Apparatus and method for handling sidelink radio bearer configuration in wireless communication system

Abstract

The present disclosure relates to a communication technique and a system for integrating a 5G communication system with IoT technology to support higher data transmission rates than those of a 4G system. The present disclosure may be applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. The present disclosure is for setting configuration parameter information of a sidelink wireless bearer in a wireless communication system, and the method of operation of a terminal may include a process of determining the necessity of SLRB configuration, a process of obtaining SLRB configuration, a process of performing sidelink data transmission and reception using SLRB configuration, a process of determining whether there is a conflict of SLRB configuration, and a process of performing a procedure for adjusting the SLRB configuration conflict.

Description

Technology Field

[0001] The present disclosure generally relates to a wireless communication system, and more specifically to an apparatus and method for processing side-link wireless bearer configuration information in a wireless communication system. Background Technology

[0002] 4G(4 th To meet the increasing demand for wireless data traffic following the commercialization of the (generation) communication system, improved 5G (5 th Efforts are being made to develop 5G communication systems or pre-5G communication systems. For this reason, 5G communication systems or pre-5G communication systems are referred to as Beyond 4G Network communication systems or Post-LTE systems.

[0003] To achieve high data transmission rates, 5G communication systems are being considered for implementation in the mmWave band (e.g., the 60 GHz band). To mitigate path loss and increase the transmission distance of radio waves in the mmWave band, beamforming, massive MIMO, full Dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large-scale antenna technologies are being discussed for 5G communication systems.

[0004] In addition, to improve the network of the system, technologies such as advanced small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation are being developed in 5G communication systems.

[0005] In addition, advanced coding modulation (ACM) methods such as FQAM (Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation) and SWSC (Sliding Window Superposition Coding), as well as advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (Non Orthogonal Multiple Access), and SCMA (Sparse Code Multiple Access) are being developed in 5G systems.

[0006] Meanwhile, the Internet is evolving from a human-centric network where humans generate and consume information into an IoT (Internet of Things) network that processes information by exchanging it among distributed components, such as objects. IoE (Internet of Everything) technology, which combines IoT with Big Data processing technologies through connections with cloud servers, is also emerging. To implement IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required; consequently, technologies such as sensor networks, Machine-to-Machine (M2M) communication, and Machine-Type Communication (MTC) are currently being researched to facilitate the connection of objects. In an IoT environment, intelligent IT services that create new value for human life by collecting and analyzing data generated from connected objects can be provided. Through the convergence and integration of existing IT technologies with various industries, IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0007] Accordingly, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, Machine to Machine (M2M), and Machine Type Communication (MTC) are being implemented using 5G communication techniques such as beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology, as previously described, can also be considered an example of the convergence of 5G and IoT technologies.

[0008] In addition, sidelink communication using 5G communication systems is being researched, and it is expected that this sidelink communication will be applied, for example, to vehicle-to-everything (V2X) communication to provide various services to users. The problem to be solved

[0009] Based on the discussion above, the present disclosure provides an apparatus and method for processing sidelink configuration information in a wireless communication system.

[0010] In addition, the present disclosure provides an apparatus and method for setting wireless bearer configuration information between terminals performing side-link unicast, side-link groupcast, and side-link broadcast-based transmission and reception in a wireless communication system. means of solving the problem

[0011] According to various embodiments of the present disclosure, a method of operation of a terminal in a wireless communication system may include a process of determining the necessity of obtaining a sidelink radio bearer (SLRB) configuration, a process of obtaining an SLRB configuration from a network (NW) or system, and a process of transmitting and receiving sidelink data with a counterpart terminal of a sidelink unicast using the obtained SLRB configuration.

[0012] In addition, the method of operation of a terminal according to various embodiments of the present disclosure may include a process of determining a conflict in SLRB configuration and, if a conflict in SLRB configuration is determined, a process of determining a failure of a sidelink unicast setting procedure.

[0013] In addition, the method of operation of a terminal according to various embodiments of the present disclosure may include a process of determining a conflict of SLRB configurations, a process of determining the need to adjust conflicted configuration parameters, and a process of performing a configuration parameter adjustment procedure.

[0014] In addition, the operation method of a terminal according to various embodiments of the present disclosure may include a process of reporting to the NW when the need to adjust the SLRB configuration is determined, and a process of receiving confirmation of the configuration parameters of the NW.

[0015] Additionally, according to various embodiments of the present disclosure, a terminal in a wireless communication system comprises a transceiver and at least one processor connected to the transceiver. The at least one processor may determine the need to obtain an SLRB configuration, obtain an SLRB configuration, transmit and receive sidelink data using the SLRB configuration, determine the need to adjust SLRB configuration parameters, and perform a procedure for adjusting SLRB configuration parameters. Effects of the invention

[0016] The apparatus and method according to various embodiments of the present disclosure can effectively resolve terminal operation errors caused by inconsistencies in configuration information between terminals performing direct communication and service quality degradation caused by service interruption.

[0017] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below. Brief explanation of the drawing

[0018] FIG. 1 illustrates a wireless communication system according to various embodiments of the present disclosure. FIG. 2 illustrates the configuration of a base station in a wireless communication system according to various embodiments of the present disclosure. FIG. 3 illustrates the configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure. FIG. 4 illustrates the configuration of a communication unit in a wireless communication system according to various embodiments of the present disclosure. FIG. 5 illustrates the structure of a wireless time-frequency resource of a wireless communication system according to various embodiments of the present disclosure. FIGS. 6a through 6d illustrate examples of scenarios for sidelink communication in a wireless communication system according to various embodiments of the present disclosure. FIGS. 7a and 7b illustrate examples of transmission methods for sidelink communication in wireless communication systems according to various embodiments of the present disclosure. FIGS. 8a and 8b illustrate signaling flow between terminals using a NW coordination scheme according to various embodiments of the present disclosure. FIG. 9 illustrates a method for selecting a terminal that determines an SLRB configuration according to various embodiments of the present disclosure. FIGS. 10 to 12 illustrate a method for coordinating an SLRB configuration that a terminal determines and decides on its own according to various embodiments of the present disclosure. FIGS. 13 to 15 illustrate an SLRB configuration coordination method in which a terminal determines and decides on its own according to various embodiments of the present disclosure. FIGS. 16 to 18 illustrate a method for coordinating SLRB configuration using base station cooperation according to various embodiments of the present disclosure. FIG. 19 illustrates a signal flow for handling SLRB configuration processing failures according to various embodiments of the present disclosure. FIG. 20 illustrates a signal flow between terminals handling a collision of SLRB configurations according to various embodiments of the present disclosure. Specific details for implementing the invention

[0019] The terms used in this disclosure are used merely to describe specific embodiments and are not intended to limit the scope of other embodiments. A singular expression may include a plural expression unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as generally understood by those skilled in the art described in this disclosure. Terms used in this disclosure that are defined in a general dictionary may be interpreted as having the same or similar meaning as they have in the context of the relevant technology, and are not to be interpreted in an ideal or overly formal sense unless explicitly defined in this disclosure. In some cases, even terms defined in this disclosure are not to be interpreted to exclude the embodiments of this disclosure.

[0020] In the various embodiments of the present disclosure described below, a hardware-based approach is described as an example. However, since the various embodiments of the present disclosure include techniques using both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.

[0022] The present disclosure relates to an apparatus and method for processing sidelink configuration information in a wireless communication system. Specifically, the present disclosure relates to a method and apparatus for configuring a bi-directional wireless bearer or a uni-directional wireless bearer in sidelink communication between terminals, and for processing configuration information among the configuration information of a wireless bearer between terminals, wherein the settings between the two terminals must match.

[0023] In the present disclosure, the sidelink configuration information may include, as an example, the configuration information of a sidelink wireless bearer, and may include configuration information for processing at least one of a signaling wireless bearer and a data wireless bearer. Specifically, the configuration information may include at least one of PDCP layer configuration information, RLC layer configuration information, MAC layer configuration information, and physical layer configuration information of a signaling wireless bearer to which sidelink RRC signaling and sidelink PC5-S signaling are transmitted. The configuration information may include at least one of SDAP layer configuration information, PDCP layer configuration information, RLC layer configuration information, MAC layer configuration information, and physical layer configuration information of a data wireless bearer to which sidelink user data is transmitted.

[0025] Terms referring to signals, channels, control information, network entities, and device components used in the following description are examples provided for the convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

[0026] In the following description, the terms "physical channel" and "signal" may be used interchangeably with "data" or "control signal." For example, PDSCH (physical downlink shared channel) is a term referring to a physical channel through which data is transmitted, but PDSCH may also be used to refer to data. That is, in this disclosure, the expression "transmits a physical channel" may be interpreted as equivalent to the expression "transmits data or a signal through a physical channel."

[0027] In the present disclosure, upper signaling refers to a signal transmission method transmitted from a base station to a terminal using a physical layer downlink data channel, or from a terminal to a base station using a physical layer uplink data channel. Upper signaling may be understood as radio resource control (RRC) signaling or a media access control (MAC) control element (CE).

[0028] Additionally, in this disclosure, expressions such as "greater than" or "less than" have been used to determine whether specific conditions are satisfied or fulfilled; however, this is merely for illustrative purposes and does not exclude descriptions of "greater than" or "less than." Conditions described as "greater than" may be replaced with "greater than," conditions described as "less than" with "less than," and conditions described as "greater than and less than" with "greater than and less than."

[0029] Additionally, the present disclosure describes various embodiments using terms used in some communication standards (e.g., 3GPP (3rd Generation Partnership Project)), but this is merely illustrative. Various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0031] FIG. 1 illustrates a wireless communication system according to various embodiments of the present disclosure.

[0032] FIG. 1 illustrates a base station (110), a terminal (120), and a terminal (130) as part of nodes utilizing a wireless channel in a wireless communication system. FIG. 1 illustrates only one base station, but other base stations identical or similar to the base station (110) may be included.

[0033] A base station (110) is a network infrastructure that provides wireless access to terminals (120, 130). The base station (110) has coverage defined as a certain geographical area based on the distance at which it can transmit signals. In addition to being a base station, the base station (110) may be referred to as an 'access point (AP)', 'eNodeB (eNB)', '5G node (5th generation node)', 'next generation nodeB (gNB)', 'wireless point', 'transmission / reception point (TRP)', or other terms having an equivalent technical meaning.

[0034] Each of the terminal (120) and terminal (130) is a device used by a user and performs communication with the base station (110) via a wireless channel. The link from the base station (110) toward the terminal (120) or terminal (130) is referred to as a downlink (DL), and the link from the terminal (120) or terminal (130) toward the base station (110) is referred to as an uplink (UL). Additionally, the terminal (120) and terminal (130) can perform communication with each other via a wireless channel. In this case, the link between the terminal (120) and terminal (130) is referred to as a sidelink, and the sidelink may be used interchangeably with the PC5 interface. In some cases, at least one of the terminal (120) and terminal (130) may be operated without user involvement. That is, at least one of the terminal (120) and terminal (130) is a device that performs machine type communication (MTC) and may not be carried by the user. Each of the terminal (120) and terminal (130) may be referred to as 'user equipment (UE)', 'mobile station', 'subscriber station', 'remote terminal', 'wireless terminal', or 'user device' or other terms having an equivalent technical meaning.

[0035] A base station (110), a terminal (120), and a terminal (130) can transmit and receive wireless signals in a millimeter wave (mmWave) band (e.g., 28 GHz, 30 GHz, 38 GHz, 60 GHz). At this time, to improve channel gain, the base station (110), the terminal (120), and the terminal (130) can perform beamforming. Here, beamforming may include transmission beamforming and reception beamforming. That is, the base station (110), the terminal (120), and the terminal (130) can impart directivity to the transmission signal or the reception signal. To this end, the base station (110) and the terminals (120, 130) can select serving beams (112, 113, 121, 131) through a beam search or beam management procedure. After serving beams (112, 113, 121, 131) are selected, subsequent communication can be performed through a resource that is in a quasi-co-located (QCL) relationship with the resource that transmitted the serving beams (112, 113, 121, 131).

[0036] If large-scale characteristics of the channel transmitting the symbol on the first antenna port can be inferred from the channel transmitting the symbol on the second antenna port, the first antenna port and the second antenna port may be evaluated to have a QCL relationship. For example, the large-scale characteristics may include at least one of a delay spread, a Doppler spread, a Doppler shift, an average gain, an average delay, and a spatial receiver parameter.

[0037] The terminal (120) illustrated in FIG. 1 can support vehicle communication. In the case of vehicle communication, standardization work for V2X technology based on the device-to-device (D2D) communication structure in LTE systems was completed in 3GPP Release 14 and Release 15, and efforts to develop V2X technology based on 5G NR are currently underway. NR V2X is expected to support unicast communication, groupcast (or multicast) communication, and broadcast communication between terminals. Furthermore, unlike LTE V2X, which aims to transmit and receive basic safety information necessary for vehicle road driving, NR V2X aims to provide more advanced services such as platooning, advanced driving, extended sensors, and remote driving.

