Method and apparatus for handling of interruptions for vehicle-to-everything communications

Abstract

The disclosure relates to a communication method and system for fusing a fifth generation (5G) communication system supporting higher data rates than a fourth generation (4G) system with Internet of Things (IoT) technology. The disclosure can be applied to intelligent services based on 5G communication technology and IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A method and apparatus for interruption handling for V2X communication are provided.

Description

Technical Field

[0001] This disclosure relates to a wireless communication system. More specifically, this disclosure relates to an apparatus, method, and system for interrupt handling of vehicle-to-everything (V2X) communication in a wireless communication system. Background Technology

[0002] To meet the growing demand for wireless data services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "super-4G networks" or "post-LTE systems." 5G communication systems are considered to be implemented in higher frequency (millimeter wave) bands (e.g., the 60GHz band) to achieve higher data rates. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies have been discussed in 5G communication systems. Furthermore, in 5G communication systems, system network improvements are being developed based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and receiver interference cancellation. In 5G systems, hybrid frequency shift keying (FSK), quadrature amplitude modulation (QAM) and sliding window superposition coding (SWSC) have been developed as advanced coding and modulation (ACM), as well as filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies.

[0003] The Internet, as a human-centric network where information is generated and consumed, is now evolving into the Internet of Things (IoT), where distributed entities (such as things) exchange and process information without human intervention. The Internet of Everything (IoE) has emerged, combining big data processing technologies with IoT technologies through connections to cloud servers. Because IoT implementations require technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology, sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) have recently been studied. Such an IoT environment can provide intelligent Internet technology services that create new value for human life by collecting and analyzing data generated between connected things. Through the convergence and combination of existing information technology (IT) and various industrial applications, IoT can be applied to a wide range of fields, including smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0004] Correspondingly, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-type communication (MTC), and machine-to-machine (M2M) communication can be implemented using beamforming, MIMO, and array antennas. Cloud radio access networks (RAN), as an application of the aforementioned big data processing technologies, can also be considered an example of the convergence between 5G and IoT technologies.

[0005] At the same time, there is a recent need to enhance V2X communication in wireless communication systems.

[0006] The above information is presented as background information only to aid in understanding this disclosure. No determination or assertion is made as to whether any of the above content can be applied to this disclosure as prior art. Summary of the Invention

[0007] Technical issues

[0008] There is a need to enhance V2X communication in wireless communication systems.

[0009] Technical solution

[0010] The aspects of this disclosure at least address the aforementioned problems and / or disadvantages, and provide at least the following advantages. Accordingly, one aspect of this disclosure is to provide a communication method and system for integrating fifth-generation (5G) communication systems that support higher data rates than fourth-generation (4G).

[0011] Additional aspects will be set forth in part in the description which follows, and will be apparent in part from the description, or may be learned by practice of the presented embodiments.

[0012] According to one aspect of this disclosure, a method performed by a first terminal is provided. The method includes: receiving from a base station a control message including configuration for configuring sidelink grants; transmitting a sidelink signal to a second terminal based on the configured sidelink grants for a first sidelink logical channel that is allowed to use the configured sidelink grants; starting a timer associated with a radio link failure upon receiving a continuous asynchrony indication for a cell from a lower layer; identifying whether a second sidelink logical channel that is unavailable for the configured sidelink grants exists; transmitting a sidelink signal to the second terminal based on the configured sidelink grants while the timer is running if no such sidelink logical channel exists; and transmitting a sidelink signal to the second terminal based on resources from an exception transmission pool while the timer is running if a second sidelink logical channel that is unavailable for the configured sidelink grants exists.

[0013] According to another aspect of this disclosure, a method performed by a second terminal is provided. The method includes: receiving from a base station a control message including a configuration for configuring sidelink grants; and receiving a sidelink signal from the first terminal based on the configured sidelink grants for a first sidelink logical channel that is allowed to use the configured sidelink grants, wherein, in the absence of a sidelink logical channel that is not available for the configured sidelink grants, the sidelink signal is received from the first terminal based on the configured grants during the execution of a timer associated with a radio link failure; and wherein, in the presence of a second logical channel that is not available for the configured sidelink grants, the sidelink signal is received from the first terminal based on resources from an exceptional transmission pool during the execution of a timer.

[0014] According to another aspect of this disclosure, a first terminal is provided. The first terminal includes: a transceiver configured to transmit and receive signals; and a controller configured to: receive a control message from a base station including a configuration for configuring sidelink grants; transmit a sidelink signal to a second terminal based on the configured sidelink grants for a first sidelink logical channel that is allowed to use the configured sidelink grants; initiate a timer associated with a radio link failure upon receiving a continuous asynchrony indication for a cell from a lower layer; identify whether a second sidelink logical channel that is not available for the configured sidelink grants exists; transmit a sidelink signal to the second terminal based on the configured sidelink grants while the timer is running if no sidelink logical channel that is not available for the configured sidelink grants exists; and transmit a sidelink signal to the second terminal based on resources from an exception transmission pool while the timer is running if a second sidelink logical channel that is not available for the configured sidelink grants exists.

[0015] According to another aspect of this disclosure, a second terminal is provided. The second terminal includes: a transceiver configured to transmit and receive signals; and a controller configured to: receive from a base station a control message including a configuration for configuring sidelink grants, and receive sidelink signals from the first terminal based on the configured sidelink grants for a first sidelink logical channel that is allowed to use the configured sidelink grants, wherein, in the absence of a sidelink logical channel that is not available for the configured sidelink grants, the sidelink signals are received from the first terminal based on the configured grants during the execution of a timer associated with a radio link failure, and wherein, in the presence of a second logical channel that is not available for the configured sidelink grants, the sidelink signals are received from the first terminal based on resources from an exceptional transmission pool during the execution of a timer.

[0016] Other aspects, advantages, and distinctive features of this disclosure will become apparent to those skilled in the art from the following detailed description of various embodiments disclosed in conjunction with the accompanying drawings.

[0017] Technical effect

[0018] According to various embodiments of this disclosure, V2X communication systems can be efficiently enhanced. Attached Figure Description

[0019] The above and other aspects, features, and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0020] Figure 1 This is an architecture supporting the PC5 interface according to embodiments of this disclosure;

[0021] Figure 2 A flowchart illustrating an embodiment according to this disclosure is shown;

[0022] Figure 3 A flowchart illustrating an embodiment according to this disclosure is shown;

[0023] Figure 4 A flowchart illustrating an embodiment according to this disclosure is shown;

[0024] Figure 5 A flowchart illustrating an embodiment according to this disclosure is shown;

[0025] Figure 6 A flowchart illustrating an embodiment according to this disclosure is shown;

[0026] Figure 7 A flowchart illustrating an embodiment according to this disclosure is shown;

[0027] Figure 8 A block diagram of a terminal according to an embodiment of the present disclosure; and

[0028] Figure 9 This is a block diagram of a base station according to an embodiment of the present disclosure.

[0029] In all the accompanying drawings, similar reference numerals will be understood to refer to similar parts, components and structures. Detailed Implementation

[0030] The following description, provided with reference to the accompanying drawings, is intended to aid in a full understanding of the various embodiments of this disclosure as defined by the claims and their equivalents. It includes various specific details to aid understanding, but these are to be considered exemplary only. Accordingly, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of this disclosure. Furthermore, for clarity and brevity, descriptions of well-known functions and structures may be omitted.

[0031] The terms and words used in the following description and claims are not limited to their documentary meaning, but are used solely by the inventors to enable a clear and consistent understanding of this disclosure. Accordingly, it will be apparent to those skilled in the art that the following description of various embodiments of this disclosure is provided for illustrative purposes only and is not intended to limit the disclosure as defined by the appended claims and their equivalents.

[0032] It should be understood that the singular forms “a,” “an,” and “the” include plural indicators unless the context explicitly specifies otherwise. Thus, for example, a reference to “component surface” includes a reference to one or more such surfaces.

[0033] The term "substantially" means that the characteristic, parameter, or value does not need to be achieved precisely, but deviations or variations (including, for example, tolerances, measurement errors, measurement accuracy limitations, and other factors known to those skilled in the art) may occur in an amount that does not preclude the effect that the characteristic is intended to provide.

[0034] Those skilled in the art will understand that the blocks and combinations of flowcharts (or sequence diagrams) can be represented and executed by computer program instructions. These computer program instructions can be loaded onto a processor of a general-purpose computer, a special-purpose computer, or a programmable data processing apparatus. When the loaded program instructions are executed by the processor, they create parts for performing the functions described in the flowchart. Because the computer program instructions can be stored in a computer-readable storage device available in a special-purpose computer or programmable data processing apparatus, they can also create articles of art that perform the functions described in the flowchart. Because the computer program instructions can be loaded onto a computer or programmable data processing apparatus, when executed as a process, they can perform the operations of the functions described in the flowchart.

[0035] A flowchart's boxes may correspond to modules, segments, or code containing one or more executable instructions that implement one or more logical functions, or they may correspond to a portion thereof. In some cases, the functions described by the boxes may be executed in a different order than they are listed. For example, two boxes listed in sequence may be executed simultaneously or in reverse order.

