CG type 1 resources, the BS may send an RRC message including information related to the CG resources to the first UE. For example, for CG type 2 resources, the BS may send an RRC message including information related to the CG resources to the first UE, and the BS may send a DCI for activation or release of the CG resources to the first UE.

[0135] In step S8010, the first UE may send a PSCCH (e.g., sidelink control information (SCI) or a first-level SCI) to the second UE based on resource scheduling. In step S8020, the first UE may send a PSSCH related to the PSCCH to the second UE (e.g., a second-level SCI, a MAC PDU, data, etc.). In step S8030, the first UE may receive a PSFCH related to the PSCCH / PSSCH from the second UE. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second UE via the PSFCH. In step S8040, the first UE may send / report HARQ feedback information to the BS via the PUCCH or PUSCH. For example, the HARQ feedback information reported to the BS may include information generated by the first UE based on the HARQ feedback information received from the second UE. For example, the HARQ feedback information reported to the BS may include information generated by the first UE according to a preset rule. For example, the DCI may be a DCI for scheduling of the SL. For example, the format of the DCI may include DCI format 3_0 or DCI format 3_1. Table 7 shows an example of DCI for scheduling of SL.

[0136] [Table 7]

[0137]

[0138]

[0139] refer to Fig.11 (b), in LTE transmission mode 2, LTE transmission mode 4 or NR resource allocation mode 2, the UE may determine the SL transmission resources within the SL resources configured by the BS / network or the pre-configured SL resources. For example, the configured SL resources or the pre-configured SL resources may be a resource pool. For example, the UE may select or schedule resources for SL transmission by itself. For example, the UE may perform SL communication by selecting resources by itself within the configured resource pool. For example, the UE may perform a sensing and resource (re)selection process to select resources by itself within a selection window. For example, sensing may be performed in units of subchannels. For example, in step S8010, a first UE that selects resources in a resource pool may use the resources to send a PSCCH (e.g., sidelink control information (SCI) or a first-level SCI) to a second UE. In step S8020, the first UE may send a PSSCH (e.g., a second-level SCI, a MAC PDU, data, etc.) related to the PSCCH to the second UE. In step S8030, the first UE may receive a PSFCH related to the PSCCH / PSSCH from the second UE.

[0140] refer to Fig.11 (a) or Fig.11 (b), for example, the first UE may send SCI to the second UE on the PSCCH. Or, for example, the first UE may send two consecutive SCIs (e.g., two-level SCIs) to the second UE on the PSCCH and / or PSSCH. In this case, the second UE may decode two consecutive SCIs (e.g., two-level SCIs) to receive the PSSCH from the first UE. In this specification, the SCI sent on the PSCCH may be referred to as the first SCI, the first-level SCI, or the first-level SCI format, and the SCI sent on the PSSCH may be referred to as the second SCI, the second SCI, or the second-level SCI format. For example, the first-level SCI format may include SCI format 1-A, and the second-level SCI format may include SCI format 2-A and / or SCI format 2-B. Table 8 shows an example of a first-level SCI format.

[0141] [Table 8]

[0142]

[0143]

[0144] Table 9 shows an exemplary second level SCI format.

[0145] [Table 9]

[0146]

[0147] Reference Fig.11 (a) or Fig.11 In (b), in step S8030, the first UE may receive the PSFCH based on Table 10. For example, the first UE and the second UE may determine the PSFCH resources based on Table 10, and the second UE may send HARQ feedback to the first UE on the PSFCH resources.

[0148] [Table 10]

[0149]

[0150]

[0151] Reference Fig.11 In (a), in step S8040, the first UE may send SL HARQ feedback to the BS via PUCCH and / or PUSCH based on Table 11.

[0152] [Table 11]

[0153]

[0154]

[0155] Table 12 below shows details of selection and reselection of SL relay UE defined in 3GPP TS 36.331. The content of Table 12 is used as the prior art of the present disclosure, and the relevant necessary details can be found in 3GPP TS 36.331.

[0156] [Table 12]

[0157]

[0158]

[0159] Fig.12 The connection management and the process of switching from direct to indirect path captured in the TR document (3GPP TR 38.836) related to Rel-17 NR SL are shown. The remote UE needs to establish its own PDU session / DRB with the network before user plane data transmission.

[0160] Before the remote UE establishes a Uu RRC connection with the network through the relay UE, the PC5 unicast link establishment procedure in the PC5-RRC aspect of Rel-16 NR V2X can be reused to establish a secure unicast link for L2 UE to network relay between the remote UE and the relay UE.

[0161] For both in-coverage and out-of-coverage, when the remote UE initiates the first RRC message for establishing a connection with the gNB, the PC5 L2 configuration for transmission between the remote UE and the UE to network relay UE can be based on the RLC / MAC configuration defined in the standard. The establishment of Uu SRB1 / SRB2 and DRBs for the remote UE follows the conventional Uu configuration procedure for L2 UE to network relay.

[0162] Fig.12 The high-level connection establishment procedure shown in is applied to L2 UE to network relay.

[0163] In operation S1200 , the remote UE and the relay UE may perform a discovery procedure, and in operation S1201 , establish a PC5-RRC connection based on an existing Rel-16 procedure.

[0164] In operation S1202, the remote UE may send a first RRC message (i.e., an RRC setup request (RRCSetupRequest)) for connection establishment with the gNB through the relay UE by using the default L2 configuration of PC5. The gNB responds to the remote UE with an RRC setup (RRCSetup) message (S1203). The transmission of the RRCSetup to the remote UE uses the default configuration of PC5. When the relay UE is not started in RRC_CONNECTED, the relay UE needs to perform its own connection setup after receiving a message about the default L2 configuration of PC5. In this operation, the details of the relay UE sending the RRCSetupRequest / RRCSetup message to the remote UE can be discussed in stage WI.

[0165] In operation S1204, the gNB and the relay UE perform a relay channel setup procedure via Uu. According to the configuration of the gNB, the relay / remote UE establishes an RLC channel for relaying SRB1 with the remote UE via PC5. In this operation, a relay channel for SRB1 is prepared.

[0166] In operation S1205, a remote UE SRB1 message (e.g., RRC Setup Complete message) is sent to the gNB via the relay UE using the SRB1 relay channel via PC5. The remote UE performs an RRC connection via Uu.

[0167] In operation S1206, the remote UE and the gNB configure security according to conventional procedures, and send a security message through the relay UE.

[0168] In operation S1210, the gNB configures an additional RLC channel between the gNB and the relay UE for service relay. According to the configuration of the gNB, the relay / remote UE configures an RLC channel between the remote UE and the relay UE for service relay. The gNB sends an RRC reconfiguration (RRCReconfiguration) to the remote UE through the relay UE to configure the relay SRB2 / DRB. The remote UE responds to the gNB sending an RRC reconfiguration completion (RRCReconfigurationComplete) through the relay UE.

