Method and device for managing carrier failure

Abstract

Provided are a method by which a first device performs wireless communication, and a device supporting same. The method may comprise the steps of: establishing a PC5 unicast link with a second device; detecting a carrier failure for a first carrier related to the PC5 unicast link; on the basis of information related to the carrier failure, determining that there is no available carrier for a first quality of service (QoS) flow related to the PC5 unicast link; and removing the first QoS flow on the basis of the determination.

Description

Method and device for managing carrier failure

[0001] The present disclosure relates to a wireless communication system.

[0002] 5G NR, the successor to LTE (long-term evolution), is a new clean-slate mobile communications system characterized by high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, mid-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz.

[0003] The 6G (wireless communication) system aims to achieve (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) low energy consumption for battery-free Internet of Things (IoT) devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be divided into four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity, and the 6G system can satisfy the requirements as shown in Table 1 below. For example, Table 1 can represent an example of the requirements of a 6G system.

[0004] Per device peak data rate 1 Tbps E2E latency 1 ms Maximum spectral efficiency 100 bps / Hz Mobility support Up to 1000 km / hr Satellite integration Fully AI Fully autonomous vehicle Fully XR Fully haptic communication Fully

[0005] In one embodiment, a method for a first device to perform wireless communication is provided. The method may include: establishing a PC5 unicast link with a second device; detecting a carrier failure for a first carrier associated with the PC5 unicast link; determining, based on information associated with the carrier failure, that there is no available carrier for a first quality of service (QoS) flow associated with the PC5 unicast link; and removing the first QoS flow based on the determination.

[0006] In one embodiment, a first device configured to perform wireless communication is provided. The first device may include at least one transceiver; at least one processor; and at least one memory coupled to the at least one processor and storing instructions. For example, the instructions, when executed by the at least one processor, may cause the first device to: establish a PC5 unicast link with a second device; detect a carrier failure for a first carrier associated with the PC5 unicast link; determine, based on information associated with the carrier failure, that no carrier is available for a first quality of service (QoS) flow associated with the PC5 unicast link; and, based on the determination, remove the first QoS flow.

[0007] In one embodiment, a processing device is provided that is configured to control a first device. The processing device comprises at least one processor; and at least one memory coupled to the at least one processor and storing instructions, wherein the instructions, when executed by the at least one processor, cause the first device to: establish a PC5 unicast link with a second device; detect a carrier failure for a first carrier associated with the PC5 unicast link; determine, based on information associated with the carrier failure, that there is no available carrier for a first quality of service (QoS) flow associated with the PC5 unicast link; and, based on the determination, remove the first QoS flow.

[0008] In one embodiment, a non-transitory computer-readable storage medium having instructions recorded thereon is provided. The instructions, when executed, cause a first device to: establish a PC5 unicast link with a second device; detect a carrier failure for a first carrier associated with the PC5 unicast link; determine, based on information related to the carrier failure, that no carrier is available for a first quality of service (QoS) flow associated with the PC5 unicast link; and remove the first QoS flow based on the determination.

[0009] Figure 1 illustrates a device-to-device communication procedure according to one embodiment of the present disclosure.

[0010] FIG. 2 illustrates a radio protocol architecture according to one embodiment of the present disclosure.

[0011] FIG. 3 illustrates the structure of a wireless frame according to one embodiment of the present disclosure.

[0012] FIG. 4 illustrates a slot structure of a frame according to one embodiment of the present disclosure.

[0013] FIG. 5 illustrates an example of a BWP according to one embodiment of the present disclosure.

[0014] FIG. 6 illustrates a procedure for a terminal to perform V2X or SL communication according to a resource allocation mode, according to one embodiment of the present disclosure.

[0015] FIG. 7 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure.

[0016] FIG. 8 illustrates an example of a communication scenario based on a 6G system according to an embodiment of the present disclosure.

[0017] FIG. 9 illustrates an example of a sensing operation according to one embodiment of the present disclosure.

[0018] FIG. 10 illustrates a method for adding a carrier when a carrier fails, according to one embodiment of the present disclosure.

[0019] FIG. 11 illustrates a method for removing a PC5 QoS flow upon carrier failure according to one embodiment of the present disclosure.

[0020] FIG. 12 illustrates a method for removing a PC5 QoS flow upon carrier failure according to one embodiment of the present disclosure.

[0021] FIG. 13 illustrates a method for a first device to perform wireless communication according to one embodiment of the present disclosure.

[0022] FIG. 14 illustrates a method for a second device to perform wireless communication according to one embodiment of the present disclosure.

[0023] FIG. 15 illustrates a communication system (1) according to one embodiment of the present disclosure.

[0024] FIG. 16 illustrates a wireless device according to one embodiment of the present disclosure.

[0025] FIG. 17 illustrates a signal processing circuit for a transmission signal according to one embodiment of the present disclosure.

[0026] FIG. 18 illustrates a wireless device according to one embodiment of the present disclosure.

[0027] FIG. 19 illustrates a mobile device according to an embodiment of the present disclosure.

[0028] FIG. 20 illustrates a vehicle or autonomous vehicle according to one embodiment of the present disclosure.

[0029] In this disclosure, "A or B" can mean "only A," "only B," or "both A and B." In other words, "A or B" in this disclosure can be interpreted as "A and / or B." For example, "A, B or C" in this disclosure can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0030] As used herein, a slash ( / ) or a comma may mean "and / or." For example, "A / B" may mean "A and / or B." Accordingly, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B, or C."

[0031] In the present disclosure, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in the present disclosure, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”

[0032] Additionally, in the present disclosure, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0033] Additionally, parentheses used in the present disclosure may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information." In other words, "control information" in the present disclosure is not limited to "PDCCH," and "PDCCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information."

[0034] In the following explanation, ‘when, if, in case of’ can be replaced with ‘based on’.

[0035] Technical features individually described in one drawing in this disclosure may be implemented individually or simultaneously.

[0036] In the present disclosure, higher layer parameters may be parameters set for the terminal, preset, or predefined. For example, a base station or network may transmit higher layer parameters to the terminal. For example, the higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0037] In the present disclosure, "setting or defining" may be interpreted as being set or preset to a device through predefined signaling (e.g., SIB, MAC, RRC) from a base station or a network. In the present disclosure, "setting or defining" may be interpreted as being preset to a device. In the present disclosure, "setting or defining" may be interpreted as being set or preset to a device through predefined signaling (e.g., MAC, RRC, SCI (sidelink control information), device-to-device signaling control information, etc.) from another device. In the present disclosure, "setting or defining" may be interpreted as being preset to a device.

[0038] In the present disclosure, a user equipment (UE) may refer to a device, a portable device, a wireless device, etc. In the present disclosure, a base station (BS) may refer to a radio access network (RAN) node, a non-terrestrial network (NTN) cell / node, a transmission reception point (TRP), a network, an integrated access and backhaul (IAB) node, a device, a portable device, a wireless device, etc.

[0039] The technology proposed in the present disclosure can be used in various wireless communication systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), LTE (long term evolution), and 5G NR.

[0040] The technology proposed in this disclosure can be implemented with 6G wireless technology and applied to various 6G systems. For example, 6G systems can have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), artificial intelligence (AI) integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0041] FIG. 1 illustrates a device-to-device communication procedure according to one embodiment of the present disclosure. The embodiment of FIG. 1 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0042] Referring to FIG. 1, in step S101, a first device and a second device can perform synchronization. For example, the first device can be a terminal and / or at least one of the devices proposed in the present disclosure. For example, the second device can be a base station, a network, a RAN node, an NTN node / cell, a TRP, a terminal and / or at least one of the devices proposed in the present disclosure. For example, the first device can perform an initial cell search operation. For example, the first device can detect at least one synchronization signal transmitted by the second device according to a predefined rule. Here, for example, the synchronization signal can include a plurality of synchronization signals classified according to a structure or purpose (e.g., a primary synchronization signal, a secondary synchronization signal, etc.). Through this, the first device can identify the boundaries of the frame, subframe, time unit, slot, and / or symbol of the second device, and the first device can obtain information about the second device (e.g., a cell identifier).

[0043] In step S103, the first device can obtain system information transmitted by the second device. For example, the system information may include information related to the properties, characteristics, and / or capabilities of the second device required to connect to the second device and use the service. For example, the system information may be classified according to content (e.g., whether it is essential for connection), transmission structure (e.g., the channel used, whether it is provided on-demand), etc. For example, the system information may be classified into a master information block (MIB) and a system information block (SIB). For example, if necessary, the first device may transmit a signal requesting system information before receiving the system information. For example, the request and provision of system information may be performed after a random access procedure described below.

[0044] In step S105, the first device and the second device can perform a random access procedure. For example, the first device can transmit and / or receive at least one message (e.g., a random access preamble, a random access response message, etc.) for the random access procedure based on information related to a random access channel of the second device obtained through system information (e.g., channel location, channel structure, structure of supported preamble, etc.). For example, the first device can transmit a preamble (e.g., Msg1) through the random access channel, the first device can receive a random access response message (e.g., Msg2), the first device can transmit a message (e.g., Msg3) including information related to the first device (e.g., identification information) to the second device using scheduling information included in the random access response message, and the first device can receive a message (e.g., Msg4) for contention resolution and / or connection establishment. For example, Msg1 and Msg3 may be sent and received as one message (e.g., MsgA), and / or Msg2 and Msg4 may be sent and received as one message (e.g., MsgB).

[0045] In step S107, the first device and the second device may perform signaling of control information. Here, for example, the control information may be defined in various layers, such as a layer that controls a connection (e.g., a radio resource control (RRC) layer), a layer that handles mapping between logical channels and transport channels (e.g., a media access control (MAC) layer), a layer that handles physical channels (e.g., a physical (PHY) layer), etc. For example, the first device and the second device may perform at least one of signaling for establishing a connection, signaling for determining settings related to communication, and / or signaling for indicating allocated resources. For example, the control information may be signaled / transmitted via a control channel. For example, the control information and / or the control channel may be used to schedule at least one of data, a data channel (e.g., a shared channel), and / or control information on the data channel.

[0046] In step S109, the first device and the second device may transmit and / or receive data. For example, the first device and the second device may process, transmit, and / or receive data based on signaling of control information. For example, when transmitting data, the first device or the second device may perform at least one of channel encoding, rate matching, scrambling, constellation mapping, layer mapping, waveform modulation, antenna mapping, and / or resource mapping on the information bits. For example, when receiving data, the first device or the second device may perform at least one of signal extraction from resources, waveform demodulation for each antenna, signal arrangement considering layer mapping, constellation demapping, descrambling, and / or channel decoding.

[0047] For example, the layers of a radio interface protocol between a first device and a second device can be divided into L1 (layer 1), L2 (layer 2), L3 (layer 3), etc. For example, a physical layer belonging to the first layer can provide an information transfer service using a physical channel, and an RRC (radio resource control) layer located in the third layer can play a role in controlling radio resources between the first device and the second device. For this purpose, for example, the RRC layer can exchange RRC messages between the first device and the second device.

[0048] FIG. 2 illustrates a radio protocol architecture according to an embodiment of the present disclosure. The embodiment of FIG. 2 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted. For example, (a) of FIG. 2 may illustrate a radio protocol stack of a user plane for uplink communication or downlink communication, and (b) of FIG. 2 may illustrate a radio protocol stack of a control plane for uplink communication or downlink communication. For example, (c) of FIG. 2 may illustrate a radio protocol stack of a user plane for device-to-device communication, and (d) of FIG. 2 may illustrate a radio protocol stack of a control plane for device-to-device communication.

[0049] For example, the physical layer can provide information transmission services to upper layers using physical channels. For example, the physical layer can be connected to the upper layer, the medium access control (MAC) layer, through a transport channel. For example, data can be transmitted between the MAC layer and the physical layer through the transport channel. For example, transport channels can be classified according to how and with what characteristics data is transmitted over the wireless interface. For example, data can be transmitted between different physical layers (e.g., between the physical layers of a first device and a second device) through a physical channel. For example, the physical channel can be modulated using an orthogonal frequency division multiplexing (OFDM) scheme, and time and frequency can be utilized as radio resources.

[0050] For example, the MAC layer can provide services to the upper layer, the radio link control (RLC) layer, through logical channels. For example, the MAC layer can provide a mapping function from multiple logical channels to multiple transport channels. For example, the MAC layer can provide a logical channel multiplexing function by mapping multiple logical channels to a single transport channel. For example, the MAC sublayer can provide data transmission services on logical channels.

[0051] For example, the RLC layer can perform concatenation, segmentation, and reassembly of RLC service data units (SDUs). For example, to guarantee the various quality of service (QoS) required by radio bearers (RBs), the RLC layer can provide three operating modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). For example, AM RLC can provide error correction through automatic repeat request (ARQ).

[0052] For example, the RRC (radio resource control) layer can be defined only in the control plane. For example, the RRC layer can be responsible for controlling logical channels, transport channels, and physical channels in relation to the configuration, re-configuration, and release of radio bearers. For example, an RB can mean a logical path provided by a first layer (e.g., a physical layer) and a second layer (e.g., a MAC layer, an RLC layer, a PDCP (packet data convergence protocol) layer, a SDAP (service data adaptation protocol) layer, etc.) for data transmission between a first device and a second device.

[0053] For example, the functions of the PDCP layer in the user plane may include forwarding of user data, header compression, and ciphering. For example, the functions of the PDCP layer in the control plane may include forwarding of control plane data and ciphering / integrity protection.

[0054] For example, establishing an RB can refer to the process of defining the characteristics of the radio protocol layer and channel to provide a specific service, and setting specific parameters and operating methods for each. For example, RBs can be divided into two types: signaling radio bearers (SRBs) and data radio bearers (DRBs). For example, SRBs can be used as a channel to transmit RRC messages in the control plane, while DRBs can be used as a channel to transmit user data in the user plane.