[0038] V2X services can be classified into basic safety services and advanced services. Basic safety services may include detailed services ranging from vehicle alerts (CAM (cooperative awareness messages) or BSM (basic safety message)) to left-turn alerts, front collision warnings, emergency vehicle approach alerts, forward obstacle warnings, and intersection signal information services; V2X information can be transmitted and received using broadcast, unicast, or groupcast transmission methods. Advanced services not only have stricter QoS (quality of service) requirements than basic safety services but also require methods to transmit and receive V2X information using unicast and groupcast transmission methods in addition to broadcast, enabling transmission and reception within a specific vehicle group or between two vehicles. Advanced services may include detailed services such as platooning services, autonomous driving services, remote driving services, and extended sensor-based V2X services.

[0039] Hereinafter, the sidelink (SL) refers to the signal transmission and reception path between terminals, and may be used interchangeably with the PC5 interface. Hereinafter, the base station is the entity that performs resource allocation for terminals and may be a base station that supports both V2X communication and general cellular communication, or a base station that supports only V2X communication. That is, the base station may refer to an NR base station (e.g., gNB), an LTE base station (e.g., eNB), or an RSU (road site unit). A terminal may include general user equipment and mobile stations, as well as vehicles supporting vehicular-to-vehicular (V2V) communication, vehicles or pedestrian handsets (e.g., smartphones) supporting vehicular-to-pedestrian (V2P) communication, vehicles supporting vehicular-to-network (V2N) communication, or vehicles supporting vehicular-to-infrastructure (V2I) communication, and RSUs equipped with terminal functions, RSUs equipped with base station functions, or RSUs equipped with some base station functions and some terminal functions. Additionally, the V2X terminal used in the following description may also be referred to as a terminal. That is, in relation to V2X communication, a terminal may be used as a V2X terminal.

[0040] The base station and the terminal are connected through the Uu interface. The uplink (UL) refers to the wireless link through which the terminal transmits data or control signals to the base station, and the downlink (DL) refers to the wireless link through which the base station transmits data or control signals to the terminal.

[0042] FIG. 2 illustrates the configuration of a base station in a wireless communication system according to various embodiments of the present disclosure. The configuration exemplified in FIG. 2 can be understood as the configuration of a base station (110). Terms such as '... unit', '... unit' used below refer to a unit that processes at least one function or operation, and this may be implemented in hardware or software, or a combination of hardware and software.

[0043] Referring to FIG. 2, the base station (110) includes a wireless communication unit (210), a backhaul communication unit (220), a storage unit (230), and a control unit (240).

[0044] The wireless communication unit (210) performs functions for transmitting and receiving signals through a wireless channel. For example, the wireless communication unit (210) performs a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the system. For example, when transmitting data, the wireless communication unit (210) generates complex symbols by encoding and modulating the transmitted bit sequence. Also, when receiving data, the wireless communication unit (210) restores the received bit sequence by demodulating and decoding the baseband signal.

[0045] Additionally, the wireless communication unit (210) upconverts a baseband signal into an RF (radio frequency) band signal and transmits it through an antenna, and downconverts the RF band signal received through the antenna into a baseband signal. To this end, the wireless communication unit (210) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC (digital to analog converter), an ADC (analog to digital converter), etc. Additionally, the wireless communication unit (210) may include a plurality of transmission and reception paths. Furthermore, the wireless communication unit (210) may include at least one antenna array composed of a plurality of antenna elements.

[0046] In terms of hardware, the wireless communication unit (210) may be composed of a digital unit and an analog unit, and the analog unit may be composed of a plurality of sub-units depending on operating power, operating frequency, etc. The digital unit may be implemented with at least one processor (e.g., a digital signal processor (DSP)).

[0047] The wireless communication unit (210) transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit (210) may be referred to as a 'transmitter', a 'receiver', or a 'transceiver'. Furthermore, in the following description, transmission and reception performed through a wireless channel are used to mean that processing as described above is performed by the wireless communication unit (210).

[0048] The backhaul communication unit (220) provides an interface for communicating with other nodes within the network. That is, the backhaul communication unit (220) converts a bit sequence transmitted from the base station (110) to another node, e.g., another connection node, another base station, an upper node, a core network, etc., into a physical signal, and converts a physical signal received from another node into a bit sequence.

[0049] The storage unit (230) stores data such as basic programs, application programs, and configuration information for the operation of the base station (110). The storage unit (230) may be composed of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Additionally, the storage unit (230) provides the stored data upon the request of the control unit (240).

[0050] The control unit (240) controls the overall operations of the base station (110). For example, the control unit (240) transmits and receives signals through the wireless communication unit (210) or through the backhaul communication unit (220). Additionally, the control unit (240) writes and reads data to and from the storage unit (230). Furthermore, the control unit (240) can perform the functions of a protocol stack required by the communication standard. According to other implementation examples, the protocol stack may be included in the wireless communication unit (210). To this end, the control unit (240) may include at least one processor. According to various embodiments, the control unit (240) can control the base station (110) to perform operations according to various embodiments described below.

[0052] FIG. 3 illustrates the configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure.

[0053] The configuration exemplified in FIG. 3 can be understood as a configuration of a terminal (120). Terms such as '...part', '...unit' used below refer to a unit that processes at least one function or operation, and this can be implemented as hardware or software, or a combination of hardware and software.

[0054] Referring to FIG. 3, the terminal (120) includes a communication unit (310), a storage unit (320), and a control unit (330).

[0055] The communication unit (310) performs functions for transmitting and receiving signals through a wireless channel. For example, the communication unit (310) performs a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the system. For example, when transmitting data, the communication unit (310) generates complex symbols by encoding and modulating the transmitted bit sequence. Also, when receiving data, the communication unit (310) restores the received bit sequence by demodulating and decoding the baseband signal. Additionally, the communication unit (310) upconverts the baseband signal into an RF band signal and transmits it through an antenna, and downconverts the RF band signal received through the antenna into a baseband signal. For example, the communication unit (310) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

[0056] Additionally, the communication unit (310) may include a plurality of transmission and reception paths. Furthermore, the communication unit (310) may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit (310) may be composed of a digital circuit and an analog circuit (e.g., a radio frequency integrated circuit (RFIC)). Here, the digital circuit and the analog circuit may be implemented as a single package. Additionally, the communication unit (310) may include a plurality of RF chains. Furthermore, the communication unit (310) may perform beamforming.

[0057] The communication unit (310) transmits and receives signals as described above. Accordingly, all or part of the communication unit (310) may be referred to as a 'transmitter', a 'receiver', or a 'transmitter / receiver'. Additionally, in the following description, transmission and reception performed via a wireless channel are used to mean that processing as described above is performed by the communication unit (310).

[0058] The storage unit (320) stores data such as basic programs, application programs, and setting information for the operation of the terminal (120). The storage unit (320) may be composed of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Additionally, the storage unit (320) provides the stored data upon the request of the control unit (330).

[0059] The control unit (330) controls the overall operations of the terminal (120). For example, the control unit (330) transmits and receives signals through the communication unit (310). Additionally, the control unit (330) writes and reads data to and from the storage unit (320). Furthermore, the control unit (330) can perform the functions of the protocol stack required by the communication standard. To this end, the control unit (330) may include at least one processor or microprocessor, or be part of a processor. Additionally, part of the communication unit (310) and the control unit (330) may be referred to as a communication processor (CP). According to various embodiments, the control unit (330) can control the terminal (120) to perform operations according to the various embodiments described below.

[0061] FIG. 4 illustrates the configuration of a communication unit in a wireless communication system according to various embodiments of the present disclosure.

[0062] FIG. 4 illustrates an example of the detailed configuration of the wireless communication unit (210) of FIG. 2 or the communication unit (310) of FIG. 3. Specifically, FIG. 4 illustrates components for performing beamforming as part of the wireless communication unit (210) of FIG. 2 or the communication unit (310) of FIG. 3.

[0063] Referring to FIG. 4, the wireless communication unit (210) or the communication unit (310) includes an encoding and modulation unit (402), a digital beamforming unit (404), a plurality of transmission paths (406-1 to 406-N), and an analog beamforming unit (408).

[0064] The encoding and modulation unit (402) performs channel encoding. For channel encoding, at least one of a low density parity check (LDPC) code, a convolution code, and a polar code may be used. The encoding and modulation unit (402) generates modulation symbols by performing constellation mapping.

[0065] The digital beamforming unit (404) performs beamforming on a digital signal (e.g., modulation symbols). To do this, the digital beamforming unit (404) multiplies the modulation symbols by beamforming weights. Here, the beamforming weights are used to change the magnitude and phase of the signal and may be referred to as a 'precoding matrix', 'precoder', etc. The digital beamforming unit (404) outputs the digitally beamformed modulation symbols to a plurality of transmission paths (406-1 to 406-N). At this time, according to the MIMO (multiple input multiple output) transmission technique, the modulation symbols may be multiplexed, or the same modulation symbols may be provided to a plurality of transmission paths (406-1 to 406-N).

[0066] Multiple transmission paths (406-1 to 406-N) convert digitally beamformed digital signals into analog signals. To this end, each of the multiple transmission paths (406-1 to 406-N) may include an inverse fast Fourier transform (IFFT) operation unit, a cyclic prefix (CP) insertion unit, a DAC, and an up-conversion unit. The CP insertion unit is intended for orthogonal frequency division multiplexing (OFDM) and may be excluded when other physical layer methods (e.g., filter bank multi-carrier (FBMC)) are applied. That is, the multiple transmission paths (406-1 to 406-N) provide independent signal processing processes for multiple streams generated through digital beamforming. However, depending on the implementation method, some of the components of the multiple transmission paths (406-1 to 406-N) may be used in common.

[0067] The analog beamforming unit (408) performs beamforming on the analog signal. To this end, the digital beamforming unit (404) multiplies the analog signals by beamforming weights. Here, the beamforming weights are used to change the magnitude and phase of the signal. Specifically, the analog beamforming unit (440) can be configured in various ways depending on the connection structure between the multiple transmission paths (406-1 to 406-N) and antennas. For example, each of the multiple transmission paths (406-1 to 406-N) can be connected to a single antenna array. As another example, the multiple transmission paths (406-1 to 406-N) can be connected to a single antenna array. As yet another example, the multiple transmission paths (406-1 to 406-N) can be adaptively connected to a single antenna array or connected to two or more antenna arrays.

[0069] FIG. 5 illustrates the structure of a wireless time-frequency resource of a wireless communication system according to various embodiments of the present disclosure.

[0070] Referring to Fig. 5, in the wireless resource domain, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol or a DFT-S-OFDM symbol, where N symb OFDM symbols or DFT-S-OFDM symbols (530) are contained in a single slot (505). Unlike slots, in an NR system, the length of a subframe can be defined as 1.0 ms, and the length of a radio frame (500) can be defined as 10 ms. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth is a total of N BW It may include several subcarriers (525). N symb , N BW Specific figures such as these may be applied variably depending on the system.

[0071] The basic unit of the time-frequency resource domain is the resource element (RE) (510), which can be represented as an OFDM symbol index or a DFT-S-OFDM symbol index and subcarrier index. The resource block (RB, 515) is N in the frequency domain. RB It can be defined as a series of consecutive subcarriers (520). Generally, the minimum transmission unit of data is an RB unit, and in an NR system, generally N symb = 14, N RB = 12.

[0072] The structure of the wireless time-frequency resource shown in Fig. 5 is applied to the Uu interface. In addition, the wireless time-frequency resource shown in Fig. 5 can be similarly applied to the side link.

[0074] FIGS. 6a through 6d illustrate examples of scenarios for sidelink communication in a wireless communication system according to various embodiments of the present disclosure.

[0075] FIG. 6a illustrates an in-coverage scenario in which sidelink terminals (620a, 620b) are located within the coverage of a base station (610). The sidelink terminals (620a, 620b) may receive data and control information from the base station (610) via a downlink (DL) or transmit data and control information to the base station via an uplink (UL). In this case, the data and control information may be data and control information for sidelink communication or data and control information for general cellular communication other than sidelink communication. Additionally, in FIG. 6a, the sidelink terminals (620a, 520b) may transmit and receive data and control information for sidelink communication via the sidelink.

[0076] FIG. 6b illustrates a case of partial coverage in which, among the sidelink terminals, the first terminal (620a) is located within the coverage of the base station (610) and the second terminal (620b) is located outside the coverage of the base station (610). The first terminal (620a), located within the coverage of the base station (610), can receive data and control information from the base station via a downlink or transmit data and control information to the base station via an uplink. The second terminal (620b), located outside the coverage of the base station (610), cannot receive data and control information from the base station via a downlink and cannot transmit data and control information to the base station via an uplink. The second terminal (620b) can transmit and receive data and control information for sidelink communication with the first terminal (620a) via a sidelink.

[0077] FIG. 6c is an example of a case where sidelink terminals (e.g., first terminal (620a), second terminal (620b)) are located outside the coverage of a base station. Therefore, the first terminal (620a) and the second terminal (620b) cannot receive data and control information from the base station via a downlink, nor can they transmit data and control information to the base station via an uplink. The first terminal (620a) and the second terminal (620b) can transmit and receive data and control information for sidelink communication via the sidelink.