[0169] For L2 UE to network relay except the connection establishment procedure:

[0170] -RRC reconfiguration and RRC disconnection procedures can reuse the traditional RRC procedures, where the message content / configuration design is left to phase WI.

[0171] -RRC connection reconfiguration and RRC connection recovery procedures can reuse existing RRC procedures as a baseline by considering the above L2 UE to network relay connection establishment procedure to handle the relay specific parts along with the message content / configuration design. The message content / configuration can be defined later.

[0172] Fig.13 Direct to indirect path switching is illustrated. For service continuity of L2 UE to network relay, when remote UE switches to indirect relay UE, Fig.13 process.

[0173] Reference Fig.13 In operation S1301, the remote UE measures / discovers candidate relay UEs and then reports one or more candidate relay UEs. The remote UE may filter out appropriate relay UEs that meet higher layer criteria during reporting. The report may include the ID and SL RSRP information of the relay UE, in which case the PC5 measurement details may be determined later.

[0174] In operation S1302, the gNB determines to switch to a target relay UE and optionally sends a target (re)configuration to the relay UE.

[0175] In operation S1304, the RRC reconfiguration message for the remote UE may include the ID of the target relay UE, the target Uu, and the PC5 configuration.

[0176] In operation S1305 , when the connection is not established, the remote UE establishes a PC5 connection with the target relay UE.

[0177] In operation S1306, the remote UE feeds back RRCReconfigurationComplete to the gNB via the target path by using the target configuration provided in RRCReconfiguration.

[0178] In operation S1307 , the data path is switched.

[0179] The contents of Tables 13 to 18 are disclosed in the standard document 3GPP TS 38.423 related to handover, and are used as the prior art of the present disclosure. Figure 8 .2.1.2-1 corresponds to Fig.14 , and other references refer to the above standard document 3GPPTS 38.423.

[0180] [Table 13]

[0181]

[0182]

[0183] [Table 14]

[0184]

[0185]

[0186] [Table 15]

[0187]

[0188]

[0189] [Table 16]

[0190]

[0191]

[0192]

[0193] [Table 17]

[0194]

[0195] [Table 18]

[0196]

[0197] Based on Tables 13 to 18, the general handover (HO) process of the UE is described as follows. The UE reports the Uu link measurement results (the Uu link signal strength of its serving cell and the Uu link signal strength of the surrounding neighbor cells) to the base station, and the base station selects the target cell using the reported measurement results. The serving base station (serving gNB) can send a HO request to the target base station (target gNB) to which the target cell belongs. If the target gNB allows HO, the target gNB sends an RRCReconfiguration (withSync) message for HO through the serving gNB.

[0198] The following Table 19 is the “New Rel-18 WID regarding NR sidelink relay enhancement” and corresponds to the prior art of the present disclosure.

[0199] [Table 19]

[0200]

[0201] The relay operation being prepared in 3GPP NR Rel-18 allows the remote UE to activate both the direct path and the indirect path through the relay UE. In this case, the connection between the remote UE and the relay UE can be SL or an ideal link.

[0202] In multipath operation, the RRC state of the relay UE selected by the remote UE may be an RRC IDLE / INACTIVE / CONNECTED state. When a remote UE (and / or a serving gNB of the remote UE) with a direct (and / or indirect) link determines a relay UE for establishing a SL connection, the selected relay UE may be in an RRC IDLE / INACTIVE state. Before establishing a SL connection with the remote UE, the relay UE may enter a CONNECTED state (and / or perform a RACH process) where the cell (and / or gNB) is different from the cell (and / or gNB) previously indicated as the resident cell (and / or gNB) via a discovery message. Alternatively, a relay UE in an RRC IDLE / INACTIVE state may establish an SL connection with the remote UE, which may trigger the relay UE to enter an RRC_CONNECTED state. In this case, if the relay UE that is triggered to enter the RRC_CONNECTED state is connected to a cell (and / or gNB) different from the cell (and / or gNB) previously broadcast via a discovery message, a discussion may be raised about how the remote UE operates.

[0203] Therefore, the present disclosure describes a method for solving the above-mentioned problems that may occur during the process of a remote UE having a direct / indirect link establishing a multi-path relay connection with a relay UE in an RRC IDLE / INACTIVE state.

[0204] There may be a situation where a remote UE with a direct (and / or indirect) link establishes a SL connection with a relay UE in RRC_IDLE / INACTIVE state. When specific conditions are triggered according to the measurement configuration of the gNB, the remote UE with a direct / indirect link can report the ID, cell ID, sidelink reference signal received power (SD-RSRP) and RRC state of the surrounding candidate relay UEs to its serving gNB (serving cell) when these conditions are triggered. Upon receiving this information, the serving gNB of the remote UE can select a relay UE and notify the remote UE of the relay UE. The selected relay UE can be in RRC_CONNECTED, IDLE or INACTIVE state. This operation may be necessary for the remote UE to configure an indirect link to establish multipath relay operation or to perform HO via an indirect link.

[0205] In one embodiment, the remote UE may report the measurement results for the candidate relay UE to the gNB ( Fig.15 The remote UE may receive an RRCReconfiguration message including a target relay UE ID from the gNB (S1502). In response, the remote UE may attempt to establish a PC5 connection with the target relay UE (S1503).

[0206] Based on the remote UE knowing that the camping cell of the target relay UE has changed or the target relay UE has performed cell reselection during the RRC connection through the discovery message sent by the candidate relay UE, the remote UE may send information notifying the gNB that the camping cell of the target relay UE has changed. Based on the remote UE knowing that the camping cell of the target relay UE has changed or the target relay UE has performed cell reselection during the RRC connection through the discovery message sent by the candidate relay UE, the remote UE may omit triggering RRC reestablishment.

[0207] Based on the remote UE learning through the discovery message sent by the candidate relay UE that the target relay UE's camped cell has changed or the target relay UE has performed cell reselection during the RRC connection, the remote UE may report a new candidate relay UE to the gNB.

[0208] In other words, when the remote UE receives a command for multipath (and / or HO) operation from its serving gNB, and when the remote UE detects that the cell (gNB) ID of the relay UE has changed from the previous cell (gNB) ID (e.g., the cell (gNB) ID of the relay UE when performing measurement reporting), the remote UE may report the change to its current serving gNB without triggering RRC re-establishment. In addition, the remote UE may discover new candidate relay UEs and report them to the gNB.

[0209] The target relay UE may be in RRC IDLE / INACTIVE state. In other words, before the relay UE establishes a SL connection with the remote UE, the relay UE may access (RACH) a cell (and / or gNB) different from the cell previously indicated as the resident cell via the discovery message and enter the RRC_CONNECTED state. Alternatively, the resident cell of the relay UE in IDLE / INACTIVE state may change.

