KR20210098814A - Method and apparatus for drx for device-to-device communication in wireless communication system - Google Patents

Abstract

The present disclosure relates to a discontinuous reception (DRX) method and apparatus for device-to-device communications in a wireless communications system. In accordance with one embodiment of the present invention, the DRX method for device-to-device communications in a wireless communications system comprises: determining, by a second terminal, a DRX parameter based on one or more pieces of DRX parameter information or sidelink resource allocation information from a first terminal; and side link performing, by the second terminal, DRX operation based on the determined DRX parameter, wherein the DRX operation includes application of the DRX parameter in accordance with one or more of a start or restart time of an inactivity timer, a start time of a retransmission timer, and a start exception condition of the inactivity timer, and the sidelink resource allocation information may include information indicating an activated resource allocation configuration when a resource allocation of a set grant method is applied.

Description

DRX method and apparatus for communication between terminals in a wireless communication system

The present disclosure relates to communication between terminals in a wireless communication system, and specifically to a DRX method and apparatus for communication between terminals.

Device-to-Device (D2D) communication refers to direct communication between one terminal and another terminal. Direct communication means that one terminal communicates with another terminal through network control or through the terminal's own judgment without passing through another network device.

Such inter-terminal communication can be applied to vehicle communication and is collectively referred to as vehicle-to-everything (V2X). V2X communication refers to a communication method that exchanges or shares information such as traffic conditions while communicating with road infrastructure and other vehicles while driving. The V2X-based service may include, for example, an autonomous driving service, a car remote control service, an interactive service such as a game, and a large-capacity short-distance audio/video service such as AR or VR. Based on the performance requirements to support various V2X-based services through the 5G system, we are discussing specific technologies additionally required for LTE and NR systems, which are radio access technologies (RATs) in 5G systems.

When inter-terminal communication is applied for V2X, it is required to reduce the energy consumption of the terminal by applying discontinuous reception (DRX) in which a reception operation is not performed at a time when data reception is unnecessary. However, a specific method for applying DRX to communication between terminals has not yet been prepared.

An object of the present disclosure is to provide a DRX method and apparatus for communication between terminals in a wireless communication system.

An additional technical problem of the present disclosure is to provide a method and apparatus for transmitting and receiving DRX parameters necessary for applying DRX to communication between terminals.

An additional technical problem of the present disclosure is to provide a DRX method and apparatus for communication between terminals using a dynamic resource allocation scheme.

An additional technical problem of the present disclosure is to provide a DRX method and apparatus for communication between terminals of a configured grant scheme.

The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present disclosure belongs from the description below. will be able

In a DRX method for inter-terminal communication in a wireless communication system according to an aspect of the present disclosure, the second terminal determines a DRX parameter based on one or more of DRX parameter information or sidelink resource allocation information from a first terminal. ; and performing, by the second terminal, a DRX operation based on the determined DRX parameter, wherein the DRX operation is a start or restart time of an inactivity timer, a start time of a retransmission timer, an inactivity timer start exception condition When the DRX parameter according to one or more of the above is applied and the configured grant scheme resource allocation is applied, the sidelink resource allocation information may include information indicating an activated resource allocation configuration.

The features briefly summarized above with respect to the present disclosure are merely exemplary aspects of the detailed description of the present disclosure that follows, and do not limit the scope of the present disclosure.

According to the present disclosure, a DRX method and apparatus for communication between terminals in a wireless communication system may be provided.

According to the present disclosure, a method and apparatus for transmitting and receiving DRX parameters necessary for applying DRX to terminal-to-device communication may be provided.

According to the present disclosure, a DRX method and apparatus for communication between terminals of a dynamic resource allocation scheme may be provided.

According to the present disclosure, it is to provide a DRX method and apparatus for communication between terminals of a configured grant method.

According to the present disclosure, it is possible to reduce the energy consumption of the terminal by applying the DRX operation to the communication between terminals.

Effects obtainable in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the art to which the present disclosure belongs from the description below. will be.

1 is a diagram for explaining a wireless communication system to which the present disclosure can be applied.
2 is a diagram for explaining a link considered in V2X communication to which the present disclosure can be applied.
3 is a diagram for explaining a standalone scenario supporting 5G V2X using NR sidelink communication to which the present disclosure can be applied.
4 is a diagram for explaining a Multi-RAT Dual Connectivity (MR-DC) scenario supporting 5G V2X using NR sidelink communication to which the present disclosure can be applied.
5 is a diagram for explaining a V2X operation scenario using communication with a terminal and a base station to which the present disclosure can be applied.
6 is a diagram for explaining a V2X resource allocation scheme to which the present disclosure can be applied.
7 is a diagram for explaining the structure of V2X communication to which the present disclosure can be applied.
8 is a diagram exemplarily illustrating a protocol stack of a PC5 interface to which the present disclosure can be applied.
9 and 10 are diagrams for explaining a sidelink transmission scheme.
11 to 13 are diagrams for explaining examples of an SLRB setting method to which the present disclosure can be applied.
14 is a diagram for describing a DRX operation to which the present disclosure can be applied.
15 is a diagram for explaining an example of a DRX operation for communication between terminals to which the present disclosure can be applied.
16 is a diagram for explaining an example of a DRX operation applicable to a dynamic resource allocation scheme of inter-terminal communication to which the present disclosure can be applied.
17 is a diagram for explaining an additional example of a DRX operation for communication between terminals to which the present disclosure can be applied.
18 is a diagram illustrating an exemplary format of sidelink configured grant information to which the present disclosure can be applied.
19 is a diagram for explaining an additional example of a DRX operation for communication between terminals to which the present disclosure can be applied.
20 is a diagram illustrating the configuration of a first terminal device and a second terminal device according to the present disclosure.

Hereinafter, with reference to the accompanying drawings, the embodiments of the present disclosure will be described in detail so that those of ordinary skill in the art to which the present disclosure pertains can easily implement them. However, the present disclosure may be embodied in several different forms and is not limited to the embodiments described herein.

In describing the embodiments of the present disclosure, if it is determined that a detailed description of a well-known configuration or function may obscure the gist of the present disclosure, a detailed description thereof will be omitted. And, in the drawings, parts not related to the description of the present disclosure are omitted, and similar reference numerals are attached to similar parts.

In the present disclosure, when a component is "connected", "coupled" or "connected" to another component, it is not only a direct connection relationship, but also an indirect connection relationship in which another component exists in the middle. may also include. In addition, when a component is said to "include" or "have" another component, it means that another component may be further included without excluding other components unless otherwise stated. .

In the present disclosure, terms such as first, second, etc. are used only for the purpose of distinguishing one component from other components, and unless otherwise specified, the order or importance between the components is not limited. Accordingly, within the scope of the present disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment is referred to as a first component in another embodiment. can also be called

In the present disclosure, components that are distinguished from each other are for clearly explaining each characteristic, and do not necessarily mean that the components are separated. That is, a plurality of components may be integrated to form one hardware or software unit, or one component may be distributed to form a plurality of hardware or software units. Accordingly, even if not specifically mentioned, such integrated or dispersed embodiments are also included in the scope of the present disclosure.

In the present disclosure, components described in various embodiments do not necessarily mean essential components, and some may be optional components. Accordingly, an embodiment composed of a subset of components described in one embodiment is also included in the scope of the present disclosure. In addition, embodiments including other components in addition to components described in various embodiments are also included in the scope of the present disclosure.

The present disclosure describes a wireless communication network as a target, and an operation performed in the wireless communication network is performed in the process of controlling the network and transmitting or receiving a signal in a system (eg, a base station) having jurisdiction over the wireless communication network, or This may be done in the process of transmitting or receiving a signal from a terminal coupled to a wireless network.

It is obvious that various operations performed for communication with a terminal in a network including a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. 'Base station (BS: Base Station)' may be replaced by terms such as fixed station, Node B, eNodeB (eNB), ng-eNB, gNodeB (gNB), and access point (AP). . In addition, 'terminal' may be replaced with terms such as User Equipment (UE), Mobile Station (MS), Mobile Subscriber Station (MSS), Subscriber Station (SS), and non-AP station. can

In the present disclosure, transmitting or receiving a channel includes the meaning of transmitting or receiving information or a signal through a corresponding channel. For example, transmitting the control channel means transmitting control information or a signal through the control channel. Similarly, to transmit a data channel means to transmit data information or a signal over the data channel.

Definitions for abbreviations used in the present disclosure are as follows.

AS: Access Stratum

BSR: Buffer Status Reporting

D2D: Device to Device (communication)

DCI: Downlink Control Information

GNSS: Global Navigation Satellite System

LC or LCH: Logical Channel

MAC: Media Access Control

MCS: Modulation and Coding Scheme

RLC: Radio Link Control

RSU: RoadSide Unit

V2X: Vehicle to X(everything)

V2V: Vehicle to Vehicle

V2P: Vehicle to Pedestrian

V2I/N: Vehicle to Infrastructure/Network

SL: Sidelink

SCI: Sidelink Control Information

SFCI: Sidelink Feedback Control Information

PSSCH: Physical Sidelink Shared Channel

PSBCH: Physical Sidelink Broadcast Channel

PSCCH: Physical Sidelink Control Channel

PSDCH: Physical Sidelink Discovery Channel

ProSe: (Device to Device) Proximity Services

PPPP: ProSe Per-Packet Priority

PPPR: ProSe Per-Packet Reliability

QoS: Quality of Service

PQI: PC5 QoS Indicator

Examples of the present disclosure described below may be applied to a 5G system. The 5G system may be defined as including all of the existing Long Term Evolution (LTE)-based systems as well as the NR system. That is, the 5G system may include not only the case where the NR radio access technology is applied alone, but also the case where the LTE-based radio access technology and the NR radio access technology are applied together. Examples of the present disclosure are not limited to being applied to a 5G system, and may be applied to various wireless communication systems.

Examples of the present disclosure may be applied for communication between terminals, and communication between terminals may be used for V2X communication. V2X is V2V (vehicle-to-vehicle), which means LTE/NR-based communication between vehicles, V2P (vehicle-to-pedestrian), which means LTE/NR-based communication between terminals carried by a vehicle and an individual, and vehicle and It may include vehicle-to-infrastructure/network (V2I/N), which means LTE/NR-based communication between roadside units/networks. In this case, the roadside unit (RSU) may be a transport infrastructure entity implemented by a base station or a fixed terminal. For example, the RSU may be an entity that transmits a speed notification to a vehicle.