[0078] FIG. 6d illustrates a case in which a first terminal (620a) and a second terminal (620b) performing sidelink communication perform inter-cell sidelink communication, in which they are connected to different base stations (e.g., first base station (610a), second base station (610b)) (e.g., RRC connected state) or are camping (e.g., RRC disconnected state, i.e., RRC idle state). In this case, the first terminal (620a) may be a sidelink transmitting terminal and the second terminal (620b) may be a sidelink receiving terminal. Alternatively, the first terminal (620a) may be a sidelink receiving terminal and the second terminal (620b) may be a sidelink transmitting terminal. The first terminal (620a) can receive a sidelink-only SIB (system information block) from the base station (610a) to which it is connected (or is camping), and the second terminal (620b) can receive a sidelink-only SIB from another base station (620b) to which it is connected (or is camping). At this time, the information in the sidelink-only SIB received by the first terminal (620a) and the information in the sidelink-only SIB received by the second terminal (620b) may be different from each other. Therefore, in order to perform sidelink communication between terminals located in different cells, it is necessary to unify the information.

[0079] In the examples of FIGS. 6a to 6d, for convenience of explanation, a side link system composed of two terminals (e.g., a first terminal (610a), a second terminal (620b)) has been described as an example; however, the present invention is not limited thereto and can be applied to a side link system in which three or more terminals participate. Additionally, the uplink and downlink between the base station (610) and the side link terminals may be referred to as the Uu interface, and the side link between the side link terminals may be referred to as the PC-5 interface. In the following description, the uplink or downlink, the Uu interface, the side link, and the PC-5 may be used interchangeably.

[0080] Meanwhile, in the present disclosure, a terminal may refer to a vehicle supporting vehicular-to-vehicular (V2V) communication, a vehicle or pedestrian's handset (e.g., a smartphone) supporting vehicular-to-pedestrian (V2P) communication, a vehicle supporting vehicular-to-network (V2N) communication, or a vehicle supporting vehicular-to-infrastructure (V2I) communication. Additionally, in the present disclosure, a terminal may refer to a roadside unit (RSU) equipped with terminal functions, an RSU equipped with base station functions, or an RSU equipped with part of base station functions and part of terminal functions.

[0082] FIGS. 7a and 7b illustrate examples of transmission methods for sidelink communication in wireless communication systems according to various embodiments of the present disclosure. FIG. 7a illustrates a unicast method, and FIG. 7b illustrates a groupcast method.

[0083] As shown in FIG. 7a, a transmitting terminal (720a) and a receiving terminal (720b) ​​can communicate one-to-one. A transmission method like that of FIG. 7a may be referred to as unicast communication. As shown in FIG. 7b, a transmitting terminal (720a or 720d) and receiving terminals (720b, 720c, 720e, 720f, 720g) can communicate one-to-many. A transmission method like that of FIG. 7b may be referred to as groupcast or multicast. In FIG. 7b, the first terminal (720a), the second terminal (720b), and the third terminal (720c) form a group and perform group cast communication, and the fourth terminal (720d), the fifth terminal (720e), the sixth terminal (720f), and the seventh terminal (720g) form another group and perform group cast communication. The terminals perform group cast communication within the group to which they belong and can perform unicast, group cast, or broadcast communication with at least one other terminal belonging to a different group. In FIG. 7b, two groups are exemplified, but the present invention is not limited thereto and may be applied even when a larger number of groups are formed.

[0084] Meanwhile, although not illustrated in FIG. 7a or FIG. 7b, sidelink terminals can perform broadcast communication. Broadcast communication refers to a method in which all sidelink terminals receive data and control information transmitted by a sidelink transmitting terminal through the sidelink. For example, if the first terminal (720a) in FIG. 7b is a transmitting terminal, the remaining terminals (720b, 720c, 720d, 720e, 720f, 720g) can receive data and control information transmitted by the first terminal (720a).

[0085] The aforementioned sidelink unicast communication, groupcast communication, and broadcast communication can be supported in in-coverage scenarios, partial-coverage scenarios, or out-of-coverage scenarios.

[0086] In the case of NR sidelinks, unlike LTE sidelinks, support for transmission methods in which a vehicle terminal transmits data to only one specific terminal via unicast and to multiple specific terminals via groupcast may be considered. For example, when considering service scenarios such as platooning, a technology in which two or more vehicles are connected to a single network and move as a cluster, these unicast and groupcast technologies can be effectively utilized. Specifically, unicast communication may be used for the purpose of a leader terminal of a platooning-connected group controlling one specific terminal, and groupcast communication may be used for the purpose of simultaneously controlling a group consisting of multiple specific terminals.

[0088] In V2X systems, resource allocation can be performed using the following methods.

[0089] (1) Mode 1 resource allocation

[0090] Scheduled resource allocation is a method in which a base station allocates resources used for sidelink transmission to RRC-connected terminals using a dedicated scheduling method. Since the scheduled resource allocation method allows the base station to manage sidelink resources, it can be effective for interference management and resource pool management (dynamic allocation and / or semi-persistent transmission). When an RRC-connected terminal has data to transmit to other terminal(s), it can transmit information to the base station notifying the other terminal(s) that there is data to transmit using an RRC message or a MAC control element (hereinafter 'CE'). For example, the RRC message transmitted by the terminal to the base station may be a Sidelink UEInformation or UEAssistanceInformation message, and the MAC CE may be a BSR MAC CE, SR (scheduling request), etc., which includes at least one of an indicator indicating that it is a buffer status report (BSR) for V2X communication and information about the size of the data buffered for sidelink communication.

[0091] (2) Mode 2 Resource Allocation

[0092] Secondly, UE autonomous resource selection is a method in which a pool of sidelink transmit and receive resources for V2X is provided to the terminal via system information or RRC messages (e.g., RRCReconfiguration messages, PC5-RRC messages), and the terminal selects the resource pool and resources according to defined rules. UE autonomous resource selection may correspond to one or more of the following resource allocation methods.

[0093] The terminal autonomously selects a sidelink resource for transmission.

[0094] The terminal assists sidelink resource selection for other UEs.

[0095] The terminal receives the configured NR grant for sidelink transmission (UE is configured with NR configured grant for sidelink transmission).

[0096] A terminal can schedule sidelink transmission of other terminals (UE schedules sidelink transmission of other UEs).

[0097] - Resource selection methods for the terminal may include zone mapping, sensing-based resource selection, and random selection.

[0098] Additionally, even if the terminal is within the base station's coverage, resource allocation or resource selection may not be performed via scheduled resource allocation or terminal autonomous resource selection mode; in such cases, the terminal may perform V2X sidelink communication through a preconfigured sidelink transmission and reception resource pool.

[0099] In addition, if terminals for V2X communication are located outside the base station's coverage area, the terminal may perform V2X sidelink communication through a pre-configured sidelink transmission and reception resource pool.

[0100] An SLRB configuration and SLRB for transmitting sidelink flows or packets are mapped to an SL logical channel group (LCG), and an SL LCG can be mapped to an SL logical channel. An SLRB configuration and SLRB can be distinguished by a combination of source index, destination index, cast type, QFI (QoS flow identifier) / PFI (ProSe flow identifier or PC5 flow identifier) ​​or priority.

[0102] In a wireless communication system according to various embodiments of the present disclosure, a sidelink wireless bearer may be configured to transmit and receive data based on a sidelink between terminals. The sidelink wireless bearer may be used for at least one of sidelink unicast, sidelink groupcast, and sidelink broadcast. When performing sidelink-based packet transmission and reception between terminals, the sidelink wireless bearer may be configured as a bi-directional connection or a uni-directional connection. When the sidelink wireless bearer is configured as a bi-directional connection, each terminal may perform both the roles of a transmitting terminal and a receiving terminal. When the sidelink wireless bearer between two terminals is configured as a bi-directional connection, some of the configuration information used for data transmission and reception between the two terminals needs to be configured identically. For example, the RLC layer mode (RLC mode) may be configured as RLC AM or RLC UM; for a sidelink wireless bearer configured as a bi-directional connection, it is necessary for both terminals to be configured as bi-directional RLC AM or bi-directional RLC UM. As another example, when a sidelink wireless bearer between two terminals is configured as a uni-directional connection, some of the configuration information used for data transmission and reception between the two terminals needs to be set identically. For a sidelink wireless bearer configured as a uni-directional connection, it needs to be set identically to uni-directional RLC AM for both terminals or identically to uni-directional RLC UM for both terminals.For another example, if a sidelink wireless bearer configured with a bi-directional connection is set to RLC AM, the sidelink logical channel configured for the two terminals needs to be configured as a logical channel corresponding to bi-directional RLC AM. If a sidelink wireless bearer configured with a bi-directional connection is set to RLC UM, the sidelink logical channel configured for the two terminals needs to be configured as a logical channel corresponding to bi-directional RLC UM. For another example, if a sidelink wireless bearer configured with a uni-directional connection is set to RLC AM, the sidelink logical channel configured for the two terminals needs to be configured as a logical channel corresponding to uni-directional RLC AM. If a sidelink wireless bearer configured with a uni-directional connection is set to RLC UM, the sidelink logical channel configured for the two terminals needs to be configured as a logical channel corresponding to uni-directional RLC UM. The transmission parameter configuration information set for each terminal and / or the transmission / reception parameter configuration information that must be synchronized between two terminals can be set using information obtained from the system (at least one of obtained from an RRC dedicated message, obtained from a SIB message, or obtained from pre-configuration). The reception parameter configuration information set for each terminal can be arbitrarily set by the terminal. Therefore, when terminals obtain configuration information for a sidelink wireless bearer configured as a bi-directional connection from the system, a method is required for the terminals to obtain the same configuration information. When terminals obtain configuration information for a sidelink wireless bearer configured as a uni-directional connection from the system, a method is required for the terminals to obtain the same configuration information.This is because the two terminals can each obtain configuration information from different base stations, or one terminal can obtain configuration information from the base station's RRC dedicated message while the other terminal obtains configuration information from the SIB, or one terminal can obtain configuration information from the base station's RRC dedicated message / SIB while the other terminal obtains configuration information from the pre-configuration.

[0104] In wireless communication systems according to various embodiments of the present disclosure, NW coordination may be applied as a method to set the configuration information of bi-directional or uni-directional sidelink wireless bearers between terminals identically. The NW coordination method may be applied to at least one of a system of the same PLMN, a system of the same service provider, a system in a region to which the same regulation applies, or the same NW. The NW coordination method ensures that the same sidelink wireless bearer configuration information is used for the same PQI (ProSe QoS indicator) for at least one of the same PLMN or same operator system, same regulation system, or same NW. In another embodiment, the same sidelink wireless bearer configuration information is used for at least one of the same destination ID, the same PC5 flow ID, or the same unicast ID instead of the PQI. Two terminals performing sidelink-based communication may exchange at least one of PLMN, service provider, regulation, or NW information to determine that they belong to a network using the same sidelink wireless bearer configuration information according to NW coordination. If it is determined that the two terminals do not belong to the same NW, the two terminals can perform a configuration coordination operation so that they can have the same configuration information for a bi-directional or uni-directional sidelink wireless bearer.

[0105] Information regarding the use of a bi-directional or uni-directional sidelink wireless bearer between two terminals that have decided to perform direct communication may be exchanged during the PC5-S signaling setup procedure used to establish a sidelink unicast connection between the two terminals. In another embodiment, information regarding the use of a bi-directional or uni-directional sidelink wireless bearer between the two terminals may be exchanged during the PC5 RRC connection procedure for the sidelink unicast connection between the two terminals. If it is determined to use a bi-directional or uni-directional sidelink wireless bearer based on the information exchanged between the two terminals, the necessity of an SLRB configuration coordination operation may be determined in the procedure for establishing an SLRB configuration for a sidelink unicast connection between the two terminals based on at least one of PLMN information, operator information, regulation information, or NW information.

[0107] FIGS. 8a and 8b illustrate signaling flows between terminals using a NW coordination scheme according to various embodiments of the present disclosure. FIG. 8a is an embodiment in which two terminals exchange NW coordination information while performing a PC5-S signaling setup procedure to establish a PC5 unicast connection, and FIG. 8b is an embodiment in which two terminals exchange NW coordination information while performing a PC5-RRC configuration procedure to establish a PC5 unicast connection.

[0108] Referring to FIG. 8a, UE1 (800) and UE2 (830) may perform a PC5 signaling procedure in step 801 to establish a sidelink-based unicast connection. The information exchanged between the two terminals (800, 830) during the PC5 signaling procedure may include at least one or a combination of a PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. During the PC5 signaling procedure, the two terminals (800, 830) may exchange bi-directional bearer indication information or uni-directional bearer indication information. During the PC5 signaling procedure, the two terminals (800, 830) may exchange NW coordination information. The NW coordination information may include at least one or a combination of a PLMN ID, a service provider identifier, a regulation identifier, and a NW identifier.

