Method and apparatus for configuring sidelink discontinuous reception in wireless communication system

Abstract

A method and apparatus for configuring sidelink discontinuous reception in a wireless communication system are disclosed. A method performed by a first UE according to one embodiment of the present disclosure may comprise the steps of: receiving information on a first SL DRX configuration from a second UE; determining an SL activity time for monitoring the SCI from the second UE based on the first SL DRX configuration; and re-determining the SL activity time based on receiving the information about the second SL DRX configuration from the base station or receiving the information about the third SL DRX configuration from the second UE.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for configuring sidelink discontinuous reception (DRX) in a wireless communication system. Background Art

[0002] A mobile communication system has been developed to provide voice services while ensuring user mobility. However, the mobile communication system has been extended to data services as well as voice services, and currently, the explosive growth of services has led to resource shortages, and users have demanded faster services, thus requiring more advanced mobile communication systems.

[0003] The overall requirement for the next generation of mobile communication systems should be able to support the accommodation of explosive data services, a significant increase in the transmission rate per user, the accommodation of a significantly increased number of connected devices, very low end-to-end latency and high energy efficiency. To this end, various technologies have been studied, including dual connectivity, massive multiple-input multiple-output (massive MIMO), in-band full-duplex, non-orthogonal multiple access (NOMA), ultra-wideband support, and device networking. Summary of the invention

[0004] Technical issues

[0005] The technical purpose of the present disclosure is to provide a method and device for configuring / generating SL DRX configuration.

[0006] In addition, an additional technical objective of the present disclosure is to provide a method and apparatus for determining SL active time based on SL DRX configuration.

[0007] The technical objectives achieved by the present disclosure are not limited to the above-mentioned technical objectives, and other technical objectives not described herein will be clearly understood by those skilled in the relevant art from the following description.

[0008] Technical Solution

[0009] A method performed by a first user equipment (UE) in a wireless communication system according to one aspect of the present disclosure may include: receiving information for a first sidelink (SL) discontinuous reception (DRX) configuration from a second UE; determining a SL active time for monitoring sidelink control information (SCI) from the second UE based on the first SL DRX configuration; and redetermining the SL active time based on receiving information for a second SL DRX configuration from a base station or receiving information for a third SL DRX configuration from the second UE. The SL active time may be redetermined based on i) both the first SL DRX configuration and the second SL DRX configuration or ii) both the first SL DRX configuration and the third SL DRX configuration.

[0010] Technical Effects

[0011] According to an embodiment of the present disclosure, by adjusting the SL active time by reflecting the SL DRX configuration received from a base station or another UE, the power consumption of the UE can be reduced.

[0012] Effects achievable by the present disclosure are not limited to the above-described effects, and other effects not described herein may be clearly understood by those skilled in the art through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which are included as a part of the detailed description for understanding the present disclosure, provide embodiments of the present disclosure and describe technical features of the present disclosure through the detailed description.

[0014] Figure 1 The diagram shows a structure of a wireless communication system to which the present disclosure can be applied.

[0015] Figure 2 The figure illustrates a frame structure in a wireless communication system to which the present disclosure can be applied.

[0016] Figure 3 The diagram illustrates a resource grid in a wireless communication system to which the present disclosure may be applied.

[0017] Figure 4 The figure illustrates physical resource blocks in a wireless communication system to which the present disclosure can be applied.

[0018] Figure 5 The diagram illustrates a time slot structure in a wireless communication system to which the present disclosure can be applied.

[0019] Figure 6 Physical channels used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the physical channels are illustrated.

[0020] Figure 7 is a diagram illustrating a DRX cycle in a wireless communication system to which the present disclosure can be applied.

[0021] Figure 8 The diagram illustrates a process for performing V2X or SL communication according to a transmission mode in a wireless communication system to which the present disclosure can be applied.

[0022] Fig. 9 The diagram illustrates a SL DRX configuration method according to an embodiment of the present disclosure.

[0023] Fig.10 The figure illustrates a signaling process for a SL DRX configuration method according to an embodiment of the present disclosure.

[0024] Fig.11 is a diagram illustrating the operation of a UE for a SL DRX configuration method according to an embodiment of the present disclosure.

[0025] Fig.12 A block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description to be disclosed by the accompanying drawings is intended to describe exemplary embodiments of the present disclosure, rather than to represent the only embodiment in which the present disclosure can be implemented. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the relevant art will appreciate that the present disclosure can be implemented without these specific details.

[0027] In some cases, well-known structures and devices may be omitted, or may be shown in the form of a block diagram based on the core functions of each structure and device in order to prevent ambiguity in the concepts of the present disclosure.

[0028] In the present disclosure, when an element is referred to as being "connected", "combined" or "linked" to another element, it may include an indirect connection relationship between another element and a direct connection relationship. In addition, in the present disclosure, the term "comprising" or "having" specifies the presence of the mentioned features, steps, operations, components and / or elements, but does not exclude the presence or addition of one or more other features, stages, operations, components, elements and / or groups thereof.

[0029] In the present invention, terms such as "first", "second", etc. are only used to distinguish one element from another element and are not used to limit the elements, and unless otherwise specified, they do not limit the order or importance between the elements. Therefore, within the scope of the present disclosure, the first element in an embodiment may be referred to as the second element in another embodiment, and similarly, the second element in an embodiment may be referred to as the first element in another embodiment.

[0030] The terms used in this disclosure are intended to describe specific embodiments rather than to limit the claims. As used in the description of the embodiments and the appended claims, the singular form is intended to include the plural form unless the context clearly indicates otherwise. The term "and / or" used in this disclosure may refer to one of the related enumerated items, or mean that it refers to and includes any and all possible combinations of two or more of them. In addition, unless otherwise stated, the " / " between words in the present invention has the same meaning as "and / or".

[0031] The present disclosure describes a wireless communication network or a wireless communication system, and operations performed in the wireless communication network may be performed in a process in which a device (e.g., a base station) controlling the corresponding wireless communication network controls the network and sends or receives signals, or may be performed in a process in which a terminal associated with the corresponding wireless network sends or receives signals between the network or the terminal.

[0032] In the present disclosure, sending or receiving a channel includes the meaning of sending or receiving information or signals through the corresponding channel. For example, sending a control channel means sending control information or control signals through the control channel. Similarly, sending a data channel means sending data information or data signals through the data channel.

[0033] Hereinafter, downlink (DL) means communication from a base station to a terminal, and uplink (UL) means communication from a terminal to a base station. In the downlink, the transmitter may be a part of a base station, and the receiver may be a part of a terminal. In the uplink, the transmitter may be a part of a terminal, and the receiver may be a part of a base station. The base station may be expressed as a first communication device, and the terminal may be expressed as a second communication device. The base station (BS) may be replaced by terms such as a fixed station, a node B, an eNB (evolved node B), a gNB (next generation node B), a BTS (base station transceiver system), an access point (AP), a network (5G network), an AI (artificial intelligence) system / module, an RSU (roadside unit), a robot, a drone (UAV: unmanned aerial vehicle), an AR (augmented reality) device, a VR (virtual reality) device, and the like. In addition, the terminal may be fixed or mobile, and may be replaced by terms such as UE (user equipment), MS (mobile station), UT (user terminal), MSS (mobile subscriber station), SS (subscriber station), AMS (advanced mobile station), WT (wireless terminal), MTC (machine type communication) device, M2M (machine to machine) device, D2D (device to device) device, vehicle, RSU (roadside unit), robot, AI (artificial intelligence) module, drone (UAV: unmanned aerial vehicle), AR (augmented reality) device, VR (virtual reality) device, etc.

[0034] The following description may be used for various radio access systems such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA may be implemented by, for example, UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA may be implemented by radio technologies such as GSM (Global System for Mobile Communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA may be implemented by radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802-20, E-UTRA (Evolved UTRA), etc. 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) using E-UTRA, and LTE-A (Advanced) / LTE-A pro is an advanced version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an advanced version of 3GPP LTE / LTE-A / LTE-A pro.

[0035] In order to make the description clearer, the description is based on the 3GPP communication system (e.g., LTE-A, NR), but the technical idea of ​​the present disclosure is not limited to this. LTE means the technology after 3GPP TS (Technical Specification) 36.xxx version 8. Specifically, the LTE technology in or after 3GPP TS 36.xxx version 10 is called LTE-A, and the LTE technology in or after 3GPP TS 36.xxx version 13 is called LTE-A pro. 3GPP NR means the technology in or after TS 38.xxx version 15. LTE / NR can be referred to as a 3GPP system. "xxx" means the detailed number of the standard document. LTE / NR can generally be referred to as a 3GPP system. For the background technology, terms, abbreviations, etc. used to describe the present disclosure, reference can be made to the matters described in the standard documents disclosed before the present disclosure. For example, reference can be made to the following documents.

[0036] For 3GPP LTE, reference may be made to TS 36.211 (Physical Channels and Modulation), TS 36.212 (Multiplexing and Channel Coding), TS 36.213 (Physical Layer Procedures), TS 36.300 (Overall Description), and TS 36.331 (Radio Resource Control).

[0037] For 3GPP NR, you can refer to TS 38.211 (Physical channels and modulation), TS 38.212 (Multiplexing and channel coding), TS 38.213 (Physical layer procedures for control), TS 38.214 (Physical layer procedures for data), TS 38.300 (NR and NG-RAN (Next Generation Radio Access Network) overall description), and TS 38.331 (Radio Resource Control Protocol Specification).

[0038] Abbreviations of terms that may be used in the present disclosure are defined as follows.

