Method and apparatus for allocating sidelink resource in communication system

Abstract

A method and apparatus for allocating sidelink resources in a communication system are disclosed. A method of operation of a first terminal includes: generating a first-stage SCI comprising first resource allocation information and a first indicator indicating whether the second-stage SCI includes the second resource allocation information; transmitting the first-stage SCI to the second terminal via PSCCH; and performing sidelink communication with the second terminal using a first resource area indicated by the first resource allocation information.

Description

Technology Field

[0001] The present invention relates to sidelink communication technology, and more specifically, to a technology for allocating sidelink resources in a communication system. Background Technology

[0002] To handle the surge in wireless data following the commercialization of 4G (4th Generation) communication systems (e.g., LTE (Long Term Evolution) communication systems, LTE-A (Advanced) communication systems), 5G (5th Generation) communication systems (e.g., NR (New Radio) communication systems) that use frequency bands higher than those of 4G communication systems (e.g., frequency bands below 6 GHz) are being considered. 5G communication systems can support eMBB (enhanced Mobile BroadBand), URLLC (Ultra-Reliable and Low Latency Communication), and mMTC (massive Machine Type Communication).

[0003] 4G communication systems and 5G communication systems can support V2X (Vehicle to everything) communication (e.g., sidelink communication). V2X communication supported by cellular communication systems such as 4G communication systems and 5G communication systems may be referred to as "C-V2X (Cellular-Vehicle to everything) communication." V2X communication (e.g., C-V2X communication) may include V2V (Vehicle to Vehicle) communication, V2I (Vehicle to Infrastructure) communication, V2P (Vehicle to Pedestrian) communication, V2N (Vehicle to Network) communication, etc.

[0004] In a cellular communication system, V2X communication (e.g., C-V2X communication) can be performed based on sidelink communication technology (e.g., ProSe (Proximity based Services) communication technology, D2D (Device to Device) communication technology). For example, a sidelink channel can be established for vehicles participating in V2V communication (e.g., sidelink communication), and communication between vehicles can be performed using the sidelink channel. Sidelink communication can be performed using configured grant (CG) resources. CG resources can be configured periodically, and periodic data (e.g., periodic sidelink data) can be transmitted using the CG resources.

[0005] Meanwhile, the allocation of sidelink resources may be required for the transmission of data (e.g., V2X data). When a resource allocation mode based on sensing of time and frequency resources is used, a resource reservation-based operation method may be necessary to reliably allocate resources for data transmission. To support this resource reservation-based operation method, an efficient operation method for the sidelink channel may be required. The problem to be solved

[0006] The objective of the present invention to solve the above-mentioned problems is to provide a method and apparatus for allocating sidelink resources in a communication system. means of solving the problem

[0007] A method of operation of a first terminal according to a first embodiment of the present invention for achieving the above objective comprises: generating a first stage SCI including first resource allocation information and a first indicator indicating whether the second stage SCI includes second resource allocation information; transmitting the first stage SCI to the second terminal via PSCCH; and performing sidelink communication with the second terminal using a first resource area indicated by the first resource allocation information.

[0008] Here, the method of operation of the first terminal may further include the step of transmitting the second stage SCI containing the second resource allocation information to the second terminal via PSSCH when the first indicator indicates that the second stage SCI contains the second resource allocation information, and the second resource area indicated by the second resource allocation information may be different from the first resource area.

[0009] Here, if the first indicator indicates that the second stage SCI does not include the second resource allocation information, the transmission of the second stage SCI associated with the first stage SCI may be omitted.

[0010] Here, the first stage SCI may further include a second indicator that indicates the usage method of the SL channel, and the second indicator set to a first value may indicate that "the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI and data," and the second indicator set to a second value may indicate that "the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI."

[0011] Here, the usage method of the SL channel including the PSCCH and PSSCH can be classified into a first method and a second method, and when the first method is used, the PSCCH can be used for the transmission of the first stage SCI and the PSSCH can be used for the transmission of the second stage SCI and data, and when the second method is used, the PSCCH can be used for the transmission of the first stage SCI and the PSSCH can be used for the transmission of the second stage SCI, and the first method can be used when the size of the data is below a threshold value, and the second method can be used when the size of the data exceeds a threshold value.

[0012] Here, the first resource allocation information may indicate resource regions of n SL channels, and the second resource allocation information may indicate resource regions of k SL channels, and each of the n SL channels and the k SL channels may include one PSCCH and one PSSCH belonging to the same RB set, and n and k may each be natural numbers.

[0013] Here, one of the above n, the above k, and the above n+k can be obtained from a base station through one or more of upper layer signaling, MAC signaling, and PHY signaling.

[0014] Here, the SL channel including the PSCCH and PSSCH can be transmitted in a monitoring occupancy, and the monitoring occupancy can be configured for a specific cast method, and the specific cast method can be one of a unicast method, a group cast method, and a broadcast method.

[0015] A method of operation of a second terminal according to a first embodiment of the present invention for achieving the above objective comprises: receiving a first stage SCI from a first terminal in a PSCCH; checking a first indicator that indicates whether the first resource allocation information included in the first stage SCI and the second stage SCI includes the second resource allocation information; and, if the first indicator indicates that the second stage SCI includes the second resource allocation information, performing a monitoring operation in the PSSCH to receive the second stage SCI from the second terminal.

[0016] Here, the first resource allocation information may indicate resource regions of n SL channels, and the second resource allocation information may indicate resource regions of k SL channels, and each of the n SL channels and the k SL channels may include one PSCCH and one PSSCH belonging to the same RB set, and n and k may each be natural numbers.

[0017] Here, one of the above n, the above k, and the above n+k can be obtained from a base station through one or more of upper layer signaling, MAC signaling, and PHY signaling.

[0018] Here, the SL channel including the PSCCH and the PSSCH can be received at a monitoring occupancy, and the monitoring occupancy can be configured for a specific cast method, and the specific cast method can be one of a unicast method, a group cast method, and a broadcast method.

[0019] Here, the first stage SCI may further include a second indicator that indicates the usage method of the SL channel, and the second indicator set to a first value may indicate that "the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI and data," and the second indicator set to a second value may indicate that "the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI."

[0020] Here, the usage method of the SL channel including the PSCCH and the PSSCH can be classified into a first method and a second method, and when the first method is used, the PSCCH can be used for the transmission of the first stage SCI and the PSSCH can be used for the transmission of the second stage SCI and data, and when the second method is used, the PSCCH can be used for the transmission of the first stage SCI and the PSSCH can be used for the transmission of the second stage SCI, and the first method can be used when the size of the data is below a threshold value, and the second method can be used when the size of the data exceeds the threshold value.

[0021] Here, the threshold value can be obtained from the base station through one or more of upper layer signaling, MAC signaling, and PHY signaling.

[0022] A first terminal according to a third embodiment of the present invention for achieving the above objective comprises a processor and a memory for storing one or more instructions executed by the processor, wherein the one or more instructions are executed to generate a first stage SCI including first resource allocation information and a first indicator indicating whether the second stage SCI includes the second resource allocation information, transmit the first stage SCI to the second terminal via PSCCH, and perform sidelink communication with the second terminal using a first resource area indicated by the first resource allocation information.

[0023] Here, the above one or more commands may be further executed to transmit the second stage SCI containing the second resource allocation information to the second terminal via PSSCH when the first indicator indicates that the second stage SCI contains the second resource allocation information, and the second resource area indicated by the second resource allocation information may be different from the first resource area.

[0024] Here, the first stage SCI may further include a second indicator that indicates the usage method of the SL channel, and the second indicator set to a first value may indicate that "the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI and data," and the second indicator set to a second value may indicate that "the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI."

[0025] Here, the first resource allocation information may indicate resource regions of n SL channels, and the second resource allocation information may indicate resource regions of k SL channels, and each of the n SL channels and the k SL channels may include one PSCCH and one PSSCH belonging to the same RB set, and n and k may each be natural numbers.