[0036] In this specification, the terms "unit," "module," etc., can refer to software components or hardware components, such as, for example, field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs) capable of performing functions or operations. However, "unit," etc., is not limited to hardware or software. Units, etc., can be configured to reside in addressable memory media or drive one or more processors. Units, etc., can refer to software components, object-oriented software components, class components, task components, procedures, functions, attributes, programs, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, or variables. The functionality provided by components and units can be a combination of smaller components and units, and can be combined with other components and units to form larger components and units. Components and units can be configured to drive devices or one or more processors in a secure multimedia card.

[0037] Before the detailed description, terms or definitions necessary for understanding this disclosure are described. However, these terms should be interpreted in a non-limiting manner.

[0038] A “base station (BS)” is an entity that communicates with a user equipment (UE) and can be referred to as a BS, base transceiver station (BTS), node B (NB), evolved NB (eNB), access point (AP), 5G NB (5GNB), or gNB.

[0039] "UE" is an entity that communicates with BS and can be referred to as UE, device, mobile station (MS), mobile device (ME), or terminal.

[0040] In recent years, several broadband wireless technologies have been developed to meet the growing number of broadband subscribers and provide more and better applications and services. Second-generation wireless communication systems have been developed to provide voice services while ensuring user mobility. Third-generation wireless communication systems support not only voice services but also data services. Fourth-generation wireless communication systems have been developed in recent years to provide high-speed data services. However, currently, fourth-generation wireless communication systems lack the resources to meet the growing demand for high-speed data services. Therefore, fifth-generation wireless communication systems (also known as next-generation radio or NR) are being developed to meet the increasing demand for high-speed data services and support ultra-reliable and low-latency applications.

[0041] In fifth-generation wireless communication systems operating in higher frequency (millimeter-wave) bands, UEs and gNBs use beamforming to communicate with each other. Beamforming technology is used to mitigate propagation path loss and increase propagation distance for communication at higher frequency bands. Beamforming uses high-gain antennas to enhance transmit and receive performance. Beamforming can be classified into transmit (TX) beamforming performed at the transmitter and receive (RX) beamforming performed at the receiver. Typically, TX beamforming increases directivity by using multiple antennas to allow the area to be propagated to be densely located in a specific direction. In this case, the collection of multiple antennas can be called an antenna array, and each antenna included in the array can be called an array element. Antenna arrays can be configured in various forms, such as linear arrays, planar arrays, etc. The use of TX beamforming results in increased signal directivity, thereby increasing propagation distance. Furthermore, since the signal is transmitted almost entirely in directions other than the directional direction, signal interference acting on the other receiver is significantly reduced. The receiver can perform beamforming on the RX signal by using an RX antenna array. RX beamforming increases the strength of the RX signal transmitted in a specific direction by allowing propagation to be concentrated in that direction, and excludes signals transmitted in other directions from the RX signal, thus providing a blocking effect against interfering signals. By using beamforming technology, a transmitter can generate multiple transmit beam patterns in different directions. Each of these transmit beam patterns can also be referred to as a TX beam. High-frequency wireless communication systems use multiple narrow TX beams to transmit signals within a cell because each narrow TX beam provides coverage for a portion of the cell. The narrower the TX beam, the higher the antenna gain, and therefore the greater the propagation distance of the signal transmitted using beamforming. Receivers can also generate multiple receive (RX) beam patterns in different directions. Each of these receive patterns can also be referred to as a receive (RX) beam.

[0042] Fifth-generation wireless communication systems support standalone operation mode and dual connectivity (DC). In DC, multiple Rx / Tx UEs can be configured to utilize resources provided by two different nodes (or NBs) via a non-ideal backhaul connection. One node acts as the master node (MN), and the other acts as the secondary node (SN). The MN and SN are connected via a network interface, and at least the MN is connected to the core network. NR also supports multiple RAT dual connectivity (MR-DC) operation, whereby UEs in a Radio Resource Control (RRC_CONNECTED) connection are configured to utilize radio resources provided by two different schedulers located in two different nodes via a non-ideal backhaul connection and providing Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (E-UTRA) (i.e., if the node is an ng-eNB) or NR access (i.e., if the node is a gNB). In NR, for UEs in an RRC_CONNECTED connection without a configured CA / DC, only one serving cell, including the master cell, exists. For UEs configured with CA / DC in RRC_CONNECTED mode, the term "serving cell" refers to the set of cells including the primary cell and all secondary cells. In NR, the term Primary Cell Group (MCG) refers to a group of serving cells associated with the primary node, including the primary cell (PCell) and one or more optional secondary cells (SCells). In NR, the term Secondary Cell Group (SCG) refers to a group of serving cells associated with the secondary node, including the primary SCG cell (PSCell) and one or more optional SCells. In NR, a PCell refers to the serving cell in the MCG on the primary frequency on which the UE either performs an initial connection establishment procedure or initiates a connection re-establishment procedure. In NR, for UEs configured with CA, an SCell is a cell that provides additional radio resources above the primary cell. The primary SCG cell is the serving cell in the SCG where the UE performs random access during a reconfiguration procedure with synchronization. For dual connectivity operation, the term SpCell (i.e., the primary cell) refers to either the PCell of the MCG or the PSCell of the SCG; otherwise, the term primary cell refers to the PCell.

[0043] In fifth-generation wireless communication systems, the Physical Downlink Control Channel (PDCCH) is used to schedule DL transmissions on the Physical Downlink Shared Channel (PDSCH) and UL transmissions on the Physical Uplink Shared Channel (PUSCH). The downlink control information (DCI) on the PDCCH includes: downlink assignments containing at least modulation and coding formats, resource allocation, and hybrid ARQ information related to the DL-SCH; and uplink scheduling authorizations containing at least modulation and coding formats, resource allocation, and hybrid ARQ information related to the UL-SCH. Besides scheduling, PDCCH can be used for: activating and deactivating PUSCH transmissions with configured grants; activating and deactivating PDSCH semi-persistent transmissions; informing one or more UEs of the slot format; informing one or more UEs that they can assume there are no Physical Resource Blocks (PRBs) and Orthogonal Frequency Division Multiplexing (OFDM) symbols in the PDCCH; transmitting Transmission Power Commands (TPCs) for Physical Uplink Control Channel (PUCCH) and PUSCH; transmitting one or more TPCs for Sounding Reference Signals (SRS) transmissions by one or more UEs; switching the active bandwidth portion of a UE; and initiating random access procedures. The UE monitors the PDCCH candidate set during the monitoring period configured in one or more configuration Control Resource Sets (CORESETs) according to the corresponding search space configuration. A CORESET consists of a set of PRBs with a duration of 1 to 3 OFDM symbols. Resource Element Groups (REGs) and Control Channel Elements (CCEs) are defined within a CORESET, where each CCE includes a set of REGs. The control channel is formed by the aggregation of CCEs. Different code rates for the control channel are achieved by aggregating different numbers of CCEs. Interleaved and non-interleaved CCE-to-REG mapping is supported in CORESET. Polar coordinate coding is used for the PDCCH. Each resource element group carrying the PDCCH carries its own demodulation reference signal (DMRS). Quadrature phase shift keying (QPSK) modulation is used for the PDCCH.

[0044] In fifth-generation wireless communication systems, the search space configuration list is signaled by the gNB for each configuration's BWP, where each search configuration is uniquely identified by an identifier. The identifier of the search space configuration to be used for a specific purpose (such as paging reception, SI reception, random access response reception) is explicitly signaled by the gNB. In NR, the search space configuration includes the parameters Monitoring-periodicity-PDCCH-slot, Monitoring-offset-PDCCH-slot, Monitoring-symbols-PDCCH-within-slot, and duration. The UE uses the parameters Monitoring-periodicity-PDCCH-slot, Monitoring-offset-PDCCH-slot, and Monitoring-symbols-PDCCH-within-slot to determine the timing of PDCCH monitoring within a slot. PDCCH monitoring opportunities exist in the duration from time slot "x" to x+, where time slot "x" in radio frame number "y" satisfies the following Equation 1:

[0045] [Equation 1]

[0046] (y*(number of time slots in radio frames)+x-Monitoring-offset-PDCCH-slot)mod(Monitoring-periodicity-PDCCH-slot)=0

[0047] The start symbol of the PDCCH monitoring time in each slot with a PDCCH monitoring time is given by Monitoring-symbols-PDCCH-within-slot. The length of the PDCCH monitoring time (in symbols) is given in the CORESET associated with the search space. The search space configuration includes an identifier for the associated CORESET configuration. The gNB signals the list of CORESET configurations for each configuration via BWP, where each CORESET configuration is uniquely identified by an identifier. Note that the duration of each radio frame is 10 ms. Radio frames are identified by either the radio frame number or the system frame number. Each radio frame consists of several time slots, where the number of time slots and the duration of the time slots in the radio frame depend on the subcarrier spacing. The number of time slots and the duration of the time slots in the radio frame depend on the radio frames predefined in the NR for each supported subcarrier spacing (SCS). Each CORESET configuration is associated with a Transport Configuration Indicator (TCI) status list. Each TCI state is configured with a Downlink (DL) Reference Signal (RS) Identifier (ID) (Synchronization Signal Block (SSB) or Channel State Information Reference Signal (CSI-RS)). The list of TCI states corresponding to the CORESET configuration is signaled by the gNB via Radio Resource Control (RRC) signaling. When one TCI state in the TCI state list is activated, it is indicated to the UE by the gNB. The TCI state indication is used by the gNB to transmit the DL TX beam of the PDCCH during PDCCH monitoring in the search space (the DL TX beam and the SSB / CSI-RS of the TCI state are quasi-collocated (QCL)).