[0039] -BM: Beam Management

[0040] -CQI: Channel Quality Indicator

[0041] -CRI: Channel State Information-Reference Signal Resource Indicator

[0042] -CSI: Channel State Information

[0043] -CSI-IM: Channel State Information-Interference Measurement

[0044] -CSI-RS: Channel State Information-Reference Signal

[0045] -DMRS: Demodulation Reference Signal

[0046] -FDM: Frequency Division Multiplexing

[0047] - FFT: Fast Fourier Transform

[0048] -IFDMA: Interleaved Frequency Division Multiple Access

[0049] -IFFT: Inverse Fast Fourier Transform

[0050] -L1-RSRP: Layer 1 reference signal received power

[0051] -L1-RSRQ: Layer 1 reference signal reception quality

[0052] -MAC: Media Access Control

[0053] -NZP: Non-Zero Power

[0054] - OFDM: Orthogonal Frequency Division Multiplexing

[0055] -PDCCH: Physical Downlink Control Channel

[0056] -PDSCH: Physical Downlink Shared Channel

[0057] -PMI: Precoding Matrix Indicator

[0058] -RE: Resource Element

[0059] -RI: Rank Indicator

[0060] -RRC: Radio Resource Control

[0061] -RSSI: Received Signal Strength Indicator

[0062] - Rx: Receive

[0063] - QCL: Quasi Co-sited

[0064] -SINR: Signal to Interference and Noise Ratio

[0065] -SSB (or SS / PBCH block): Synchronization signal block (including PSS (primary synchronization signal), SSS (secondary synchronization signal) and PBCH (physical broadcast channel))

[0066] -TDM: Time Division Multiplexing

[0067] -TRP: Transmit and Receive Point

[0068] -TRS: Tracking Reference Signal

[0069] -Tx: Send

[0070] -UE: User Equipment

[0071] -ZP: Zero Power

[0072] Overall system

[0073] As more communication devices require higher capacity, there has been a demand for improved mobile broadband communications compared to existing radio access technologies (RATs). In addition, large-scale MTC (machine type communication) that provides various services anytime and anywhere by connecting multiple devices and things is also one of the main issues to be considered in the next generation of communications. In addition, the design of communication systems considering services / terminals that are sensitive to reliability and latency is also discussed. Therefore, the introduction of next-generation RATs considering eMBB (enhanced mobile broadband communication), mMTC (massive MTC), URLLC (ultra-reliable low-latency communication), etc. is discussed, and for convenience, the corresponding technology is referred to as NR in this disclosure. NR is an expression representing an example of 5G RAT.

[0074] The new RAT system including NR uses an OFDM transmission method or a transmission method similar thereto. The new RAT system may follow OFDM parameters different from those of LTE. Alternatively, the new RAT system follows the parameters of the existing LTE / LTE-A as is, but may support a wider system bandwidth (e.g., 100 MHz). Alternatively, one cell may support multiple parameter sets. In other words, terminals operating according to different parameter sets may coexist in one cell.

[0075] A parameter set corresponds to one subcarrier spacing in the frequency domain. As the reference subcarrier spacing is scaled by an integer N, different parameter sets can be defined.

[0076] Figure 1 The diagram illustrates a structure of a wireless communication system to which the present disclosure can be applied.

[0077] refer to Figure 1 , NG-RAN is configured with gNBs that provide the control plane (RRC) protocol side for the NG-RA (NG Radio Access) user plane (i.e., the new AS (Access Stratum) sublayer / PDCP (Packet Data Convergence Protocol) / RLC (Radio Link Control) / MAC / PHY) and the UE. The gNBs are interconnected through the Xn interface. In addition, the gNBs are connected to the NGC (Next Generation Core) through the NG interface. More specifically, the gNB is connected to the AMF (Access and Mobility Management Power) through the N2 interface, and to the UPF (User Plane Function) through the N3 interface.

[0078] Figure 2 The diagram illustrates a frame structure in a wireless communication system to which the present disclosure may be applied.

[0079] The NR system may support multiple parameter sets. Here, the parameter set may be defined by subcarrier spacing and cyclic prefix (CP) overhead. Here, multiple subcarrier spacings may be derived by scaling the basic (reference) subcarrier spacing by an integer N (or, μ). In addition, although it is assumed that very low subcarrier spacings are not used in very high carrier frequencies, the parameter set used may be selected independently of the frequency band. In addition, various frame structures according to multiple parameter sets may be supported in the NR system.

[0080] In the following, OFDM parameter sets and frame structures that can be considered in the NR system are described. Multiple OFDM parameter sets supported in the NR system can be defined as shown in Table 1 below.

[0081] [Table 1]

[0082]

[0083] NR supports multiple parameter sets (or subcarrier spacing (SCS)) for supporting various 5G services. For example, when the SCS is 15kHz, it supports wide areas of traditional cellular bands; when the SCS is 30kHz / 60kHz, it supports dense cities, lower latency and wider carrier bandwidth; and when the SCS is 60kHz or higher, it supports bandwidths exceeding 24.25GHz to overcome phase noise.

[0084] The NR band is defined as two types of frequency ranges (FR1, FR2). FR1, FR2 can be configured as shown in Table 2 below. In addition, FR2 may mean millimeter wave (mmW).

[0085] [Table 2]

[0086]

[0087] Regarding the frame structure in the NR system, the sizes of various fields in the time domain are expressed as T c =1 / (Δf max ·N f ) is a multiple of the time unit. Here, Δf max i is 480·10 3 Hz, and N f is 4096. Downlink and uplink transmissions are configured (organized) to have duration T f= 1 / (Δf max N f / 100)·T c =10ms radio frame. Here, the radio frame is configured with 10 subframes, each of which has T sf =(Δf max N f / 1000)·T c In this case, there may be one frame set for the uplink and one frame set for the downlink. Furthermore, the transmission in the i-th uplink frame from the terminal should start T earlier than the corresponding downlink frame in the corresponding terminal. TA =(N TA +N TA,offset )T c For subcarrier spacing configuration μ, the time slots are arranged in n subframes. s μ ∈{0,..., N slot subframe,μ -1} and in the radio frame the number is incremented by n s,f μ ∈{0,..., N slot frame,μ -1}. A time slot is configured with Nsymb slot consecutive OFDM symbols, and N symb slot Determined according to CP. Time slot n in a subframe s μ The beginning of the OFDM symbol n in the same subframe s μ N symb slot All terminals may not perform transmission and reception at the same time, which means that all OFDM symbols of a downlink time slot or an uplink time slot may not be used.

[0088] Table 3 shows the number of OFDM symbols per time slot in a normal CP (N symb slot ), the number of time slots per radio frame (N slot frame,μ ) and the number of time slots per subframe (N slot subframe,μ ), and Table 4 represents the number of OFDM symbols per slot, the number of slots per radio frame, and the number of slots per subframe in the extended CP.

[0089] [Table 3]

[0090]

[0091] [Table 4]

[0092]

[0093] Figure 2 This is an example of μ=2 (SCS is 60kHz), see Table 3, 1 subframe can include 4 time slots. Figure 2 1 subframe = {1, 2, 4} shown in is an example, and the number of slots that can be included in 1 subframe is defined as in Table 3 or Table 4. In addition, a mini-slot may include 2, 4, or 7 symbols or more or less symbols.

[0094] Regarding the physical resources in the NR system, antenna ports, resource grids, resource elements, resource blocks, carrier parts, etc. can be considered. Hereinafter, the physical resources that can be considered in the NR system will be described in detail.

[0095] First, regarding antenna ports, the antenna ports are defined so that the channel carrying the symbol in the antenna port can be inferred from the channel carrying the other symbol in the same antenna port. When the large-scale properties of the channel on which the symbol in one antenna port is carried can be inferred from the channel carrying the symbol of another antenna port, the two antenna ports can be said to be in a QC / QCL (quasi-co-located or quasi-co-located) relationship. In this case, the large-scale properties include at least one of delay spread, Doppler spread, frequency shift, average received power, and receive timing.

[0096] Figure 3 A resource grid in a wireless communication system to which the present disclosure may be applied is illustrated.

[0097] refer to Figure 3 , which graphically depicts a resource grid configuration with N in the frequency domain RB μ N sc RB subcarriers, and one subframe is configured with 14·2 μ OFDM symbols, but not limited to this. In the NR system, the transmitted signal consists of 2 μ N symb （μ） OFDM symbols and N RB μ N sc RB Here, N RB μ ≤ N RB max,μ . N RB max,μ represents the maximum transmission bandwidth, which may differ between uplink and downlink and between parameter sets. In this case, one resource grid can be configured for each μ and antenna port p. Each element of the resource grid for μ and antenna port p is called a resource element and is uniquely identified by an index pair (k, l'). Here, k = 0, ..., N RB μ N sc RB -1 is the index in the frequency domain, and l'=0,...,2 μ N symb （μ） -1 refers to the symbol position in the subframe. When referencing resource elements in a slot, an index pair (k, l) is used. Here, l = 0, ..., N symb μ -1. The resource element (k, l') for μ and antenna port p corresponds to the complex value a k,l' （p,μ）When there is no risk of confusion or when no specific antenna port or parameter set is specified, the indices p and μ may be dropped and the complex value may be a k,l' （p） or a k,l' In addition, a resource block (RB) is defined as N sc RB =12 consecutive subcarriers.

[0098] Point A serves as a common reference point for the resource block grid and is obtained as follows.

[0099] -OffsetToPointA for the primary cell (PCell) downlink represents the frequency offset between point A and the lowest subcarrier of the lowest resource block overlapping with the SS / PBCH block, which is used by the terminal for initial cell selection. Assuming a subcarrier spacing of 15kHz for FR1 and a subcarrier spacing of 60kHz for FR2, it is expressed in resource blocks.

[0100] -absoluteFrequencyPointA represents the frequency position of point A, expressed in ARFCN (Absolute Radio Frequency Channel Number).

[0101] For subcarrier spacing configuration μ, the common resource blocks are numbered from 0 upwards in the frequency domain. The center of subcarrier 0 of common resource block 0 for subcarrier spacing configuration μ is the same as "point A". Common resource block number n for subcarrier spacing configuration μ in the frequency domain CRB μ The relationship between and resource elements (k, l) is given by the following equation 1.

[0102] [Formula 1]

[0103]

[0104] In Equation 1, k is defined relative to point A, so that k = 0 corresponds to a subcarrier centered at point A. Physical resource blocks are numbered from 0 to N in a bandwidth part (BWP). BWP,i size,μ -1 numbering and i is the number of the BWP. Physical resource block n in BWP i PRB and public resource block n CRB The relationship between is given by the following formula 2.

[0105] [Formula 2]

[0106]

[0107] N BWP,i start,μ is the common resource block where the BWP starts relative to common resource block 0.

[0108] Figure 4 The figure illustrates a physical resource block in a wireless communication system to which the present disclosure can be applied. Figure 5 The diagram illustrates a time slot structure in a wireless communication system to which the present disclosure may be applied.

[0109] refer to Figure 4 and Figure 5 , a slot includes a plurality of symbols in the time domain. For example, for a normal CP, 1 slot includes 7 symbols, but for an extended CP, 1 slot includes 6 symbols.