[0055] For example, a downlink transmission channel may include at least one of a broadcast channel (BCH) for transmitting system information, and / or a downlink shared channel (SCH) for transmitting user traffic or control messages. For example, traffic or control messages of a downlink multicast or broadcast service may be transmitted through the downlink SCH, or may be transmitted through a separate downlink multicast channel (MCH). Meanwhile, an uplink transmission channel may include at least one of a random access channel (RACH) for transmitting initial control messages, and / or an uplink shared channel (SCH) for transmitting user traffic or control messages. For example, a logical channel located above a transmission channel and mapped to the transmission channel may include at least one of a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), and / or a multicast traffic channel (MTCH).

[0056] FIG. 3 illustrates the structure of a wireless frame according to an embodiment of the present disclosure. The embodiment of FIG. 3 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0057] Referring to FIG. 3, for example, a radio frame may be used in uplink transmission, downlink transmission, and / or device-to-device transmission. For example, a radio frame may have a length of 10 ms and may be defined as two 5 ms half-frames (HF). For example, a half-frame may include five 1 ms subframes (SF). For example, a subframe may be divided into one or more slots, and the number of slots within a subframe may be determined according to a subcarrier spacing (SCS). For example, each slot may include 12 or 14 OFDM (A) symbols, depending on a cyclic prefix (CP).

[0058] For example, when normal CP is used, each slot can contain 14 symbols. For example, when extended CP is used, each slot can contain 12 symbols. Here, for example, the symbols can contain OFDM symbols (or CP-OFDM symbols), SC-FDMA (single carrier-FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0059] Table 2 below shows the number of symbols per slot (N) depending on the SCS setting (u) when normal CP or extended CP is used. slot symb ), number of slots per frame (N frame,u slot ) and the number of slots per subframe (N subframe,u slot) is an example.

[0060] CP type SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot Normal CP15kHz (u=0)1410130kHz (u=1)1420260kHz (u=2)14404120kHz (u=3)14808240kHz (u=4)1416016Extended CP60kHz (u=2)12404

[0061] For example, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of time resources (e.g., subframes, slots, or transmit time intervals (TTIs)) composed of the same number of symbols may be set differently between the merged cells. For example, in the present disclosure, time resources such as subframes, slots, TTIs, etc. may be referred to as time units.

[0062] For example, multiple numerologies, or SCSs, may be supported to support various services. For example, a 15 kHz SCS may support wide areas in traditional cellular bands, while a 30 kHz / 60 kHz SCS may support dense urban areas, lower latency, and wider carrier bandwidth. For example, a 60 kHz or higher SCS may support bandwidths greater than 24.25 GHz to overcome phase noise.

[0063] FIG. 4 illustrates a slot structure of a frame according to an embodiment of the present disclosure. The embodiment of FIG. 4 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0064] Referring to FIG. 4, for example, a slot may include multiple symbols in the time domain. For example, a carrier may include multiple subcarriers in the frequency domain. For example, a resource block (RB) may be defined as multiple consecutive subcarriers in the frequency domain. For example, a bandwidth part (BWP) may be defined as multiple consecutive (P)RBs ((physical) resource blocks) in the frequency domain, and may correspond to one numerology (e.g., SCS, CP length, etc.). For example, a carrier may include at most N BWPs (where N is a positive integer). For example, data communication may be performed through an activated BWP. For example, each element may be referred to as a resource element (RE) in the resource grid, and one complex symbol may be mapped to it.

[0065] For example, a BWP may be a contiguous set of PRBs in a given numerology. For example, a PRB may be selected from a contiguous subset of common resource blocks (CRBs) for a given numerology on a given carrier.

[0066] For example, the BWP may be at least one of an active BWP, an initial BWP, and / or a default BWP. For example, the UE may not monitor the downlink radio link quality in a DL BWP other than the active DL BWP on the PCell (primary cell). For example, the UE may not receive a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), or a channel state information-reference signal (CSI-RS) (except for radio resource management (RRM)) outside of the active DL BWP. For example, the UE may not trigger channel state information (CSI) reporting for an inactive DL BWP. For example, the UE may not transmit a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH) outside of the active UL BWP. For example, for downlink, the initial BWP can be given as a set of consecutive resource blocks (RBs) for the remaining minimum system information (RMSI) CORESET (control resource set) (set by the physical broadcast channel (PBCH)). For uplink, for example, the initial BWP can be given by the system information block (SIB) for the random access procedure. For example, the default BWP can be set by a higher layer. For example, the initial value of the default BWP can be the initial DL BWP.For energy saving, if a terminal does not detect DCI (downlink control information) for a certain period of time, the terminal may switch its active BWP to a default BWP.

[0067] FIG. 5 illustrates an example of a BWP according to an embodiment of the present disclosure. The embodiment of FIG. 5 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted. In the embodiment of FIG. 5, it is assumed that there are three BWPs.

[0068] Referring to FIG. 5, for example, a common resource block (CRB) may be a carrier resource block numbered from one end of a carrier band to the other, and a PRB may be a numbered resource block within each BWP. For example, point A may indicate a common reference point for a resource block grid.

[0069] For example, BWP is point A, offset from point A (N start BWP ) and bandwidth (N size BWP ) can be set by. For example, point A can be an outer reference point of the PRB of a carrier where subcarrier 0 of all numerologies (e.g., all numerologies supported by the network on that carrier) aligns. For example, the offset can be the PRB spacing between the lowest subcarrier in a given numerology and point A. For example, the bandwidth can be the number of PRBs in a given numerology.

[0070] Meanwhile, in the present disclosure, the PSCCH may be replaced by a control channel, a physical control channel, a control channel associated with a sidelink, a physical control channel associated with a sidelink, etc. In the present disclosure, the PSSCH may be replaced by a shared channel, a physical shared channel, a shared channel associated with a sidelink, a physical shared channel associated with a sidelink, etc.

[0071] FIG. 6 illustrates a procedure for a terminal to perform V2X or SL communication according to a resource allocation mode, according to an embodiment of the present disclosure. The embodiment of FIG. 6 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0072] Referring to (a) of FIG. 6, in resource allocation mode 1, the base station may schedule SL resources to be used by the terminal for SL transmission. For example, in step S600, the base station may transmit information related to SL resources and / or information related to UL resources to the first terminal. For example, the UL resources may include PUCCH resources and / or PUSCH resources. For example, the UL resources may be resources for reporting SL HARQ feedback to the base station.

[0073] For example, a first terminal may receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from a base station. For example, a CG resource may include a CG type 1 resource or a CG type 2 resource. In this specification, a DG resource may be a resource that a base station configures / allocates to the first terminal via downlink control information (DCI). In this specification, a CG resource may be a (periodic) resource that a base station configures / allocates to the first terminal via DCI and / or an RRC message. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message including information related to the CG resource to the first terminal. For example, in the case of a CG type 2 resource, the base station may transmit an RRC message including information related to the CG resource to the first terminal, and the base station may transmit a DCI related to activation or release of the CG resource to the first terminal.

[0074] In step S610, the first terminal may transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to the second terminal based on the resource scheduling. In step S620, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S630, the first terminal may receive a PSFCH related to the PSCCH / PSSCH from the second terminal. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second terminal via the PSFCH. In step S640, the first terminal may transmit / report HARQ feedback information to the base station via a PUCCH or a PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on the HARQ feedback information received from the second terminal. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on a rule set in advance. For example, the DCI may be DCI for scheduling SL.

[0075] Referring to (b) of FIG. 6, in resource allocation mode 2, the terminal can determine SL transmission resources within SL resources set by the base station / network or preset SL resources. For example, the set SL resources or preset SL resources may be a resource pool. For example, the terminal can autonomously select or schedule resources for SL transmission. For example, the terminal can perform SL communication by selecting resources by itself within the set resource pool. For example, the terminal can select resources by itself within a selection window by performing sensing and resource (re)selection procedures. For example, the sensing can be performed on a subchannel basis. For example, in step S610, the first terminal that has selected resources by itself within the resource pool transmits PSCCH (e.g., SCI (Sidelink Control Information) or 1) using the resources. st -stage SCI) can be transmitted to the second terminal. In step S620, the first terminal transmits the PSSCH (e.g., 2) related to the PSCCH. nd -stage SCI, MAC PDU, data, etc.) can be transmitted to the second terminal. In step S630, the first terminal can receive a PSFCH related to the PSCCH / PSSCH from the second terminal.

[0076] Referring to (a) or (b) of FIG. 6, for example, a first terminal may transmit an SCI to a second terminal on a PSCCH. Or, for example, the first terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal on the PSCCH and / or the PSSCH. In this case, the second terminal may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first terminal. In the present specification, an SCI transmitted on a PSCCH is 1 st SCI, 1st SCI, 1st -stage SCI or 1 st -stage SCI format, and the SCI transmitted on the PSSCH is 2 nd SCI, 2nd SCI, 2 nd -stage SCI or 2 nd -It can be called a stage SCI format.

[0077] Referring to (a) or (b) of FIG. 6, in step S630, the first terminal may receive a PSFCH. For example, the first terminal and the second terminal may determine PSFCH resources, and the second terminal may use the PSFCH resources to transmit HARQ feedback to the first terminal.

[0078] Referring to (a) of FIG. 6, in step S640, the first terminal may transmit SL HARQ feedback to the base station via PUCCH and / or PUSCH.

[0079] FIG. 7 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure. The embodiment of FIG. 7 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0080] As core implementation technologies of the 6G system, technologies such as artificial intelligence (AI), THz (terahertz) communication, optical wireless technology, free-space optical transmission (FSO) backhaul networks, massive MIMO (multiple input multiple output) technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS) can be adopted.

[0081] - Artificial Intelligence: Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analytics to determine how complex target tasks should be performed. For example, AI can increase efficiency and reduce processing delays. Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly using AI. AI can also play a crucial role in machine-to-machine (M2M), machine-to-human, and human-to-machine communications. AI can also facilitate rapid communication in brain-computer interfaces (BCIs). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0082] - THz communication (terahertz communication): Data rates can be increased by increasing the bandwidth. This can be achieved by using sub-THz communication with wide bandwidths and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz, with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (sub-THz band) is considered a key part of the THz spectrum for cellular communications. Adding the sub-THz band to the mmWave band will increase the capacity of 6G cellular communications. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While part of the optical band, the 300 GHz to 3 THz band lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF. Key characteristics of THz communications include (i) the widely available bandwidth to support very high data rates and (ii) the high path loss that occurs at high frequencies (requiring highly directional antennas). The narrow beamwidths generated by highly directional antennas reduce interference. The small wavelength of THz signals allows for a significantly larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array technologies to overcome range limitations.

[0083] - Large-scale MIMO technology

[0084] - Hologram beamforming (HBF)

[0085] - Optical wireless technology

[0086] - Free-space optical transmission backhaul network (FSO backhaul network)

[0087] - Quantum communication

[0088] - Cell-free communication

[0089] - Integration of wireless information and power transmission

[0090] - Integration of wireless communication and sensing

[0091] - Integrated access and backhaul network

[0092] - Big data analysis

[0093] - Reconfigurable intelligent surface

[0094] - metaverse

[0095] - Block chain

[0096] Advanced Air Mobility (AAM): AAM can be a broad concept encompassing urban air mobility (UAM), regional air mobility (RAM), and uncrewed aerial systems (UAS). For example, AAM can include UAM, RAM, UAS, and uncrewed aerial vehicles (UAVs).

[0097] - Autonomous driving (self-driving): V2X (vehicle to everything), a key element in building autonomous driving infrastructure, can be a technology that allows cars to communicate and share with various elements on the road for autonomous driving, such as vehicle to vehicle (V2V) wireless communication and vehicle to infrastructure (V2I) wireless communication.

[0098] Non-terrestrial network (NTN): NTN can refer to a network or network segment that utilizes radio frequency (RF) resources mounted on satellites (or UAS platforms). NTN services may be considered to secure wider coverage or provide wireless communication services in locations where the installation of wireless communication base stations is difficult.

[0099] - Integrated sensing and communication (ISAC)

[0100] - Reconfigurable intelligent surface (RIS): RIS can be used to manipulate and enhance signal propagation in wireless communication environments. For example, a RIS can be composed of many small antennas, or metasurfaces, arranged on a surface, each of which can actively control the phase, amplitude, polarization, etc. of the reflected signal. For example, a RIS can improve signal reception by controlling the path, phase, and / or intensity of the propagating signal. For example, in the case of a RIS, power consumption can be very low because power is consumed only for controlling the phase and amplitude of the small antennas. For example, because a RIS can be reconfigured to suit different environments, it can meet diverse communication requirements and operate effectively in dynamic network environments.

[0101] FIG. 8 illustrates an example of a communication scenario based on a 6G system, according to an embodiment of the present disclosure. The embodiment of FIG. 8 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0102] Referring to FIG. 8, NTN communication can be performed based on satellite networks, high-altitude platform stations (HAPS) as international mobile telecommunications (IMT) base stations (BS), terminals capable of aerial communication (e.g., AAM), etc. For example, to improve coverage, etc., devices such as satellite networks, HIBS, terminals capable of aerial communication (e.g., AAM), etc. can act as relays. For example, AAMs can communicate with base stations, satellite networks, etc., and / or AAMs can communicate directly with terminals, other AAMs, etc.

[0103] Below, the integrated sensing and communication (ISAC) mentioned above is described in detail.

[0104] Integrated Sensing and Communications (ISAC) is a technology that uses radio frequencies to determine the instantaneous linear velocity, angle, distance (range), etc. of an object, thereby obtaining information about the environment and / or the characteristics of objects within the environment. Because radio frequency sensing does not require a device to connect to the object through a network, it can provide services for object positioning without a device. The ability to obtain range, velocity, and angle information from radio frequency signals can enable a wide range of new capabilities, such as various object detection, object recognition (e.g., vehicles, humans, animals, UAVs), and high-precision localization, tracking, and activity recognition. Wireless sensing services can provide information to a variety of industries (e.g., unmanned aerial vehicles, smart homes, V2X, factories, railways, public safety, etc.), enabling applications such as intruder detection, assisted vehicle steering and navigation, trajectory tracking, collision avoidance, traffic management, and health and traffic management. In some cases, wireless sensing can utilize non-3GPP type sensors (e.g., radar, cameras) to further support 3GPP-based sensing. For example, the operation of a wireless sensing service (e.g., sensing operation) may depend on the transmission, reflection, and scattering processing of wireless sensing signals. Therefore, wireless sensing may provide an opportunity to enhance existing communication systems from communication networks to wireless communication and sensing networks. FIG. 9 illustrates an example of a sensing operation according to an embodiment of the present disclosure. The embodiment of FIG. 9 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted. Specifically, FIG. 9 (a) illustrates an example of sensing using a sensing receiver and a sensing transmitter located at the same location (e.g., monostatic sensing), and FIG. 9 (b) illustrates an example of sensing using a separated sensing receiver and a sensing transmitter (e.g., bistatic sensing).

