Method and device for saving power for sidelink communication in NR V2X

Abstract

According to one embodiment of the present disclosure, a method is provided for a first device to perform sidelink communication. In one example, a method is provided for the first device to save power for sidelink communication in NR V2X.

Description

Technology Field

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

[0002] Sidelink (SL) refers to a communication method in which User Equipment (UE) establishes a direct link to directly exchange voice or data between terminals without passing through a Base Station (BS). SL is being considered as a solution to address the burden on base stations caused by rapidly increasing data traffic.

[0003] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-equipped objects through wired or wireless communication. V2X can be classified into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through PC5 interfaces and / or Uu interfaces.

[0004] Meanwhile, as more communication devices require larger communication capacities, the need for improved mobile broadband communication compared to existing Radio Access Technology (RAT) is emerging. Accordingly, communication systems considering services or terminals sensitive to reliability and latency are being discussed; next-generation radio access technology that incorporates improved mobile broadband communication, Massive Machine Type Communication (MTC), and Ultra-Reliable and Low Latency Communication (URLC) can be referred to as new radio access technology (new RAT) or new radio (NR). Vehicle-to-everything (V2X) communication can also be supported in NR.

[0005] FIG. 1 is a diagram illustrating a comparison between V2X communication based on RAT prior to NR and V2X communication based on NR. An embodiment of FIG. 1 can be combined with various embodiments of the present disclosure.

[0006] Regarding V2X communication, prior to NR, RATs mainly discussed methods for providing safety services based on V2X messages such as BSM (Basic Safety Message), CAM (Cooperative Awareness Message), and DENM (Decentralized Environmental Notification Message). V2X messages can include location information, dynamic information, attribute information, etc. For example, a terminal can transmit a CAM of the periodic message type and / or a DENM of the event-triggered message type to another terminal.

[0007] For example, the CAM may include basic vehicle information such as dynamic state information of the vehicle, such as direction and speed, static data of the vehicle, such as dimensions, external lighting conditions, and route history. For example, a terminal may broadcast the CAM, and the latency of the CAM may be less than 100ms. For example, in the event of an unexpected situation such as a vehicle breakdown or accident, the terminal may generate a DENM and transmit it to other terminals. For example, all vehicles within the transmission range of the terminal may receive the CAM and / or DENM. In this case, the DENM may have a higher priority than the CAM.

[0008] Since then, various V2X scenarios regarding V2X communication have been presented in NR. For example, various V2X scenarios may include vehicle platooning, advanced driving, extended sensors, remote driving, etc.

[0009] For example, based on vehicle platooning, vehicles can dynamically form groups and move together. For example, to perform platoon operations based on vehicle platooning, vehicles belonging to said group can receive periodic data from the lead vehicle. For example, vehicles belonging to said group can use said periodic data to reduce or increase the distance between vehicles.

[0010] For example, based on enhanced driving, vehicles can be semi-automated or fully automated. For example, each vehicle can adjust trajectories or maneuvers based on data acquired from local sensors of nearby vehicles and / or nearby logical entities. Additionally, for example, each vehicle can mutually share driving intentions with nearby vehicles.

[0011] For example, based on extended sensors, raw data or processed data or live video data acquired through local sensors can be exchanged between vehicles, logical entities, pedestrian terminals and / or V2X application servers. Thus, for example, a vehicle can perceive an environment that is enhanced compared to the environment it can detect using its own sensors.

[0012] For example, based on remote driving, a remote driver or V2X application can operate or control a remote vehicle for a person unable to drive or for a remote vehicle located in a dangerous environment. For example, in cases where the route is predictable, such as in public transportation, cloud computing-based driving can be used for the operation or control of the remote vehicle. Additionally, access to a cloud-based back-end service platform, for example, can be considered for remote driving.

[0013] Meanwhile, methods to specify service requirements for various V2X scenarios, such as vehicle platooning, enhanced driving, extended sensors, and remote driving, are being discussed in NR-based V2X communication. The problem to be solved

[0014] The technical problem of the present disclosure is to provide a sidelink (SL) communication method between devices (or terminals) and a device (or terminal) that performs the same.

[0015] Another technical objective of the present disclosure is to provide a method for saving power for sidelink communication in NR V2X and a device (or terminal) for performing the same. means of solving the problem

[0016] According to one embodiment of the present disclosure, a method may be provided for a first device to perform side-link communication. The above method comprises the steps of: transmitting Sidelink Control Information (SCI) to a second device; transmitting data related to the SCI through a Physical Sidelink Shared Channel (PSSCH) to the second device; determining a PSFCH resource for receiving a Physical Sidelink Feedback Channel (PSFCH) from the second device based on an index of a slot and an index of a subchannel associated with the PSSCH; initiating a first timer associated with the PSFCH resource based on failure to monitor the PSFCH at the PSFCH resource; initiating a second timer associated with a Sidelink HARQ retransmission grant for retransmitting the data based on expiration of the first timer; and retransmitting the Sidelink HARQ to the second device based on a Sidelink retransmission resource determined based on the Sidelink HARQ retransmission grant. The method includes the step of transmitting data, wherein the sidelink HARQ retransmission grant is received from the base station after the second timer is initiated, and the second timer may be stopped after the sidelink HARQ retransmission data is transmitted to the second device.

[0017] According to one embodiment of the present disclosure, a first device for performing side-link communication may be provided.The first device comprises at least one memory for storing instructions, at least one transceiver, and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor controls the at least one transceiver to transmit Sidelink Control Information (SCI) to a second device, controls the at least one transceiver to transmit data related to the SCI through a Physical Sidelink Shared Channel (PSSCH) to the second device, determines a PSFCH resource for receiving a Physical Sidelink Feedback Channel (PSFCH) from the second device based on an index of a slot and an index of a subchannel related to the PSSCH, initiates a first timer related to the PSFCH resource based on a failure to monitor the PSFCH at the PSFCH resource, and the first Based on the expiration of the timer, a second timer associated with a sidelink HARQ retransmission grant for the retransmission of the data is initiated, and the at least one transceiver is controlled to transmit sidelink HARQ retransmission data to the second device based on a sidelink retransmission resource determined based on the sidelink HARQ retransmission grant, wherein the sidelink HARQ retransmission grant is received from a base station after the second timer is initiated, and the second timer may be stopped after the sidelink HARQ retransmission data is transmitted to the second device.

[0018] According to one embodiment of the present disclosure, a device (or chip (set)) for controlling a first terminal may be provided. The device comprises at least one processor and at least one computer memory executablely connected to the at least one processor and storing instructions, wherein, by the at least one processor executing the instructions, the first terminal transmits Sidelink Control Information (SCI) to the second terminal, transmits data associated with the SCI to the second terminal via a Physical Sidelink Shared Channel (PSSCH), determines a PSFCH resource for receiving a Physical Sidelink Feedback Channel (PSFCH) from the second terminal based on an index of a slot associated with the PSSCH and an index of a subchannel associated with the PSSCH, initiates a first timer associated with the PSFCH resource based on failure to monitor the PSFCH at the PSFCH resource, and performs a Sidelink HARQ retransmission for the retransmission of the data based on the expiration of the first timer. A second timer associated with a grant is initiated, and based on a sidelink retransmission resource determined based on the sidelink HARQ retransmission grant, sidelink HARQ retransmission data is transmitted to the second terminal, wherein the sidelink HARQ retransmission grant is received from a base station after the second timer is initiated, and the second timer may be stopped after the sidelink HARQ retransmission data is transmitted to the second terminal.

[0019] According to one embodiment of the present disclosure, a non-transitory computer-readable storage medium for storing instructions (or instructions) may be provided. The above-mentioned non-transient computer-readable storage medium, upon execution of the above instructions, causes the first device to: transmit Sidelink Control Information (SCI) to the second device; transmit data associated with the SCI to the second device via a Physical Sidelink Shared Channel (PSSCH); determine a PSFCH resource for receiving a Physical Sidelink Feedback Channel (PSFCH) from the second device based on an index of a slot associated with the PSSCH and an index of a subchannel associated with the PSSCH; initiate a first timer associated with the PSFCH resource based on a failure to monitor the PSFCH at the PSFCH resource; initiate a second timer associated with a Sidelink HARQ retransmission grant for the retransmission of the data based on the expiration of the first timer; and based on the Sidelink HARQ retransmission grant Based on the determined sidelink retransmission resource, sidelink HARQ retransmission data is transmitted to the second device, wherein the sidelink HARQ retransmission grant is received from the base station after the second timer is started, and the second timer may be stopped after the sidelink HARQ retransmission data is transmitted to the second device.

[0020] According to one embodiment of the present disclosure, a method is provided in which a third device performs side-link communication. The above method comprises the steps of: receiving Sidelink Control Information (SCI) from a fourth device; receiving data related to the SCI via a Physical Sidelink Shared Channel (PSSCH) from the fourth device; initiating a first timer related to the Sidelink Automatic Repeat Request (HARQ) feedback information based on a first priority value of the Sidelink HARQ feedback information related to the data; initiating a second timer related to a Sidelink HARQ retransmission packet for the SCI or the PSSCH based on the expiration of the first timer; and receiving the Sidelink HARQ retransmission packet from the fourth device, wherein the Sidelink HARQ retransmission packet is received from the fourth device after the second timer is initiated, and the second timer is set after the Sidelink HARQ retransmission packet is received from the fourth device It is stopped, and the first priority value of the sidelink HARQ feedback information may be greater than the second priority value related to uplink transmission to the base station.

[0021] According to one embodiment of the present disclosure, a third device for performing side-link communication is provided. The third device comprises at least one memory for storing instructions, at least one transceiver, and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor controls the at least one transceiver to receive Sidelink Control Information (SCI) from the fourth device, controls the at least one transceiver to receive data related to the SCI via a Physical Sidelink Shared Channel (PSSCH) from the fourth device, initiates a first timer related to the Sidelink HARQ feedback information based on a first priority value of the Sidelink HARQ feedback information related to the data, initiates a second timer related to a Sidelink HARQ retransmission packet for the SCI or the PSSCH based on the expiration of the first timer, and the fourth The at least one transceiver is controlled to receive the sidelink HARQ retransmission packet from the device, wherein the sidelink HARQ retransmission packet is received from the fourth device after the second timer is started, and the second timer is stopped after the sidelink HARQ retransmission packet is received from the fourth device, and the first priority value of the sidelink HARQ feedback information may be greater than the second priority value related to uplink transmission to the base station. Effects of the invention

[0022] According to the present disclosure, sidelink communication between devices (or terminals) can be performed efficiently.

[0023] According to the present disclosure, power for sidelink communication in NR V2X can be efficiently saved.

[0024] According to the present disclosure, a TX UE (Transmission User Equipment) operating in Sidelink DRX (Discontinuous Reception) may remain in active mode and continue to perform Sidelink transmission without transitioning to sleep mode if conditions are satisfied that determine that the transmission and reception of Sidelink data is necessary, even if its Sidelink DRX on-duration period has expired. Additionally, if conditions are satisfied that determine that the transmission and reception of Sidelink data is not necessary, it may transition to sleep mode to reduce power consumption. Brief explanation of the drawing

[0025] Figure 1 is a diagram illustrating a comparison between V2X communication based on RAT prior to NR and V2X communication based on NR. FIG. 2 shows the structure of an NR system according to one embodiment of the present disclosure. FIG. 3 shows a functional split between NG-RAN and 5GC according to one embodiment of the present disclosure. FIGS. 4a and FIGS. 4b illustrate a radio protocol architecture according to one embodiment of the present disclosure. FIG. 5 shows the structure of a wireless frame of NR according to one embodiment of the present disclosure. FIG. 6 shows a slot structure of an NR frame according to one embodiment of the present disclosure. FIG. 7 shows an example of a BWP according to one embodiment of the present disclosure. FIGS. 8a and 8b illustrate a radio protocol architecture for SL communication according to one embodiment of the present disclosure. FIG. 9 shows a terminal performing V2X or SL communication according to one embodiment of the present disclosure. FIGS. 10a and FIGS. 10b illustrate a procedure in which a terminal performs V2X or SL communication according to a transmission mode, according to one embodiment of the present disclosure. FIGS. 11a to 11c show three cast types according to one embodiment of the present disclosure. FIG. 12 illustrates an example of a method for a TX UE to save power consumption for sidelink communication according to one embodiment. FIG. 13 illustrates another example of a method for a TX UE to save power consumption for sidelink communication according to another embodiment. FIG. 14 illustrates another example of a method for a TX UE to save power consumption for sidelink communication according to another embodiment. FIG. 15 illustrates an example of a method for an RX UE to save power consumption for sidelink communication according to one embodiment. FIG. 16 is a flowchart illustrating a method in which a first device performs side-link communication with a second device according to one embodiment of the present disclosure. FIG. 17 is a flowchart illustrating a method in which a third device performs side-link communication with a fourth device according to one embodiment of the present disclosure. FIG. 18 shows a communication system (1) according to one embodiment of the present disclosure. FIG. 19 shows a wireless device according to one embodiment of the present disclosure. FIG. 20 shows a signal processing circuit for a transmission signal according to one embodiment of the present disclosure. FIG. 21 shows a wireless device according to one embodiment of the present disclosure. FIG. 22 shows a portable device according to one embodiment of the present disclosure. FIG. 23 shows a vehicle or an autonomous vehicle according to one embodiment of the present disclosure. Specific details for implementing the invention

[0026] In this specification, “A or B” may mean “only A,” “only B,” or “both A and B.” Alternatively, in this specification, “A or B” may be interpreted as “A and / or B.” For example, in this specification, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0027] 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.”

[0028] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as synonymous with “at least one of A and B.”

[0029] Additionally, in this specification, “at least one of A, B and C” may 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” may mean “at least one of A, B and C.”

[0030] Additionally, parentheses used in this specification 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 this specification is not limited to “PDCCH,” and “PDDCH” 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.”

[0031] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously.

[0032] The following technologies 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 using wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented using wireless technologies such as GSM (global system for mobile communications), GPRS (general packet radio service), and EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented using wireless technologies such as IEEE (institute of electrical and electronics engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e. UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is part of E-UMTS (evolved UMTS) which uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink.LTE-A (advanced) is an evolution of 3GPP LTE.

[0033] 5G NR is a successor technology to LTE-A and is a new clean-slate type mobile communication system with characteristics such as high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, ranging from low frequency bands below 1 GHz to mid-frequency bands from 1 GHz to 10 GHz, and high frequency (millimeter wave) bands above 24 GHz.

[0034] For clarity of explanation, the description focuses on 5G NR, but the technical concept according to one embodiment of the present disclosure is not limited thereto.

[0035] FIG. 2 shows the structure of an NR system according to one embodiment of the present disclosure. The embodiment of FIG. 2 can be combined with various embodiments of the present disclosure.

[0036] Referring to FIG. 2, the NG-RAN (Next Generation - Radio Access Network) may include a base station (20) that provides user plane and control plane protocol termination to a terminal (10). For example, the base station (20) may include a gNB (next generation-Node B) and / or an eNB (evolved-Node B). For example, the terminal (10) may be fixed or mobile and may be referred to by other terms such as MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), MT (Mobile Terminal), or Wireless Device. For example, the base station may be a fixed station communicating with the terminal (10) and may be referred to by other terms such as BTS (Base Transceiver System) or Access Point.