In terms related to V2X, D2D may mean communication between terminals. In addition, ProSe may mean a proximity service for a terminal performing D2D communication. In addition, sidelink control information (SCI) may mean control information related to the above-described sidelink. In addition, a Physical Sidelink Shared Channel (PSSCH) may be a channel through which data is transmitted through a sidelink, and a Physical Sidelink Control Channel (PSCCH) may be a channel through which control information is transmitted through a sidelink. In addition, a Physical Sidelink Broadcast Channel (PSBCH) is a channel for transmitting a signal through a sidelink in a broadcast manner, and system information may be transmitted.

In an example related to V2X, the terminal may be used in the sense of including a vehicle. For example, the terminal may refer to a device capable of performing sidelink communication and/or communication with a base station.

Although the present disclosure includes examples applied to V2X communication, the scope of the present disclosure is not limited to being applied only to V2X. That is, embodiments of the present invention may be applied to various types of inter-terminal communication such as D2D or ProSe communication through a PC5 link or a sidelink.

1 is a diagram for explaining a wireless communication system to which the present disclosure can be applied.

The network structure shown in FIG. 1 may be an Evolved-Universal Terrestrial Radio Access Network (E-UTRAN), which is a radio network structure of a Next Generation Radio Access Network (NG-RAN) or an Evolved-Universal Mobile Telecommunications System (E-UMTS). . The NG-RAN or E-UMTS system may include a Long Term Evolution (LTE), an LTE-A (advanced) system, or the like, or a 5G mobile communication network, new radio (NR), and the like.

Referring to FIG. 1 , in a wireless communication system 10 , a base station (BS) 11 and a user equipment (UE) 12 may wirelessly transmit and receive data. In addition, the wireless communication system 10 may support device-to-device (D2D) communication. Hereinafter, the term "terminal" includes both the concept of a terminal device used by a general user, such as a smart phone, and a terminal device mounted on a vehicle. D2D communication in a wireless communication system will be described later.

In the wireless communication system 10 , the base station 11 may provide a communication service to a terminal existing within the coverage of the base station through a specific frequency band. The coverage serviced by the base station may also be expressed in terms of a site. A site may include a plurality of regions 15a, 15b, and 15c, which may be referred to as sectors. Each sector included in the site may be identified based on a different identifier. Each of the sectors 15a, 15b, and 15c may be interpreted as a partial area covered by the base station 11 .

The base station 11 generally refers to a station communicating with the terminal 12, eNodeB (evolved-NodeB), gNB (g-NodeB), BTS (Base Transceiver System), access point (Access Point), femto Base station (Femto eNodeB), home base station (HeNodeB: Home eNodeB), relay (relay), remote radio head (RRH: Remote Radio Head), DU (Distributed Unit), such as other terms may be called.

The terminal 12 may be fixed or mobile, and may include a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, and a personal digital assistant (PDA). , a wireless modem, a handheld device, and the like.

Also, the base station 11 may be referred to by various terms such as a megacell, a macrocell, a microcell, a picocell, and a femtocell, depending on the size of coverage provided by the base station. The cell may be used as a term indicating all or part of a frequency band provided by the base station, coverage of the base station, or the base station.

Hereinafter, downlink (DL: DownLink) refers to a communication or communication path from the base station 11 to the terminal 12, and uplink (UL: UpLink) refers to communication from the terminal 12 to the base station 11 or communication path. In the downlink, the transmitter may be a part of the base station 11 , and the receiver may be a part of the terminal 12 . In the uplink, the transmitter may be a part of the terminal 12 , and the receiver may be a part of the base station 11 .

On the other hand, there is no limitation on the multiple access technique applied to the wireless communication system 10 . For example, Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA (SC-FDMA), OFDM-FDMA , OFDM-TDMA, and various multiple access schemes such as OFDM-CDMA can be used. In addition, a Time Division Duplex (TDD) method transmitted using different times or a Frequency Division Duplex (FDD) method transmitted using different frequencies may be used for uplink transmission and downlink transmission.

2 is a diagram for explaining a link considered in V2X communication to which the present disclosure can be applied.

Downlink (DL), uplink (UL) and sidelink (SL) communication may be possible in a communication system supporting V2X.

Referring to FIG. 2 , a communication system supporting V2X may support a PC5 link, which is a link between a terminal (UE) and a terminal (UE) defined in D2D (or ProSe). The PC5 link refers to an interface defined between a terminal and a terminal, and may be defined as a sidelink (SL: SideLink) in the radio access layer. The side link refers to a link in the radio access layer for direct communication between the vehicle and the vehicle, but is not limited thereto.

3 is a diagram for explaining a standalone scenario supporting 5G V2X using NR sidelink communication to which the present disclosure can be applied.

5G V2X scenarios in which the UE uses NR sidelink communication can be classified as follows.

Referring to FIG. 3( a ), the gNB may provide control and configuration of LTE SL and NR SL for V2X communication of the terminal.

Referring to FIG. 3( b ), the ng-eNB may provide control and configuration of LTE SL and NR SL for V2X communication of the terminal.

Referring to FIG. 3( c ), the eNB may provide control and configuration of LTE SL and NR SL for V2X communication of the UE.

4 is a diagram for explaining a Multi-RAT Dual Connectivity (MR-DC) scenario supporting 5G V2X using NR sidelink communication to which the present disclosure can be applied.

Referring to FIG. 4( a ), LTE SL and NR SL may be controlled or configured by Uu while the UE is configured with NR-E-UTRA Dual Connectivity (NE-DC). NE-DC may refer to a scenario in which a UE is connected to one gNB operating as a Master Node (MN) and one ng-eNB operating as a Secondary Node (SN) in a dual connectivity (DC) structure. In this case, both the MN and the SN may be connected to a 5G core network (5GC).

Referring to FIG. 4( b ), LTE SL and NR SL may be controlled or configured by Uu while the terminal is set to NGEN-DC (NG-RAN - E-UTRA NR Dual Connectivity). NGEN-DC may refer to a scenario in which a UE is connected to one ng-eNB operating as an MN and one gNB operating as an SN in a DC structure. In this case, both the MN and the SN may be connected to 5GC.

Referring to FIG. 4( c ), LTE SL and NR SL may be controlled or configured by Uu while the UE is set to EN-DC (E-UTRA - NR Dual Connectivity). EN-DC may refer to a scenario in which a UE is connected to one ng-eNB operating as an MN and one gNB operating as an SN in a DC structure. In this case, both the MN and the SN may be connected to an Evolved Packet Core (EPC).

As such, the UE may use LTE RAT or NR RAT for sidelink transmission. This is determined according to the service type, and RAT selection can be performed in the V2X application layer. As an example, a given service type may relate to 1) LTE RAT only, 2) NR RAT only, 3) LTE or NR RAT, or 4) LTE and NR RAT. In this case, since unicast and groupcast, which will be described later, are transmission types newly introduced in NR V2X communication, the transmission mode is supported only by NR RAT, so RAT selection can be applied only to broadcast.

5 is a diagram for explaining a V2X operation scenario using communication with a terminal and a base station to which the present disclosure can be applied.

Referring to FIG. 5 , a communication system supporting V2X may support only a Uu link, which is a link between a base station and a terminal (UE), or between a radio access network and a terminal (UE). The Uu link may include an uplink (UL), a path through which the terminal transmits a signal to the base station, and a downlink (DL), a path through which the base station transmits a signal to the terminal.

The terminal may use a PC5 interface and/or a Uu interface in performing V2X communication. Interface selection may be performed in the V2X application layer, which may be determined based on Uu/PC5 interface availability information. In particular, for the Uu interface, whether the Uu interface can be used depending on whether the terminal is located within (In-coverage, IC) or out of network coverage (Out-of-coverage, OOC) network coverage (base station coverage) can be determined.

As described above, V2X communication may be achieved through a base station, or may be achieved through direct communication between terminals. In this case, when passing through the base station, in LTE-based V2X communication, transmission and/or reception may be performed through a Uu link, which is a communication interface between the base station and the terminal of LTE. In addition, when a sidelink is used as direct communication between terminals, transmission and/or reception may be made through a PC5 link, which is a communication interface between a terminal of LTE and a terminal, in LTE-based V2X communication.

6 is a diagram for explaining a V2X resource allocation scheme to which the present disclosure can be applied.

The V2X terminal may have an operation mode defined according to a resource allocation method.

In the NR V2X system, like the LTE V2X system, a network scheduling mode in which resource setting and scheduling is performed by the base station and a non-network scheduling mode in which the transmitting terminal autonomously finally determines the resource without network scheduling may exist. there is.

The network scheduling mode may be a mode in which the base station schedules sidelink physical resources for NR V2X sidelink communication. Here, the base station means 3GPP NG-RAN and may be gNB or ng-eNB. The base station is for the purpose of directly controlling NR V2X sidelink communication within the coverage of the base station based on the sidelink resource allocation request received from each terminal, a Physical Downlink Control Channel (PDCCH) (e.g., for NR V2X SL) DCI format), it is possible to directly perform data transmission scheduling for a sidelink physical resource to a transmitting terminal.

The non-network scheduling mode may be a mode in which the terminal directly (or autonomously) selects and uses a sidelink physical resource from a pre-configured resource or resources set by the base station, without scheduling by the base station. .

In the following description, among the resource allocation methods in V2X communication, the network scheduling mode may be referred to as mode 1, and the non-network scheduling mode may be referred to as mode 2.

6(a) shows an example for mode 1, and FIG. 6(b) shows an example for mode 2.

Referring to FIG. 6A , the base station may provide scheduling information on a resource to be used for sidelink data transmission to the sidelink transmission terminal (ie, the first terminal) through PDCCH downlink control information (DCI). Accordingly, the first terminal may provide the sidelink receiving terminal (ie, the second terminal) with scheduling information on a resource to be used for sidelink data transmission through the PSCCH sidelink control information (SCI). Thereafter, the first terminal may transmit the PSSCH sidelink data to the second terminal on a resource designated through the scheduling information. The second terminal may receive PSSCH sidelink data based on the PSSCH scheduling information provided through the PSCCH SCI. A reference signal (DMRS) for PSSCH demodulation may be transmitted together with PSSCH transmission.

Referring to FIG. 6B , the first terminal may autonomously select a resource for transmitting control information and data on the sidelink by the terminal itself. The first terminal may select a resource from a preset resource pool (ie, a set of resource candidates) by a method such as sensing. Through this, the first terminal may transmit control information and data to the second terminal. For example, the first terminal may transmit the PSCCH SCI to the second terminal in the resource selected by the first terminal. The SCI may include PSSCH scheduling information that the first terminal intends to transmit to the second terminal (ie, information indicating a sidelink data transmission resource selected by the first terminal). Thereafter, the first terminal may transmit the PSSCH sidelink data to the second terminal on a resource designated through the scheduling information. The second terminal may receive PSSCH sidelink data based on the PSSCH scheduling information provided through the PSCCH SCI. A reference signal (DMRS) for PSSCH demodulation may be transmitted together with PSSCH transmission.