[0105] Meanwhile, in conventional LTE V2X, a terminal supporting multi-channel operation (e.g., multi-carrier operation or carrier aggregation (CA)) can select a specific carrier for transmitting sidelink data, select available resources on the selected carrier, and transmit sidelink data through the selected resources and carrier.

[0106] Meanwhile, according to the prior art, when a link established between terminals (e.g., a PC5 unicast link or a PC5 RRC connection) is released, a quality of service (QoS) flow associated with the link may be released. However, in the prior art, a method for managing the QoS flow while maintaining the established link between terminals (e.g., a PC5 unicast link or a PC5 RRC connection) is not defined if it is impossible to perform transmission related to the QoS flow associated with the link.

[0107] In this case, the following problem may occur. For example, assuming that multiple available carriers are established via RRC and at least one of the multiple available carriers is mapped to each QoS flow, if a discontinuous transmission (DTX)-based carrier failure (e.g., a case where a PSSCH transmission is performed based on a carrier, but there is no PSFCH reception for the PSSCH and the number of times that the PSFCH is not received reaches a threshold set for the carrier) is detected on both of the carriers (e.g., carrier #1 and carrier #2) mapped to QoS flow #1 associated with an established link between terminals (e.g., a PC5 unicast link or a PC5 RRC connection), there may be no more available carriers for the QoS flow #1. In this case, even though transmissions related to the QoS flow #1 can no longer be performed, since carrier failure is not detected / declared on all of the multiple available carriers configured via the RRC and thus radio link failure (RLF) is not detected / declared, the link (e.g., PC5 unicast link or PC5 RRC connection) related to the QoS flow #1 itself cannot be released to remove the QoS flow #1. For example, even if transmissions related to the QoS flow #1 cannot be performed, the buffer related to the data radio bearer (DRB) mapped to the QoS flow #1 may not be flushed due to the pending of the QoS flow #1. In this case, data may be lost due to, for example, a buffer overflow. In addition, for example, latency may occur when the buffer becomes full, which may result in a degradation of quality of real-time services, etc.In addition, for example, if the buffer is not flushed, it may occupy a lot of memory, which may cause other processes or services to perform unstably. Or, for example, due to the pending of the QoS flow #1, the grant allocated for transmission related to the QoS flow #1 may not be cleared. In this case, for example, the grant cannot be used for transmission for QoS flow #2 other than the QoS flow #1, which may result in inefficiency in resource usage. In addition, for example, due to the pending of the QoS flow #1, unnecessary scheduling may be performed, which may increase the overhead of the terminal and may cause unnecessary power consumption of the terminal.

[0108] In this disclosure, we propose an operation of a terminal supporting multi-carrier operation when a carrier failure is detected. In addition, in this disclosure, we propose an operation for recovery when a carrier failure is detected in an out-of-coverage (OCC) terminal, an RRC inactive terminal, an RRC idle terminal, and an RRC connected terminal in a multi-carrier environment.

[0109] Meanwhile, the operations related to Tx carrier (re-)selection may be as follows.

[0110] For example, a MAC entity may consider the CBR measured by a lower layer as the carrier's CBR according to TS 38.215 if the CBR measurement result is available, and may consider the corresponding sl-defaultTxConfigIndex set by the upper layer if the CBR measurement result is not available.

[0111] For example, if Tx carrier (re)selection is triggered for a sidelink process according to Section 5.22.1.1, Section 5.22.1.2, or Section 5.22.1.3.3, the MAC entity can:

[0112] 1> If there is no selected sidelink grant on the allowed carrier for the sidelink logical channel on which data is available as indicated by the upper layer (TS 38.331 and TS 23.287):

[0113] 2> For each carrier configured at the upper layer associated with the concerned sidelink logical channel:

[0114] 3> If the carrier's CBR is lower than sl-threshCBR-FreqReselection, which is related to the priority of the sidelink logical channel:

[0115] Note: If multiple resource pools are configured for a carrier, the specific resource pool used to determine the CBR for that carrier may vary depending on the UE implementation and may take into account sl-HARQ-FeedbackEnabled for the sidelink logical channel.

[0116] 4> The above carrier may be considered as a candidate carrier for Tx carrier (re)selection for the concerned sidelink logical channel.

[0117] 1> If not:

[0118] 2> For each sidelink logical channel (if any) allowed on the carrier where data is available and Tx carrier (re)selection is triggered according to Section 5.22.1.1, if the carrier's CBR is lower than sl-threshCBR-FreqKeeping, which is related to the priority of the sidelink logical channel:

[0119] 3> The carrier and associated pool of resources can be selected.

[0120] 2> If not:

[0121] 3> For each carrier configured by the upper layer that allows sidelink logical channels, if the carrier's CBR is lower than sl-threshCBR-FreqReselection, which is associated with the priority of the sidelink logical channel:

[0122] 4> For each carrier configured by the upper layer that allows sidelink logical channels, the carrier may be considered as a candidate carrier for Tx carrier (re)selection.

[0123] For example, a MAC entity can:

[0124] 1> If more than one carrier is considered a candidate carrier for Tx carrier (re)selection:

[0125] 2> When Tx carrier (re)selection is triggered, for each sidelink logical channel on which data is allowed on the available carrier:

[0126] 3> One or more carriers can be selected from among the candidate carriers in order of increasing CBR from the lowest CBR, and an associated resource pool can be selected.

[0127] 4> If sl-HARQ-FeedbackEnabled is set to enabled for the sidelink logical channel:

[0128] 5> One resource pool with PSFCH resources set can be selected from among the resource pools excluding the pool of sl-BWP-DiscPoolConfig or sl-BWP-DiscPoolConfigCommon (if set).

[0129] 4> If not:

[0130] 5> You can select a resource pool from among the resource pools other than those in sl-BWP-DiscPoolConfig or sl-BWP-DiscPoolConfigCommon (if set).

[0131] Note: How many carriers are selected may depend on UE implementation, depending on UE capability.

[0132] NOTE: It may be up to the UE implementation to determine which sidelink logical channels are available for data and which are allowed on which carrier Tx carrier (re)selection is triggered.

[0133] Note: It may be up to the UE implementation to decide whether to reuse the resource pool for CBR measurements as the resource pool for SL (sidelink) grant generation.

[0134] Meanwhile, the operation to detect carrier failure and radio link failure (RLF) based on discontinuous transmission (DTX) may be as follows.

[0135] For example, for each carrier associated with a PC5-RRC connection, a HARQ-based sidelink radio link failure (RLF) detection procedure can be used to detect sidelink RLF based on the number of consecutive DTXs of PSFCH reception occasions for the PC5-RRC connection.

[0136] RRC can set the following parameters to control HARQ-based sidelink RLF detection:

[0137] - sl-maxNumConsecutiveDTX.

[0138] The following UE variables can be used for HARQ-based sidelink RLF detection.

[0139] - numConsecutiveDTX: Per PC5-RRC connection per carrier can be maintained.

[0140] For example, for each carrier associated with a PC5-RRC connection, the sidelink HARQ entity may (re)initialize numConsecutiveDTX to 0 for each PC5-RRC connection established by the upper layer upon PC5-RRC connection establishment or sl-maxNumConsecutiveDTX (re)establishment.

[0141] For example, for each carrier associated with a PC5-RRC connection, the sidelink HARQ entity may do the following for each PSFCH reception occasion associated with a PSSCH transmission:

[0142] 1> If there is no PSFCH reception in a PSFCH reception occasion:

[0143] 2> numConsecutiveDTX can be increased by 1.

[0144] NOTE: For SL operation using shared spectrum channel access, the UE may increment numConsecutiveDTX by 1 if it does not detect HARQ feedback on all relevant PSFCH resources, as per clause 16.3.0 of TS 38.213.

[0145] 2> If two or more carriers selected as defined in Section 5.22.1.11 are considered carriers for HARQ-based sidelink RLF detection:

[0146] 3> When numConsecutiveDTX reaches sl-maxNumConsecutiveDTX for a carrier applied to HARQ-based sidelink RLF detection:

[0147] 4> As specified in Section 5.22.1.11, it may trigger a Tx carrier (re)selection procedure.

[0148] 4> HARQ-based sidelink carrier failure can be indicated to the upper layer.

[0149] 3> When numConsecutiveDTX reaches sl-maxNumConsecutiveDTX for all carriers applied to HARQ-based sidelink RLF detection:

[0150] 4> HARQ-based sidelink RLF detection can be indicated in the upper layer.

[0151] 2> Otherwise:

[0152] 3> When numConsecutiveDTX reaches sl-maxNumConsecutiveDTX:

[0153] 4> HARQ-based sidelink RLF detection can be indicated in the upper layer.

[0154] 1> Otherwise:

[0155] 2> numConsecutiveDTX can be reinitialized to 0.

[0156] Meanwhile, the action to terminate the carrier when a carrier failure is detected may be as follows.

[0157] For example, for NR sidelink communications, sidelink carrier release can be initiated when:

[0158] 1> In case of unicast, if the sl-Carrier-Id of the sidelink carrier is received in the sl-CarrierToReleaseList of RRCReconfigurationSidelink; or

[0159] 1> In case of unicast, if sidelink carrier failure is indicated at the MAC layer; or

[0160] 1> For unicast, if sidelink carrier release is triggered by sl-ConfigDedicatedNR, SIB12, SidelinkPreconfigNR, or a setting received from a higher layer; or

[0161] 1> For unicast, if the sidelink SRB, DRB or additional sidelink RLC bearer associated with the sidelink carrier is released according to Section 5.8.9.1a.3.1, Section 5.8.9.1a.1.1 or Section 5.8.9.1a.5.1;

[0162] For example, the UE can:

[0163] 1> For unicast, if sidelink carrier release is triggered by receiving an RRCReconfigurationSidelink message:

[0164] 2> For each sl-Carrier-Id value contained in sl-CarrierToReleaseList:

[0165] 3> If the current UE configuration contains a sidelink carrier with the sl-Carrier-Id value:

[0166] 4> The sidelink carrier can be released for reception.

[0167] 1> For unicast, if sidelink carrier release is triggered by the configuration received in sl-ConfigDedicatedNR, SIB12, SidelinkPreconfigNR or the configuration indicated by the upper layer after receiving the RRCReconfigurationCompleteSidelink message:

[0168] 2> For each sl-Carrier-Id value contained in sl-CarrierToReleaseList:

[0169] 3> If the current UE configuration contains a sidelink carrier with the sl-Carrier-Id value:

[0170] 4> The sidelink carrier can be released for transmission.

[0171] Meanwhile, actions related to sending a SidelinkUEInformationNR message may be as follows.

[0172] For example, the UE can set the contents of the SidelinkUEInformationNR message as follows.

[0173] 1> When the UE initiates a procedure indicating that it is not interested in receiving NR sidelink communications / positioning; or

[0174] 1> When the UE initiates a procedure to request (set up / release) NR sidelink communication / positioning transmission resources or to report to the network that a sidelink radio link failure, sidelink RRC reconfiguration failure, or sidelink carrier failure has been declared;

[0175] 2> When sidelink carrier failure is indicated at the MAC layer;

[0176] 3> sl-CarrierFailureList can be included and the following fields can be set for each destination reporting a sidelink carrier failure:

[0177] 4> sl-DestinationIdentity can be set to the destination ID that indicates the sidelink carrier failure.

[0178] 4> sl-CarrierFailure can be set to include carriers that indicate sidelink carrier failure.

[0179] Meanwhile, the dedicated sidelink configuration could be as follows:

[0180] For example, upon initiating the above procedure, the UE may:

[0181] 1> If sl-FreqInfoToReleaseList is included in sl-ConfigDedicatedNR within RRCReconfiguration:

[0182] 2> For each entry contained in the received sl-FreqInfoToReleaseList that is part of the current UE configuration:

[0183] 3> Related configurations can be released from the saved NR sidelink communication / discovery configuration.

[0184] Meanwhile, in the present disclosure, when a carrier failure is detected, a procedure is proposed for updating a set of carriers allowed for a logical channel associated with a carrier in which a carrier failure is detected.

[0185] For example, according to the above-described prior art, when a transmitting terminal detects a carrier failure (e.g., when a DTX (e.g., an event of not receiving a PSFCH for a PSCCH / PSSCH transmission) on a specific carrier occurs a preset threshold number of times, the transmitting terminal may declare a carrier failure for the corresponding carrier) on a specific sidelink carrier (or one of the selected carriers, or all the selected carriers, or all the configured available carriers), the transmitting terminal may report the carrier failure to a higher layer (e.g., an RRC layer). For example, when the higher layer receives a report of a carrier failure from the MAC layer, the upper layer may release (or remove) the carrier on which the reported carrier failure is detected from the candidate carrier (or carrier set) used by the terminal (or the allowed carrier set per logical channel, or the allowed carrier per logical channel). For example, the terminal may select a carrier to use for data transmission by considering newly updated carriers (or carrier sets) that have been released (or removed) from the RRC layer (e.g., Tx carrier (re)selection procedure). In addition, for example, the terminal may declare an RLF and terminate all unicast links and / or all PC5 RRC connections if a carrier failure occurs in all carriers configured from the RRC layer.