[0026] Here, the SL channel including the PSCCH and PSSCH can be transmitted in a monitoring occupancy, and the monitoring occupancy can be configured for a specific cast method, and the specific cast method can be one of a unicast method, a group cast method, and a broadcast method. Effects of the invention

[0027] According to the present invention, sidelink resources can be allocated by a first-stage SCI (sidelink control information) and / or a second-stage SCI, and sidelink communication can be performed using the allocated sidelink resources. Additionally, the first-stage SCI may include information element(s) to support the allocation of sidelink resources, and sidelink resources can be efficiently allocated based on the information element(s) included in the first-stage SCI. Accordingly, the performance of the communication system can be improved. Brief explanation of the drawing

[0028] Figure 1 is a conceptual diagram illustrating V2X communication scenarios. FIG. 2 is a conceptual diagram illustrating a first embodiment of a cellular communication system. FIG. 3 is a block diagram illustrating a first embodiment of a communication node constituting a cellular communication system. FIG. 4 is a block diagram illustrating a first embodiment of a user plane protocol stack of a UE performing sidelink communication. FIG. 5 is a block diagram illustrating a first embodiment of a control plane protocol stack of a UE performing sidelink communication. FIG. 6 is a block diagram illustrating a second embodiment of a control plane protocol stack of a UE performing sidelink communication. FIG. 7 is a conceptual diagram illustrating a first embodiment of a method for allocating side link resources. FIG. 8 is a conceptual diagram illustrating a second embodiment of a method for allocating side link resources. FIG. 9 is a conceptual diagram illustrating a third embodiment of a method for allocating side link resources. FIG. 10 is a flowchart illustrating a first embodiment of a side-link communication method. FIG. 11 is a flowchart illustrating a second embodiment of a side-link communication method. FIG. 12 is a flowchart illustrating a third embodiment of a side-link communication method. FIG. 13 is a flowchart illustrating a fourth embodiment of a side-link communication method. Specific details for implementing the invention

[0029] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0030] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any of a plurality of related described items.

[0031] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0032] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0033] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0034] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings. In order to facilitate an overall understanding of the present invention, the same reference numerals are used for identical components in the drawings, and redundant descriptions of identical components are omitted.

[0035] Figure 1 is a conceptual diagram illustrating scenarios of V2X (Vehicle to everything) communication.

[0036] Referring to FIG. 1, V2X communication may include V2V (Vehicle to Vehicle) communication, V2I (Vehicle to Infrastructure) communication, V2P (Vehicle to Pedestrian) communication, V2N (Vehicle to Network) communication, etc. V2X communication may be supported by a cellular communication system (e.g., a cellular communication network) (140), and V2X communication supported by the cellular communication system (140) may be referred to as "C-V2X (Cellular-Vehicle to everything) communication." The cellular communication system (140) may include a 4G (4th Generation) communication system (e.g., an LTE (Long Term Evolution) communication system, an LTE-A (Advanced) communication system), a 5G (5th Generation) communication system (e.g., an NR (New Radio) communication system), etc.

[0037] V2V communication may refer to communication between Vehicle #1 (100) (e.g., a communication node located in Vehicle #1 (100)) and Vehicle #2 (110) (e.g., a communication node located in Vehicle #1 (100)). Through V2V communication, driving information (e.g., velocity, heading, time, position, etc.) can be exchanged between the vehicles (100, 110). Based on the driving information exchanged through V2V communication, autonomous driving (e.g., platooning) can be supported. V2V communication supported by a cellular communication system (140) can be performed based on sidelink communication technology (e.g., ProSe (Proximity based Services) communication technology, D2D (Device to Device) communication technology). In this case, communication between the vehicles (100, 110) can be performed using a sidelink channel.

[0038] V2I communication may refer to communication between Vehicle #1 (100) and infrastructure located on the roadside (e.g., RSU (road side unit)) (120). Infrastructure (120) may be traffic lights, streetlights, etc. located on the roadside. For example, when V2I communication is performed, communication may be performed between a communication node located at Vehicle #1 (100) and a communication node located at a traffic light. Through V2I communication, driving information, traffic information, etc., may be exchanged between Vehicle #1 (100) and infrastructure (120). V2I communication supported by a cellular communication system (140) may be performed based on side-link communication technology (e.g., ProSe communication technology, D2D communication technology). In this case, communication between Vehicle #1 (100) and infrastructure (120) may be performed using a side-link channel.

[0039] V2P communication may refer to communication between Vehicle #1 (100) (e.g., a communication node located in Vehicle #1 (100)) and a person (130) (e.g., a communication node held by the person (130)). Through V2P communication, driving information of Vehicle #1 (100) and movement information of the person (130) (e.g., speed, direction, time, location, etc.) can be exchanged between Vehicle #1 (100) and the person (130). The communication node located in Vehicle #1 (100) or the communication node held by the person (130) can generate an alarm indicating danger by determining a dangerous situation based on the acquired driving information and movement information. V2P communication supported by a cellular communication system (140) may be performed based on sidelink communication technology (e.g., ProSe communication technology, D2D communication technology). In this case, communication between a communication node located in vehicle #1 (100) or a communication node held by a person (130) can be performed using a sidelink channel.

[0040] V2N communication may refer to communication between Vehicle #1 (100) (e.g., a communication node located in Vehicle #1 (100)) and a cellular communication system (e.g., a cellular communication network) (140). V2N communication may be performed based on 4G communication technology (e.g., LTE communication technology and LTE-A communication technology specified in 3GPP standards), 5G communication technology (e.g., NR communication technology specified in 3GPP standards), etc. Additionally, V2N communication may be performed based on communication technology specified in IEEE (Institute of Electrical and Electronics Engineers) 702.11 standards (e.g., WAVE (Wireless Access in Vehicular Environments) communication technology, WLAN (Wireless Local Area Network) communication technology, etc.), communication technology specified in IEEE 702.15 standards (e.g., WPAN (Wireless Personal Area Network), etc.).

[0041] Meanwhile, a cellular communication system (140) that supports V2X communication can be configured as follows.

[0042] FIG. 2 is a conceptual diagram illustrating a first embodiment of a cellular communication system.

[0043] Referring to FIG. 2, the cellular communication system may include an access network, a core network, etc. The access network may include a base station (210), a relay (220), User Equipment (UE) (231 to 236), etc. The UE (231 to 236) may be a communication node located in the vehicle (100 and 110) of FIG. 1, a communication node located in the infrastructure (120) of FIG. 1, a communication node carried by a person (130) of FIG. 1, etc. If the cellular communication system supports 4G communication technology, the core network may include a serving-gateway (S-GW) (250), a packet data network (PDN)-gateway (260), a mobility management entity (MME) (270), etc.

[0044] If the cellular communication system supports 5G communication technology, the core network may include a user plane function (UPF) (250), a session management function (SMF) (260), an access and mobility management function (AMF) (270), etc. Alternatively, if the cellular communication system supports Non-StandAlone (NSA), the core network composed of an S-GW (250), a P-GW (260), an MME (270), etc. may support 5G communication technology as well as 4G communication technology, and the core network composed of a UPF (250), an SMF (260), an AMF (270), etc. may support 4G communication technology as well as 5G communication technology.

[0045] In addition, if the cellular communication system supports network slicing technology, the core network can be divided into multiple logical network slices. For example, network slices that support V2X communication (e.g., V2V network slice, V2I network slice, V2P network slice, V2N network slice, etc.) can be configured, and V2X communication can be supported by the V2X network slice configured in the core network.

[0046] Communication nodes constituting a cellular communication system (e.g., base station, relay, UE, S-GW, P-GW, MME, UPF, SMF, AMF, etc.) can perform communication using at least one of the following communication technologies: CDMA (code division multiple access) technology, WCDMA (wideband CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division multiplexing) technology, Filtered OFDM technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA technology, NOMA (non-orthogonal multiple access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, and SDMA (space division multiple access) technology.