[0110] A carrier includes multiple subcarriers in the frequency domain. An RB (resource block) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (bandwidth part) is defined as multiple consecutive (physical) resource blocks in the frequency domain and may correspond to one parameter set (e.g., SCS, CP length, etc.). A carrier may include up to N (e.g., 5) BWPs. Data communication may be performed through activated BWPs, and only one BWP may be activated for one terminal. In a resource grid, each element is called a resource element (RE) and may map one complex symbol.

[0111] In the NR system, each component carrier (CC) can support up to 400MHz. If a terminal operating in such a wideband CC always operates to turn on the radio frequency (FR) chip for the entire CC, the terminal battery consumption may increase. Alternatively, when considering multiple application scenarios operating in one wideband CC (e.g., eMBB, URLLC, Mmtc, V2X, etc.), different parameter sets (e.g., subcarrier spacing, etc.) may be supported in each frequency band in the corresponding CC. Alternatively, each terminal may have different capabilities for the maximum bandwidth. Taking this into account, the base station may instruct the terminal to operate only in part of the bandwidth, rather than in the full bandwidth of the wideband CC, and for convenience, the corresponding part of the bandwidth is defined as a bandwidth part (BWP). The BWP may be configured with continuous RBs on the frequency axis and may correspond to a parameter set (e.g., subcarrier spacing, CP length, slot / microslot duration).

[0112] At the same time, even in one CC configured to the terminal, the base station can configure multiple BWPs. For example, a BWP occupying a relatively small frequency domain can be configured in the PDCCH monitoring time slot, and the PDSCH indicated by the PDCCH can be scheduled in a larger BWP. Alternatively, when the UE is congested in a specific BWP, other BWPs can be configured for some terminals for load balancing. Alternatively, considering the frequency domain inter-cell interference elimination between adjacent cells, etc., some full-bandwidth intermediate spectrums may not be included, and BWPs on two edges may be configured in the same time slot. In other words, the base station can configure at least one DL / UL BWP to a terminal associated with a broadband CC. The base station can activate at least one DL / UL BWP in the configured DL / UL BWP at a specific time (through L1 signaling or MAC CE (control element) or RRC signaling, etc.). In addition, the base station can indicate switching to other configured DL / UL BWPs (through L1 signaling or MAC CE or RRC signaling, etc.). Alternatively, based on a timer, when the timer value expires, it can switch to a determined DL / UL BWP. Here, the activated DL / UL BWP is defined as the active DL / UL BWP. However, when the terminal performs an initial access procedure or sets up an RRC connection, the configuration on the DL / UL BWP may not be received, so the DL / UL BWP assumed by the terminal in these cases is defined as the initial active DL / UL BWP.

[0113] Figure 6 Physical channels used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the physical channels are illustrated.

[0114] In a wireless communication system, a terminal receives information from a base station via a downlink and transmits information to the base station via an uplink. The information transmitted and received by the base station and the terminal includes data and various control information, and there are various physical channels according to the type / usage of the information they transmit and receive.

[0115] When the terminal is turned on or newly enters a cell, it performs an initial cell search including synchronization with a base station (S601). For the initial cell search, the terminal can synchronize with the base station by receiving a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station, and obtain information such as a cell identifier (ID). Then, the terminal can obtain broadcast information in the cell by receiving a physical broadcast channel (PBCH) from the base station. At the same time, the terminal can check the downlink channel status by receiving a downlink reference signal (DL RS) in the initial cell search phase.

[0116] The terminal that has completed the initial cell search may obtain more detailed system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to information carried in the PDCCH (S602).

[0117] Meanwhile, when the terminal accesses the base station for the first time or has no radio resources for signal transmission, it may perform a random access (RACH) procedure on the base station (S603 to S606). For the random access procedure, the terminal may send a specific sequence as a preamble through a physical random access channel (PRACH) (S603 and S605), and may receive a response message to the preamble through a PDCCH and a corresponding PDSCH (S604 and S606). The contention-based RACH may additionally perform a contention resolution procedure.

[0118] The terminal that subsequently performs the above process may perform PDCCH / PDSCH reception (S607) and PUSCH (Physical Uplink Shared Channel) / PUCCH (Physical Uplink Control Channel) transmission (S608) as a general uplink / downlink signal transmission process. Specifically, the terminal receives downlink control information (DCI) through the PDCCH. Here, DCI includes control information such as resource allocation information for the terminal, and the format varies according to its purpose of use.

[0119] At the same time, the control information sent by the terminal to the base station through the uplink or received by the terminal from the base station includes downlink / uplink ACK / NACK (acknowledgement / non-acknowledgement) signal, CQI (channel instruction indicator), PMI (precoding matrix indicator), RI (rank indicator), etc. For the 3GPP LTE system, the terminal can send the above-mentioned CQI / PMI / RI and other control information through PUSCH and / or PUCCH.

[0120] Table 5 shows an example of the DCI format in the NR system.

[0121] [Table 5]

[0122]

[0123] Referring to Table 5, DCI formats 0_0, 0_1, and 0_2 may include resource information (e.g., UL / SUL (supplementary UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), information related to a transport block (TB) (e.g., MCS (modulation coding and scheme), NDI (new data indicator), RV (redundancy version), etc.), information related to HARQ (hybrid-automatic repeat and request) (e.g., process number, DAI (downlink assignment index), PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., DMRS sequence initialization information, antenna port, CSI request, etc.), power control information related to scheduling of PUSCH (e.g., PUSCH power control, etc.), and control information included in each DCI format may be predefined.

[0124] DCI format 0_0 is used to schedule PUSCH in one cell. Information included in DCI format 0_0 is CRC (Cyclic Redundancy Check) scrambled by C-RNTI (Cell Radio Network Temporary Identifier) ​​or CS-RNTI (Configured Scheduling RNTI) or MCS-C-RNTI (Modulation Coding Scheme Cell RNTI) and transmitted.

[0125] DCI format 0_1 ​​is used to indicate the scheduling of one or more PUSCHs or to configure grant (CG) downlink feedback information to a terminal in one cell. The information included in DCI format 0_1 ​​is scrambled and transmitted by C-RNTI or CS-RNTI or SP-CSI-RNTI (semi-persistent CSI RNTI) or MCS-C-RNTI.

[0126] DCI format 0_2 is used to schedule PUSCH in one cell. Information included in DCI format 0_2 is scrambled and transmitted by C-RNTI, CS-RNTI, SP-CSI-RNTI, or MCS-C-RNTI.

[0127] Next, DCI formats 1_0, 1_1 and 1_2 may include resource information (e.g., frequency resource allocation, time resource allocation, VRB (virtual resource block) -PRB (physical resource block) mapping, etc.), information related to transport blocks (TBs) (e.g., MCS, NDI, RV, etc.), information related to HARQ (e.g., process number, DAI, PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., antenna ports, TCI (transmission configuration indicator), SRS (sounding reference signal) requests, etc.), information related to PUCCH scheduling regarding PDSCH (e.g., PUCCH power control, PUCCH resource indicator, etc.), and the control information included in each DCI format may be predefined.

[0128] DCI format 1_0 is used to schedule PDSCH in one DL cell. Information included in DCI format 1_0 is CRC scrambled and transmitted by C-RNTI or CS-RNTI or MCS-C-RNTI.

[0129] DCI format 1_1 is used to schedule PDSCH in one cell. Information included in DCI format 1_1 is CRC scrambled and transmitted by C-RNTI or CS-RNTI or MCS-C-RNTI.

[0130] DCI format 1_2 is used to schedule PDSCH in one cell. Information included in DCI format 1_2 is CRC scrambled and transmitted by C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0131] Discontinuous Reception (DRX) Operation

[0132] A UE configured with DRX can discontinuously receive DL signals to reduce power consumption. DRX can be performed in RRC_IDLE state, RRC_INACTIVE state, and RRC_CONNECTED state.

[0133] Hereinafter, a DRX operation in the RRC_CONNECTED state will be described.

[0134] In the RRC_CONNECTED state, DRX is used for discontinuous reception of PDCCH. For convenience, DRX performed in the RRC_CONNECTED state is referred to as RRC_CONNECTED DRX.

[0135] Figure 7 is a diagram illustrating a DRX cycle in a wireless communication system to which the present disclosure can be applied.

[0136] refer to Figure 7 , the DRX cycle includes an on-duration and an opportunity for DRX. The DRX cycle defines a time interval during which the on-duration is periodically repeated. The on-duration indicates the time period during which the UE monitors to receive the PDCCH. When DRX is configured, the UE performs PDCCH monitoring during the on-duration. If there is a successfully detected PDCCH during the PDCCH monitoring, the UE starts an inactivity timer and remains awake. On the other hand, if there is no successfully detected PDCCH during the PDCCH monitoring, the UE enters a sleep state after the on-duration ends. Therefore, when DRX is configured, when performing the processes and / or methods described / proposed above, PDCCH monitoring / reception can be performed discontinuously in the time domain.

[0137] Table 6 shows the procedures of the UE related to DRX (RRC_CONNECTED state).

[0138]

Table 6

[0139]

[0140] Referring to Table 6, DRX-related configuration information is received via higher layer (e.g., RRC) signaling (e.g., DRX-Config), and whether DRX is turned on / off is controlled by the DRX command MAC CE of the MAC layer. When configuring DRX, the UE can Figure 7 As shown in FIG. 1 , PDCCH monitoring is performed discontinuously.

[0141] Here, the configuration information for the MAC cell group (MAC-CellGroupConfig) includes configuration information required to configure MAC parameters for the cell group. MAC-CellGroupConfig may also include configuration information about DRX (e.g., DRX-Config). For example, the configuration information about DRX (e.g., DRX-Config) may include information defining DRX as follows:

[0142] - drx-onDurationTimer: defines the duration in the DRX cycle time.

[0143] - drx-SlotOffset: defines the delay before drx-onDurationTimer starts.

[0144] - drx-InactivityTimer: defines the duration after a PDCCH opportunity indicating a new UL, DL or SL for the MAC entity.

[0145] - drx-RetransmissionTimerDL: defines the maximum duration until a DL retransmission is received.

[0146] - drx-RetransmissionTimerUL: defines the maximum duration until a grant for UL retransmission is received.

[0147] - drx-LongCycleStartOffset: Indicates the long DRX cycle and also defines the subframes where the long and short DRX cycles start.

[0148] - drx-ShortCycle (optional): defines the short DRX cycle.