[0037] The embodiment of FIG. 2 illustrates a case including only gNB. Base stations (20) may be connected to each other via an Xn interface. Base stations (20) may be connected to a 5th generation core network (5G Core Network: 5GC) via an NG interface. More specifically, base stations (20) may be connected to an access and mobility management function (AMF) (30) via an NG-C interface and to a user plane function (UPF) (30) via an NG-U interface.

[0038] FIG. 3 illustrates a functional partition between NG-RAN and 5GC according to one embodiment of the present disclosure. The embodiment of FIG. 3 can be combined with various embodiments of the present disclosure.

[0039] Referring to FIG. 3, the gNB can provide functions such as Inter Cell Radio Resource Management (Inter Cell RRM), Radio Bearer Management (RB control), Connection Mobility Control, Radio Admission Control, Measurement Configuration & Provision, and Dynamic Resource Allocation. The AMF can provide functions such as Non Access Stratum (NAS) security and idle state mobility processing. The UPF can provide functions such as Mobility Anchoring and Protocol Data Unit (PDU) processing. The Session Management Function (SMF) can provide functions such as terminal IP (Internet Protocol) address allocation and PDU session control.

[0040] The layers of the Radio Interface Protocol between a terminal and a network can be classified into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) based on the lower three layers of the Open System Interconnection (OSI) model, which is widely known in communication systems. Among these, the Physical Layer, belonging to Layer 1, provides Information Transfer Services using a physical channel, while the Radio Resource Control (RRC) layer, located at Layer 3, performs the role of controlling radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0041] FIGS. 4a and 4b illustrate a radio protocol architecture according to one embodiment of the present disclosure. The embodiment of FIGS. 4a and 4b may be combined with various embodiments of the present disclosure. Specifically, FIG. 4a illustrates a radio protocol architecture for a user plane, and FIG. 4b illustrates a radio protocol architecture for a control plane. The user plane is a protocol stack for user data transmission, and the control plane is a protocol stack for control signal transmission.

[0042] Referring to FIGS. 4a and 4b, the physical layer provides information transmission services to the upper layer using a physical channel. The physical layer is connected to the upper layer, the MAC (Medium Access Control) layer, through a transport channel. Data travels between the MAC layer and the physical layer through the transport channel. Transport channels are classified according to how and with what characteristics data is transmitted through a wireless interface.

[0043] Data travels between different physical layers, specifically between the physical layers of the transmitter and the receiver, through a physical channel. This physical channel can be modulated using Orthogonal Frequency Division Multiplexing (OFDM) and utilizes time and frequency as wireless resources.

[0044] The MAC layer provides services to the upper layer, the RLC (radio link control) layer, through logical channels. The MAC layer provides mapping functions from multiple logical channels to multiple transmission channels. Additionally, the MAC layer provides logical channel multiplexing functions through mapping from multiple logical channels to a single transmission channel. The MAC sublayer provides data transmission services over logical channels.

[0045] The RLC layer performs the concatenation, segmentation, and reassembly of RLC Serving Data Units (SDUs). To guarantee the various Quality of Service (QoS) required by the Radio Bearer (RB), the RLC layer provides three operating modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction through Automatic Repeat Requests (ARQ).

[0046] The RRC (Radio Resource Control) layer is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transmission channels, and physical channels in relation to the configuration, reconfiguration, and release of wireless bearers. RB refers to the logical path provided by the first layer (physical layer or PHY layer) and the second layer (MAC layer, RLC layer, PDCP (Packet Data Convergence Protocol) layer) for data transmission between a terminal and a network.

[0047] The functions of the PDCP layer in the user plane include the delivery of user data, header compression, and ciphering. The functions of the PDCP layer in the control plane include the delivery of control plane data and encryption / integrity protection.

[0048] The SDAP (Service Data Adaptation Protocol) layer is defined only in the user plane. The SDAP layer performs tasks such as mapping QoS flows between data radio bearers and marking QoS flow identifiers (IDs) within downlink and uplink packets.

[0049] The establishment of an RB refers to the process of defining the characteristics of the wireless protocol layer and channel to provide specific services, and setting their respective specific parameters and operating methods. RBs can be further divided into two types: SRBs (Signaling Radio Bearers) and DRBs (Data Radio Bearers). SRBs are used as a channel for transmitting RRC messages in the control plane, while DRBs are used as a channel for transmitting user data in the user plane.

[0050] When an RRC connection is established between the RRC layer of the terminal and the RRC layer of the base station, the terminal is in the RRC_CONNECTED state; otherwise, it is in the RRC_IDLE state. For NR, the RRC_INACTIVE state is additionally defined, and a terminal in the RRC_INACTIVE state maintains a connection with the core network while being able to release the connection with the base station.

[0051] Downlink transmission channels for transmitting data from a network to a terminal include a Broadcast Channel (BCH) for transmitting system information and a Shared Channel (SCH) for transmitting user traffic or control messages. Traffic or control messages for downlink multicast or broadcast services may be transmitted via the Shared Channel (SCH) or via a separate Multicast Channel (MCH). Meanwhile, uplink transmission channels for transmitting data from a terminal to a network include a Random Access Channel (RACH) for transmitting initial control messages and a Shared Channel (SCH) for transmitting user traffic or control messages.

[0052] Logical channels that are above the transmission channel and mapped to the transmission channel include BCCH (Broadcast Control Channel), PCCH (Paging Control Channel), CCCH (Common Control Channel), MCCH (Multicast Control Channel), and MTCH (Multicast Traffic Channel).

[0053] A physical channel consists of multiple OFDM symbols in the time domain and multiple subcarriers in the frequency domain. A single subframe consists of multiple OFDM symbols in the time domain. A resource block is a resource allocation unit composed of multiple OFDM symbols and multiple subcarriers. Additionally, each subframe may utilize specific subcarriers of specific OFDM symbols (e.g., the first OFDM symbol) within that subframe for the Physical Downlink Control Channel (PDCCH), i.e., the L1 / L2 control channel. The Transmission Time Interval (TTI) is the unit time for subframe transmission.

[0054] FIG. 5 shows the structure of a wireless frame of NR according to one embodiment of the present disclosure. The embodiment of FIG. 5 can be combined with various embodiments of the present disclosure.

[0055] Referring to FIG. 5, radio frames can be used for uplink and downlink transmission in NR. The radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (HF). A half-frame may contain five 1 ms subframes (SF). A subframe may be divided into one or more slots, and the number of slots within a subframe may be determined by the subcarrier spacing (SCS). Each slot may contain 12 or 14 OFDM(A) symbols according to the cyclic prefix (CP).

[0056] When normal CP is used, each slot may contain 14 symbols. When extended CP is used, each slot may contain 12 symbols. Here, the symbols may include OFDM symbols (or CP-OFDM symbols) and SC-FDMA (Single Carrier - FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0057] Table 1 below shows the number of symbols per slot (Nslotsymb), the number of slots per frame (Nframe,uslot), and the number of slots per subframe (Nsubframe,uslot) according to the SCS setting (u) when normal CP is used.

[0058] SCS (15*2 u ) N slot symb N frame,u slot N subframe,u slot 15KHz (u=0) 14 10 1 30KHz (u=1) 14 20 2 60KHz (u=2) 14 40 4 120KHz (u=3) 14 80 8 240KHz (u=4) 14 160 16

[0059] Table 2 shows the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to the SCS when an extended CP is used.

[0060] SCS (15*2 u ) N slot symb N frame,u slot N subframe,u slot 60KHz (u=2) 12 40 4

[0061] In an NR system, the OFDM(A) numerology (e.g., SCS, CP length, etc.) can be configured differently among multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., subframe, slot, or TTI) (collectively referred to as TU (Time Unit) for convenience) composed of the same number of symbols can be configured differently among the merged cells.

[0062] In NR, multiple numerologies or SCSs may be supported to support various 5G services. For example, if the SCS is 15 kHz, a wide area in traditional cellular bands may be supported, and if the SCS is 30 kHz / 60 kHz, dense-urban, lower latency, and wider carrier bandwidth may be supported. If the SCS is 60 kHz or higher, a bandwidth greater than 24.25 GHz may be supported to overcome phase noise.

[0063] The NR frequency band can be defined by two types of frequency ranges. The two types of frequency ranges may be FR1 and FR2. The numerical values ​​of the frequency ranges may change, for example, as shown in Table 3 below. Among the frequency ranges used in an NR system, FR1 may mean the “sub 6 GHz range” and FR2 may mean the “above 6 GHz range” and may be referred to as millimeter wave (mmW).

[0064] Frequency Range designation Corresponding frequency range Subcarrier Spacing (SCS) FR1 450MHz - 6000MHz 15, 30, 60kHz FR2 24250MHz - 52600MHz 60, 120, 240kHz

[0065] As described above, the numerical value of the frequency range of the NR system may change. For example, FR1 may include a band of 410 MHz to 7125 MHz as shown in Table 4 below. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher. For example, the frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, for example, for communication for vehicles (e.g., autonomous driving).

[0066] Frequency Range designation Corresponding frequency range Subcarrier Spacing (SCS) FR1 410MHz - 7125MHz 15, 30, 60kHz FR2 24250MHz - 52600MHz 60, 120, 240kHz

[0067] FIG. 6 shows a slot structure of an NR frame according to one embodiment of the present disclosure. The embodiment of FIG. 6 can be combined with various embodiments of the present disclosure.

[0068] Referring to FIG. 6, a slot contains multiple symbols in the time domain. For example, in the case of a normal CP, one slot may contain 14 symbols, but in the case of an extended CP, one slot may contain 12 symbols. Alternatively, in the case of a normal CP, one slot may contain 7 symbols, but in the case of an extended CP, one slot may contain 6 symbols.

[0069] A carrier includes multiple subcarriers in the frequency domain. A Resource Block (RB) can be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) can be defined as multiple consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed through the active BWPs. Each element can be referred to as a Resource Element (RE) in a resource grid and can be mapped to a single complex symbol.

[0070] Meanwhile, a wireless interface between terminals or a wireless interface between a terminal and a network may be composed of L1, L2, and L3 layers. In various embodiments of the present disclosure, L1 layer may refer to the physical layer. Additionally, for example, L2 layer may refer to at least one of the MAC layer, RLC layer, PDCP layer, and SDAP layer. Additionally, for example, L3 layer may refer to the RRC layer.

[0071] The Bandwidth Part (BWP) and Carrier are described below.

[0072] A Bandwidth Part (BWP) may be a continuous set of Physical Resource Blocks (PRB) in a given Numenology. A PRB may be selected from a continuous subset of Common Resource Blocks (CRB) for a given Numenology on a given carrier.

[0073] By using Bandwidth Adaptation (BA), the terminal's receiving bandwidth and transmission bandwidth do not need to be as large as the cell's bandwidth, and the terminal's receiving bandwidth and transmission bandwidth can be adjusted. For example, the network / base station can notify the terminal of bandwidth adjustment. For example, the terminal can receive information / settings for bandwidth adjustment from the network / base station. In this case, the terminal can perform bandwidth adjustment based on the received information / settings. For example, the bandwidth adjustment may include reducing / expanding the bandwidth, changing the position of the bandwidth, or changing the subcarrier spacing of the bandwidth.

[0074] For example, bandwidth may be reduced during periods of low activity to save power. For example, the position of bandwidth may be shifted within the frequency domain. For example, the position of bandwidth may be shifted within the frequency domain to increase scheduling flexibility. For example, the subcarrier spacing of bandwidth may be changed. For example, the subcarrier spacing of bandwidth may be changed to allow for different services. A subset of the total cell bandwidth of a cell may be referred to as a Bandwidth Part (BWP). BA can be performed by the base station / network setting the BWP for the terminal and by the base station / network notifying the terminal of the currently active BWP among the set BWPs.

[0075] For example, the BWP may be at least one of an active BWP, an initial BWP, and / or a default BWP. For example, the terminal may not monitor downlink radio link quality on DL BWPs other than the active DL BWP on the PCell (primary cell). For example, the terminal may not receive PDCCH, PDSCH, or CSI-RS (except RRM) outside of the active DL BWP. For example, the terminal may not trigger Channel State Information (CSI) reporting for an inactive DL BWP. For example, the terminal may not transmit PUCCH or PUSCH outside of the active UL BWP. For example, for the downlink, the initial BWP may be given as a successive set of RBs for the RMSI CORESET (set by the PBCH). For example, in the case of an uplink, an initial BWP may be given by the SIB for random access procedures. For example, a default BWP may be set by the upper layer. For example, the initial value of the default BWP may be an initial DL BWP. For energy saving, if a terminal does not detect DCI for a certain period, the terminal may switch its active BWP to the default BWP.

[0076] Meanwhile, a BWP may be defined for an SL. The same SL BWP may be used for transmission and reception. For example, a transmitting terminal may transmit an SL channel or an SL signal on a specific BWP, and a receiving terminal may receive an SL channel or an SL signal on said specific BWP. In a licensed carrier, an SL BWP may be defined separately from a Uu BWP, and the SL BWP may have separate configuration signaling from the Uu BWP. For example, a terminal may receive a configuration for an SL BWP from a base station / network. An SL BWP may be (pre-)configured within the carrier for out-of-coverage NR V2X terminals and RRC_IDLE terminals. For a terminal in RRC_CONNECTED mode, at least one SL BWP may be activated within the carrier.

[0077] FIG. 7 illustrates an example of a BWP according to one embodiment of the present disclosure. The embodiment of FIG. 7 may be combined with various embodiments of the present disclosure. In the embodiment of FIG. 7, it is assumed that there are three BWPs.

[0078] Referring to FIG. 7, the common resource block (CRB) may be a numbered carrier resource block extending from one end of the carrier band to the other. And, the PRB may be a numbered resource block within each BWP. Point A may indicate a common reference point for the resource block grid.

[0079] A BWP can be configured by point A, an offset from point A (NstartBWP), and a bandwidth (NsizeBWP). For example, point A may be an external reference point of the PRB of a carrier where the subcarrier 0 of all numerologies (e.g., all numerologies supported by the network on that carrier) is aligned. For example, the offset may be the PRB interval between the lowest subcarrier in a given numerology and point A. For example, the bandwidth may be the number of PRBs in a given numerology.

[0080] V2X or SL communication will be explained below.

[0081] FIGS. 8A and 8B illustrate a radio protocol architecture for SL communication according to one embodiment of the present disclosure. The embodiment of FIGS. 8A and 8B may be combined with various embodiments of the present disclosure. Specifically, FIG. 8A illustrates a user plane protocol stack, and FIG. 8B illustrates a control plane protocol stack.

[0082] The Sidelink Synchronization Signal (SLSS) and synchronization information are described below.

[0083] SLSS is an SL-specific sequence that may include PSSS (Primary Sidelink Synchronization Signal) and SSSS (Secondary Sidelink Synchronization Signal). The PSSS may be referred to as S-PSS (Sidelink Primary Synchronization Signal), and the SSSS may be referred to as S-SSS (Sidelink Secondary Synchronization Signal). For example, length-127 M-sequences may be used for S-PSS, and length-127 Gold sequences may be used for S-SSS. For example, a terminal may use S-PSS to detect a primary signal and obtain synchronization. For example, a terminal may use S-PSS and S-SSSS to obtain detailed synchronization and detect a synchronization signal ID.