[0047] Communication nodes constituting a cellular communication system (e.g., base station, relay, UE, S-GW, P-GW, MME, UPF, SMF, AMF, etc.) can be configured as follows.

[0048] FIG. 3 is a block diagram illustrating a first embodiment of a communication node constituting a cellular communication system.

[0049] Referring to FIG. 3, the communication node (300) may include at least one processor (310), a memory (320), and a transceiver (330) that is connected to a network to perform communication. Additionally, the communication node (300) may further include an input interface device (340), an output interface device (350), a storage device (360), etc. Each component included in the communication node (300) may be connected by a bus (370) to communicate with one another.

[0050] However, each component included in the communication node (300) may be connected via individual interfaces or individual buses centered around the processor (310), rather than via a common bus (370). For example, the processor (310) may be connected via a dedicated interface to at least one of the memory (320), the transmission / reception device (330), the input interface device (340), the output interface device (350), and the storage device (360).

[0051] The processor (310) can execute a program command stored in at least one of the memory (320) and the storage device (360). The processor (310) may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory (320) and the storage device (360) may be composed of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (320) may be composed of at least one of read-only memory (ROM) and random access memory (RAM).

[0052] Referring again to FIG. 2, in a communication system, a base station (210) may form a macro cell or a small cell and may be connected to a core network via an ideal backhaul or a non-ideal backhaul. The base station (210) may transmit signals received from the core network to UEs (231 to 236) and a relay (220), and may transmit signals received from UEs (231 to 236) and a relay (220) to the core network. UEs #1, #2, #4, #5 and #6 (231, 232, 234, 235, 236) may be within the cell coverage of the base station (210). UE #1, #2, #4, #5 and #6 (231, 232, 234, 235, 236) can be connected to the base station (210) by performing a connection establishment procedure with the base station (210). UE #1, #2, #4, #5 and #6 (231, 232, 234, 235, 236) can communicate with the base station (210) after being connected to the base station (210).

[0053] The relay (220) can be connected to the base station (210) and can relay communication between the base station (210) and UE #3 and #4 (233, 234). The relay (220) can transmit signals received from the base station (210) to UE #3 and #4 (233, 234) and transmit signals received from UE #3 and #4 (233, 234) to the base station (210). UE #4 (234) can be within the cell coverage of the base station (210) and the cell coverage of the relay (220), and UE #3 (233) can be within the cell coverage of the relay (220). That is, UE #3 (233) can be located outside the cell coverage of the base station (210). UE #3 and #4 (233, 234) can be connected to the relay (220) by performing a connection establishment procedure with the relay (220). UE #3 and #4 (233, 234) can communicate with the relay (220) after being connected to the relay (220).

[0054] The base station (210) and the relay (220) can support MIMO communication technology (e.g., SU (single user)-MIMO, MU (multi user)-MIMO, massive MIMO, etc.), CoMP (coordinated multipoint) communication technology, CA (Carrier Aggregation) communication technology, unlicensed band communication technology (e.g., LAA (Licensed Assisted Access), eLAA (enhanced LAA)), sidelink communication technology (e.g., ProSe communication technology, D2D communication technology), etc. UE #1, #2, #5 and #6 (231, 232, 235, 236) can perform operations corresponding to the base station (210), operations supported by the base station (210), etc. UE #3 and #4 (233, 234) can perform operations corresponding to the relay (220), operations supported by the relay (220), etc.

[0055] Here, the base station (210) may be referred to as Node B, evolved Node B, base transceiver station (BTS), radio remote head (RRH), transmission reception point (TRP), radio unit (RU), road side unit (RSU), radio transceiver, access point, access node, etc. The relay (220) may be referred to as a small base station, relay node, etc. The UE (231 to 236) may be referred to as a terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, OBU (on-broad unit), etc.

[0056] Meanwhile, communication between UE #5 (235) and UE #6 (236) can be performed based on Cylink communication technology (e.g., ProSe communication technology, D2D communication technology). Cylink communication can be performed based on a one-to-one or one-to-many method. When V2V communication is performed using Cylink communication technology, UE #5 (235) can indicate a communication node located in Vehicle #1 (100) of FIG. 1, and UE #6 (236) can indicate a communication node located in Vehicle #2 (110) of FIG. 1. When V2I communication is performed using Cylink communication technology, UE #5 (235) can indicate a communication node located in Vehicle #1 (100) of FIG. 1, and UE #6 (236) can indicate a communication node located in the infrastructure (120) of FIG. 1. When V2P communication is performed using Cyclink communication technology, UE #5 (235) can indicate a communication node located in vehicle #1 (100) of FIG. 1, and UE #6 (236) can indicate a communication node held by person (130) of FIG. 1.

[0057] Scenarios in which sidelink communication is applied can be classified as shown in Table 1 below according to the locations of the UEs participating in the sidelink communication (e.g., UE #5 (235), UE #6 (236)). For example, the scenario for sidelink communication between UE #5 (235) and UE #6 (236) shown in FIG. 2 may be sidelink communication scenario #C.

[0058]

[0059] Meanwhile, the user plane protocol stack of UEs performing sidelink communication (e.g., UE #5 (235), UE #6 (236)) can be configured as follows.

[0060] FIG. 4 is a block diagram illustrating a first embodiment of a user plane protocol stack of a UE performing sidelink communication.

[0061] Referring to FIG. 4, UE #5 (235) may be UE #5 (235) shown in FIG. 2, and UE #6 (236) may be UE #6 (236) shown in FIG. 2. The scenario for sidelink communication between UE #5 (235) and UE #6 (236) may be one of the sidelink communication scenarios #A to #D in Table 1. The user plane protocol stack of UE #5 (235) and UE #6 (236), respectively, may include a PHY (Physical) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, etc.

[0062] Sidelink communication between UE #5 (235) and UE #6 (236) can be performed using a PC5 interface (e.g., a PC5-U interface). For sidelink communication, a Layer 2-ID (identifier) ​​(e.g., source Layer 2-ID, destination Layer 2-ID) may be used, and the Layer 2-ID may be an ID set for V2X communication. Additionally, HARQ (hybrid ARQ (automatic repeat request)) feedback operation may be supported in sidelink communication, and RLC AM (Acknowledged Mode) or RLC UM (Unacknowledged Mode) may be supported.

[0063] Meanwhile, the control plane protocol stack of UEs performing sidelink communication (e.g., UE #5 (235), UE #6 (236)) can be configured as follows.

[0064] FIG. 5 is a block diagram illustrating a first embodiment of a control plane protocol stack of a UE performing sidelink communication, and FIG. 6 is a block diagram illustrating a second embodiment of a control plane protocol stack of a UE performing sidelink communication.

[0065] Referring to FIGS. 5 and FIGS. 6, UE #5 (235) may be UE #5 (235) shown in FIGS. 2, and UE #6 (236) may be UE #6 (236) shown in FIGS. 2. The scenario for sidelink communication between UE #5 (235) and UE #6 (236) may be one of the sidelink communication scenarios #A to #D of Table 1. The control plane protocol stack shown in FIGS. 5 may be a control plane protocol stack for transmitting and receiving broadcast information (e.g., PSBCH (Physical Sidelink Broadcast Channel)).

[0066] The control plane protocol stack illustrated in FIG. 5 may include a PHY layer, a MAC layer, an RLC layer, a radio resource control (RRC) layer, etc. Sidelink communication between UE #5 (235) and UE #6 (236) may be performed using a PC5 interface (e.g., a PC5-C interface). The control plane protocol stack illustrated in FIG. 6 may be a control plane protocol stack for one-to-one sidelink communication. The control plane protocol stack illustrated in FIG. 6 may include a PHY layer, a MAC layer, an RLC layer, a PDCP layer, a PC5 signaling protocol layer, etc.