[0048] In fifth-generation wireless communication systems, bandwidth adaptation (BA) is supported. Using BA, the UE's receive and transmit bandwidth does not need to be as large as the cell's bandwidth and can be adjusted: the bandwidth can be commanded to change (e.g., to shrink during periods of low activity to save power); the location can be moved in the frequency domain (e.g., to increase scheduling flexibility); and the subcarrier spacing can be commanded to change (e.g., to allow different services). A subset of the cell's total cell bandwidth is called the bandwidth portion (BWP). BA is implemented by configuring the UE with an RRC connection using BWPs and telling the UE which configured BWP is currently active. When BA is configured, the UE only needs to monitor the PDCCH on one active BWP; that is, it does not need to monitor the PDCCH on the entire DL frequency of the serving cell. In RRC connected state, for each configured serving cell (i.e., PCell or SCell), the UE is configured with one or more DL and UL BWPs. For an active serving cell, there is always one active UL and DL BWP at any given time. BWP handover for the serving cell is used to activate inactive BWPs and deactivate active BWPs at a given time. BWP handover is controlled by the PDCCH indicating downlink assignment or uplink grant, by the bwp-InactivityTimer, by RRC signaling, or by the MAC entity itself when initiating a random access procedure. When adding a SpCell or activating an SCell, the DL BWP and UL BWP indicated by firstActiveDownlinkBWP-Id and firstActiveUplinkBWP-Id, respectively, are active without receiving a PDCCH indicating downlink assignment or uplink grant. The active BWP of the serving cell is indicated by RRC or PDCCH. For unpaired spectrum, the DL BWP is paired with the UL BWP, and BWP handover is common to both UL and DL. When the BWP inactivity timer expires, the UE hands over to the active DL BWP, to the default DL BWP, or to the initial DL BWP (if the default DL BWP is not configured).

[0049] In fifth-generation wireless communication systems, Node B (gNB) or base station in a cell broadcasts a Synchronization Signal and Physical Broadcast Channel (PBCH) block (SSB) consisting of a primary synchronization signal, secondary synchronization signals (PSS, SSS), and system information. System information includes common parameters required for communication within the cell. In fifth-generation wireless communication systems (also known as next-generation radio or NR), system information (SI) is divided into a main information block (MIB) and multiple system information blocks (SIBs), where:

[0050] - The MIB is always transmitted on the BCH with a period of 80ms and a repetition within 80ms, and it includes the parameters required to obtain SIB1 from the cell.

[0051] SIB1 is transmitted on the DL-SCH with a period of 160ms and variable transmission repetition. The default transmission repetition period of SIB1 is 20ms, but the actual transmission repetition period depends on the network implementation. The scheduling information in SIB1 includes the mapping between SIBs and SI messages, the periodicity of each SI message, and the SI window length. The scheduling information in SIB1 includes an indicator for each SI message, indicating whether the relevant SI message is being broadcast. If at least one SI message is not being broadcast, SIB1 may include random access resources (Physical Random Access Channel (PRACH) preamble and PRACH resources) for requesting the gNB to broadcast one or more SI messages.

[0052] - SIBs other than SIB1 are carried in SystemInformation (SI) messages, which are transmitted on DL-SCH. Only SIBs with the same periodicity can be mapped to the same SI message. Each SI message is transmitted within a periodically occurring time-domain window (referred to as an SI window of equal length for all SI messages). Each SI message is associated with an SI window, and the SI windows of different SI messages do not overlap. That is, within an SI window, only the corresponding SI message is transmitted. Using the indication in SIB1, any SIB other than SIB1 can be configured as cell-specific or area-specific. Cell-specific SIBs are only applicable within the cell providing the SIB, while area-specific SIBs are applicable within an area called an SI area, which consists of one or more cells and is identified by the systemInformationAreaID.

[0053] Figure 1 This is an architecture supporting the PC5 interface according to embodiments of the present disclosure.

[0054] refer to Figure 1 4G and 5G wireless communication systems support vehicle communication services. Vehicle communication services, represented by V2X services, can consist of four different types: vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). In fifth-generation (also known as NR or New Radio) wireless communication systems, V2X communication is being enhanced to support enhanced V2X use cases, which are broadly categorized into four groups:

[0055] 1) Vehicle queuing enables vehicles to dynamically form convoys that move together. All vehicles in the convoy receive information from the lead vehicle that manages the convoy. This information allows vehicles to move closer together in a coordinated manner than normal, thus heading in the same direction and traveling together.

[0056] 2) Extended sensor coverage enables the exchange of raw or processed data or real-time video images collected by local sensors between vehicles, roadside units (RSUs), pedestrian equipment, and V2X application servers. Vehicles can enhance their perception of their surroundings beyond the range detected by their own sensors and gain a broader and more comprehensive understanding of the local situation. High data rates are one of the key features.

[0057] 3) Advanced driving enables semi-autonomous or fully autonomous driving. Each vehicle and / or RSU shares its own perception data obtained from its local sensors with nearby vehicles, which allows vehicles to synchronize and coordinate their trajectories or maneuvers. Each vehicle also shares its driving intentions with nearby vehicles.

[0058] 4) Remote driving enables remote drivers or V2X applications to operate remote vehicles for passengers who cannot drive themselves or for vehicles in hazardous environments. Cloud-based driving can be used for situations with limited variation and predictable routes (such as public transportation). High reliability and low latency are primary requirements.

[0059] V2X services can be provided via the PC5 interface and / or the Uu interface. Support for V2X services via the PC5 interface is provided by NR sidelink communication or V2X sidelink communication (which is a communication mode), allowing UEs to communicate directly with each other via the PC5 interface using either NR or E-UTRA technology, without traversing any network nodes. This communication mode is supported when the UE is served by the RAN and when the UE is outside RAN coverage. Only UEs authorized for V2X services can perform NR or V2X sidelink communication. The NG-RAN architecture supports, for example... Figure 1 The PC5 interface is shown. Sidelink transmission and reception via the PC5 interface are supported when the UE is within NG-RAN coverage, regardless of its RRC state, and also when the UE is outside NG-RAN coverage. Support for V2X services via the PC5 interface can be provided by NR sidelink communication and / or V2X sidelink communication. NR sidelink communication can be used to support services other than V2X services.

[0060] NR or V2X sidelink communication can support three types of transmission modes: Unicast transmission, characterized by supporting at least one PC5-RRC connection between peer UEs; transmission and reception of control information and user services between peer UEs in the sidelink; support for sidelink Hybrid Automatic Repeat Request (HARQ) feedback; support for Radio Link Control (RLC) Acknowledgment mode (AM); and support for sidelink radio link monitoring (RLM) for two peer UEs to detect radio link failures (RLF). Multicast transmission, characterized by transmission and reception of user services between UEs belonging to a group in the sidelink; and support for HARQ feedback. Broadcast transmission, characterized by transmission and reception of user services between UEs in the sidelink.

[0061] The AS protocol stack for the control plane in the PC5 interface consists of RRC, Packet Data Convergence Protocol (PDCP), RLC, Media Access Control (MAC) sublayers, and the physical layer. The AS protocol stack for the user plane in the PC5 interface consists of Serving Data Adaptation Protocol (SDAP), PDCP, RLC, MAC sublayers, and the physical layer. Sidelink radio bearers (SLRBs) are divided into two groups: Sidelink Data Radio Bearers (SLDRBs) for user plane data and Sidelink Signaling Radio Bearers (SLSRBs) for control plane data. Separate SLSRBs are used for PC5-RRC and PC5-S signaling configurations, each using a different Sidelink Control Channel (SCCH).

[0062] The MAC sublayer provides the following services and functions through the PC5 interface: radio resource selection; packet filtering; priority handling between uplink and sidelink transmissions for a given UE; and sidelink CSI reporting. With Logical Channel Priority Ordering (LCP) restrictions in the MAC, only sidelink logical channels belonging to the same destination can be multiplexed into a MAC Protocol Data Unit (PDU) for each unicast, multicast, and broadcast transmission associated with a destination. NG-RAN can also control whether sidelink logical channels can utilize resources allocated to the configured sidelink license type 1. For packet filtering, a sidelink shared channel (SL-SCH) MAC header, including portions of both the source stratum 2 ID and the destination stratum 2 ID, is added to each MAC PDU. The Logical Channel ID (LCID) included in the MAC subheader uniquely identifies logical channels within the range of the source stratum 2 ID and destination stratum 2 ID combination. The following logical channels are used in the sidelink:

[0063] - Sidelink Control Channel (SCCH): A sidelink channel used to send control information from one UE to other UEs;

[0064] - Sidelink Traffic Channel (STCH): A sidelink channel used to send user information from one UE to other UEs; and

[0065] - Sidelink Broadcast Control Channel (SBCCH): A sidelink channel used to broadcast sidelink system information from one UE to other UEs.