[0186] However, for example, in the above-described prior art, the following problems may occur. For example, the RRC layer may set {Carrier #1, Carrier #2, Carrier #3} among the available carriers {Carrier #1, Carrier #2, Carrier #3, Carrier #4, Carrier #5, Carrier #6, Carrier #7, Carrier #8, Carrier #9} as carriers allowed for transmission of logical channel #A (or, QoS (quality of service) flow related to logical channel #A). And, for example, {Carrier #4, Carrier #5, Carrier #6} may be set as carriers allowed for transmission of logical channel #B (or, QoS flow related to logical channel #B). Also, for example, the transmitting terminal may perform a Tx carrier (re)selection procedure to select a carrier for data transmission of logical channel #A, and may determine the carrier to use (based on the lowest CBR (channel busy ratio)) in the order of carrier #1, carrier #2, and carrier #3. In this case, for example, according to the above-described prior art, if carrier failure occurs in all of carrier #1, carrier #2, and carrier #3, the RRC layer may release (or remove) carrier #1, carrier #2, and carrier #3 from the set of carriers allowed for transmission of logical channel #A. In this case, for example, the terminal may not declare an RLF because there are remaining carriers allowed for transmission of logical channel #B, etc. However, for example, a problem may arise where the terminal cannot perform transmission of logical channel #A permanently (or continuously) even though the unicast link is not in a RLF declared state (unicast link release and / or PC5 RRC connection release) because there is no carrier to use for transmission of logical channel #A.

[0187] Therefore, in the present disclosure, when a carrier failure occurs, in addition to the operation of releasing (or removing) the carrier in which the carrier failure occurred from the carrier set at the RRC layer as in the prior art, a carrier addition procedure is proposed to add a new carrier to the available carriers, as follows.

[0188] For example, in the above-described embodiment, if a carrier failure is declared for carrier #1 among the carriers {carrier #1, carrier #2, carrier #3} allowed for transmission of logical channel #A, the RRC layer may perform a procedure for adding carrier #7 as a new carrier to the set of carriers allowed for transmission of logical channel #A. For example, the terminal may transmit newly added carrier information through this carrier addition procedure to the counterpart terminal (e.g., the counterpart terminal for establishing a unicast connection or the counterpart terminal for establishing a PC5 RRC connection) via a PC5 RRC message. For example, the carriers allowed for transmission of logical channel #A may be updated to {carrier #2, carrier #3, carrier #7}.

[0189] Alternatively, for example, if carrier failure is declared for carrier #1, carrier #2, and carrier #3 in the carriers {carrier #1, carrier #2, and carrier #3} allowed for transmission of logical channel #A, the RRC layer may perform a procedure to add carrier #7, carrier #8, and carrier #9 as new carriers to the set of carriers allowed for transmission of logical channel #A.

[0190] Alternatively, for example, if a carrier failure is declared for "Carrier #1" or "Carrier #1, Carrier #2, Carrier #3" in the allowed carriers {Carrier #1, Carrier #2, Carrier #3} for transmission on logical channel #A, the RRC layer may update the carrier configuration of logical channel #A to allow the use of other allowed carriers (e.g., the allowed carrier set {Carrier #4, Carrier #5, Carrier #6} for logical channel #B) together with the allowed carrier set for transmission on logical channel #A (e.g., "Carrier #2, Carrier #3, Carrier #4, Carrier #5" or "Carrier #4, Carrier #5", etc.). For example, the allowed carriers for transmission on logical channel #A may be updated to {Carrier #7, Carrier #8, Carrier #9}. And, for example, the MAC layer can perform Tx carrier (re)selection based on the updated carrier set information {Carrier #7, Carrier #8, Carrier #9} and continue transmitting logical channel #A data using the selected carrier.

[0191] Additionally, for example, when the carrier (or carrier set) allowed for a logical channel is reset by the RRC layer (e.g., when a new carrier is added, or in the case of carrier modification that adds a carrier allowed for another logical channel to the set of carriers allowed for its own logical channel, or when all the carriers allowed for a specific logical channel are reset to new carriers), the transmitting terminal can trigger a Tx carrier (re)selection procedure to perform carrier selection again for data transmission based on the reset carrier (or carrier set).

[0192] Alternatively, for example, the RRC layer can define an exception carrier that can be used exceptionally when a carrier failure occurs for all carriers configured for each logical channel. For example, if a carrier failure is declared for all carriers {Carrier #1, Carrier #2, Carrier #3} allowed for transmission of logical channel #A, the transmitting terminal can continue transmission of logical channel #A using the exception carrier configured in the RRC layer.

[0193] Alternatively, for example, even if a carrier failure occurs at the MAC layer, the RRC layer may not remove the carrier where the carrier failure occurred from the carrier list. And, for example, the transmitting terminal may trigger a Tx carrier (re)selection procedure whenever a carrier failure occurs, so as to perform CBR measurement again for the carrier where the carrier failure occurred. For example, if the CBR measurement value for the carrier where the carrier failure occurred is below a threshold (e.g., sl-threshCBR-FreqReselection or sl-threshCBR-FreqKeeping), the carrier where the carrier failure occurred may be used again to perform data transmission.

[0194] Meanwhile, according to the prior art, the base station can receive a report of carrier failure from the terminal and include the corresponding carrier in the sl-FreqInfoToReleaseList, thereby preventing the terminal from using the carrier included in the sl-FreqInfoToReleaseList for sidelink transmission or reception. However, in this case, even though the transmitting terminal does not have a carrier failure in any available carrier and thus no RLF is declared, as described above, a problem may occur in which the transmitting terminal cannot transmit the logical channel data (or the QoS flow related to the logical channel data) because all carriers for the specific logical channel data (or the QoS flow related to the logical channel data) are released (or removed).

[0195] Accordingly, according to an embodiment proposed in the present disclosure, as a solution of the base station to solve this, when the base station includes a carrier in which a carrier failure reported from a terminal has occurred in the sl-FreqInfoToReleaseList, a timer (e.g., set or pre-configured by the base station) can be started, and when the timer reaches a threshold time or expires, the carrier in which the carrier failure is declared included in the sl-FreqInfoToReleaseList can be deleted to refresh (or reconfigure) the sl-FreqInfoToReleaseList configuration. And, for example, a terminal that has received sl-FreqInfoToReleaseList that has been refreshed (or reconfigured) from a base station can transmit the carrier information (e.g., sl-CarrierToReleaseList) deleted from sl-FreqInfoToReleaseList to a counterpart terminal (e.g., a unicast-connected counterpart (receiving) terminal) via a PC5 RRC message (or can indicate to the counterpart terminal via sl-CarrierToAddModList that a carrier for which a carrier failure has been declared can be used again).

[0196] Meanwhile, for example, the base station can configure one or more carriers {sl-FreqInfoToAddModList / sl-FreqInfoToAddModListExt(Carrier #1, Carrier #2, Carrier #3, Carrier #4, Carrier #5, Carrier #6, Carrier #7, Carrier #8, Carrier #9)} to be used by the terminal and transmit them to the terminal (e.g., via a dedicated RRC message and / or system information and / or pre-configuration). In addition, for example, a higher layer of the terminal (e.g., V2X layer) can configure {Carrier #1, Carrier #2, Carrier #3} as allowed carriers for transmission of a specific service #a (e.g., destination layer-2 ID or a specific QoS flow). And, for example, {Carrier #4, Carrier #5, Carrier #6} can be set as the carriers allowed for transmission of a specific service #b (e.g., destination layer-2 ID or specific QoS flow). Also, for example, the transmitting terminal can perform a Tx carrier (re)selection procedure to select a carrier for data transmission of service #a, and determine the carrier to use in the order of carrier #1, carrier #2, and carrier #3 (based on the lowest CBR (channel busy ratio)).

[0197] In this case, for example, according to the prior art, if carrier failure occurs in all of carrier #1, carrier #2, and carrier #3, the RRC layer may release carrier #1, carrier #2, and carrier #3 from the set of carriers allowed for data transmission related to service #a (e.g., destination layer-2 ID or specific QoS flow). In this case, for example, the terminal may not declare an RLF because there are still carriers allowed to be used for transmission of service #b (e.g., destination layer-2 ID or specific QoS flow), and there are still carriers to be used in the available carriers {sl-FreqInfoToAddModList / sl-FreqInfoToAddModListExt (carrier #1, carrier #2, carrier #3, carrier #4, carrier #5, carrier #6, carrier #7, carrier #8, carrier #9)} configured by the base station. However, for example, a problem may arise where the terminal cannot perform data transmission related to service #a (e.g., destination layer-2 ID or specific QoS flow) permanently (or continuously) even though the unicast link is not in a RLF declared state (unicast link release and / or PC5 RRC connection release) because there is no carrier to use for data transmission related to service #a (e.g., destination layer-2 ID or specific QoS flow).

[0198] Accordingly, according to the embodiment proposed in the present disclosure, if a carrier failure occurs in all carriers {Carrier #1, Carrier #2, Carrier #3} allowed for transmission of service #a (e.g., destination layer-2 ID or specific QoS flow), the base station may select one of the other available carriers configured by the base station (e.g., carriers {Carrier #4, Carrier #5, Carrier #6} allowed for transmission of service #b (e.g., destination layer-2 ID or specific QoS flow) or sl-FreqInfoToAddModList / sl-FreqInfoToAddModListExt (Carrier #7, Carrier #8, Carrier #9)) to continue data transmission related to service #a (e.g., destination layer-2 ID or specific QoS flow).

[0199] Alternatively, for example, according to the prior art, when a terminal declares a carrier failure, the terminal may report the carrier failure to the base station and transmit information about the carrier for which the carrier failure was declared together. For example, when the base station receives a report of a carrier failure from the terminal, the base station may include the corresponding carrier in sl-FreqInfoToReleaseList and update the carrier configuration (e.g., sl-FreqInfoToReleaseList) and transmit it to the terminal. For example, when the terminal receives updated carrier configuration information (e.g., sl-FreqInfoToReleaseList) from the base station, the terminal may delete the carrier included in the sl-FreqInfoToReleaseList from the stored (or used) carriers (or carrier list) for sidelink data transmission. For example, the carrier included in the sl-FreqInfoToReleaseList may be excluded from the carrier (or carrier list) for sidelink data transmission (or TX carrier (re)selection procedure).

[0200] According to an embodiment proposed in the present disclosure, a timer (e.g., Carrier_Resume_Timer) may be defined for the purpose of allowing carrier(s) included in the sl-FreqInfoToReleaseList to be reused for sidelink data transmission (or, TX carrier (re)selection procedure). For example, when the base station receives a carrier failure report, the base station may start the timer, and when the timer expires, the base station may delete the carrier for which the carrier failure has been declared from the sl-FreqInfoToReleaseList, reset the carrier configuration, and transmit the reset carrier information to the terminal. In addition, for example, the transmitting terminal may also indicate to the opposite receiving terminal via a PC5 RRC message that the carrier for which the carrier failure has been declared is to be reused (e.g., add information about the carrier to be reused to sl-CarrierToAddModList). Or, for example, the terminal may start the Carrier_Resume_Timer when it declares a carrier failure. And, for example, even if the terminal receives sl-FreqInfoToReleaseList containing a carrier for which a carrier failure has been declared from the base station, the terminal may reuse the carrier for which the carrier failure has been declared for sidelink data transmission (or, TX carrier (re)selection procedure) when the Carrier_Resume_Timer has expired. In addition, for example, the transmitting terminal may also indicate to the receiving terminal that the carrier for which the carrier failure has been declared is to be reused via a PC5 RRC message (e.g., adding information about the carrier to be reused to sl-CarrierToAddModList).

[0201] Meanwhile, for example, when the terminal detects an event in which it does not receive HARQ feedback for PSCCH / PSSCH transmission on the corresponding carrier (e.g., when DTX detects a threshold value or more), the terminal may start a timer (e.g., a carrier recovery timer: configured or pre-configured by the base station) and may continue to perform PSSCH / PSSCH transmission on the corresponding carrier while the timer is running. For example, if it does not receive one or more PSCCH / PSSCH from the opposite receiving terminal until the timer expires, the terminal may declare a carrier failure and report the carrier failure to the base station (e.g., the index of the carrier on which the carrier failure is declared). In addition, for example, the terminal that declared the carrier failure may transmit information on the carrier on which the carrier failure is declared to the opposite receiving terminal via a PC5 RRC message. Additionally, for example, a terminal that has declared a carrier failure can indicate to the counterpart terminal via a PC5 RRC message that the carrier can be used again (e.g., carrier resume) after a certain period of time (e.g., set by the base station or pre-configuration) after transmitting carrier information related to the carrier failure to the counterpart terminal.

[0202] Meanwhile, in this disclosure, a carrier addition procedure is proposed as follows.

[0203] For example, for NR sidelink communication, sidelink carrier addition can be initiated in the following cases:

[0204] 1> In case of unicast, if the sl-Carrier-Id of the sidelink carrier is received in the sl-CarrierToAddModList of RRCReconfigurationSidelink; or

[0205] 1> For unicast, if the sl-Carrier-Id of the sidelink carrier is received in the sl-CarrierToAddModList of RRCReconfigurationCompleteSidelink; or

[0206] 1> For unicast, if the sidelink SRB, DRB or additional sidelink RLC bearer associated with the sidelink carrier (taking into account the carrier mapped to the sidelink QoS flow configured in the upper layer, the carrier configured in sl-ConfigDedicatedNR, SIB12 or SidelinkPreconfigNR, and the carrier supported by both UEs) is configured according to Section 5.8.9.1a.4, Section 5.8.9.1a.2.1 or Section 5.8.9.1a.6.1; or

[0207] 1> For unicast, when a sidelink carrier failure is detected (or indicated) (at the MAC layer); or

[0208] 1> In case of unicast, after a certain period of time (e.g., set or pre-configuration by the base station) has expired after a carrier failure is indicated from the MAC layer;

[0209] For example, the UE can:

[0210] 1> For unicast, if sidelink carrier addition is triggered by carrier failure:

[0211] 2> For each sl-Carrier-Id value contained in sl-CarrierToAddModList that does not belong to the current UE configuration (e.g., sidelink carrier addition) (e.g., this action could be interpreted as adding a carrier other than the one for which carrier failure was declared):

[0212] 3> For reception, a sidelink carrier corresponding to sl-Carrier-Id can be added according to sl-AbsoluteFrequencyPointA.