[0067] Meanwhile, the channels used for sidelink communication between UE #5 (235) and UE #6 (236) may include PSSCH (Physical Sidelink Shared Channel), PSCCH (Physical Sidelink Control Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. PSSCH may be used for transmitting and receiving sidelink data and may be set to UEs (e.g., UE #5 (235), UE #6 (236)) by upper layer signaling. PSCCH may be used for transmitting and receiving sidelink control information (SCI) and may be set to UEs (e.g., UE #5 (235), UE #6 (236)) by upper layer signaling.

[0068] PSDCH can be used for discovery procedures. For example, a discovery signal can be transmitted via PSDCH. PSBCH can be used for the transmission and reception of broadcast information (e.g., system information). Additionally, DM-RS (demodulation-reference signal), synchronization signals, etc., may be used in sidelink communication between UE #5 (235) and UE #6 (236). Synchronization signals may include PSSS (primary sidelink synchronization signal) and SSSS (secondary sidelink synchronization signal).

[0069] Meanwhile, sidelink transmission modes (TM) can be classified into sidelink TM #1 to #4 as shown in Table 2 below.

[0070]

[0071] If Sidelink TM #3 or #4 is supported, UE #5 (235) and UE #6 (236) can each perform sidelink communication using a resource pool set by the base station (210). The resource pool can be set for sidelink control information or sidelink data, respectively.

[0072] A resource pool for sidelink control information may be established based on an RRC signaling procedure (e.g., a dedicated RRC signaling procedure, a broadcast RRC signaling procedure). A resource pool used for receiving sidelink control information may be established by a broadcast RRC signaling procedure. If sidelink TM #3 is supported, a resource pool used for transmitting sidelink control information may be established by a dedicated RRC signaling procedure. In this case, sidelink control information may be transmitted through resources scheduled by the base station (210) within a resource pool established by a dedicated RRC signaling procedure. If sidelink TM #4 is supported, a resource pool used for transmitting sidelink control information may be established by a dedicated RRC signaling procedure or a broadcast RRC signaling procedure. In this case, sidelink control information may be transmitted through a resource autonomously selected by a UE (e.g., UE #5 (235), UE #6 (236)) within a resource pool established by a dedicated RRC signaling procedure or a broadcast RRC signaling procedure.

[0073] If Sidelink TM #3 is supported, a resource pool for transmitting and receiving sidelink data may not be configured. In this case, sidelink data may be transmitted and received through resources scheduled by the base station (210). If Sidelink TM #4 is supported, a resource pool for transmitting and receiving sidelink data may be configured by a dedicated RRC signaling procedure or a broadcast RRC signaling procedure. In this case, sidelink data may be transmitted and received through resources autonomously selected by a UE (e.g., UE #5 (235), UE #6 (236)) within a resource pool configured by the RRC signaling procedure or the broadcast RRC signaling procedure.

[0074] Next, methods for allocating sidelink resources will be described. Even when a method performed at a first communication node among the communication nodes (e.g., transmission or reception of a signal) is described, the corresponding second communication node may perform a method corresponding to the method performed at the first communication node (e.g., reception or transmission of a signal). That is, if the operation of UE #1 (e.g., Vehicle #1) is described, the corresponding UE #2 (e.g., Vehicle #2) may perform an operation corresponding to the operation of UE #1. Conversely, if the operation of UE #2 is described, the corresponding UE #1 may perform an operation corresponding to the operation of UE #2. In the embodiments described below, the operation of the vehicle may be the operation of a communication node located in the vehicle.

[0075] In the embodiments, signaling may be one or more combinations of upper-layer signaling, MAC signaling, and PHY (physical) signaling. Signaling may refer to the operation of a first communication node transmitting information (e.g., control information, configuration information, information elements) to a second communication node. If the first communication node is a base station, the second communication node may be a transmitting terminal and / or a receiving terminal. If the first communication node is a terminal, the second communication node may be a base station. If the first communication node is a transmitting node, the second communication node may be a receiving node. If the first communication node is a receiving node, the second communication node may be a transmitting node. A transmitting terminal may be a terminal that transmits data, and a receiving terminal may be a terminal that receives data.

[0076] Messages used for upper-layer signaling may be referred to as "upper-layer messages" or "upper-layer signaling messages." Messages used for MAC signaling may be referred to as "MAC messages" or "MAC signaling messages." Messages used for PHY signaling may be referred to as "PHY messages" or "PHY signaling messages." Upper-layer signaling may refer to the transmission and reception operations of system information (e.g., MIB (master information block), SIB (system information block)) and / or RRC messages. MAC signaling may refer to the transmission and reception operations of MAC CE (control element). PHY signaling may refer to the transmission and reception operations of control information (e.g., DCI (downlink control information), UCI (uplink control information), SCI).

[0077] Sidelink signals may be synchronization signals and reference signals used for sidelink communication. For example, the synchronization signal may be an SS / PBCH (synchronization signal / physical broadcast channel) block, SLSS (sidelink synchronization signal), PSSS (primary sidelink synchronization signal), SSSS (secondary sidelink synchronization signal), etc. The reference signal may be a CSI-RS (channel state information-reference signal), DM-RS, PT-RS (phase tracking-reference signal), CRS (cell specific reference signal), SRS (sounding reference signal), DRS (discovery reference signal), etc.

[0078] A sidelink channel may be PSSCH, PSCCH, PSDCH, PSBCH, PSFCH (physical sidelink feedback channel), etc. Additionally, a sidelink channel may refer to a sidelink channel containing sidelink signals mapped to specific resources within that sidelink channel. Sidelink communication may support broadcast services, multicast services, groupcast services, and unicast services.

[0079] Sidelink communication can be performed based on a single SCI or a multi-SCI method. When the single SCI method is used, data transmission (e.g., sidelink data transmission, SL-SCH (sidelink-shared channel) transmission) is performed using one SCI (e.g., 1 stIt can be performed based on -stage SCI). When a multi-SCI scheme is used, data transmission is performed using two SCIs (e.g., 1 st -stage SCI and 2 nd It can be performed using -stage SCI). SCI can be transmitted via PSCCH and / or PSSCH. If a single SCI method is used, SCI (e.g., 1 st -stage SCI) can be transmitted over PSCCH. When a multiple SCI scheme is used, 1 st -stage SCI can be transmitted from PSCCH, and 2 nd -Stage SCI can be transmitted over PSCCH or PSSCH. 1 st -stage SCI can be referred to as "Stage 1 SCI," and 2 nd -stage SCI can be referred to as "Stage 2 SCI".

[0080] The first stage SCI may include one or more information elements among priority information, frequency resource assignment information, time resource assignment information, resource reservation period information, DMRS pattern information, second stage SCI format information, beta_offset indicator, number of DMRS ports, and modulation and coding scheme (MCS) information. The second stage SCI may include one or more information elements among HARQ processor ID (identifier), redundancy version (RV), source ID, destination ID, CSI request information, zone ID, and communication range requirement.

[0081] FIG. 7 is a conceptual diagram illustrating a first embodiment of a method for allocating side link resources.

[0082] Referring to FIG. 7, a resource pool may be configured for sidelink communication. The resource pool may consist of one or more slots, one or more mini-slots, or one or more symbols in the time domain. The number of symbols constituting a mini-slot may be smaller than the number of symbols constituting a slot. The resource pool may consist of one or more sets of resource blocks (RBs), one or more physical resource blocks (PRBs), or one or more subcarriers in the frequency domain. A set of RBs may be referred to as a sub-channel. A set of RBs may include one or more subcarriers or one or more PRBs. A single sub-channel may be a combination of a time resource domain and a frequency resource domain. A frequency resource domain may be configured on a sub-channel basis, and one sub-channel may be used as a frequency resource domain. In the embodiments, a PRB may be interpreted as a common resource block (CRB) or a virtual resource block (VRB). The resource pool may be interpreted as a logical resource. Resource pools can be non-continuous time and frequency resources.