[0066] The following connection exists between the logical channel and the transport channel:

[0067] -SCCH can be mapped to SL-SCH;

[0068] -STCH can be mapped to SL-SCH; and

[0069] -SBCCH can be mapped to the sidelink broadcast channel (SL-BCH).

[0070] The RRC sublayer provides the following services and functions through the PC5 interface:

[0071] - Transmit PC5-RRC messages between peer UEs;

[0072] - Maintain and release the PC5-RRC connection between two UEs; and

[0073] - Detected a sidelink radio link failure for the PC5-RRC connection.

[0074] A PC5-RRC connection is a logical connection between two UEs for a pair of source and destination Layer-2 IDs. This logical connection is considered to be established after the corresponding PC5 unicast link is established. There is a one-to-one correspondence between PC5-RRC connections and PC5 unicast links. For different source and destination Layer-2 ID pairs, a UE can have multiple PC5-RRC connections with one or more UEs. Separate PC5-RRC procedures and messages are used by the UE to transmit UE capabilities and sidelink configurations, including SLRB configurations, to its peer UE. Two peer UEs can use separate bidirectional procedures in both sidelink directions to exchange their own UE capabilities and sidelink configurations. The UE releases the PC5-RRC connection if it is not interested in sidelink transmissions, if a sidelink RLF is declared on the PC5-RRC connection, or if the Layer-2 link release procedure is completed as specified in TS 23.287.

[0075] For resource allocation in the sidelink, the UE can operate in two modes:

[0076] - The resource allocation of the schedule is characterized by:

[0077] *The UE needs to be in RRC_CONNECTED state in order to transmit data;

[0078] *NG-RAN schedules transmission resources.

[0079] -UE autonomous resource selection, characterized by:

[0080] *When within NG-RAN coverage, the UE can transmit data regardless of its RRC state, and when outside NG-RAN coverage, the UE can transmit data.

[0081] *The UE autonomously selects transmission resources from the resource pool.

[0082] - For NR sidelink communication, the UE performs sidelink transmission on only a single carrier.

[0083] Resource allocation for scheduling: NG-RAN can dynamically allocate resources to the UE via the Sidelink Radio Network Temporary Identifier (SL-RNTI) on the PDCCH for NR sidelink communication. Furthermore, NG-RAN can allocate sidelink resources to the UE using two types of configured sidelink grants:

[0084] - For type 1, RRC directly provides configured sidelink authorization for NR sidelink communication.

[0085] For Type 2, RRC provides periodicity for configured sidelink grants, while PDCCH can signal and activate or deactivate the configured sidelink grants. PDCCH provides the actual grants (i.e., resources) to be used. PDCCH is addressed to SL-CS-RNTI for NR sidelink communication and SL semi-persistent scheduling V-RNTI for V2X sidelink communication.

[0086] For a UE performing NR sidelink communication, more than one configured sidelink grant can be active at a time on a carrier configured for sidelink transmission. When beam failure or physical layer problems occur on the NR Uu, the UE can continue to use the configured sidelink grant type 1. During handover, the configured sidelink grant, regardless of type, can be provided to the UE via a handover command. If provided, the UE activates the configured sidelink grant type 1 upon receiving the handover command. The UE can send a sidelink buffer status report to support scheduler operation in NG-RAN. The sidelink buffer status report refers to the data buffered in the UE for a set of logical channels (LCGs) for each destination. Eight LCGs are used to report the sidelink buffer status report. Two formats are used: SL BSR and truncated SL BSR.

[0087] UE autonomous resource allocation: When within NG-RAN coverage, the UE autonomously selects a sidelink grant from the resource pool provided by broadcast system information or dedicated signaling, or when outside NG-RAN coverage, it selects a sidelink grant from the resource pool provided by pre-configuration.

[0088] For NR sidelink communication, resource pools can be provided for a given valid area, where the UE does not need to acquire a new resource pool when moving within that valid area, at least when the pool is provided by the SIB (e.g., reusing the valid area of ​​the NR SIB). The NR SIB validity mechanism is reused to implement the valid area of ​​the SL resource pool configured via broadcast system information. Based on the configuration of the exception transmission resource pool, the UE is allowed to temporarily use UE-autonomous resource selection with random selection for sidelink transmission.

[0089] For V2X sidelink transmissions, during handover, the handover command can signal the configuration of the transmission resource pool, including the exception transmission resource pool for the target cell, to reduce transmission interruptions. In this way, the UE can use the V2X sidelink transmission resource pool of the target cell before handover is complete, provided that the eNB is configured as a synchronization source and performs synchronization with the target cell, or that the GNSS is configured as a synchronization source and performs synchronization with the Global Network Satellite System (GNSS). If the exception transmission resource pool is included in the handover command, the UE uses resources randomly selected from the exception transmission resource pool from the moment the handover command is received. If the UE is configured with scheduled resource allocation in the handover command, the UE continues to use the exception transmission resource pool while the handover-related timer is running. If the UE is configured with autonomous resource selection in the target cell, the UE continues to use the exception transmission resource pool until a sensing result regarding the transmission resource pool for autonomous resource selection is available. In exceptional cases (e.g., during RLF, during transition from RRC IDLE to RRC CONNECTED, or during changes to the dedicated V2X sidelink resource pool within the cell), the UE can randomly select resources from the exception pool provided in the serving cell's SIB21 or dedicated signaling and use them temporarily. During cell reselection, the RRC_IDLE UE can use resources randomly selected from the exception transport resource pool of the reselected cell until a sensing result regarding the transport resource pool for autonomous resource selection is available.

[0090] Meanwhile, if the UE is configured with resource allocation for V2X communication scheduling, the gNB notifies one or more configured grant (CG) type 1 and / or CG type 2 SL grant configurations via signaling. Dynamic SL grants and CG type 1 and / or CG type 2 SL grants are used for V2X communication transmission. The UE is also configured with RLM-RS resources. On each RLM-RS resource, the UE estimates the downlink radio link quality and compares it with a threshold Q. out and Q in Compare. Q out This is the level at which downlink radio links cannot be reliably received, and corresponds to the out-of-sync block error rate (BLER). out Q in It refers to the level of downlink radio link quality that enables higher reliability of downlink reception, and corresponds to the in-sync block error rate (BLER). in ). BLER out and BLER in The gNB notifies the UE via signaling when the downlink radio link quality on all configured RLM-RS resources is higher than Q. out In worse cases, an out-of-sync indication is generated. This occurs when the downlink radio link quality on at least one of the configured RLM-RS resources is lower than Q... in Ideally, an in-sync indication is generated. When a physical layer problem is detected for the SpCell, i.e., when N310 consecutive asynchronous indications are received from a lower layer, timer T310 is started. The values ​​of N310 and T310 are signaled to the UE by the gNB. While timer T310 is running, the UE continues to use the configured SL grant. When timer T310 expires, the UE uses resources from the exceptional TX resource pool. The problem is that the configured SL grant usage is limited to certain SL LCHs, and therefore, V2X transmissions will be interrupted for one or more SL LCHs that are not allowed to use the configured SL grant.

[0091] [Example 1-1]

[0092] Figure 2 A flowchart of an embodiment according to this disclosure is shown.

[0093] In one method of this disclosure, the UE operation for SL communication transmission is as follows: Figure 2 As shown.

[0094] refer to Figure 2The UE is in an RRC connected state and is performing NR sidelink communication using a resource configuration scheduled by the serving cell (in one embodiment, the serving cell may be a PCell; in another embodiment, the serving cell may be a SpCell). The RRC reconfiguration message receives a resource configuration (210) from the gNB for scheduling resource allocation. The RRC reconfiguration message includes a list of one or more configured SL authorization configurations. The configured SL authorization configurations may be either CG type 1 or CG type 2.

[0095] Each configured SL grant includes an SL LCH priority list, and SL grants based on this configuration apply to this priority list. Each SL LCH is associated with an SL LCH priority. If an SL LCH's SL LCH priority is included in the SL LCH priority list in the configured SL grant, then the SL grant based on this configuration can be used for SL transports from that SL LCH. In each configured SL grant, the UE schedules data (220) from one or more SL LCHs that are allowed to use the SL grant of that configuration.