The information indicating the above-described resource pool may be provided in advance by the base station to the first terminal and/or the second terminal through broadcast or higher layer (eg, RRC (Radio Resource Control) layer) signaling.

Mode 2 may be subdivided and defined as follows.

Mode 2-1 corresponds to a mode in which the terminal autonomously selects a sidelink physical resource. In this case, the terminal itself may sense a necessary resource and directly determine the resource to perform sidelink communication.

Mode 2-2 corresponds to a mode in which the terminal can help other terminals select a sidelink physical resource. In this case, one representative terminal may assist in resource selection of other transmitting terminals by providing a guide or information necessary for scheduling resources for sidelink communication of other terminals.

Mode 2-3 corresponds to a mode in which the terminal uses a preset sidelink physical resource. In this case, the terminal may perform sidelink transmission on a pre-set sidelink physical resource without a separate resource selection operation.

Mode 2-4 corresponds to a mode in which the terminal schedules sidelink physical resources of other terminals. In this case, a specific terminal may perform scheduling on a sidelink physical resource of another terminal similar to the base station in mode 1.

The aforementioned V2X network scheduling mode (mode 1) may correspond to mode 3 in direct link communication, and V2X non-network scheduling mode (mode 2) may correspond to mode 4 in direct link communication. However, this is only an example, and the scope of the present disclosure is not limited by the name of the mode.

The following examples refer to mode 1, mode 2, or mode 2-1, 2-2, 2-3, and 2-4 for convenience of explanation, but the scope of the present disclosure is not limited to the V2X scheduling mode . That is, the following examples may be equally applied to communication for other services based on a sidelink, such as inter-terminal communication for AR, VR, etc., inter-terminal communication for disaster communication, and ProSe inter-terminal communication.

In addition, the V2X terminal may transmit or receive data regardless of the RRC state (eg, RRC CONNECTED, RRC IDLE, RRC INACTIVE state, etc.) of the terminal. In addition, the V2X terminal may transmit or receive data both when it exists within network coverage (IC) or exists outside network coverage (OOC). For example, inter-terminal communication may be performed between an IC terminal and an IC terminal, between an OOC terminal and an OOC terminal, and between an IC terminal and an OOC terminal.

When the UE is within NG-RAN coverage, NR sidelink communication and/or V2X sidelink communication may be configured or controlled through dedicated signaling or system information by the NG-RAN.

For example, the UE in the RRC CONNECTED state may request sidelink resources by transmitting sidelink UE information to the serving cell. As an additional example, the UE in the RRC CONNECTED state configures a sidelink radio bearer (SLRB) from the base station by transmitting QoS information (eg, QoS flow or QoS profile) to the serving cell. information can be received. As an additional example, the UE in the RRC CONNECTED state may receive information on one or more preset resources from the base station by transmitting UE assistance information indicating a traffic pattern to the serving cell. As an additional example, the UE in the RRC CONNECTED state may report a channel busy ratio (CBR) measurement value, location information, etc. to the base station for sidelink resource allocation.

For example, when the terminal is in the RRC IDLE state or the RRC INACTIVE state, the base station may provide SLRB configuration information through system information.

For example, SLRB configuration information may be preconfigured for a terminal outside the NG-RAN coverage.

For example, during handover, the UE may perform sidelink transmission and reception based on an exception pool of the target cell.

7 is a diagram for explaining the structure of V2X communication to which the present disclosure can be applied.

Each V2X terminal may include an application layer, a V2X layer, and an Access Stratum (AS) layer.

The application layer of the transmitting terminal may set PC5 QoS parameters for each V2X message and deliver it to the V2X layer.

The V2X layer of the transmitting terminal may check the V2X service of the packet based on the higher layer parameters and determine one or more transmission profiles (Tx Profile) corresponding thereto. Here, the higher layer parameters may include a service ID and/or QoS parameters such as a Provider Service Identifier (PSID) or an Intelligent Transport System-Application Identifier (ITS-AID). According to the determined one or more transmission profiles, the V2X layer may deliver a packet to the LTE and/or NR PC5 AS layer.

The AS layer of the transmitting terminal may check QoS information of the received packet and map the packet to a corresponding SLRB. The AS layer forwards the packet through the protocol stack (ie, Packet Data Convergence Protocol (PDCP), Radio Link Control (RLC), Medium Access Control (MAC), and Physical (PHY) layers)), and accordingly prepares the packet for transmission and transmission may be performed.

In the receiving terminal, the packet received through the AS layer may be delivered to the V2X layer and the application layer.

A detailed configuration of the AS layer will be described with reference to FIG. 8 .

8 is a diagram exemplarily illustrating a protocol stack of a PC5 interface to which the present disclosure can be applied.

Referring to FIG. 8( a ), the AS protocol stack for the control plane (PC5-C) of the PC5 interface of the terminal may include RRC, PDCP, RLC, MAC and PHY layers. Referring to FIG. 8(b), the AS protocol stack for the user plane (PC5-U) of the PC5 interface of the terminal may include Service Data Adaptation Protocol (SDAP), PDCP, RLC, MAC, and PHY layers.

The MAC layer includes radio resource selection, packet filtering, priority processing between uplink and sidelink, sidelink HARQ (Hybrid Automatic Repeat request) transmission, sidelink LCP (Link Control Protocol), sidelink SR (Scheduling Request), sidelink A Buffer Status Report (BSR) or the like may be performed. In addition, the MAC layer may perform LCP based on the sidelink logical channel. As the sidelink logical channel, two types of a sidelink control channel (SCCH) through which control information is transmitted and a sidelink traffic channel (STCH) through which user information is transmitted can be used, and the logical channel is a sidelink-shared channel (SL-SCH) transmission channel. can be mapped to

The RLC layer may perform a function of dividing and reassembling an RLC service data unit (SDU) and a function of discarding an RLC SDU. In addition, the RLC layer may support RLC UM (Unacknowledged Mode) or RLC AM (Acknowledged Mode) mode. UM or AM mode may be used for unicast transmission, and UM mode may be used for groupcast or broadcast transmission.

The PDCP layer may perform a timer-based SDU discard function.

The SDAP layer may perform mapping between QoS flows and SLRBs.

The RRC layer may transmit a PC5-RRC message between terminals through a PC5 interface. More specifically, the UE may exchange UE capability information and AS layer configuration information through a PC5-RRC message. The information may be stored as a UE context, and the UE may use the stored sidelink UE context for a service scheduled under a PC5-RRC connection.

9 and 10 are diagrams for explaining a sidelink transmission scheme.

Referring to FIG. 9 , unicast transmission may mean that one terminal 910 transmits a message to another terminal 920 . That is, unicast transmission may mean one-to-one transmission.

Broadcast transmission may be a method of transmitting a message to all terminals regardless of whether the receiving terminal supports the service. In FIG. 9 , one terminal 930 may transmit a message regardless of whether the plurality of receiving terminals 940 , 950 , and 960 support the service.

Referring to FIG. 10 , the groupcast transmission method may be a method of sending a message to a plurality of terminals belonging to a group. For example, the terminal 1010 included in the group A may transmit a message to the receiving terminals 1020 and 1030 included in the group A through the groupcast method. Here, since the message transmitted by the terminal 1010 is not transmitted to the receiving terminals included in the group B, the groupcast method and the broadcast method can be distinguished in this respect. Meanwhile, the terminal 1030 included in the group B may transmit a message to the receiving terminals 1040 and 1050 included in the group B through the groupcast method.

Unicast and groupcast transmission methods may be applied for a new V2X service. For example, low latency and high reliability may be required to support a new V2X service. When information is shared based on broadcast, it may be difficult to satisfy these requirements. Therefore, in NR V2X, in addition to the broadcast method, there is a need to support unicast and/or groupcast, which are new two-way transmission mechanisms to handle high-speed data transmission between vehicles.

Table 1 shows examples of use cases including new V2X services.

Similar to the aforementioned V2X service, a new use case for interactive services and large-capacity short-distance multimedia services such as AR and VR can be applied. Therefore, it is necessary to consider various QoS information for the new V2X service, as well as the large-capacity short-distance multimedia service, for communication between terminals. That is, in order to support QoS requirements for various services in inter-terminal communication, it is required to newly define a QoS management operation in inter-terminal communication.

Hereinafter, a QoS management operation in communication between terminals will be described.

QoS management may be related to V2X communication in terms of resource allocation, congestion control, in-device coexistence, power control, and SLRB setting. In the case of sidelink unicast, groupcast, and broadcast, QoS parameters of V2X packets can be provided to the AS by higher layers, and these QoS parameters include traffic priority, latency, reliability, minimum required communication range, and data rate. It may include requirements for SLRB may be configured in the terminal according to QoS information.

11 to 13 are diagrams for explaining examples of an SLRB setting method to which the present disclosure can be applied.

11 corresponds to an example in which SLRB is configured in a UE in an RRC CONNECTED state.

When the terminal is within NG-RAN coverage, NR sidelink communication and/or V2X sidelink communication may be configured and controlled by the NG-RAN through dedicated signaling or system information.

In step 0, a PC5 QoS profile (eg, a specific PC5 QoS parameter set and a PC5 QoS rule for each PC5 QoS flow) may be provided to the terminal in advance through the service authorization and provisioning procedure. In addition, similarly, the PC5 QoS profile for each QoS flow may also be provided to the UE in advance by the base station (eg, gNB/ng-eNB).

In step 1, when the packet is delivered to the AS layer of the terminal, in step 2, the terminal is based on the PC5 QoS rule set in step 0, the identifier of the related PC5 QoS flow(s) (ie, PC5 QFI (QoS Flow Identifier)(s)) In step 3, the UE may transmit the PC5 QFI derived in step 2 to the base station in step 3.

The base station may derive the QoS profile of the reported PC5 QFI(s) based on the provisioning from 5GC in step 0. In step 4, the base station may transmit SLRB configuration information related to the PC5 QFI to the terminal through RRC dedicated signaling. The SLRB configuration information may include a PC5 QoS flow for SLRB mapping, SDAP/PDCP/RLC/LCH configuration, and the like.

In step 5, the AS layer of the terminal may set the SLRB(s) related to the PC5 QFI(s) of the packet according to the setting provided from the base station, and map the available packets to the configured SLRB(s). Thereafter, the terminal may perform sidelink unicast, groupcast or broadcast transmission in step 6.