[0083] PSCCH and PSSCH can be allocated within a resource pool. PSCCH and PSSCH can belong to a single set of RBs (i.e., the same set of RBs) in the frequency domain. PSCCH and PSSCH established within a single set of RBs (i.e., the same set of RBs) may be referred to as a "single-RB set channel." Control information (e.g., SCI, first-stage SCI) can be transmitted via a PSCCH (e.g., PSCCH candidate) within a PSCCH monitoring occupation (e.g., search space). A PSCCH monitoring occupation can be established within a single set of RBs.

[0084] An information element indicating whether a single-RB set channel is being used may be transmitted by one or more combinations of upper-layer signaling, MAC signaling, and PHY signaling. For example, an information element set to a first value may indicate that a single-RB set channel is being used. An information element set to a second value may indicate that a single-RB set channel is not being used. In this case, PSCCH and / or PSSCH may be set in multiple RB sets. Alternatively, PSCCH and PSSCH may be set in different RB sets.

[0085] When Sidelink TM #2 is used, instead of the base station, the terminal can select a radio resource (e.g., time and / or frequency resources) by performing a sensing operation, and can perform sidelink communication using the selected radio resource. Transmission schemes of a single-RB aggregation channel for the initial transmission and / or retransmission resource allocation (e.g., resource reservation) of data can be defined as shown in Table 3 below.

[0086]

[0087] Method #3 may be a combination of Method #1 and Method #2. The terminal may use Method #1 or Method #2 as needed. To support the method(s) defined in Table 3, a single-RB aggregation channel may be established within a resource pool set up for each of the terminals (e.g., transmitting terminal and / or receiving terminal).

[0088] FIG. 8 is a conceptual diagram illustrating a second embodiment of a method for allocating side link resources.

[0089] Referring to FIG. 8, a single-RB set channel #1 may include PSCCH #1 and PSSCH #1 and may be configured within a single-RB set channel monitoring occupancy. The single-RB set channel #1 may be used for the allocation (e.g., reservation) of resources (e.g., PSCCH #2 resources and / or PSSCH #2 resources) for subsequent sidelink communication. The single-RB set channel monitoring occupancy may be composed of one or more slots or one or more mini-slots in the time domain. The single-RB set channel monitoring occupancy may be composed of one or more RB sets or one or more PRBs in the frequency domain. One or more single-RB set channels may be transmitted within the single-RB set channel monitoring occupancy.

[0090] Configuration information for a single-RB aggregation channel monitoring application may be transmitted by one or more combinations of upper-layer signaling, MAC signaling, and PHY signaling. A single-RB aggregation channel monitoring application may be configured by one or more combinations of resource pool-specific signaling, SL (sidelink)-specific signaling, and UE-specific signaling.

[0091] Single-RB aggregation channel monitoring applications can be configured per resource pool as shown in Table 4 below. Configuration information (e.g., resource information) of a single-RB aggregation channel monitoring application may be included in the configuration information of the corresponding resource pool. Each of frequency domains #0 to #2 may indicate a frequency domain resource of a single-RB aggregation channel configured within the corresponding resource pool. Each of time domains #0 to #2 may indicate a time domain resource of a single-RB aggregation channel configured within the corresponding resource pool.

[0092]

[0093] The frequency domain defined in Table 4 may be part or all of the frequency domain resources of the corresponding resource pool. The frequency domain may include one or more subcarriers or one or more PRBs. The frequency domain may indicate the entirety of the frequency domain resources of the corresponding single-RB aggregation channel monitoring occupancy or a starting point (e.g., a starting PRB). The information indicating the frequency domain may be one or more combinations of the starting PRB index, the ending PRB index, and the number of PRBs of the corresponding single-RB aggregation channel monitoring occupancy.

[0094] Each of time domains #0 through #2 may be part or all of the time domain resources of the corresponding resource pool. Each of time domains #0 through #2 may include one or more symbols, one or more mini-slots, or one or more slots. A time domain may indicate the entirety of the time domain resources of the corresponding single-RB aggregation channel monitoring occupancy or a starting point (e.g., a starting symbol, a starting mini-slot, or a starting slot). Information indicating a time domain may be one or more combinations of the starting symbol index, ending symbol index, starting mini-slot index, ending mini-slot index, starting slot index, ending slot index, number of symbols, number of mini-slots, and number of slots of the corresponding single-RB aggregation channel monitoring occupancy.

[0095] A cast method can be configured for a single-RB aggregation channel monitoring application. Cast methods can be classified into broadcast, group cast, multicast, and unicast methods. Single-RB aggregation channel monitoring applications to which a specific cast method applies can be defined as shown in Table 5 below.

[0096]

[0097] The cast method applied to a single-RB aggregate channel monitoring occupation can be determined based on the characteristics of the transmission environment. Resource regions of a single-RB aggregate channel monitoring occupation configured per cast method may overlap. Alternatively, resource regions of a single-RB aggregate channel monitoring occupation configured per cast method may be orthogonal. The cast method may be configured independently per resource pool. That is, the cast method may be configured by resource pool-specific signaling. Alternatively, the cast method may be configured by SL-specific signaling within a resource pool.

[0098] The information defined in Table 4 and / or Table 5 may be set by one or more combinations of upper layer signaling, MAC signaling, and PHY signaling. The information defined in Table 4 may be set in a transmitting terminal, and the transmitting terminal may inform the receiving terminal of the information defined in Table 4 using MAC signaling and / or PHY signaling (e.g., PSCCH and / or PSSCH). In this case, the receiving terminal may expect reception of a single-RB set channel within the resource area indicated by the transmitting terminal.

[0099] Meanwhile, a single-RB aggregate channel monitoring location may be configured based on Table 6 below instead of "Tables 4 and 5". Configuration information for a single-RB aggregate channel monitoring location defined in Table 6 may be transmitted by one or more combinations of upper-layer signaling, MAC signaling, and PHY signaling. For example, a table defined in Table 6 below may be pre-configured, and an information element indicating a single-RB aggregate channel monitoring location may be transmitted. In this case, the resource pool associated with the information element, the resource area of ​​the single-RB aggregate channel monitoring location, and / or the cast method may be used.

[0100]

[0101] FIG. 9 is a conceptual diagram illustrating a third embodiment of a method for allocating side link resources.

[0102] Referring to FIG. 9, a single-RB aggregate channel monitoring application can be configured within a resource pool and divided into multiple resource areas. One or more resource areas can be configured as a single resource pattern. Configuration information of the resource patterns constituting the single-RB aggregate channel monitoring application (e.g., index, time resource information, and / or frequency resource information) can be transmitted through one or more combinations of upper layer signaling, MAC signaling, and PHY signaling.

[0103] For example, if a single-RB aggregation channel monitoring occupancy includes four resource patterns (e.g., resource patterns #1 through #4), the index of each of the four resource patterns can be defined as shown in Table 7 below. Among the four resource patterns, the indices of one or more resource patterns used for the transmission of the single-RB aggregation channel may be transmitted via one or more combinations of upper layer signaling, MAC signaling, and PHY signaling. The indices of one or more resource patterns may be transmitted from the base station to the transmitting terminal and / or the receiving terminal. Alternatively, the indices of one or more resource patterns may be transmitted from the transmitting terminal to the receiving terminal. In this case, the transmitting terminal may transmit the index(s) of the resource pattern(s) to the receiving terminal using PSCCH, PSSCH, and / or MAC CE. Thus, the receiving terminal can expect to receive the single-RB aggregation channel at the resource pattern(s) indicated by the transmitting terminal (or base station).

[0104]

[0105] Meanwhile, a single-RB aggregation channel may be transmitted based on Method #1, Method #2, Method #3, or Method #4 defined in Table 3. The first stage SCI may include information elements indicating one or more SL resource regions. The maximum number of SL resource regions that can be reserved (e.g., allocated) by a single SCI scheduling the transmission of a single TB (transport block) may be pre-set. Alternatively, the maximum number of SL resource regions that can be reserved by a single SCI may be set by one or more combinations of upper layer signaling, MAC signaling, and PHY signaling.