[0096] In RRC connected state, the UE performs radio link monitoring. The downlink radio link quality of the primary cell is monitored by the physical layer in the UE to indicate the desynchronization / synchronization status to higher layers. When the radio link quality is worse than the threshold Q_out for all resources in the resource set used for radio link monitoring, the physical layer in the UE indicates desynchronization to higher layers in the radio link quality evaluation frame. When the radio link quality is better than the threshold Q_in for any resource in the resource set used for radio link monitoring, the physical layer in the UE indicates synchronization to higher layers (i.e., RRC) in the radio link quality evaluation frame.

[0097] Upon receiving N310 consecutive asynchronous indications from a lower layer (i.e., the physical layer), the higher layer (i.e., the RRC) starts timer T310 in operation 230. The values ​​of N310 and T310 are configured by the network using RRC signaling. During T310, the UE uses the configured SL grant for all SL LCHs in operation 240, regardless of whether the SL LCH is allowed to use the configured SL grant according to the configuration received from the gNB. When timer T310 expires, the configured SL grant configuration received from the gNB is released. When timer T310 expires, in operation 250, the UE uses resources from the exception TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission. During T310, the UE can continue to use the dynamic SL grant received from the gNB, and when T310 expires, the UE stops monitoring the dynamic SL grant. Alternatively, when T310 is started, the UE stops monitoring the dynamic SL grant. If T310 stops due to a synchronization indication, then in each configured SL grant, the UE schedules data from one or more SL LCHs that are allowed to use that configured SL grant.

[0098] In one embodiment, during T310 operation, a specified SL grant is designated for use by all SL LCHs in a list of configured SL grant configurations, regardless of whether the SL LCHs are permitted to use that SL grant according to the configuration received from the gNB. The index of the specified configuration can be predefined (e.g., the first or last in a list) or can be notified via signaling. For all other SL grant configurations, the UE schedules data from one or more SL LCHs that are permitted to use that SL grant. Before T310 starts (or when T310 stops), in the SL grant used for that specified configuration, the UE schedules data from one or more SL LCHs that are permitted to use that SL grant.

[0099] In another embodiment, when the UE is configured with scheduled resource allocation and the configured SL authorization is not configured:

[0100] Option 1: During T310 operation, the UE can continue to use the dynamic SL grant received from the gNB, and when T310 expires, the UE stops monitoring the dynamic SL grant. When timer T310 expires, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission.

[0101] Option 2: When timer T310 starts, the UE stops monitoring dynamic SL grants. Dynamic SL grants are not used for SL transmissions when timer T310 starts. When timer T310 starts, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmissions. If T310 stops due to a synchronization indication, the UE starts monitoring dynamic SL grants and begins using dynamic SL grants for SL transmissions.

[0102] For example, suppose a UE has four SL LCHs (e.g., LCH 1, LCH 2, LCH 3, and LCH 4) established for NR sidelink communication. The network configures CG type 1 SL grants in a reconfiguration message. According to the configuration received from the network, CG type 1 SL grants are allowed for LCH 1 and LCH 2. The UE uses CG type 1 SL grants for LCH 1 and LCH 2 until timer T310 starts. During T310, the UE uses CG type 1 for LCH 1 through LCH 4. When T310 expires, the UE stops using CG type 1 SL grants.

[0103] In one embodiment of the above operations, the configured SL license is CG type 1. In another embodiment of the above operations, the configured SL license is CG type 2. In yet another embodiment of the above operations, the configured SL license can be either CG type 1 or CG type 2.

[0104] Figure 3 A flowchart of an embodiment according to this disclosure is shown.

[0105] refer to Figure 3 In an alternative embodiment of the method disclosed herein, during operations 340 and 350, the network may instruct the UE during T310 whether it is permitted to use the configured SL LCH for all SL LCHs or only for the indicated SL LCHs. The presence of the new parameter (UseCGforAllSLLCCHs) in the RRC reconfiguration message may instruct the UE to use the CG for all SL LCHs during T310. The new parameter (UseCGforAllSLLCCHs) in the RRC reconfiguration message may be set to TRUE to instruct the UE to use the CG for all SL LCHs during T310. If the new parameter (UseCGforAllSLLCCHs) is absent or set to FALSE, then during operation 345, the CG may be used for one or more SL LCHs that are permitted (or instructed) to use the configured SL authorization. In either case, during operation 360, when the T310 timer expires, the UE may use resources from the exceptional TX pool for SL transport. Figure 2The operations described in [the document] can be similarly applied to [other applications]. Figure 3 Steps not specified in the text.

[0106] [Examples 1-2]

[0107] Figure 4 A flowchart of an embodiment according to this disclosure is shown.

[0108] In one method of this disclosure, the UE operation for SL communication transmission is as follows: Figure 4 As shown.

[0109] refer to Figure 4 The UE is in RRC connected state and is performing NR sidelink communication using resource configurations scheduled by the serving cell (in one embodiment, the serving cell may be PCell; in another embodiment, the serving cell may be SpCell). The RRC reconfiguration message receives resource configurations for scheduling resource allocations from the gNB. In operation 410, the RRC reconfiguration message includes a list of one or more configured SL authorization configurations. Each configured SL authorization configuration may be either CG type 1 or CG type 2.

[0110] Each configured SL grant includes an SL LCH priority list, and the SL grant based on this configuration applies to that priority list. Each SL LCH is associated with an SL LCH priority. If an SL LCH's SL LCH priority is included in the SL LCH priority list in the configured SL grant, then the SL grant based on that configuration can be used for SL transmissions from that SL LCH. In each configured SL grant, during operation 420, the UE schedules data from one or more SL LCHs that are allowed to use that configured SL grant according to the Logical Channel Priority (LCP) procedure.

[0111] In RRC connected state, the UE performs radio link monitoring. The downlink radio link quality of the primary cell is monitored by the physical layer in the UE to indicate the desynchronization / synchronization status to higher layers. When the radio link quality is worse than the threshold Q_out for all resources in the resource set used for radio link monitoring, the physical layer in the UE indicates desynchronization to higher layers in the radio link quality evaluation frame. When the radio link quality is better than the threshold Q_in for any resource in the resource set used for radio link monitoring, the physical layer in the UE indicates synchronization to higher layers (i.e., RRC) in the radio link quality evaluation frame.

[0112] In operation 430, upon receiving N310 consecutive asynchronous indications from a lower layer (i.e., the physical layer), a higher layer (i.e., the RRC) starts timer T310. The values ​​of N310 and T310 are configured by the network using RRC signaling. While T310 is running, if an exceptional TX resource pool is not configured in operation 440, the UE uses the configured SL grant for all SL LCHs in operation 450, regardless of whether the SL LCHs are allowed to use the configured SL grant according to the configuration received from the gNB. When timer T310 expires, the configured SL grant configuration received from the gNB is released.

[0113] During T310 startup, if the Exception TX resource pool is available in Operation 440, then in Operation 460, the UE uses resources from the Exception TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission. In Operation 445, during T310 startup, the UE stops using dynamic SL authorization and the configured SL authorization. If T310 stops due to a synchronization indication, the UE will stop using the Exception TX resource pool for SL transmission and begin using dynamic SL authorization and the configured SL authorization in the same manner as before T310 startup.

[0114] In one embodiment of the above operations, the configured SL license is CG type 1. In another embodiment of the above operations, the configured SL license is CG type 2. In yet another embodiment of the above operations, the configured SL license can be either CG type 1 or CG type 2.

[0115] [Examples 1-3]

[0116] Figure 5 and Figure 6 Flowcharts of various embodiments according to this disclosure are shown.

[0117] In one method of this disclosure, the UE operation for SL communication transmission is as follows: Figure 5 and Figure 6 As shown.

[0118] refer to Figure 5 and Figure 6 The UE is in RRC connected state and is performing NR sidelink communication using a resource configuration scheduled by the serving cell (in one embodiment, the serving cell may be PCell; in another embodiment, the serving cell may be SpCell). The resource configuration for scheduling resource allocation is received from the gNB in ​​the RRC reconfiguration message. The RRC reconfiguration message includes a list (510, 610) of one or more configured SL authorization configurations. Each configured SL authorization configuration may be one of CG type 1 or CG type 2.

[0119] Each configured SL grant includes an SL LCH priority list, and SL grants based on this configuration apply to that priority list. Each SL LCH is associated with an SL LCH priority. If an SL LCH's SL LCH priority is included in the SL LCH priority list within a configured SL grant, then the SL grant based on that configuration can be used for SL transmissions from that SL LCH. Within each configured SL grant, the UE schedules data from one or more SL LCHs that are allowed to use that configured SL grant according to logical channel priority order.

[0120] In RRC connected state, the UE performs radio link monitoring. The downlink radio link quality of the primary cell is monitored by the physical layer in the UE to indicate the desynchronization / synchronization status to higher layers. When the radio link quality is worse than the threshold Q_out for all resources in the resource set used for radio link monitoring, the physical layer in the UE indicates desynchronization to higher layers in the radio link quality evaluation frame. When the radio link quality is better than the threshold Q_in for any resource in the resource set used for radio link monitoring, the physical layer in the UE indicates synchronization to higher layers (i.e., RRC) in the radio link quality evaluation frame.