[0149] - drx-ShortCycleTimer (optional): defines the period during which the UE should follow a short DRX cycle.

[0150] - drx-HARQ-RTT-TimerDL: defines the minimum period before a DL assignment that the MAC entity expects a HARQ retransmission.

[0151] - drx-HARQ-RTT-TimerUL: defines the minimum period before a UL HARQ retransmission grant is expected by the MAC entity.

[0152] More specifically, regarding short DRX and long DRX operations, first, after receiving a PDCCH indicating initial UL or DL ​​data, a DRX inactivity timer (drx-InactivityTimer) is started / restarted, and the UE remains awake until the DRX inactivity timer (drx-InactivityTimer) expires.

[0153] When the DRX inactivity timer (drx-InactivityTimer) expires, a short DRX cycle can be optionally performed. That is, the base station can configure the UE to use a short DRX cycle by including a short DRX parameter set (i.e., drx-ShortCycle, drx-ShortCycleTimer) in the DRX-Config. In other words, if the short DRX parameter set in the DRX-Config is not configured, the UE can use the long DRX cycle described below. During the period of the short DRX cycle, if [(SFN×10)+subframe number] modulo (drx-ShortCycle) = (drx-StartOffset) modulo (drx-ShortCycle) is satisfied at the beginning of a specific subframe, the DRX active cycle starts after the DRX offset (drx-SlotOffset).

[0154] The UE maintains the DRX active state for a period defined by the DRX on duration timer (drx-onDurationTimer). If data transmission is initiated during the DRX active period, the DRX inactivity timer (drx-InactivityTimer) is restarted and the above operations are performed thereafter.

[0155] The long DRX cycle starts when the short DRX cycle (drx-ShortCycle×drx-ShortCycleTimer) ends. Alternatively, if the short DRX parameter set in DRX-Config is not configured, the long DRX cycle can be started when the DRX inactivity timer (drx-InactivityTimer) expires. During the long DRX cycle period, if [(SFN×10)+subframe number] modulo (drx-LongCycle)=drx-StartOffset is satisfied at the beginning of a specific subframe, the DRX active cycle starts after the DRX offset (drx-SlotOffset).

[0156] In addition, if the UE changes to DRX inactive state after sending uplink data on PUSCH, the UE needs to temporarily return to DRX active state to check for retransmission requests from the base station. The DRX UL HARQ RTT (Round Trip Time) Timer (drx-HARQ-RTT-TimerUL) specifies the timing of returning to DRX active state relative to the end of the first repetition of PUSCH transmission (or the end of PUSCH transmission if PUSCH repetition is not configured). That is, when the DRX UL HARQ RTT (Round Trip Time) Timer (drx-HARQ-RTT-TimerUL) expires, the UE transitions from DRX inactive state to DRX active state. The UE remains in DRX active state for the period defined by the DRX UL retransmission timer (drx-RetransmissionTimerUL).

[0157] Similarly, if the UE is in the DRX inactive state after receiving downlink data on the PDSCH and the UE sends a NACK (negative acknowledgement) for the data on the PUCCH, the UE needs to return to the DRX active state to receive a retransmission from the base station. In such a case, after the UE sends the NACK on the PUCCH, the DRX DL HARQ RTT timer (drx-HARQ-RTT-TimerDL) is started. That is, after the DRX DL HARQ RTT timer (drx-HARQ-RTT-TimerDL) expires, the UE transitions from the DRX inactive state to the DRX active state. The UE maintains the DRX active state for a period defined by the DRX DL retransmission timer (drx-RetransmissionTimerDL).

[0158] At the same time, DRX Command MAC CE and Long DRX Command MAC CE are used to make the UE enter the DRX active state immediately without waiting for the DRX inactivity timer (drx-InactivityTimer) to expire. The DRX Command MAC CE instructs the UE to enter the DRX inactive state, and if short DRX is configured, the UE starts a short DRX cycle, and if short DRX is not configured, the UE starts a long DRX cycle. The Long DRX Command MAC CE instructs the UE to enter the DRX inactive state and start a long DRX cycle.

[0159] V2X (Vehicle-to-Everything) / Sidelink (SL) communications

[0160] Figure 8 The diagram illustrates a process for performing V2X or SL communication according to a transmission mode in a wireless communication system to which the present disclosure can be applied.

[0161] Figure 8 The embodiments of the present disclosure can 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.

[0162] For example, Figure 8 (a) illustrates the operation of the UE related to LTE transmission mode 1 or LTE transmission mode 3. Alternatively, for example, Figure 8 (a) illustrates the operation of the UE 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.

[0163] For example, Figure 8 (b) illustrates the operation of a UE associated with LTE transmission mode 2 or LTE transmission mode 4. Alternatively, for example, Figure 8 (b) illustrates the operation of the UE associated with NR resource allocation mode 2.

[0164] refer to Figure 8 (a), in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, the base station may schedule SL resources for the UE to use for SL transmission (S8000). For example, the base station may send information related to the SL resources and / or information related to the UL resources to the first UE. For example, the UL resources may include PUCCH resources and / or PUSCH resources. For example, the UL resources may be resources for reporting SL HARQ feedback to the base station.

[0165] For example, the first UE may receive information related to dynamic grant (DG) resources and / or information related to configured grant (CG) resources from the base station. For example, the CG resources may include CG type 1 resources or CG type 2 resources. In the present disclosure, the DG resources may be resources that the base station configures / allocates to the first UE via DCI. In the present disclosure, the CG resources may be (periodic) resources that the base station configures / allocates to the first UE via DCI and / or RRC messages. For example, in the case of CG type 1 resources, the base station may send an RRC message including information related to the CG resources to the first UE. For example, for CG type 2 resources, the base station may send an RRC message including information related to the CG resources to the first UE, and the base station may send a DCI related to the activation or release of the CG resources to the first UE.

[0166] The first UE may transmit a PSCCH (eg, sidelink control information (SCI) or first-stage SCI) to the second UE based on resource scheduling ( S8010 ).

[0167] The first UE may transmit a PSSCH (eg, a second stage SCI, a MAC protocol data unit (PDU), data, etc.) related to the PSCCH to the second UE ( S8020 ).

[0168] The first UE may receive a PSFCH related to the PSCCH / PSSCH from the second UE (S8030). For example, HARQ feedback information (eg, NACK information or ACK information) may be received from the second UE via the PSFCH.

[0169] The first UE can send / report HARQ feedback information to the base station via PUCCH or PUSCH (S8040). For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on the HARQ feedback information received from the second UE. For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on a pre-configured rule. For example, the DCI may be a DCI for scheduling a SL. For example, the format of the DCI may be DCI format 3_0 or DCI format 3_1.

[0170] refer to Figure 8(b), in LTE transmission mode 2, LTE transmission mode 4 or NR resource allocation mode 2, the UE may determine the SL transmission resources within the SL resources configured by the base station / network or the pre-configured SL resources. For example, the configured SL resources or the pre-configured SL resources may be a resource pool. For example, the UE may autonomously select or schedule resources for SL transmission. For example, the UE may perform SL communication by selecting resources within the configured resource pool. For example, the UE may perform a sensing and resource (re)selection process to select resources within the selection window by itself. For example, sensing may be performed based on subchannels.

[0171] The first UE that has selected a resource within the resource pool can use the resource to send a PSCCH (eg, SCI or first-stage SCI) to the second UE ( S8010 ).

[0172] The first UE can transmit a PSSCH (eg, stage 2 SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal ( S8020 ).

[0173] The first UE can receive a PSFCH related to the PSCCH / PSSCH from the second UE ( S8030 ).

[0174] refer to Figure 8 (a) or Figure 8 (b), for example, the first UE may send the SCI on the PSCCH to the second UE. Alternatively, for example, the first UE may send two consecutive SCIs (e.g., stage 2 SCI) to the second UE on the PSCCH and / or PSSCH. In this case, the second UE may decode the two consecutive SCIs (e.g., stage 2 SCI) to receive the PSSCH from the first UE. In the present disclosure, the SCI sent on the PSCCH may be referred to as the first (first) SCI, the first SCI, the first stage SCI, or the first stage SCI format, and the SCI sent on the PSSCH may be referred to as the second (second) SCI, the second SCI, the second stage SCI, or the second stage SCI format. For example, the first stage SCI format may include SCI format 1-A, and the second stage SCI format may include SCI format 2-A and / or SCI format 2-B.

[0175] refer to Figure 8 (a) or Figure 8 (b), in step S8030, the first UE may receive PSFCH based on the content to be described below. For example, the first UE and the second UE may determine PSFCH resources based on the content to be described below, and the second UE may send HARQ feedback to the first UE using the PSFCH resources.

[0176] Sidelink Discontinuous Reception (SL DRX)

[0177] SL supports SL DRX for unicast, multicast and broadcast. To determine the SL active time for SL DRX, similar parameters (on-duration, inactivity timer, retransmission timer, cycles) defined for Uu (i.e., link between base station and UE) are defined for SL. During SL active time, UE performs SCI monitoring for data reception (i.e., 2-step SCI for PSCCH, PSSCH). UE is able to skip SCI monitoring for data reception during SL DRX inactive time.

[0178] The SL active time of the RX UE includes the time when the applicable SL On-Duration timer, SL Inactivity timer or SL Retransmission timer is running (for unicast, multicast or broadcast). In addition, the time slots associated with the periodic transmission announced by the TX UE and the time when the UE expects a CSI report after a CSI request (for unicast) are considered as the SL active time of the RX UE.

[0179] The TX UE maintains a set of timers corresponding to the SL DRX timers of the RX UE for a pair of source / destination L2 (Layer 2) IDs (identifiers) for unicast or a destination L2 ID for multicast / broadcast. When data for transmission is available for one or more RX UEs configured with SL DRX, the TX UE selects resources taking into account the active time of the RX UE as determined by the timers maintained in the TX UE.

[0180] Supports alignment of Uu DRX and SL DRX in RRC_CONNECTED for unicast, multicast and broadcast. Supports alignment of Uu DRX and SL DRX in the same UE. In addition, for Mode 1 scheduling, supports alignment of Uu DRX of TX UE and SLDRX of RX UE.

[0181] The alignment may include full or partial overlap in time between Uu DRX and SL DRX. For SL RX UEs in RRC_CONNECTED, the alignment is performed by the gNB.