[0106] The maximum number of SL resource regions that can be reserved by a single SCI can be set by resource pool-specific signaling. In this case, the maximum number of SL resource regions can be set to a specific value per resource pool. If resource pools are classified as shown in Table 8 below, the maximum number of SL resource regions can be set per resource pool. Here, resource pools #1 through #4 may have different sizes. For example, the time resources and / or frequency resources constituting each of resource pools #1 through #4 may be different from each other.

[0107]

[0108] When Method 1 is used, the first stage SCI may include resource information for transmitting and receiving the second stage SCI, resource information for transmitting and receiving data (e.g., sidelink data), and / or information for decoding the second stage SCI, and the second stage SCI may include information for decoding the data. When Method 2 is used, the first stage SCI may include resource information for transmitting and receiving the second stage SCI and / or information for decoding the second stage SCI. In Method 2, since data is not transmitted at the PSSCH where the second stage SCI is located, the first stage SCI may not include resource information for transmitting and receiving data, and the second stage SCI may not include information for decoding.

[0109] The SL resource domains can be defined as shown in Table 9 below. Transmission resources for SL channel #0 may include frequency domain #0 and time domain #0, transmission resources for SL channel #1 may include frequency domain #1 and time domain #1, and transmission resources for SL channel #2 may include frequency domain #2 and time domain #2.

[0110]

[0111] If the number of SL resource regions (e.g., SL channels) reservable by a single SCI is 3, the first stage SCI (e.g., the payload of the first stage SCI) may include information elements indicating the time and frequency domains defined in Table 9. SL channel #0 may be a single-RB set channel. The first stage SCI transmitted on PSCCH #0 may include resource information (e.g., frequency domain #0 and time domain #0) of the second stage SCI and data transmitted on PSSCH #0. A combination of frequency domain #0 and time domain #0 may indicate a specific resource region.

[0112] Additionally, a combination of frequency domain #1 and time domain #1 associated with SL channel #1 may indicate a specific resource domain, and a combination of frequency domain #2 and time domain #2 associated with SL channel #2 may indicate a specific resource domain. Here, frequency resources may be indicated by a subcarrier index, number of subcarriers, PRB index, number of PRBs, RB set index, number of RB sets, RE (resource element) index, and / or number of REs. Time resources may be indicated by a symbol index, number of symbols, mini-slot index, number of mini-slots, slot index, number of slots, subframe index, number of subframes, RE index, and / or number of REs. The entire resource domain may be indicated by a combination of the parameters described above.

[0113] For example, a time domain may be indicated by a start symbol index and an end symbol index. Alternatively, a time domain may be indicated by a start symbol index and the number of symbols constituting the time domain. If the time domain is allocated on a slot basis, the time domain may be indicated by a start slot index and an end slot index. Alternatively, the time domain may be indicated by a start slot index and the number of slots constituting the time domain.

[0114] The frequency domain may be indicated by a start subcarrier index and an end subcarrier index. Alternatively, the frequency domain may be indicated by a start subcarrier index and the number of subcarriers constituting the frequency domain. If the frequency domain is allocated in PRB units, the frequency domain may be indicated by a start PRB index and an end PRB index. Alternatively, the frequency domain may be indicated by a start PRB index and the number of PRBs constituting the frequency domain. If the frequency domain is allocated in RB set units, the frequency domain may be indicated by a start RB set index and an end RB set index. Alternatively, the frequency domain may be indicated by a start RB set index and the number of RB sets constituting the frequency domain. Each of the time domain and the frequency domain may be indicated using various methods other than those described above.

[0115] When SL Channel #1 and / or SL Channel #2 defined in Table 9 are used for retransmission, SL Channel #1 and / or SL Channel #2 may be located after SL Channel #0. In this case, Time Domain #1 of SL Channel #1 may be indicated by a time offset from Time Domain #0 indicated by SL Channel #0. Additionally, Time Domain #2 of SL Channel #2 may be indicated by a time offset from Time Domain #0 indicated by SL Channel #0. For example, SL Channel #1 may be located i slots after the end point (or start point) of Time Domain #0. Additionally, SL Channel #2 may be located p slots after the end point (or start point) of Time Domain #0 or Time Domain #1. That is, i and p may each be a time offset. i and p may each be natural numbers. The time offset can be set by one or more combinations of upper-layer signaling, MAC signaling, and PHY signaling.

[0116] FIG. 10 is a flowchart illustrating a first embodiment of a side-link communication method.

[0117] Referring to FIG. 10, sidelink communication between a transmitting terminal and a receiving terminal may be performed. The transmitting terminal may be UE #5 (235) shown in FIG. 2, and the receiving terminal may be UE #6 (236) shown in FIG. 2. Each of the transmitting terminal and the receiving terminal may be configured to be identical or similar to the communication node (300) shown in FIG. 3. Each of the transmitting terminal and the receiving terminal may support the protocol stack shown in FIG. 4 through 6.

[0118] Communication between the transmitting terminal and the receiving terminal can be performed using a single-RB set channel. The transmitting terminal can generate a first-stage SCI (S1001). The first-stage SCI may include resource area information of SL channel #0, resource area information of SL channel #1, and resource area information of SL channel #2 as defined in Table 9. Additionally, the first-stage SCI may include an allocation indicator. An allocation indicator set to a first value (e.g., 0) may indicate that the second-stage SCI associated with the first-stage SCI does not include resource area information (e.g., resource allocation information or resource reservation information). That is, an allocation indicator set to a first value may indicate that resource area information of all SL channels is included in the first-stage SCI.

[0119] An allocation indicator set to a second value (e.g., 1) may indicate that a second-stage SCI associated with a first-stage SCI includes resource area information (e.g., resource allocation information or resource reservation information). That is, an allocation indicator set to a second value may indicate that resource area information of the remaining SL channels, excluding the SL channel (e.g., SL channel #0) through which the first-stage SCI containing the allocation indicator is transmitted, is included in the second-stage SCI. When the allocation indicator is set to a second value, the receiving terminal may decode up to the second-stage SCI for resource sensing. The first-stage SCI generated in step S1001 may not include an allocation indicator. In this case (i.e., when the first-stage SCI received from the transmitting terminal does not include an allocation indicator), the receiving terminal may perform a monitoring operation to acquire the second-stage SCI. Alternatively, the first-stage SCI generated in step S1001 may include an allocation indicator set to a first value.

[0120] The transmitting terminal can transmit the first stage SCI on PSCCH #0 (e.g., PSCCH #0 belonging to SL channel #0) (S1002). The receiving terminal can receive the first stage SCI from the transmitting terminal by performing a monitoring operation on PSCCH #0 (e.g., a single-RB set channel monitoring occupancy). The receiving terminal can verify the resource area information of SL channel #0, the resource area information of SL channel #1, and the resource area information of SL channel #2 included in the first stage SCI (S1003). Sidelink communication between the transmitting terminal and the receiving terminal can be performed using the resource area(s) indicated by the first stage SCI (S1004). In step S1004, the performance of sidelink communication may mean the performance of "an operation necessary for the transmission and reception of data" and / or "an operation for the transmission and reception of data."

[0121] FIG. 11 is a flowchart illustrating a second embodiment of a side-link communication method.

[0122] Referring to FIG. 11, sidelink communication between a transmitting terminal and a receiving terminal may be performed. The transmitting terminal may be UE #5 (235) shown in FIG. 2, and the receiving terminal may be UE #6 (236) shown in FIG. 2. Each of the transmitting terminal and the receiving terminal may be configured to be identical or similar to the communication node (300) shown in FIG. 3. Each of the transmitting terminal and the receiving terminal may support the protocol stack shown in FIG. 4 through 6.