[0084] The PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel through which basic (system) information that the terminal must know first is transmitted before transmitting or receiving SL signals. For example, the basic information may include information related to SLSS, Duplex Mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, information related to resource pools, types of applications related to SLSS, subframe offsets, broadcast information, etc. For example, to evaluate PSBCH performance, in NR V2X, the payload size of the PSBCH may be 56 bits, including a 24-bit CRC.

[0085] S-PSS, S-SSS, and PSBCH may be included in a block format that supports periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP lengths) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) within the carrier, and the transmission bandwidth may be within a (pre-)set SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RB (Resource Block). For example, the PSBCH may span 11 RB. Additionally, the frequency position of the S-SSB may be (pre-)set. Therefore, the terminal does not need to perform hypothesis detection at the frequency to discover the S-SSB in the carrier.

[0086] FIG. 9 shows a terminal performing V2X or SL communication according to one embodiment of the present disclosure. The embodiment of FIG. 9 may be combined with various embodiments of the present disclosure.

[0087] Referring to FIG. 9, in V2X or SL communication, the term terminal may primarily refer to a user's terminal. However, if network equipment such as a base station transmits and receives signals according to the communication method between terminals, the base station may also be considered a type of terminal. For example, terminal 1 may be a first device (100), and terminal 2 may be a second device (200).

[0088] For example, terminal 1 can select a resource unit corresponding to a specific resource within a resource pool, which represents a set of resources. Then, terminal 1 can transmit an SL signal using the said resource unit. For example, terminal 2, which is a receiving terminal, can be configured with a resource pool in which terminal 1 can transmit a signal, and can detect terminal 1's signal within said resource pool.

[0089] Here, if terminal 1 is within the connection range of the base station, the base station may inform terminal 1 of the resource pool. On the other hand, if terminal 1 is outside the connection range of the base station, another terminal may inform terminal 1 of the resource pool, or terminal 1 may use a pre-configured resource pool.

[0090] Generally, a resource pool can be composed of multiple resource units, and each terminal can select one or more resource units to use for its SL signal transmission.

[0091] Resource allocation in SL is explained below.

[0092] FIGS. 10a and 10b illustrate a procedure in which a terminal performs V2X or SL communication according to a transmission mode, according to one embodiment of the present disclosure. The embodiment of FIGS. 10a and 10b may be combined with various embodiments of the present disclosure. In various embodiments of the present disclosure, the transmission mode may be referred to as a mode or a resource allocation mode. Hereinafter, for convenience of explanation, the transmission mode in LTE may be referred to as an LTE transmission mode, and the transmission mode in NR may be referred to as an NR resource allocation mode.

[0093] For example, FIG. 10a illustrates terminal operation related to LTE transmission mode 1 or LTE transmission mode 3. Or, for example, FIG. 10a illustrates terminal operation related to NR resource allocation mode 1. For example, LTE transmission mode 1 can be applied to general SL communication, and LTE transmission mode 3 can be applied to V2X communication.

[0094] For example, FIG. 10b illustrates terminal operation related to LTE transmission mode 2 or LTE transmission mode 4. Or, for example, FIG. 10b illustrates terminal operation related to NR resource allocation mode 2.

[0095] Referring to FIG. 10a, in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, the base station can schedule SL resources to be used by the terminal for SL transmission. For example, the base station can perform resource scheduling to terminal 1 via PDCCH (more specifically, DCI (Downlink Control Information)), and terminal 1 can perform V2X or SL communication with terminal 2 according to the resource scheduling. For example, terminal 1 can transmit sidelink control information to terminal 2 via PSCCH (Physical Sidelink Control Channel), and then transmit data based on the sidelink control information to terminal 2 via PSSCH (Physical Sidelink Shared Channel).

[0096] Referring to FIG. 10b, in LTE transmission mode 2, LTE transmission mode 4, or NR resource allocation mode 2, a terminal can determine an SL transmission resource within an SL resource set by a base station / network or a preset SL resource. For example, the set SL resource or the preset SL resource may be a resource pool. For example, the terminal may autonomously select or schedule a resource for SL transmission. For example, the terminal may perform SL communication by selecting a resource itself within a set resource pool. For example, the terminal may select a resource itself within a selection window by performing a sensing and resource (re)selection procedure. For example, the sensing may be performed on a subchannel basis. Then, terminal 1, having selected a resource itself within the resource pool, can transmit sidelink control information to terminal 2 via PSCCH, and then transmit data based on the sidelink control information to terminal 2 via PSSCH.

[0097] FIGS. 11a to 11c illustrate three cast types according to one embodiment of the present disclosure. The embodiments of FIGS. 11a to 11c may be combined with various embodiments of the present disclosure. Specifically, FIG. 11a illustrates a broadcast type SL communication, FIG. 11b illustrates a unicast type SL communication, and FIG. 11c illustrates a group cast type SL communication. In the case of a unicast type SL communication, a terminal may perform one-to-one communication with another terminal. In the case of a group cast type SL communication, a terminal may perform SL communication with one or more terminals within a group to which it belongs. In various embodiments of the present disclosure, SL group cast communication may be replaced with SL multicast communication, SL one-to-many communication, etc.

[0098] Meanwhile, in sidelink communication, a terminal needs to efficiently select resources for sidelink transmission. Hereinafter, according to various embodiments of the present disclosure, a method for a terminal to efficiently select resources for sidelink transmission and an apparatus supporting the same will be described. In various embodiments of the present disclosure, sidelink communication may include V2X communication.

[0099] According to various embodiments of the present disclosure, at least one proposed method may be applied to at least one of unicast communication, group cast communication, and / or broadcast communication.

[0100] According to various embodiments of the present disclosure, at least one proposed method can be applied not only to sidelink communication or V2X communication based on a PC5 interface or SL interface (e.g., PSCCH, PSSCH, PSBCH, PSSS / SSSS, etc.), but also to sidelink communication or V2X communication based on a Uu interface (e.g., PUSCH, PDSCH, PDCCH, PUCCH, etc.).

[0101] In various embodiments of the present disclosure, the receiving operation of the terminal may include a decoding operation and / or a receiving operation of a sidelink channel and / or a sidelink signal (e.g., PSCCH, PSSCH, PSFCH, PSBCH, PSSS / SSSS, etc.). The receiving operation of the terminal may include a decoding operation and / or a receiving operation of a WAN DL channel and / or a WAN DL signal (e.g., PDCCH, PDSCH, PSS / SSS, etc.). The receiving operation of the terminal may include a sensing operation and / or a CBR measurement operation. In various embodiments of the present disclosure, the sensing operation of the terminal may include a PSSCH-RSRP measurement operation based on a PSSCH DM-RS sequence, a PSSCH-RSRP measurement operation based on a PSSCH DM-RS sequence scheduled by a PSCCH successfully decoded by the terminal, an S-RSSI (sidelink RSSI) measurement operation, and / or an S-RSSI measurement operation based on a V2X resource pool-related subchannel. In various embodiments of the present disclosure, the transmission operation of the terminal may include a transmission operation of a sidelink channel and / or a sidelink signal (e.g., PSCCH, PSSCH, PSFCH, PSBCH, PSSS / SSSS, etc.). The transmission operation of the terminal may include a transmission operation of a WAN UL channel and / or a WAN UL signal (e.g., PUSCH, PUCCH, SRS, etc.). In various embodiments of the present disclosure, the synchronization signal may include SLSS and / or PSBCH.

[0102] In various embodiments of the present disclosure, a setting may include signaling, signaling from a network, a setting from a network, and / or a preset from a network. In various embodiments of the present disclosure, a definition may include signaling, signaling from a network, a setting from a network, and / or a preset from a network. In various embodiments of the present disclosure, a designation may include signaling, signaling from a network, a setting from a network, and / or a preset from a network.

[0103] In various embodiments of the present disclosure, PPPP (ProSe Per Packet Priority) may be replaced with PPPR (ProSe Per Packet Reliability), and PPPR may be replaced with PPPP. For example, a smaller PPPP value may indicate a higher priority, and a larger PPPP value may indicate a lower priority. For example, a smaller PPPR value may indicate higher reliability, and a larger PPPR value may indicate lower reliability. For example, a PPPP value associated with a high priority service, packet, or message may be smaller than a PPPP value associated with a low priority service, packet, or message. For example, a PPPR value associated with a high reliability service, packet, or message may be smaller than a PPPR value associated with a low reliability service, packet, or message.

[0104] Meanwhile, in various embodiments of the present disclosure, a high priority may mean a small priority value, and a low priority may mean a large priority value. For example, Table 5 shows an example of a priority.

[0105] Service or logical channel Priority value Service A or Logical Channel A 1 Service B or Logical Channel B 2 Service C or Logical Channel C 3

[0106] Referring to Table 5, for example, the priority of Service A or Logical Channel A associated with the smallest priority value may be the highest. For example, the priority of Service C or Logical Channel C associated with the largest priority value may be the lowest.

[0107] In various embodiments of the present disclosure, a session may include at least one of a unicast session (e.g., a unicast session for a sidelink), a groupcast / multicast session (e.g., a groupcast / multicast session for a sidelink), and / or a broadcast session (e.g., a broadcast session for a sidelink).

[0108] In various embodiments of the present disclosure, a carrier may be mutually extended to at least one of a BWP and / or a resource pool. For example, a carrier may include at least one of a BWP and / or a resource pool. For example, a carrier may include one or more BWPs. For example, a BWP may include one or more resource pools.

[0109] Meanwhile, NR V2X in Release 16 did not support power saving operations for UE (user equipment), and NR V2X in Release 17 is scheduled to support power saving operations for UE.

[0110] Meanwhile, in a discontinuous reception (Uu DRX) operation according to one embodiment, timers such as drx-HARQ-RTT-TimerDL, drx-HARQ-RTT-TimerUL, drx-RetransmissionTimerDL, and drx-RetransmissionTimerUL are defined to ensure that when performing UE HARQ retransmission, the system transitions to sleep mode while the round trip time (RTT) timers (drx-HARQ-RTT-TimerDL, drx-HARQ-RTT-TimerUL) are operating, or maintains an active state while the retransmission timers (drx-RetransmissionTimerDL, drx-RetransmissionTimerUL) are operating.

[0111] In the present disclosure, in one embodiment, a method is proposed to perform a power saving operation when a UE performs retransmission for a Transport Block in NR V2X by defining “Sidelink drx-HARQ-RTT-Timer-TX” and “Sidelink drx-RetransmissionTimer-TX”.

[0112] In one embodiment of the present disclosure, a method is proposed for a UE to perform a power saving operation based on the following sidelink DRX configuration. More specifically, the present disclosure proposes a method of operation for “Sidelink drx-HARQ-RTT-Timer-TX” and “Sidelink drx-RetransmissionTimer-TX” that can be applied to enable the UE to operate in sleep mode or active mode during Uu DRX operation or sidelink DRX operation.

[0113] The “Sidelink drx-HARQ-RTT-Timer-TX” and “Sidelink drx-RetransmissionTimer-TX” proposed in the present disclosure may be timers for supporting an operation in which the UE stays in active mode to receive a signal from a base station and an operation in which the UE stays in sleep mode to not receive a signal from a base station. Alternatively, the “Sidelink drx-HARQ-RTT-Timer-TX (or SL drx-HARQ-RTT-Timer-TX, first timer, etc.)” and “Sidelink drx-RetransmissionTimer-TX (or SL drx-RetransmissionTimer-TX, second timer, etc.)” proposed in the present disclosure may be timers for supporting an operation in which the UE stays in active mode to receive a signal from a sidelink and an operation in which the UE stays in sleep mode to not receive a signal from a sidelink. In the following description, monitoring a specific channel (e.g., PDCCH, PSCCH, PSSCH, PSFCH) may mean receiving the specific channel, performing (blind) decoding, or attempting to decode.

[0114] An example of a sidelink DRX configuration is shown in Table 6 below.

[0115]

[0116] Referring to Table 6, SL drx-RetransmissionTimer-TX according to one example may represent the maximum time interval until a grant for sidelink retransmission is received. For example, the SL drx-RetransmissionTimer-TX timer is a timer that starts when the SL drx-HARQ-RTT-Timer-TX timer expires, and may be a timer that causes the TX UE to transition to an active state for HARQ retransmission. From the start of SL drx-RetransmissionTimer-TX, the TX UE begins monitoring whether retransmission resources to the RX UE (e.g., a grant for sidelink retransmission) are ready, and when the retransmission resources are ready, it can perform a sidelink HARQ retransmission to the RX UE. When the HARQ retransmission packet is sent to the RX UE, the TX UE can stop the SL drx-RetransmissionTimer-TX timer. The UE can remain active while the SL drx-RetransmissionTimer-TX timer is running.

[0117] Referring to Table 6, SL drx-HARQ-RTT-Timer-TX according to one example can represent the minimum time interval until a sidelink HARQ retransmission grant is expected by the MAC entity. That is, resources for sidelink HARQ retransmission cannot be prepared until the SL drx-HARQ-RTT-Timer-TX timer expires. Therefore, the TX UE can reduce power consumption by transitioning to sleep mode while the SL drx-HARQ-RTT-Timer-TX timer is operating. When the SL drx-HARQ-RTT-Timer-TX timer expires, the TX UE determines that a resource for SL retransmission may be ready, starts the SL drx-RetransmissionTimer-TX timer, and can monitor whether a resource for SL HARQ retransmission is received (since the SL HARQ retransmission resource may or may not be received immediately upon the expiration of the SL drx-HARQ-RTT-Timer-TX timer, the TX UE can start the SL drx-RetransmissionTimer-TX timer and monitor whether a resource for SL HARQ retransmission is received).

[0118] In some of the following embodiments, a method may be provided for a TX UE performing sidelink communication to save power based on the operation of SL drx-HARQ-RTT-Timer-TX and SL drx-RetransmissionTimer-TX.

[0119] In one embodiment, the SL drx-HARQ-RTT-Timer-TX and SL drx-RetransmissionTimer-TX operated by the TX UE may be timers for performing Uu DRX operations in relation to the base station. Through the Uu DRX operations, monitoring of, for example, a PDCCH (Physical Downlink Control Channel) (or DCI (Downlink Control Information) transmitted through the PDCCH) may be controlled.

[0120] In another embodiment, the SL drx-HARQ-RTT-Timer-TX and SL drx-RetransmissionTimer-TX operated by the TX UE may be timers operated for the purpose of synchronizing with the SL drx-HARQ-RTT-Timer-RX and / or SL drx-RetransmissionTimer-RX operated by the Rx UE for the operation of the Rx UE's SL DRX. That is, the TX UE may determine / recognize / consider that the RX UE has (re)started or stopped the SL drx-HARQ-RTT-Timer-RX and / or SL drx-RetransmissionTimer-RX if the following conditions are satisfied.