12 corresponds to an example in which the SLRB is configured in a terminal located outside the network coverage.

In step 0, PC5 QoS rules and SLRB configuration information for each PC5 QoS flow may be preset. In step 1 to step 3, when the packet is delivered to the AS layer of the terminal, the terminal derives the PC5 QoS flow identifier of the packet, sets the SLRB(s) related to the PC5 QFI(s) of the packet according to the preset information, and , it is possible to map the available packets to the configured SLRB(s). Thereafter, the terminal may perform sidelink unicast, groupcast, or broadcast transmission in step 4.

As an additional example related to FIG. 11 or 12 , the UE may self-assign a PC5 QoS flow identifier for PC5 QoS. In this case, the base station cannot know the corresponding PC5 QoS profile only by the PC5 QoS flow identifier reported by the terminal. Accordingly, the base station may configure the SLRB based on the PC5 QoS profile. The SLRB configuration information may be transmitted to the UE through RRC dedicated signaling, and may include SLRB mapping information and SDAP/PDCP/RLC/LCH configuration information according to a QoS profile. The AS layer of the terminal may set the SLRB(s) related to the QoS profile of the packet according to the setting provided from the base station, and map the available packets to the configured SLRB(s). Thereafter, the terminal may perform sidelink unicast, groupcast or broadcast transmission.

13 corresponds to an example in which SLRB is configured in a UE in RRC IDLE or RRC INACTIVE state.

In step 0, the base station can broadcast the SLRB settings related to each available PC5 QoS profile using a V2X specific SIB (System Information Block). In steps 1 and 2, the UE checks the SLRB configuration information through the SIB, sets the SLRB(s) corresponding to the QoS profile of the available packet, and maps the packet to the configured SLRB(s). . Thereafter, the terminal may perform sidelink unicast, groupcast, or broadcast transmission in step 4.

Hereinafter, a detailed operation of the resource allocation mode in inter-terminal communication will be described. In the following description, mode 1 corresponds to a network scheduling mode, and mode 2 corresponds to a non-network scheduling mode (or terminal autonomous resource allocation mode).

For a terminal operating in mode 1, the resource allocation method that the base station can apply to the terminal for inter-terminal communication may include a dynamic resource allocation method and a configured grant method. Here, the configured grant scheme may include a grant-free (GF) scheme and a semi-persistent scheduling (SPS) scheme, and may be referred to as a configured grant type 1 and a configured grant type 2, respectively. there is.

In the dynamic resource allocation method, the base station may allocate resources necessary for inter-terminal communication to the first terminal through a predetermined DCI.

Here, the first terminal may determine the sidelink control information based on the DCI information and generate the determined sidelink control information as the first SCI and the second SCI. The first terminal may transmit the first SCI to the second terminal through the PSCCH, and the second SCI may be transmitted to the second terminal by using some of the PSSCH transmittable resources.

The second terminal may identify a sidelink resource through which the first terminal intends to transmit the PSSCH based on the first and second SCIs received from the first terminal. The second terminal may receive sidelink data from the first terminal on the identified resource through the PSSCH.

Since the aforementioned DCI information is one-time, when the first terminal wants to perform new data transmission to the second terminal, it must receive additional resource allocation information from the base station through DCI.

A resource allocation method in the configured grant method is as follows.

In the case of the configured grant type 1 (i.e., GF method), the base station together with information on the radio resource of the sidelink, information on repetitive allocation such as the period and offset of the corresponding radio resource allocation (hereinafter, GF transmission resource allocation information) , information indicating activation of the corresponding GF transmission resource allocation information (hereinafter, GF transmission resource activation information) may be transmitted to the first terminal through RRC signaling.

The first terminal may determine sidelink control information based on the GF transmission resource allocation information activated by the base station, and may generate the determined sidelink control information as the first SCI and the second SCI. The first terminal may transmit the first SCI to the second terminal through the PSCCH, and the second SCI may be transmitted to the second terminal by using some of the PSSCH transmittable resources.

The second terminal may identify a sidelink resource through which the first terminal intends to transmit the PSSCH based on the first and second SCIs received from the first terminal. The second terminal may receive sidelink data from the first terminal on the identified resource through the PSSCH.

The GF transmission resource allocation information received by the first terminal from the base station is valid until it receives a message indicating deactivation of the GF transmission resource through separate RRC signaling after being activated. Therefore, when the first terminal intends to transmit new data to the second terminal while the GF resource allocation information is valid or activated, using the sidelink radio resource arriving in the next period according to the GF resource allocation information. data can be transmitted.

If the first terminal transmits the PSSCH data to the second terminal and then receives a HARQ NACK message for the corresponding data from the second terminal, retransmission of the corresponding data may be performed. Here, the sidelink resource for retransmission is not the sidelink resource indicated by the GF transmission resource allocation information, but the first terminal may be newly allocated from the base station in a dynamic resource allocation method.

Next, in the case of the configured grant type 2 (ie, the SPS scheme), the base station provides information on the radio resource of the sidelink, and information on repetitive allocation such as the period and offset of the radio resource allocation (hereinafter, SPS transmission resource allocation information). ) may be transmitted to the first terminal through RRC signaling.

Thereafter, the base station may transmit information indicating activation of SPS transmission resource allocation information (hereinafter, SPS transmission resource activation information) to the first terminal through separate signaling such as DCI.

The first terminal may determine sidelink control information based on the SPS transmission resource allocation information activated by the base station and generate the determined sidelink control information as the first SCI and the second SCI. The first terminal may transmit the first SCI to the second terminal through the PSCCH, and the second SCI may be transmitted to the second terminal by using some of the PSSCH transmittable resources.

The second terminal may identify a sidelink resource through which the first terminal intends to transmit the PSSCH based on the first and second SCIs received from the first terminal. The second terminal may receive sidelink data from the first terminal on the identified resource through the PSSCH.

The SPS transmission resource allocation information received by the first terminal from the base station is valid until it receives a message indicating deactivation of the SPS transmission resource through separate signaling such as DCI after being activated. Therefore, when the first terminal intends to transmit new data to the second terminal while the SPS resource allocation information is valid or activated, using the sidelink radio resource arriving in the next period according to the SPS resource allocation information. data can be transmitted.

In the configured grant scheme including the aforementioned GF or SPS, when the first terminal transmits PSSCH data to the second terminal and receives a HARQ NACK message for the corresponding data from the second terminal, Retransmission may be performed. Here, the sidelink resource for retransmission does not use the sidelink resource indicated by the GF/SPS transmission resource allocation information, and the first terminal may be newly allocated from the base station in a dynamic resource allocation method.

Next, in mode 2, since the UE selects the resource for inter-terminal communication by itself, there is no need to be allocated a resource dynamically or in a configured grant method from the base station. In mode 2, a procedure for the first terminal to select a resource may be performed. For example, according to the sub-mode subdivided into mode 2, the first terminal may sense a necessary resource, assist another terminal in selecting a resource, use a preset resource, or provide a resource to another terminal. can also be assigned.

Even in the case of mode 2, the first terminal may generate scheduling information for the PSSCH to be transmitted on the selected sidelink resource as the first and second SCIs and transmit it to the second terminal.

Hereinafter, the first and second SCIs transmitted by the first terminal to the second terminal in the various resource allocation schemes described above will be described in detail.

The first SCI is also referred to as a first stage SCI, for example, SCI format 0-1 may be used. The first SCI may correspond to the SCI transmitted through the PSCCH.

The first SCI may include information such as priority, time and/or frequency resource allocation for PSSCH, resource reservation period, DMRS pattern, second SCI format, MCS, and the like.

Here, the second SCI format information may indicate the format of the second SCI transmitted through the PSSCH. The size of the second SCI may be determined differently according to the indicated format. Accordingly, the size of time and/or frequency resources allocated for the second SCI in the PSSCH may be changed. For example, a format that requires resources of 2 symbols and 10 resource blocks (RBs), or a format that requires 3 symbols and 7 RBs, etc., may be set differently depending on the format of the second SCI. .

Next, the second SCI is also referred to as a second stage SCI (2nd stage SCI), and for example, SCI format 0-2 may be used. The second SCI may correspond to an SCI transmitted through the PSSCH.

Second SCI, HARQ process identifier (HARQ process ID), NDI (New data indicator), RV (Redundancy Version), source identifier (Source ID), destination identifier (Destination ID), CSI report request indicator (Channel State Information report) request indicator) and the like. Additionally, by the first SCI, the second SCI is a specific type of groupcast (eg, HARQ NACK transmission resource is shared by all terminals in one group, and only in case of NACK, through the shared resource (or feedback channel)) When it is indicated to have a format corresponding to a groupcast method that transmits HARQ feedback and does not transmit HARQ feedback in the case of ACK, the second SCI is a zone ID, a communication range requirement ) may further include information and the like.

Here, the NDI has a size of 1 bit, and may not be toggled in the case of transmission of the same data as the previous transmission, but may have a toggled value in the case of new data different from the previous transmission.

RV corresponds to a value for indicating a data area set according to a predetermined channel coding method and transmission data classification during HARQ retransmission.

The source ID is an identifier of a terminal that transmits sidelink data, and corresponds to the least significant (LSB) 8 bits among Source L2 IDs of a total size of 24 bits.

The destination ID is an identifier of the terminal receiving the sidelink data, and corresponds to the least significant (LSB) 16 bits among the destination L2 IDs with a total size of 24 bits.

The CSI report request indicator has a size of 1 bit, and when 0, CSI report including RI (Rank Indicator), CQI (Channel Quality Indicator), etc. for the sidelink channel is not requested, and when 1, CSI report is requested. indicates.

The area ID corresponds to an indicator for each area divided according to geographic location.

The communication range requirement generally corresponds to the minimum reach distance for smooth communication in consideration of the QoS of the corresponding service.

Hereinafter, examples of the present disclosure in which discontinuous reception (DRX) is applied on a sidelink in order to reduce unnecessary energy consumption in communication between terminals will be described.

First, the basic operation of DRX and related parameters will be described. Some or all of these DRX operations may be applied to inter-terminal communication according to the present disclosure.