[0213] 1> For unicast, after a certain period of time (e.g., set or pre-configuration by the base station) has elapsed after a carrier failure is indicated from the MAC layer:

[0214] 2> For each sl-Carrier-Id value contained in sl-CarrierToAddModList that is (or is not) part of the current UE configuration (e.g., sidelink carrier addition) (e.g., this action could be interpreted as considering a carrier that has declared carrier failure as a reusable carrier):

[0215] 3> For reception, a sidelink carrier corresponding to sl-Carrier-Id can be added according to sl-AbsoluteFrequencyPointA.

[0216] 1> For unicast, if sidelink carrier addition is triggered by receiving an RRCReconfigurationSidelink message:

[0217] 2> For each sl-Carrier-Id value contained in sl-CarrierToAddModList that does not belong to the current UE configuration (e.g., sidelink carrier addition):

[0218] 3> A sidelink carrier corresponding to sl-Carrier-Id can be added according to sl-AbsoluteFrequencyPointA for reception.

[0219] 1> For unicast, if sidelink carrier addition is triggered by the configuration received in sl-ConfigDedicatedNR, SIB12, SidelinkPreconfigNR or the configuration indicated by the upper layer after receiving the RRCReconfigurationCompleteSidelink message:

[0220] 2> For each sl-Carrier-Id value contained in sl-CarrierToAddModList that is not part of the current UE configuration (e.g., sidelink carrier addition):

[0221] 3> A sidelink carrier corresponding to sl-Carrier-Id can be added for transmission according to sl-AbsoluteFrequencyPointA.

[0222] FIG. 10 illustrates a method for adding a carrier when a carrier fails, according to an embodiment of the present disclosure. The embodiment of FIG. 10 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0223] Referring to FIG. 10, UE A may establish a PC5 unicast link (1000) between UE A and UE B to perform unicast communication with UE B. For example, the PC5 unicast link (1000) may support one or more services (e.g., V2X service), and one or more PC5 QoS flows may be mapped for each service supported by the PC5 unicast link. Although not specified in FIG. 10 for convenience of explanation, the PC5 unicast link (1000) may support service #A and service #B, and PC5 QoS flow #1 (1010) may be mapped to service #A, and PC5 QoS flow #2 (1020) may be mapped to service #B.

[0224] And, for example, in order to perform a transmission related to a PC5 QoS flow (or, in order to perform a transmission related to a service for which the PC5 QoS flow is used), at least one carrier (or radio frequency, or radio frequency resource) may be mapped to the PC5 QoS flow. For example, in order to perform a transmission related to the PC5 QoS flow #1 (1010) (or, in order to perform a transmission related to a service #A for which the PC5 QoS flow #1 is used), carrier #1 (or radio frequency #1, or radio frequency resource #1) (1011) and carrier #2 (or radio frequency #2, or radio frequency resource #2) (1012) may be mapped to the PC5 QoS flow #1 (1010). For example, in order to perform transmission related to the PC5 QoS flow #2 (1020) (or, in order to perform transmission related to service #B in which PC5 QoS flow #2 is used), carrier #3 (or radio frequency #3, or radio frequency resource #3) (1021) and carrier #4 (or radio frequency #4, or radio frequency resource #4) (1022) may be mapped to the PC5 QoS flow #2 (1020).

[0225] For example, UE A may perform PSSCH transmission (or transmission related to the PC5 QoS flow #1 (1010)) to UE B based on carrier #1 (or radio frequency #1, or radio frequency resource #1) (1011). For example, if UE A performs PSSCH transmission based on carrier #1 (or radio frequency #1, or radio frequency resource #1) (1011) (if HARQ feedback is enabled), but does not receive PSFCH (or HARQ feedback) related to PSSCH transmission from UE B, UE A may increase the value of the first DTX counter (e.g., numConsecutiveDTX) set on carrier #1 (or radio frequency #1, or radio frequency resource #1). For example, if the above-described PSSCH transmission and PSFCH reception failures are repeated and the cumulatively increased value of the first DTX counter (e.g., numConsecutiveDTX) reaches a DTX threshold (e.g., sl-maxNumConsecutiveDTX), UE A may detect a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #1 (or radio frequency #1, or radio frequency resource #1) (1011). And, for example, after the carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #1 (or radio frequency #1, or radio frequency resource #1) (1011), UE A may perform PSSCH transmission based on carrier #2 (or radio frequency #2, or radio frequency resource #2) (1012) mapped to the PC5 QoS flow #1 (1010).Similarly, for example, if UE A performs a PSSCH transmission based on carrier #2 (or radio frequency #2, or radio frequency resource #2) (1012) (if HARQ feedback is enabled), but does not receive a PSFCH (or HARQ feedback) related to the PSSCH transmission from UE B, UE A may increment the value of a second DTX counter (e.g., numConsecutiveDTX) set on carrier #2 (or radio frequency #2, or radio frequency resource #2). For example, if the above-described PSSCH transmission and PSFCH reception failures are repeated and the cumulatively increased value of the second DTX counter (e.g., numConsecutiveDTX) reaches a DTX threshold (e.g., sl-maxNumConsecutiveDTX), UE A may detect a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #2 (or radio frequency #2, or radio frequency resource #2) (1012).

[0226] For example, UE A may determine that there is no available carrier (or available radio frequency, or available radio frequency resource) for the PC5 QoS flow #1 (1010) based on a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #1 (or radio frequency #1, or radio frequency resource #1) mapped to the PC5 QoS flow #1 (1010) and a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #2 (or radio frequency #2, or radio frequency resource #2). In this case, for example, UE A may use at least one carrier (or radio frequency, or radio frequency resource) mapped to PC5 QoS flow #2 (1020) other than PC5 QoS flow #1 (1010) among the PC5 QoS flows associated with the PC5 unicast link (1000) for transmission associated with the PC5 QoS flow #1. For example, UE A may add carrier #3 (or radio frequency #3, or radio frequency resource #3) (1021) among at least one carrier (or radio frequency, or radio frequency resource) mapped to PC5 QoS flow #2 (1020) to the carrier set (or radio frequency set, or radio frequency resource set) associated with PC5 QoS flow #1 (1010) (1013).And, for example, after the carrier #3 (or radio frequency #3, or radio frequency resource #3) (1021) is added to the carrier set (or radio frequency set, or radio frequency resource set) related to the PC5 QoS flow #1 (1010) (or, after the carrier (or radio frequency, or radio frequency resource) related to the PC5 QoS flow #1 (1010) is updated), UE A can perform transmission related to the PC5 QoS flow #1 based on the carrier #3 (or radio frequency #3, or radio frequency resource #3) (1021).

[0227] Alternatively, for example, although not specified in FIG. 10 for convenience of explanation, if the UE A determines that there is no available carrier (or available radio frequency, or available radio frequency resource) for the PC5 QoS flow #1 (1010), both carrier #3 (or radio frequency #3, or radio frequency resource #3) (1021) and carrier #4 (or radio frequency #4, or radio frequency resource #4) (1022) mapped to the PC5 QoS flow #2 (1020) may be used as carriers (or radio frequencies, or radio frequency resources) for transmissions associated with the PC5 QoS flow #1. Alternatively, for example, although not specified in FIG. 10 for convenience of explanation, if the UE A determines that there is no available carrier (or available radio frequency, or available radio frequency resource) for the PC5 QoS flow #1 (1010), the UE A may use at least one carrier (or radio frequency, or radio frequency resource) associated with the PC5 unicast link (1000) as a carrier (or radio frequency, or radio frequency resource) for transmission associated with the PC5 QoS flow #1 in addition to the carriers (or radio frequencies, or radio frequency resources) mapped to the PC5 QoS flow #1 (1010) and the PC5 QoS flow #2 (1020).

[0228] Meanwhile, for example, the base station can configure one or more carriers {sl-FreqInfoToAddModList / sl-FreqInfoToAddModListExt (Carrier #1, Carrier #2, Carrier #3, Carrier #4, Carrier #5, Carrier #6, Carrier #7, Carrier #8, Carrier #9)} to be used by the terminal and transmit them to the terminal (e.g., dedicated RRC message and / or system information and / or pre-configuration). In addition, for example, the upper layer of the terminal (e.g., V2X layer) can configure {Carrier #1, Carrier #2, Carrier #3} as carriers allowed for transmission of a specific service #a (e.g., destination layer-2 ID or specific QoS flow). And, for example, {Carrier #4, Carrier #5, Carrier #6} can be set as the carriers allowed for transmission of a specific service #b (e.g., destination layer-2 ID or specific QoS flow). Also, for example, the transmitting terminal can perform a Tx carrier (re)selection procedure to select a carrier for data transmission of service #a, and determine the carrier to use in the order of carrier #1, carrier #2, and carrier #3 (based on the lowest CBR (channel busy ratio)).

[0229] In this case, for example, according to the prior art, if carrier failures occur in all of carrier #1, carrier #2, and carrier #3, the RRC layer may release (or remove) carrier #1, carrier #2, and carrier #3 from the set of carriers allowed for data transmission related to service #a (e.g., destination layer-2 ID or specific QoS flow). In this case, for example, the terminal may not declare an RLF because there are still carriers allowed to be used for transmission of service #b (e.g., destination layer-2 ID or specific QoS flow), and there are still carriers to be used in the available carriers {sl-FreqInfoToAddModList / sl-FreqInfoToAddModListExt (carrier #1, carrier #2, carrier #3, carrier #4, carrier #5, carrier #6, carrier #7, carrier #8, carrier #9)} configured by the base station. However, for example, a problem may arise where the terminal cannot perform data transmission related to service #a (e.g., destination layer-2 ID or specific QoS flow) permanently (or continuously) even though the unicast link is not in a state where RLF is declared (unicast link termination and / or PC5 RRC connection termination) because there is no carrier to use for data transmission related to service #a (e.g., destination layer-2 ID or specific QoS flow).

[0230] Therefore, according to the embodiment proposed in the present disclosure, if a carrier failure occurs in all carriers {Carrier #1, Carrier #2, Carrier #3} that are allowed to transmit service #a (e.g., destination layer-2 ID or specific QoS flow), the upper layer (e.g., V2X layer or RRC layer) can release (or remove) the SL data communication for service #a (e.g., destination layer-2 ID or specific QoS flow) and notify the AS (access stratum) layer of this. In addition, for example, when the AS layer is instructed to release (or remove) SL data communication for service #a (e.g., destination layer-2 ID or specific QoS flow) from a higher layer (e.g., V2X layer or RRC layer), the AS layer may clear the Mode 1 grant allocated or the Mode 2 grant generated for the service #a (e.g., destination layer-2 ID or specific QoS flow). In addition, for example, when the terminal performs the Mode 1 operation, the base station may report an ACK (acknowledgement) to the PUCCH (physical uplink control channel) so that the base station does not allocate any more Mode 1 (re)transmission resources for service #a (e.g., destination layer-2 ID or specific QoS flow). Also, for example, the AS layer receives service #a (e.g., from a higher layer (e.g., V2X layer or RRC layer)When termination of SL data communication for a destination layer-2 ID or a specific QoS flow is instructed, parameters (e.g., numConsecutiveDTX, initialize SBj to 0 for each logical channel associated with service #a (e.g., destination layer-2 ID or specific QoS flow)) associated with all MACs running for that service #a (e.g., destination layer-2 ID or specific QoS flow), timers (e.g., all timers associated with service #a (e.g., destination layer-2 ID or specific QoS flow) (if running)), and procedures (e.g., triggered sidelink consistent listen before talk (LBT) failure, triggered sidelink Consistent beam failure recovery, triggered sidelink DRX command indication, triggered sidelink channel state information (CSI) reporting, triggered sidelink inter-UE coordination (IUC) information reporting, triggered sidelink inter-UE coordination (IUC) request transmission, triggered sidelink buffer status report (BSR) procedure relevant only to service #a (e.g., destination layer-2 ID or specific QoS flow), service #a (e.g.,A triggered scheduling request (SR) procedure related only to a destination layer-2 ID or a specific QoS flow may be stopped and / or canceled and / or reset. In addition, for example, the terminal may consider all sidelink processes related to service #a (e.g., destination layer-2 ID or a specific QoS flow) as unoccupied. Alternatively, for example, when the AS layer is instructed by a higher layer (e.g., V2X layer or RRC layer) to release (or remove) SL data communication for service #a (e.g., destination layer-2 ID or specific QoS flow), the AS layer may perform a MAC reset operation for the service #a (e.g., destination layer-2 ID or specific QoS flow). In addition, for example, when a carrier failure occurs in a carrier or a set of carriers associated with a specific service #a (e.g., a destination layer-2 ID or a specific QoS flow), the terminal may report information about the carrier failure (e.g., a carrier index for the carrier where the carrier failure occurred, a carrier failure indication, or a carrier failure cause) to a higher layer (e.g., the terminal may declare a carrier failure when DTX exceeds a threshold for PSCCH / PSSCH transmission using a specific carrier).

[0231] FIG. 11 illustrates a method for removing a PC5 QoS flow upon carrier failure, according to an embodiment of the present disclosure. The embodiment of FIG. 11 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0232] Referring to FIG. 11, UE A may establish a PC5 unicast link (1100) between UE A and UE B to perform unicast communication with UE B. For example, the PC5 unicast link (1100) may support one or more services (e.g., V2X service), and one or more PC5 QoS flows may be mapped to each service supported by the PC5 unicast link. Although not specified in FIG. 11 for convenience of explanation, the PC5 unicast link (1100) may support service #A and service #B, and PC5 QoS flow #1 (1110) may be mapped to service #A, and PC5 QoS flow #2 (1120) may be mapped to service #B.