[0121] In one embodiment, when the SL drx-HARQ-RTT-Timer-TX and SL drx-RetransmissionTimer-TX operated by the TX UE are timers for performing Uu DRX operations in relation to the base station, the operation is between three devices: the UE (Tx UE), the UE (Rx UE), and the base station, and can be (clearly) distinguished from the prior art (Uu DRX operation between the UE and the base station, i.e., two devices) (or another embodiment). For example, some embodiments according to the present disclosure involve the Tx UE initiating SL drx-HARQ-RTT-Timer-TX when it receives a PSFCH (HARQ feedback NACK or ACK) from the Rx UE, not monitoring the Uu signal (e.g., PDCCH), or entering Uu sleep mode (during the RTT period); and when SL drx-HARQ-RTT-Timer-TX expires, initiating SL drx-RetransmissionTimer-TX and monitoring a Mode 1 SL grant from the base station (during the retransmission timer period) (between the three devices of the Tx UE, Rx UE, and base station). In the prior art (or other embodiment), when the UE transmits DL HARQ feedback to the base station, it initiates the Uu DRX HARQ RTT timer and does not monitor the Uu signal (e.g., PDCCH) or enters Uu sleep mode (during the RTT period); and when the Uu DRX HARQ RTT timer expires, it initiates the retransmission timer and monitors the DL from the base station It can be clearly distinguished from the content of monitoring assignment (during the retransmission timer period) (between the UE and the base station).

[0122] In another embodiment, when the SL drx-HARQ-RTT-Timer-TX and SL drx-RetransmissionTimer-TX operated by the TX UE are timers for performing Uu DRX operations in relation to the base station, the TX UE can perform monitoring operations for the PDCCH (Physical Downlink Control Channel) including the Mode 1 SL retransmission grant as shown in Table 7 below.

[0123]

[0124] In one embodiment (or, in the first embodiment), the TX UE may initiate SL drx-HARQ-RTT-Timer-TX after receiving HARQ NACK feedback from the RX UE after transmitting SCI (sidelink control information) and / or PSSCH (sidelink data) to the RX UE. The TX UE may transition to sleep mode and maintain a sleep state until SL drx-HARQ-RTT-Timer-TX expires. When the SL drx-HARQ-RTT-Timer-TX timer expires, the TX UE transitions to an active state, starts the SL drx-RetransmissionTimer-TX timer, and monitors whether resources for sidelink HARQ retransmission (retransmission resources allocated by the base station to the TX UE) are ready (retransmission resources dynamically allocated by the base station, or configured grant type 1 or configured grant type 2 resources allocated via an RRC message). When resources for sidelink HARQ retransmission are received, the TX UE can send a sidelink HARQ retransmission packet to the RX UE and stop the SL drx-RetransmissionTimer-TX timer. If the TX UE receives a HARQ NACK from the RX UE for a sidelink HARQ retransmission, it may restart SL drx-HARQ-RTT-Timer-TX and transition to sleep mode. Then, when the SL drx-HARQ-RTT-Timer-TX timer expires, it may transition to an active state, restart the SL drx-RetransmissionTimer-TX timer, and monitor whether a resource for a sidelink HARQ retransmission is received.

[0125] In one embodiment (or, in a second embodiment), if the TX UE does not receive HARQ feedback (HARQ ACK or NACK) from the RX UE after transmitting SCI and PSSCH (sidelink data) to the RX UE (HARQ DTX (discontinuous transmission) occurs), it may initiate SL drx-HARQ-RTT-Timer-TX. At this time, the TX UE may transmit SL HARQ NACK to the base station via PUCCH to request retransmission resources. The TX UE may transition to sleep mode and maintain a sleep state until SL drx-HARQ-RTT-Timer-TX expires. When the SL drx-HARQ-RTT-Timer-TX timer expires, the TX UE transitions to an active state, initiates the SL drx-RetransmissionTimer-TX timer, and monitors whether resources for sidelink HARQ retransmission (retransmission resources allocated by the base station to the TX UE) are ready (retransmission resources dynamically allocated by the base station or configured grant type 1 or configured grant type 2 resources allocated via an RRC message). When resources for sidelink HARQ retransmission are ready, the TX UE can send an SL HARQ retransmission packet to the RX UE and stop the SL drx-RetransmissionTimer-TX timer. If the TX UE does not receive HARQ feedback (HARQ ACK or HARQ NACK) for the Sidelink HARQ retransmission, it resumes SL drx-HARQ-RTT-Timer-TX, transmits SL HARQ NACK to the base station via PUCCH, and then transitions to sleep mode. Then, when the SL drx-HARQ-RTT-Timer-TX timer expires, the TX UE transitions to an active state, restarts the SL drx-RetransmissionTimer-TX timer, and can monitor whether resources are ready for the Sidelink HARQ retransmission.Tx UE may transition to sleep mode if SL drx-HARQ-RTT-Timer-TX / SL drx-RetransmissionTimer-TX is not executed or if SL drx-HARQ-RTT-Timer-TX / SL drx-RetransmissionTimer-TX is in operation.

[0126] In one embodiment (or, in a third embodiment), the TX UE may initiate SL drx-HARQ-RTT-Timer-TX when it transmits SCI and PSSCH (sidelink data) to the RX UE, or receives a HARQ NACK from the RX UE after transmitting PSSCH (Sidelink Data) to the RX UE, or transmits a HARQ NACK to the base station via PUCCH (i.e., a request for retransmission resources for sidelink retransmission) because it fails to receive HARQ feedback (SL HARQ ACK or SL HARQ NACK) after transmitting PSSCH (Sidelink Data) to the RX UE (HARQ DTX occurs). The TX UE may transition to sleep mode and maintain a sleep state until SL drx-HARQ-RTT-Timer-TX expires. When the SL drx-HARQ-RTT-Timer-TX timer expires, the TX UE transitions to an active state, initiates the SL drx-RetransmissionTimer-TX timer, and monitors whether resources for sidelink HARQ retransmission (retransmission resources allocated to the TX UE by the base station) are received. When resources for sidelink HARQ retransmission are received, the TX UE can send an SL HARQ retransmission packet to the RX UE and stop the SL drx-RetransmissionTimer-TX timer. If the TX UE receives a HARQ NACK from the RX UE regarding the sidelink HARQ retransmission, it can send the HARQ NACK to the base station via PUCCH, resume SL drx-HARQ-RTT-Timer-TX, and transition to sleep mode. And when the SL drx-HARQ-RTT-Timer-TX timer expires, it transitions to an active state to restart the SL drx-RetransmissionTimer-TX timer and monitor whether resources for sidelink HARQ retransmission are received.Additionally, when the Tx UE receives SL HARQ NACKs from the Rx UE up to the maximum threshold value, it may not initiate SL drx-HARQ-RTT-Timer-TX / SL drx-RetransmissionTimer-TX, or if SL drx-HARQ-RTT-Timer-TX / SL drx-RetransmissionTimer-TX is in operation, it may stop it and transition to sleep mode. It may also transmit SL HARQ ACKs to the PUCCH to indicate to the base station that retransmission resources are no longer needed.

[0127] In one embodiment (or, in a fourth embodiment), if the TX UE has used up all currently allocated resources (e.g., Mode 1 dynamic scheduling-based resources or Sidelink Configured Grant resources) while performing HARQ retransmission for the PSSCH transmitted to the RX UE but has not reached the maximum number of retransmissions, it may transmit a PUCCH to the base station to transmit a HARQ NACK for requesting Sidelink retransmission resources. If there is a PUCCH resource available for transmitting a HARQ NACK, the TX UE may transmit a PUCCH (e.g., may include a HARQ NACK for requesting Sidelink resources) to the base station and initiate SL drx-HARQ-RTT-Timer-TX. The TX UE may transition to sleep mode and maintain a sleep state until SL drx-HARQ-RTT-Timer-TX expires. When the SL drx-HARQ-RTT-Timer-TX timer expires, the TX UE transitions to an active state, initiates the SL drx-RetransmissionTimer-TX timer, and monitors whether resources for sidelink HARQ retransmission (retransmission resources allocated by the base station to the TX UE) are received. When resources for sidelink HARQ retransmission are received, the TX UE can send an SL HARQ retransmission packet to the RX UE and stop the SL drx-RetransmissionTimer-TX timer. If the TX UE receives a HARQ NACK related to sidelink HARQ retransmission from the RX UE and there are PUCCH resources for transmitting the HARQ NACK, the TX UE can send a PUCCH (e.g., including a HARQ NACK for a sidelink resource request) to the base station, resume SL drx-HARQ-RTT-Timer-TX, and transition to sleep mode.And, when the SL drx-HARQ-RTT-Timer-TX timer expires, the TX UE transitions to an active state to restart the SL drx-RetransmissionTimer-TX timer and monitors whether resources for sidelink HARQ retransmission are received.

[0128] In one embodiment (or in the fifth embodiment), if the TX UE has used up all currently allocated resources (e.g., Mode 1 dynamic scheduling-based resources or Sidelink Configured Grant resources) while performing HARQ retransmission for the PSSCH transmitted to the RX UE but has not reached the maximum number of retransmissions, it may transmit a PUCCH to transmit a HARQ NACK to the base station for requesting Sidelink retransmission resources. If the TX UE does not have PUCCH resources to transmit the HARQ NACK and therefore cannot report the HARQ NACK (for the PSSCH) to the base station, it may not initiate SL drx-HARQ-RTT-Timer-TX. Additionally, even if there is a remaining SL DRX On-Duration period (or if operating in SL Active Time), it may transition to sleep mode to reduce power consumption.

[0129] In one embodiment (or, in the sixth embodiment), if there are no Mode 1 resources for sidelink transmission (SR / BSR-based resources or RRC signaling-based configured grant resources), the TX UE may switch to a Mode 2 resource allocation method and perform retransmission of the Transport Block transmitted to the RX UE. In this case, when the TX UE switches to a Mode 2 resource allocation method, the TX UE may initiate SL drx-HARQ-RTT-Timer-TX. The TX UE may transition to sleep mode and maintain a sleep state until SL drx-HARQ-RTT-Timer-TX expires. When SL drx-HARQ-RTT-Timer-TX expires, the TX UE can restart the SL drx-RetransmissionTimer-TX timer, perform a sidelink HARQ retransmission when a mode 2 resource for sidelink HARQ retransmission is ready, and stop the SL drx-RetransmissionTimer-TX timer.

[0130] In one embodiment (or, in the seventh embodiment), while performing HARQ retransmission for the PSSCH transmitted by the TX UE to the RX UE, if the maximum number of retransmissions has not been reached but there is no PUCCH resource available to transmit a HARQ NACK to request a sidelink retransmission resource from the base station, the TX UE may switch to a Mode 2 resource allocation method and perform retransmission for the transmission block transmitted to the RX UE. In this case, when the TX UE switches to a Mode 2 resource allocation method, the TX UE in this embodiment may initiate SL drx-HARQ-RTT-Timer-TX. The TX UE may transition to sleep mode and maintain a sleep state until SL drx-HARQ-RTT-Timer-TX expires. When SL drx-HARQ-RTT-Timer-TX expires, the TX UE may restart the SL drx-RetransmissionTimer-TX timer, perform a sidelink HARQ retransmission when a Mode 2 resource for the sidelink HARQ retransmission is ready, and stop the SL drx-RetransmissionTimer-TX timer. Alternatively, when the Mode 2 resource allocation method is changed, the TX UE may not start drx-HARQ-RTT-Timer-TX and may remain active until the retransmission is performed.

[0131] In one embodiment (or, in the eighth embodiment), if the TX UE does not receive HARQ feedback (SL HARQ ACK or SL HARQ NACK) from the RX UE after transmitting PSCCH and / or PSSCH (sidelink data) to the RX UE or after transmitting PSSCH (sidelink data) to the RX UE (SL HARQ DTX occurs), it may report the SL HARQ DTX occurrence from the physical layer to the MAC layer and initiate SL drx-HARQ-RTT-Timer-TX. The TX UE transitions to sleep mode and remains in a sleep state until SL drx-HARQ-RTT-Timer-TX expires. When the SL drx-HARQ-RTT-Timer-TX timer expires, the TX UE transitions to an active state, starts the SL drx-RetransmissionTimer-TX timer, and monitors whether resources for sidelink HARQ retransmission (retransmission resources allocated by the base station to the TX UE) are ready (e.g., retransmission resources dynamically allocated by the base station or configured grant type 1 or configured grant type 2 resources allocated via an RRC message). When resources for sidelink HARQ retransmission are ready, the TX UE transmits an SL HARQ retransmission packet to the RX UE and stops the SL drx-RetransmissionTimer-TX timer. If the TX UE does not receive HARQ feedback (SL HARQ ACK or SL HARQ NACK) for the sidelink HARQ retransmission (PSCCH / PSSCH), it may report the occurrence of SL HARQ DTX from the physical layer to the MAC layer, resume SL drx-HARQ-RTT-Timer-TX, and transition to sleep mode.And when the SL drx-HARQ-RTT-Timer-TX timer expires, it transitions to an active state to restart the SL drx-RetransmissionTimer-TX timer and monitor whether resources are ready for sidelink HARQ retransmission.

[0132] In one embodiment (or, in the ninth embodiment), the TX UE must monitor the SL HARQ feedback (SL HARQ ACK or SL HARQ NACK) transmitted by the RX UE after transmitting PSCCH (SCI) and / or PSSCH (sidelink data) to the RX UE, but may initiate SL drx-HARQ-RTT-Timer-TX even if it failed to monitor PSFCH due to a half-duplex problem (a problem that occurs when a terminal cannot transmit and receive simultaneously) (if there had been no half-duplex problem, it could have monitored PSFCH and received the SL HARQ feedback transmitted by the RX UE). (Since it could have monitored PSFCH and received the SL HARQ feedback transmitted by the RX UE if there had been no half-duplex problem, it must initiate the SL drx-HARQ-RTT-Timer-TX timer). The TX UE may transition to sleep mode and remain in a sleep state until the SL drx-HARQ-RTT-Timer-TX expires. When the SL drx-HARQ-RTT-Timer-TX timer expires, the TX UE transitions to an active state, initiates the SL drx-RetransmissionTimer-TX timer, and monitors whether resources for sidelink HARQ retransmission (retransmission resources allocated by the base station to the TX UE) are ready (retransmission resources dynamically allocated by the base station or configured grant type 1 or configured grant type 2 resources allocated via an RRC message). When resources for sidelink HARQ retransmission are ready, the TX UE can send an SL HARQ retransmission packet to the RX UE and stop the SL drx-RetransmissionTimer-TX timer. And the TX UE can monitor the PSFCH to receive SL HARQ feedback (SL HARQ ACK or SL HARQ NACK) transmitted by the RX UE.

[0133] FIG. 12 illustrates an example of a method for a TX UE to save power consumption for sidelink communication according to one embodiment.

[0134] More specifically, FIG. 12 illustrates an example of a method for a TX UE to save power based on the operation of SL drx-HARQ-RTT-Timer-TX and SL drx-RetransmissionTimer-TX, as proposed in some of the embodiments of the present disclosure.

[0135] As shown in FIG. 12, when the TX UE transmits PSSCH to the RX UE or receives a HARQ NACK from the RX UE after transmitting PSSCH to the RX UE, it may initiate SL drx-HARQ-RTT-Timer-TX and transition to sleep mode until SL resources for retransmission are ready (until SL drx-HARQ-RTT-Timer-TX expires). When SL drx-HARQ-RTT-Timer-TX expires (when retransmission resources are ready), the TX UE may transition back to the active state and initiate SL DRX Retransmission timer-TX. Then, when retransmission is performed through the retransmission resources for the transmission block determined by the HARQ NACK, it may stop SL DRX Retransmission timer-TX, initiate SL DRX HARQ RTT timer-TX, and transition to sleep state.