[0182] The SL DRX feature can be used to configure the MAC entity through RRC to control the SCI (i.e., first stage SCI and second stage SCI) of the UE to monitor activities for unicast, multicast, and broadcast. When using SL DRX operation, the MAC entity should also monitor the SCI (i.e., first stage SCI and second stage SCI) as needed.

[0183] RRC controls the sidelink DRX operation by setting the following parameters:

[0184] - sl-drx-onDurationTimer: defines the duration when the SL DRX cycle starts. - sl-drx-SlotOffset: defines the delay before starting the sl-drx-onDurationTimer.

[0185] - sl-drx-SlotOffset: defines the delay before starting the sl-drx-onDurationTimer.

[0186] - sl-drx-InactivityTimer (excluding broadcast transmissions): defines the duration after the first timeslot of receiving an SCI indicating a new SL transmission to the MAC entity (i.e., first phase SCI and second phase SCI).

[0187] - sl-drx-RetransmissionTimer (per sidelink process, excluding broadcast transmissions): defines the maximum duration before a SL retransmission is received.

[0188] - sl-drx-StartOffset: defines the time slot at which the SL DRX cycle starts.

[0189] - sl-drx-Cycle: defines the sidelink DRX cycle.

[0190] - sl-drx-HARQ-RTT-Timer (per sidelink process, excluding broadcast transmissions): defines the minimum duration before a SL HARQ retransmission expected by the MAC entity.

[0191] When SL DRX is configured, the activity timer includes the following times:

[0192] - the duration that the sl-drx-onDurationTimer or sl-drx-InactivityTimer is running; or

[0193] - the duration that the sl-drx-RetransmissionTimer is running; or

[0194] - if no SL-CSI Report MAC CE is received, the duration of sl-LatencyBoundCSI-Report configured by RRC; or

[0195] - if a SL-CSI reporting MAC CE is received, the duration between the sending of the SL-CSI reporting request and the reception of the SL-CSI reporting MAC CE; or

[0196] - The timeslot associated with the periodic transmission announced when the UE sends SL-SCH data.

[0197] UEs transmitting Side Link Shared Channel (SL-SCH) data must be aligned with UEs receiving SL-SCH data relative to the above SL DRX active time.

[0198] In addition, the UE sending SL-SCH data determines the SL DRX activity time based on the SL DRX timer (e.g., sl-drx-onDurationTimer, sl-drx-InactivityTimer, sl-drx-RetransmissionTimer) that is running or will run in the UE receiving SL-SCH data. The UE is able to select resources for initial transmission of multicast within the time during which the sl-drx-onDurationTimer or sl-drx-InactivityTimer of the destination is running.

[0199] Method for configuring SL discontinuous reception (DRX) in side link (SL) communication

[0200] In the following, in the description of the present disclosure, for the sake of convenience of explanation, it is assumed that the specific UE performing the side link communication is a relay UE and / or a remote UE, but the present disclosure is not limited thereto. That is, in the following description of the present disclosure, the relay UE and the remote UE can be replaced by the first UE and the second UE, respectively, and vice versa.

[0201] Here, the relay UE may refer to a UE connected to a base station via a Uu interface (i.e., an interface / link between a UE and a base station) and connected to a remote UE via a PC5 interface (i.e., an interface / link between a UE and a UE). In addition, in the description of the present disclosure, the relay UE may also be referred to as a U2N relay UE in a UE-to-network relay (U2N relay) architecture, but this is for the convenience of description and the present disclosure is not limited thereto.

[0202] In addition, the remote UE may mean, but is not limited to, a UE that is indirectly connected to the base station via a relay UE, and further, a UE that is directly connected to the base station without passing through a relay UE. For example, in the description of the present disclosure, the remote UE may be referred to as a U2N remote UE in a U2N relay architecture, but this is for the convenience of description and the present disclosure is not limited thereto.

[0203] In addition, in the description of the present disclosure, PC5 or PC5-RRC connection means an interface / link / connection used for communication between UE and UE, and can be interpreted as having the same meaning as a side link (connection) between UE and UE. In addition, Uu or UuRRC connection means an interface / link / connection used for communication between UE and base station, and can be interpreted as having the same meaning as an uplink / downlink (connection) between a base station and UE.

[0204] According to the prior art, when the relay UE and the remote UE are configured with UE-to-network relay (U2N relay) functionality, the relay UE provides the U2N remote UE with a connection to the network. If the U2N relay functionality is based on the L3 (Layer 3) U2N relay architecture, the base station cannot accurately know the SL active time used by the relay UE and the remote UE. Therefore, the SL active time may not be well coordinated with the UL transmission and DL reception of the relay UE, which may result in non-optimal UE power consumption.

[0205] In order to solve these problems, the present disclosure proposes a method for configuring / constructing SL DRX configuration by a relay UE and / or a remote UE. In addition, a method for performing data transmission and reception by a relay UE and / or a remote UE for this purpose is also proposed.

[0206] The method proposed in the present disclosure comprises the following steps:

[0207] - The remote UE can establish a PC5-RRC connection with the relay UE. That is, the remote UE and the relay UE can establish a SL connection.

[0208] - The relay UE and the remote UE can each construct and configure a first SL DRX configuration for a PC5-RRC connection (ie, SL connection). The remote UE can send the first SL DRX configuration to the relay UE, or vice versa, the relay UE can send the first SL DRX configuration to the remote UE.

[0209] Here, the relay UE and the remote UE can determine the SL active time based on the first SL DRX configuration, respectively.

[0210] - If the remote UE is not in RRC_CONNECTED state, the remote UE establishes a Uu RRC connection through the relay UE for an indirect Uu RRC connection (i.e., uplink / downlink connection).

[0211] Here, if the remote UE has a direct Uu RRC connection with the base station in addition to the indirect Uu RRC connection (i.e., not via a relay UE), the base station may configure SL mode 1 (or NR resource allocation mode 1, see Figure 8 ).

[0212] In addition, the base station may configure SL mode 2 (or NR resource allocation mode 2, see NR resource allocation mode 2) for SL transmission of the remote UE, regardless of whether the remote UE has a direct Uu RRC connection with the base station (i.e., not via a relay UE). Figure 8 ).

[0213] -The remote UE may report the preferred DRX configuration to the base station via the relay UE. Alternatively, the remote UE may report the first SL DRX configuration to the gNB via the relay UE.

[0214] Here, the preferred DRX configuration can be constructed based on the first SL DRX configuration.

[0215] -The base station is able to configure the first SL DRX configuration based on the PC5-RRC connection or the preferred DRX for the remote UE.

[0216] -The relay UE is capable of receiving the second SL DRX configuration from the base station and sending all or part of the second SL DRX configuration to the remote UE.

[0217] For example, the relay UE can send all or part of the second SL DRX configuration to the remote UE via a PC5-RRC message (or a Uu RRC message).

[0218] Alternatively, the relay UE can configure a third SL DRX configuration based on the second SL DRX configuration, and send the third SL DRX configuration to the remote UE via a sidelink RRC message.

[0219] -The remote UE is able to configure the SL DRX with the second or third SL DRX configuration received from the relay UE for the PC5-RRC connection.

[0220] - According to the proposed method of the present disclosure, when the second or third SL DRX configuration is applied, the remote UE and / or the relay UE can determine the SL active time as follows:

[0221] For example, the UE can remove the first SL DRX configuration and apply the second or third SL DRX configuration to determine the SL active time for the PC5-RRC connection. In addition, the UE can determine the SL active time for the PC5-RRC connection based only on the second or third SL DRX configuration.

[0222] Alternatively, the UE may determine the SL active time for the PC5-RRC connection based on i) both the first SL DRX configuration and the second SL DRX configuration or ii) both the first SL DRX configuration and the third SL DRX configuration. For example, the UE may determine the first SL active time based on the first SL DRX configuration, and determine the second SL active time based on the second or third SL DRX configuration. In addition, the UE may determine the final SL active time based on the sum of the first SL active time and the second SL active time for the PC5-RRC connection. As another example, the UE may determine the final SL active time as a larger value between the first SL active time and the second SL active time.

[0223] Additionally, the UE may be configured with one or more other SL DRX configurations for one or more other PC5-RRC connections or for one or more other destinations (eg, for one or more of unicast, groupcast, and broadcast).

[0224] Fig. 9 The diagram illustrates a SL DRX configuration method according to an embodiment of the present disclosure.

[0225] refer to Fig. 9 , a method for performing data reception by a receiving UE may include the following steps.

[0226] 1. The U2N remote and U2N relay UEs perform a discovery process and establish a PC5-RRC connection using a predefined process (e.g., an NR V2X process). The U2N remote UE then constructs and sends a first SL DRX configuration to the U2N relay UE via a SL RRC reconfiguration message (e.g., RRCReconfigurationSidelink) for the PC5-RRC connection (i.e., SL connection), and the U2N relay UE may send the first SL DRX configuration to the U2N remote via a SL RRC reconfiguration completion message (e.g., RRCReconfigurationSidelinkComplete). Alternatively, instead, the U2N relay UE may configure / establish a first SL DRX configuration and send the first SL DRX configuration to the U2N remote UE via a SL RRC reconfiguration message (e.g., RRCReconfigurationSidelink) for the PC5-RRC connection (i.e., the SL connection), and the U2N remote UE may send a SL RRC reconfiguration completion message (e.g., RRCReconfigurationSidelinkComplete) to the U2N relay.

[0227] (If the U2N relay UE receives the first SL DRX configuration) The U2N relay UE may apply the first SL DRX configuration to determine the SL active time for monitoring the SCI from the U2N remote UE for the PC5-RRC connection (i.e., the SL connection). Alternatively, (if the U2N remote UE receives the first SL DRX configuration) The U2N remote UE may apply the first SL DRX configuration to determine the SL active time for monitoring the SCI from the U2N relay UE for the PC5-RRC connection (i.e., the SL connection).

[0228] 2. If the U2N remote UE does not have a direct Uu RRC connection (i.e., an uplink / downlink connection with the base station), the U2N remote UE may send a first RRC message (i.e., an RRC setup request (RRCSetupRequest) message) to the U2N relay UE to establish a connection with the base station by configuring using a designated PC5 channel (e.g., a PC5 relay RLC channel). If the U2N relay UE is not in the RRC_CONNECTED state, it may need to establish its own connection when receiving a message on the designated PC5 channel (e.g., a PC5 relay RLC channel). During the RRC connection establishment process of the U2N relay UE, the base station may configure SRB0 (Signaling Radio Bearer 0) for relaying (e.g., relaying the U2N relay RLC channel) to the U2N relay UE. The base station may respond to the U2N remote UE with an RRC setup (RRCSetup) message. The RRCSetup message can be sent to the U2N remote UE using an SRB0 relay channel over Uu (ie, a channel between the base station and the relay UE) and a designated PC5 relay channel over PC5 (ie, a channel between the relay UE and the remote UE).