DRX operation may be configured by RRC signaling for a MAC entity. This DRX operation is for controlling the activation of PDCCH monitoring of the MAC entity of the UE. PDCCH monitoring is a specific PDCCH (eg, C-RNTI (Cell-Radio Network Temporary Identifier), CS-RNTI (Configured Scheduling-RNTI), INT-RNTI (Interruption-RNTI), SFI-RNTI (Slot Format Indication-) RNTI), Semi-Persistent CSI-RNTI (SP-CSI-RNTI), Transmit Power Control-Physical Uplink Control Channel-RNTI (TPC-PUCCH-RNTI), TPC-Physical Uplink Shared Channel-RNTI (TPC-PUSCH-RNTI) Alternatively, it may be defined as monitoring limited to a PDCCH scrambled and transmitted with a TPC-Sounding Reference Symbol-RNTI (TPC-SRS-RNTI). However, even if DRX is configured for the UE, the UE is not limited to only performing the specific PDCCH monitoring operation.

RRC can control DRX operation by setting the following parameters:

- drx-onDurationTimer : a timer defining a periodic PDCCH opportunity (occasion) period from the start of the DRX cycle;

- drx-SlotOffset : delay value for the start time of drx-onDurationTimer;

- drx-InactivityTimer : a timer defining an interval after the PDCCH occasion including a PDCCH indicating that there is a new uplink or downlink transmission for the corresponding MAC entity;

- drx-RetransmissionTimerDL (operated for every downlink (DL) HARQ process except for the broadcast HARQ process): a timer defining a maximum interval until a downlink retransmission is received;

- drx-RetransmissionTimerUL (operated for each uplink (UL) HARQ process): a timer defining a maximum interval until resource allocation information (grant) for uplink retransmission is received;

- drx-RetransmissionTimerSL (operated for each sidelink (SL) HARQ process): A timer defining the maximum interval until receiving a sidelink retransmission

- drx-LongCycleStartOffset : a drx-StartOffset value defining a subframe in which a long DRX cycle and a long and short DRX cycle start;

- drx-ShortCycle (optional): Short DRX cycle;

- drx-ShortCycleTimer (optional): a section in which the UE must use the Short DRX cycle;

- drx-HARQ-RTT-TimerDL (operated for each downlink (DL) HARQ process except for the broadcast HARQ process): the minimum interval before the time when there can be downlink resource allocation for HARQ retransmission expected by the MAC entity;

- drx-HARQ-RTT-TimerUL (operated for each uplink (UL) HARQ process): the minimum interval before the time when uplink resource allocation for HARQ retransmission expected by the MAC entity can be;

- drx-HARQ-RTT-TimerSL (operated for each sidelink (SL) HARQ process): the minimum interval before the time when sidelink resource allocation for HARQ retransmission expected by the MAC entity can be;

- active time (active time): the time the MAC entity monitors the PDCCH;

- DRX Cycle: Defined as a period in which on-duration is periodically repeated. For example, referring to FIG. 14 to be described later, the inactivation period from the end of the on duration to the end of the DRX Cycle is periodically may be repeated;

- PDCCH occasion (PDCCH occasion): It is defined as a time interval expressed by the number of one or consecutive OFDM (Orthogonal Frequency Division Multiplex) symbols, and is set in the MAC entity to monitor the PDCCH.

One or more of the above-described parameters for DL/UL may be included in DRX configuration information for a radio link (eg, Uu link) between the base station and the terminal.

One or more of the above-described parameters for SL may be included in DRX configuration information for a radio link between terminals (eg, sidelink).

Other DRX parameter(s) values may be independently configured according to the DRX configuration information Uu interface and sidelink. Therefore, it may not be necessary to define a variable for distinguishing Uu and SL for these DRX parameter(s). That is, among the DRX parameter(s), those defined without being related to the Uu link (eg, DL/UL) or SL may be applied to the Uu link, may be applied to the SL, and are common to the Uu link and the SL. It may be applied, or it may be applied independently to each of the Uu link and the SL (even though the names of the parameters are the same, whether for Uu or SL is distinguished in the parameter setting process). In this way, the DRX operation and parameter setting between the base station and the terminal and the sidelink DRX operation and parameter setting may be applied individually.

14 is a diagram for describing a DRX operation to which the present disclosure can be applied.

An example of the DRX operation described below will be described on the assumption that it is applied between a base station and a terminal (eg, Uu link). For example, the DRX operation between the base station and the terminal may be described in relation to the operation of the terminal monitoring PDCCH transmission from the base station. However, the following description is not limitedly applied only to the DRX operation between the base station and the terminal, and the same description may be applied to the DRX operation for communication between terminals (eg, sidelink). For example, the DRX operation for communication between terminals may be described in relation to the operation of the second terminal monitoring PSCCH transmission from the first terminal. In addition, during the DRX operation between the base station and the terminal, operations related to DRX command MAC CE (Control Element), long DRX command MAC CE, CSI-mask, etc. are not mentioned separately in the DRX operation for communication between terminals. Even if not, it can be equally applied to the DRX operation for communication between terminals.

Referring to FIG. 14 , the UE repeats On Duration and DRX opportunity according to the DRX cycle. That is, the DRX cycle may correspond to a cycle that repeats On Duration. On Duration means a time during which the terminal needs to wake up and perform PDCCH monitoring, and the DRX opportunity means a time during which the terminal may not attempt reception in a sleep state. For example, if the terminal does not receive valid control information from the base station during On Duration, it may sleep by performing a DRX operation.

Hereinafter, the above-described DRX operation will be described in more detail with reference to FIG. 14 .

When DRX is configured, the active time includes a case in which the following operations are in progress:

- when the drx-onDurationTimer or drx-InactivityTimer or drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or drx-RetransmissionTimerSL timer is running;

- When a scheduling request (SR) is sent over the PUCCH or transmission is pending.

When DRX is configured, the MAC entity may operate as follows:

1> If any MAC PDU is received from a resource (GF or SPS) configured in downlink:

2> Starts the drx-HARQ-RTT-TimerDL related to the HARQ process of the corresponding MAC PDU from the first symbol after the transmission including the DL HARQ feedback for the MAC PDU is finished;

2> Stop the drx-RetransmissionTimerDL related to the HARQ process of the corresponding MAC PDU.

1> If any MAC PDU is transmitted through a resource (GF or SPS) configured in uplink:

2> drx-HARQ-RTT-TimerUL related to the HARQ process of the corresponding MAC PDU starts from the first symbol after the first PUSCH transmission for the MAC PDU is finished;

2> Stop the drx-RetransmissionTimerUL related to the HARQ process of the corresponding MAC PDU.

1> If any drx-HARQ-RTT-TimerDL expires:

2> If the decoding of the data of the corresponding HARQ process fails:

3> Start the drx-RetransmissionTimerDL related to the HARQ process of the corresponding MAC PDU from the first symbol after the drx-HARQ-RTT-TimerDL expires.

1> If any drx-HARQ-RTT-TimerUL expires:

2> Start the drx-RetransmissionTimerUL related to the HARQ process of the corresponding MAC PDU from the first symbol after drx-HARQ-RTT-TimerUL expires.

1> If DRX Command MAC CE or Long DRX Command MAC CE is received:

2> Stop drx-onDurationTimer;

2> Stop drx-InactivityTimer.

1> If drx-InactivityTimer has expired or DRX Command MAC CE is received:

2> If Short DRX cycle is set:

3> Start drx-ShortCycleTimer at the first symbol after drx-InactivityTimer expires, or at the first symbol after receiving DRX Command MAC CE, or restart the timer if in progress;

3> Use Short DRX Cycle.

2> For anything other than:

3> Long DRX cycle is used.

1> If drx-ShortCycleTimer has expired:

2> Long DRX cycle is used.

1> If Long DRX Command MAC CE is received:

2> Stop drx-ShortCycleTimer;

2> Long DRX cycle is used.

1> If Short DRX Cycle is applied, [(SFN × 10) + subframe number] modulo ( drx-ShortCycle ) = ( drx-StartOffset ) modulo ( drx-ShortCycle ); or

1> If Long DRX Cycle is applied and [(SFN × 10) + subframe number] modulo ( drx-LongCycle ) = drx-StartOffset :

2> Start drx-onDurationTimer after drx-SlotOffset from the start point of subframe.

1> If the MAC entity is active time:

2> monitor the PDCCH;

2> If the PDCCH indicates DL transmission:

3> Starts the drx-HARQ-RTT-TimerDL related to the HARQ process of the corresponding MAC PDU from the first symbol after the transmission including the DL HARQ feedback for the MAC PDU is finished;

3> Stop the drx-RetransmissionTimerDL related to the HARQ process of the corresponding MAC PDU.

2> If the PDCCH indicates UL transmission:

3> drx-HARQ-RTT-TimerUL related to the HARQ process of the corresponding MAC PDU starts from the first symbol after the first PUSCH transmission for the MAC PDU is finished;

3> Stop the drx-RetransmissionTimerUL related to the HARQ process of the corresponding MAC PDU.

2> If the PDCCH indicates new transmission of DL or indicates new UL transmission:

3> Start drx-InactivityTimer in the first symbol after PDCCH reception is finished, or restart if the timer is in progress.

1> In the current symbol n, if the MAC entity considers all conditions related to active time such as resource allocation, DRX Command MAC CE, Long DRX Command MAC CE, and SR transmission, from symbol n to a time before 4 ms If not active time:

2> Periodic sounding reference signaling (SRS) and SPS SRS transmission are not performed.

1> If the CSI-mask (channel status information masking) is set by the upper layers:

2> In the current symbol n, if the MAC entity considers all conditions related to active time, such as resource allocation, DRX Command MAC CE, Long DRX Command MAC CE, and SR transmission, from symbol n to a time before 4 ms If drx-onDurationTimer is not in progress:

3> Do not report CSI through PUCCH.

1> Otherwise:

2> In the current symbol n, if the MAC entity considers all conditions related to active time, such as resource allocation, DRX Command MAC CE, Long DRX Command MAC CE, and SR transmission, from symbol n to a time before 4 ms If not active time:

3> CSI through PUCCH and SPS CSI through PUSCH are not reported.

In the above-described DRX operation, the MAC entity may transmit aperiodic CSI report and aperiodic SRS through HARQ feedback and PUSCH regardless of whether PDCCH monitoring is progressed.

In addition, the MAC entity may not perform PDCCH monitoring in a period other than a complete PDCCH occasion in which all PDCCH occasions are included in the active time.

Hereinafter, examples of DRX operation for inter-terminal communication (or sidelink) according to the present disclosure will be described.

The following examples include a DRX operation according to a resource allocation scheme for a second terminal (ie, a sidelink receiving terminal) by a first terminal (ie, a sidelink transmitting terminal). Specifically, in the following, when the first terminal dynamically schedules sidelink data transmission for the second terminal, or the first terminal performs sidelink data transmission with a set grant method such as GF or SPS for the second terminal. Examples of the present disclosure for the case of scheduling will be described.