[0210] The discovery message may be received after reporting the measurement result. In this regard, when the ID of the selected relay UE when reporting the measurement result is different from the ID of the candidate relay UE included in the discovery message, a change in the target relay UE's camped cell or a cell reselection performed by the target relay UE during the RRC connection may occur.

[0211] In addition, if the remote UE establishes a SL connection for relay purposes before the relay UE broadcasts the newly changed cell (and / or gNB) via a discovery message, the relay UE may expect that the remote UE is unaware of the changed cell (and / or gNB) of the relay UE and sends a rejection (and / or RRCReconfigurationFailure) message regarding the remote UE's SL connection. In this case, a cause value may be used to indicate that the cell (and / or gNB) has changed from the previous cell (and / or gNB). In addition, the message used in this case 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 (for connections with multipath relays), or where the remote UE performs a HO from a direct / indirect link to an indirect link. In cases where the operation is limited, the remote UE may indicate that the SL connection is established with the relay UE for the purpose of multipath relaying or performing a HO via an indirect link.

[0212] When the relay UE notifies the cell (and / or gNB) ID change from the previous cell via a discovery message, if the remote UE subsequently attempts to establish a SL connection, it can be assumed that the remote UE knows the new cell (and / or gNB) ID of the relay UE. In this case, the relay UE can establish a SL connection with the remote UE. This is because it can be assumed that the remote UE already knows the cell (and / or gNB) ID change of the relay UE.

[0213] When establishing a SL connection (PC5-S / RRC) with a relay UE in IDLE / INACTIVE state for SL multipath (or HO) purposes, the remote UE with a direct / indirect link may inform the relay UE of its current cell (and / or gNB) ID. The relay UE may reject the SL connection with the remote UE if the cell (and / or gNB) ID of the remote UE is different from the cell / gNB value where the relay UE is currently residing (or the serving cell if the relay UE is in RRC_CONNECTED state).

[0214] Based on the remote UE's knowledge that the target relay UE's resident cell has changed after establishing a PC connection with the target relay UE, the remote UE may release the PC5 connection with the target relay UE. This may correspond to the following situation: the remote UE has established a SL connection with the relay UE selected by the gNB for multipath (and / or HO) purposes, but the relay UE has entered the RRC_CONNECTED state by accessing (RACH) a cell (and / or gNB) different from the cell (and / or gNB) previously indicated as the resident cell by the discovery message. In this case, the remote UE may report to the gNB that the cell (and / or gNB) ID value of the relay UE determined by the serving gNB has changed without triggering RRC re-establishment. Alternatively, the remote UE may notify the serving gNB of the SL connection failure. This operation is different from the previous situation, in which RRC re-establishment is always performed after the handover failure due to disconnection from the existing cell caused by the handover command. In the present disclosure, the remote UE may perform RRC re-establishment.

[0215] If the remote UE activated the indirect link through the relay UE, the remote UE may deactivate the indirect link. Alternatively, the remote UE may release the SL connection with the relay UE and report it to the gNB as SL RLF. Since the SL connection is released, the remote UE may also report it as SUI.

[0216] Alternatively, until a release command for the indirect link is received from the gNB, the remote UE may deactivate the indirect connection and wait for an RRCReconfiguration message from the gNB. In addition, the remote UE may discover a new relay UE and report the new relay UE.

[0217] The order of operations is as follows: the remote UE may deactivate the indirect link, discover a new relay UE, and report the new relay UE to the gNB. Alternatively, after deactivating the indirect link, the remote UE may report a failure (RLF) to the gNB and then discover a new relay UE (and / or report a new candidate relay UE).

[0218] Alternatively, if the serving / target gNB of the relay UE does not establish a connection with the selected relay UE after a certain period of time, the serving / target gNB may send an RRCReconfiguration message to the remote UE to select a new relay UE and notify the new relay UE or release the connection with the current relay UE. For example, when the gNB selects a relay UE for multipath relay operation but does not receive a connection from the selected relay UE after a certain period of time, the gNB may configure a new RRCReconfiguration message for the remote UE. In the case of HO, if the target cell does not receive a connection from the relay UE to which a connection should be established, the target cell may notify the serving gNB, and the serving gNB may select a different relay UE and continue the HO process. That is, the serving gNB may decide to perform a HO to the newly selected relay UE and send a HO request to the target cell of the determined relay UE.

[0219] When the remote UE receives a configuration to establish a SL connection with a relay UE selected by the gNB for multipath (and / or HO) purposes, and when the remote UE attempts to establish the SL connection but fails, that is, if the remote UE fails to establish a SL connection with the relay UE assigned by the serving gNB for multipath (and / or HO) purposes, the remote UE may perform RRC re-establishment.

[0220] Alternatively, the remote UE may report to the gNB that the remote UE failed to establish a SL connection with the relay UE without triggering RRC re-establishment. If the relay UE provides a reason for rejecting the SL connection as a cause value, the remote UE may report the cause to the gNB. In addition, if the remote UE detects that the cell (gNB) ID value included in the discovery message from the relay UE is different from the value used in the measurement report of the relay UE's previous serving gNB, the remote UE may report to the gNB the change in the cell (and / or gNB) ID value of the selected relay UE without establishing a SL connection with the relay UE determined by the serving gNB.

[0221] According to the present disclosure, the remote UE can quickly establish a new indirect link by performing appropriate operations.

[0222] In the above method, an indirect link for a remote UE has been described, and the relay UE is selected by the serving gNB of the remote UE. However, the same operation can also be applied in the case where the serving gNB sends information about candidate relay UEs to the target gNB and the final relay UE is selected by the target gNB.

[0223] The above method can also be similarly applied when the remote UE receives a notification message from the relay UE. In this case, the notification message can refer to a message delivered by the relay UE to the remote UE in the rel-17 relay operation (3GPP TS38.331). Alternatively, when the remote UE detects a SL RLF, the method can also be similarly applied.

[0224] For example,

[0225] (Option 1) When the remote UE performs multipath relay operation, the remote UE may report the notification / SL-RLF to the gNB without triggering re-establishment.

[0226] (Option 2) The remote UE may deactivate the indirect link (and / or connection) with the relay UE. In multipath relay operation, the remote UE and the relay UE belong to the same gNB. Therefore, when a notification message is sent from the relay UE to the remote UE, the gNB can be informed of the situation of the relay UE even if the remote UE does not report separately. Therefore, the gNB may receive a new RRCReconfiguration message for releasing the indirect link. However, the remote UE may deactivate the indirect link before receiving a new RRCReconfiguration message from the gNB and expects a new RRCReconfiguration message to be sent from the gNB.

[0227] (Option 3) In this case, the remote UE can autonomously release the indirect link even without a command from the gNB.