[0123] Communication between a transmitting terminal and a receiving terminal can be performed using a single-RB set channel. The transmitting terminal can generate a first-stage SCI (S1101). The first-stage SCI may include resource allocation information (e.g., resource area information) and an allocation indicator. The first-stage SCI may include resource area information of SL channel #0 to which PSCCH #0, to which the first-stage SCI is transmitted, belongs. The allocation indicator may indicate that the second-stage SCI associated with the first-stage SCI includes resource allocation information. That is, the allocation indicator may be set to a second value.

[0124] A transmitting terminal can transmit a first-stage SCI on PSCCH #0 (e.g., PSCCH #0 belonging to SL channel #0) (S1102). A receiving terminal can receive the first-stage SCI from the transmitting terminal by performing a monitoring operation on PSCCH #0 (e.g., a single-RB set channel monitoring occupancy). The receiving terminal can verify the resource area information and allocation indicator of SL channel #0 included in the first-stage SCI (S1103). If the allocation indicator is set to a second value, the receiving terminal can determine that the second-stage SCI associated with the first-stage SCI includes resource area information of the remaining SL channel(s) excluding SL channel #0.

[0125] Meanwhile, the transmitting terminal may generate a second-stage SCI containing resource area information of SL Channel #1 and resource area information of SL Channel #2 (S1104). The transmitting terminal may transmit the second-stage SCI on PSSCH #0 (e.g., PSSCH #0 belonging to SL Channel #0) (S1105). The receiving terminal may receive the second-stage SCI from the transmitting terminal by performing a monitoring operation on PSSCH #0 (e.g., a single-RB aggregation channel monitoring occupancy). The receiving terminal may verify the resource area information of SL Channel #1 and the resource area information of SL Channel #2 included in the second-stage SCI (S1106). Sidelink communication between the transmitting terminal and the receiving terminal may be performed using the resource area(s) indicated by the first-stage SCI and / or the second-stage SCI (S1107). In step S1107, the performance of sidelink communication may mean the performance of "operations necessary for the transmission and reception of data" and / or "operations for the transmission and reception of data".

[0126] FIG. 12 is a flowchart illustrating a third embodiment of a side-link communication method.

[0127] Referring to FIG. 12, sidelink communication can be performed between a transmitting terminal and a receiving terminal. The transmitting terminal may be UE #5 (235) shown in FIG. 2, and the receiving terminal may be UE #6 (236) shown in FIG. 2. Each of the transmitting terminal and the receiving terminal may be configured to be identical or similar to the communication node (300) shown in FIG. 3. Each of the transmitting terminal and the receiving terminal may support the protocol stack shown in FIG. 4 through 6.

[0128] Communication between the transmitting terminal and the receiving terminal can be performed using a single-RB set channel. The transmitting terminal can generate a first-stage SCI (S1201). The first-stage SCI may include resource area information of n SL channel(s). The n SL channel(s) may include the SL channel to which the PSCCH to which the first-stage SCI is transmitted belongs (e.g., SL channel #0) and (n-1) SL channel(s) located after SL channel #0.

[0129] In the time domain, SL Channel #1 may be located after SL Channel #0, SL Channel #2 may be located after SL Channel #1, and SL Channel #3 may be located after SL Channel #2. SL Channel #1 may be the earliest SL channel in time among the SL channels located after SL Channel #0, SL Channel #2 may be the earliest SL channel in time among the SL channels located after SL Channel #1, and SL Channel #3 may be the earliest SL channel in time among the SL channels located after SL Channel #2.

[0130] When n is 2, the first stage SCI may include resource area information of SL channel #0 and resource area information of SL channel #1. When n is 3, the first stage SCI may include resource area information of SL channel #0, resource area information of SL channel #1, and resource area information of SL channel #2. n may be set by one or more combinations of upper layer signaling, MAC signaling, and PHY signaling.

[0131] In the embodiment illustrated in FIG. 12, n is assumed to be 2. A transmitting terminal can transmit a first-stage SCI containing resource area information of SL channel #0 and resource area information of SL channel #1 on PSCCH #0 (e.g., PSCCH #0 belonging to SL channel #0) (S1202). A receiving terminal can receive the first-stage SCI from the transmitting terminal by performing a monitoring operation on PSCCH #0 (e.g., a single-RB aggregation channel monitoring occupancy). The receiving terminal can verify the resource area information of SL channel #0 and resource area information of SL channel #1 included in the first-stage SCI (S1203).

[0132] Meanwhile, the transmitting terminal may generate a second stage SCI containing information on resource area information of the remaining SL channel (e.g., SL channel #2) (S1204). The transmitting terminal may transmit the second stage SCI on PSSCH #0 (e.g., PSSCH #0 belonging to SL channel #0) (S1205). The maximum number of SL channels (hereinafter referred to as "m") that can be allocated (e.g., reserved) by the SCI (e.g., the first stage SCI and the second stage SCI) may be pre-set. m may be set by one or more combinations of upper layer signaling, MAC signaling, and PHY signaling. In this case, the second stage SCI may contain resource area information of (mn) SL channel(s). (mn) may be set by one or more combinations of upper layer signaling, MAC signaling, and PHY signaling.

[0133] The receiving terminal can receive a second-stage SCI from the transmitting terminal by performing a monitoring operation on PSSCH #0 (e.g., a single-RB set channel monitoring occupancy). The receiving terminal can check the resource area information of SL Channel #2 included in the second-stage SCI (S1206). Sidelink communication between the transmitting terminal and the receiving terminal can be performed using the resource area(s) indicated by the first-stage SCI and / or the second-stage SCI (S1207). In step S1207, the performance of sidelink communication may mean the performance of "an operation necessary for the transmission and reception of data" and / or "an operation for the transmission and reception of data."

[0134] Meanwhile, after step S1206 illustrated in FIG. 12, the transmitting terminal may reserve additional resources to perform sidelink communication using SL channel #1. The procedure for reserving additional resources may be performed as shown in FIG. 13 below.

[0135] FIG. 13 is a flowchart illustrating a fourth embodiment of a side-link communication method.

[0136] Referring to FIG. 13, when n is 2, the transmitting terminal can generate a first stage SCI including resource area information of SL Channel #1 and resource area information of SL Channel #2 (S1301). The transmitting terminal can transmit the first stage SCI on PSCCH #1 (e.g., PSCCH #1 belonging to SL Channel #1) (S1302). The receiving terminal can receive the first stage SCI from the transmitting terminal by performing a monitoring operation on PSCCH #1 (e.g., a single-RB aggregation channel monitoring occupancy). The receiving terminal can verify the resource area information of SL Channel #1 and the resource area information of SL Channel #2 included in the first stage SCI (S1303).

[0137] The transmitting terminal can generate a second stage SCI containing resource area information of the remaining SL channel (e.g., SL channel #3) (S1304). The transmitting terminal can transmit the second stage SCI on PSSCH #1 (e.g., PSSCH #1 belonging to SL channel #1) (S1305). When m is 3, the second stage SCI may contain resource area information of one SL channel (e.g., (3-2) SL channels).

[0138] The receiving terminal can receive a second-stage SCI from the transmitting terminal by performing a monitoring operation on PSSCH #1 (e.g., a single-RB set channel monitoring occupancy). The receiving terminal can check the resource area information of SL Channel #3 included in the second-stage SCI (S1306). Sidelink communication between the transmitting terminal and the receiving terminal can be performed using the resource area(s) indicated by the first-stage SCI and / or the second-stage SCI (S1307).

[0139] Meanwhile, when the embodiment(s) illustrated in FIG. 12 and / or FIG. 13 are used, resources (e.g., resource regions) may be reserved one by one according to a chain rule based on the first stage SCI. The receiving terminal may verify resource allocation information (e.g., resource reservation information) by receiving consecutive first stage SCIs without the second stage SCI. If the receiving terminal wishes to know the information of resource regions of all allocated (e.g., reserved) SL channels, it may obtain the corresponding resource information by decoding not only the first stage SCI but also the second stage SCI. In the embodiment(s) illustrated in FIG. 12 and / or FIG. 13, n and m may each be set to various values. The first stage SCI may further include an allocation indicator in addition to the resource region information of the SL channel. The allocation indicator may indicate whether the second stage SCI includes the resource region information of the SL channel.