Here, the aforementioned resource allocation method for the second terminal should be distinguished from the resource allocation method for the first terminal (ie, mode 1 based on network scheduling or mode 2 based on non-network scheduling).

15 is a diagram for explaining an example of a DRX operation for communication between terminals to which the present disclosure can be applied.

The example of FIG. 15 may correspond to the DRX operation of the second terminal when the sidelink resource allocation of the dynamic resource allocation method for the second terminal is applied by the first terminal.

In step S1510, the first terminal may receive a DRX parameter for the sidelink DRX operation from the base station through higher layer signaling. Here, higher layer signaling may correspond to RRC signaling.

In addition, the base station may provide resource allocation information to the first terminal together with or separately from step S1510. For example, for the first terminal operating in mode 1, configured grant-based resource allocation information (eg, GF or SPS configuration information) may be provided from the base station through higher layer signaling. Alternatively, for the first terminal operating in mode 2, resource allocation information from the base station is not provided, and the first terminal may autonomously determine the sidelink resource.

In step S1520, the first terminal may determine a DRX parameter for the sidelink DRX operation. If the first terminal receives the DRX parameter from the base station in step S1510, it may determine the sidelink DRX parameter based thereon. Alternatively, when the first terminal does not receive the DRX parameter or the like from the base station in step S1510, the first terminal may autonomously determine the sidelink DRX parameter. As an example, when the base station transmits only a message allowing DRX configuration and does not set DRX parameters, the first terminal considers QoS of data to be transmitted through the sidelink, whether to configure sidelink DRX and configures each DRX parameter can decide autonomously.

In step S1530, the first terminal may provide the DRX parameter determined in step S1520 to the second terminal through higher layer signaling. Here, higher layer signaling may correspond to PC5-RRC signaling. For example, the PC5-RRC signaling may be an access stratum (AS) configuration information message including information required when the second terminal receives data of the first terminal.

In step S1540, the second terminal may start a DRX operation based on the received DRX parameter.

In step S1550, the second terminal may receive the SCI through the PSCCH transmitted from the first terminal, and in step S1560, the second terminal may receive sidelink data through the PSSCH based on the sidelink data scheduling information indicated by the SCI.

Here, the second terminal performing the DRX operation may perform PSCCH monitoring during on-duration. If the second terminal receives the PSCCH when the on-duration timer is in progress, it may perform PSSCH reception based on PSSCH scheduling information (ie, SCI) included in the PSCCH. If the PSSCH reception time indicated by the SCI is not the active time of the second terminal, the second terminal should be able to receive the PSSCH.

Hereinafter, the DRX parameter determination according to the mode 1 or mode 2 operation of the first terminal and the DRX operation of the second terminal according to this will be described in more detail.

When the first terminal operates in mode 1, the following DRX operation may be applied.

In relation to step S1520, the first terminal based on the resource allocation information (eg, GF or SPS configuration information) received from the base station, DRX cycle, on-duration timer (on-duration timer), inactivity timer (inactivity) DRX parameters such as timer) may be determined. Alternatively, the base station provides resource allocation information (eg, GF or SPS configuration information) to the first terminal, along with DRX parameters such as a DRX cycle, an offset value, an on-duration timer, an inactivity timer, and a retransmission timer. It is provided to the first terminal, and the first terminal may determine the DRX parameter based thereon.

Next, when the first terminal operates in mode 2, the following DRX operation may be applied.

In relation to step S1520, the first terminal considers the QoS of the generated data (that is, sidelink data to be transmitted to the second terminal), DRX cycle, offset value, on-duration timer, inactivity timer, retransmission timer, etc. DRX parameters may be autonomously determined.

For example, the first terminal may determine a smaller DRX cycle value according to the packet data minimum request delay time. In addition, when the irregularity of data generation is high, the first terminal may determine a long on-duration timer parameter value in consideration of this and set the inactivity timer to be long.

For a case in which the first terminal operates in mode 1 or mode 2 (or regardless of whether it operates in mode 1 or mode 2), the following DRX operation may be equally applied.

In the following examples, the time unit related to the DRX timer operation may be set to one or a combination of two or more of a symbol, a slot, or a subframe. For example, when a time unit is a symbol unit, if a time point satisfying a predetermined condition is a symbol index x, it may mean that the timer starts from (at) symbol index x+1. Alternatively, when a time unit is a slot unit, it may mean that a timer starts from (at) slot index x+1 if a time point that satisfies a predetermined condition is slot index x.

In relation to steps S1540 to S1560, the second terminal may start the inactivity timer when receiving the PSCCH while the on-duration timer is in progress. In addition, the second terminal may restart the inactivity timer when receiving the PSCCH while the inactivity timer is in progress. Here, the reference time at which the second terminal starts or restarts the inactivity timer may be determined based on the time when the reception of the first SCI is completed or the time when the reception of both the first and the second SCI is completed.

For example, when the reception of the first SCI in the PSCCH is successful, if the time unit index at which the reception of the first SCI is completed is x, the inactivity timer may be started at the time unit corresponding to the index of x+1. In this case, in determining whether to start the inactivity timer, whether the second SCI reception is successful may not be considered.

As an additional example, when the reception of the first SCI in the PSCCH and the reception of the second SCI in the PSSCH indicated by the first SCI are successful, if the time unit index in which both the first and the second SCI reception is completed is x, x The inactivity timer can be started at the time unit corresponding to the index of +1.

If the second terminal fails to decode data received through the PSSCH based on the scheduling information indicated through the PSCCH, in the first time unit in which the data can be retransmitted by the first terminal, the second terminal sets a retransmission timer can start

Here, the operation related to the retransmission timer of the second terminal may be performed when HARQ feedback for sidelink data is possible.

More specifically, when the second terminal can transmit HARQ feedback (HARQ ACK/NACK) for a logical channel (LC) corresponding to data received through the PSSCH, the retransmission timer-related operation of the second terminal is performed. can be

If the second terminal cannot transmit the HARQ feedback for the LC corresponding to the data received through the PSSCH, the second terminal drx-RetransmissionTimerSL, which is a timer related to retransmission of the corresponding data (or SL MAC PDU) and drx-HARQ-RTT-TimerSL may not be started.

Whether or not HARQ is enabled may be configured in units of SLRBs, and SLRBs may be mapped one-to-one with LCs. Accordingly, the situation in which HARQ feedback transmission is possible for a certain LC may include a case in which HARQ is set to enable for an SLRB mapped to the corresponding LC. Whether the HARQ operation for the SLRB is possible may be configured by the base station.

As an additional example, even if it is set to enable HARQ operation for LC or SLRB, if it is determined that the second terminal deviated from the minimum reach based on the communication range requirement information among the information added by the second SCI, finally may be determined that HARQ feedback transmission is impossible.

When set to enable HARQ operation, the second terminal sets drx-RetransmissionTimerSL related to HARQ process of sidelink data (or SL MAC PDU) received through PSSCH in the first time unit after drx-HARQ-RTT-TimerSL expires. can start

Here, the first time unit in which the data can be retransmitted by the first terminal may be determined by drx-HARQ-RTT-TimerSL.

For example, the second terminal may start the drx-HARQ-RTT-TimerSL related to the HARQ process of the corresponding SL MAC PDU from the first time unit after the transmission including the SL HARQ feedback for the SL MAC PDU is finished.

As a further example , the parameter value for the HARQ-RTT-TimerSL timer may be provided from the base station to the first terminal.

If the parameter value for HARQ-RTT-TimerSL is not provided to the first terminal by the base station, the following operation may be performed according to the mode of the first terminal.

When the first terminal operates in mode 1, the first terminal may determine the parameter value of the HARQ-RTT-TimerSL timer in consideration of at least one of the following conditions L, M, or N.

- the minimum time (L) consumed for the first terminal to transmit a resource request for retransmission to the base station,

- Minimum time (M) consumed for the base station to determine and transmit resource allocation for retransmission to the first terminal,

- The minimum time interval (N) for receiving the resource allocation information and transmitting the first terminal.

When the first terminal operates in mode 2, the first terminal receives the HARQ ACK information and the first terminal considers the minimum time interval (P) that the first terminal can transmit, the parameter value of the HARQ-RTT-TimerSL timer can be decided

As an additional example, a parameter value of the HARQ-RTT-TimerSL timer may be determined as a predefined (or default) value. For example, when the second terminal does not know the resource allocation mode of the first terminal, the HARQ-RTT-TimerSL timer may be set to a predefined value. In this case, the first terminal and the second terminal store the same value in memory as a parameter value of the HARQ-RTT-TimerSL timer in advance, and apply it when the retransmission timer (eg, drx-RetransmissionTimerSL ) operates. .

16 is a diagram for explaining an example of a DRX operation applicable to a dynamic resource allocation scheme of inter-terminal communication to which the present disclosure can be applied.

In step S1610, the first terminal may generate SL data to be transmitted on the sidelink.

In step S1620, the first terminal may transmit SL scheduling information (eg, SCI) for SL data transmission to the second terminal. The SL scheduling information may include the first SCI transmitted through the PDCCH and additionally include the second SCI transmitted through the PSSCH.

The second terminal may wake up according to the DRX cycle and attempt to receive the PSCCH during the on-duration timer. If the second terminal receives the PSCCH during the on-duration timer, the inactivity timer may be started, and if the second terminal receives the PSCCH during the inactivity timer, the inactivity timer may be restarted.

Here, when the second terminal starts/restarts the inactivity timer, as described above, it may be determined based on the first SCI or based on the first and second SCIs. For example, when the first/second SCI reception completion time is the time unit index x, the inactivity timer may be started at the time unit index x+1.

In step S1630, the first terminal may transmit SL data to the second terminal through the PSSCH on the resource indicated according to the SL scheduling information. That is, the second terminal may attempt to receive SL data through the PSSCH on a resource indicated according to the SL scheduling information. The illustrated SL data transmission/reception timing is exemplary, and the SL data transmission/reception timing may be before or after expiration of the on-duration timer and/or inactivity timer.

When the second terminal fails to decode the SL data in step S1640, the second terminal may transmit HARQ feedback information to the first terminal according to whether HARQ feedback transmission is enabled. For example, when HARQ operation is set to be enabled for the LC or SLRB related to the received SL data, the second terminal may transmit HARQ NACK information to the first terminal in step S1650.

Here, when the NACK transmission is completed at the time unit index n, the second terminal may start the HARQ RTT timer at the time unit index n+1. And, when the HARQ RTT timer expires at the time unit index m, the second terminal may start the retransmission timer at the time unit index m+1.