[0233] And, for example, in order to perform transmission related to a PC5 QoS flow (or, in order to perform transmission related to a service for which the PC5 QoS flow is used), at least one carrier (or radio frequency, or radio frequency resource) may be mapped to the PC5 QoS flow. For example, in order to perform transmission related to the PC5 QoS flow #1 (1110) (or, in order to perform transmission related to a service #A for which the PC5 QoS flow #1 is used), carrier #1 (or radio frequency #1, or radio frequency resource #1) (1111) and carrier #2 (or radio frequency #2, or radio frequency resource #2) (1112) may be mapped to the PC5 QoS flow #1 (1110). For example, in order to perform transmission related to the PC5 QoS flow #2 (1120) (or, in order to perform transmission related to service #B in which PC5 QoS flow #2 is used), carrier #3 (or radio frequency #3, or radio frequency resource #3) (1121) and carrier #4 (or radio frequency #4, or radio frequency resource #4) (1122) may be mapped to the PC5 QoS flow #2 (1120).

[0234] For example, carrier #1 (or radio frequency #1, or radio frequency resource #1) (1111) and carrier #2 (or radio frequency #2, or radio frequency resource #2) (1112) mapped to the PC5 QoS flow #1 (1110) may be carriers selected based on a Tx carrier selection procedure. For example, when UE A acquires configuration information related to multiple carriers (or multiple radio frequencies, or multiple radio frequency resources), UE A may measure a CBR (channel busy ratio) for each of the multiple carriers. And, for example, UE A may determine carriers for each of the multiple carriers (or multiple radio frequencies, or multiple radio frequency resources) having a CBR lower than a CBR threshold as candidate carriers. And, for example, UE A may select a carrier for HARQ-based RLF detection in the order of a carrier (or radio frequency, or radio frequency resource) with a lower CBR among the candidate carriers. In summary, for example, carrier #1 (or radio frequency #1, or radio frequency resource #1) (1111) and carrier #2 (or radio frequency #2, or radio frequency resource #2) (1112) mapped to the PC5 QoS flow #1 (1110) may be carriers selected as carriers for HARQ-based RLF detection.

[0235] For example, UE A may perform PSSCH transmission to UE B based on carrier #1 (or radio frequency #1, or radio frequency resource #1) (1111). For example, if UE A performs PSSCH transmission based on carrier #1 (or radio frequency #1, or radio frequency resource #1) (1111) (if HARQ feedback is enabled), but does not receive PSFCH (or HARQ feedback) related to PSSCH transmission from UE B, UE A may increase the value of the first DTX counter (e.g., numConsecutiveDTX) set on carrier #1 (or radio frequency #1, or radio frequency resource #1). For example, if the above-described PSSCH transmission and PSFCH reception failures are repeated and the cumulatively increased value of the first DTX counter (e.g., numConsecutiveDTX) reaches a DTX threshold (e.g., sl-maxNumConsecutiveDTX), UE A may detect a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #1 (or radio frequency #1, or radio frequency resource #1) (1111). For example, a lower layer of UE A (e.g., MAC layer or AS layer) may increase the value of the first DTX counter (e.g., numConsecutiveDTX), and when the value of the first DTX counter (e.g., numConsecutiveDTX) reaches a DTX threshold (e.g., sl-maxNumConsecutiveDTX), the lower layer of UE A may indicate a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #1 (or radio frequency #1, or radio frequency resource #1) (1111) to a higher layer of UE A (e.g., V2X layer, etc.).

[0236] For example, after a carrier failure (or radio frequency failure, or radio frequency resource failure) for the carrier #1 (or radio frequency #1, or radio frequency resource #1) (1111), UE A may perform PSSCH transmission based on carrier #2 (or radio frequency #2, or radio frequency resource #2) (1112) mapped to the PC5 QoS flow #1 (1110). Similarly, for example, even though UE A performs PSSCH transmission based on carrier #2 (or radio frequency #2, or radio frequency resource #2) (1112) (if HARQ feedback is enabled), if UE A does not receive PSFCH (or HARQ feedback) related to PSSCH transmission from UE B, UE A may increase the value of a second DTX counter (e.g., numConsecutiveDTX) set for carrier #2 (or radio frequency #2, or radio frequency resource #2). For example, if the above-described PSSCH transmission and PSFCH reception failures are repeated and the cumulatively increased value of the second DTX counter (e.g., numConsecutiveDTX) reaches a DTX threshold (e.g., sl-maxNumConsecutiveDTX), UE A may detect a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #2 (or radio frequency #2, or radio frequency resource #2) (1112).For example, a lower layer of UE A (e.g., MAC layer or AS layer) may increase the value of the second DTX counter (e.g., numConsecutiveDTX), and when the value of the second DTX counter (e.g., numConsecutiveDTX) reaches a DTX threshold (e.g., sl-maxNumConsecutiveDTX), the lower layer of UE A may indicate a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #2 (or radio frequency #2, or radio frequency resource #2) (1112) to a higher layer of UE A (e.g., V2X layer, etc.).

[0237] In this case, for example, UE A may determine that there is no carrier (or available radio frequency, or available radio frequency resource) available for the PC5 QoS flow #1 based on a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #1 (or radio frequency #1, or radio frequency resource #1) (1111) mapped to the PC5 QoS flow #1 (1110) and a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #2 (or radio frequency #2, or radio frequency resource #2) (1112). For example, if UE A determines that there is no carrier (or available radio frequency, or available radio frequency resource) available for the PC5 QoS flow #1, it may remove (or release) the PC5 QoS flow #1 (1110) from the PC5 unicast link (1100). For example, in the PC5 unicast link (1100), only the PC5 QoS flow #1 (1110) may be removed, and the PC5 QoS flow #2 (1120) with available carriers (or available radio frequencies, or available radio frequency resources) (e.g., carrier #3 (1121) and carrier #4 (1122)) may be maintained. For example, based on a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #1 (or radio frequency #1, or radio frequency resource #1) (1111) mapped to the PC5 QoS flow #1 (1110) and a carrier failure (or radio frequency failure, or radio frequency resource failure) for carrier #2 (or radio frequency #2, or radio frequency resource #2) (1112), even if there is no carrier (or available radio frequency, or available radio frequency resource) available to the PC5 QoS flow #1, the PC5 unicast link (1100) can be maintained.

[0238] FIG. 12 illustrates a method for removing a PC5 QoS flow upon carrier failure, according to an embodiment of the present disclosure. The embodiment of FIG. 12 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0239] Referring to FIG. 12, in step S1210, UE A may establish a PC5 unicast link with UE B. For example, the PC5 unicast link may be established between UE A and UE B based on the fact that the application layer ID of UE A and the application layer ID of UE B are a pair of peer application layer IDs. For example, multiple PC5 QoS flows may be mapped to the PC5 unicast link. For example, each of the multiple PC5 QoS flows may be mapped to one or more services (e.g., V2X services).

[0240] In step S1220, UE A may perform a Tx carrier selection procedure to perform transmission based on the PC5 unicast link. For example, when UE A receives information related to multiple carriers, it may perform CBR measurement for each of the multiple carriers. For example, UE A may determine a carrier associated with a CBR lower than a CBR threshold among the multiple carriers as a candidate carrier. For example, when the candidate carriers include one or more carriers, UE A may select a carrier associated with the lowest CBR among the one or more carriers as a carrier for HARQ-based RLF detection. In summary, for example, among the multiple PC5 QoS flows mapped to the PC5 unicast link, there may be one or more carriers associated with a first PC5 QoS flow, and UE A may perform HARQ-based RLF detection by using the carrier associated with the lowest CBR among the one or more carriers associated with the first PC5 QoS flow for PSSCH transmission.

[0241] In step S1230, (for convenience of explanation, it is assumed that there is only one carrier (or radio frequency, or radio frequency resource) associated with the first PC5 QoS flow) UE A may transmit a PSSCH to UE B based on the carrier (or radio frequency, or radio frequency resource) associated with the first PC5 QoS flow.

[0242] In step S1240, UE A may not receive a PSFCH for the PSSCH transmitted in step S1230 described above from UE B. For example, UE A may fail to receive HARQ feedback (ACK / NACK) for the PSSCH transmission on a PSFCH resource within a PSFCH occasion associated with the PSSCH transmission.

[0243] In step S1250, UE A may increase the value of the DTX count (e.g., numConsecutiveDTX) set for the carrier based on the absence of PSFCH reception for the PSSCH transmitted based on the carrier. For example, if the value of the DTX count (e.g., numConsecutiveDTX) set for the carrier reaches a DTX threshold (e.g., sl-maxNumConsecutiveDTX) (e.g., if steps S1230 to S1240 described above are repeatedly performed so that the value of the DTX count (e.g., numConsecutiveDTX) reaches the DTX threshold (e.g., sl-maxNumConsecutiveDTX), or if the DTX threshold (e.g., sl-maxNumConsecutiveDTX) is set to "1"), UE A may detect (or declare) a carrier failure (or a radio frequency failure, or a radio frequency resource failure) for the carrier (or a radio frequency, or a radio frequency resource).

[0244] In step S1260, UE A may determine whether there is an available carrier (or an available radio frequency, or an available radio frequency resource) for the first PC5 QoS flow. For example, UE A may determine whether there is an available carrier (or an available radio frequency, or an available radio frequency resource) excluding a carrier (or a radio frequency, or a radio frequency resource) for which a carrier failure (or a radio frequency failure, or a radio frequency resource failure) was detected in step S1250 described above among at least one carrier (or a radio frequency, or a radio frequency resource) associated with the first PC5 QoS flow.

[0245] In step S1270, UE A may determine that there is no carrier (or available radio frequency, or available radio frequency resource) available for the first PC5 QoS flow. For example, if there was only one carrier (or available radio frequency, or available radio frequency resource) available for the first PC5 QoS flow, due to carrier failure (or radio frequency failure, or radio frequency resource failure) in step S1250 described above, there may no longer be any carrier (or available radio frequency, or available radio frequency resource) available for the first PC5 QoS flow. In this case, for example, UE A may not perform transmission related to the first PC5 QoS flow using at least one carrier mapped to a PC5 QoS flow other than the first PC5 QoS flow among the plurality of PC5 QoS flows, and UE A may remove (or release) only the first PC5 QoS flow among the plurality of PC5 QoS flows mapped to the PC5 unicast link. In this case, for example, the PC5 unicast link established between UE A and UE B may be maintained, and the remaining PC5 QoS flows mapped to the PC5 unicast link may be maintained. In summary, for example, if UE A determines that there is no available carrier (or available radio frequency, or available radio frequency resource) for the first PC5 QoS flow among the plurality of PC5 QoS flows mapped to the PC5 unicast link, UE A may remove (or release) the first PC5 QoS flow among the plurality of PC5 QoS flows mapped to the PC5 unicast link.

[0246] The terminal (or UE) mentioned in the present disclosure may be alternatively interpreted as an RRC connected terminal (or UE) and / or an RRC idle terminal (or UE) and / or an RRC inactive terminal (or UE) and / or an OOC (out of coverage) terminal (or UE).

[0247] The present disclosure (or a part of the present disclosure) is a solution that can be applied not only to an RRC CONNECTED terminal that is connected to a base station, but also to an RRC idle, RRC inactive, or OOC (out of coverage) terminal that is not connected to a base station.

[0248] The wording of multi-carrier as specified in this disclosure may be extended to carrier aggregation (CA).

[0249] The CBR threshold associated with a sidelink carrier / SL sidelink bandwidth part (BWP) / SL HARQ entity specified in the present disclosure can be set per priority, per QoS profile (e.g., packet delay budget (PDB) or reliability), per SL radio bearer, or per logical channel.

[0250] The wording of the sidelink carrier specified in this disclosure may be extended to a sidelink BWP or a sidelink HARQ entity.

[0251] The unicast service specified in this disclosure may be interpreted as a pair of source layer-2 ID and destination layer-2 ID.

[0252] The groupcast service specified in this disclosure may be interpreted as a groupcast destination layer-2 ID.

[0253] The broadcast service specified in this disclosure may be interpreted as a broadcast destination layer-2 ID.

[0254] The term “carrier” as specified in the present disclosure may be replaced with “band” or “set of resource blocks (RBs) of a specific carrier” or “set of resource pools of a specific carrier” or “channel” or “radio frequency”.

[0255] The carrier failure specified in this disclosure may be replaced with radio frequency failure.

[0256] The wording of release as specified in this disclosure may be applied by replacing it with remove.

[0257] The PC5 RRC connection or unicast link specified in this disclosure may be applied as a replacement for a PC5 unicast link.

[0258] For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) may be set specifically (or differently or independently) for SL-Channel Access Priority Class (CAPC). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) may be set specifically (or differently or independently) for SL-LBT types (e.g., Type 1 LBT, Type 2A LBT, Type 2B LTB, Type 2C LBT). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) may be set specifically (or differently or independently) depending on whether FBE (Frame Based LBT) is applied. For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or the relevant parameters (e.g., thresholds) may be set specifically (or differently or independently) depending on whether LBE (Load Based LBT) is applied.

[0259] For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or their associated parameters (e.g., thresholds) can be set resource pool-specifically (or differently or independently). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or their associated parameters (e.g., thresholds) can be set congestion level-specifically (or differently or independently). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or their associated parameters (e.g., thresholds) can be set service priority-specifically (or differently or independently). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or their associated parameters (e.g., thresholds) can be set service type-specifically (or differently or independently). For example, whether (some) of the proposed schemes / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) can be set specifically (or differently or independently) for QoS requirements (e.g., latency, reliability). For example, whether (some) of the proposed schemes / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) can be set specifically (or differently or independently) for PQI (5QI (5G QoS identifier) ​​for PC5). For example, whether (some) of the proposed schemes / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) can be set specifically (or differently or independently) for traffic types (e.g., periodic generation or aperiodic generation). For example, whether (some) of the proposed schemes / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) can be set specifically (or differently or independently) for SL transmission resource allocation modes (e.g., mode 1 or mode 2).For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) may be configured specifically (or differently or independently) for a Tx profile (e.g., a Tx profile indicating that the service supports sidelink DRX operation or a Tx profile indicating that the service does not need to support sidelink DRX operation).