[0109] The terminal (830) that receives the above NW coordination information can determine whether to apply the SLRB configuration coordination function in step 803. In the embodiment of FIG. 8a, it is shown that UE2 (830) determines whether to apply the SLRB configuration coordination function, but it is obvious that UE1 (800) can determine whether to apply the SLRB configuration coordination function. The determination of whether to apply the SLRB configuration coordination function is an operation to determine whether UE1 (800) and UE2 (830) belong to the same NW or different NWs based on the above NW coordination information. If it is determined that the application of the SLRB configuration coordination function is necessary according to the determination in step 803, UE1 (800) and UE2 (830) can perform an operation to apply the SLRB configuration coordination function in step 805. Alternatively, if it is determined in step 803 that the application of the SLRB configuration coordination function is not necessary, UE1 (800) and UE2 (830) may perform the operation resulting from the non-application of the SLRB configuration coordination function in step 805. In the case where the SLRB configuration coordination function is not applied, the two terminals (800, 830) may perform the PC5-RRC connection setup procedure (at least one of the UE capability negotiation and AS configuration procedures). Instruction information regarding the application or non-application of the SLRB configuration coordination function may be exchanged between UE1 (800) and UE2 (830) based on the result of the judgment in step 803.The SLRB configuration coordination function that UE1 (800) and UE2 (830) can perform in step 805 above may include at least one or a combination of the following: a method in which the terminal itself determines and decides, a method in which the base station's coordination is utilized, a method in which a designated terminal is utilized, and a method in which it is processed as an AS configuration failure, as shown in FIGS. 9 to 20.

[0111] Referring to FIG. 8b, UE1 (850) and UE2 (880) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 851. The information exchanged between the two terminals (850, 880) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (850) and UE2 (880), having performed the PC5-S signaling setup procedure, may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 853. UE1 (850) and UE2 (880) may perform an AS configuration procedure during the PC5 RRC connection procedure in step 855. The AS configuration procedure may correspond to a procedure for setting configuration information of a sidelink wireless bearer between the two terminals (850, 880). The information exchanged during the AS configuration procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 SLRB configuration. During the AS configuration procedure, the two terminals (850, 880) may exchange bi-directional bearer instruction information or uni-directional bearer instruction information. During the AS configuration procedure, the two terminals may exchange NW coordination information. The NW coordination information may include at least one or a combination of PLMN ID, service provider identifier, regulation identifier, and NW identifier.

[0112] The terminal (880) that receives the above NW coordination information can determine whether to apply the SLRB configuration coordination function in step 857. In the embodiment of FIG. 8b, UE2 (880) is shown determining whether to apply the SLRB configuration coordination function, but it is obvious that UE1 (850) can determine whether to apply the SLRB configuration coordination function. The determination of whether to apply the SLRB configuration coordination function is an operation to determine whether UE1 (850) and UE2 (880) belong to the same NW or different NWs based on the above NW coordination information.

[0113] If it is determined in step 857 that the application of the SLRB configuration coordination function is necessary, UE1 (850) and UE2 (880) may perform an operation to apply the SLRB configuration coordination function in step 859. Alternatively, if it is determined in step 857 that the application of the SLRB configuration coordination function is not necessary, UE1 (850) and UE2 (880) may perform an operation to not apply the SLRB configuration coordination function in step 859. In the case where the SLRB configuration coordination function is not applied, the two terminals (850, 880) may perform a PC5-RRC connection setup procedure (at least one of the UE capability negotiation and AS configuration procedures). Instruction information regarding the application or non-application of the SLRB configuration coordination function may be exchanged between UE1 (850) and UE2 (880) based on the result of the judgment in step 857. The SLRB configuration coordination function that UE1 (850) and UE2 (880) can perform in step 859 above may include at least one or a combination of the following: a method in which the terminal itself determines and decides, a method in which the base station's coordination is utilized, a method in which a designated terminal is utilized, and a method in which it is processed as an AS configuration failure, as shown in FIGS. 9 to 20.

[0115] According to various embodiments of the present disclosure, a method for coordinating configuration information of sidelink wireless bearers between terminals performing sidelink-based direct communication may include at least one or a combination of the following.

[0116] (1) Terminals make their own judgments and decisions: Wireless bearer configuration information can be coordinated through signaling exchange between two terminals. The two terminals may correspond to an initiating UE or a peer UE that performs a PC5-S signaling procedure to establish a sidelink connection. In various embodiments of the present disclosure, the terminal that transmits the first message of the PC5-S signaling procedure is referred to as the initiating UE, and the terminal that receives the first message of the PC5-S signaling procedure and transmits a response (acceptance of connection establishment) message to the first message is referred to as the peer UE.

[0117] (2) Decision made by coordination by the base station: The two terminals can coordinate the wireless bearer configuration information by reporting the wireless bearer configuration information to the connected base station and obtaining confirmation and coordination information regarding the wireless bearer configuration information from the base station.

[0118] (3) Designate a terminal that determines the SLRB (sidelink radio bearer) configuration, and the designated terminal determines and decides: For example, the designated terminal may be a terminal that obtains and provides a bi-directional SLRB configuration and / or a uni-directional SLRB configuration. Other terminals may receive and use the bi-directional SLRB configuration and / or a uni-directional SLRB configuration from the designated terminal. For example, the designated terminal may be a terminal that determines whether the bi-directional SLRB configuration and / or a uni-directional SLRB configuration obtained by each terminal matches or does not match, and informs other terminals of whether the configuration matches or does not match. When other terminals receive information on the SLRB configuration mismatch from the designated terminal, they may perform a procedure to coordinate the bi-directional SLRB configuration and / or a uni-directional SLRB configuration with the designated terminal. For example, a designated terminal may be a terminal that performs SLRB configuration coordination and determines the SLRB configuration to be used by each terminal when determining whether there is a discrepancy regarding the bi-directional SLRB configuration and / or uni-directional SLRB configuration obtained by each terminal. Other terminals may receive and use the final bi-directional SLRB configuration and / or uni-directional SLRB configuration from the designated terminal.

[0119] A designated terminal may perform the operation of determining a bi-directional SLRB configuration and / or a uni-directional SLRB configuration based on sidelink radio bearer configuration information obtained by itself (obtained through at least one of a dedicated RRC message, SIB, or pre-configuration of the NW), or determining coordination with an SLRB configuration received from another terminal based on the obtained SLRB configuration and determining the bi-directional SLRB configuration and / or the uni-directional SLRB configuration, or reporting SLRB configuration information received from another terminal to its own base station and determining the bi-directional SLRB configuration and / or the uni-directional SLRB configuration based on information confirmed by the base station, or reporting SLRB configuration information received from another terminal to its own base station and obtaining the final bi-directional SLRB configuration and / or the uni-directional SLRB configuration from the base station. When the final bi-directional SLRB configuration and / or the uni-directional SLRB configuration is obtained, the designated terminal may transmit this information to the other terminal.

[0120] An embodiment of the designated terminal selection method includes at least one of a method of selecting an Initiating UE as the designated terminal, a method of selecting a Peer UE as the designated terminal, or a method of selecting an RRC_Connected UE as the designated terminal. According to various embodiments of the present disclosure, a method of selecting an SLRB configuration determining terminal will be described with reference to FIG. 9.

[0121] (4) Determination of AS configuration information acquisition failure (AS configuration failure): If it is determined that it is difficult to coordinate the bi-directional SLRB configuration and / or uni-directional SLRB configuration between the two terminals, and / or if it is determined that the bi-directional SLRB configuration and / or uni-directional SLRB configuration information acquired by each of the two terminals is inconsistent, it is determined that there is an AS configuration failure, and the terminals may perform an AS configuration failure procedure. The AS configuration failure handling method can be used in combination with the methods of (1) to (2) to (3) above, or can be used alone. A terminal that determines an AS configuration failure due to a conflict between the bi-directional SLRB configuration and / or uni-directional SLRB configuration may transmit an AS configuration failure message to the other terminal, and the AS configuration failure message may include at least one of AS configuration failure instruction information and conflicted SLRB configuration parameter information.

[0123] FIG. 9 illustrates a method for selecting a terminal that determines an SLRB configuration according to various embodiments of the present disclosure.

[0124] UE1 (900) may transmit a PC5-S signaling message A in step 901 to initiate a sidelink unicast connection setup procedure. The message A may include at least one or a combination of a PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. The message A may include information indicating a bi-directional connection and / or a uni-directional connection. The message A may include information indicating an SLRB configuration designated terminal for the bi-directional connection and / or the uni-directional connection. For example, the information indicating the designated terminal may indicate that UE1 (900) will perform the designated terminal. For example, the information indicating the designated terminal may indicate that a peer UE will perform the designated terminal. For example, the information indicating the designated terminal may indicate that the peer UE will perform the designated terminal if it is an RRC_Connected UE.

[0125] If UE2 (930) receives message A and accepts the sidelink connection setup requested in message A, it can transmit PC5-S signaling message B to UE1 (900) in step 903 and perform the role of a peer UE. If UE2 (930) receives message A and does not accept the sidelink connection setup requested in message A, it may not transmit a response message to UE1 (900) or may transmit a connection setup rejection message. If the sidelink connection setup requested in message A is accepted, message B may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID corresponding to message A. Message B may include bi-directional connection and / or uni-directional connection response information. Message B may include SLRB configuration specified terminal response information for bi-directional connection and / or uni-directional connection. For example, the designated terminal response information may include an ack indicating that the UE1 (900) will perform the designated terminal. For example, the designated terminal response information may include information indicating that the UE2 (930) will perform the designated terminal. For example, the designated terminal response information may include information indicating that the UE2 (930) cannot perform the designated terminal. If the UE2 (930) responds that it cannot perform the designated terminal, the UE1 (900) can perform the role of the designated terminal.

[0126] Upon receiving the response message of step 903, UE1 (900) can verify information regarding the bi-directional connection and / or uni-directional connection and designated terminal information (step 905). Upon transmitting the response message of step 903, UE2 (930) can verify information regarding the bi-directional connection and / or uni-directional connection and designated terminal information (step 907). UE1 (900) and UE2 (930) can perform an RRC connection setup procedure for a sidelink bi-directional wireless bearer connection and / or uni-directional wireless bearer connection (step 909). The sidelink RRC connection setup procedure may include at least one of a UE capability that exchanges Sidelink UE capability information and an AS configuration that exchanges Sidelink wireless bearer configuration information. While performing the AS configuration procedure, the designated terminal may perform operations such as obtaining and determining a bi-directional SLRB configuration and / or a uni-directional SLRB configuration and / or determining the need for coordination of the bi-directional SLRB configuration and / or uni-directional SLRB configuration, and determining the bi-directional SLRB configuration and / or uni-directional SLRB configuration to be used by the two terminals.

[0128] FIGS. 10 to 12 illustrate a method for coordinating an SLRB configuration that a terminal determines and decides on its own according to various embodiments of the present disclosure.

[0129] The above terminal may correspond to an initiating UE and / or peer UE that intends to perform data transmission and reception via a sidelink unicast connection, and the terminals may determine a bi-directional SLRB configuration or a uni-directional SLRB configuration to be used in the sidelink unicast connection. A UE that transmits the first PC5-S signaling message to initiate the sidelink unicast connection setup procedure is referred to as the initiating UE. A peer UE refers to a UE that receives the first PC5-S signaling message initiating the sidelink unicast connection setup procedure and transmits a corresponding response (acceptance of connection setup) message. In one embodiment, the initiating UE may include a bi-directional SLRB configuration or a uni-directional SLRB configuration in an AS configuration message and transmit it to the peer UE. In one embodiment, the SLRB configuration may include at least one or a combination of an RLC mode, bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. In one embodiment, the Peer UE waits until it receives an AS configuration from the initiating UE, and when it receives an AS configuration containing a bi-directional SLRB configuration or a uni-directional SLRB configuration from the initiating UE, it can perform sidelink-based data transmission and reception according to the SLRB configuration.In one embodiment, the peer UE may operate a timer during the waiting time while receiving an AS configuration containing a bi-directional SLRB configuration or a uni-directional SLRB configuration from the initiating UE, and may release the timer when the AS configuration is received. In one embodiment, if the peer UE determines that it has not received an AS configuration containing a bi-directional SLRB configuration or a uni-directional SLRB configuration by the timer expiration, the peer UE may acquire the bi-directional SLRB configuration or the uni-directional SLRB configuration and transmit the AS configuration containing the bi-directional SLRB configuration or the uni-directional SLRB configuration to the initiating UE. In one embodiment, the peer UE may transmit to the initiating UE an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration, including information indicating that the AS configuration is transmitted after the timer expiration. In one embodiment, when an initiating UE receives an AS configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration from a peer UE, it may decide to follow the bi-directional SLRB configuration or the uni-directional SLRB configuration obtained from the peer UE.In one embodiment, when an initiating UE receives an AS configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration from a peer UE, it may perform a configuration information coordination procedure with the peer UE regarding the configuration information that requires coordination. In one embodiment, when an initiating UE receives an AS configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration from a peer UE and determines that the SLRB configuration cannot be applied, it may send a message to the peer UE indicating an AS configuration failure.