[0140] Meanwhile, when Method 3 defined in Table 3 is used, Method 1 or Method 2 may be selected depending on the situation. For example, if the size of the data to be transmitted is small (e.g., if the size of the data is below a threshold), Method 1 may be used. In this case, the data may be transmitted through a single-RB aggregation channel. If the size of the data to be transmitted is large (e.g., if the size of the data exceeds a threshold), Method 2 may be used. In this case, the single-RB aggregation channel may be used to reserve data transmission resources, and the data may be transmitted through the reserved resources.

[0141] Here, the threshold may be X bytes. The threshold (e.g., X) may be set by one or more combinations of upper layer signaling, MAC signaling, and PHY signaling. The first stage SCI may include a mode indicator that indicates the mode used. The mode indicator may indicate mode 1 or mode 2 as defined in Table 3. As another example, the mode indicator may indicate mode 1, mode 2, or mode 3 as defined in Table 3. As yet another example, the mode indicator may indicate mode 1, mode 2, mode 3, or mode 4 as defined in Table 3. To represent the mode indicator, a field included in the first stage SCI (e.g., a field providing other information) may be reused. The mode indicator may be explicitly or implicitly indicated by the first stage SCI.

[0142] The methods according to the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., either alone or in combination. The program instructions recorded on the computer-readable medium may be those specifically designed and configured for the present invention, or they may be those known and available to those skilled in the art of computer software.

[0143] Examples of computer-readable media include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include machine code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The aforementioned hardware devices may be configured to operate as at least one software module to perform the operation of the present invention, and vice versa.

[0144] Although the invention has been described with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims.

Claims

Claim 1 A method of operation of a first terminal in a communication system, comprising: generating a first stage SCI (sidelink control information) including a first resource allocation information and a first indicator indicating whether the second stage SCI (sidelink control information) includes second resource allocation information; transmitting the first stage SCI to a second terminal via a physical sidelink control channel (PSCCH); and performing sidelink communication with the second terminal using a first resource area indicated by the first resource allocation information, wherein the second resource allocation information included in the second stage SCI indicates a second resource area, and the second resource area is different from the first resource area. Claim 2 delete Claim 3 delete Claim 4 A method of operation of a first terminal according to claim 1, wherein the first stage SCI further includes a second indicator indicating a method of using an SL (sidelink) channel, wherein the second indicator set to a first value indicates "that the PSCCH is used for transmission of the first stage SCI and the PSSCH is used for transmission of the second stage SCI and data," and the second indicator set to a second value indicates "that the PSCCH is used for transmission of the first stage SCI and the PSSCH is used for transmission of the second stage SCI." Claim 5 A method of operation of a first terminal, wherein, in claim 1, the usage method of the SL channel including the PSCCH and PSSCH is classified into a first method and a second method, and when the first method is used, the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI and data, and when the second method is used, the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI, and when the size of the data is less than or equal to a threshold value, the first method is used, and when the size of the data exceeds a threshold value, the second method is used. Claim 6 A method of operation of a first terminal according to claim 1, wherein the first resource allocation information indicates resource regions of n SL channels and the second resource allocation information indicates resource regions of k SL channels, and each of the n SL channels and the k SL channels includes one PSCCH and one PSSCH belonging to the same set of resource blocks (RB), and n and k are each natural numbers. Claim 7 A method of operation of a first terminal according to claim 6, wherein one of n, k, and n+k is obtained from a base station through one or more of upper layer signaling, MAC (medium access control) signaling, and PHY (physical) signaling. Claim 8 A method of operation of a first terminal according to claim 1, wherein the SL channel including the PSCCH and PSSCH is transmitted at a monitoring occasion, the monitoring occasion is configured for a specific cast method, and the specific cast method is one of a unicast method, a groupcast method, and a broadcast method. Claim 9 A method of operation of a second terminal in a communication system, comprising: receiving a first-stage sidelink control information (SCI) from a first terminal in a physical sidelink control channel (PSCCH); confirming a first resource allocation information included in the first-stage SCI and a first indicator indicating whether the second-stage SCI includes second resource allocation information; and performing a monitoring operation in a physical sidelink shared channel (PSSCH) to receive the second-stage SCI from the first terminal, wherein the first resource allocation information included in the first-stage SCI indicates a first resource area, the second resource allocation information included in the second-stage SCI indicates a second resource area, and the second resource area is different from the first resource area. Claim 10 A method of operation of a second terminal according to claim 9, wherein the first resource allocation information indicates resource regions of n SL (sidelink) channels and the second resource allocation information indicates resource regions of k SL channels, and each of the n SL channels and the k SL channels includes one PSCCH and one PSSCH belonging to the same set of RB (resource block), and n and k are each natural numbers. Claim 11 A method of operation of a second terminal according to claim 10, wherein one of n, k, and n+k is obtained from a base station through one or more of upper layer signaling, MAC (medium access control) signaling, and PHY (physical) signaling. Claim 12 A method of operation of a second terminal according to claim 9, wherein the SL channel including the PSCCH and the PSSCH is received at a monitoring occasion, the monitoring occasion is configured for a specific cast method, and the specific cast method is one of a unicast method, a groupcast method, and a broadcast method. Claim 13 A method of operation of a second terminal according to claim 9, wherein the first stage SCI further includes a second indicator indicating a method of using an SL channel, wherein the second indicator set to a first value indicates "that the PSCCH is used for transmission of the first stage SCI and the PSSCH is used for transmission of the second stage SCI and data," and the second indicator set to a second value indicates "that the PSCCH is used for transmission of the first stage SCI and the PSSCH is used for transmission of the second stage SCI." Claim 14 A method of operation of a second terminal, wherein the usage method of an SL channel including the PSCCH and the PSSCH is classified into a first method and a second method, wherein when the first method is used, the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI and data, and when the second method is used, the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI, wherein the first method is used when the size of the data is below a threshold value and the second method is used when the size of the data exceeds the threshold value. Claim 15 A method of operation of a second terminal according to claim 14, wherein the threshold value is obtained from a base station through one or more of upper layer signaling, MAC signaling, and PHY signaling. Claim 16 A first terminal in a communication system comprises: a processor; and a memory that stores one or more instructions executed by the processor, wherein the one or more instructions generate a first stage SCI (sidelink control information) comprising a first indicator indicating whether the second stage SCI (sidelink control information) includes the first resource allocation information; transmit the first stage SCI to a second terminal via a physical sidelink control channel (PSCCH); and execute to perform sidelink communication with the second terminal using a first resource area indicated by the first resource allocation information, wherein the second resource allocation information included in the second stage SCI indicates a second resource area, and the second resource area is different from the first resource area. Claim 17 delete Claim 18 In claim 16, the first stage SCI further includes a second indicator indicating a method of using an SL (sidelink) channel, wherein the second indicator set to a first value indicates "that the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI and data," and the second indicator set to a second value indicates "that the PSCCH is used for the transmission of the first stage SCI and the PSSCH is used for the transmission of the second stage SCI," a first terminal. Claim 19 A first terminal according to claim 16, wherein the first resource allocation information indicates resource regions of n SL channels and the second resource allocation information indicates resource regions of k SL channels, and each of the n SL channels and the k SL channels includes one PSCCH and one PSSCH belonging to the same set of RB (resource block), and n and k are each natural numbers. Claim 20 A first terminal according to claim 16, wherein the SL channel including the PSCCH and PSSCH is transmitted at a monitoring occasion, the monitoring occasion is configured for a specific cast method, and the specific cast method is one of a unicast method, a groupcast method, and a broadcast method.

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