[0136] FIG. 13 illustrates another example of a method for a TX UE to save power consumption for sidelink communication according to another embodiment.

[0137] More specifically, FIG. 13 illustrates another embodiment of a method for a TX UE to save power based on the operation of SL drx-HARQ-RTT-Timer-TX and SL drx-RetransmissionTimer-TX, as proposed in some of the embodiments of the present disclosure.

[0138] As shown in Fig. 13, if the TX UE receives a HARQ NACK from the RX UE after transmitting a PSSCH to the RX UE, or if it does not receive HARQ feedback (HARQ DTX occurs), and if there are no more allocated SL retransmission resources, it can request sidelink retransmission resources by reporting the HARQ NACK to the base station via PUCCH. However, if there are no PUCCH resources among the allocated resources, the TX UE cannot report the HARQ NACK to the base station and thus cannot be allocated retransmission resources. Therefore, in this case (where the maximum number of retransmissions remains, but there are no sidelink retransmission resources and no PUCCH resources to request sidelink retransmission resources), the TX UE can transition to sleep mode to reduce power consumption.

[0139] FIG. 14 illustrates another example of a method for a TX UE to save power consumption for sidelink communication according to another embodiment.

[0140] More specifically, FIG. 14 illustrates another embodiment of a method for a TX UE to save power based on the operation of SL drx-HARQ-RTT-Timer-TX and SL drx-RetransmissionTimer-TX, as proposed in some of the embodiments of the present disclosure.

[0141] As shown in FIG. 14, if the TX UE receives a HARQ NACK from the RX UE after transmitting a PSSCH to the RX UE and there are no Mode 1 resources available, it can switch to the Mode 2 resource allocation method to continue sidelink communication. If the TX UE receives a HARQ NACK from the RX UE and there are no Mode 1 resources available, it can switch to the Mode 2 resource allocation mode and simultaneously start SL DRX HARQ RTT-TX and transition to sleep mode until SL resources for retransmission are ready (until SL drx-HARQ-RTT-Timer-TX expires). When SL drx-HARQ-RTT-Timer-TX expires (Mode 2 retransmission resources are ready), the TX UE can transition back to the active state and start SL drx-RetransmissionTimer-TX. Then, when retransmission is performed through the mode 2 retransmission resource for the transmission block determined by HARQ NACK, SL drx-RetransmissionTimer-TX is stopped, SL drx-HARQ-RTT-Timer-TX is initiated, and the system can transition to a sleep state.

[0142] In some embodiments of the present disclosure, even if the current sidelink DRX time is a sidelink DRX off-duration period (e.g., a period during which the sidelink signal is not sensed / monitored / received / transmitted), if the following conditions are satisfied, the UE (TX UE or RX UE) remains active for a certain period of time (Predefined time, Predefined Timer, “Sidelink DRX-RTTTimer: the time during which resources for the UE (TX UE or RX UE)’s sidelink retransmission are prepared or the minimum time during which sidelink retransmission is expected (a time during which the UE can operate in sleep mode expecting that a sidelink retransmission will not be transmitted from the counterpart UE before the expiration of said time)”, “Sidelink DRX-RetransmissionTimer: the time during which the UE (TX UE or RX UE) monitors the sidelink retransmission packet transmitted by the counterpart UE or the time during which retransmission is performed using sidelink retransmission resources”, and otherwise the UE (TX UE or RX UE) remains active for the duration of the timer during the sidelink DRX off-duration period. It can be made to operate in an active state / time (e.g., a period during which sidelink signals can be sensed / transmitted / received) during a Timer defined to operate in a state / time.

[0143] The condition according to one example (or, the first condition) is when the sidelink congestion level is above a certain threshold.

[0144] A condition according to one example (or a second condition) is when Sidelink TX data with a Sidelink Priority greater than or equal to a threshold is buffered in the TX UE's buffer during the Sidelink DRX off-duration (a period during which the Sidelink signal is not sensed / monitored / received / transmitted).

[0145] A condition according to one example (or a third condition) is when the TX UE receives a PSFCH (e.g., the PSFCH may include a sidelink HARQ NACK) for the PSCCH / PSSCH transmitted from the RX UE above a threshold.

[0146] A condition according to one example (or a fourth condition) is when a sidelink DTX (e.g., when a sidelink HARQ ACK or NACK is not received, or when a PSFCH is not monitored) for a PSCCH / PSSCH transmitted by the TX UE from the RX UE occurs above a threshold.

[0147] The condition according to the example (or, the fifth condition) is that the number of remaining transfers in the maximum number of transfers of 1 TB (transport block) transmitted by the TX UE does not exceed the threshold, that is, the number of remaining transfers in the maximum number of transfers of 1 TB is small. That is, for example, the difference between the maximum number of transfers possible of the said transfer block and the current number of transfers is less than or equal to the threshold.

[0148] In one embodiment, the sidelink DRX timers mentioned in some embodiments of the present disclosure (or related to some embodiments) are, for example, as follows.

[0149] - Sidelink DRX Duration Timer: Refers to the period during which a UE performing a sidelink DRX operation must operate in an active time / state by default to receive PSCCH / PSSCH from the other UE.

[0150] - Sidelink DRX Inactivity Timer: This refers to the period during which the Sidelink DRX Onduration Timer is extended, which is the period during which a UE performing Sidelink DRX operations must operate in an active time / state by default to receive PSCCH / PSSCH from the other UE. In other words, the Sidelink DRX Onduration Timer can be extended by the duration of the Sidelink DRX Inactivity Timer. Additionally, when the UE receives a new packet (new PSSCH transmission) from the other UE, it can start the Sidelink DRX Inactivity Timer to extend the Sidelink DRX Onduration Timer.

[0151] - Sidelink DRX HARQ RTT Timer: This refers to the period during which a UE performing a sidelink DRX operation operates in sleep mode until it receives a retransmission packet (or PSSCH allocation) transmitted by the other UE. In other words, when a UE starts the Sidelink DRX HARQ RTT Timer, it determines that the other UE will not send a sidelink retransmission packet to it until the Sidelink DRX HARQ RTT Timer expires, and it may operate in sleep mode during that timer.

[0152] - Sidelink DRX Retransmission Timer: Refers to the period during which a UE performing a sidelink DRX operation operates in an active time / state to receive retransmission packets (or PSSCH assignments) transmitted by the other UE. During this timer period, the UE can monitor the reception of retransmission sidelink packets (or PSSCH assignments) transmitted by the other UE.

[0153] In the above description, the names of the timers (Uu DRX HARQ RTT TimerSL, Uu DRX Retransmission TimerSL, Sidelink DRX Onduration Timer, Sidelink DRX Inactdivity Timer, Sidelink DRX HARQ RTT Timer, Sidelink DRX Retransmission Timer, etc.) are exemplary, and timers that perform the same or similar functions based on the description of each timer may be considered the same or similar timers regardless of their names.

[0154] In one embodiment, the proposal included in some embodiments of the present disclosure is a solution that can be applied and extended to solve the problem of loss caused by interruption occurring during the switching of the Uu Bandwidth Part (BWP).

[0155] In addition, this solution can be applied and extended to resolve the problem of loss caused by interference during the switching of the Sidelink Bandwidth Part (BWP) when the terminal supports Sidelink Multiple Bandwidth Part (BWP).

[0156] The proposals included in some embodiments of the present disclosure may be extended to include not only the Default / Common Sidelink DRX configuration or the Default / Common Sidelink DRX pattern or the parameters (and timers) included in the Default / Common Sidelink DRX configuration, but also the UE-Pair Specific Sidelink DRX configuration or the UE-Pair Specific Sidelink DRX pattern or the parameters (and timers) included in the UE-Pair Specific Sidelink DRX configuration. Additionally, the term "onduration" mentioned in the proposals included in some embodiments of the present disclosure may be interpreted to extend to the active time period (a period during which the device operates in a wake-up state (RF module is “On”) to receive / transmit wireless signals), and the term "offduration" may be interpreted to extend to the sleep time period (a period during which the device operates in a sleep mode state (RF module is “Off”) for power saving; the TX UE is not obligated to operate in sleep mode during the sleep time period. If necessary, it is permitted to operate in active time for a short period for sensing operations / transmission operations even during sleep time). In addition, “the applicability of (some) of the proposed methods / rules of the present disclosure and / or related parameters (e.g., thresholds) may be specifically (or differently or independently) configured depending on the resource pool, congestion level, service priority (and / or type), QoS requirements (e.g., latency, reliability) or PQI, traffic type (e.g., (non)periodic generation), Sidelink transport resource allocation mode (mode 1, mode 2), etc.”

[0157] For example, the applicability of proposed rules (and / or related parameter setting values) included in some embodiments of the present disclosure depends on the resource pool, service / packet type (and / or priority), QoS requirements (e.g., URLLC / EMBB traffic, reliability, latency), PQI, cast type (e.g., unicast, groupcast, broadcast), (resource pool) congestion level (e.g., CBR), SL HARQ feedback method (e.g., NACK Only feedback, ACK / NACK feedback), whether HARQ Feedback Enabled MAC PDU (and / or HARQ Feedback Disabled MAC PDU) is transmitted, whether PUCCH-based SL HARQ feedback reporting behavior is configured, whether Pre-emption (and / or Re-Evaluation) is performed (or resource reselection based on), (L2 or L1) (Source and / or Destination) identifier, (L2 or L1) (combination of Source layer ID and Destination layer ID) identifier, (L2 or L1) (Source layer ID and Destination For at least one of the following: an identifier (combination of layer ID pair and Cast type), the direction of the Source layer ID and Destination layer ID pair, PC5 RRC connection / link, SL DRX execution case, SL mode type (resource allocation mode 1, resource allocation mode 2), and (non)periodic resource reservation execution case, it may be specifically (and / or independently and / or differently) configured.

[0158] The term “certain time” mentioned in the proposal of the present disclosure may refer to a time during which a UE operates in an active time for a predefined amount of time to receive a sidelink signal or sidelink data from a counterpart UE, or for a time or a specific timer (Sidelink DRX Retransmission Timer or Sidelink DRX Inactivity Timer or a timer that ensures the UE can operate in an active time during the DRX operation of the RX UE).

[0159] In addition, the proposal of the present invention and whether the proposal rules are applied (and / or related parameter setting values) may also be applied to mmWave sidelink operations.

[0160] According to various embodiments of the present disclosure, a TX UE operating as a sidelink DRX can remain in active mode and continue to perform sidelink transmission without transitioning to sleep mode if it satisfies conditions where it is determined that the transmission and reception of sidelink data is necessary, even if its sidelink DRX onduration period has expired. Additionally, it can transition to sleep mode to reduce power consumption if it satisfies conditions where it is determined that the transmission and reception of sidelink data is not necessary.

[0161] Various embodiments of the present disclosure may be combined with the synchronization operation of the terminal and / or the SL HARQ feedback operation of the terminal.

[0162] Meanwhile, in some embodiments according to the present disclosure below, a method is proposed in which an RX UE in NR V2X receives a transmission block for sidelink communication from a TX UE, and performs a power saving operation according to the status of HARQ feedback (HARQ ACK, HARQ NACK, HARQ DTX) for the received transmission block (TB).

[0163] Table 8 below shows another example of a sidelink DRX setup.

[0164]

[0165] Referring to Table 8, SL drx-RetransmissionTimer-RX according to one embodiment may represent a maximum time interval until PSCCH (sidelink control information) and PSSCH for SL HARQ retransmission are received. For example, SL drx-RetransmissionTimer-RX may be defined as the time during which the RX UE monitors PSCCH and / or PSSCH to receive SL HARQ retransmission transmitted by the TX UE. When the SL drx-HARQ-RTT-Timer-RX timer expires, the RX UE transitions to an active state and starts the SL drx-RetransmissionTimer-RX timer to begin the operation of receiving PSCCH and / or PSSCH for SL HARQ retransmission transmitted by the TX UE. If the SL drx-RetransmissionTimer-RX timer receives an SL HARQ retransmission transmitted by the TX UE while the SL drx-RetransmissionTimer-RX timer is running, the RX UE can stop the SL drx-RetransmissionTimer-RX timer.

[0166] Referring to Table 8, SL drx-HARQ-RTT-Timer-RX according to one embodiment may represent a minimum time interval until a PSSCH (sidelink control information) and / or a PSSCH for SL HARQ retransmission is expected by the MAC entity of the RX UE. For example, SL drx-HARQ-RTT-Timer-RX may be defined as the minimum time required to monitor the PSCCH and / or PSSCH for the sidelink HARQ retransmission packet transmitted by the TX UE when the MAC entity of the RX UE receives and successfully decodes the PSCCH (sidelink control information) transmitted by the TX UE, but fails to decode the received PSSCH (sidelink data) and transmits a HARQ NACK to the TX UE. That is, this may mean that PSCCH and / or PSSCH for SL HARQ retransmission are not delivered from the TX UE before SL drx-HARQ-RTT-Timer-RX expires. The RX UE may operate in sleep mode while SL drx-HARQ-RTT-Timer-RX is running, and when SL drx-HARQ-RTT-Timer-RX expires, it may transition to an active state and start the SL drx-RetransmissionTimer-RX timer.

[0167] In some of the following embodiments, a method for saving power based on the operation of SL drx-HARQ-RTT-Timer-RX and SL drx-retransmissionTimer-RX of an RX UE performing sidelink communication may be provided.

[0168] In one embodiment, regarding the operation of the SL drx-HARQ-RTT-Timer-RX and SL drx-retransmissionTimer-RX of the RX UE, in the HARQ feedback disabled mode, the Tx UE can transmit SL packets to the Rx UE as blind retransmission. In this case, since the Rx UE does not transmit SL HARQ feedback, it may not be able to operate the RTT / retransmission timer based on the transmission of PSFCH as in the HARQ feedback enabled mode. Therefore, when the Rx UE receives the PSSCH transmitted by the Tx UE, it needs to start the retransmission timer to ensure that it receives the blind retransmission (including additional transmission) packets transmitted by the Tx UE.

[0169] In one embodiment, the inactivity timer and the HARQ RTT timer and / or retransmission timer may each be timers that operate independently. The inactivity timer is a common DRX timer, and when the Rx UE receives a new TB from the Tx UE, it may start the inactivity timer and monitor whether there is additional SL data transmitted by the Tx UE. When the Rx UE receives the PSSCH (new TB) transmitted by the Tx UE and starts the inactivity timer, and simultaneously a HARQ NACK occurs, it may start the HARQ RTT timer / retransmission timer independently of the inactivity timer. Meanwhile, the SL HARQ RTT timer / retransmission timer may be a timer that operates per sidelink process or per HARQ process. Accordingly, the TX UE and the RX UE may operate according to the following process. i) The transmitting terminal may transmit a PSSCH (new TB) to the receiving terminal (e.g., HARQ disabled). ii) The receiving terminal may start an SL DRX inactivity timer based on receiving the PSSCH and monitor for new additional PSSCHs. iii) The receiving terminal may start a HARQ RTT / retransmission timer and monitor for blind retransmission packets. iv) The transmitting terminal may transmit a new PSSCH (new TB). v) The transmitting terminal may transmit blind retransmission packets for i) to the receiving terminal. vi) The transmitting terminal may transmit blind retransmission packets for i) back to the receiving terminal. Afterward, the inactivity timer may expire / terminate after it has started, and afterward, the HARQ RTT / retransmission timer may expire / terminate after it has started.