[0130] In one embodiment, if the peer UE determines that it has not received an AS configuration containing a bi-directional SLRB configuration or a uni-directional SLRB configuration by the timer expiration date, the peer UE may determine that there is an AS configuration failure and transmit the AS configuration failure to the initiating UE. In one embodiment, the initiating UE may decide not to proceed with further AS configuration setup procedures upon receiving a message notifying of an AS configuration failure from the peer UE. In one embodiment, the initiating UE may decide not to proceed with further AS configuration setup procedures if it does not receive an AS configuration complete message from the peer UE. Here, the initiating UE may operate a separate timer (starting the timer when an AS configuration message is transmitted and releasing the timer upon receiving an AS configuration complete message) to determine whether an AS configuration complete message has been received. In one embodiment, if the initiating UE operates a separate timer until it receives an AS configuration complete message as a response to an AS configuration message, the initiating UE may release the separate timer when it determines that it has received an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration from the peer UE.In one embodiment, when a peer UE transmits an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration to an initiating UE, the peer UE may operate a separate timer (starting the timer when the AS configuration message is transmitted and releasing the timer when an AS configuration complete message is received). Here, if the peer UE does not receive an AS configuration complete message from the initiating UE before the separate timer expires, it may decide not to proceed with any further AS configuration setup procedures. In one embodiment, after transmitting an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration, the peer UE may decide not to proceed with any further AS configuration setup procedures if it receives a message indicating an AS configuration failure from the initiating UE.

[0131] The operation of a UE operating a timer for the purpose of setting up a bi-directional SLRB configuration or a uni-directional SLRB configuration may apply at least one of the following methods. The timer may be operated for a corresponding sidelink connection that requires a bi-directional SLRB configuration or a uni-directional SLRB configuration, wherein the corresponding sidelink connection may be identified by at least one or a combination of a destination ID, source ID, PC5 flow ID, PC5 unicast ID, and PQI. In one embodiment, the timer operated until the peer UE receives the bi-directional SLRB configuration or the uni-directional SLRB configuration may start after the PC5-S unicast connection setup procedure. In one embodiment, the timer operated until the peer UE receives the bi-directional SLRB configuration or the uni-directional SLRB configuration may start after the peer UE's UE capability information is transmitted to the initiating UE. In one embodiment, a timer that operates until the peer UE receives a bi-directional SLRB configuration or a uni-directional SLRB configuration may start after receiving UE capability information from the initiating UE. The timer may be released when the initiating UE receives an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration.

[0132] When an initiating UE or a peer UE receives an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration, respectively, and transmits a message indicating an AS configuration failure, the AS configuration complete message may include at least one of an AS configuration failure indicator and / or information indicating configuration information that causes the AS configuration failure (e.g., at least one of RLC mode, bi-directional RLC, uni-directional RLC, and logical channel information mapped to RLC mode).

[0134] Referring to FIG. 10a, UE1 (1000) and UE2 (1030) can perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1001. The information exchanged between the two terminals (1000, 1030) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1000) and UE2 (1030) can perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1003.

[0135] UE1 (1000) can obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1005. According to one embodiment, the SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration. UE1 (1000) can transmit an AS configuration message to UE2 (1030) in step 1007 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1030). The AS configuration message may include at least one or a combination of a PC5 flow ID, a destination ID, a source ID, a PQI, QoS characteristics, a PC5 SLRB configuration, and a PC5 SLRB ID.

[0136] When UE2 (1030) receives an AS configuration message, it may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration at step 1009. UE2 (1030) may transmit an AS configuration complete message to UE1 (1000) at step 1011 as a response to the AS configuration message. The AS configuration complete message may include at least one or a combination of information corresponding to the AS configuration message, a PC5 flow ID, a destination ID, a source ID, a PQI, a PC5 SLRB configuration, and a PC5 SLRB ID. UE1 (1000) and UE2 (1030) may perform sidelink data transmission and reception at step 1013 by applying the AS configuration including the bi-directional SLRB configuration or the uni-directional SLRB configuration.

[0138] Referring to FIG. 10b, UE1 (1050) and UE2 (1080) can perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1051. The information exchanged between the two terminals (1050, 1080) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE2 (1080) can start a timer for AS configuration setting in step 1053. UE1 (1050) and UE2 (1080) can perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1055.

[0139] UE1 (1050) can obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration at step 1057. For example, the SLRB configuration may include at least one or a combination of RLC mode, bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, or a pre-configuration. UE1 (1050) can transmit an AS configuration message to UE2 (1080) at step 1059 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1080). The AS configuration message may include at least one or a combination of a PC5 flow ID, a destination ID, a source ID, a PQI, QoS characteristics, a PC5 SLRB configuration, and a PC5 SLRB ID.

[0140] UE2 (1080) may release the timer at step 1061 upon receiving an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration. UE2 (1080) may obtain the bi-directional SLRB configuration or the uni-directional SLRB configuration included in the AS configuration message at step 1063. UE2 (1080) may transmit an AS configuration complete message to UE1 (1050) at step 1065 as a response to the AS configuration message. The AS configuration complete message may include at least one or a combination of information corresponding to the AS configuration message, a PC5 flow ID, a destination ID, a source ID, a PQI, a PC5 SLRB configuration, and a PC5 SLRB ID. UE1 (1050) and UE2 (1080) may perform sidelink data transmission and reception at step 1067 by applying the AS configuration containing the bi-directional SLRB configuration or the uni-directional SLRB configuration.

[0142] Referring to FIG. 11, UE1 (1100) and UE2 (1150) can perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1101. The information exchanged between the two terminals (1100, 1150) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE2 (1150) can start a timer for setting AS configuration in step 1103. UE1 (1105) and UE2 (1107) can perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1105.

[0143] UE2 (1150) can determine that the timer has expired at step 1107 and that an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration has not been received from UE1 (1100). UE2 (1150) can obtain an SLRB configuration containing a bi-directional SLRB configuration or a uni-directional SLRB configuration at step 1109. For example, the SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, or a pre-configuration.

[0144] UE2 (1150) may transmit an AS configuration message containing the acquired bi-directional SLRB configuration or uni-directional SLRB configuration to UE1 (1100) in step 1111. The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID. According to one embodiment, the AS configuration message may include information indicating that the AS configuration is transmitted after the timer expires.

[0145] When UE1 (1100) receives an AS configuration message, it may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration at step 1113. UE1 (1100) may transmit an AS configuration complete message to UE2 (1150) at step 1115 as a response to the AS configuration message. The AS configuration complete message may include at least one or a combination of information corresponding to the AS configuration message, a PC5 flow ID, a destination ID, a source ID, a PQI, a PC5 SLRB configuration, and a PC5 SLRB ID. UE1 (1100) and UE2 (1150) may perform sidelink data transmission and reception at step 1117 by applying the AS configuration including the bi-directional SLRB configuration or the uni-directional SLRB configuration.

[0147] Referring to FIG. 12, UE1 (1200) and UE2 (1250) can perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1201. The information exchanged between the two terminals (1200, 1250) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE2 (1250) can start a timer for AS configuration setting in step 1203. UE1 (1200) and UE2 (1250) can perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1205.

[0148] UE1 (1200) can obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1207. For example, the SLRB configuration may include at least one or a combination of RLC mode, bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, or a pre-configuration. UE1 (1200) can transmit an AS configuration message to UE2 (1250) in step 1209 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1250). The AS configuration message may include at least one or a combination of a PC5 flow ID, a destination ID, a source ID, a PQI, QoS characteristics, a PC5 SLRB configuration, and a PC5 SLRB ID.

[0149] UE2 (1250) can determine that the timer has expired at step 1211 and that an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration has not been received from UE1 (12100). UE2 (1250) can obtain an SLRB configuration containing a bi-directional SLRB configuration or a uni-directional SLRB configuration at step 1213. For example, the SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, or a pre-configuration.

[0150] UE2 (1250) may transmit an AS configuration message containing the acquired bi-directional SLRB configuration or uni-directional SLRB configuration to UE1 (1200) in step 1215. The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID. The information of at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, and QoS characteristics may be set to be identical to the information exchanged between UE1 (1200) and UE2 (1250) in step 1201. According to one embodiment, UE2 (1250) may include information in the AS configuration message transmitted in step 1215 indicating that the AS configuration is transmitted after the expiration of the bi-directional SLRB configuration setting timer or the expiration of the uni-directional SLRB configuration setting timer.

[0151] If UE2 (1250) receives an AS configuration message transmitted by UE1 (1200) after transmitting an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1215 (step 1209), it may ignore the AS configuration message transmitted by UE1 (1200). If UE1 (1200) receives a bi-directional SLRB configuration or a uni-directional SLRB configuration for the same sidelink connection from UE2 (1250) after transmitting an AS configuration message containing a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1209, it decides to ignore the SLRB configuration transmitted in step 1209, and may obtain the bi-directional SLRB configuration or uni-directional SLRB configuration received from UE2 (1250) in step 1215 in step 1217.

[0152] UE1 (1200) may send an AS configuration complete message to UE2 (1250) in step 1219 in response to the AS configuration message of step 1215. The AS configuration complete message may include at least one or a combination of information corresponding to the AS configuration message of step 1215, PC5 flow ID, destination ID, source ID, PQI, PC5 SLRB configuration, and PC5 SLRB ID. UE1 (1200) and UE2 (1250) may perform sidelink data transmission and reception in step 1221 by applying an AS configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration.

[0153] Meanwhile, in the embodiments of FIGS. 10, 11, and 12 above, if UE1 does not receive an AS configuration complete message from UE2 after transmitting an AS configuration message, or receives an AS configuration complete message indicating an AS configuration failure, UE1 and UE2 may not proceed further with the AS configuration setting procedure. In the embodiment of FIG. 12 above, if UE2 does not receive an AS configuration complete message from UE1 after transmitting an AS configuration message, or receives an AS configuration complete message indicating an AS configuration failure, UE1 and UE2 may not proceed further with the AS configuration setting procedure.

[0155] FIGS. 13 to 15 illustrate an SLRB configuration coordination method in which a terminal determines and decides on its own according to various embodiments of the present disclosure.

[0156] The embodiments of FIGS. 13 to 15 above are methods for determining and processing whether there is a conflict between bi-directional SLRB configuration information or uni-directional SLRB configuration information while an initiating UE and a peer UE establishing a sidelink unicast connection each acquire sidelink configuration information and perform an AS configuration setting procedure between two terminals.

[0157] For example, the initiating UE transmits the SLRB configuration it has acquired to the peer UE, and the peer UE can determine whether there is a conflict between the SLRB configuration it has acquired and the SLRB configuration received from the initiating UE. For example, if the peer UE determines that there is no conflict between the SLRB configuration received from the initiating UE and the SLRB configuration it has acquired, it can transmit a response message to the initiating UE confirming the application of the said SLRB configuration. For example, if the peer UE determines that there is a conflict between the SLRB configuration received from the initiating UE and the SLRB configuration it has acquired, it can transmit a message to the initiating UE indicating an AS configuration failure.

[0158] For example, if a peer UE determines that the SLRB configuration received from the initiating UE conflicts with the SLRB configuration it has acquired, it may decide to perform an SLRB configuration adjustment procedure with the initiating UE. For example, the peer UE may transmit an SLRB configuration adjustment message containing adjustable parameter information to the initiating UE. For example, the initiating UE may receive a response message from the peer UE confirming the application of the SLRB configuration it has acquired. For example, the initiating UE may receive a message from the peer UE indicating an AS configuration failure. For example, the initiating UE may receive an SLRB configuration adjustment message from the peer UE containing adjustable parameter information.

[0159] For example, when an initiating UE receives an SLRB configuration adjustment message containing adjustable parameter information from a peer UE, it may determine whether the adjustable parameter can be accepted and send an SLRB configuration adjustment response message to the peer UE that includes acceptance of the parameter. For example, when an initiating UE receives an SLRB configuration adjustment message containing adjustable parameter information from a peer UE, it may determine whether the adjustable parameter can be accepted and send an SLRB configuration adjustment response message to the peer UE indicating an AS configuration failure due to inability to accept the parameter.

[0160] For example, when an initiating UE receives an SLRB configuration adjustment message containing information on a set of adjustable parameters from a peer UE, it may select a parameter to apply from the set of adjustable parameters and send an SLRB configuration adjustment message containing the selected parameter information to the peer UE. The peer UE may receive an SLRB configuration adjustment message containing information on a parameter to apply from the set of adjustable parameters from the initiating UE. For example, if the initiating UE does not receive a response message from the peer UE regarding an AS configuration containing a bi-directional SLRB configuration that it has acquired, it may determine that there is an AS configuration failure.

[0162] Referring to FIG. 13, UE1 (1300) and UE2 (1330) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1301. The information exchanged between the two terminals (1300, 1330) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1300) and UE2 (1330) may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1303. UE1 (1300) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1305. UE2 (1330) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1307. The above SLRB configuration may include at least one or a combination of RLC mode, bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The above SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0163] UE1 (1300) can send an AS configuration message to UE2 (1330) at step 1309 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1330). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0164] When UE2 (1330) receives an AS configuration message, it can determine in step 1311 whether there is a conflict between the SLRB configuration obtained in step 1307 and the SLRB configuration included in the AS configuration message. The target parameter for determining whether there is a conflict in the SLRB configuration may include at least one configuration parameter of each RLC mode operation, including at least one or a combination of logical channels corresponding to RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, and RLC mode.