[0229] 3. The base station and the U2N relay UE perform a relay channel setup procedure via Uu (i.e., uplink / downlink connection with the base station). Depending on the configuration of the base station, the U2N relay / remote UE is able to establish a PC5 channel (e.g., a PC5 relay RLC channel) to relay SRB1 (i.e., a SL connection between the relay UE and the remote UE) towards the U2N remote / relay UE via PC5.

[0230] 4. Using the SRB1 relay channel configured to the U2N relay UE via Uu and the SRB1 relay channel via PC5, the U2N remote UE can send an RRC Setup Complete message to the base station via the U2N relay UE. In this case, the U2N remote UE transitions to the RRC connected state via Uu.

[0231] 5. The U2N remote UE and the base station can set up security according to the Uu procedure and can send security messages (ie, SecurityModeCommand message and SecurityModeComplete message) through the U2N relay UE.

[0232] 6. The U2N remote UE may inform the base station of the SL DRX configuration through the U2N relay UE by sending a SL UE Information (SidelinkUEInformationNR) message. Here, the SL UE Information (SidelinkUEInformationNR) message may include a first SL DRX configuration using the SRB1 (or SRB2, if configured) relay channel through PC5 and the SRB1 (or SRB2, if configured) relay channel configured to the U2N relay UE through Uu.

[0233] Alternatively, the U2N relay UE may inform the base station of the first SL DRX configuration received from the U2N remote UE (ie, without receiving a SL UE Information (SidelinkUEInformationNR) message from the remote UE).

[0234] 7. The base station may send an RRC reconfiguration message indirectly to the U2N remote UE via the U2N relay UE to set up signaling radio bearer 2 (SRB2) / data radio bearer (DRB) and / or set up SL DRX for relay. The U2N remote UE may send an RRC reconfiguration complete message to the base station via the U2N relay UE in response.

[0235] Alternatively, if the U2N remote UE has a direct Uu RRC connection between the U2N remote UE and the base station in addition to the indirect Uu RRC connection with the base station via the U2N relay UE, the U2N remote UE may also send an RRCReconfigurationComplete message indirectly to the base station via the U2N relay UE or directly send an RRCReconfigurationComplete message in the uplink as a response.

[0236] In addition, the base station may additionally set up a Uu channel for relaying services (eg, a Uu relay RLC channel) between the base station and the U2N relay UE, and set up a PC5 channel (eg, a PC5 relay RLC channel) between the U2N relay UE and the U2N remote UE.

[0237] Here, the RRC reconfiguration message may include information about the second SL DRX configuration.

[0238] Alternatively, if the U2N remote UE has a direct Uu RRC connection between the U2N remote UE and the base station in addition to the indirect Uu RRC connection with the base station via the U2N relay UE, the base station may send an RRC reconfiguration message directly to the U2N remote UE in the downlink via the direct Uu RRC connection. In this case, the U2N remote UE may send an RRC reconfiguration complete message to the base station in response, either indirectly via the U2N relay UE or directly in the uplink.

[0239] Alternatively, the base station may directly send an RRC reconfiguration (RRCReconfiguration) message including the second SL DRX configuration to the U2N relay UE. In this case, the relay UE may configure a third SL DRX configuration based on the second SL DRX configuration, and send the third SL DRX configuration to the remote UE via an SL RRC reconfiguration (RRCReconfigurationSidelink) message. Alternatively, the relay UE may send the second SL DRX configuration to the remote UE via an SL RRC reconfiguration (RRCReconfigurationSidelink) message. Then, the relay UE and / or the remote UE may skip step 8. The relay UE and / or the remote UE may determine the SL active time based on the second SL DRX configuration and / or the third SL DRX configuration.

[0240] In this case, the RRCReconfiguration message may include one or more second SL DRX configurations (for example, as a list of second SL DRX configurations). When the relay UE receives the list, the relay UE may select a SL DRX configuration from the list. For example, the relay UE may select a SL DRX configuration based on the PC5-RRC connection and / or the U2N relay connection and / or the QoS characteristics of the DL DRX for the relay UE. The relay UE may then send the selected SL DRX configuration as a third SL DRX configuration to the remote UE. Thereafter, the relay UE may notify the base station of the selected SL DRX configuration via an RRCReconfigurationComplete message or another SL UE information (SidelinkUEInformationNR) message.

[0241] 8. If the RRCReconfiguration message includes the second SL DRX configuration, the U2N remote UE may send the second SL DRX configuration to the U2N relay UE via the SL RRCReconfigurationSidelink message for the PC5-RRC connection. Alternatively, the U2N relay UE may send the second SL DRX configuration to the U2N remote UE via the SL RRCReconfigurationSidelink message for the PC5-RRC connection. The U2N relay UE may apply the second SL DRX configuration to determine the SL active time for monitoring the SCI in the U2N remote UE for the PC5-RRC connection.

[0242] Here, the RRC reconfiguration message may include one or more second SL DRX configurations (e.g., as a list of second SL DRX configurations). When the remote UE receives the list, the remote UE may select a SL DRX configuration from the list. For example, the remote UE may select a SL DRX configuration based on the QoS (Quality of Service) characteristics of the DL DRX for the PC5-RRC connection and / or the U2N relay connection and / or the remote UE. The remote UE may then send the selected SL DRX configuration as the second SL DRX configuration to the relay UE. Thereafter, the remote UE may directly or indirectly notify the base station of the selected SL DRX configuration via an RRC reconfiguration complete message or another SL UE information (SidelinkUEInformationNR) message.

[0243] If the RRCReconfiguration message does not include the second SL DRX configuration or the remote UE does not select any second SL DRX configuration (e.g., because no second SL DRX configuration can meet the QoS requirements for the PC5-RRC connection), the U2N remote UE and the U2N relay UE may skip step 8. Therefore, the U2N remote UE and the U2N relay UE may continue to use the first SL DRX configuration for the relay UE to determine the SL active time for monitoring the SCI from the U2N remote UE for the PC5-RRC connection.

[0244] Alternatively, the base station may directly send an RRCReconfiguration message including the second SL DRX configuration to the U2N relay UE. In this case, the U2N remote UE does not need to send the second SL DRX configuration to the U2N relay UE.

[0245] According to one embodiment of the present disclosure, when the second SL DRX configuration or the third SL DRX configuration is applied, the remote UE and / or the relay UE may determine the SL active time as follows.

[0246] For example, the UE may remove the first SL DRX configuration and apply the second SL DRX configuration or the third SL DRX configuration to determine the SL active time for the PC5-RRC connection. And the UE may determine the SL active time for the PC5-RRC connection based only on the second SL DRX configuration or the third SL DRX configuration.

[0247] Alternatively, for example, the UE may determine the SL activity time for the PC5-RRC connection based on i) both the first SL DRX configuration and the second SL DRX configuration or ii) both the first SL DRX configuration and the third SL DRX configuration. For example, the UE may determine the first SL activity time based on the first SL DRX configuration and determine the second SL activity time based on the second or third SL DRX configuration. Then, the UE may determine the final SL activity time based on the sum of the first SL activity time and the second SL activity time for the PC5-RRC connection. In addition, the UE may notify the base station of the final SL activity time.

[0248] Here, the UE may be configured with one or more different SL DRX configurations for one or more different PC5-RRC connections or one or more different destinations (eg, one or more unicast, groupcast, broadcast).

[0249] At the same time, the remote UE may directly or indirectly receive a second SL DRX configuration from the base station. In addition, the remote UE may receive a first and / or third SL DRX configuration from the relay UE. In this case, in order to receive an SCI for a PC5-RRC connection and / or a U2N relay connection from the relay UE, the remote UE may determine the SL active time based on the second SL DRX configuration from the relay UE and the first and / or third SL DRX configuration. For example, the UE may determine a first SL active time based on the first and / or third SL DRX configuration, and determine a second SL active time based on the second SL DRX configuration. Then, the UE may determine the final SL active time based on the sum of the first SL active time and the second SL active time for the PC5-RRC connection. In addition, the UE may notify the base station of the final SL active time.

[0250] By using the proposed method of the present disclosure described above, UE power can be saved when the UE performs SL transmission and / or reception, especially when the UE is configured with SL DRX and U2N relay functions.

[0251] Although conventional technology does not define a method for providing a UE power saving mechanism for sidelink relay, the method proposed in the present disclosure is effective because the system can appropriately provide energy-saving sidelink reception based on an indirect Uu RRC connection configured through U2N relay and SL DRX.

[0252] Fig.10 The figure illustrates a signaling process for a SL DRX configuration method according to an embodiment of the present disclosure.

[0253] exist Fig.10 In the embodiment, the first UE may correspond to a relay UE and the second UE may correspond to a remote UE.

[0254] Alternatively, conversely, the first UE may correspond to a remote UE, and the second UE may correspond to a relay UE. In this case, signaling between the first UE and the base station may be performed via a direct link (if a direct link is established), or may be performed indirectly via the second UE.

[0255] refer to Fig.10 , the first UE sends information about the first SL DRX configuration to the second UE (S1001).

[0256] For example, the information about the first SL DRX configuration may include at least one of the following information:

[0257] - sl-drx-onDurationTimer: Duration when SL DRX cycle starts

[0258] - sl-drx-SlotOffset: Delay before starting sl-drx-onDurationTimer

[0259] - sl-drx-InactivityTimer (excluding broadcast transmissions): Duration after the first timeslot of receiving an SCI indicating a new SL transmission to the MAC entity (i.e., first phase SCI and second phase SCI)

[0260] - sl-drx-RetransmissionTimer (per sidelink process, excluding broadcast transmissions): Maximum duration before a SL retransmission is received

[0261] - sl-drx-StartOffset: The time slot at which the SL DRX cycle starts

[0262] - sl-drx-Cycle: Sidelink DRX cycle

[0263] - sl-drx-HARQ-RTT-Timer (per sidelink process, excluding broadcast transmissions): minimum duration before a SL HARQ retransmission expected by the MAC entity

[0264] The second UE determines a SL active time based on received information about the first SL DRX configuration ( S1002 ).