[0121] When N310 consecutive asynchronous indications are received from a lower layer (i.e., the physical layer), a higher layer (i.e., RRC) starts timer T310. The values ​​of N310 and T310 are configured by the network using RRC signaling (520, 620).

[0122] During T310 startup, if the UE is configured with SL configuration authorization, the UE determines whether there is at least one SL LCH (530, 630) that cannot use SL configuration authorization. This determination is based on the association between the SL LCH priority notified by the gNB via signaling and the SL configuration authorization.

[0123] - If at least one SL LCH (530, 630) cannot be licensed using SL configuration:

[0124] *The UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission (540, 640).

[0125] *UE stops using dynamic SL authorization and configured SL authorization for SL transport.

[0126] -Otherwise (530, 630)

[0127] * During T310 operation, the UE uses the configured SL grant (550, 650). While T310 is running, the UE can continue to use the dynamic SL grant received from the gNB, and the UE stops monitoring dynamic SL grants when T310 expires. Alternatively, the UE stops monitoring dynamic SL grants upon T310 startup.

[0128] When timer T310 expires, the SL authorization configuration received from the gNB is released. When timer T310 expires, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission.

[0129] In another embodiment, when the UE is configured with scheduled resource allocation and the configured SL authorization is not configured:

[0130] Option 1: During T310 operation, the UE can continue to use the dynamic SL grant received from the gNB, and when T310 expires, the UE stops monitoring the dynamic SL grant. When timer T310 expires, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission.

[0131] Option 2: When timer T310 starts, the UE stops monitoring dynamic SL grant. When timer T310 starts, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission. If T310 stops due to a synchronization indication, the UE begins monitoring dynamic SL grant.

[0132] In one embodiment of the above operations, the configured SL license is CG type 1. In another embodiment of the above operations, the configured SL license is CG type 2. In yet another embodiment of the above operations, the configured SL license can be either CG type 1 or CG type 2.

[0133] [Examples 1-4]

[0134] Figure 7 A flowchart of an embodiment according to this disclosure is shown.

[0135] In one method of this disclosure, the UE operation for SL communication transmission is as follows: Figure 7 As shown.

[0136] refer to Figure 7The UE is in RRC connected state and is performing NR sidelink communication using resource configurations scheduled by the serving cell (in one embodiment, the serving cell may be PCell; in another embodiment, the serving cell may be SpCell). The RRC reconfiguration message receives resource configurations for scheduling resource allocations from the gNB. In operation 710, the RRC reconfiguration message includes a list of one or more configured SL authorization configurations. Each configured SL authorization configuration may be either CG type 1 or CG type 2.

[0137] Each configured SL grant includes an SL LCH priority list, and SL grants based on this configuration apply to that priority list. Each SL LCH is associated with an SL LCH priority. If an SL LCH's SL LCH priority is included in the SL LCH priority list within a configured SL grant, then the SL grant based on that configuration can be used for SL transmissions from that SL LCH. Within each configured SL grant, the UE schedules data from one or more SL LCHs that are allowed to use that configured SL grant according to logical channel priority order.

[0138] In RRC connected state, the UE performs radio link monitoring. The downlink radio link quality of the primary cell is monitored by the physical layer in the UE to indicate the desynchronization / synchronization status to higher layers. When the radio link quality is worse than the threshold Q_out for all resources in the resource set used for radio link monitoring, the physical layer in the UE indicates desynchronization to higher layers in the radio link quality evaluation frame. When the radio link quality is better than the threshold Q_in for any resource in the resource set used for radio link monitoring, the physical layer in the UE indicates synchronization to higher layers (i.e., RRC) in the radio link quality evaluation frame.

[0139] Upon receiving N310 consecutive asynchronous indications from a lower layer (i.e., the physical layer), a higher layer (i.e., the RRC) initiates timer T310 in operation 720. The values ​​of N310 and T310 are configured by the network using RRC signaling.

[0140] During T310 startup, if the UE is configured with SL configuration authorization, then in operation 730, the UE determines whether there exists at least one SL LCH whose SL LCH priority is <= PriorityThreshold and cannot use the configured SL authorization. This determination is based on the correlation between SL LCH priority and SL configuration authorization, as well as the priority threshold (PriorityThreshold) notified by the gNB via signaling.

[0141] - In operation 730, if there exists at least one SL LCH whose SL LCH priority is <= PriorityThreshold and cannot use the configured SL authorization:

[0142] *In Operation 740, the UE uses resources from the Exception TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission.

[0143] *UE stops using dynamic SL authorization and configured SL authorization for SL transport.

[0144] -Otherwise, in operation 730

[0145] *In Operation 750, during T310 operation, the UE uses the configured SL grant. During T310 operation, the UE can continue to use the dynamic SL grant received from the gNB, and when T310 expires, the UE stops monitoring the dynamic SL grant. Alternatively, the UE stops monitoring the dynamic SL grant upon T310 startup.

[0146] When timer T310 expires, the SL authorization configuration received from the gNB is released. When timer T310 expires, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission.

[0147] In another embodiment, when the UE is configured with scheduled resource allocation and the configured SL authorization is not configured:

[0148] Option 1: During T310 operation, the UE can continue to use the dynamic SL grant received from the gNB, and when T310 expires, the UE stops monitoring the dynamic SL grant. When timer T310 expires, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission.

[0149] Option 2: When timer T310 starts, the UE stops monitoring dynamic SL grant. When timer T310 starts, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission. If T310 stops due to a synchronization indication, the UE begins monitoring dynamic SL grant.

[0150] In one embodiment of the above operations, the configured SL license is CG type 1. In another embodiment of the above operations, the configured SL license is CG type 2. In yet another embodiment of the above operations, the configured SL license can be either CG type 1 or CG type 2.

[0151] [Examples 1-5]

[0152] The UE is in RRC connected state and is performing NR sidelink communication using resource configurations scheduled by the serving cell (in one embodiment, the serving cell may be PCell; in another embodiment, the serving cell may be SpCell). The resource configurations for scheduling resource allocations are received from the gNB in ​​the RRC reconfiguration message. The RRC reconfiguration message includes a list of one or more configured SL grant configurations. Each configured SL grant configuration can be either CG type 1 or CG type 2.

[0153] Each configured SL grant includes an SL LCH priority list, and SL grants based on this configuration apply to that priority list. Each SL LCH is associated with an SL LCH priority. If an SL LCH's SL LCH priority is included in the SL LCH priority list within a configured SL grant, then the SL grant based on that configuration can be used for SL transmissions from that SL LCH. Within each configured SL grant, the UE schedules data from one or more SL LCHs that are allowed to use that configured SL grant according to logical channel priority order.

[0154] In RRC connected state, the UE performs radio link monitoring. The downlink radio link quality of the primary cell is monitored by the physical layer in the UE to indicate the desynchronization / synchronization status to higher layers. When the radio link quality is worse than the threshold Q_out for all resources in the resource set used for radio link monitoring, the physical layer in the UE indicates desynchronization to higher layers in the radio link quality evaluation frame. When the radio link quality is better than the threshold Q_in for any resource in the resource set used for radio link monitoring, the physical layer in the UE indicates synchronization to higher layers (i.e., RRC) in the radio link quality evaluation frame.

[0155] When N310 consecutive asynchronous indications are received from a lower layer (i.e., the physical layer), a higher layer (i.e., RRC) starts timer T310. The values ​​of N310 and T310 are configured by the network using RRC signaling.

[0156] When the T310 starts up:

[0157] - If the UE is configured with SL configuration grant and receives a UseConfiguredGrant indication from the gNB,

[0158] *During T310 operation, the UE continues to use the configured SL grant. Within each configured SL grant, the UE schedules data from one or more SL LCHs that are allowed to use that configured SL grant, based on logical channel priority. During T310 operation, the UE may continue to use dynamic SL grants received from the gNB, and the UE stops monitoring dynamic SL grants when T310 expires. Alternatively, the UE stops monitoring dynamic SL grants upon T310 startup.

[0159] -otherwise

[0160] The UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transport. The UE stops using dynamic SL grants and configured SL grants for SL transport.

[0161] When timer T310 expires, the SL authorization configuration received from the gNB is released. When timer T310 expires, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission.

[0162] In another embodiment, when the UE is configured with scheduled resource allocation and the configured SL authorization is not configured:

[0163] Option 1: During T310 operation, the UE can continue to use the dynamic SL grant received from the gNB, and when T310 expires, the UE stops monitoring the dynamic SL grant. When timer T310 expires, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission.

[0164] Option 2: When timer T310 starts, the UE stops monitoring dynamic SL grant. When timer T310 starts, the UE uses resources from the exceptional TX resource pool received from the gNB in ​​SI or dedicated RRC signaling for SL transmission. If T310 stops due to a synchronization indication, the UE begins monitoring dynamic SL grant.

[0165] In one embodiment of the above operations, the configured SL license is CG type 1. In another embodiment of the above operations, the configured SL license is CG type 2. In yet another embodiment of the above operations, the configured SL license can be either CG type 1 or CG type 2.