[0170] In some of the following embodiments of the present disclosure, Sidelink DRX operation of the RX UE and / or operation of the RX UE receiving a Sidelink HARQ retransmission are described.

[0171] In one embodiment (or, in the 10th embodiment), if the RX UE successfully decoded the Sidelink Control Information (PSCCH) transmitted by the TX UE but failed to decode the PSSCH and transmitted a HARQ NACK to the TX UE, it may initiate the Sidelink HARQ-RTT-Timer-RX timer and transition to sleep mode. When the SL drx-HARQ-RTT-Timer-RX timer expires, the RX UE transitions to active mode to receive the PSCCH and PSSCH for the SL HARQ retransmission packet transmitted by the TX UE, initiates the SL drx-RetransmissionTimer-RX timer, and receives the PSCCH and PSSCH transmitted by the TX UE. Upon receiving the PSCCH and PSSCH for the SL HARQ retransmission transmitted by the TX UE, the RX UE may stop the SL drx-RetransmissionTimer-RX timer. If the RX UE receives the PSCCH and PSSCH for SL HARQ retransmission transmitted by the TX UE, but the decoding of the PSSCH fails again (PSCCH decoding succeeds, PSSCH decoding fails) and transmits a HARQ NACK to the TX UE, the RX UE may restart the Sidelink HARQ-RTT-Timer-RX timer and transition to sleep mode until the Sidelink HARQ-RTT-Timer-RX expires. When the Sidelink HARQ-RTT-Timer-RX timer expires, the RX UE may transition back to an active state to receive the PSCCH and PSSCH for SL HARQ retransmission transmitted by the TX UE and start the SL drx-RetransmissionTimer-RX timer. The RX UE can stop the SL drx-RetransmissionTimer when it receives the PSCCH and PSSCH for the SL HARQ retransmission transmitted by the TX UE.

[0172] In one embodiment (or, in the 11th embodiment), when the TX UE transmits to the RX UE via PSCCH (SCI) with the HARQ feedback option set to HARQ Feedback Disable (not transmitting HARQ NACK to the TX UE even if PSSCH decoding fails; the TX UE performs retransmission via blind retransmission), the RX UE can perform an operation to receive sidelink DRX and sidelink HARQ retransmission as follows. That is, if the RX UE successfully decoded the SCI transmitted by the TX UE but failed PSSCH decoding, it can receive the sidelink retransmission packet transmitted by the TX UE via blind retransmission without transmitting HARQ NACK feedback to the TX UE. Therefore, if the RX UE successfully decodes the SCI (containing information indicating HARQ Feedback Disabled) transmitted by the TX UE but fails to decode the PSSCH, it may initiate the Sidelink HARQ-RTT-Timer-RX timer and transition to sleep mode. That is, the RX UE may transition to sleep mode, determining that the TX UE will not perform a blind retransmission until the SL drx-HARQ-RTT-Timer-RX timer expires. When the SL drx-HARQ-RTT-Timer-RX timer expires, the RX UE transitions to active mode to receive packets retransmitted by the TX UE via blind retransmission, initiates the SL drx-RetransmissionTimer-RX, and can receive retransmission packets transmitted by the TX UE. When the RX UE receives the PSCCH and PSSCH for blind retransmission transmitted by the TX UE, it can stop the SL drx-RetransmissionTimer-RX timer.If the RX UE fails again to decode the PSSCH for blind retransmission transmitted by the TX UE (decoding of the PSCCH indicating HARQ Feedback Disabled succeeds, but PSSCH decoding fails), it may restart the Sidelink HARQ-RTT-Timer-RX timer and operate in sleep mode while the timer is running. When the Sidelink HARQ-RTT-Timer-RX timer expires, the RX UE may transition back to the active state to receive the PSCCH and PSSCH for blind retransmission transmitted by the TX UE and initiate SL drx-RetransmissionTimer-RX. When the RX UE receives the PSCCH and PSSCH for blind retransmission transmitted by the TX UE, it may stop SL drx-RetransmissionTimer.

[0173] In one embodiment (or, in the 12th embodiment), when the TX UE transmits to the RX UE via PSCCH (SCI) with the HARQ feedback option set to HARQ feedback disable (not sending HARQ ACK to the TX UE even if PSSCH decoding is successful; the TX UE performs retransmission via blind retransmission; the RX UE receives the retransmission packet that the TX UE blindly retransmits), the RX UE can perform the receiving operations of sidelink DRX and sidelink HARQ retransmission. That is, if the RX UE successfully decodes the PSCCH (SCI) transmitted by the TX UE and also succeeds in PSSCH decoding, it may not send HARQ ACK feedback to the TX UE. It may also receive the retransmission packet transmitted by the TX UE via blind retransmission. Therefore, even if the RX UE successfully decodes the SCI (containing information indicating HARQ feedback Disabled) transmitted by the TX UE and also succeeds in PSSCH decoding. If the HARQ feedback option is instructed to HARQ feedback Disabled via PSCCH (e.g., sidelink control information), the RX UE can transition to sleep mode while successfully receiving PSCCH and PSSCH and initiating the Sidelink HARQ-RTT-Timer-RX timer. When the SL drx-HARQ-RTT-Timer-RX timer expires, the RX UE transitions to active mode to receive PSCCH and PSSCH for packets retransmitted by the TX UE via blind retransmission, initiating the SL drx-RetransmissionTimer-RX timer, and can receive PSCCH and PSSCH for sidelink blind retransmission transmitted by the TX UE. Upon receiving the PSCCH and PSSCH for blind retransmission transmitted by the TX UE, the RX UE can stop the SL drx-RetransmissionTimer-RX.Additionally, the RX UE may operate in sleep mode until it starts the Sidelink HARQ-RTT-Timer-RX timer and monitors the PSCCH and PSSCH for the next blind retransmission when the decoding of the blind retransmission packet transmitted by the TX UE is successful or fails (decoding of the PSCCH containing information indicating HARQ Feedback Disabled is successful, and PSSCH decoding is failed). When the Sidelink HARQ-RTT-Timer-RX timer expires, the RX UE may transition to active mode to receive the PSCCH and PSSCH for the blind retransmission retransmitted by the TX UE and start the SL drx-RetransmissionTimer-RX timer.

[0174] In one embodiment (or, in the 13th embodiment), if the RX UE successfully decodes the PSCCH (sidelink control information) regardless of whether the decoding of the PSSCH (sidelink data) transmitted by the TX UE is successful or not, it may start the Sidelink HARQ-RTT-Timer-RX timer and transition to sleep mode. When the SL drx-HARQ-RTT-Timer-RX timer expires, the RX UE transitions to active mode to receive the PSCCH and PSSCH for the SL HARQ retransmission packet transmitted by the TX UE, starts the SL drx-RetransmissionTimer-RX timer, and receives the PSCCH and PSSCH transmitted by the TX UE. Upon receiving the PSCCH and PSSCH for the SL HARQ retransmission transmitted by the TX UE, the RX UE may stop the SL drx-RetransmissionTimer-RX timer. If the decoding of the PSCCH for SL HARQ retransmission transmitted by the TX UE is successful, the Sidelink HARQ-RTT-Timer-RX timer may be restarted, and the RX UE may transition to sleep mode until the Sidelink HARQ-RTT-Timer-RX timer expires. When the Sidelink HARQ-RTT-Timer-RX timer expires, the RX UE may transition back to an active state to receive the PSCCH and PSSCH for SL HARQ retransmission transmitted by the TX UE and start the SL drx-RetransmissionTimer-RX timer. When the RX UE receives the PSCCH and PSSCH for SL HARQ retransmission transmitted by the TX UE, the SL drx-RetransmissionTimer may be stopped.

[0175] In one embodiment (or, in the 14th embodiment), if the decoding of the PSCCH (SCI) transmitted by the TX UE is successful but the decoding of the PSSCH (SL data) fails, the RX UE must transmit an SL HARQ NACK to the TX UE; however, if it fails to transmit for the reasons below, it may start the Sidelink HARQ-RTT-Timer-RX timer and transition to sleep mode (the Sidelink HARQ-RTT-Timer-RX timer must be started because the TX UE may transmit an SL HARQ retransmission packet to the RX UE even if the SL HARQ NACK was not transmitted to the TX UE).

[0176] (Reason) If the RX UE has SL data to transmit to the other UE (e.g., SL HARQ feedback) and simultaneously generates UL data to transmit to the base station, the SL data and UL data can be compared in priority, and the data with the higher priority can be transmitted first. If the UL data has a higher priority in the priority comparison, a problem may arise where the SL HARQ feedback cannot be transmitted to the TX UE and the UL data must be transmitted to the base station.

[0177] When the SL drx-HARQ-RTT-Timer-RX timer expires, the RX UE transitions to active mode to receive the PSCCH and PSSCH for the SL HARQ retransmission packets transmitted by the TX UE, starts the SL drx-RetransmissionTimer-RX timer, and can receive the PSCCH and PSSCH transmitted by the TX UE. When the RX UE receives the PSCCH and PSSCH for the SL HARQ retransmission transmitted by the TX UE, the RX UE can stop the SL drx-RetransmissionTimer-RX timer. If the RX UE receives the PSCCH and PSSCH for SL HARQ retransmission transmitted by the TX UE, but fails to decode the PSSCH again (decoding the PSCCH succeeds, decoding the PSSCH fails) and transmits a HARQ NACK to the TX UE, the RX UE may restart the Sidelink HARQ-RTT-Timer-RX timer and transition to sleep mode until the Sidelink HARQ-RTT-Timer-RX timer expires. When the Sidelink HARQ-RTT-Timer-RX timer expires, the RX UE may transition back to an active state to receive the PSCCH and PSSCH for SL HARQ retransmission transmitted by the TX UE and start the SL drx-RetransmissionTimer-RX timer. The RX UE can stop the SL drx-RetransmissionTimer when it receives the PSCCH and PSSCH for the SL HARQ retransmission transmitted by the TX UE.

[0178] FIG. 15 illustrates an example of a method for an RX UE to save power consumption for sidelink communication according to one embodiment.

[0179] More specifically, FIG. 15 illustrates an example of a method for an RX UE to save power based on the operation of the RX SL HARQ RTT Timer-RX and the SL DRX retransmission timer-RX, as proposed in some of the embodiments of the present disclosure.

[0180] As shown in FIG. 15, if the RX UE successfully decodes the PSCCH (sidelink control information) transmitted by the TX UE but fails to decode the PSSCH and transmits a HARQ NACK to the TX UE, it may start the Sidelink HARQ-RTT-Timer-RX timer and transition to sleep mode. When the SL drx-HARQ-RTT-Timer-RX timer expires, the RX UE transitions to active mode to receive the PSCCH and PSSCH for the SL HARQ retransmission packet transmitted by the TX UE, starts the SL drx-RetransmissionTimer-RX timer, and receives the PSCCH and PSSCH transmitted by the TX UE. Upon receiving the PSCCH and PSSCH for the SL HARQ retransmission transmitted by the TX UE, the RX UE may stop the SL drx-RetransmissionTimer-RX timer.

[0181] Some of the various embodiments of the present disclosure provide a method that enables an RX UE operating as a sidelink DRX to efficiently receive PSCCH and PSSCH for sidelink HARQ retransmission transmitted by a TX UE through switching between sleep mode and active mode. That is, it is intended to ensure that the RX UE receives PSCCH and PSSCH transmitted by the TX UE while operating in a power saving mode.

[0182] Various embodiments of the present disclosure may be combined with at least one of a power control operation of a terminal, a congestion control operation of a terminal, a channel coding operation of a terminal, and / or an SL HARQ feedback operation of a terminal.

[0183] FIG. 16 is a flowchart illustrating a method in which a first device performs side-link communication with a second device according to one embodiment of the present disclosure.

[0184] The operations disclosed in the flowchart of FIG. 16 may be performed in combination with various embodiments of the present disclosure. In one example, the operations disclosed in the flowchart of FIG. 16 may be performed based on at least one of the devices shown in FIG. 18 through FIG. 23. In one example, the first device of FIG. 16 corresponds to the first wireless device (100) of FIG. 19 described below, and the second device may correspond to the second wireless device (200) of FIG. 19. In another example, the first device of FIG. 16 corresponds to the second wireless device (200) of FIG. 19 described below, and the second device may correspond to the first wireless device (100).

[0185] In step S1610, the first device according to one embodiment can transmit SCI (Sidelink Control Information) to the second device.

[0186] In step S1620, the first device according to one embodiment can transmit data related to the SCI to the second device through the PSSCH (Physical Sidelink Shared Channel).

[0187] In step S1630, the first device according to one embodiment can determine a PSFCH resource for receiving a PSFCH (Physical Sidelink Feedback Channel) from the second device based on the index of a slot and the index of a subchannel associated with the PSSCH.

[0188] In step S1640, the first device according to one embodiment may initiate a first timer associated with the PSFCH resource based on the failure to monitor the PSFCH in the PSFCH resource.

[0189] In another embodiment, the first timer may be a timer associated with an SL grant received from a base station via a PDCCH. For example, the first timer may be a timer for a time when the first device is expected not to receive an SL grant from the base station.

[0190] In step S1650, the first device according to one embodiment may initiate a second timer associated with a sidelink HARQ retransmission grant for the retransmission of the data based on the fact that the first timer has expired.

[0191] In another embodiment, the second timer may be a timer associated with the interval during which the first device performs a sidelink HARQ retransmission to the second device. Alternatively, the second timer may be a timer for the time when the first device is expected to receive an SL grant from the base station.

[0192] In step S1660, the first device according to one embodiment can transmit sidelink HARQ retransmission data to the second device based on a sidelink retransmission resource determined based on the sidelink HARQ retransmission grant.

[0193] In one embodiment, the first timer may correspond to / identical to / similar to the aforementioned SL drx-HARQ-RTT-Timer-TX, and the second timer may correspond to / identical to / similar to the aforementioned SL drx-RetransmissionTimer-TX.

[0194] In one embodiment, the sidelink HARQ retransmission grant may be received from the base station after the second timer has started.

[0195] In one embodiment, the second timer may be stopped after the sidelink HARQ retransmission data is transmitted to the second device.

[0196] In one embodiment, monitoring of the PSFCH may fail due to a transmission of the first device performed in a time domain overlapping with the PSFCH resource.

[0197] In one embodiment, the first timer may not be initiated or may be stopped based on the fact that the number of occurrences of Sidelink HARQ (Hybrid Automatic Repeat Request) DTX (Discontinuous Transmission) reaches a maximum threshold due to failure to receive Sidelink HARQ (Hybrid Automatic Repeat Request) feedback from the second device through the PSFCH resource.

[0198] In one embodiment, the first timer may not be initiated or its operation may be stopped based on the fact that the number of HACK NACK receptions has reached a maximum threshold by receiving a HARQ NACK (negative acknowledgment) from the second device through the PSFCH resource indicating that the PSSCH was not decoded by the second device.