In step S1660, the first terminal may determine a retransmission resource. The retransmission resource may be determined by the first terminal based on information obtained from the base station, or may be autonomously determined by the first terminal.

In step S1670, the first terminal may perform SL data retransmission to the second terminal. The second terminal may receive the SL data retransmitted from the first terminal during the retransmission timer operation.

17 is a diagram for explaining an additional example of a DRX operation for communication between terminals to which the present disclosure can be applied.

The example of FIG. 17 is for the DRX operation of the second terminal when the sidelink resource allocation of the grant method configured for the second terminal is applied by the first terminal.

By providing the GF or SPS related information to the second terminal, the first terminal can perform SL data transmission through the PSSCH without transmitting the SL scheduling information through the PSCCH. This SL scheduling method is based on periodic resource allocation, and if retransmission is required, retransmission may be performed based on scheduling information through a separate PSCCH. Therefore, it is necessary to define a DRX operation different from the DRX operation applied to the dynamic resource allocation scheme as in the examples of FIGS. 15 and 16 .

In step S1710, the base station may provide the first terminal with information necessary for resource allocation of the grant method configured on the sidelink through higher layer signaling. Here, higher layer signaling may correspond to RRC signaling.

For example, for the first terminal operating in mode 1, configured grant-based resource allocation information (eg, GF/SPS configuration information) may be provided from the base station through higher layer signaling. Alternatively, for the first terminal operating in mode 2, resource allocation information from the base station is not provided, and the first terminal may autonomously determine the sidelink resource.

In step S1720, the first terminal may provide the second terminal with resource allocation information (eg, GF/SPS configuration information) of a sidelink configured grant method through higher layer signaling. Here, the higher layer signaling may be PC5-RRC signaling.

Here, the first terminal may transmit information related to the configured grant method transmission to be performed to the second terminal.

Specifically, the first terminal may provide the second terminal with information indicating the activated resource allocation configuration (ie, the activated GF/SPS configuration) among all information related to the GF/SPS configuration configured therein.

For example, if the first terminal was previously inactive but additionally activated, or when a GF/SPS setting that was previously activated but deactivated occurs, GF/SPS configuration information is provided to the second terminal based on the changed state can do.

As an additional example, the first terminal includes information related to all GF/SPS settings configured to itself (hereinafter, first sidelink configured grant information, or candidate (or potential) sidelink configured grant information), and additionally the currently activated GF Information indicating what the /SPS configuration is (hereinafter, second sidelink configured grant information or activated sidelink configured grant information) may be generated. When the first terminal performs scheduling to the second terminal for the first time, both the first and second sidelink configured grant information may be provided to the second terminal.

18 is a diagram illustrating an exemplary format of sidelink configured grant information to which the present disclosure can be applied.

For example, the second sidelink configured grant information may be configured in the form of a PC5-RRC signaling message. More specifically, the second sidelink configured grant information may have the form of a list consisting of an index value for the activated configuration information.

As an additional example, the second sidelink configured grant information may be configured in the form of an SL MAC CE. More specifically, the second sidelink configured grant information may have the form of a bitmap for the activated configuration information. For example, the position of each bit in ascending or descending order from the rightmost bit may correspond to an index value for one GF/SPS setting. When a certain bit position has a first value (eg, 1) or a second value (eg, 0), activation or deactivation of a GF/SPS setting corresponding to the corresponding bit position may be indicated.

The example of FIG. 18 shows the format of information indicating whether to activate up to 8 GF/SPS settings on the sidelink. The maximum number of GF/SPS configurations is not limited to 8, and may be defined as a number of multiples of 8 in consideration of the number of services with different characteristics supportable through the sidelink. In addition, even if the second sidelink configured grant information is defined as a bitmap having a length of a multiple of 8, when the number of all GF/SPS settings configured for the first terminal is less than a multiple of 8, only some bit positions This is used to indicate the activated GF / SPS setting and the rest may be reserved.

After the first terminal provides the first and second sidelink configured grant information to the second terminal, if a change occurs in whether to activate the GF/SPS configuration, the first terminal provides the second terminal with the second sidelink configured Only grant information (ie, activation or non-activation indication information) may be provided.

As an additional example, the first terminal may provide the first sidelink configured grant information (ie, the candidate sidelink configured grant information) without providing the second sidelink configured grant information (ie, activation indication information). Since the first sidelink configured grant information includes information related to all GF/SPS settings configured for the first terminal, the second terminal attempts to receive according to all GF/SPS settings, which may increase energy consumption. However, DRX information between the first terminal and the second terminal during the time required to provide the information indicating activation to the second terminal when the specific GF/SPS setting in the first terminal is changed from the inactive state to the active state It is possible to remove the ambiguity caused by the asynchronous section of

Upon receiving the first and/or second sidelink configured grant information in step S1730, the second terminal may start the DRX operation based on the resource according to the GF/SPS configuration of the first terminal.

The second terminal may determine some or all of the DRX parameters based on the resource according to the GF/SPS configuration of the first terminal.

For example, the second terminal may determine a drx-SlotOffset value, a DRX cycle value, and a parameter value for the on-duration timer to include a time point at which a resource is located according to the GF/SPS configuration of the first terminal.

In step S1740, the second terminal may perform SL data reception according to the determined DRX parameter. Specifically, the second terminal determines a parameter value for the on-duration timer, and the on-duration timer is in progress, or the second terminal recognizes a time point at which a resource is located according to the GF/SPS configuration of the first terminal, and transmits potential SL data. When attempting to receive , the second terminal may attempt to receive the PSSCH in consideration of the time and/or frequency resource location according to the GF/SPS configuration. For example, when the frequency resource location information is included in the GF/SPS setting, the second terminal may adjust the reception frequency band to the corresponding frequency resource in order to receive the SL data transmitted from the first terminal in the corresponding frequency resource. there is.

Next, in the sidelink DRX operation, basically, the second terminal can start the inactivity timer after receiving the PSCCH. It can be defined as not starting the timer.

In addition, in the configured grant-based transmission between the base station and the UE, data transmission is performed through the PDSCH without providing scheduling information through the PDCCH, whereas in the grant-based transmission configured for the sidelink for communication between the UEs, the PSCCH and/or the PSSCH are used. After the first and/or second SCI transmission is performed, sidelink data transmission through the PSSCH may be performed on a resource indicated by the SCI. Therefore, in the grant-based transmission configured between the base station and the UE, the inactivity timer operation related to PDCCH monitoring is not defined, but in the grant-based transmission configured for the sidelink for communication between the UEs, it is necessary to define the inactivity timer operation related to the PSCCH monitoring.

Specifically, when it is determined that the sidelink data that the first terminal wants to transmit to the second terminal is related to the GF/SPS configuration, the second terminal determines that there is no potential additional PSCCH transmission and does not start the inactivity timer. can

For example, if the second terminal receives the first and/or second SCI from the first terminal and succeeds in decoding, but satisfies the following condition (ie, inactivity timer start exception condition), the second terminal is inactivity The timer may not start.

- the second terminal receives one or more of the first or the second SCI on a resource (eg, time-frequency resource) according to the GF/SPS configuration provided by the first terminal;

- indicates that the NDI information included in the second SCI received by the second terminal is not retransmission (eg, the value of the NDI field is toggled);

- The HARQ process ID value included in the second SCI received by the second terminal is the same as the HARQ process ID corresponding to the resource according to the GF/SPS configuration provided by the first terminal.

Next, when the second terminal does not receive one or more of the first SCI through the PSCCH or the second SCI through the PSSCH, a DTX message indicating this (that is, a message indicating that the PSCCH/PSSCH itself cannot be received) is 1 can be transmitted to the terminal. In addition, when the second terminal receives the SL data through the PSSCH but fails to decode it, the second terminal may transmit a NACK message to the first terminal. Here, the DTX or NACK message may be transmitted when HARQ is enabled for the LC or SLRB corresponding to the SL MAC PDU.

In this case, the second terminal assumes that the first terminal can retransmit data that has failed to be received or decoded, and the second terminal can start the retransmission timer at the first time unit in which the data can be retransmitted by the first terminal. there is.

For example, the second terminal may start the drx-RetransmissionTimerSL related to the HARQ process of SL data (or SL MAC PDU) at the first time unit after the drx-HARQ-RTT-TimerSL expires.

Here, the first time unit in which the data can be retransmitted by the first terminal may be determined by drx-HARQ-RTT-TimerSL.

For example, the second terminal may start the drx-HARQ-RTT-TimerSL related to the HARQ process of the corresponding SL MAC PDU from the first time unit after the transmission including the SL HARQ feedback for the SL MAC PDU is finished.

As a further example , the parameter value for the HARQ-RTT-TimerSL timer may be provided to the second terminal by the first terminal.

If the parameter value for HARQ-RTT-TimerSL is not provided to the second terminal by the first terminal and the second terminal determines that the first terminal is operating in mode 2, the first terminal transmits HARQ ACK information The second terminal may determine the parameter value of the HARQ-RTT-TimerSL timer in consideration of the minimum time interval (P) during which the first terminal can receive and transmit.

Alternatively, the second terminal determines the P value based on QoS information related to the sidelink data to be transmitted from the first terminal, and the second terminal determines the parameter value of the HARQ-RTT-TimerSL timer in consideration of the P value. may be

As an additional example, a parameter value of the HARQ-RTT-TimerSL timer may be determined as a predefined (or default) value. For example, when the second terminal does not know the resource allocation mode of the first terminal, the HARQ-RTT-TimerSL timer may be set to a predefined value. In this case, the first terminal and the second terminal store the same value in memory as a parameter value of the HARQ-RTT-TimerSL timer in advance, and apply it when the retransmission timer (eg, drx-RetransmissionTimerSL ) operates. .

19 is a diagram for explaining an additional example of a DRX operation for communication between terminals to which the present disclosure can be applied.

The example of FIG. 19 is for the DRX operation of the second terminal when the sidelink resource allocation of the grant method configured for the first terminal is applied by the second terminal.

In the example of FIG. 17 , the first terminal (ie, the sidelink transmitting terminal) provides the resource allocation information of the grant scheme configured for the second terminal (ie, the sidelink receiving terminal), and based on this, the first terminal provides the second terminal The DRX operation of the second terminal in the case of performing SL data transmission to the terminal has been described.

On the other hand, in the example of FIG. 19, the second terminal (ie, the sidelink receiving terminal) provides the resource allocation information of the grant method configured for the first terminal (ie, the sidelink transmitting terminal), and based on this, the first terminal A DRX operation of the second terminal in the case of performing SL data transmission to the second terminal will be described.