[0265] For example, the SL activity time may be determined to include at least one of the following times:

[0266] - the amount of time that sl-drx-onDurationTimer or sl-drx-InactivityTimer is running; or

[0267] - the time that sl-drx-RetransmissionTimer is running; or

[0268] - if no SL-CSI Report MAC CE is received, the duration of sl-LatencyBoundCSI-Report configured by RRC; or

[0269] - if a SL-CSI reporting MAC CE is received, the time between the sending of the SL-CSI reporting request and the reception of the SL-CSI reporting MAC CE; or

[0270] - The timeslot associated with a periodic transmission announced by a UE sending SL-SCH data.

[0271] The second UE may receive information about the second SL DRX configuration from the base station, or receive information about the third SL DRX configuration from the first UE ( S1003 , S1004 ).

[0272] Here, for example, the information about the second SL DRX configuration or the information about the third SL DRX configuration may include at least one of the following information:

[0273] - sl-drx-onDurationTimer: Duration when SL DRX cycle starts

[0274] - sl-drx-SlotOffset: Delay before starting sl-drx-onDurationTimer

[0275] - sl-drx-InactivityTimer (excluding broadcast transmissions): Duration after the first timeslot of reception of an SCI indicating a new SL transmission to the MAC entity (i.e., Phase 1 SCI and Phase 2 SCI)

[0276] - sl-drx-RetransmissionTimer (per sidelink process, excluding broadcast transmissions): maximum duration until SL retransmission is received

[0277] - sl-drx-StartOffset: The time slot at which the SL DRX cycle starts

[0278] - sl-drx-Cycle: Sidelink DRX cycle

[0279] - sl-drx-HARQ-RTT-Timer (per sidelink process, excluding broadcast transmissions): minimum time to live before a SL HARQ retransmission expected by the MAC entity.

[0280] Here, when the second UE receives the information about the second SL DRX configuration from the base station, the information about the second SL DRX configuration may be directly received from the base station via an RRC (Radio Resource Control) reconfiguration message, or may be indirectly received via the first UE.

[0281] In addition, the RRC reconfiguration message includes a list of one or more SL DRX configurations, and is capable of selecting and determining a second SL DRX configuration from the list. For example, the second SL DRX configuration can be selected from the list based on at least one of the QoS characteristics for the SL connection between the first UE and the second UE, the QoS characteristics for the connection with the base station, and the DL DRX configuration of the second UE. In this case, when the second UE sends an RRC reconfiguration complete message in response to the RRC reconfiguration message, information about the selected second SL DRX configuration can be sent directly to the base station via the RRC reconfiguration complete message, or can be sent indirectly via the first UE.

[0282] Here, if the second UE receives information about the third SL DRX configuration from the first UE, the third SL DRX configuration can be determined based on the SL DRX configuration provided from the base station. For example, the third SL DRX configuration can be determined by selecting from a list of one or more SL DRX configurations provided by the base station via an RRC reconfiguration message. For example, the third SL DRX configuration can be selected from the list based on the QoS characteristics for the SL connection between the first UE and the second UE, the QoS characteristics for the connection with the base station, and at least one of the DLDRX configurations of the first UE.

[0283] The second UE re-determines the SL active time based on the second SL DRX configuration or the third SL DRX configuration ( S1005 ).

[0284] Here, the SL active time may be i) re-determined based on both the first SL DRX configuration and the second SL DRX configuration, or ii) re-determined based on both the first SL DRX configuration and the third SL DRX configuration.

[0285] For example, the second UE may determine the first SL activity time based on the previous first SL DRX configuration received from the first UE, and determine the second SL activity time based on the second SL DRX configuration or the third SL DRX configuration received in step S1003 or S1004. Then, the final SL activity time may be determined again as the sum of the first SL activity time and the second SL activity time.

[0286] Fig.11 is a diagram illustrating the operation of a UE for a SL DRX configuration method according to an embodiment of the present disclosure.

[0287] Fig.11 The operation of the UE based on the previously proposed method is illustrated. Fig.11 The examples are for convenience of explanation and do not limit the scope of the present disclosure. Fig.11 Some of the steps illustrated in the figure may be omitted depending on the situation and / or setting. Fig.11 The UE in the example is only an example and can be implemented as follows Fig.12 For example, Fig.12 The processor (102 / 202) can control to use the transceiver (106 / 206) to send and receive channels / signals / data / information, etc. In addition, Fig.12 The processor (102 / 202) can control to store the channel / signal / data / information to be transmitted in the memory (104 / 204), and can also control to store the received channel / signal / data / information in the memory (104 / 204).

[0288] exist Fig.11 In the embodiment of the present invention, the first UE may correspond to the relay UE, and the second UE may correspond to the remote UE. Alternatively, conversely, the first UE may correspond to the remote UE, and the second UE may correspond to the relay UE.

[0289] refer to Fig.11 , the first UE receives information about the first SL DRX setting from the second UE (S1101).

[0290] For example, the information about the first SL DRX configuration may include at least one of the following information:

[0291] - sl-drx-onDurationTimer: Duration when SL DRX cycle starts

[0292] - sl-drx-SlotOffset: Delay before starting sl-drx-onDurationTimer

[0293] - sl-drx-InactivityTimer (excluding broadcast transmissions): Duration after the first timeslot of receiving an SCI indicating a new SL transmission to the MAC entity (i.e., first phase SCI and second phase SCI)

[0294] - sl-drx-RetransmissionTimer (per sidelink process, excluding broadcast transmissions): maximum duration until SL retransmission is received

[0295] - sl-drx-StartOffset: The time slot at which the SL DRX cycle starts

[0296] - sl-drx-Cycle: Sidelink DRX cycle

[0297] - sl-drx-HARQ-RTT-Timer (per sidelink process, excluding broadcast transmissions): minimum duration before a SLHARQ retransmission expected by the MAC entity

[0298] The first UE determines a SL active time based on received information about a first SL DRX configuration ( S1102 ).

[0299] For example, the SL activity time may be determined to include at least one of the following times:

[0300] – the time that sl-drx-onDurationTimer or sl-drx-InactivityTimer is running; or

[0301] - the time that sl-drx-RetransmissionTimer is running; or

[0302] - if no SL-CSI Report MAC CE is received, the duration of sl-LatencyBoundCSI-Report configured by RRC; or

[0303] - if a SL-CSI reporting MAC CE is received, the time between the sending of the SL-CSI reporting request and the receipt of the SL-CSI reporting MAC CE; or

[0304] - The timeslot associated with the periodic transmission announced by the UE sending SL-SCH data.

[0305] The first UE may receive information about the second SL DRX configuration from the base station, or may receive information about the third SL DRX configuration from the second UE ( S1103 ).

[0306] Here, for example, the information about the second SL DRX configuration or the information about the third SL DRX configuration may include at least one of the following information:

[0307] - sl-drx-onDurationTimer: Duration when SL DRX cycle starts

[0308] - sl-drx-SlotOffset: Delay before starting sl-drx-onDurationTimer

[0309] - sl-drx-InactivityTimer (excluding broadcast transmissions): Duration after the first timeslot of reception of an SCI indicating a new SL transmission to the MAC entity (i.e., Phase 1 SCI and Phase 2 SCI)

[0310] - sl-drx-RetransmissionTimer (per sidelink process, excluding broadcast transmissions): maximum duration until SL retransmission is received

[0311] - sl-drx-StartOffset: The time slot at which the SL DRX cycle starts

[0312] - sl-drx-Cycle: Sidelink DRX cycle

[0313] - sl-drx-HARQ-RTT-Timer (per sidelink process, excluding broadcast transmissions): Minimum time to live before a SL HARQ retransmission expected by the MAC entity.

[0314] Here, when the first UE receives the information about the second SL DRX configuration from the base station, the information about the second SL DRX configuration may be directly received from the base station via an RRC (Radio Resource Control) reconfiguration message, or may be indirectly received via the second UE.

[0315] In addition, the RRC reconfiguration message includes a list of one or more SL DRX configurations, and is capable of selecting and determining a second SL DRX configuration from the list. For example, the second SL DRX configuration can be selected from the list based on at least one of the QoS characteristics for the SL connection between the first UE and the second UE, the QoS characteristics for the connection with the base station, and the DL DRX configuration of the first UE. In this case, when the first UE sends an RRC reconfiguration complete message in response to the RRC reconfiguration message, information about the selected second SL DRX configuration can be sent directly to the base station via the RRC reconfiguration complete message, or can be sent indirectly via the second UE.

[0316] Here, if the first UE receives information about the third SL DRX configuration from the second UE, the third SL DRX configuration can be determined based on the SL DRX configuration provided from the base station. For example, the third SL DRX configuration can be determined by selecting from a list of one or more SL DRX configurations provided by the base station via an RRC reconfiguration message. For example, the third SL DRX configuration can be selected from the list based on at least one of the QoS characteristics for the SL connection between the first UE and the second UE, the QoS characteristics for the connection with the base station, and the DL DRX configuration of the second UE.

[0317] The first UE re-determines the SL active time based on the second SL DRX configuration or the third SL DRX configuration ( S1104 ).

[0318] Here, the SL active time may be i) re-determined based on both the first SL DRX configuration and the second SL DRX configuration, or ii) re-determined based on both the first SL DRX configuration and the third SL DRX configuration.

[0319] For example, the first UE may determine the first SL activity time based on the previous first SL DRX configuration received from the second UE, and determine the second SL activity time based on the second SL DRX configuration or the third SL DRX configuration received in step S1103. Then, the final SL activity time may be determined again as the sum of the first SL activity time and the second SL activity time.

[0320] General equipment to which the present disclosure can be applied

[0321] Fig.12 is a diagram illustrating a block diagram of a wireless communication device according to an embodiment of the present disclosure.

[0322] refer to Fig.12, the first wireless device 100 and the second wireless device 200 can send and receive wireless signals through a variety of radio access technologies (e.g., LTE, NR).