[0228] (Option 4) The remote UE may discover a new candidate relay UE and report the new candidate relay UE to the gNB together with the measurement results. In other words, this situation may trigger an event for measurement and reporting.

[0229] (Option 5) Since the remote UE and the relay UE are connected to the same gNB, it is assumed that the gNB is aware of the situation of the remote UE and waits to receive a new RRCReconfiguration message. However, even in this case, the SL RLF needs to be reported. If the remote UE does not receive a new RRCReconfiguration message from the gNB within a specific time period after receiving a notification or reporting SL RLF from the relay UE, the remote UE can trigger RRC re-establishment. A separate timer for a specific time period may be required. For example, when the remote UE receives a notification or reporting SL RLF from the relay UE, the timer can be started, and once a new RRCReconfiguration message is received, the timer can be stopped. In addition, if the timer expires, RRC re-establishment can be performed.

[0230] The above proposed options may be applied in combination. For example, the remote UE may deactivate the indirect link without triggering re-establishment, report the failure to the gNB, discover a new candidate relay UE, and report the new candidate relay UE to the gNB. Alternatively, the remote UE may discover a new candidate relay UE and report the new candidate relay UE to the gNB without triggering re-establishment.

[0231] With respect to the above description, the remote UE may include: at least one processor; and at least one computer memory, the at least one computer memory being operatively connected to the at least one processor, and the at least one computer memory being configured to store instructions, which, when executed, cause the at least one processor to perform operations. The operations may include: the remote UE reporting measurement results for the candidate relay UE to the gNB; the remote UE receiving an RRCReconfiguration message including an ID of the target relay UE from the gNB; and the remote UE attempting to establish a PC5 connection with the target relay UE. Based on the remote UE learning that the target relay UE's resident cell has changed through a discovery message sent by the candidate relay UE or that the target relay UE has performed a cell reselection during the RRC connection, the remote UE may send information to the gNB notifying the target relay UE of the resident cell change.

[0232] In addition, a non-transitory computer-readable storage medium is provided, which is configured to store at least one computer program, the 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. These operations may include: reporting, by the remote UE, measurement results for a candidate relay UE to a gNB; receiving, by the remote UE, an RRCReconfiguration message including an ID of a target relay UE from a gNB; and attempting, by the remote UE, to establish a PC5 connection with the target relay UE. Based on the remote UE learning, through a discovery message sent by the candidate relay UE, that the target relay UE's resident cell has changed or that the target relay UE has performed a cell reselection during an RRC connection, the remote UE may send information to the gNB notifying the target relay UE of a resident cell change.

[0233] In addition, a method for operating a relay UE is provided. The method may include the following steps: the relay UE sends a discovery message; and the relay UE receives a PC5 message for a multipath connection from a remote UE. Based on the fact that the camping cell of the relay UE when sending the discovery message is different from the camping cell of the relay UE when receiving the PC5 message or the RRC connection cell when receiving the PC5 message, the relay UE may reject the SL connection request related to the multipath connection from the remote UE, and the remote UE may send information notifying the target relay UE of the change of the camping cell to the gNB.

[0234] In addition, a relay UE is provided. The relay UE may include: at least one processor; and at least one computer memory, the at least one computer memory is operatively connected to the at least one processor, and the at least one computer memory is configured to store instructions, which, when executed, cause the at least one processor to perform operations. These operations may include: sending a discovery message; and receiving a PC5 message for a multipath connection from a remote UE. Based on the fact that the resident cell of the relay UE when sending the discovery message is different from the resident cell of the relay UE when receiving the PC5 message or the RRC connection cell when receiving the PC5 message, the relay UE may reject the SL connection request related to the multipath connection from the remote UE, and the remote UE may send information to the gNB notifying the target relay UE of the change of the resident cell.

[0235] In multipath operation, if the remote UE has a direct link, the remote UE can establish a new connection via an indirect link. In this case, the remote UE reports information about the candidate relay UE (e.g., the ID of the candidate relay UE, measurement values ​​(such as SD-RSRP, UuRSRP of the remote / relay UE), the serving cell / resident cell ID of the relay UE, PLMNID, etc.) to the serving gNB via a direct link. The serving gNB can provide the remote UE with one or more relay lists among the candidate relay UEs via a direct link. The lists can be sent via an RRCReconfiguration message. Upon receiving these lists, the remote UE establishes a SL connection with the relay UE included in the RRCReconfiguration message. The remote UE can send an RRCReconfigurationComplete message to the serving gNB (serving gNB or serving cell) via an indirect link via the relay UE.

[0236] Regarding HO operation for a remote UE, the remote UE may have both a direct link and an indirect link at the same time. When a remote UE with a direct / indirect link accesses a target gNB (target gNB or target cell) through a direct / indirect link, the remote UE may operate in a manner similar to the multipath operation described previously. The remote UE may report candidate relay UEs to its serving gNB and receive an RRCReconfiguration message related to HO from the serving gNB. The remote UE may establish a SL connection with the relay UE included in the RRCReconfiguration message and send an RRCReconfigurationComplete message via the relay UE over an indirect link.

[0237] The RRC state of the relay UE, which may be selected by the serving gNB and / or the target gNB of the remote UE, may be IDLE / INACTIVE / CONNECTED state. When the RRC state of the relay UE is in the RRC_CONNECTED state, the serving gNB of the remote UE may pre-configure the configuration of the indirect link between the remote UE and the relay UE. For example, when performing RRC reconfiguration related to multipath (and / or HO) for the remote UE, the serving gNB of the remote UE may configure the configuration (e.g., bearer mapping) of the indirect link between the remote UE and the relay UE in the RRC_CONNECTED state.

[0238] However, when the relay UE prepares configuration for an indirect connection of a remote UE, if the remote UE fails to establish a SL connection or if a SL connection is not established with the relay UE for any other reason, the operation of the relay UE may need to be specified. Hereinafter, the operation of the relay UE in this case will be described.

[0239] In a multipath (and / or handover) operation, when a relay UE selected by a serving gNB and / or a target gNB of a remote UE is in an RRC_CONNECTED state, and the serving gNB and / or the target gNB performs RRC reconfiguration with the relay UE for the remote UE (i.e., when RRC reconfiguration is configured for a remote UE for which a SL connection has not yet been established), there are the following possible implementations:

[0240] (Option 1) After completing the SL connection with the (intended) remote UE included in the RRCReconfiguration message, the relay UE sends an RRCReconfigurationComplete message to the gNB. Alternatively, after receiving an RRCReconfigurationComplete message indicating completion of the multipath (and / or handover) operation from the (intended) remote UE, the relay UE sends an RRCReconfigurationComplete message to the gNB indicating that the relay UE received the configuration for the remote UE. If the relay UE fails to establish a SL connection with the intended remote UE, or does not receive the RRCReconfigurationComplete message from the remote UE, the relay UE reports the failure to the gNB.