[0199] In one embodiment, by transmitting the PSSCH to the second device, the maximum number of possible transmissions of the transport block regarding the PSSCH and the current number of transmissions differ by less than a threshold, and based on the fact that there is no PUCCH resource to transmit the PUCCH (Physical Uplink Control Channel) to the base station, the first timer may not be started or its operation may be stopped.

[0200] In one embodiment, the mode for sidelink communication of the first device may be switched from mode 1, in which sidelink communication is performed based on resource configuration information received from the base station, to mode 2, in which sidelink communication is performed based on sensing of the first device performed within a resource pool, and the first timer may not be started or its operation may be stopped.

[0201] In one embodiment, the step of initiating the first timer may further include the step of initiating the first timer based on failing to monitor the PSFCH in the PSFCH resource and transmitting the PUCCH to the base station through the PUCCH resource set by the base station. At this time, through the PUCCH, a HARQ NACK indicating that the PSSCH was not decoded in the second device may be transmitted from the first device to the base station.

[0202] In one embodiment, the step of initiating the first timer may further include the step of initiating the first timer based on failing to monitor the PSFCH in the PSFCH resource and not receiving a PUCCH resource from the base station.

[0203] In one embodiment, the expiration time of the first timer may be earlier than the highest priority time when the sidelink HARQ retransmission grant is expected to be received from the base station.

[0204] In one embodiment, the sidelink HARQ retransmission grant may be transmitted from the base station to the first device via a Physical Downlink Control Channel (PDCCH). During the time interval in which the first timer operates, PDCCH monitoring for receiving the PDCCH from the base station may not be performed.

[0205] In one embodiment, during the time interval in which the second timer operates, PDCCH monitoring for receiving the PDCCH from the base station may be performed.

[0206] In one embodiment, during the time interval in which the second timer operates, the first device may be in a DRX (Discontinuous Reception) active state capable of receiving a signal from the base station.

[0207] In one embodiment, when the first device (or Tx UE) is missing PSFCH (due to a half-duplex problem), Mode 1 DCI monitoring (Uu DRX RTT / Retransmission timer) operation may be proposed. A half-duplex problem refers to a case where PSFCH monitoring is not performed due to a problem that occurs when the terminal cannot transmit and receive simultaneously. In this case, in one example, the conditions under which the timer is not stopped or started may be as follows: i) when the DTX reaches a maximum threshold, ii) when the maximum threshold of HARQ NACKs is received, iii) when the maximum number of transmissions reaches a threshold and there are no PUCCH resources, iv) when switching to Mode 2, etc.

[0208] In another example, the above Half duplex problem can correspond to the start condition of a timer.

[0209] In one embodiment, the Tx UE may start the HARQ RTT timer / retransmission timer at the start of the transmission of sidelink data (SL TB).

[0210] In one embodiment, for HARQ feedback Disabled MAC PDU transmission (blind transmission), the Tx UE may initiate a HARQ RTT timer / retransmission timer at the start of sidelink data (SL TB) transmission.

[0211] In one embodiment, for the transmission of a HARQ feedback disabled MAC PDU, the Uu DRX operation may be as follows. In one example, when a PUCCH (resource) is configured, i) the HARQ RTT timer may be initiated regardless of whether a HARQ ACK or a NACK is transmitted to the base station via the PUCCH, and ii) the retransmission timer may be initiated only when a HARQ NACK is transmitted via the PUCCH. And / or, the retransmission timer may be initiated only when a NACK is received from the Rx UE via the PSFCH (i.e., a HARQ feedback enabled MAC PDU).

[0212] In another example, if PUCCH (resource) is not set, the Tx UE can start a timer (mode 1 PDCCH monitoring) when the transmission of sidelink data (SL TB) begins.

[0213] In another example, regarding a HARQ feedback disabled MAC PDU, after a PUCCH transmission containing SL HARQ feedback information, an RTT / retransmission timer related to MODE 1 DCI monitoring may be initiated. For example, the TX UE may start the RTT TIMER based on the PUCCH resource and initiate the retransmission timer after the RTT TIMER expires. For example, the retransmission timer (and / or RTT timer) may be initiated based on the start time of a TB-related scheduled MODE 1 resource.

[0214] In one embodiment, Uu DRX operation may be provided when the Tx UE misses monitoring the PSFCH. In one example, the base station's retransmission grant monitoring timer (RTT / Retransmission timer) may be operated even though the Tx UE failed to perform PSFCH monitoring. In another example, if PUCCH is set even though the Tx UE failed to perform PSFCH monitoring, the TX UE may transmit an SL HARQ NACK and operate the base station's retransmission grant monitoring timer (RTT / Retransmission timer). In yet another example, if PUCCH is not set even though the Tx UE failed to perform PSFCH monitoring, the base station's retransmission grant monitoring timer (RTT / Retransmission timer) may be operated from the point where PSFCH monitoring should have been performed.

[0215] According to one embodiment of the present disclosure, a first device for performing side-link communication may be provided.The first device comprises at least one memory for storing instructions, at least one transceiver, and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor controls the at least one transceiver to transmit Sidelink Control Information (SCI) to a second device, controls the at least one transceiver to transmit data related to the SCI through a Physical Sidelink Shared Channel (PSSCH) to the second device, determines a PSFCH resource for receiving a Physical Sidelink Feedback Channel (PSFCH) from the second device based on an index of a slot and an index of a subchannel related to the PSSCH, initiates a first timer related to the PSFCH resource based on a failure to monitor the PSFCH at the PSFCH resource, and the first Based on the expiration of the timer, a second timer associated with a sidelink HARQ retransmission grant for the retransmission of the data is initiated, and the at least one transceiver is controlled to transmit sidelink HARQ retransmission data to the second device based on a sidelink retransmission resource determined based on the sidelink HARQ retransmission grant, wherein the sidelink HARQ retransmission grant is received from a base station after the second timer is initiated, and the second timer may be stopped after the sidelink HARQ retransmission data is transmitted to the second device.

[0216] According to one embodiment of the present disclosure, a device (or chip (set)) for controlling a first terminal may be provided. The device comprises at least one processor and at least one computer memory executablely connected to the at least one processor and storing instructions, wherein, by the at least one processor executing the instructions, the first terminal transmits Sidelink Control Information (SCI) to the second terminal, transmits data associated with the SCI to the second terminal via a Physical Sidelink Shared Channel (PSSCH), determines a PSFCH resource for receiving a Physical Sidelink Feedback Channel (PSFCH) from the second terminal based on an index of a slot associated with the PSSCH and an index of a subchannel associated with the PSSCH, initiates a first timer associated with the PSFCH resource based on failure to monitor the PSFCH at the PSFCH resource, and performs a Sidelink HARQ retransmission for the retransmission of the data based on the expiration of the first timer. A second timer associated with a grant is initiated, and based on a sidelink retransmission resource determined based on the sidelink HARQ retransmission grant, sidelink HARQ retransmission data is transmitted to the second terminal, wherein the sidelink HARQ retransmission grant is received from a base station after the second timer is initiated, and the second timer may be stopped after the sidelink HARQ retransmission data is transmitted to the second terminal.

[0217] In one example, the first terminal of the above embodiment may represent the first device described throughout the present disclosure. In one example, the at least one processor, the at least one memory, etc. within the device controlling the first terminal may each be implemented as a separate sub-chip, or at least two components may be implemented through a single sub-chip.

[0218] According to one embodiment of the present disclosure, a non-transitory computer-readable storage medium for storing instructions (or instructions) may be provided. The above-mentioned non-transient computer-readable storage medium, upon execution of the above instructions, causes the first device to: transmit Sidelink Control Information (SCI) to the second device; transmit data associated with the SCI to the second device via a Physical Sidelink Shared Channel (PSSCH); determine a PSFCH resource for receiving a Physical Sidelink Feedback Channel (PSFCH) from the second device based on an index of a slot associated with the PSSCH and an index of a subchannel associated with the PSSCH; initiate a first timer associated with the PSFCH resource based on a failure to monitor the PSFCH at the PSFCH resource; initiate a second timer associated with a Sidelink HARQ retransmission grant for the retransmission of the data based on the expiration of the first timer; and based on the Sidelink HARQ retransmission grant Based on the determined sidelink retransmission resource, sidelink HARQ retransmission data is transmitted to the second device, wherein the sidelink HARQ retransmission grant is received from the base station after the second timer is started, and the second timer may be stopped after the sidelink HARQ retransmission data is transmitted to the second device.

[0219] FIG. 17 is a flowchart illustrating a method in which a third device performs side-link communication with a fourth device according to one embodiment of the present disclosure.

[0220] The operations disclosed in the flowchart of FIG. 17 may be performed in combination with various embodiments of the present disclosure. In one example, the operations disclosed in the flowchart of FIG. 17 may be performed based on at least one of the devices shown in FIG. 18 through FIG. 23. In one example, the third device of FIG. 17 may correspond to the second wireless device (200) of FIG. 19 described below, and the fourth device may correspond to the first wireless device (100) of FIG. 19. In another example, the third device of FIG. 17 may correspond to the first wireless device (100) of FIG. 19 described below, and the fourth device may correspond to the second wireless device (200) of FIG. 19.

[0221] In step S1710, the third device according to one embodiment can receive SCI (Sidelink Control Information) from the fourth device.

[0222] In step S1720, a third device according to one embodiment can receive data related to the SCI from the fourth device through a Physical Sidelink Shared Channel (PSSCH).

[0223] In step S1730, the third device according to one embodiment may initiate a first timer associated with the sidelink HARQ (Hybrid Automatic Repeat Request) feedback information based on a first priority value of the sidelink HARQ feedback information associated with the data.

[0224] In step S1740, the third device according to one embodiment may initiate a second timer associated with a sidelink HARQ retransmission packet for the SCI or the PSSCH based on the fact that the first timer has expired.

[0225] In step S1750, a third device according to one embodiment can receive the sidelink HARQ retransmission packet from the fourth device.

[0226] In one embodiment, the sidelink HARQ retransmission packet may be received from the fourth device after the second timer has started.

[0227] In one embodiment, the first timer may correspond to / identical to / similar to the aforementioned SL drx-HARQ-RTT-Timer-RX, and the second timer may correspond to / identical to / similar to the aforementioned SL drx-RetransmissionTimer-RX.

[0228] In one embodiment, the second timer may be stopped after the sidelink HARQ retransmission packet is received from the fourth device.

[0229] In one embodiment, the first priority value of the sidelink HARQ feedback information may be greater than the second priority value related to uplink transmission to the base station.

[0230] In one embodiment, based on the fact that the first priority value is greater than the second priority value, the sidelink HARQ feedback information may not be transmitted to the fourth device.

[0231] In one embodiment, the sidelink HARQ feedback information may be a HARQ ACK (Acknowledgement) indicating that the third device succeeded in decoding the data or a HARQ NACK indicating that the third device failed to decode the data.

[0232] In one embodiment, the operation of the RTT / Retransmission Timer (or SL DRX operation) due to PSFCH dropping of the third device (or Rx UE) (due to priority between SL and UL or priority between LTE SL and NR SL) may be proposed. In one example, in the case of a HARQ feedback Enabled MAC PDU, i) (in the case of successful decoding) when the receiving terminal successfully receives SL data (successful decoding), the transmitting terminal may misjudge that the decoding failed even though the PSFCH was not actually transmitted, so the receiving terminal must be able to start the RTT / Retransmission timer to monitor the reception of the retransmission packet by the Tx UE. ii) (In the case of a decoding failure) If the receiving terminal fails to receive the SL data (decoding failure), the transmitting terminal may determine that the decoding has failed even if it has not actually transmitted the PSFCH, so it must be able to start the RTT / Retransmission timer to monitor whether the retransmission packet of the Tx UE is received.

[0233] In one embodiment, when a HARQ feedback Disabled MAC PDU is transmitted from the TX UE, an SL DRX operation of the Rx UE may be provided. In one example, when the receiving terminal receives SL data (decoding successful or decoding failed), it may start an RTT / Retransmission timer to monitor the next HARQ feedback Disabled MAC PDU (blind transmission) transmitted by the Tx UE.

[0234] According to one embodiment of the present disclosure, a third device for performing side-link communication is provided. The third device comprises at least one memory for storing instructions, at least one transceiver, and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor controls the at least one transceiver to receive Sidelink Control Information (SCI) from the fourth device, controls the at least one transceiver to receive data related to the SCI via a Physical Sidelink Shared Channel (PSSCH) from the fourth device, initiates a first timer related to the Sidelink HARQ feedback information based on a first priority value of the Sidelink HARQ feedback information related to the data, initiates a second timer related to a Sidelink HARQ retransmission packet for the SCI or the PSSCH based on the expiration of the first timer, and the fourth The at least one transceiver is controlled to receive the sidelink HARQ retransmission packet from the device, wherein the sidelink HARQ retransmission packet is received from the fourth device after the second timer is started, and the second timer is stopped after the sidelink HARQ retransmission packet is received from the fourth device, and the first priority value of the sidelink HARQ feedback information may be greater than the second priority value related to uplink transmission to the base station.

[0235] Various embodiments of the present disclosure may be implemented independently. Alternatively, various embodiments of the present disclosure may be implemented in combination or merged with one another. For example, various embodiments of the present disclosure have been described based on a 3GPP system for convenience of explanation, but various embodiments of the present disclosure may be extended to systems other than the 3GPP system. For example, various embodiments of the present disclosure are not limited to direct communication between terminals but may be used in uplink or downlink, in which case base stations or relay nodes may use the proposed method according to various embodiments of the present disclosure. For example, information regarding whether the method according to various embodiments of the present disclosure is applied may be defined so that a base station informs a terminal or a transmitting terminal informs a receiving terminal through a predefined signal (e.g., a physical layer signal or an upper layer signal). For example, information regarding rules according to various embodiments of the present disclosure may be defined so that a base station informs a terminal or a transmitting terminal informs a receiving terminal through a predefined signal (e.g., a physical layer signal or an upper layer signal). For example, some of the various embodiments of the present disclosure may be applied exclusively to resource allocation mode 1. For example, some of the various embodiments of the present disclosure may be applied exclusively to resource allocation mode 2.

[0236] The following describes an apparatus to which various embodiments of the present disclosure may be applied.

[0237] Although not limited to this, the various descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0238] Examples are provided in more detail below with reference to the drawings. In the following drawings and descriptions, the same reference numerals may represent the same or corresponding hardware blocks, software blocks, or function blocks unless otherwise described.

[0239] FIG. 18 shows a communication system (1) according to one embodiment of the present disclosure.

[0240] Referring to FIG. 18, 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 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 Thing) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with wireless communication capabilities, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and can be implemented in the form of HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) equipped in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Portable devices may include smartphones, smartpads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops, etc.). Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, base stations and networks may be implemented as wireless devices, and a specific wireless device (200a) may operate as a base station / network node to other wireless devices.

[0241] Here, the wireless communication technology implemented in the wireless devices (100a to 100f) of this specification may include LTE, NR, and 6G, as well as Narrowband Internet of Things for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented according to standards such as LTE Cat NB1 and / or LTE Cat NB2, but is not limited to the names mentioned above. Additionally, or generally, the wireless communication technology implemented in the wireless devices (100a to 100f) of this specification may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be referred to by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented in 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 names mentioned above. Additionally or generally, wireless communication technology implemented in the wireless devices (100a to 100f) of this specification may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) for low-power communication, and is not limited to the names mentioned above. As an example, ZigBee technology can create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and may be referred to by various names.