That is, in the sidelink resource allocation mode, when the first terminal operates according to mode 2-2, 2-3 or 2-4, the second terminal knows in advance the sidelink resource allocation information for the first terminal and and the DRX operation of the second terminal in this case is defined.

In step S1910, the base station may provide the second terminal with information necessary for resource allocation of the grant method configured on the sidelink through higher layer signaling. Here, higher layer signaling may correspond to RRC signaling.

For example, grant-based resource allocation information configured for the first terminal (eg, GF/SPS configuration information) may be provided from the base station to the second terminal through higher layer signaling. Alternatively, the second terminal may autonomously determine grant-based resource allocation information configured for the first terminal (eg, GF/SPS configuration information).

In step S1920, the second terminal may provide the first terminal with resource allocation information (eg, GF/SPS configuration information) of a sidelink configured grant method through higher layer signaling. Here, the higher layer signaling may be PC5-RRC signaling.

Here, the second terminal may transmit information related to transmission of a grant scheme configured for the first terminal to the first terminal.

Specifically, the second terminal may provide information indicating the activated GF/SPS configuration to the first terminal among all information related to the GF/SPS configuration configured for the first terminal.

For example, when a GF/SPS setting that was previously deactivated but additionally activated for the first UE or a previously activated but deactivated GF/SPS setting occurs for the 1st UE, GF/SPS setting information is displayed based on the changed status. It can be provided to the first terminal.

As an additional example, the second terminal includes information related to all GF/SPS settings configured for the first terminal (hereinafter, first sidelink configured grant information, or candidate (or potential) sidelink configured grant information), and additionally to the second terminal Information indicating what is the currently activated GF/SPS configuration for UE 1 (hereinafter, second sidelink configured grant information or activated sidelink configured grant information) may be generated. When the second terminal performs scheduling for the first terminal for the first time, both the first and second sidelink configured grant information may be provided to the second terminal.

In the example of FIG. 19 , the format of the sidelink configured grant information may follow the example of FIG. 18 .

After the second terminal first provides the first and second sidelink configured grant information to the first terminal, if a change occurs in whether to activate the GF/SPS configuration for the first terminal, the second terminal provides the first terminal with the first terminal Only the second sidelink configured grant information (ie, activation or non-activation indication information) may be provided.

As an additional example, the second terminal does not provide the second sidelink configured grant information (ie, activation indication information) but provides the first sidelink configured grant information (ie, candidate sidelink configured grant information) to the first terminal You may.

In step S1930, since the second terminal provided the first and/or second sidelink configured grant information to the first terminal, it already knows the GF/SPS configuration for the first terminal. Accordingly, the second terminal may determine the DRX parameter based on the resource according to the GF/SPS configuration of the first terminal and start the DRX operation.

As such, since the second terminal already knows the GF/SPS configuration of the first terminal, the descriptions related to steps S1730 and S1740 of FIG. 17 may be equally applied to steps S1930 and S1940 of FIG. 19, and overlapping descriptions are omitted. do.

20 is a diagram illustrating the configuration of a first terminal device and a second terminal device according to the present disclosure.

The first terminal device 2000 may include a processor 2010 , an antenna unit 2020 , a transceiver 2030 , and a memory 2040 .

The processor 2010 performs baseband-related signal processing, and may include an upper layer processing unit 2011 and a physical layer processing unit 2015 . The higher layer processing unit 2011 may process the operation of the MAC layer, the RRC layer, or higher layers. The physical layer processing unit 2015 may process operations of the PHY layer (eg, downlink reception signal processing, uplink transmission signal processing, sidelink transmission signal processing, etc.). The processor 2010 may control the overall operation of the first terminal device 2000 in addition to performing baseband-related signal processing.

The antenna unit 2020 may include one or more physical antennas, and when it includes a plurality of antennas, it may support MIMO transmission/reception. The transceiver 2030 may include an RF transmitter and an RF receiver. The memory 2040 may store information processed by the processor 2010 , software related to the operation of the first terminal device 2000 , an operating system, an application, and the like, and may include components such as a buffer.

The processor 2010 of the first terminal device 2000 may be configured to implement the operation of the sidelink transmission terminal (or the first terminal) in the embodiments described in the present invention.

For example, the upper layer processing unit 2011 of the processor 2010 of the first terminal device 2000 includes an SL resource allocation determination unit 2012, an SL DRX parameter determination unit 2013, and an SL retransmission processing unit 2014. can do.

The SL resource allocation determining unit 2012 transmits SL data based on the resource allocation information from the base station, autonomously by the first terminal device 2000, or based on the resource allocation information from the second terminal device 2050 resources can be determined for Resources for SL data transmission may be dynamically configured or configured in a configured grant scheme (eg, GF/SPS scheme).

The SL DRX parameter determiner 2013 determines a DRX parameter for the second terminal device 2050 that receives the SL data, and provides information on the determined DRX parameter to the second terminal device 2050 for higher layer signaling (eg, For example, PC5-RRC).

Alternatively, the first terminal device 2000 does not determine the DRX parameter for the second terminal device 2050, but information necessary for the second terminal device 2050 to determine the DRX parameter (eg, the first/ Second sidelink configured grant information) may be provided.

The SL retransmission processing unit 2014 may determine whether retransmission of previously transmitted SL data is possible or whether retransmission is required based on the HARQ feedback (ACK/NACK/DTX) from the second terminal device 2050 .

SL data to be transmitted or retransmitted may be transmitted to the physical layer processing unit 2015 and transmitted to the second terminal device 2050 . Specifically, the physical layer processing unit 2015 generates and transmits the first and second SCIs to the second terminal device 2050 according to the dynamic resource allocation method or the configured grant method, and is indicated by the first and second SCIs. SL data may be transmitted to the second terminal device 2050 on a resource.

The second terminal device 2050 may include a processor 2060 , an antenna unit 2070 , a transceiver 2080 , and a memory 2090 .

The processor 2060 performs baseband-related signal processing and may include an upper layer processing unit 2061 and a physical layer processing unit 2065 . The higher layer processing unit 2061 may process the operation of the MAC layer, the RRC layer, or higher layers. The physical layer processing unit 2065 may process operations of the PHY layer (eg, downlink reception signal processing, uplink transmission signal processing, sidelink reception signal processing, etc.). The processor 2060 may control the overall operation of the second terminal device 2060 in addition to performing baseband-related signal processing.

The antenna unit 2070 may include one or more physical antennas, and when it includes a plurality of antennas, it may support MIMO transmission/reception. The transceiver 2080 may include an RF transmitter and an RF receiver. The memory 2090 may store information processed by the processor 2060 , software related to the operation of the second terminal device 2050 , an operating system, an application, and the like, and may include components such as a buffer.

The processor 2060 of the second terminal device 2050 may be configured to implement the operation of the sidelink receiving terminal (or the second terminal) in the embodiments described in the present invention.

For example, the upper layer processing unit 2061 of the processor 2060 of the second terminal device 2050 controls the SL resource allocation determination unit 2062 , the SL DRX parameter determination unit 2063 , and the SL DRX operation control unit 2064 . may include

The SL resource allocation determiner 2062 may determine a resource for receiving SL data based on the SL resource allocation information provided from the first terminal device 2000 . Resources for SL data transmission may be dynamically configured or configured in a configured grant scheme (eg, GF/SPS scheme). Alternatively, the SL resource allocation determining unit 2062 determines SL resource allocation information for the first terminal device 2000 based on the resource allocation information from the base station, and sends it to the first terminal device 2000 by higher layer signaling ( For example, it may be transmitted through PC5-RRC).

The SL DRX parameter determiner 2063 may determine a DRX parameter for the second terminal device 2050 based on DRX parameter information provided from the first terminal device 2000 .

Alternatively, the SL DRX parameter determiner 2063 is configured to provide the second terminal device 2050 based on information provided from the first terminal device 2000 (eg, first/second sidelink configured grant information). DRX parameters may be determined.

Alternatively, the SL DRX parameter determiner 2063 may configure the second terminal device ( 2050) may be determined.

The SL DRX operation controller 2064 may perform a sidelink DRX operation based on the DRX parameter. The sidelink DRX operation may include a DRX operation according to examples of the present disclosure for an inactivity timer start/restart time, a retransmission timer start time, an inactivity timer start exception condition, and the like.

Additionally, the upper layer processing unit 2061 generates HARQ feedback (ACK/NACK/DTX) according to whether HARQ for sidelink data is enabled, and the first terminal device ( 2000) can also be sent.

The SL data transmitted or retransmitted from the first terminal device 2000 may be received through the physical layer processing unit 2065 . Specifically, the physical layer processing unit 2065 receives the first and second SCIs from the first terminal device 2000 according to the dynamic resource allocation method or the configured grant method, and receives the first and second SCIs on the resources indicated by the first and second SCIs. SL data may be received from the first terminal device 2000 .

In the operations of the first terminal device 2000 and the second terminal device 2050, the descriptions for the sidelink transmitting terminal and the sidelink receiving terminal in the examples of the present invention may be equally applied, and overlapping descriptions will be omitted. do.

Example methods of the present disclosure are expressed as a series of operations for clarity of description, but this is not intended to limit the order in which the steps are performed, and if necessary, each step may be performed simultaneously or in a different order. In order to implement the method according to the present disclosure, other steps may be included in addition to the illustrated steps, steps may be excluded from some steps, and/or other steps may be included except for some steps.

Various embodiments of the present disclosure do not list all possible combinations, but are intended to describe representative aspects of the present disclosure, and matters described in various embodiments may be applied independently or in combination of two or more.

In addition, various embodiments of the present disclosure may be implemented by hardware, firmware, software, or a combination thereof. For implementation by hardware, one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), general purpose It may be implemented by a processor (general processor), a controller, a microcontroller, a microprocessor, and the like.

The scope of the present disclosure includes software or machine-executable instructions (eg, operating system, application, firmware, program, etc.) that cause operation according to the method of various embodiments to be executed on a device or computer, and such software or and non-transitory computer-readable media in which instructions and the like are stored and executed on a device or computer.

Claims (1)

In a discontinuous reception (DRX) method for communication between terminals in a wireless communication system,
determining, by a second terminal, a DRX parameter based on one or more of DRX parameter information or sidelink resource allocation information from the first terminal; and
and performing, by the second terminal, a DRX operation based on the determined DRX parameter,
The DRX operation includes application of the DRX parameter according to one or more of a start or restart time of an inactivity timer, a start time of a retransmission timer, and an inactivity timer start exception condition,
When the configured grant method resource allocation is applied, the sidelink resource allocation information includes information indicating an activated resource allocation configuration,
Discontinuous reception method for communication between terminals.

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