[0241] In this case, the relay UE may send only a completion / failure message for a portion of the configuration to the (serving / target) gNB. For example, if the relay UE does not receive a SL Connect or RRCReconfigurationComplete message from the remote UE to which it plans to connect, the relay UE may send only a completion message for the remaining configuration except for the configuration related to the remote UE. Alternatively, the relay UE may send only a failure message for the configuration related to the remote UE and follow the remaining configuration.

[0242] (Option 2) Regardless of whether the relay UE has established a connection with the intended remote UE, if the relay UE receives an RRCReconfiguration message for the intended remote UE, the relay UE may send an RRCReconfigurationComplete message to the gNB. If the gNB maintains a timer for the remote UE and does not receive an RRCReconfigurationComplete message from the remote UE by the relay UE before the timer expires, the gNB releases the configuration associated with the intended remote UE. The relay UE expects the gNB to process the release operation and does not perform any operation.

[0243] (Option 3) When the relay UE receives the configuration for the intended remote UE from the gNB, the relay UE may start a timer (e.g., T304, T304-like, T420, T420-like, T400, etc.) expected to run on the remote UE. Even if the timer expires, if the SL connection with the intended remote UE is not established (or completed) (and / or if the relay UE does not receive the RRCReconfigurationComplete message from the remote UE), the relay UE may notify the gNB of the SL connection. Alternatively, the relay UE sends an RRCReconfiguration Failure message related to the intended remote UE to the gNB.

[0244] In a multipath (and / or handover) operation, if the relay UE selected by the remote UE’s serving gNB and / or target gNB is in RRC_IDLE / INACTIVE state, and if the relay UE performs a connection establishment procedure for the multipath (and / or handover) operation but does not access the target gNB (in the case of multipath operation, the target gNB may be the remote UE’s serving gNB),

[0245] If the remote UE sends an RRCReconfigurationComplete message to the base station to which the relay UE is connected (the serving gNB of the relay UE) through the relay UE, the serving gNB of the relay UE may not recognize the RRCReconfigurationComplete message sent by the remote UE. This is because the RRCReconfigurationComplete message sent by the remote UE through the relay UE may be a security-related encrypted message (which the target gNB may not be able to decrypt). Therefore, if unreadable (or undecodable) data is sent through the relay UE, the serving gNB of the relay UE may send a command to the relay UE to release the SL connection with the remote UE. Upon receiving the command, the relay UE may release the SL connection with the remote UE.

[0246] The present disclosure proposes a condition for stopping a multipath (and / or handover) timer when a remote UE performs a multipath (and / or handover) related operation and an application of a timer when direct and indirect link configurations are allowed. Therefore, the timer operation and multipath (and / or handover) operation of the remote UE can be performed efficiently.

[0247] Examples of communication systems suitable for the present disclosure

[0248] The various descriptions, functions, processes, proposals, methods and / or operational flowcharts of the present disclosure described in this document may be applied to, without limitation, various fields requiring wireless communication / connection between devices (e.g., 5G).

[0249] Hereinafter, a description will be given in more detail with reference to the accompanying drawings. In the following drawings / descriptions, unless otherwise described, the same reference numerals may represent the same or corresponding hardware blocks, software blocks or functional blocks.

[0250] Fig.16 A communication system 1 applied to the present disclosure is illustrated.

[0251] Reference Fig.16, the communication system 1 applied to the present disclosure includes a wireless device, a BS, and a network. Herein, a wireless device refers to a device that performs communication using a RAT (e.g., 5G NR or LTE), and may be referred to as a communication / radio / 5G device. The wireless device may include, but is not limited to, a robot 100a, a vehicle 100b-1 and 100b-2, an extended reality (XR) device 100c, a handheld device 100d, a home appliance 100e, an Internet of Things (IoT) device 100f, and an artificial intelligence (AI) device / server 400. For example, a vehicle may include a vehicle with a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing inter-vehicle communication. Herein, a vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device may include an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) installed in a vehicle, a television, a smart phone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, and the like. Handheld devices may include smart phones, smart boards, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., notebooks). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters. For example, a BS and a network may be implemented as wireless devices, and a specific wireless device 200a may operate as a BS / network node relative to other wireless devices.

[0252] The wireless devices 100a to 100f may be connected to the network 300 via the BS 200. AI technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI ​​server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100a to 100f may communicate with each other via the BS 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., side link communication) with each other without passing through the BS / network. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., V2V / V2X communication). An IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., a sensor) or other wireless devices 100a to 100f.

[0253] Wireless communication / connection 150a, 150b or 150c can be established between wireless devices 100a to 100f / BS200 or BS200 / BS200. Herein, wireless communication / connection can be established through various RATs (e.g., 5G NR) such as UL / DL communication 150a, side link communication 150b (or D2D communication) or inter-BS communication (e.g., relay, integrated access backhaul (IAB)). The wireless device and the BS / wireless device can send / receive radio signals to each other through wireless communication / connection 150a and 150b. For example, wireless communication / connection 150a and 150b can send / receive signals through various physical channels. To this end, various configuration information configuration processes for sending / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping) and at least a part of the resource allocation process can be performed based on various proposals of the present disclosure.

[0254] Examples of wireless devices suitable for the present disclosure

[0255] Fig.17 A wireless device suitable for use with the present disclosure is illustrated.

[0256] Reference Fig.17 , the first wireless device 100 and the second wireless device 200 may transmit radio signals through various RATs (e.g., LTE and NR). Herein, {the first wireless device 100 and the second wireless device 200} may correspond to Fig.16 {wireless device 100x and BS200} and / or {wireless device 100x and wireless device 100x} in.

[0257] The first wireless device 100 may include one or more processors 102 and one or more memories 104, and further include one or more transceivers 106 and / or one or more antennas (antenna units) 108. The processor 102 may control the memory 104 and / or the transceiver 106, and may be configured to implement the descriptions, functions, processes, proposals, methods and / or operational flow charts disclosed herein. For example, the processor 102 may process the information in the memory 104 to generate first information / signals, and then transmit a radio signal including the first information / signals through the transceiver 106. The processor 102 may receive a radio signal including second information / signals through the transceiver 106, and then store information obtained by processing the second information / signals in the memory 104. The memory 104 may be connected to the processor 102, and may store various information related to the operation of the processor 102. For example, the memory 104 may store software codes including commands for executing part or all of the processing controlled by the processor 102 or for executing the descriptions, functions, processes, proposals, methods, and / or operational flowcharts disclosed herein. Herein, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and / or receive radio signals through one or more antennas 108. Each of the transceivers 106 may include a transmitter and / or a receiver. The transceiver 106 may be used interchangeably with (one or more) radio frequency (RF) units. In the present disclosure, a wireless device may represent a communication modem / circuit / chip.