[0165] If UE2 (1330) determines at step 1311 that the SLRB configuration does not conflict, it may transmit an AS configuration complete message to UE1 (1300) at step 1313 as a response to the AS configuration message received at step 1309. The AS configuration complete message may include at least one or a combination of information corresponding to the AS configuration message, PC5 flow ID, destination ID, source ID, PQI, PC5 SLRB configuration, and PC5 SLRB ID. UE1 (1300) and UE2 (1330) may perform sidelink data transmission and reception at step 1315 by applying an AS configuration that includes the SLRB configuration.

[0167] Referring to FIG. 14, UE1 (1400) and UE2 (1430) can perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1401. The information exchanged between the two terminals (1400, 1430) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1400) and UE2 (1430) can perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1403.

[0168] UE1 (1400) can obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration at step 1405. UE2 (1430) can obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration at step 1407. For example, the SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0169] UE1 (1400) can send an AS configuration message to UE2 (1430) at step 1409 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1430). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0170] When UE2 (1430) receives an AS configuration message, it can determine in step 1411 whether there is a conflict between the SLRB configuration obtained in step 1407 and the SLRB configuration included in the AS configuration message. The target parameter for determining whether there is a conflict in the SLRB configuration may include at least one configuration parameter of each RLC mode operation, including at least one or a combination of logical channels corresponding to RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, and RLC mode. If UE2 (1430) determines in step 1411 that the SLRB configurations conflict, it determines it as an AS configuration failure and can transmit an AS configuration complete message to UE1 (1400) in step 1413 as a response to the AS configuration message received in step 1409. The AS configuration complete message may include at least one or a combination of information corresponding to the AS configuration message, PC5 flow ID, destination ID, source ID, PQI, PC5 SLRB ID, and failure indication information. For example, UE2 (1430) may include parameter information that causes the SLRB configuration conflict in the AS configuration complete message.

[0171] When UE1 (1400) receives an AS configuration complete message from UE2 (1430) indicating an AS configuration failure, it can determine the AS configuration failure and stop the AS configuration procedure (step 1413). If the AS configuration complete message includes information indicating that the cause of the AS configuration failure is an SLRB configuration parameter, UE1 (1400) can determine that an SLRB configuration conflict has occurred (step 1415). In one embodiment, UE1 (1400) can report to NW that an AS configuration failure has occurred due to a conflict in the SLRB configuration. The information reported to NW may include at least one or a combination of PQI, PC5 QoS characteristics, PC5 flow ID, the configuration parameter where the conflict occurred, for example, RLC mode, bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode.

[0173] Referring to FIG. 15a, UE1 (1500) and UE2 (1530) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1501. The information exchanged between the two terminals (1500, 1530) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1500) and UE2 (1530) may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1503. UE1 (1500) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1505. UE2 (1530) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1507. For example, an SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an RLC operation parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0174] UE1 (1500) can send an AS configuration message to UE2 (1530) at step 1509 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1530). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0175] When UE2 (1530) receives an AS configuration message, it can determine in step 1511 whether there is a conflict between the SLRB configuration obtained in step 1507 and the SLRB configuration included in the AS configuration message. The target parameter for determining whether there is a conflict in the SLRB configuration may include at least one of an RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and a configuration parameter required for RLC mode operation.

[0176] If UE2 (1530) determines in step 1511 that the SLRB configuration conflicts, it can identify configuration parameter information that requires adjustment due to the discrepancy. UE2 (1530) can transmit an AS configuration message containing configuration parameter information that requires adjustment in step 1513. The AS configuration message in step 1513 may include configuration parameter information that requires adjustment corresponding to at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID received in step 1509. The information of the configuration parameter that requires adjustment may include at least one of an adjustable RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and configuration parameters required for RLC mode operation.

[0177] UE1 (1500), having received the AS configuration message of step 1513, may determine in step 1515 that SLRB configuration adjustment is required. UE1 (1500) may perform parameter adjustment on the configuration parameters determined to require adjustment and transmit an AS configuration message containing this information to UE2 (1530) in step 1517. The AS configuration message of step 1517 may include adjusted configuration parameter information corresponding to at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID received in step 1513. The adjusted configuration parameter information may include at least one of RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and configuration parameters required for RLC mode operation.

[0178] When UE2 (1530) receives the AS configuration message of step 1517, it may send an AS configuration complete message in response (step 1519). The AS configuration complete message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID. UE1 (1500) and UE2 (1530) may perform sidelink data transmission and reception in step 1521 by applying an AS configuration that includes the SLRB configuration.

[0180] Referring to FIG. 15b, UE1 (1540) and UE2 (1560) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1541. The information exchanged between the two terminals (1540, 4560) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1540) and UE2 (1560) may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1543. UE1 (1540) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1545. UE2 (1560) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1547. For example, an SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0181] UE1 (1540) can send an AS configuration message to UE2 (1560) at step 1549 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1560). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0182] When UE2 (1560) receives an AS configuration message, it can determine in step 1551 whether there is a conflict between the SLRB configuration obtained in step 1547 and the SLRB configuration included in the AS configuration message. The target parameter for determining whether there is a conflict in the SLRB configuration may include at least one of an RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and a configuration parameter required for RLC mode operation. If UE2 (1560) determines in step 1551 that there is a conflict in the SLRB configuration, it can check the configuration parameter information that requires adjustment due to the discrepancy.

[0183] UE2 (1560) may transmit an AS configuration message containing configuration parameter information requiring adjustment at step 1553. The AS configuration message at step 1553 may include configuration parameter information requiring adjustment corresponding to at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID received at step 1549. The information of the configuration parameter requiring adjustment may include at least one of an adjustable RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and configuration parameters required for RLC mode operation.

[0184] UE1 (1540), having received the AS configuration message of step 1553, can determine in step 1555 that SLRB configuration adjustment is possible based on the configuration parameter information of the AS configuration received in step 1553. If UE1 (1540) determines that adjustment is possible for the configuration parameters, it can send an AS configuration complete message to UE2 (1560) in step 1557. The AS configuration complete message may include at least one or a combination of the PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID of the AS configuration message received in step 1553. UE1 (15400) and UE2 (1560) can perform sidelink data transmission and reception in step 1559 by applying the AS configuration including the SLRB configuration.

[0186] Referring to FIG. 15c, UE1 (1570) and UE2 (1590) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1571. The information exchanged between the two terminals (1570, 1590) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1570) and UE2 (1590) may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1573. UE1 (1570) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1575. UE2 (1590) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1577. For example, an SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0187] UE1 (1570) can send an AS configuration message to UE2 (1590) at step 1579 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1590). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0188] When UE2 (1590) receives an AS configuration message, it can determine in step 1581 whether there is a conflict between the SLRB configuration obtained in step 1577 and the SLRB configuration included in the AS configuration message. The target parameter for determining whether there is a conflict in the SLRB configuration may include at least one of an RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and a configuration parameter required for RLC mode operation. If UE2 (1590) determines in step 1581 that the SLRB configurations conflict, it can check the configuration parameter information that requires adjustment due to the discrepancy.

[0189] UE2 (1590) may transmit an AS configuration message containing configuration parameter information requiring adjustment at step 1583. The AS configuration message at step 1583 may include configuration parameter information requiring adjustment corresponding to at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID received at step 1579. The information on configuration parameters requiring adjustment (or adjustable configuration parameter information) may include at least one of RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and configuration parameters required for RLC mode operation. UE1 (1570), having received the AS configuration message at step 1583, may determine whether SLRB configuration adjustment is possible based on the configuration parameter information (or adjustable configuration parameter information) of the AS configuration received at step 1583 (step 1585).

[0190] If UE1 (1570) determines that adjustment is not possible for the above configuration parameters, it may send an AS configuration complete message containing AS configuration failure instruction information to UE2 (1590) at step 1587. The AS configuration complete message may include at least one or a combination of the PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID of the AS configuration message received at step 1583.

[0191] Meanwhile, in the embodiments of FIGS. 13, 14, 15a, 15b, and 15c above, if UE1 does not receive an AS configuration complete message from UE2 after transmitting an AS configuration message, or receives an AS configuration complete message indicating an AS configuration failure, UE1 and UE2 may not proceed further with the AS configuration setup procedure.

[0192] In the embodiments of FIGS. 15a, 15b, and 15c above, if UE2 does not receive an AS configuration complete message from UE1 after transmitting an AS configuration message, or receives an AS configuration complete message indicating an AS configuration failure, UE1 and UE2 may not proceed further with the AS configuration setup procedure.

[0194] According to various embodiments of the present disclosure, when the initiating UE and / or peer UE are RRC_Connected UEs, the operation of determining and / or processing conflicts between bi-directional SLRB configuration parameters or uni-directional SLRB configuration parameters between the two terminals may be performed by utilizing the coordination of the NW of each terminal. For example, the peer UE may transmit (report) bi-directional SLRB configuration information or uni-directional SLRB configuration information received from the initiating UE to its own NW. The NW may determine whether to accept or / and adjust the reported bi-directional SLRB configuration or uni-directional SLRB configuration, and may set the parameter information that can be accepted or / and adjusted or / and adjusted parameter information to the peer UE. The NW may set the SLRB configuration to the peer UE so as not to conflict with the SLRB configuration of the initiating UE.

[0195] For example, the NW can set the same RLC mode. For example, the NW can set the same bi-directional RLC. For example, the NW can set the same uni-directional RLC. If the NW determines that it is difficult to coordinate the SLRB configuration between the two terminals, it can instruct the peer UE to an AS configuration failure. The peer UE can transmit the AS configuration failure instruction information to the initiating UE. The NW can determine the configuration parameter information that can be coordinated between the two terminals. The NW can transmit the configuration parameter information that can be adjusted through the peer UE to the initiating UE.

[0196] The Peer UE may transmit to the initiating UE whether to accept or / and adjust or / and information on adjustable parameters or / and information on parameters determined by adjustment. The initiating UE may report to its own NW information determined by judgment and processing in the peer UE's NW. The information reported by the initiating UE to its own NW may include whether to accept or / and adjust the bi-directional SLRB configuration or uni-directional SLRB configuration in the peer UE, information on adjustable parameters or / and information on parameters determined by adjustment. If the initiating UE determines that the configuration parameters can be adjusted, it may set up the bi-directional SLRB configuration or uni-directional SLRB configuration. If the initiating UE determines that the configuration parameters cannot be adjusted, it may determine this as an AS configuration failure.

[0198] FIGS. 16 to 18 illustrate a method for coordinating SLRB configuration using base station cooperation according to various embodiments of the present disclosure. NW1 or NW2 in FIGS. 16 to 18 may correspond to the same NW or a different NW.

[0199] Referring to FIG. 16a, UE1 (1600) and UE2 (1630) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1601. The information exchanged between the two terminals (1600, 1630) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1600) and UE2 (1630) may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1603. UE1 (1600) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1605. For example, an SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0200] UE1 (1600) can send an AS configuration message to UE2 (1630) in step 1607 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1630). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0201] UE2 (1630) may transmit a PC5 SLRB configuration report message to NW (1640) in step 1609 to obtain the SLRB configuration. The PC5 SLRB configuration report message may be replaced with a SidelinkUEInformation message or a UEAssistanceInformation message. The PC5 SLRB configuration report message may include at least one or a combination of the PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID received in step 1607. The PC5 SLRB configuration information reported above may include at least one of an RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and configuration parameters required for RLC mode operation.

[0202] NW (1640) can determine the SLRB configuration of UE2 (1630) based on the information in the PC5 SLRB configuration report message. If NW (1640) determines that the SLRB configuration reported in step 1609 can be accepted, it can send a PC5 SLRB configuration confirm message to UE2 (1630) in step 1611 as a response to the message received in step 1609. Here, the PC5 SLRB configuration confirm message may be replaced with an RRCReconfiguration message. The PC5 SLRB configuration confirm message may include at least one or a combination of acknowledgment or failure information regarding the SLRB configuration reported in step 1609, PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0203] UE2 (1630) determines in step 1613 that it has obtained an SLRB configuration from NW (1640) and can send an AS configuration complete message to UE1 (1600) in step 1615 as a response to the AS configuration message in step 1607. The AS configuration complete message may include at least one or a combination of information corresponding to the AS configuration message, PC5 flow ID, destination ID, source ID, PQI, and PC5 SLRB ID. UE1 (1600) and UE2 (1630) can perform sidelink data transmission and reception in step 1617 by applying an AS configuration that includes the SLRB configuration.

[0205] Referring to FIG. 16b, UE1 (1650) and UE2 (1680) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1651. The information exchanged between the two terminals (1650, 1680) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1650) and UE2 (1680) may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1653. UE1 (1650) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1655. For example, an SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0206] UE1 (1650) can send an AS configuration message to UE2 (1680) at step 1657 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1680). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0207] UE2 (1680) may send a PC5 SLRB configuration report message to NW (1690) at step 1659 to obtain the SLRB configuration. The PC5 SLRB configuration report message may be replaced with a SidelinkUEInformation message or a UEAssistanceInformation message. The PC5 SLRB configuration report message may include at least one or a combination of the PC5 flow ID, destination ID, source ID, PQI, and QoS characteristics received at 1657.