[0260] For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on whether PUCCH configuration is supported (e.g., when PUCCH resources are configured or when PUCCH resources are not configured). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set for a resource pool (e.g., a resource pool where PSFCH is configured or a resource pool where PSFCH is not configured). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set for a type of service / packet. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set for a priority of a service / packet. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a QoS profile or QoS requirement (e.g., URLLC / EMBB traffic, reliability, latency). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a PQI. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a PFI. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a cast type (e.g., unicast, groupcast, broadcast). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a (resource pool) congestion level (e.g., CBR).For example, whether the proposed rule of the present disclosure is applicable and / or the related parameter setting value can be set specifically (or differently or independently) for an SL HARQ feedback scheme (e.g., NACK-only feedback, ACK / NACK feedback). For example, whether the proposed rule of the present disclosure is applicable and / or the related parameter setting value can be set specifically (or differently or independently) for HARQ Feedback Enabled MAC PDU transmission. For example, whether the proposed rule of the present disclosure is applicable and / or the related parameter setting value can be set specifically (or differently or independently) for HARQ Feedback Disabled MAC PDU transmission. For example, whether the proposed rule of the present disclosure is applicable and / or the related parameter setting value can be set specifically (or differently or independently) depending on whether a PUCCH-based SL HARQ feedback reporting operation is set. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) depending on whether pre-emption or pre-emption-based resource reselection is performed. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) depending on whether re-evaluation or re-evaluation-based resource reselection is performed. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for (L2 or L1) (source and / or destination) identifiers. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for (L2 or L1) (a combination of source ID and destination ID) identifiers.For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for an identifier (L2 or L1) (a combination of a pair of source ID and destination ID and a cast type). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a direction of a pair of source layer ID and destination layer ID. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a PC5 RRC connection / link. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) depending on whether SL DRX is performed. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) depending on whether SL DRX is supported. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for the SL mode type (e.g., resource allocation mode 1 or resource allocation mode 2). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for the case of performing (a)periodic resource reservation. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a Tx profile (e.g., a Tx profile indicating that the service supports sidelink DRX operation or a Tx profile indicating that the service does not need to support sidelink DRX operation).

[0261] The applicability of the proposals and proposed rules of the present disclosure (and / or the associated parameter settings) may also be applied to mmWave SL operation.

[0262] FIG. 13 illustrates a method for a first device to perform wireless communication, according to an embodiment of the present disclosure. The embodiment of FIG. 13 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0263] Referring to FIG. 13, in step S1310, a first device may establish a PC5 unicast link with a second device. In step S1320, the first device may detect a carrier failure for a first carrier associated with the PC5 unicast link. In step S1330, the first device may determine, based on information related to the carrier failure, that there is no available carrier for a first quality of service (QoS) flow associated with the PC5 unicast link. In step S1340, the first device may remove the first QoS flow based on the determination.

[0264] For example, based on a lower layer of the first device detecting a carrier failure for the first carrier, information related to the carrier failure may be indicated from the lower layer of the first device to a higher layer of the first device. For example, the upper layer of the first device may determine that there is no available carrier for the first QoS flow associated with the PC5 unicast link based on the information related to the carrier failure indicated from the lower layer of the first device. And, for example, based on the determination that there is no available carrier for the first QoS flow, the upper layer of the first device may remove the first QoS flow from the PC5 unicast link. For example, the upper layer of the first device may be a vehicle-to-everything (V2X) layer of the first device. And, for example, the lower layer of the first device may be an access stratum (AS) layer of the first device.

[0265] For example, based on the CBR (channel busy ratio) of the first carrier being lower than a threshold, the first carrier may be determined as a candidate carrier.

[0266] For example, based on the CBR of the first carrier, the first carrier may be selected as a carrier for HARQ (hybrid automatic repeat request)-based radio link failure (RLF) detection.

[0267] Additionally, for example, the first device may transmit a physical sidelink shared channel (PSSCH) to the second device based on the first carrier. For example, a value of a counter configured for the first carrier may be incremented based on the absence of a physical sidelink feedback channel (PSFCH) reception from the second device in a PSFCH occasion associated with transmission of the PSSCH. For example, a carrier failure for the first carrier may be detected based on the value of the counter reaching a threshold. For example, the value of the counter may be incremented by 1 based on the first device not detecting a hybrid automatic repeat request (HARQ) feedback for the PSSCH on a PSFCH resource associated with the PSFCH occasion.

[0268] For example, information related to the first carrier in which the carrier failure was detected may be transmitted to the base station.

[0269] Additionally, for example, the first device may obtain configuration information related to a first radio frequency of the first carrier. For example, based on a failure of the first radio frequency associated with a carrier failure for the first carrier, the first device may determine that there is no available radio frequency for the first QoS flow associated with the PC5 unicast link. And, for example, based on a determination that there is no available radio frequency for the first QoS flow associated with the PC5 unicast link, the first device may remove the first QoS flow.

[0270] For example, based on the absence of an available carrier for a second QoS flow associated with the PC5 unicast link, use of at least one carrier mapped to a third QoS flow associated with the PC5 unicast link may be permitted.

[0271] Additionally, for example, the first device may initiate a timer based on obtaining information related to a carrier failure for a second carrier mapped to a second QoS flow associated with the PC5 unicast link. For example, reuse of the second carrier may be permitted based on the expiration of the timer.

[0272] The proposed method can be applied to devices according to various embodiments of the present disclosure. First, the processor (102) of the first device (100) can establish a PC5 unicast link with the second device. Then, the processor (102) of the first device (100) can detect a carrier failure for a first carrier associated with the PC5 unicast link. Then, the processor (102) of the first device (100) can determine, based on information related to the carrier failure, that there is no available carrier for a first quality of service (QoS) flow associated with the PC5 unicast link. Then, the processor (102) of the first device (100) can remove the first QoS flow based on the determination.

[0273] According to one embodiment of the present disclosure, a first device configured to perform wireless communication may be provided. For example, the first device may include at least one transceiver; at least one processor; and at least one memory coupled to the at least one processor and storing instructions. For example, the instructions, based on execution by the at least one processor, may cause the first device to: establish a PC5 unicast link with a second device; detect a carrier failure for a first carrier associated with the PC5 unicast link; determine, based on information related to the carrier failure, that there is no available carrier for a first quality of service (QoS) flow associated with the PC5 unicast link; and based on the determination, remove the first QoS flow.

[0274] According to one embodiment of the present disclosure, a processing device configured to control a first device may be provided. For example, the processing device may include at least one processor; and at least one memory coupled to the at least one processor and storing instructions. For example, the instructions, based on execution by the at least one processor, may cause the first device to: establish a PC5 unicast link with a second device; detect a carrier failure for a first carrier associated with the PC5 unicast link; determine, based on information related to the carrier failure, that there is no available carrier for a first quality of service (QoS) flow associated with the PC5 unicast link; and based on the determination, remove the first QoS flow.

[0275] According to one embodiment of the present disclosure, a non-transitory computer-readable storage medium having instructions recorded thereon may be provided. For example, the instructions, when executed, may cause a first device to: establish a PC5 unicast link with a second device; detect a carrier failure for a first carrier associated with the PC5 unicast link; determine, based on information related to the carrier failure, that no carrier is available for a first quality of service (QoS) flow associated with the PC5 unicast link; and remove the first QoS flow based on the determination.

[0276] FIG. 14 illustrates a method for a second device to perform wireless communication according to an embodiment of the present disclosure. The embodiment of FIG. 14 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0277] Referring to FIG. 14, in step S1410, a second device may establish a PC5 unicast link with a first device. In step S1420, the second device may perform reception based on at least one carrier mapped to a second QoS flow associated with the PC5 unicast link. For example, a first QoS flow other than the second QoS flow associated with the PC5 unicast link may be removed based on a determination that there is no available carrier for the first QoS flow.

[0278] The proposed method can be applied to devices according to various embodiments of the present disclosure. First, the processor (202) of the second device (200) can establish a PC5 unicast link with the first device. Then, the processor (202) of the second device (200) can control the transceiver (206) to perform reception based on at least one carrier mapped to a second QoS flow associated with the PC5 unicast link. For example, a first QoS flow other than the second QoS flow associated with the PC5 unicast link can be removed based on a determination that there is no available carrier for the first QoS flow.

[0279] According to one embodiment of the present disclosure, a second device configured to perform wireless communication may be provided. For example, the second device may include at least one transceiver; at least one processor; and at least one memory coupled to the at least one processor and storing instructions. For example, the instructions, based on execution by the at least one processor, may cause the second device to: establish a PC5 unicast link with a first device; and perform reception based on at least one carrier mapped to a second QoS flow associated with the PC5 unicast link. For example, a first QoS flow other than the second QoS flow associated with the PC5 unicast link may be dropped based on a determination that there is no available carrier for the first QoS flow.

[0280] According to one embodiment of the present disclosure, a processing device configured to control a second device may be provided. For example, the processing device may include at least one processor; and at least one memory coupled to the at least one processor and storing instructions. For example, the instructions, based on execution by the at least one processor, may cause the second device to: establish a PC5 unicast link with a first device; and perform reception based on at least one carrier mapped to a second QoS flow associated with the PC5 unicast link. For example, a first QoS flow other than the second QoS flow associated with the PC5 unicast link may be dropped based on a determination that there is no available carrier for the first QoS flow.

[0281] According to one embodiment of the present disclosure, a non-transitory computer-readable storage medium having instructions recorded thereon may be provided. For example, the instructions, when executed, may cause a second device to: establish a PC5 unicast link with a first device; and perform reception based on at least one carrier mapped to a second QoS flow associated with the PC5 unicast link. For example, a first QoS flow other than the second QoS flow associated with the PC5 unicast link may be dropped based on a determination that there is no available carrier for the first QoS flow.

[0282] According to various embodiments of the present disclosure, even if a carrier failure (or radio frequency failure, or radio frequency resource failure) is detected for at least one QoS flow among a plurality of QoS flows associated with a PC5 unicast link established between terminals and there is no available carrier (or available radio frequency, or available radio frequency resource) for the corresponding QoS flow, transmission for the QoS flow associated with the carrier failure (or radio frequency failure, or radio frequency resource failure) can be performed using a carrier (or radio frequency, or radio frequency resource) mapped to a QoS flow other than the QoS flow associated with the carrier failure (or radio frequency failure, or radio frequency resource failure) among the plurality of QoS flows. In this case, for example, since an available carrier established through an existing RRC can be used without performing an RRC re-establishment or a PC5 unicast link release and re-establishment, the efficiency of frequency resource use can be improved, and latency can be reduced to improve the quality of service associated with the corresponding QoS flow.

[0283] In addition, according to various embodiments of the present disclosure, when a carrier failure (or radio frequency failure, or radio frequency resource failure) is detected for at least one QoS flow among a plurality of QoS flows associated with a PC5 unicast link established between terminals and there is no available carrier (or available radio frequency, or available radio frequency resource) for the corresponding QoS flow, only the QoS flow determined to have no available carrier (or available radio frequency, or available radio frequency resource) among the plurality of QoS flows associated with the PC5 unicast link may be removed, without releasing the PC5 unicast link itself. In this case, for example, since the QoS flow determined to have no available carrier (or available radio frequency, or available radio frequency resource) may no longer be pending, a buffer associated with a DRB (data radio bearer) mapped to the corresponding QoS flow may be flushed, and buffer overflow may be prevented. In addition, for example, latency can be prevented by flushing the buffers associated with the DRB mapped to the corresponding QoS flow, thereby ensuring the quality of real-time services, etc. In addition, for example, buffers associated with the DRB mapped to the corresponding QoS flow can be flushed to ensure that other processes or services can be performed stably. Alternatively, for example, a QoS flow determined to have no available carrier (or available radio frequency, or available radio frequency resources) can no longer be pending, thereby clearing the grant allocated for transmission associated with the corresponding QoS flow.In this case, since the grant can be used for transmissions related to QoS flows other than the QoS flow for which the available carrier (or available radio frequency, or available radio frequency resources) is determined to be absent, resource utilization efficiency can be improved. In addition, for example, since the QoS flow for which the available carrier (or available radio frequency, or available radio frequency resources) is determined to be absent can no longer be pending, unnecessary scheduling for the QoS flow can be prevented. In this case, for example, terminal overhead can be reduced, and unnecessary power consumption of the terminal can be prevented.

[0284] The various embodiments of the present disclosure may be combined with each other, and some descriptions, functions, procedures, proposals, methods and / or operations of the various embodiments may be omitted.

[0285] Below, a description is given of devices to which various embodiments of the present disclosure can be applied.

[0286] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document may be applied to various fields requiring wireless communication / connectivity (e.g., 5G) between devices.

[0287] Hereinafter, more specific examples will be provided with reference to the drawings. In the drawings / descriptions below, the same drawing reference numerals may represent identical or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise described.

[0288] FIG. 15 illustrates a communication system (1) according to one embodiment of the present disclosure. The embodiment of FIG. 15 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0289] Referring to FIG. 15, a communication system (1) to which various embodiments of the present disclosure are applied includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone) and / or an Aerial Vehicle (AV) (e.g., an Advanced Air Mobility (AAM)). The XR device may include an Augmented Reality (AR) / Virtual Reality (VR) / Mixed Reality (MR) device, and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. The portable device may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.), etc. The home appliance may include a TV, a refrigerator, a washing machine, etc. The IoT device may include a sensor, a smart meter, etc. For example, a base station and a network may also be implemented as a wireless device, and a specific wireless device (200a) may operate as a base station / network node to other wireless devices.

[0290] Here, the wireless communication technology implemented in the wireless devices (100a to 100f) of the present specification may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. At this time, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices (100a to 100f) of the present specification may perform communication based on LTE-M technology. At this time, for example, LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices (100a to 100f) of the present specification can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PAN) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0291] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0292] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or, D2D communication), and communication between base stations (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present disclosure.

[0293] FIG. 16 illustrates a wireless device according to an embodiment of the present disclosure. The embodiment of FIG. 16 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0294] Referring to FIG. 16, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals via various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the base station (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 15.