[0258] The second wireless device 200 may include one or more processors 202 and one or more memories 204, and further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206, and may be configured to implement the description, functions, processes, proposals, methods, and / or operation flowcharts disclosed herein. For example, the processor 202 may process the information in the memory 204 to generate third information / signals, and then transmit a radio signal including the third information / signals through the transceiver 206. The processor 202 may receive a radio signal including fourth information / signals through the transceiver 106, and then store information obtained by processing the fourth information / signals in the memory 204. The memory 204 may be connected to the processor 202, and may store various information related to the operation of the processor 202. For example, the memory 204 may store software codes including commands for executing part or all of the processing controlled by the processor 202 or for executing the description, functions, processes, proposals, methods, and / or operation flowcharts disclosed herein. Herein, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and / or receive radio signals through one or more antennas 208. Each of the transceivers 206 may include a transmitter and / or a receiver. The transceiver 206 may be used interchangeably with an RF unit. In the present disclosure, a wireless device may represent a communication modem / circuit / chip.

[0259] Hereinafter, the hardware elements of the wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by one or more processors 102 and 202 without limitation. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). One or more processors 102 and 202 may generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the descriptions, functions, processes, proposals, methods, and / or operational flow diagrams disclosed herein. One or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operational flows disclosed herein. One or more processors 102 and 202 may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the description, functions, procedures, proposals, methods, and / or operational flow diagrams disclosed herein, and provide the generated signal to one or more transceivers 106 and 206. One or more processors 102 and 202 may receive a signal (e.g., a baseband signal) from one or more transceivers 106 and 206 and obtain the PDU, SDU, message, control information, data, or information according to the description, functions, procedures, proposals, methods, and / or operational flow diagrams disclosed herein.

[0260] One or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 102 and 202. Firmware or software may be used to implement the description, function, process, proposal, method, and / or operational flow chart disclosed herein, and the firmware or software may be configured to include modules, processes, or functions. Firmware or software configured to perform the description, function, process, proposal, method, and / or operational flow chart disclosed herein may be included in one or more processors 102 and 202 or stored in one or more memories 104 and 204 so as to be driven by one or more processors 102 and 202. The descriptions, functions, processes, proposals, methods and / or operational flows disclosed herein may be implemented using firmware or software in the form of codes, commands and / or command sets.

[0261] One or more memories 104 and 204 may be connected to one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, codes, instructions and / or commands. One or more memories 104 and 204 may be composed of read-only memory (ROM), random access memory (RAM), electrically erasable programmable read-only memory (EPROM), flash memory, hard drive, register, cache memory, computer-readable storage medium and / or a combination thereof. One or more memories 104 and 204 may be located inside and / or outside of one or more processors 102 and 202. One or more memories 104 and 204 may be connected to one or more processors 102 and 202 by respective technologies such as wired or wireless connections.

[0262] One or more transceivers 106 and 206 can send the user data, control information and / or radio signal / channel mentioned in the method and / or operation flow chart of this article to one or more other devices. One or more transceivers 106 and 206 can receive the user data, control information and / or radio signal / channel mentioned in the description, function, process, proposal, method and / or operation flow chart disclosed in this article from one or more other devices. For example, one or more transceivers 106 and 206 can be connected to one or more processors 102 and 202, and send and receive radio signals. For example, one or more processors 102 and 202 can perform control so that one or more transceivers 106 and 206 can send user data, control information or radio signal to one or more other devices. One or more processors 102 and 202 can perform control so that one or more transceivers 106 and 206 can receive user data, control information or radio signal from one or more other devices. One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208, and one or more transceivers 106 and 206 may be configured to send and receive user data, control information, and / or radio signals / channels mentioned in the description, functions, processes, proposals, methods, and / or operation flow charts disclosed herein through one or more antennas 108 and 208. In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106 and 206 may convert received radio signals / channels, etc. from RF band signals into baseband signals so as to process received user data, control information, radio signals / channels, etc. using one or more processors 102 and 202. One or more transceivers 106 and 206 may convert user data, control information, radio signals / channels, etc. processed using one or more processors 102 and 202 from baseband signals into RF band signals. To this end, one or more of the transceivers 106 and 206 may include (analog) oscillators and / or filters.

[0263] Examples of vehicles or autonomous vehicles suitable for the present disclosure

[0264] Fig.18 The vehicle or autonomous driving vehicle applied to the present disclosure is illustrated. The vehicle or autonomous driving vehicle can be realized by a mobile robot, a car, a train, a manned / unmanned aerial vehicle (AV), a ship, etc.

[0265] Reference Fig.18The vehicle or autonomous driving vehicle 100 may include an antenna unit 108, a communication unit 110, a control unit 120, a driving unit 140a, a power supply unit 140b, a sensor unit 140c, and an autonomous driving unit 140d. The antenna unit 108 may be configured as a part of the communication unit 110.

[0266] The communication unit 110 may send signals (e.g., data and control signals) to and receive signals from external devices such as other vehicles, BSs (e.g., gNBs and roadside units), and servers. The control unit 120 may perform various operations by controlling elements of the vehicle or autonomous driving vehicle 100. The control unit 120 may include an ECU. The drive unit 140a may enable the vehicle or autonomous driving vehicle 100 to travel on a road. The drive unit 140a may include an engine, a motor, a powertrain, wheels, brakes, a steering device, and the like. The power supply unit 140b may supply power to the vehicle or autonomous driving vehicle 100 and include a wired / wireless charging circuit, a battery, and the like. The sensor unit 140c may acquire vehicle status, surrounding environment information, user information, and the like. The sensor unit 140c may include an inertial measurement unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a slope sensor, a weight 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 illumination sensor, a pedal position sensor, etc. The autonomous driving unit 140d may implement a technology for maintaining a lane on which the vehicle is driving, a technology for automatically adjusting a speed such as an adaptive cruise control, a technology for autonomous driving along a determined path, a technology for driving by automatically setting a path when a destination is set, and the like.

[0267] For example, the communication unit 110 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140d may generate an autonomous driving path and a driving plan from the obtained data. The control unit 120 may control the drive unit 140a so that the vehicle or the autonomous driving vehicle 100 may move along the autonomous driving path according to the driving plan (e.g., speed / direction control). In autonomous driving, the communication unit 110 may obtain the latest traffic information data from the external server irregularly / regularly, and may obtain surrounding traffic information data from neighboring vehicles. In autonomous driving, the sensor unit 140c may obtain vehicle status and / or surrounding environment information. The autonomous driving unit 140d may update the autonomous driving path and driving plan based on the newly obtained data / information. The communication unit 110 may transmit information about the vehicle position, autonomous driving path, and / or driving plan to an external server. The external server may predict traffic information data based on information collected from the vehicle or autonomous driving vehicle, using AI technology, etc., and provide the predicted traffic information data to the vehicle or autonomous driving vehicle.