[0208] NW (1690) can determine the SLRB configuration of UE2 (1680) based on the information of the PC5 SLRB configuration report message. NW (1690) can send a PC5 SLRB configuration confirm message to UE2 (1680) in step 1661 as a response to step 1659. Here, the PC5 SLRB configuration confirm message can be replaced with an RRCReconfiguration message. The PC5 SLRB configuration confirm message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID. Here, NW (1690) has the ability to set configuration parameters so that no conflicts occur in the SLRB configurations corresponding to at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, and QoS characteristics. For example, conflicts regarding bi-directional SLRB configuration parameters or uni-directional SLRB configuration parameters can be adjusted or controlled by utilizing a coordination procedure between the above NW (1690) and other NWs, or by utilizing a coordination procedure for SLRB configuration between systems of the same PLMN, same operator, same regulation, or same NW as in the embodiment of FIG. 8.

[0209] UE2 (1680) determines in step 1663 that it has obtained an SLRB configuration from NW (1690) and can send an AS configuration complete message to UE1 (1650) in step 1665 as a response to the AS configuration message in step 1657. The AS configuration complete message may include at least one or a combination of information corresponding to the AS configuration message, PC5 flow ID, destination ID, source ID, PQI, and PC5 SLRB ID. UE1 (1650) and UE2 (1680) can perform sidelink data transmission and reception in step 1667 by applying an AS configuration that includes the SLRB configuration.

[0211] Referring to FIG. 17a, UE1 (1700) and UE2 (1730) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1701. The information exchanged between the two terminals (1700, 1730) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1700) and UE2 (1730) may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1703. UE1 (1700) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1705. For example, an SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0212] UE1 (1700) can send an AS configuration message to UE2 (1730) in step 1707 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1730). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0213] UE2 (1730) may send a PC5 SLRB configuration report message to NW (1740) at step 1709 to obtain the SLRB configuration. The PC5 SLRB configuration report message may be replaced with a SidelinkUEInformation message or a UEAssistanceInformation message. The PC5 SLRB configuration report message may include at least one or a combination of the PC5 flow ID, destination ID, source ID, PQI, and QoS characteristics received at 1707.

[0214] NW (1740) can determine the SLRB configuration of UE2 (1730) based on the information in the PC5 SLRB configuration report message. NW (1740) can send a PC5 SLRB configuration confirm message to UE2 (1730) in step 1711 as a response to step 1709. Here, the PC5 SLRB configuration confirm message may be replaced with an RRCReconfiguration message. The PC5 SLRB configuration confirm message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0215] UE2 (1730) can determine in step 1713 whether it has obtained an SLRB configuration from NW (1740). In step 1713, UE2 (7130) can determine whether there is a conflict in SLRB configuration parameters by checking the SLRB configuration received in step 1707 and the SLRB configuration obtained in step 1711. If a conflict in SLRB configuration parameters is determined based on the determination in step 1713, UE2 (7130) determines that it is an AS configuration failure and can send an AS configuration complete message to UE1 (1700) in step 1715 as a response to the AS configuration message of step 1707. The AS configuration complete message may include failure indication information and at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, and PC5 SLRB ID corresponding to the AS configuration message. If the AS configuration complete message indicates a failure, it may include information on the conflicted SLRB configuration parameters. The conflicted SLRB configuration parameter information may include at least one or a combination of RLC mode, bi-directional RLC, uni-directional RLC, a logical channel for RLC mode, and RLC mode operation parameters.

[0216] UE1 (1700) can determine that there is an SLRB configuration failure when it receives an AS configuration complete message containing failure indication information due to an SLRB configuration failure (step 1717). UE1 (1700) and UE2 (1730) can recognize the AS configuration failure and stop the AS configuration procedure.

[0217] The above embodiment is described assuming that UE2 (1730) is an RRC_Connected UE. If UE2 (1730) is an RRC_Idle UE or an RRC_Inactive UE, the operation of step 1713 can be performed based on the SLRB configuration obtained by receiving the SIB message from the NW. If UE2 (1730) is an out-of-coverage UE, the operation of step 1713 can be performed based on the SLRB configuration obtained from the pre-configuration.

[0219] Referring to FIG. 17b, UE1 (1750) and UE2 (1780) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1751. The information exchanged between the two terminals (1750, 1780) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1750) and UE2 (1780) may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1753. UE1 (1750) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1755. For example, an SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0220] UE1 (1750) can send an AS configuration message to UE2 (1780) at step 1757 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1780). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0221] UE2 (1780) may transmit a PC5 SLRB configuration report message to NW (1790) at step 1759 to obtain SLRB configuration. The PC5 SLRB configuration report message may be replaced with a SidelinkUEInformation message or a UEAssistanceInformation message. The PC5 SLRB configuration report message may include at least one or a combination of the PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID received at 1757. The PC5 SLRB configuration information reported above may include at least one of an RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and configuration parameters required for RLC mode operation.

[0222] NW (1790) can determine the SLRB configuration of UE2 (1780) based on the information in the PC5 SLRB configuration report message. If NW (1790) determines that the SLRB configuration reported in step 1759 can be accepted, it can send a PC5 SLRB configuration confirm message to UE2 (1780) in step 1761 as a response to the message received in step 1759. Here, the PC5 SLRB configuration confirm message may be replaced with an RRCReconfiguration message. The PC5 SLRB configuration confirm message may include at least one or a combination of acknowledgment or failure information regarding the SLRB configuration reported in step 1759, PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0223] When UE2 (1780) receives SLRB configuration from NW (1790), it may send an AS configuration complete message to UE1 (1750) in step 1763 as a response to the AS configuration message of step 1757. If UE2 (1780) determines that it has received SLRB configuration failure information from NW (1790), it may include failure instruction information in the AS configuration complete message, such as at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, and PC5 SLRB ID corresponding to the AS configuration message. When UE1 (1750) receives an AS configuration complete message containing failure instruction information due to an SLRB configuration conflict, it may determine that there is an SLRB configuration conflict (step 1765). UE1 (1750) and UE2 (1780) may recognize the AS configuration failure and not proceed further with the AS configuration procedure.

[0225] Referring to FIG. 18, UE1 (1800) and UE2 (1830) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 1801. The information exchanged between the two terminals (1800, 1830) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (1800) and UE2 (1830) may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 1803. UE1 (1800) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 1805. For example, an SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0226] UE1 (1800) can send an AS configuration message to UE2 (1830) in step 1807 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (1830). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0227] UE2 (1830) may transmit a PC5 SLRB configuration report message to NW2 (1850) in step 1809 to obtain the SLRB configuration. The PC5 SLRB configuration report message may be replaced with a SidelinkUEInformation message or a UEAssistanceInformation message. The PC5 SLRB configuration report message may include at least one or a combination of the PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID received in step 1807. The PC5 SLRB configuration information reported above may include at least one or a combination of RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, a logical channel corresponding to the RLC mode, and configuration parameters required for RLC mode operation.

[0228] NW2 (1850) can determine the SLRB configuration of UE2 (1830) based on the information in the PC5 SLRB configuration report message. NW2 (1850) can determine whether the SLRB configuration reported in step 1809 can be accepted, and if it determines a conflict of SLRB configuration parameters, it can identify the SLRB configuration parameters that are determined to be adjustable. The SLRB configuration parameters determined to be adjustable may include at least one of RLC mode, bi-directional RLC, uni-directional RLC, a logical channel corresponding to RLC mode, and configuration parameters required for RLC mode operation. In step 1811, NW2 (1850) can send a PC5 SLRB configuration confirm message to UE2 (1830) as a response to the message received in step 1809. Here, the PC5 SLRB configuration confirm message may be replaced with an RRCReconfiguration message. The above PC5 SLRB configuration confirm message may include at least one or a combination of acknowledgment or failure information regarding the SLRB configuration reported in step 1811, SLRB configuration parameter information determined to be adjustable, PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0229] UE2 (1830) can determine whether to obtain an SLRB configuration from NW2 (1850). If the obtained SLRB configuration includes adjustable SLRB configuration parameter information, UE2 (1830) can construct an AS configuration message containing the adjustable SLRB configuration parameter information and transmit it to UE1 (1800) in step 1813. The AS configuration message in step 1813 may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, and PC5 SLRB ID, which are information corresponding to the AS configuration message in step 1807, and adjustable SLRB configuration parameter information.

[0230] UE1 (1800) can determine a SLRB configuration conflict in step 1815 when it receives an AS configuration message containing information on adjustable SLRB configuration parameters. UE1 (1800) can report the SLRB configuration conflict to the NW1 (1840) it is connected to. UE1 (1800) can send a PC5 SLRB configuration report message in step 1817. The PC5 SLRB configuration report message may be replaced by a SidelinkUEInformation message or a UEAssistanceInformation message. The PC5 SLRB configuration report message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, PC5 SLRB ID, and adjustable SLRB configuration parameters.

[0231] UE1 (1800) may receive a PC5 SLRB configuration confirm message from NW1 (1840) at step 1819. The PC5 SLRB configuration confirm message may be replaced with an RRCReconfiguration message. The PC5 SLRB configuration confirm message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, PC5 SLRB ID, approval of SLRB configuration parameter adjustment, and adjustable SLRB configuration parameters.

[0232] UE1 (1800) may send an AS configuration complete message to UE2 (1830) in step 1821 as a response to the message received in step 1813. The AS configuration complete message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, PC5 SLRB ID, approval of SLRB configuration parameter adjustment, and adjustable SLRB configuration parameters.

[0233] When performing PC5 SLRB configuration parameter adjustments using NW1 (1840) and NW2 (1850) as described above, in the embodiment of FIG. 18, NW2 (1850) may provide at least one or a combination of an adjustable parameter set, an adjustable parameter, and a parameter to be adjusted. NW1 (1840) may determine whether at least one or a combination of the adjustable parameter set, the adjustable parameter, and the parameter to be adjusted is acceptable. If an adjustable parameter set is provided, NW1 (1840) may select one acceptable parameter. If NW1 (1840) determines that an adjustable parameter or a parameter to be adjusted is acceptable, it may indicate acceptance of the adjustment parameter through an AS configuration complete signaling transmitted by UE1 (1800) to UE2 (1830). UE2 (1830) can report to NW2 (1850) information such as failure or acknowledgment of the adjustment of PC5 SLRB configuration or which parameters have been adjusted.

[0235] Meanwhile, in the embodiments of FIGS. 16a, 16b, 17a, 17b, and 18, if UE1 does not receive an AS configuration complete message from UE2 after transmitting an AS configuration message, or receives an AS configuration complete message indicating an AS configuration failure, UE1 and UE2 may not proceed further with the AS configuration setup procedure.

[0236] In the embodiment of FIG. 18 above, if UE2 does not receive an AS configuration complete message from UE1 after transmitting an AS configuration message, or receives an AS configuration complete message indicating an AS configuration failure, UE1 and UE2 may not proceed further with the AS configuration setup procedure.

[0238] FIG. 19 illustrates a signal flow for handling SLRB configuration processing failures according to various embodiments of the present disclosure.

[0239] Referring to FIG. 19, UE1 (1900) can determine in step 1901 that the AS configuration setting failed due to a conflict in the SLRB configuration to be applied to the sidelink unicast connection with the other terminal. UE1 (1900) corresponds to at least one of the initiating UE, peer UE, or designated terminal.

[0240] UE1 (1900) can transmit a PC5 SLRB configuration report message to its NW3 (1940) at step 1903. The PC5 SLRB configuration report message can be used to indicate that the SLRB configuration obtained from the NW3 (1940) is inconsistent with the SLRB configuration received from the other terminal. The PC5 SLRB configuration report message may include at least one or a combination of PQI, PC5 QoS characteristics, PC5 flow ID, PC5 SLRB ID, destination ID, and source ID obtained from the NW3 (1940). The above PC5 SLRB configuration report message may include at least one of the configuration parameter information determined to be inconsistent among the SLRB configuration parameters corresponding to the above PQI, PC5 QoS characteristics, PC5 flow ID, PC5 SLRB ID, destination ID, and source ID, for example, RLC mode, bi-directional RLC, uni-directional RLC, logical channel information corresponding to RLC mode, and operational parameter corresponding to RLC mode.

[0241] Based on the information received from the above PC5 SLRB configuration report, NW3 (1940) can perform a side-link configuration information coordination operation with another NW, NW4 (1950) of FIG. 19, in step 1905. The information exchanged between NW3 (1940) and NW4 (1950) in the side-link configuration information coordination operation may include at least one of an RLC mode, bi-directional RLC, uni-directional RLC, logical channel information for each RLC mode, and operational parameters for each RLC mode corresponding to at least one of PQI, PC5 QoS characteristics, PC5 flow ID, PC5 SLRB ID, destination ID, and source ID. The NW coordination operation in step 1905 may be performed for the purpose of setting the same SLRB configuration between NWs for at least one or a combination of the same PQI, PC5 QoS characteristics, destination ID, source ID, PC5 SLRB ID, and PC5 flow ID.