[0295] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). Furthermore, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present disclosure, a wireless device may also mean a communication modem / circuit / chip.

[0296] A second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). In addition, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present disclosure, a wireless device may also mean a communication modem / circuit / chip.

[0297] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0298] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0299] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0300] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0301] Fig. 17 illustrates a signal processing circuit for a transmission signal according to an embodiment of the present disclosure. The embodiment of Fig. 17 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0302] Referring to FIG. 17, the signal processing circuit (1000) may include a scrambler (1010), a modulator (1020), a layer mapper (1030), a precoder (1040), a resource mapper (1050), and a signal generator (1060). Although not limited thereto, the operations / functions of FIG. 17 may be performed in the processor (102, 202) and / or the transceiver (106, 206) of FIG. 16. The hardware elements of FIG. 17 may be implemented in the processor (102, 202) and / or the transceiver (106, 206) of FIG. 16. For example, blocks 1010 to 1060 may be implemented in the processor (102, 202) of FIG. 16. Additionally, blocks 1010 to 1050 may be implemented in the processor (102, 202) of FIG. 16, and block 1060 may be implemented in the transceiver (106, 206) of FIG. 16.

[0303] The codeword can be converted into a wireless signal through the signal processing circuit (1000) of FIG. 17. Here, the codeword is an encoded bit sequence of an information block. The information block can include a transport block (e.g., an UL-SCH transport block, a DL-SCH transport block). The wireless signal can be transmitted through various physical channels (e.g., a PUSCH or a PDSCH).

[0304] Specifically, the codeword can be converted into a bit sequence scrambled by a scrambler (1010). The scramble sequence used for scrambling is generated based on an initialization value, and the initialization value may include ID information of the wireless device, etc. The scrambled bit sequence can be modulated into a modulation symbol sequence by a modulator (1020). The modulation method may include pi / 2-BPSK (pi / 2-Binary Phase Shift Keying), m-PSK (m-Phase Shift Keying), m-QAM (m-Quadrature Amplitude Modulation), etc. The complex modulation symbol sequence can be mapped to one or more transmission layers by a layer mapper (1030). The modulation symbols of each transmission layer can be mapped to the corresponding antenna port(s) by a precoder (1040) (precoding). The output z of the precoder (1040) can be obtained by multiplying the output y of the layer mapper (1030) by a precoding matrix W of N*M. Here, N is the number of antenna ports, and M is the number of transmission layers. Here, the precoder (1040) can perform precoding after performing transform precoding (e.g., DFT transform) on complex modulation symbols. In addition, the precoder (1040) can perform precoding without performing transform precoding.

[0305] The resource mapper (1050) can map modulation symbols of each antenna port to time-frequency resources. The time-frequency resources can include multiple symbols (e.g., CP-OFDMA symbols, DFT-s-OFDMA symbols) in the time domain and multiple subcarriers in the frequency domain. The signal generator (1060) generates a wireless signal from the mapped modulation symbols, and the generated wireless signal can be transmitted to another device through each antenna. To this end, the signal generator (1060) can include an Inverse Fast Fourier Transform (IFFT) module, a Cyclic Prefix (CP) inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0306] The signal processing process for receiving signals in a wireless device can be configured in reverse order of the signal processing process (1010 to 1060) of FIG. 17. For example, a wireless device (e.g., 100, 200 of FIG. 16) can receive wireless signals from the outside through an antenna port / transceiver. The received wireless signals can be converted into baseband signals through a signal restorer. For this purpose, the signal restorer can include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast Fourier transform (FFT) module. Thereafter, the baseband signal can be restored to a codeword through a resource demapper process, a postcoding process, a demodulation process, and a descrambling process. The codewords can be restored to the original information blocks through decoding. Accordingly, a signal processing circuit (not shown) for a received signal may include a signal restorer, a resource de-mapper, a postcoder, a demodulator, a de-scrambler, and a decoder.

[0307] Figure 18 illustrates a wireless device according to an embodiment of the present disclosure. The wireless device may be implemented in various forms depending on the use case / service (see Figure 15). The embodiment of Figure 18 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0308] Referring to FIG. 18, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 16 and may be composed of various elements, components, units / units, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 16. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 16. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0309] The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 15, 100a), a vehicle (Fig. 15, 100b-1, 100b-2), an XR device (Fig. 15, 100c), a portable device (Fig. 15, 100d), a home appliance (Fig. 15, 100e), an IoT device (Fig. 15, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 15, 400), a base station (Fig. 15, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0310] In FIG. 18, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and the first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of one or more processor sets. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of a random access memory (RAM), a dynamic RAM (DRAM), a read only memory (ROM), a flash memory, a volatile memory, a non-volatile memory, and / or a combination thereof.

[0311] Below, the implementation example of Fig. 18 is described in more detail with reference to the drawings.

[0312] FIG. 19 illustrates a mobile device according to an embodiment of the present disclosure. The mobile device may include a smartphone, a smart pad, a wearable device (e.g., a smartwatch, smartglasses), or a portable computer (e.g., a laptop, etc.). The mobile device may be referred to as a Mobile Station (MS), a User Terminal (UT), a Mobile Subscriber Station (MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), or a Wireless Terminal (WT). The embodiment of FIG. 19 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0313] Referring to FIG. 19, the portable device (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a memory unit (130), a power supply unit (140a), an interface unit (140b), and an input / output unit (140c). The antenna unit (108) may be configured as a part of the communication unit (110). Blocks 110 to 130 / 140a to 140c correspond to blocks 110 to 130 / 140 of FIG. 18, respectively.

[0314] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with other wireless devices and base stations. The control unit (120) can control components of the mobile device (100) to perform various operations. The control unit (120) can include an AP (Application Processor). The memory unit (130) can store data / parameters / programs / codes / commands required for operating the mobile device (100). In addition, the memory unit (130) can store input / output data / information, etc. The power supply unit (140a) supplies power to the mobile device (100) and can include a wired / wireless charging circuit, a battery, etc. The interface unit (140b) can support connection between the mobile device (100) and other external devices. The interface unit (140b) can include various ports (e.g., audio input / output ports, video input / output ports) for connection with external devices. The input / output unit (140c) can input or output video information / signals, audio information / signals, data, and / or information input from a user. The input / output unit (140c) may include a camera, a microphone, a user input unit, a display unit (140d), a speaker, and / or a haptic module.

[0315] For example, in the case of data communication, the input / output unit (140c) obtains information / signals (e.g., touch, text, voice, image, video) input by the user, and the obtained information / signals can be stored in the memory unit (130). The communication unit (110) converts the information / signals stored in the memory into wireless signals, and can directly transmit the converted wireless signals to other wireless devices or to a base station. In addition, the communication unit (110) can receive wireless signals from other wireless devices or base stations, and then restore the received wireless signals to the original information / signals. The restored information / signals can be stored in the memory unit (130) and then output in various forms (e.g., text, voice, image, video, haptic) through the input / output unit (140c).

[0316] FIG. 20 illustrates a vehicle or autonomous vehicle according to one embodiment of the present disclosure. The vehicle or autonomous vehicle may be implemented as a mobile robot, a car, a train, a manned / unmanned aerial vehicle (AV), a ship, etc. The embodiment of FIG. 20 may be combined with various embodiments of the present disclosure, and some descriptions, functions, procedures, proposals, methods, and / or operations of the embodiments may be omitted.

[0317] Referring to FIG. 20, a vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a driving unit (140a), a power supply unit (140b), a sensor unit (140c), and an autonomous driving unit (140d). The antenna unit (108) may be configured as a part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 18, respectively.

[0318] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, road side units, etc.), and servers. The control unit (120) can control elements of the vehicle or autonomous vehicle (100) to perform various operations. The control unit (120) can include an ECU (Electronic Control Unit). The drive unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The drive unit (140a) can include an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and can include a wired / wireless charging circuit, a battery, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an incline sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement a technology for maintaining a driving lane, a technology for automatically controlling speed such as adaptive cruise control, a technology for automatically driving along a set path, a technology for automatically setting a path and driving when a destination is set, etc.

[0319] For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving route and driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or autonomous vehicle (100) moves along the autonomous driving route according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can irregularly / periodically acquire the latest traffic information data from an external server and can acquire surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving route and driving plan based on newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving route, driving plan, etc. to the external server. External servers can predict traffic information data in advance using AI technology or other technologies based on information collected from vehicles or autonomous vehicles, and provide the predicted traffic information data to the vehicles or autonomous vehicles.

[0320] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method.

Claims

1. In the method, A step in which a first device establishes a PC5 unicast link with a second device; A step of detecting a carrier failure for a first carrier associated with the PC5 unicast link; A step of determining that there is no available carrier for a first quality of service (QoS) flow associated with the PC5 unicast link based on information related to the carrier failure; and A method comprising: removing the first QoS flow based on the above decision; 2. In paragraph 1, A method wherein, based on the lower layer of the first device detecting a carrier failure for the first carrier, information related to the carrier failure is indicated from the lower layer of the first device to the higher layer of the first device.

3. In paragraph 2, The upper layer of the first device determines that there is no available carrier for the first QoS flow associated with the PC5 unicast link based on information related to the carrier failure indicated from the lower layer of the first device, and A method wherein, based on the determination that there is no available carrier for the first QoS flow, the upper layer of the first device removes the first QoS flow from the PC5 unicast link.

4. In paragraph 3, The upper layer of the first device is the V2X (vehicle-to-everything) layer of the first device, and A method wherein the lower layer of the first device is an AS (access stratum) layer of the first device.

5. In paragraph 1, A method in which the first carrier is determined as a candidate carrier based on a CBR (channel busy ratio) of the first carrier being lower than a threshold value.

6. In paragraph 1, A method wherein, based on the CBR of the first carrier, the first carrier is selected as a carrier for HARQ (hybrid automatic repeat request)-based RLF (radio link failure) detection.

7. In paragraph 1, Further comprising a step of transmitting a PSSCH (physical sidelink shared channel) to the second device based on the first carrier; A method in which the value of a counter set in the first carrier is incremented based on the absence of PSFCH reception in a PSFCH (physical sidelink feedback channel) occasion related to transmission of the PSSCH from the second device.

8. In paragraph 7, A method wherein a carrier failure for the first carrier is detected based on the value of the counter reaching a threshold.

9. In paragraph 7, A method in which the value of the counter is increased by 1 based on the first device not detecting HARQ (hybrid automatic repeat request) feedback for the PSSCH on the PSFCH resource associated with the PSFCH occasion.

10. In paragraph 1, A method in which information related to the first carrier in which the carrier failure is detected is transmitted to the base station.

11. In paragraph 1, A step of obtaining configuration information related to a first radio frequency of the first carrier; further comprising: Based on a failure of the first radio frequency associated with a carrier failure for the first carrier, the first device determines that there is no available radio frequency for the first QoS flow associated with the PC5 unicast link, and A method wherein the first device removes the first QoS flow based on a determination that there is no available radio frequency for the first QoS flow associated with the PC5 unicast link.

12. In paragraph 1, A method wherein use of at least one carrier mapped to a third QoS flow associated with the PC5 unicast link is permitted based on the absence of an available carrier for the second QoS flow associated with the PC5 unicast link.

13. In paragraph 1, Further comprising: a step of initiating a timer based on obtaining information related to a carrier failure for a second carrier mapped to a second QoS flow associated with the PC5 unicast link; A method wherein reuse of the second carrier is permitted based on the expiration of the above timer.

14. In the first device, At least one transmitter / receiver; at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said first device causes: Establish a unicast link with the second device and the PC5; Detecting a carrier failure for a first carrier associated with the above PC5 unicast link; Based on information related to the carrier failure, determining that there is no available carrier for the first quality of service (QoS) flow associated with the PC5 unicast link; and A first device, based on the above decision, to remove the first QoS flow.

15. In a processing device set to control the first device, at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said first device causes: Establish a unicast link with the second device and the PC5; Detecting a carrier failure for a first carrier associated with the above PC5 unicast link; Based on information related to the carrier failure, determining that there is no available carrier for the first quality of service (QoS) flow associated with the PC5 unicast link; and A processing device that removes the first QoS flow based on the above decision.

16. A non-transitory computer-readable storage medium that records commands, The above commands, when executed, cause the first device to: Establish a unicast link with the second device and the PC5; Detecting a carrier failure for a first carrier associated with the above PC5 unicast link; Based on information related to the carrier failure, determining that there is no available carrier for the first quality of service (QoS) flow associated with the PC5 unicast link; and A non-transitory computer-readable storage medium that causes the first QoS flow to be removed based on the above decision.

17. In the method, A step in which a second device establishes a PC5 unicast link with a first device; and A step of performing reception based on at least one carrier mapped to a second QoS flow associated with the PC5 unicast link; comprising: A method wherein a first QoS flow other than the second QoS flow associated with the PC5 unicast link is removed based on a determination that there is no available carrier for the first QoS flow.

18. In the second device, At least one transmitter / receiver; at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said second device causes: Establish a unicast link between the first device and the PC5; and Perform reception based on at least one carrier mapped to a second QoS flow associated with the above PC5 unicast link, A second device, wherein a first QoS flow other than the second QoS flow associated with the PC5 unicast link is dropped based on a determination that there is no available carrier for the first QoS flow.

19. In a processing device set to control a second device, at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said second device causes: Establish a unicast link between the first device and the PC5; and Perform reception based on at least one carrier mapped to a second QoS flow associated with the above PC5 unicast link, A processing device wherein a first QoS flow other than the second QoS flow associated with the PC5 unicast link is removed based on a determination that there is no available carrier for the first QoS flow.

20. A non-transitory computer-readable storage medium that records commands, The above commands, when executed, cause the second device to: Establish a unicast link between the first device and the PC5; and Perform reception based on at least one carrier mapped to a second QoS flow associated with the above PC5 unicast link, A non-transitory computer-readable storage medium wherein a first QoS flow other than the second QoS flow associated with the PC5 unicast link is removed based on a determination that there is no available carrier for the first QoS flow.

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