[0268] Examples of Vehicles and AR / VR Applicable to the Disclosure

[0269] Fig.19 The vehicle applied to the present disclosure is exemplified. The vehicle can be implemented as a transportation tool, an aircraft, a ship, etc.

[0270] Reference Fig.19 , the vehicle 100 may include a communication unit 110, a control unit 120, a storage unit 130, an I / O unit 140a, and a positioning unit 140b.

[0271] The communication unit 110 may send signals (e.g., data and control signals) to and receive signals from external devices such as other vehicles or BSs. The control unit 120 may perform various operations by controlling the constituent elements of the vehicle 100. The storage unit 130 may store data / parameters / programs / codes / commands for supporting various functions of the vehicle 100. The I / O unit 140a may output AR / VR objects based on the information in the storage unit 130. The I / O unit 140a may include a HUD. The positioning unit 140b may obtain information about the location of the vehicle 100. The location information may include information about the absolute position of the vehicle 100, information about the position of the vehicle 100 in the driving lane, acceleration information, and information about the position of the vehicle 100 relative to neighboring vehicles. The positioning unit 140b may include a GPS and various sensors.

[0272] As an example, the communication unit 110 of the vehicle 100 may receive map information and traffic information from an external server, and store the received information in the storage unit 130. The positioning unit 140b may obtain vehicle location information through GPS and various sensors, and store the obtained information in the storage unit 130. The control unit 120 may generate a virtual object based on the map information, traffic information, and vehicle location information, and the I / O unit 140a may display the generated virtual object in a window (1410 and 1420) in the vehicle. The control unit 120 may determine whether the vehicle 100 is driving normally in the driving lane based on the vehicle location information. If the vehicle 100 leaves the driving lane abnormally, the control unit 120 may display a warning on a window in the vehicle through the I / O unit 140a. In addition, the control unit 120 may broadcast a warning message about driving abnormality to neighboring vehicles through the communication unit 110. Depending on the situation, the control unit 120 may send the vehicle location information and information about driving / vehicle abnormality to a relevant organization.

[0273] Examples of XR Devices Suitable for the Present Disclosure

[0274] Fig. 20 The XR device applied to the present disclosure is illustrated. The XR device can be implemented by HMD, HUD installed in a vehicle, TV, smart phone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc.

[0275] Reference Fig. 20 , the XR device 100a may include a communication unit 110, a control unit 120, a storage unit 130, an I / O unit 140a, a sensor unit 140b, and a power supply unit 140c.

[0276] The communication unit 110 may send signals (e.g., media data and control signals) to and receive signals from external devices such as other wireless devices, handheld devices, or media servers. The media data may include video, images, and sounds. The control unit 120 may perform various operations by controlling the constituent elements of the XR device 100a. For example, the control unit 120 may be configured to control and / or perform processes such as video / image acquisition, (video / image) encoding, and metadata generation and processing. The storage unit 130 may store data / parameters / programs / codes / commands required to drive the XR device 100a / generate an XR object. The I / O unit 140a may obtain control information and data from the outside and output the generated XR object. The I / O unit 140a may include a camera, a microphone, a user input unit, a display unit, a speaker, and / or a tactile module. The sensor unit 140b may obtain the XR device status, surrounding environment information, user information, and the like. The sensor unit 140b may include a proximity sensor, an illumination 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. The power supply unit 140c may supply power to the XR device 100a and include a wired / wireless charging circuit, a battery, and the like.

[0277] For example, the storage unit 130 of the XR device 100a may include information (e.g., data) required to generate an XR object (e.g., an AR / VR / MR object). The I / O unit 140a may receive a command for manipulating the XR device 100a from a user, and the control unit 120 may drive the XR device 100a according to the user's drive command. For example, when a user desires to watch a movie or news through the XR device 100a, the control unit 120 sends content request information to another device (e.g., a handheld device 100b) or a media server through the communication unit 110. The communication unit 110 may download / stream content such as a movie or news from another device (e.g., a handheld device 100b) or a media server to the storage unit 130. The control unit 120 may control and / or perform processes such as video / image acquisition, (video / image) encoding, and metadata generation / processing for content, and generate / output an XR object based on information about the surrounding space or real objects obtained through the I / O unit 140a / sensor unit 140b.

[0278] The XR device 100a may be wirelessly connected to the handheld device 100b through the communication unit 110, and the operation of the XR device 100a may be controlled by the handheld device 100b. For example, the handheld device 100b may operate as a controller of the XR device 100a. To this end, the XR device 100a may obtain information about the 3D position of the handheld device 100b, generate and output an XR object corresponding to the handheld device 100b.

[0279] Examples of robots suitable for the present disclosure

[0280] Fig.21 The robot applied to the present disclosure is exemplified. According to the purpose or field of use, the robot can be divided into industrial robots, medical robots, household robots, military robots, etc.

[0281] Reference Fig.21 , the robot 100 may include a communication unit 110, a control unit 120, a storage unit 130, an I / O unit 140a, a sensor unit 140b, and a driving unit 140c.

[0282] The communication unit 110 may send signals (e.g., drive information and control signals) to and receive signals from external devices such as other wireless devices, other robots, or control servers. The control unit 120 may perform various operations by controlling the constituent elements of the robot 100. The storage unit 130 may store data / parameters / programs / codes / commands for supporting various functions of the robot 100. The I / O unit 140a may obtain information from the outside of the robot 100 and output the information to the outside of the robot 100. The I / O unit 140a may include a camera, a microphone, a user input unit, a display unit, a speaker, and / or a tactile module. The sensor unit 140b may obtain internal information, surrounding environment information, user information, etc. of the robot 100. The sensor unit 140b may include a proximity sensor, an illumination sensor, an acceleration sensor, a magnetic sensor, a gyroscope 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 may perform various physical operations such as moving a robot joint. In addition, the driving unit 140c may enable the robot 100 to travel or fly on a road. The driving unit 140c may include an actuator, a motor, wheels, brakes, propellers, and the like.

[0283] Examples of AI devices to which the present disclosure is applied

[0284] Fig. 22The AI ​​device applied to the present disclosure is illustrated. The AI ​​device can be implemented by a fixed device or a mobile device such as a TV, a projector, a smart phone, a PC, a notebook, a digital broadcast terminal, a tablet PC, a wearable device, a set-top box (STB), a radio, a washing machine, a refrigerator, a digital signage, a robot, a vehicle, etc.

[0285] Reference Fig. 22 , the AI ​​device 100 may include a communication unit 110, a control unit 120, a storage unit 130, an I / O unit 140a / 140b, a learning processor unit 140c, and a sensor unit 140d.