[0242] Wireless devices (100a to 100f) can be connected to a network (300) through a base station (200). Artificial Intelligence (AI) technology may be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) through the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices (100a to 100f) may communicate with each other through the base station (200) / network (300), but they may 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). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0243] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base station (200) and base station (200) / base station (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 inter-base station communication (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 / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various proposals of the present disclosure, at least some of the following may be performed: 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.), resource allocation processes, etc.

[0244] FIG. 19 shows a wireless device according to one embodiment of the present disclosure.

[0245] Referring to FIG. 19, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} may correspond to {wireless device (100x), base station (200)} and / or {wireless device (100x), wireless device (100x)} of FIG. 18.

[0246] The first wireless device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memory (104) and / or transceivers (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or sequences of operation disclosed in this document. For example, the processor (102) may process information within the memory (104) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (106). Additionally, the processor (102) may receive a wireless signal containing a second information / signal through the transceiver (106) and then store information obtained from the 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 store software code containing instructions for performing some or all of the processes controlled by the processor (102) or for performing the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement 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 through one or more antennas (108). The transceiver (106) may include a transmitter and / or receiver. The transceiver (106) may be combined with an RF (Radio Frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0247] The second wireless device (200) includes one or more processors (202) and one or more memories (204), and may additionally include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memory (204) and / or transceivers (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or sequences of operation disclosed in this document. For example, the processor (202) may process information within the memory (204) to generate a third information / signal and then transmit a wireless signal containing the third information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and then store information obtained from the signal processing of the fourth information / signal in the memory (204). Memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, memory (204) may store software code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through one or more antennas (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeable with an RF unit. In this disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0248] Hereinafter, 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 Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation 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 flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate a signal (e.g., baseband signal) containing a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this document and provide it to one or more transceivers (106, 206). One or more processors (102, 202) may receive a signal (e.g., baseband signal) from one or more transceivers (106, 206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document.

[0249] One or more processors (102, 202) may be referred to as a controller, microcontroller, microprocessor, or 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 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. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be contained in one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0250] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memories (104, 204) may be composed of ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0251] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc., of this document to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc., disclosed in this document from one or more other devices. For example, one or more transceivers (106, 206) may be connected to one or more processors (102, 202) and may transmit and receive wireless signals. For example, one or more processors (102, 202) may control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. 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 connected 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, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document through 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 the received wireless signal / channel, etc. from an RF band signal to a baseband signal in order to process the received user data, control information, wireless signal / channel, etc. using one or more processors (102, 202).One or more transceivers (106, 206) can convert user data, control information, wireless signals / channels, etc. processed using one or more processors (102, 202) from baseband signals to RF band signals. To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters.

[0252] FIG. 20 shows a signal processing circuit for a transmission signal according to one embodiment of the present disclosure.

[0253] Referring to FIG. 20, 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 operation / function of FIG. 20 may be performed in the processor (102, 202) and / or transceiver (106, 206) of FIG. 19. The hardware elements of FIG. 20 may be implemented in the processor (102, 202) and / or transceiver (106, 206) of FIG. 19. For example, blocks 1010 through 1060 may be implemented in the processor (102, 202) of FIG. 19. Additionally, blocks 1010 to 1050 may be implemented in the processor (102, 202) of FIG. 19, and block 1060 may be implemented in the transceiver (106, 206) of FIG. 19.

[0254] The codeword can be converted into a wireless signal through the signal processing circuit (1000) of FIG. 20. Here, the codeword is an encoded bit sequence of an information block. The information block may include a transmission block (e.g., UL-SCH transmission block, DL-SCH transmission block). The wireless signal can be transmitted through various physical channels (e.g., PUSCH, PDSCH).

[0255] Specifically, a codeword can be converted into a scrambled bit sequence by a scrambler (1010). The scrambled sequence used for scrambling is generated based on an initialization value, which may include ID information of a 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 an N*M precoding matrix W. 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 the complex modulation symbols. Additionally, the precoder (1040) can perform precoding without performing transform precoding.

[0256] A resource mapper (1050) can map the modulation symbols of each antenna port to a time-frequency resource. The time-frequency resource may include multiple symbols (e.g., CP-OFDMA symbols, DFT-s-OFDMA symbols) in the time domain and multiple subcarriers in the frequency domain. A signal generator (1060) generates a radio signal from the mapped modulation symbols, and the generated radio signal can be transmitted to another device through each antenna. To this end, the signal generator (1060) may include an Inverse Fast Fourier Transform (IFFT) module, a Cyclic Prefix (CP) inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0257] The signal processing process for a received signal in a wireless device can be configured as the inverse of the signal processing process (1010–1060) of FIG. 20. For example, a wireless device (e.g., 100, 200 in FIG. 19) can receive a wireless signal from the outside through an antenna port / transceiver. The received wireless signal can be converted into a baseband signal through a signal restorer. To this end, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a Fast Fourier Transform (FFT) module. Subsequently, the baseband signal can be restored into a codeword through a resource de-mapper process, a postcoding process, a demodulation process, and a de-scrambling process. The codeword can be restored to the original information block 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.

[0258] FIG. 21 shows a wireless device according to one embodiment of the present disclosure. The wireless device may be implemented in various forms depending on the use—example / service (see FIG. 18).

[0259] Referring to FIG. 21, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 19 and may be composed of various elements, components, units / parts, 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 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. 19. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 19. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and additional elements (140) and controls the general operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on a program / code / command / information stored in the memory unit (130). Additionally, the control unit (120) may transmit information stored in the memory unit (130) to an external (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external (e.g., another communication device) via a wireless / wired interface through the communication unit (110) in the memory unit (130).

[0260] The additional element (140) can be configured in various ways depending on the type of 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. 18, 100a), a vehicle (Fig. 18, 100b-1, 100b-2), an XR device (Fig. 18, 100c), a portable device (Fig. 18, 100d), a home appliance (Fig. 18, 100e), an IoT device (Fig. 18, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or financial device), a security device, a climate / environment device, an AI server / device (Fig. 18, 400), a base station (Fig. 18, 200), a network node, etc. Wireless devices can be used in a movable or fixed location depending on the use—e.g., service.

[0261] In FIG. 21, 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 a portion 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). Additionally, each element, component, unit / part, and / or module within the wireless device (100, 200) may include one or more additional elements. For example, the control unit (120) may be composed of one or more sets of processors. 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 RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory and / or a combination thereof.

[0262] Hereinafter, an implementation example of FIG. 21 will be described in more detail with reference to other drawings.

[0263] FIG. 22 illustrates a portable device according to one embodiment of the present disclosure. The portable device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch, smart glasses), a portable computer (e.g., a laptop, etc.). The portable device may be referred to as an MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), or WT (Wireless terminal).

[0264] Referring to FIG. 22, 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 part of the communication unit (110). Blocks 110 to 130 / 140a to 140c each correspond to blocks 110 to 130 / 140 of FIG. 21.

[0265] 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 the components of the portable device (100) to perform various operations. The control unit (120) may include an AP (Application Processor). The memory unit (130) can store data / parameters / programs / code / commands required for the operation of the portable device (100). Additionally, the memory unit (130) can store input / output data / information, etc. The power supply unit (140a) supplies power to the portable device (100) and may include wired / wireless charging circuits, batteries, etc. The interface unit (140b) can support the connection between the portable device (100) and other external devices. The interface unit (140b) may include various ports (e.g., audio input / output ports, video input / output ports) for connection with external devices. The input / output unit (140c) can receive or output video information / signals, audio information / signals, data, and / or information input by 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, etc.

[0266] For example, in the case of data communication, the input / output unit (140c) acquires information / signals (e.g., touch, text, voice, image, video) input from the user, and the acquired 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 another wireless device or to a base station. Additionally, the communication unit (110) can receive wireless signals from another wireless device or base station and then restore the received wireless signals to their 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).

[0267] FIG. 23 illustrates a vehicle or an autonomous vehicle according to one embodiment of the present disclosure. The vehicle or autonomous vehicle may be implemented as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, etc.

[0268] Referring to FIG. 23, 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 part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 21, respectively.

[0269] 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, roadside base stations (Roadside units), etc.), and servers. The control unit (120) can perform various operations by controlling elements of the vehicle or autonomous vehicle (100). The control unit (120) may include an Electronic Control Unit (ECU). The driving unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The driving unit (140a) may include an engine, motor, power train, wheels, brakes, steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and may include wired / wireless charging circuits, batteries, 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 inclination sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement technologies such as maintaining the driving lane, technologies for automatically adjusting speed such as adaptive cruise control, technologies for automatically driving along a predetermined path, and technologies for automatically setting a path and driving when a destination is set.

[0270] 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 path and a driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or the autonomous vehicle (100) moves along the autonomous driving path according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can acquire the latest traffic information data from an external server non-periodically and can acquire surrounding traffic information data from surrounding vehicles. Additionally, 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 path and the driving plan based on the newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving path, driving plan, etc. to an external server. An external server can predict traffic information data in advance using AI technology, etc., based on information collected from vehicles or autonomous vehicles, and can provide the predicted traffic information data to vehicles or autonomous vehicles.

[0271] The scope of the disclosure may be indicated by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the disclosure.

[0272] The claims described in this specification may be combined in various ways. For example, the technical features of the method claims in this specification may be combined to be implemented as a device, and the technical features of the device claims in this specification may be combined to be implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a device, and the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a method.

Claims

Claim 1 In a method, the first device transmits sidelink control information (SCI) to the second device; the first device transmits data related to the SCI to the second device via a physical sidelink shared channel (PSSCH); based on an index of a slot and an index of a subchannel related to the PSSCH, the first device determines a PSFCH resource for receiving a physical sidelink feedback channel (PSFCH) from the second device; based on failure to monitor the PSFCH in the PSFCH resource, the first device initiates a first timer associated with a minimum duration prior to the sidelink retransmission grant being expected by the first device; based on the first timer expiring, the first device initiates a second timer associated with a maximum duration until the sidelink retransmission grant is received A method comprising: a step of initiating a timer; and a step of the first device retransmitting the data to the second device based on the sidelink retransmission grant, wherein the sidelink retransmission grant is not received during the time interval in which the first timer operates, and is received from a base station after the second timer is initiated, and the second timer is stopped after the data is retransmitted to the second device. Claim 2 A method according to claim 1, wherein monitoring of the PSFCH fails due to a transmission of the first device performed in a time domain overlapping with the PSFCH resource. Claim 3 A method according to claim 1, wherein the first timer is not initiated or its operation is stopped based on the fact that the number of occurrences of a sidelink HARQ (hybrid automatic repeat request) DTX (discontinuous transmission) reaches a maximum threshold due to a failure to receive sidelink HARQ (hybrid automatic repeat request) feedback from the second device through the PSFCH resource. Claim 4 A method according to claim 1, wherein, by receiving a HARQ NACK (negative acknowledgment) from the second device indicating that the PSSCH was not decoded by the second device through the PSFCH resource, the first timer is not initiated or operation is stopped based on the fact that the number of HACK NACK receptions has reached a maximum threshold. Claim 5 A method according to claim 1, wherein by transmitting the PSSCH to the second device, the maximum number of possible transmissions of the transport block regarding the PSSCH and the current number of transmissions differ by less than or equal to a threshold, and based on the fact that there is no PUCCH resource for transmitting a PUCCH (physical uplink control channel) to the base station, the first timer is not initiated or operation is stopped. Claim 6 A method according to claim 1, wherein the mode for sidelink communication of the first device is switched from mode 1, in which sidelink communication is performed based on resource configuration information received from the base station, to mode 2, in which sidelink communication is performed based on sensing of the first device performed within a resource pool, and the first timer is not started or operation is stopped. Claim 7 The method according to claim 1, wherein the step of initiating the first timer further comprises the step of initiating the first timer based on the fact that the first device fails to monitor the PSFCH in the PSFCH resource and transmits the PUCCH to the base station through the PUCCH resource set by the base station, wherein a HARQ NACK indicating that the PSSCH was not decoded by the second device is transmitted from the first device to the base station through the PUCCH. Claim 8 The method according to claim 1, further comprising the step of initiating the first timer, wherein the first device fails to monitor the PSFCH in the PSFCH resource and does not receive a PUCCH resource from the base station. Claim 9 A method according to claim 1, wherein the expiration time of the first timer precedes the highest priority time when the sidelink retransmission grant is expected to be received from the base station. Claim 10 A method according to claim 1, wherein the sidelink retransmission grant is transmitted from the base station to the first device via a physical downlink control channel (PDCCH), and during the time interval in which the first timer operates, PDCCH monitoring for receiving the PDCCH from the base station is not performed. Claim 11 A method according to claim 10, wherein the PDCCH monitoring for receiving the PDCCH from the base station is performed during the time interval in which the second timer operates. Claim 12 A method according to claim 11, wherein, during the time interval in which the second timer operates, the first device is in a DRX (discontinuous reception) active state capable of receiving a signal from the base station. Claim 13 In the first device, at least one transceiver; at least one processor; and includes at least one memory connected to the at least one processor and storing instructions, wherein the instructions are executed by the at least one processor, and the first device is caused to: transmit sidelink control information (SCI) to the second device; transmit data associated with the SCI to the second device via a physical sidelink shared channel (PSSCH); determine a PSFCH resource for receiving a physical sidelink feedback channel (PSFCH) from the second device based on an index of a slot associated with the PSSCH and an index of a subchannel; initiate a first timer associated with a minimum duration prior to a sidelink retransmission grant being expected by the first device based on failure to monitor the PSFCH at the PSFCH resource; and, based on the expiration of the first timer, a maximum until the sidelink retransmission grant is received A first device that initiates a second timer associated with a maximum duration; and retransmits the data to the second device based on the sidelink retransmission grant, wherein the sidelink retransmission grant is not received during the time interval in which the first timer operates, and is received from a base station after the second timer is initiated, and the second timer is stopped after the data is retransmitted to the second device. Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 In a processing device, at least one processor; and includes at least one memory connected to the at least one processor and storing instructions, wherein the instructions are executed by the at least one processor, and the first device causes: to transmit sidelink control information (SCI) to the second device; to transmit data associated with the SCI to the second device via a physical sidelink shared channel (PSSCH); to determine a PSFCH resource for receiving a physical sidelink feedback channel (PSFCH) from the second device based on an index of a slot associated with the PSSCH and an index of a subchannel; to initiate a first timer associated with a minimum duration prior to a sidelink retransmission grant being expected by the first device based on failure to monitor the PSFCH at the PSFCH resource; and, based on the expiration of the first timer, a maximum until the sidelink retransmission grant is received A processing device that initiates a second timer associated with a maximum duration; and retransmits the data to the second device based on the sidelink retransmission grant, wherein the sidelink retransmission grant is not received during the time interval in which the first timer operates, and is received from a base station after the second timer is initiated, and the second timer is stopped after the data is retransmitted to the second device. Claim 18 delete Claim 19 delete Claim 20 delete

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