[0243] According to various embodiments of the present disclosure, when the initiating UE and / or peer UE is an RRC_Inactive UE, an RRC_Idle UE, or an Out-of-coverage UE, the operation of determining and / or processing a conflict of SLRB configuration parameters between two terminals may correspond to at least one or a combination of FIG. 10a, FIG. 10b, FIG. 11, FIG. 12, FIG. 13, FIG. 14, FIG. 15a, FIG. 15b, or FIG. 15c.

[0245] According to various embodiments of the present disclosure, the operation for determining and processing an SLRB configuration mismatch considering an SLRB configuration designated terminal selected by the method of FIG. 9 may apply FIG. 10a or FIG. 10b. The designated terminal may perform the same operation as the initiating UE of FIG. 10a or FIG. 10b. Here, the designated terminal may perform the operation of obtaining a bi-directional SLRB configuration or a uni-directional SLRB configuration and transmitting it to the other terminal.

[0246] In another embodiment, the designated terminal may perform an operation to determine and process whether there is a discrepancy between the SLRB configuration it has obtained and the SLRB configuration received from the counterpart. Here, the designated terminal may perform the same operation as the peer UE of FIG. 13, FIG. 14, FIG. 15b, FIG. 16, FIG. 17, or FIG. 18, and may perform an operation to transmit to the counterpart terminal at least one of information on whether there is a match / discord, adjustment information for configuration parameters determined to be inconsistent, and adjustment configuration parameter information for inconsistent configuration parameters. If the designated terminal is an RRC_Connected UE, it may perform at least one or a combination of the following operations: obtaining an SLRB configuration from the NW, reporting the SLRB configuration information received from the counterpart terminal to the NW to verify the SLRB configuration, obtaining inconsistent configuration parameter information from the NW, obtaining adjustable configuration parameter information from the NW, and obtaining adjusted SLRB configuration information from the NW.

[0248] If it is determined that coordination of SLRB configuration information between UE1 and UE2 is necessary, as shown in FIG. 15a, FIG. 15b, FIG. 15c, or FIG. 18, UE2 may provide UE1 with at least one or a combination of RLC mode, bi-directional RLC, uni-directional RLC, logical channels applicable to RLC mode, and operational parameters of RLC mode as SLRB configuration parameters requiring coordination. For example, a method of indicating applicable logical channels may use at least one of one or more available logical channel values, one or more logical channel values ​​currently in use, or a bitmap of available or currently in use logical channel information.

[0250] FIG. 20 illustrates a signal flow between terminals handling a collision of SLRB configurations according to various embodiments of the present disclosure. An embodiment of FIG. 20 illustrates a signal procedure in which terminals that have determined a collision of SLRB configurations decide to use a default SLRB configuration for a sidelink unicast connection and exchange information about this.

[0251] Referring to FIG. 20, UE1 (2000) and UE2 (2030) may perform a PC5 signaling procedure to establish a sidelink-based unicast connection in step 2001. The information exchanged between the two terminals (2000, 2030) in the PC5 signaling procedure may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, and PC5 unicast ID. UE1 (2000) and UE2 (2030) may perform a Sidelink UE capability information exchange procedure during the PC5 RRC connection procedure in step 2003. UE1 (2000) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 2005. UE2 (2030) may obtain an SLRB configuration including a bi-directional SLRB configuration or a uni-directional SLRB configuration in step 2007. For example, the SLRB configuration may include at least one or a combination of an RLC mode, a bi-directional RLC, a uni-directional RLC, a logical channel corresponding to the RLC mode, and an operational parameter corresponding to the RLC mode. The SLRB configuration may be obtained through at least one of a dedicated RRC message, a SIB, and a pre-configuration.

[0252] UE1 (2000) can send an AS configuration message to UE2 (2030) in step 2009 to perform an AS configuration procedure during the PC5 RRC connection procedure with UE2 (2030). The AS configuration message may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, QoS characteristics, PC5 SLRB configuration, and PC5 SLRB ID.

[0253] When UE2 (2030) receives an AS configuration message, it can determine in step 2011 whether there is a conflict between the SLRB configuration obtained in step 2007 and the SLRB configuration included in the AS configuration message. The target parameter for determining whether there is a conflict in the SLRB configuration may include at least one configuration parameter of each RLC mode operation, such as an RLC mode (RLC AM or RLC UM), bi-directional RLC, uni-directional RLC, and a logical channel corresponding to the RLC mode.

[0254] If UE2 (2030) determines that the SLRB configuration conflicts in step 2011, it determines this as an AS configuration failure and can transmit an AS configuration complete message to UE1 (2000) in step 2013 as a response to the AS configuration message received in step 2009. The AS configuration complete message may include at least one or a combination of information corresponding to the AS configuration message, PC5 flow ID, destination ID, source ID, PQI, PC5 SLRB ID, failure instruction information, and default SLRB configuration usage instruction information. As an example, UE2 (2030) may include parameter information that causes the SLRB configuration conflict in the AS configuration complete message. When UE1 (2000) receives an AS configuration complete message from UE2 (2030) containing AS configuration failure instructions and default SLRB configuration instructions, it can determine to use the default SLRB configuration for a sidelink unicast corresponding to at least one or a combination of the PC5 flow ID, destination ID, source ID, and PQI (step 2015).

[0255] UE1 (2000) can transmit an AS configuration complete message corresponding to the message of step 2013 to UE2 (2030) in step 2017. The AS configuration complete message transmitted in step 2017 may include at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, and default SLRB configuration instruction information. UE1 (2000) and UE2 (2030) can perform sidelink data transmission and reception in step 2019 by applying the default SLRB configuration.

[0256] In another embodiment, UE1 (2000) may use a procedure in which, at step 2017, UE1 (2000) transmits an AS configuration message containing at least one or a combination of PC5 flow ID, destination ID, source ID, PQI, and default SLRB configuration instruction information, and UE2 (2030) transmits an AS configuration complete message in response to the AS configuration message transmitted by UE1 (2000). After the procedure of transmitting and receiving the AS configuration message and the AS configuration complete message, UE1 (2000) and UE2 (2030) may perform sidelink data transmission and reception by applying the default SLRB configuration.

[0258] Methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0259] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of this disclosure.

[0260] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disc storage devices, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0261] Additionally, the program may be stored on an attachable storage device accessible via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to the device performing the embodiment of the present disclosure through an external port. Additionally, a separate storage device on the communication network may be connected to the device performing the embodiment of the present disclosure.

[0262] In the specific embodiments of the present disclosure described above, the components included in the disclosure are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0263] Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, it is understood that various modifications are possible within the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof.

Claims

Claim 1 A method performed by a first terminal comprising: receiving a first message from a second terminal that includes a sidelink radio bearer (SLRB) setting that includes a radio link control (RLC) mode; identifying a conflict in an access stratum (AS) setting related to a bidirectional sidelink connection based on the RLC mode included in the SLRB setting; if adjustment of the AS setting is determined based on the conflict in the AS setting: transmitting a second message to the second terminal that includes parameters related to the conflict in the AS setting; and receiving a third message from the second terminal that includes a SLRB setting that includes new parameters for clearing the conflict in the AS setting; if failure of the AS setting is determined based on the conflict in the AS setting: transmitting a fourth message to the second terminal that includes information indicating the failure of the AS setting; and, if sidelink terminal information is transmitted from the second terminal to a base station based on the failure of the AS setting, the sidelink terminal information includes information indicating the failure of the AS setting and a sidelink destination identifier related to the AS setting. Claim 2 A method according to claim 1, comprising the step of transmitting a fifth message to the second terminal containing information instructing the application of the SLRB setting if the failure of the AS setting is not identified based on the RLC mode included in the SLRB setting. Claim 3 A method according to claim 1, characterized in that a failure of the AS setting is identified based on the RLC mode included in the SLRB setting received from the second terminal and the RLC mode received from the base station. Claim 4 A method according to claim 1, characterized in that the side link terminal information further includes information regarding the RLC mode. Claim 5 A method according to claim 4, characterized in that an RRC (radio resource control) reset message including a new SLRB setting related to the SLRB setting is transmitted from the base station to the second terminal in response to the sidelink terminal information. Claim 6 A method performed by a second terminal comprises: transmitting a first message to the first terminal that includes a sidelink radio bearer (SLRB) setting that includes a radio link control (RLC) mode; receiving a second message from the first terminal in response to the first message; if the second message corresponds to a message that includes information indicating a failure of an access stratum (AS) setting: identifying a failure of the AS setting related to a bidirectional sidelink connection based on the RLC mode included in the SLRB setting; and if the failure of the AS setting is identified, transmitting sidelink terminal information to a base station, wherein the sidelink terminal information includes information indicating a failure of the AS setting and a sidelink destination identifier related to the AS setting; and if the second message corresponds to a message that includes parameters related to a collision of the AS setting: if the collision of the AS setting is overcomeable, transmitting a third message from the second terminal that includes a SLRB setting that includes new parameters for clearing the collision of the AS setting. A method characterized by including the step of transmitting the sidelink terminal information, which includes information indicating the failure of the AS setting, to the base station if the conflict of the AS setting is insurmountable. Claim 7 A method according to claim 6, characterized in that if the second message corresponds to a message containing information instructing the application of the SLRB setting, the SLRB setting is identified as being set on the first terminal. Claim 8 A method according to claim 6, characterized by including the step of receiving an RRC (radio resource control) reset message from the base station, which includes a new SLRB setting related to the SLRB setting, in response to the sidelink terminal information. Claim 9 A method according to claim 8, characterized in that the side link terminal information further includes information regarding the RLC mode. Claim 10 A method according to claim 6, characterized in that a timer is started in response to the transmission of the first message and the timer is stopped in response to the reception of the second message. Claim 11 In the first terminal, a transmitting and receiving unit; A first terminal comprising a control unit, wherein the control unit receives a first message from a second terminal that includes a sidelink radio bearer (SLRB) setting that includes a radio link control (RLC) mode, identifies a conflict in an access stratum (AS) setting related to a bidirectional sidelink connection based on the RLC mode included in the SLRB setting, and when the control unit determines to adjust the AS setting based on the conflict in the AS setting: transmits a second message containing parameters related to the conflict in the AS setting to the second terminal, and controls the reception of a third message from the second terminal that includes a new parameter for clearing the conflict in the AS setting, and when the control unit determines a failure of the AS setting based on the conflict in the AS setting: controls the transmission of a fourth message containing information indicating a failure of the AS setting to the second terminal, and when the sidelink terminal information is transmitted from the second terminal to a base station based on the failure of the AS setting, the sidelink terminal information includes information indicating a failure of the AS setting and a sidelink destination identifier related to the AS setting. Claim 12 A first terminal according to claim 11, wherein the control unit controls the transmission of a fifth message containing information instructing the application of the SLRB setting to the second terminal if a failure of the AS setting is not identified based on the RLC mode included in the SLRB setting. Claim 13 A first terminal characterized in that, in claim 11, a failure of the AS setting is identified based on the RLC mode included in the SLRB setting received from the second terminal and the RLC mode received from the base station. Claim 14 A first terminal characterized in that, in claim 11, the side link terminal information further includes information regarding the RLC mode. Claim 15 A first terminal according to claim 14, characterized in that an RRC (radio resource control) reset message including a new SLRB setting related to the SLRB setting is transmitted from the base station to the second terminal in response to the sidelink terminal information. Claim 16 In the second terminal, a transmitting and receiving unit; The control unit includes a control unit, wherein the control unit transmits a first message to a first terminal that includes a sidelink radio bearer (SLRB) setting that includes a radio link control (RLC) mode, receives a second message from the first terminal in response to the first message, and if the second message corresponds to a message that includes information indicating a failure of an access stratum (AS) setting: identifies a failure of the AS setting related to a bidirectional sidelink connection based on the RLC mode included in the SLRB setting, and if the failure of the AS setting is identified, controls the transmission of sidelink terminal information to a base station, wherein the sidelink terminal information includes information indicating a failure of the AS setting and a sidelink destination identifier related to the AS setting, and if the second message corresponds to a message that includes parameters related to a collision of the AS setting: if the collision of the AS setting is overcome, transmits a third message from the second terminal that includes a SLRB setting that includes new parameters for clearing the collision of the AS setting, and if the collision of the AS setting is insurmountable, the control unit includes information indicating a failure of the AS setting. A second terminal characterized by controlling the transmission of sidelink terminal information to the base station. Claim 17 A second terminal according to claim 16, characterized in that if the second message corresponds to a message containing information instructing the application of the SLRB setting, the SLRB setting is identified as being set on the first terminal. Claim 18 A second terminal according to claim 16, characterized by controlling to receive an RRC (radio resource control) reset message from the base station, which includes a new SLRB setting related to the SLRB setting, in response to the sidelink terminal information. Claim 19 A second terminal characterized in that, in paragraph 18, the above-mentioned side-link terminal information further includes information regarding the RLC mode. Claim 20 A second terminal according to claim 16, characterized in that a timer is started in response to the transmission of the first message and the timer is stopped in response to the reception of the second message.

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