[0286] The communication unit 110 can use wired / wireless communication technology to / from other AI devices (e.g., Fig.16 100x, 200, or 400) or AI servers (e.g. Fig.16 400) sends / receives wired / radio signals (e.g., sensor information, user input, learning model, or control signal). To this end, the communication unit 110 can send information in the storage unit 130 to an external device, and send a signal received from an external device to the storage unit 130.

[0287] The control unit 120 may determine at least one feasible operation 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 may perform an operation determined by controlling the constituent elements of the AI ​​device 100. For example, the control unit 120 may request, search, receive, or use data of the learning processor unit 140c or the storage unit 130, and control the constituent elements of the AI ​​device 100 to perform a predicted operation or an operation determined to be preferred among at least one feasible operation. The control unit 120 may collect historical information including the operation content of the AI ​​device 100 and the user's operation feedback, and store the collected information in the storage unit 130 or the learning processor unit 140c, or send the collected information to a server such as an AI server ( Fig.16 The collected historical information can be used to update the learning model.

[0288] The storage unit 130 may store data for supporting various functions of the AI ​​device 100. For example, the storage unit 130 may store data obtained from the input unit 140a, data obtained from the communication unit 110, output data of the learning processor unit 140c, and data obtained from the sensor unit 140. The storage unit 130 may store control information and / or software codes required to operate / drive the control unit 120.

[0289] The input unit 140a may acquire various types of data from outside the AI ​​device 100. For example, the input unit 140a may acquire learning data for model learning and input data to which the learning model will be applied. The input unit 140a may include a camera, a microphone, and / or a user input unit. The output unit 140b may generate an output related to visual, auditory, or tactile sensations. The output unit 140b may include a display unit, a speaker, and / or a tactile module. The sensor unit 140 may use various sensors to obtain at least one of the internal information of the AI ​​device 100, the surrounding environment information of the AI ​​device 100, and the user information. The sensor unit 140 may include a proximity sensor, an illumination 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.

[0290] The learning processor unit 140c can use the learning data to learn a model including an artificial neural network. The learning processor unit 140c can communicate with the AI ​​server ( Fig.16 The learning processor unit 140c may perform AI processing together with the learning processor unit 400 of FIG. 400. The learning processor unit 140c may process information received from an external device through the communication unit 110 and / or information stored in the storage unit 130. In addition, the output value of the learning processor unit 140c may be sent to an external device through the communication unit 110 and may be stored in the storage unit 130.

[0291] Industrial Applicability

[0292] The above-mentioned embodiments of the present disclosure are applicable to various mobile communication systems.

Claims

1. A method for operating a remote user equipment (UE) associated with a multipath relay in a wireless communication system, the method comprising the following steps: The remote UE reports the measurement result for the candidate relay UE to the base station; Receiving, by the remote UE from the base station, an RRCReconfiguration message including an identifier ID of a target relay UE; as well as The remote UE attempts to establish a PC5 connection with the target relay UE, Wherein, based on the remote UE learning the change of the target relay UE's resident cell through a discovery message sent by the candidate relay UE or the target relay UE performing cell reselection during a radio resource control RRC connection, the remote UE sends information to the base station notifying the target relay UE of the change of the resident cell.

2. The method according to claim 1, wherein: When the remote UE learns 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.

3. The method according to claim 1, wherein: Based on the remote UE learning the camping cell change of the target relay UE through the discovery message sent by the candidate relay UE or the cell reselection performed by the target relay UE during the RRC connection, the remote UE skips triggering RRC reestablishment.

4. The method according to claim 1, wherein: Based on the remote UE learning the camping cell change of the target relay UE through the discovery message sent by the candidate relay UE or the cell reselection performed by the target relay UE during the RRC connection, the remote UE reports a new candidate relay UE to the base station.

5. The method according to claim 1, wherein: The camping cell change of the target relay UE occurs or the target relay UE performs the cell reselection during the RRC connection based on that the ID of the candidate relay UE when reporting the measurement result is different from the ID of the candidate relay UE included in the discovery message.

6. The method according to claim 1, wherein: The discovery message is received after reporting the measurement result.

7. The method according to claim 1, wherein: The target relay UE is in RRC IDLE / INACTIVE state.

8. A remote user equipment UE in a wireless communication system, the remote UE comprising: at least one processor; as well as at least one computer memory operatively connected to the at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations comprising: Reporting measurement results for candidate relay UEs to the base station; receiving, from the base station, an RRCReconfiguration message including an identifier ID of a target relay UE; and Try to establish a PC5 connection with the target relay UE, Wherein, based on the remote UE learning the change of the target relay UE's resident cell through a discovery message sent by the candidate relay UE or the target relay UE performing cell reselection during a radio resource control RRC connection, the remote UE sends information to the base station notifying the target relay UE of the change of the resident cell.

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

10. A non-volatile computer-readable storage medium, the non-volatile computer-readable storage medium being configured to store at least one computer program, the at least one computer program comprising instructions, the instructions, when executed by at least one processor, causing the at least one processor to perform operations for a remote user equipment UE, the operations comprising: Reporting measurement results for candidate relay UEs to the base station; receiving, from the base station, an RRCReconfiguration message including an identifier ID of a target relay UE; Try to establish a PC5 connection with the target relay UE, Wherein, based on the remote UE learning the change of the target relay UE's resident cell through a discovery message sent by the candidate relay UE or the target relay UE performing cell reselection during a radio resource control RRC connection, the remote UE sends information to the base station notifying the target relay UE of the change of the resident cell.

11. A method for operating a relay user equipment UE associated with multipath relay in a wireless communication system, the method comprising the following steps: The relay UE sends a discovery message; as well as receiving, by the relay UE, a PC5 message for a multipath connection from a remote UE, Wherein, based on the fact that the resident cell of the relay UE when sending the discovery message is different from the resident cell of the relay UE when receiving the PC5 message or is different from the radio resource control RRC connection cell when receiving the PC5 message, the relay UE rejects the side link SL connection request related to the multipath connection from the remote UE, and the remote UE sends information to the base station to notify the target relay UE of the change of the resident cell.

12. A relay user equipment UE in a wireless communication system, the relay UE comprising: at least one processor; at least one computer memory operatively connected to the at least one processor and configured to store instructions that, when executed, cause the at least one processor to perform operations comprising: Sending a discovery message; and receiving a PC5 message for a multipath connection from a remote UE, Wherein, based on the fact that the resident cell of the relay UE when sending the discovery message is different from the resident cell of the relay UE when receiving the PC5 message or is different from the radio resource control RRC connection cell when receiving the PC5 message, the relay UE rejects the side link SL connection request related to the multipath connection from the remote UE, and the remote UE sends information to the base station to notify the target relay UE of the change of the resident cell.

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