[0323] The first wireless device 100 may include one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106 and may be configured to implement the description, function, process, proposal, method and / or operation flowchart disclosed in the present disclosure. For example, the processor 102 may send a wireless signal including the first information / signal through the transceiver 106 after generating the first information / signal by processing the information in the memory 104. In addition, the processor 102 may receive a wireless signal including the second information / signal through the transceiver 106, and then store the information obtained by 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 including commands for executing all or part of the process controlled by the processor 102 or for executing the description, function, process, proposal, method and / or operation flowchart disclosed in the present disclosure. 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 send and / or receive wireless signals through one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used in conjunction with an RF (radio frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0324] The second wireless device 200 may include one or more processors 202 and one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206 and may be configured to implement the description, function, process, proposal, method and / or operation flowchart disclosed in the present disclosure. For example, the processor 202 may generate third information / signal by processing the information in the memory 204, and then transmit the wireless signal including the third information / signal through the transceiver 206. In addition, the processor 202 may receive a wireless signal including fourth information / signal through the transceiver 206, and then store the information obtained by signal processing of the fourth information / signal in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software code including commands for executing all or part of the process controlled by the processor 202 or for executing the description, function, process, proposal, method and / or operation flowchart disclosed in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver 206 may be connected to the processor 202 and may send and / or receive wireless signals through one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used in conjunction with an RF unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0325] In the following, the hardware elements of the wireless device 100, 200 will be described in more detail. It is not limited thereto, and 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 PDUs (protocol data units) and / or one or more SDUs (service data units) according to the descriptions, functions, processes, proposals, methods, and / or operational flow charts included in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operational flow charts disclosed in the present disclosure. One or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, processes, proposals, and / or methods disclosed in the present disclosure to provide them to one or more transceivers 106, 206. The one or more processors 102, 202 may receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operational flow charts disclosed in the present disclosure.

[0326] One or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 may be implemented by hardware, firmware, software, or a combination thereof. In an example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors 102, 202. The description, functions, processes, proposals, methods, and / or operational flowcharts disclosed in the present disclosure may be implemented by using firmware or software and the firmware or software may be implemented to include modules, processes, functions, etc. Firmware or software configured to execute the description, functions, processes, proposals, methods, and / or operational flowcharts disclosed in the present disclosure may be included in one or more processors 102, 202 or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The description, functions, processes, proposals, methods, and / or operational flowcharts disclosed in the present disclosure may be implemented by firmware or software in the form of codes, commands, and / or command sets.

[0327] One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store data, signals, messages, information, programs, codes, instructions, and / or commands in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard drive, registers, cash memory, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 may be located inside and / or outside one or more processors 102, 202. In addition, one or more memories 104, 204 may be connected to one or more processors 102, 202 via a variety of technologies such as wired or wireless connections.

[0328] One or more transceivers 106, 206 may send user data, control information, wireless signals / channels, etc. mentioned in the methods and / or operation flow charts, etc. of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc. mentioned in the description, function, process, proposal, method and / or operation flow chart, etc. disclosed in the present disclosure 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 send and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to send user data, control information or wireless signals to one or more other devices. In addition, 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. In addition, 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 send and receive user data, control information, wireless signals / channels, etc. mentioned in the description, functions, processes, proposals, methods and / or operation flow charts disclosed in the present disclosure through one or more antennas 108, 208. In the present invention, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert received wireless signals / channels, etc. from RF band signals to baseband signals by using one or more processors 102, 202 to process received user data, control information, wireless signals / channels, etc. One or more transceivers 106, 206 may convert user data, control information, wireless signals / channels, etc. processed by using one or more processors 102, 202 from baseband signals to RF band signals. Therefore, one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0329] The above-mentioned embodiments are elements and features of the present disclosure combined in a predetermined form. Unless otherwise explicitly mentioned, each element or feature should be considered optional. Each element or feature can be implemented in a form that is not combined with other elements or features. In addition, the embodiments of the present disclosure may include combined partial elements and / or features. The order of the operations described in the embodiments of the present disclosure may be changed. Some elements or features of an embodiment may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. It is clear that an embodiment may include a combined claim without an explicit dependency in the claim, or may be included as a new claim by modification after application.

[0330] It is clear to those skilled in the art that the present disclosure can be implemented in other specific forms within the scope of the essential features of the present disclosure. Therefore, the above detailed description should not be interpreted restrictively in every aspect, but should be considered as illustrative. The scope of the present invention should be determined by the reasonable interpretation of the attached claims, and all changes within the equivalent scope of the present disclosure are included in the scope of the present invention.

[0331] The scope of the present disclosure includes software or machine executable commands (e.g., operating systems, applications, firmware, programs, etc.) that perform operations in a device or computer according to the methods of various embodiments, and non-transitory computer-readable media that store such software or commands, etc. and can be executed in a device or computer. Commands that can be used to program a processing system that performs the features described in the present disclosure can be stored in a storage medium or a computer-readable storage medium, and the features described in the present disclosure can be implemented by using a computer program product that includes such a storage medium. The storage medium may include a high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, but is not limited thereto, and it may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices located away from the processor. The memory or alternatively, the non-volatile memory device in the memory includes a non-transitory computer-readable storage medium. The features described in this disclosure may be stored in any machine-readable medium to control the hardware of a processing system, and may be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using the results from embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0332] Here, the wireless communication technology implemented in the wireless devices 100 and 200 of the present disclosure may include narrowband Internet of Things for low-power communication, as well as LTE, NR and 6G. Here, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, which may be implemented in standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above names. In addition or alternatively, the wireless communication technology implemented in the wireless devices 100 and 200 of the present disclosure may perform communication based on LTE-M technology. Here, in the example, LTE-M technology may be an example of LPWAN technology and may be referred to as various names such as eMTC (enhanced machine type communication). For example, LTE-M technology may be implemented in at least any one of the various standards including 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, etc., and is not limited to the above names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100, 200 of the present disclosure may include at least any one of ZigBee, Bluetooth, and a low power wide area network (LPWAN) considering low power communication, and it is not limited to the above names. In an example, the ZigBee technology may generate a PAN (Personal Area Network) related to small / low power digital communication based on various standards such as IEEE 802.15.4, etc., and may be referred to by various names.

[0333] [Industrial Availability]

[0334] The method proposed in the present invention is mainly described by taking the application in 3GPP LTE / LTE-A and 5G systems as an example, but can also be applied to various wireless communication systems other than 3GPP LTE / LTE-A and 5G systems.

Claims

1. A method performed by a first user equipment (UE) in a wireless communication system, the method comprising: receiving information for a first sidelink (SL) discontinuous reception (DRX) configuration from a second UE; determining a SL active time for monitoring sidelink control information (SCI) from the second UE based on the first SL DRX configuration; and re-determining the SL active time based on receiving information for a second SL DRX configuration from a base station or receiving information for a third SL DRX configuration from the second UE, The SL active time is re-determined based on i) both the first SL DRX configuration and the second SL DRX configuration or ii) both the first SL DRX configuration and the third SL DRX configuration.

2. The method according to claim 1, wherein: determining the first SL active time from the first SL DRX configuration, determining the second SL active time based on the second SL DRX configuration or the third SL DRX configuration, and Among them, the SL activity time is re-determined as the sum of the first SL activity time and the second SL activity time.

3. The method according to claim 1, wherein: The information for the second SL DRX configuration is directly received from the base station through an RRC (Radio Resource Control) reconfiguration message or indirectly received through the second UE.

4. The method according to claim 3, wherein: The RRC reconfiguration message includes a list of one or more SL DRX configurations, and the second SL DRX configuration is selected and determined from the list.

5. The method according to claim 4, wherein: The second SL DRX configuration is selected from the list based on at least one of a quality of service (QoS) characteristic for a SL connection between the first UE and the second UE, a QoS characteristic for a connection with the base station, and a downlink (DL) DRX configuration of the first UE.

6. The method according to claim 4, further comprising: In response to the RRC reconfiguration message, directly or indirectly sending an RRC (Radio Resource Control) reconfiguration complete message to the base station through the second UE, The RRC reconfiguration completion message includes information for the second SL DRX configuration.

7. The method according to claim 1, wherein: The third SL DRX configuration is determined based on the SL DRX configuration provided from the base station.

8. The method according to claim 7, wherein: The third SL DRX configuration is selected and determined from a list of one or more SL DRX configurations provided from the base station via an RRC (Radio Resource Control) reconfiguration message.

9. The method according to claim 8, wherein: The third SL DRX configuration is selected from the list based on at least one of a quality of service (QoS) characteristic for the SL connection between the first UE and the second UE, a QoS characteristic for the connection with the base station, and a downlink (DL) DRX configuration of the first UE.

10. A first user equipment (UE) operating in a wireless communication system, the first UE comprising: at least one transceiver, the at least one transceiver configured to send and receive wireless signals; as well as at least one processor configured to control the at least one transceiver, Wherein, the at least one processor is configured to: receiving information for a first sidelink (SL) discontinuous reception (DRX) configuration from a second UE; determining a SL active time for monitoring sidelink control information (SCI) from the second UE based on the first SL DRX configuration; and re-determining the SL active time based on receiving information for a second SL DRX configuration from a base station or receiving information for a third SL DRX configuration from the second UE, The SL active time is re-determined based on i) both the first SL DRX configuration and the second SL DRX configuration or ii) both the first SL DRX configuration and the third SL DRX configuration.

11. At least one non-transitory computer-readable medium storing at least one instruction, wherein the at least one instruction executable by at least one processor controls a first user equipment (UE) to: receiving information for a first sidelink (SL) discontinuous reception (DRX) configuration from a second UE; determining a SL active time for monitoring sidelink control information (SCI) from the second UE based on the first SL DRX configuration; and re-determining the SL active time based on receiving information for a second SL DRX configuration from a base station or receiving information for a third SL DRX configuration from the second UE, in, The SL active time is re-determined based on i) both the first SL DRX configuration and the second SL DRX configuration or ii) both the first SL DRX configuration and the third SL DRX configuration.

12. A processing device configured to control a first user equipment (UE) operating in a wireless communication system, the processing device comprising: at least one processor; as well as at least one computer memory operatively connected to the at least one processor and storing instructions that, upon execution by the at least one processor, perform operations comprising: receiving information for a first sidelink (SL) discontinuous reception (DRX) configuration from a second UE; determining a SL active time for monitoring sidelink control information (SCI) from the second UE based on the first SL DRX configuration; and re-determining the SL active time based on receiving information for a second SL DRX configuration from a base station or receiving information for a third SL DRX configuration from the second UE, The SL active time is re-determined based on i) both the first SL DRX configuration and the second SL DRX configuration or ii) both the first SL DRX configuration and the third SL DRX configuration.

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