[0166] [Example 2]

[0167] Dual Active Protocol Stack (DAPS) and Interrupt Handling

[0168] The current operation is as follows:

[0169] 1. The UE receives an RRCReconfiguration message that includes a synchronized reconfiguration.

[0170] 2. UE starts T304.

[0171] 3. Sidelink configuration of the target PCell for UE application (i.e., the configuration received in sl-ConfigDedicatedNR IE)

[0172] - If mode 1 (i.e., sl-ScheduledConfig) is configured in sl-ConfigDedicatedNR.

[0173] *If the exception resource pool used for SL transmission is notified via signaling, the UE will use the exception resource pool for SL transmission during T304 operation.

[0174] - Otherwise, if mode 2 (i.e., sl-UE-SelectedConfig) is configured in sl-ConfigDedicatedNR.

[0175] *If the exception resource pool used for SL transmission is notified via signaling, the UE uses the exception resource pool for SL transmission until the sensing results are available for the normal TX resource pool.

[0176] 4. The UE performs DL synchronization and RA procedures toward the target cell.

[0177] 5. Stop T304 when the RA procedure is completed.

[0178] The problem is that the current operation is designed for normal handover. Recently, DAPS HO was introduced for handover interruptions on the link between the UE and gNB. During handover, the UE performing V2X communication also experiences an interruption, which can be further enhanced using DAPS handover.

[0179] [Example 2-1]

[0180] 1. The UE is in RRC connected state. The UE receives an RRCReconfiguration message that includes the SL configuration for SL communication.

[0181] 2. The UE receives an RRCReconfiguration message that includes reconfigurationWithSync. reconfigurationWithSync is included in spCellConfig of the MCG's CellGroupConfig. The RRCReconfiguration message includes the SL configuration for SL communication. This SL configuration comes from the target cell (i.e., PCell).

[0182] 3. UE starts T304.

[0183] 4. The UE determines whether dapsConfig is configured for any DRB (i.e., UuDRB) in the RRCReconfiguration message received in Operation 2.

[0184] 5. If dapsConfig is not configured for any DRB:

[0185] - Reset the MAC entity for the cell group (MCG)

[0186] - The sidelink configuration of the target PCell applied by the UE (i.e., the configuration received in sl-ConfigDedicatedNR in Operation 2).

[0187] *If mode 1 (i.e., sl-ScheduledConfig) is configured in sl-ConfigDedicatedNR.

[0188] **If the UE is configured with sl-TxPoolExceptional for the relevant frequency in RRCReconfiguration included in sl-ConfigDedicatedNR, then during T304 operation, the UE uses the exception resource pool for SL transmission.**

[0189] Otherwise, if mode 2 (i.e., sl-UE-SelectedConfig) is configured in sl-ConfigDedicatedNR.

[0190] **If the UE is configured with sl-TxPoolExceptional for the relevant frequency in RRCReconfiguration, then SL transmission is performed using the exception resource pool until the sensing results are available for the normal TX resource pool.**

[0191] - Use this MAC entity to perform SL operations

[0192] 6. If dapsConfig is configured for any DRB:

[0193] - A MAC entity is created for the target. The source MAC entity is not released. Therefore, there will be two MAC entities for the same cell group (MCG).

[0194] - The UE continues to use the source cell configuration (received in Operation 1) for sidelink communication until the random access procedure is completed on the target cell (or until the source release indication is received in the RRC reconfiguration message); continues to perform DL / UL reception / transmission related to the sidelink communication of the source cell until the random access procedure is completed on the target cell (or until the source release indication is received in the RRC reconfiguration message);

[0195] - Perform the SL operation using the source cell MAC entity (using the source cell's SL configuration received in Operation 1) until the random access procedure is completed on the target cell (or until the source release indication is received in the RRC reconfiguration message).

[0196] - In one embodiment, if a scheduled resource allocation is configured in the target cell, the SL operation is performed using the source cell MAC entity (using the source cell's SL configuration received in Operation 1) until the random access procedure is completed on the target cell. In one embodiment, if a UE-selected resource allocation is configured in the target cell, the SL operation is performed using the source cell MAC entity (using the source cell's SL configuration received in Operation 1) until a source release indication is received in the RRC reconfiguration message.

[0197] 7. The UE performs DL synchronization and RA procedures toward the target cell.

[0198] 8. When the RA procedure is complete:

[0199] -Stop T304

[0200] 9. If dapsConfig is configured for any DRB, then upon completion of the RA procedure (or upon receiving a source release indication in an RRC reconfiguration message):

[0201] A. The UE applies the sidelink configuration of the target PCell (i.e., the sl-ConfigDedicatedNR received in the RRC reconfiguration message including reconfigurationWithSync in Operation 2).

[0202] B. Perform SL operation using the target cell MAC entity.

[0203] [Example 2-2]

[0204] The RRCReconfiguration message may include an indication to indicate whether the SL operation can continue in the source MAC entity until the RA procedure is completed in the target cell (i.e., the target MAC entity).

[0205] 1. The UE is in RRC connected state. The UE receives an RRCReconfiguration message that includes the SL configuration for SL communication.

[0206] 2. The UE receives an RRCReconfiguration message that includes reconfigurationWithSync. reconfigurationWithSync is included in spCellConfig of the MCG's CellGroupConfig. The RRCReconfiguration message includes the SL configuration for SL communication. This SL configuration comes from the target cell (i.e., PCell).

[0207] 3. UE starts T304.

[0208] 4. The UE determines whether dapsConfig is configured for any DRB (i.e., UuDRB) in the RRCReconfiguration message received in Operation 2.

[0209] 5. If dapsConfig is not configured for any DRB:

[0210] - Reset the MAC entity for the cell group (MCG)

[0211] - The sidelink configuration of the target PCell applied by the UE (i.e., the sl-ConfigDedicatedNR in the RRCReconfiguration message received in Operation 2).

[0212] *If Mode 1 (i.e., sl-ScheduledConfig) is configured in sl-ConfigDedicatedNR: If the UE is configured with sl-TxPoolExceptional for the relevant frequency in RRCReconfiguration included in sl-ConfigDedicatedNR, then during T304 operation, SL transmission will be performed using the exception resource pool.

[0213] *Otherwise, if Mode 2 (i.e., sl-UE-SelectedConfig) is configured in sl-ConfigDedicatedNR: if the UE is configured with sl-TxPoolExceptional for the relevant frequency in RRCReconfiguration, then SL transmission is performed using the exception resource pool until the sensing results are available for the normal TX pool.

[0214] * Use this MAC entity to perform SL operations

[0215] 6. If dapsConfig is configured for any DRB:

[0216] - A MAC entity is created for the target. The source MAC entity is not released. Therefore, there will be two MAC entities for the same cell group (MCG).

[0217] -If ContinueSLOperationinSource is received in the RRCReconfiguration message of Operation 2

[0218] A. The UE continues to use the source cell configuration (received in Operation 1) for sidelink communication until the random access procedure is completed on the target cell (or until the source release indication is received in the RRC reconfiguration message); continues to perform DL / UL reception / transmission related to the sidelink communication of the source cell until the random access procedure is completed on the target cell (or until the source release indication is received in the RRC reconfiguration message).

[0219] B. Perform the SL operation using the source cell MAC entity until the random access procedure is completed on the target cell (or until a source release indication is received in the RRC reconfiguration message).

[0220] C. In one embodiment, if a scheduled resource allocation is configured in the target cell, the SL operation is performed using the source cell MAC entity (using the source cell's SL configuration received in Operation 1) until the random access procedure is completed on the target cell. In one embodiment, if a UE-selected resource allocation is configured in the target cell, the SL operation is performed using the source cell MAC entity (using the source cell's SL configuration received in Operation 1) until a source release indication is received in the RRC reconfiguration message.

[0221] - Otherwise, if ContinueSLOperationinSource is not received in the RRCReconfiguration message of Operation 2 (or is set to FALSE);

[0222] A. The UE applies the sidelink configuration of the target PCell (i.e., the sl-ConfigDedicatedNR received in the RRC reconfiguration message including reconfigurationWithSync in Operation 2).

[0223] B. If Mode 1 (i.e., sl-ScheduledConfig) is configured in sl-ConfigDedicatedNR: If the UE is configured with sl-TxPoolExceptional for the relevant frequency in RRCReconfiguration included in sl-ConfigDedicatedNR, then during T304 operation, SL transmission is performed using the exception resource pool.

[0224] C. Otherwise, if Mode 2 (i.e., sl-UE-SelectedConfig) is configured in sl-ConfigDedicatedNR: if the UE is configured with sl-TxPoolExceptional for the relevant frequency in RRCReconfiguration, then SL transmission is performed using the exception resource pool until the sensing results are available for the normal TX pool.

[0225] D. Perform SL operation using the target cell MAC entity

[0226] 7. The UE performs DL synchronization and RA procedures toward the target cell.

[0227] 8. When completing the RA procedure:

[0228] -Stop T304

[0229] 9. Upon completion of the RA procedure (or upon receiving a source release indication in the RRC reconfiguration message):

[0230] - If dapsConfig is configured for any DRB, and ContinueSLOperationinSource is received in the RRCReconfiguration message in Operation 2:

[0231] i. The sidelink configuration of the target PCell applied by the UE (i.e., the sl-ConfigDedicatedNR received in the RRC reconfiguration message including reconfigurationWithSync in Operation 2).

[0232] ii. Perform SL operation using the target cell MAC entity

[0233] [Examples 2-3]

[0234] For some SL DRBs (as indicated in the RRCReconfiguration message), the source MAC entity is used to perform the SL operation, and for other SL DRBs, the target MAC entity is used to perform the SL operation.

[0235] Figure 8 This is a block diagram of a terminal according to an embodiment of the present disclosure.

[0236] refer to Figure 8 The terminal includes a transceiver 810, a controller 820, and a memory 830. The controller 820 may refer to a circuit, an application-specific integrated circuit (ASIC), or at least one processor. The transceiver 810, controller 820, and memory 830 are configured to perform actions as shown in the accompanying drawings (e.g., ...). Figures 1 to 7 The operation of the terminal shown in the diagram or described above. Although the transceiver 810, controller 820, and memory 830 are shown as separate entities, they can be implemented as a single entity like a single chip. Alternatively, the transceiver 810, controller 820, and memory 830 can be electrically connected or coupled to each other.

[0237] Transceiver 810 can send signals to and receive signals from other network entities (e.g., base stations). Controller 820 can control the terminal to perform functions according to one of the above embodiments. Controller 820 can refer to a circuit, an ASIC, or at least one processor. In one embodiment, the operation of the terminal can be implemented using memory 830 storing corresponding program code. Specifically, the terminal may be equipped with memory 830 to store program code that implements the desired operation. To perform the desired operation, controller 820 can read and execute the program code stored in memory 830 using a processor or central processing unit (CPU).

[0238] Figure 9 This is a block diagram of a base station according to an embodiment of the present disclosure.

[0239] refer to Figure 9 The base station includes a transceiver 910, a controller 920, and a memory 930. The transceiver 910, controller 920, and memory 930 are configured to perform actions as shown in the accompanying drawings (e.g., ...). Figures 1 to 7 The operation of the network entity (e.g., gNB) shown in the diagram or described above. Although transceiver 910, controller 920, and memory 930 are shown as separate entities, they can be implemented as a single entity like a single chip. Transceiver 910, controller 920, and memory 930 can be electrically connected or coupled to each other.

[0240] Transceiver 910 can send signals to and receive signals from other network entities (e.g., terminals). Controller 920 can control the base station to perform functions according to one of the above embodiments. Controller 920 can refer to a circuit, an ASIC, or at least one processor. In one embodiment, the operation of the base station can be implemented using memory 930 storing corresponding program code. Specifically, the base station can be equipped with memory 930 to store program code for implementing the desired operation. To perform the desired operation, controller 920 can read and execute the program code stored in memory 930 using a processor or CPU.

[0241] Although this disclosure has been shown and described with reference to various embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of this disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a first terminal in a wireless communication system, the method comprising: Receive control messages from the base station, the control messages including configuration of sidelink authorization for configuration; For the first sidelink logical channel that is allowed to use the configured sidelink authorization, a sidelink signal is sent to the second terminal based on the configured sidelink authorization; In the event of continuous asynchrony indications for the cell received from a lower layer, a timer associated with radio link failure is started; Identify whether a second sidelink logical channel exists that is not available for sidelink authorization in the configuration; In the absence of a sidelink logical channel that is not available for the sidelink authorization configured, a sidelink signal is sent to the second terminal based on the configured sidelink authorization during the timer's operation; as well as In the event that a second sidelink logical channel is available that is not available for the sidelink authorization of the configuration, a sidelink signal is sent to the second terminal based on resources from the exception transport pool during the timer's operation.

2. The method according to claim 1, wherein, Identifying the existence of the second sidelink logical channel also includes identifying whether an indication has been received from the base station to use the configured sidelink authorization for both the first sidelink logical channel and the second sidelink logical channel.

3. The method according to claim 1, wherein, Identifying the existence of the second sidelink logical channel also includes identifying whether an association between the second sidelink logical channel and the configured sidelink authorization is received from the base station.

4. The method according to claim 1, wherein, Identifying the existence of a second sidelink logical channel also includes identifying whether the logical channel priority of the second sidelink logical channel is included in the configured sidelink grant logical channel priority list, or The identification of the existence of the second sidelink logical channel also includes identifying whether the logical channel priority of the second sidelink logical channel is equal to or lower than the priority threshold of the sidelink authorization that cannot be used.

5. A method performed by a second terminal in a wireless communication system, the method comprising: Receive control messages from the base station, the control messages including configuration of sidelink authorization for configuration; as well as For a first sidelink logical channel that is permitted to use the configured sidelink authorization, a sidelink signal is received from the first terminal based on the configured sidelink authorization. Where no sidelink logical channel is available that cannot be used for the configured sidelink grant, the sidelink signal is received from the first terminal based on the configured sidelink grant during the execution of a timer associated with a radio link failure. In the event that a second sidelink logical channel is available but cannot be used for the configured sidelink authorization, the sidelink signal is received from the first terminal based on resources from the exception transmission pool during the timer's operation.

6. The method according to claim 5, wherein, Whether an indication has been received to use the configured sidelink authorization for both the first and second sidelink logical channels is identified to determine the second sidelink logical channel, or Specifically, whether the association between the second sidelink logical channel and the configured sidelink authorization is received is identified to determine the second sidelink logical channel.

7. The method according to claim 5, wherein, Whether the logical channel priority of the second sidelink logical channel is included in the configured sidelink grant logical channel priority list is identified to determine the second sidelink logical channel, or Specifically, the logical channel priority of the second sidelink logical channel is identified as being equal to or lower than the priority threshold that prevents the use of the configured sidelink authorization, in order to determine the second sidelink logical channel.

8. A first terminal in a wireless communication system, the first terminal comprising: A transceiver is configured to send and receive signals; as well as The controller is configured as follows: Receive control messages from the base station, the control messages including sidelink authorization configuration for configuration. For the first sidelink logical channel that is allowed to use the configured sidelink authorization, a sidelink signal is sent to the second terminal based on the configured sidelink authorization. Upon receiving continuous asynchrony indications for the cell from a lower layer, a timer associated with radio link failure is started. Identify whether there is a second sidelink logical channel that cannot be used for the sidelink authorization in the configuration. In the absence of a sidelink logical channel that cannot be used for the configured sidelink grant, a sidelink signal is sent to the second terminal based on the configured sidelink grant during the timer's execution. In the event that a second sidelink logical channel is available that is not available for the sidelink authorization of the configuration, a sidelink signal is sent to the second terminal based on resources from the exception transmission pool during the timer's operation.

9. The first terminal according to claim 8, wherein, The controller is also configured to identify whether it receives from the base station an indication to use the configured sidelink authorization for all of the first sidelink logical channels and the second sidelink logical channels.

10. The first terminal according to claim 8, wherein, The controller is also configured to identify whether an association between the second sidelink logical channel and the configured sidelink grant is received from the base station.

11. The first terminal according to claim 8, wherein, The controller is also configured to identify whether the logical channel priority of the second sidelink logical channel is included in the configured sidelink-granted logical channel priority list, or The controller is further configured to identify whether the logical channel priority of the second sidelink logical channel is equal to or lower than the priority threshold that prevents the use of the configured sidelink license.

12. A second terminal in a wireless communication system, the second terminal comprising: A transceiver is configured to send and receive signals; as well as The controller is configured as follows: Receive control messages from the base station, the control messages including configuration of sidelink authorization for configuration, and For a first sidelink logical channel that is permitted to use the configured sidelink authorization, a sidelink signal is received from the first terminal based on the configured sidelink authorization. Where no sidelink logical channel is available that cannot be used for the configured sidelink grant, the sidelink signal is received from the first terminal based on the configured sidelink grant during the execution of a timer associated with a radio link failure. In the event that a second sidelink logical channel is available but cannot be used for the configured sidelink authorization, the sidelink signal is received from the first terminal based on resources from the exception transmission pool during the timer's operation.

13. The second terminal according to claim 12, wherein, Whether an indication is received for using the configured sidelink authorization for both the first and second sidelink logical channels is identified to determine the second sidelink logical channel.

14. The second terminal according to claim 12, wherein, Whether the association between the second sidelink logical channel and the configured sidelink authorization is received is identified to determine the second sidelink logical channel.

15. The second terminal according to claim 12, wherein, Whether the logical channel priority of the second sidelink logical channel is included in the configured sidelink grant logical channel priority list is identified to determine the second sidelink logical channel, or Specifically, the logical channel priority of the second sidelink logical channel is identified as being equal to or lower than the priority threshold that prevents the use of the configured sidelink authorization, in order to determine the second sidelink logical channel.

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